TY - JOUR A1 - Winckelmann, Alexander A1 - Roik, Janina A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique A1 - You, Zengchao T1 - Investigation of matrix effects in nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) for trace element analysis in steels N2 - We investigated the performance of nitrogen microwave inductively coupled atmospheric-pressure plasma mass spectrometry (MICAP-MS) under matrix effects and its applicability to trace element analysis in steels. Influences of different gas flows and ion optics on the matrix tolerance are studied, indicating that nebulizer gas flow has the most significant impact. Optimization of ion optics improves matrix tolerance for light elements due to the reduction of the inelastic collisional scattering effect. With optimized operating conditions, MICAP-MS achieves an internal standard intensity recovery of over 90% at an Fe concentration of 500 mg L−1. Even at an Fe concentration of 1 g L−1, the recovery remains above 80%. Three certified reference materials – non-alloy, low-alloy and high-alloy steel – were analyzed using MICAP-MS. The determined mass concentrations of the trace and minor components show metrological compatibility to the reference values. No significant differences are observed between the results obtained with aqueous and matrix-matched calibration, demonstrating the strong matrix tolerance of MICAP-MS, and its promising applicability to steel analysis. KW - MICAP-MS KW - Trace Analysis KW - Steel PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-576323 DO - https://doi.org/10.1039/d3ja00088e SN - 0267-9477 VL - 38 IS - 6 SP - 1253 EP - 1260 PB - Royal Society of Chemistry AN - OPUS4-57632 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Tanz der Moleküle: Herkunftsbestimmung mittels optischer Spektroskopie N2 - Wie lässt sich die Herkunft von Rohstoffen, Lebensmitteln oder Umweltschadstoffen einfacher, schneller und kostengünstiger als mit bisherigen Methoden bestimmen? Die Dissertation zeigt auf, dass man das grundlegende physikalische Prinzip einer Isotopverschiebung mit in Adlershof entwickelten Optik-Instrumenten für die Herkunftsbestimmung nutzen kann. Die entwickelte Methode ermöglicht es in Zukunft den Ursprung von Rohstoffen, Lebensmitteln oder Umweltschadstoffen kostengünstiger und wesentlich schneller bestimmen, als dies mit bisherigen Methoden möglich ist. Kann man das grundlegende physikalische Prinzip einer Isotopieverschiebung mit einem Optik-Instrument für die Herkunftsbestimmung nutzen? Carlos Abad hat eine wegweisende Methode entwickelt, die es in Zukunft ermöglicht den Ursprung von Rohstoffen, Lebensmitteln oder Umweltschadstoffen kostengünstiger und wesentlich schneller bestimmen, als dies mit bisherigen Techniken möglich ist. T2 - Dissertationspreis Adlershof 2019 CY - Berlin, Germany DA - 12.02.2020 KW - Herkunftsbestimmung KW - Isotopenanalyse KW - Isotope KW - Optischer Spektroskopie KW - Coltan PY - 2020 AN - OPUS4-51993 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Isotopic analysis by high-resolution optical spectroscopy N2 - Isotope analysis can be used to determine the age and provenance of geological samples or to study dynamic systems like Li-ion batteries. Modern techniques in optical spectrometry allow us a fast and slow-cost isotope analysis. These techniques include high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS) and laser ablation molecular isotopic spectrometry. This seminar will discuss our recent work on precise and accurate isotope analysis of boron, magnesium, and lithium with geology, climate, and energy research applications. T2 - Recent Trends in Chemical Science and Technology, Christian College Chengannur, India CY - Online meeting DA - 29.09.2020 KW - Isotopes KW - Optical spectrometry KW - Machine learning PY - 2020 AN - OPUS4-51997 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Isotope analysis by high-resolution optical spectroscopy: a tool for planetary science N2 - Isotope analysis can be used to determine the age and provenance of geological samples. Modern techniques in optical spectrometry allow us a stand-off isotope analysis. This seminar will discuss how planetary science with the next Moon and Mars missions drive optical spectrometry into precise and accurate isotope analysis and how BAM will contribute. T2 - Adlershofer Kolloquium CY - Online meeting DA - 19.05.2020 KW - Provenance KW - Dating KW - Isotopes KW - Optical spectroscopy KW - Isotopic shift KW - Planetary science PY - 2020 AN - OPUS4-51995 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Advances and Applications of Molecular Absorption Spectrometry: from Non-Metals to Isotope Analysis N2 - Wie kann Nicht-Messbares messbar gemacht werden? Die Antwort der Dissertation auf diese zentrale Frage der analytischen Chemie lautet: die Anwendung der hochauflösenden optischen Spektroskopie der diatomischen Moleküle. In der Arbeit wird in einem ersten Schritt in Grafitöfen, die wie Chemiereaktoren funktionieren, und durch die Anwendung verschiedener analytischer Methoden die diatomische Molekülbildung nachvollzogen. In einem zweiten Schritt werden die aufgedeckten Mechanismen auf die Bestimmung von Nichtmetallen und die Analyse von Isotopen angewendet. Die Isotopenanalytik ist das zukunftsweisendes Herzstück der Dissertation und von alltäglicher und politischer Relevanz: Mittels dieser Technik lässt sich die Herkunft von Lebensmitteln aber auch Chemiewaffen kostengünstiger und wesentlich schneller bestimmen als mit bisherigen Methoden der Massenspektrometrie. Möglich ist die Bestimmung, da alles um uns herum aus Atomen verschiedener Elemente besteht und die meisten Elemente mehrere Isotope haben. Isotope unterscheiden sich hinsichtlich ihres Gewichts, da sie über eine unterschiedliche Anzahl an Neutronen verfügen. Die Informationen über das Verhältnis von schweren und leichten Isotopen lässt sich nutzen, um zu bestimmen wo etwas entstanden ist. Jeder Ort auf unserem Planeten hat seinen persönlichen Element- und Isotopenanteil (Isotopenfingerabdruck). Das in der Arbeit angewandte Instrument misst das Verhältnis indirekt und nutzt hierzu die Interaktion zwischen Licht und Materie. Für das schwerere Isotop wird mehr Licht/Energie benötigt, um es in Bewegung zu bringen, als für das leichtere. Diese kleinen Unterschiede an Energie, die wir dafür aufwenden müssen, werden gemessen und ermöglichen die Herkunftsbestimmung. Damit leistet die Arbeit nicht nur einen wichtigen Beitrag zur Grundlagenforschung in der analytischen Chemie, sondern kann mit den aufgezeigten Ergebnissen auch Anwendung in den Bereichen Verbraucherschutz, Umweltforschung und Waffenkontrolle finden. N2 - The present work covers two main aspects of high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS), an analytical technique for elemental trace analysis. First, a comprehensive mechanistic study of molecule formation in graphite furnaces is presented, which is a key step into the recovery of analytical signals. For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in HR-CS-GFMAS. A zirconium coating catalyzes the CaF formation, and its structure was investigated. The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. Here a mechanism is proposed, where ZrO2 works as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. Second, analytical methods were developed by using HR-CS-MAS as detector for non-metals and isotope analysis. Therefore, the determination of organic absorbable chlorine in water, the quantification of fluorine in consume care products with declared perfluorinated ingredients, and the determination of sulfur content in crude oils were investigated. Finally, the high resolution of the instrumentation allows to measure isotopic shifts with high precision in some observed molecular spectra. Consequently, the molecular spectra of enriched isotopes of boron and magnesium were investigated, establishing so the potential of HR-CS-MAS for the accurate and precise determination of isotopic amount ratios. T2 - Applied Photonics Award 2020 CY - Jena, Germany DA - 22.09.2020 KW - Herkunftsbestimmung KW - Isotopenanalyse KW - Isotope KW - Optischer Spektroskopie PY - 2020 AN - OPUS4-51996 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Stable isotope amount ratio analysis by using high-resolution continuum source graphite furnace molecular absorption spectrometry N2 - Analysis of stable isotopes has been used as proof of provenance of mineral and biological samples, to estimate a contamination source and to determine geological processes. This kind of analysis needs high accuracy and precision for reliable conclusions. Currently, stable isotope analysis is dominated by mass spectrometric techniques that are time consuming and expensive. Here we present a fast and low cost alternative for isotope analysis of boron and magnesium: high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). Two stable isotope systems were evaluated separately: boron (10B:11B) and magnesium (24Mg:25Mg:26Mg). Their isotope amount ratios were estimated by monitoring their absorption spectra in-situ generated monohydrides. The molecular absorption spectrum of a XH molecule (X= B or Mg) with n isotopes would be a linear combination of n isotopologue spectra and the amount of each component (isotope) could be calculated by a multivariate regression (n= 2 and 3 for B and Mg respectively). For the analysis of boron certified reference materials (CRM), the band 1→1 for the electronic transition X1Σ+ → A1Π was measured around wavelength 437.1 nm. Since boron has a memory effect in graphite furnaces, a combination of 2 % (v/v) hydrogen gas in argon, 1 % trifluoromethane in argon, an acid solution of calcium chloride and mannitol as chemical modifiers were used during the BH vaporization at 2600 °C. Partial least square regression (PLS) for analysis of samples was applied. For this, a spectral library with different isotope ratios for PLS regression was created. Magnesium does not have memory effect. Therefore, only 2 % of hydrogen in argon as gas modifier during vaporization at 2500 °C was employed for analysis of magnesium CRM. Absorption spectra of MgH for the X2Σ→A2Π electronic transition (band 0→0) were recorded around wavelength 513.45 nm. A similar PLS procedure to the BH was applied. Results for B and Mg CRM are metrologically compatible with those reported by mass spectrometric methods. An accuracy of 0.08 ‰ for B and 0.1 ‰ Mg was obtained as the average deviation from the isotope CRM. Expanded uncertainties with a coverage factor of k = 2 range between 0.10 - 0.40 ‰. T2 - FACSS / SciX Conference 2017 CY - Reno, NV, USA DA - 08.10.2017 KW - Boron isotopes KW - High-Resolution Continuum Source Molecular Absorption Spectrometry KW - Graphite furnace KW - Isotopic shift KW - Hydride KW - Isotope ratio PY - 2017 AN - OPUS4-43350 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Stable isotope analysis via hydrides using molecular absorption spectrometry N2 - Small variations in the isotopic composition of some elements have been used as proof of provenance of mineral and biological samples, to describe geological processes, and to estimate a contamination source. Routinely, isotope compositions are measured by mass spectrometry; the working horse of the isotope analysis. However, mass spectrometric methods are expensive, time-consuming and they require a high qualified analyst. Here, an alternative faster and low-cost optical method for isotope ratio determination is investigated: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Stable isotope amount composition of X = Li, B, Mg, Ca and Sr have been determined by monitoring the absorption spectra of their in situ generated hydrides (XH) in graphite furnace HR-CS-MAS. For example, the system of two stable isotopes of boron (10B and 11B) was studied via its hydride for the electronic transition X1Σ+ → A1Π (Fig. 1a). The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, isotopic composition of samples and reference materials are calculated by a partial least square regression (PLS). For this, a spectral library is built by using samples with known isotope composition. Results are metrologically compatible with those reported by mass spectrometric methods. [1] Similar results are obtained for n isotope systems like Mg (24Mg, 25Mg, and 26Mg), where isotope shift of their isotopologues can be resolved as shown in Fig.1 b. The extension of this methodology to other elements like Li, Ca and Sr is discussed [2]. References: [1] C. Abad, S. Florek, H. Becker-Ross, M.-D. Huang, H.-J. Heinrich, S. Recknagel, J. Vogl, N. Jakubowski, U. Panne, Determination of boron isotope ratios by high-resolution continuum source molecular absorption spectrometry using graphite furnace vaporizers, Spectrochim. Acta, Part B, 136 (2017) 116-122. [2] C. Abad et al., unpublished results, 2018. T2 - ESAS & CANAS 2018 CY - Berlin, Germany DA - 20.03.2018 KW - Isotope KW - HR-CS-MAS KW - Mono-hydride KW - Spectrometry PY - 2018 AN - OPUS4-45826 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Optical spectrometry versus mass spectrometry for stable isotope analysis of B and Mg N2 - Mass spectrometric methods (MC-ICP-MS and TIMS) are without doubt the working horse of stable isotope analysis. However, drawbacks of these methods include the high costs for instruments and their operation, experienced operators and elaborate chromatographic sample preparation which are time consuming. We propose a lower-cost and faster optical alternative for the analysis of isotope ratios of selected elements: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Stable isotope amount compositions of boron (B) and magnesium (Mg) were determined based on the absorption spectra of in-situ generated mono-hydrides and halide (MH and MX) using graphite furnace HR-CS-MAS. The use of a modular simultaneous echelle spectrograph (MOSES) helps to find the maximal isotope shift in the diatomic molecular spectra produced in a graphite furnace by using isotopic spike solutions. Isotopes of boron (10B and 11B) were studied via their hydrides for the electronic transition X 1Σ+ → A 1Π. The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, the isotopic composition of samples can be calculated by a partial least square regression (PLS). For this, a spectral library was built by using samples and spikes with known isotope composition. Boron isotope ratios measured by HR-CS-MAS are identical with those measured by mass spectrometric methods at the 0.15 ‰ level. Similar results were obtained for a multiple isotope system like Mg (24Mg, 25Mg, and 26Mg), where isotope shifts of their isotopologues can be resolved in the MgF molecule for the electronic transition X 2Σ → A 2 Πi. The extension of this methodology to other elements like Li, Ca, Cu, and Sr is discussed. T2 - 13. Symposium „Massenspektrometrische Verfahren der Elementspurenanalyse“ zusammen mit dem 26. ICPMS-Anwendertreffen CY - Berlin, Germany DA - 03.09.2018 KW - Isotope KW - HR-CS-MAS KW - Isotopic shift KW - Spectrometry KW - Boron monohydride KW - Magnesium monofluoride KW - Molecular absorption spectrometry PY - 2018 AN - OPUS4-45868 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Stable Isotope Analysis Using Molecular Absorption Spectrometry N2 - We propose an alternative faster and low-cost optical method for isotope analysis: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Stable isotope amount composition of X = Li, B, Mg, Ca and Sr were determined by monitoring the absorption spectra of their in situ generated mono-hydrides (XH) in graphite furnace HR-CS-MAS. Isotopes of boron (10B and 11B) were studied via their hydrides for the electronic transition X1Σ+ → A1Π (Fig. 1a). The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, the isotopic composition of samples can be calculated by a partial least square regression (PLS). For this, a spectral library is built by using samples with known isotope composition. Results with an accuracy of 0.15 ‰ are metrologically compatible with those reported by mass spectrometric methods. Similar results are obtained for n isotope systems like Mg (24Mg, 25Mg, and 26Mg), where isotope shifts of their isotopologues can be resolved as shown in Fig.1b. The extension of this methodology to other elements like Li, Ca and Sr is discussed. T2 - Goldschmidt Conference 2018 CY - Boston, MA, USA DA - 12.08.2018 KW - Isotope KW - HR-CS-MAS KW - Mono-hydride KW - Spectrometry PY - 2018 AN - OPUS4-45825 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winckelmann, Alexander A1 - Morcillo Garcia-Morato, Dalia A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Riedel, Jens A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Determination of lithium in human serum by isotope dilution atomic absorption spectrometry N2 - The therapeutic dose of lithium (Li) compounds, which are widely used for the treatment of psychiatric and hematologic disorders, is close to its toxic level; therefore, drug monitoring protocols are mandatory. Herein, we propose a fast, simple, and low-cost analytical procedure for the traceable determination of Li concentration in human serum, based on the monitoring of the Li isotope dilution through the partially resolved isotope shift in its electronic transition around 670.80 nm using a commercially available high-resolution continuum source graphite furnace atomic absorption spectrometer. With this technique, serum samples only require acidic digestion before analysis. The procedure requires three measurements—an enriched 6Li spike, a mixture of a certified standard solution and spike, and a mixture of the sample and spike with a nominal 7Li/6Li ratio of 0.82. Lanthanum has been used as an internal spectral standard for wavelength correction. The spectra are described as the linear superposition of the contributions of the respective isotopes, each consisting of a spin-orbit doublet, which can be expressed as Gaussian components with constant spectral position and width and different relative intensity, reflecting the isotope ratio in the sample. Both the spectral constants and the correlation between isotope ratio and relative band intensity have been experimentally obtained using commercially available materials enriched with Li isotopes. The Li characteristic mass (mc) obtained corresponds to 0.6 pg. The procedure has been validated using five human serum certified reference materials. The results are metrologically comparable and compatible to the certified values. The measurement uncertainties are comparable to those obtained by the more complex and expensive technique, isotope dilution mass spectrometry. KW - Lithium KW - Human serum KW - Isotope dilution KW - Atomic absorption spectrometry KW - High-resolution continuum source graphite furnace atomic absorption spectrometry PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532446 DO - https://doi.org/10.1007/s00216-021-03636-6 VL - 414 IS - 1 SP - 251 EP - 256 PB - Springer CY - Berlin AN - OPUS4-53244 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Applications of atomic absorption spectrometry for lithium isotope analysis N2 - An alternative method for lithium isotope analysis by using high-resolution atomic absorption spectrometry (HR-CS-AAS) is proposed herein. This method is based on monitoring the isotope shift of approximately 15 pm for the electronic transition 22P←22S at around the wavelength of 670.8 nm, which can be measured by state-of-the-art HR-CS-AAS. Isotope analysis can be used for (i) the traceable determination of Li concentration and (ii) isotope amount ratio analysis based on a combination of HR-CS-AAS and spectral data analysis by machine learning (ML). In the first case, the Li spectra are described as the linear superposition of the contributions of the respective isotopes, each consisting of a spin-orbit doublet, which can be expressed as Gaussian components with constant spectral position and width and different relative intensity, reflecting the isotope ratio in the sample. Precision was further improved by using lanthanum as internal spectral standard. The procedure has been validated using human serum-certified reference materials. The results are metrologically comparable and compatible with the certified values. In the second case, for isotope amount ratio analysis, a scalable tree boosting ML algorithm (XGBoost) was employed and calibrated using a set of samples with 6Li isotope amount fractions ranging from 0.06 to 0.99 mol mol−1. The training ML model was validated with certified reference materials. The procedure was applied to the isotope amount ratio determination of a set of stock chemicals and a BAM candidate reference material NMC111 (LiNi1/3Mn1/3Co1/3O2), a Li-battery cathode material. These determinations were compared with those obtained by MC-ICP-MS and found to be metrologically comparable and compatible. The residual bias was −1.8‰, and the precision obtained ranged from 1.9‰ to 6.2‰. This precision was sufficient to resolve naturally occurring variations. The NMC111 cathode candidate reference material was analyzed using high-resolution continuum source atomic absorption spectrometry with and without matrix purification to assess its suitability for technical applications. The results obtained were metrologically compatible with each other. T2 - Colloquium Spectroscopicum Internationale XLII (CSI XLII) CY - Gijón, Spain DA - 30.05.2022 KW - Lithium KW - HR-CS-AAS KW - Chemometrics KW - Atomic spectrometry PY - 2022 AN - OPUS4-56498 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Winckelmann, Alexander A1 - Nowak, S. A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Riedel, Jens A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - High-Resolution Atomic Absorption Spectrometry Combined With Machine Learning Data Processing for Isotope Amount Ratio Analysis of Lithium N2 - An alternative method for lithium isotope amount ratio analysis based on a combination of high-resolution atomic absorption spectrometry and spectral data analysis by machine learning (ML) is proposed herein. It is based on the well-known isotope shift of approximately 15 pm for the electronic transition 22P←22S at around the wavelength of 670.8 nm, which can be measured by the state-of-the-art high-resolution continuum source graphite furnace atomic absorption spectrometry. For isotope amount ratio analysis, a scalable tree boosting ML algorithm (XGBoost) was employed and calibrated using a set of samples with 6Li isotope amount fractions, ranging from 0.06 to 0.99 mol mol–1, previously determined by a multicollector inductively coupled plasma mass spectrometer (MC-ICP-MS). The calibration ML model was validated with two certified reference materials (LSVEC and IRMM-016). The procedure was applied toward the isotope amount ratio determination of a set of stock chemicals (Li2CO3, LiNO3, LiCl, and LiOH) and a BAM candidate reference material NMC111 (LiNi1/3Mn1/3Co1/3O2), a Li-battery cathode material. The results of these determinations were compared with those obtained by MC-ICP-MS and found to be metrologically comparable and compatible. The residual bias was −1.8‰, and the precision obtained ranged from 1.9 to 6.2‰. This precision was sufficient to resolve naturally occurring variations, as demonstrated for samples ranging from approximately −3 to +15‰. To assess its suitability to technical applications, the NMC111 cathode candidate reference material was analyzed using high-resolution continuum source atomic absorption spectrometry with and without matrix purification. The results obtained were metrologically compatible with each other. KW - Lithium KW - Isotope KW - Machine learning KW - Algorithms KW - Reference material KW - AAS KW - Atomic Absorption Spectrometry PY - 2021 DO - https://doi.org/10.1021/acs.analchem.1c00206 SN - 1520-6882 VL - 93 IS - 29 SP - 10022 EP - 10030 PB - American Chemical Society CY - Washington, DC, USA AN - OPUS4-53028 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Frick, Daniel A. A1 - Jacobsen, Lars A1 - Seger, Tino A1 - Florek, Stefan A1 - Richter, Silke A1 - Vogl, Jochen A1 - Recknagel, Sebastian A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Lithium isotope ratio analysis of geological samples using atomic absorption spectrometry with improved spectral resolution N2 - This study introduces an improved spectrometric method with enhanced precision to determine isotope ratios in geological samples without chromatographic separation. Firstly, the improvement is achieved by increasing the spectral resolution of the spectrometer applied in well-known high-resolution continuum source atomic absorption spectrometry (HR-CS-AAS). The resulting resolving power and linear dispersion of the upgraded setup, which is denoted in the following as HR+CS-AAS, is well adapted to the line widths of the Li isotope components we investigated. Secondly, our proposed method combines optical absorption spectrometry with machine learning data analysis using an extreme gradient boosting algorithm (XGBoost). This method was applied to analyze certified geological reference materials with δLSVEC(7Li/6Li) (hereafter δ7Li) values ranging from −0.5 ‰ to 4.5 ‰. With a pixel related optical resolving power of λ/∆λ ≈ 780 000, we obtain precisions in δ7Li measurements from 1.0 ‰ to 2.5 ‰. The method is validated by comparing the results with multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS), confirming its metrological compatibility. This work presents a fast, robust, and reliable method for δ7Li measurement in geological samples. KW - Isotope KW - High-resolution continuum source atomic absorption spectroscopy KW - Lithium KW - Machine learning KW - Echelle spectrometer PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-611807 DO - https://doi.org/10.1016/j.sab.2024.107013 VL - 220 SP - 1 EP - 5 PB - Elsevier BV AN - OPUS4-61180 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - The use of reference materials to improve the calibration strategy in glow discharge optical emission spectroscopy with machine learning N2 - Glow discharge optical emission spectroscopy (GD-OES) is a technique for the analysis of solids such as metals, semiconductors, and ceramics. A low-pressure glow discharge plasma is applied in this system, which ‘sputters’ and promotes the sample atoms to a higher energy state. When the atoms return to their ground state, they emit light with characteristic wavelengths, which a spectrometer can detect. Thus, GD-OES combines the advantages of ICP-OES with solid sampling techniques, which enables it to determine the bulk elemental composition and depth profiles. However, direct solid sampling methods such as glow-discharge spectroscopy require reference materials for calibration due to the strong matrix effect. Reference materials are essential when the accuracy and reliability of measurement results need to be guaranteed to generate confidence in the analysis. These materials are frequently used to determine measurement uncertainty, validate methods, suitability testing, and quality assurance. In addition, they guarantee that measurement results can be compared to recognized reference values. Unfortunately, the availability of certified reference materials suited to calibrate all elements in different matrix materials is limited. Therefore various calibration strategies and the preparation of traceable matrix-matched calibration standards will be discussed. Machine learning is an essential component of the growing field of data science. Through statistical methods, algorithms are trained to make classifications or predictions, uncovering key insights within data mining projects. Therefore, it was tried in our work to combine GD-OES with machine learning strategies to establish a new and robust calibration model, which can be used to identify the elemental composition and concentration of metals from a single spectrum. For this purpose, copper reference materials from different manufacturers, which contain various impurity elements, were investigated using GD-OES. The obtained spectra information are evaluated with different algorithms (e.g., gradient boosting and artificial neural networks), and the results are compared and discussed in detail. T2 - Winter Conference on Plasma Chemistry 2022 CY - Tucson, AZ, USA DA - 17.01.2022 KW - GDOES KW - Machine learning KW - Reference materials KW - Calibration KW - Cooper PY - 2022 AN - OPUS4-56497 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - What does GD-OES reveal about the aging and manufacturing processes of lithium-ion batteries? N2 - Glow-Discharge Optical Emission Spectroscopy (GD-OES), a powerful analytical technique, sheds light on the two critical aspects of lithium-ion batteries (LIBs): manufacturing and aging 1, 2. We optimized cell production in manufacturing by adjusting parameters, including cathode doping, electrolyte concentration, and pressing force. GD-OES provided in-depth elemental composition and homogeneity analysis, which is crucial for identifying optimal manufacturing conditions. These findings were validated by electrochemical impedance spectroscopy, confirming the quality of the manufactured batteries. Shifting the focus to aging, we use GD-OES for fluorine depth profiling, a key element in understanding polymer and electrolyte degradation. However, fluorine presents analytical challenges. We addressed this by substituting argon with a neon:argon mixture, which significantly enhanced fluorine detection sensitivity. This advancement not only improves accuracy but also holds the potential to guide sustainable and cost-efficient manufacturing strategies. Through its versatility, GD-OES has proven to be a powerful tool for not only optimizing LIB manufacturing processes but also gaining deeper insights into their aging mechanisms. This research extends beyond academic interest, offering tangible benefits for the industry by translating into improved battery quality, extended lifespan, and overall performance. T2 - The 6th International Glow Discharge Spectroscopy Symposium CY - Liverpool, United Kingdom DA - 21.04.2024 KW - GD-OES KW - Depth profiles KW - Lithium KW - Battery KW - Fluorine KW - Aging KW - Manufacturing KW - Glow-discharge PY - 2024 AN - OPUS4-59945 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - You, Zengchao A1 - Hoffmann, V. A1 - Morcillo, Dalia A1 - Agudo Jácome, Leonardo A1 - Leonhardt, Robert A1 - Winckelmann, Alexander A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Investigation of aluminum current collector degradation in lithium-ion batteries using glow discharge optical emission spectrometry N2 - In this work, we employed glow discharge optical emission spectrometry (GD-OES) depth profiling as a fast and semi-quantitative method to investigate the aluminum (Al) current collector degradation in commercial lithium cobalt oxide (LCO) pouch cells with no Al2O3 pretreatment. After battery aging, a heterogeneous deposit was found on the surface of the cathode. Gray hotspot areas within an extensive pale white region were formed. Consistent with energy dispersive X-ray (EDX) analysis of micro-cross sections milled via targeted focused ion beam (FIB), an Al-containing layer of approximately 3 µm can be observed using GD-OES. We attribute one main cause of this layer is the degradation of the Al current collector. The nonuniform growth of this layer was investigated by performing GD-OES depth profiling at different in-plane positions. We found that the gray area has a higher mass concentration of Al, probably in metallic form, whereas the white area was probably covered more homogeneously with Al2O3, resulting from the inhomogeneous distribution of the pitting positions on the current collector. Compared to FIB-EDX, GD-OES enables a faster and more convenient depth profile analysis, which allows the more productive characterization of lithium-ion batteries (LIBs), and consequently benefits the development of preferable battery materials. KW - GD-OES KW - depth profiles KW - Li-ion battery KW - battery aging mechanism KW - current collector corrosion PY - 2023 DO - https://doi.org/10.1016/j.sab.2023.106681 SN - 0584-8547 VL - 205 SP - 106681 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-57383 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Improvement of manufacturing processes of Li-ion batteries by Glow Discharge Optical Emission Spectroscopy N2 - Manufacturing lithium-ion coin cells (LIBs) for scientific research demands reproducibility, precision, and thorough metrology to ensure consistent quality and performance. Glow-discharge optical emission spectroscopy (GD-OES) emerges as a crucial analytical technique in this context, providing detailed insights into elemental composition and material homogeneity [1,2]. This study focuses on using GD-OES to optimize and standardize the manufacturing processes of LIBs, emphasizing metrology and traceability to develop reproducible and high-quality batteries for research purposes. We refined cell production by adjusting key parameters such as cathode doping, electrolyte concentration, and calendar pressing. GD-OES facilitated depth analysis of elemental composition and distribution, which is essential for identifying and maintaining optimal manufacturing conditions. Validation was achieved through electrochemical impedance spectroscopy (EIS), ensuring the quality and consistency of the manufactured batteries. GD-OES analysis revealed critical insights into elemental uniformity and impurities, guiding adjustments significantly improving cell performance and reproducibility. The method proved fast and effective in detecting and correcting variations in the manufacturing process, leading to enhanced battery quality. To understand the aging mechanisms, GD-OES was employed for fluorine depth profiling, which is crucial for studying polymer and electrolyte degradation. We significantly enhanced fluorine detection sensitivity by substituting the argon plasma with a neon/argon mixture, providing a more accurate aging analysis. By demonstrating the versatility and efficacy of GD-OES in optimizing LIB manufacturing processes and gaining deeper insights into aging mechanisms, this research has significant practical implications. It not only advances lab research but also offers tangible industrial benefits, including improved battery quality, extended lifespan, and enhanced performance. By ensuring metrology and traceability, GD-OES contributes to developing a robust method for the reproducible manufacturing of Li-ion coin cells, boosting innovation and sustainability in battery technology. T2 - SciX 2025 CY - Covington, KY, USA DA - 05.10.2025 KW - GD-OES KW - Battery analysis KW - Depth profile KW - Lithium-ion battery PY - 2025 AN - OPUS4-64878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Bashiri, Termeh A1 - Yu, Phelan A1 - Hutzler, Nicholas R. A1 - Steimle, Timothy C. A1 - Abad Andrade, Carlos Enrique A1 - Okumura, Mitchio T1 - A Molecular Beam Study of the (0,0) A2Π<- X2Σ+ Band of CaF Isotopologues N2 - This study presents an experimental determination of spectroscopic parameters for the less-abundant isotopologues 42CaF and 44CaF, alongside 40CaF, by high resolution laser-induced fluorescence spectroscopy in a skimmed free jet expansion. We recorded spectra near the natural linewidth limit and derived spectroscopic constants for both X2Σ+ and A2Π states, including the fine and 19F magnetic hyperfine parameters. We also estimated the r (44Ca/40Ca) isotope amount ratio, demonstrating the potential use of optical spectroscopy for isotope analysis. KW - High-resolution spectroscopy KW - Molecular beam spectrometer KW - Isotope ratios KW - Calcium isotopes KW - Isotopologues PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648804 DO - https://doi.org/10.48550/arXiv.2505.03045 SP - 1 EP - 23 PB - Cornell University AN - OPUS4-64880 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Recknagel, Sebastian A1 - Richter, Silke A1 - Hoppe, Marion A1 - Meckelburg, Angela A1 - Prinz, Carsten A1 - Roik, Janina A1 - Abad Andrade, Carlos Enrique T1 - Powering precision: development of a certified reference material for elemental composition analysis of lithium nickel manganese cobalt oxide (Li-NMC) cathode material for lithium-ion batteries N2 - This work presents the development and certification of the world’s first certified reference material (CRM), BAM-S014, for a lithium nickel manganese cobalt oxide (LiNi0.33Mn0.33Co0.33O2 or Li-NMC 111) cathode material—an integral component in high-energy-density lithium-ion batteries that power electric vehicles (EVs), portable electronics, and stationary energy storage systems. By providing certified mass fractions for 11 elements, this CRM addresses a critical need for accurate and traceable elemental analysis, supporting quality control and regulatory compliance in the global battery industry. Ensuring reliable and harmonized measurements supports the efficient use of resources, including the reuse of recycled materials, and ultimately helps maintain product performance and safety. The values were assigned through an interlaboratory comparison involving 16 participating laboratories and various analytical techniques such as inductively coupled plasma optical emission spectrometry (ICP-OES), inductively coupled plasma mass spectrometry (ICP-MS), X-ray fluorescence (XRF) spectrometry, and combustion analysis. In addition to chemical characterization, the certification process includes homogeneity and stability testing of the candidate material. Details are provided on the analytical methods used for chemical characterization and the calculation of the uncertainties of the certified mass fractions. In addition to detailing the development of the CRMs, this work provides an overview of ongoing standardization activities in Li-component analysis, thereby guiding the calibration of analytical methods and contributing to the establishment of globally accepted standards for evaluating energy storage materials and advancing sustainable mobility and clean energy solutions. KW - Certified reference material KW - Lithium nickel manganese cobalt oxide KW - LNMC KW - Lithium-ion battery KW - Cathode material PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643763 DO - https://doi.org/10.1007/s00216-025-05766-7 SN - 1618-2642 VL - 417 IS - 12 SP - 2643 EP - 2653 PB - Springer Nature AN - OPUS4-64376 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - Lopez-Linares, F. A1 - Poirier, L. A1 - Jakubowski, Norbert A1 - Recknagel, Sebastian A1 - Panne, Ulrich T1 - Shake, shut, and go – A fast screening of sulfur in heavy crude oils by highresolution continuum source graphite furnace molecular absorption spectrometry via GeS molecule detection N2 - A fast and simple method for sulfur quantification in crude oils was developed by using high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). For this, heavy crude oil samples were prepared as microemulsion (shake) and injected into a graphite furnace (shut). Finally, the concentration of sulfur was determined by monitoring in situ the transient molecular spectrum of GeS at wavelength 295.205nm after adding a germanium solution as molecular forming agent (and go). Zirconium dioxide in the form of nanoparticles (45–55nm) was employed as a permanent modifier of the graphite furnace. Calibration was done with an aqueous solution standard of ammonium sulfate, and a characteristic mass (m0) of 7.5ng was achieved. The effectiveness of the proposed method was evaluated analizing, ten heavy crude oil samples with Sulfur amounts ranging between 0.3 and 4.5% as well as two NIST standard reference materials, 1620c and 1622e. Results were compared with those obtained by routine ICP-OES analysis, and no statistical relevant differences were found. KW - Heavy crude oil KW - Sulfur KW - HR-CS-MAS KW - Germanium sulfide KW - Microemulsion PY - 2019 DO - https://doi.org/10.1016/j.sab.2019.105671 SN - 0584-8547 VL - 160 SP - 105671 PB - Elsevier B.V. CY - Amsterdam, Netherlands AN - OPUS4-48747 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Critical evaluation of optical spectrometry vs mass spectrometry for stable isotope analysis N2 - Mass spectrometric Methods MC-ICP-MS and TIMS) are without doubt the working horse of stable isotope analysis. However, drawbacks of these methods include the high costs for instruments and their operation, experienced operators and elaborate chromatographic sample preparation which are time consuming. Optical spectrometric methods are proposed as faster and low-cost alternative for the analysis of isotope ratios of selected elements by means of high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS) and laser ablation molecular isotopic spectrometry (LAMIS). First, stable isotope amount compositions of boron (B) and magnesium (Mg) were determined based on the absorption spectra of in-situ generated heteronuclear diatomic molecules (MH or MX) in graphite furnace HR-CS-MAS. The use of a modular simultaneous echelle spectrograph (MOSES) helps to find the maximal isotope shift in the diatomic molecular spectra produced in a graphite furnace by using isotopic spike solutions. Isotopes of boron (10B and 11B) were studied via their hydrides for the electronic transition X 1Σ+ → A 1Π. The spectrum of a given sample is a linear combination of the 10BH molecule and its isotopologue 11BH. Therefore, the isotopic composition of samples can be calculated by a partial least square regression (PLS). For this, a spectral library was built by using samples and spikes with known isotope composition. Boron isotope ratios measured by HR-CS-MAS are identical with those measured by mass spectrometric methods at the 0.15 ‰ level. Similar results were obtained for a multiple isotope system like Mg (24Mg, 25Mg, and 26Mg), where isotope shifts of their isotopologues can be resolved in the MgF molecule for the electronic transition X 2Σ → A 2 Πi. Finally, the application of molecular spectrometry via emission by LAMIS is compared and discussed. T2 - European Winter Conference on Plasma Spectrochemistry EWCPS 2019 CY - Pau, France DA - 03.02.2019 KW - Isotope analysis KW - HR-CS-MAS KW - LIBS KW - MS-ICP-MS KW - Optical spectroscopy KW - Mass spectrometry PY - 2019 AN - OPUS4-49874 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Determination of isotope ratios by molecular absorption spectrometry N2 - Boron and Magnesium present two and three stable isotopes respectevely. It is due to their relatively large mass difference (~ 10%) that isotope fractionation leads to considerable isotope amount ratio variations in the nature. These have been used as a proof of provenance of mineral and biological samples, to estimate a contamination source and to the determination of geological processes by erosion or subduction. Additionally, boron is employed in the nuclear industry due to the capability of its isotope 10B to thermal-neutron capture and therefore 10B enriched boric acid solutions are used in the cooling system of thermonuclear facilities and in the alloying of steel and carbides for protective shielding. Traditionally, isotope ratio variations have been determined by mass spectroscopic methods. Here an alternative faster and low cost method for isotope ratio determination is proposed: high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS). Isotope amount ratios have been determined by monitoring the absorption spectrum of boron monohydride (BH) for boron and Magnesium monofluoride (MgF) for magnesium in a graphite furnace HR-CS-MAS. Bands (0→0) and (1→1) were evaluated. Partial least square regression (PLS) for analysis of samples and reference materials were applied. For this, a spectral library with different isotopes ratios for PLS regression was built. Results obtained are metrologically compatible with those reported by mass spectrometric methods. Moreover, a precision and accuracy of the method of ± 0.5 ‰. This accuracy and precision is comparable with those obtained by thermal ionization mass spectrometry (TIMS) and multiple collector inductively coupled plasma mass spectrometry (MC-ICP-MS) for boron isotope ratio measurements T2 - Analytik Jena Days CY - Idstein, Germany DA - 26.06.2019 KW - Isotope anaylsis KW - HR-CS-MAS KW - Boron KW - Magnesium KW - Optical spectroscopy KW - Diatomic molecule PY - 2019 AN - OPUS4-49877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Stable isotope analysis of magnesium by optical spectrometry N2 - Magnesium is a naturally occurring element that can be found in several mineral forms in the earth crust. This element presents three stable isotopes 24Mg, 25Mg and 26Mg with a natural abundance of 79%, 10%, and 11% respectively. It is due to their relatively large mass difference (~8% between 24Mg and 26Mg) that isotope fractionation leads to slight isotope amount ratio variations n(26Mg)/n(24Mg) in biological and geological samples. Traditionally, isotope amount ratios have been measured by mass spectrometric methods. However, drawbacks of these methods include the high costs for instruments and their operation, experienced operators and elaborate chromatographic sample preparation which are time-consuming. Recently, optical spectrometric methods have been proposed as faster and low-cost alternative for the analysis of isotope ratios of selected elements by means of high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS) and laser ablation molecular isotopic spectrometry (LAMIS). For the determination of Mg isotope amount ratios, the molecular spectrum of the in-situ generated MgF and MgO molecules were studied. In the case of HR-CS-GFMAS, the absorption spectrum was recorded for MgF for the electronic transitions X 2Σ → A 2 Πi and X 2Σ → B 2Σ+ around wavelengths 358 nm and 268 nm respectively. In the case of LAMIS, it was studied the MgF molecule for the electronic transitions A 2Πi → X 2Σ as well as the MgO molecule for the electronic transition A 1Π+ → X 1Σ around 500 nm. The MgF and MgO spectra are composed by the linear combination of their isotopic components or isotopologues: 24MgF, 25MgF, and 26MgF for the MgF and 24MgO, 25MgO, and 26MgO for the MgO (F is monoisotopic, and the isotope composition of O is assumed as constant). By HR-CS-GFMAS the analysis of Mg was done by deconvolution of the MgF spectrum by a partial least square regression (PLS) calibrated with enriched isotope spikes. The isotope amount ratios in rock samples with and without matrix separation were analyzed. Resulting delta values were obtained with precisions ranging between 0.2-0.5 ‰. On the other hand, LAMIS allows the direct analysis of solid samples with the extended possibility of in-situ analysis. Main advantages, limitations, and scopes of both optical techniques are going to be discussed and compared with MC-ICP-MS. T2 - ANAKON 2019 CY - Münster, Germany DA - 25.03.2019 KW - Isotope analysis KW - HR-CS-MAS KW - LIBS KW - MC-ICP-MS KW - Magnesium PY - 2019 AN - OPUS4-49876 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Chemometric analysis of High resolution spectra for precise and accurate isotope amount ratio determination N2 - Magnesium is a major element in the hydrosphere and biosphere and plays important roles in (bio-) geochemical and physiological cycles. Mg has three stable isotopes, 24Mg, 25Mg and 26Mg. It is due to their relatively large mass difference (~8% between) that isotope fractionation leads to slight variations of isotope amount ratios in biological, environmental and geological samples. Traditionally, isotope amount ratios are measured by mass spectrometric methods. Their drawbacks include the high costs for instruments and their operation, experienced operators and elaborate time-consuming chromatographic sample preparation. Recently, an optical spectrometric method has been proposed as faster and low-cost alternative for the analysis of isotope ratios: high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). For the determination of Mg isotope ratios in selected rock reference materials, the high-resolution molecular absorption spectrum of in-situ generated MgF molecule was studied applying multivariate analysis and the results compared with MC-ICP-MS. Samples were dissolved by acid digestion and Mg isotopes analyzed with and without matrix. The absorption spectra were recorded for MgF for the electronic transition X 2Σ → B 2Σ+. The MgF spectrum is described as the linear combination of their isotopic components or isotopologues: 24MgF, 25MgF, and 26MgF. The isotope analysis was done by deconvolution of the MgF spectrum by partial least square regression (PLS). A PLS model was built and calibrated with enriched isotope spikes and certified reference materials. Spectra data was preprocessed by a derivate of second order and venetian blinds cross-validation was employed for finding the optimum latent variables. Finally, the model was refined by a genetic algorithm which identified the best subset of variables for a precise and accurate regression. Results are compatible with those obtained by MC-ICP-MS with an accuracy of ± 0.3‰ with uncertainties ranging between 0.02 to 0.6‰. T2 - Colloquium Analytische Atomspektroskopie CANAS 2019 CY - Freiberg, Germany DA - 23.09.2019 KW - Isotope analysis KW - Chemometric KW - Multivariate analysis KW - HR-CS-MAS KW - Molecular spectrum KW - Magnesium PY - 2019 AN - OPUS4-49878 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - A comparative analysis of optical spectrometry methods and MC-ICP-MS for stable isotope analysis of magnesium in geological samples N2 - Society for Applied Spectroscopy (SAS) Atomic Section Student Award. Magnesium is a major element in the hydrosphere and biosphere and plays important roles in (bio-) geochemical and physiological cycles. Mg has three stable isotopes, 24Mg, 25Mg and 26Mg. It is due to their relatively large mass difference (~8% between) that isotope fractionation leads to slight variations of isotope amount ratios in biological, environmental and geological samples. Traditionally, isotope ratios are measured by mass spectrometric methods. Their drawbacks include the high costs for instruments and their operation, experienced operators and elaborate time-consuming chromatographic sample preparation. Recently, optical spectrometric methods have been proposed as faster and low-cost alternative for the analysis of isotope ratios of selected elements by means of high-resolution continuum source molecular absorption spectrometry (HR-CS-MAS), and laser ablation molecular isotopic spectrometry (LAMIS). For the determination of Mg isotope ratios in selected rock reference materials, the molecular spectrum of the in-situ generated MgF and MgO molecules were studied and their results compared with MC-ICP-MS. By HR-CS-MAS, samples were dissolved by acid digestion and Mg isotopes analyzed with and without matrix. The absorption spectrum was recorded for MgF for the electronic transitions X 2Σ → A 2 Πi, and X 2Σ → B 2Σ+. In the case of LAMIS, we investigated the MgF molecule for the electronic transition A 2Πi → X 2Σ, as well as direct analysis by the MgO molecule for the electronic transition A 1Π+ → X 1Σ. The MgF and MgO spectra are described as the linear combination of their isotopic components or isotopologues: 24MgF, 25MgF, and 26MgF for the MgF and 24MgO, 25MgO, and 26MgO for the MgO. The isotope analysis was done by deconvolution of the MgF spectrum by partial least square regression (PLS) calibrated with enriched isotope spikes. Results were accurate with precisions ranging between 0.2 ‰ and 0.8 ‰ (2 SD, n= 10) for HR-CS-GFMAS. No statistically significant differences were observed for samples w/o matrix extraction. On the other hand, LAMIS allows the direct analysis of solid samples with the extended possibility of direct analysis, however the precision is lower due the lack of solid isotopic calibration standards. T2 - SciX 2019. 46th Annual North American Meeting of the Federation of Analytical Chemistry and Spectroscopy Societies (FACSS) CY - Palm Springs, CA, USA DA - 13.10.2019 KW - Isotope analysis KW - Diatomic molecule KW - Magnesium KW - MC-ICP-MS KW - HR-CS-MAS KW - LIBS PY - 2019 AN - OPUS4-49883 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Shedding light on global warming: high-resolution optical spectroscopy for magnesium isotope analysis N2 - Magnesium is a major element in the hydrosphere and biosphere, and it is direct correlated with the carbon cycle. Therefore, the study of its isotopic fractionation in sediments and sea water helps to understand the earth’s climate and global warming. Mg has three stable isotopes, 24Mg, 25Mg and 26Mg, and traditionally isotope amount ratios are measured by mass spectrometric methods. Their drawbacks include the high costs for instruments and their operation, experienced operators and elaborate time-consuming chromatographic sample preparation. Recently, an optical spectrometric method has been proposed as faster and low-cost alternative for the analysis of isotope ratios: high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). For the determination of Mg isotope ratios in selected rock reference materials, the high-resolution molecular absorption spectrum of in-situ generated MgF molecule was studied applying multivariate analysis and the results compared with MC-ICP-MS. Samples were dissolved by acid digestion and Mg isotopes analyzed with and without matrix extraction. The absorption spectra were recorded for MgF for the electronic transition X 2Σ → B 2Σ+. The MgF spectrum is described as the linear combination of their isotopic components or isotopologues: 24MgF, 25MgF, and 26MgF. The isotope analysis was done by deconvolution of the MgF spectrum by partial least square regression (PLS). A PLS model was built and calibrated with enriched isotope spikes and certified reference materials. Spectra data was preprocessed by a derivate of second order and venetian blinds cross-validation was employed for finding the optimum latent variables. Finally, the model was refined by a genetic algorithm which identified the best subset of variables for a precise and accurate regression. Results are compatible with those obtained by MC-ICP-MS with an accuracy of ± 0.3‰ with uncertainties ranging between 0.02 to 0.6‰. This accuracy and precision discriminate the isotope fractionation in geological samples, and it is suitable for earth’s climate studies. T2 - Adlershofer Forschungsforum 2019 CY - Berlin, Germany DA - 11.11.2019 KW - Isotope analysis KW - Geological thermometer KW - Magnesium KW - Optical spectroscopy PY - 2019 AN - OPUS4-49890 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Origin, Provenance, and Isotope analysis N2 - Is it a parmesan cheese from Italy? Who painted the Mona Lisa? The determination of the place of origin is essential for consumer protection, detection of falsifications, and also to bring justice. All the tangible possess an isotopic fingerprint. However, current technologies are too expensive. We work on the development of fast and low-cost optical instruments and methods for isotope analysis. T2 - Berlin Sciendce Week – Zukunftsorte – Innovation Made in Berlin CY - Berlin, Germany DA - 07.11.2019 KW - Isotope analysis KW - Optical spectroscopy KW - Provenance KW - Iisotopic signature KW - Isotopic fingerprints PY - 2019 AN - OPUS4-49889 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Breaking the wall of uncertain origin N2 - Is it a parmesan cheese from Italy? Who painted the Mona Lisa? The determination of the place of origin is essential for consumer protection, detection of falsifications, and also to bring justice. All the tangible possess an isotopic fingerprint. However, current technologies are too expensive. We work on the development of fast and low-cost optical instruments and methods for isotope analysis. T2 - Falling Walls Lab Adlershof CY - Berlin, Germany DA - 27.09.2019 KW - Isotope analysis KW - Optical spectroscopy KW - Provenance PY - 2019 AN - OPUS4-49882 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Florek, S. A1 - Becker-Ross, H. A1 - Huang, M.-D. A1 - de Oliveira Guilherme Buzanich, Ana A1 - Radtke, Martin A1 - Lippitz, Andreas A1 - Hodoroaba, Vasile-Dan A1 - Schmid, Thomas A1 - Heinrich, Hans-Joachim A1 - Recknagel, Sebastian A1 - Jakubowski, Norbert A1 - Panne, Ulrich T1 - Zirconium permanent modifiers for graphite furnaces used in absorption spectrometry: understanding their structure and mechanism of action N2 - The mechanism of action of zirconium permanent modifiers on graphite surfaces was investigated in order to understand its influence on the analytical signal in atomic and molecular absorption spectrometry (AAS/MAS). For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS). The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEMEDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. We propose here a mechanism, where ZrO2 acts as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. No evidence of the formation of zirconium carbide was found. Consequently, as the CaF formation is catalysed by a heterogeneous catalyst, surface modifications with ZrO2 nanoparticles and ZrO xerogels were investigated in order to increase the surface area. Their influence was evaluated in the molecule formation of CaF, CaCl, CaBr, and CaI. Graphite furnace modification with zirconium oxide nanoparticles proves to be the best choice for fluorine analysis with a signal enhancement of more than eleven times with respect a non-coated graphite furnace. However, the influence of zirconium modifications in the analytical signals of Cl, and I is lower than the F signals or even negative in case of the Br. Understanding zirconium modifiers as heterogeneous catalysts offers a new perspective to AAS and MAS, and reveals the potential of surface analytical methods for development of improved permanent modifiers and graphite furnace coatings. KW - Zirconium KW - HR-CS-MAS KW - Graphite furnace KW - Nanoparticles KW - Xerogel KW - Calcium monofluoride KW - Absorption spectrometry PY - 2018 UR - https://pubs.rsc.org/en/content/articlelanding/2018/ja/c8ja00190a DO - https://doi.org/10.1039/C8JA00190A SN - 0267-9477 VL - 33 IS - 12 SP - 2034 EP - 2042 PB - Royal Society of Chemistry AN - OPUS4-46775 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Simultaneous multielemental analysis of crude oils by high-resolutions absorption spectrometry N2 - When crude oil arrives at a refinery it needs a lot of processing before it is suitable for cracking into lighter fractions. Sulfur has to be extracted to meet ultra-low sulfur legislation for most of the fuel grades, and desalination is a crucial process as chlorine within salts is corrosive to refinery equipment. Measuring the amounts of sulfur and chlorine within crude oil is the first step in a complex clean-up process. Heavy metals, such as vanadium, nickel and iron need to be removed too. These metals can poison the catalyst used to crack the oil into lighter fractions. This is costly as it reduces the useful life of the catalyst. Like chlorine, heavy metals also have a corrosive effect on the plant. There is some evidence that the presence of some metals in the final product can reduce performance. A fast determination of elements and size of suspended particles is vital for diagnosis and safeguard of refinery equipment. However, sample preparation for current analytical methods consumes precious time and lost particle size information. High-resolution continuum source graphite furnace absorption spectrometry (HR-CS-GFAS) is proposed as a fast analytical method for elemental determination in crude oils and potentially for simultaneous multielement and particle size analysis. This HR-CS-GFAS instrumentation is coupled to a modular simultaneous echelle spectrometer (MOSES) and provides a full optical window with high resolution (from 180 to 900 nm with bandwidth λ/170,000). By using this set-up, it is possible to generate a multiparameter 3D spectral image (atomic and molecular lines, isotopic shift, atomization delay, and intensities). The generated spectral images can be analyzed by multivariate regressions for the elemental and particle size analysis. Additionally, if several atomic and molecular lines are simultaneously measured, they may be used in multi-energy calibration (MEC), a method based on the use of many wavelengths of the same absorbing/emitting entity to improve the accuracy in analytical atomic spectrometry. This MEC approach combined with multivariate image analysis allows the quantification of selected elements (Si, Al, Ni, Fe, V, S, and Cl) and overcomes matrix effects. T2 - Chevron Seminar- Group Chemical Characterization and Atomic Spectroscopy CY - Richmond, CA, USA DA - 22.10.2019 KW - Crude oil KW - Multielemental analysis KW - HR-CS-AAS KW - Optical spectroscopy KW - MOSES PY - 2019 AN - OPUS4-49885 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Stable isotope analysis of magnesium by optical spectrometry N2 - Magnesium (Mg) is a major element in a range of silicate and carbonate minerals, the hydrosphere and biosphere and plays important roles in (bio-) geochemical and physiological cycles. Mg has three stable isotopes, 24Mg, 25Mg and 26Mg with natural abundances of 79 %, 10 %, and 11 %, respectively. It is due to their relatively large mass difference (~8% between 24Mg and 26Mg) that isotope fractionation leads to slight variations of isotope amount ratios n(26Mg)/n(24Mg) in biological, environmental and geological samples. Traditionally, isotope ratios are measured by mass spectrometric methods and isotope ratios are expressed as deviation from an internationally agreed upon material, i.e. the zero-point of the δ-value scale. Drawbacks of this method include the high costs for instruments and their operation, experienced operators and elaborate, time-consuming chromatographic sample preparation. Recently, optical spectrometric methods have been proposed as faster and low-cost alternative for the analysis of isotope ratios of selected elements by means of high- resolution continuum source graphite furnace molecular absorption spectrometry (HR- CS-GFMAS) and laser ablation molecular isotopic spectrometry (LAMIS). For the determination of Mg isotope amount ratios, the molecular spectrum of the in-situ generated MgF and MgO molecules were studied. In the case of HR-CS-GFMAS, the absorption spectrum was recorded for MgF for the electronic transitions X2Σ → A2Πi and X 2Σ → B2Σ+ around wavelengths 358 nm and 268 nm, respectively. In the case of LAMIS, we investigated the MgF molecule for the electronic transition A2Πi → X2Σ as well as the MgO molecule for the electronic transition A1Π+ → X1Σ around 500 nm. The MgF and MgO spectra are described by the linear combination of their isotopic components or isotopologues: 24MgF, 25MgF, and 26MgF for the MgF and 24MgO, 25MgO, and 26MgO for the MgO (F is monoisotopic, and the isotope composition of O is assumed as constant). By HR-CS-GFMAS the analysis of Mg was done by deconvolution of the MgF spectrum by partial least square regression (PLS) calibrated with enriched isotope spikes. Isotope amount ratios in rock samples with and without matrix separation were analyzed. Calculated δ-values were accurate and obtained with precisions ranging between 0.2 ‰ and 0.5 ‰ (1 SD, n = 10). On the other hand, LAMIS allows the direct analysis of solid samples with the extended possibility of in-situ analysis. Main advantages, limitations, and scopes of both optical techniques are going to be discussed and compared to MC-ICP-MS. T2 - Seminars Earth Surface Geochemistry- Deutsches GeoForschungsZentrum GFZ CY - Potsdam, Germany DA - 06.08.2019 KW - Isotope analysis KW - Magnesium KW - HR-CS-MAS KW - LIBS KW - Diatomic KW - Optical spectroscopy PY - 2019 AN - OPUS4-49904 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Obenlüneschloß, Jorit A1 - Boysen, Nils A1 - Rönnby, Karl A1 - Muriqi, Arbresha A1 - Hoffmann, Volker A1 - Abad Andrade, Carlos Enrique A1 - Rogalla, Detlef A1 - Brokmann, Ulrike A1 - Rädlein, Edda A1 - Nolan, Michael A1 - Devi, Anjana T1 - Ein seltener mononuklearer Lithium‐Carben‐Komplex für die Atomlagenabscheidung von lithiumhaltigen Dünnschichten N2 - KurzfassungLithium ist das zentrale Element moderner Batterietechnologien, und die Herstellung von lithiumhaltigen Materialien mittels Atomlagenabscheidung (engl. Atomic Layer Deposition, ALD) bietet erhebliche Vorteile bei der Kontrolle der Schichtdicke und ‐zusammensetzung. In dieser Studie wird ein neuer mononuklearer, durch ein N‐heterocyclisches Carben (NHC) stabilisierter Lithiumkomplex, [Li(tBuNHC)(hmds)], als vielversprechender Präkursor für die ALD von lithiumhaltigen Dünnschichten vorgestellt. Die strukturelle Charakterisierung erfolgt durch den Vergleich von Dichtefunktionaltheorie (DFT) und Einkristall‐Röntgenbeugung (engl. Single‐Crystal X‐ray Diffraction, SC‐XRD), wobei die seltene mononukleare Struktur bestätigt wird. Thermogravimetrische Analysen (TGA) zeigen vorteilhafte thermische Eigenschaften für ALD‐Anwendungen. Die Verbindung weist einen niedrigen Schmelzpunkt, saubere Verdampfung und ermutigende Volatilitätsparameter im Vergleich zu anderen Lithium‐Präkursoren auf. ALD‐Experimente mit [Li(tBuNHC)(hmds)] und Ozon zeigen dessen Effektivität bei der Abscheidung von LiSixOy‐Filmen. Der ALD‐Prozess zeigt ein gesättigtes Wachstum pro Zyklus (engl. Growth per Cycle, GPC) von 0,95 Å. Die Zusammensetzung, analysiert mittels Rutherford‐Rückstreu‐Spektrometrie/Kernreaktionsanalyse (engl. Rutherford Backscattering Spectrometry/Nuclear Reaction Analysis, RBS/NRA), Röntgenphotoelektronenspektroskopie (engl. X‐ray Photoelectron Spectroscopy, XPS) und Glimmentladungsspektroskopie (engl. Glow Discharge Optical Emission Spectrometry, GD‐OES), bestätigt das Vorhandensein von Lithium und Silizium in den erwarteten Verhältnissen. Diese Arbeit stellt nicht nur einen neuen ALD‐Präkursor vor, sondern trägt auch zum Verständnis der Lithiumchemie bei und bietet Einblicke in die faszinierende Koordinationschemie und das thermische Verhalten von durch NHC‐Liganden stabilisierten Lithiumkomplexen. KW - Atomlagenabscheidung KW - N-heterozyklischer-Carben-(NHC)-stabilisierter Lithium-Präkursor KW - Mononuklearer Li–Carben-Komplex KW - Lithiumsilicat-Dünnfilme KW - Filmanalytik/-Charakterisierung PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-644045 DO - https://doi.org/10.1002/ange.202513066 SN - 0044-8249 N1 - Es gibt eine parallele Sprachausgabe (englisch), ein Link befindet sich im Feld zugehöriger Identifikator - There is a parallel language edition (English), a link is in the field related identifier SP - 1 EP - 12 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64404 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Obenlüneschloß, Jorit A1 - Boysen, Nils A1 - Rönnby, Karl A1 - Muriqi, Arbresha A1 - Hoffmann, Volker A1 - Abad Andrade, Carlos Enrique A1 - Rogalla, Detlef A1 - Brokmann, Ulrike A1 - Rädlein, Edda A1 - Nolan, Michael A1 - Devi, Anjana T1 - Rare Mononuclear Lithium-Carbene Complex for Atomic Layer Deposition of Lithium Containing Thin Films N2 - Lithium is the core material of modern battery technologies and fabricating the lithium‐containing materials with atomic layer deposition (ALD) confers significant benefits in control of film composition and thickness. In this work, a new mononuclear N‐heterocyclic carbene (NHC) stabilized lithium complex, [Li(tBuNHC)(hmds)], is introduced as a promising precursor for ALD of lithium‐containing thin films. Structural characterization is performed, comparing density functional theory (DFT) and single‐crystal X‐ray diffraction (SC‐XRD), confirming a rare mononuclear structure. Favorable thermal properties for ALD applications are evidenced by thermogravimetric analysis (TGA). The compound exhibits a low melting point, clean evaporation, and its volatility parameters are encouraging compared to other lithium precursors. ALD trials using [Li(tBuNHC)(hmds)] with ozone demonstrate its effectiveness in depositing LiSixOy films. The ALD process exhibits a saturated growth per cycle (GPC) of 0.95 Å. Compositional analysis using Rutherford backscattering spectrometry/nuclear reaction analysis (RBS/NRA), X‐ray photoelectron spectrometry (XPS), and glow discharge optical emission spectrometry (GD‐OES), confirms the presence of lithium and silicon in the expected ratios. This work not only presents a new ALD precursor but also contributes to the understanding of lithium chemistry, offering insights into the intriguing coordination chemistry and thermal behavior of lithium complexes stabilized by NHC ligands. KW - Atomic layer deposition (ALD) KW - N-heterocyclic carbene (NHC) ligands KW - Lithium ALD precursor chemistry KW - Mononuclear Li–carbene complex [Li(tBuNHC)(hmds)] KW - Li-silicate thin films (LiSixOy) KW - Thermal properties & TGA/volatility KW - Compositional analysis (RBS/NRA, XPS, GD-OES) PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643790 DO - https://doi.org/10.1002/anie.202513066 SN - 1433-7851 N1 - Es gibt eine parallele Sprachausgabe (deutsch), ein Link befindet sich im Feld zugehöriger Identifikator - There is a parallel language edition (German), a link is in the field related identifier SP - 1 EP - 11 PB - Wiley-VCH CY - Weinheim AN - OPUS4-64379 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - A proposed mechanism of action of permanent modifiers for molecular absorption spectrometry: the case of calcium monofluoride N2 - High-Resolution Continuum Source Molecular Absorption Spectrometry (HR-CS-MAS) with graphite furnace atomizers has been successfully used for the analytical determination of non-metals. The use of permanent modifiers (or coatings) for molecule formation is necessary, but their mechanisms of action remain unclear. In order to understand and improve the current analytical methods, we present a comprehensive mechanistic study of molecule formation in graphite furnaces: a key step into the recovery of analytical signals. Therefore, a well-known system for fluorine determination was studied: the molecule formation of CaF, with Zr as permanent modifier. Through a kinetic approach, an Arrhenius plot showed a pseudo first order reaction respect to F-. By spectroscopic methods (XPS, XAS, EDX) it was possible to elucidate an intermediate state. Here a mechanism is proposed, where ZrO2 works as heterogeneous catalyst: after a pyrolytic step, it is activated to the intermediate state of ZrO(OCaF) and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. With this analytical information, improved surface modifications and coatings for graphite furnaces can be designed and some of them, for example with Zr nanoparticle and Zr xerogels are here presented. T2 - ANAKON 2017 CY - Tübingen, Germany DA - 03.04.2017 KW - Fluorine KW - High-resolution continuum source Molecular Absorption Spectrometry KW - HR-CS-MAS KW - Zirconium oxide KW - Modifier KW - Coating PY - 2017 AN - OPUS4-39902 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Glauber, J.-P. A1 - Lorenz, J. A1 - Liu, J. A1 - Seifert, M. A1 - Hoffmann, V. A1 - Abad Andrade, Carlos Enrique A1 - Rogalla, D. A1 - Harms, C. A1 - Wark, M. A1 - Nolan, M. A1 - Devi, A. T1 - High Quality Crystalline VN Thin Films via MOCVD from a New Vanadium Precursor: Linking Growth Chemistry to Functional Catalytic Surfaces N2 - Vanadium nitride (VN) has been identified as a promising material for numerous applications including electrochemical nitrogen reduction reaction (eNRR). For such applications, catalyst nanoengineering will help to experimentally test its theoretically predicted eNRR activity, but the majority of investigated VN catalysts are prepared by fabrication methods that do not allow for nanoengineering to the required degree. Herein, we report on a new metalorganic chemical vapor deposition (MOCVD) process for the growth of high quality, facetted and crystalline VN thin films relevant for eNRR applications. N,N’-diisopropylformamidinato [V(dpfamd)3] was identified as a promising precursor as it possesses favorable thermal properties relevant for MOCVD. The application of [V(dpfamd)3] in a MOCVD process with NH3 as co-reactant yielded crystalline VN thin films on Si substrates with high compositional purity. With the potential of using the catalytic activity of VN towards eNRR, the structure-property correlation is of relevance and in this context, the thin films were subjected to complementary analysis including X-ray diffraction (XRD), Rutherford backscattering spectrometry in combination with nuclear reaction analysis (RBS/NRA), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Based on the observation of the significant influence NH3 has on the growth characteristics, we conducted first principles density functional theory (DFT) simulations of the precursor reactivity in the absence and presence of NH3 towards VN, supporting experimental findings of energetically more favorable decomposition of [V(dpfamd)3] to VN in the presence of NH3. Process transfer from Si to conductive Ti substrates, relevant for prospective electrochemical testing, revealed comparable VN thin film properties rendering these films promising for further investigation of eNRR applications in follow up studies. KW - Metal nitrades KW - MOCVD KW - Nitrogen reduction reaction KW - Precursors KW - DFT PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648600 DO - https://doi.org/10.26434/chemrxiv-2025-1t4gq SP - 1 EP - 25 AN - OPUS4-64860 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rua-Ibarz, Ana A1 - Nakadi, Flávio V. A1 - Bolea-Fernandez, Eduardo A1 - Bazo, Antonio A1 - Battistella, Beatrice A1 - Matiushkina, Anna A1 - Resch-Genger, Ute A1 - Abad Andrade, Carlos Enrique A1 - Resano, Martín T1 - Discrete entity analysis via microwave-induced nitrogen plasma–mass spectrometry in single-event mode N2 - In this work, single-event microwave-induced nitrogen plasma–mass spectrometry (single-event MINP-MS) was evaluated for the first time for the analysis of discrete entities such as nanoparticles, biological cells, and microplastics. Nitrogen (N2) effectively overcomes Ar-based polyatomic interferences, enabling (ultra)trace element determination of Fe and Se using their most abundant isotopes, 56Fe (91.66%) and 80Se (49.82%). Iron oxide nanoparticles (Fe2O3 NPs) ranging from 20 to 70 nm were accurately characterized, with excellent agreement with established sizing techniques, such as transmission electron microscopy (TEM) and dynamic light scattering (DLS). A limit of detection (LoD) of 8.6 ag for Fe─equivalent to an LoDsize of 19 nm for Fe2O3─was achieved, which is significantly lower than recent values reported for high-end quadrupole-based ICP-MS. Selenium nanoparticles (SeNPs) of 150 and 250 nm were also accurately characterized, without the N2-based plasma experiencing issues handling relatively large metallic NPs (linearity, R2 = 0.9994). Se-enriched yeast cells (SELM-1 certified reference material) were successfully analyzed via single-cell MINP-MS using external calibration based on SeNPs and a transport efficiency-independent approach. In addition, 2–3 μm polystyrene (PS) and polytetrafluoroethylene (PTFE) were accurately sized by monitoring 12C+, confirming the method’s suitability for handling micrometer-sized polymeric materials (microplastics). The average duration of individual events (680 ± 160 μs) suggests that the digestion of individual entities in N2-based plasmas is comparable to that in Ar-based plasmas. These results open new avenues for this instrumentation as an alternative to ICP ionization sources, also in the context of discrete entity analysis. KW - Microwave-Induced Nitrogen Plasma KW - Discrete entity analysis KW - Particle/droplet event counting KW - Comparison to SP-ICP-MS methodologies KW - Nitrogen plasma vs. argon ICP trade-offs KW - Trace elemental quantification at the single-entity level KW - Time-resolved mass spectrometry for discrete entities PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643825 DO - https://doi.org/10.1021/acs.analchem.5c04341 SN - 0003-2700 SP - 1 EP - 8 PB - American Chemical Society (ACS) AN - OPUS4-64382 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Morcillo, Dalia A1 - Winckelmann, Alexander A1 - Oelze, Marcus A1 - Leonhardt, Robert A1 - Schmidt, Anita A1 - Richter, Silke A1 - Recknagel, Sebastian A1 - Vogl, Jochen A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Exploring Age-Induced Lithium Isotope Fractionation in Lithium-Ion Batteries using Microwave-Induced Cold Nitrogen Plasma Mass Spectrometry N2 - This study explores Microwave-Inductively Coupled Atmospheric-pressure Plasma Mass Spectrometry (MICAP-MS) as a cost-effective alternative to Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICP-MS) for analyzing lithium isotopic composition in lithium-ion batteries (LIBs). We investigate the performance of MICAP-MS in measuring Li isotope ratios in new and aged commercial lithium cobalt oxide (LCO) batteries. Our results show that MICAP-MS, operating under cold plasma conditions at 800 W with an 8 mm torch position, achieves results metrologically compatible with MC-ICP-MS, with a precision ranging from 0.6‰ to 3.4‰ for δ7Li values. MICAP-MS benefits from a dielectric resonator for uniform plasma, better ion velocity control, and higher energy efficiency. Optimal settings were identified with dwell times of 10 ms for 6Li and 1 ms for 7Li. The study of LIBs revealed that 6Li migrates towards the anode over multiple charge–discharge cycles, causing 7Li to accumulate in the cathode, a fractionation effect that becomes more pronounced with prolonged cycling. MICAP-MS provides a cost-effective, precise alternative to MC-ICP-MS, with lower operational costs and enhanced portability, advancing the study of isotopic fractionation and aging in lithium-ion batteries. KW - MICAP-MS KW - Lithium KW - Battery aging KW - Lithium isotopes KW - Nitrogen plasma KW - Isotope fractionation KW - lithium cobalt oxide KW - LCO PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643777 DO - https://doi.org/10.1039/d4ja00324a SN - 0267-9477 SP - 1 EP - 11 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64377 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Data-Driven Spectrochemical Sensing for Elemental and Isotopic Analysis—from Energy Systems to Biomedicine N2 - High-resolution optical spectrometers generate spectra containing tens of thousands of data points per sample. Picometre-scale isotope shifts, matrix-induced line broadening, and strong inter-feature correlations render classical peak fitting unreliable. Current analytical challenges, therefore, require rigorous algorithms able to expose latent structure, quantify uncertainty, and remain chemically interpretable. The research program presented in this lecture integrates state-of-the-art spectrochemical instrumentation with mathematically disciplined data models. Principal Component Analysis and Partial Least Squares provide chemically meaningful latent variables, while gradient-boosted decision trees or deep neural networks (ANNDL) capture residual non-linearity without sacrificing traceability. All models are trained on isotope-enriched or synthetically generated spectra and distributed with full validation workflows. Two research areas illustrate this strategy: (1) Isotopic analytics for materials, environment, and medicine. (2) Data-fusion diagnostics for battery ageing and failure. T2 - Temple University: Mechanical Engineering Transformative Science and Technology Engineering Lecture Series CY - Philadelphia, PA, USA DA - 02.10.2025 KW - Isotope KW - Data analysis KW - Machine learning KW - Elemental analysis KW - Battery PY - 2025 AN - OPUS4-64877 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Abad Andrade, Carlos Enrique A1 - Jegielka, Dennis A1 - Aloysius, Allen A1 - Recknagel, Sebastian T1 - SI-traceable total analysis of nitrate and nitrite by isotope dilution optical spectroscopy and its application to Berlin surface waters N2 - Accurate nitrate and nitrite data support water-quality regulation, yet routine methods rely on external calibration and rarely achieve SI traceability. We report a calibration-free determination of nitrate and nitrite by combining isotope dilution with high-resolution continuum-source graphite furnace molecular absorption spectrometry (ID-HR-CS-GF-MAS). A 15N-enriched nitrate spike (its concentration verified by reverse isotope dilution against the standard reference material NIST 3185) provides the SI link, and it is gravimetrically added to samples; nitrate and residual nitrite are converted in situ to nitric oxide (NO), whose 215 nm band is recorded at a pixel resolution of λ/Δλ ≈ 140 000. The 0.2127 nm shift between 14NO and 15NO electronic spectra is resolved, and a three-latent-variable partial least squares regression model yields the 15N/14N ratio with 0.3% precision. Instrumental LoD values of 4.8 ng (14N) and 3.2 ng (15N) translate to a method LoD of 4.8 ng of nitrogen (equivalent to 1.05 mg L−1 NO3− for a 20 μL aliquot). The furnace program allows for successive drying/pyrolysis loops, so additional 20 μL aliquots can be layered onto the graphite platform. Alternatively, a 10 mL anion-exchange solid-phase extraction step concentrates nitrate and nitrite fivefold, allowing for the analysis of even lower sample concentrations. Results for four certified reference materials (2.9 to 1000 mg L−1 NO3−) agreed with certified values, giving relative expanded uncertainties of 2 to 4%. Analysis of twenty Berlin surface-water samples revealed concentrations ranging from 0.10 to 7.3 mg L−1 NO3−, indicating that the Panke River and Teltow Canal are the primary sources of nitrogen. ID-HR-CS-GF-MAS thus delivers ID-MS-level accuracy in a few minutes per run with bench-top optics, and, with optional on-platform or SPE pre-concentration, extends SI-traceable nitrate/nitrite monitoring into the low-ng regime. KW - Isotope dilution KW - Nitrate and nitrite determination KW - SI-traceable quantification KW - Calibration-free analysis KW - Water quality KW - Berlin surface waters KW - NO molecular absorption bands PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-643785 DO - https://doi.org/10.1039/D5JA00252D SN - 0267-9477 VL - 40 IS - 10 SP - 2692 EP - 2701 PB - Royal Society of Chemistry (RSC) AN - OPUS4-64378 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Tracking Lithium-Ion Battery Ageing via Lithium Isotope Fractionation N2 - Lithium-ion batteries power portable devices, electric vehicles, and stationary power grids, yet hidden aging reactions still shorten their service life and raise concerns about cost and safety. An analytical proxy is needed to report these reactions and accelerate product development, quality control, and recycling. Here, we demonstrate that subtle shifts in the natural 7Li/6Li ratio accurately record the two decisive stages of cell aging, solid-electrolyte interphase (SEI) formation and field-driven aging, which can be detected using multi-collector ICP-MS. Because Li is easily stripped from digested electrodes or electrolyte in a one-step cation-exchange column, high-purity solutions reach the spectrometer in minutes. A streamlined MC-ICP-MS run yields a δ7LiLSVEC precision of 0.4 ‰, enabling dozens of battery fractions to be analyzed per day. Applying the workflow to LiCoO2 coin cells as models, sampled from pristine to 700 cycles, reveals a clear isotopic narrative. During the first ≈45 cycles, 7Li leaves the LiCoO2 lattice, dissolves into the electrolyte, and is locked in the SEI on graphite, driving cathode δ7Li from +8 to –10 ‰ and raising the anode to +13 ‰ while capacity drops by 10 %. After the interphase matures, the electric field takes over: the lighter 6Li migrates faster to the anode, 7Li accumulates in the contracting Li1-xCoO2 lattice, and the bulk separation factor rises to α≈1.045 by 700 cycles. The δ7Li curve flattens roughly 70 cycles before capacity falls to 80%, providing an early warning of end-of-life. Isotopic gradients scale linearly with impedance growth, SEI thickness, and crack density confirmed by LA-ICP-MS mapping, FIB-SEM, XANES, and EXAFS. Although each data point requires one cell, lithium-isotope fractionation provides direct, element-specific, and structural fatigue insight unavailable from non-destructive tests. The straightforward chemistry and fast MC-ICP-MS routine make the approach practical for targeted aging studies, additive screening, and forensic autopsies, complementing high-throughput electrochemical methods and supporting the design of longer-lived batteries. T2 - SciX 2025 CY - Covington, KY, USA DA - 05.10.2025 KW - Isotope KW - Lithium KW - MC-ICP-MS KW - MICAP-MS KW - Isotope fractionation KW - Battery PY - 2025 AN - OPUS4-64879 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Chapartegui-Arias, Ander A1 - Raysyan, A. A1 - Belenguer, A. M. A1 - Jaeger, Carsten A1 - Tchipilov, Teodor A1 - Prinz, Carsten A1 - Abad Andrade, Carlos Enrique A1 - Beyer, S. A1 - Schneider, Rudolf A1 - Emmerling, Franziska T1 - Tailored mobility in a zeolite imidazolate framework (ZIF) antibody conjugate N2 - Zeolitic imidazolate framework (ZIF) hybrid fluorescent nanoparticles and ZIF antibody conjugates have been synthesized, characterized, and employed in lateral-flow immunoassay (LFIA). The bright fluorescence of the conjugates and the possibility to tailor their mobility gives a huge potential for diagnostic assays. An enzyme-linked immunosorbent assay (ELISA) with horseradish peroxidase (HRP) as label, proved the integrity, stability, and dispersibility of the antibody conjugates, LC-MS/MS provided evidence that a covalent link was established between these metal-organic frameworks and lysine residues in IgG antibodies. KW - ZIF KW - ELISA PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-532096 DO - https://doi.org/10.1002/chem.202100803 SN - 0947-6539 SN - 1521-3765 VL - 27 IS - 36 SP - 9414 EP - 9421 PB - Wiley-VCH CY - Weinheim AN - OPUS4-53209 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Morcillo, Dalia A1 - Oelze, Marcus A1 - Seena Prem, Pranav A1 - de Oliveira Guilherme Buzanich, Ana A1 - Emmerling, Franziska A1 - Recknagel, Sebastian A1 - Panne, Ulrich A1 - Abad Andrade, Carlos Enrique T1 - Lithium isotope fractionation as an early indicator of degradation mechanisms in lithium-ion batteries N2 - Aging in lithium-ion batteries (LIBs) degrades performance and hinders sustainability, demanding advanced diagnostics for early failure prediction. We investigate lithium isotope fractionation (LIF) as an innovative probe of degradation in lithium cobalt oxide (LCO) coin cells aged over 0−700 cycles. High-precision multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) quantified δ7Li variations across cell stages: non-cycled (0 cycles), newly formed (5 cycles), semi-aged (250 cycles), and fully aged (700 cycles). During early cycling (≤ 45 cycles), chemical processes drive 7Li enrichment at the anode (δ7Li vs LSVEC = +12 ‰) through solid electrolyte interphase (SEI) formation, while the cathode depletes in 7Li (δ7Li vs LSVEC = −0.7 ‰). Beyond 45 cycles, electric field-induced migration predominates, promoting 6Li intercalation into the anode and increasing the δ7Li of the cathode by 8.1 ‰. Mass balance verifies isotope conservation, attributing shifts to redistribution and trapping. Complementary electrochemical impedance spectroscopy (EIS) and X-ray absorption spectroscopy and diffraction confirm SEI expansion, cobalt oxidation, lattice shrinkage, and changes in electrode structure, corroborating LIF trends. Notably, a δ7Li inflection at approximately 270 cycles anticipates end-of-life by 70 cycles, surpassing traditional methods in sensitivity. LIF emerges as a predictive indicator of aging mechanisms, informing optimized designs for durable LIBs. KW - Lithium isotope fractionation KW - Lithium-ion batteries KW - Degradation mechanisms KW - LiCoO2 cathodes KW - LCO KW - Isotopic tracing KW - Lithium isotopes PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-650945 DO - https://doi.org/10.26434/chemrxiv-2025-16lvq SP - 1 EP - 19 AN - OPUS4-65094 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - THES A1 - Abad Andrade, Carlos Enrique T1 - Advances and Applications of Molecular Absorption Spectrometry: from Non-Metals to Isotope Analysis N2 - The present work covers two main aspects of high-resolution continuum source graphite furnace molecular absorption spectrometry (HR-CS-GFMAS), an analytical technique for elemental trace analysis. First, a comprehensive mechanistic study of molecule formation in graphite furnaces is presented, which is a key step into the recovery of analytical signals. For this, the molecule formation of CaF was studied, which is used for the indirect analytical determination of fluorine in HR-CS-GFMAS. A zirconium coating catalyzes the CaF formation, and its structure was investigated. The kinetics of this reaction was established by monitoring its molecular spectrum at different atomisation temperatures. An Arrhenius plot showed a pseudo-first order reaction with respect to fluorine (n = 1). An intermediate state was isolated, and its structure was elucidated by spectroscopic methods: scanning electron microscopy with energy dispersive X-ray spectroscopy (SEM-EDX), X-ray photoelectron spectroscopy (XPS), X-ray absorption spectroscopy (XANES and EXAFS), and Raman microspectroscopy. Here a mechanism is proposed, where ZrO2 works as a heterogeneous catalyst: after a pyrolytic step, an intermediate state of ZrO(OCaF) is activated, and at higher temperatures, CaF(g) is released from the zirconium-coated graphite surface. Second, analytical methods were developed by using HR-CS-MAS as detector for non-metals and isotope analysis. Therefore, the determination of organic absorbable chlorine in water, the quantification of fluorine in consume care products with declared perfluorinated ingredients, and the determination of sulfur content in crude oils were investigated. Finally, the high resolution of the instrumentation allows to measure isotopic shifts with high precision in some observed molecular spectra. Consequently, the molecular spectra of enriched isotopes of boron and magnesium were investigated, establishing so the potential of HR-CS-MAS for the accurate and precise determination of isotopic amount ratios. Zusammenfassung Die vorliegende Arbeit befasst sich mit zwei zentralen Aspekten der High-Resolution-Continuum-Source-Molekülabsorptionsspektrometrie mit Graphitrohrtechnik (HR-CS-GFMAS), einer Analysetechnik für elementare Spurenanalyse. Der erste Teil der Arbeit umfasst eine mechanistische Studie zur Molekülbildung auf Graphitoberflächen. Dies ist ein wichtiger Schritt, um analytische Signale zu entdecken. Dazu wurde die Molekülbildung von CaF analysiert, welches für die indirekte, analytische Bestimmung von Fluor in HR-CS-GFMAS genutzt wird. Die CaF Bildung wurde mittels einer Beschichtung aus Zirconium katalysiert und deren Struktur analysiert. Die Kinetik dieser Reaktion wurde durch Beobachtung des jeweiligen Molekülspektrums bei verschiedenen Atomisierungstemperaturen beobachtet. Ein Arrheniusplot zeigte für Fluor (n = 1) eine Reaktion Pseudo-erster Ordnung. Ein Übergangszustand wurde über die mit Zirconium überzogene Grafitoberfläche isoliert und seine Struktur mittels spektroskopischer Methoden Energiedispersive Rasterelektronenmikroskopie / Röntgenspektroskopie (REM-EDX), Röntgenphoto¬elektronenspektroskopie (XPS), Röntgenabsorptionsspektroskopie (XAS) und Raman Spektroskopie untersucht. Auf Grundlage dieser Ergebnisse wird ein Mechanismus vorgeschlagen, bei dem ZrO2 als heterogener Katalysator fungiert; in Folge einer Pyrolysestufe wird ein Übergangszustand des ZrO(OCaF) aktiviert, welcher bei höheren Temperaturen CaF(g) an der Zirconium-Graphitoberfläche freisetzt. Im zweiten Teil der Arbeit werden Analysemethoden entwickelt, in dem HR-CS-MAS als Detektor für Nichtmetalle und Isotopanalyse angewandt wird. Hierfür wurde organisch gebundenes Chlor im Wasser bestimmt, der Fluorgehalt in Pflegeprodukten mit perfluorierten Inhaltsstoffen quantifiziert und der Schwefelgehalt in Erdöl untersucht. Weiterhin ermöglicht die hohe Auflösung der Messgeräte eine präzise Bestimmung der Isotopenverschiebung einiger untersuchter Molekülspektren. Daher wurden die Molekülspektren angereicherter Bor- und Magnesiumisotope untersucht. Auf diese Weise wurde das Potential von HR-CS-MAS für die akkurate und präzise Bestimmung von Isotop-Mengenverhältnissen nachgewiesen. KW - Isotope analysis KW - Non-metals analysis KW - Molecular absorption spectrometry KW - Boron KW - Fluorine KW - Graphite furnace KW - HR-CS-MAS KW - Applied optical spectroscopy PY - 2019 UR - https://hu-berlin.hosted.exlibrisgroup.com/permalink/f/jl2ii5/HUB_UB_ALMA_DS21669801300002882 SP - X EP - 118 CY - Berlin, Germany AN - OPUS4-49891 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - INPR A1 - Battistella, Beatrice A1 - Revill, Adam A1 - Venzago, Cornel A1 - Hoffmann, Volker A1 - Agudo Jácome, Leonardo A1 - Al-Sabbagh, Dominik A1 - Recknagel, Sebastian A1 - Abad Andrade, Carlos Enrique T1 - Depth-Resolved Lithium Isotope Fractionation as a Diagnostic of Interphase Evolution and Degradation in Lithium Ion Batteries N2 - Lithium isotopic fractionation is well-established in dynamic geochemical systems; however, its role in lithium-ion batteries (LIBs) remains uninvestigated. Herein, we report the first depth-resolved demonstration that isotopic separation occurs during Li-ion cell operation whose magnitude depends on the cycling history. Using depth-resolved glow discharge mass spectrometry, we monitored the 7Li/6Li ratio in LiNi0.333Mn0.333Co0.333O2 (NMC111)||graphite coin cell electrodes at defined life-cycle stages. Different charging rates were examined to get mechanistic insight into kinetic and thermodynamic control in the fractionation process. Although pristine electrodes exhibit a uniform isotopic ratio, cycled electrodes show a distinct 7Li enrichment in the positive electrode and a corresponding accumulation of 6Li at the surface of the negative electrode. The degree of isotopic separation varies with the charging rate. Isotopic signatures correlate with capacity fading, indicating lithium isotope mapping as a sensitive diagnostic tool for tracking electrode degradation and the evolution of the electrode–electrolyte interphases in LIBs. KW - Li-ion batteries KW - Lithium isotopes KW - Post-mortem analysis KW - GD-MS KW - Depth profile KW - Mass spectrometry PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-651287 DO - https://doi.org/10.26434/chemrxiv-2025-5rvlk SP - 1 EP - 19 AN - OPUS4-65128 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -