TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Molecular absorption spectrometry: a fast and accurate optical method for boron isotope analysis comparable to mass spectrometry N2 - Boron presents two stable isotopes, 10B and 11B and due to their relatively large mass difference (~ 10%) isotope fractionation leads to considerable isotope amount ratio variations n(10B)/n(11B) in natural occurrence. 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. Usually, isotope ratio variations are 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). Boron isotope amount ratios have been determined by monitoring the absorption spectrum of boron monohydride (BH) in graphite furnace HR-CS-MAS. Bands (0→0) and (1→1) for the electronic transition X1Σ+ → A1Π were evaluated around wavelengths 433.1 nm and 437.1 nm respectively. 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 around the 433.1 nm and 437.1 nm spectral regions are metrologically compatible with those reported by mass spectrometric methods. Moreover, a precision and accuracy of the method of ± 0.5 ‰ for the evaluated spectral region around 437.1 nm is reported here. 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 - 30. Tag der Chemie CY - Berlin, Germany DA - 05.07.2017 KW - Boron isotopes KW - High-Resolution Continuum Source Molecular Absorption Spectrometry KW - HR-CS-MAS KW - Isotopic shift KW - Boron monohydride KW - Isotope ratio KW - Molecular absorption KW - Memory effect KW - Graphite furnace PY - 2017 AN - OPUS4-41060 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Following fluorinated drugs by molecular absorption spectrometry – from cancer cells to body fluids N2 - Fluorine has been widely introduced into pharmaceutical drugs. Due to the high C-F bond strength, a single atom substitution with fluorine produces drastic desirable and tunable changes in the molecular properties. However, the clinical monitoring of these drugs is not straightforward. Organofluorine compounds are elusive for a non-targeted analysis; a significant problem in fluorine determination is the lack of suitable detection techniques. Standard atomic absorption and emission spectrometers cannot access fluorine, because their resonance lines lie in the VUV spectral range below 100 nm. In the case of conventional inductively coupled argon plasmas (ICP), the plasma energy is too low to generate a significant population of excited fluorine atoms. Recently, our group introduces high-resolution continuum source absorption spectrometry (HR-CS MAS) as a new way for the indirect monitoring of fluorinated compounds. Main benefits of HR-CS-MAS includes low limits of detection, complete analyte recovery, simple to no sample preparation, and short time analysis. T2 - 16th Annual Congress of International Drug Discovery Science and Technology 2018 CY - Cambridge, MA, USA DA - 16.08.2018 KW - Fluorine KW - Anti-cancer KW - Capecitabine KW - Fluorouracil KW - HR-CS-MAS PY - 2018 AN - OPUS4-45822 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 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 - SAS meeting 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 - Molecular absorption PY - 2017 AN - OPUS4-43528 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Optical spectrometry for isotope analysis N2 - Isotope analysis plays a critical role in various disciplines, including environmental science, archaeology, and forensic investigations. Traditional methods such as mass spectrometry provide precise isotopic data but often require complex, costly setups and extensive sample preparation. As an alternative, optical spectrometry has emerged as a versatile and less invasive technique. This presentation explores the advancements and applications of optical spectrometry methods in isotope analysis, emphasizing their benefits and challenges. T2 - University of Calgary PHYS 561 - Stable And Radioactive Isotope - Winter 2024 CY - Online meeting DA - 07.03.2024 KW - Isotopes KW - HR-CS-MAS KW - Chemometrics KW - Laser Ablation Molecular Absorption spectrometry KW - LAMIS PY - 2024 AN - OPUS4-59948 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Isotope analysis through the integration of chemometrics into optical spectroscopy N2 - Lithium (Li), Boron (B), Nitrogen (N), Magnesium (Mg), and Calcium (Ca) are pivotal elements across various spheres such as the hydrosphere, biosphere, and lithosphere, significantly impacting (bio-) geochemical and physiological processes. These elements exhibit stable isotopes with substantial roles in geological, environmental, and biological studies. The traditional method for measuring isotope amount ratios has been through mass spectrometry, which, despite its accuracy, comes with high operational costs, the need for skilled operators, and time-consuming sample preparation processes. Combining optical spectroscopy with chemometrics introduces an innovative, cost-effective approach by the hand of high-resolution continuum source atomic and molecular absorption spectrometry (HR-CS-AAS and HR-CS-MAS) for the analysis of isotope ratios in Li, B, N, Mg, and Ca. By analyzing the atomic or molecular absorption spectrum of the in-situ generated cloud of atoms of diatomic molecules (e.g., Li, BH, NO, MgF, CaF) during the electronic transition from the fundamental state, this method allows for the rapid determination of isotope ratios directly from sample solutions without the need for complex sample preparation. For each element, the respective atomic or molecule's absorption spectrum was deconvoluted into its isotopic components using partial least squares regression or machine learning algorithms. Robust calibration models were developed, calibrated with enriched isotope, and validated against certified reference materials. Spectral data underwent preprocessing to optimize the modeling to determine the optimal number of latent variables. The findings showcase that this optical spectrometric method yields results that agree with those obtained via inductively coupled plasma mass spectrometry (ICP-MS), offering a promising, cost-effective, and rapid alternative for isotope analysis with precisions as low as ± 0.2‰. This approach is a significant advancement in analytical chemistry, providing a new way to study isotope variations in biological, environmental, and geological samples. T2 - Analytica Conference CY - Munich, Germany DA - 09.04.2024 KW - Isotopes KW - HR-CS-MAS KW - Chemometrics KW - Lithium KW - Boron KW - Magnesium KW - Nitrogen PY - 2024 AN - OPUS4-59946 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Abad Andrade, Carlos Enrique T1 - Versatility of nitrogen microwave-induced plasma mass spectrometry in elemental and isotopic analysis N2 - The introduction of Nitrogen-based Microwave Inductively Coupled Atmospheric-Pressure Plasma Mass Spectrometry (MICAP-MS) addresses the necessity for a plasma source that matches the capabilities of traditional argon-based Inductively Coupled Plasma Mass Spectrometry (ICP-MS) while exploiting the availability and cost-effectiveness of nitrogen gas. MICAP-MS uses nitrogen plasma, offering significant advantages such as reduced operational costs and eliminating specific isobaric interferences common in argon plasma systems [1]. This presentation explores the principles of MICAP-MS, highlighting its similarities to conventional ICP-MS in terms of analytical performance while emphasizing unique benefits like eliminating interferences from argon-based polyatomic species. MICAP-MS exhibits robust performance using nitrogen gas of varying purities—including ultra-high purity and industrial-grade nitrogen—without compromising analytical results [2]. We have applied MICAP-MS for multielement analysis in soil samples, serving as a proof of concept for environmental monitoring applications. The technique achieved figures of merit comparable to traditional ICP-MS, even when analyzing real-world samples with complex matrices [2]. MICAP-MS demonstrated high tolerance to high-concentration matrices, maintaining accuracy and precision without extensive sample preparation or matrix separation [3]. In clinical diagnostics, MICAP-MS was employed for the precise and traceable quantification of calcium, iron, and selenium in human serum using isotope dilution analysis [4]. These elements often face interferences in argon-based ICP-MS due to argon-associated isobaric interferences (40Ca+, 56Fe+, and 80Se+); however, MICAP-MS effectively overcomes these challenges, providing traceable and accurate determinations. The stability of the microwave plasma in MICAP-MS facilitates precise isotopic analysis. This capability investigated age-induced lithium isotope fractionation in lithium-ion batteries, offering critical insights into battery aging mechanisms and performance degradation [5]. MICAP-MS is a versatile analytical tool that combines the operational benefits of nitrogen plasma with the strengths of traditional ICP-MS. Its ability to handle complex matrices, reduce interferences, and perform precise elemental and isotopic analyses across various applications makes it a valuable instrument. T2 - European Winter Conference on Plasma Spectrochemistry CY - Berlin, Germany DA - 02.03.2025 KW - MICAP-MS KW - Nitrogen plasma KW - Isotope dilution analysis KW - Matrix tolerance KW - Argon interference elimination KW - Trace analysis PY - 2025 AN - OPUS4-63485 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 -