Filtern
Erscheinungsjahr
Dokumenttyp
- Vortrag (19709)
- Zeitschriftenartikel (17883)
- Posterpräsentation (6150)
- Beitrag zu einem Tagungsband (5975)
- Beitrag zu einem Sammelband (2316)
- Forschungsbericht (758)
- Sonstiges (387)
- Buchkapitel (355)
- Dissertation (296)
- Zeitschriftenheft (Herausgeberschaft für das komplette Heft) (243)
Sprache
- Deutsch (30405)
- Englisch (23806)
- Mehrsprachig (191)
- Französisch (41)
- Russisch (31)
- Spanisch (21)
- Ungarisch (11)
- Tschechisch (7)
- Italienisch (7)
- Japanisch (5)
Schlagworte
- Korrosion (424)
- Corrosion (410)
- Concrete (388)
- Fluorescence (341)
- Nanoparticles (326)
- Additive manufacturing (289)
- Simulation (255)
- LIBS (247)
- Zerstörungsfreie Prüfung (246)
- XPS (230)
Organisationseinheit der BAM
- 8 Zerstörungsfreie Prüfung (2227)
- 6 Materialchemie (2184)
- 1 Analytische Chemie; Referenzmaterialien (1765)
- 7 Bauwerkssicherheit (1754)
- 9 Komponentensicherheit (1448)
- 4 Material und Umwelt (1074)
- 5 Werkstofftechnik (1043)
- 3 Gefahrgutumschließungen; Energiespeicher (788)
- 6.3 Strukturanalytik (613)
- 6.1 Oberflächen- und Dünnschichtanalyse (571)
- 7.6 Korrosion und Korrosionsschutz (561)
- 9.4 Integrität von Schweißverbindungen (555)
- 2 Prozess- und Anlagensicherheit (545)
- 8.5 Röntgenbildgebung (543)
- 8.0 Abteilungsleitung und andere (541)
- 6.6 Physik und chemische Analytik der Polymere (488)
- 9.3 Schweißtechnische Fertigungsverfahren (467)
- 8.2 Zerstörungsfreie Prüfmethoden für das Bauwesen (462)
- 1.4 Prozessanalytik (338)
- 2.1 Sicherheit von Energieträgern (337)
- 1.2 Biophotonik (335)
- 8.4 Akustische und elektromagnetische Verfahren (326)
- 7.2 Ingenieurbau (324)
- 5.1 Materialographie, Fraktographie und Alterung technischer Werkstoffe (323)
- 8.1 Sensorik, mess- und prüftechnische Verfahren (319)
- 1.1 Anorganische Spurenanalytik (318)
- 7.5 Technische Eigenschaften von Polymerwerkstoffen (306)
- 4.1 Biologische Materialschädigung und Referenzorganismen (266)
- 5.2 Metallische Hochtemperaturwerkstoffe (242)
- 7.4 Baustofftechnologie (240)
- 1.8 Umweltanalytik (237)
- 6.2 Material- und Oberflächentechnologien (237)
- 1.9 Chemische und optische Sensorik (229)
- 8.6 Faseroptische Sensorik (225)
- 9.2 Versuchsanlagen und Prüftechnik (224)
- 9.0 Abteilungsleitung und andere (221)
- 4.3 Schadstofftransfer und Umwelttechnologien (218)
- 6.5 Synthese und Streuverfahren nanostrukturierter Materialien (218)
- S Qualitätsinfrastruktur (216)
- 7.1 Baustoffe (213)
- 6.0 Abteilungsleitung und andere (199)
- 5.4 Multimateriale Fertigungsprozesse (196)
- 4.4 Thermochemische Reststoffbehandlung und Wertstoffrückgewinnung (181)
- 4.2 Material-Mikrobiom Wechselwirkungen (170)
- 3.1 Sicherheit von Gefahrgutverpackungen und Batterien (169)
- 9.5 Tribologie und Verschleißschutz (166)
- 1.7 Organische Spuren- und Lebensmittelanalytik (163)
- 3.2 Gefahrguttanks und Unfallmechanik (160)
- 3.3 Sicherheit von Transportbehältern (159)
- 4.5 Kunst- und Kulturgutanalyse (158)
- 3.4 Sicherheit von Lagerbehältern (149)
- 9.6 Additive Fertigung metallischer Komponenten (145)
- 5.3 Polymere Verbundwerkstoffe (128)
- 4.0 Abteilungsleitung und andere (126)
- 5.6 Glas (123)
- 1.5 Proteinanalytik (122)
- S.2 Digitalisierung der Qualitätsinfrastruktur (118)
- 1.6 Anorganische Referenzmaterialien (110)
- 6.7 Materialsynthese und Design (110)
- 5.5 Materialmodellierung (109)
- 3.0 Abteilungsleitung und andere (94)
- 7.7 Modellierung und Simulation (87)
- 1.3 Instrumentelle Analytik (77)
- VP Vizepräsident (77)
- 3.5 Sicherheit von Gasspeichern (75)
- S.3 Ökodesign und Energieverbrauchskennzeichnung (75)
- VP.1 eScience (75)
- 7.0 Abteilungsleitung und andere (74)
- 5.0 Abteilungsleitung und andere (69)
- 7.3 Brandingenieurwesen (64)
- 2.0 Abteilungsleitung und andere (63)
- 2.2 Prozesssimulation (56)
- 2.5 Konformitätsbewertung Explosivstoffe/Pyrotechnik (49)
- 1.0 Abteilungsleitung und andere (44)
- P Präsident (42)
- P.0 Präsident und andere (42)
- 2.3 Einstufung von Gefahrstoffen und -gütern (37)
- 2.4 Prüfung und Bewertung von Explosivstoffen/Pyrotechnik (33)
- 6.4 Materialinformatik (31)
- S.1 Qualität im Prüfwesen (19)
- MP Mitglied des Präsidiums (16)
- PST Präsidiale Stabsstelle (15)
- 3.6 Elektrochemische Energiematerialien (14)
- 4.6 Molekulare und angewandte Entomologie (13)
- Z Zentrale Dienstleistungen (6)
- Z.1 Organisation, Controlling (6)
- S.0 Abteilungsleitung und andere (5)
- VP.2 Informationstechnik (5)
- 9.1 Komponenten für Energieträger (2)
- KM Kommunikation, Marketing (1)
- MP.0 Mitglied des Präsidiums und andere (1)
Paper des Monats
- ja (77)
Isotope analysis is a tool for material research. For example, it may provide information about the provenance of a sample or changes in dynamic systems. Here is presented optical spectroscopy as an analytical alternative to mass spectrometry for isotope quantification based on the isotopic shift of atoms and diatomic molecules.
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.
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.
Calcium isotope analysis can be an important tool for paleoclimate studies of the carbon cycle, as well in carbon capture technology, but its utility is limited by challenges using conventional mass spectrometry. We propose a new fast, precise, and high-throughput technology based on multiple complementary high-resolution spectroscopies analyzed by machine-learning.
Der Bunsen-Kirchhoff-Preis 2022 wurde am 23.06.2022 anlässlich der analytica conference in München an Dr. Carlos Abad verliehen - in Anerkennung seiner exzellenten Entwicklungen im Bereich der continuum source atomic absorption spectrometry (CS-AAS).
Dr. Carlos Abad ist ein herausragender Experte auf dem Gebiet der Atom- und molekularen Absorptionsspektrometrie. insbesondere trug er maßgeblich zur substanziellen Weiterentwicklung von Echelle-Spektrometern für die CS-AAS bei. So gelang es, einen quantitativen Zugang zu Elementen wie Bor, Chlor, Fluor und Schwefel, mittels AAS zu erreichen. Erstmals demonstriert Dr. Carlos Abad am Beispiel eines Zr-Modifier, dass durch die Zeitauflösung der eingesetzten Echelle-Systeme mechanistische Untersuchungen zur Wirkung des Modifiers im Graphitrohrofen möglich sind.
Besonders hervorzuheben sind seine Arbeiten zum Einsatz der CS-AAS für die Analyse von Isotopen, die eine Genauigkeit aufweist, welche an die der Multikollektor-induktiv gekoppelten Plasma-Massenspektrometrie (MC-ICP-MS) heranreicht. Damit ergeben sich völlig neue Einsatzmöglichkeiten für technologisch hochrelevante Applikationen, wie z.B. die Untersuchung der Alterung von Lithium-Batterien oder die Lithium-Analyse in Blutserum.
The introduction of HR-CS-MAS instrumentation, as it is shown in Fig. 1, provides a new way for the determination of non-metals including fluorine via molecular absorption. We present a sensitive and fluorine-specific method for total fluorine determination in fifteen consume care products in which perfluordecalin were declared (nail polishes, eye shadows and body creams). After pyrohydrolytic digestion of samples, fluorine content was determined by GF-HR-CS-MAS. Calcium was used as a molecule forming element and the molecular absorption of calcium monofluoride (CaF) at the wavelength 606.440 nm was used for its quantification. No matrix effect was observed. Analytical signal depends only on the fluorine concentration and therefore pure sodium fluoride NaF was used as calibration standard. The use of zirconium oxide nanoparticles as permanent modifier improves the limit of detection (from 0.2 to 0.1 ng) and characteristic mass (from 0.10 to 0.05 ng) from a previous reported method. These results were also compared with ISE method (standard DIN 51-084) and no significant difference was found
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.
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.
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.
Simultaneous multielemental analysis of crude oils by high-resolutions absorption spectrometry
(2019)
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.