TY - CONF A1 - Raab, A. A1 - Vogl, Jochen A1 - Solovyev, N. A1 - El-Khatib, Platt A1 - Costas-Rodriguez, M. A1 - Schwab, K. A1 - Griffin, E. A1 - Platt, B. A1 - Theuring, F. A1 - Vanhaecke, F. T1 - Isotope signature of iron, copper and zinc in mouse models (L66 and 5XFAD) and their controls used for dementia research N2 - Introduction: The influence of copper, iron and zinc concentrations on the formation of ß-amyloid plaques and neurofibrillary tangles in Alzheimer’s disease (AD) is widely discussed in the community. The results from human and animal studies so far are mixed with some studies showing a correlation and others not. From a number of studies, it is known that disease state and isotopic composition of essential elements can be coupled. Aim: The aim of the study was to identify changes in element content and isotopic composition in two transgenic mouse models used in AD research compared to their genetic WT relatives and to establish whether element content and isotopic signature between different laboratories is comparable. Methods: ß-amyloid (5xFAD) and tau overexpressing (L66) mice together with their matching wild-types were bred at dedicated facilities in accordance with the European Communities Council Directive (63/2010/EU). Serum and brain were sampled after sacrifice and the samples distributed among the participants of the study. The tissues were acid digested for total element determination and high-precision isotope ratio determination. Element content was determined by either sector-field or quadrupole-based inductively coupled plasma mass spectrometry (ICPMS). For the determination of isotope ratios multi-collector ICPMS was used. Results: Total copper content was significantly higher for L66 and their matched WT compared to 5xFAD and WT. Brains of L66 mice contained more Fe in brain than their WT, Zn and Cu were not significantly different between L66 and WT. Whereas 5xFAD mice had a slightly lower Cu and slightly higher Zn concentration in brain compared to WT. The isotopic signature in brain of L66 mice for Fe was different from their controls, whereas Zn isotope ratios were influenced in 5xFAD mice compared to their WT. The Cu isotopic ratio did not seem to be influenced in either strain. In serum, the shifts were less pronounced. Conclusion: Even though neither Tau-protein nor amyloid precursor protein are known to be metal-dependent / -containing proteins, the overexpression of both influences the Fe, Cu and Zn metabolism in brain and to some extent also in serum as can be seen not only using total element determination but probably more clearly studying the isotopic signature of Fe, Cu and Zn. T2 - The International Conference of Trace Elements and Minerals (ICTEM) 2022 CY - Aachen, Germany DA - 05.06.2022 KW - Isotope ratio KW - Isotope delta value KW - Metrology KW - Alzheimer disease KW - Measurement uncertainty PY - 2022 AN - OPUS4-55204 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Isotope ratio working group at CCQM N2 - The presentation gives the reasons for initiation of an isotope ratio working group at CCQM level, describes the process and provides the auduince with the initial working plan. T2 - EURAMET TC-MC Workshop on Isotope Ratio Analysis CY - Bern, Switzerland DA - 05.02.2020 KW - Metrology KW - Absolute isotope ratio KW - Isotope ratio KW - Delta value PY - 2020 AN - OPUS4-50344 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Pb isotope ratio analysis N2 - The determination of Pb isotope ratios by TIMS and ICP-MS is discussed and applications from archaeology are provided. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Isotope reference material KW - Provenance KW - Silver artefacts KW - Curse tablets PY - 2023 AN - OPUS4-59167 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Measurement Uncertainty in Isotope Ratio Measurements N2 - The importance for measurement uncertainty in isotope ratio measurements is expalined and different approaches for calculating measurement uncertainty for absolute isotope ratios, isotope deltas and conventional isotope ratios are presented. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Isotope delta KW - Absolute isotope ratio KW - Conventional isotope ratio PY - 2023 AN - OPUS4-59169 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Sr isotope ratio analysis N2 - The measurment of Sr isotope ratios is described and examples from food authenticity, provenancing of cement and pietas are provided. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Conventional isotope ratios KW - Gypsum KW - Cement KW - Cheese PY - 2023 AN - OPUS4-59168 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Detector deadtime N2 - Deadtime effects for counting detectors in ICP-MS and deadtime correction are discussed. Approaches for determining the deadtime are presented. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Counting detector KW - Detector deadtime KW - Isotope ratio KW - Dual mode detector PY - 2023 AN - OPUS4-59166 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Isotope Ratio Analysis N2 - Basic information on isotope ratio analysis is provided. Isotope fractionation is discussed and the measurement process is described. Additionally, practical examples are provided. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Isotope fractionation KW - Mass spectrometry KW - Terminology PY - 2023 AN - OPUS4-59164 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - Isotope Ratio Measurement - Quantities and calibration N2 - The quantities and the terminoly in isotope ratio measurements is presented, followed by explaining calibration approaches for isotope ratio measurements. Sources of error and bias are presented and special focus is given on single detector mass spectrometry. T2 - Workshop & Training "Isotope Ratio Analysis" CY - Pathum Thani, Thailand DA - 06.12.2023 KW - Isotope fractionation KW - Matrix separation KW - Interferences KW - Noise KW - Optimization PY - 2023 AN - OPUS4-59165 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pramann, A. A1 - Vogl, Jochen A1 - Flierl, L. A1 - Rienitz, O. T1 - Determination of absolute (SI‐traceable) isotope ratios: The use of Gravimetric Isotope Mixtures N2 - The presentation is brief overview on how to use gravimetric isotope mixtures to determine SI traceable isotope ratios. There is no mass spectrometer on earth that directly measures isotope ratios. Mass spectrometers will always measure signal intensity ratios instead. The actual problem is that the measured intensity ratios differ more or less from the isotope ratios. The difference can be up to more than 10 % in case of lithium while it‘s below 1 % in case of the heavier elements like lead or uranium. Consequently, the signal intensity ratios are expressed for example in V/V depending on the type of mass spectrometer you are using, while the isotope ratios are expressed in mol/mol. This phenomenon is called Instrumental Isotopic Fractionation (or short IIF) but the more common name is still mass bias (even though this name is not entirely correct). To convert the measured into the isotope ratio usually a simple multiplication with a so-called correction (or short K) factor is done. Therefore, the problem is to determine the K factor. In absence of isotope reference materials the golden route is via gravimetric isotope mixtures, which will be explained within the presentation. T2 - CCRI-CCQM Workshop on the use of mass spectrometry in radionuclide metrology: Opportunities and challenges - Video Tutorial CY - Online meeting DA - 14.02.2023 KW - Absolute isotope ratio KW - Traceability KW - Uncertainty KW - Isotope mixtures PY - 2023 AN - OPUS4-57172 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Vogl, Jochen T1 - The triple isotope calibration approach BT - A new calibration approach for obtaining absolute isotope ratios of multi-isotopic elements N2 - The calibration of isotope ratio measurements is an ongoing challenge since instrumental isotope fractionation (IIF) has been detected in mass spectrometry (MS). There is a variety of approaches which either bypass IIF such as delta measurements or refer to reference materials (RMs) and thus shifting the problem of calibration to somebody else: the RM producer. For certifying isotope RMs with absolute isotope ratios only a few approaches are available, namely the isotope mixture approach, the double spike approach, the mass bias regression model and total evaporation in TIMS. All of them require either enriched isotopes, isotope RMs of another element or an RM for correcting residual error. As the enriched isotopes required for the isotope mixture and the double spike approach need to be fully characterized beforehand, all mentioned calibration approaches require a standard. Here, a new and standard-free calibration approach for obtaining absolute isotope ratios of multi-isotopic elements has been developed. The underlying principle is that each MS suffers from IIF and thus yields a specific isotope fractionation line in a three-isotope diagram. When applying a second MS featuring a different ionization mechanism, we obtain a second isotope fractionation line with a different slope in the same three-isotope diagram. In both cases the absolute isotope ratios range somewhere on the isotope fractionation line. Consequentially, the intersect of both lines yield the absolute isotope ratios of the measured sample. This theory has been tested by measuring Cd and Pb isotope ratios of suitable isotope RMs with a TIMS and an ICP-MS, both equipped with multi-collector array. During the measurements the ionization conditions were changed such that different extent of the isotope fractionation has been achieved. With the resulting data set the theory described above could be verified. The obtained absolute isotope ratios were metrologically compatible with the certified isotope ratios. The remaining average bias of -5 ‰ can be reduced with further improvements. The calibration approach is universal and can be applied to any multi-isotopic element and it is not limited by the type of the mass spectrometer. T2 - Virtual Goldschmidt 2021 CY - Online meeting DA - 04.07.2021 KW - Absolute isotope ratio KW - Traceability KW - Metrology KW - Calibration KW - Uncertainty KW - Triple isotope fractionation PY - 2021 AN - OPUS4-53023 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -