Isotope-ratio mass spectrometry IRMS

For example, little is known about the isotopic composition of formaldehyde in the atmosphere. Formaldehyde is a chemical intermediate in hydrocarbon oxidation. The carbon (8 C) and hydrogen (8D) isotopic composition of atmospheric formaldehyde is analyzed using continuous flow gas chromatography isotope ratio mass spectrometry." Isotope ratios were measured using GC-IRMS (Finnigan MAT 253 stable isotope ratio mass spectrometer, single-sector field with electron impact ion source and multiple ion collection) with a precision of 1.1 and 50%(lo ) for 8 C and 8D, respectively. The accuracy of the online continuous flow isotope technique was verified by calibrating three aliquots of the gas phase standard via the offline dual inlet IRMS technique. The concentration of formaldehyde in ambient air was determined on IRMS major ion peak areas (i.e., mass 44 for 8 C and mass 2 for 8D)." ... [Pg.220]

Fig. 6.14 Schematic diagram of a multi-dimensional gas chromatographic-pyrolysis-isotope ratio mass spectrometry (MDGC-P-IRMS) device. After [210] with kind permission of the American Chemical Society. For application see Fig. 6.20...

C. Ruff, K. Hor, B. Weckerle, P. Schreier, T. Konig (2000) H/ H ratio analysis of flavor compounds by on-line gas chromatography pyrolysis isotope ratio mass spectrometry (HRGC-P-IRMS) Benzaldehyde. J. High Resol. Chromatogr. 23, 357-358... [Pg.658]

D. Sample Preparation for Gas Chromatography-Combustion-Isotope Ratio Mass Spectrometry (GC-C-IRMS)... [Pg.55]

GC-(high resolution)MS after enzymatic hydrolysis of the glucuro- and sulphoconjugates and trimethyl-silylation is the most widely used method for the determination of anabolic steroids and their metabolites in the urine of athletes. The most up-to-date technique for the solution of the difficult problem of differentiating between endogenous and exogenous testosterone is gas chromatography - combustion/ isotope ratio (C /C ) mass spectrometry (GC-C-IRMS). [Pg.2102]

FIGURE 35.6 A schema representing a continuous-flow isotope ratio mass spectrometry system (CF-IRMS). [Pg.773]

FIGURE 35.10 Schema representing a gas chromatography isotope ratio mass spectrometry (GC-C-IRMS) system. [Pg.777]

The innovations in Es-GC analysis have concerned not only the development and applications of distinct CSPs but also the development of distinct enantioselective analytical techniques, such as Es-GC-MS, Es-GC-0, enantioselective multidimensional GC (Es-MDGC), Es-MDGC-MS, Es-GC hyphenated to isotopic ratio mass spectrometry (Es-GC-IRMS), and Es-MDGC-IRMS. [Pg.209]

The use of GC/combustion/isotope-ratio mass spectrometry (GC/C/ IRMS) has demonstrated distinguished capabilities to reveal misuse of endogenous steroids such as testosterone, dihydrotestosterone, dehy-droepiandrosterone (DHEA), etc. and was reported for the first time in 1994. The analysis of carbon isotope ratios of steroids in doping control specimens progressively improved, and in 1998 at the... [Pg.22]

GD/IRMS. glow discharge isotope ratio mass spectrometry HPLC. high-pressure liquid chromatography... [Pg.445]

IKES. ion kinetic energy spectroscopy IRMS. isotope ratio mass spectrometry ISDMS. isotope dilution mass spectrometry ITMS. ion trap mass spectrometry LA. laser ablation... [Pg.446]

S. Nitz, B. Weinreich and F. Draweit, Multidimensional gas cliromatography-isotope ratio mass spectrometry (MDGC-IRMS). Part A system description and technical requirements , 7. High Resolut. Chromatogr. 15 387-391 (1992). [Pg.75]

HTS High-throughput screening IRMS Isotope ratio mass spectrometry... [Pg.755]

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