Variation of compound‐specific hydrogen isotope ratios under changing temperature program in gas chromatography/thermal conversion/isotope ratio mass spectrometry

Abstract

Higher pyrolysis efficiency could reduce the tailing of the H(2) peak and the related isotopic variations at increased GC temperature ramp rates. In addition, too slow a temperature ramp rate could broaden the peak width and thus increase the background effect and possible isotopic fractionations in the split interface; this could also influence the hydrogen isotope values. We therefore suggest that the appropriate temperature ramp rate is an important factor in improving the precision in analyzing compound-specific hydrogen isotopes.

Comparison of three pretreatment methods for the analysis of distributions and hydrogen isotopic compositions of leaf waxn-fatty acids in natural samples

“…Due to the source specificity of certain individual compounds and their short‐chain relative lability, molecular distributions of n ‐FAs have been extensively studied by organic geochemists as tracers of biogenic sources and diagenetic alteration of organic matter in sediments. Especially with the development of compound‐specific hydrogen isotope ratio analysis using gas chromatography/thermal conversion/isotope ratio mass spectrometry (GC/TC/IRMS), hydrogen isotopic compositions (δ 2 H values) of leaf wax n ‐FAs from natural samples (e.g. plants, soils, and sediments) have been increasingly used as powerful and promising tools for studying modern biosynthetic mechanisms, biogeochemical cycles, paleoclimatic changes, and paleohydrological processes …”

An evaluation of alumina reaction tube conditioning for high‐precision 2H/1H isotope measurements via gas chromatography/thermal conversion/isotope ratio mass spectrometry

“…This on‐line analytical method is convenient, highly efficient and highly precise, and has advanced molecular hydrogen isotope research in many fields. These include paleoclimate and paleoenvironmental research, biogeochemistry, environmental research, including hydrogen compound specific isotope analysis of n‐alkanes in petroleum crudes, hydrogen isotopic fractionation due to evaporation, degradation, GC oven programs, atmospheric chemistry, and food research . Due to the very low abundance of 2 H (0.015%) in nature, high accuracy and precision are necessary for high‐resolution research and routine isotopic analysis.…”