2019/07/21 by Caiming Tang, Jianhua Tan, Tang, Caiming +9
Chemistry · Environmental Science · #Analytical chemistry methods development #Chemical Physics (physics.chem-ph) #FOS: Physical sciences #Instrumentation and Detectors (physics.ins-det) #Isotope Analysis in Ecology #Toxic Organic Pollutants Impact
paper · pdf · doi:10.48550/arxiv.1907.08897
openalex publication_date 2019/07/21 · openalex created_date 2019/07/30 · openalex updated_date 2026/07/28
This study investigated the consistency/inconsistency of carbon isotope compositions of chlorine-isotopologue pairs, e.g., 12C235Cl4 vs. 12C13C35Cl4, of individual organochlorines including two chloroethylenes, three polychlorinated biphenyls, methyl-triclosan and hexachlorobenzene. The raw carbon isotope ratios were measured by gas chromatography-high resolution mass spectrometry. Data simulations in terms of background subtraction, background addition, dual 13C-atoms substitution, deuterium substitution and hydrogen-transfer were conducted to confirm the validity of measured carbon isotope ratios and their differences. Inconsistent carbon isotope ratios derived from chlorine-isotopologue pairs of individual organochlorines were observed, and the isotopologues of each organochlorine were thus inferred to be non-randomly distributed. Mechanistic interpretation for these findings was tentatively proposed according to a basic principle in clumped-isotope geochemistry, reaction thermodynamics and kinetics, along with isotope effects occurring on electron ionization mass spectrometry. This study sheds light on the actual carbon isotope compositions of chlorine-isotopologue pairs of organochlorines, and yields new insights into the real distributions of carbon and chlorine isotopologues. The inconsistent carbon isotope compositions of chlorine-isotopologue pairs are anticipated to benefit the exploration of formation conditions and source identification of organochlorine pollutants.