Stable chlorine isotope ratio analysis of subnanomolar level methyl chloride by continuous-flow isotope ratio mass spectrometry

Abstract

An analytical system using continuous-flow isotope ratio mass spectrometry (CF-IRMS) was developed to determine the stable chlorine isotope ratios (δ37CI) lor CH3Cl. By using appropriate devices for sample processing prior to introduction into the spectrometer, the newly developed system successfully reduces sample requirements (>0.6 nmol-CH 3CI) to less than one hundredth of that required by the previous CF-IRMS systems while maintaining comparable precision in the δ37CI determination (±0.1%, 1σ). This system is also able to determine carbon isotope ratio for CH3CI with comparable precision (±0.3% 1σ >0.3 nmol-CH3CI) to the previous study. δ37CISMOC and δ13C VPDB values of CH3CI in commercial tank were determined to be -6.8 ± 0.1 % and -46.9 ± 0.3% respectively. Copyright © 2013 by The Geochemical Society of Japan.