Compound-specific chlorine isotope analysis: A comparison of gas chromatography/isotope ratio mass spectrometry and gas chromatography/quadrupole mass spectrometry methods in an interlaboratory study

Anat Bernstein, Orfan Shouakar-Stash, Karin Ebert, Christine Laskov, Daniel Hunkeler, Simon Jeannottat, Kaori Sakaguchi-Söder, Jens Laaks, Maik A. Jochmann, Stefan Cretnik, Johannes Jager, Stefan B. Haderlein, Torsten C. Schmidt, Ramon Aravena, Martin Elsner

Research output: Contribution to journalArticlepeer-review

87 Scopus citations

Abstract

Chlorine isotope analysis of chlorinated hydrocarbons like trichloroethylene (TCE) is of emerging demand because these species are important environmental pollutants. Continuous flow analysis of noncombusted TCE molecules, either by gas chromatography/isotope ratio mass spectrometry (GC/IRMS) or by GC/quadrupole mass spectrometry (GC/qMS), was recently brought forward as innovative analytical solution. Despite early implementations, a benchmark for routine applications has been missing. This study systematically compared the performance of GC/qMS versus GC/IRMS in six laboratories involving eight different instruments (GC/IRMS, Isoprime and Thermo MAT-253; GC/qMS, Agilent 5973N, two Agilent 5975C, two Thermo DSQII, and one Thermo DSQI). Calibrations of 37Cl/ 35Cl instrument data against the international SMOC scale (Standard Mean Ocean Chloride) deviated between instruments and over time. Therefore, at least two calibration standards are required to obtain true differences between samples. Amount dependency of δ 37Cl was pronounced for some instruments, but could be eliminated by corrections, or by adjusting amplitudes of standards and samples. Precision decreased in the order GC/IRMS (1σ ≈ 0.1°), to GC/qMS (1σ ≈ 0.2-0.5° for Agilent GC/qMS and 1σ ≈ 0.2-0.9° for Thermo GC/qMS). Nonetheless, δ 37Cl values between laboratories showed good agreement when the same external standards were used. These results lend confidence to the methods and may serve as a benchmark for future applications.

Original languageEnglish
Pages (from-to)7624-7634
Number of pages11
JournalAnalytical Chemistry
Volume83
Issue number20
DOIs
StatePublished - 15 Oct 2011

ASJC Scopus subject areas

  • Analytical Chemistry

Fingerprint

Dive into the research topics of 'Compound-specific chlorine isotope analysis: A comparison of gas chromatography/isotope ratio mass spectrometry and gas chromatography/quadrupole mass spectrometry methods in an interlaboratory study'. Together they form a unique fingerprint.

Cite this