Stable chlorine isotope analysis of chlorinated acetic acids using gas chromatography/quadrupole mass spectrometry
Number of Authors: 3
2015 (English)In: Rapid Communications in Mass Spectrometry, ISSN 0951-4198, E-ISSN 1097-0231, Vol. 29, no 24, 2341-2348 p.Article in journal (Refereed) Published
RationaleThe environmental occurrence of chlorinated acetic acids (CAAs) has been extensively studied, but the sources and transport are still not yet fully understood. A promising approach for source apportionment and process studies is the isotopic characterization of target compounds. We present the first on-line stable chlorine isotope analysis of CAAs by use of gas chromatography/quadrupole mass spectrometry (GC/qMS). MethodsFollowing approved procedures for concentration analysis, CAAs extracted into MTBE were methylated to GC-amenable methyl esters (mCAAs). These mCAAs were then analyzed by GC/qMS for their stable chlorine isotope composition using a sample/standard-bracketing approach (CAA standards in the range Cl-37 -6.3 to -0.2 , Standard Mean Ocean Chloride). ResultsCross-calibration of the herein presented method with off-line reference methods (thermal ionization and continuous-flow GC isotope ratio mass spectrometry; TI-MS and CF-GC/IRMS, respectively) shows good agreement between the methods (regression slope for GC/qMS vs reference method data sets: 0.92 +/- 0.29). Sample amounts as small as 10 pmol Cl can herewith be analyzed with a precision of 0.1 to 0.4 parts per thousand. ConclusionsThis method should be useful for environmental studies of CAAs at ambient concentrations in precipitations (<0.06 to 100nmolL(-1)), surface waters (<0.2 to 5nmolL(-1)) and soil (<0.6 to 2000nmolkg(-1) dry soil) where conventional off-line methods cannot be applied.
Place, publisher, year, edition, pages
2015. Vol. 29, no 24, 2341-2348 p.
Biological Sciences Chemical Sciences
IdentifiersURN: urn:nbn:se:su:diva-125645DOI: 10.1002/rcm.7407ISI: 000364876400004PubMedID: 26563705OAI: oai:DiVA.org:su-125645DiVA: diva2:895500