Stable chlorine isotope analysis of chlorinated acetic acids using gas chromatography/quadrupole mass spectrometry.
Rapid Commun Mass Spectrom
; 29(24): 2341-8, 2015 Dec 30.
Article
em En
| MEDLINE
| ID: mdl-26563705
ABSTRACT
RATIONALE The 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). METHODS:
Following 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 δ(37) Cl -6.3 to -0.2 , Standard Mean Ocean Chloride).RESULTS:
Cross-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 .CONCLUSIONS:
This method should be useful for environmental studies of CAAs at ambient concentrations in precipitations (<0.06 to 100 nmol L(-1) ), surface waters (<0.2 to 5 nmol L(-1) ) and soil (<0.6 to 2000 nmol kg(-1) dry soil) where conventional off-line methods cannot be applied.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Cloro
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Isótopos
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Cromatografia Gasosa-Espectrometria de Massas
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Acetatos
Idioma:
En
Revista:
Rapid Commun Mass Spectrom
Ano de publicação:
2015
Tipo de documento:
Article