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Matrix-enhanced degradation of p,p'-DDT during gas chromatographic analysis: A consideration

Environmental Science and Technology

By:
,
DOI: 10.1021/es960671q

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Abstract

Analysis of p,p'-DDT in environmental samples requires monitoring the GC-derived breakdown of this insecticide, which produces p,p'-DDD and/or p,p'-DDE, both also primary environmental degradation products. A performance evaluation standard (PES) containing p,p'-DDT but not p,p'-DDD or p,p'-DDE can be injected at regular intervals throughout an analytical sequence to monitor GC degradation. Some U.S. EPA methods limit GC breakdown of DDT in the PES to ???20% GC/MS analysis of large-volume natural water samples fortified with deuterium- and 13C-labeled p,p'-DDT exhibited up to 65% DDT breakdown by the GC inlet. These matrix-enhanced GC degradation amounts substantially exceeded the <20% breakdown levels indicated by bracketing injections of the PES containing unlabeled and labeled DDT. Substantial matrix-enhanced GC degradation was not observed during analysis of a limited number of fractionated bed-sediment extracts containing labeled DDT. Use of isotopically labeled DDT seems to provide an effective tool for monitoring sample-specific DDT breakdown during GC/MS analysis. However, analyte co- elutions render impractical their use in GC/ECD analysis. The occurrence of matrix-enhanced GC degradation might have important implications on data quality and the resultant interpretations of the environmental degradation of DDT and other thermolabile contaminants.

Additional Publication Details

Publication type:
Article
Publication Subtype:
Journal Article
Title:
Matrix-enhanced degradation of p,p'-DDT during gas chromatographic analysis: A consideration
Series title:
Environmental Science and Technology
DOI:
10.1021/es960671q
Volume
31
Issue:
3
Year Published:
1997
Language:
English
Larger Work Type:
Article
Larger Work Subtype:
Journal Article
First page:
905
Last page:
910
Number of Pages:
6