ECD-Dual-Column Pesticide Method Verification by Ion Trap GC/MS and GC/MS/MS

• Published in: Environmental science & technology Vol. 32; no. 20; pp. 3213 - 3217
• Main Authors: Pyle, Steven M, Marcus, Alvin B, Robertson, Gary L
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 15.10.1998
• Subjects: Analysis methods; Applied sciences; Chemistry; DETECTION; Earth sciences; Earth, ocean, space; ELECTRON CAPTURE DETECTION; Engineering and environment geology. Geothermics; Exact sciences and technology; GAS CHROMATOGRAPHY; Ions; MASS SPECTROMETRY; ORGANOCHLORINE COMPOUNDS; PESTICIDES; Pollution; Pollution, environment geology; Scientific imaging; SOIL; Soil and sediments pollution; Soils; TANDEM MASS SPECTROMETRY; United States; North America; America; Electron impact; Electron capture detector; Chemical analysis; Coupled method; Pesticides; Soil pollution; Gas chromatography; Soils; Ion trap; Chlorine Organic compounds; Detection limit; Mass spectrometry MS/MS; Performance; Mass spectrometry; Comparative study
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es9802192

Soil extracts from five Superfund Contract Laboratory Program (CLP) laboratories were analyzed for organochlorine pesticides using gas chromatographic separation with ion trap mass spectrometric detection in both electron impact (GC/EIMS) and tandem mass spectrometry (GC/MS/MS) modes. These results were compared with those from the standard CLP dual-column gas chromatography electron capture detection (GC/ECD) pesticide method. This was accomplished to (a) determine the number of false positives and false negatives in the CLP data, (b) evaluate ion trap GC/MS/MS as a potential technique to replace/augment conventional ECD-dual-column methodology, and (c) to compare conventional ion trap GC/EIMS with the relatively new ion trap GC/MS/MS. In all, 16 pesticide extracts from five CLP laboratories were analyzed for 20 pesticides by GC/EIMS and GC/MS/MS, and the data were compared with the results from the CLP method (ECD-dual-column pesticide method). Of a possible 960 parameters (20 analytes × 16 samples × 3 data sets), there were 253 detections with concentrations ranging from 1 pg/μL to 77 ng/μL. The respective number of false positives and false negatives were 27 and 1 for GC/MS/MS, 6 and 10 for GC/EIMS, and 25 and 9 for the CLP data. Causes of erroneous results are discussed.