|Huang, Chi hua|
Submitted to: Environmental Pollution
Publication Type: Peer reviewed journal
Publication Acceptance Date: 4/25/2007
Publication Date: 3/1/2008
Citation: Rocha, C., Pappas, E.A., Huang, C. 2008. Determination of trace triazine and chloroacetamide herbicides in tile-fed drainage ditch water using solid-phase microextraction coupled with GC-MS. Environmental Pollution. 152:239-244. Interpretive Summary: Water samples to be analyzed for pesticide concentration are typically prepared using solid phase extraction methods, which require large volumes (200 ' 1000 mL). When it is necessary to determine low levels of pesticides in small sample volumes, alternative techniques are required. A solid phase microextraction sample preparation method was used successfully with gas chromatography and mass spectrometry to prepare and analyze water samples for low levels of common pesticides. This method will be useful to researchers and regulatory agencies in the assessment of extent of pesticide pollution in water and effectiveness of water pollution reduction strategies.
Technical Abstract: Solid phase microextraction coupled to gas chromatography-mass spectrometry (SPME-GC-MS) was used to analyze two triazine (atrazine and simazine) and three chloroacetamide pesticides (acetochlor, alachlor, and metolachlor) in surface water samples. A 100 um polydimethilsiloxane-coated fiber was used to extract the analytes from the samples. The effects of salt concentration, sample size, extraction time, and desorption time were investigated. The addition of salt enhances the extraction for all analytes and the best result was observed when 83% NaCl was used. Increasing the sample volume from 10 mL to 20 mL had a negligible effect on analyte peak areas. An extraction time of 50 min was optimal overall for the studied analytes, while the optimum desorption time observed was 15 min. The results showed that using these conditions, it is possible to detect 0.5 ugL-1 simazine and 0.25 ugL-1 atrazine, acetochlor, alachlor, and metolachlor.