Solid-phase microextraction for the determination of systemic and non-volatile pesticides in fiver water using gas chromatography with nitrogen-phosphorous and electron-capture detection

A solid-phase microextraction (SPME) method combined with gas chromatograph y with nitrogen-phosphorous and electron capture detection for the analysis of the pesticides terbumeton, metribuzine, isomethiozine, pyridafenthion a nd triadimenol in river water has been developed. For this purpose, polyacr ylate and polydimethylsiloxane coated fibres have been utilised and the fac tors affecting throughput, precision and accuracy of the SPME method have b een investigated and optimised. These factors include: matrix influence, ad sorption time, pH, salt effect, desorption time, temperature and also the l apse of time between sampling and injection. The performed analytical proce dure showed detectability ranging from 2.0 ng l(-1) to 3.0 mu g l(-1) and p recision from 1.9 to 27.7% (as relative standard deviation) depending on th e pesticide, the fibre and the detector used. The results demonstrate the s uitability of the SPME method to analyse these non-volatile pesticides in r iver water. (C) 2000 Elsevier Science B.V. All rights reserved.