LC-ESI-MS/MS determination of phenylurea and triazine herbicides and their dealkylated degradation products in oysters

A method was developed for the determination of several phenylurea and triazine herbicides and their transformation products in oysters at the low mu g/kg level. Pressurised liquid extraction (PLE) of lyophilisated samples had required successive SPE combined with a liquid/liquid extraction to provide relatively clean extracts for the determination in LC-MS/MS. This procedure was validated according to the 2002/657/EC analytical decision. Efficiency of the analytical method led to confirmatory CC alpha. values ranging from 0.1 to 14 mu g/kg with an R.S.D. value ranging from 14% to 66% and a recovery yield ranging from 32% to 46% for phenylureas and from 29% to 75% for triazines. (c) 2006 Elsevier B.V. All rights reserved.