Water framework directive : watch list method analytical method for determination of compounds selected for the first surface water watch list

The validation of an analytical method is a necessary step in controlling the quality of quantitative analysis. Method validation is an established process which provides documentary evidence that a system fulfils its pre-defined specification, or shows that an analytical method is acceptable for its intended purpose. The purpose of the present study was to develop and validate analytical procedures for the quantitative determination in surface water of substances selected in the first watch list. Two different methods were developed and validated: - a multi-residual method based on SPE-LC-MS/MS analysis, using OASIS HLB as sorbent material for the extraction of 1 litre water samples and quantitative determination of EE2, E2, E1, diclofenac, azithromycin, clarythromycin, methiocarb acetamiprid, clothianidin, imidacloprid, thiacloprid, thiametoxam and oxadiazon; - a multi-residual method based on LLE-GC-MS, using hexane as an extraction solvent for the extraction of 0.01 litre water samples and quantitative determination of BHT, EHMC and Triallate. The calibration curves, working ranges, recoveries, detection and quantification limits, trueness as well as repeatability were determined. The uncertainty budget was estimated based on in-house validation data.