An SPE Method for the Concurrent Extraction of Organochlorine and Phenoxy Acidic Pesticides in River Water

We present the validation of a multiresidue method for the concurrent SPE of organochlorine (OCP) and phenoxy-acidic pesticides (PA) in river water. The two classes of compounds show very different chemical characteristics. The analyses were performed by gas chromatography-mass spectrometry and by liquid chromatography-electrospray ionization-mass spectrometry. The method was validated at three different concentrations: method limit of quantitation, 0.5 and 5 mu g L-1. The recoveries were in the range 65-135% for all the target compounds and in the range 83-113% with RSD < 20% for most of them at all the concentrations tested. The method showed good accuracy, precision, and sensitivity, and allowed the analysis of the selected pesticides at a concentration lower than that required by the EU current legislation for surface water [1]. The single-step procedure reduced artifacts, matrix effects, and speeded up sample preparation.