Comparison of sample preparation methods applied for determination of atrazine in freshwater biofilms by gas chromatograph-mass spectrometer system

A sample preparation procedure was developed for the determination of atrazine in freshwater biofilms by gas chromatography-mass spectrometry. Different methods of sample preservation (immediate extraction, deep-freezing, cooling, vacuum-drying, freeze-drying) were tested for atrazine pretreated freshwater biofilms, followed by combined liquid- and solid-phase extraction (SPE). The immediate extraction of atrazine with acetonitrile, and a SPE, proved to be the best sample preparation procedure. Applying our method, atrazine pollution of the Lake Velence (Hungary) could be detected in the biofilms. At the same time in the lake freshwater samples, prepared by SPE and analyzed the same way, the atrazine concentration did not exceed the limit of detection. (C) 2002 Elsevier Science B.V. All rights reserved.