Determination of pesticides and their degradation products in soil:: critical review and comparison of methods

Pesticides are applied widely to protect plants from disease, weeds and insect damage, and usually come into contact with soil, where they undergo a variety of transformations that provide a complex pattern of metabolites. This article reviews the most relevant analytical methods for determining pesticides and their transformation products in soils. We address some recent advances in sampling and sample-preparation technologies for soil analysis. We discuss and critically evaluate procedures, such as liquid extraction methods (pressurized liquid extraction or microwave-assisted extraction) and solid-phase based methods (headspace solid-phase microextraction, solid-phase microextraction or matrix-solid-phase dispersion). Analysis of pesticides is generally carried out by gas chromatography (GC) or liquid chromatography (LC) coupled to different detectors, especially to mass spectrometers (MSs). However, alternative and/or complementary methods, using capillary electrophoresis (CE), biosensors and bioassays have emerged recently. We also consider the advantages and the disadvantages of the various methodologies. (C) 2004 Elsevier Ltd. All rights reserved.