A comprehensive collection of robust methods for the detection of pesticide compounds or their metabolites useful in food, environmental, and biological monitoring, and in studies of exposure via food, water, air, and the skin or lungs. The readily reproducible methods range from gas and liquid chromatography coupled to mass spectrometry detection and other classic detectors, to capillary electrophoresis and immunochemical or radioimmunoassay methods. The authors have focused on extraction and cleanup procedures, in order to develop and optimize more fullyautomated and miniaturized methods, including solid-phase extraction, solid-phase microextraction, microwave-assisted extraction, and on-line tandem liquid chromatography (LC/LC) trace enrichment, among others. The protocols offer step-by-step laboratory instructions, an introduction outlining the principles behind the technique, lists of the necessary equipment and reagents, and tips on troubleshooting and avoiding known pitfalls.