Determination of Pesticides in Soil
Pesticides may reach the soil compartment by different ways. Once in the soil, pesticides may undergo a series of transformation and distribution processes. The distribution of pesticides can be originated by various processes, such as volatilization, leaching, runoff, and absorption by plants. Pesticides and their degradation or transformation products may cause toxic effects to man and the environment, making it necessary to evaluate if their application may originate an unacceptable risk. Selective methods are needed for their determination, using preconcentration procedures to obtain samples suitable for analysis, with appropriate techniques able to detect trace levels of pesticides in soil samples. In this chapter, the current methods (2007–2017) used in the analysis of pesticides in soil samples have been discussed. Extraction techniques, such as QuEChERS, matrix solid-phase dispersion, and some recently developed techniques employed for the cleanup of soil extracts, such as magnetic solid-phase extraction using nanoparticles, are discussed. In addition, the application of new analytical techniques such as quadrupole–time-of-flight mass spectrometry to determine pesticide residues is also discussed.