An Efficient Extraction Method of Persistent Organic Pesticides in Soil Samples for Their Chromatographic Determination

In order to determine persistent organic pesticides (OPs) and their metabolites in soil samples, an analytical procedure was developed, optimized and validated. It possesses advantages like suitable limits of detection, low solvent volume and time consume, and requires a chromatography detector commonly used in routine laboratories. The method allows the determination of Methoxychlor, p,p’-DDT, Endosulfan sulfate, Endrin aldehyde, p,p’-DDD, Endosulfan II, Endrin, Dieldrin, p,p’-DDE, Endosulfan I, Heptachlor epoxide, Aldrin, Heptachlor, δ-HCH, γ-HCH, β-HCH, α-HCH, Etridiazole, Trifluralin, Hexachlorobencene, Chlorothalonil, Chlorpyrifos, DCPA, γ-Chlordane, α-Chlordane, Clorbenzilate, trans-Permethrin, cis-Permethrin. Linearity is evaluated and the analytical parameters are presented. The average recoveries obtained for each pesticide (28 OPs) by using 3, 15 and 22.5 µg kg^?1 spiked samples ranged between 50 and 97.3%, 57 and 103% and from 60 to 100% for each case. The limits of detection and quantification vary from 0.18 to 1.28 μg kg^?1 and from 0.60 to 4.22 μg kg^?1. The reproducibility obtained as relative standard deviation percentages is less than 7.5, 5.3 and 4.2% for low, middle and high level of concentrations, respectively. The procedure is statistically validated for its application to soil samples and compared with other published methods.