Gas chromatographic determination of organochlorine pesticides in snow cover in agricultural areas

A method for determining organochlorine pesticides in snow cover using gas chromatography with an electron capture detector is proposed. The proposed method is characterized by accuracy (δ = ±14%), reproducibility (σ_R = 1%) and repeatability (σ_r = 2%). The range of determination of mass concentrations of OCPs is 0.001 – 1.000 g/cm³. The completeness of extraction for 9 OCPs varies in the range of 95 – 97%. This method was used to analyze snow cover on 13 agricultural sites in the Ufa and Sterlitamak districts. Five organochlorine pesticides were detected: β-HCH, γ-HCH, DDT, DDD and heptachlor. It was found that all the studied sites are contaminated to a greater extent with DDD. The detected OCP content at all sampling points does not exceed the MAC of organochlorine pesticides in natural waters. The obtained data show that the most polluted with organochlorine pesticides is the arable land of the APC «Alekseevsky» (Republic of Bashkortostan, Ufimsky district, Alekseyevka village). The total concentration of OCPs was 0.40 μg/dm³. The least polluted territory is the arable land of the state farm «Roshchinsky» (Republic of Bashkortostan, Sterlitamaksky district, Podlesnoye village). The total concentration of OCPs was 0.09 μg/dm³.