Determination of Organochlorine Pesticides in Sediments Using Gas Chromatography and Mass Spectrometry

Abstract

Seventeen Organochlorine Pesticides (OCPs) were evaluated in 14 surface sediment samples from a dam lake in Northwestern Turkey. As analytical tool GC-Mass system; HP (Hewlett Packard) 6890 series gas chromatograph coupled with HP 5973 mass spectrometer was used. The HP 5MS capillary column had 30 m length with 0.32 mm internal diameter. A 0.25 mm film thickness cross-linked with stationary phase of 5% Phenyl methyl siloxane and Ultra-pure Helium gas was used as mobile phase. Ultrasonic bath extraction method was applied and cleaned up process were carried up with anhydrous Na2SO4 and Florisil column. Total pesticides concentrations were ranged from=0.237-2.39 mg/kg for dry weA„±ght. Percent total organic carbon (TOC) were observed between 1 and 3%. Average total OCP concentrations was 58.00 ± 45.44 mg/kg. The total concentrations of OCPs in sediment samples ranged from 12.9 to 169.9 mg/kg, with a mean value of 58.00 mg/kg. Although organochlorine pesticides have been banned in Turkey still the residues can be seen in sediment samples indicating the use of prohibited pesticides in the country. Comparison of organochlorine pesticides concentrations in sediment samples with other lakes in Turkey implies the higher concentration therefore higher usage of synthetic chemicals.