Tag Archives: Modified QuEChERS Method

Application of Modified-Quechers Method to Fish Tissues for the Determination of Organochlorine Pesticides by Gas Chromatography, With Optimisation Using 14c-Lindane and 14c-Ddt (Published)

In this study, Ethyl acetate modified-QuEChERS method has been applied to fish matrix for the determination of recommended target organochlorine pesticides by keeping in view the importance of fish as food and an important indicator of sediment contamination and water quality problems. Fish and shell-fish monitoring facilitate effective risk management practices for responsible agencies and competent authorities by determining levels of contaminants that may be harmful to human consumers. A simple, rapid and inexpensive method has been proposed for the analysis of organochlorine pesticides in fish tissues.  The method has been adapted from a previously validated method in IAEA laboratories, for pesticide residues in fruits and vegetables using ethyl acetate extraction, dispersive solid phase clean-up and gas chromatographic analysis with ECD and NPD detection. The method has been validated on fish fillets at fortification levels 10, 100 and 1000 μg/kg levels, far below the Codex permissible limits in fish tissue. Average recovery obtained for all 12-pesticides at three fortification levels is 90% with relative standard deviation of 8% (n=479).  Two radiolabelled compounds, 14C-lindane and 14C-DDT, were used in the initial stages of method optimization and characterization. Limits of detection (LOD) were less than 3 μg/kg for all analytes except dieldrin, which had a LOD of about 5 μg/kg. The method offered is proven to provide efficient recoveries and most sensitive detection limits. 

Keywords: 14C-lindane and 14C-DDT., Fish, GC-ECD, Modified QuEChERS Method, Organochlorine Pesticides, Radiotracer Technique