Dixit, V.P.Brajmadhuri2019-06-222019-06-222005-04http://krishikosh.egranth.ac.in/handle/1/5810109574In the present study, residual concentrations of chlorpyrifos and endosulphan in fish tissue samples (300) collected from various locations of Udham Singh Nagar and Nainital districts of Uttaranchal were determined. Liquid-liquid partitioning was employed for the extraction, followed by alumina column chromatography for the cleanup of these residues from fish. Detection and quantification of these residues was undertaken with the help of high performance liquid chromatography. Chlorpyrifos residues were detected in 7(2.34%) of the total 300 samples analyzed with mean residual concentration of 0.0508 μg/g, while 21(7%) samples showed the residues of total endosulphan with mean residual concentration of 0.3237, 0.1793 and 0.1846 μg/g, respectively, for endosulphan alpha, beta and sulphate. Of 300 samples analyzed, 0.33 and 5.33% samples violated the prescribed MRL for chlorpyrifos and endosulphan, respectively. The edible fish tissues were also subjected to heat treatment. Upon frying for 10 min. in oil and spices, chlorpyrifos was reduced from 20 μg/g to 8.98 μg/g indicating 55.11% reduction in the active ingredient. Significant reduction in the amount of active endosulphan was also noted after frying. Ten minutes frying in oil and spices resulted in the reduction of endosulphan alpha, beta and sulphate to the extent of 25.5%, 22.5% and 19%, respectively. Boiling also resulted in the significant reduction of the active ingredients. With respect to chlorpyrifos upon boiling for 10, 20 and 30 minutes there was reduction up to 24.83, 34.94 and 40.85%, respectively at 100 oC in water bath. At 10 minutes, up to 16.08, 18.2 and 10% reduction was recorded with respect to endosulphan alpha, beta and sulphate, respectively. While, at 20 min., 25.42, 43.5 and 20.55% reduction was found. However, at 30 minutes 31.14, 49.75 and 32.7% reduction was observed for endosulphan alpha, beta and sulphate, respectively.ennullThesis