Twelve samples each of soil and ground water were collected from paddy-wheat, paddy-cotton, sugarcane fields and tube wells from same or near by fields around Hisar, Haryana, India during 2002-2003 to monitor pesticide residues. Residues were estimated by GC-ECD and GC-NPD systems equipped with capillary columns for organochlorine, synthetic pyrethroid and organophosphate insecticides. In soil, HCH (0.002-0.051 microg g(-1)), DDT (0.001-0.066 microg g(-1)), endosulfan (0.002-0.039 microg g(-1)) and chlordane (0.0002-0.019 microg g(-1)) among organochlorines, cypermethrin (0.001-0.035 microg g(-1)) and fenvalerate (0.001-0.022 microg g(-1)) among synthetic pyrethroids and chlorpyriphos (0.002-0.172 microg g(-1)), malathion (0.002-0.008 microg g(-1)), quinalphos (0.001-0.010 microg g(-1)) among organophosphates were detected. Dominant contaminants were DDT, cypermethrin and chlorpyriphos from the respective groups. In water samples, HCH, DDT, endosulfan and cypermethrin residues were observed frequently. Only chlorpyriphos among organophosphates was detected in 10 samples. On consideration of tube well water for drinking purpose, about 80% samples were found to contain residues above the regulatory limits.
Analysis of 84 farm gate samples of seasonal vegetables carried out on GC-ECD and GC-NPD systems equipped with capillary columns by using a multi residue analytical technique revealed that 26% samples contained residues above MRL values. The contamination was mainly with organophosphates followed by synthetic pyrethroids and organochlorines. Among organophosphates, residues of monocrotophos, quinalphos and chlorpyriphos exceeded the MRL value in 23% samples. Residues of monocrotophos were higher than MRL value in 3 samples of brinjal and one sample each of okra, cauliflower and smooth gourd, of chlorpyriphos in 3 samples of cauliflower and 8 of cabbage and of quinalphos in one sample each of okra and cauliflower. Among synthetic pyrethroids, cypermethrin was the major contaminant and its residue exceeded the MRL value in one sample each of brinjal, okra and cucumber. Only aldicarb among the carbamates was detected in potato. The residues of some organochlorines, i.e. HCH, DDT and endosulfan were found in all the samples but did not exceed the tolerence limit.
~(+)-3-Hydroxybutyryl-CoA dehydrogenase was purified 18 fold with a 29O/, yield from extracts of Clostridium kluyveri. The enzyme was found to be homogeneous by gel electrophoresis and ultracentrifugation. The analysis of the sedimentation equilibrium and gel filtration experiments gave a molecular weight of 220000 and 215000, respectively. Gel electrophoresis in the presence of sodium dodecylsulfate revealed the presence of 8 subunits per enzyme molecule. The subunits contain approx. 5 sulfhydryl groups per mole of protein (260OOxg).L( +)-3-Hydroxybutyryl-CoA dehydrogenase from C. kluyveri is NADP-dependent. The enzyme does not oxidize 3-hydroxyvaleryl-CoA or 3-hydroxycaproyl-CoA. The specific activity of the pure enzyme as measured by acetoacetyl-CoA reduction at the optimum p H of 6.5 is approx. 450 U/mg protein a t 25 "C. The oxidation of 3-hydroxybutyryl-CoA a t pH 9.5 proceeds with 70l0 of the rate of acetoacetyl-CoA reduction. N-Acetyl-S-acetoacetyl-cysteamine is reduced with 15O/, of the rate of acetoacetyl-CoA.Measurements of the Michaelis constants for the substrates of L( +)-3-hydroxybutyryl-CoA dehydrogenase gave values of 50 pM for acetoacetyl-CoA and 70 pM for NADPH,.
Fruit samples of ber, grapes and guava analysed for pesticide residues employing multiresidue analysis by gas liquid chromatography equipped with ECD and NPD detectors and capillary columns showed contamination with organochlorine, synthetic pyrethroid and organophosphate insecticides. Among organochlorines, HCH, DDT and endosulfan were detected in almost all the samples. Residues of HCH and DDT were maximum in ber followed by grapes and guava where as of endosulfan were maximum in guava followed by grapes and ber. All the fruit samples showed the presence of residues with one or the other group of pesticides. Residues of none of the pesticides exceeded the MRL values in any sample. On the basis of these studies, it is suggested that monitoring studies should be extended to other fruits grown in different agro climatic regions which may serve as basis for future policy in chemical use.
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