The persistence of fenoxaprop ethyl {Ethyl (RS)-2-[4-(6-chloro-1,3-benzoxazol-2-yloxy) phenoxy] propionate} herbicide and its active metabolite fenoxaprop acid was investigated in soil and wheat crop. Fenoxaprop acid was prepared by alkaline hydrolysis of fenoxaprop ethyl. A HPLC method was developed in which fenoxaprop ethyl herbicide and its acid metabolite showed sharp single peak at 6.
View Article and Find Full Text PDFBull Environ Contam Toxicol
February 2012
A microwave assisted extraction (MAE) method for determination of thiamethoxam residues in vegetable and soil samples was standardized. Insecticide spiked vegetable and soil samples were extracted by MAE using water as an extraction solvent, cleaned up by solid phase extraction and analysed by high performance liquid chromatography on photodiode array detector. The recoveries of the insecticide from various vegetable (tomato, radish, brinjal, okra, French been, sugarbeet) and soil (sandy loam, silty clay loam, sandy clay loam, loamy sand) samples at 0.
View Article and Find Full Text PDFJ Agric Food Chem
November 2010
The degradation of mixed (DDT and chlorpyrifos) insecticides by mixed insecticide enriched cultures was investigated. The mixed fungal population was isolated from mixed insecticide acclimatized sewage sludge over a period of 90 days. Gas chromatography was used to detect the concentration of mixed insecticides and calculate the degradation efficiency.
View Article and Find Full Text PDFThe degradation of thiamethoxam [(EZ)-3-(2-chloro-1,3-thiazol-5-yl-methyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene (nitro) amine] insecticide in buffers at different pH and temperature levels was investigated in laboratory studies. Acidic hydrolysis under conventional heating conditions and alkaline hydrolysis under both conventional heating and microwave conditions were carried out. Different hydrolysis products were found to form under alkaline and acidic conditions.
View Article and Find Full Text PDFStudies were undertaken to analyze the residues of commonly used pesticides viz. chlorpyrifos, endosulfan, dicofol, cypermethrin, fenvalerate, propargite, malathion, phorate, carbendazim, carbosulfan, thiamethoxam, and mancozeb in apple of integrated pest management (IPM) and non-IPM samples collected from the IPM and non-IPM fields of Shimla. We also present a method for the determination of these pesticides in apple samples.
View Article and Find Full Text PDFThe metabolism of thiamethoxam [(EZ)-3-(2-chloro-1,3-thiazol-5-yl-methyl)-5-methyl-1,3,5-oxadiazinan-4-ylidene (nitro) amine] was investigated in whole plant, callus, and heterotrophic cell suspension culture of aseptically and field grown tomato (Lycopersicon esculentum Mill.) plants. The structure of the metabolites was elucidated by chromatographic (HPLC) and spectroscopic (IR, NMR, and MS) methods.
View Article and Find Full Text PDFPest Manag Sci
August 2009
Background: Thiamethoxam, a neonicotinoid insecticide, has been widely accepted for use in various crops, including vegetables, owing to its high efficacy against various chewing and sucking insect pests. In this particular study, the authors examined the residue dynamics of this insecticide in tomato and soil and calculated a safety index for this insecticide in an Indian context.
Results: In tomato fruits, the insecticide dissipated from 82 to 87% in 10 days with a half-life of 4 days, whereas dissipation in soil, under tomato crop, varied between 72 and 75% in 15 days with a half-life of 9 days.
Background: Metsulfuron-methyl is a low-application-rate sulfonylurea herbicide that is widely used to control broad-leaved weeds in wheat. Owing to its persistent nature, its residues may be present at phytotoxic levels for the next crop in rotation. Therefore, a comparative evaluation of HPLC and bioassay techniques was made for the analysis of this herbicide in wheat field soil.
View Article and Find Full Text PDFStudies were conducted to analyze the residue of commonly used pesticides viz. methyl parathion, chloropyrifos, endosulfan, cypermethrin, fenvalerate, carbendazim, imidacloprid and carbaryl in mango, Dashehari variety, integrated pest management (IPM) and non-IPM samples were collected from the IPM and non-IPM orchards, Lucknow, India. We also present a method for the simultaneous determination of these pesticides in mango samples.
View Article and Find Full Text PDFA fungal strain able to use atrazine (2-chloro-4-ethylamino-5-isopropylamino-1,3,5-triazine) as a source of nitrogen was isolated from a corn field soil that has been previously treated with the herbicide. This strain was purified and acclimatized to atrazine at a higher level in the laboratory. A supplemented N was required to trigger the reaction.
View Article and Find Full Text PDFA novel and cost-effective method of sulfosulfuron extraction has been developed using distilled water as an extraction solvent. Using this method, the environmental fate of sulfosulfuron was investigated in soil under wheat crop. Studies were conducted under natural field conditions in randomized block design and herbicide (75% water dispersible granules (WG)) was applied after 24 days of sowing.
View Article and Find Full Text PDFJ Environ Sci Health B
August 2006
Persistence of triasulfuron [3-(6-methoxy-4methyl-1,3,5-triazin-2-yl)-1-{2-(2-chloroethoxy)-phenylsulfonyl}-urea] in soil was studied under wheat crop and laboratory conditions. Field experiment was conducted in the farms of Agronomy Division, Indian Agricultural Research Institute (IARI), New Delhi. Randomized block design (RBD) was followed with four replicates and two rates of treatments along with control and weedy check.
View Article and Find Full Text PDFCrude enzyme from a soil fungus, Aspergillus flavus, was isolated from a field soil following repeated applications of metolachlor [2-Chloro-N-(methoxy-1-methylethyl)-2'-ethyl-6'-methyl acetanilide]. Metolachlor hydrolysis by the crude enzyme extract was determined by enzyme assay. The tests were performed in phosphate buffer, pH 7.
View Article and Find Full Text PDFJ Environ Sci Health B
May 2004
Eggplant samples were analyzed for endosulfan residues using ELISA, a technique recognized as a promising tool for screening environmental contaminants. Calibration curve for endosulfan was standardized using kits developed by CFTRI Mysore. Farm gate samples of eggplant from 12 different locations were analyzed.
View Article and Find Full Text PDFJ Environ Sci Health B
May 2003
A method was developed for sulfosulfuron [(1-(2-ethylsulfonylimidazo [1,2-a] pyridin-3-ylsulfonyl)-3-(4,6-dimethoxy pyrimidin-2yl)] and its three major metabolites by HPLC utilizing photodiode array detector. The method makes use of Lichrosphere RP-8 column and acetonitrile:water:orthophosphoric acid (80:20:0.1 v/v/v) as mobile phase at a flow rate of 1 ml min(-1).
View Article and Find Full Text PDFDissipation of dithiopyr in soil was monitored after application to wheat crop as pre- or post-emergence applications at two rates, viz 100 and 200 g AI ha(-1). The level of dithiopyr in the soil was assessed by gas chromatography, and its disappearence was found to follow a first-order decay curve irrespective of rate or method of application. The half-life in soil ranged between 17.
View Article and Find Full Text PDFA laboratory experiment was conducted to study the stability of sulfosulfuron [1-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-ylsulfonyl)-3-(4,6-dimethoxypyrimidin-2yl) urea] in a controlled environment of pH, temperature, solvent, and surface. In another experiment the photostability of sulfosulfuron was studied after irradiation under sunlight. Under alkaline condition, it yielded 1-(2-ethylsulfonylimidazo[1,2-a]pyridin-3-yl-3-(4,6-dimethoxypyrimidin-2-yl) amine, and under acidic condition it degraded to 1-(2-ethylsulfonylimidazo[1,2-a] pyridin)-3-sulfonamide and 4,6-dimethoxy-2-aminopyrimidine.
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