Duhan, AnilNaincy Rani2019-12-062019-12-062019http://krishikosh.egranth.ac.in/handle/1/5810137024Persistence and leaching potential of tembotrione and its metabolite in two different soils (sandy and clay loam) was studied in Agrochemicals Residues Testing Laboratory, Department of Agronomy, Chaudhary Charan Singh Haryana Agricultural University. Tembotrione (Laudis OD) was applied in soil taken in plastic pots at two doses i.e., 120 and 240 g a.i./ha for persistence study. Soil samples were collected periodically on 0 (1h), 1, 3, 7, 10, 15, 30, 45 and 60 days after application. In leaching experiment, tembotrione and its metabolite was applied at 50 μg (single dose) and 100 μg (double dose) in both soils packed in plexi glass columns. Various sample preparation techniques i.e. Matrix solid phase dispersion (MSPD), Liquid-solid extraction (LSE) and modified QuEChERS were optimized for both soils at different fortification levels of 0.005 and 0.01 μg/g before taking up analysis of test samples. Maximum recoveries (86.6 to 95.6%) were obtained by using modified QuEChERS with MgSO4 avoiding PSA. The test samples were analysed over GC-MS/MS for the first time, hence provides a novel, efficient and innovative approach. Limits of detection and quantification were 0.001 and 0.003 μg/g, respectively for both soils. A first order dissipation kinetics was followed with half-lives of 8.4 and 9.3 days in sandy loam and 14.9 and 13.4 days in clay loam soil and in case of metabolite, 7.2 and 8.1 days in sandy loam soil and 10.0 and 12.3 days in clay loam soil at both the doses, respectively. The residues were below detectable limit (0.003 μg/g) after 45 days for both the treatments. Leaching experiments were carried out in laboratory under continuous flow conditions. The residues of tembotrione and its metabolite were retained up to soil depth of 35-40 cm depth in both soil types. No residues were detected in leachate fractions of both soils, hence posing minimum threat for surface and ground water contamination.ennullThesis