Gas chromatography- residue analysis of Pesticide (Malathion) in field samples of two varieties (K-21 and DS-22) of tomato (Lycopersicum esculentum L.) grown in Gwalior region, M.P, India

The experiment was carried out at three different sites in Gwalior region namely Badagaon (rural), Bijauli ( periurban) and Birla nagar (urban) on two commonly grown varieties of tomato in Gwalior region namely K-21 and DS-22. Recommended doses of malathion were applied. The experimental plots were maintained in triplicates for both the varieties at each site. Three samplings were done after 110 days of sowing, at an interval of every 20 days to 150 days of sowing. Malathion (insecticide) was sprayed at 50th day (flowering stage) and at 100th day (fruiting stage) from the date of sowing. Extraction of insecticide was carried out by Dichloromethane, Acetone, Hexane. Malathion residue was analyzed by using Gas Chromatograph (GC) (model-chemito, GC-1000) with ECD (electron capture detector). The residue level of malathion is observed and reported.