Mressa, Fatuma2022-03-112022-03-112021Mressa, F. (2021). Determination and treatment of pesticide residues in grapes (vitis vinifera) and their supportive soil from vineyards implementing good agricultural practices in the Dodoma region(Master's dissertation). The University of Dodoma, Dodoma.http://hdl.handle.net/20.500.12661/3477Dissertation (Msc Chemistry)This study describes the levels of 7 pesticide residues in untreated and treated grapes and their supporting soil using GC technique. Target compounds belongs to the organochlorine, organophosphorus and triazole groups. Sample preparation was done using acetonitrile extraction and subsequent cleanup by dispersive solid phase extraction with polymer-based sorbent. Identification and quantification of pesticide residues was done using GC-MS/MS operating in MRM mode an electron impact ionization. Average recoveries or analytes ranged between 79-105% at three fortification levels of 0.025, 0.05 and 0.1 mg/kg. Limit of detection were below 0.001 and limit o quantification was below 0.01 which were sufficiently below the maximum residue levels set by European legislation. The proposed method was applied for determination of pesticide residues in untreated and treated grape samples and their supporting soil from the selected vineyards. Treatment method used was washing with different solution such as vinegar, sodium bicarbonate, tap water and table salt(sodium chloride ) solution. Higher levels of pesticide residues were found in soil than in grape samples. Hexaconazole were detected more than the other pesticides with the concentrations up to 0.5 mg/kg and 0.6 mg/kg in soil samples. The levels of hexaconazole found in the untreated grape samples were much higher than in treated grapes and exceeding its respective MRLs (0.5 mg/kg). This means that some grapes which contain pesticides, are available on the market. This is due to lack of information reporting their presence and their effects to human and animalsen7 pesticideVitis viniferaGrapesOrganophosphorus and triazoleDodomaDissertation