Edmond Sanganyado - Occurrence of pesticides used in tobacco farming in edible vegetables and environmental samples

Version 1

      Publication Details (including relevant citation   information):

      6th SETAC Africa Conference

      21st Century Africa and Beyond–Balancing Economic Growth   Opportunities With Environmental Sustainability

      2–3 September 2013, Lusaka, Zambia

      Abstract:

      A   method was developed and validated for the analysis of   chlorothalonil (CT), dimethoate (DM) and triadimenol (TD) in   soil, surface water and edible green vegetables. In method   development, A range of solvents were evaluated, and ethyl   acetate was observed to be the best extracting solvent in soil   and vegetable samples, while acetonitrile was the best extracting   solvent in water samples. The effect of solvent type, solvent   volume and extraction time on recovery of pesticides was studied.   Analysis was carried on HPLC-UV a C18 column using a   mobile phase comprising CH3CN/water (50:50, v/v) with   a flow rate of 1.0ml/min in isocratic mode. The pesticides were   extracted by ultrasonication and obtained recoveries in water,   soil and vegetables ranged from 65-91 %. Furthermore, the   detection limit in water, soil and vegetables was 0.01 µg/L, 2.8   µg/kg and 0.005 µg/kg, respectively. Limits of quantification   ranged from 0.25-1.25 µg/kg for vegetables, 1.35- 2.3µg/kg and   0.02-0.05µg/l. Precision was measured in terms of the RSD, and   values were less than 10%. The method was successfully applied to   the analysis of incurred vegetable, soil and water samples from 3   farms from Bromley A2 agricultural area near Marondera, Zimbabwe.   About 1.6 µg/kg of CT was detected at one farm in soil samples;   DM (0.025µg/l) was detected at another farm in well water.   However, TD was not detected in all samples and no pesticides   were detected in vegetable samples.

      Address (URL): http://http://www.setac.org/event/africa-2013