Determination of the Organophosphorus Pesticide Diclorvos by Enzymatic Flow- Injection Analysis with Conductimetric Detection

¹ Institute of Chemistry, University of Campinas, 13083-970 Campinas, São Paulo, Brazil
² Pharmacy Course, Sorocaba University, Sorocaba, SP, Brazil
³ Hochschule für Angewandte Wissenschaften, HAW, Hamburg, Germany
⁴ Universidade do Estado de Minas Gerais, UEMG, Brazil
⁵ Instituto Federal da Bahia, Campus Ilhéus, Ilhéus, Brazil

^a tubino@iqm.unicamp.br

Abstract

Brazil is one of the world largest consumers of pesticides. When used properly pesticides help increase production. But when misused they can be extremely detrimental to the environment and to the population, which has led civil society to demand tighter control from environmental agencies and increased the demand for analytical data. In this work, we developed a scanning method for the determination of organophosphorus pesticides using a FIA procedure associated with an enzymatic biosensor based on acetyl cholinesterase. Although immunosensor systems have been proposed as powerful pesticide monitoring tools. The method is based on the generation of acetic acid by the reaction of acetylcholine with the enzyme cholinesterase. Which was chemically immobilized on “CPG” the acetic acid formed permeate through a poly- (tetrauoroethylene) (PTFE) membrane into a de-ionized water stream. The developed method is extremely simple, sensitive and low cost and selective for inhibitors of this enzyme. For the pesticide paroxon the detection limit was about 10^–18 mol L^–1, the correlation coefficient was 0.9966 and the standard deviation of 0.0403 (n = 6).