ANALYSIS OF PESTICIDES USING A POLYPYRROLE MODIFIED ELECTRODE

Electrochemical methods can provide fast, sensitive and sometimes real time detection of pesticides. In the course of this work, a dispersed mercury electrode has been used to detect pesticides electrochemicall y. The electrode was prepared by depositing a thin mercury film on a g lassy carbon disc and then coating a layer of polypyrrole on the disc, The effect of coating thickness on detection sensitivity was studied. A thin mercury film of 0.34 mu m dispersed by one cycle polymerizatio n of pyrrole was preferred. The influence of electrolyte, pH and organ ic solvent content on pesticide response was also investigated. nle po lypyrrole dispersed mercury electrode (Hg-PPy/GC) was not suitable for a pH above 6 but it can tolerate acetonitrile up to 10% at which conc entration tile mercury film coated glassy carbon electrode (Hg/GC) fai led to response. Methyl parathion, methyl azinphos, parathion and feni trothion were detected. The sensitivity of the dispersed mercury elect rode was similar to a normal thin mercury film electrode in this case. A good response carl be obtained for 1 ppm pesticides using fast line ar sweeping voltammetry.