Voltammetric Determination of Aclonifen at a Silver Amalgam Electrode in Drinking and River Water

A method for the determination of pesticide Aclonifen (AC) in drinking and river water by differential pulse voltammetry (DPV) on a meniscus modified silver solid amalgam electrode (m-AgSAE) using solid phase extraction (SPE) as a cleanup and preconcentration procedure is described. The limit of detection (LOD) for direct DPV determination of AC in deionized water is 2.7·10^-8 mol·dm^-3. LOD for DPV determination of AC in tap water after SPE is 1.6·10^-10 mol·dm^-3, the recovery being 55%. LOD for the determination of AC in Vltava river water is 1.9·10^-9 mol·dm^-3, the recovery being 65%. Humic acids interfere with the determination in river water; this problem can be resolved by adjusting the pH of the extracted sample to 6. The advantages of this approach are high sensitivity, low LOD, quick and easy sample preparation and fast determination.