Extractive fluorimetric determination of malathion residues in water samples

Abstract

A sensitive, extractive fluorimetric method for the determination of malathion is described. Malathion was hydrolyzed with sodium ethoxide into sodium dimethyl dithiophosphate (Na-DMDTP), the Na-DMDTP was extracted with Rhodamine 6G, a cationic fluorescent dye, as an ion pair into toluene. The fluorescence of the organic layer was measured at 560 nm after excitation at 536 nm. The method was applied to the determination of malathion residues in water samples up to the ppb level with preconcentration on Amberlite XAD-2.