Reactive pre-concentration of trace amounts of pesticides in environmental analysis procedures. Part I. Determination of carbamates by indirect spectrophotometry

Details are given of a procedure for the indirect spectrophotometric determination of traces of the pesticide aldicarb in water. It involved decomposition of aldicarb by passage through a strongly basic anion exchange resin to produce an oximate which was adsorbed on the resin. Subsequent addition of sulphuric acid resulted in in situ formation and elution of hydroxylamine, which was used for quantitative reduction of trivalent iron to the ferrous state; this was then determined spectrophotometrically.