SPECTROPHOTOMETRIC DETERMINATION OF ZIRAM AND ZINEB WITH 1-(2'-PYRIDYLAZO)-2-NAPHTHOL (PAN)

A rapid, simple, sensitive and selective spectrophotometric method has been developed for the determination of ziram (zinc dimethyldithiocar bamate) and zineb (zinc ethylenebisdithiocarbamate). The zinc-PAN comp lex is extracted into isobutyl methyl ketone in the pH range 9.0-11.0 and absorbance measured at 550 nm against a reagent blank. Beer's law is obeyed over the concentration range 0.2-2.2 mug/ml and 0.5-2.4 mug/ ml respectively. The molar absorptivity is found to be 5.06 x 10(4) dm 3 mol-1 cm-1. The values of Sandell's sensitivity are 0.0063 mug cm-2 and 0.0055 mug cm-1 for ziram and zineb respectively. The interference s of various other ions and pesticides have been studied. The method h as been tested for the determination of ziram and zineb in commercial formulations, synthetic mixtures, grain and in the presence of various other pesticides.