Determination of Lead using 2, 5-Dimercapto-1, 3, 4-Thiodiazole (DMTD)

A new spectrophotometric method which is fairly selective, non extractive, is described here for the determination of lead based upon its colour reaction with 2,5- dimercapto-1, 3,4-thiodiazole (DMTD). According to this lead (II) can be determined within the range from 1.0 to 50 mu g per mL in a slightly acidic media (0.005 M HCl), to give a greenish yellow chelate complex, which has an absorption at 375 nm. The reaction proceeds fastly and color remains stable. While no special conditions are followed. The method is recommended for its routine use and is quite accurate, precise, and sensitive. Effect of Foreign ions is also studied at 40 mu g/mL of lead.