Spectrophotometric determination of bismuth in pharmaceutical preparations using 1-[di(2-pyridyl)--methylene]-5-salicylidene-thiocarbonohydrazide.

A simple and fast spectrophotometric method for the determination of bismuth in pharmaceutical preparations is described. The used chromatic reactive is 1-[di(2-pyridyl)methylene]-5-salicilydene-thiocarbonohydrazide+ ++ forming a yellow complex with bismuth. In a solution containing 40% v/v of dimethylformamide molar absorption is 5.7 x 10(4) l.mol-1.cm-1 at 421 nm and at pH 4.3. The optimal conditions for the color development and the possible interferences are studied.

Application of a new spectrophotometric method for zinc determination in beverages and condiments.

A new spectrophotometric method has been applied to the determination of zinc in bottled mineral water (with and without gas), refreshments, vinegar, and table salt. The method introduces the 1-[di-(2-pyridyl)-methylidene]-5-(salicylidene)-thiocarbo hydrazone (DPST) as chromogenic reagent. This procedure is simple, rapid, reproducible and does not demand costly outfit and chemicals.