Heterocyclic compound diamino and dihydroxy- pyramidine was synthesized and proposed as chelating agent for the determination of trace amounts of zinc. Zinc(II) forms the ripen-mango-colour complex with DADHP (Diamino dihydroxypyrimidine) in 1:3 stoichiometric ratio at pH-6 in acetic acid and sodium acetate buffer in the presence of pyrideniumchloride as salting out agent. The maximum absorbance is observed at 480 nm. The Beer's law is obeyed in the range of 1-6 µg. The molar absorptivity (ε) and Sandell’s sensitivity of the complex is 0.1484x104 L mol-1 cm-1 and 0.04545 µg cm-1 respectively. The method was successfully applied for the quantification of Zn(II) in pharmaceutical multi vitamin preparations in the presence of other trace elements. The statistical data evaluated reveals the sensitivity and accuracy of the method than the other methods reported.
Zinc determination, Direct and derivative spectrophotometry, DADHP