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-mangocolour 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 0.1484 x 10 4 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.

Abstract:The quantification of copper in water, vegetables, foodstuffs, human hair and pharmaceutical samples was determined by a simple more sensitive and selective spectrophotometric method. Cu(II) forms an orange -red color complex with 5-{ά -methyl-3-hydroxy benzylidene} rhodanine [5M, 3H-BR], at pH 5.5 in sodium acetate and acetic acid buffer. The maximum absorbance was measured at 430 nm. The Beer's law is obeyed in the range of (0.05 µg -13 µg/mL). The molar absorptivity (ε) and the Sandell's sensitivity of the complex were 0.6027× 10 4 mol -1 cm -1 and 0.01054 µg cm -2 respectively. First, second and third derivative spectrophotometry were also proposed and employed successfully for the determination of copper in the supra. The performance of the present method was also evaluated in terms of RMSEP, REP and RSD, students t-test. This indicates the greater importance of the method than other methods reported in the literature.