Original Articles: 2011 Vol: 3 Issue: 2
Selective Kinetic Spectrophotometric Determination of Copper(II) in Food and Medicinal Leafy Samples
Abstract
A simple, sensitive and fairly selective kinetic spectrophotometric method has been developed for the determination
of copper(II) using 2,3,4-trihydroxyacetophenonephenylhydrazone (THAPPH) as an analytical reagent. The metal
ion has formed 1:2 (M:L) bluish green coloured complex with THAPPH in hydrochloric acid-potassium chloride
buffer of pH 2.5. Beer’s law was obeyed in the range 0.04-0.64 μg/ml of Cu(II) at λmax of 385 nm. The sensitivity of
the method was calculated in terms of molar absorptivity (1.0053 x 105 L. mol-1 cm-1) and Sandell’s
sensitivity(0.0006265μg cm-2), which explains the method is more sensitive. The standard deviation (0.0024),
relative standard deviation (0.47%), confidence limit (±0.0017), and standard error (0.0008) found that the
developed method has more precision and accuracy. The stability constant was calculated by Ausmu’s (2.35×10-11)
and Edmonds & Birnbaum's(2.44×10-11) methods at room temperature. The interfering effect of various cations and
anions was also studied. The reliability of the method was assured by analyzing the standard alloys, Brass (BCS 5g)
H.T. Bronze (BCS 10g) and Phosphor-Bronze (BCS 7a). The proposed method was successfully employed for the
determination of copper(II) in food and medicinal leafy samples and inter compared the experimental values using
atomic absorption spectrophotometer and statistically evaluated using F-test