Determination of sub microgram amounts of copper (ll) by its catalytic effect on Hexacyanoferrate (lll)–Citric acid Redox reaction

Swarn Lata Bansal; Sanjay Asthana

Volume : IV, Issue : VI, June - 2015

Determination of sub microgram amounts of copper (ll) by its catalytic effect on Hexacyanoferrate (lll)–Citric acid Redox reaction

Swarn Lata Bansal, Sanjay Asthana

Abstract :

A catalytic kinetic–spectrophotometric method for the determination of copper (ll) concentration as low as 250 ng/ ml, based on its catalytic effect on oxidation of citric acid by alkaline hexacyanoferrate (lll) is developed. The reaction has been followed by measuring the decrease in absorbance at 420nm (max of Fe (CN)6)3– =1020 dm3 mol–1 cm–1). A �Fixed–time–procedure� is used to obtain a linear caliation curve between the initial rate and the log of catalyst concentration (log [Cu 2+]) in the range 4x 10–3M–4x10–6M. The Maximum percentage error is 5% for the lowest concentration limit. The effect of presence of some cations commonly associated with Cu2+ and some anions has also been discussed. The method is sensitive, accurate, rapid and inexpensive compared to other techniques available for such low concentrations.