A high sensitive colorimetric assay for the determination of dopamine hydrochloride in pharmaceutical preparations Using charge transfer complex reaction

Abstract

A simple , rapid and sensitive spectrophotometric method for the determination
of trace amounts of dopamine hydrochloride in aqueous solution is described. The
method is based on a reaction between dopamine hydrochloride with the mixture of
Fe+3 and hexacynoferrate(III) ions to form an intense Prussian blue color complex that
has a maximum absorption at 710nm with a molar absorptivity of 2.138x104l.mole-1.
cm-1 and a sandell sensitivity of 8.862x10-6μg.cm-2. Under optimum reaction
conditions the absorbance of the Prussian blue color complex were found to increase
linearly with increase in concentration of dopamine hydrochloride in the range (0.4-
12ppm) with a relative standard deviation of 0.138-0.350% and a relative error of -
1.983 to 2.9%. The proposed method was successfully applied for the determination
of the selected drug in pharmaceutical preparations with very good recoveries of
98.02- 103.02%.