Batch and Flow Injection Spectrophotometric Methods for the Determination of Clonazepam in Pharmaceutical Preparations via Oxidative Coupling with Pyrocatechol

A simple, fast, and sensitive batch and flow injection spectrophotometric methods have been developed for the determination of clonazepam(CZP) in pure form and in pharmaceutical preparations. The proposed methods are based on the oxidative coupling reaction of the reduced clonazepam using Zn powders and conc. HCl with payrocatechol and in the presence of ferric sulphate. The resulting reddish colored product had a maximum absorbance at 515 nm. The optimum reaction conditions and other analytical parameters have been evaluated . The linear ranges for the batch and FI methods determination of CZP were 0.5-32, 50-400 μg mL^-1 and the detection limits were 0.193, 22.60 μg mL^-1 for both methods respectively. Statistical analysis of the results and comparison with results by the British Pharmacopoeia method are also reported.