SPECTROPHOTOMETRIC DETERMINATION OF

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SPECTROPHOTOMETRIC DETERMINATION OF OFLOXACIN .... 20–160. Less sensitive, signifi- cant blank absorbance. [38]. 6. Iron(III) alum/H2SO4.

Т. 78, № 3 V. 78, N 3

ЖУРНАЛ ПРИКЛАДНОЙ СПЕКТРОСКОПИИ JOURNAL OF APPLIED SPECTROSCOPY

МАЙ — ИЮНЬ 2011 MAY — JUNE

2011

SPECTROPHOTOMETRIC DETERMINATION OF OFLOXACIN IN PHARMACEUTICALS BY REDOX REACTION P. J. Ramesh, K. Basavaiah *, N. Rajendraprasad, O. Zenita Devi, K. B. Vinay University of Mysore, Department of Chemistry, Manasagangothri, Mysore-570 006, Karnataka, India; e-mail: [email protected]

Two simple spectrophotometric methods have been developed to analyze ofloxacin (OFX) in pharmaceuticals. The methods are based on the oxidation of OFX by a measured excess of cerium(IV) sulphate in an H2SO4 medium. This was followed by the determination of the unreacted oxidant by reacting it with either p-toluidine (p-TD) and measuring the absorbance at 525 nm (method A) or odianisidine (o-DA) and measuring the absorbance at 470 nm (method B). In both methods, the amount of cerium(IV) sulphate reacted corresponds to the amount of OFX. Calibration graphs were linear over the ranges of 0–120 and 0–4 µg/ml OFX for the methods A and B, respectively. The calculated molar absorptivity (2.34  103 and 5.99  104), Sandell sensitivity, and limit of quantification for the methods are reported. The intra-day precision (%RSD) and accuracy (%RE) were