Continuous-flow chemiluminometric determination of tetracyclines in pharmaceutical preparations and honey by oxidation with N-bromosuccinimide

Abstract

A continuous flow chemiluminometric method for determining 0.050–3.00 µg cm^–3 of tetracycline, 0.50–5.00 µg cm^–3 of oxytetracycline, 0.50–7.00 µg cm^–3 of doxycycline and chlorotetracycline and 0.30–3.00 µg cm^–3 of demeclocycline in pharmaceutical preparations and honey is described. The method is based on the chemiluminescence produced by the action of N-bromosuccinimide on tetracyclines in alkaline solution. The emission intensity is greatly enhanced by the presence of ammonia. The procedure is automated and solutions can be analysed at a rate of 130 h^–1 with a relative error of about 2%. During evaluation of possible interferences of the method, recoveries from solutions with common excipients and other concomitant compounds were in the ranges 97.8–104.0 and 96.6–109.4%, respectively. Recoveries of various tetracyclines from commercial formulations and honey samples were in the ranges 95.2–103.7 and 89.2–106.6%, respectively. The results obtained for the assay of commercial pharmaceutical preparations compared well with those obtained by an official method and demonstrated accuracy and precision (⩽5%).