A novel method for the spectrophotometric determination of cefradine by using sodium nitroprusside as chromogenic reagent

Abstract

A novel method is developed for the determination of cefradine by using sodium nitroprusside as chromogenic reagent. The experiment indicates that a russety product is formed by the reaction of cefradine with sodium nitroprusside in basic solution, and the maximum absorption wavelength ( λ max) of russety product is 505 nm. And the sensitization of tetradecyl benzyl dimethyl ammonium chloride for the reaction of cefradine with sodium nitroprusside is remarkable. The apparent molar absorption coefficient ( ɛ 505) is 2.81 × 10 3 L/mol cm. The linear equation is A = 0.0657 + 0.00804 C (μg/mL) in the range of 1.50–55.0 μg/mL of cefradine with a correlation coefficient r = 0.9992, and the detection limit is 1.38 μg/mL. This method has been applied to determine cefradine in capsule and tablet samples.