A Novel Method for the Determination of Streptomycin Using Sodium Nitroprusside as a Chromogenic Reagent by Spectrophotometry

A rapid and simple spectrophotometric method for the determination of streptomycin has been developed and validated. The method was based on the reaction of streptomycin with sodium nitroprusside in the alkaline medium forming a red product measured at the maximum absorption of 495 nm. The stoichiometric ratio of the product is 1:1. Beer's law is obeyed in a range of 1.87 µg mL−1 ∼ 279.8 µg mL−1 of streptomycin and ∊495 is 6.0 × 103 L·mol−1 cm−1.Under the optimum condition, the equation of linear regression is A = 0.00742 + 0.05683 C (× 105 mol·L−1), with a linear correlation coefficient of 0.9990. The detection limit (3σ/k) is 0.96 µg mL−1, the relative standard deviation (RSD) is 2.40%, and the average recovery rate is 98.3%–102.7%. Every parameter has been optimized, and the reaction mechanism has been studied. The proposed method has been successfully applied to the determination of streptomycin for injections and tablets of pharmaceutical preparation. Analytical results obtained by this new method were very gratifying.