KINETIC SPECTROPHOTOMETRIC METHOD FOR THE QUANTITATIVE ANALYSIS OF STREPTOMYCIN SULFATE

摘要

Kinetic method has been developed for the quantitative analysis of streptomycin. The method is based on the oxidation of the drug with the mixture of potassium iodide and potassium iodate to form a yellow colored product. Two methods are adopted for the determination process, the initial rate method and fixed time, absorbance difference method. Both the method followed Beer's law in the range of 4 μg ml-1- 72 μg ml-1. The linear regression equation of initial rate and fixed time (absorbance difference) method was evaluated to be Rate (U) = -1.026 x 10-6 + 5.93 x 10-4 C and ΔA = -1.63x10-3 + 8.0x10-3C. The limit of detection of initial rate method and fixed time method was obtained to be 0.011 and 0.50, respectively while limit of quantitation upon calculation came out to be 0.032 and 1.5 for initial rate and fixed time absorbance difference methods, respectively. Another important study in the proposed method is the activation parameter study which was done at four different temperatures i.e 298 K, 303 K, 308 K and 313 K. Using the elevated temperature various activation parameters such as change in enthalpy (Ä H), change in entropy (Δ S) and Gibbs free energy (Δ G) was calculated and obtained to be -34.41 kJ mol-1, -143.16 and -77.0 5 9 x 103 kJ, respectively Probable mechanism of the reaction has been mentioned in the text.