RESONANCE RAYLEIGH SCATTERING STUDY OF STREPTOMYCIN - CONGO RED IONIC ASSOCIATION IN VIEW OF ANALYTICAL APPLICATION
MARINELA FLOREA*1, CRINA-MARIA MONCIU1, MIHAELA ILIE2
University of Medicine and Pharmacy „Carol Davila”, Faculty of Pharmacy, 6 Traian Vuia Str., postal code 020956, Bucharest, Romania
1Department of Analytical Chemistry
2Department of Toxicology
* corresponding author: florea.marinela@gmail.com
Download Full Article

Abstract:

Streptomycin (STR) and Congo red (CR) react in weak acidic medium to give an ionic association complex which was studied by resonance Rayleigh scattering (RRS) and UV-VIS absorption. The combinative sites were defined by calculating the charge distribution on the STR and CR molecules in the ground state using Austin Model 1 quantum chemistry method. The maximum intensity of RRS signal (384 nm) was obtained at pH 5.5 created with Britton-Robinson buffer at a 2·10-8M Congo red concentration; the reaction time was of 30 minutes. The ratio of the reagents (1:1) was determined using Job’s method. The linear relationship between the RRS intensity and the antibiotic concentration was found within the concentration range 6.49 – 9.74 μg·mL-1. The method was successfully applied for the determination of streptomycin in pharmaceutical formulations.

Top