Spectrophotometric determination of sodium chondroitin sulfate in eye drops after derivatization with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole

Abstract

A spectrophotometric method is described for the determination of sodium chondroitin sulfate. The method is based on the interaction of sodium chondroitin sulfate with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole to yield a violet product, 6-mercapto-3-substituted-s-triazolo-[4,3,-b]-s-tetrazine derivatives. This colour can be quantified spectrophotometrically at 543 nm. The calibration graph was linear over the range 0.1–1.0 mg ml^–1 of sodium chondroitin sulfate. The method is rapid, simple and sensitive and can be applied to the analysis of sodium chondroitin sulfate in eye drops without interference.