Determination the content of cysteine in food by potassium dichromate spectrophotometry

Abstract

In this paper, a new method for the determination of cysteine by potassium dichromate spectrophotometry is established. In the H2SO4 medium, potassium dichromate has strong oxidation. Potassium dichromate can react with the hydrosulfuryl(-SH) in cysteine, which makes potassium dichromate fade, and the fading degree of potassium dichromate is proportional to the amount of cysteine added. Therefore, the content of cysteine can be quantitatively determined by determinating the decrease value of absorbance. The various influencing factors for the determination the content of cysteine by potassium bichromate spectrophotometry are investigated. Under the optimal conditions, the content of cysteine in food is determined, and the results are satisfactory.