Determination of Tyrosine and Tryptophan by Sequential Injection Analysis and Chemiluminescence Detection

Abstract

A sequential injection procedure with chemiluminescence detection was developed for the determination of tyrosine and tryptophan without chromatographic separation. Two reaction systems were included in this method; one is based on the inhibition of tyrosine and tryptophan to the chemiluminescence reaction of cerium (IV)–quinine–cysteine; the other is grounded on the enhancement of tryptophan to the chemiluminescence reaction of cerium (IV)–Tween40. The two reaction systems were integrated by two syringe pumps and a multiposition valve, and they were separated by an air column to avoid interferences. The procedure was applied to the determination of tyrosine and tryptophan in an amino acid injection, beer, milk, and soybean milk.

Keywords:

• Chemiluminescence
• Sequential injection
• Tryptophan
• Tyrosine

Acknowledgments

This work was supported by the National Nature Science Foundation of China Project (No. 20077028).