Colorimetric Determination of Aromatic and Thiol Amino Acids by Oxidation With Tris, 1-10-Phenanthroline-Iron (III) Complex

Salama B. Salama, Fakhr Eldin O. Suliman, Salma Al-Kindy and Moza Al-Jabri

Department of Chemistry, College of Science, Sultan Qaboos University, P. O. Box 36, Al-Khod(123), Sultanate of Oman.

Download this article as:

ABSTRACT:

A simple and sensitive colorimetric method for the determination of some amino acids (methionine, cysteine, tryptophan and tyrosine) is described. The method is based on the formation of ferroine from the oxidation of the amino acid with tris, 1-10 phenanthroline-Fe(III) complex and measurement of the absorbance at 512nm. the optimum conditions for each measurement (pH and time of heationg) are studied. Tyrosine and tryptophan have been successfully determined in the presence of methionine.

KEYWORDS:

Amino acids; tris; 1, 10 phenanthroline-iron (III); spectrophotometry