结合态含硫氨基酸的间接气相色谱法测定

The Determination of Bound Sulfur-Containing Amino Acids by Indirect Gas Chromatography (GC)

生物体中含硫氨基酸[蛋氨酸（Met）、甲基半胱氨酸（CysCH3）、半胱氨酸（CysH）、胱氨酸（Cys）]主要以结合态存在,参与生物体的重要生理功能与代谢。

A method for the determination of bound sulfur-containing amino acids (methionine, methyl-cysteine, cysteine and cystine ) by indirect GC has been established. The principles of this method are that the double sulfur bond of cystine is converted to methyl-cysteine by reduction and methylation, and then the methyl-cysteine reacts with CNBr to release CH3SCN, which can be determined by GC. The detection limit and the linear range of this method are 4. 0× 10-8g and 4. 0 × 10-6-3. 2× 10-7g cystine, respectively. The results of the four sulfur-containing amino acids in reduced and oxidized glutathlone, eggwhite lysozyme, selenium-yeast are given. The result for the determination of cystine in eggwhite lysozyme was 87. 8% of the theoretical value with a±4. 9% of relative standard deviation.