[Studies of complexing action mechanism in indirect determination of cysteine by FAAS with ZnS].
Each state of cysteine and zinc ion in aqueous solution at different pH conditions was calculated by computer, giving out the distribution curve. The mechanism of complexing action in indirectly determining cysteine by flame atomic absorption spectrometry with ZnS, and the influence of solution pH were studied. The state of cysteine and zinc ion in aqueous solution at different pH is different. The reason for forming the peak is the change of concentration of cysteine and zinc ion at different pH. The soluble complexing ion of -1 is composed valence cysteine Cys- and Zn(OH)2. The theoretical analysis is well conformable with the data determined from the experiments. The structure of complexing ion is [HS-CH2CH(NH2)-COO]2Zn(OH)2.
Liu
Wen-han
WH
State Key Laboratory, Breeding Base of Green Chemistry-Synthesis Technology, Zhejiang University of Technology, Hangzhou 310032, China.
Shan
Shen-yan
SY
Zhang
Dan
D
Wu
Xiao-qiong
XQ
D003545:Cysteine / Q000032:analysis* / Q000737:chemistry; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D013054:Spectrophotometry, Atomic / Q000379:methods*; D013440:Sulfides / Q000737:chemistry*; D017967:Zinc Compounds / Q000737:chemistry*
D013440:Sulfides; D017967:Zinc Compounds; D003545:Cysteine; C031238:zinc sulfide