[Determination of stability constant of zinc cysteinate by indirect determination using FAAS with ZnS].

On the bases of exploring measurement mechanism and complex compound components of indirect determination of cysteine acid by flame atomic absorption spectrometry with zinc sulfide, the stability constants of the complex compound of zinc cysteinate were studied successfully, after the numeric measurements and theoretical investigations under the best optimized acidity for the determination. In conclusion, at the best optimized acidity pH 9.7, the stability constant of alkalescence zinc cysteinate is between 2.998 x 10(30) and 3.858 x 10(30), with the average value beta w = 3.286 x 10(30) and log beta w = 30.517, and the standard deviation is 0.315 x 10(30). While the stability constant of zinc cysteinate is between 7.853 x 10(21) and 1.011 x 10(22), with the average value beta w = 8.607 x 10(21) and log beta w = 21.935, and the standard deviation is 0.315 x 10(21). It is shown that the atomic absorption spectrometry can not only be used for the determination of trace elements and the indirect determination of organic compound, but also can carry out the study of physical configuration and the determination of physical constant of complex ion.