[Studies of complexing action mechanism in the indirect determination of arginine by FAAS with ZnS].

Each state of arginine and zinc ion in aqueous solution under different pH conditions was calculated by computer, giving out the scattergram. After the investigation, the mechanism of complexing action in indirectly determining arginine by flame atomic absorption spectrometry with ZnS was studied in terms of the influence of solution pH. It is with different state of arginine and zinc ion in aqueous solution in differential pH that the response peak with pH in given conditions is obtained. The reason for forming the left peak is different from the reason for forming the right peak. The soluble complexing ion is composed of + 1 valence arginine Arg+ + - and Zn(OH)2. The theoretical analysis from computing and scattergram dovetails very well the data determined from the experiments. The structure of complexing ion is [HN[double bond]CH(NH3+ )--NH--(CH2)3--CH(NH3+)--COO]2Zn(OH)2.