Zn(Ⅱ)-TPPS_4-CTAB显色反应及三波长吸光光度法测定痕量锌的研究

Studies of the Color System of Zn( Ⅱ)-TPPS4-CTAB and the Determination of Trace Zinc with Triwave- length Spectrophotometry

本文报道以TPPS_4为显色剂、Hg(Ⅱ)为催化剂、CTAB为辅助配合剂,Zn(Ⅱ)在室温下极易形成Zn(Ⅱ)-TPPS_4-CTAB三元配合物。以三峰三波长胶束吸光光度法测定痕量锌,具有极高的灵敏度,ε=8.5×10~5 L·mol^(-1)·cm^(-1)。应用本法测定了部分人发、水样、矿石、铝合金等试样中的痕量锌,获得了满意的结果。

Zinc(Ⅱ) reacts quickly with tetrakis- (4-sulphophenyl) porphyrin (TPPS4) and cethyltrimethylammonium bromide (CTAB) in the presence of mercury(Ⅱ) at room temperature. The complexes Zn( n)-TPPS4-CTAB, Hg( Ⅱ )-TPPS4-GTAB and the reagent show maximum absorption wavelengths at 427 nm, 447 nm and 417 nm, respectively. A new method for the determination of trace zinc with triwavelength spectrophotometry is described and the molar absorptivity is 8.5 ×10s L.mol- 1 cm- 1. After the ion-exchange separation, this method is of high selectivity and has been successfully applied to the determination of zinc in aluminium alloys, ores, natural water and human hair.