N-丙基-N′-(氨基对苯磺酸钠)硫脲与金显色反应的研究与应用

Research on color reaction between N-Propyl-N′-(sodium p-aminobenzenesulfonate) thiourea and Au(Ⅲ) and its application

研究了N -丙基-N′- (氨基对苯磺酸钠)硫脲(PSAT)与金的显色反应,结果发现,在pH5 .0～6 .0的HAc -NaAc缓冲体系中,溴化十六烷基三甲基铵(CTMAB)存在条件下,Au(Ⅲ)和显色剂形成1∶3的黄色水溶性络合物。该络合物最大吸收波长为313.0nm ,摩尔吸光系数为4 .6 0×10 4 L/ (mol·cm) ,Au(Ⅲ)的质量浓度在0～6 0 μg/ 2 5ml范围内符合比尔定律,相关系数r =0 .9989。该方法应用于矿石中金的测定,结果令人满意。

The color reaction between N-Propyl-N′- (sodium p-aminobenzenesulfonate) thiourea (PSAT) and Au(Ⅲ) is studied.The result shows that a yellow water-soluble complex is formed in HAc-NaAc buffer solution (the pH value of the solution is 5.4～6.0 and the CTMAB exists in the solution).The maximum absorptive wave length is 313.0 nm and the molar absorption coefficient is 4.60×10 4L/(mol·cm).The proportion of Au: PSAT is 1∶3.Beer′s law is obeyed when the mass concentration of Au(Ⅲ) is in the range of 0～60μg/25ml with the correlation coefficient is 0.998 9.This method has been applied to the determination of Au(Ⅲ) in gold samples with satisfactory results.