微乳液介质-5-Br-PADAP分光光度法测定铝合金中锌

Microemulsion medium-spectrophotometric determination of zinc in aluminium alloy with 5-Br-PADAP

研究了以水的体积分数为80%的油-水型(十二烷基硫酸钠-正丁醇-正庚烷-水)微乳液为介质,5 Br PADAP为显色剂,分光光度法测定铝合金中锌。在弱碱性介质中,5 Br PADAP与Zn(Ⅱ)形成络合物的最大吸收峰位于555nm,其表观摩尔吸光系数ε555=1 24×105,在10mL溶液中,锌质量在0～10μg范围内服从比尔定律。采用三乙醇胺和硫脲作为掩蔽剂消除了铁(Ⅲ)、钴(Ⅱ)、铜(Ⅱ)、铝(Ⅲ)等干扰。人工合成样品平均回收率为99 96%,RSD为1 30%。使用该方法测定了铝合金(LD6063)和普铝中锌含量,其RSD分别为0 96%和3 17%。

In the medium of oil-80% H_2O(O/80%W) microemulsion (SDS-n-C_4H_9OH-n-C_7H_(16)-H_2O) and weak base.Zn with 5-Br-PADAP forms a complex with maximum absorption wavelength of 555 nm.The apparent molar absorption coefficient is 1.24×10~5 L·mol^(-1)·cm^(-1).Beer's law is obeyed in the range of 0-10 μg/10 mL for Zn.Interference ions Cu^(2+),Al^(3+),Fe^(3+),Co^(2+) and so on can be masked by adding triethanolamine and sulfourea solution.The mean recovery of the synthetic sample is 99.96%.The RSD is 1.30%.The method has been used for the determination of Zn in aluminium alloy(LD6063) and common aluminium.The RSD is 0.96% and 3.17% respectively.