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应用络合物极谱吸附波法测定微量金属离子,是一种灵敏度高,且简便快速的测试方法。锡的络合物极谱吸附波研究已有报道,但有关Sn(Ⅳ)-桑色素体系的极谱研究尚未见报道。我们在研究镓-桑色素体系的吸附伏安性质的基础上,试验了Sn(Ⅳ)-桑色素配合物的极谱行为,发现在0.2mol·L~(-1)的HOAc-NaOAc(pH=3.3)介质中,Sn(Ⅳ)-桑色素配合物在滴汞电极上于-0.65V(vs.SCE)电位处产生一良好配合物吸附还原波,其2.5次微分极谱图波形好,灵敏度高,其峰峰值e″pp(2.5次微分峰值)与Sn(Ⅳ)浓度在1.5×10~(～8)～7.0×10~(-7)mol·L~(-1)范围内呈良好线性关系,检出下限达2×10~(-9)mol·L~(-1),用该法对食品罐头中微量锡进行了测定,相对误差≤3.5%,回收率在94%～103%之间,结果较好。
The determination of trace metal ions by polarographic adsorption complex method is a highly sensitive and simple and rapid method for the determination of trace metal ions. Polarographic polarographic adsorption wave studies of tin have been reported, but polarographic studies on Sn (Ⅳ) -morphine have not been reported yet. We investigated the polarographic behavior of the Sn (Ⅳ) -cyanine complex on the basis of the study of the voltammetric behavior of the gallium-morin system. It was found that under the condition of 0.2mol·L -1 HOAc-NaOAc = 3.3), Sn (Ⅳ) - morin complex produced a good complex adsorption - reduced wave at the potential of -0.65V (vs.SCE) on the droplet mercury electrode. The 2.5th differential polarographic waveforms were good, The results showed that the peak e "pp (2.5 differential peak) and Sn (Ⅳ) concentrations were within the range of 1.5 × 10 ~ (-8) -7.0 × 10 ~ (-7) mol·L -1 The detection limit was up to 2 × 10 ~ (-9) mol·L -1. The method was applied to the determination of trace tin in canned food. The relative error was less than 3.5% and the recovery was 94% ~ 103%, the result is better.