硫醇甲基锡因其卓越的稳定性、 良好的透明性、 优异的兼容性和耐候性, 目前是聚氯乙烯(PVC)加工过程中效果最好、 使用最广泛的一类热稳定剂, 其中硫和锡的含量是影响其质量和性能非常重要的指标, 因此发展同时测定硫和锡的分析方法具有十分重要的意义。 电感耦合等离子体原子发射光谱法(ICP-OES)因其检出限低, 线性范围宽, 干扰小, 可多元素同时分析, 样品通量高, 已被广泛用于复杂样品的分析。 微波消解做样品前处理可大幅缩短消化时间, 且样品和试剂的使用量少, 相对于传统的敞开消解法, 还可减少挥发性元素的损失。 我们建立了一种微波辅助酸消解-ICP-OES同时测定硫醇甲基锡中的硫和锡的新方法, 该方法简单、 快速、 准确、 绿色、 样品用量少。 采用DX-181样品, 通过与化学分析方法的测试结果相比较, 优化了微波辅助酸消解体系和消解时间。 在消解体系为HNO3-HCl-HClO4(v/v/v=9∶3∶1), 消解时间为10 min的优化条件下, 分别用标准加入法和标准曲线法测定了DX-181样品中硫和锡的含量, 测定结果无显著性差异, 与化学方法测定参考值的相对偏差均小于2%。 最后选择标准曲线法测定了元素含量分别为高、 中、 低的三个样品(DX-181, DX-990, DX-960), 相对偏差小于3%, 加标回收率在99%～102%之间, 结果令人满意。

Methyltin mercaptide is widely used as one of the best heat stabilizer in the polyvinylchloride (PVC) thermal processing due to its excellent stability, good transparency, high compatibility and weather resistance. The content of sulfur and tin significantly affects its quality and performance, so it is of great significance to develop an analytical method for the simultaneous determination of sulfur and tin. Inductively coupled plasma atomic emission spectrometry (ICP-OES) has been a powerful analytical tool for a myriad of complex samples owing to its advantages of the low detection limits, rapid and precise determinations over wide dynamic ranges, freedom from chemical inter-element interferences, the high sample throughput and above all, simultaneous multi-elements analysis. Microwave technique as a well-developed method for sample preparation can dramatically reduce the digestion time and the loss of volatile elements compared with the traditional open digestion. Hereby, a microwave-assisted acid digestion (MW-AAD) procedure followed by inductively coupled plasma optical emission spectroscopy (ICP-OES) analysis was developed for the simultaneous determination of Sn and S in methyltin mercaptide. This method has the advantages of simplicity, rapidness, good accuracy, green and less use of samples. Parameters affecting the MW-AAD such as the digestion solution and digestion time were optimized by using a chemical analyzed reference sample (DX-181) to attain tin and sulfur quantitative recoveries. HNO3-HCl-HClO4 (v/v/v=9∶3∶1) and 10 min were the optimum digestion solution and digestion time, respectively. Under optimum conditions, the standard addition method and the standard calibration curve method were both been used to detect Sn and S in DX-181. There was no significant difference between two methods and the relative deviations to the chemical analysis values were both less than 2%. Additionally, the accuracy of the MW-AAD method was examined by analyzing three methyltin mercaptide samples (DX-181, DX-990, DX-960). The results were satisfactory with the relative deviations (<3%) and the recoveries of standard addition (99%～102%).