采用微波消解-电感耦合等离子体质谱法(ICP-MS)测定聚碳酸酯塑料中锑含量。考察了消解介质、消解样品量的选择对消解结果的影响,优化选择了电感藕合等离子体-质谱法(ICP-MS)的测定参数。在选定的最佳消解和测定条件下,称取0.200 0g聚碳酸酯塑料样品于5mL HNO3试剂下消解,实验相对标准偏差RSD为3.68%,对实验样品添加5.00ng/mL标准进行加标回收实验,加标回收率在95.1%~110.9%之间,检出限为0.022ng/mL。该方法具有准确、简便、快速等优点,可以满足聚碳酸酯触塑料材料中锑的检测要求。通过建立不确定性评定数学模型,分析了影响不确定度的主要来源,对样品质量、体积定容、仪器测量重复性、标准储备液、曲线拟合等影响不确定度的分量进行分析,最后计算出合成标准不确定度和扩展不确定度。ICP-MS法测试塑料中锑含量可以表示为(0.568±0.057)mg/kg,可使实验结果更具客观性和准确性。

A method was studied for the determination of Sb in polycarbonate plastic materials by adopting inductively coupled plasma mass(ICP-MS).The sample was decomposed by microwave digestion.The effects of digestion system,digestion weight on digestion results were investigated.The working conditions for ICP-MS determination were optimized.Under the optimum condition of digestion and determination,That is to take 0.200 0g polycarbonate plastic sample at 5mL HNO3 digestion reagents,and the relative standard deviation(RSD)was 3.68%,Adding to the standard experimental sample 5.00ng/mL to calculation recovery,the recovery was 95.1%~110.9%,and the detection limit was 0.022ng/mL.The method presented was characterized with accuracy,simplicity and rapidness.This method is fully able to meet the testing requirements of Antimony content of the food contact materials.A mathematic model was established,the sources of uncertainty in the process of determination of Sb,including sample weight,volume,reappearance for the experiment process,standard solution,standard curve,finished up with the combined standard uncertainty and the expanding uncertainty.The antimony content in plastics measured by ICP-MS was(0.568±0.057)mg/kg,which makes the expression of result more objective and true.