微波消解-电感耦合等离子体质谱法同时测定一次性纸杯中7种重金属元素的残留量

建立了同时测定一次性纸杯中Pb、Cr、Ni、As、Sb、Cd和Ba7种重金属元素的微波消解仪-电感耦合等离子体质谱仪法。样品以硝酸和双氧水为消解液,通过微波消解仪消解样品,采用动能歧视消除模式(kinetic energy discrimination,KED)和在线引入内标溶液进行检测。检测信号(CPS)与7种重金属元素含量之间呈现良好的线性关系,相关系数R~2均0.9997,样品回收率在85.0%~112.2%之间,相对标准偏差(RSD)小于6.46%。利用该方法分析了国家标准物质GBW10045中的7种重金属元素,所得结果与标准值基本一致。该方法具有灵敏快速和定量准确的特点,适用于一次性纸杯中7种痕量重金属元素的检测分析。

Determination of Seven Heavy Metal Element Residues in Disposable Cups by Microwave Digestion-inductively Coupled Plasma Mass Spectrometry

A method for the determination of seven heavy metal element residues (lead, chromium, nickel, arsenic, antimony, cadmium, and barium) in disposable paper cups was established using microwave digestion and inductively coupled plasma mass spectrometry (ICP-MS). Samples were digested by microwave digestion with nitric acid and hydrogen peroxide as the digestion solutions, and then analyzed with the kinetic energy discrimination model (KED) and an online internal standard solution. The detection signal (counts per second, CPS) showed a good linear relationship with the content of seven heavy metal elements; the correlation coefficient R2 was>0.9997, the recovery was in the range of 85.0%~112.2%, and the relative standard deviation (RSD) was less than 6.46%. This method was used to analyze the seven heavy metal elements in the national standard material GBW10045, and the results were consistent with the standard values. The method developed in this study is sensitive, rapid, and accurate, and it is suitable for the analysis and detection of seven trace heavy metal elements in disposable paper cups.