微波消解电感耦合等离子体质谱法测定蔬菜中的6种有害元素

Determination of 6 toxic elements in vegetables by microwave digestion-inductively coupled plasma mass spectrometer

目的建立电感耦合等离子体质谱(ICP-MS)测定蔬菜中铅、镉、总砷、铬、镍和总汞的方法。方法样品经微波消解后,利用ICP-MS法检测。结果 6种元素在1.0μg/L^100.0μg/L时,有良好的线性关系,相关系数(r)均≥0.999 1。LOD为0.3μg/kg^13.0μg/kg,LOQ为0.9μg/kg^39.0μg/kg。平均加标回收率为90.8%~99.3%,RSD为2.6%~10.1%。50份蔬菜样品中,6种元素均检出。根据GB 2762—2012《食品安全国家标准食品中污染物限量》,对江西省萍乡、宜春、吉安和新余4地市的50份蔬菜样品进行检测,检出4份铅超标;2份总汞超标;2份铬超标;1份镉超标。结论该方法灵敏度高,回收率高,检出限低,符合分析要求,适合蔬菜中这6种有害元素的检测要求。

Objective To establish an inductively coupled plasma mass spectrometer（ ICP- MS） method for the determination of 6 toxic elements including lead, cadmium, arsenic, chromium, nickel and mercury in vegetables. Methods The samples were digested with microwave and then detected by ICP - MS. Results When the concentration of the 6 elements was within 1.0 μg/L- 100.0 μg/L, good linearity was obtained with the correlation eoeffeetients（r） ≥0. 999 1. The LODs were within 0.3 μg/kg - 13.0 μg/kg, and the LOQs were within 0.9 μg/kg - 39.0 μg/kg. The average spiked recoveries were within 90.8% - 99.3% with the relative standard deviation（RSD） of 2.6% - 10.1%. The 6 toxic elements were detected in 50 vege- table samples. According to GB 2762-2012 Food Safety National Standard -food Pollutant Limits, 50 vegetable samples were detected in 4 cities of Jiangxi, Yichun, Pingxiang, Ji＇an and Xinyu, and detection results showed that lead in 4 vegetables was over - standard ; the total mercury in 2 vegetables was over - standard ; chromium in 2 vegetables was over - standard, and cad- mium in 1 sample was over -standard. Conclusion The method is sensitive with high recovery rate and low detection limit, which meets the requirements of analysis and can be applied for the detection of the 6 toxic elements in vegetables.