微波消解-ICP-MS法测定白菜和酸菜中的微量元素

Determination of Trace Elements in Chinese Cabbage and Pickled Cabbage by Microwave Digestion-ICP-MS

随着对食品安全重视的加深,人们对蔬菜中微量元素含量及是否存在重金属污染也越发关注。试验采用微波消解法处理样品,电感耦合等离子体质谱(ICP-MS)法测定白菜和酸菜两种样品中的10种微量元素(As、Cd、Cr、Cu、Fe、Hg、Se、Sn、Pb、Zn)。通过试验结果的对比表明,白菜和酸菜中人体必需微量元素含量十分丰富,潜在毒性微量元素含量较低,白菜腌制成酸菜前后的各元素含量虽然发生明显变化,但污染物元素含量均符合食品安全国家标准。试验各元素标准曲线在0~500μg/L质量浓度范围内线性关系良好(r≥0.999 6),检出限为0.000 8~0.021 9mg/kg,相对标准偏差小于2.73%(n=6);加标质量分数在0.05,0.50和5.00 mg/kg 3个水平下回收率为86.8%~107.6%。该方法操作简单,灵敏度高,适合样品中多种元素的同时测定。

With the emphasis on food safety,more and more attention had been paid to the content of trace elements in vegetables and the existence of heavy metal pollution.Microwave digestion method was used to treat the samples,and inductively coupled plasma mass spectrometry(ICP-MS) was used to determine 10 trace elements(Cd,Cr,Cu,Fe,Hg,Se,Sn,Pb and Zn) in Chinese cabbage and pickled cabbage.The comparison of the test results showed that the contents of essential trace elements in Chinese cabbage and pickled cabbage were rich,while the contents of potential toxic trace elements were low.The content of elements in Chinese cabbage before and after pickled into sauerkraut changed significantly,and the content of pollutants met the national food safety standards.The linear range of the standard curve was 0-500 μg/L(r≥0.999 6);The detection limit was 0.000 8-0.021 9 mg/kg;The relative standard deviation was less than 2.73%(n=6);The recoveries were 86.8%-107.6% at the levels of 0.05,0.50 and 5.00 mg/kg.The method was simple,sensitive and suitable for simultaneous determination of multiple elements in samples.