不同消解方式对电感耦合等离子体质谱法测定 水产品中无机元素的影响

目的为研究不同消解方法对水产品中重金属元素测定的影响,找到最佳的前处理方法。分别采用高压消解罐消解、微波消解和湿法消解3种方法对紫菜(GBW10023)、扇贝(GBW10024)、大虾(GBW10050)等成分分析标准物质进行前处理。方法在电感耦合等离子体质谱(ICP-MS)优化条件下,测定3种标准物质3种消解方法的9种元素(Pb、Cd、Cr、As、Sn、Ni、Cu、Mn、Sr)含量,与标准参考值做对比,并测定各元素的回收率。结果 3种消解方法的测定结果基本在参考范围内,消解效果均较为理想,而微波消解法消解最彻底且消解液澄清,所受环境干扰最小,测定值更接近参考值,回收率也基本在90%~105%之间,较为理想;紫菜标物的湿法消解和高压消解罐消解法中均有剩余残渣;且湿法消解的回收率结果较不理想;9种元素标准曲线的线性关系较好,相关系数均大于0.999,仪器灵敏度、精准度较高。结论综合比较认为,微波消解法更适合扇贝、大虾、紫菜等水产品中无机元素测定的前处理要求。

Effect of different digestion methods on the determination of inorganic elements in aquatic products by inductively coupled plasma mass spectrometry

Objective To investigate the effects of 3 kinds of digestion methods (high pressure closed-vessel digestion, microwave digestion and platen heating digestion) on analysis of inorganic element in the national standard reference material laver (GBW10023), scallop (GBW10024) and prawn (GBW10050). Method Three kinds of national standard reference material mentioned above were digested respectively with 3 methods and were analyzed for 9 types of elements (Pb, Cd, Cr, As, Sn, Ni, Cu, Mn, and Sr) by inductively coupled plasma mass spectrometry (ICP-MS) under its optimized model. The result was compared with the reference value and the recovery of each element measured. Results The results suggested that the testing value of 3 methods brought into correspondence with standard value in certified reference material. Basically, anyone of 3 digestion methods was valid, but the microwave digestion was the most complete method and its digestion solution was most clarified, and it suffered minimal environmental interference, the measured value is closer to the reference value. The recovery is also substantially between 90%~105%, which was preferable. The laver standard material had the remaining residue both in the other 2 digestion methods. Correlative coefficient of the calibration curves was over 0.999 by using ICP-MS determination of 9 types of elements. The sensitivity and accuracy of ICP-MS were satisfied. Conclusion The method of microwave digestion was first recommended to digest the aquatic product such as scallop, prawn, laver and so on.