微波消解-ICP-MS同时测定中药海藻及其混伪品中20种重金属及微量元素

Simultaneous Determination of 20 Heavy Metals and Trace Elements in Sargassum Pallidum and Sargassum Fusiforme and Its Adulterants by Microwave Digestion-ICP-MS

关键词:  海藻  电感耦合等离子体质谱  重金属  微量元素  微波消解

Key words:  Sargassum pallidum and Sargassum fusiforme  ICP-MS  heavy metals  trace elements  microwave digestion

摘要:

目的 建立电感耦合等离子体质谱法（inductively coupled plasma mass spectrometry，ICP-MS）测定中药海藻及其混伪品中20种重金属及微量元素的方法，并对海藻中重金属及微量元素分布情况进行测定。方法 样品加入3.0 mL硝酸和1.0 mL的超纯水，按照微波消解程序消解后，采用电感耦合等离子体质谱法进行测定。载气为氩气，碰撞气为氦气，等离子体气流速为15.0 L·min^-1，载气流速1.17 L·min^-1，等离子体射频功率1.3 kw，蠕动泵转数30 r·min^-1；采用全定量分析模式。结果 测定的20种重金属及微量元素线性关系良好，各元素的检出限在0.001~1.701 μg·L^-1，回收率在78.6%~108.2%，砷是有害元素中含量较高的元素，镁、钙、铁、锌、硒含量较其他元素高。结论 该方法操作简便、准确、专属性强、重复性好、灵敏度高，内标法更能提高测定结果的准确性，能用于测定中药海藻及其混伪品中重金属及微量元素的测定。

Abstract:

OBJECTIVE To establish a method for the determination of 20 heavy metals and trace elements in Sargassum pallidum and Sargassum fusiforme and its adulterants by inductively coupled plasma mass spectrometry(ICP-MS), and to determine the distribution of heavy metals and trace elements in Sargassum pallidum and Sargassum fusiforme. METHODS The 3.0 mL nitric acid and 1.0 mL ultrapure water were added into the sample and digested to the microwave digestion procedure and then determined by ICP-MS. The carrier gas was argon, the collision gas was helium, the plasma gas flow rate was 15.0 L·min^-1, the carrier gas flow rate was 1.17 L·min^-1, the plasma radio frequency power was 1.3 kw, and the creep pump rotation number was 30 r·min^-1. Full quantitative analysis model was adopted. RESULTS The 20 heavy metals and trace elements measured had a good linear relationship. The detection limit for each element was of 0.001-1.701 μg·L^-1, with the average recovery from 78.6% to 108.2%. As was the highest content of harmful element, Mg, Ca, Fe, Zn, Sr were higher than other elements. CONCLUSION The method is simple, accurate, specialized, repeatable and sensitive, internal standard method can improve the accuracy of measurement results and can be used for the determination of heavy metals and trace elements in Sargassum pallidum and Sargassum fusiforme and its adulterants.