微波消解-石墨炉原子吸收法测定酵母粉中的微量铅和镉

Determination of Microamounts of Lead and Cadmium in Yeast by Graphite Furnace Atomic Absorption Spectrometry after Microwave-digestion

本文采用微波消解-石墨炉原子吸收法直接测定酵母粉中微量铅和镉的含量。利用硝酸和过氧化氢消解样品，对微波消解的条件，基体改进剂的选择，铅原子化温度的效果以及常见元素对测定的干扰进行了研究。在优化的实验条件下，方法对铅和镉的检出限（3a）分别为0．062ng／mL和0．013ng／mL，相对标准偏差（RSD）分别为0．64％～1．11％、0．75％～4．70％，加标回收率在95．00％～102．0％之间。本法已用于酵母粉中微量铅和镉的测定，分析结果与电感耦合等离子体-质谱（ICPMS）法具有良好的一致性。

The microamounts of lead and absorption spectrometry after microwave cadmium in yeast were determined by graphite furnace atomic digestion. The sample were digested more effectively by HNO3 and H2O2 in a closed-vessel. The effects of microwave digestion, matrix modifier, ashing temperature,atomization temperature, and common coexisting components on the determination of lead and cadmium were studied. Under the optimized operating conditions, the detection limits of the method for Pb and Cd were 0. 062 ng/mL and 0. 013 ng/mL, the relative standard deviations （RSDs） were 0. 64%-1.11% for Pb, 0. 75%-4. 70% for Cd, and the recoveries of for the spiked samples were between 95.00% to 102.0%, respectively. The proposed method has been applied to the determination of Pb and Cd in yeast samples and the results obtained by the proposed method agreed with those provided by ICP-MS.