微波消解-双道原子荧光法测定天麻等5种药材中的硒和锗

目的：用氢化物发生-原子荧光光谱法同时测定天麻、首乌、当归、沙参、黄连5种中药材中的硒和锗。方法：样品经硝酸-过氧化氢微波消解后，在磷酸介质中，以硫脲为预还原剂，采用双道原子荧光法进行中药材中硒和锗的测定。结果：在选定的最佳条件下，仪器对硒与锗的检出限分别为0.25 ng·mL^-1和1.46 ng·mL^-1，RSD分别为1.9%和2.9%，回收率分别为91.7%~97.2%和89.5~95.7%，RSD均小于5%。线性范围均为0~300 ng·mL^-1。干扰离子Cr³⁺、Cu²⁺、Zn²⁺、Co²⁺对硒的影响最大，Pb²⁺、Ni²⁺对锗的干扰最大，因待测液中浓度并未达到干扰硒锗测定的程度，故不予考虑。结论：5种药材中硒的含量范围为533.1~1773 ng·g^-1，其 顺序为野生天麻>黄连>首乌>当归>沙参，沙参最低；锗的含量范围是253.9~842.5 ng·g^-1，其顺序为野生天麻>沙参>当归>首乌>黄连，黄连最低。野生天麻样品中两元素的含量均高于其他栽培样品。

Objective: To simultaneously determine selenium and germanium in Gastrodiae Rhizoma,Polygoni Multiflori Radix,Angelicae Sinensis Radix,Adenophorae Radix and Coptidis Rhizoma by hydride generation-atomic fluorescence spectrometry. Methods: After samples were digested by nitric acid and hydrogen peroxide,selenium and germanium in five Chinese herbs were simultaneously determined in 5% H₃PO₄ by dual channel-atomic fluorescence spectrometry with thiourea as pre-reductant. Results: Under optimal conditions,the detection limits of selenium and germanium were 0.25 ng·mL^-1 and 1.46 ng·mL^-1;RSDs were 1.9% and 2.9%,respectively.The recoveries of Se and Ge were 91.7%-97.2% and 89.5%-95.7%,respectively,with RSD less than 5%.The interferences from Cr³⁺,Cu²⁺,Pb²⁺,Ni²⁺,Zn²⁺,Co²⁺ were investigated in detail.It showed that Cr³⁺,Cu²⁺,Zn²⁺ and Co²⁺ had serious influence on Se and Pb²⁺,Ni²⁺ affected Ge determination.Because the concentrations of the six selected ions did not reach the interference level,the influences of whidn can be ignored in this study. Conclusion: It was found that the contents of Se in the five samples were in the range of 533.1-1773 ng·g^-1,in the order of wild Gastrodiae Rhizoma> Coptidis Rhizoma> Polygoni Multiflori Radix> Angelicae Sinensis Radix> Adenophorae Radix and the Ge range was 253.9-842.5 ng·g^-1,following the order of wide Gastrodiae Rhizoma> Adenophorae Radix> Angelicae Sinensis Radix> Polygoni Multiflori Radix> Coptidis Rhizoma.The contents of both elements were higher in wild Gastrodiae Rhizoma than in the cultivated samples.