微波消解-双道原子荧光法同时测定中药材中的硒和碲

目的：建立一种以微波消解-双道原子荧光法同时测定中药材中的硒、碲的方法。 方法：采用微波消解处理样品，于盐酸介质中，以硫脲为预还原剂，硼氢化钾为还原剂，对中药材进行测定，并详细考察了仪器的最佳测试条件；研究了消解液中HNO₃和H₂O₂的最佳使用比例；探讨了共存离子及残余消解液对硒、碲测定的干扰和消除方法。 结果：不同地区的5种中药材中硒、碲的含量范围分别为598.9~2414 ng·g^-1及459.6~2576 ng·g^-1，其中天麻中硒、碲含量均远高于其他中药材。硒、碲的回收率在94.1%~104.3%之间，仪器检出限DL_Se=0.122 μg·L^-1，DL_Te=0.192 μg·L^-1。 结论：该方法同时测定中药材中的硒、碲，具有快速、准确、成本低的特点。

Objective: To develop a method for the simultaneous determination of the trace amounts of selenium and tellurium in Chinese herbal medicines by microwave digestion hydride generation-atomic fluorescence spectrometry. Methods: In hydrochloric acid medium,with thiourea as the pre-reducing agent,and potassium borohydride as the reducing agent,Chinese herbal medicines were measured by double channel atomic fluorescence spectrometry after microwave digestion.Optimal instrumental and analytical conditions for determination were investigated in detail;optimal proportion of HNO₃ and H₂O₂ in the digestion solution was studied;the interference of coexisting ions and residual digestion solution on determination of selenium and tellurium,and the methods of elimination were discussed. Results: The contents of Se and Te in the five herbal medicines from different regions ranged from 598.9 to 2414 ng·g^-1 and 459.6 to 2576 ng·g^-1,respectively.The contents of selenium and tellurium in the Gastrodia were higher than those in other herbs.The recoveries of Se and Te were 94.1%-104.3%.The detection limits of selenium and tellurium were 0.122 μg·L^-1 and 0.192 μg·L^-1,respectively. Conclusion :This determination method of selenium and tellurium in Chinese herbal medicine is rapid,accurate and of low cost.