微波消解-原子吸收光谱法测定9种中药材中重金属含量

Determination of five heavy metals in nine Chinese medicines by atomic absorption spectrometry coupled with microwave digestion

目的:建立原子吸收光谱法测定三七、葛根、虎杖、丹参、川芎、当归、黄连、大黄、苦参9种中药材中镉、铬、铅、砷和汞的含量。方法:采用微波消解,以硝酸镁、硝酸钯及硝酸钯+硝酸镁作为基体改进剂配合石墨炉原子吸收光谱法测定9种中药材中镉、铬、铅、砷含量,冷原子吸收光谱法测定其中的汞含量。结果:方法线性关系良好,相关系数r>0.999;精密度试验RSD(n=5)为0.01%～3.9%;平均回收率为80.2%～112.0%。结论:该法快速、干扰少、精密度高,能满足中药材中重金属含量的测定。

Objective：To develop atomic absorption spectrometry（AAS） method for determination of cadmium（Cd）,chromium（Cr）,lead（Pb）,arsenic（As）,and mercury（Hg） in nine Chinese medicines（Radix et Rhizoma Notoginseng,Radix et Rhizome Salviae Miltiorrhizae,Rhizoma et Radix Polygoni Cuspidate,Radix Puerariae Lobatae,Rhizoma Chuanxiong,Radix Angelicae Sinensis,Rhizoma Copidis,Radix Rhizome Rhei and Radix Sophorae Flavescentis）.Methods：After microwave digestion,sample diluted by matrix modifiers／[Mg（NO3）2,Pd（NO3）2,Pd（NO3）2＋Mg（NO3）2／] respectively,Cd,Cr,Pb,and As were directly determined by graphite furnace atomic absorption spectrometry（GF-AAS）,and Hg were directly determined by cold vapor atomic adsorption spectrometry（CV-AAS）.Results：All calibration curves showed good linearity（r0.999） within test ranges.The precision（RSD） of the analytical method obtained from five replicate determinations of an authentic sample were 0.01%-3.9%.The accuracy was verified against a GBW 07604 poplar leaves certified reference material and the recoveries were from 80.2% to 112.0%.Conclusion：This method is rapidity,anti-interference and sensitivity.It can be used for quality control of heavy metals in Chinese medicines.