电感耦合等离子体-原子发射光谱法测定滇龙胆中的镉和铅

Study on the Determination of Cd and Pb in Gentiana Rigescens Franch. by ICP-AES

利用电感耦合等离子体-原子发射光谱法(ICP-AES)测定滇龙胆中重金属元素Cd和Pb,比较了干灰化法和湿化法2种样品处理方法对分析结果的影响,并测定了云南一些地区滇龙胆中的Cd和Pb含量。结果表明:采用电感耦合等离子体原子发射光谱法检测滇龙胆中的Cd和Pb,最低检出限(DL)分别为1.43ng·mL-1和1.16ng·mL-1;相对标准偏差(RSD)分别为4.37%和4.05%;回收率分别为96.25%和92.25%。利用湿法消解样品,精密度好,回收率高,优于干灰化法。干灰化法适合测定滇龙胆中Pb,但不适合测定Cd,其回收率仅为0.2%。用湿法消解样品,测定不同产地滇龙胆的Cd和Pb含量,结果表明:所测地区滇龙胆的Cd,Pb含量大大低于《中华人民共和国药典》(2005)规定的中药材重金属含量标准,符合GAP生产的要求。

A method was developed for the determination of Cd and Pb by ICP-AES.The sample was treated with wet digestion and dry ash method,and the two methods were compared.The contents of Cd and Pb in Gentiana rigescens Franch.grown in some areas of Yunnan were determined.The results showed that it is satisfactory to apply ICP-AES to the determination of Cd and Pb with the detection limits（DL）of 1.43ng·mL^-1and 1.16ng·mL^-1,the precision values（RSD）of 4.37% and 4.05%,and the recoveries of 96.25% and 92.25% respectively.The wet digestion method is better than the dry ash method for its lower RSD and higher recoveries.The dry ash method is suitable for the determination of Pb,but not suitable for the determination of Cd due to its low recoveries.The results also show that the contents of Cd and Pb in Gentiana rigescens Franch.are lower than the standard of ＂Chinese Pharmacopoeia（2005）＂,and the method meets the standard of GAP production.