石墨炉原子吸收光谱法测定中药虎杖中的镉

Determination of Cadmium in Polygonum cus pidatum Sieb.et Zucc.by GFAAS

采用石墨炉原子吸收光谱法(GFAAS)测定了中药虎杖中镉的含量,对基体改进剂NH_4H_2PO_4的用量、灰化温度、原子化温度等实验参数进行了优化。实验结果表明,加入NH_4H_2PO_4不仅能提高测定的灵敏度,还能有效消除共存离子的干扰,在选定的实验条件下,分析测定了中药虎杖中镉的含量,回收率为96.5%—102.2%,检出限为0.072μg·mL^(-1),线性范围为0—0.2ng/mL。

The content of cadmium in traditional Chinese medicine Polygonum cuspidatum Sieb. et Zucc. was determinated by graphite furnace atomic absorption spectrometry （GFAAS）. The experimental conditions such as amount of matrix modifier NH4H2PO4, ashing temperature and atomization temperature were optimized. The results showed that the addition of matrix modifier NH4H2PO4 can not only improve the sensitivity of determination, but also eliminate the interferences of foreign ions. Under the optimum conditions, cadmium in Polygonum cuspidatum Sieb. et Zucc. was determined,and the recovery is 96.5 %-102.2%, the detection limit is 0. 072μg/mL, the linear range was 0-0.2ng/mL.