超声辅助分离富集-催化极谱法测定中草药中痕量镉

Polarographic determination of trace cadmium in Chinese herbs with ultrasonication assistant for separation and enrichment

针对中草药中重金属镉含量较低,不易直接测定的问题,本文提出了以巯基棉在超声辅助条件下分离富集,催化极谱法测定中草药中痕量镉的新方法.研究发现,在超声辅助下巯基棉对草药中痕量镉具有良好的吸附作用,被吸附的镉可用醋酸和磷酸分步定量洗脱,基于此建立了超声辅助巯基棉分离富集中草药中痕量镉的方法.在最佳条件下,巯基棉对镉的富集因子为8,方法检出限为0.52 ng/mL,加标回收率为97.1%ц102%,将该方法用于麦冬和鱼腥草中痕量镉的测定,结果满意.

Directly determination of cadmium in chinese herbs is very difficult due to its low con-tent. To solve this problem, a method for determination of trace cadmium in Chinese herbs by cata-lytic polarography after separation and enrichment using sulfhydryl cotton with ultrasonication assis-tant was present. It was found that sulfhydryl cotton was of good performance in adsorption of trace cadmium in herbal medicine with ultrasonication assistant;the absorbed cadmium could be quantita-tively eluted from sulfhydryl cotton using acetic acid and phosphoric acid, respectively. Based on this, a new method for catalytic determination of trace cadmium in Chinese herbs was proposed. Un-der the optimum experimental conditions, the enrichment factor was 8 after separation and enrich-ment with ultrasonication assistant and using sulfhydryl cotton. The detection limit was 0. 52 ng/mL, standard addition recovery is 97. 1% ц97. 1%. This method was used to determination of trace cad-mium in ophiopogon and cordate houttuynia with satisfactory results.