微波酸提取/液相色谱-电感耦合等离子体质谱法测定动物源性中药中6种砷形态

摘要

建立了微波酸提取/液相色谱-电感耦合等离子体质谱联用(LC-ICP-MS)测定动物源性中药中6种砷形态(亚砷酸盐As(Ⅲ),砷酸盐As(V),一甲基砷MMA,二甲基砷DMA,砷甜菜碱AsB和砷胆碱AsC)的分析方法.采用1％ HNO3溶液在80℃微波提取10 min,经离心分层,过固相萃取SEP C18柱和0.45μm滤膜,以25 mmol/L NH4H2 PO4溶液(pH 6.7)-乙醇(99∶1,体积比)为流动相进行等度洗脱,各砷形态在10 min内实现基线分离.结果显示,6种砷形态在1.0～100.0μg/L范围内线性关系良好,相关系数为0.999 5 ～0.999 7,方法检出限(LOD)为0.24 ～ 1.0.μg/kg,相对标准偏差(RSD)为0.96％ ～ 2.0％.将方法应用于地龙、水蛭、海螵蛸、桑螵蛸、石决明和鸡内金中6种砷形态的测定,加标回收率为94.2％ ～ 103.8％,提取效率为95.5％ ～ 102.8％,优于热提取法.方法快速、准确、重现性好,适用于动物源性中药及类似样品中的砷元素形态分析及质量监控.%A method was established for the determination of six arsenic species including arsenite (As (Ⅲ)),arsenate (As (Ⅴ)),monomethylarsine (MMA),dimethyarsine (DMA),arsenobetaine(AsB) and arsenocholine (AsC),in animal derived traditional Chinese medicines by liquid chromatography coupled with inductively coupled plasma mass spectrometry(LC-ICP-MS) assisted by microwave acid extration.After microwave extraction with 1％ HNO3 solution within 10 min and centrifugation,the sample was purified with solid phase extraction SPE C1s and 0.45 μm hybrid filter membrane,and then eluted with 25 mmol/L NH4H2PO4 (pH 6.7)-ethanol(99 ∶ 1,by volume)as mobile phase by isocratic elution.The arsenic species could reach a baseline separation within 10 min.The results showed that the linear ranges for six arsenic species were in the range of 1.0-100.0 μg/L with correlative coefficients of 0.999 5-0.999 7.The limits of detection (LOD) for six anions were in the range of 0.24-1.0 μg/kg with relative standard derivations (RSD) of 0.96％-2.0％.The method was used in the determination of arsenic speeiation in six samples involved pberetima,leech,euttlebon,ootheca mantidis,shell of abalone and ventriculi galli mucosa.The spiked recoveries were between 94.2％ and 103.8％ and the extraction efficiencies were in the range of 95.5％-102.8％,which are better than those obtained by heat extraction.With the advantages of quickness,accuracy and good reproducibility,the method was suitable for the arsenic species detection and quality monitoring of animal derived traditional Chinese medicine and similar samples.