液相色谱-氢化物发生-原子荧光光谱法测定中药样品中的4种砷形态

Determination of Four Arsenic Species in Traditional Chinese Medicine by Liquid Chromatography-Hydride Generation-Atomic Fluorescence Spectrometry

目的 建立一种液相色谱-氢化物发生-原子荧光光谱测定中药样品中4种砷形态的方法。方法 以0.15 mol/L硝酸溶液为提取溶剂,提取处理后的中药样品,全自动石墨消解仪90℃热浸提,离心,取上清,0.45μm滤膜过滤后注入液相色谱仪,梯度洗脱,4种砷形态可在360 s中内完全分离,分离后的亚砷酸根[As(Ⅲ)]、砷酸根[As(Ⅴ)]、一甲基砷(MMA)、二甲基砷(DMA)4种砷形态进入氢化物发生-原子荧光光谱仪进行检测,根据保留时间定性,峰面积定量。结果 本方法在1.0~50.0μg/L范围内线性良好,相关系数(r)均>0.999,加标回收率为96.7%~101.9%,不同浓度水平的RSD均小于3%。所检测的7种中药材样品中,砷主要以As(Ⅲ)和As(Ⅴ)形态存在。结论 本方法前处理简便、检测速度快、检出限低、准确度和精密度较高,可用于中药材样品中4种砷形态的测定。

Objective To develop a method for the determination of four arsenic species in traditional Chinese medicine(TCM)by liquid chromatography-hydride generation-atomic fluorescence spectrometry.Methods 0.15 mol/L nitric acid solution was used as the extraction solvent to extract the processed TCM samples.After hot extraction at 90℃by using automatic graphite digestion and centrifugation,the supernatant was filtered through 0.45μm filter membrane and then injected into the liquid chromatograph for gradient elution.The four arsenic species can be completely separated within 360 s,and then As(III),As(V),MMA and DMA levels were detected by hydride generation-atomic fluorescence spectrometry.Finally,retention time and peak area were used for qualitative and quantitative determination,respectively.Results The linear relationship of the method was good in the range of 1.0-50.0μg/L with the correlation coefficient greater than 0.999.The recoveries were 96.7%-101.9%,with RSDs less than 3%at different concentration levels.As(III)and As(V)were the main arsenic forms in the seven kinds of TCM samples tested.Conclusion This method has the advantages of simple pretreatment,fast detection speed,low detection limit,high accuracy and precision,and can be used for the determination of four arsenic species in TCM samples.