高效液相色谱-电感耦合等离子体质谱法分析食用菌中6种砷形态及其分布特征

Analysis of speciation of arsenic and distributive characteristics in edible mushrooms by HPLC-ICP-MS

建立同时测定食用菌中亚砷酸根、砷酸根、一甲基砷酸、二甲基砷酸、砷甜菜碱、砷胆碱6种砷形态化合物的高效液相色谱-电感耦合等离子体质谱分析方法。选择5 mmol/L和80 mmol/L(pH 8.0)碳酸铵溶液作为梯度洗脱的流动相,0.50 mol/L乙酸溶液作为提取剂,采用微波萃取的提取方式进行分析。6种砷形态化合物的质量浓度在0~100μg/L范围内与色谱峰面积线性关系良好,相关系数均大于0.9990,亚砷酸根、砷酸根、一甲基砷酸、二甲基砷酸、砷甜菜碱、砷胆碱的检出限分别为0.04、0.05、0.08、0.07、0.05、0.09μg/L,定量限分别为0.13、0.15、0.20、0.20、0.16、0.28μg/L。样品加标回收率为88.3%~96.3%,测定结果的相对标准偏差为4.37%~8.98%(n=6)。采用该方法研究市售食用菌中砷形态分布特征,结果表明,不同类型食用菌中砷形态分布种类和含量不同,需综合无机砷和有机砷的含量评估食用菌中砷的危害性。

A method for the simultaneous determination of six forms arsenic compounds(including arsenite,arsenate,monomethyl arsenate,dimethyl arsenate,arsenic betaine and arsenic choline)in edible fungi by high performance liquid chromatography inductively coupled plasma mass spectrometry(HPLC-ICP-MS)was established.5 mmol/L and 80 mmol/L ammonium carbonate solution with pH 8.0 was selected as the mobile phase of gradient elution,and microwave extraction with 0.50 mol/L acetic acid solution as extractant was used for analysis.The mass concentration of six arsenic speciation compounds had a good linear relationship with the chromatographic peak area in the range of 0-100μg/L,and the correlation coefficient were all more than 0.9990.The detection limits of arsenite,arsenate,monomethyl arsenate,dimethyl arsenate,arsenic betaine and arsenic choline were 0.04,0.05,0.08,0.07,0.05 and 0.09μg/L,and the quantitative limits were 0.13,0.15,0.20,0.20,0.16 and 0.28μg/L,respectively.The recoveries of the samples were 88.3%-96.3%,and the relative standard deviations of the determination results were 4.37%-8.98%(n=6).The method was used to study the morphological distribution characteristics of arsenic in commercial edible mushroom,and the results showed that the forms,distribution types and contents of arsenic in different types of edible mushroom were different.It was necessary to evaluate the harm of arsenic in edible mushroom by synthesizing the contents of inorganic arsenic and organic arsenic.