高效液相色谱-电感耦合等离子体质谱法测定海鱼中无机砷

目的建立测定海鱼中无机砷含量的高效液相色谱-电感耦合等离子体质谱法。方法海鱼样品经稀硝酸超声热水浴提取后,AS7阴离子交换色谱柱分离,3.5 mmol/L(NH4)2CO3+1%甲醇与100 mmol/L(NH4)2CO3+1%甲醇流动相梯度洗脱,电感耦合等离子体质谱仪测定,以保留时间定性,外标法定量。结果在1~100μg/L的线性范围,6种砷形态化合物的回归方程均呈良好的线性关系,相关系数均优于0.9996,检出限为0.05~0.25μg/L,定量限为0.17~0.84μg/L,3个浓度加标回收率为88.5%~106.4%,相对标准偏差为2.5%~4.9%。结论本方法满足海鱼中无机砷含量的测定要求,提取快速,稳定,操作简单,检出限低,方法的重现性好,灵敏度高。

Determination of Inorganic Arsenic in Marine Fish by High Performance Liquid Chromatography-Inductively Coupled Plasma Mass Spectrometry

Objective To set up a method for the quantitative analysis of innorganic arsenic in marine fish by high performance liquid chromatography-inductively coupled plasma mass spectrometry.Methods The samples were extracted by ultrasonic hot water bath with dilute nitric acid and separated by AS7 anion exchange chromatography column,and the samples were eluted by 3.5 mmol/L(NH4)2CO3+1%methanoland 100 mmol/L(NH4)2CO3+1%methanol mobile phase gradient,and they were determined by inductively coupled plasma mass spectrometer,retention time for qualitative assay and external reference method were used for quantitative assay.Results Good linearities of the method were achieved over the concentration of 1~100μg/L of six compounds of arsenic form,with correlation coefficients above 0.9996.The limits of detection were0.05~0.25μg/L,and the limits of quantitation were 0.17~0.84μg/L.The relative standard deviation was 2.5%to 4.9%and recovery of 3 concentrations ranged from 88.5%to 106.4%.Conclusion The method meets the requirements of innorganic arsenic determination in marine fish.The extraction is rapid,stable,and the operation is simple.With low detection limit,it has good reproducibitity and high sensitivity.