高效液相色谱-原子荧光光谱法测定人发中3种形态汞

Determination of three forms of mercury in human hair by high performance liquid chromatography-atomic fluorescence spectrometry

目的建立高效液相色谱-原子荧光光谱(HPLC-AFS)法测定汞接触人群头发中无机汞、甲基汞和乙基汞的方法。方法称取0.20 g头发,加入5.0 mL浓度为5.00 mol/L的盐酸,放置12 h后室温下超声提取30 min,离心后取上层液体2.0 mL,在冷水浴过程中滴加氨水调节pH值至4~5,加入0.2 mL质量浓度为10.0 g/L的L-半胱氨酸溶液,用纯水定容至10.0 mL,经过滤后以体积分数为5.0%甲醇溶液+浓度为0.06 mol/L乙酸铵溶液+体积分数为0.1%L-半胱氨酸溶液组合作为流动相,经C18液相色谱柱分离,紫外消解后以原子荧光光谱仪测定。结果人发中无机汞、甲基汞、乙基汞在质量浓度为0.0~10.0μg/L时线性关系良好,相关系数均>0.9990,方法的检出限分别为0.008、0.008和0.010μg/g;3种汞形态的批内、批间相对标准偏差分别为1.6%~4.3%和2.0%~5.6%,样品加标回收率为94.0%~101.2%。结论该方法操作简单、检出限低、灵敏度高及准确度好,适用于汞接触人群发中无机汞、甲基汞和乙基汞的同时测定。

Objective To establish a method for the determination of mercury,methylmercury(MeHg)and ethylmercury(EtHg)in the hair of mercury-exposed individuals using high performance liquid chromatography-atomic fluorescence spectrometry.Methods About 0.20 g of hair was mixed with 5.0 mL of hydrochloric acid to a concentration of 5.00 mol/L.After standing for 12 hours,ultrasonic extraction was carried out for 30 minutes at room temperature.Ammonia solution was added dropwise into 2.0 mL supernatant after centrifuge to adjust the pH to 4-5.The solution was diluted to 10.0 mL with pure water after mixed with 0.2 mL of L-cysteine with a mass concentration of 10.0 g/L.The mobile phase consisted of 5.0%methanol+a mass concentration of 0.06 mol/L ammonium acetate+a 0.1%L-cysteine,and was used for separation by a C_(18)liquid chromatography column,followed by detection using atomic fluorescence spectrometry after UV digestion.Results The linear relationship of mercury,MeHg and EtHg in human hair was good at mass concentrations of 0.0-10.0μg/L,with all correlation coefficients>0.9990.The detection limit of mercury,MeHg and EtHg was 0.008,0.008,and 0.010μg/g,respectively.The within-and between-run relative standard deviations of the three forms of mercury were 1.6%-4.3%and 2.0%-5.6%,respectively,and the recovery rates were 94.0%-101.2%.Conclusion This method is simple,with low detection limit,high sensitivity,and good accuracy,and is suitable for the simultaneous determination of mercury,MeHg and EtHg in the hair of mercury-exposed individuals.