微波消解-氢化物发生原子荧光法测定重油中的砷和汞

采用微波消解处理样品,以硫脲为预还原剂硼氢化钾为还原剂,氢化物发生原子荧光法测定重油中的砷和汞。采用微波消解方法进行样品处理,其结果表明,方法具有高效快速、试剂消耗量少、节能、环保等优点。考察了预还原剂硫脲和抗坏血酸对测定结果的影响。考察了酸度、还原剂浓度、基体效应、光电倍增管负高压、原子化器高度、灯电流和载气流量的影响,优化操作条件。测定砷和汞的线性范围分别为2~12μg/L和0.2~1.2μg/L,线性回归方程为If=a*c+b(c:μg/L),相关系数分别为0.9998和0.9981,砷和汞的检出限分别为0.009μg/L和0.007μg/L,对7个样品进行回收实验,砷、汞的回收率分别为90%~109%、92%~105%准确度较高;11次测定的标准偏差小于5%,精密度较好。本方法用于重油中砷和汞分析,可满足科研和生产需要。

Microwave Digestion HG-AFS Method for Determining Arsenic and Mercury in Heavy Oil

The heavy oil was treated by microwave digestion.The arsenic and mercury were pre-reduced by thiourea,and then determined by hydricde generation atomic fluorescence spectrometry.The linear ranges were 2～12 ppb for As and 0.2～1.2 ppb for Hg.The equation of linear regression is If=a*c+b.The coefficients of correlation were 0.9998 and 0.9981 respectively.The determination limit of arsenice is 0.009 μg/L,and 0.007 μg/L for mercury.Incpected the acidity,pre-reducing agent and reducing agent usage,matrix modifier and carrier flow rate,the acidity of carrier,light current,as well as the impact of coexistence element interference.The recoveries were 90%～109%(n=7) for arsenic,and 92%～105%(n=7)for mercury,with good accuracy.The relative standard deviations(n=11) were lower than 10%.The accuracy of arsenic was 2.5%,the accuracy of mercury was 3.3%.It can contented the requirement of scientific research and production.In this paper,The heavy oil was treated by microwave digestion,and the results showed that the microwave digestion method is efficient,rapid and less reagent consumption and energy-saving and environmental protection features.The analysis of the results is satisfy.