微波消解样品-原子荧光光谱法测定原油中铅、砷和汞含量

AFS Determination of Pb, As and Hg in Crude Oil with Microwave Assisted Sample Digestion

摘要: 采用微波消解法,用硝酸-过氧化氢(10+2)溶液作消解剂,以硫脲溶液作为预还原剂,以溶于氢氧化钾溶液中的硼氢化钾溶液作为还原剂,利用原子荧光光谱法测定原油中铅、砷和汞的含量。分析中采用载气及屏蔽气的流量依次为300 mL·min-1及800 mL·min-1。铅、砷和汞的荧光强度与它们的质量浓度依次在2.0~80.0,2.0~100.0,1.0~20.0 μg·L-1之间呈线性关系,方法的检出限(3S/N)依次为0.05,0.05,0.01 mg·kg-1。应用此法对原油样品进行分析,铅、砷和汞的回收率分别在103%~115%,87.5%~92.1%,87.5%~102%之间。

Abstract: AFS was applied to the determination of Pb, As and Hg in crude oil. The sample was digested with mixed solution of HNO3-H2O2(10+2), and thiourea solution was added to the sample solution as pre-reductant and KBH4 solution (dissolved in KOH solution) as reductant. Flow-rates of 300 mL·min-1 for carrier gas and 800 mL·min-1 for shielding gas were taken in the analysis. Linear relationships between values of fluorescence intensity and mass concentration of Pb, As and Hg found were in the ranges of 2.0-80.0, 2.0-100.0 and 1.0-20.0 μg·L-1, with detection limit (3S/N) of 0.05, 0.05 and 0.01 mg·kg-1 respectively. The proposed method was applied to the analysis of samples of crude oil, giving values of recovery in the ranges of 103%-115% for Pb, 87.5%-92.1% for As and 87.5%-102% for Hg.