【摘要】 本研究发展了应用ICP-MS及其专用的有机进样系统对高挥发性的石脑油进行直接进样分析的方法。该方法采用乙醇对石脑油样品进行最简单的1∶1稀释后直接进样,采用标准加入法工作曲线转外标法工作曲线方法,克服了水性标准溶液无法溶于憎水性有机溶剂的问题。摸索出最适当的仪器工作条件,包括进样量(50~100μL/m in)、氧气加入量(20%比例)、灵敏度(Y>80 000 cps/ng/g)、氧化物干扰(<1.5%)等重要参数,从而克服了高挥发性有机试剂对ICP-MS分析形成的积碳、灭火问题。方法快速同时检测了石脑油样品中超痕量Hg、Pb、As,检出限达到Hg 0.05 ng/g,Pb 0.01 ng/g和As 0.1 ng/g,1 h连续测定RSD为Hg1.0%,Pb 4.0%和As 8.0%,加标回收率在86%~95%之间。本研究不必使用碰撞/反应池技术,但对其在石化行业关键元素分析的潜在优势进行了探讨。更多还原

【Abstract】 A rapid method was developed for the determination of Pb,Hg and As in naphtha by inductively coupled plasma mass spectrometry（ICP-MS）.Direct sample introduction was performed with a special organic sample kit after a 1+1 dilution of the naphtha sample with ethanol. The standard addition calibration curve based on aqueous solutions was transformed into the external standard calibration curve with the software installed in the instrument,thus allowing the hydophobe organic sample to be calibrated.The sample up-take rate was optimized to 50-100 μL/min with a continuous dose of additional O₂（20%） in the aerosol gas to prevent the deposition of carbon on the sampler and the extinction of plasma by the high volatility of naphtha.The detection limits were 0.05 ng/g,0.01 ng/g and 0.1 ng/g for Hg,Pb and As respectively.The relative standard deviations for stability monitoring within 1 h were 1.0%,4.0% and 8.0% for Hg,Pb and As,respectively.The spiked recoveries were 94%,95% and 86% for Hg,Pb and As.更多还原