甲苯中微量金属元素测定及特征分析

利用乙醇-水-稀硝酸乳化体系分散溶解甲苯样品，建立了电感耦合等离子体质谱(ICP-MS)同时测定甲苯中V、Cr、Mn、Fe、 Co、Ni、Cu、Zn、Ag、Cd及Pb等微量金属元素的新方法。采用有机进样系统，以Re多元素混标为内标元素，优化了仪器射频功率、载气流速、采样深度等仪器参数，以及乙醇-水比例和硝酸含量等样品前处理条件。结果表明，在最佳实验条件下，甲苯中多数微量金属元素的检出限均可达 ng/L级，各元素的线性关系良好(线性系数r=0.998 4~1.000)；方法精密度较高，相对标准偏差(RSD)不大于8.0%；准确度和重现性较好，相对误差不高于10%。对不同厂家的甲苯样品进行分析，结果发现不同厂家样品的Zn、Mn与Co元素差异较大。该方法能够对不同厂家来源的甲苯进行区分，从而为实现海洋泄漏污染工业苯系物的鉴别提供一种新的辅助分析方法。

Determination of Trace Metal Elements in Toluene and Their Feature Analysis

An inductively coupled plasma mass spectrometric(ICP-MS) method was established for the determination of trace metal elements,including V,Cr,Mn,Fe,Co,Ni,Cu,Zn,Ag,Cd and Pb in toluene.The toluene were dissolved in ethanol-water-nitric acid system.The organic sampling system and the internal standard element Re were used in this experiment.The experimental conditions,such as RF power,carrier gas,sampling depth,ethanol-water ratio and nitric acid concentration were optimized.The results showed that,under the optimal conditions,the detection limits for the most trace metal elements could reach up to ng /L level.The linear correlation of the method was preferable with correlation coefficient of 0.998 4-1.000.The relative standard deviation(n=3) was less than 8.0% and the relative error was not more than 10%.The toluenes from different factories were analyzed.Results indicated that the concentrations of trace metal elements in the toluenes were obvious different.Therefore,a new identification method for benzenes spilled in ocean was provided by feature analysis of metals in the benzene compounds.