ICP-OES雾化系统对汽油中不同硅化学形态测量的适应性研究

Adaptability of Different Nebulizer Systems to Different Silicon Chemical Forms for Gasoline in Inductively Coupled Plasma Optical Emission Spectrometry

汽油中含硅化合物的存在会在燃烧时形成二氧化硅沉积于汽车燃烧系统的不同部位,进而导致车辆故障的发生。汽油中的含硅化合物可能以不同的形态存在。采用有机直接进样模式的电感耦合等离子体发射光谱（ICP-OES）法测定油品中的微量杂质因其方便、快速正得到越来越多的应用。本文研究了不同的ICP-OES雾化系统对不同形态含硅化合物测量的影响。对于微量旋流雾化系统,硅的发射强度与硅化学形态有明显关系,硅化合物挥发性越大,硅元素的发射强度就越强。微量可控温旋流雾化系统可改善易挥发性硅元素的发射强度增强效应,但仍无法完全消除此增强效应。直接注入高效雾化器（DIHEN）雾化系统的应用,可有效消除易挥发性硅的发射强度增强效应,比较适合汽油中硅含量的测定。DIHEN-ICP-OES方法的加标回收率为92.8%-108.7%,相对标准偏差（RSD,n=10）为1.05%-4.63%,方法检出限为0.05mg·kg-1。与传统微波消解法相比,DIHEN-ICP-OES具有简便,快速,灵敏,准确度较高的优点,可用于汽油中硅含量的直接检测。

Silicon is not a natural component of gasoline but it can cause silica deposition in vehicle combustion system which may lead to severe engine failure.Silicon is present in gasoline in different chemical forms.The analysis of oil products by directly measuring under organic phase through inductively coupled plasma optical emission spectrometry（ICP-OES）is becoming a widely accepted approach as it is found to be simple and fast.The work focused on the influence of the sample nebulizer systems to different silicon chemical forms by ICP-OES.For a sample introduction system consisting of micronebulizer coupled to a cyclonic spray chamber,the results indicated that the ICP-OES signals depended strongly on the silicon chemical forms,and the higher emission intensities have been attributed to the compound volatility.The variability of the signals induced by the different silicon compounds was less significant for the same nebulizer system with a temperature control device.Nevertheless,the interferences were not effectively mitigated.Nevertheless,direct injection high efficiency nebulizer（DIHEN）introduced in the present work can effectively mitigate the interferences of different silicon chemical forms,is suitable for the determination of silicon in gasoline.The quantitative method with the potential DIHEN nebulizer system showed good linearity and the recoveries ranged from92.8%-108.7%,the limit of detection was 0.05mg·kg-1.The relative standard deviation（RSD）was between 1.05% and4.63%.Compared with the microwavedigestion method,the proposed method was found to be highly simple,rapid,sensitive and accurate,which has foreseen a promising application for silicon determination in gasoline.