汽油中微量硅和磷的质谱分析

采用电感耦合等离子体质谱( ICP-MS)法测定了汽油中硅（Si）和磷（P）元素的质量浓度。在等离子气中混入少量O₂以防止炭在采样锥锥口沉积,应用碰撞/反应池(CRC)技术消除了多原子离子对待测元素产生的质谱干扰,考察了碰撞/反应气流速对Si和P预估检测限(EDL)的影响,确定了最佳碰撞/反应气流速,采用Sc为内标元素校正了质谱分析中基体效应。Si和P元素的检出限分别为0.18 μg/L和0.34 μg/L,加标回收率分别为103.81%和96.43%,相对标准偏差(RSD)小于2.80%。

Determination of Si and P in Gasoline by Inductively Coupled Plasma Mass Spectrometry

An inductively coupled plasma mass spectrometry (ICP-MS) was used for the determination of Si and P in gasoline. A small amount of O₂ was added into the Ar line to burn carbon in gasoline to avoid the deposition of carbon on the sampling cone, which eventually could result in clogging of the orifice and a reduction in sensitivity. The collision/reaction cell (CRC) was used by introducing H₂ and He to eliminate the interference of polyatomic ions. The effects of H₂ and He flow rates on the estimated detection limits of Si and P were investigated. The matrix effects and the instrument drift could be commendably calibrated with Sc as internal standard element. Under the optimal conditions, the detection limits for Si and P were 0.18 μg/L and 0.34 μg/L with the recovery of standard addition of 103.81% and 96.43%, respectively, and the RSD was less than 2.80%.