气相色谱-串联质谱法测定汽油中甲缩醛

GC-MS/MS Determination of Methylal in Gasoline

采用气相色谱-串联质谱法测定汽油中甲缩醛的含量,并对不确定度进行了评价。汽油样品直接进样,在气相色谱分离中用HP-5MS色谱柱(15m×0.25mm,0.25μm)为固定相,在质谱分析中采用多反应监测模式。甲缩醛的线性范围为20~500μL·L^(-1),方法的检出限(3S/N)为0.01μL·L^(-1)。方法用于汽油样品的分析,加标回收率为90.4%~113%,测定值的相对标准偏差(n=6)为0.90%~2.7%。不确定度主要来源于标准曲线不确定度。

GC-MS/MS was applied to the determination of methylal in gasoline, and the uncertainty was also evaluated. The gasoline sample was injected directly. The HP-5MS chromatographic column （15 m）× 0. 25 mm, 0. 25 μm） was used for CK2 separation and the multiple reaction monitoring mode was adopted in MS determination. Linearity range of methylal was found between 20 μL · L-1 and 500μL · L-1 with detection limit （3S/N） of 0. 01 μL · L-1. The proposed method was applied to analysis of the gasoline sample, giving values of recovery and RSD＇ s （n = 6） in the ranges of 90. 4% -- 113% and 0. 90% -- 2. 7 % respectively. The uncertainty was mainly from standard curve.