GC-MS/MS Determination of Methylal in Gasoline

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 GC separation and the multiple reaction monitoring mode was adopted in MS determination. Linearity range of methylal was found between 20 μL·L^-1 and 500 μL·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.