GC Determination of Methanol and Benzene in Car-gasoline

In the GC determination of methanol and benzene in car-gasoline,a micro column (56 cm×1.6 mm) packed with 1,2,3-tris-(2-cyanoethoxy)-propane (abbreviated as TCEP),and a HP-1 capillary column (30 m×0.53 mm,0.5 μm) were used in combination for the separation of various components in the gasoline sample.One μL of sample was introduced by the automatic sample injector.A preliminary separation was done in the TCEP microcolumn,and detections were made by FID B.Components coming out before methanol and benzene were let out to air.Components remaining in the TCEP microcolumn were blown to the capillary column by changing the 10-way valve,to be separated further and detected by FID A.Methanol and benzene of the sample were determined simultaneously by using the external standard method.Linear relationship between values of peak area and concentration of methanol and of benzene were obtained in the ranges within 50.0 g·L-1 and 100.0 g·L-1 respectively.Detection limits (3S/N) found were 0.5 g·L-1 for methanol and 0.02 g·L-1 for benzene.Recovery of the method was tested and values found were 93.3% for methanol and 97.0% for benzene.