气相色谱法测定汽油中甲缩醛、碳酸二甲酯、乙酸仲丁酯

Determination of methylal,dimethyl carbonate and sec-butyl acetate in gasoline by gas chromatography

建立了采用阀切换和预分离柱的气相色谱法测定汽油中甲缩醛、乙酸仲丁酯、碳酸二甲酯含量的方法。结果表明,当柱温为60℃、阀切换时间0. 45 min时,各目标物含量在0. 2%～10. 0%范围内,线性相关系数均大于0. 9995。方法的加标回收率均90%～110%,相对标准偏差均小于1%,3种目标化合物的检出限分别为:甲缩醛0. 03%、碳酸二甲酯0. 02%、乙酸仲丁酯0. 3%。

For the detection of illegal additions in gasoline,such as methylal,dimethyl carbonate and sec-butyl acetate,a test method was developed for the analysis of methylal,dimethyl carbonate and sec-butyl acetate in gasoline using a gas chromatography(GC)with valve switching and pre-column.The results showed that when the column temperature was 60℃ and the switching time was 0.45 min,the linear correlation coefficient of each target compound is higher than 0.9995 in the range of 0.2%to 10.0%.The method has recoveries of 90%-110% and relative standard deviations of less than1.0%.The detection limits of methylal dimethyl carbonate and sec-butyl acetate are 0.03%,0.02%,0.3%,respectively.