GC-MS法检测车用汽油中C1~C4醇

C1~C4醇是生产无铅汽油的常用添加物，其含量需严格控制，以满足车用汽油的性能与环保要求。利用气相色谱-质谱联用仪（GC-MS）建立了车用汽油中C1~C4醇类添加物的定性和定量分析方法。定性分析采用全扫描，利用标准物质的质谱谱图与色谱保留时间确定待测醇类化合物的种类；定量分析采用选择离子扫描（SIM），有效降低了汽油本底对测试的干扰，提高了方法的选择性，并结合内标法进行测试，减小了仪器状态波动对定量分析结果的影响。实验结果表明：所建立的方法对质量分数在0.1% ~9.0%范围内的C1~C4醇有良好的线性响应，线性相关系数均在0.995以上，具有良好的准确度和重复性，加标回收率在91.47% ~104.56%之间，相对标准偏差（RSD）均小于2.3%，能够用于车用汽油中C1~C4醇的快速、准确分析。

DETERMINATION OF C1-C4 ALCOHOLS IN MOTOR GASOLINE BY GC-MS METHOD

C1-C4 alcohols have been used as additives to produce unleaded gasoline. However, the contents of them should be controlled strictly. Gas chromatograph-mass spectrometry (GC-MS) method for determination of C1-C4 alcohols in motor gasoline was proposed. The qualitative analysis was conducted by full scan, and each peak was identified by mass spectra of the standard substances and GC retention time. The quantitative analysis was carried out by selected ion monitoring (SIM) scan, which can reduce the interference of the matrix efficiently. The internal standard was introduced to improve the stability of detection. The results exhibit that the GC-MS method has a good linear response to C1-C4 in the mass fraction range of 0.1% to 9.0% (R2≥0.995). The recoveries of standard additions are in the range of 91.47%-104.56% and the relative standard deviations are less than 2.3%. The good accuracy and repeatability make this method available for rapid and accurate determination of C1-C4 alcohols in motor gasoline.