浅谈汽油中醚醇类含氧化合物应用气相色谱柱切换-反吹技术

Gas Chromatography Determine Oxygenated compounds in Gasoline by Column Switching-Back Flushing Technique

本文采用柱切换-反吹气相色谱技术分析检测汽油中含氧化合物(醇类和醚类)的含量。该方法利用强极性的微填充TCEP不锈钢柱作预切柱,放空挥发性轻烃,保留醇醚类含氧化合物,并将其反吹至石英毛细管WCOT柱进行详细分离。分析了阀切换时间可能影响定量准确性的原因,通过调节分流比和阻力阀阻力建立最佳实验条件。在25min内,用内标法定量可以完成汽油中可能存在的13种醇醚类含氧化合物的分析。准确度实验表明,含氧化合物的回收率在95.2%~100.7%之间,方法的相对标准偏差(RSD)≤0.55%。

A method for determination of certain alcohols and ether in gasoline by GC column switching-back flushing tech- nique was studied. From the TCEP polar pre column, the light hydrocarbon flowed out in air and the oxygenated compounds entered the WCOT analytical column. Working condition of GC system was established perfectly by removing the reasons, which including mistaken time of column switching, split ratio and resistance of valve. All of the oxygenated compounds were detected completely by internal standard method within 25 min and the recovery was 95.2% - 100.7%, RSD≤ 0.55%.