有效碳数法在对二甲苯气相色谱定量分析中的应用

摘要

The test method for p-xylene by gas chromatography was optimized,and a further study was done about the accuracy of effective carbon number(ECN) correction factors in the determination of purity and impurities in p-xylene.The results showed that ECN correction factors have the same accuracy in quantization as external standard method and internal standard method.The recoveries of the components with baseline separation were in the range of 95％-103％.The relative standard deviation was less than 2％,and the limits of detection were in the range of 0.000 4％-0.000 5％(w).The recovery of m-xylene,which is hard to be separated from p-xylene,was higher than 90％ when the valley/peak ratio(S) was less than 20％,and was higher than 95％ when S was less than 10％.The gas chromatography with ECN correction factors is simple,fast and environment protection,and it is promising in test and quality control for aromatic hydrocarbon and related products.%优化了对二甲苯气相色谱分离条件,深入研究了有效碳数校正面积归一化法(简称有效碳数法)测定对二甲苯纯度及杂质定量的准确性.实验结果表明,有效碳数法的定量结果与外标法和内标法的定量结果基本一致.对于基线分离的组分回收率为95％～ 103％,相对标准偏差小于2.0％,最低检出限可达0.000 4％～ 0.000 5％(w).对于难分离的间二甲苯,当峰谷/峰高比值(S)小于20％时,回收率在90％以上;当S小于10％时,回收率可达95％以上.有效碳数法具有简便、环保的特点,在芳烃产品及相关物料检测和质量监控中具有很好的应用前景.