减压共沸塔顶乙腈杂质含量测定方法探讨

Discussion on Determination Methods of Impurity Content in Acetonitrile at the Top of Vacuum Azeotropic Tower

建立气相色谱法测定乙腈装置减压共沸塔顶(T202顶)粗乙腈杂质含量的分析方法。采用DB-FFAP毛细管色谱柱、氢火焰检测器,带范围校正归一化法定量。通过实验选择最佳分析操作条件,成功分析出粗乙噁腈中微量丙烯腈、丙酮、唑、丙腈等杂质含量。解决了填充柱在分析此样品时,主要杂质丙烯腈与未知杂质色谱峰重叠的问题。测定的相对标准偏差均小于5.0%,各组分加标回收率在97%～102%之间,能满足分析要求。

A gas chromatography analysis method for determining impurity content in acetonitrile at the top of vacuum azeotropic tower was established through adopting capillary column DB-FFAP,flame ionization detector and correcting the area with normalization.The best analysis conditions were obtained through experiments,and impurity content in acetonitrile was successfully analyzed,such as trace acrylonitrile,acetone,oxazole,propionitrile and so on.The problem of overlapping chromatographic peaks in chromatography analysis with the packed column was solved.The relative standard deviation was less than 5.0%,the recovery rates of components were in the range of 97%-102%,so the method can satisfy the analysis requirement.