用石墨化炭黑色谱柱分析异戊二烯单体中微量甲缩醛

The Analysis of Methylal Impurity in Isoprene Monomer by GC with Graphitized Carbonblack Column

异戊二烯单体中微量甲缩醛是异戊二烯聚合的主要有害杂质之一,过去用两台色谱仪小柱富集法测定,操作繁琐,时间长。现在改用石墨化炭黑柱(STH-2),使甲缩醛杂质可在异戊二烯主峰之前出峰。并改装了SP-2308色谱仪,利用交替使用两根STH-2柱的方法使全部分析能在一台仪器上进行。工作效率提高8倍。分析结果的相对标准偏差为2.2％,最小检出量为0.2ppm,满足了控制分析的要求。

In this paper the analysis by gas chromatography of trace amount of methylal in isoprene monomer (IP) is described, The methylal is one of the main harmful impurities in IP. In the past two sets of gas chromatograph were used to trap methylal in a small column for determination. This method is time-consumming and complicated. Now, graphitized carbonblack column packing (STH-2) is used, by which methylal elutes before IP peak. At the same time the SP-2308 chromatograph is revamped, By using two STH-2 columns alternately in a SP-2308, the analysis can be completed in a single set of instrument. Thus tie efficiency of analysis is increased by 8 times; the relative variance of the analysis results is 2.2% and the minimum detection limit is 0.2ppm. These satisfy the requirements of the control analysis.