气相色谱法分析甲苯二异氰酸酯方法优化

Optimization on analysis method of toluene diisocyanate by gas chromatography

针对采用气相色谱法测定甲苯二异氰酸酯纯度过程中采用分流/不分流模式的进样方式时,大部分样品经分流系统管路进入分流,对EPC(电子控制系统)的通路影响比较大,严重影响了进样口EPC使用寿命的情况,对进样方进行了改变,即采用气相色谱脉冲不分流的进样方式。实验结果表明,对样品进行预处理气化后,全部进入气相色谱柱,分离效果较好,完全能满足分析要求,能准确测定甲苯二异氰酸酯的纯度,避免了样品对进样口EPC(电子控制系统)的不良影响。

When gas chromatography is used to determine the purity of toluene diisocyanate,which sampling method is shunt or unshunt,the flow of most samples into the stream of the shunt system has a great effect on the access of the EPC(Electronic contiol system),which seriously affects the service life of the EPC in the injection port,so the sampling mode was changed into gas chromatographic pulse unshunt mode.The experimental results show that the sample which entered the gas chromatographic column after being vaporized during pretreatment has good separation effect and can meet the requirement of analysis.It can accurately determine the purity of toluene diisocyanate and avoid the negative effect of the sample on EPC.