气相色谱法测定烷烃混合物组成及含量实验的改进

Improvement of the Experiment for Determining the Composition and Content of Alkane Mixture by Gas Chromatography

在“气相色谱法测定烷烃混合物的组成及含量”本科教学实验中,一般选用的TCD检测器,基本不能实现微量组分的测定,实验效果有限。文章改进气相色谱仪中检测器的选用,即增设FID检测器,利用FID高灵敏性的特点,显著提高了测量精度。同时在检测过程中增设甲烷转化炉,扩充了实验对象的范围。配置不同含量的混合气体,通过TCD检测器、甲烷转化炉与FID检测器,比较甲烷转化炉打开状态对FID检测信号的影响。实验结果表明,TCD检测微量气体的灵敏度较低,而FID对微量气体的检测具有极高的灵敏度,而甲烷转化炉使某些FID无法检测到的成分如CO/CO_(2)得到有效的检测。新的实验方案优化了实验方法,巩固了原有气相色谱原理知识,拓宽了学生知识面,也培养学生的减碳意识,提高了实践能力。

Now only the TCD detector is involved to determine the content of mixture alkane in the undergraduate experiments,and the determination of trace components can not be realized.Improving the detector selection in the gas chromatography-adding the FID detector with the help of its high sensitivity-can greatly improve the accuracy of measurement.Meanwhile,the addition of the methanizer expands the scope of experimental objects.Configure different contents of mixed gas,let it enter the TCD detector,mathanizer and FID detector by turn,compare the signal of FID detector to confirm the impact of methanizer.The experiment result shows that TCD has a low sensitivity for trace gas,and the FID detector has greatly high sensitivity for the detection of trace gas,while the addition of the methanizer allows some components undetectable by FID such as CO/CO_(2)to be detected.