离子迁移谱作为气相色谱的检测器,兼有色谱的高分离能力和离子迁移谱的高灵敏度,有利于实现复杂混合物的实时在线监测。基于在色谱、离子迁移谱方面的研究基础,本实验室搭建了一套以离子迁移谱为检测器的气相色谱仪,分别对检测器的温度、总电压、尾吹气流速等参数进行了系统优化,并用于碘甲烷、1,2-二氯乙烷、四氯化碳和二溴甲烷4种卤代烃化合物的检测。实验结果表明,参数优化后的离子迁移谱检测器对碘甲烷、1,2-二氯乙烷、四氯化碳和二溴甲烷的检出限可分别达到2、0.02、1和0.1 ng,线性范围有两个数量级。离子迁移谱与气相色谱联用,其二维的分离能力可以为复杂混合物的准确定性提供更多的信息,还可以实现不同化合物的选择性检测。
Ion mobility spectrometry(IMS)is an attractive detector of gas chromatography(GC) due to its high sensitivity,short response time,and comparatively low cost.The hyphenated GC-IMS instrument can simultaneously provide high separation ability of GC and high sensitivity of IMS.In this paper,one setup of a GC-IMS instrument is introduced.The parameters of IMS as the GC detector were evaluated and studied with respect to the resolution and sensitivity including temperature,total voltage and drift gas flow rate.Under the optimal conditions,GC-IMS was used to detect iodomethane,1,2-dichloroethane,tetrachloromethane and dibromomethane and the detection limits were 2,0.02,1 and 0.1 ng,respectively.And the linear ranges of two orders of magnitude were achieved.As the detector of gas chromatography,IMS can provide more information for compound identification because of its second dimensional separation and can realize selective detection of different compounds.