Institute of Chemistry, Military University of Technology, Warsaw 00-908, Poland.
Siedlce University, Faculty of Sciences, 08-110 Siedlce, Poland.
Talanta. 2019 Mar 1;194:259-265. doi: 10.1016/j.talanta.2018.10.022. Epub 2018 Oct 13.
Electron capture detectors (ECDs) and detectors used in ion mobility spectrometry (IMS) have been successfully used for the detection of numerous compounds including hazardous substances. The general principles of their operations are similar and based on sample component ionization and measurement of the signal using the differences in the mobility of electric charge carriers. Differences in sensitivity result from various parameters of these instruments. Value of electric field intensity in ionic reactors have an influence on ionization process. The main goal of the performed tests was to compare the analytical properties of ECD and two types of IMS detectors: a drift tube spectrometer (DT IMS) and a differential mobility spectrometer (DMS). In the work performed, the efficiency of ionization and the response of detectors to selected analytes were compared. ECD, DT IMS and DMS were equipped with 63-Ni radioactive sources. Analytes have been ionized via electron capture process or dissociative electron transfer. Results obtained for oxygen and chloro-substituted organic compounds (carbon tetrachloride, benzyl chloride, chloroform, 2-chloroethyl ethyl sulfide) were used to calculate the relative signal and to compare the ionization efficiency for three detectors. The phenomena observed experimentally were related to energy dependencies and electron capture cross-sections of analytes. The efficiency of ionization in DT IMS was also compared for electron capture when nitrogen was used as the carrier gas, and when the ionization process was based on the collisions of the analyte molecules with the O with the use of air.
电子俘获检测器（ECD）和用于离子迁移谱（IMS）的检测器已成功用于检测包括危险物质在内的众多化合物。它们的操作原理基本相同，都是基于样品成分的电离，并通过测量电荷载流子迁移率的差异来测量信号。灵敏度的差异源于这些仪器的各种参数。离子反应中电场强度的值对电离过程有影响。进行这些测试的主要目的是比较 ECD 和两种类型的 IMS 检测器（漂移管光谱仪（DT IMS）和差分迁移率光谱仪（DMS））的分析性能。在进行的工作中，比较了检测器的电离效率和对选定分析物的响应。ECD、DT IMS 和 DMS 均配备了 63-Ni 放射性源。通过电子俘获过程或离解电子转移使分析物离子化。使用获得的氧和氯取代有机化合物（四氯化碳、氯化苄、氯仿、2-氯乙基乙基硫醚）的结果来计算相对信号，并比较三种检测器的电离效率。观察到的实验现象与分析物的能量依赖性和电子俘获截面有关。当氮气作为载气时，在 DT IMS 中还比较了电子俘获的电离效率，并且当使用空气时，基于分析物分子与 O 的碰撞进行电离过程。
