Ion mobility spectrometers and electron capture detector - A comparison of detection capabilities

Edyta Budzyńska; Michał Grabka; Janina Kopyra; Mirosław Maziejuk; Zahra Safaei; Bartłomiej Fliszkiewicz; Monika Wiśnik; Jarosław Puton

doi:10.1016/j.talanta.2018.10.022

Ion mobility spectrometers and electron capture detector - A comparison of detection capabilities

Talanta. 2019 Mar 1:194:259-265. doi: 10.1016/j.talanta.2018.10.022. Epub 2018 Oct 13.

Authors

Edyta Budzyńska¹, Michał Grabka¹, Janina Kopyra², Mirosław Maziejuk³, Zahra Safaei⁴, Bartłomiej Fliszkiewicz¹, Monika Wiśnik¹, Jarosław Puton⁵

Affiliations

¹ Institute of Chemistry, Military University of Technology, Warsaw 00-908, Poland.
² Siedlce University, Faculty of Sciences, 08-110 Siedlce, Poland.
³ Military Institute of Chemistry and Radiometry, al. Chruściela 105, 00-910 Warsaw, Poland.
⁴ Laboratory of Green Chemistry, Lappeenranta University of Technology, Mikkeli FI-50130, Finland.
⁵ Institute of Chemistry, Military University of Technology, Warsaw 00-908, Poland. Electronic address: jaroslaw.puton@wat.edu.pl.

PMID: 30609528
DOI: 10.1016/j.talanta.2018.10.022

Abstract

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 O₂^- with the use of air.

Keywords: Chemical ionization; Differential mobility spectrometry; Electron capture detector; Ion mobility spectrometry; Sensitivity of detectors.