Ion mobility studies on the negative ion-molecule chemistry of pentachloroethane

• Published in: International journal of mass spectrometry Vol. 417; pp. 16 - 21
• Main Authors: González-Méndez, Ramón, Watts, Peter, Howse, David C., Procino, Immacolata, McIntyre, Henry, Mayhew, Chris A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2017
• Subjects: Chlorinated ethane; IMS–MS; Ion mobility spectrometry; Ion-molecule chemistry; Pentachloroethane; Ion-molecule chemistry; Pentachloroethane; Chlorinated ethane; Ion mobility spectrometry; IMS–MS
• ISSN: 1387-3806; 1873-2798
• DOI: 10.1016/j.ijms.2017.04.011

[Display omitted] •Investigation of the negative ion-molecule chemistry of PCE in IMS and IMS-MS.•Observed product ions are Cl− and Cl−.HOO.•Product ions are observed as a doublet in a ‘dry’ system.•Product ions are observed as a singlet in a ‘wet’ system.•Care must be taken in interpreting even simple chemical systems in IMS instruments. In this study we present an investigation of the negative ion-molecule chemistry of pentachloroethane (PCE) in air based ion mobility spectrometry and ion mobility spectrometry–mass spectrometry systems. The observed product ions are Cl−, produced by dissociative electron attachment, and Cl−·HOO resulting from a reaction with O2−. Based upon the moisture content of the system, these ions can be observed as a doublet in a ‘dry’ system or as a singlet in a ‘wet’ system. The nature of the Cl−·HOO product ion was investigated by using isoflurane (ISOF) as a probe to monitor the changing ratios of Cl− and Cl−·HOO as the PCE concentration decreased. This confirmed the origins of the two product anions. Electronic structure calculations are provided. These have aided the understanding of the reaction processes observed.