title: Selected ion flow tube studies of the reactions of H3O+, NO+ and O2+ with the anaesthetic gases halothane, isoflurane and sevoflurane.
abstract: We have carried out a study of the reactions of H(3)O(+), NO(+) and O(2) (+), the commonly used precursor ions for selected ion flow tube mass spectrometry (SIFT-MS), with three anaesthetic gases, halothane, isoflurane and sevoflurane. The motivation for this study was to provide the necessary kinetic data that would allow the quantification of these anaesthetic gases in operating theatre air and in the breath of theatre staff and post-operative patients. A clear negative result from these experiments is that NO(+), although undergoing the simplest chemistry, is unsuitable for this SIFT-MS application. However, although the ion chemistry of H(3)O(+) and O(2) (+) with these compounds is very complex, there being several product ions in each reaction, many of which react rapidly with water molecules, monitor ions have been identified for all three anaesthetic gases when using H(3)O(+) and O(2) (+) as precursor ions. The detailed ion chemistry is discussed and the specific monitor ions are indicated. Hence, the feasibility of on-line breath monitoring is demonstrated by simple examples. These studies have opened the way to measurements in the clinical environment.
authors.affiliation: Centre for Science and Technology in Medicine, School of Medicine, University of Keele, Thornburrow Drive Hartshill, Stoke-on-Trent ST4 7QB, UK.
authors.forename: Tianshu
authors.initials: T
authors.lastname: Wang
authors.forename: David
authors.initials: D
authors.lastname: Smith
authors.forename: Patrik
authors.initials: P
authors.lastname: Spanĕl
mesh_terms: D018685:Anesthetics, Inhalation / Q000737:chemistry*; D005609:Free Radicals / Q000737:chemistry*; D006221:Halothane / Q000737:chemistry*; D007530:Isoflurane / Q000737:chemistry*; D013058:Mass Spectrometry; D008738:Methyl Ethers / Q000737:chemistry*; D008970:Molecular Weight; D009589:Nitrogen Oxides / Q000737:chemistry; D016273:Occupational Exposure / Q000032:analysis; D009873:Operating Rooms; D010100:Oxygen / Q000737:chemistry; D000077149:Sevoflurane
chemical_list: D018685:Anesthetics, Inhalation; D005609:Free Radicals; D008738:Methyl Ethers; D009589:Nitrogen Oxides; D000077149:Sevoflurane; D007530:Isoflurane; D010100:Oxygen; D006221:Halothane