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Selected ion flow tube: a technique for quantitative trace gas analysis of air and breath.
Med Biol Eng Comput. 1996 Nov; 34(6):409-19.MB

Abstract

The selected ion flow tube (SIFT) technique for trace gas analysis of air and breath is based on soft chemical ionisation of the trace gases to the exclusion of the major air and breath gases, in fast-flowing inert carrier gas, exploiting the ion-molecule reactions that occur between the trace gases and the pre selected precursor ions (H3O+, NO+ and O2+). The physics and ion chemistry involved in the SIFT technique are described, as are the kinetics of the ion-molecule reactions that are exploited to quantitatively analyse the trace gases. Fast on-line data-acquisition hardware and software have been developed to analyse the mass spectra obtained, from which partial pressures of the trace gases down to about 10 parts per billion can be measured. The time response of the instrument is 20 ms, allowing the profiles of the trace gas concentrations on breath to be obtained during a normal breathing cycle. Pilot results obtained with this SIFT technique include detection and quantification of the most abundant breath trace gases, analysis of cigarette smoke, detection of gases present on smokers' breath and accurate measurement of the partial pressures of NH3, NO and NO2 in air. The simultaneous analysis of several breath trace gases during a single exhalation is clearly demonstrated, and thus different elution times for isoprene and methanol along the respiratory tract are observed. This technique has great potential in many clinical and biological disciplines, and in health and safety monitoring.

Authors+Show Affiliations

Department of Biomedical Engineering and Medical Physics, Hospital Centre, University of Keele, Stoke-on-Trent, Staffs, UK.No affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9039741

Citation

Spanĕl, P, and D Smith. "Selected Ion Flow Tube: a Technique for Quantitative Trace Gas Analysis of Air and Breath." Medical & Biological Engineering & Computing, vol. 34, no. 6, 1996, pp. 409-19.
Spanĕl P, Smith D. Selected ion flow tube: a technique for quantitative trace gas analysis of air and breath. Med Biol Eng Comput. 1996;34(6):409-19.
Spanĕl, P., & Smith, D. (1996). Selected ion flow tube: a technique for quantitative trace gas analysis of air and breath. Medical & Biological Engineering & Computing, 34(6), 409-19.
Spanĕl P, Smith D. Selected Ion Flow Tube: a Technique for Quantitative Trace Gas Analysis of Air and Breath. Med Biol Eng Comput. 1996;34(6):409-19. PubMed PMID: 9039741.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Selected ion flow tube: a technique for quantitative trace gas analysis of air and breath. AU - Spanĕl,P, AU - Smith,D, PY - 1996/11/1/pubmed PY - 1996/11/1/medline PY - 1996/11/1/entrez SP - 409 EP - 19 JF - Medical & biological engineering & computing JO - Med Biol Eng Comput VL - 34 IS - 6 N2 - The selected ion flow tube (SIFT) technique for trace gas analysis of air and breath is based on soft chemical ionisation of the trace gases to the exclusion of the major air and breath gases, in fast-flowing inert carrier gas, exploiting the ion-molecule reactions that occur between the trace gases and the pre selected precursor ions (H3O+, NO+ and O2+). The physics and ion chemistry involved in the SIFT technique are described, as are the kinetics of the ion-molecule reactions that are exploited to quantitatively analyse the trace gases. Fast on-line data-acquisition hardware and software have been developed to analyse the mass spectra obtained, from which partial pressures of the trace gases down to about 10 parts per billion can be measured. The time response of the instrument is 20 ms, allowing the profiles of the trace gas concentrations on breath to be obtained during a normal breathing cycle. Pilot results obtained with this SIFT technique include detection and quantification of the most abundant breath trace gases, analysis of cigarette smoke, detection of gases present on smokers' breath and accurate measurement of the partial pressures of NH3, NO and NO2 in air. The simultaneous analysis of several breath trace gases during a single exhalation is clearly demonstrated, and thus different elution times for isoprene and methanol along the respiratory tract are observed. This technique has great potential in many clinical and biological disciplines, and in health and safety monitoring. SN - 0140-0118 UR - https://www.unboundmedicine.com/medline/citation/9039741/Selected_ion_flow_tube:_a_technique_for_quantitative_trace_gas_analysis_of_air_and_breath_ L2 - https://www.lens.org/lens/search/patent/list?q=citation_id:9039741 DB - PRIME DP - Unbound Medicine ER -