Ternary association reactions of H3O+, NO+ and O-2(+center dot) with N-2, O-2, CO2 and H2O. Implications for selected ion flow tube mass spectrometry analyses of air and breath

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F61388955%3A_____%2F22%3A00555203" target="_blank" >RIV/61388955:_____/22:00555203 - isvavai.cz</a>

Result on the web

<a href="http://hdl.handle.net/11104/0329721" target="_blank" >http://hdl.handle.net/11104/0329721</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1002/rcm.9241" target="_blank" >10.1002/rcm.9241</a>

Result language

angličtina

Original language name

Ternary association reactions of H3O+, NO+ and O-2(+center dot) with N-2, O-2, CO2 and H2O. Implications for selected ion flow tube mass spectrometry analyses of air and breath

Original language description

Rationale The reactions of the reagent ions used for trace gas analysis in selected ion flow tube mass spectrometry (SIFT-MS), R+, viz. H3O+, NO+ and O-2(+), with the major gases in air and breath samples, M, viz. N-2, O-2, CO2 and H2O, are investigated. These reactions are seen to form weakly-bound adduct ions, R+M, by ternary association reactions that must not be mistaken for genuine volatile organic compound (VOC) analyte ions. Methods The ternary association rate coefficients mediated by helium (He) carrier gas atoms, k(3a), have been determined for all combinations of R+ and M, which form R+M adduct ions ranging in m/z from 47 (H3O+N2) to 76 (O2+center dot CO2). This was achieved by adding variable amounts of M (up to 0.5 mbar pressure) into the He carrier gas (pressure of 1.33 mbar) in a SIFT-MS flow tube at 300 K. Parabolic curvature was observed on some of the semi-logarithmic decay curves that allowed the rate coefficients mediated by M molecules, k(3b), to be estimated. Results Values of k(3a) were found to range from 1 x 10(-31) cm(6) s(-1) to 5 x 10(-29) cm(6) s(-1), which form mass spectral R+M ´ghost peaks´ of significant strength when analysing VOCs at parts-per-billion concentrations. It was seen that the R+M adduct ions (except when M is H2O) react with H2O molecules by ligand switching forming the readily recognised monohydrates of the initial reagent cations R+H2O. Whilst this ligand switching diminishes the R+M adduct ghost peaks, it does not eliminate them entirely. Conclusions The significance of these adduct ions for trace gas analysis by SIFT-MS in the low m/z region is alluded to, and some examples are given of m/z spectral overlaps of the R+M and R+H2O adduct cations with analyte cations of VOCs formed by analysis of complex media like exhaled breath, warning that ghost peaks will be enhanced using nitrogen carrier gas in SIFT-MS.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10403 - Physical chemistry

Project

<a href="/en/project/GA21-25486S" target="_blank" >GA21-25486S: Selected ion flow drift tube mass spectrometry with negative ions and nitrogen carrier gas</a><br>

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2022

Confidentiality

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Name of the periodical

Rapid Communications in Mass Spectrometry

ISSN

0951-4198

e-ISSN

1097-0231

Volume of the periodical

36

Issue of the periodical within the volume

6

Country of publishing house

GB - UNITED KINGDOM

Number of pages

8

Pages from-to

e9241

UT code for WoS article

000759752500007

EID of the result in the Scopus database

2-s2.0-85125152187