"2"^^ . . "3"^^ . . . "Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis" . "RIV/61388955:_____/07:00088033!RIV08-AV0-61388955" . . "NL - Nizozemsko" . "Mikrovlnn\u00E9 plazmatick\u00E9 iontov\u00E9 zdroje pro hmotnostn\u00ED spektrometrii v proudov\u00E9 trubici s vybran\u00FDmi ionty. Optimalizace jejich v\u00FDkonnosti a detek\u010Dn\u00EDch limit\u016F pro anal\u00FDzu stopov\u00FDch plyn\u016F"@cs . "Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis" . "P(GA202/06/0776), Z(AV0Z40400503)" . "Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis"@en . "Dryahina, Kseniya" . . . "RIV/61388955:_____/07:00088033" . "8"^^ . "The performance of the ion sources used in selected ion flow tube mass spectrometry, SIFT-MS, instruments is paramount in determining their sensitivities and detection limits for trace gas analysis. The microwave discharge plasma ion source that is currently used for the production of currents of the precursor H3O+, NO+ and O2+ ions for SIFT-MS is described, and the ion chemistry occurring within the plasma and the dissociation of the precursor ions on the helium carrier gas are considered. Thus, it is shown that the most suitable ion source gas composition is a mixture comprising maximal water vapour and minimal air at the lowest total pressure at which the discharge is sustained and stable. It is also shown that the injection energies of the precursor ions into the helium carrier gas must be kept low to minimize collisional dissociation of the ions and thus to minimize the fraction of reactive impurity ions in the carrier gas." . . "microwave plasma ion source; selected ion flow tube mass spectrometry; SIFT-MS; breath analysis"@en . "International Journal of Mass Spectrometry" . "Microwave plasma ion sources for selected ion flow tube mass spectrometry: Optimizing their performance and detection limits for trace gas analysis"@en . "433816" . . "Mikrovlnn\u00E9 plazmatick\u00E9 iontov\u00E9 zdroje pro hmotnostn\u00ED spektrometrii v proudov\u00E9 trubici s vybran\u00FDmi ionty. Optimalizace jejich v\u00FDkonnosti a detek\u010Dn\u00EDch limit\u016F pro anal\u00FDzu stopov\u00FDch plyn\u016F"@cs . "267" . "V\u00FDkonnost mikrovlnn\u00FDch plazmatick\u00FDch iontov\u00FDch zdroj\u016F pro hmotnostn\u00ED spektrometrii v proudov\u00E9 trubici s vybran\u00FDmi ionty, SIFT-MS, je z\u00E1sadn\u00ED pro zaji\u0161t\u011Bn\u00ED jejich citlivosti a dosa\u017Een\u00ED lep\u0161\u00EDch detek\u010Dn\u00EDch limit\u016F pro anal\u00FDzu stopov\u00FDch plyn\u016F. Pr\u00E1ce pojedn\u00E1v\u00E1 o iontov\u00E9 chemii prob\u00EDhaj\u00EDc\u00ED v plynov\u00E9m v\u00FDboji ve zdroji pou\u017E\u00EDvan\u00E9m pro p\u0159\u00EDpravu iont\u016F H3O+, NO+ a O2+ pro SIFT-MS. V\u00FDsledku ukazuj\u00ED, \u017Ee optim\u00E1ln\u00ED je sm\u011Bs obsahuj\u00EDc\u00ED maximum vodn\u00ED p\u00E1ry a minim\u00E1ln\u00ED mno\u017Estv\u00ED vzduchu za nejni\u017E\u0161\u00EDho mo\u017En\u00E9ho tlaku, p\u0159i kter\u00E9m se udr\u017E\u00ED stabiln\u00ED v\u00FDboj. V\u00FDsledky d\u00E1le ukazuj\u00ED \u017Ee injek\u010Dn\u00ED energie mus\u00ED b\u00FDt udr\u017Eena pod ur\u010Dit\u00FDm limitem, tak aby nedoch\u00E1zelo ke kolizn\u00ED disociaci iont\u016F. Za t\u011Bchto podm\u00EDnek je mo\u017Eno dos\u00E1hnou iontov\u00FDch sign\u00E1l\u016F v\u011Bt\u0161\u00EDch ne\u017E mili\u00F3n puls\u016F za sekundu. Zastoupen\u00ED ne\u010Distot v iontech prekurzoru bylo p\u0159i tom men\u0161\u00ED ne\u017E 1%. Detek\u010Dn\u00ED limit metody SIFT-MS se tak dost\u00E1v\u00E1 do oblasti z\u0159ed\u011Bn\u00ED jedn\u00E9 molekuly na deset miliard molekul vzduchu."@cs . . . . "Smith, D." . . . "117;124" . . . "\u0160pan\u011Bl, Patrik" . . "The performance of the ion sources used in selected ion flow tube mass spectrometry, SIFT-MS, instruments is paramount in determining their sensitivities and detection limits for trace gas analysis. The microwave discharge plasma ion source that is currently used for the production of currents of the precursor H3O+, NO+ and O2+ ions for SIFT-MS is described, and the ion chemistry occurring within the plasma and the dissociation of the precursor ions on the helium carrier gas are considered. Thus, it is shown that the most suitable ion source gas composition is a mixture comprising maximal water vapour and minimal air at the lowest total pressure at which the discharge is sustained and stable. It is also shown that the injection energies of the precursor ions into the helium carrier gas must be kept low to minimize collisional dissociation of the ions and thus to minimize the fraction of reactive impurity ions in the carrier gas."@en . "[843B41791ADF]" . . . "1-3" . "1387-3806" . .