{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,17]],"date-time":"2026-10-17T23:33:00Z","timestamp":1792279980861,"version":"4.4.0"},"reference-count":14,"publisher":"Wiley","issue":"23","license":[{"start":{"date-parts":[[2012,10,15]],"date-time":"2012-10-15T00:00:00Z","timestamp":1350259200000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Rapid Comm Mass Spectrometry"],"published-print":{"date-parts":[[2012,12,15]]},"abstract":"<jats:sec>\n                    <jats:title>RATIONALE<\/jats:title>\n                    <jats:p>The aim of this study was to investigate the mass spectral fragmentation of a small set of stimulants in a high\u2010resolution time\u2010of\u2010flight mass spectrometer equipped with a soft ionization source using vacuum ultraviolet (VUV) photons emitted from different plasma gases. It was postulated that the use of a plasma gas such as Xe, which emits photons at a lower energy than Kr or Ar, would lead to softer ionization of the test compounds, and thus to less fragmentation.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>METHODS<\/jats:title>\n                    <jats:p>A set of nine stimulants: cocaine, codeine, nicotine, methadone, phenmetrazine, pentylenetetrazole, niketamide, fencamfamine, and caffeine, was analyzed by gas chromatography\/time\u2010of\u2010flight mass spectrometry (GC\/TOFMS) in positive ion mode with this soft ionization source, using either Xe, Kr, or Ar as plasma gases. Working solutions of the test compounds at 0.1 to 100\u2009ng\/\u03bcL were used to establish instrument sensitivity and linearity.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>RESULTS<\/jats:title>\n                    <jats:p>All test compounds, except methadone and pentylenetetrazole, exhibited strong molecular ions and no fragmentation with Xe\u2010microplasma photoionization (MPPI). Methadone exhibited significant fragmentation not only with Xe, but also with Kr and Ar, and pentylenetetrazole could not be ionized with Xe, probably because its ionization energy is above 8.44\u2009eV. The Kr\u2010 and Ar\u2010MPPI mass spectra of the test compounds showed that the relative intensity of the molecular ion decreased as the photon energy increased.<\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>CONCLUSIONS<\/jats:title>\n                    <jats:p>When coupled to a TOF mass spectrometer this soft ionization source has demonstrated signal\u2010to\u2010noise (S\/N) ratios from 7 to 730 at 100\u2009pg per injection (depending on the compound), and a dynamic range of three orders of magnitude (100\u2009pg to 100\u2009ng) for some of the test compounds. Copyright \u00a9 2012 John Wiley &amp; Sons, Ltd.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.1002\/rcm.6398","type":"journal-article","created":{"date-parts":[[2012,10,16]],"date-time":"2012-10-16T00:04:12Z","timestamp":1350345852000},"page":"2714-2724","source":"Crossref","is-referenced-by-count":13,"title":["Determination of stimulants using gas chromatography\/high\u2010resolution time\u2010of\u2010flight mass spectrometry and a soft ionization source"],"prefix":"10.1002","volume":"26","author":[{"given":"Viorica","family":"Lopez\u2010Avila","sequence":"first","affiliation":[{"name":"Agilent Technologies  Santa Clara CA 95051 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"James","family":"Cooley","sequence":"additional","affiliation":[{"name":"Agilent Technologies  Santa Clara CA 95051 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Randall","family":"Urdahl","sequence":"additional","affiliation":[{"name":"Agilent Technologies  Santa Clara CA 95051 USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mario","family":"Thevis","sequence":"additional","affiliation":[{"name":"German Sport University Cologne Institute of Biochemistry\/Center for Preventive Doping Research  Am Sportspark, Muengerdorf 6 Cologne 50933 Germany"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"311","published-online":{"date-parts":[[2012,10,15]]},"reference":[{"key":"e_1_2_5_2_1","doi-asserted-by":"publisher","DOI":"10.1021\/ac60337a026"},{"key":"e_1_2_5_3_1","doi-asserted-by":"publisher","DOI":"10.1021\/ac50029a023"},{"key":"e_1_2_5_4_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.464215"},{"key":"e_1_2_5_5_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.chroma.2007.08.081"},{"key":"e_1_2_5_6_1","doi-asserted-by":"publisher","DOI":"10.1021\/ac049535r"},{"key":"e_1_2_5_7_1","doi-asserted-by":"publisher","DOI":"10.1021\/ac200356t"},{"key":"e_1_2_5_8_1","doi-asserted-by":"publisher","DOI":"10.1063\/1.3681146"},{"key":"e_1_2_5_9_1","doi-asserted-by":"publisher","DOI":"10.1002\/9780470626634"},{"key":"e_1_2_5_10_1","unstructured":"NIST Chemistry WebBook NIST Standard Reference Database Number 69. Available:http:\/\/www.workbook.nist.gov\/chemistry."},{"key":"e_1_2_5_11_1","doi-asserted-by":"publisher","DOI":"10.1021\/ja00993a044"},{"key":"e_1_2_5_12_1","doi-asserted-by":"publisher","DOI":"10.1016\/j.phytochem.2004.05.005"},{"key":"e_1_2_5_13_1","volume-title":"Mass Spectrometry of Heterocyclic Compounds","author":"Porter Q. N.","year":"1985"},{"key":"e_1_2_5_14_1","unstructured":"J. L.Banyasz.The physical chemistry of nicotine. Available:http:\/\/legacy.library.ucsf.edu\/tid\/oiw37c00\/pdf."},{"key":"e_1_2_5_15_1","first-page":"67","volume-title":"Recent Advances in Doping Analysis","author":"Parr M. K.","year":"2003"}],"container-title":["Rapid Communications in Mass Spectrometry"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1002%2Frcm.6398","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/pdf\/10.1002\/rcm.6398","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,26]],"date-time":"2025-10-26T16:32:02Z","timestamp":1761496322000},"score":1,"resource":{"primary":{"URL":"https:\/\/analyticalsciencejournals.onlinelibrary.wiley.com\/doi\/10.1002\/rcm.6398"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2012,10,15]]},"references-count":14,"journal-issue":{"issue":"23","published-print":{"date-parts":[[2012,12,15]]}},"alternative-id":["10.1002\/rcm.6398"],"URL":"https:\/\/doi.org\/10.1002\/rcm.6398","archive":["Portico"],"relation":{},"ISSN":["0951-4198","1097-0231"],"issn-type":[{"value":"0951-4198","type":"print"},{"value":"1097-0231","type":"electronic"}],"subject":[],"published":{"date-parts":[[2012,10,15]]}}}