« Previous AbstractMating communication systems of four Plusiinae species distributed in Japan: identification of the sex pheromones and field evaluation    Next AbstractDifferentiation of isomeric compounds by two-stage proton transfer reaction time-of-flight mass spectrometry »

Rapid Commun Mass Spectrom

Title:		"A novel discharge source of hydronium ions for proton transfer reaction ionization: design, characterization, and performance"
Author(s):		Inomata S; Tanimoto H; Aoki N; Hirokawa J; Sadanaga Y;
Address:		"Atmospheric Environment Division, National Institute for Environmental Studies, 16-2 Onogawa, Tsukuba, Ibaraki 305-8506, Japan. ino@nies.go.jp"
Journal Title:		Rapid Commun Mass Spectrom
Year:		2006
Volume:		20
Issue:		6
Page Number:		1025 - 1029
DOI:		10.1002/rcm.2405
ISSN/ISBN:		0951-4198 (Print) 0951-4198 (Linking)
Abstract:		"A novel ion source based on direct current (d.c.) discharge has been developed for proton transfer reaction ionization operated at relatively high ion drift tube pressure. The shape and geometry of the ion source are designed to maximize overall ion intensity and to minimize interference from sample air. The initial performance of the technique, including speciation and intensity of reagent ions, their stability, and the impact of artifact signals, is evaluated by means of a proton transfer reaction time-of-flight mass spectrometer (PTR-TOFMS) newly built in our laboratory. Intensities of the hydronium (H(3)O(+)) ions are typically (5-7) x 10(5) counts for a 1-min integration time with a duty cycle of approximately 1%. The fluctuations of the ion signals over a period of hours are within 4%. Although the formation of artifact ions from sample air (NO(+) and O(2) (+)), which react with volatile organic compounds (VOCs) and subsequently cause fragmentation, is observed as background signals in addition to hydronium and mono- and di-hydrate H(3)O(+) ions, intensities of both NO(+) and O(2) (+) ions are only approximately 0.5% of those of H(3)O(+) ions. Using our PTR-TOFMS system at a drift tube pressure of approximately 5 Torr, the detection sensitivities are significantly improved and the detection limits for propene, acetaldehyde, acetone, isoprene, benzene, toluene, and p-xylene are estimated to be at the sub-ppbv level for 1-min integration"
Keywords:
Notes:		"PubMed-not-MEDLINEInomata, Satoshi Tanimoto, Hiroshi Aoki, Nobuyuki Hirokawa, Jun Sadanaga, Yasuhiro eng England 2006/02/17 Rapid Commun Mass Spectrom. 2006; 20(6):1025-9. doi: 10.1002/rcm.2405"