Online volatile organic compound measurements using a newly developed proton-transfer ion-trap mass spectrometry instrument during New England Air Quality Study--Intercontinental Transport and Chemical Transformation 2004: performance, intercomparison, and compound identification.
We have used a newly developed proton-transfer ion-trap mass spectrometry (PIT-MS) instrument for online trace gas analysis of volatile organic compounds (VOCs) during the 2004 New England Air Quality Study-Intercontinental Transport and Chemical Transformation study. The PIT-MS instrument uses proton-transfer reactions with H3O+ ions to ionize VOCs, similarto a PTR-MS (proton-transfer reaction mass spectrometry) instrument but uses an ion trap mass spectrometer to analyze the product ions. The advantages of an ion trap are the improved identification of VOCs and a near 100% duty cycle. During the experiment, the PIT-MS instrument had a detection limit between 0.05 and 0.3 pbbv (S/N = 3 (signal-to-noise ratio)) for 2-min integration time for most tested VOCs. PIT-MS was used for ambient air measurements onboard a research ship and agreed well with a gas chromatography mass spectrometer). The comparison included oxygenated VOCs, aromatic compounds, and others such as isoprene, monoterpenes, acetonitrile, and dimethyl sulfide. Automated collision-induced dissociation measurements were used to determine the contributions of acetone and propanal to the measured signal at 59 amu; both species are detected at this mass and are thus indistinguishable in conventional PTR-MS.
Warneke
Carsten
C
National Oceanic and Atmospheric Administration, Aeronomy Laboratory, 325 Broadway, Boulder, Colorado 80305, USA. Carsten.Warneke@noaa.gov
Kato
Shuji
S
De Gouw
Joost A
JA
Goldan
Paul D
PD
Kuster
William C
WC
Shao
Min
M
Lovejoy
Edward R
ER
Fall
Ray
R
Fehsenfeld
Fred C
FC
D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D001331:Automation; D004784:Environmental Monitoring / Q000379:methods*; D020407:Internet; D013058:Mass Spectrometry / Q000379:methods*; D009511:New England; D009930:Organic Chemicals / Q000032:analysis; D014835:Volatilization
D000393:Air Pollutants; D009930:Organic Chemicals