title: Analysis of polar organic compounds using charge exchange ionization and membrane introduction mass spectrometry.
abstract: Charge exchange ionization in conjunction with membrane introduction mass spectrometry provides a sensitive method for the detection of polar volatile organic compounds and semivolatile compounds in air. Sample introduction into an ion trap mass spectrometer was accomplished with a hollow fiber silicone membrane assembly. Atmospheric oxygen, which diffuses through the membrane, was used as the charge exchange reagent. Chemical ionization parameters were optimized using methyl ethyl ketone (2-butanone) standards in air. Several other oxygen-containing compounds, including acetone (2-propanone), methyl isobutyl ketone (4-methyl-2-pentanone), propanal, isopropyl alcohol (2-propanol), cyclohexanol, dimethyl sulfoxide (sulfinylbismethane), 2-(diethylamino)ethanol, and dimethyl methylphosphonate were analyzed with this technique. This method was used to obtain mass spectra for a variety of classes of compounds and produced a 4-20-fold improvement in response for all of the polar compounds we examined when compared to signal obtained from electron ionization.
authors: Chemical Sciences and Technology Division, MS J565, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 and Department of Chemistry and Geochemistry, Montana Tech of the University of Montana, Butte, Montana 59701.
authors: M E
authors: ME
authors: Cisper
authors: A W
authors: AW
authors: Garrett
authors: D
authors: D
authors: Cameron
authors: P H
authors: PH
authors: Hemberger