%A Mark William Morris
%T USING THE FLOWING AFTERGLOW AS A CHEMICAL REACTION MASS SPECTROMETER
%X The flowing afterglow was used to study the formation and reaction of protonated hexamethyldisiloxane, protonated trimethylsilanol, and the trimethylsilyl cation with a variety of neutrals. The neutrals were selected based on their importance in volatile organic compound (VOC) monitoring and/or their type (i.e. amines, ketones, etc.). The reagent ions contain the trimethylsilyl group, which has been referred as a "large proton". The hydronium ion is used in VOC analysis; this ion clusters with water and only provides molecular weight information. Various products were identified such as proton transfer, trimethylsilyl transfer, hydride ion transfer, etc. Secondary products were also identified, which formed because of the presence of excess neutrals. These secondary products are unimportant if the reagent ions listed above are used for trace gas analysis.The flowing afterglow was used as a chemical reaction mass spectrometer to measure Henry's law constants. The Henry's law constant for acetonitrile was measured to be 49 ? 7, while the average value in the literature is 52 ? 3 mol/kg bar; the constant for acetone was measured to be 27 ? 3 and the literature value is 28 ? 3 mol/kg bar. The chemical reaction mass spectrometer was also used to detect VOCs from thermal decomposition of phenolic resin coated on a graphitic board. A custom SS vessel was used to decompose the resin. Phenol, ammonia, methyl and dimethyl phenol, and other VOCs were detected and quantified. Concentrations ranged from 0.1 to 10 ppm for a 50.5 mg piece of graphitic board.
%D 2007
%K  flowing afterglow; volatile organic compounds; ion/molecule reactions; mass spectrometry
%I University of Pittsburgh
%L pittir7937