AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Evaluation of Selective Ion Flow Tube Mass Spectrometry for Controlled Laboratory Studies
ASHLEY VIZENOR, Chia-Li Chen, Derek Price, Mary Kacarab, Xinze Peng, Kelly McCoy, Igor Irianto, Shaokai Gao, David R. Cocker III, Akua Asa-Awuku, University of California, Riverside
Abstract Number: 643 Working Group: Instrumentation and Methods
Abstract Selective Ion Flow Tube Mass Spectrometry (SIFT-MS) is a form of direct mass spectrometry that utilizes precisely controlled chemical ionization reactions to detect and quantify trace amounts of volatile organic compounds (VOCs) from whole air in real time, with typical detection limits at the part-per-trillion level (by volume – pptv). Chemical ionization is induced by one of three positively charged reagent ions: hydronium, nitric oxide, or diatomic oxygen. Soft-ionization reactions occur and the larger fragments of product ions are characterized and quantified. The instrument is operated in two modes: SIM (Selected Ion Mode) and mass modes. A mass scan takes a mass spectrum for each reagent ion, and can be used for identifying products from reactions. In a SIM scan, specific compounds are detected and quantified by detection of product ions. In the research presented, emphasis was placed on the SIM scan mode as accuracy and precision of quantification were the main goal of this study. A Syft Technologies Voice200 SIFT-MS was used to compare known amounts of VOCs with detected concentrations to better understand the accuracy and precision of the instrument. The compounds studied were 1-methylnapthalene, alpha-pinene, benzene, isoprene, m-xylene, naphthalene, toluene, beta-caryophyllene, and longifolene. The data show that SIFT-MS is a helpful tool for approximating concentrations of VOCs, as well as identifying products of reactions from the upper part-per-trillion to lower part-per-million range.