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Non-targeted analysis of firefighter breath samples using GC-MS and synchronous SIM/scan mode
Wallace, A., J. Pleil, K. Oliver, D. Whitaker, S. Mentese, K. Fent, AND G. Horn. Non-targeted analysis of firefighter breath samples using GC-MS and synchronous SIM/scan mode. 2018 ENTACT Meeting, Research Triangle Park, NC, August 13 - 15, 2018.
Firefighters have a high incidence of cancer and are exposed to environmental pollutants during live firefighting activities; this includes both domestic and wildland firefighters. The use of personal protective gear, including breathing masks, during firefighting can reduce exposure to harmful compounds. Most studies of exposure focus on targeted analysis of known contaminants; however, unknown and unmonitored compounds may also pose health risks to individuals. In this study, we analyzed firefighter breath samples for both targeted and non-targeted compounds simultaneously using a SIM/scan mode method and GC/MS instrumentation. The application of SIM/scan mode decreases the number of field samples need by half, as both analyses can be performed at the same time. Targeted compounds of interest were quantified and non-targeted compounds that may be of future use were identified. The developed method has long term importance as it can be used for any analyses of gas-phase samples in which both targeted and non-targeted analyses are required. This work also shows that there are additional compounds in the breath of firefighters that could be indicative of exogenous exposure or endogenous response to fire exposure. These can be used to develop additional biomarkers other than currently monitored volatile organic compounds (VOCs). These results are of interest to scientists performing field studies and non-targeted analyses, as well as local firefighting communities.
Non-targeted analysis can be used to identify new chemicals indicative of environmental contamination and human exposure in addition to chemicals that are already targeted for their known toxicity. Most non-targeted analyses use liquid chromatography-mass spectrometry (LC-MS); herein we describe a novel implementation of this technique using gas chromatography-mass spectrometry (GC-MS) platforms. Most GC-MS laboratories use single quadrupole mass spectrometers with unit mass resolution; however, recent improvements in instrument software allow collection of both selected ion monitoring (SIM) and scan spectra simultaneously, known as SIM/scan mode. This has made non-targeted investigation of environmental samples possible without the need for duplication sample collection and analysis. In this study, we performed targeted and non-targeted analyses of over 400 exhaled breath samples to assess levels of environmental contaminants after firefighters participated in controlled structure burns. Pre-, post-, and 1-h post-exposure breath samples were collected onto sorbent tubes, which were analyzed by automated thermal desorption (ATD)-GC/MS at U.S. Environmental Protection Agency (EPA). Volatile organic compounds (VOCs) with known toxicity such as benzene, toluene, and xylene were targeted in SIM mode, while data for non-targeted compounds were simultaneously collected in scan mode. The identification of these non-targeted compounds is important to increase the list of chemicals that may be important biomarkers of firefighting activity and fire exposure, as well as to detect biomarkers of response indicated by changes in endogenous compounds.
Record Details:Record Type: DOCUMENT (PRESENTATION/POSTER)
Organization:U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF RESEARCH AND DEVELOPMENT
NATIONAL EXPOSURE RESEARCH LABORATORY
EXPOSURE METHODS & MEASUREMENT DIVISION
INTERNAL EXPOSURE INDICATORS BRANCH