title: Online hourly determination of 62 VOCs in ambient air: system evaluation and comparison with another two analytical techniques.
abstract: This paper presents results of the processing and validation of data collected by an automatic gas chromatograph (AGC). This system was used to monitor 62 volatile organic compounds (VOCs) in urban air in the Basque Country, Spain. The nonpolar compounds (C2-C10) identified-paraffins, olefins, aromatics, and chlorinated compounds-accounted for 88% of the mass of total non-methane hydrocarbons (TNMHCs) in ambient air. The evaluation of linearity, precision, detection limits (DLs), and stability of retention times (RTs) indicates that the equipment is suitable for measuring ambient air automatically for prolonged periods (6 months). The calibration of the equipment using response factors calculated on the basis of the effective carbon number (ECN) showed variations of over 10% for acetylene, isoprene, and n-hexane. The results provided by the automatic chromatograph correlated significantly with simultaneous results from other widely used techniques for determining VOCs in ambient air: (1) portable GC, equipped with photoionization detector (PID), and (2) active adsorption on Tenax-TA followed by thermal desorption and chromatographic analysis.
authors.affiliation: Department of Chemical and Environmental Engineering, School of Engineering, University of the Basque Country, Bilbao, Spain. iapdujin@bi.ehu.es
authors.forename: Nieves
authors.initials: N
authors.lastname: Durana
authors.forename: Marino
authors.initials: M
authors.lastname: Navazo
authors.forename: Luclo
authors.initials: L
authors.lastname: Alonso
authors.forename: José A
authors.initials: JA
authors.lastname: García
authors.forename: Juan L
authors.initials: JL
authors.lastname: Ilardia
authors.forename: M Carmen
authors.initials: MC
authors.lastname: Gómez
authors.forename: Gotzon
authors.initials: G
authors.lastname: Gangoiti
mesh_terms: D000393:Air Pollutants / Q000032:analysis*; D001331:Automation; D002849:Chromatography, Gas / Q000379:methods*; D004784:Environmental Monitoring / Q000379:methods*; D010083:Oxidants, Photochemical / Q000032:analysis*; D013997:Time Factors; D014835:Volatilization
chemical_list: D000393:Air Pollutants; D010083:Oxidants, Photochemical