title: Inter-comparison of laser photoacoustic spectroscopy and gas chromatography techniques for measurements of ethene in the atmosphere.
abstract: Laser photoacoustic spectroscopy (LPAS) is highly suitable for the detection of ethene in air due to the overlap between its strongest absorption lines and the wavelengths accessible by high-powered CO2 lasers. Here, we test the ability of LPAS to measure ethene in ambient air by comparing the measurements in urban air with those from a gas chromatography flame-ionization detection (GC-FID) instrument. Over the course of several days, we obtained quantitative agreement between the two measurements. Over this period, the LPAS instrument had a positive offset of 330 +/- 140 pptv (parts-per-trillion by volume) relative to the GC-FID instrument, possibly caused by interference from other species. The detection limit of the LPAS instrument is currently estimated around 1 ppbv and is limited by this offset and the statistical noise in the data. We conclude that LPAS has the potential to provide fast-response measurements of ethene in the atmosphere, with significant advantages over existing techniques when measuring from moving platforms and in the vicinity of emission sources.
authors.affiliation: NOAA Aeronomy Laboratory, Boulder, Colorado 80305, USA. bkuster@al.noaa.gov
authors.forename: William C
authors.initials: WC
authors.lastname: Kuster
authors.forename: Frans J M
authors.initials: FJ
authors.lastname: Harren
authors.forename: Joost A
authors.initials: JA
authors.lastname: de Gouw
mesh_terms: D001272:Atmosphere / Q000032:analysis*; D002623:Chemistry Techniques, Analytical / Q000295:instrumentation / Q000379:methods*; D004784:Environmental Monitoring / Q000295:instrumentation / Q000379:methods*; D005030:Ethylenes / Q000032:analysis*; D005410:Flame Ionization / Q000379:methods*; D007834:Lasers; D013057:Spectrum Analysis / Q000379:methods*
chemical_list: D005030:Ethylenes; C036216:ethylene