Kuster William C, Harren Frans J M, de Gouw Joost A
NOAA Aeronomy Laboratory, Boulder, Colorado 80305, USA.
Environ Sci Technol. 2005 Jun 15;39(12):4581-5. doi: 10.1021/es0504385.
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.
激光光声光谱法（LPAS）非常适合用于检测空气中的乙烯，因为其最强吸收线与高功率二氧化碳激光器可及的波长存在重叠。在此，我们通过将城市空气中的测量结果与气相色谱火焰离子化检测（GC-FID）仪器的测量结果进行比较，来测试LPAS测量环境空气中乙烯的能力。在几天的时间里，我们在两种测量之间获得了定量一致性。在此期间，LPAS仪器相对于GC-FID仪器有330±140 pptv（体积万亿分之一）的正偏差，这可能是由其他物种的干扰导致的。LPAS仪器的检测限目前估计约为1 ppbv，并且受此偏差和数据中的统计噪声限制。我们得出结论，LPAS有潜力提供大气中乙烯的快速响应测量，在从移动平台测量以及在排放源附近测量时，相对于现有技术具有显著优势。
