Detection Of Nitrous Acid Research Articles

Detection of nitrous acid in the atmospheric simulation chamber SAPHIR using open-path incoherent broadband cavity-enhanced absorption spectroscopy and extractive long-path absorption photometry

Abstract. An instrument based on 20 m open-path incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) was established at the Jülich SAPHIR chamber in spring 2011. The setup was optimized for the detection of HONO and NO2 in the near-UV region 352–386 nm, utilizing a bright hot-spot Xe-arc lamp and a UV-enhanced charge-coupled device (CCD) detector. A 2σ detection limit of 26 pptv for HONO and 76 pptv for NO2 was achieved for an integration time of 1 min. Methacrolein (MACR) was also detected at mixing ratios below 5 ppbv with an estimated 2σ detection limit of 340 pptv for the same integration time. The IBBCEAS instrument's performance for HONO and NO2 detection was compared to that of extractive wet techniques, long-path absorption photometry (LOPAP), and chemiluminescence spectrometry (CLS) NOx detection, respectively. For the combined data sets an overall good agreement for both trend and absolute mixing ratios was observed between IBBCEAS and these established instruments at SAPHIR. Correlation coefficients r for HONO range from 0.930 to 0.994 and for NO2 from 0.937 to 0.992. For the single measurement of MACR r=0.981 is found in comparison to proton-transfer-reaction mass spectrometry (PTRMS).

Detection of Nitrous Acid by Cavity Ring-Down Spectroscopy

Nitrous acid (HONO) plays an important role in the formation of hydroxyl radical and the nitrogen cycle in atmospheric chemistry. Cavity ring-down spectroscopy (CRDS) has been utilized for detectio...

Detection of nitrous acid in the atmosphere by differential optical absorption

HNO2 was investigated by long path optical absorption at three sites in Western Europe. It vas definitely identified and measured in moderately polluted air at Jülich. Mixing ratios as high as 0.8 ppb were observed before sunrise. After sunrise the HNO2 is photolyzed and considerable amounts of OH are produced. The formation of HNO2 is unclear and possible reactions are discussed.

On the detection of nitrous acid in natural waters and other dilute solutions

On the detection of nitrous acid in natural waters and other dilute solutions