In situ measurement of N2O5 in the urban atmosphere by thermal decomposition/laser-induced fluorescence technique
In situ measurement of N2O5 in the urban atmosphere by thermal decomposition/laser-induced fluorescence technique
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DOI：
10.1016/j.atmosenv.2005.07.055
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发表时间：
2005-11
影响因子：
5
通讯作者：
J. Matsumoto;Hidekazu Imai;N. Kosugi;Y. Kajii
中科院分区：
文献类型：
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作者：
J. Matsumoto;Hidekazu Imai;N. Kosugi;Y. Kajii
研制了一种带热转换器的激光诱导荧光（LIF）探测器，用于测量大气中的N2O5。平均10 min， n2o5的检出限为11pptv （S/N=2, [NO2]=0）。在冬季对城市大气中n2o5进行了野外测量。连续4个晚上成功监测了n2o5。通常，观测到的n2o5水平在0-200pptv范围内。注意，在nox浓度极高、温度较低的情况下，n2o5在一个晚上达到800pptv。在选取了NOx稳定性数据后，以城市夜间为代表案例，讨论了n2o5的化学性质。n2o5的观测趋势与理论预测趋势进行了比较。n2o5在气溶胶表面的非均匀损失率估计为5.2×10−4s−1。因此，与NO3的nox损失相比，n2o5损失对冬季城市大气中的nox收支至关重要。LIF仪器被证明对研究n2o5源区的夜间化学是有用的。
The laser-induced fluorescence (LIF) detector with a thermal converter has been developed for measuring atmospheric N2O5. The detection limit for N2O5was 11pptv for 10-min averaging (S/N=2, [NO2]=0). The field measurements of N2O5were conducted in the urban atmosphere in winter. N2O5was successfully monitored during four nights. Typically, observed N2O5level was in the range of 0–200pptv. Note that N2O5reached 800pptv at one night, when NOxlevel was extremely high and the temperature was low. After the data were selected by the stability of NOx, N2O5chemistry was discussed for a representative case of the urban night. Observed trend of N2O5was compared with the theoretically predicted one. The heterogeneous loss rate of N2O5on the aerosol surfaces was estimated as 5.2×10−4s−1. Consequently, it was confirmed that N2O5loss was critical for NOxbudget in the urban atmosphere in winter, in comparison with NOxloss via NO3. The LIF instrument proved to be useful for studying nocturnal chemistry of N2O5in the source region.