A thermal-dissociation–cavity ring-down spectrometer (TD-CRDS) was developed to measure NO₂, peroxy nitrates (PNs), alkyl nitrates (ANs), and HNO₃ in the gas and particle phase, built using a commercial Los Gatos Research NO₂ analyzer. The detection limit of the TD-CRDS is 0.66 ppb for ANs, PNs, and HNO₃ and 0.48 ppb for NO₂. For all four classes of NO_y, the time resolution for separate gas and particle measurements is 8 min, and for total gas + particle measurements it is 3 min. The accuracy of the TD-CRDS was tested by comparison of NO₂ measurements with a chemiluminescent NO_x monitor and aerosol-phase ANs with an aerosol mass spectrometer (AMS). N₂O₅ causes significant interference in the PN and AN channel under high oxidant concentration chamber conditions, and ozone pyrolysis causes a negative interference in the HNO₃ channel. Both interferences can be quantified and corrected for but must be considered when using TD techniques for measurements of organic nitrates. This instrument has been successfully deployed for chamber measurements at widely varying concentrations, as well as ambient measurements of NO_y.

中文翻译：

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热解腔衰荡光谱仪（TD-CRDS），用于检测气相和颗粒相中的有机硝酸盐

开发了一种热解离腔衰荡光谱仪（TD-CRDS），用于测量气相和颗粒相中的NO ₂，过氧硝酸盐（PNs），硝酸烷基酯（ANs）和HNO ₃，这是使用商用Los Gatos建造的研究NO ₂分析仪。TD-CRDS的检出限对于ANs，PNs和HNO ₃为0.66 ppb，对于NO ₂为0.48 ppb 。对于所有四类NO _y，分别进行气体和颗粒测量的时间分辨率为8分钟，对于总气体+颗粒测量的时间分辨率为3分钟。通过比较NO _2来测试TD-CRDS的准确性用化学发光测量NO _X监视器和气溶胶相的AN与气溶胶质谱仪（AMS）。N ₂ O ₅在高氧化剂浓度腔室条件下会在PN和AN通道中造成严重干扰，而臭氧热解会在HNO ₃通道中造成负面干扰。可以对两种干扰进行量化和校正，但在使用TD技术测量有机硝酸盐时必须考虑。该仪器已成功用于各种浓度的腔室测量以及NO _y的环境测量。