Nitrogen oxides (${\mathrm{NO}}_x=\mathrm{NO}+{\mathrm{NO}}_{\mathrm{2}}$) are critical intermediates in atmospheric chemistry and air pollution. NO_x levels control the cycling and hence abundance of the primary atmospheric oxidants OH and NO₃ and regulate the ozone production which results from the degradation of volatile organic compounds (VOCs) in the presence of sunlight. They are also atmospheric pollutants, and NO₂ is commonly included in air quality objectives and regulations. NO_x levels also affect the production of the nitrate component of secondary aerosol particles and other pollutants, such as the lachrymator peroxyacetyl nitrate (PAN). The accurate measurement of NO and NO₂ is therefore crucial for air quality monitoring and understanding atmospheric composition. The most commonly used approach for the measurement of NO is the chemiluminescent detection of electronically excited NO₂ (NO${}_{\mathrm{2}}^{\ast }$) formed from the NO + O₃ reaction within the NO_x analyser. Alkenes, ubiquitous in the atmosphere from biogenic and anthropogenic sources, also react with ozone to produce chemiluminescence and thus may contribute to the measured NO_x signal. Their ozonolysis reaction may also be sufficiently rapid that their abundance in conventional instrument background cycles, which also utilises the reaction with ozone, differs from that in the measurement cycle such that the background subtraction is incomplete, and an interference effect results. This interference has been noted previously, and indeed, the effect has been used to measure both alkenes and ozone in the atmosphere. Here we report the results of a systematic investigation of the response of a selection of commercial NO_x monitors to a series of alkenes. These NO_x monitors range from systems used for routine air quality monitoring to atmospheric research instrumentation. The species-investigated range was from short-chain alkenes, such as ethene, to the biogenic monoterpenes. Experiments were performed in the European PHOtoREactor (EUPHORE) to ensure common calibration and samples for the monitors and to unequivocally confirm the alkene levels present (via Fourier transform infrared spectroscopy – FTIR). The instrument interference responses ranged from negligible levels up to 11 %, depending upon the alkene present and conditions used (e.g. the presence of co-reactants and differing humidity). Such interferences may be of substantial importance for the interpretation of ambient NO_x data, particularly for high VOC, low NO_x environments such as forests or indoor environments where alkene abundance from personal care and cleaning products may be significant.

中文翻译：

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从化学发光NO烯烃干扰_X测量

氮氧化物 （${\mathrm{没有}}_X=\mathrm{没有}+{\mathrm{没有}}_{\mathrm{2}}$）是大气化学和空气污染的关键中间体。NO _x 含量控制主要大气氧化剂OH和NO ₃的循环并因此控制其含量，并调节臭氧的产生，这是由于存在阳光下挥发性有机化合物（VOC）降解而产生的。它们也是大气污染物，NO ₂通常包含在空气质量目标和法规中。NO _x含量也会影响次级气溶胶颗粒和其他污染物（例如催泪剂过氧乙酰硝酸盐（PAN））中硝酸盐成分的产生。准确测量NO和NO ₂因此对于空气质量监测和了解大气成分至关重要。测量NO的最常用方法是化学发光检测电子激发的NO ₂（NO${}_{\mathrm{2}}^{\ast }$）是由NO _x分析仪中的NO +  O ₃反应形成的 。烯烃，在从生物和人为来源的气氛无处不在，也与臭氧反应，产生化学发光，并且因此可以有助于测量的NO _X信号。它们的臭氧分解反应也可能足够快，以至于它们在传统仪器背景循环中的丰度（也利用与臭氧的反应）不同于测量循环中的丰度，因此背景扣除不完全，从而产生干扰效果。以前已经注意到了这种干扰，实际上，这种影响已被用于测量大气中的烯烃和臭氧。在这里，我们报告一个选择的商业NO的反应进行了系统的调查结果_X显示器的一系列烯烃。这些NO _X监测器的范围从用于常规空气质量监测的系统到大气研究仪器。物种调查的范围是从短链烯烃（例如乙烯）到生物单萜。在欧洲的PHOtoREactor（EUPHORE）中进行了实验，以确保监视器的通用校准和样品，并明确地确认存在的烯烃含量（通过傅里叶变换红外光谱-FTIR）。仪器的干扰响应范围可忽略不计，最高可达到11％，这取决于存在的烯烃和使用的条件（例如，共反应物的存在和湿度的不同）。这样的干扰对于环境NO _x数据的解释可能非常重要，尤其是对于高VOC，低NO _x而言 在诸如森林或室内环境之类的环境中，个人护理和清洁产品中的烯烃含量可能很高。