Despite its importance as a radical precursor and a hazardous pollutant, the chemistry of nitrous acid (HONO) in the indoor environment is not fully understood. We present results from a comparison of HONO measurements from a time-of-flight chemical ionization mass spectrometer (ToF-CIMS) and a laser photofragmentation/laser-induced fluorescence (LP/LIF) instrument during the House Observations of Microbial and Environmental Chemistry (HOMEChem) campaign. Experiments during HOMEChem simulated typical household activities and provided a dynamic range of HONO mixing ratios. The instruments measured HONO at different locations in a house featuring a typical air change rate (ACR) (0.5 h^–1) and an enhanced mixing rate (∼8 h^–1). Despite the distance between the instruments, measurements from the two instruments agreed to within their respective uncertainties (slope = 0.85, R² = 0.92), indicating that the lifetime of HONO is long enough for it to be quickly distributed indoors, although spatial gradients occurred during ventilation periods. This suggests that emissions of HONO from any source can mix throughout the house and can contribute to OH radical production in sunlit regions, enhancing the oxidative capacity indoors. Measurement discrepancies were likely due to interferences with the LP/LIF instrument as well as calibration uncertainties associated with both instruments.

中文翻译：

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室内亚硝酸同时测量的比较：对室内 HONO 排放空间分布的影响


尽管亚硝酸 (HONO) 作为自由基前体和有害污染物很重要，但其在室内环境中的化学性质尚不完全清楚。我们展示了在微生物和环境化学众议院观测期间飞行时间化学电离质谱仪 (ToF-CIMS) 和激光光碎裂/激光诱导荧光 (LP/LIF) 仪器的 HONO 测量结果的比较结果（ HOMEChem）活动。 HOMEChem 期间的实验模拟了典型的家庭活动，并提供了 HONO 混合比例的动态范围。这些仪器在具有典型换气率 (ACR) (0.5 h ^–1 ) 和增强混合率 (∼8 h ^–1 ) 的房屋内不同位置测量 HONO。尽管仪器之间存在距离，但两台仪器的测量结果在各自的不确定度范围内一致（斜率 = 0.85， R ² = 0.92），这表明 HONO 的寿命足够长，足以使其在室内快速分布，尽管存在空间梯度通风期间。这表明任何来源排放的 HONO 都可以在整个房屋中混合，并有助于阳光照射区域产生 OH 自由基，从而增强室内的氧化能力。测量差异可能是由于 LP/LIF 仪器的干扰以及与这两种仪器相关的校准不确定性造成的。