当前位置:
X-MOL 学术
›
Atmos. Meas. Tech.
›
论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
A Systematic Re-evaluation of Methods for Quantification of Bulk Particle-phase Organic Nitrates Using Real-time Aerosol Mass Spectrometry
Atmospheric Measurement Techniques ( IF 3.8 ) Pub Date : 2021-09-06 , DOI: 10.5194/amt-2021-263 Douglas A. Day , Pedro Campuzano-Jost , Benjamin A. Nault , Brett B. Palm , Weiwei Hu , Hongyu Guo , Paul J. Wooldridge , Ronald C. Cohen , Kenneth S. Docherty , J. Alex Huffman , Suzane S. de Sá , Scot T. Martin , Jose L. Jimenez
Atmospheric Measurement Techniques ( IF 3.8 ) Pub Date : 2021-09-06 , DOI: 10.5194/amt-2021-263 Douglas A. Day , Pedro Campuzano-Jost , Benjamin A. Nault , Brett B. Palm , Weiwei Hu , Hongyu Guo , Paul J. Wooldridge , Ronald C. Cohen , Kenneth S. Docherty , J. Alex Huffman , Suzane S. de Sá , Scot T. Martin , Jose L. Jimenez
Abstract. Organic nitrate (RONO2) formation in the atmosphere represents a sink of NOx (NOx = NO + NO2) and termination of the NOx/HOx (HOx = HO2 + OH) ozone formation and radical propagation cycles, can act as a NOx reservoir transporting reactive nitrogen, and contributes to secondary organic aerosol formation. While some fraction of RONO2 is thought to reside in the particle phase, particle-phase organic nitrates (pRONO2) are infrequently measured and thus poorly understood. There is an increasing prevalence of aerosol mass spectrometer (AMS) instruments, which have shown promise for determining quantitative total organic nitrate functional group contribution to aerosols. A simple approach that relies on the relative intensities of NO+ and NO2+ ions in the AMS spectrum, the calibrated NOx+ ratio for NH4NO3, and the inferred ratio for pRONO2 has been proposed as a way to apportion the total nitrate signal to NH4NO3 and pRONO2. This method is increasingly being applied to field and laboratory data. However, the methods applied have been largely inconsistent and poorly characterized, and therefore, a detailed evaluation is timely. Here, we compile an extensive survey of NOx+ ratios measured for various pRONO2 compounds and mixtures from multiple AMS instruments, groups, and laboratory and field measurements. We show that, in the absence of pRONO2 standards, the pRONO2 NOx+ ratio can be estimated using a ratio referenced to the calibrated NH4NO3 ratio, a so-called
中文翻译:
使用实时气溶胶质谱法对散装颗粒相有机硝酸盐的定量方法进行系统重新评估
摘要。大气中有机硝酸盐 (RONO 2 ) 的形成代表了 NO x (NO x = NO + NO 2 )汇和 NO x /HO x (HO x = HO 2 + OH) 臭氧形成和自由基传播循环的终止,可以充当NO X储存器输送活性氮,并且有助于二次有机气溶胶的形成。虽然认为一部分 RONO 2存在于颗粒相中,但颗粒相有机硝酸盐 (pRONO 2) 很少被测量,因此知之甚少。气溶胶质谱仪 (AMS) 越来越流行,它们已显示出用于确定定量总有机硝酸盐官能团对气溶胶的贡献的前景。一种简单的方法依赖于AMS 光谱中 NO +和 NO 2 +离子的相对强度、NH 4 NO 3的校准 NO x +比率以及 pRONO 2的推断比率,已被提议作为一种方法来分配NH 4 NO 3和 proNO 2 的总硝酸盐信号. 这种方法越来越多地应用于现场和实验室数据。然而,所采用的方法在很大程度上不一致且特征不佳,因此,进行详细评估是及时的。在这里,我们对来自多个 AMS 仪器、组以及实验室和现场测量的各种 pRONO 2化合物和混合物的 NO x +比率进行了广泛调查。我们表明,在没有 pRONO 2标准的情况下,可以使用参考校准的 NH 4 NO 3比率的比率来估计pRONO 2 NO x +比率,即所谓的
更新日期:2021-09-06
Ratio-of-Ratiosmethod (RoR = 2.75 ± 0.41). We systematically explore the basis for quantifying pRONO2 (and NH4NO3) with the RoR method using ground and aircraft field measurements conducted over a large range of conditions. The method is compared to another AMS method (positive matrix factorization, PMF) and other pRONO2 and related (e.g., total gas + particle RONO2) measurements, generally showing good agreement/correlation. A broad survey of ground and aircraft AMS measurements shows a pervasive trend of higher fractional contribution of pRONO2 to total nitrate with lower total nitrate concentrations, which generally corresponds to shifts from urban-influenced to rural/remote regions. Compared to ground campaigns, observations from all aircraft campaigns showed substantially lower pRONO2 contributions at mid ranges of total nitrate (0.01–0.1 up to 2–5 μg m−3), suggesting that the balance of effects controlling NH4NO3 and pRONO2 formation and lifetimes — such as higher humidity, lower temperatures, greater dilution, different sources, higher particle acidity, and pRONO2 hydrolysis (possibly accelerated by particle acidity) — favors lower pRONO2 contributions for those environments and altitudes sampled.
中文翻译:
使用实时气溶胶质谱法对散装颗粒相有机硝酸盐的定量方法进行系统重新评估
摘要。大气中有机硝酸盐 (RONO 2 ) 的形成代表了 NO x (NO x = NO + NO 2 )汇和 NO x /HO x (HO x = HO 2 + OH) 臭氧形成和自由基传播循环的终止,可以充当NO X储存器输送活性氮,并且有助于二次有机气溶胶的形成。虽然认为一部分 RONO 2存在于颗粒相中,但颗粒相有机硝酸盐 (pRONO 2) 很少被测量,因此知之甚少。气溶胶质谱仪 (AMS) 越来越流行,它们已显示出用于确定定量总有机硝酸盐官能团对气溶胶的贡献的前景。一种简单的方法依赖于AMS 光谱中 NO +和 NO 2 +离子的相对强度、NH 4 NO 3的校准 NO x +比率以及 pRONO 2的推断比率,已被提议作为一种方法来分配NH 4 NO 3和 proNO 2 的总硝酸盐信号. 这种方法越来越多地应用于现场和实验室数据。然而,所采用的方法在很大程度上不一致且特征不佳,因此,进行详细评估是及时的。在这里,我们对来自多个 AMS 仪器、组以及实验室和现场测量的各种 pRONO 2化合物和混合物的 NO x +比率进行了广泛调查。我们表明,在没有 pRONO 2标准的情况下,可以使用参考校准的 NH 4 NO 3比率的比率来估计pRONO 2 NO x +比率,即所谓的
比率比率方法 ( RoR = 2.75 ± 0.41)。我们系统地探索了使用RoR方法量化 pRONO 2(和 NH 4 NO 3)的基础,该方法使用在大范围条件下进行的地面和飞机场测量。将该方法与另一种 AMS 方法(正矩阵分解,PMF)和其他 pRONO 2和相关(例如,总气体 + 粒子 RONO 2)测量进行比较,通常显示出良好的一致性/相关性。对地面和飞机 AMS 测量的广泛调查显示,pRONO 2 的比例贡献较高的普遍趋势到总硝酸盐浓度较低的总硝酸盐,这通常对应于从受城市影响到农村/偏远地区的转变。与地面活动相比,所有飞机活动的观察结果表明,在总硝酸盐的中等范围(0.01-0.1 至 2-5 μg m -3)中,pRONO 2 的贡献显着降低,这表明控制 NH 4 NO 3和 pRONO的影响平衡2 的形成和寿命——例如更高的湿度、更低的温度、更大的稀释度、不同的来源、更高的颗粒酸度和 pRONO 2水解(可能由颗粒酸度加速)——有利于较低的 pRONO 2 对采样的环境和海拔的贡献。