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首页> 外文期刊>Atmospheric Measurement Techniques >Development, characterization and first deployment of an improved online reactive oxygen species analyzer
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Development, characterization and first deployment of an improved online reactive oxygen species analyzer

机译：改进的在线反应性氧物种分析仪的开发，表征和首先部署

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Inhalation of atmospheric particles is linked to human diseases. Reactive oxygen species (ROS) present in these atmospheric aerosols may play an important role. However, the ROS content in aerosols and their formation pathways are still largely unknown. Here, we have developed an online and offline ROS analyzer using a 2′,7′-dichlorofluorescin (DCFH) based assay. The ROS analyzer was calibrated with Hsub2/subOsub2/sub and its sensitivity was characterized using a suite of model organic compounds. The instrument detection limit determined as 3?times the noise is 1.3?nmol?Lsup?1/sup for offline analysis and 2?nmol?msup?3/sup of sampled air when the instrument is operated online at a fluorescence response time of approximately 8?min, while the offline method detection limit is 18?nmol?Lsup?1/sup. Potential interferences from gas-phase Osub3/sub and NOsub2/sub as well as matrix effects of particulate SOsub4/subsup2?/sup and NOsub3/subsup?/sup were tested, but not observed. Fesup3+/sup had no influence on the ROS signal, while soluble Fesup2+/sup reduced it if present at high concentrations in the extracts. Both online and offline methods were applied to identify the ROS content of different aerosol types, i.e., ambient aerosols as well as fresh and aged aerosols from wood combustion emissions. The stability of the ROS was assessed by comparing the ROS concentration measured by the same instrumentation online in situ with offline measurements. We also analyzed the evolution of ROS in specific samples by conducting the analysis after storage times of up to 4?months. The ROS were observed to decay with increasing storage duration. From their decay behavior, ROS in secondary organic aerosol (SOA) can be separated into short- and long-lived fractions. The half-life of the short-lived fraction was 1.7?±?0.4?h, while the half-life of the long-lived fraction could not be determined with our uncertainties. All these measurements showed consistently that on average 60?±?20?% of the ROS were very reactive and disappeared during the filter storage time. This demonstrates the importance of a fast online measurement of ROS.
机译：吸入大气颗粒与人类疾病相关联。这些大气气溶胶中存在的活性氧物种（ROS）可能发挥重要作用。然而，气溶胶中的ROS含量及其形成途径仍然很大程度上是未知的。在这里，我们使用基于2'，7'-二氯氟丝（DCFH）的测定来开发了一个在线和离线ROS分析仪。 ROS分析仪用H 2 O 2 校准，并且其灵敏度是使用型式的有机化合物套件表征。仪器检测限定为3？噪声的噪声为1.3？nmol？l ？1 用于离线分析，2？nmol？m ？3 当仪器时采样空气在线在线运行，在荧光响应时间约为8？分钟，而离线方法检测限为18？nmol？l ？1 。来自气相O 3 和NO 2 的潜在干扰，以及颗粒的基质效应 4 2？并且测试了NO 3 ？但未观察到。 Fe 3 + 对ROS信号没有影响，而可溶性Fe 2 + / sup>如果在提取物中的高浓度下存在，则减少它。应用在线和离线方法都被应用于鉴定不同气溶胶类型的ROS含量，即环境气溶胶以及来自木燃烧排放的新鲜和老化气溶胶。通过将通过在线测量的ROS浓度与在线测量相同的仪器测量来评估ROS的稳定性。我们还通过在最多4个月的储存时间进行分析，分析了特定样品中ROS的演变。观察到ROS衰减随着储存持续时间而衰减。从它们的衰减行为来看，次级有机气溶胶（SOA）中的RO可以分成短寿命的级分。短寿命分数的半衰期为1.7？±0.4？H，而长寿分数的半衰期无法通过我们的不确定性确定。所有这些测量始终显示，平均60？±20？±20？％ROS在过滤器储存时间期间的ROS非常反应并消失。这证明了ROS快速在线测量的重要性。

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