The second ACTRIS inter-comparison (2016) for Aerosol Chemical Speciation Monitors (ACSM): Calibration protocols and instrument performance evaluations
The second ACTRIS inter-comparison (2016) for Aerosol Chemical Speciation Monitors (ACSM): Calibration protocols and instrument performance evaluations
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DOI：
10.1080/02786826.2019.1608901
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发表时间：
2019-05-21
影响因子：
5.2
通讯作者：
Favez, Olivier
中科院分区：
文献类型：
--
作者：
Freney, Evelyn;Zhang, Yunjiang;Favez, Olivier
这项工作介绍了在气溶胶化学监测校准中心(法国ACMCC)进行的2016年气溶胶化学形态监测(ACSM)比对工作取得的结果。来自欧洲气溶胶、云和痕量气体观测基础设施(ACTRIS)网络的15个四极ACSM(Q_ACSM)使用一种新的程序进行了校准，该程序在与采样期间使用的相同操作条件下获取校准数据，从而获得代表仪器性能的信息。新的校准程序显著减少了测量的硫酸盐质量浓度的分布，提高了ACSM之间无机物种测量的重复性，以及与共置的独立仪器的一致性。经测试的校准程序还允许对个别仪器中的伪影进行调查，例如高估有机气溶胶的m/z 44。这种影响是通过在硝酸铵校准过程中测量的m/z(质量与电荷)44与硝酸盐的比率来量化的，数值范围从0.03到0.26，表明它对某些仪器可能是重要的。将先前提出的用于解释这一伪影的碎片表校正应用于在本研究期间获得的测量值。对于某些仪器(带有高伪影的仪器)，这种碎片表调整导致F44(m/z 44/Org)信号的“过度校正”。这一修正是基于用纯NH4NO3进行的测量，假设伪影的大小与化学成分无关。利用在不同NH4NO3混合比下(从NH4NO3和(NH4)(2)SO4溶液中)获得的数据，我们观察到伪影的大小随组成的变化而变化。在这里，我们应用了依赖于环境NO_3质量分数的最新校正，这导致了仪器之间有机信号的更好的一致性。这项工作说明了整合新的校准程序和伪影校正的好处，但也突出了这些相互比较工作的好处，以继续提高我们对这些仪器如何运作的知识，并帮助我们解释大气化学。
This work describes results obtained from the 2016 Aerosol Chemical Speciation Monitor (ACSM) intercomparison exercise performed at the Aerosol Chemical Monitor Calibration Center (ACMCC, France). Fifteen quadrupole ACSMs (Q_ACSM) from the European Research Infrastructure for the observation of Aerosols, Clouds and Trace gases (ACTRIS) network were calibrated using a new procedure that acquires calibration data under the same operating conditions as those used during sampling and hence gets information representative of instrument performance. The new calibration procedure notably resulted in a decrease in the spread of the measured sulfate mass concentrations, improving the reproducibility of inorganic species measurements between ACSMs as well as the consistency with co-located independent instruments. Tested calibration procedures also allowed for the investigation of artifacts in individual instruments, such as the overestimation of m/z 44 from organic aerosol. This effect was quantified by the m/z (mass-to-charge) 44 to nitrate ratio measured during ammonium nitrate calibrations, with values ranging from 0.03 to 0.26, showing that it can be significant for some instruments. The fragmentation table correction previously proposed to account for this artifact was applied to the measurements acquired during this study. For some instruments (those with high artifacts), this fragmentation table adjustment led to an "overcorrection" of the f44 (m/z 44/Org) signal. This correction based on measurements made with pure NH4NO3, assumes that the magnitude of the artifact is independent of chemical composition. Using data acquired at different NH4NO3 mixing ratios (from solutions of NH4NO3 and (NH4)(2)SO4) we observe that the magnitude of the artifact varies as a function of composition. Here we applied an updated correction, dependent on the ambient NO3 mass fraction, which resulted in an improved agreement in organic signal among instruments. This work illustrates the benefits of integrating new calibration procedures and artifact corrections, but also highlights the benefits of these intercomparison exercises to continue to improve our knowledge of how these instruments operate, and assist us in interpreting atmospheric chemistry.