An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS) for fast PAN and PPN measurements
An aircraft-borne chemical ionization – ion trap mass spectrometer (CI-ITMS) for fast PAN and PPN measurements
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DOI：
10.5194/amt-4-173-2011
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发表时间：
2010-10
影响因子：
3.8
通讯作者：
A. Roiger;H. Aufmhoff;P. Stock;F. Arnold;H. Schlager
中科院分区：
文献类型：
--
作者：
A. Roiger;H. Aufmhoff;P. Stock;F. Arnold;H. Schlager
抽象。研制了一台机载化学电离离子阱质谱仪（CI-ITMS），用于对流层和平流层PAN（过氧乙酰硝酸酯）和PPN（过氧丙酰硝酸酯）的快速原位测量。在2008年夏季POLARCAT-GRACE活动框架内，德国航天中心研究飞机“猎鹰”号执行了18次飞行任务，在北极首次科学部署了FASTPEX仪器（FASTPEX =过氧酰基硝酸盐快速测量）。介绍了FASTPEX仪器，讨论了所用离子阱质谱仪的特性。介绍了从边界层到平流层最低层在高度高达~12公里处获得的大气数据。采样数据的时间分辨率为2 s，2σ检测限为25 pmol mol−1。同位素标记的标准用于永久在线校准。因此，对于大于200 pmol mol−1的混合比，PAN测量的准确度优于±10%。夏季北极对流层中的PAN混合比大约为几百pmol mol−1，通常与CO相关良好。在北极边界层和平流层最低层中，由于PAN前体气体的本地来源缺失和有效的去除过程（热分解/光解），观察到较小的PAN混合比。PPN，第二丰富的PAN同系物，同时测量。观察到的PPN/PAN比值范围在约0.03和0.3之间。
Abstract. An airborne chemical ionization ion trap mass spectrometer instrument (CI-ITMS) has been developed for tropospheric and stratospheric fast in-situ measurements of PAN (peroxyacetyl nitrate) and PPN (peroxypropionyl nitrate). The first scientific deployment of the FASTPEX instrument (FASTPEX = Fast Measurement of Peroxyacyl nitrates) took place in the Arctic during 18 missions aboard the DLR research aircraft Falcon, within the framework of the POLARCAT-GRACE campaign in the summer of 2008. The FASTPEX instrument is described and characteristic properties of the employed ion trap mass spectrometer are discussed. Atmospheric data obtained at altitudes of up to ~12 km are presented, from the boundary layer to the lowermost stratosphere. Data were sampled with a time resolution of 2 s and a 2σ detection limit of 25 pmol mol−1. An isotopically labelled standard was used for a permanent on-line calibration. For this reason the accuracy of the PAN measurements is better than ±10% for mixing ratios greater than 200 pmol mol−1. PAN mixing ratios in the summer Arctic troposphere were in the order of a few hundred pmol mol−1 and generally correlated well with CO. In the Arctic boundary layer and lowermost stratosphere smaller PAN mixing ratios were observed due to a combination of missing local sources of PAN precursor gases and efficient removal processes (thermolysis/photolysis). PPN, the second most abundant PAN homologue, was measured simultaneously. Observed PPN/PAN ratios range between ~0.03 and 0.3.