Development and application of a low-cost vaporizer for rapid, quantitative, in situ addition of organic gases and particles to an environmental chamber
Development and application of a low-cost vaporizer for rapid, quantitative, in situ addition of organic gases and particles to an environmental chamber
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DOI：
10.1080/02786826.2020.1808186
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发表时间：
2020-09-04
影响因子：
5.2
通讯作者：
Ziemann, Paul J.
中科院分区：
文献类型：
--
作者：
Finewax, Zachary;Jimenez, Jose L.;Ziemann, Paul J.
环境室研究被广泛用于研究大气化学和气溶胶的形成。然而，一个燃烧室的大表面积体积比导致需要考虑的影响，以便将燃烧室研究的结果应用于环境大气。这些包括但不限于气壁分配和颗粒沉积到壁上，这两者都会影响反应产物的定量。在这里，开发了一种低成本的汽化器，以提供一种在腔室内快速产生具有良好特征的有机蒸汽和气溶胶颗粒的方法。这种原位方法消除了在室外的设备中产生有机气体或颗粒然后通过管道输送到室内时可能发生的表面损失，从而为实现定量添加提供了一种简单的方法。热稳定的挥发性有机化合物可以在1分钟内添加到腔室中，这可以使用气相色谱法精确测量气壁分配时间尺度和平衡。该汽化器还可用于制造低挥发性有机气溶胶颗粒，其平均直径约为150纳米，可选择的质量浓度低至5 μ g m(-3)，通过均匀成核在几分钟内。这种气溶胶可用于校准或评估仪器的性能，如实验室和实地研究中的扫描迁移率粒度仪。Copyright (c) 2020美国气溶胶研究协会
Environmental chamber studies are widely employed to investigate atmospheric chemistry and aerosol formation. However, the large surface area-to-volume ratio of a chamber leads to effects that need to be accounted for in order to apply the results of chamber studies to the ambient atmosphere. These include, but are not limited to, gas-wall partitioning and particle deposition to walls, both of which can impact quantification of reaction products. Here, a low-cost vaporizer was developed to provide a means to rapidly create well-characterized organic vapors and aerosol particles inside the chamber. This in situ approach eliminates the losses to surfaces that can occur when organic gases or particles are created in a device outside the chamber and then transported inside through tubing, thus providing a simple means for achieving quantitative addition. Thermally stable volatile organic compounds can be added to the chamber within similar to 1 min, which allows for accurate measurements of gas-wall partitioning timescales and equilibrium using gas chromatography. The vaporizer can also be used to create low-volatility organic aerosol particles with a mean diameter of similar to 150 nm and selectable mass concentration as low as 5 mu g m(-3)via homogeneous nucleation within a few minutes. Such an aerosol can be used to calibrate or evaluate the performance of instruments such as the scanning mobility particle sizer in laboratory and field studies. Copyright (c) 2020 American Association for Aerosol Research