عنوان انگلیسی مقاله:
Anthropogenic and biogenic hydrophobic VOCs detected in clouds at the puy de Dôme station using Stir Bar Sorptive Extraction: Deviation from the Henrys law prediction
ترجمه فارسی عنوان مقاله:
VOC های ضد آب و انسان و بیولوژیکی آبگریز شناسایی شده در ابرها در ایستگاه پوی دووم با استفاده از استخراج Stir Bar Sorptive: انحراف از پیش بینی قانون هنری
Sciencedirect - Elsevier - Atmospheric Research, 237 (2020) 104844: doi:10:1016/j:atmosres:2020:104844
Miao Wanga, Hélène Perrouxa, Jennifer Fleureta, Angelica Biancoa, Laetitia Bouviera,b, Aurélie Colomba, Agnès Borbona,⁎, Laurent Deguillaumea
Cloud droplets are able to trap many gaseous compounds and represent a very reactive media in the atmosphere.
However, phase-partitioning of Volatile Organic Compounds (VOCs) between gaseous phase (interstitial air) and
atmospheric liquid phase (cloud droplets) is still poorly characterized. In the present work, air samples and cloud
water were collected simultaneously and hydrophobic organic compounds from anthropogenic and biogenic
origins were quantified in order to evaluate their air/water partitioning. For this, cloud events were sampled at
the puy de Dôme station (PUY). A new analytical approach was optimized to explore dissolved VOCs in the
aqueous phase by Stir Bar Sorptive Extraction (SBSE) and gaseous samples were collected using sorbent tubes.
All samples were analyzed by Thermal Desorption (TD) Gas Chromatography (GC) coupled with Mass
Spectrometry (MS). Extraction efficiencies by SBSE vary between 22% and 97% and the detection limit of VOCs
in aqueous cloud samples lies between 1.0 and 8.7 ng L−1. Experimental partitioning is evaluated towards the
theoretical one described by the Henrys Law constants. Our results show that observed concentrations of hydrophobic
VOCs are supersaturated by a factor of 10–103 in comparison with Henrys law equilibrium.
Calculations have been performed to evaluate the potential role of adsorption at the air/water interface and of
sorption with non-dissolved organic carbon. However, the supersaturation in the cloud droplets requires more
laboratory experiments to understand processes at the air/water interface and constrain cloud chemistry models.
Keywords: Volatile organic compounds (VOCs) | Cloud | Gas-liquid partitioning | Henrys law | PUY station | Stir Bar Sorptive Extraction (SBSE)