Field measurements of biogenic volatile organic compounds in the atmosphere using solid-phase microextraction Arrow

Luís Miguel Feijó Barreira,Kari Hartonen,Enna Heikkinen,Jevgeni Parshintsev,Geoffroy Duporté,Marja-Liisa Riekkola,Tuukka Rönkkö,Markku Kulmala,Lydia Hyrsky,Matti Jussila

doi:10.5194/amt-11-881-2018

Abstract

Abstract. Biogenic volatile organic compounds (BVOCs) emitted by terrestrial vegetation participate in a diversity of natural processes. These compounds impact both short-range processes, such as on plant protection and communication, and long-range processes, for example by participating in aerosol particle formation and growth. The biodiversity of plant species around the Earth, the vast assortment of emitted BVOCs, and their trace atmospheric concentrations contribute to the substantial remaining uncertainties about the effects of these compounds on atmospheric chemistry and physics, and call for the development of novel collection devices that can offer portability with improved selectivity and capacity. In this study, a novel solid-phase microextraction (SPME) Arrow sampling system was used for the static and dynamic collection of BVOCs from a boreal forest, and samples were subsequently analyzed on site by gas chromatography–mass spectrometry (GC-MS). This system offers higher sampling capacity and improved robustness when compared to traditional equilibrium-based SPME techniques, such as SPME fibers. Field measurements were performed in summer 2017 at the Station for Measuring Ecosystem–Atmosphere Relations (SMEAR II) in Hyytiälä, Finland. Complementary laboratory tests were also performed to compare the SPME-based techniques under controlled experimental conditions and to evaluate the effect of temperature and relative humidity on their extraction performance. The most abundant monoterpenes and aldehydes were successfully collected. A significant improvement on sampling capacity was observed with the new SPME Arrow system over SPME fibers, with collected amounts being approximately 2× higher for monoterpenes and 7–8× higher for aldehydes. BVOC species exhibited different affinities for the type of sorbent materials used (polydimethylsiloxane (PDMS)–carbon wide range (WR) vs. PDMS–divinylbenzene (DVB)). Higher extraction efficiencies were obtained with dynamic collection prior to equilibrium regime, but this benefit during the field measurements was small, probably due to the natural agitation provided by the wind. An increase in temperature and relative humidity caused a decrease in the amounts of analytes extracted under controlled experimental conditions, even though the effect was more significant for PDMS–carbon WR than for PDMS–DVB. Overall, results demonstrated the benefits and challenges of using SPME Arrow for the sampling of BVOCs in the atmosphere.

Highlights

Vegetation covering Earth landmasses release a diversity of biogenic volatile organic compounds (BVOCs), which comprise a large variety of molecules that differ in size, physicochemical properties, and metabolic origin (Laothawornkitkul et al, 2009; Peñuelas and Llusià, 2001; Peñuelas and Staudt, 2010)
A novel solid-phase microextraction (SPME) Arrow system was optimized and tested in the laboratory to study its applicability for the field measurement of Biogenic volatile organic compounds (BVOCs) in forest atmosphere
The measurements performed in the field and comparison with atmospheric temperature, relative humidity, ozone, precipitation, photosynthetically active radiation (PAR), and particle number concentration (PNC; available at http://avaa.tdata.fi/web/smart and provided by Junninen et al, 2009) are further discussed

Summary

Introduction

Vegetation covering Earth landmasses release a diversity of biogenic volatile organic compounds (BVOCs), which comprise a large variety of molecules that differ in size, physicochemical properties, and metabolic origin (Laothawornkitkul et al, 2009; Peñuelas and Llusià, 2001; Peñuelas and Staudt, 2010). BVOCs participate in atmospheric reactions, which leads to the formation of numerous secondary products (Atkinson and Arey, 2003). The lifetime of BVOCs varies to a large extent, depending on the compound and oxidants involved (Atkinson and Arey, 2003). The low-volatility secondary products formed in these photooxidation reactions can subsequently result in the formation of secondary organic aerosols (SOA; Jimenez et al, 2009). BVOCs are believed to be the largest source of SOA on a global scale (Henze and Seinfeld, 2006)

Methods

Results

Conclusion