A plant chamber system with downstream reaction chamber to study the effects of pollution on biogenic emissions

Abstract

A system of two plant chambers and a downstream reaction chamber has been set up to investigate the emission of biogenic volatile organic compounds (BVOCs) and possible effects of pollutants such as ozone. The system can be used to compare BVOC emissions from two sets of differently treated plants, or to study the photochemistry of real plant emissions under polluted conditions without exposing the plants to pollutants. The main analytical tool is a proton-transfer-reaction time-of-flight mass spectrometer (PTR-TOF-MS) which allows online monitoring of biogenic emissions and chemical degradation products. The identification of BVOCs and their oxidation products is aided by cryogenic trapping and subsequent in situ gas chromatographic analysis. Environmental impactIn this paper we describe a new laboratory setup to study the response of volatile plant emissions to different types of environmental stress. The centerpiece is the combination of two plant chambers with a reaction chamber that allows for photochemical processing of the plant emissions. Modern analytical tools such as proton-transfer-reaction time-of-ight mass spectrometry and gas chromatography allow for fast, precise and detailed chemical analysis. Results from a pilot study demonstrate the capacity of the system to investigate environmental issues of high importance, such as the discrepancy between the observed and predicted chemical loss of ozone via reactions with plant emissions; the impact of pollution and UV-B radiation on plant emissions.

A new plant chamber facility, PLUS, coupled to the atmosphere simulation chamber SAPHIR

“…The use of direct emissions from plants is a way of progressing towards more realistic experimental simulations. Recently a number of setups implementing the use of direct plant emissions in atmospheric chemistry experiments have emerged, ranging from the investigation of BVOC oxidation within a greenhouse (Pinto et al, 2007;Joutsensaari et al, 2005) to designs implementing two separate chambers for independent variation of emission and oxidation conditions (Timkovsky et al, 2014;Wyche et al, 2014;Hao et al, 2009;Mentel et al, 2009;VanReken et al, 2006).…”

Stress-Induced Volatile Emissions and Signalling in Inter-Plant Communication

“…It is important, however, to consider changes that may occur in the plant’s micro-environment while in the headspace collection chambers. Increases in humidity [ 39 ] and temperature, as well as reduced light intensity in the chambers [ 244 , 245 ] are likely to affect transpiration rates and, subsequently, VOC composition and emission rates. Additionally, given the potential for the scalping of VOCs by hydrophobic materials, their adsorption by the lining of collection chambers or sampling bags may require the use of non-reactive materials such as fluorinated ethylene propylene (FEP) or polytetrafluoroethylene (PTFE), which have been shown to be effective in plant VOC sampling [ 210 , 246 , 247 ].…”

Direct Contact Sorptive Extraction: A Robust Method for Sampling Plant Volatiles in the Field

“…First, changes in temperature, humidity, and light due to chamber materials occur. For example, polyester and glass chambers increase the temperature by as much as 5.2 and 7.5 °C, respectively, leading to changes in VOC composition and emission rates. ,, Humidity inside the chamber is also higher effecting stomatal closure, which controls the emission rate of some but not all plant VOCs. , Glass and plastic chambers block up to 40% and 76% UVB light, respectively, causing significant differences in volatile composition and concentration. ,, Second, despite lower cost and ease of portability and disposal, sampling chambers made of polyethylene terephthalate (PET), polyacetate, or nylon often leach into the sample potentially masking compounds of interest. , Third, adsorption onto or diffusion through chamber materials results in loss of analyte. For example, poor recovery was obtained for Z -jasmone, geraniol, nerolidol, and vanillin due to adsorption and diffusion effects through these materials. , Additional problems associated with using sorbent tubes includes analyte breakthrough and the inability to collect multiple samples easily.…”

“…10,11 Glass and plastic chambers block up to 40% and 76% UVB light, respectively, causing significant differences in volatile composition and concentration. 9,12,13 Second, despite lower cost and ease of portability and disposal, sampling chambers made of polyethylene terephthalate (PET), polyacetate, or nylon often leach into the sample potentially masking compounds of interest. 14,15 Third, adsorption onto or diffusion through chamber materials results in loss of analyte.…”