Leaf level emission measurement of sesquiterpenes and oxygenated sesquiterpenes from desert shrubs and temperate forest trees using a liquid extraction technique

Abstract

Biogenic emission of sesquiterpene (SQT) and oxygenated SQT (OSQT) were measured from the dominant vegetation in a desert shrubland and urban area (Las Vegas, Nevada, U.S.A.), and at temperate forest sites at Niwot Ridge, Colorado, U.S.A., Tomakomai, Hokkaido, Japan and Tumbarumba, New South Wales, Australia. Additional measurements were conducted using greenhouse grown plants. The sampling technique, based on solid adsorbent preconcentration and liquid extraction, is suitable for measuring high molecular weight and low volatility compounds such as OSQTs. Fourteen SQT and OSQT (10 SQT and 4 OSQT) were identified in the field experiments. Total emission rates of SQTs and OSQTs varied from the detection limit to 7.6 µgC g -1 h -1 (average: 0.74) and 3.7 µgC g -1 h -1 (average: 0.31), respectively, and varied with plant species and location. Environmental conditions, including temperature and precipitation, appeared to influence emission rates. Canopy level emission of SQT and OSQT in Tomakomai were also estimated using an emission model. The emission rate of SQT and OSQT ranged from 72 to 710 µgC m -2 h -1 (average, 460 in daytime) and from 38 to 370 µgC m -2 h -1 (average, 240 in daytime), respectively. Their contributions can be very high in specific regions and seasons. Given the relatively high reactivity and secondary organic aerosol yields of SQTs and OSQTs, it is likely that these compounds influence atmospheric constituents in at least some areas.

The impacts of reactive terpene emissions from plants on air quality in Las Vegas, Nevada

“…Our lower emission rate could be due to drought stress typical for the Las Vegas area; extreme drought has been shown to suppress isoprene emissions after an initial stimulation (Pegoraro et al, 2007). The lack of SQT emissions from cottonwoods was confirmed by concurrent measurements reported by Matsunaga et al (2009).…”

“…Mesquite could therefore be considered a 'good' species for landscaping in Las Vegas since it is native, has low water needs, and has low BVOC emissions. But a companion measurement made by Matsunaga et al (2009) ) amounts of eight MTs. Rosemary and barometer bush are popular for landscaping in Las Vegas, and rosemary is often used in road medians and traffic corridors, which places emissions of BVOCs very near emissions of NO x .…”

“…First, we are only performing compound identification with these techniques, and peaks matched with the GC-FID measurements. Second, the SuperQ method was thoroughly explored in several studies (Matsunaga et al, , 2009). …”

Emission of Biogenic Volatile Organic Compounds from Trees along Streets and in Urban Parks in Tokyo, Japan

“…The adsorbed BVOCs were extracted by approximately 1 mL of hexane (hexane for pesticide residue and polychlorinated biphenyl analysis, which is 5000 times concentrated and tested), (Wako, Osaka, Japan) and replaced into a 1.5 mL glass vial with a PTFE lined cap. The extract was concentrated by a gentle nitrogen flow to approximately 20 μL in the laboratory (Matsunaga et al, 2009;Matsunaga et al, 2008). One μL of the concentrated extract was injected into a GC-MS (7890GC and 5975C MSD).…”

Monoterpene emissions from an understory species, Pteridium aquilinum

“…Monoterpenes were extracted from the VCT using the technique described by Matsunaga et al (2009) and then analyzed with a gas chromatograph coupled with a flame ionization detector (SRI Model 310, SRI instruments, Menlo Park, CA). An aliquot of the extraction was injected into a low polarity column (Restek, MXT Ò -5, 5% diphenyl and 95% dimethyl polisiloxane, 30 m, 0.53 mm ID, stainless steel, Restek Corporation, Bellephonte, PA).…”