Analysis of sesquiterpene emissions by plants using solid phase microextraction

Solid phase microextraction (SPME) was characterized for the sampling and analysis of sesquiterpenes (SQTs) emitted by plants. Constant mixing ratio SQT standards were produced using a capillary diffusion system. Polydimethylsiloxane SPME fibers were characterized with respect to relative absorption of SQTs, and the effects of sample linear velocity and sample relative humidity on SQT absorption. SPME was then utilized to measure SQT emissions from gray pine (Pinus sabiniana) and ponderosa pine (Pinus ponderosa). Total SQT emission rates at a photosynthetic photon flux density of 1200 μmol m−2 s−1 and 28 °C ranged 0.025–0.050 μgC m−2 h−1 (α-farnesene) and 0.450–3.325 μgC m−2 h−1 (α-farnesene, β-farnesene, and α-bergamotene) for gray pine and ponderosa pine, respectively.