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 micromol m(-2)s(-1) and 28 degrees C ranged 0.025-0.050 microg Cm(-2)h(-1) (alpha-farnesene) and 0.450-3.325 microg Cm(-2)h(-1) (alpha-farnesene, beta-farnesene, and alpha-bergamotene) for gray pine and ponderosa pine, respectively.