A Technique for Measurement of Volatile Organic Compound (VOC) Emission Rates from Small Salad Crops 2001-01-2427

An open system for collection of volatile organic compounds (VOC) was constructed to measure the emission rate of VOC from a whole plant of the small salad crops intended for use in NASA’s Advanced Life Support Systems (ALSS). The design of the system provides a controlled plant growth environment in order to maintain normal plant physiology during VOC sampling. The system air is re-circulated through a heat exchanger to control the plant chamber temperature and humidity. An inlet air stream of 20 cc/min is purged through the system to prevent build-up of VOC to levels that may have adverse effects and to maintain system pressure at 1 atm. CO₂ is added to maintain canopy concentration of 1000 μmole/mole and light is set at 250 μmol.m⁻².sec⁻¹ (photosynthetic photon flux, PPF). Overall, this system provides a nondestructive, steady state rate measurement of emitted plant VOC even at very low levels, regardless of plant age. Ethylene emission rates from USU-Apogee wheat (Triticum aestivum L.) are presented here.