Gases (medical air, CO2, and ethylene/air mixtures) were
purchased from Linde gas (Cleveland, OH). In certain experiments, ethylene/air mixtures were prepared in our
laboratory by mixing medical air with ethylene, to achieve
the appropriate final ethylene concentration for use in the
flow-through system. No significant differential effects
were observed for purchased gas mixtures or mixtures
made in our laboratory.
O2, CO2, and ethylene concentrations were monitored by
gas chromatography (GC) using two different instruments:
one for ethylene (Carle AGC series 400, HACH Carle
Chromatography, Loveland, CO) and the other for CO2 or
O2 (ADC.225.MK3, The Analytical Dev. Co. Ltd.,
Hoddesdon, England). Standards were analyzed prior to
analysis of each set of samples. Sample concentrations were
calculated based on concentration of standards. Samples
were obtained from the in-port and out-port of each desiccator.