HOW EFFICIENT ARE ALL-GLASS SYSTEMS FOR COLLECTION OF AIRBORNE VOLATILES

Airborne volatiles of saturated and unsaturated acetates and alcohols with the dodecane, tetradecane, and hexadecane chains released from fr esh polyethylene pheromone dispensers were collected in Pasteur pipets attached to an all-glass collecting system. A maximum of 300-500 ng o f pheromone in the first pipet (in a row of three or four) could be ac cumulated. The total amount that can be collected from an active rich source in 10-15 min of aeration (at 40-50 ml/min/cage) can reach 0.5-1 mu g. Breakthrough from a pipet starts after an accumulation of 40-50 ng. There is a direct relationship among airflow rate in the system, the period of collection, and the vapor pressure of the chemicals on t he amount adsorbed on the glass surface of the pipets. Polar functiona lities, such as hydrogen bonding and pi electrons play a significant r ole in the strength of adsorption to the glass surface. The system and technique are simple, fast, and easy to handle for collection of airb orne Volatiles from plants, animals, and nonliving sources.