Capillaries as controlled release devices for insect pheromones and other volatile substances-A reevaluation : Part I. Kinetics and development of predictive model for glass capillaries.

Controlled release formulations are required for the dissemination of behavior-modifying chemicals in insect control strategies. Among the types of formulations that have been used for some time are glass and plastic capillaries. Erratic release rates on field use of such capillaries prompted us to reexamine the release of volatile materials with regard to (1) kinetics of the release, (2) the effect of the vapor-air column above the liquid, and (3) developing a predictive model. Results indicate that the release is not zero order, and that the length of the vapor-air column is a critical factor of the system; a predictive model has been developed that will allow better design of capillary controlled-release formulations.