Controlled-release formulations laboratory testing

Our first step was to develop a simple effective wind tunnel which allowed us to age formulations in the laboratory under very nearly natural conditions. Rather than attempt to control all climatic parameters - temperature, pressure, humidity, light intensity, wind speed, turbulence, etc. - which would have been a formidable engineering task, a very simple design was chosen in which only air speed, temperature and illumination were controlled The only real deficiency in this system is the lack of control of humidity. However, that aspect was addressed separately by measuring the pheromone release rate of each formulation under conditions of very high and very low humidity. To date, none of the candidates tested has shown a major humidity dependence. 

Because of the complexity of real systems, inhibitor selection is by far not straightforward and requires testing by laboratory and field studies. Commercial formulations usually contain a combination of several active inhibitors, blended with a specific surfactant/solvent package, which controls the release of the inhibitors into the environment (i.e. the available inhibitor concentration). The protection of multimetal systems requires particular care, since efficient inhibitors for one metal may be ineffective or even corrosion-accelerating for another metal. In general, the performance of formulations depends on the system parameters and has to be evaluated by field tests to ensure protection. 

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