Analyses of chlorothalonil and dichlofluanid in greenhouse air.

A method to sample and analyze chlorothalonil and dichlofluanid in greenhouse air was evaluated. Analysis was performed by gas chromatography with electron capture detection and gas chromatography-mass spectrometry. Solid sorbents such as Chromosorb 102, Porapak R, Supelpak-2, Amberlite XAD-2, Amberlite XAD-4, and polyurethane foam were studied. The use of Soxhlet extraction and solvent desorption with sonication to desorb the pesticides from these sorbents were compared. A procedure to generate atmospheres containing known concentrations of these fungicides was established to study sorption capacity and sampling conditions. Breakthrough and storage of pesticides also were studied. Dissipation of analytes in a 24 h period after application was studied by using personal samplers in a field experiment.