Evaluation of solid sorbents for the determination of fenhexamid, metalaxyl-M, pyrimethanil, malathion and myclobutanil residues in air samples: Application to monitoring malathion and fenhexamid dissipation in greenhouse air using C-18 or Supelpak-2 for

A methodology is described for greenhouse air analysis by sampling fenhexamid, pyrimethanil, malathion, metalaxyl-M and myclobutanil in solid sorbents. Pesticides were determined by gas chromatography with NP Detector. The trapping efficiency of XAD-2, XAD-4, Supelpak-2, Florisil and C-18 at different sampling conditions (rate, time and air humidity) and pesticides concentration levels has been evaluated. No breakthrough was observed in the range of concentration studied (0.10–75 μg of each pesticide). In almost all the cases good stability results were obtained. Personal pumps have been used with selected sorbents (Supelpak-2 and C-18) in order to sample malathion and fenhexamid in air of experimental greenhouse after their application in a tomato crop. The dissipation process of the analytes in various time periods after application has been studied. Malathion concentrations varied between 20.1 μg m−3 just after application and 1.06 μg m−3 3 days later. Fenhexamid concentrations, determined by high performance liquid chromatography with UV detection, fall rapidly; after 12 h post-application being below 0.50 μg m−3.