High performance liquid chromatographic determination of pesticides in grape skin

Preventive procedures to minimize crop losses caused by grape berry moth (Lobesia botrana) include the study of its oviposition's behaviour. Among many factors influencing either the moth's attraction or repulsion to different grape varieties, the interference of pesticides applied to vine may play an important role. The residual pesticide concentration detected in grape skin may be altered when in water leaching conditions. This study presents (i) the development of an HPLC-DAD method to analyse twelve fungicides and three insecticides in grape skin and (ii) the comparison of the pesticides levels before and after grape skin water washing. Considering the global uncertainty (30% on average) set for the analytical result in the range of concentrations studied, the efficiencies of the water washing procedure did not exceed 76%. The most removed pesticides were fenhexamid and procymidone. All pesticides levels were below the MRL set for table grapes.