Drying factors for medicinal and aromatic plants and effect of the sampling method on the content of pesticide residues

Abstract

In this work drying factors for in the province of Bolzano cultivated medicinal and aromatic plants were determined using data from the years 1991-2018. The obtained drying factors were compared with values found in the literature. The calculated drying factors can be used as reference values for the calculation of the allowed residue level for dried medicinal and aromatic plants. To study the effect of the sampling method and the repeatability of residue analyses on a dried mixture of medicinal and aromatic plants a series of residue analyses on a contaminated sample were performed. A high repeatability of the residue analyses on the mixture containing a contamination with the pesticide chloropyrifos-ethyl was found. The sampling did not show a significant effect on residue analysis and is not the cause for high or not reliable residue values on medicinal and aromatic plants.