Herbicide determination in Brazilian propolis using high pressure liquid chromatography.

Propolis is a widely used medicinal product sourced by bees from vegetation that may be frequently irrigated with herbicides. Exposure to herbicides can affect bees' health and the quality of commercial propolis. The objective of this study was to calculate the concentrations of glyphosate, aminomethylphosphonic acid (AMPA), picloram and atrazine in different types of propolis from Brazil using high-performance liquid chromatography (HPLC). Four types of propolis (brown, green, red, and yellow) were evaluated for a total of 19 samples. Of these types of propolis, 47% tested positive for the herbicides atrazine (5 to 17.4 µg/g) and AMPA (10.2 to 11.3 µg/g). No samples were reported to be positive for glyphosate; however, the presence of AMPA indicates its existence. The concentrations observed in this study are less than international maximum-residue-level standards.