Glyphosate residues in Brazilian honey – method validation and occurrence

Resumo

The concern with the management of pesticides is related to food safety and
environmental damage. Bees are susceptible to environmental disturbances. Their
products (such as honey) can be used as bioindicators to define impacts resulting from
anthropogenic activities once bees can transport pesticide residues to the hive and
contaminate it. Honey is a complex matrix with more than 200 known substances.
Therefore, to analyze pesticide residues in this matrix, the analytical method should be
developed and validated to provide reliable results. Glyphosate (GLY) is the most widely
used herbicide and studies have shown that exposure to this herbicide at sublethal doses
has led to reduced sensitivity and decreased associative memory in bees. The
development, validation, and application of a method to quantify GLY in Brazilian honey
samples were done. The validation data as recoveries averages ranged from 74-79% for
GLY and precision values up to 12% were observed. The presence of GLY residues in
honey was evaluated in 40 samples from the eucalyptus, orange, and polyfloral origins
from five Brazilian States. GLY residues ranged from <LOQ to 0.22 µg g-1, six samples
showed GLY levels above the EU limit (0.05 µg g-1). These results suggest that
agricultural practices in Brazil affect honeybee and bee products.