All collected samples were produced by Apis mellifera honey bees except one sample from Pará, which was produced by Melipona scutellaris. The blank honey samples were acquired from the consumer market. The samples were stored at ambient temperature (20 C) until analysis. Honey sample from the provider BIPEA, code 18-3619-0038, analyzed in the proficiency test, was maintained under refrigeration (5 C) until analysis.