Development and comparison of two analytical methods to quantify the mercury content in honey

• Published in: Journal of food composition and analysis 2014-05, Vol.34 (1), p.1-6
• Main Authors: Vieira, Heulla Pereira, Nascentes, Clésia Cristina, Windmöller, Cláudia Carvalhinho
• Format: Article
• Language: English
• Subjects: Analytical method; Biological and medical sciences; CVAAS; DMA; Food analysis; Food composition; Food industries; Food safety; Fundamental and applied biological sciences. Psychology; General aspects; Honey; Methods of analysis, processing and quality control, regulation, standards; Total mercury; Validation
• ISSN: 0889-1575; 1096-0481
• DOI: 10.1016/j.jfca.2014.02.001

•Development and validation of 2 methods for Hg in honey using 35 honey samples in Brazil.•Determination of mercury in honey carried out by direct mercury analyzer.•Analysis by cold vapor atomic absorption spectrometry did not need sample digestion.•Multivariate optimization used to obtain optimal experimental conditions.•The 2 methods are rapid and simple, and do not require decomposition of sample. The traditional method routinely used in laboratories to analyze mercury (Hg) in honey includes decomposition of samples, cold vapor generation and atomic absorption detection. Methods that avoid sample digestion could be applied in these laboratories and would represent an innovation relevant to the control of Hg in honey. In this paper, two methods were developed to determine Hg concentration in honey samples: one utilized cold vapor atomic absorption spectrometry (CVAAS), and the other used a direct mercury analyzer (DMA). The CVAAS method consisted of preparing solutions containing 5.0% (w/v) honey, 4.0% (v/v) H2O2 and 6.0% (v/v) HNO3. Hg determination was accomplished by treatment with 0.6% (w/v) NaBH4 in 0.5% (w/v) NaOH and 6.0mol/L HCl. In the DMA method, measurements were made using up to 100mg of honey sample without any prior treatment. The drying and decomposition times along with drying temperature were each optimized. After validation, the methods were used to quantify Hg in 35 honey samples collected from several cities in Minas Gerais, Brazil. All honey samples showed Hg concentrations below 2.5ng/g. The proposed methods were rapid, simple and did not require sample decomposition using concentrated acids at high temperatures, which is advantageous considering the high volatility of Hg.