Produção e avaliação de material de referência para o escopo dioxinas, furanos e bifenilas policloradas em filé de pescado

Abstract

Polychlorinated dibenzo-p-dioxins (PCDD), polychlorinated dibenzo-furans (PCDF), dioxin and furans, respectively, and polychlorinated biphenyls (PCB) comprise a class of persistent organic pollutants formed in trace amounts in combustion and thermal processes, which presents carcinogenic properties. The presence of these pollutants in food is an important topic of food safety, highlighting the fish matrix. Fishing is expanding in Brazil, especially aquaculture, being tilapia (Oreochromis niloticus) the most produced specie. In this context, the production of a reference material (RM) for this analytical scope is of great importance for ensuring the reliability of the results produced in monitoring programs. For the production of RM, the best condition for the incorporation of native standard of dioxins, furans and PCBs in tilapia filletmatrix was investigated, including fish oil and nonane. Mean recoveries of 67% was obtained for nonane and 87% for fish oil, being this last one selected. The RM was produced by spiking thematrix with standard solution of 29 contaminants, followed by lyophilization and homogenization. The RM was filled in amber glass bottleswith a screw capsand stored under refrigeration (2 to 10) ºC. The material was considered homogeneous for all of the analytes based on the criteria established by the IUPAC and ISO 13528:2005. The short-term stability was demonstrated for 27compounds, when the material was kept at (45 ± 2) °C during 9 days, simulating drastic temperature conditions in transportation. Long-term stability was evaluated in 2, 4, 6 and 8 months and demonstrated for 22 contaminants up to four months of storage, considering criteria defined in ISO Guide 35, ISO 13528:2005 and in the IUPAC harmonized protocol. The contributions of the homogeneity, stability in the short and long term uncertainties were estimated.