Determinação da composição inorgânica empregando métodos eletroanalíticos e análise de risco de suplementos alimentares

Abstract

Food supplements are intended to provide vitamins, minerals and bioactive substances from animal or vegetable origin. The manufacture of these products requires specific quality control that considers all stages of production up to the final product, due to the potential for contamination through the use of chemicals of low quality or the use of medicinal plants without proper analysis of their mineral composition. The main objective of this work was the study of the presence of potentially toxic elements (U, Cd, Pb, Zn, Cu, Ni and Co) in food supplements using electroanalytical methods based on the stripping voltammetry to calculate the health risk analysis by excessive and continued consumption of products. For this purpose, voltammetric methods for the simultaneous determination of the elements cadmium, cobalt, copper, lead, nickel, uranium and zinc associated with the mineralization steps of the solid samples were systematically studied. The simultaneous determination of the elements uranium, lead and cadmium was optimized by stripping adsorptive voltammetry using the cupferron as a complexing agent, which allows the determination of these elements without mutual interference in samples of previously mineralized supplements. The simultaneous determination of cadmium, cobalt, copper, lead, nickel and zinc in samples of previously mineralized supplements was optimized by anodic stripping voltammetry using acetate buffer, ammonium buffer and dimethylglyoxime as supporting electrolyte. The analytical strategies adopted in the sample pre-treatment step involved a comparative study of the mineralization of solid samples for the selective and sensitive determination of the elements of interest as contaminants in the formulations. Sample decomposition techniques involved the oxidative mineralization in HNO3 and H2O2 medium in an open and closed system (microwave oven), as well as calcination in a muffle furnace for total carbonization of the samples at high temperatures. Based on the optimized methodologies, the quantitative determination of the elements allowed to assess the toxicological risk of food supplements based on risk analysis calculations using different mathematical approaches. A total of 97 samples were studied with the quantification of 6 studied elements (Cd, Pb, Zn, Cu, Ni and Co) as inorganic contaminants.