Síntese e aplicação de nanopartículas magnéticas para a pré- concentração e determinação de As em cosméticos por FIA-HG- AAS

• Autor(a) principal: Costa, Marina Araujo João Lopes da
• Data de Publicação: 2021
• Outros Autores: [e-mail]
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/18941
• topic: Arsenic; Cosmetic; Experimental design; Materiais nanoestruturados; Maghemita; Arsênico; Toxicologia; Cosmético; γ-Fe2O3; Planejamento de experimento; Nanomaterial; ENGENHARIAS::ENGENHARIA QUIMICA::TECNOLOGIA QUIMICA

This work proposes a new method for arsenic preconcentration in child makeup samples using maghemite nanoparticles (γ-Fe 2 O 3 ) and determination by atomic absorption spectrometry with hydride generation with a flow injection analysis system coupled. Maghemite nanoparticles were synthesized by a co-precipitation method and chemically characterized using X-ray diffraction, Fourier transform infrared spectroscopy and by the Brunauer-Emmett-Teller and the Barrett, Joyner and Halenda methods, obtaining as a result a crystalline size equals to 9.1 nm, surface area of 106.165 m 2 g −1 , specific volume of pores equals to 0.274 cm 3 g −1 and mesopores with pore diameter equals to 101.783 Å. The experimental conditions for the hydride generation system and for the adsorption process were optimized using a central composite design. For hydride generation, the levels of the factors concentration of HCl, NaBH 4 and flow of carrier gas were optimized, obtaining as optimal condition 4 mol L −1 , 1.1 %(m/v) and 145 mL min −1 , respectively. While the optimized condition obtained for the adsorption process was at pH equal to 5.3, mass of γ-Fe 2 O 3 of 184 mg and stirring time of 41 min. The limits of detection and quantification of the method were, respectively, 0.9 μg g −1 and 2.6 μg g −1 . The accuracy of the proposed method was studied through recovery tests, which ranged from 75% to 99%. The method was applied to 4 child makeup samples obtained in local market. The As concentration for all samples was below the limit of quantification of the method and below the maximum concentration allowed by RDC no. 44 (BRASIL, 2012) .