UVA:UVB sunscreen determination by second-order derivative ultraviolet spectrophotometry.

• Autor(a) principal: Souza, Jacqueline de
• Data de Publicação: 1999
• Outros Autores: Viana Júnior, Nilton de Souza, Soares, Cristina Duarte Vianna
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Institucional da UFOP
• Texto Completo: http://www.repositorio.ufop.br/handle/123456789/3622; https://doi.org/10.1016/S0014-827X(99)00063-4
• topic: UVA:UVB sunscreen; Ultraviolet spectrophotometry; Second-order derivative; Cosmetics determination

UVA:UVB protective agents are important constituents in many cosmetics and sunscreen preparations. Analytical methodologies which enable the determination of combined substances with different spectrophotometric characteristics are therefore useful and cost-effective. To this end, the following substances in a sunscreen gel were analyzed: the UVB and UVA protective substances, 2-hydroxy-4-methoxy-benzophenone-5-sulphonic acid (BZP) and 2 phenylbenzymidazole-5-sulphonic acid (PBS), respectively, were evaluated by second-order derivative ultraviolet spectrophotometry in distinct solvents and wavelengths. The method used for determination of BZP in 95% ethanol was the zero-peak (ZP) at 356.0 nm. For PBS, the solvent used was 0.1 mol l_1 triethanolamine, and the methods were the ZP at 317.5 nm and the peak-peak (PP) at 317.5–323.0 nm. Statistical results for the methods showed linearity of 0.9999 and an average precision of 1.12% (ZP) for BZP, and 0.55% (ZP) and 0.63% (PP) for PBS. The average recovery for BZP and PBS were 97.28% (ZP), 103.13% (ZP) and 103.71% (PP), respectively. © 1999 Elsevier Science S.A. All rights reserved.