Souza, Jacqueline deViana Júnior, Nilton de SouzaSoares, Cristina Duarte Vianna2014-09-082014-09-081999SOUZA, J.; VIANA JÚNIOR, N. de S.; SOARES, C. D. V. UVA:UVB sunscreen determination by second-order derivative ultraviolet spectrophotometry. Il Farmaco, Itália, v. 54, p. 573-578, 1999. Disponível em: <http://www.sciencedirect.com/science/article/pii/S0014827X99000634#>. Acesso em: 2 set. 2014.0014-827Xhttp://www.repositorio.ufop.br/handle/123456789/3622UVA: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.en-USUVA:UVB sunscreenUltraviolet spectrophotometrySecond-order derivativeCosmetics determinationArtigo publicado em periodicoO periódico Il Farmaco concede permissão para depósito deste artigo no Repositório Institucional da UFOP. Número da licença: 3456021267480.https://doi.org/10.1016/S0014-827X(99)00063-4