title: Simultaneous analysis of parabens in cosmetic products by stir bar sorptive extraction and liquid chromatography.
abstract: A sensitive and precise stir bar sorptive extraction (SBSE) combined with LC (SBSE/LC) analysis is described for simultaneous determination of methyl, ethyl, propyl, and butyl parabens in commercial cosmetic products in agreement with the European Union Cosmetics Directive 76/768/EEC. Important factors in the optimization of SBSE efficiency are discussed, such as time and temperature of extraction, pH, and ionic strength of the sample, matrix effects, and liquid desorption conditions by different modes (magnetic stirring, ultrasonic). The LOQs of the SBSE/LC method ranged from 30 to 200 ng/mg, with linear response over a dynamic range, from the LOQ to 2.5 microg/mg, with a coefficient of determination higher than 0.993. The interday precision of the SBSE/LC method presented a coefficient of variation lower than 5%. The effectiveness of the proposed method was proven for analysis of commercial cosmetic products such as body creams, antiperspirant creams, and sunscreens.
authors.affiliation: Departamento de Química, Faculdade de Filosofia Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Ribeirão Preto, SP, Brazil.
authors.forename: Lidervan P
authors.initials: LP
authors.lastname: Melo
authors.forename: Maria Eugênia C
authors.initials: ME
authors.lastname: Queiroz
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D003358:Cosmetics / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D057230:Limit of Detection; D009994:Osmolar Concentration; D010226:Parabens / Q000032:analysis*; D015203:Reproducibility of Results; D013056:Spectrophotometry, Ultraviolet
chemical_list: D003358:Cosmetics; D010226:Parabens