title: Determination of parabens in shampoo using high performance liquid chromatography with amperometric detection on a boron-doped diamond electrode.
abstract: Methylparaben (MePa), ethylparaben (EtPa) and propylparaben (PrPa) have been widely used, among others, as chemical preservatives in cosmetics, drugs and foods. As these compounds are linked with allergies, dermatitis and estrogenic properties, it is necessary to control the concentration of these substances in different matrices. The aim of this paper are: to evaluate the electrochemical behavior of parabens on the boron-doped diamond (BDD) electrode and the development of a chromatographic method, with electrochemical detection (HPLC-ED), for determination of parabens in shampoo. A BDD (8000 ppm) electrode was adapted in a thin layer mode analytical cell consisting of a stainless steel and a platinum wire as reference and auxiliary electrodes, respectively. Chromatographic separations were obtained with a reversed phase C8 analytical column and a mobile phase of 0.025 molL(-1) disodium phosphate, pH 7.0, and acetonitrile (40:60, v/v), delivered at a flow rate of 1.0 mL min(-1). Sample preparation was performed by solid phase extraction using C18 cartridges and acetonitrile for elution. Benzylparaben was employed as internal standard. The HPLC-ED method developed, using the BDD electrode, was validated for the determination of parabens in shampoos and presented adequate linearity (>0.999), in the range of 0.0125-0.500% (w/w), detectability 0.01% (w/w), precision (RSD of 2.3-9.8%) and accuracy (93.1-104.4%) and could be applied for routine quality control of shampoos containing MePa, EtPa and PrPa.
authors.affiliation: Laboratory of Toxicological Analysis, Department of Clinical and Toxicological Analysis, Federal University of Alfenas, Rua Gabriel Monteiro 700, 37130-000 Alfenas, MG, Brazil. isarita@unifal-mg.edu.br
authors.forename: Isarita
authors.initials: I
authors.lastname: Martins
authors.forename: Franciely Cristiani
authors.initials: FC
authors.lastname: Carreira
authors.forename: Larissa S
authors.initials: LS
authors.lastname: Canaes
authors.forename: Francisco Alberto
authors.initials: FA
authors.lastname: de Souza Campos Junior
authors.forename: Letícia Maria
authors.initials: LM
authors.lastname: da Silva Cruz
authors.forename: Susanne
authors.initials: S
authors.lastname: Rath
mesh_terms: D000900:Anti-Bacterial Agents; D001895:Boron; D002851:Chromatography, High Pressure Liquid; D003358:Cosmetics / Q000032:analysis*; D003902:Detergents; D018130:Diamond; D055664:Electrochemical Techniques / Q000295:instrumentation / Q000379:methods; D004566:Electrodes; D005520:Food Preservatives; D010226:Parabens / Q000032:analysis*; D011310:Preservatives, Pharmaceutical / Q000032:analysis; D011786:Quality Control
chemical_list: D000900:Anti-Bacterial Agents; D003358:Cosmetics; D003902:Detergents; D005520:Food Preservatives; D010226:Parabens; D011310:Preservatives, Pharmaceutical; D018130:Diamond; D001895:Boron