Determination of sorbate and benzoate in beverage samples by capillary electrophoresis - Optimization of the method with inspection of ionic mobilities

Autor(es)

Costa, Ana Carolina O. ^[1] ; Perfeito, Lisliane da Silva ^[2] ; Tavares, Marina F. M. ^[1] ; Micke, Gustavo A. ^[2]

Afiliação do(s) autor(es)

^[1] Univ Sao Paulo, Inst Chem, Sao Paulo - Brazil

^[2] Univ Fed Santa Catarina, Dept Chem, BR-88040900 Florianopolis, SC - Brazil

• Tipo de documento: Artigo Científico
• Fonte: Journal of Chromatography A; v. 1204, n. 1, p. 123-127, SEP 12 2008.
• Citações Web of Science: 33

Resumo

The aim of this study was to develop a fast capillary electrophoresis method for the determination of benzoate and sorbate ions in commercial beverages. In the method development the pH and constituents of the background electrolyte were selected using the effective mobility versus pH curves. As the high resolution obtained experimentally for sorbate and benzoate in the studies presented in the literature is not in agreement with that expected from the ionic mobility values published, a procedure to determine these values was carried out. The salicylate ion was used as the internal standard. The background electrolyte was composed of 25 mmol L(-1) tris(hydroxymethyl)aminomethane and 12.5 mmol L(-1) 2-hydroxyisobutyric acid, atpH 8.1.Separation was conducted in a fused-silica capillary(32 cm total length and 8.5 cm effective length, 50 mu m I.D.), with short-end injection configuration and direct UV detection at 200 nm for benzoate and salicylate and 254 nm for sorbate ions. The run time was only 28 s. A few figures of merit of the proposed method include: good linearity (R(2) > 0.999), limit of detection of 0.9 and 0.3 mg L(-1) for benzoate and sorbate, respectively, inter-day precision better than 2.7% (n =9) and recovery in the range 97.9-105%. Beverage samples were prepared by simple dilution with deionized water (1:11, v/v). Concentrations in the range of 197-401 mg L(-1) for benzoate and 28-144 mg L(-1) for sorbate were found in soft drinks and tea. (c) 2008 Elsevier B.V. All rights reserved. (AU)

• Processo FAPESP: 97/01320-4 - Estratégias para aumento de sensibilidade em eletroforese capilar
• Beneficiário: Marina Franco Maggi Tavares
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 04/08503-2 - Propostas metodológicas para a análise de fármacos em águas doces utilizadas no abastecimento público do estado de São Paulo
• Beneficiário: Marina Franco Maggi Tavares
• Modalidade de apoio: Auxílio à Pesquisa - Regular
• Processo FAPESP: 04/01382-5 - Investigação de fármacos em águas doces utilizadas no abastecimento público do estado de São Paulo por eletroforese capilar acoplada à espectrometria de massas
• Beneficiário: Ana Carolina de Oliveira Costa
• Modalidade de apoio: Bolsas no Brasil - Doutorado Direto