Please use this identifier to cite or link to this item:
https://repositorio.ufba.br/handle/ri/13541
metadata.dc.type: | Artigo de Periódico |
Title: | Multivariate optimisation of the experimental conditions for determination of three methylxanthines by reversed-phase high-performance liquid chromatography |
Other Titles: | Talanta |
Authors: | Bispo, Márcia Sousa Ferreira, Sergio Luis Costa Andrade, Jailson Bittencourt de Aragão, Nádia Machado de Veloso, Márcia Cristina da Cunha |
metadata.dc.creator: | Bispo, Márcia Sousa Ferreira, Sergio Luis Costa Andrade, Jailson Bittencourt de Aragão, Nádia Machado de Veloso, Márcia Cristina da Cunha |
Abstract: | Caffeine (1,3,7-trimethylxanthine), theobromine (3,7-dimethylxanthine) and theophylline (1,3-dimethylxanthine) are the most important naturally occurring methylxanthines. Caffeine is a constituent of coffee and other beverage and included in many medicines. Theobromine and theophylline are formed as metabolites of caffeine in humans, and are also present in tea, cocoa and chocolate products. In order to improve the chromatographic resolution (Rs) with a good analysis time, experimental designs were applied for multivariate optimisation of the experimental conditions of an isocratic reversed-phase high-performance liquid chromatographic (RP-HPLC) method used for the simultaneous determination of caffeine, theobromine and theophylline. The optimisation process was carried out in two steps using full three-level factorial designs. The factors optimised were: flow rate and mobile phase composition. Optimal conditions for the separation of the three methylxanthines were obtained using a mixture of water/ethanol/acetic acid (75:24:1%, v/v/v) as mobile phase and a flow rate of 1.0 mL min−1. The RP-HPLC/UV method was validated in terms of limit of detection (LOD), limit of quantitation (LOQ), linearity, recovery and the precision, calculated as relative standard deviation (R.S.D.). In these conditions, the LOD was 0.10 μg L−1 for caffeine, 0.07 μg L−1 for theobromine and 0.06 μg L−1 for theophylline. The proposed method is fast, requires no extraction step or derivatization and was suitable for quantification of these methylxanthines in coffee, tea and human urine samples. |
Keywords: | Methylxanthines Multivariate optimisation Isocratic elution RP-HPLC/UV |
metadata.dc.rights: | Acesso Aberto |
URI: | http://repositorio.ufba.br/ri/handle/ri/13541 |
Issue Date: | 2005 |
Appears in Collections: | Artigo Publicado em Periódico (Química) |
Files in This Item:
File | Description | Size | Format | |
---|---|---|---|---|
Márcia Bispo.pdf | 442,12 kB | Adobe PDF | View/Open |
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.