Simultaneous Differential Pulse Voltammetric Determination of Ascorbic Acid and Caffeine in Pharmaceutical Formulations Using a Boron‐Doped Diamond Electrode |
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| Authors: | Bruna Cláudia Lourenção Roberta Antigo Medeiros Romeu C Rocha‐Filho Orlando Fatibello‐Filho |
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| Institution: | 1. Instituto de Química de S?o Carlos, Universidade de S?o Paulo, C.P. 780, 13560‐970 S?o Carlos – SP, Brazil;2. Departamento de Química, Universidade Federal de S?o Carlos, C.P. 676, 13560‐970 S?o Carlos – SP, Brazil tel.: +55?16?33518098;3. fax: +55?16?33518350 |
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| Abstract: | A cathodically pretreated boron‐doped diamond electrode was used for the simultaneous anodic determination of ascorbic acid (AA) and caffeine (CAF) by differential pulse voltammetry. Linear calibration curves (r=0.999) were obtained from 1.9×10?5 to 2.1×10?4 mol L?1 for AA and from 9.7×10?6 to 1.1×10?4 mol L?1 for CAF, with detection limits of 19 μmol L?1 and 7.0 μmol L?1, respectively. This method was successfully applied for the determination of AA and CAF in pharmaceutical formulations, with results equal to those obtained using a HPLC reference method. |
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| Keywords: | Ascorbic acid determination Caffeine determination Differential pulse voltammetry Boron‐doped diamond electrode Cathodic pretreatment |
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