Flufenamic Acid Determination in Human Serum by Adsorptive Voltammetry with In Situ Surfactant Modified Carbon Paste Electrodes

✍ Scribed by I. Amor-García; M. C. Blanco-López; M. J. Lobo-Castañón; A. J. Miranda-Ordieres; P. Tuñón-Blanco

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 345 KB
• Volume: 17
• Category: Article
• ISSN: 1040-0397
• DOI: 10.1002/elan.200403262

✦ Synopsis

Abstract

A simple and sensitive adsorptive‐ differential pulse‐ voltammetric method for the determination of flufenamic acid (FFA) is presented. The method is based on the preconcentration of FFA on carbon paste electrodes modified in situ with cationic surfactants, dodecyltrimethylammonium chloride (DTAC) or cetyltrimethylammonium chloride (CTAC), at submicellar concentrations. The best results were obtained with DTAC‐modified electrodes. After optimization, with these electrodes and using an accumulation step at 0 V for 3 minutes in 0.1 M phosphate solutions pH 7, the peak current of the main oxidation process of FFA varies linearly with its concentration from 1×10^−9^ M to 5×10^−5^ M, with a limit of detection of 0.64 nM (0.2 ng/mL). The proposed method has been applied to the determination of FFA in spiked serum samples, treated with acetonitrile to separate the proteins. In the concentration range studied (3 μM to 65 μM) the recovery was near 100 % and the lowest concentration attainable in these samples is below 3 μM (0.8 ppm).