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Selective Electrochemical Determination of Uric Acid in the Presence of Ascorbic Acid Using a Carbon Paste Electrode Modified with β‐Cyclodextrin |
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| Authors: | Minerva Ramírez‐Berriozabal Laura Galicia Silvia Gutiérrez‐Granados José?Sandoval Cortes Pilar Herrasti |
| Institution: | 1. Departamento de Química, Universidad Autónoma Metropolitana‐Iztapalapa, San Rafael Atlixco No.?186, Col. Vicentina C.P. 09340, México;2. Instituto de Investigaciones Científicas, Universidad de Guanajuato, Cerro de la Venada s/n, Pueblito de Rocha 36040, Guanajuato, Gto., México;3. Facultad de Ciencias Químicas, Universidad Autónoma de Coahuila, Blvd. V. Carranza, Col. Republica, Saltillo Coah., C.P. 25280, México;4. Facultad de Ciencias, Departamento de Química Física Aplicada. Universidad Autónoma de Madrid. Cantoblanco s/n 28049?Madrid, Spain |
| Abstract: | Uric acid (UA) was determined in the presence of ascorbic acid (AA) by using a carbon paste electrode modified superficially by a β‐cyclodextrin film (CPE/β‐CD). The surface carbon paste electrode was prepared applying a 30 cycles potential program and using a 1 M HClO4+0.01 M β‐CD electrolytic solution. The UA and AA solutions were used to evaluate the electrode selectivity and sensitivity by cyclic voltammetric and amperometric methods. In these experiments the detection limit for UA was (4.6±0.01)×10?6 M and the RSD calculated from the amperometric curves was 10%. From the data obtained it was possible to quantify UA in the urine and saliva samples. Selective detection of UA was improved by formation of an inclusion complex between β‐CD and UA. The results show that the CPE/β‐CD is a good candidate due to its selectivity and sensitivity in the UA determination in complex samples like the biological fluids. |
| Keywords: | Uric acid Ascorbic acid Carbon paste electrode β ‐Cyclodextrin modified electrode Inclusion complexes |