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Amperometric Biosensor for Oxalate Determination in Urine Using Sequential Injection Analysis
Chemical Research Center, Universidad Autonoma el Estado de Hidalgo, Carr. Pachuca-Tulancingo km 4.5, 42076, Pachuca, Hidalgo, Mexico
Analytical Chemistry Department, Faculty of Sciences, Universidad de Valladolid, Campus Miguel Delibes s/n, 47011 Valladolid, Spain
* Author to whom correspondence should be addressed.
Received: 16 May 2012; in revised form: 9 July 2012 / Accepted: 11 July 2012 / Published: 26 July 2012
Abstract: An amperometric flow biosensor for oxalate determination in urine samples after enzymatic reaction with oxalate oxidase immobilized on a modified magnetic solid is described. The solid was magnetically retained on the electrode surface of an electrode modified with Fe (III)-tris-(2-thiopyridone) borate placed into a sequential injection system preceding the amperometric detector. The variables involved in the system such as flow rate, aspired volumes (modified magnetic suspension and sample) and reaction coil length were evaluated using a Taguchi parameter design. Under optimal conditions, the calibration curve of oxalate was linear between 3.0–50.0 mg·L−1, with a limit of detection of 1.0 mg·L−1. The repeatability for a 30.0 mg·L−1 oxalate solution was 0.7%. The method was validated by comparing the obtained results to those provided by the spectrophotometric method; no significant differences were observed.
Keywords: oxalate; urine; sequential injection analysis; magnetic particles
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Rodriguez, J.A.; Hernandez, P.; Salazar, V.; Castrillejo, Y.; Barrado, E. Amperometric Biosensor for Oxalate Determination in Urine Using Sequential Injection Analysis. Molecules 2012, 17, 8859-8871.
Rodriguez JA, Hernandez P, Salazar V, Castrillejo Y, Barrado E. Amperometric Biosensor for Oxalate Determination in Urine Using Sequential Injection Analysis. Molecules. 2012; 17(8):8859-8871.
Rodriguez, Jose A.; Hernandez, Prisciliano; Salazar, Veronica; Castrillejo, Yolanda; Barrado, Enrique. 2012. "Amperometric Biosensor for Oxalate Determination in Urine Using Sequential Injection Analysis." Molecules 17, no. 8: 8859-8871.