ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Determination of orotic acid in human urine using a combination of two capillaries with different internal diameters

Andrea Šebestová and Jan Petr

Department of Analytical Chemistry, Faculty of Science, Palacký University in Olomouc, Olomouc, Czech Republic

E-mail: secjpetr@gmail.com

Received: 8 July 2019  Accepted: 27 January 2020

Abstract:

The aim of this study was to develop a fast method of screening for orotic acid in untreated urine by capillary electrophoresis with using a combination of two capillaries with different internal diameters, 50 μm and 100 μm. Under the optimized conditions, 100 mM sodium phosphate buffer pH 2.2, voltage of 5 kV, hydrodynamic injection at 50 mbar for 5 s, and detection at 214 nm, the migration time of orotic acid was only 2.1 min. The validation of the method resulted in orotic acid recoveries of 96.5 ± 0.8%. We achieved good precision with RSD of migration times at less than 0.8% and peak areas lower than 3.1% intraday precision. We obtained a very good linearity in the validated range 1–100 μmol L⁻¹, R² 0.9993, and a limit of detection of 2.4 μmol L⁻¹. Finally, we proved that the method is robust, including the connection of capillaries, using the Youden test.

Keywords: Capillary electrophoresis; Coupled capillaries; High-speed separation; Orotic acid; Urine

Full paper is available at www.springerlink.com.

DOI: 10.1007/s11696-020-01076-7

Chemical Papers 74 (7) 2375–2379 (2020)