title: Very fast electrophoretic determination of creatinine and uric acid in human urine using a combination of two capillaries with different internal diameters.
abstract: A capillary system formed by combining 25 and 100 μm id capillaries was used in the short-end injection mode to determine creatinine and uric acid in human urine. The separation was performed at an electric field intensity of 2.3 kV/cm. Creatinine was determined in a BGE with a composition of 20 mM citric acid/NaOH (pH 3.0), and uric acid was determined in 20 mM MES/NaOH (pH 6.0). Under these conditions, migration times of 12.2 s for creatinine and 8.6 s for uric acid were achieved. The LOD value is 2.4 mg/L for creatinine and 0.9 mg/L for uric acid; the RSD for the migration time varies in the range 0.7-1.1% (intra day) to 1.0-7.5% (inter day); RSDs for the peak areas equalled 3.4-4.0% (intra day) and 4.3-4.7% (inter day). The determined creatinine values in seven urine samples vary in the range 221-1394 mg/L for creatinine and 87-615 mg/L for uric acid. t-Test did not reveal any statistically significant difference between the developed CE methodologies and reference methods - Jaffé reaction for creatinine and enzymatic uricase test for uric acid.
authors.affiliation: Third Faculty of Medicine, Institute of Biochemistry, Cell and Molecular Biology, Charles University in Prague, Czech Republic.
authors.forename: Václav
authors.initials: V
authors.lastname: Pavlíček
authors.forename: Petr
authors.initials: P
authors.lastname: Tůma
authors.forename: Jana
authors.initials: J
authors.lastname: Matějčková
authors.forename: Eva
authors.initials: E
authors.lastname: Samcová
mesh_terms: D000328:Adult; D003404:Creatinine / Q000652:urine*; D019075:Electrophoresis, Capillary / Q000295:instrumentation* / Q000379:methods*; D006801:Humans; D057230:Limit of Detection; D016014:Linear Models; D015203:Reproducibility of Results; D013997:Time Factors; D014527:Uric Acid / Q000652:urine*
chemical_list: D014527:Uric Acid; D003404:Creatinine
keywords: Capillary electrophoresis; Clinical analysis; Creatinine; High-speed analysis; Uric acid