Determination of ammonia, creatinine and inorganic cations in urine using CE with contactless conductivity detection.
CE with capacitively coupled contactless conductivity detection (C(4)D) was used to determine waste products of the nitrogen metabolism (ammonia and creatinine) and of biogenic inorganic cations in samples of human urine. The CE separation was performed in two BGEs, consisting of 2 M acetic acid + 1.5 mM crown ether 18-crown-6 (BGE I) and 2 M acetic acid + 2% w/v PEG (BGE II). Only BGE II permitted complete separation of all the analytes in a model sample and in real urine samples. The LOD values for the optimized procedure ranged from 0.8 microM for Ca(2+) and Mg(2+) to 2.9 microM for NH(4)(+) (in terms of mass concentration units, from 7 microg/L for Li(+) to 102 microg/L for creatinine). These values are adequate for determination of NH(4)(+), creatinine, Na(+), K(+), Ca(2+) and Mg(2+) in real urine samples.
Institute of Biochemistry, Cell and Molecular Biology, Third Faculty of Medicine, Charles University, Prague, Czech Republic. petr.tuma@lf3.cuni.cz
Petr
P
Tůma
Eva
E
Samcová
Frantisek
F
Duska
D000641:Ammonia / Q000652:urine*; D002412:Cations / Q000652:urine; D003404:Creatinine / Q000652:urine*; D004553:Electric Conductivity; D019075:Electrophoresis, Capillary / Q000379:methods* / Q000706:statistics & numerical data; D006801:Humans; D011092:Polyethylene Glycols; D015203:Reproducibility of Results; D012996:Solutions
D002412:Cations; D012996:Solutions; D011092:Polyethylene Glycols; D000641:Ammonia; D003404:Creatinine