Creatinine determination in serum by capillary electrophoresis

✍ Scribed by Rita Paroni; Isabella Fermo; Giuliana Cighetti; Carlo Alberto Ferrero; Anna Carobene; Ferruccio Ceriotti

• Publisher: John Wiley and Sons
• Year: 2004
• Tongue: English
• Weight: 109 KB
• Volume: 25
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200305687

✦ Synopsis

Abstract

Creatinine in human serum was separated in a fused‐silica capillary with H~3~PO~4~ (75 mmol/L, pH 2.5) as BGE, followed by UV detection at 200 nm. Serum with methylimidazole added as internal standard was deproteinized with acetonitrile and the supernatant, after dilution with water was injected at pressure mode. Creatinine and methylimidazole were baseline‐resolved in 6.5 min. Linearity in the 0–880 μmol/L range gave an r^2^ ≥ 0.998, recovery was 102 ± 2.8% (n = 6). Enzymatic breakdown with creatininase confirmed that serum does not interfere. The within‐day and between‐days coefficient of variation (CV) were ≤ 2.16 and 2.7%, respectively. The accuracy, determined for lyophilized samples by isotope dilution gas chromatography‐mass spectrometry was ≤ ± 2.0%. The results were compared with HPLC for 32 lyophilized samples and on 27 serum pools. Capillary electrophoresis, rapid and inexpensive, seems a promising alternative to high‐performance liquid chromatography (HPLC) for creatinine determination in human serum.