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Assay for the simultaneous determination of guanidinoacetic acid, creatinine and creatine in plasma and urine by capillary electrophoresis UV‐detection
Author(s) -
Zinellu Angelo,
Sotgia Salvatore,
Zinellu Elisabetta,
Chessa Roberto,
Deiana Luca,
Carru Ciriaco
Publication year - 2006
Publication title -
journal of separation science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.72
H-Index - 102
eISSN - 1615-9314
pISSN - 1615-9306
DOI - 10.1002/jssc.200500428
Subject(s) - chromatography , capillary electrophoresis , creatine , chemistry , derivatization , urine , creatinine , detection limit , dilution , capillary action , quantitative analysis (chemistry) , high performance liquid chromatography , biochemistry , physics , materials science , composite material , thermodynamics
Abstract Guanidinoacetic acid (GAA) measurement has recently become of great interest for the diagnosis of creatine (Cn) metabolism disorders, and research calls for rapid and inexpensive methods for its detection in plasma and urine in order to assess a large number of patients. We propose a new assay for the measurement of GAA by a simple CZE UV‐detection without previous sample derivatization. Plasma samples were filtered by Microcon‐10 microconcentrators and directly injected into the capillary, while for urine specimens a simple water dilution before injection was needed. A baseline separation was obtained in less than 8 min using a 60.2 cm×75 μm uncoated silica capillary, 75 mmol/L Tris‐phosphate buffer pH 2.25 at 15°C. The performance of the developed method was assessed by measuring plasma creatinine and Cn in 32 normal subjects and comparing the data obtained by the new method with those found with the previous CE assay. Our new method seems to be an inexpensive, fast and specific tool to assess a large number of patients both in clinical and in research laboratories.