Capillary electrochromatography of caffeine and its metabolites in rat brain microdialysate

✍ Scribed by Kaname Ohyama; Mitsuhiro Wada; Gwyn A. Lord; Yoshihito Ohba; Mihoko N. Nakashima; Kenichiro Nakashima; Shuzo Akiyama; Chang Kee Lim; Naotaka Kuroda

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 192 KB
• Volume: 26
• Category: Article
• ISSN: 0173-0835
• DOI: 10.1002/elps.200410292

✦ Synopsis

Abstract

A capillary electrochromatography (CEC) method has been developed for the separation of caffeine and its two metabolites 1‐methylxanthine (1‐MX) and 1,7‐dimethylxanthine (1,7‐DX). The stationary phase was 3‐(1,8‐naphthalimido) propyl‐modified silyl silica gel (NAIP) and the best separations were achieved with 4.0 mM citrate buffer (pH 5.0) containing 80% methanol at an applied voltage of 25 kV. The compounds were completely separated in less than 3.5 min with good repeatability, which was approximately 3‐times less than that in high‐performance liquid chromatography (HPLC) with NAIP. The proposed method coupled with microdialysis was successfully applied to the monitoring of caffeine concentration in rat brain with detection limits of 1.11 μg/mL.