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Capillary electrochromatography of caffeine and its metabolites in rat brain microdialysate
Author(s) -
Ohyama Kaname,
Wada Mitsuhiro,
Lord Gwyn A.,
Ohba Yoshihito,
Nakashima Mihoko N.,
Nakashima Kenichiro,
Akiyama Shuzo,
Lim Chang Kee,
Kuroda Naotaka
Publication year - 2005
Publication title -
electrophoresis
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.666
H-Index - 158
eISSN - 1522-2683
pISSN - 0173-0835
DOI - 10.1002/elps.200410292
Subject(s) - capillary electrochromatography , chromatography , microdialysis , electrochromatography , chemistry , repeatability , high performance liquid chromatography , caffeine , silylation , capillary electrophoresis , extracellular , biochemistry , biology , endocrinology , catalysis
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 m M 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.