IMPROVED MICRO-METHOD FOR THE HPLC ANALYSIS OF CAFFEINE AND ITS DEMETHYLATED METABOLITES IN HUMAN BIOLOGICAL FLUIDS AFTER SPE
- 15 May 2000
- journal article
- Published by Informa UK Limited in Journal of Liquid Chromatography & Related Technologies
- Vol. 23 (10), 1523-1537
- https://doi.org/10.1081/jlc-100100432
Abstract
An improved high performance liquid chromatographic-photodiode array method, using a multi-linear gradient elution, is described for the simultaneous determination of caffeine and its eight primary metabolites: xanthine (XA), 7-methylxanthine (7-MX), 3-methylxanthine (3-MX), 1-methylxanthine (1-MX), isocaffeine (IC), theobromine (TB), paraxanthine (PA) and theophylline (TP). The separation method Is based on mobile phase optimization and off-line solid-phase extraction (SPE) from human biological fluids: blood serum and urine. The eluting system consisted of ammonium acetate 0.05 M (pH=7) and methanol (90:10 v/v) changing to (40:60 v/v) over a period of 30 min. Identification of metabolites was achieved by photodiode array detector at 270 nm resulting in 2 ng limit of detection, while linearity held up to 20 ng/μL for each compound. Lamotrigine was used as internal standard at a concentration of 10.0 ng/μL. The statistical evaluation of the method was examined performing intra-day (n=8) and inter-day (n=8...Keywords
This publication has 12 references indexed in Scilit:
- A Sensitive Method for the Simultaneous Determination of Caffeine and its Dimethylxanthine Metabolites in Human Plasma: Application to CYP1A2 PhenotypingJournal of Liquid Chromatography & Related Technologies, 1998
- Optimized and validated HPLC Methods for Compendial Quality Assessment I. Methylxanthine DerivativesJournal of Liquid Chromatography & Related Technologies, 1997
- Threshold level for theophylline in doping analysisJournal of Chromatography B: Biomedical Sciences and Applications, 1996
- Solid-Phase Extraction Study and Photodiode Array RP-HPLC Analysis of Xanthine Derivatives in Human Biological FluidsJournal of Liquid Chromatography & Related Technologies, 1996
- Simultaneous determination of caffeine and its primary demethylated metabolites in human plasma by high-performance liquid chromatographyJournal of Chromatography B: Biomedical Sciences and Applications, 1992
- Quantification of theophylline in human plasma by reversed-phase ion-interaction high-performance liquid chromatography and comparison with the TDx fluorescence polarization immunoassay procedureThe Analyst, 1992
- High-performance liquid chromatographic separation of caffeine, theophylline, theobromine and paraxanthine in rat brain and serumJournal of Chromatography B: Biomedical Sciences and Applications, 1991
- Determination of theophylline in serum and saliva in the presence of caffeine and its metabolitesJournal of Chromatography B: Biomedical Sciences and Applications, 1991
- Simple and sensitive method for the simultaneous determination of enprofylline, theobromine, paraxanthine, theophylline and caffeine using high-performance liquid chromatographyJournal of Chromatography B: Biomedical Sciences and Applications, 1986
- Simultaneous determination of caffeine and its N-demethylated metabolites in umbilical cord plasma using high-performance liquid chromatographyJournal of Chromatography B: Biomedical Sciences and Applications, 1984