Validation of a high-performance liquid chromatography assay for quantification of caffeine and paraxanthine in human serum in the context of CYP1A2 phenotyping

✍ Scribed by J. P. Koch; G. W. ten Tusscher; J. G. Koppe; H. J. Guchelaar

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 73 KB
• Volume: 13
• Category: Article
• ISSN: 0269-3879
• DOI: 10.1002/(sici)1099-0801(199906)13:4<309::aid-bmc881>3.0.co;2-j

✦ Synopsis

In this study the validation of a reversed-phase high-performance liquid chromatography (HPLC) method, with UVdetection, for both caffeine and paraxanthine in human serum is described. This method is feasible for cytochrome P450 1A2 (CYP1A2) phenotyping, according to the results of a pilot study. With this HPLC method caffeine and paraxanthine can be determined selectively and specifically. In the expected concentration range, caffeine recoveries were 98-108% (within-run variation 4.0-6.4%, between-run variation 6.4-8.8%), paraxanthine recoveries were 96.6-97.5% (within-run variation 5.0-7.2%, between-run variation 7.2-10.8%). The limits of detection for caffeine and paraxanthine using this HPLC system were 0.3 and 0.1 mg/L, respectively. Linear calibration curves for both caffeine and paraxanthine were obtained in the concentration range 0.5-30 mg/L (r b 0.9999. Serum samples were stable for a week, when stored at À20 and 4°C.