A Rapid UPLC Method for the Assay of Retinol α-Tocopherol in Human Serum

Friday, June 27, 2008

The capability of UltraPerformance® UPLC® coupled with diode array detection in the high-throughput quantitative analysis of retinol and α(alpha)-tocopherol in human serum has been investigated. Sample preparation involved protein precipitation with ethanol and liquid-liquid extraction using hexane as the extraction solvent. UPLC analysis was performed isocratically on an ACQUITY® UPLC BEH™ C18 analytical column (50 μ— 2.1 mm, 1.7 μm particle size). The mobile phase consisted of pure methanol and was pumped at a flow rate of 0.6 mL/min. Performance characteristics were compared with those of a conventional HPLC. The imprecision of the two approaches was similar and results obtained with the two methods correlated well (r >0.99). Compared with the HPLC method, the UPLC method offered a sixfold decrease in analysis time and up to 15-fold increase in sensitivity (expressed as on-column amount), with up to a sixfold decrease in peak width measured at half peak .../continued/