Improved liquid-chromatographic determination of caffeine in plasma
Blanchard, J.; Mohammadi, J.D.; Conrad, K.A.
Clinical Chemistry 26(9): 1351-1354
1980
ISSN/ISBN: 0009-9147 PMID: 7398051 Document Number: 161513
We describe a rapid, specific, and sensitive liquid-chromatographic micro-method for caffeine in plasma. Each plasma sample can be assayed within about 15 min of its receipt. Samples are denatured with acetonitrile, centrifuged, and the supernate is chromatographed on a reversed-phase column. Only 100 microL of plasma is required, and concentrations as low as 0.3 mg/L can be measured accurately. Other xanthines and their metabolites do not interfere. The small sample required makes the procedure ideally suited for measuring caffeine in the plasma of infants and small animals as well as adults.