Solid-phase extraction of 18beta-glycyrrhetinic acid from plasma and subsequent analysis by high-performance liquid chromatography.
A new method is described for the solid-phase extraction of 18beta-glycyrrhetinic acid from plasma or serum, with subsequent analysis by HPLC. New aspects of the method include the use of commercially available 18alpha-glycyrrhetinic acid as the internal standard and the use of a Bond Elut C2 (ethyl) extraction column, to avoid the need to use large volumes of organic solvent to elute the isolates from the columns. Separation was achieved on a Shandon Hypersil BDS C18 analytical column, with a mobile phase consisting of acetonitrile-0.02 M phosphate buffer, pH 5.7 (55:45, v/v). The column effluent was monitored at 248 nm. Compared with previous methods, the procedure is much easier to carry out, whereas the sensitivity (limit of detection, 10 ng/ml, and limit of quantitation, 50 ng/ml), the precision (0.3-6.2%) and the accuracy (97.2-101.9%) are of the same order of magnitude.
Department of Pharmacology 233, Faculty of Medical Sciences, University of Nijmegen, The Netherlands.
F G
FG
Russel
S
S
van Uum
Y
Y
Tan
P
P
Smits
D002138:Calibration; D002845:Chromatography / Q000379:methods*; D002851:Chromatography, High Pressure Liquid; D005069:Evaluation Studies as Topic; D006034:Glycyrrhetinic Acid / Q000097:blood*; D006801:Humans; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D006034:Glycyrrhetinic Acid