Solid-phase extraction of 18 beta-glycyrrhetinic acid from plasma and subsequent analysis by high-performance liquid chromatography

摘要

A new method is described for the solid-phase extraction of 18 beta-glycyrrhetinic acid from plasma or serum, with subsequent analysis by HPLC. New aspects of the method include the use of commercially available 18 alpha-glycyrrhetinic acid as the internal standard and the use of a Bond Elut C-2 (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 C-18 analytical column, with a mobile phase consisting of acetonitrile-0.02 M phosphate buffer, pH 5.7 (55:35, 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. (C) 1998 Elsevier Science B.V. All rights reserved. [References: 14]