DETERMINATION OF CYCLODEXTRINS IN SERUM BY REVERSED-PHASE CHROMATOGRAPHY WITH PULSED AMPEROMETRIC DETECTION AND A MEMBRANE REACTOR

A high-performance liquid chromatographic method has been developed fo r the determination of cyclodextrins (CDs) in serum. The method involv es solid-phase extraction of CDs, separation on a C18 reversed-phase c olumn using a mixture of water, tetrahydrofuran and methanol as an elu ent, eluent pH modification with a cation-exchange membrane reactor su rrounded by 1.5 M sodium hydroxide solutions, and pulsed amperometric detection (PAD) with a gold working electrode. The solid-phase extract ion on a C18 bonded-silica column was effective for removing the PAD s ensitive components in serum. The calibration graphs constructed by in ternal standard method were linear over the range 6.25-200 pmol of CDs in serum. The detection limits for CDs were about 5 pmol at a signal- to-noise ratio of 3.