[Direct injection of plasma to determine gliquidone in plasma using HPLC column switching technique]

An automated clean up and concentration method by column switching is described for the assay of gliquidone, a hypoglycemic agent, in plasma. The system uses Merck Lichroprep RP2 (25-40 microns) as short precolumn packing material for on--line clean up and concentration. A Shimpack CLC--ODS (5 microns) is used as analytical column. Water is used as the pretreatment mobile phase and a mixture of methanol--isopropanol--0.2 mol/L ammonium acetate solution (61:5:34) is used as the analytical mobile phase. The plasma is diluted with a solution of 0.2 mol/L acetic acid and injected directly on the precolumn. The low speed of 0.2 ml/min of pretreatment mobile phase during transfer of plasma sample on the precolumn can get recovery of 80.7%. The detection is at 310 nm and the detection limit is 30 ng/ml plasma. The procedure is simple and automatic.