DIRECT INJECTION OF PLASMA TO DETERMINE GLIQUIDONE IN PLASMA USING HPLC COLUMN SWITCHING TECHNIQUE

An automated clean up and concentration method by column switchingis described for the assay of gliquidone, a hypoglycemic agent, in plasma. The systemuses Merck Lichroprep RP2 (25～40μm) as short precolumn packing material foron-line slean up and concentration. A Shimpack CLC-ODS (5μm) is used as analyti-cal column. Water is used as the pretreatment mobile phase and a mixture ofmethanol-isopropanol-0.2 mol/L ammonium acetate solution (61: 5: 34) isused as the analytical mobile phase. The plasma is diluted with a soluton of 0. 2 mol/Lacetic acid and injected directdly on the precolumn. The low speed of 0. 2 ml/min of pre-treatment mobile phase during transfer of plasma sample on the precolumn can get re-covery of 80.7%. The detection is at 310 nm and the detection limit is 30 ng/mlplasma. The procedure is simple and automatic.