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

An automated high performance liquid chromatographic switching system is described for the analysis of famotidine, an H2-receptor antagonist in plasma. The system used YWG-C18 short precolumn for on-line sample clean-up and a Shimpack CLC-ODS analytical column for separation. A solution of 0.2 mol/L acetic acid was used as pretreatment mobile phase and 14% (v/v) methanol in ammonium acetate (0.2 mol/L) was used as analytical mobile phase. The detection was at 267 nm and the detection limit was 12 ng/ml plasma. Plasma sample was diluted with acetic acid (0.2 mol/L) and injected directly on the HPLC system. The procedure of clean-up is simple and automatic. The recovery of clean-up is 84.1%.