Determination of ranitidine in urine by capillary electrophoresis-electrochemiluminescent detection

The fast analysis of ranitidine is of clinical importance in understanding its efficiency and a patient's treatment history. In this paper, a novel determination method for ranitidine based on capillary electrophoresis-electrochemiluminescence detection is described. The conditions affecting separation and detection were investigated in detail. End-column detection of ranitidine in 5 mM Ru(bpy)32+ solution at applied voltage of 1.20 V was performed. Favorable ECL intensity with higher column efficiency was achieved by electrokinetic injection for 10 s at 10 kV. The R.S.D. values of ECL intensity and migration time were 6.38 and 1.84% for 10−4 M and 6.01 and 0.60% for 10−5 M, respectively. A detection limit of 7 × 10−8 M (S/N = 3) was achieved. The proposed method was applied satisfactorily to the determination of ranitidine in urine in 6 min.