FI-Chemiluminescence Determination of Famotidine

In a weakly allkaline medium of sodium polyphosphate of pH 8.68,chemiluminescence (CL),produced by the reaction among cupric ion,hydrogen peroxide and rhodamine B was strongly inhibited by the drug,famotidine.By applying the flow injection technique,a method of determination of famotidine by CL was proposed.Magnitude of CL intensity inhibited was found to keep linear relationship with the concentration of famotidine in the range of 5.0-1 000 μg·L-1 with a detection limit (as defined by IUPAC) of 2.7 μg·L-1.Precision of the method was tested at the concentration level of 300 μg·L-1 for 11 determinations,giving value of RSD 2.1%.The proposed method was applied to the analysis of famotidine injection and tablet samples,giving values of recovery in the range of 99.5% to 102.8%.The chemism of the CL-inhibition process was also discussed briefly.