Cerium(IV)-based chemiluminescence of phentolamine sensitized by rhodamine 6G

A new chemiluminescence (CL) method is proposed for the determination of phentolamine, which is based on the reaction between studied drug and Cerium(IV) (Ce (IV)) in a nitric acid medium and measurement of the CL intensity produced by rhodamine 6G used as a sensitizer. In the optimum conditions, CL intensities are proportional to concentrations of the studied drug over the range 1×10^-9–1×10^-6 g/ml with a detection limit of 4×10^-10 g/ml. The relative standard deviation (R.S.D.) is 3.4% for 1×10^-7 g/ml phentolamine (n=11). The method has been applied to the determination of studied drug in injections and biological fluids with satisfactory results.