Determination of Remifentanil in Pharmaceuticals Using Chemiluminescence System of Ru(phen)3 2+-Ce(IV)

In this study, new chemiluminescence (CL) method was proposed to determine the amount of remifentanil in pharmaceuticals. We found that the weak CL intensity in the reaction between acidic cerium(IV) and Ru(phen)3 2+ complex increases significantly in the presence of remifentanil. Effect of remifentanil was investigated in some other CL systems such as luminol-IO4 -, direct oxidation using acidic cerium(IV) or acidic KMnO4. Moreover, the effect of different dyes as a sensitizer was investigated in the KMnO4-Dye CL system. The dyes used in this study were crystal violet, amido black, naphthol green, amaranth, rhodamine 6G, safranin, orange G, fluorescein, and chromotrope 2R. The results showed that remifentanil has the highest CL intensity and S/B ratio in the acidic cerium(IV)-Ru(phen)3 2+CL system. The reaction mechanism was evaluated by studying the CL reaction kinetics in the presence and absence of remifentanil and spectrophotometric spectra. The results indicate that remifentanil can convert Ru(phen)3 3+ complex rapidly to Ru(phen)3 2+* complex, which emits light when it returns to its ground-state. The method's linear dynamic range, detection limit, and reproducibility for four repetitive measurements of 109.39 μg ml-1 were 1.75-145.85, 1.41 μg ml-1, and 2.3%, respectively. The method proposed in this study was used to determine the content of remifentanil in pharmaceutical preparations.