Flow injection chemiluminescence determination of dobutamine hydrochloride injection using luminol-ferricyanide/ferrocyanide system

It was found that the weak chemiluminescence produced from the reaction of dobutamine hydrochloride with luminol in alkaline solution could be strongly enhanced by potassium ferricyanide and potassium ferrocyanide. Based on this found, a new flow injection chemiluminescence method is proposed for the determination of dobutamine hydrochloride. Under the optimum conditions, the proposed method has a linear range of 1.0 × 10−10 to 1.0 × 10−7 g ml−1, with a detection limit of 2.6 × 10−11 g ml−1 for dobutamine hydrochloride (3σ). A complete analysis could be performed in 40 s including washing and sampling, giving a throughout of about 90 h−1. The relative standard deviation (R.S.D.) for 11 parallel measurements of 1.0 × 10−8 g ml−1 dobutamine is 1.23%. The proposed method has been applied for the determination of dobutamine hydrochloride in its pharmaceutical formulations. The results obtained compared well with those by an official method. The possible mechanism of this chemiluminescence reaction was also proposed.