Determination of omeprazole with a new flow-injection chemiluminescence method

Objective: To develop a new flow-injection chemiluminescence (FI-CL) method for the determination of omeprazole. Methods: Strong chemiluminescence (CL) signal was found generated when omeprazole was injected into the reaction mixture of KMnO₄ and luminol. The experimental conditions that affected the CL reaction were optimized by using FI mode. Results: Under the optimum experimental conditions (150cm of mixing tubing, 0.15 mol/L NaOH, 7.0 X 10^-5 mol/L luminol, 2.0X10^-5 mol/L KMnO₄ and 2.8 mL/min of flow rate), CL intensity was linearly related to the concentration within the range of 2.0X10^-8-1.0X10^-5g/mL. The detection limit was 3X10^-9g/mL omeprazole, and the relative standard deviations (n = 11) were 1.0% and 2.6% for 1.0X10^-7g/mL and 1.0X10 ^-6g/mL omeprazole solutions, respectively. Conclusion: The proposed method is simple, rapid, sensitive, and suitable for determining omeprazole content in pharmaceutical preparations.