Chemiluminescence determination of metformin based on hydroxyl radical reaction and molecularly imprinted polymer on-line enrichment

A novel and simple chemiluminescence (CL) method has been developed and validated for determination of metformin. This method is based on hydroxyl radical chemiluminescence—the hydroxyl radical generated by reaction of Cu(II) and hydrogen peroxide oxidizes rhodamine B (RhB) to produce weak CL which can be enhanced by metformin. At the same time, metformin molecularly imprinted polymer (MIP) was synthesized. After enrichment based on the selectivity of metformin-MIP, the CL method was successfully applied to the determination of metformin in human serum. The linear range was from 1.0×10⁻⁸ to 1.0×10⁻⁶ g mL⁻¹ and the detection limit was 4×10⁻⁹ g mL⁻¹. The relative standard deviation at 2.0×10⁻⁷ g mL⁻¹ by use of MIP was 3.67% (n=7).