Simultaneous determination of proton pump inhibitors by high performance liquid chromatography with resonance Rayleigh scattering: A study of mechanism, performance and application

In the present study, a convenient, selective and sensitive method of high performance liquid chromatography combined with resonance Rayleigh scattering (HPLC-RRS) for the detection of proton pump inhibitors (PPIs) was proposed based on enhancing the volume and hydrophobicity of PPIs by introducing Eosin Y (EY) and Pd(II). In order to investigate the interaction and the mechanism of signal enhancement, the complexes were characterized by ultraviolet-visible spectrum (UV), dynamic light scattering (DLS), RRS, scanning electron microscope (SEM) and the calculation of the density functional theory (DFT). The results indicated that PPIs, Pd(II) and EY formed ionic associations at 1:1:2 due to electrostatic attraction, which increased the volume and hydrophobicity of the system, resulting in the enhancement of RRS signals. Under the optimized experimental conditions, a linear relationship was found between RRS intensity and the concentration of PPIs within 0.02-25.00 mu g mL-1. The limits of detection were 10.1, 5.6, 7.5 and 8.3 ng mL-1 for rabeprazole, omeprazole, pantoprazole, and lansoprazole, respectively. In addition, the established simple, reliable and cheap method was validated and applied for the human serum samples, which indicated broad application prospects in drugs.