Double-wavelength overlapping resonance Rayleigh scattering technique for the simultaneous quantitative analysis of three β-adrenergic blockade

• Novel method developed for simultaneous determination of β-adrenergic blockade
• Double-wavelength overlapping resonance Rayleigh scattering (DW-RRS) technique was used.
• Homologous ray measurement analytical method was used to handle the data.

Four simple and accurate spectrophotometric methods were proposed for the simultaneous determination of three β-adrenergic blockade, e.g. atenolol, metoprolol and propranolol. The methods were based on the reaction of the three drugs with erythrosine B (EB) in a Britton–Robinson buffer solution at pH 4.6. EB could combine with the drugs to form three ion-association complexes, which resulted in the resonance Rayleigh scattering (RRS) intensity that is enhanced significantly with new RRS peaks that appeared at 337 nm and 370 nm, respectively. In addition, the fluorescence intensity of EB was also quenched. The enhanced scattering intensities of the two peaks and the fluorescence quenched intensity of EB were proportional to the concentrations of the drugs, respectively. What is more, the RRS intensity overlapped with the double-wavelength of 337 nm and 370 nm (so short for DW-RRS) was also proportional to the drugs concentrations. So, a new method with highly sensitive for simultaneous determination of three bisoprolol drugs was established. Finally, the optimum reaction conditions, influencing factors and spectral enhanced mechanism were investigated. The new DW-RRS method has been applied to simultaneously detect the three β-blockers in fresh serum with satisfactory results.

The RRS spectra of (a) EB, (b) EB–AL system, (c) EB–ML system, (d) EB–PL system in 0.5 mL BR buffer solution 4.6 (EB: 8 × 10− 6 M; AL, ML and PL: 8 × 10− 6 M). (The inset is the RRS spectra of only AL (curve 1), ML (curve 2) and PL (curve 3) in pH 4.6 buffer solution)Figure optionsDownload as PowerPoint slide