A spectrofluorimetric method for the determination of pindolol in natural waters using various organic and cyclodextrin media

A simple, sensitive, and rapid spectrofluorimetric method was developed for the determination of the beta-blocker pindolol. The native fluorescence of pindolol was measured in different organic solvents and in cyclodextrin aqueous media. The highest fluorescence signal was obtained in 2-propanol at lambda(em) = 303 nm with lambda(ex) = 260 nm. Analytical figures of merit for the spectrofluorimetric determination of pindolol were satisfactory, with wide linear dynamic range (LDR) values of two orders of magnitude, and rather low limit of detection (LOD) values between 0.2 and 8.7 ng/mL. Moreover, the addition of cyclodextrins (HP-beta-CD and beta-CD) in aqueous media enhanced the fluorescence of pindolol. In addition, the inclusion complexes of pindolol with cyclodextrins were investigated and the stability constants of complexes were calculated by means of the method of nonlinear regression (NLR). The method was successfully applied to the analysis of tap water and natural water samples, spiked with pindolol.

Automated summary

A spectrofluorimetric method was developed for the determination of beta-blocker pindolol, with successful measurement in different solvents and aqueous media. The addition of cyclodextrins was found to enhance the fluorescence of pindolol, and the method was successfully applied to the analysis of water samples.