Determination of bopindolol using the flow injection technique coupled with solid phase extraction

Abstract

In the proposed procedure, the determination of bopindolol using a flow injection analysis (FIA) technique, with spectrophotometric detection at 635 nm, is described. The method is based on the production of a green, water-soluble complex with ferric ions in acid medium. The automated lab-made FIA system was used for the direct determination of bopindolol in tablets. Bopindolol was adsorbed onto the solid phase in a mini-column, which was integrated directly into the flow system. The positive feature of the use of solid phase extraction (SPE) was the pre-concentration of bopindolol (seven times). The sample throughput was 50 samples per hour. Using the SPE method, bopindolol was determined with a linear range from 125 to 1000 μg ml −1 (Relative standard deviation (R.S.D.)=1.87%), with a detection limit (3σ) of 70 μg ml −1. The method was applied to the determination of bopindolol in Sandonorm® tablets. The results obtained were compared with a conventional HPLC method, both analytical techniques were in good agreement.