Flow injection-solid phase spectrofluorimetric determination of pyridoxine in presence of group B-vitamins

Abstract

A flow-through optosensor has been prepared for the sensitive and selective determination of pyridoxine (vitamin B₆) in aqueous solutions. The sensor was developed in conjunction with a monochannel flow-injection analysis system with fluorimetric detection using Sephadex SP-C25 resin as an active sorbent substrate. This method of determination is carried out without any derivatization. The wavelengths of excitation and emission were 295 and 385 nm, respectively. When a HCl (10^–3 mol L^–1) / NaCl (3 × 10^–2 mol L^–1) solution is used as carrier solution, the sensor responds linearly in the measuring range of 5–200, 10–400 and 50–1800 ng mL^–1 with detection limits of 0.33, 0.67, and 5.70 ng mL^–1 for 2000, 1000 and 200 μL of sample volume, respectively. The relative standard deviation for ten independent determinations is less than 0.75% for 0.2 and 1.0 mL of sample volumes used, and 1.31% for 2.0 mL of sample volume used. The method was satisfactorily applied to the determination of vitamin B₆ in pharmaceutical preparations.