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

A flow-through optosensor has been prepared for the sensitive and selective determination of pyridoxine (vitamin Bg) in aqueous solutions. The sensor was developed in conjunction with a monochannel flow-injection analysis sys tem with fluorimetric detection using Sephadex SP-C25 resin as an active so rbent substrate. This method of determination is carried out without any de rivatization. The wavelengths of excitation and emission were 295 and 385 n m, respectively. When a HCl (10(-3) mol L-1)/NaCl (3 x 10(-2) mol L-1) solu tion is used as carrier solution, the sensor responds linearly in the measu ring 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 mu L of sample volume , respectively. The relative standard deviation for ten independent determi nations is less than 0.75% for 0.2 and 1.0 mt of sample volumes used, and 1 .31% for 2.0 mi, of sample volume used. The method was satisfactorily appli ed to the determination of vitamin Bg in pharmaceutical preparations.