ONLINE ANALYSIS DEVICE WITH HYDRODYNAMIC INJECTION INTO THE FLUX - C-VITAMIN DETERMINATION

A FIA assembly set up by the authors, where the sample injection into the flux is done hydrodynamically (without using an injection valve) i s presented. The detection is done spectrophotometrically. The influen ce upon the registered signals of the main operational parameters (vol ume of the injected sample, flow rate of the carrier and length of the tube where the dispersion takes place) were studied. The FIA assembly was used for vitamin C determination, when a solution of iodine in io dide was employed as carrier flux. Duration of a measurement is 20 s a nd both sensitivity and selectivity are similar to those of the manual analysis procedure. The FIA assembly was used for vitamin C determina tion in the orange juice.