Journal of Chemical Metrology Articles

One flow injection analysis (FIA) procedure for the successive potentiometric and spectrophotometric determination of ascorbic acid (AA) and thiols (cysteine, cys; N-acetyl-L-cysteine, NAC; penicillamine, pen; glutathione, glu) in mixtures has been described. The potentiometric FIA signal is based on the reaction of formation the sparingly soluble salts, RSAg, between thiols (designated also as RSH) and Ag + ions. Ascorbic acid has had no influence on potentiometric signal at any experimental concentration. The spectrophotometric FIA signal is based on redox-reaction of chosen compounds with 1,10-phenanthroline-iron(III) complex. For potentiometric determination of thiols and spectrophotometric determination of selected compounds a rectilinear calibration graphs were obtained.