SPECTROFLUOROMETRIC DETECTION-OF ZINC AND CADMIUM WITH 8-(BENZENESULFONAMIDO)-QUINOLINE IMMOBILIZED ON A POLYMERIC MATRIX

A chelating resin, 8-(benzenesulfonamido)quinoline immobilized on an X AD-7 support, was prepared and its use for the spectrofluorimetric det ermination of Zn and Cd was investigated. The immobilized material was placed in a how cell in a spectrofluorimeter and used in a flow injec tion system; the fluorescent complex was formed and immobilized in the cell. The chelating resin could be stored for at least three months a nd used repeatedly without any appreciable amount of reagent being los t. Calibration graphs were linear for up to 500 mu g l(-1) of Zn or Cd . Detection limits were 1.6 mu g l(-1) for Zn and 1.9 mu g l(-1) for C d. Quantification limits were 5.5 mu g l(-1) for Zn and 6.8 mu g l(-1) for Cd. Precisions at 50 mu g l(-1) were 1.7% for Zn and 1.2% for Cd. Detection Limits can be improved by injecting larger volumes of sampl e. Preconcentration factors of up to 10 were obtained for both metal i ons.