Qe. Cao et al., Sequential fluorescent determination of copper(II) and cobalt(II) in food samples by flow injection analysis, FOOD CHEM, 65(3), 1999, pp. 405-409
Copper (II) can react with a new fluorescence reagent, 5-(4-chlorophenylazo
)-8-aminoquinoline (APAQCL), forming a fluorescence product only in slightl
y acidic medium, while the fluorescence product of cobalt (II) with APAQCL
forms only in basic medium and in the presence of H2O2 Based on the differe
nce of the reaction between cobalt (II) and copper (II) with APAQCL, a new
flow injection method for the sequential determination of cobalt and copper
in binary mixtures by use of a fluorimetric detector and APAQCL as reagent
was proposed. Linear calibration graphs were obtained over the concentrati
on range 0.010-1.20 (mu g/ml) of cobalt (II) and 0.05-5.00 (mu g/ml) of cop
per (II) with the detection limit of 0.0030 (mu g/ml) of cobalt (II) and 0.
010 (mu g/ml) of copper (II), respectively. The applicability of the method
to the sequential determination of cobalt (II) and copper (II) in food sam
ples was demonstrated by investigating the potential interference and by th
e analysis of synthetic mixtures of copper (II) and cobalt (II). The method
was successfully applied to the determination of copper and cobalt in food
samples. (C) 1999 Elsevier Science Ltd. All rights reserved.