In this scenario, Lemos et al. developed two systems for flow-injection determination of copper [21] and cobalt [22] by F AAS using Amberlite XAD-2 resin functionalized with 3,4-dihydroxybenzoic acid and R-nitroso salt, respectively.
The system developed for copper determination achieved an enrichment factor of 33 (120 s preconcentration time) while
that developed for cobalt presented enrichment factors of 79 and 223 depending on the preconcentration time employed
(60 or 180 s, respectively). Both methodologies were validated by the analysis of certified materials of organic samples
and by the analysis of spiked water samples.