The spectrophotometric determination of Cu(II) with 4-methyl-5-[(sulfomethyl)amino]-2-(2-thiazolylazo)benzoic acid(TAMSMB) was carried out by a cyclic flow-injection analysis. A cation -exchange column for on-line regeneration of the main reagent was incorporated in this FIA system, allowing a repetitive determination of Cu(II). A solution of 5 10 5 M TAMSMB in 0.1 M acetate buffer (pH 3.7) in a single reservoir (50 ml) was continuously circulated at a constant flow rate of 1.25 ml min 1 . Into the stream, an aliquot (20 µl) of a sample containing Cu 2 was quickly injected by means of a 6-way valve. The complex formed was monitored spectrophotometrically at 585 nm in the flow system. Then, the stream passed through a cation-exchange column, which was introduced after the flow-through cell. A successful ligand-exchange reaction of Cu 2 between the TAMSMB reagent and a cation-exchanger, as well as a simultaneous regeneration of the free reagent took place. The stream then returned to the reservoir. The regeneration and recycling of the TAMSMB reagent allowed as many as 500 repetitive determinations of 1.5 mg l 1 Cu 2 solutions with the same 50 ml circulating solution.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.