Reversed-phase extraction chromatography-neutron activation analysis (RPEC-NAA) for copper in natural waters using Amberlite XAD-4 resin coated with 1-(2-thiazolylazo)-2-naphthol

A preconcentration neutron activation analysis method has been developed for the determination of trace levels of Cu in natural waters including seawater with an absolute detection limit of 0.106 μg. The method involves the preconcentration of Cu onto Amberlite XAD-4 resin coated with 1-(2-thiazolylazo)-2-naphthol using reversed-phase extraction chromatography (RPEC). Copper is assayed through its neutron activation product 66Cu (half-life = 5.10 min) by direct irradiation of the resin bed. Factors affecting the uptake of Cu onto the ligand-impregnated resin have been investigated; these include flow rate, pH, column height, presence of other trace elements, major elements, and interfering matrix. The RPEC-NAA method has been validated by analyzing NIST and NRC water reference materials. (author)