Simultaneous assay of copper iron and uranium in phosphate media by ion-pair liquid chromatography

Summary Ion-pair, high-performance liquid chromatography has been used for the simultaneous separation of Cu(II), Fe(II) and U(VI) as their proposed, anionic [M(H₂PO₄)₃]^– and neutral complexes with tetrabutylammonium (TBA)⁺ as ion-pairing reagent. The concentration effect of (TBA)⁺, organic modifier and pH of the eluent on the separation was investigated. The UV detector response at various wavelengths has been optimized. Detection limits of Cu(II), Fe(II) and U(VI) were 12, 6 and 12 ng respectively. The method is compared with atomic absorption spectroscopy spectrophotometry for determination of metal ions in synthetic mixtures as well as in Standard Reference Materials (SRMs).