Liquid-Liquid Extraction and Liquid Chromatographic Studies on Interactions of Inorganic Anions with Coordinatively Unsaturated Copper(II) Complexes of Heterocyclic Azo Compounds

Determination of cobalt, nickel and iron at trace level in natural water samples by in-column chelation-reversed phase high-performance liquid chromatography

“…On the other hand, high-performance liquid chromatography (HPLC) is a promising technique for multielement determination of ultratrace metal ions as metal chelates, providing advantages in sensitivity, robustness, and cost-effectiveness (Takahashi et al 2008;Yang et al 2005Yang et al , 2004Zhang et al 2005;Yasui et al 2008;). HPLC with a convenient detector meets most of the analytical requirements of simultaneous metal determination such as separation, identification, and quantification of different species down to trace levels.…”

Redox Potentials and HPLC Behavior of Cobalt and Iron Complexes with Pyridylazo Compounds

“…3 + as well as an excess ligand, HL were satisfactorily separated using an aqueous acetonitrile mobile phase containing thiocyanate ion, 5 which guaranteed a reproducible and appropriate retention of cationic complexes as ion-pairs, such as [CoL2] + SCN -and [CuL] + SCN -. 9 Although common heterocyclic azo compounds showed similar behavior to b-PAN, a few exceptions were reported. In the HPLC system with 2-(5-nitro-2-pyridylazo)-1-naphthol, Co 2+ was detected as a neutral 1:2 complex, [Co II L2], without any reducing reagents.…”