REVERSED-PHASE HPLC DETERMINATION OF Co(II), Ni(II) AND Fe(III) AS THEIR 2-(2-THIAZOLYLAZO)-5-DIMETHYLAMINOPHENOL CHELATES

摘要

The optimum chromatographic separation conditions for Co(II), Ni(Il), and Fe(III) chelates with 2-(2-thiazolylazo)-5-dimethylaminophenol (TAM) were investigated. The compositions of chelates were also determined by the HPLC method and thus the possible structure of chelates was given. A precolumn derivatization method was used, followed by separation on an octyl-bonded silica stationary phase with a methanol-tetrahydrofuran-water (40:9:51, v/v/v) mobile phase containing pH 5.8 acetate buffer and 1 x10~(-4) M TAM. The detection limits of Co(II), Ni(II), and Fe(III) at 560 nm are 0.03, 0.02 and 0.1 ng (S/N = 2), respectively. They can be determined by means of the proposed method without interference from other common metal ions and have been determined in five standard alloys with < satisfactory results.