HIGH-PERFORMANCE LIQUID-CHROMATOGRAPHIC SEPARATION AND DETERMINATION OF COBALT(II), COBALT(III) AND IRON(II) USING BIS(SALICYLALDEHYDE)TETRAMETHYLETHYLENEDIIMINE

The reactions of bis(salicyclaldehyde)tetramethylethylene (H(2)SA(2)Ten) with cobalt(II), cobalt(III), iron(II) and iron(III) were studied and conditions for their extraction as metal chelates from aqueous solution into chloroform were optimized. Cobalt(II), cobalt(III) and iron(II) were completely separated on a 3-mu m Microsorb ODS column when eluted isocratically with methanol-water-acetonitriie (60:39:1, v/v/v), with spectrophotometric detection at 270 nm. Linear calibrations were obtained over the range 0-125 mu g per 2 ml of extract. The detection limits were in the range 0.25-1.0 mu g/ml. The oxidation of cobalt(II) to cobalt(III) with air and nitric acid was examined and the method was applied to the determination of cobalt and iron in pharmaceutical preparations. The results obtained were compared with those given by atomic absorption spectrometry.