DETERMINATION OF COBALT IN 2 GLASSES BY ATOMIC-ABSORPTION SPECTROMETRY AFTER FLOW-INJECTION ION-EXCHANGE PRECONCENTRATION

A flow injection ion-exchange preconcentration scheme, using a minicolumn loaded with Chelex-100 coupled on-line with the atomic detector, is described for the simple and quantitative determination of trace amounts of Co by atomic absorption spectrometry. The detection limit obtained for Co was 20 ng ml-1 with a precision of +/- 1.5% at the 0.5-mu-g ml-1 level, by preconcentrating 1 ml of the sample solution. The applicability of the optimized procedure to real problems is demonstrated by determining Co in two commercially available soda-lime-magnesia silica glasses produced in a local factory. The results were satisfactory as indicated by the results of the analysis of the same two samples carried out by inductively coupled plasma atomic emission spectrometry.