THE APPLICATION OF SOLID SORBENTS FOR THE PURIFICATION OF ALUMINUM CONTAMINATED CHEMICALS USED AS MODIFIERS IN ELECTROTHERMAL ATOMIC-ABSORPTION SPECTROMETRY

Various microcolumns with solid sorbents (ion exchange resins, functio nalised cellulose sorbents, chelating resins) have been tested with re spect to their ability for the purification of aluminum contaminated c hemicals used as modifiers in electrothermal atomic absorption spectro metry. The purification of NaNO3, Mg(NO3)(2), K2SO4 and (NH4)(2)HPO4 h as been the most effective with an almost 100% efficiency, when Sphero n-Oxine was used as chelating resin. The sorption of aluminum from KOH solution has been found to be very high (around 90%) for all investig ated sorbents. However, the best results have been obtained with anion -exchange resins. It has been difficult to purify concentrated mineral acids (HCl, H2SO4). A retention of aluminum above 80% has been achiev ed only when Cellex P, Chelex 100 or Amberlite XAD-2 have been used.