Colorimetric determination of manganese(II) in natural and waste waters after preconcentration on a polymeric adsorbent

A combined procedure has been developed for the colorimetric determination of manganese(II) in natural and waste waters based on the selective preconcentration of metal ions on a polymer complexing adsorbent,—polystyrene-2-oxy-〈1-azo-1′〉-2′-oxy-3′-sulfo-5′-nitrobenzene, followed by the digital detection of the analytical signal. Manganese(II) is extracted (95–100%) in the batch mode in the pH range from 4.9 to 6.8. The determination is not interfered by n × 105-fold excess (by weight) of K, Na; n × 104-fold excess of Ca, Mg; n × 103-fold excess of Ba, Sr, Al, Fe(III); n × 102-fold excess of Ti(IV), Ni, Co, Zn, Pb, Cu. The accuracy of the procedure has been examined by the standard addition method. The relative standard deviation varies from 9 to 16%. The advantages of the procedure include simplicity, availability of the apparatus, rapidity, and the possibility of its application in field conditions.