DETERMINATION OF AVAILABLE FORMS OF THE MANGANESE IN SOILS BY STRIPPING VOLTAMMETRY

Conditions of determination of manganese(II) in soils samples using differential pulse cathodic stripping voltammetry in an electrochemically enriched solution (DPCSV-EE) at hanging mercury drop electrode have been optimized. Manganese was extracted from soils with 1 mol.dm(-3) HCI. 0.2 mol.dm(-3) ammonia/ammonium chloride buffer (pH = 8 divided by 9) was supporting electrolyte. Deposition time was 15 divided by 30 s, deposition potential -1.7 V, initial potential -1.15 V and end potential -1.7 V vs. NEK. In the above conditions Mn(II) peak height vs. its concentration dependence is linear up to 7 . 10(-5) mol.dm(-3) Mn(II). The accuracy and precision of the proposed method are also satisfactory. The relative standard deviation for 90 ppm Mn(II) equals 12.8% and for 145 ppm equals 8.9%. The method has been applied to study the content of available forms of the manganese in soils from the vicinity of Zawiercie Steel Mill and Huta Glogow Smeltery.