DETERMINATION OF Na-DITHIONITE AND NH4-OXALATE EXTRACTABLE Fe, Al AND Mn IN SOILS BY ATOMIC ABSORPTION SPECTROSCOPY

Fe, Al and Mn in distilled warer, NH4-oxaIate, and Na-dithionite solutions were determined by atomic absorption spectroscopy. Concentration ranges for sensitive absorption by Fe, Al, and Mn were 2.5 to 20, 25 to 125 and 2 to 10 ppm, respectively. Concentration ranges of extracting solutions for the determination of Fe, Al and Mn were 0.01 M, 0.20 M and 0.04 M, respectively. Accurate and rapid determinations of Fe, Al, and Mn in NH4-oxalate and Na-dithionite solutions are obtained by atomic absorption spectroscopy without the destruction of the organic extractants.