ANALYTICAL APPLICATION OF SOME CHEMICAL MODIFIERS IN ATOMIC-ABSORPTION SPECTROMETRIC INVESTIGATION AND DETERMINATION OF MN(II) AND MN(VII)

The interfering effects of a range of cations, acids and organic compo unds on the absorption signal of manganese(II) and manganese(VII) were studied in different media under diverse flame profile of different o bservation heights and fuel now rates. The signal response of Mn(II) a nd Mn(VII) is slightly changed under different name conditions, wherea s it is markedly affected in the presence of concomitants. Several che mical modifiers were successfully applied for controlling such: effect s. Of these, boric acid, lanthanum chloride, strontium chloride, ammon ium chloride and aluminium chloride were found to be effective as inor ganic chemical modifiers in eliminating specific interferences on Mn(I I) and Mn(VII) encountered from inorganic addenda. A combination of bo ric acid and strontium chloride, 500 ppm each, was able to overcome th e potential effects of all inorganic interferences studied. Butylamine and piperidine were also used as excellent chemical modifiers organic reagents for controlling inorganic and organic interferences on manga nese. The mechanism of the interfering effects and the releasing actio n is discussed which is based on masking the interferent(s) with the i norganic reagent(s) through the formation of refractory species, where as the organic reagent(s) protect(s) the analyte by forming an easily dissociated complex in the name. A procedure was described for precise determination of manganese in synthetic mixture and some manganese co mplexes.