COMPARATIVE-STUDY OF SOME METHODS OF OXIDATION OF PLANT MATERIALS FOR ELEMENTAL ANALYSIS

Four different methods were used to dissolve eleven different plant materials for simultaneous estimation of several elements. In comparison to wet digestion in nitric acid, dry-ashing at 500-degrees-C resulted in lower estimates of S, As, Pb and Cd. The digestion with diacid caused the loss of P, K, Ca, Mg, Na, Ln, Cu, Mn and B, the loss being statistically significant and much higher when the ratio of the two acids was 3:1 as compared to 10:1. The loss in K values was higher when concentration was greater than 1%. Therefore, among the four tested methods, the digestion with nitric acid is proposed for elemental analysis.