ICP-OES-Analysis for Humic Substance

Abstract

The possibilities of optical emission spectrometry with inductively coupled plasma (OES-ICP analysis) (in radial plasma observation) of humic preparations (HP) are evaluated, the proposed technique allows quantifying up to 24 elements (As, Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Si, S, Sr, Ti, V and Zn). The list of these elements will allow determining the value of such preparations for soil nutrition, and will also help to avoid danger if the content of toxic impurities in them goes beyond their maximum permissible concentrations. In the absence of standard samples with certified contents of the elements to be determined, the correctness of the analysis for the macrocomponent composition is confirmed by comparing the results of gravimetric determination of the ash content of the studied objects with the calculated data obtained when processing the results of OES-ICP analysis. Systematic errors in the determination of trace impurities were minimized by using the method of adding standard solutions (from matrix influences), as well as 6 parallel measurements of samples prepared independently of each other. The correctness of the methodology was also evaluated by using model solutions close to the possible micro-impurity mineral composition of HP using the Student’s t-test. The results obtained for the isolated fraction of humic acids are compared with the literature data.