Determination of Niobium and Tantalum in Geological Samples by ICP-AES After Preconcentration by Solid Phase Extraction on Activated Carbon or Chitin

Niobium and tantalum at low levels in geological samples have been determined by ICP-AES after preconcentration/separation by solid phase extraction using activated carbon or chitin as sorbents. Systematic investigations were carried out on the effect of various parameters on the sorption of niobium and tantalum on activated carbon and also on chitin and their quantitative desorption/recovery. Investigations were also carried out on interferences from other concomitant ions in the sorption process. Accuracy of the method was ascertained by applying it to certified reference materials. The method was then applied to selected rock samples and relative standard deviation (RSD) values ranging from 1.0 to 6.0% were obtained. The values obtained were in good agreement with those obtained by other techniques. The method is simple, accurate, selective and eco-friendly as non-toxic/bio-compatible sorbents have been employed. The present method also leads to a significant reduction in the amount of total dissolved salts present in the sample solution arising from the fusion flux and the matrix for aspiration into the plasma.