Determination of tin, tungsten, niobium, and tantalum in rocks and minerals by inductively coupled plasma-atomic emission spectrometry

An ICP-AES method for the determination of tin, tungsten, niobium, and tantalum in cassiterite-bearing rocks is described. The method involves volatilization of tin by heating with ammonium iodide, followed by ICP-AES determination of tin from a solution of the sublimate. The residue left after volatilization of the tin is dissolved in an hydrofluoric-perchloric acid mixture. The resultant solution is measured for niobium, tantalum, and tungsten by ICP-AES. The proposed method of sample decomposition is very fast and superior to the existing flux fusion procedures. The method has been applied to the determination of Sn, W, Nb, and Ta in a number of rocks and minerals and the results have been compared with those obtained by other established methods.