Direct determination of tin and aluminium in zirconium by ICP-vacuum ultraviolet AES

A method is described for the direct determination of tin and aluminium in zirconium and zirconium alloys by ICP-AES using spectral lines (Sn II 189.99 nm, Al II 167.08 nm) in the vacuum ultraviolet region. After four ICP instruments were examined for the BEC (background equivalent concentration), sensitivity, detection limit and Is/Ib ratio for Sn and Al, one of the system was used in this experiment. Sample (0.5 g) was dissolved in 5 ml of (1+6) hydrofluoric acid and 4 ml of (1+1) hydrochloric acid by gentle heating in a polyethylene beaker. After cooling to room temperature, the sample solution was diluted to 50 ml (for tin) or 100 ml (for aluminium) with distilled water. The method of matrix matching was used for the calibration of both elements. For the determination of aluminium, the corrected calibration curves based on the estimation of the influence by a neighbouring iron line were used. The detection limits (3σ) were 8.8 ppm for tin and 1.4 ppm for aluminium. The present method was applied to the analyses of zirconium and zirconium alloys of NIST SRM's and JAERI CRM's; tin of 14∼221 ppm and aluminium of 21∼71 ppm were determined with the precision of 18.4∼6.1% for Sn and 2.8∼0.8% for Al as the relative standard deviations. (author)