DETERMINATION OF SCANDIUM IN HIGH-PURITY TITANIUM USING INDUCTIVELY-COUPLED PLASMA-MASS SPECTROMETRY AND GLOW-DISCHARGE MASS-SPECTROMETRY AS PART OF ITS CERTIFICATION AS A REFERENCE MATERIAL

Scandium was determined in high-purity titanium by inductively coupled plasma mass spectrometry (ICP-MS) and glow discharge mass spectrometry (GDMS), The analysis was carried out as part of the certification campaign for certifying Sc in a titanium neutron dosimetry reference material (NRM 531) from the Institute of Reference Materials and Measurements (IRMM). The scandium concentration in the titanium was found to be less than 2.5 ng g(-1). This is based on the analysis of four NRM 531 titanium samples. This value was established using ICP-R?IS preceded by ion exchange for the matrix separation, The mean recovery for this separation was 92 +/- 12%, A comparative measurement using GDMS confirmed the results obtained by ICP-MS. The relative sensitivity factor of scandium in titanium, RSF(Sc/Ti), for GDMS was determined by using four doped titanium samples prepared at IRMM. The data for the doped titanium samples were cross checked using ICP-MS. NRM 531 titanium was analysed four times with GDMS and scandium levels were found to be below the detection limit of 25 ng g(-1). This relatively high detection limit for GDMS was due to an interfering polyatomic species on the same nominal mass as scandium ((TiAr2+)-Ti-50-Ar-40). The features of the two methods used in this work were compared.