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 spectrometr y (GDMS), The analysis was carried out as part of the certification ca mpaign for certifying Sc in a titanium neutron dosimetry reference mat erial (NRM 531) from the Institute of Reference Materials and Measurem ents (IRMM). The scandium concentration in the titanium was found to b e less than 2.5 ng g(-1). This is based on the analysis of four NRM 53 1 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 confi rmed the results obtained by ICP-MS. The relative sensitivity factor o f scandium in titanium, RSF(Sc/Ti), for GDMS was determined by using f our doped titanium samples prepared at IRMM. The data for the doped ti tanium samples were cross checked using ICP-MS. NRM 531 titanium was a nalysed four times with GDMS and scandium levels were found to be belo w the detection limit of 25 ng g(-1). This relatively high detection l imit 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.