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

Abstract

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-MS 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 (⁵⁰Ti⁴⁰ Ar²⁺). The features of the two methods used in this work were compared.