Absolute isotopic composition and atomic weight of selenium using multi-collector inductively coupled plasma mass spectrometry

The isotopic composition of selenium was measured with high precision using a collision cell multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). Gravimetric synthetic mixtures prepared from three highly enriched isotope of Se-76, Se-78 and Se-82 with well defined purity were used to calibrate a MC-ICP-MS. Measurements of seven various natural selenium materials including Se NIST SRM 3149 yielded the absolute isotopic composition (in at.%) of Se-74 0.8623(38), Se-76 9.228(10), Se-77 7.5975(50), Se-78 23.693(12), Se-80 49.800(17) and Se-82 8.8188(85). The new atomic weight of selenium was calculated as 78.9711(9). (C) 2011 Elsevier B.V. All rights reserved.