Determination of Hf isotope ratios in zircon using multiple collector-inductively coupled plasma mass spectrometry equipped with laser ablation and desolvating nebulizer dual sample introduction system

Abstract

Copyright © 2012 by The Geochemical Society of Japan. tained from Hf, e.g., using 179Hf/177Hf, is not applicable to Yb. Therefore, the use of 171Yb/173Yb is strongly encouraged to estimate the 176Yb intensity (Iizuka and Hirata, 2005; Kemp et al., 2009; Woodhead et al., 2004). However, since the reported isotope ratios for 171Yb, 173Yb, and 176Yb varied between reports, the “appropriate” isotope ratios were rigorously discussed and a consensus was reached (Iizuka and Hirata, 2005; Kemp et al., 2009). Even so, there seems no consensus on how to correct for the interference of 176Yb. The means of 176Yb correction used in recent studies are classified into three types: (1) using a modified 176Yb/172Yb, which yields the correct 176Hf/177Hf for mixed Yb–Hf standard solution using solution MC-ICPMS without obtaining mass bias factor β(Yb) (Griffin et al., 2006); (2) using β(Yb) obtained with reported 173Yb/171Yb and 176Yb/173Yb (Iizuka and Hirata, 2005; Iizuka et al., 2010; Kemp et al., 2009; Thirlwall and Anczkiewicz, 2004); and (3) using β(Yb) and slightly modified 176Yb/172Yb to reproduce accurate values for 91500 and TEMORA zircon standards (Wu et al., 2006). Determination of Hf isotope ratios in zircon using multiple collector-inductively coupled plasma mass spectrometry equipped with laser ablation and desolvating nebulizer dual sample introduction system