Accurate isotope ratio measurements of ytterbium by multiple collection inductively coupled plasma mass spectrometry applying erbium and hafnium in an improved double external normalization procedure

Abstract

Four series of experiments had been carried out for correct ytterbium isotope ratios measurements (IRM).(1) For erbium IRM, 167 Er/ 166 Er ~0.682 60, derived from recently published thermal ionization mass spectrometry (TIMS) measurements, was applied as an internal normalization factor. (2) Ytterbium has no calibrated isotope ratio values. In an erbium-ytterbium-hafnium mixture solution we determined ( 171 Yb/ 172 Yb) Er-corr ~0.653 436(4) using the above 167 Er/ 166 Er ratio as external normalization factor. In the same mixture we also determined ( 171 Yb/ 172 Yb) Hf-corr ~0.653 297(25) using the well-known IUPAC value for the ratio 179 Hf/ 177 Hf ~0.732 50 as external normalization factor. In these measurements no atomic isobaric interference exists at the corresponding mass numbers. (3) These two 171 Yb/ 172 Yb ratios, derived with data at mass intervals 166-167 and y178, were interpolated to mass interval 171-172, applying linear and slightly curved (exponential) line interpolations. 171 Yb/ 172 Yb ~0.653 367 and 0.653 344 are the linear and curved line interpolated values, respectively. Then, all ytterbium isotope ratios were measured in pure ytterbium solutions and internally corrected with each of the two 171 Yb/ 172 Yb ratios. ( 4) Using the literature value for 178 Hf/ 177 Hf ~1.467 290, we obtained 179 Hf/ 177 Hf ~0.732 49(2), which is in very good agreement with the above mentioned IUPAC value. The exponential correction equation was applied in this work. The mean Er ratio values are in good agreement with literature, except for the 162 Er/ 166 Er ratio, which is 2.19% lower than the reported absolute TIMS value. The mean Yb ratio values obtained in this work are in fair agreement with data reported in the last 25 years. We believe that they are the closest to the true values. The precision (2s) is at least 3-8 times better comparing to the measured TIMS precision.

The origin of the Palaeoproterozoic AMCG complexes in the Ukrainian shield: New U-Pb ages and Hf isotopes in zircon

“…The data were acquired with a Thermo-Scientific Neptune multicollector inductively coupled plasma mass spectrometer (ICP-MS) coupled to a New Wave 193 nm ArF laser ablation sampling system operating at 4 Hz and using a 50 mm spot size over a 60 s ablation period. The Yb isotope compositions of Segal et al (2003) Lu=0.02655 , assuming that the mass bias behaviour of Lu is analogous to that of Yb Kemp et al (2009).…”

Hafnium isotope analysis of mixed standard solutions by multi-collector inductively coupled plasma mass spectrometry: an evaluation of isobaric interference corrections

“…The 176 Hf/ 177 Hf ratio of the Hf isotopic measurements for a mixed standard solution of which concentrations were 298.7 ng ml -1 for JMC 14375 Hf, 30.4 ng ml -1 for Accu-Trace Yb and 3.0 ng ml -1 for Accu-Trace Lu. The isobaric interference corrections were made after previous reports on Yb isotopic composition (Chu et al 2002;McCulloch et al 1977;Segal et As depicted in Figure 2, the results of 11 measurements (20 cycles, integration time=4.194 s) indicate that reports of Yb isotope ratios in (Chu et al 2002;McCulloch et al 1977) Hf is typically very small in the crustal materials (ca. 1%, (Rudnick & Fountain 1995)).…”

“…B8045141, reference standard). For the calculation of β(Yb) and isobaric interference correction, an accurate Yb isotopic composition is needed but previous reports are not uniform (Chu et al 2002;McCulloch et al 1977;Segal et al 2003;Thirlwall & Anczkiewicz 2004;Vervoort et al 2004). The 176 Hf/ 177 Hf ratio of the Hf isotopic measurements for a mixed standard solution of which concentrations were 298.7 ng ml -1 for JMC 14375 Hf, 30.4 ng ml -1 for Accu-Trace Yb and 3.0 ng ml -1 for Accu-Trace Lu.…”

Zircon U-Pb, Hf and O isotope constraints on growth versus reworking of continental crust in the subsurface Grenville orogen, Ohio, USA

“…173 Yb/ 171 Yb = 1.1301 and 176 Yb/ 171 Yb = 0.7938 (Segal et al, 2003) and the exponential law were used for mass bias correction of Yb. No invariant ratio for Lu is available as Lu only has two naturally occurring isotopes ( 175 Lu and 176 Lu).…”