Trace and Rare Earth Element geochemical data

Digestion reagents blanks and international standards were processed along samples. All the solutions were then analysed by inductively coupled plasma mass spectrometry (ICP-MS) on an Agilent®-7700x instrument within 48 hours of dilution. Calibration of the instrument involved high purity standards solutions (CHOICE Analytical ®) for quantification and for estimation of isobaric interferences from Ba, Ce, Nd, Pr and Zr, all prepared in the same matrix.

Multi-elemental calibration solutions were prepared at concentrations 5, 10 and 20 μg/ml. Data reduction and Quality control Mass-spectral data were collected as counts per second using Mass Hunter (Agilent ®) software and reduced through home-developed spread sheet (CODES, UTAS) using Excel Software (Microsoft Corporation ®). Reduction includes corrections by isobaric interferences, background and digestion procedure blank contribution, instrumental drift and dilution.

Quantification includes a secondary correction by linear regression on three standard referenced materials (SRM), namely TASGRAN, TASBAS and AGV-1. The overall analytical uncertainty was estimated for each analysis (see report). In addition, the data quality, precision and accuracy, can be estimated on replicates for the analysed unknown samples and a very well-known SRM, basalt BCR-2, as it has a similar matrix to the analysed samples.

Elements analysed Li, Be, Sc, Ti, V , Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y , Zr, Nb, Mo, Ag, Cd, Sn, Sb, Te, Cs, Ba, REE (La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu), Hf, Ta, W , Tl, Pb, Bi, Th, U Reagents used: Seastar BASELINE high purite grade (Seastar Chemicals Inc, USA), Type-I Mili-Q ultra-pure water (Merk Millipore) and high purity standards (HPS) (CHOICE Analytical). Environment for Sample preparation: Clean lab class ISO5.

References: Agilent agilent.com/about/companyinfo/ CHOICE Analytical choiceanalytical.com.au/standards-and-crms/high-purity-standards/ GEOREM georem.mpch-mainz.gwdg.de/sample_query_pref.asp. PicoTrace picotrace.de/products-das.html