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The selective adsorption of metasilicate species by N-methyl D-glucamine functional groups in Amberlite IRA 743 resin was observed, which is clarified as the formation of sugar-metasilicate complexes and possible physical adsorptions. The existence of metasilicate matrices causes obvious discrepancies in the δ11B values of silicate materials. It opens the possibility for exploring relevant procedures for the separation/purification of silicon from geological samples.

A new approach is presented for the analysis of lead isotopes in gold using solution and laser ablation multi-collector inductively-coupled plasma mass-spectrometry (MC-ICP-MS). Repeat analyses of two gold reference materials (RAuGP3: 34.1 ± 0.5 ppm Pb and RAuGP5: 129 ± 4 ppm Pb, from SPEX CertiPrep Ltd) yield an external reproducibility of 20. Instrumental mass bias is corrected by standard sample bracketing, using NIST SRM981 for solution analyses and NIST SRM610 for laser ablation analyses. Both techniques agree within error, and they have been further demonstrated through the analyses of both geological and archaeological samples: multiple grains from two Irish alluvial gold deposits and samples of two Early Bronze Age Irish gold lunulae. The applicability of these techniques to studies concerning the sources and age of gold mineralisation, and the identification of gold sources exploited in antiquity, is highlighted.

We present a new multicollector inductively coupled plasma mass spectrometric (MC-ICP-MS) method for measuring isotopic ratios of 234U/238U and 230Th/232Th in volcanic rocks using the Thermo Fisher Neptune. Uranium isotope measurements using SRM U010 as bracketing standard produce agreement within several permil for NBL 112A, REMP-18, as well as for equilibrium rock standards. We also demonstrate that uranium standards are not appropriate for correcting thorium isotopic measurements due to differences between U and Th in both mass bias and mass-dependent ion transmission. Use of the thorium synthetic standard, UCSC ThA, as a bracketing standard produces data that agree well with ‘accepted values’ for other synthetic Th isotope standards and equilibrium rock standards.

A two-stage column purification method for Hf from Zr and other elements in silicate samples using the extraction chromatographic resin, UTEVA has been developed. In the first column, using an anion-exchange resin, AG 1X8, Hf, Zr and Ti were collected. In the second, using UTEVA, and after eliminating F− by evaporation with HClO4 and re-dissolution with H2O2–HNO3, Hf was purified from Ti and Zr, based on characteristic of the UTEVA resin that Hf distribution coefficient (Kd) decreases from 770 to 40, while Kd of Zr decreases less from 890 to 200, in 9 and 6 mol l−1 HNO3, respectively. The recovery yield of Hf was ∼88% and total blank was ∼4 pg. A MC-ICP-MS Hf isotope ratio determination method was also developed, which uses 179Hf spike for simultaneous determination of the Hf concentration and 176Hf/177Hf ratio. Combining the chemistry and ICP-MS techniques, 176Hf/177Hf ratios in silicate reference materials were determined with and without the spike, which gave identical results, showing the applicability of this method.

Measurements of SRM 981 Pb isotope standard mixed with Tl for mass bias corrections were conducted with a MC-ICP-MS (Nu Plasma) using a Nu Instruments desolvating nebulizer. During the initial experiments, Pb and Tl from single-element, concentrated stock solutions were mixed in 2% HNO3 prior to isotope ratio measurements. The results revealed relatively poor precision and accuracy of the Pb isotope measurements, large variations in e205Tl in the same standard (ranging from −3.9 to +30.1), and large variations in the observed Pb/Tl intensity ratios. When analyses were restricted to freshly mixed (

An ICP-MS equipped with collision cell, sector field and multi-collector technology has been applied to developing analytical procedures for Fe in terms of isotope ratio measurements and isotope dilution analysis. Therefore a detailed study on the reduction of molecular interferences by a variety of collision gases (He, Ar, Kr, H2, D2 and N2) was performed. The efficiency of the reduction has been checked by high resolution mass scans. The argon based interferences disturbing the determination of 54Fe and 56Fe could be completely removed when using Faraday detectors. The interferences on mass 57 could be reduced to a level which enables accurate measurements. Also, the 40Ar12C interference, which disturbs the chromium correction, could be completely removed. Reproducibilities of 0.01% could be reached for 54Fe/56Fe isotope ratios and 0.02% for 57Fe/56Fe isotope ratios. Under these measurement conditions a sensitivity of 1.2 V per 50 µg kg−1 Fe is available. This corresponds to 1.5 × 109 cps per mg kg−1. Based on these results highly accurate procedures for Fe isotope ratio determinations were set up, reaching a performance level superior to that of other ICP-MS instruments. Consequently, IDMS procedures were developed on this basis in order to perform certification measurements at the highest metrological level. The first application was the contribution to the Fe reference value by IMEP-12, an interlaboratory comparison with approximately 350 participants worldwide. The analysed Fe mass content is 0.2150 mg kg−1 with its expanded uncertainty (k = 2) of 0.0012 mg kg−1 (0.56%), which is ten times less than the uncertainty of the second certification laboratory. Another application was the certification campaign of the two reference materials Tea Leaves and Polish Herbs. The results obtained with the ICP-MS procedure, 542 ± 11 mg kg−1 and 543 ± 12 mg kg−1, were compared with the results analysed by TIMS, 541 ± 12 mg kg−1 and 541 ± 13 mg kg−1, and agree very well within the stated uncertainties (k = 2). The results presented demonstrate quite well the suitability of the developed IDMS procedures for certification or reference measurements.