The Advanced Geochemical Facility for Indian Ocean Research was launched in November 2011. It was established by UWA’s Premier’s Fellow Winthrop Professor Malcolm McCulloch, from the School of Earth and Environment and the UWA Ocean Institute.
The facility hosts 2 multi-collector inductively coupled plasma mass spectrometers (Thermo Neptune Plus; Nu Plasma II), 1 X-series-2 Q-ICPMS quadrupole inductively coupled plasma mass spectrometer (Thermo), 1 Thermo Triton thermal ionisation mass spectrometer (TIMS), and 1 argon fluoride 193nm excimer laser system (Coherent COMPex Pro 110).
The ICPS and laser system were purchased from an Australian Research Council Linkage Infrastructure Equipment and Facilities (ARC LIEF) grant awarded to Prof McCulloch, with contributions from The University of Western Australia, the John De Laeter Centre for Isotope Research, Curtin University, Edith Cowan University, Murdoch University, and Charles Darwin University.
The facility has two state-of-the-art double focusing MC-ICP-MS, a Thermo Finnigan NEPTUNE Plus, and an NU Instruments Plasma II. The MC-ICPMS systems combine the advantage of inductively coupled plasma for superior ionization with the high precision obtained from simultaneous multi-collector data acquisition possible with a high dispersion magnetic sector mass spectrometer. This enables the ionization and hence analysis of most elements, and the measurement of their isotopes ratios and relative mass-fractionations at high precision. The ICP source also provides greater flexibility of how samples are introduced into the mass spectrometer, allowing the analysis of either aspirated solutions or as aerosols produced by direct laser ablation (LA-MC-ICP-MS) of solid materials.
Applications: the ability to obtain high precision isotopic analyses of a large range of elements made possible by MC-ICPMS enables applications across all fields of science. They are commonly used in geochemistry, geochronology, and the environmental sciences. Our research has a strong focus on environmental geochemistry using biogenic skeletons as archives of seawater chemistry and environmental change, on modern and geological timescales.
The new Thermo Scientific NEPTUNE Plus is equipped with eight adjustable Faraday ion collectors, one fixed central collector, and two ion counters, a 1012 Ohm DC-amplifier with reduced noise level, and a larger interface pump for enhanced sensitivity. A high resolution filter (RPQ) is present in the central channel.
The multi-ion counting package consists of two CDDs with positions to accommodate precise U-Th and B isotope determinations of very small sample volumes. In addition to standard facilities for introduction of solution samples, when combined with our 193 nm Ar-F excimer laser micro-sampling system, the Neptune MC-ICP-MS has the capability for direct in-situ analysis of isotopic systematics from a wide range of elements in a solid sample.
The Nu Instruments Plasma II features sixteen fixed Faraday ion collectors to maximize the number and range of isotope analysis. Three full-size discrete dynode multipliers enable isotope ratio measurements of very low abundance isotopes. Enhanced zoom optics focus the ion beams into the fixed collectors and allows instantaneous switching between collector configurations for a range of elements.
The Nu Plasma II plasma source operates at high voltage with the analyser being at ground potential operation. Samples can be introduced via conventional spray chamber, a Cetac autosampler, an NU desolvation system, or our 193nm Ar-F excimer laser ablation system.
The Thermo Scientific TRITON thermal ionisation mass spectrometer (TIMS) features six adjustable and one fixed central Faraday ion collectors, Dynamic Zoom optics, amplifiers with 50 Volt dynamic range, Virtual Amplifier system, and a Retarding Potential Quadrupole Lens (RPQ). Our TRITON is specifically equipped with a high mass double cup assembly for enhanced PTIMS boron isotope analysis. Sample preparation requires chemical separation of elements by ion exchange chromatography in the clean laboratory, then loading onto Re or Ta filaments. Samples are thermally ionized within the high vacuum source chamber, the lower energy spread of ions compared to an ICP providing greater precision of isotopic ratio measurements.
The Thermo Scientific X-SERIES 2 Quadrupole Inductively Coupled Plasma Mass Spectrometer (Q-ICPMS) enables simultaneous measurements of elemental concentrations from most of the periodic table. Our X-Series 2 has an ESI SC-FAST auto-sampling system which enables high volume throughput of solution samples. The Q-ICPMS can be coupled to our 193nm Ar-F excimer laser ablation system for in-situ elemental analysis of solid samples.Back to top
Back to top