Our state of the art laboratory facilities allow measurement of a wide range of trace elements and determination of isotopic ratios, in materials such as minerals, rocks, ice, foraminifera and biological samples.
Inductively coupled plasma mass spectrometry
Inductively Coupled Plasma Mass Spectrometry (ICPMS) uses a high temperature argon plasma source to ionise samples for mass spectrometric analysis.The Geochemistry Lab has:
- an Agilent 7500CS ICPMS
- a Thermo Scientific Element2 sector-field ICPMS
- a Nu-Plasma multi-collector ICPMS (MC-ICPMS)
- a Resonetics S155-SE, 193nm excimer laser ablation system for in situ analyses.
The Agilent ICPMS is a quadrupole mass spectrometer which allows near-simultaneous acquisition of trace element concentrations across the mass range from lithium to uranium. Samples can be introduced either as acidified solutions following some chemical treatment, or as solid material sampled by a focused laser beam that ablates a tiny amount of the material (a 0.01 – 0.1 mm diameter spot).
The Element2 ICPMS is a single-collector, double focusing magnetic sector-field mass spectrometer, the only one of its kind in New Zealand. Installed in late 2011, it allows rapid trace element concentration analysis of trace elements across the mass range at high resolution. When operated in lower resolution, its greater sensitivity allows for the measurement of trace elements present in samples at very low natural abundances. As with the Agilent quadrupole ICPMS, samples can be introduced either as acidified solutions or as solid material sampled by the excimer laser.
The Nu-Plasma MC-ICPMS combines an ICP ion source with a magnetic sector mass spectrometer and multiple collectors (12 Faraday cups and two ion counters), allowing the greater mass resolution required for isotope analysis.
The Nu Plasma is used for measuring the isotopic ratios of specific elements following purification of the samples in the ultra-clean laboratory. We routinely measure both radiogenic isotopes, based on variations in the amount of a daughter isotope produced by the radioactive decay of an unstable parent isotope eg: Sr and Pb, and non-radiogenic (stable) isotopes such as Mg and Pt.
Ultra-clean preparation facilities
The ultra-clean chemical separation laboratory is equipped with four PicoTrace laminar flow workstations to prepare samples for chemical and isotopic analysis.
Read more about the research we undertake in the Volcanology, Geochemistry and Petrology group pages