Earth and Environmental Sciences (SEES)
Inductively-Coupled Plasma Mass Spectrometry
This has become a well-established modern analytical technique with a versatility that makes it suitable for a whole range of Earth and Environmental Science applications. It combines the ionisation efficiency of a high-temperature argon plasma (ca. 10000K) with the sensitivity and elemental range of a quadrupole mass spectrometer. The result is an instrument capable of analysing most of the elements on the Periodic Table to detection limits way down in the parts per trillion range. Since analyte distinction is by mass, isotopic ratios may also be measured.
At SEES we have an Agilent 7500ce with collision cell Octopole Reaction System (ORS) technology. The machine works in two modes; (a) He collision mode for reliable, predictable removal of all matrix interferences (b) H2 reaction mode for the removal of Ar-based interfering species such as ArO or Ar2. The ICP-MS is also equipped with an I-AS autosampler and a High-Matrix Introduction (HMI) system enabling the analysis of samples with up to 1% total dissolved solids including sea water. In solution mode the ICP-MS has been used to analyse a suite of transition metals in matrixes ranging from contaminated river water to coastal seawater, and also acid digests of particulate material, sediments and soils.
The ICP-MS has also been used to measure actinides (U, Th) in natural waters as well as undertaking studies on U isotopes. One of the main uses is measuring the acid extracts from passive samplers such as DGT and ChemCatcher for a suite of trace metals including U. The He collision mode also allows full-scan semiquantitative analysis (Semiquant) of unknowns - with no interferences and all in a single acquisition mode - this has been utilised on a number of samples where a first look is needed.
If you are interested in analysing samples using the ICP-MS, contact:
Routine applications include:
- trace and ultra-trace elements in petrology
- toxic metals in contaminated land investigation
- drinking water screening for major, minor and trace cations
- river water and ground water chemistry
- chemical oceanography
- biogeochemical cycling of metals
- forensic chemical fingerprinting
- dust attribution to source
- isotopic differentiation of anthropogenic pollution
A new Laser Ablation System has also been installed for solid state analysis.