ICP laboratories and equipment

Room 225 of the Grant Institute.

The samples destined to be analysed by ICP OES/MS are prepared in the clean laboratory room. 

It is a trace metal clean laboratory equipped with:

• two laminar flow benches
• two extracting eco-power fume hoods
• acid distillation system
• hot plates 
• microbalance. 

The rock, sediment, soil or plant samples to be analysed are digested on a hot plate using clean, concentrated acids. The calibration solutions are also prepared in this laboratory, and the standards are kept in a ventilated cabinet. The digested samples are diluted to required concentration range and/or purified via ion exchange resin column chemistry in the clean laboratory prior to analyses by ICP-OES or ICP-MS. 

All users have access to the clean laboratory, providing they have had the appropriate training and health and safety tour by the facility manager.

Room 235 of the Grant Institute.

The Inductively Coupled Plasma-Optical Emission Spectrometer (ICP-OES) Laboratory is equipped with a Laminar Flow Bench and a Vista Pro ICP-OES. Final sample preparation steps are done in the Laminar Flow Bench. 

The ICP-OES technique provides quantitative bulk elemental (major and trace) composition of rock, water or soil samples at concentrations ranging from ppm to ppb. Analyses of trace and redox-sensitive elements in sediments and of contaminants in soil and plants are common examples of ICP-OES applications.

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Varian Vista Pro ICP-OES

This facility includes a Varian Vista Pro instrument with axial view.  It is continuously maintained by qualified staff. 

An APEX-E sample introduction system has recently become available, which improves the detection limit by factor 5-10 for a range of elements, enabling us to analyse the smallest sample sizes. 

A microwave digestion unit (CEM Mars XPress) with microwave-assisted evaporation system is also available. This system can digest a wide range of environmental samples in a closed system, allowing the evaporation of acids after digestion in a safe and rapid manner without the risk of contaminating or oxidising the analytes, as often given in hotplate evaporation. The system is configured to prepare 24 solid samples for ICP analysis in one day, including digestion, evaporation and subsequent dilution for the ICP. The digestion method, which allows rapid processing of high-resolution marine sediment cores, has been described in Martinez-Garcia et al. (2009)

The main applications of this instrument are studies on marine sediments and seawater in the context of past and present global change.

Our analytical capabilities comprise the precise determination of Mg/Ca ratios for:

• the reconstruction of past ocean temperatures from the shells of foraminifera
• the determination of trace elements in diatom frustules for the reconstruction of biogeochemical cycles
• the chemical composition of coral skeletons as high-resolution climate proxy
• the bulk composition of marine sediments as a recorder of past environmental conditions

Room 241 of the Grant Institute

The Brian Price ICP facility is equipped with:

• a high resolution Inductively Coupled Plasma-Mass Spectrometer (AttoM, HR-ICP-MS) 
• a multi-collector Inductively Coupled Plasma- Mass Spectrometer (Plasma II MC-ICP-MS)

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Both instruments can be coupled to a laser ablation system for analysing non-dissolved samples (e.g. rocks, shells). The AttoM provides rapid and precise isotope ratio and quantitative analysis of trace elements in solid (with laser ablation) and liquid phases at a concentration below ppm levels. For more demanding isotopic ratio measurements and some specific applications (Si and Fe isotopes), the plasma II MC-ICP-MS is used.

Multi-collector ICP-MS

The multi-collector ICP-MS facility (Nu Plasma II) was established in November 2014.

This technique is used for the very precise determination of isotope ratios, as required for uranium and thorium series dating, and many other isotope systems with very small variations in abundance. In addition, the system is extremely efficient in transmitting ions, which may allow the quantification of isotopes that are present with only a few 10,000 atoms in a sample.

Initial analytical targets in the School of GeoSciences include the uranium-series elements thorium, protactinium and radium, as well as silicon isotope ratios. More isotope systems will be added to the analytical portfolio in the coming months and years.

The MC-ICP-MS can be coupled to a 193 nm laser ablation system (Cetac Teledyne Excite).

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High-resolution ICP-MS

The high-resolution mass spectrometer facility (Nu Attom) was established in November 2014. This analytical method enables a better resolution of mass than the more frequently used quadrupole ICP-MS.

It is a particularly powerful method for elements that are difficult to quantify in very low concentrations by other methods (usually due to interferences at the same mass).  Typical elements are lithium, phosphorus, iron, chromium, rare earth elements, and many others. Quantification is possible for concentrations on the order of parts per trillion, and often below, depending on the sample matrix and the analyte.

HR-ICP-MS is also required for analyses of extreme isotope ratios, due to its excellent abundance sensitivity. Thorium-230 excess ( 230 Th ex ) in marine sediments, uranium isotope ratios, and lead isotope ratios are typical examples.  In addition, the instrument has capabilities to scan nearly the full mass range of the periodic table several times per second. This enables comprehensive analyses of microscopic samples, together with the attached 193 nm laser ablation facility.

If you are considering this type of analysis for your project, please consider that specific clean sampling techniques are essential to make full use of the physical detection limits of the instrument.