Wolfson Stable Isotope Ratio Mass Spectrometer (IRMS) facility

The Wolfson Stable IRMS Laboratory - established in 1996 and partially funded by the Wolfson Foundation - is equipped with three gas source isotope ratio mass spectrometers (IRMS).  

To date, the facility offers carbonate analysis via acidification, providing stable carbon and oxygen isotopes, elemental analysis via combustion for stable carbon and nitrogen isotopes and carbon and nitrogen percentages (materials analysed: plants, soils, sediments, rock powders) and normal and low-concentration nitrous oxide analysis from seawater samples with offline preparation via denitrifier method obtaining stable Nitrogen and Oxygen isotopes.

The Wolfson Stable IRMS Laboratory, established in 1996 and partially funded then by the Wolfson Foundation, is equipped with three gas source isotope ratio mass spectrometers (IRMS).  To date it offers carbonate analysis via acidification, providing stable carbon and oxygen isotopes, elemental analysis via combustion for stable carbon and nitrogen isotopes and carbon and nitrogen percentages (materials analysed: plants, soils, sediments, rock powders) and normal and low-concentration nitrous oxide analysis from seawater samples with offline preparation via denitrifier method obtaining stable Nitrogen and Oxygen isotopes.

The facility houses three gas source isotope ratio mass spectrometers (IRMS) with a range of specialist interfaces, supporting several analytical techniques:

• Carbonate isotope analysis – Rapid, high-precision analysis of sub-milligram carbonate samples, including corals, bulk carbonates, foraminifera and ostracods, to determine stable carbon and oxygen isotope compositions.
• Low-concentration nitrous oxide analysis – A bespoke interface, based on the method described by Weigand et al. (2016), enables analysis of nitrate concentrations down to 2 µM in seawater. Samples are prepared offline using the denitrifier method, in which facultative denitrifying bacteria convert dissolved nitrate into nitrous oxide for nitrogen and oxygen isotope analysis.
• Carbon and nitrogen isotopic data – Elemental analysers convert homogenised solid samples into the gas phase via flash combustion for stable carbon and nitrogen isotope analysis. The facility has particular expertise in sediments, plant material and coral symbionts.

The laboratory is also developing headspace equilibration methods for oxygen and hydrogen isotope analysis of water samples. Researchers interested in this capability are encouraged to get in touch.

The Wolfson IRMS suite doesn’t analyse isotopically enriched samples - e.g., experiments spiking plants with extreme isotope values - to ensure that the natural abundance isotopic range samples can run smoothly to the lowest concentrations possible without memory effects. These isotope systems are key for understanding past environmental conditions and climate change.

• An elementar precisION interfaced with an Elemental Analyser, a bespoke build Greenhouse gas device for Nitrous oxide analysis, and isoflow for Carbonate analysis for samples greater then 0.3 milligrams.
• A Thermo Delta V interfaced with a gas bench (mainly used for normal concentration Nitrous oxide analysis) and NA2500 for C:N analysis linked via a ConFlow III to the IRMS.
• A Thermo Delta plus Advantage interfaced with a Kiel Carbonate III preparation system. This system will run Carbonate samples as small as 30 micrograms in size.