Isotope Ratio Mass Spectrometry

Sandy Bay Campus, Chemistry Building, Level 4

Stable Isotope Analysis

Being most of the work currently carried out related to Geology (ore formation), Antarctic Research (climate records) and Marine Science, the determination of stable isotopes of the elements hydrogen, carbon, nitrogen, oxygen and sulphur can aid resolving problems  in a wide range of disciplines, e.g. Agricultural Science, Ecology, Physics, Archaeology,  Medicine, Food Safety and Forensics, just to name a few.

The following analyses are available at CSL:

• C, N, and S in solid samples, such as minerals, soils, plant or animal tissue, dried extracts (EA-IRMS)
• H and O in solid organic samples (EA pyr IRMS)
• H and O in liquid samples (EA pyr IRMS)
• C in breath CO₂ (MF-CI-IRMS)
• ultra high precision H and O in liquid samples, including enriched (eq-DI- IRMS)
• H and O in liquid samples, including enriched (double labelled water) ice cores, fresh or seawater and urine (eq-CF-IRMS)
• C and O of inorganic or organic carbonate (apatite) (eq-DI- IRMS)
• Compound-specific isotope analysis using GC-HCNO-IRMS
• Compound-specific isotope analysis using LC-C-IRMS

This facility houses:

Isoprime 100 continuous flow Mass Spectrometer with:

• Elementar isoCube Elemental Analyser - for routine flash combustion C, N and S-isotopic analysis of a wide range of solid biological and inorganic materials. It also allows the isotopic analysis of small (sub-milligram) sulfide samples obtained by micro-milling sulfide-bearing specimens in polished thick ore and rock sections.
• Elementar PyroCube Elemental Analyser – for pyrolysis O and H isotopic analysis of a wide range of solid biological and inorganic materials, excluding quartz.

GV Isoprime continuous flow Mass Spectrometer with:

• Euro pyr OH Elemental Analyser – direct liquid injection for H and O isotopic analysis from ice cores, sea ice, fresh and saltwater samples.
• Isoprime MultiFlow headspace analyzer – automated equilibration for H and O isotopic analysis, including doubly labelled water experiments, in liquid samples. The system further provides phosphoric acid digestion on small (<100 µg) carbonate samples and breath analysis.

Elementar precisION isotope ratio Mass Spectrometer with:

• Elementar Dual Inlet and Elementar isoMultiPrep - system for the automated phosphoric acid digestion and analysis of carbonate materials down to 20 µg with the highest precision for δ¹³C and δ¹⁸O. Equipped with a microvolume LN₂ cold finger, the system allows for analysis of the smallest foraminifera samples. In the AquaPrep mode, it also allows for ultra-high precision H and O analysis of liquid samples using the equilibration technique. Precisions typically achieved are in the range of 0.02 ‰.
• Agilent 1260 Infinity II liquid chromatograph and Elementar isoChrom LC interface – provides compound-specific carbon isotope analysis of dissolved organic compounds using separation by liquid chromatography and online conversion of the carbon in the separated organic compounds to CO₂. The system is currently set-up for separation of sugars in honey for quality control purposes.
• Agilent 7890B gas chromatograph with Elementar GC5 interface - online measurement of HCNO isotopes in compounds separated by capillary chromatography. Target compounds include fatty acid methyl esters, n-alkanes, polycyclic aromatic hydrocarbons or amino acids. Prior to analysis, compounds must generally be isolated from bulk sample materials using multi-step preparative procedures, non-volatile target compounds must be derivatised.

The laboratory also has manual vacuum extraction lines for production and clean-up of SO₂ and CO₂ from sulphate, sulphide, graphite and organic carbon, and carbonate minerals.

For more information contact Dr Christian Dietz