TA2 Facility 22 – Open University Laser Fluorination Oxygen Isotope Facility

TA2 Facility 22 – Open University Laser Fluorination Oxygen Isotope Facility

Average visit: 5 days

This is the pioneering facility for laser assisted fluorination for high precision oxygen 3-isotope (¹⁶O, ¹⁷O, ¹⁸O) ratio measurements.

The system is equipped with a powerful and highly controllable 50W CO₂ laser (10.6 μm radiation) used to heat small samples of meteorites or other planetary materials in the presence of high purity BrF₅ in order to liberate oxygen gas for isotopic measurement in a Thermo MAT 253 mass spectrometer.

Sample size requirement for the highest precision is 0.5 to 2μg of silicate – providing typical precision for individual analyses of at least ±0.08‰ for δ¹⁷O, ±0.16‰ for δ¹⁸O, and ±0.05‰ for Δ¹⁷O (2σ). Smaller samples, down to ~ 30μg can be analysed, albeit with slightly lower precision.

Samples of most silicates and oxides can be measured, with specialist protocols available for volatile-rich samples (e.g. phyllosilicates).

Contact:

Ian Franchi, School of Physical Sciences, The Open University, Walton Hall, Milton Keynes, MK7 6AA, UK. ian.franchi@open.ac.uk
Main facility website

TA 2.22: Laser assisted fluorination system at the OU — TA 2.22: Laser assisted fluorination system at the Open University. Credit: OU.

TA 2.22: Thermo MAT 253 mass spectrometer used to perform high precision oxygen 3 isotope ratio measurements. Credit: OU.

TA 2.22: 50W CO2 laser producing 10.6 micrometer radiation used to heat samples in the presence of bromine pentafluoride in order to quantitatively liberate oxygen gas for isotope analysis. The sample chamber is on the lab jack and is held in a fixed position while the laser is moved. The sample chamber can hold up to 22 samples and standards. Credit: OU.

TA 2.22: Oxygen isotope composition of achondrite meteorites – showing relationship between angrites, HEDs and pallasite stony-iron meteorites. D17O is a measure of deviation from the terrestrial fractionation line – therefore mass fractionation lines are horizontal in this plot. Credit: Greenwood et al 2017.

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20-EPN2-009: High-precision oxygen isotope composition of Martian meteorites and their components...

Publications related to TA2.22 facilities and visits

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