Measurement of δ18O of liquid water and ice.
Isotope ratio mass spectrometer Finningan MAT252 coupled to an equilibration bench
Description of the instrument:
Water samples (3mL) are equilibrated for 8 hours with CO2. The gas is then introduced in the mass spectrometer in dual inlet mode. Each sample is measured with respect to a laboratory standard for 15 min.
Generally speaking, in a mass spectrometer, the molecules are ionized in the source, accelerated in an electric field, and deviated depending on the mass to charge ratio by a magnetic field. Three faraday cages are placed at the outlet, and are aligned with mass 44, 45, 46 (for CO2).
Principle of the analysis:
http://www.thermo.com.cn/Resources/200802/File_28763.pdf
Type of analysis performed on this instrument:
This instrument is dedicated to the routine analysis of the oxygen isotopic composition (18O) of natural waters.
Analytical uncertainty: 2 = 0.05‰ for 18O
Contacts :
Bénédicte Minster
δ13C and δ18O in cellulose and wood
Vario PYRO cube - Isoprime PrecisION, Elementar®
Instrument description:
PrecisION isoprime magnetic sector mass spectrometer (Elementar®) coupled to a vario PYRO cube high-temperature elemental analyser (Elementar®).
Principle of the analysis:
The solid samples (weighed in silver capsules) undergo pyrolysis at 1400°C. They are converted into CO gas. The sample gas is then introduced into the spectrometer source under helium flow and analysed against a standard commercial CO gas.
The gas molecules are ionised in the source, accelerated by an electric field and deflected according to their mass by a magnetic field. Three Faraday cages are placed at the outlet, allowing masses 28, 29 and 30 to be recovered.
δ13C and δ18O are determined simultaneously from the same sample with an accuracy of 0.15‰ for δ13C and 0.30‰ for δ18O (see Loader et al. 2014, for a description of the method: DOI: 10.1021/ac502557x).
Type of analysis performed on this instrument:
Stable carbon and oxygen isotopes ratios in cellulose and wood.
Fundings:
Projet : RIOCAS, IDF-DIM-MAP-2021-3-001
Contacts:
Monique Pierre : 01.69.08.31.20 / This email address is being protected from spambots. You need JavaScript enabled to view it.
Michel Stievenard : 01.69.08.71.70 / This email address is being protected from spambots. You need JavaScript enabled to view it.