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