Abstract
For hydrogen embrittlement studies, hydrogen is charged in materials to study the H-trapping. As hydrogen is present in the atmosphere, it is tedious to quantify. When measuring hydrogen at higher temperatures by Thermal Desorption Spectroscopy (TDS), the hydrogen from the chamber walls desorbs, resulting in a rising background.
The hydrogen isotope deuterium has a relatively lower natural abundance and is therefore frequently used to investigate the pick-up of hydrogen as the peaks of deuterium can be linked to effusion from the tested sample [1].
The quantification of deuterium by Thermal Desorption Spectroscopy (TDS) is time consuming and expensive, therefore a fast, cost-effective quantification of deuterium is wanted.
The purpose of this study is to investigate the possibility of deuterium quantification by an Inert Gas Fusion Analyzer, equipped with a thermal conductivity detector for hydrogen. A mass spectrometer coupled to the IGF-analyzer is a more obvious solution, but not all laboratories have access to a mass spectrometer, which is quite expensive.
To check the deuterium detection, a gas calibration with deuterium gas was compared to a gas calibration with hydrogen gas. This study confirms that a theoretical factor (as a combination of the thermal conductivity and molecular mass), can be used to quantify deuterium with a TCD-detector in an Inert Gas Fusion Analyzer without using the expensive deuterium gas to calibrate.
Preliminary results show that inert gas fusion without the option of a mass spectrometer (MS) can be applied as a quick screening method for a large set of samples. Further investigation is ongoing in an attempt to separate the signals for H and D, hence making it possible to selectively quantify both fractions instead of only the total amount.