Solutions to the world Helium shortage with the H2 generator for GC and GCMS carrier gas

Application Notes 15 December 2013

Why change from Helium ?

Gas Chromatography can use alternative gases and this is where F-DGSi can help. Helium has dominated gas chromatography due to the level comparison between it, hydrogen and nitrogen. Nitrogen is less efficient than helium and hydrogen has been avoided in the past due to safety concerns with hydrogen cylinders. These concerns are based on hydrogen cylinders being fairly unstable if not stored correctly or containing too much pressure.
Many GC leading manufacturers have started actively to recommend switching your carrier gas from Helium to H2. F-DGSi’s solution to this is the Hydrogen Gas Generator

What are the major benefits to use H2 as your carrier gas?

Fast analysis :
The diffusion rate of hydrogen and helium are roughly the same,but hydrogen is half as viscous as helium and therefore the linear gas velocity is higher and retention times are shorter in isothermal analysis.

However, it is not always possible to analyze a sample at a higher linear speed because the resolution of the peaks is insufficient

High efficiency
Hydrogen has the flattest Van Deemter curve.Compared to helium and nitrogen, hydrogen needs the lowest plate number to achieve the same resolution over a large range of linear velocity

Prolonged column life

Reduced costs
Helium, a rival to Hydrogen has its advantages as a carrier gas for GC; but it also has key disadvantages which are cost and availability. A tank of GC quality hydrogen is approximately 3 times less expensive than its helium equivalent. The price disparity between the two will not improve as the existing helium reserves are drying up and the demand is increasing across different industries.

Availability
Hydrogen is readily available through the electrolysis of water and with a F-DGSi gas generator, it can be generated on demand The use of a hydrogen generator also provides long term cost savings. It allows for the production of the gas on an as needed basis; which avoids the costs associated with storing gas.

The Van Deemter curve shows the efficiency of helium, nitrogen and hydrogen at different flow rates :

La courbe de Van Deemter

Published in International labmate, dec. 2013