Helium Crisis or Helium Hype?
John Hinshaw offers his insights into how the current helium shortage will affect gas chromatographers and answers some concerns of LCGC Europe readers selected from the CHROMmunity.
Firstly, why is there a shortage of helium and how will this affect gas chromatographers in the short term and long term?
JH: According to a recent article in Chemical and Engineering News1 the current helium shortage is, for the most part, the result of supply issues. Scheduled maintenance of helium production plants and pipelines this past summer caused the shortage in the United States, while low natural gas demand overseas has curtailed concomitant helium production in many regions. There is plenty of helium in the ground, but getting it out, purifying it, and distributing it does not make enough helium available to meet demand. Significant new helium capacity is poised to come on line over the next year or so, but until then the supply is likely to remain tight.
Only a fraction of total helium consumption is accounted for by all laboratory uses. Of that, the vast majority is taken to cool superconducting magnets used in, for example, nuclear magnetic resonance (NMR) spectroscopy; only a small part flows down gas chromatography columns. As a result, chromatographers will have to find whatever GC-grade helium they can. And with high demand, prices should continue to rise in the short term.
Will supplies ever return to “normal” levels?
JH: Within a year or two, as the new worldwide capacity for helium production becomes fully available, the supply shortage should abate. Don't expect prices of high-purity helium to drop down to the pre-shortage levels seen before 2006, but some relief should be in the works.
Can most methods be transferred to hydrogen? Are there alternative to hydrogen for specific applications?
JH: Yes, hydrogen carrier gas is suitable for almost all GC methods, except of course for the analysis of hydrogen as a component in a mixture. The GC method has to be converted to conditions suitable for hydrogen, and detectors may require special consideration. For example, a flame ionization detector (FID) also uses hydrogen as a support gas; total FID hydrogen flow should be kept constant and equal to the manufacturer's specified amount. Some electron capture detectors (ECD) support hydrogen carrier gas while others may not; it is best to consult the manufacturer in this case. Thermal conductivity detectors (TCD) will function well, but the size of the peaks will not be the same as with helium carrier (see below for more on this).
JH: Higher vacuum pump capacities are needed to obtain the same source pressure at the same hydrogen flow rate as for helium. Often it may make good sense to change to a narrower i.d. column with a lower flow rate when converting GC–MS methods. Some manufacturers of mass spectrometric detectors have recommended minor hardware updates for the best performance with hydrogen carrier. Consult them to see what might be required for your specific model.
An extended version of this article with more readers’ questions will be published in the next issue of our digital magazine “The Column”. If you have any questions relating to the helium shortage, please post them on the CHROMmunity using the link: http://www.chromacademy.com/forum-cm-signup.html
A special webinar on the helium shortage — Translating GC Methods from Helium to Hydrogen Carrier Gas – will be presented by John Hinshaw and Tony Taylor on our CHROMacademy e-learning platform on October 18, 2012 (11:00am EST /16:00 BST). Sign up at http://www.chromacademy.com/Translating-GC-Methods-from-Helium-to-Hydrogen-Carrier-Gas.html
For further related content please click here to read Incognito's views on the helium shortage.