There has been a recent surge in discussions amongst gas chromatographers about switching from helium to hydrogen for carrier gas. Most GC manufacturers, column suppliers, and suppliers of bottled gases and/or gas generators have been feeding the discussions (mostly in a positive, informative way) through publications, webinars, and/or advertising pushes. So what prompted the current fervor and where is it headed?
From a theoretical viewpoint, the argument for hydrogen use as a carrier gas centers on the fact that it can produce the same peak resolution with the same column and GC system in approximately 40% less time. It is, after all, THE fast carrier gas. Other advantages include its lower cost and convenience since it is already needed (and therefore present) for FIDs.
The current debate is not necessarily whether or not there are advantages to hydrogen as a carrier gas. Hydrogen is being used successfully in labs all over the world. The highest angst comes from conversion of existing helium based methods to hydrogen. The total time needed to translate (method translation is the way to go) and reverify/revalidate is often stated as the biggest hurdle. Depending on the industry, regulatory and internal requirements, this length and cost of the process alone can more than offset any perceived advantages to switching. Additional concerns that are expressed include the risk of not being able to meet the performance of the current method (ruggedness, detection limits, linearity, etc.), safety concerns, and fear of unknown issues one might encounter (like a lengthy “cleanout period”).
These are some of the same concerns that have been talked about for the past decades. Little has changed during that time except for maybe introduction of method translation concepts and software for predictably migrating method conditions and incorporation of safety features in instrumentation to avoid or minimize problems from potential H2 explosions. So what explains the recent uptick in comments recently?
Concern about supply of helium piqued when several He plants across the world went down for maintenance earlier this year and the scheduled opening of a new plant in Wyoming (APMTG Helium plant in Big Piney, Wyoming) was delayed. At the same time, one of the largest suppliers of He, the US government, raised the price to help pay off costs of its plant. At some point, there was even talk of rationing (with chromatography use not getting the highest priority – what’s up with that?).
The United States government got involved with helium production in 1925 primarily for defense needs. It currently supplies approximately 40% of the US and 35% of the foreign needs and has been doing so with little fanfare until the 1990s. By passage of the 1996 Helium Privatization Act , legislators mandated that the US Government get out of the helium business and sell off its commercial reserves by 2015. Demand has increased in the interim, but the government has no interest or authority in investing to increase production - and at the same time, no significant commercial suppliers have emerged to take up the slack. From the website of the US Bureau of Land Management , the situation is summarized by following: “The bottom line in terms of helium supply is that there is very little excess helium refining capacity, and domestic supplies of crude helium are growing ever tighter. Until overseas plants are fully online and/or additional plants are built, we’re potentially facing additional supply disruptions, if not shortages. “ The BLM also pointed out that the government offers for sale 2.1 billion ft3/yr, which is the approximate full current production capacity of their only production site (Cliffside Gas Field, northwest of Amarillo, TX) where He concentration in natural gas is very high (1.9%). Some predict that the reserves at the site will be depleted by 2018 or so (if extraction continues beyond 2015) and that in the meantime production will drop to half of the current level (to 1 billion ft3/yr) by as early as 2014.
This blog article series is produced in collaboration with Dr Matthew S. Klee, internationally recognized for contributions to the theory and practice of gas chromatography. His experience in chemical, pharmaceutical and instrument companies spans over 30 years. During this time, Dr Klee’s work has focused on elucidation and practical demonstration of the many processes involved with GC analysis, with the ultimate goal of improving the ease of use of GC systems, ruggedness of methods and overall quality of results. If you have any questions about this article send them to techtips@sepscience.com
