Introduction
Owing to the worldwide helium shortage, many labs are facing supply difficulties of helium, one of the most commonly used carrier gases and as a consequence are facing rapid price increases. Many chromatography labs are therefore looking for alternative carrier gases and for many GC applications, hydrogen provides a good, in some cases better, alternative to helium. The perceived danger of having hydrogen in the lab can be mitigated by using a hydrogen generator which can fulfil the requirements of a lab whilst storing a fraction of the volume of gas. Here we show the reasons behind the helium shortage, what hydrogen offers the chromatographer and show how hydrogen can improve the separation of analytes in a complex mixture of compounds whilst improving the throughput of sample.
Helium is distilled from natural gas deposits that have collected in the presence of uranium and thorium. These radioactive elements produce helium when they undergo alpha decay1 and the gas remains trapped along with the natural gas until it is extracted. The presence of helium together with natural gas was first discovered in 1903 in Kansas2 and since then the physical qualities of helium (inertness, lightness, low liquid temperature) have made its use essential in a number of areas in industry and science, as well as it being a mainstay at birthday parties. At levels of 0.3% and above by volume in natural gas deposits, helium is deemed to be worth extracting3 and some natural gas deposits are reported to contain up to 7% helium by volume. In 1925, the United States established the National Helium Reserve (NHR)4, located in the plains of Texas, and from 1929 the NHR was the world’s largest producer of helium, with the Bureau of Mines coordinating extraction and refining programs. Helium was primarily produced and stored for military use and until 1960 the federal government was the sole producer of helium in the United States. In 1960, Congress amended the Helium Act to provide natural gas producers with incentives to extract crude helium and sell it to the government. Much of this helium was stored at the NHR and prices were fixed with a view to cover the costs of the program and to pay off debts. However, post-war federal helium demand was lower than predicted and with private demand far exceeding federal demand, the United States government passed the Helium Privatization Act (HPA) in 1996. The HPA was an attempt to wipe out the site’s $1.4 billion debt, through selling off all of the national reserves by 2015. Private companies did not move in to refine helium in the quantities expected at the time the bill was passed and the resulting supply problem has prompted other countries to begin extracting helium. Refineries are now producing helium in a number of countries worldwide including Russia, Qatar, Algeria and Australia.In 2012 the United States produced an estimated 78% of the world’s helium of which around 30% came from the NHR4. The shortage of helium has been caused by a number of factors, including worldwide refinery equipment failures and shutdowns, 5 with scheduled maintenance in several of the world’s natural gas refineries disrupting supply. These factors, coupled with an increasing demand for helium from newly industrialised countries such as China, mean that we are moving even closer to a worldwide shortage with customers already seeing stark price increases and supply problems as private companies struggle to meet the demand. A look at the figures published by the United States Geological Survey (USGS) shows that while the volume of helium extracted from natural gas fields has remained steady over the past 5 years, consumption from the NHR has steadily increased. In the same period, exports of helium from the United States have risen to 60% of the total6, and with the NHR rapidly emptying the current situation appears to be unsustainable. Worldwide helium demand far exceeds production and therefore alternatives to helium must be sought for a number of technologies. The result of the helium shortage has filtered down to the point where even laboratories, who are consuming a fraction of the helium on the market, are affected. Many labs, even those classed as ‘preferred customers’ are struggling to source helium and are also seeing increasing prices. The helium shortage has prompted the GC manufacturers to developing systems to reduce helium consumption, such as the Agilent EPC device for the 7890B which allows the system to switch from helium to nitrogen carrier gas when the system is idle. In addition to gas saving systems, the GC manufacturers have also invested in new systems capable of running on hydrogen and helium. Agilent and Shimadzu have both developed GC/MS systems that are ready to run with hydrogen or helium carrier gas. Other systems have been designed specifically for the use of hydrogen as carrier gas such as the Bruker Scion SQ and TQ.
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