Why don’t many use hydrogen as a carrier?
We use helium in Gas Chromatography and GC/Mass Spectrometry because it is effective, safe, and inert, but it is also rare, non-renewable, and expensive… Our Moon’s supply of helium is constantly replenished, to a depth of several metres, because the solar winds drive it into the ground at a rate faster than it can escape—on Earth, however, the solar wind is neutralised by out magnetosphere and helium essentially bounces off of our atmosphere. The only remaining helium on Earth comes from the time before our planet had an atmosphere; we can’t make He, and there is no alternative source of it on our planet. What we have is trapped underground, usually combined with natural gas, and when it runs out, we can’t get any more from this planet. Declining supply means its price will continue to rise.
Being Safe
Everyone is in favour of safety, of course. And He streamlines our operation speed, letting us get fast results and be very effective. It doesn’t combine with the substances we are testing so it enhances accuracy; it is also completely non-inflammable. Eventually fusion energy generation will allow us to make irreplaceable He, but the truth is that we already have something better for GC, and that is hydrogen. Its intrinsic characteristics allow it to outperform He as your carrier gas. It enhances the throughput of any GC lab, potentially doubling your annual output. H2 will also save 95% of your carrier gas costs per year compared to using He as a carrier. Being the most common element in the entire universe, it is incredibly easy to come by, and it costs next to nothing. Helium’s effective range extends from µ18-48 (cm/sec) for a total range of µ28. Compare that to hydrogen’s wider effective range of µ25-65, or a total of µ40. That is more than a 42% improvement, meaning the process rate can be faster. Combine that with H2’s faster elution times and you have a real winner. So why aren’t we using hydrogen in GC?
H2 is dangerous!
It certainly can be, particularly if your laboratory is using hydrogen cylinders. Every joint, connection, or hydrogen tap is a potential source for leaks. Escapes of large volumes, such as one which occurred in December of 2018, at the Indian Institute of Science in the Super-Wave Technology Laboratory cost one life, three severe burn injuries, and much property damage, serving only to illustrate that stockpiling H2 is a bad idea. And, unfortunately this was not an isolated incident. There are, however, safe alternatives for utilising H2.
You Breathe what you Sample
Airborne agents can be carcinogenic, toxic, or simply act as an asphyxiant. While these releases can harm anyone in the lab, all of them are particularly dangerous to pregnant women. Stopping them before they escape is the key. Using split/splitless injection systems, your septum purge alone is probably consuming 5-10% of your carrier gas (typically at least a µ2-3 loss is required to minimise the “oily” build-up on the septum). Of course this is absolutely essential to prevent ghost peaks (contamination) and provide a smoother (lower) background against which to measure. The bulk of the carrier gas and its analytes must be dealt with post-analysis. But where does it go? On average, only one part in 25-150 of the carrier gas actually enters the columns. By way of example, if your column flow is 2 ml/min and split ratio is 1:75 then you use about 153 ml/min of He for your run. The remainder, along with all of its analytes and by-products, are released into the laboratory environment. Hopefully, this is drawn away by exhaust fans or hoods, and released in the outside environment (which potentially might be seen as being rather irresponsible). Sometimes it is sent to filters in hopes of capturing waste analytes, but there are no guarantees! Surprisingly often these filters are not replaced on schedule in order to save money…but what if you didn’t even need them? We can do so much better than this! Let’s see how…
The UCS-1000
USC stands for Ultimate Carrier Solution, and it really does live up to its name. The UCS-1000 allows laboratories to use hydrogen gas in a perfectly safe manner because the by-products/end-products of GC or GC/MS are routed directly back to the UCS-1000 to be completely and safely burned, leaving only harmless water vapour and CO2 to be vented or released into the lab. Whether you use traditional H2 tanks (with all their inherent risks and hazards), or whether you use the UCS-1000 with an H2 gas generator, it still means that all of the waste gas and analytes are disposed of safely, within the built-in burner unit. You and your employees will enjoy a healthier, safer working environment. When Sion’s remarkable UCS-1000 is combined with Sion’s H-300/H-500 hydrogen gas generators, you get a safe reliable system where both units are ready to react in the event of a fault. Integration allows either one to automatically shut down the other if anything goes wrong, for an additional layer of safety! Also, in those rare instances where you might still wish to use nitrogen gas or helium gas, the UCS-1000 is capable of switching electronically to an alternative carrier with minimal interruption. Such a switch does not compromise the ability of the UCS-1000 to continue burning the excess carrier gas and destroying the analytes. Your laboratory remains a safe and healthy environment.
The Takeaway
Clearly helium is a very expensive choice, offers slower throughput, does not provide the best results, and is no longer necessary. Hydrogen is the cheaper, faster, more efficient alternative that is equally safe with the proper equipment. It also enjoys a very small learning curve for conversion—it’s practically automatic! In practice, H2 allows you to lower your column temperature, and H2 itself is a reducing gas that neutralises acid sites within the column. Together these features extend your equipment life significantly, just adding to your cost savings. It is truly quite difficult to make a counter-argument against using hydrogen gas as a carrier for your GC or GC/MS. The “Pros” significantly outweigh the “Cons”, so get in touch with us and we can arrange an in-laboratory demonstration for you that should answer all of your questions. fact, your only remaining question will be: