6 Replies Latest reply on Dec 17, 2018 8:05 AM by crystalnipp

    Have you switched to hydrogen carrier gas? What are your experiences?

      Hi everyone,

      Have you switched to hydrogen from helium as your default carrier gas? What were your experiences? What preparation did you have, and what do you wish you knew?

       

      I'm wondering about helium this week after C&ENews' article on NMR, which discussed helium and the problems associated with its availability.

      Securing The Future Of NMR | February 15, 2016 Issue - Vol. 94 Issue 7 | Chemical & Engineering News

       

      Our colleagues in NMR don't have a substitute, but in GC one can switch to hydrogen if helium availability is a problem.

       

      What are your thoughts on...

      • how long did it take you to set it up and get accurate results
      • were you able to translate your methods effectively?
      • did you encounter any institutional safety problems?

       

      Thanks for your insights!

      - Josh

        • Re: Have you switched to hydrogen carrier gas? What are your experiences?
          shannon

          Using hydrogen as a carrier gas has been tested on our new Refinery Gas Analyzers and even shows an improvement in sensitivity on the TCD due to the difference of it's thermal conductivity compared to other analytes. See the link to presentation starting with slide 22 Alternative Carrier Gasses for more info.  This presentation was given by Roger Firor and JAMES MCCURRY for C&EN

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          • Re: Have you switched to hydrogen carrier gas? What are your experiences?
            paulsalverda

            Here are some tips in no particular order:

            You must be careful with halogenated solvents and carbon disulfide as you may make acid in the inlet when using hydrogen carrier.  Some analyses cannot be run with hydrogen because of that.

            The optimum carrier gas linear velocity is different than helium so use the available tools to get it right.

            The signal to noise ratio on a GCMS system will be less than when running helium - up to 2x to 5x worse.

            Library matching will not be the same as when running helium.

            Hydrogen scrubs the inside of the gas regulator and supply tubing and you will see more noise for a while -- up to a few weeks -- as it does a better job cleaning than the manufacturer.

            Make sure and read the Hydrogen Safety Manual -  G3870-90101.

            The MSD pumping capacity for H2 is approximately 1/2 that of Helium.

             

            – Performance turbo: 2 mL/min

             

            – Standard turbo: 1 mL/min

             

            – Diffusion pump: 0.75 mL/min

             

            – Pressure pulsing: turbo < 3 mL/min, diffusion < 2.5 mL/min

             

            2 people found this helpful
            • Re: Have you switched to hydrogen carrier gas? What are your experiences?
              ron_tackett

              Attached are the documents on switching from Helium to Hydrogen for GCMS.

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              • Re: Have you switched to hydrogen carrier gas? What are your experiences?
                crystalnipp

                We have about 20 GC's and GC's with HSA units.  That's 34 FID's total.  We made the switch to hydrogen years ago (like in 2000) when He availability first became an issue.  We run all of our FID's with H2 and use N2 as the makeup.  We have a few TCD's that we still run with He as we found H2 or N2 to not work well for us in those applications.  We have one H2 generator that we supplement with cylinders...it is currently in for repair.  Since the cost of He has just kept climbing (over $300 now) we have saved literally thousands of dollars on gases over the years.  We have had zero safety issues.  Most modern day GC's have safety shutdown built in.  And paying careful attention to gas usage will flag leaks if they occur. 

                We are an industrial QC lab, so have some flexibility in the methods that we run so we can choose whatever flows and such that get us the resolution and reproducibility that we need.  If you are locked into regulated methods you may not have that flexibility although I have noticed some ASTM methods finally having some flexibility to use H2 instead of the default He. 

                There are calculators available on-line from several companies to help make the switch in terms of flows and such.  I think Agilent has one.  I know Restek does.  If you are using OpenLab or ChemStation software it is pretty easy to set methods up using an optimum linear velocity (which is significantly different for H2 as opposed to He).  As long as you have specified H2 as the carrier it will do all the calculations for you.