Analysis of chlorine and phosgene using TCD

 Dear All,

Is it OK to analyze chlorine using TCD or chlorine makes TCD filament go bad pretty quickly ? We are expecting 1% chlorine and 1% CO in phosgene. Besides these components, sample will have some amount of HCl. We are positive that HCl will affect GC badly and so are there any suggestions to remove HCl from the sample mix ?

  • Hi and thanks for the detailed question!  

    You are correct that HCl is rough on GC parts.  However, I think the analysis is possible with a few considerations.  If you plan to inject using a gas sampling valve, the valve needs to be made from Hastelloy to minimize corrosion.  Also, having a dry sample (minimal water content) will extend your system performance.  If your sample stream is wet, the chlorine in your sample with react with the TCD mechanism, and will accelerate corrosion of the detector.  

    The TCD cell is considered a consumable part, so I would recommend keeping one or two in inventory to decrease your potential down time.  I'm not sure which model of GC you are using, but this part should be fairly easy to track down using either our website or calling into technical support.  

    I haven't been successful in locating a proven method that would selectively neutralize your HCl content without affecting your other analytes, so I don't have any suggestions on the sample piece.  

    Best of luck, and please do keep us posted on your progress!


Was this helpful?