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serum vials for gas sample collection and analysis
Posted: Thu Apr 27, 2006 9:30 pm
by www_ups
I need to collect small amts of gas samples from a reactor and analyze them in a Shimadzu GC-FID. I have used tedlar gas sampling bags in the past, but they are simply too big; I am looking at sample volumes of ~1-10 cc per analysis.
I have come across gas sampling serum vials (used primarily in microbiology and biogeochemistry) to collect small amts of gases. This link is one of many
http://rydberg.biology.colostate.edu/~j ... _vials.htm
Does anyone in this forum have experience in doing this kind of stuff ? what is the quality of serum vials (and septa) that can be used for this purpose ? Is a normal vacuum pump ok ?
Thanks,
Pradeep
Get headspace vials
Posted: Tue May 02, 2006 6:32 am
by Peter Apps
Hi Pradeep
I would advise againbst using serum vials - the septa are not designed for GC work, and will bleed volatiles into your samples.
Rather use GC headspace vials - these also have septum caps but they are designed for GC and will have low bleed.
Peter
Re: Get headspace vials
Posted: Sat May 06, 2006 6:51 pm
by www_ups
hi Peter,
Thank you very much for the suggestion. Could you kindly also tell me if this could be used to analyze just gases ? (i.e., my samples are gaseous & so i dont have a liquid phase.) can i evacuate the vial too ? lastly, can i inject gases into a evacuated head space vial without appreciable bleed?
thanks,
pradeep
Hi Pradeep
I would advise againbst using serum vials - the septa are not designed for GC work, and will bleed volatiles into your samples.
Rather use GC headspace vials - these also have septum caps but they are designed for GC and will have low bleed.
Peter
Posted: Mon May 15, 2006 11:39 am
by Peter Apps
Hi Pradeep
If you only want to analyse gasses i.e. carbon dioxide, oxygen, hydrogen etc etc than a serum vial will probably be OK - the septum will bleed organic volatiles that might not interfere with the gas analysis.
A GC headspace vial is very similar to a serum vial, and has the same crimp cap with rubber septum, but the rubber is designed to tolerate higher temperatures. What you can do with a serum vial in terms of evacuation and filling you will be able to do with a headspace vial.
If you already have serum vials, try them first before you spend money on headsapce vials.
Regards Peter