Tenax / Drager tube sorption before GC / ECD analysis

[Ruth1770]

I would like to be able to sample a volatile compound which can be analysed by GC / ECD. I want to be able to trap the compound on an absorbant matrix and then wash it off in a solvent before running it on the GC.

What are the differences between Tenax and Drager tubes? I have a Drager pump to hand but would I need an equivalent pump for Tenax tubes?

Many thanks

[AICMM]

Ruth1770,

First, are you trying to collect just a little bit of sample? If so, a hand pump might work but then you do a huge dilution by extracting with a solvent? Using ECD this might be appropriate. More likely, I am guessing you are looking for low levels of sample so unless you want a forearm workout, I would recommend an air sampling pump like a Gilian or a Sensidyne pump.

Second, Draegers are typically (as far as I have looked, which is not exhaustive) reaction tubes which determine concentration by reacting with the analyte to give a color change. It does not sound to me like what you want to do. If you look at Draeger tubes, make sure you are getting an adsorbent and not a color indicating tube.

Third, you might look at Scientific Instrument Services web site since they have a pretty extensive page on adsorbent resins that might help you out.

Fourth, be aware that you probably cannot use CS2 as the solvent since this is a very good responder on ECD.

Out of curiosity, what compound and why an ECD? A subject near and dear to me because I am developing a non-rad ECD and looking for applications beyond the obvious pesticides and PCB's.

Best regards,

AICMM

[Ruth1770]

Thanks for this info AICMM.

I am looking to sample nitroglycerine. I am trying to follow NIOSH method 2507.

http://www.cdc.gov/niosh/docs/2003-154/pdfs/2507NIT.pdf