Hi, it's me with chem questions again...=(
but anyway,
there are these ground vents/sewer vents around, and they release steamy gas ever so often. I'm trying to collect samples of the gas and determine its composition, and I need some suggestions.

Collection Process
I'm thinking of using a 25mL~50mL valved gas-tight syringe (any suggested brand?) to collect the sample. Does anyone have suggestions on storage? besides rubber-topped test tubes or steel cells....er

I'm hoping the main composition of the vapour is water...so it'll condense and dissolving other stuff at some point...aqueous phase is easier to work with i think, but what if some stuff doesn't dissolve at reasonable temp?
err

Analysis
Thinking of spectrophotometry, gas chromotography, IR spec, and reactions to test for ions/organics

This is a list of species what I'm thinking of to test for:
Water- with gas-phase IR spectrometre
CO2- with GP IR spec
NOx- with GP IR spec
CFCs- hmm
organic compounds- any suggestions on what and how?
metal ions-...lead, iron, chromium....suggestions?
...what else...

GC would detect metal ions right...?

man...i'm in deep trouble, am i not..

anyway, I appreciate any help or comment.
Thanks for your time.

man...i'm in deep trouble, am i not..

Yes, I think you are :)

The problem with mixture analysis is that you need to test for everything that you are looking for. It sounds obvious, but it is not: if you do not test for plutonium, then you will not find it.

There are many chemical elements.
There are many molecular bindings.

Hence it requires many tests to determine the exact composition.

Also, I doubt that a spectral analysis will be useful. My guess is that this would be useful if you have 3 or 4 elements that really form the majority in these gases (e.g. hydrogen and carbon), but there doesn't seem to be a reason for that I think.

Anyway, it is loads of work, and if you decide to go for it, I wish you many happy days in the lab :)

Bye!

Crisp