haven't popped one yet. You need to be a doctor or a junkie to get a syringe around here. I'm neither. I tried to get one off my doctor's nurse when I went in for an allergy shot but no can do. I was actually waiting for instructions from DanH on how I should go about this before I made an attempt.
Andrew,
When I lived in Saskatchewan, I'm pretty sure that our local TSC had them. You might give the one in Amprior a call. Either TSC or perhaps you could call a "country" veterinarian. Another source would be a family member that is diabetic, which makes me think that a local Shoppers might have them too. The only thing that these syringes are good for liquid samples. I've noticed quite a few reports of dry blisters, in which case there would be nothing to sample.
For dry blisters, what is really needed is a gas tight syringe, suitable for taking gas samples. By gas I am referring to compressed gasses like hydrogen or helium. They are typically glass barreled with tygon pistons and have a positive locking valves on the front of the syringe body. In my former life, I used to use them to collect hydrogen samples for purity checks back in our lab. I would collect a gas sample bring it to the lab and inject the sample on gas chromatograph. In my case, I knew exactly what I was looking for in the way of impurities so a standard GC was quite suitable. In this case as this is an unknown sample, the ideal instrument would be a GC-MS (gas chromatograph coupled to a mass spectrometer detector). Almost every modern mass spectrometer has a built in library function that makes identification of simple unknowns as trivial as hovering a mouse over the chromatograph peaks and letting the computer tell you with 99% certainty what the unknown peaks are. Its quite an amazing thing to see in action, and while its not quite what Hollywood and CSI would have you believe, its not far off.
My thinking is that there are a few ways to get this done.
The preferred method (IMHO) would be to take a "sample" from an unpopped paint blister with a gas tight syringe. Ideally, this would be injected "on site" (at the airport) into a portable GC-MS. I think the guys in the oil patch can do this type of on site analysis, but I personally don't know any labs or companies set up to do this.
A second option would be to collect the unknown as above and mail the entire syringe to a lab capable of this type of analysis. This would take some coordination with the lab, but my thinking is that they would send you the syringes, you collect the sample according to their instructions, lock the syringe and overnight mail the gas filled syringe back to them. They would then proceed with a GC-MS analysis. The lab chemist would have to tell you if this is a viable option or not. The syringes are gas tight, but I don't know if that means they are gas tight for a few hours or for a few weeks. In my example above, I was doing analysis within 2 minutes of collecting the sample, so time was not a factor.
The third option would be to collect the unknown as in the above examples, but immediately inject the unknown into a pre-purged and sealed glass vials. You would then mail the vial to the lab. The laboratory would then analyze the sample with a headspace analyzer coupled to the GC-MS. I would imagine a good lab could send you several prepared and purged vials, ready for unknown injection.
The other problem I see is that Andrew is in Ontario, which means he would be sending unknown samples (either liquid or gas) across the border. There may be some issues getting samples like this to a lab in the States from Canada. The pictures he provided show ideal blisters to obtain samples from however. Andrew, do you do much cross border flying? It might be a heck of a lot easier to simply fly to an airport on this side and meet an RV'er here to collect a sample.
I feel just as frustrated as most people reading this thread. If this had happened about 10 years ago, I could have easily done all of the analysis for us for free as I had access to this equipment on a daily basis. Unfortunately, the company I work for now doesn't have a lab capable of this type of analysis.
Dan, if you're reading this, you might offer up some of the options I mentioned above to the lab you are speaking with and see if they are capable of doing any headspace analysis with GC-MS. They may be able to suggest even better gas sampling ideas than what I thought of. They also need to know that we are dealing with micro liter volumes of an unknown.