How to make 100ppm v/v R113 in R133a Standard?

[davidlbrooks2000]

Note: R113 is a liquid @25C and bp @48C. R133a is gas @25C and bp @6C.

[Johnny Rod]

I guess you're after a vapour-phase standard? You can make it in a glass flask with a septum, fill the flask with R133a (100%), and inject the appropriate amount of R113 with a syringe. Work out the volume of the flask first (fill with distilled water, weigh, and measure temperature) and work out the amounts of each component you need. The R113 should vaporise no problem as it's a small amount. If you need a regular or certified standard then try talking to BOC Special Gases, it would have to be made at low pressure though so you wouldn't get a lot in a cylinder. For ad hoc analysis the glass flask method is good but I'd make/analyse the standard 3 times to reduce variations.