dlbenach wrote:
If you treat your sample the same as the standard ie putting 50 uL of sample into a 20 mL headspace vial, then you can base your results on the standard being 100 ug/mL. you do not have to take into account the volume of the headspace vial.
Just curious, how do you make a 1000 ug/mL butane standard? What is the solvent?
Dave
In a lot of volatiles analysis you make stock standards of permanent gasses by filling a gas tight syringe with the gas then either bubbling it into a partially filled volumetric flask that has methanol in it that is on a balance until you get the desired change in mass. You can also just flow the gas above the solvent and watch the increase in mass without bubbling, both ways are often used.
If analyzing butane by FID it would probably be better to use carbon disulfide as the solvent since it would elute later and have a much lower response.
Personally I prefer to just purchase pre-made high concentration solutions.