hexane by headspace

[WK]

Hi All,
What headspace vial temperature should I start to use for C6 type hydrocarbons in solid plant extract matrices?
Does anyone do this analysis?
Roughly what are your other parameters?
Thanks in advance
WK

[chromatographer1]

Are you going to dissolve the plant extract into a solvent of some type?

What solvent would you choose?

Once you determine this then the other parameters can be chosen.

If you are only placing the extract without solvent into the vial, you won't really know if you are measuring all the hydrocarbon content of the sample. I would fill the vial with inert gas (nitrogen or helium) before heating if that is the case.

Water as a solvent, use 60°C for 5 to 10 min. Methanol, Toluene, DMSO, DMAc ........ all would have different temperatures.

Ethyl cellusolve? try 40°C for 15 min.

share more info and I will try to be of asssistance.

[WK]

Thanks C1,
I moved a stage further today by dissolving samples in miglyol (coconut fraction I think) and preparing standards in it too.
I think this will help since my samples need dilution and it will reduce differences in matrix.
I am therefore using 80degC for 15mins - this seems to be OK - plenty of sensitivity.
I had a problem with the headspace autosampler today so I will do reproducibility and linearity studies next week.
Regards WK

[chromatographer1]

15 min is a bit long but that depends upon the amount of sample you are using in your headspace vial and the size of the vial (smaller is better for LOD and RSD. counter-intuitive, I know, but I wrote a paper on it) you are going in the right direction.

Sounds like you have everything under control.