Chromatography Forum

I want to know about liners of Thermo Focus GC
Does it have 2 mm Splitless liner?
I am having trouble in analysis of API Residual Solvent as it says that blank (DMSO) should be analyte free and I am having methanol peak in it.
method parameters,
Det temp 200
Inj temp 140
gas Nitrogen

Please provide suggestion

The peak you are seeing is not methanol but it elutes where methanol elutes. (unless you have exposed your DMSO to methanol in the air or elsewhere) The peak may be dimethylsulfide.

You can pull vacuum on a portion of DMSO while warming and stirring it to remove volatile impurities

Nitrogen sparging would be helpful also.

If you heat a portion of DMSO try not to expose it to atmosphere as water vapor can contaminate your sample which can encourage reactions producing DMS.

Good luck.

Rod

will it be possible to use Rotavapour for it?
If yes then please tell me temp and other parameters like vaccum