solvent preference in GC solvent preparation

[cygg168]

We tried to validate a method that used DMSO as solvent. I was told that DMSO is a very bad solvent for the column and the detector, and was adviced to switch to DMF. I tried to find more detailed information regarding to the solvents used in GC sample preparation, their properties, advantages and disadvantages. I.e, the order of the solvent choice and the reason. If any one could please provide the information, I would very appreciate.

Thanks,

cygg

[chromatographer1]

This is a very broad question with a very broad range of answers.

It may be helpful to your situation to specify what issues you have and the nature of the chemicals with which you are dealing.

Then perhaps a good answer to your specific question can be formulated.

best wishes,

Rod

[cygg168]

thank you very much for the quick reply. We are currently testing Residual Solvent Toluene in a drug product. The vendor used DMSO as solvent in its method, probably due to solubility reason. However, if DMSO is not good for the column, I would like to switch to DMF or other solvent. I would like to know in general, when people have a choice, which one is the first or second solvent to consider and why. Just like Methanol and Acetonitrile in HPLC.

Thank you very much

[chromatographer1]

cygg168

There are several desired qualities of a dissolution solvent when it is used to determine residual solvents in some drug matrix.

It must dissolve the matrix without excessive heating or mixing, as these actions may change the residual solvent content of the drug matrix solution.

It must be able to mix with and retain volatile solvents (at ambient if possible). (Try to measure ppm levels of ethyl ether from a water soluble drug matrix when dissolved in water)

It must separate from other solvents when injected onto commonly used GC columns or when heated in a sealed headspace vial for static headspace analysis.

DMSO, DMF, and DMAc are commonly used solvents which meet the above criteria.

Water is another solvent often used but while it does not separate well from many solvents it does have a very low FID response and FID is the most often used detector for residual solvent analysis. The partition constants for many common solvents are often good for headspace analysis using water.

I hope I have been helpful,

best wishes,

Rod

[cygg168]

Rod:

Thank you very much, that is very helpful.

We called Phenomenex Tech support and was told that DMSO will not give any problem for the column. Therefore, we will stay with the DMSO. But your information are very useful. Thanks again.