Hexane is contaminated with an unidentified compound (20-40 ppm). GC with a HALL detector identified the presence of a halogen containing compound. Based on standards used it could be concluded that the boiling point of this material is rather low (~30-40 C). i need to identify the contaminant and I would like to use GC-MS analysis for that. However the sensitivity of the MS is not high enough for these low levels. Coelution of the Hexane and the contaminant are also a problem. I thought about SPE, and I am willing to give it a try, but I am not sure if it will work. Any other ideas or suggestions.

Thanks for all your help.

If the BP is that low, do you think it's a solvent in there? If so, i don't think SPE will help you. If it is something else, you will need to know something about the functional group(s) before you can do SPE. If it's a solvent, maybe distillation?