How to Work with Volatile Compounds

Compound with molecular weights below 200 require special handling, especially if they do not contain a hydroxyl moiety or another similar highly polar functional group.

Here is a list of precautions you can take to avoid losing these volatile substances during your experiment:

1. To remove solvent from a volatile product, avoid using a high vacuum line, and take care when working under reduced pressure. Recovering product from the vacuum trap is not a high-yielding experience. Reduce the vacuum strength on your rotovap as much as possible. If your compound is still ending up in the solvent trap, you could try a Kugelrohr distillation apparatus, or distill the solvent away from your compound in a conventional way, with a distillation head and heat at atmospheric pressure.
2. To run a reaction at elevated temperature with a volatile reagent, use a Vigreaux condenser or research sealed-tube apparatus/ techniques.
3. To purify a volatile product using column chromatography, choose your solvent system carefully. For example, you can substitute pentane for hexanes, and typically avoid ethyl acetate. These precautions will simply rotoevaporation (see above).
4. Store extra-volatile compounds at low temperature.
5. If you work with volatile compounds on an inert gas line, be aware that the compound can get into your inert gas and therefore end up in other flasks connected with the gas line. You might choose to remove other samples on your line while handling a volatile compound, and then purge the line with inert gas afterwards