Addition to “A Versatile Method of Ambient-Temperature Solvent Removal”

Click to copy article linkArticle link copied!

The procedure described in this article should be performed only by an experienced researcher/experimenter who is properly trained in vacuum techniques and handling cryogens. The experimenter must be aware of a potential cryogenic burn hazard associated with dry ice and liquid nitrogen and must recognize that liquid oxygen can accumulate in a system or apparatus that is being chilled with liquid nitrogen if it is vented to the atmosphere (this includes but is not limited to accidental removal of a stopper or opening of a stopcock in the system or any other cause leading to a leak in the system when it is still being chilled with liquid nitrogen). A combination of liquid oxygen with organic or organometallic materials is extremely dangerous and can cause fire and explosion hazards. It is relevant to recall that oxyliquit, an explosive used in the mining industry, is exactly this—a mixture of a combustible substance with liquid oxygen. Organic solvents and volatile organometallics condensed in a solvent trap are especially prone to mixing with liquid oxygen if the trap is vented to the atmosphere while still being chilled with liquid nitrogen.