Old Benzaldehyde

[wimpy]

SWIM has refound an old bottle of of pure Benzaldehyde someone forgot in the Basement for nearly 20 years. On the bottom of the bottle crystals have formed. As it's not so very easy for SWIM to obtain pure Benzaldehyde he'd like to know if the stuff is still usable ...
Thanks a lot!

[GC_MS]

Pure benzaldehyde is colorless or faintly yellow. You can try to distill it. If the bottle has been firmly closed for that time, and not being exposed to light, you may recover alot of benzaldehyde. If the bottle was open (or not firmly closed) and/or exposed to light, your product may have formed quite some auto-oxidation product(s).

[Osmium]

The crystals are benzoic acid. You definitely need to distill the benzaldehyde.

[ApprenticeCook]

On the bottom of the bottle crystals have formed

Inside or outside the bottle?

Could just distill it and find out...

as far as getting benzaldehyde its the main component of bitter almond oil...

[wimpy]

Hey All - thanks a lot for all the answers!
ApprenticeCook: The crystals formed inside the bottle, and it was closed for nearly 20 years
I know about the almond oil thing, but they never write the ingredients on the package, so i don't know if one might also use the pure almont arome extract for baking. I've read it would generaly consist of Benzaldehyde, Water and Alcohol, so i think SWIM might use it more or less "as is" for, say, Biosynthesis of L-PAC? SWIM hopes he can avoid distilling at this time, 'cause he has no equipment for that yet ...