Sciencemadness Discussion Board

Cleaning molecular sieves?

LD5050 - 6-7-2017 at 08:24

I have some molecular sieves, some where used for drying EtOH, some drying ether and some drying DCM I was wondering if I could use these sieves for drying other reagents now that they have already been used without risk of contamination. Should I somehow wash them first then dry in oven?

Texium - 6-7-2017 at 08:35

Just drying them in the oven should be fine since you used them with volatile solvents. To test if they're dry, just take a sieve from the oven, allow it to cool in a dry place, and place it in the palm of your hand. Add a few drops of water, and it should heat up noticeably. If it doesn't, they need more time in the oven.

unionised - 6-7-2017 at 11:57

Don't put flammable solvents in the oven.
:o
It's a good idea to leave the used stuff exposed to air, outside or somewhere well ventilated for a while, then soak it with water and let it dry in air before slowly drying in an oven.