Recent discussion (Nov 08) topic regarding sudden deaths of a mature tank with shrimps when new plants were introduced into the tank. Take Note!
Here's Bro Silane's advice
See on the plant:
http://www.arofanatics.com/forums/sh...d.php?t=346398
I would suggest to soak the plant for a few days and do a few water changes.
For now, you can use active carbon to remove the residue toxic, use trustable brands like Sera. Put 3/4 cup into your canister filter.