Removal of tetrabutylammonium from an organic reaction
I know it is a relative old issue but I had the same problem with nucleosides during my PhD. I tried a wide range of reagents but all of them lead to the decomposition of compounds or no reaction occurred. The only one that worked was TBAF 1 M in THF. I could not extract them because they are too polar. FCC did not work at all. 

Solution (at least it worked for me): after FCC, I dissolved my product with TBAF in water and pass it through a Supelco SPE DSC-C8 3 mL, 500 mg for up to 10 mg of my compound. Use only water and do it slowly. I always get the desired compound from tube one to 6-7 and no TBAF is present. It is useful if you can use a LC-MS to analyze each tube. I tried other brands and no one worked except this one. I don't work for them, just want to share my solution.