After the reaction of phenylalanine Boc deprotection used TFA/DCM(1:1) condition,I don't know why weight of product is over what I expected.I think free amine could be a salt with TFA. But more over weighted than what I calculated with TFA.When I added little solvent(EA, DCM) TFA fume was detected, so I thought TFA was difficult remove.But bp of TFA is just 72 degrees celcius.What should I do to remove TFA in product? I have already tried vacuum and evaporation with DCM several times. Any method suggestions for this?