Dear Razie,

thanks for posting this interesting question. It is not quite clear to me what you mean by separate in this case. I assume that you want to completely liberate the free dimethylaminoethanol (DMAE) from its bitartrate salt, right? In that case please check the closely related discussion cited below in which this question has been answered

https://chemistry.stackexchange.com/questions/129334/how-can-i-remove-the-bitartrate-anion-from-an-organic-bitartrate-salt

Good luck with your work and best wishes!

If you added a stoichiometric amount of potassium bicarbonate (KHCO3, quite safe) to an aqueous solution of DMAE, you would precipitate almost all of the bitartrate, leaving the DMAE in water.

Ion chromatography with cation exchange mode or reverse of it to get DMAE as a flow-through.