liquid extraction

[kfsa1]

Hi guys,
I just had a question about liquid - liquid extraction. In the Ochem examcracker book, the last lab technique they talk about is the liquid extraction. What I do not understand is how there is an organic layer composed of bases and acids which can apparently stay imiscible with the aqueous layer....from what I have learned, bases or acids are usually polar which can be solvated by H2O. I mean, just take the example they gave. According to the book, they will first extract amines by protonating them via acid. But don't amines dissolve in H2O already bc of hydrogen bonding?

Please help.
Thank you in advance.

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[Rabolisk]

Not everything that is polar will dissolve to a great extent in water. Large carboxylic acids (e.g. benzoic acid) will dissolve in organic solvents (e.g. dichloromethane, ether) rather than in water. When they are deprotonated, though, they are negatively charged, and will dissolve in water. Amines are the opposite; you need to protonate them to give them a positive charge. Surely you've done this sort of acid/base organic/water extraction in an organic lab?