Dissolve it in a water/dichloromethane-mixture and measure the pH of the separated water-phase... then rotovap both phases.
check solubility and then develop TLC for polarity thereafter check pH in aq. media
Water/dichloromethane, methanol/dichloromethane, water/chloroform, etc are available mixture as Benjamin stated. For pH, use litmus paper or Merc's pH paper indicator in advance....
Concerning polarity, run a TLC in a normal silica plate using dichloromethane as eluent. If your compound as an Rf>= 0.6 will indicate a non-polar or only slightly polar. An Rf< ~0.3 may indicate a polar compound. You can play with the polarity of the eluent adding for example hexanes (lowering polarity) or adding ethyl acetate or ethanol (enhancing polarity) to help in your conclusions. Good luck, wish it helps.
If you chose to do it with TLC (which will give you a better approximation about polarity and not just "polar" or "non-polar"), you can stain the TLC afterwards with a neutralized solution of bromocresol green (neutralize if necessary to a green color). Depending on the pH your spot will turn blue or yellow (so with this option the pH is not too exact).
Also, it depends on the amount of substance you have... for tiny amounts i would definitely go with TLC.
I agree to all options above but the simplest phenomenon " LIKE DISSOLVES LIKE" is more significant for preliminary identification. If your compound dissolves in polar solvents ( like methanol, acetone, DMF, etc.) then your compound is polar, where as if it dissolves in non polar solvents ( like n-hexane, benzene, toluene, etc. ) then your compound must be non polar. In case to study whether it is acidic or basic, most of the acidic compounds dissolves in basic aqueous solutions and vice versa. Hope it will help you.
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