Mr. Rocchetti,

From the point of view of analytical instrumentation, your experimental design includes among the most recommended coupling methods.

Successful extraction of phenol from goat milk will involve the following

Eliminate lipids and proteins

Extract with polar solvents such as methanol/acetonitrile

Test for phenol activity 

If found, then quantify.

Phenolic molecules are acidic; Can use liquid - liquid extraction in alkaline state, pH 10 maybe. Acidic functional group or groups will be absorb hydrogens and leave the acid group in its polar state. Many of lipids present in food and other sources have carboxylic acid groups that are composed of a number of acid groups. The more carboxylic acid functional groups the higher the alkaline pH. Might be able to extract phenols that have only one acid group; pH7.5,  8, 8.5 and 9.0. 

Extract with combination of dichloromethane, methanol and water. 

Around pH 8.5 may be able to push phenols into the aqueous and water layers; the other more acidic lipids and most that are more hydrophobic may stay in chlorinated solvent. 

The water fraction can be extracted with acidic buffer in any suitable organic solvent you choose; rotary evaporate and tlc for comparison.

LLE is an often used technique and might do the trick for your experiment. A couple of articles on extracting (bis)phenols out of milk (human) can be found. For example:

- Sun et al (2004): DOI: 10.1002/bmc.345

SPE is also an option, following article coupled online SPE to LC-tandem mass spectrometry:

- Ye et al (2006): DOI: 10.1016/j.jchromb.2005.11.050

I suggest you first treat with trichloroacetic acid (8-10% final) to acidify solution and precipitate protein, clarify, and then apply solution to an appropriately conditioned C18 solid phase extraction cartridge.  Wash with water, maybe pre-elute the SPE cartridge with 5-10% solvent, and then elute phenolics with aqueous solvent (e.g., 80% EtOH or ACN). 

To add to Dr. Savary's comments, you'll still probably need to do some column or dSPE cleanup to eliminate lipids but his recommendations are a great starting point.

Thank you all for your valuable answers.