The most common test system for liquid-liquid extraction is toluene/acetone/water.  I would recommend benchmarking your equipment with this extraction mixture.  The pulsed extraction data could be compared with those published for this system. 

Another recommended test system is n-butanol/succinic acid/water.  This system provides a very low interfacial tension (~ 2 dynes/cm compared to 25 dynes/cm with the acetone system).  The analytical for both systems utilizes simple titration.  It is highly recommended that these extractions be performed in a well-ventilated hood.  Butanol has a very strong odor.