The Snyder polarity index can be used to develop an appropriate mobile phase for the samples of interest.  
Systems for this technique generally include a vacuum degasser unit, a pump, an autosampler, a column compartment, and a detector, usually either UV or refractive index.  The Snyder polarity index can be used to develop an appropriate mobile phase for the samples of interest.  By way of historical accident, the most popular method of this procedure is known as reversed-phase, which passes a polar mobile phase generally containing a mixture of water, methanol, and acetonitrile through porous silica particles coated with a hydrocarbon.  FTP, name this technique that separates substances by forcing them through a packed column at several thousand p.s.i.
Systems for this technique generally include a vacuum degasser unit, a pump, an autosampler, a column compartment, and a detector, usually either UV or refractive index.  
High Performance Liquid Chromatography (accept "Pressure" instead of "Performance")