{TAIL ~ Fractionation} of a sample reduces {HEAD ~ the complexity} of the constituents of each fraction 
{ TAIL ~ Fractionation } of a sample reduces { HEAD ~ the complexity } of the constituents of each fraction
TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH OTH OTH