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