{HEAD ~ Peaks} corresponding to {TAIL ~ the specified components} in the chromatogram are identified, and presences and absences of these specified components in the sample are thereby determined 
{ HEAD ~ Peaks } corresponding to { TAIL ~ the specified components } in the chromatogram are identified , and presences and absences of these specified components in the sample are thereby determined
HEAD HEAD HEAD HEAD HEAD REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH