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