An effective trapping media functions by binding gels that carry {HEAD ~ ultratrace analytes} on {TAIL ~ their surfaces} 
on
An effective trapping media functions by binding gels that carry { HEAD ~ ultratrace analytes } on { TAIL ~ their surfaces }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL