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