More particularly, it relates to a procedure and {HEAD ~ materials} for {TAIL ~ the preconcentration} of analytes in order to facilitate the analytic process 
More particularly , it relates to a procedure and { HEAD ~ materials } for { TAIL ~ the preconcentration } of analytes in order to facilitate the analytic process
OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL OTH OTH OTH OTH OTH OTH OTH OTH OTH