Extraction is effected by equilibrating homoionically saturated ion exchange resin beads with {HEAD ~ a sample} of the complex matrix under {TAIL ~ study} 
Extraction is effected by equilibrating homoionically saturated ion exchange resin beads with { HEAD ~ a sample } of the complex matrix under { TAIL ~ study }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH OTH REL TAIL TAIL TAIL TAIL TAIL