title: Sorption of heavy metal ions by silica gel-immobilized, proton-ionizable calix[4]arenes.
abstract: Silica gel-immobilized, di-ionizable calix[4]arenes are employed as stationary phases in ion-exchange chromatography for selected heavy metal ions. Sorption efficiencies for Pb(2+) are dependent on the structure of the calix[4]arene ligand and the linker that joins the ligand to the silica gel, as well as the acidity of the sample solution. Although the resins exhibit only poor sorption of Cd(2+), they are found to be scavengers for Hg(2+). Competitive sorption studies are conducted with selected resins.
authors.affiliation: Department of Chemistry and Biochemistry, Texas Tech University, Lubbock, TX 79409-1061, USA.
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Dongmei
authors.initials: D
authors.lastname: Zhang
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Lawson
authors.forename: Richard A
authors.initials: RA
authors.lastname: Bartsch
mesh_terms: D000327:Adsorption; D002104:Cadmium / Q000302:isolation & purification; D047250:Calixarenes; D002852:Chromatography, Ion Exchange / Q000379:methods; D007477:Ions; D007854:Lead / Q000302:isolation & purification; D008628:Mercury / Q000302:isolation & purification; D019216:Metals, Heavy / Q000302:isolation & purification*; D010636:Phenols; D058428:Silica Gel; D012822:Silicon Dioxide; D014874:Water Pollutants, Chemical / Q000302:isolation & purification
chemical_list: D007477:Ions; D019216:Metals, Heavy; D010636:Phenols; D014874:Water Pollutants, Chemical; C121325:calix(4)arene; D002104:Cadmium; D047250:Calixarenes; D007854:Lead; D058428:Silica Gel; D012822:Silicon Dioxide; D008628:Mercury