Pore glass immobilized chelate controlled

Off-line dicarbamate solvent extraction and ICP-MS analysis [317] provided part-per-trillion detection limits Cd (0.2 ppt), Co (0.3 ppt), Cu (3 ppt), Fe (21 ppt), Ni (2 ppt), Pb (0.5 ppt), and Zn (2 ppt). Off-line matrix removal and preconcentration using cellulose-immobilized ethylenediaminetetraacetic acid (EDTA) have also been reported [318]. Transition metals and rare earth elements were preconcentrated and separated from the matrix using on-line ion chromatography with a NTA chelating resin [319]. Isotope-dilution-based concentration measurement has also been used after matrix separation with a Chelex ion-exchange resin [320]. The pH, flow rate, resin volume, elution volume, and time required for isotope equilibration were optimized. A controlled-pore glass immobilized iminodiacetate based automated on-line matrix separation system has also been described [321]. Recoveries for most metals were between 62% and 113%. 

Ion Removal and Metal Oxide Electrodes. The ethylenediamine ( -functional silane, shown in Table 3 (No. 5), has been studied extensively as a silylating agent on silica gel to preconcentrate polyvalent anions and cations from dilute aqueous solutions (26,27). Numerous other chelate-functional silanes have been immobilized on silica gel, controlled-pore glass, and fiber glass for removal of metal ions from solution (28,29). 

Allen EA, Boardman M and Plunkett B (1987) Comparison of two chelating agents immobilized on controlled-pore glass for the preconcentration of aluminium from aqueous solutions. Anal Chim Acta 196 323-327. 

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