Copper resin bound complexes

Metal ion complexes. These classic CSPs were developed independently by Davankov and Bernauer in the late 1960s. In a typical implementation, copper (II) is complexed with L-proline moieties bound to the surface of a porous polymer support such as a Merrifield resin [28-30]. They only separate well a limited number of racemates such as amino acids, amino alcohols, and hydroxy acids. 

Chelex-100 (Whatman) resin was suspended in 1 M CuCl2 overnight, washed repeatedly in water and suspended in 1 N ammonia overnight. A column (0.9 x 45 cm) was packed with a small volume of non-CuCl2 treated resin at the bottom followed by the copper complexed resin above. After washing the column, the nucleic acid components were loaded in a small volume of water and eluted with water (nucleotides followed by weakly basic nucleosides), 1 N ammonia (other nucleosides) and/or 2.5 N ammonia (bases). The nucleotides are not bound by the column and so are not fractionated. The nucleosides and bases are, however, well fractionated. Several minor components are well separated. The method is relatively quick and the eluants are volatile. 

When the EDTA concentration exceeded the stoichiometric amount of copper Initially on the resin, a total release of 80 percent of the Initially bound copper was observed. This result Is not unexpected because of the high formation constant for copper -EDTA complexes. In addition some of the copper In solution was probably due once again to the surface water. 

Some polystyrene resins (cross-linked with DVB) are specially modified to have chelating functional groups bound to the matrix so as to make them selective towards certain ions. Such resins with iminodiacetic acid groups are marketed under the trade names Dowex A-1 (Dow Chemical) and Chelex 100 (Bio-Rad Laboratories). The complex (XXVI) formation constants with metal ions of the chelating resin are so large that the resin absorbs metal ions equivalent to the iminodiacetic acid groups (used in sodium salt form), i.e., the efficiency of metal ion adsorption is near 100%. A particular metal ion can be removed by controlling the pH of aqueous solution. For example, at pH 2, mercury and copper ions are... 

Betts et al. developed a new methodology to purify copper-64 radiopharmaceuticals. Scheme 13.12 illustrates the purification technique based on a commercial DMAP-supported resin. In the approach A, the resin was able to selectively purify a pre-formed solution mixture of copper-64 and zinc-containing metalloradiopharmaceuticals. By the Jahn-Teller effect, the DMAP ligand selectively bound to the zinc-containing complex and the [ Cu]-labeled metalloradiopharmaceuticals remained in solution after filtration of... 

---