Synthesis of chelating resins and its application in ligand exchange chromatography

Abstract

Three kinds of new chelating resin containing /?-hydroxydithiocinnamic acid, ethyl /~-hydroxydithiocinnamate and N-(hydroxymethyl)-thioamide functional groups were synthesized. Cu(II), Cd(II) and Hg(II) were used as complex forming metal ions. By varying the combination of metal ion and chelating resin, a great variety of separation systems could be realized. For the on-line trace enrichment of 2-mercaptobenzimidazole, the copper-loaded N-(hydroxymethyl)-thioamide concentration column was found most suitable. UV detection at 300 nm was used. The detection limit was 0.2 ng/g. A 10 ml sample was found to be sufficient to attain the described sensitivity, and linear relationship was obtained-in the range of 0.75 ng/g to 12 ng/g. The best separation of the thiol compound mixture thioglycolic acid, methionine, cysteine and 2mercaptoethanol was obtained with coppeMoaded ethyl/~hydroxydithiocinnamate resin; UV absorbance detection was at 215 nm.

Ligand Separation with a Copper(II)-Loaded Polymeric Ligand Exchanger

“…In general, a ligand exchanger consists of a supporting resin with a transition metal (Lewis acid) immobilized on it. Polymeric cation-exchange resins such as sulfonic resins and chelating resins such as iminodiacetate resins have been commonly employed for hosting the Lewis acid sites . Sulfonic resins retain metal ions in the resin (stationary phase) through electrostatic interactions or ion pairing, which are much weaker forces compared to chemical bonding.…”

“…Polymeric cation-exchange resins such as sulfonic resins and chelating resins such as iminodiacetate resins have been commonly employed for hosting the Lewis acid sites. 3 Sulfonic resins retain metal ions in the resin (stationary phase) through electrostatic interactions or ion pairing, which are much weaker forces compared to chemical bonding. Consequently, low metal capacity and significant metal bleeding have been some of the major drawbacks associated with these types of sorbents in the conventional elution chromatography.…”

Novel hollow-electrode glow discharge mass spectrometry for the quantitative analysis of protein content in food

“…34 At present, the main detection objects of existing mass spectrometry at home and abroad are focused on the analysis of metal elements and organic compounds. 35,36 Since the products of food combustion are very complex, there is no mass spectrometry dedicated to the quantitative analysis of the main elements of protein in food. We built an experimental platform of "combustion furnace + mass spectrometry".…”

Polystyrene monolithic column functionalized with copper–iminodiacetate complex as a stationary phase for open tubular capillary electrochromatography

“…The ligand exchange mode has been widely used in separation science, some selected topics include liquid chromatography [14][15][16], gas chromatography with metallomesogens as stationary phases [17][18][19][20], CE [21][22][23], CEC [1,10,[24][25][26] and micellar electrokinetic chromatography [27,28]. Recently, Chen et al [1,25] used l-phenylalaninamide-modified monolithic silica column and l-amino acid amides as chiral selectors for lig-and exchange CEC enantioseparation of dansyl amino acids.…”