Polyfunctional low-capacity cation-exchange packing material for the separation of underivatized amino acids

Elution Profile of Di-peptides on a Sulfonated Ethylstyrene-Divinylbenzene Copolymer Resin Column by High-performance Liquid Chromatography

“…1a, also revealed that the retention of the di-peptides on the column packed with sulfonated copolymer resin was due to the preferential cation-exchange interactions with the basic moieties of the peptides. By considering the report that increasing the pH using phosphate salts was effective for amino acid separations on low-capacity cation-exchange columns, 15 we applied the following elution system for di-peptide separation: mobile phase A, 10% MeOH or CH3CN containing 5 mmol L -1 NaH2PO4 buffer (pH 4.8); mobile phase B, 50% MeOH or CH3CN containing 5 mmol L -1 Na2HPO4 buffer (pH 8.9). As shown in Figs.…”

“…Specifically, a prototype cation-exchange/reversed phase HPLC column packed with a partially sulfonated ethylstyrenedivinylbenzene copolymer resin was investigated for the separation of di-peptides, since Yokoyama et al 15 demonstrated that the simultaneous separation of 20 amino acids without derivatization could be achieved using the mixed-mode of a cation-exchange/reversed phase HPLC column. Di-peptides with diverse isoelectric points (pIs) and hydrophobicities (log P) values were synthesized in order to obtain information regarding the separation characteristics of the prototype column for extensive peptide separations.…”

Fast and Efficient Separation and Determination of UV-absorbing Amino Acids, Nucleobases, and Creatinine Using a Carboxy-functionalized Cation-exchange Column

“…We recently have developed a capacity analyzing system, 24 which looks like an ion-chromatography system without sample injector, and also have improved the equilibration buffer system. 9 This can provide a dynamic capacity curve, that is, plots of the changes in dynamic exchange capacities (DECs) over the column effluent pH after equilibration with several buffer solutions. The mole flux of H + required for exchanging from Na + -form to H + -form of the cation-exchange resin (molar concentration × time × flow-rate) can correspond to the dynamic cation-exchange capacity 24 under the buffer pH conditions subjected.…”

“…Such low-capacity columns can facilitate a 50-min separation of underivatized proteinogenic amino acids using a binary gradient high-performance liquid chromatography (HPLC). 4 After this, a more efficient and selective packing material was developed, 9 and a 23-min separation of 17 underivatized proteinogenic amino acids was attained with a resolution of 1.0 for critical peak pair (isoleucine and leucine), using a self-made polyfunctional low-capacity cation-exchange column. This can provide cost-effective results or information for the high-risk screening or chemical diagnosis of inborn errors of amino-acid metabolism.…”

“…13,14 Therefore, it is useful to construct a simultaneous separation method for such organo-cationic species coexisting in biogenic fluids. Reported in recent years have been some LC methods targeting nucleosides and/or nucleobases [15][16][17][18][19] or amino acids 4,9,20,21 individually; however, a liquid chromatography method has not been reported so far except liquid chromatography/mass spectrometry (LC/ MS) methods with 22 and without 23 precolumn derivatization. As is often the case with LC/MS, the mass identification may make up the insufficient LC separation.…”