کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5131197 | 1490868 | 2017 | 8 صفحه PDF | دانلود رایگان |
- Novel PS-DVB anion exchangers with functional layers of branched polyethyleneimine.
- Use of glycidol and 1,4-BDDGE for quaternization of branched polyethyleneimine layer.
- Significant selectivity increase for anion exchanger cross-linked with 1,4-BDDGE.
- Separation of 16 anions within 26Â min in gradient mode on the 10Â cm long column.
For the first time novel pellicular anion-exchangers with functional layers of quaternized branched polyethyleneimine (PEI) covalently bonded to the surface of aminated poly(styrene-divinylbenzene) (PS-DVB) with 1,4-butanediol diglycidyl ether (1,4-BDDGE) as a linker are obtained and studied. The proposed method of synthesis includes alkylation of PS-DVB substrate containing secondary aminogroups with 1,4-BDDGE followed by amination with branched PEI containing primary, secondary, and tertiary amino groups. Quaternization of amino groups of PEI required for increasing ion-exchange capacity of the stationary phase is provided with two epoxides - glycidol and 1,4-BDDGE, which results in the considerable variations of ion-exchange selectivity. Chromatographic properties of the obtained anion-exchangers are evaluated using various model mixtures of anions (Fâ, HCOOâ, CH3COOâ, C2H5COOâ, Clâ, BrO3â, NO2â, Brâ, NO3â, ClO3â, S2O32â, C2O42â, CrO42â, SO42â, PO43â, Iâ, SCNâ) in hydroxide and carbonate/bicarbonte eluents. All anion-exchangers show better selectivity toward the anions of weakly retained organic acids (acetate, formate, propionate) as compared with previously reported chemically derivatized anion-exchangers with monomeric functional sites in the ion-exchange layer. In terms of separation abilities, novel anion-exchangers with covalently-bonded PEI are not inferior to some commercial columns with grafted polymeric anion-exchange layer. Anion-exchanger quaternized with more hydrophilic glycidol packed in 10-cm long column enables the separation of 16 anions including weakly retained and highly retained polarizable ones within 26Â min using gradient elution. Column efficiencies for both anion-exchangers with quaternized PEI are up to 32000Â N/m and 37000Â N/m in case of hydroxide and carbonate eluent, respectively, which is comparable with the values demonstrated by commercially available columns of related chemistry.
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Journal: Analytica Chimica Acta - Volume 964, 29 April 2017, Pages 187-194