Sulfonated and sulfoacylated poly(styrene?divinylbenzene) copolymers as packing materials for cation chromatography

Abstract

Three different types of cation exchangers were produced from four basic poly(styrene-divinylbenzene) substrates with different properties. Porous PS-DVB resin beads were functionalized by sulfonation and sulfoacylation under various conditions to produce sulfonated resins with exchange capacities of 0.03-1.80 mM g(-1). The matrix with 50% of cross-linking is most suitable for updating by the proposed technique. Sulfuric and chlorosulfonic acids were used as the reagents for sulfonation. The sulfonating conditions, capacities, and the technique of the synthesis are given. The effects of parameters of the sulfonation reaction and the composition of the reactionary mixture on ion-exchange capacity of the sorbents were investigated. Selectivity and efficiency of the separation of some inorganic cations and derivatives of amines and hydrazines on the resins obtained are compared by ion chromatography with conductometric detection. As a result, the sulfoacylated resin was proved more efficient for the separation of these analytes. The resolution of the analytes strongly depends on the degree of functionalization. The best performance about 19,000 plates m(-1) was obtained using the sulfopropionylated beads with an ion-exchange capacity of 0.3 mM g(-1). The prepared sulfoacylated cation exchanger was compared with the commercially available Dionex CS-12 packing material. It was found that the separation of alkaline ions and 1,1-dimethylhydrazine (UDMH) were much better that those for the commercial material.

Strong cation exchange column allow for symmetrical peak shape and increased sample loading in the separation of basic compounds

“…In a previous work, Pirogov et al had investigated a serial of cation-exchange resins with capacities of 0.03-1.80 mMg −1 and they found that a moderate capacity of 0.3 mMg −1 could provide the most satisfying separation for all the analytes of interest with the highest efficiency. [16]. The capacity of the XCharge SCX was just close to that and it might benefit for the performance of HPLC use of this column.…”

“…The dominant SCX materials typically feature sulfonic acid functionalities with different "spacers" attached to supports. According to their supports, SCXs can be mainly classified into organic polymer-based SCXs [15,16] and silica-based SCXs [17,18]. Polymeric materials are used mostly in ion-exchange chromatography, with a high chemical stability within a very wide pH range.…”

“…Silica-based SCX columns, either commercially available or self made, are now emerging in literatures [20][21][22]. However, the SCX mode is still adapted mostly in separations of biomacromolecules like peptides and proteins [23][24][25][26][27], and only a few used for analysis of basic drugs or alkaloids [16,[18][19][20]22,28], possibly due to low efficiency and asymmetric peak shape of bases. Furthermore, few silica-based SCX columns which allow for symmetrical peak shape and high sample loading in the chromatographic preparation of basic compounds was reported.…”

A non-aqueous solid phase extraction method for alkaloid enrichment and its application in the determination of hyoscyamine and scopolamine

“…According to a previous study, 25 salts are eluted from SCX columns in the following order: Na + , Li + , K + , NH 4 + . This implies that ammonia ions are retained longest on SCX columns among these ions.…”

The influence of organic sample solvents on the separation efficiency of basic compounds under strong cation exchange mode

“…Strong cation exchange (SCX) is widely applied to separate various analytes including ions [1], proteins [2][3][4], peptides [5][6][7] and basic compounds [8][9][10][11][12][13][14]. Using SCX to separate basic compounds offers following advantages: (i) strong retention of polar basic compounds [12,14]; (ii) quite different separation mechanism [13] from reversed phase liquid chromatography (RPLC) [15] and (iii) high selectivity between basic compounds and non-basic compounds which can be used to selectively enrich [16] or separate basic compounds [15].…”