Selective separation and purification of highly polar basic compounds using a silica-based strong cation exchange stationary phase.

Compared to moderately and weakly hydrophilic bases, highly polar basic compounds are even more difficult to separate due to their poor retention in reversed phase (RP) mode. This study described the successful applications of a strong cation exchange (SCX) stationary phase to achieve symmetric peak shape, adequate retention and selectivity in the separation of very polar basic compounds. Salt and acetonitrile concentrations were adjusted to optimize the separation.

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

Strong cation exchange (SCX) mode, an alternative to reversed-phase (RP) mode, was described in this paper to obtain symmetrical peak shape and high sample loading for the separation of basic compounds. The retention mechanisms on SCX modified silica sorbents have been demonstrated including electrostatic and hydrophobic interactions. The effects of eluent ionic strength, apparent pH on retention were investigated and the cation-exchange capacity was also characterized.

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

A non-aqueous solid phase extraction (SPE) method utilizing silica based strong cation exchange (SCX) was developed and optimized for the enrichment of alkaloids. In this method, silica based SCX SPE columns were used for the elimination of non-alkaloid compounds and the preconcentration of alkaloids from the extracts. Mass spectrometry was employed to analyze the alkaloid-enriched fraction, and results showed that the SPE method developed in this study was effective for the removal of non-alkaloids.