Two-Dimensional Separation of Ionic Species by Hyphenation of Capillary Ion Chromatography × Capillary Electrophoresis-Mass Spectrometry

Abstract

The separation of complex mixtures such as biological or environmental samples requires high peak capacities, which cannot be established with a single separation technique. Therefore, multidimensional systems are in demand. In this work, we present the hyphenation of the two most important (orthogonal) techniques in ion analysis, namely, ion chromatography (IC) and capillary electrophoresis (CE), in combination with mass spectrometry. A modulator was developed ensuring a well-controlled coupling of IC and CE separations. Proof-of-concept measurements were performed using a model system consisting of nucleotides and cyclic nucleotides. The data are presented in a multidimensional contour plot. Analyte stacking in the CE separation could be exploited on the basis of the fact that the suppressed IC effluent is pure water.

Electrokinetic sample preconcentration and hydrodynamic sample injection for microchip electrophoresis using a pneumatic microvalve

“…Finally, further development of the platform is needed to enable the broader application to analysis of cationic species. With these developments, it is likely that this platform, with its ability to concentrate samples without interfering with ongoing separations will also find new applications, including coupling multidimensional separations such as liquid chromatography to CE without wasting the majority of the sample between separation modes.…”

Recent Studies on Online Sample Preconcentration Methods inCapillary Electrophoresis Coupled with Mass Spectrometry

“…They identified 30 proteins in the mass range between 30-80 kDa from Pseudomonas aeruginosa. Metabolome analysis is also important application [45][46][47][48][49]. Moreno-Gonzalez et al reports FASS-CE-ESI-MS of nine aminoglycosides in honey and 5-fold sensitivity increase was achieved [47].…”

“…Moreno-Gonzalez et al reports FASS-CE-ESI-MS of nine aminoglycosides in honey and 5-fold sensitivity increase was achieved [47]. Beutner et al reports two dimensional separation of ion chromatography (IC) and CE coupled with ESI-MS [48]. Since unnecessary salts are removed by the suppressor in IC, hyphenation of IC and CE via FASS is quite an effective approach.…”

Fraction transfer process in on‐line comprehensive two‐dimensional liquid‐phase separations

“…electric voltage. Thus, besides the valve-based interfaces, several other approaches have been reported for coupling of LC with CE, as gating interfaces [94][95][96][97][98][99][100][101][102][103], microchip arrangement of the whole 2-D system [104], and mechanical positioning of the electrophoretic separation, or fraction transfer capillaries [105][106][107]. The flow gating interfaces, which typically involve coaxial arrangement of the capillary connected to the outlet of the LC column with the electrophoretic separation capillary separated by a small gap, are the most commonly used ones.…”