SIELC Technologies has developed a new generation of unique stationary phases combining mixed-mode and core-shell approaches -CoresepTM
In single single mode on a reversed-phase column compounds elute according to their hydrophobicity and analytes with similar hydrophobicity may co-elute or show poor resolution.
In Ion-Exchange columns compounds are retained based on their ionic properties. Similarly, using ion-exchange chromatography, other compounds may be closely eluting because they are identical in terms of the strength of ionic interaction between stationary phase and analyte
In mixed-mode chromatography you have two interactions, reversed-phase and ion-exchange. This enables to explore very small difference in reversed-phase and ionic properties of compounds. These differences are enhanced due to synergy of two mechanisms which results in much better separation (mixed-mode example).
Sielc Coresep Comparison mixed mode vs RP-IEX
Core-shell particles are constructed with solid core and porous outer layer. This porous layer is used as a stationary support for chemical attachment of specific separation phases.
The reduced pore length offers faster diffusion of molecules and as a result has the ability to do chromatography faster compared to particles with through-pore structure. The same result can beachieved with smaller particles, but then the pressure needs to be higher in order to produce the same flow rate and speed of analysis.
Sielc porous-small particle
Core-shell technology offers the unique ability to achieve high efficiency at higher flow rates whilst generating back pressures which can be achieved using traditional HPLC systems. This offers the end user the opportunity to improve separation speed and quality without the requirement toÂ purchase UHPLC equipment. We have recognized the exciting opportunities afforded by combining these two great technologies in stationary phases which achieve unique selectivity and high efficiency with traditional HPLC systems which are rated to 4000 or 6000 psi.
Mixed-mode columns offer much higher capacity and retention than traditional reversed-phase columns. Since the surface area of core-shell particles is reduced, mixed-mode phases address potential loadability issues whilst maintaining the selectivity advantages of multiple interactions. Newly optimized ligand density and ionic / hydrophobic ratios further increases the capacity of mixed-mode core-shell columns.