Columns with negatively charged functional groups due to the embedded anionic ion-pairing reagent.
Columns with positively charged functional groups. 
Column with unique unparalleled selectivity. Primesep C
Three interactions within one column:
Mixed-mode Stationary Phases
For decades, liquid chromatography stationary phase design has been dominated by the idea of elimination of multiple, or “unwanted” interactions that occur in mixed-mode separations. Reverse-phase chromatography is making the point of eliminating silanol interactions with amine-containing analytes by developing base-deactivated phases.
Within the same trend, adsorption interactions are considered undesirable as opposed to steric interactions in size-exclusion chromatography, and non-ionic interactions are generally viewed as complications in ion-exchange and ion-exclusion chromatography.
However, there are ways to benefit from multiple interactions on the stationary phase. SIELC Technologies introduces Primesep® HPLC columns, specifically designed for mixed-mode separations and capable of separating a tremendous range of compounds by different separation modes based only upon mobile phase selection. MORE
Currently, SIELC Technologies offers the following types of silica-based mixed-mode phases.
