Non-linear effects of TMS capping on dimethyloctyl HPLC stationary phases

Co-bonding ligands on the same support to produce “blended” HPLC stationary phases is most commonly carried out in the form of capped reversed-phase materials. Non-additive retention properties were observed over a range of trimethylsilane/dimethyloctylsilane ratios. In addition, the increase in retention per mole of bonded trimethylsilane was greatest at the highest dimethyloctylsilane coverages.