ODL C18 Columns

SMT SAM-C18 column is very stable at a wide pH range and high temperatures. Separation of most basic solutes is often possible without trifluoroacetic acid (TFA) or other mobile phase additives. SMT packings enable you to achieve a broader pH range than what is accessible with other commercially available packings. SMT utilizes a novel self-assembled monolayers technology in all its bonding chemistries to achieve maximum coverage. The technique involves pretreatment of the silica substrate including rigorous control of water molecules. A mixture of trifunctional ligands is then allowed to come in contact with the substrate. The result is an unprecedented high-density assembly of molecules on the substrate. The unique aspect of SAM is that only a monolayer of coverage is achieved when the bonding is performed accordingly.  At least one of the  ligands (e.g. C18) is functional for the separation while the other (e.g. C1) is used as a spacer molecule, although, it too can impact certain selectivity needed for some separation. A typical coverage achievable with SAM is 7-8 μmole/m2. This coverage value is equivalent to the maximum achievable coverage on any substrate and it is about 50% higher than that achievable using the most exhaustive conventional bonding and end-capping methods available in the market today.    

 

ODL Series: SMT SAM-C18 phase with the lowest functional ligand coverage confirmed with carbon analysis results of 12% carbon load. In these series, the proportional ratio of the functional C18 molecule, mixed with the proprietary spacer molecule, is reduced. The result is a packing material with maximum coverage but much lower functional ligand. Low density C18 packing material ensures faster mass transfer of solutes during separation. These phases have much lower hydrophobicity compared to the standard SMT OD-series. The spacer molecules protect the substrate from aggressive pH conditions and impact unique selectivity compared with other C18 phases.