L7 US Pharmacopoeia Columns

Merck offers a broad range of HPLC columns that are fully compliant with USP (United States Pharmacopoeia) specifications. L7 USP columns are described as octyl silane (C8), chemically linked to porous silica particles, 1.5 to 10 µm in diameter. Our high-quality L7 USP columns include: Chromolith® RP-8 endcapped.

Superior Retention for Hydrophobic Compounds

Chromolith® RP-8 endcapped HPLC columns provide better retention for hydrophobic compounds than standard reversed-phase columns. Due to their shorter alkyl chains, they offer different retention and selectivity characteristics, making it possible to achieve baseline separations on RP-8 endcapped bonded columns.

Revolutionary Monolithic Technology

Instead of containing particles, Chromolith® RP-8 endcapped is a monolithic silica column with a bimodal pore structure of macro and mesopores. The high permeability and porosity of the silica skeleton, and resulting low back pressure, enable more flexible flow rates than particle-packed columns. Thanks to their high purity, Chromolith® RP-8 endcapped columns minimize the negative effects of trace metals. Furthermore, they are chemically modified with n-alkyl chains, which possess a high ligand density, and fully endcapped to reduce the effects of unmodified silanol groups.

Features and Benefits

• Classified as L7 USP column
• Better retention for hydrophobic compounds
• High throughput at high flow rates
• Possibility of flow gradients
• Added column performance by column coupling
• Rigid monolithic structure for longer lifetime
• Lower matrix sensitivity

Application Examples

Separation of angiotensins

Separation of acids

Specifications of Chromolith® RP-8 Endcapped