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Restek Biphenyl: Better Selectivity than a C18—Separate a Wider Range of Analytes in Highly Complex Samples

  • Ideal for food, urine, blood, oral fluid, and other difficult matrices.
  • Superior selectivity separates a broader range of analytes than a C18 column.
  • Increased retention of early eluting compounds minimizes matrix effects.
  • Improved sensitivity with simple, MS-friendly mobile phases.
  • Available on both traditional Force FPP silica and Raptor SPP core-shell silica.

Whether you are analyzing foods, drug testing samples, or other complex matrices, Restek Biphenyl columns separate a broader range of compound chemistries than is possible on popular C18 phases. Launched in 2005, the innovative Biphenyl (USP L11) is Restek’s most popular LC stationary phase because it is particularly adept at separating compounds that are hard to resolve or that elute early on C18 columns or columns with other phenyl chemistries. As a result, rugged Biphenyl columns are extremely useful for fast separations—even of isobars—in challenging analyses, especially those that require a mass spectrometer (MS). Increasing retention of early eluting compounds can limit ionization suppression, and the Restek Biphenyl's heightened selectivity helps eliminate the need for complex mobile phases that are not well suited for MS detection.

With years of unrivaled performance, Restek's time-tested Biphenyl has been proven to be the ideal column for food, clinical diagnostic, pain, pharmaceutical, and environmental labs seeking universal utility for mass spec applications. Restek was the first to bring you the benefits of the Biphenyl ligand, and our LC group has the veteran technical expertise to supply and support your lab better than anyone else.

Deconstructing the Biphenyl

With USLC technology, Restek's LC experts have defined our columns' selectivity based on molecular interactions. The more rings shown, the more significant a role played in solute retention.


  • Increased retention for dipolar, unsaturated, or conjugated solutes.
  • Enhanced selectivity when used with methanolic mobile phase.
  • Ideal for increasing sensitivity and selectivity in LC-MS analyses.

Switch to Biphenyl when:

  • Limited selectivity is observed on a C18.
  • You need to increase retention of hydrophilic aromatics.

The Restek Biphenyl is the Right LC Column in Any Format:


Raptor SPP Columns: Premier performance columns that combine the speed of superficially porous particles (SPP or “core-shell”) with time-tested Restek Biphenyl selectivity.

Force FPP Columns: Long-lasting, reproducible, and fully scalable FPP (fully porous particle) columns that let you easily transfer methods across your entire lab, from trusted-but-aged HPLCs to cutting-edge UHPLCs.


Also Available

Ultra Columns: High-purity, type-B silica that minimizes activity and creates high-density bonding for reliable HPLC use.

Viva Columns: Rugged, spherical particles with a wide 300 Å pore size and narrow distribution that are designed for large-molecule separations.