The Restek Biphenyl: Leading Resolution in LC since 2005

  • Separates a wider range of compounds than other phenyl and C18 chemistries.
  • Increases sensitivity and selectivity in LC-MS while using simple, MS-friendly mobile phases.
  • Restek’s most popular LC phase—available on traditional FPP and SPP core-shell silica.
The Restek Biphenyl - Leading Resolution in LC

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 and other phenyl chemistries. As a result, rugged Biphenyl columns are extremely useful for fast separations—even with isobars—in drug, metabolite, and other 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 ten years of unrivaled performance, Restek's time-tested Biphenyl has been proven to be the ideal column for clinical diagnostic, pain, pharma, 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.

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

Raptor SPP Columns: A new species of column that combines 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.

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.


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. Learn more at


  • 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.

Raptor Biphenyl LC カラム (USP L11)

  • 薬物や代謝物分析といった生化学分野のアプリケーションに最適です。
  • C18や他のフェニルカラムでは溶出が早すぎたり、分離が難しい化合物に対する選択性や保持が向上。
  • イオンサプレッションを回避し、シンプルで質量分析計に優しい移動相が可能に。
  • Restek のコアシェルタイプRaptor LC カラム の粒子径サイズは2.7および5µm

Force Biphenyl LC カラム (USP L11)

・ 薬物や代謝物分析など、バイオアナリシスアプリケーションに最適。
・ C18や他のフェニル系カラムでは分離や保持が難しい化合物に対し、選択性と保持が強まる。
・ 質量分析計に適した移動相が使用できる。
・ Restekで最も定評のある固定相。

Ultra Biphenyl カラム (USP L11)

粒子径:3 μmまたは5 μm、球状
エンドキャップ: あり
温度上限: 80℃

Ultra Biphenyl Prep カラム

  • Easy scale-up from Restek analytical columns.
  • Popular bonded phases.

Viva Biphenyl カラム (USP L11)

Particle Size: 5 µm, spherical
Pore Size: 300 Å
Carbon Load: 7%
End-Cap: yes
pH Range: 2.5 to 8
Temperature Limit: 80 °C
USP Phase: L11
Phase Category: phenyl
Ligand Type: Biphenyl

USLC Method Development Toolbox

All the Right Tools—All in One Toolbox

  • Ultra Selective Liquid Chromatography (USLC) method development toolbox contains all four USLC stationary phases in one convenient package.
  • Available for UHPLC (1.9 μm) and HPLC (3 or 5 μm) in 50, 100, or 150 mm lengths.

EXP ダイレクト コネクト ホルダー


Raptor EXP ガードカラムカートリッジ


Force EXPガードカラムカートリッジ

・ 移動相の配管を外さずにカートリッジ交換ができます。手締めタイプで工具も必要ありません。
・ 特許取得のチタンハイブリッドフェラルは高圧下でのシール性を損なうことなく再利用可能です。
・ 自動調整機能により、あらゆる10-32 Female portに対しZDV(Zero dead volume)接続ができます。

HPLC & UHPLC用EXP フィッティング 10-32フィッティング、 1/16" 配管用

EXP Hand-Tight Fittings

  • Hand-tight fitting style achieves effortless HPLC sealsno tools needed for a 8,700+ psi seal.
  • Both hand-tight and hex-head styles wrench-tighten for reliable UHPLC use up to 20,000+ psi!
  • Patented ferrule can be installed repeatedly without compromising high-pressure seal.
  • Hybrid design combines the durability of titanium with the sealing ability of PEEK.
  • Cutting-edge system provides ZDV (zero dead volume) connection to any 10-32 female port.
  • Compatible with 1/16" PEEK and stainless steel tubing.

Ultra ガードカートリッジ

Particle size: 5 µm spherical
Pore size: 100 Å

For a detailed description of the stationary phase in this guard cartridge, see the product page for an analytical column with the same silica and stationary phase (e.g., Ultra C18).

Viva ガードカートリッジ

Particle size: 5 µm spherical
Pore size: 300 Å

For a detailed description of the stationary phase in this guard cartridge, see the product page for an analytical column with the same silica and stationary phase (e.g., Viva C18).

UltraShield UHPLC プレカラム フィルター

  • Cost-effective protection for UHPLC systems.
  • Reliable way to extend column lifetime.
  • Universal fitconnects easily to any brand column.
  • Leaktight to 15,000 psi (1,034 bar).
  • 0.5 µm or 0.2 µm stainless steel frit in a stainless steel body with PEEK ferrule.

Overcoming the Effects of Highly Organic Protein Precipitation Extracts on LC Peak Shape Using Direct Injection

Protein precipitation is frequently used to minimize matrix impact when analyzing biological samples. However, the effects of highly organic protein precipitation sample extracts on LC peak shape can negatively impact accurate quantification. Dilution or further sample preparation steps are often used to minimize these effects; however, here we show that direct injection of sample extracts is a viable option that can be used to prevent peak distortion, while avoiding the time and variability associated with additional sample preparation.


High-Throughput Analysis of Immunosuppressive Drugs from Whole Blood by LC-MS/MS

The success of organ transplant therapy depends in large part on the accurate and timely analysis of immunosuppressive drugs. In this study, we developed a fast, accurate method for cyclosporin A, tacrolimus, sirolimus, and everolimus in whole blood. The method pairs a single protein precipitation step with LC-MS/MS analysis using a Raptor Biphenyl column. A fast, 3-minute analysis time was obtained with no interference from matrix components. Excellent results were obtained for linearity, robustness, accuracy, and precision, demonstrating that the method is suitable for high-throughput therapeutic drug monitoring.



As the demand for testing of pain management drugs increases, many laboratories are turning to LC-MS/MS for its increased speed, sensitivity, and specificity. The methods shown here use a Raptor™ Biphenyl column because it provides fast, accurate analysis of 231 drugs and drug metabolites.


Novel Column Chemistry—High Impact, Low Cost Technology

Novel column chemistries are a simple change in an already budgeted consumable that can lead to optimized and more reliable methods—giving a fast return on a minimal investment.


The Role of Selectivity in Liquid Chromatography Method Development

Dr. Schug, Associate Professor and Shimadzu Distinguished Professor of Analytical Chemistry in the Department of Chemistry and Biochemistry at The University of Texas at Arlington, discusses the role of column selectivity in liquid chromatography method development.


Increase Data Quality for Sulfonamide Residue Analysis by HPLC and UHPLC Using Unique Biphenyl Column Selectivity

The unique selectivity and high retention of Biphenyl columns produce complete separation of sulfonamide residues and benefit both UV and MS detection. In addition, Biphenyl columns in a UHPLC format allow faster sample throughput when testing for these antibiotics.


A Rapid and Sensitive LC-MS/MS Method for the Analysis of Three Forms of Thyroid Hormones Using Raptor™ Biphenyl LC Columns

The Raptor Biphenyl column is excellent for rapid and sensitive analysis of thyroid hormones. With the method described here, concentrations of thyroid hormones as low as 2 pg/mL (T3) or 5 pg/mL (T4 and rT3) can be determined with less than 3.5 minutes of total analysis time. The analytical method is thus applicable to the clinical analysis of free thyroid hormone at low pg/mL levels.

PDF Document

Raptor Biphenyl LC Columns Brochure

Raptor LC columns combine the speed of superficially porous particles (i.e., SPP or “core-shell”) with the resolution of highly selective USLC technology. Featuring Restek's most popular LC stationary phase, the rugged Raptor Biphenyl is extremely useful for fast separations in bioanalytical testing applications like drug and metabolite analyses, especially those that require a mass spectrometer (MS). (PDF - 6MB)

PDF Document
PDF Document
PDF Document

Raptor Biphenyl LC Columns Sales Sheet

Fast, Rugged Raptor Columns with Time-Tested Selectivity: The industry-leading Biphenyl, first introduced by Restek in 2005, is our most popular LC stationary phase because it is particularly adept at separating compounds that are hard to resolve or that elute early on C18 and other phenyl chemistries. As a result, the rugged Raptor Biphenyl column is extremely useful for fast separations in bioanalytical testing applications like drug and metabolite analyses, especially those that require a mass spectrometer (MS). (PDF - 4MB)

PDF Document

Force LC Columns Brochure

Force LC columns are long-lasting and reproducible, even under the stress of UHPLC. Premium quality is backed by the strength of our 100% Pure Satisfaction guarantee. And perhaps most important, Force LC columns are fully scalable between 3 or 5 µm HPLC and 1.8 µm UHPLC, so you can easily transfer and optimize methods without extensive calculations. (PDF - 5MB)

PDF Document