Bidentate C18™ - Unique Reversed Phase HPLC Columns

Extremely Stable, Highly Hydrophobic C18 for Demanding HPLC Conditions

TYPE‑C™ Silica Hydride | 100% Aqueous or Non‑Polar Solvents | RP, NP & ANP/ HILIC

Bidentate C18™ HPLC columns are among MICROSOLV’s most durable and uniquely engineered reversed‑phase columns, designed to operate under conditions that quickly degrade conventional C18 phases. Built on TYPE‑C™ silica hydride technology, this stationary phase delivers exceptional chemical stability, extreme hydrophobicity, and unmatched solvent flexibility.

Bidentate C18™ columns are especially well suited for harsh pH conditions, paired‑ion chromatography (PIC), 100% aqueous mobile phases, and non‑polar solvent systems, making them a powerful problem‑solving tool for difficult separations.

Proprietary Bidentate C18 Chemistry on TYPE‑C™ Silica

Bidentate C18™ columns are manufactured using state‑of‑the‑art high‑purity silica (available in 4 µm or 2.2 µm) with a straight‑chain C18 hydrocarbon ligand. What makes this phase exceptional is its bidentate bonding:

• The C18 ligand is bonded through two separate silicon–carbon (Si–C) attachment points

• The ligand is attached directly to a silica hydride surface

• No traditional silanol‑based bonding chemistry is involved

This dual attachment dramatically increases mechanical and chemical stability, resulting in an extraordinarily long column lifetime, even under aggressive mobile‑phase conditions.

Extreme Stability Under Harsh Conditions

Because of the direct Si–C bidentate bonding and TYPE‑C™ silica hydride base, Bidentate C18™ columns are:

• Highly resistant to hydrolysis

• Stable at very low pH

• Compatible with paired‑ion (PIC) reagents

• Unaffected by conditions that strip conventional C18 phases

The phase is non‑end capped, yet remains extremely stable—eliminating concerns about end‑cap bleed or degradation.

Exceptional Hydrophobic Retention with Less Water

Bidentate C18™ is an extremely hydrophobic phase, yet it requires less water to retain hydrophobic compounds than traditional C18 columns. This property provides several practical advantages:

• Easier gradient method development

• Improved retention control

• Simplified mobile‑phase design

• Better reproducibility in difficult methods

These characteristics make the column particularly attractive for gradient RP‑HPLC and complex method optimization.

Multi‑Mode Operation: RP, NP, and ANP

One of the most distinctive features of Bidentate C18™ is its ability to function in multiple chromatographic modes:

Reversed‑Phase (RP)

Performs as an exceptionally stable and highly hydrophobic C18 phase, even under extreme pH or solvent conditions.

Aqueous Normal Phase / HILIC (ANP/ HILIC)

Like all TYPE‑C™ columns, Bidentate C18™ does not form a water shell, enabling ANP‑style retention mechanisms unavailable to conventional silica‑based C18 columns.

Normal Phase (NP)

When operated in non‑polar solvents, Bidentate C18™ exhibits an unusual NP separation mode, allowing separation of water‑labile compounds without degradation—something that often occurs on traditional silica columns.

Ideal for Water‑Labile and Challenging Compounds

Because the TYPE‑C™ surface does not adsorb water, Bidentate C18™ columns are uniquely suited for:

• Water‑sensitive analytes

• Compounds unstable on silica

• Separations requiring non‑polar solvents

• Harsh chemical environments

This makes the column a strong choice for problem compounds that cannot be handled by ordinary reversed‑phase columns.

Key Features and Benefits

• TYPE‑C™ silica hydride stationary phase

• Bidentate C18 ligand with two Si–C bonds

• Extremely stable and long‑lasting column chemistry

• Operates in RP, NP, and ANP modes

• Compatible with 100% aqueous or non‑polar solvents

• Stable at very low pH

• Excellent for paired‑ion chromatography (PIC)

• No end‑capping and no end‑cap bleed

• Unique selectivity not achievable with conventional C18 columns

Typical Applications

• Harsh pH reversed‑phase methods

• Paired‑ion chromatography (PIC)

• Water‑labile compounds

• Highly hydrophobic analytes

• Difficult separations unresolved by standard C18

• Method development under extreme conditions

• Analytical and advanced research HPLC

Additional Resources

• View Bidentate C18™ HPLC column specifications

• Learn more about TYPE‑C™ silica hydride HPLC columns

• How to use Bidentate C18™ HPLC columns

Column Protection Recommendation

Important: MICROSOLV technical support strongly recommends using the Cogent Column Filter, which is included with each column, whenever possible. Column filters help protect against particulates, extend column lifetime, and maintain consistent chromatographic performance.

👉 Learn more about the Cogent Column Filter for HPLC column protection