“Diamond-Like Carbon Chromatography Columns”

A groundbreaking new product, now officially available!

September 15, 2023

What is a diamond chromatography column?

Is it related to actual diamonds?

Where does the brilliance on the surface of the diamond column come from?

What are the unique performance characteristics of a diamond column?

To answer these questions, let’s start with the most basic structure of a chromatography column: the chromatography packing material and the stainless steel column tube.

Traditionally, people have been accustomed to this combination and may not have seen any issues with it.

However, for the older generation of chromatography column research scientists, they are well aware that such a combination had inherent problems right from the beginning.

As Professor Zhang Weibing, the Chief Separation and Purification Scientist at Welch, puts it, “Everyone knows that the current liquid chromatography columns are packed with high-purity silica gel, how pure is it? Five nines! Such pure silica gel packing material, with very low metal impurities, is housed in a metal column tube. Do you think this is a suitable combination?”

However, high-performance liquid chromatography instruments operate at high pressures, and glass or PEEK (polyetheretherketone) column tubes cannot withstand such high pressures. Only metal column tubes are up to the task. But the use of stainless steel column tubes also brings its own set of issues, including non-specific adsorption in chromatography columns, long passivation times, increased relative standard deviation (RSD), and excessively wide peak widths.

During a visit to an aerospace facility, Professor Zhang made an unexpected discovery: the face masks worn by Chinese astronauts when entering space were coated with a special treatment. This coating was exceptionally hard and extremely hydrophobic. Inspired by this finding, Professor Zhang returned with great excitement and immediately organized a research and development effort, embarking on a journey to explore the “diamond column tube.”

From aerospace materials to chromatography columns, the diamond chromatography column can be considered a revolutionary breakthrough in the world of chromatography. It makes stainless steel column tubes a suitable match for high-purity silica gel!

Today, with the official launch of the diamond chromatography column, its appearance is truly remarkable. Thanks to the diamond coating technology, the chromatography column emits a dazzling array of colors, akin to the radiance of the dawn. In terms of practical application, the diamond column excels in the realm of large biomolecules, metal-sensitive small molecules, and particularly in UHPLC and LC/MS analyses where high sensitivity is crucial. The mass spectrometry peak signals are ten times larger compared to regular chromatography columns, and the peak heights are significantly disparate, akin to “towering peaks.

The Characteristics of Diamond Columns:

  1. Inert Column Tube: Effectively reduces non-specific adsorption.
  2. Improved Peak Shapes: Enhances separation efficiency.
  3. Flatter Baselines: Increases sensitivity.
  4. Significant Reduction in Sample Residues: Decreases column activation and passivation times, thereby improving experimental efficiency.

Welch is now introducing two specifications of diamond columns:

Serial NumberProduct NameSpecification
00237-33943Xtimate® DLC SEC-3004.6×250mm,5μm
00201-11910Ultisil® DLC UHPLC XB-C182.1×50mm,1.8μm

Let’s take a look at the performance of these two diamond pillars in practical combat scenarios below!

Separation and Detection of Bovine Serum Albumin

Chromatographic Conditions

ColumnXtimate® SEC-300
4.6×250mm, 5μm, Stainless Steel Column Tube
Xtimate® DLC SEC-300
4.6×250mm, 5μm, Diamond-Coated Column Tube
Mobile PhaseAnhydrous sodium dihydrogen phosphate 8.99g+
Anhydrous disodium hydrogen phosphate 10.65g to 1000mL water,
Adjust pH6.80
Detection wavelength215nm
Flow Rate0.35mL/min
Injection Volume5μL

Solutions Preparation

Sample Solution: Precisely weigh the appropriate amount of BSA and dissolve it in the mobile phase, diluting it to prepare a sample solution containing 0.1 mg per 1 mL.

Overlap chromatogram

Blue: Stainless steel column tube Red: Diamond column tube


● The chromatogram peaks on the diamond column exhibit a more symmetrical shape.

● The diamond column shows a higher response value, and there is a significant improvement in peak tailing.

To enhance sensitivity.

The detection of dexamethasone sodium phosphate
Chromatographic conditions

Instrument ModelAB Sciex TRIPLE QUAD 4500
ColumnUltisil® UHPLC XB-C18,
(2.1×50mm, 1.8μm, stainless steel column tube)
Ultisil® DLC UHPLC XB-C18,
(2.1×50mm1.8μm, diamond column tube)
Mobile PhaseA: 5mmol/L ammonium formate solution;
B: Acetonitrile-methanol (1:1)
Flow Rate0.2mL/min
Column Temperature30℃
Injection Volume2μL
Sample configuration100ng/mL

Elution program

Time(min)Mobile phase A(%)Mobile phase B(%)

Mass Spectrometry Conditions

Ion Source: Electrospray Ionization (ESI)

Scanning Mode: Positive Ion Scan

Detection Mode: Multiple Reaction Monitoring (MRM) Mode

Multiple Reaction Monitoring (MRM) parameters

Blue: Stainless steel column tube Red: Diamond column tube


● The diamond column minimizes non-specific adsorption on the chromatographic column to a maximum extent, achieving high-resolution separation, and demonstrating higher sensitivity and response values.

● The peak signals on the diamond column are approximately ten times larger, indicating a significant advantage of diamond-coated chromatographic columns for testing metal-sensitive compounds under liquid chromatographic conditions, providing higher sensitivity and superior performance.


  1. Recommended for the analysis of biomacromolecules, such as oligonucleotides, peptides, monoclonal antibodies, bispecific antibodies, ADCs, etc.
  2. Suitable for the analysis of small molecules prone to chelate with metals.
  3. Ideal for UHPLC or LC/MS analysis with high sensitivity requirements.
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