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Chromolith® RP-18 Endcapped Monolithic HPLC Columns

Chromolith® RP-18 Endcapped Monolithic HPLC ColumnsMilliporeSigma offers a broad range of HPLC columns that are fully compliant with USP (United States Pharmacopoeia) specifications. L1 USP columns are described as octadecyl silane, chemically linked to porous silica or ceramic micro particles. Our high-quality L1 USP products deliver reliable, reproducible results – time after time. A perfect example is: Chromolith® RP-18 endcapped.

Race Through Separations

Produced from a continuous piece of porous silica using a sol-gel process, Chromolith® monolithic HPLC columns possess a defined bimodal pore structure with macro and mesopores in the micro and nanometer range. The high permeability and porosity of the silica skeleton, and the resulting low back pressure allow for more flexible flow rates than particle-packed columns. As a result, Chromolith® HPLC columns enable high-throughput analysis without loss of separation efficiency or peak capacity.

Features and Benefits

  • Classified as L1 USP column
  • High throughput at high flow rates
  • Possibility of flow gradients
  • Added column performance by column coupling
  • Rigid monolithic structure for longer column lifetime
  • Lower matrix sensitivity
  • Simple method transfer from particulate columns


High Throughput, Long Lifetime

Chromolith® RP-18 endcapped HPLC columns combine high throughput and lower matrix sensitivity with an extremely long column lifetime. Thanks to their high-purity silica base, they minimize the negative effects of trace metals. Furthermore, the columns are chemically modified with n-alkyl chains, which possess a high ligand density, and fully endcapped in order to reduce the effects of unmodified silanol groups.

High-Purity Alternative to Particulate Columns

The chemical basis of Chromolith® RP-18 endcapped columns – from starting materials to surface modifications – is identical to high-end, conventional packed columns. Hence, their selectivity is comparable to high-quality C18 endcapped reversed-phase particle packed columns. This allows the use of standard methods when developing new protocols.

Easy Transfer of Methods

Method transfer from particulate to monolithic Chromolith® columns is simple and seamless. This is because the chromatographic selectivity of Chromolith® columns is very similar to that of many modern particulate HPLC columns (e.g. Purospher®). Chromolith® columns are now included in the US Pharmacopoeia in categories L1, L3 and L7.

Chromolith® RP-18 Endcapped Products

Chromolith® Flash RP-18e, (L) 25 mm for Ultra-Fast Separation of Simple Mixtures

 Chromolith® Flash RP-18 endcapped is the fastest HPLC column on the market. Due to the very short length of the column, its number of theoretical plates is sufficient for easy separations.

Chromolith® SpeedROD RP-18e, (L) 50 mm for Fast Separation of Simple Mixtures 

These short, fast columns are not only perfect for rapid screening of samples during in-process controls, but also for laboratories specialized in research or organic synthesis (e.g. combinatorial chemistry).

Chromolith® SpeedROD RP-18e

Chromolith® Performance RP-18e, (L) 100 mm for Rapid Separation of More Complex Mixtures

This column is perfect for use as a routine analytical tool in quality control laboratories, or in research laboratories where more complex mixtures are being analyzed.

Chromolith® Performance RP-18e 

Separation of Carbidopa

Separation of Steroids

Chromolith® Performance RP-18e Validation Kit for Accurate Method Validation

The validation kit includes three columns from three different production batches, allowing you to easily compare batch-to-batch reproducibility and quality. This makes the validation kit an ideal tool for quality control and validation laboratories.

Chromolith® HighResolution RP-18e Improved Efficiency and Peak Shape for Dirty Samples

Standard Chromolith® columns have 2 μm macropores, and an efficiency equal to 4.5 μm particulate columns. These columns allow very high flow rates, extreme throughputs, and the analysis of relatively dirty samples. In contrast, Chromolith® HighResolution (HR) columns possess 1.15 μm macropores. This results in higher efficiency and improved peak shape. Although this causes higher back pressure, it is still less than half that of any particulate column of the same dimensions.

Chromolith® vs. Chromolith® HighResolution

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