Monolithic silica technology: A new age in chromatography. Chromolith® columns are based on silica so existing methods can be easily transferred with only minimal investment in new method development work. 'Sol-Gel' technology allows highly porous monolithic rods of silica to be formed. These feature a bimodal pore structure provides a unique combination of macropores and mesopores.

• Due to their extremely high porosity, very high flow rates can be used with low pressures
• Reduces separation time for high speed analysis
• Long column and HPLC system lifetime
• Several hundred scientific papers published

Macroporous structure: Each macropore is, on average, 2 μm in diameter and, in total, forms a dense network of pores through which the eluent can rapidly flow. This dramatically reduces separation times.
Mesoporous structure: These mesopores form a further fine porous structure (13 nm) of the column interior creating a very large surface area over which adsorption of target compounds can occur. This unique combination of macropores, that allow rapid transit of the eluent and mesopores which create a large surface area, mean that Chromolith® columns can provide excellent separations in a fraction of the time a standard column will take. Separations, which previously may have taken up to 30 minutes, can now be performed in a few minutes.

Chromolith® SpeedROD RP-18e endcapped: Acceleration of the analysis process has become one of the most important issues in high performance liquid chromatography. High throughput analysis, using conventional particle-packed columns, has always been a compromise between column efficiency and pressure drop. The demands of the pharmaceutical industry, especially in the field of drug discovery, where the number of samples is constantly increasing, is clearly focused on new methods and tools to dramatically reduce the time of analysis and significantly increase productivity. This cannot be sufficiently realised by using particulate HPLC columns due to the problem of high column back pressure associated with small silica particles. An answer to this 'high throughput' demand is the Chromolith® SpeedROD column, which opens the door to an era of chromatographic high speed separations. Chromolith® SpeedROD RP-18e possesses a selectivity comparable to common C18 reversed phase columns, providing the user with an excellent tool to solve separation problems.

Chromolith® Performance RP-18e endcapped: For high speed analysis, just like the Chromolith® SpeedROD columns, but with a higher separation efficiency due to the 100 mm double-column length. Chromolith performance is the best tool for the scientist who wants to combine rapid analysis with the separation performance of a true analytical column. Even more impressive, is that by using a simple column coupler it is possible to further increase the plate count by coupling several columns in series. This creates a column with a theoretical plate count which is significantly higher than any particulate column available, while still producing pressures well below the HPLC system limit. This added column performance is the key to solving even the most critical separation problems where resolution is often the limiting factor.

Chromolith® Flash RP-18e endcapped: Faster than modern high speed columns (typical column length of 50 mm), but with a separation efficiency that is still better than a normal guard column. At 25 mm long, the number of theoretical plates is sufficient for easy separations. The major focus of this column is clearly speed of analysis, since it provides the chromatographer with the fastest HPLC column on the market.

Chromolith® RP-18e columns: Technical information:
Silica type: High purity
Selectivity equivalent to: L1 (USP)
Macropore size: 2 μm
Mesopore size: 13 nm
Pore volume: 1 ml/g
Surface area: 300 m²/g
Carbon content: 18%

For more information and the latest applications contact Avantor to receive a copy of the Merck ChromBook.