Make your selection from below:

- Packing Material Differences - Hypersil
- Packing Material Selection - Inertsil
- Fastener Seperations: Resolution
vs. Column Length
- Kromasil
- Sensitivity/Solvent Sonsumption: 3mm vs. 4.6mmID - Monitor
- Column Selection Criteria - Nucleosil
- pH Protection: Why use Gaurd Cartridges? - Resiasil
- USP Categories For HPLC Columns - Spherisorb

Packing Material Differences

Silica-based packing materials that belong to the same category (i.e.C18/USP L1) do not necessarily provide equal chromatography when made by different manufacturers.

For instance, two different 5m C18 150x4.6mmID columns used for the same method may provide quite different results in terms of resolution, selectivity, efficiency, and peak shape due to the following material differences:

Silica Structure: Surface Area Pore - Volume Pore- Size/Distribution - Particle Size/Distribution

Silica Chemistry: Silanol Frequency - Silanol Types - Silica Surface Acidity

Bonding Chemistry: Type of Functional Group - Method of Bonding - Bonded Group Concentration

Minor differences between packing materials can create major differences in chromatography, but the following relationships generally apply for reversed phase chromatography:

Increased Surface Area ® Increased Retention Times

Increased Carbon Load ® Increased Retention Times

Lower Surface Acidity ® Improved Peak Symmetry

Packing Material Selection

If a specific material is specified for your method, choose it from your preferred supplier. Otherwise, start out with a column from a suggested category (C8, C18, etc.) in a standard size such as a 150 x 4.6mm.

Once you have optimized your method for this first column, you can determine what parameters or conditions you may be able to change to improve your chromatography.

For general changes in column selection, refer to the next section, Column Selection Criteria. If your selection requires knowledge of specific differences between packings, call us for technical assistance.

Step1: Select Column Criteria

Brand Name: Hypersil, Inertsil, Spherisorb, Kromasil, Nucleosil, etc.

Classification: Hypersil BDS, Inertsil ODS-2, Kromasil 100Å, Nucleosil 300-5, etc.

Bonded Phase: C8, C18(ODS, ODS-2), Phenyl, etc.

Material Lot#: It is provided with each Column Engineering column delivered.

Column Size: 150 x 4.6mm, 150 x 3.9mm, 250 x 4.6mm, etc.

Step2: Select Column Source

Choose a column manufacturer that understands packing materials from the ground up. As mentioned, many column suppliers do not control or manufacture their own base materials. They purchase bulk packings and pack the columns. This makes a world of difference in having control over the critical supply of base material in terms of choices available, consistency, and uninterrupted supplies. Column Engineering is a bulk silica manufacturer and a great source for all you column supply needs.

 

 

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