C18 HPLC Columns Using Guide
The life of the chromatographic column can be directly affected by using routine separation and analysis. In the daily use of C18 HPLC columns(ODS C18 HPLC Column, C18-Aqueous HPLC Column), samples and mobile phase were pretreated, but it was still difficult to completely avoid column pollution, fixed phase loss, hardening, column bed collapse, and column efficiency decline after using for a long time.
Renewable technologies of C18 HPLC columns
After contamination, the column can be rinsed with a suitable solvent to regenerate the column efficiency. Regeneration washing method: 60ml of methanol, trichloromethane, and methanol/water were respectively used to pass through the chromatographic column successively, followed by 100% methanol (60ml) to balance the chromatographic column and then seal.
Repair of C18 HPLC columns
When regeneration is ineffective or column pollution is serious, column repair can be adopted, but the column pollution depth shall not exceed 5mm.
The selection of C18 HPLC columns
1. The alkyl sealing filler can prevent the trailing phenomenon of alkaline compounds.
2. For columns with high carbon content, the retention value is increased.
3. The shorter columns
4. Small particle packing
5. Choose C18 HPLC columns with large pore size packing for the components with large molecular weight.
Chemical Properties of C18 HPLC Columns
The chemical properties of the chromatographic column could affect the performance of the C18 HPLC column.
1. Performance factors of C18 HPLC columns: bonding type
Single-tooth bonding can improve the mass transfer rate and accelerate column balance. Double tooth bonding can increase the stability of the column and increase the sample load.
2. Performance factors of C18 HPLC columns: carbon coverage
High carbon coverage improves resolution, but analysis takes longer. Low carbon coverage reduces running time.
3. Performance factors of C18 HPLC columns: sealing the end
The sealing end can reduce the peak dragging phenomenon caused by the reaction between the components to be measured and the residual acid silicon hydroxyl on the surface of the silica gel.
Use of C18 HPLC columns
Before use, it is better to test the performance of the column and save the results as a reference for future evaluation of column performance changes. The performance of the column may vary depending on the sample, mobile phase, column temperature, etc.
Since the column efficiency is a function of the mobile phase velocity in the column, different column efficiency can be obtained by using different velocities.