How to Extend the Life of HPLC Columns?
- Clogging of the column
Any particulate matter from the mobile phase or sample will contaminate the column screen and some particles may also migrate into the column packing, which will result in an increase in column back pressure. This puts more pressure on the pump and can cause the column to settle, creating voids and thus leading to peak splitting. HPLC columns encounter many different substances during use, such as salts in the buffer or impurities in the mobile phase and sample, that may have less or more retention than the analytes being separated. These unwanted interferences, if observed by the detector, can manifest themselves as ghost peaks, speckles, baseline reversals or even negative peaks. Absorbed impurities may negatively affect the retention mechanism (shorten retention) or begin to act as a new stationary phase (increase retention).
The HPLC column is a critical component of the HPLC system and requires careful handling and protection. the efficient operation of the HPLC system depends on the mobile phase and sample being free of chemical impurities or solid suspensions. Frequent column changes are costly, so your goal should be to maximize the life of the column to obtain the desired accuracy and consistency of results every time.
- Extend HPLC column service life
The most direct solution to extend the life of the column is to use a protective column. Protective columns will filter all particles and accumulate non-specific adsorbed substances, and will also extend the life of analytical columns used at slightly alkaline pH. However, it is important to note that the particles of the guard HPLC column should preferably be the same size as those of the analytical column, the same type of material, and the pressure specification should match that of the main column. What is more, when is it better to replace the guard column? The general recommendation is to replace the guard column when the nature of the sample changes, when the back pressure increases by about 10-15%, or on a scheduled/timed basis (e.g., every 200-500 injections – depending on the injection volume and the purity of the sample). Familiar to any analyst working in chromatography, a guard column is a typical chromatography consumable that is mounted in front of the main column and protects it from impurities from the sample, matrix or eluate by collecting and trapping particles or irreversibly bound material. It extends the life cycle of the more expensive main column and is replaced more frequently as a less expensive component.
- Use notes of protection column
Pay attention to the use of each operation in accordance with the labeled direction. Not to use the protective column will make the analytical column or preparation column directly contaminated, thus shortening its actual service life. Select the protective column volume can be 5~10% of the column volume. Select the packing of the core of the protective column preferably the same as the packing inside the chromatographic column.
The protective column provides convenient, economical and effective protection for the column, extending the life of the liquid chromatography column and ensuring the reproducibility of the analytical results. With the increase of usage time, the separation efficiency of HPLC column decreases and the column pressure increases, which is mainly caused by the contamination of a small amount of chromatographic silica packing in the inlet section of the column, while the whole column bed of the column is not destroyed. The use of column protection column is equivalent to adding an extra section of packing in front of the column, which plays the role of protecting the whole column.