The chromatographic column is the most important part of the high-performance liquid chromatograph, and the quality of the column directly affects the analysis and detection of the target compound. However, in high-performance liquid chromatography analysis, column clogging is prone to problems such as excessive system pressure, low peak efficiency, peak tailing and broadening, column contamination and damage, ghost peaks, and other problems. The internal causes of these problems are silicon hydroxyl Dead adsorption, the presence of heavy metals, carbon loss, salt precipitation in the buffer, and drying of the chromatographic column.

1.Dead adsorption of silanol:

Due to the presence of silica gel hydroxyl groups on the surface of the silica gel particles of the chromatographic column, the sample components are distributed between the mobile phase and the stationary phase, and between the mobile phase and the silicon hydroxyl groups, that is, there is a double distribution effect. The adsorption of sample components by silanol is called dead adsorption or non-specific adsorption. When the adsorption of silanol to the sample components approaches saturation, the efficiency of the column decreases, leading to peak tailing and broadening.

2. The existence of heavy metals:

No matter how high the purity of the silica gel particles of the chromatographic column is, no matter how it is processed, heavy metals will remain on the surface of the silica gel particles in the form of metal oxides. These metal oxides easily form chelates with other compounds, causing them to be oxidized, producing asymmetric peaks or tailing peaks.

3. Carbon loss:

After long-term use of the stationary phase, some carbon chains will be eluted by the mobile phase and flow out of the column with the mobile phase, causing carbon loss.

4. The precipitation of salt in the buffer:

During chromatographic analysis, the mobile phase sometimes contains a buffered saline solution. After the analysis, if the aqueous phase mobile phase with a certain ratio is not used for flushing, and the pure organic phase is used for flushing, the organic phase in the column's microenvironment is high and the aqueous phase is low. At this time, the buffered salt solution in the mobile phase is prone to salt precipitation, blocking the column, increasing the column pressure, and decreasing the column efficiency.

5. The chromatographic column is dry:

If the chromatographic column is improperly stored, the storage solution in the chromatographic column is completely volatilized, and the inside of the column becomes dry, which will damage the chromatographic column and affect the separation effect.