During the use of the HPLC columns, if the pressure rises, one may be that the sintered filter is clogged. At this time, the filter should be replaced or taken out for cleaning; another possibility is that the macromolecule enters the column so that the stigma is Contamination; if the efficiency of the column is reduced or the peak of the chromatogram is deformed, the stigma may collapse and the dead volume will increase.
In the latter two cases, carefully unscrew the HPLC columns joints, remove the column head packing with clean small steel to a height of 1 to 2 mm (note that the contaminated packing is removed) and level the packing in the column. The column is then filled with the appropriate solvent-wet stationary phase (same as in the column), flattened, and the column fittings are tightened. After this treatment, the efficiency of the column is improved, but it is difficult to restore to the level of the new column.
Column failure is usually the end of the column. A short column (5 to 30 mm) with the same stationary phase as the analytical column is placed in front of the analytical column to protect and extend the life of the column. It is worthwhile to use a guard HPLC columns to lose some efficiency.
Usually, the column life is up to 2 years when used correctly. Silica gel-based fillers can only be used in the range of pH=2-9. After the column has been used for a period of time, some substances with strong adsorption may remain on the top of the column. In particular, some colored substances are more likely to see the filler adsorbed on the top of the HPLC columns.
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