How to deal with the contamination of chromatographic column

In the daily use of chromatographic column, although the maintenance is strict and the sample and mobile phase are pretreated, it is still difficult to completely avoid the column from contamination, loss of stationary phase, hardening, collapse of column bed and decrease of column efficiency after a long time of application. Some of them can be repaired and partially recovered.
1. Column pollution regeneration technology
After the column is polluted, it can be washed with suitable solvent to regenerate the column efficiency. The conventional regeneration washing method of C18 column is: methanol, trichloromethane and methanol / water 60 ml respectively pass through the chromatographic column successively, and then use 60 ml of 100% methanol to balance the chromatographic column and then seal up. The column efficiency will recover to normal. If necessary, 0.05 mol / L H2SO4, 0.5 mol / L H3PO4 or 0.1 mol / L EDTA sodium salt are selected to wash the column according to the column pollution properties (such as organic pollution, salt pollution, etc.), and then wash with water, and then use 100% methanol to balance the chromatographic column and then seal up. For the seriously polluted C18 column, water, methanol, chloroform and ethane can be washed in sequence, and then washed once again. The solvent used for each time is 60 ml, not connected with the detector, and then sealed with a 100% methanol balanced chromatographic column.
2. Correction of column contamination
When the regeneration of column pollution is invalid or serious pollution is known, column repair can be used, but the depth of column pollution should not exceed 5 mm. The method is to dig out the contaminated part with a special shovel, and then mix the fixed phase and movable phase which are the same as the column filler to make slurry, and then carefully fill the slurry fixed phase into the excavated part (try to make the fixed phase added later close to the original tightness) and level the end face. If the pore size of the sieve plate at both ends of the column head is the same, the column can be inverted to use the general time. The intention is to recover the compactness of the column bed with the help of the scouring effect of the active phase.
3. Correction of column collapse
There are many reasons for column collapse. When the collapse is not serious, if the sieve plate aperture at both ends of the column is the same, the column can be inverted and used for general time to recover the performance. When the subsidence is serious (about 5 mm), the correction method of column pollution can be used to repair.
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