Use and maintenance of liquid chromatography columns

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I just came across something on an information website and would like to share it with everyone: 1. Use of chromatography columns – Reverse-phase chromatography columns are generally stored in methanol or acetonitrile. Be sure to check before use that the mobile phase being used is miscible with methanol or acetonitrile. During storage, the chromatography column may dry out due to the evaporation of solvents; therefore, before using it for analysis with a mobile phase, the column should be equilibrated with methanol or acetonitrile in an amount equal to 10–20 times the column volume. If the mobile phase used contains buffer salts, care should be taken to use water as a transition, rather than directly mixing the organic solvent with the buffer salts. Pay attention to this when rinsing the column after the test is completed. Another thing to note is that it is best not to rinse the chromatography column with pure water. For non-polar columns, such as C8 and C18, pure water cannot wet the surface of the packing, which causes the carbon chains to be displaced and leads to a decrease in column efficiency. Furthermore, when analyzing samples, since pure water cannot wet the surface of the packing to form a water film, the samples are not retained, which leads to reduced separation efficiency and poor reproducibility; therefore, for ordinary C8 and C18 columns, the proportion of organic solvent should not be less than 5%. II. Regeneration of the chromatography column: The volume of solvent used to flush the chromatography column during regeneration can be referred to in the table below. The regeneration process and the sequence of solvent flushing are also indicated in the table below. III. Maintenance of the chromatography column: 1. Try to use a pre-column or guard column to protect the chromatography column ； 2. The pH range for most chromatography columns is 2–8; try to avoid using them outside this range ； 3. Avoid sudden changes in the composition or ratio of the mobile phase ； 4. The mobile phase must be filtered and degassed before use ； 5. If a polar or particulate buffer is used as the mobile phase, the chromatography column should be thoroughly rinsed after the experiment. This post was last edited by fengxuemei on 2009-3-30 17:53.]