FAQ analysis and solutions about HPLC columns
1.The column pressure is too high, after a period of use.
Solution: First check whether the HPLC system is the cause. After eliminating the system cause, the reason is basically due to the accumulation of impurities in the column during the experiment. Try to improve the operating conditions. After the sample is finished, it should be rinsed off in time. For example, the mobile phase of the buffer salt must be washed with a high proportion of aqueous solution (such as 90%) and then stored with the organic phase.
Solution: First check whether the HPLC system is the cause. After eliminating the system cause, the reason is basically due to the accumulation of impurities in the column during the experiment. Try to improve the operating conditions. After the sample is finished, it should be rinsed off in time. For example, the mobile phase of the buffer salt must be washed with a high proportion of aqueous solution (such as 90%) and then stored with the organic phase.
2.Sieve plate blockage and column head collapse.
Solution: If it is determined that the filter screen of the column head is contaminated, the column can be flushed to normal pressure in the opposite direction with methanol, or the column head should be removed, the sieve plate should be carefully removed, and the solution should be sonicated for about 20 minutes with a 5% or so nitric acid solution. Then, it is sonicated with pure water for about 20 minutes and reloaded into the column.
Solution: If it is determined that the filter screen of the column head is contaminated, the column can be flushed to normal pressure in the opposite direction with methanol, or the column head should be removed, the sieve plate should be carefully removed, and the solution should be sonicated for about 20 minutes with a 5% or so nitric acid solution. Then, it is sonicated with pure water for about 20 minutes and reloaded into the column.
3.The packing of the column head is contaminated by the sample.
Solution: If it is determined that the packing of the column head is contaminated, remove the stud screws, dig out the contaminated packing in the front part of the column, refill with the same column packing. And after careful repair, reinstall the stud screws.
Solution: If it is determined that the packing of the column head is contaminated, remove the stud screws, dig out the contaminated packing in the front part of the column, refill with the same column packing. And after careful repair, reinstall the stud screws.
4.The salt in the buffer in the column encounters a high concentration of methanol or other organic solvent to form crystals and precipitate.
Solution: If it is determined to be salt crystals, rinse the column with 10% methanol/water to dissolve all the salt in the column, and then change the high concentration of methanol.
Solution: If it is determined to be salt crystals, rinse the column with 10% methanol/water to dissolve all the salt in the column, and then change the high concentration of methanol.
Notes
1. Whenever possible, the column bed must be kept dry, especially during the injection test and column flushing process, the mobile phase should not be left empty for more than 30 minutes. Otherwise, the column will dry up and can be discharged into a large amount of non-ejectable bubbles which even cause partial collapse or central cracking of the bed.
2. For use and storage, it is strictly forbidden to use force to absolutely prevent accidental violent impact or falling at high places. Otherwise, it will easily cause mechanical damage to the column bed, then there will be no regeneration.
3. When the column and the chromatograph are coupled, the valve or pipe must be cleaned.
1. Whenever possible, the column bed must be kept dry, especially during the injection test and column flushing process, the mobile phase should not be left empty for more than 30 minutes. Otherwise, the column will dry up and can be discharged into a large amount of non-ejectable bubbles which even cause partial collapse or central cracking of the bed.
2. For use and storage, it is strictly forbidden to use force to absolutely prevent accidental violent impact or falling at high places. Otherwise, it will easily cause mechanical damage to the column bed, then there will be no regeneration.
3. When the column and the chromatograph are coupled, the valve or pipe must be cleaned.
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