Seeking help with molecular sieve chromatography

There can be many reasons for the decline in the efficiency of molecular sieve chromatography columns; common ones include sample residue and column lifetime. It is recommended that you check from the following aspects: 1. Sample processing: Verify whether the quality of the sample and the processing methods are correct, to ensure that there are no impurities or residues in the sample. 2. Column lifespan: If the column has been in use for a long time, it may need to be replaced. It is recommended to use columns from reputable brands such as Waters and Agilent. 3. Mobile phase: Check whether the composition of the mobile phase is correct, and whether there are any oxidants, hydrochloric acid, etc.; also pay attention to the settings for flow rate and gradient conditions. 4. Cleaning: Try reverse washing and forward washing of the column to remove any possible impurities. 5. It is necessary to carry out timely maintenance of the column after each experiment to keep it in good condition. It is also recommended that you perform column retention before the column efficiency declines, and wash the column with an eluent to eliminate the impact of possible impurities. If the above methods do not work, you may consider contacting the manufacturer for technical support. .

Is there such a thing as aging the separation column for liquid chromatography columns?

This post was last edited by qugd on 2023-5-31 at 20:29. Since it is exclusion chromatography, the column packing material is usually one with a certain degree of porosity. Such packing material has the property of eluting from the column system first those components that are smaller than the pores in the packing. After analyzing peptides and proteins, the column efficiency decreases, as some large molecular components occupy the larger pores of the packing material, thereby reducing the retention and separation efficiency for these large molecules such as peptides and proteins. However, after the column is left unused for a while, these peptides and proteins degrade or break down into smaller molecules under the influence of the eluent; as a result, the pores that were previously occupied by these large molecules become available again, and thus the column efficiency is restored to some extent or even completely. If size-exclusion chromatography is operated continuously, it is advisable to have one or two additional separation columns installed. A similar phenomenon is also observed in size-exclusion chromatography for the analysis of some synthetic polymers. Just my humble opinion