The most complete maintenance method of liquid chromatograph

Common problems in the use of liquid chromatography column
Liquid chromatography (LC) is an efficient analytical method, and the column is the "heart" of chromatographic analysis system. Due to the variety of samples to be analyzed and the complex sample matrix, the chromatographic column is easily contaminated by strong retention substances. These strong retention substances are usually difficult to elute. After several times of sample loading, they gather at the end of the column, block the sieve plate, and even interact with the filler, resulting in the denaturation of the packing, which will lead to the decrease of column efficiency, the decrease of resolution and the abnormal peak pattern. Therefore, it is necessary to maintain the column.
Maintenance of Yuexu technology liquid chromatography column
The chromatographic column needs to be maintained, but different manufacturers have different maintenance methods. Yuexu technology liquid chromatography column is recommended to be used in forward direction and back flush. Because the aperture of the sieve plate used at both ends of Yuexu's chromatographic column is the same, there will be no back flushing out the packing. When the sample analysis is finished, most of the pollutants are concentrated in the end of the column. At this time, if the backwash is carried out immediately, the service life of the column packing can be greatly prolonged.
How to recoil liquid chromatography column
The principle of column backwash in liquid chromatography is to wash with solvent with stronger elution capacity than mobile phase.
The reversed-phase chromatographic column (C18, C8) can be reversed washed with less polar solvent
Water → methanol → acetonitrile → isopropanol → dichloromethane → isopropanol → acetonitrile
The positive phase chromatographic column (SiO2, NH2, CN, diol) can be backwashed with solvent with larger polarity
Hexane → dichloromethane → ethyl acetate → isopropanol → acetonitrile → methanol
If there is buffer salt in the mobile phase and the column pressure rises abnormally during the operation sequence, the buffer salt will precipitate on the column bed. The following maintenance methods are recommended:
Wash 60 column volumes with methanol / water = 10 / 90 at 35 ℃ and column temperature;
Wash the column with methanol / water = 10 / 90 at a flow rate of 0.2ml/min overnight.
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