Cleaning Solvent for HPLC Columns
An HPLC column is a column packed with a stationary phase to separate the mixed components. The correct use and maintenance of HPLC columns is important, and a slight carelessness will reduce column efficiency, shorten service life and even damage. During the chromatographic operation, the following issues need to be noted to maintain the HPLC column.
Cleaning solvent for HPLC columns
The silica gel column was washed sequentially with n-hexane (or heptane), dichloromethane and methanol, and then washed sequentially in the reverse order. All solvents must be strictly dehydrated. Methanol can wash away residual strong polar impurities, and hexanes reactivate the surface of the silica gel. The reverse phase column was washed successively with water, methanol, acetonitrile, methyl chloride (or chloroform), and washed sequentially in the reverse order. If the mobile phase for the next analysis does not contain buffer, then the final rinse with water can be omitted. Methyl chloride can wash away residual non-polar impurities, and repeated injections of 100-200 μl of tetrahydrofuran several times in methanol (acetonitrile) can help remove strong hydrophobic impurities. A mixed solution of tetrahydrofuran with acetonitrile or methanol can remove lipids. Sometimes dimethyl sulfoxide is injected several times. In addition, protein contamination was removed by gradient elution with acetonitrile, acetone and trifluoroacetic acid (0.1%).
The cation exchange column can be washed with a dilute acid buffer, and the anion exchange column can be washed with a dilute alkali buffer to remove the salt with strong exchangeability, and then water, methanol, dichloromethane (removing the organic matter adsorbed on the surface of the stationary phase), methanol, and water in turn. rinse.
After each work, it is best to rinse with a highly eluting eluent. For example, the ODS column should be rinsed to baseline with methanol. When using a salt buffer solution as the mobile phase, rinse with a salt-free mobile phase after use. Compounds containing halogen elements (fluorine, chlorine, bromine) may corrode stainless steel pipes and should not be in contact with them for long periods of time. If the column is not used frequently on the HPLC instrument, it should be turned on for 15 minutes every 4~5 days.