NH2 HPLC Columns
NH2 HPLC columns can be used in the positive phase or in the negative phase, but it should be noted that the positive phase solvent and the negative phase solvent are usually not mutually soluble. New NH2 HPLC columns are preserved in the positive phase environment under normal circumstances.
Preservation of NH2 HPLC column
For the reversed phase, it can be preserved with 95% methanol or acetonitrile for short term storage. Methanol should be replaced successively with isopropanol and chloroform, and finally preserved with n-ethane for long term storage.
The usage of NH2 HPLC column
1.For positive phase usage
It is not suitable to analyze the compounds containing aldehyde compounds, carbonyl compounds and reducing sugar. The mobile phase shall be completely degassed and shall not contain carbonyl compounds or peroxides. When replacing the mobile phase of NH2 HPLC columns, ensure that the new mobile phase is mutually soluble with the original column storage solution.
2.For reversed phase
The ideal PH range is 3.0-7.0. The lower the PH is the more risk of hydrolysis. If there is buffer salt in the mobile phase, use the same proportion mobile phase without buffer salt to avoid the precipitation of buffer salt.