How to Choose LC Columns for Different Applications

A liquid chromatography column is an instrument used for liquid chromatography analysis. Before choosing a column, first understand your own samples and impurities, their type structure, polarity, acidity and alkalinity, molecular weight, etc.

How to Choose LC Columns

  1. The sample is polar and weakly acidic:
    You can choose C18 at 100 Under the condition of an acidic aqueous solution, it is necessary to select a column that withstands 100% pure water and retains a good polarity for the polar compound.
  2. If the sample is too polar or too acidic:
    You can choose CN, NH2, or silica gel column. HILIC (Hydrophilic Chromatography), also uses a strong anion exchange chromatography column (the disadvantage is that the ion pair reagent has a long equilibrium time and the mobile phase pH requirement is relatively precise, otherwise it is difficult to repeat the experiment, and the ion pair reagent is difficult. Washed down, basically, the column with ion pair can not be used for other experiments)
  3. If the basic compound is too polar or too alkaline:
    You can choose a wide pH C18 column at high pH detection (the advantage is that the method development is simple, the disadvantage is that the current column of the technology to achieve this technology is relatively small, and the price is also high) or the use of HILIC column (silicone column used in reversed phase conditions, which is also very The method of detecting alkaline samples). Select a strong ion exchange column (the disadvantage is that it can not be used to analyze other samples, the pH of the mobile phase is relatively precise, otherwise it is difficult to repeat the experiment).
  4. If the sample is alkaline:
    You can choose a high-purity silica gel column (high-purity silica gel lacks metal impurities, and the silica gel end group is blocked) or some modified C18 columns (such as polar embedding technology or alkali deactivation technology, etc.), they will reduce the tailing of basic compounds, and generally choose neutral or alkaline conditions because this can increase the retention of basic samples.