The choice of HIC gel-The different commercially available HIC matrix are given in Table 31.1. Choosing a suitable HIC matrix is essential to achieve best result. The strength of the binding of analyte on a HIC column is governed by the length of the aliphatic linear ligand. Matrix with aromatic ring containing ligand makes additional Π-Π interaction and they will bind analyte more strongly than same number of carbon aliphatic ligand. In addition, presence of Π-Π interaction gives selectivity as well, such as ring containing aromatic ligand, phenylalanine. At last, ligand density plays a vital role in the strength of binding of an analyte to the matrix. Hence, these points should be consider to choose a suitable matrix for purification.

Figure 31.3: Principle of the hydrophobic interaction chromatography.