Comparison of the Properties of 3-Aminopropyl Silica with Different Nitrogen Content in HILIC Mode

Four amino phases representing 3-aminopropyl silica gel batches with different numbers of grafted functional groups are compared. To evaluate the chromatographic properties of the adsorbents, the Tanaka test for hydrophilic stationary phases is used and the retention of polar substances of various classes in the HILIC (hydrophilic) mode is studied. It is shown that even small changes in the nitrogen content between different batches of 3-aminopropyl silica gel have a significant effect on the retention of polar analytes. The hydrophilicity of a substrate is shown to have the greatest effect on its chromatographic behavior, and its evaluation using the Tanaka test is the basis for selecting a batch to separate specific classes of polar substances or for further modification to obtain new phases.