Effect of mobile phase composition on retention of 3 compounds on Obelisc R

This application shows the effect of mobile phase composition on retention of acidic, basic and neutral compound. Retention of basic and acidic compounds is controlled by buffer pH and concentration, while retention of neutral compound is controlled by the amount of acetonitrile. Buffer pH changes not only ionization state of ionizable basic and acidic compounds, but ionization state of trimodal stationary phase Obelisc R. Available detection techniques include UV, ELSD, LC/MS, and Corona.


Column Obelisc R, 4.6×150 mm, 5 µm, 100A
Mobile Phase MeCN/H2O
Buffer AmAc
Flow Rate 1.0 ml/min
Detection 250



Class of Compounds
Acid, Hydrophilic, Neutral, BasicIonizable
Analyzing Compounds Benzonitrile, Benzoic Acid, Benzylamine


Application Column

Obelisc R

SIELC has developed the Obelisc™ columns, which are mixed-mode and utilize Liquid Separation Cell technology (LiSC™). These cost-effective columns are the first of their kind to be commercially available and can replace multiple HPLC columns, including reversed-phase (RP), AQ-type reversed-phase, polar-embedded group RP columns, normal-phase, cation-exchange, anion-exchange, ion-exclusion, and HILIC (Hydrophilic Interaction Liquid Chromatography) columns. By controlling just three orthogonal method parameters - buffer concentration, buffer pH, and organic modifier concentration - users can adjust the column properties with pinpoint precision to separate complex mixtures.

Select options
Application Analytes:
Benzoic Acid

Application Detection:
UV Detection
SIELC Technologies usually develops more than one method for each compound. Therefore, this particular method may not be the best available method from our portfolio for your specific application. Before you decide to implement this method in your research, please send us an email to research@sielc.com so we can ensure you get optimal results for your compound/s of interest.