HILIC Separation of Common Preservatives – Citric Acid, Ascorbic Acid and EDTA

Citric acid, ascorbic acid, and EDTA are commonly used in food and pharmaceutical industry as preservatives. These compounds are very polar in nature. They are weak organic acids with limited UV activity. Retention and separation is achieved on HILIC mixed-mode Obelisc N column. All three compounds are retained by combination of strong HILIC and strong anion-exchange mechanisms. Separation can be monitored by ELSD, LC/MS, UV or Corona CAD. In contrast to other HILIC column, Obelisc N has two ionizable groups basic and acidic which provide ion-exchange interaction in addition to hydrophilic interaction. This allows to use less acetonitrile for HILIC separation.


Column Obelisc N , 4.6×150 mm, 5 µm, 100A
Mobile Phase MeCN/H2O
Buffer AmAc pH 4.0
Flow Rate 1.0 ml/min
Detection ELSD



Class of Compounds
Acid, Vitamin B₆, Hydrophobic, Ionizable
Analyzing Compounds Citric acid, ascorbic acid and EDTA

Application Column

Obelisc N

SIELC has developed the mixed-mode Obelisc™ columns to be the first commercially available columns with Liquid Separation Cell technology (LiSC™). This cost effective duo can replace multiple HPLC columns such as 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:
Ascorbic Acid
EDTA (Ethylenediaminetetraacetic Acid)
Vitamin C

Application Detection:
ELSD 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.