HPLC Separation of Three Isomers of Pyridinecarboxylic Acid on Coresep 100 Mixed-Mode Column

Application description

Pyridinecarboxylic acids are polar ionizable zwitterionic compounds. 3-pyridinecarboxylic acid is one of the forms of Vitamin B3. Three isomers - 2-pyridinecarboxylic acid (picolinic acid), 3-pyridinecarboxylic acid (niacin, nicotinic acid) and 4-pyridinecarboxylic acid (isonicotinic acid) - were separated on Coresep 100 core-shell mixed-mode reversed-phase cation-exchange column. Mixed-mode chromatography explores а small difference in hydrophobic and ionic properties of molecules to enhance resolution between isomers and other close related compounds. Retention time is controlled by the amount of ACN, buffer concentration, and buffer pH. Method is fast, robust, reproducible, and can be used for analysis of isomers of pyridinecarboxylic acids in various sample matrices. Various mobile phases can be used with Coresep 100 column to accommodate different detection techniques (UV, MS, CAD, ELSD detection). Isomers of other compounds can be retained and separated if they are hydrophobic and basic in nature. Core-shell mixed-mode columns provide a great combination of unique selectivity, speed, and efficiency.

Conditions of Experiment
Column: Coresep 100
Separation Modes: reversed-phase and cation-exchange
Column Dimenstions: 4.6 x 150 mm
Mobile Phase: 5% ACN with 0.15% H3PO4
Detection: UV 275 nm
Sample: 0.3 mg/ml
Injection: 1 uL
Flow rate: 1 mL/min
Class of compounds: Amino acid, Aromatic compound, Isomer, Pyridine
Nature of compounds: Hydrophilic, Polar, Zwitterionic
Compounds: 2-Pyridinecarboxylic acid, 4-Pyridinecarboxylic acid, 3-Pyridinecarboxylic acid