Comprehensive two-dimensional liquid chromatographic analysis of anthocyanins

Area of Science:

• Analytical Chemistry
• Food Chemistry
• Natural Product Analysis

Background:

• Anthocyanins are vital plant pigments with complex structures and chromatographic behaviors that challenge accurate analysis.
• On-column conversion reactions further complicate the precise quantification and identification of these compounds.

Purpose of the Study:

• To evaluate off-line comprehensive two-dimensional liquid chromatography (LC×LC) for enhanced anthocyanin analysis.
• To demonstrate the utility of HILIC×RP-LC for separating and identifying diverse anthocyanins in various natural products.

Main Methods:

• Utilized off-line hydrophilic interaction chromatography (HILIC) in the first dimension and reversed-phase liquid chromatography (RP-LC) in the second dimension.
• Employed diode array detection for selective anthocyanin detection and high-resolution quadrupole-time-of-flight mass spectrometry (Q-TOF) for compound identification.

Main Results:

• Successfully separated diverse anthocyanins from blueberries, red radish, black beans, red grape skins, and red cabbage using HILIC×RP-LC.
• Obtained crucial analytical information unobtainable with traditional one-dimensional HPLC methods.
• Demonstrated that the structured elution order simplifies anthocyanin identification and facilitates comparative analysis.

Conclusions:

• Off-line HILIC×RP-LC is a powerful technique for detailed anthocyanin profiling.
• This method enhances the identification and comparison of anthocyanins in complex natural matrices.
• The structured elution order significantly aids in the characterization of anthocyanin content.