Solid-phase extraction with metal-organic frameworks for the analysis of chiral compounds

Area of Science:

• Materials Science
• Analytical Chemistry
• Separation Science

Background:

• Metal-organic frameworks (MOFs) possess unique porous structures and high surface areas, making them suitable for adsorption applications.
• Solid-phase extraction (SPE) is a widely used technique for sample preparation and analyte isolation.
• Chiral separation is crucial for analyzing enantiomeric compounds in various scientific fields.

Purpose of the Study:

• To introduce a novel application of a chiral metal-organic framework (MOF), [Zn2(D-Cam)2(4,4'-bpy)]n, as an adsorbent in solid-phase extraction (SPE).
• To determine the enantiomeric excess (ee) of (±)-1,1'-bi-2-naphthol using the developed SPE method.
• To optimize experimental parameters influencing the extraction efficiency and assess the method's accuracy and precision.

Main Methods:

• Synthesis and characterization of the chiral MOF [Zn2(D-Cam)2(4,4'-bpy)]n.
• Application of the chiral MOF as a stationary phase in SPE for the separation of enantiomers.
• Optimization of SPE parameters such as sample loading, washing, and elution.
• Quantification of enantiomeric excess (ee) by analyzing the peak areas obtained from SPE.
• Comparison of results with those obtained from chiral High-Performance Liquid Chromatography (HPLC).

Main Results:

• The chiral MOF [Zn2(D-Cam)2(4,4'-bpy)]n was successfully employed as an adsorbent in SPE.
• Optimal experimental conditions were established for efficient extraction and determination of enantiomeric excess.
• A strong linear correlation (R² > 0.999) was observed between the ee value and the reciprocal of peak areas.
• The SPE-based assay demonstrated good accuracy and precision when compared to chiral HPLC analysis.

Conclusions:

• SPE utilizing chiral MOFs as adsorbents provides a simple and effective approach for determining the enantiomeric excess of chiral compounds.
• This method offers a promising alternative for the routine analysis of enantiomeric purity.
• The developed SPE method highlights the potential of MOFs in advanced separation and analytical applications.