Peptide-based affinity media for solid-phase extraction of Ochratoxin A from wine samples: Effect of the solid...

Area of Science:

• Analytical Chemistry
• Materials Science
• Biochemistry

Background:

• Sample cleanup is crucial for analytical method development.
• Peptide-based affinity media offer selective analyte extraction from complex matrices.
• Ochratoxin A (OTA) is a significant mycotoxin requiring accurate detection.

Purpose of the Study:

• To investigate the thermodynamic and kinetic binding properties of various stationary phases functionalized with a hexapeptide for Ochratoxin A extraction.
• To compare the performance of Lewatit CNP105 and Amberlite IRC-50 as solid supports in solid-phase extraction (SPE) of OTA from wine samples.

Main Methods:

• Functionalization of stationary phases (Amberlite IRC-50, Lewatit CNP105, Toyopearl CM-650 M, porous silica gel, micrometric glass beads) with a hexapeptide sequence.
• Thermodynamic and kinetic binding property assessment (Keq, Bmax).
• Solid-phase extraction (SPE) of OTA from fortified wine samples followed by HPLC-fluorescence detection.

Main Results:

• Lewatit CNP105 exhibited the highest equilibrium binding constant (Keq: 98.1×10^6 M⁻¹) and binding site concentration (Bmax: 30.8 μmol/g).
• Kinetic performances followed the same trend as thermodynamic properties.
• Lewatit CNP105-based SPE showed higher extraction precision (91-101% recovery) compared to Amberlite IRC-50 (71-108% recovery) in wine samples, with comparable accuracy.
• Limit of detection (LOD) and limit of quantification (LOQ) were 0.45 and 1.5 μg/L, respectively.

Conclusions:

• The surface chemistry of solid supports significantly influences their binding properties for affinity media.
• Lewatit CNP105 is a superior solid support compared to Amberlite IRC-50 for SPE of Ochratoxin A from wine, offering better extraction precision.
• Peptide-functionalized affinity media provide effective sample cleanup with minimal matrix effects for accurate toxin analysis.