Multiple pesticide analysis in wine by MEKC combined with solid-phase microextraction and sample stacking

Area of Science:

• Analytical Chemistry
• Food Science
• Environmental Science

Background:

• Pesticide residues in wine pose a potential risk to consumer health.
• Accurate and sensitive detection methods are crucial for ensuring wine quality and safety.
• Existing methods may lack the sensitivity or efficiency required for comprehensive pesticide analysis in complex matrices like wine.

Purpose of the Study:

• To develop and validate a novel analytical method for the simultaneous determination of 12 widely used pesticides in white wines.
• To optimize solid-phase microextraction (SPME) and micellar electrokinetic chromatography with diode-array detection (MEKC-DAD) for sensitive pesticide analysis.
• To assess the method's applicability for routine wine analysis and compliance with regulatory limits.

Main Methods:

• Development of a combined off-line solid-phase microextraction (SPME) and on-line reversed-electrode polarity stacking mode (REPSM) preconcentration strategy.
• Optimization of SPME using various fiber coatings, with PDMS/divinylbenzene (PDMS/DVB) showing optimal performance for most target pesticides.
• Utilized micellar electrokinetic chromatography with diode-array detection (MEKC-DAD) for separation and quantification.

Main Results:

• The optimized method successfully determined ten out of twelve target pesticides in white wine samples.
• Achieved high sensitivity, with detection limits between 0.054 and 0.113 mg/L, significantly below maximum residue limits (MRLs).
• Demonstrated the method's practical utility by analyzing ten homemade wine samples, confirming its effectiveness.

Conclusions:

• The developed SPME-MEKC-DAD method offers a sensitive, efficient, and robust approach for pesticide residue analysis in white wines.
• The combined preconcentration techniques (SPME and REPSM) significantly enhance detection capabilities.
• The method is suitable for routine quality control and ensuring the safety of wine products.