AUTOMATED QUECHERS EXTRACTION AND LC/MS/MS ANALYSIS OF MYCOTOXINS

Significance of the Topic

Mycotoxins are hazardous fungal metabolites that pose serious health risks when present in food and feed. Routine monitoring of crops such as wheat, barley, corn and dried fruits is mandated to prevent contaminated materials from entering the supply chain. Traditional assays require extensive manual sample preparation and multiple tests for different analytes, limiting throughput and increasing exposure risk.

Objectives and Overview

This study describes the development and evaluation of an automated workflow combining QuEChERS extraction with LC-MS/MS detection for six common mycotoxins in wholemeal wheat flour. Key goals were to demonstrate reproducible recoveries, sensitive quantification, and operational advantages over manual protocols.

Methodology and Instrumentation

Sample Preparation and Extraction:

• Weighed 1 g of ground flour into 10 mL vials with QuEChERS salts (magnesium sulfate, sodium acetate).
• Automated internal standard addition and acidified acetonitrile extraction (5 mL of 50:50 ACN/0.2 % formic acid).
• 10 min shake at 2000 rpm, followed by 5 min centrifugation at 4500 rpm.
• Dilution of the supernatant with water prior to injection.

Chromatography and Detection:

• Agilent 1260 HPLC with Poroshell 120 BonusRP column (2.1×100 mm, 2.7 µm).
• Mobile phase A: 0.1 % formic acid with 5 mM ammonium formate; B: 95:5 ACN/water. Gradient from 5 % to 100 % B over 11 min.
• Detection by Agilent 6470 Triple Quadrupole MS in positive ESI mode using MRM transitions for AFB1, AFB2, AFG1, AFG2, AFM1 and DON.

Main Results and Discussion

Linearity:

• Standards (0.001–50 ng/mL) and matrix spikes (0.01–100 ng/g) yielded r2 > 0.9998 and > 0.995 respectively.

Reproducibility:

• Triplicate extractions of flour spiked at 50 ng/g produced recoveries between 78 % and 109 %.
• Native DON background at ~7 ng/g confirmed method sensitivity.

These data demonstrate high extraction repeatability and analytical precision suitable for regulatory compliance testing.

Benefits and Practical Applications

• Automated sample handling reduces analyst time and exposure to toxins.
• Closed-system workflow minimizes solvent usage and waste disposal costs.
• High throughput supports large screening campaigns with unattended operation.

Future Trends and Opportunities

Automation of multi-analyte mycotoxin assays will continue to expand, integrating online sample cleanup and real-time data processing. Further miniaturization and green chemistry approaches can reduce solvent consumption. Coupling with high-resolution mass spectrometry may broaden the detectable toxin panel and improve confirmatory power.

Conclusion

The automated QuEChERS–LC-MS/MS method delivers sensitive, reproducible quantification of key mycotoxins in flour. It reduces manual workload, enhances laboratory safety and sustainability, and aligns with regulatory demands for efficient food safety testing.

Used Instrumentation

• GERSTEL Multipurpose Sampler (MPS) with QuickMix shaker and centrifuge.
• Agilent 1260 HPLC system with Poroshell 120 BonusRP column.
• Agilent 6470 Triple Quadrupole LC/MS with JetStream ESI source.