Determination of Aflatoxins in a Wide Range of Food and Agricultural Commodities Using Immunoaffinity Chromatography Column Clean-up Coupled with UPLC or HPLC with Fluorescence Detection

Significance of the topic

Aflatoxins are among the most toxic and carcinogenic mycotoxins frequently contaminating a wide range of food and agricultural commodities. Due to their severe health impact on humans and animals, stringent regulatory limits have been imposed worldwide. Reliable, sensitive, and selective analytical methods are therefore critical to ensure food safety and regulatory compliance.

Aims and overview of the study

This study evaluates a standardized procedure combining liquid–liquid extraction, immunoaffinity column clean-up (AflaTest WB SR+), and chromatographic analysis by HPLC or UPLC with fluorescence detection. The goal was to demonstrate method performance for regulated aflatoxins (B1, B2, G1, G2) across challenging matrices including spices, cocoa, coffee, dog food, and a traditional Chinese medicine.

Methodology and used instrumentation

Sample preparation involved extraction with acetonitrile–water, homogenization, and IAC clean-up using AflaTest WB SR+ columns. Chromatographic separation and detection were performed on two platforms:

• HPLC: Alliance e2695 system with 2475 Fluorescence Detector plus photochemical reactor, Nova-Pak C18 column (3.9×150 mm, 4 µm).
• UPLC: ACQUITY UPLC H-Class PLUS with FLR detector (large volume flow cell), HSS T3 column (2.1×100 mm, 1.8 µm).
• Data processing: Empower 3 software.

Main results and discussion

Chromatograms showed complete resolution of all aflatoxins within 8–12 minutes. Recoveries ranged from 82% to 119% with RSDr below 9.5%, meeting or exceeding AOAC, CODEX, and EU performance criteria. Blank samples exhibited no interfering peaks, confirming method selectivity. The UPLC approach reduced analysis time while omitting post-column derivatization, thanks to the large flow cell detector.

Benefits and practical applications

• High performance: Meets AOAC and regulatory requirements for sensitivity and selectivity.
• Comprehensive: Single method applicable to diverse commodities.
• Flexible and efficient: Shorter run times with UPLC and minimal sample dilution.

Future trends and possibilities

Advances may include integration with mass spectrometry for multi-mycotoxin screening, on-line automation of IAC clean-up, further miniaturization of UPLC, and expansion to emerging commodities.

Conclusion

The combined IAC-UPLC/HPLC method with AflaTest WB SR+ offers robust, sensitive, and rapid analysis of aflatoxins across complex food matrices. It provides a reliable tool for routine compliance monitoring and quality control in food safety laboratories.

References

1. Kaale L, et al. World Mycotoxin J. 2021;14(1):27–40.
2. Gabriella M, et al. Front Microbiol. 2020;11:1916.
3. Zhang K, Banerjee K. Toxins. 2020;12(9):539.
4. Afsah-Hejri L, et al. Food Control. 2011;22(3–4):381–388.
5. Watlking A, Wilson D. J AOAC Int. 2006;89(3):678–692.
6. Oulkar D, et al. J Environ Sci Health B. 2017;53:255–260.
7. Codex Alimentarius. CXS 193-1995, Rev. 2019.
8. Regulation (EC) 401/2006. Off J EU L 70:12–34.
9. AOAC. Appendix F, 2016.
10. AOAC. Appendix E, 2013.