Determination of aflatoxins in cereal baby food samples - from extraction to high efficient detection

Significance of the Topic

The occurrence of aflatoxins, toxic metabolites produced by Aspergillus species, poses a serious health risk, particularly in cereal‐based baby foods. Due to their stability during processing and the heightened vulnerability of infants, sensitive and reliable analytical methods are essential to ensure compliance with stringent regulatory limits and to protect consumer health.

Objectives and Study Overview

This study aims to develop and validate a robust sample preparation protocol coupled with high‐performance liquid chromatography (HPLC) and photochemical post‐column derivatization for the simultaneous detection of aflatoxins B1, B2, G1 and G2 in processed cereal baby food. The approach integrates multiple cleanup steps to minimize matrix interferences and achieve detection limits well below European regulatory thresholds.

Instrumentation

• HPLC system: KNAUER AZURA P6.1L pump, AZURA AS 6.1L autosampler, AZURA CT 2.1 column thermostat
• Column: Eurospher II 100-3 C18, 150 × 4.6 mm i.d.
• Post-column derivatization: UVE Box photochemical reactor (254 nm)
• Fluorescence detection: RF-20A detector (excitation 365 nm, emission 460 nm)

Methodology

Sample preparation comprises three sequential steps:

• Solid–liquid extraction: 50 g of baby rusk or direct puree suspension in methanol–water (17:3, v/v), sonication/rotary mixing and filtration.
• Liquid–liquid extraction: Degreasing with n-hexane and extraction with chloroform to remove lipophilic interferences; concentration to 3 mL.
• SPE cleanup: Silica‐based cartridges conditioned with hexane; wash steps with n-hexane, diethyl ether and chloroform; elution with chloroform–acetone (9:1, v/v).

Chromatographic separation uses a gradient of water, acetonitrile and methanol at 2.4 mL/min and 60 °C. Photochemical derivatization enhances fluorescence of aflatoxins B1 and G1 without halogen reagents.

Main Results and Discussion

SPE cleanup effectively removed co-eluting matrix peaks, particularly in the critical retention window (6.5–8 min). The method achieved limits of detection of 0.05 ng/mL for B1/G1 and 0.015 ng/mL for B2/G2, surpassing EU requirements by factors of 3.4 and 11.3. Chromatographic runs of spiked multi-matrix extracts demonstrated good peak resolution, reproducibility and minimal background noise.

Benefits and Practical Applications

• High sensitivity and specificity allow routine verification of trace aflatoxins in baby food and other cereals.
• Non‐toxic photochemical derivatization eliminates use of hazardous halogen reagents and simplifies waste disposal.
• Modular cleanup and analysis workflow is adaptable to diverse food and feed matrices.

Future Trends and Potential Applications

Advances may include integration with mass spectrometric detection for multi‐mycotoxin screening, further miniaturization of sample preparation, automation for high‐throughput laboratories and extension to emerging mycotoxins. Real-time monitoring during processing and stronger data integration with risk assessment models are also promising avenues.

Conclusion

The described extraction and HPLC method with photochemical post-column derivatization delivers robust, sensitive and compliant analysis of aflatoxins in cereal‐based baby foods. Its flexibility and performance support routine quality control and consumer safety assurance.

References

• World Health Organization: Aflatoxins, 2018.
• FDA: Action Levels for Aflatoxins in Animal Food, 2019.
• EU Regulation (EC) No 1881/2006 setting maximum levels for contaminants in foodstuffs.
• Folmert K., Monks K.: Quick and easy determination of aflatoxins using photochemical post-column derivatization, KNAUER AppNote VFD0178, 2019.