Aflatoxin Analysis in Infant Formula with Enhanced Matrix Removal— Lipid by LC/MS/MS

Importance of the Topic

Aflatoxins are highly toxic fungal metabolites that frequently contaminate foodstuffs and pose serious health risks, especially to infants. Regulatory agencies in the European Union and United States enforce extremely low maximum levels of aflatoxin M1 in dairy-based products, demanding analytical methods that combine low limits of quantitation with robust cleanup of lipid-rich matrices.

Study Objectives and Overview

This work describes a rapid, sensitive approach for quantifying five aflatoxins (M1, G2, G1, B2, B1) in liquid infant formula. The goals were to achieve recoveries and precision suitable for QC laboratories, extend LOQs below regulatory thresholds, and simplify sample preparation for routine implementation.

Methodology and Instrumentation

Sample preparation relies on a QuEChERS extraction with acetonitrile and nonbuffered salt packets, followed by dispersive SPE cleanup using Agilent Bond Elut Enhanced Matrix Removal—Lipid (EMR-Lipid) and MgSO4 polishing. A tenfold concentration step was introduced to lower LOQs. Chromatographic separation was performed on an Agilent 1290 Infinity LC system with a Poroshell 120 SB-C18 column (2.1×100 mm, 2.7 µm) at 40 °C and 0.3 mL/min flow. Mass detection utilized an Agilent 6460A triple quadrupole with Jet Stream ESI in positive mode and dynamic MRM transitions for each analyte.

Results and Discussion

Matrix removal by EMR-Lipid dramatically reduced lipid-derived interferences, as shown by full‐scan overlays. Limits of quantitation were established at 0.01 ng/mL for M1 and 0.05 ng/mL for other aflatoxins, below both EU and FDA action levels. Recoveries ranged from 88% to 113% across three QC levels, with RSDs below 14%. Matrix effects remained within ±13%, indicating effective cleanup. Analysis of a certified milk powder incurred sample yielded accurate quantitation of aflatoxin M1 at 0.0101 ng/mL.

Benefits and Practical Applications

• Straightforward sample workflow requiring minimal specialized equipment.
• High recovery and precision satisfy stringent regulatory requirements.
• Enhanced instrument performance and reduced maintenance due to thorough lipid removal.
• Adaptable to multiresidue testing in various high‐fat food matrices.

Future Trends and Applications

Future developments may include extending EMR-Lipid cleanup to other mycotoxin families, integration with automated high‐throughput platforms, and coupling with high‐resolution mass spectrometry for non‐targeted screening and confirmatory analysis.

Conclusion

This method offers a robust, sensitive, and reproducible solution for regulatory‐compliant aflatoxin monitoring in infant formula, balancing simplicity with high analytical performance.

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