Validation of the AgraStrip® Pro Total Aflatoxin WATEX® Method for Detection of Total Aflatoxins in Corn and Peanut Paste: AOAC Performance Tested MethodSM 032402.

Background: To protect public and animal health against risks provoked by aflatoxins contained therein, maximum limits for aflatoxins are defined. Limit values vary depending on the intended use and regulatory authority, therefore quantitative detection is essential.

Objective: Validation of a one-step competitive lateral flow immunochromatographic assay for quantitative screening of total aflatoxin (B1, B2, G1, and G2) in corn and peanut paste for the high-sensitivity range (0-50 µg/kg).

Methods: Corn or peanut paste test portions are water-based extracted and prepared for testing within 15 min. The AgraStrip® Pro Total Aflatoxin WATEX® test method quantifies the concentration of aflatoxins in the sample. Selectivity, robustness, product consistency, and stability testing were performed in addition to matrix testing.

Results: No cross-reactivity was detected against possible interferants. Corn resulted in a LOD and LOQ of 0.9 and 2.8 µg/kg and overall recoveries between 74 and 108%. Peanut paste resulted internally in a LOD and LOQ of 0.8 and 2.3 µg/kg and recoveries between 86 and 98%. Stability testing showed no influence of the age of the respective lot on the result. Robustness testing demonstrated that varying the amount of water used for extraction, extraction time, and delay between extract dilution and analysis did not significantly affect the result. Due to supply chain issues, a change to the outer cartridge required an increase in the test aliquot size, which had no effect on method performance.

Conclusion: The test kit was validated for the determination of total aflatoxins in corn and peanut paste. Recovery and precision met the requirements laid down in Codex Alimentarius CXG 71-2009 and acceptable robustness, selectivity, and product consistency and stability were demonstrated.

Highlights: The AgraStrip Pro Total Aflatoxin WATEX test kit in the high sensitivity range (0-50 µg/kg) was approved by the AOAC AOAC Research Institute (PTM number 032402).