Evaluation of a Diagnostic Method to Quantify Aflatoxins B₁ and M₁ in Animal Liver by High-Performance Liquid...

Background: Aflatoxins (AFs) are secondary metabolites of fungi and are one of the causes of toxin-related pet food recalls. An intralaboratory method was previously developed to quantify aflatoxin B₁ (AFB₁) and aflatoxin M₁ (AFM₁) in animal liver by HPLC with fluorescence detection. Objective: The aim of this study was to extensively evaluate the method performance with a single-laboratory blinded method test (BMT-S) and a multilaboratory blinded method test (BMT-M). Methods: Blinded tissue samples were prepared by a third-party laboratory and sent out to participating laboratories for both BMT-S and BMT-M. Results: In both tests, participants analyzed blinded samples prepared by an independent laboratory. In the BMT-S, accuracy ranged between 111 and 154% for AFB₁ and 113 and 159% for AFM₁ within the quantitation range of 0.1-0.5 ng/g. The HorRat values for repeatability ranged between 0.1 and 0.3 for AFB₁ and 0.3 and 0.6 for AFM₁. In the BMT-M, the interlaboratory accuracy ranged between 77 and 81% for AFB₁ and 83 and 85% for AFM₁ within the quantitation range of 0.2-10 ng/g. The HorRat values for reproducibility ranged between 0.4 and 0.7 for AFB₁ and 0.4 and 0.9 for AFM₁. Both recovery and reproducibility were acceptable. Conclusions: BMT-M evaluation demonstrated that the method was suitable for quantitation of aflatoxins B₁ and M₁ in animal liver between laboratories. Highlights: The BMT-S and BMT-M results demonstrated that the method is rugged and reproducible among the participating laboratories.