Evaluation of the Necessity of a Cleanup Step After Microwave-Assisted Extraction (MAE) of Aflatoxins in Pea Flour

Aflatoxins (AFs) are among the most hazardous mycotoxins in food, yet their occurrence in legume-based products remains poorly investigated, and official standardized analytical methods validated by international regulatory bodies are still limited for these specific matrices. This study evaluates the effectiveness of microwave-assisted extraction (MAE) coupled with HPLC-FLD for the determination of AFB1, AFB2, AFG1, and AFG2 in pea flour (Pisum sativum), with a particular focus on assessing the necessity of a solid-phase extraction (SPE) cleanup step. Two analytical workflows were compared: direct MAE and MAE followed by SPE purification. The optimized MAE conditions (60 °C, 5 min, acidified acetonitrile) provided good repeatability (RSD < 8.7%) and acceptable recoveries (70–73% at 10 µg/kg), while the inclusion of SPE improved recoveries up to 95–103% but did not yield a noteworthy reduction in matrix effects for AFB1 and AFG1. Matrix-induced signal suppression (up to −24.6%) was observed in both approaches, highlighting the necessity of matrix-matched calibration. Limits of quantification ranged from 0.09 to 0.25 µg/kg (MAE) and from 0.12 to 0.43 µg/kg (MAE + SPE), with no statistically significant differences between the two protocols. Application to commercial pea flours (n = 7) revealed no quantifiable contamination, with only one sample showing AFB1 below the LOQ. Overall, the results demonstrate that under the tested conditions, the direct MAE approach, combined with trifluoroacetic acid derivatization and HPLC-FLD analysis, provides a reliable and efficient alternative to conventional cleanup-based methods for routine AF analysis in pea flour. The application to a small batch of commercial samples confirms the method’s fitness-for-purpose as a preliminary screening tool.