Stability Evaluation of Aflatoxin B 1 Solution Certified Reference Material via Ultra-High Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry.

Aflatoxin B 1 (AFB 1 ) solution certified reference materials (CRMs) have been widely utilized in the measurements of AFB 1 contaminations in foods and agricultural products. It is of great importance to evaluate the stability of AFB 1 solution CRMs in different matrices for their practical applications. In this study, the stability of AFB 1 solution CRM was investigated and its degradation products under various conditions were elucidated using ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry for the first time. Exposure to high temperatures and UV light irradiation accelerated the degradation of AFB 1 solution significantly, and the degradation products were largely dependent on the solvents. Two degradation pathways were proposed based on the degradation products. The addition reaction, oxidation reaction, and modification of the methoxy group are the major processes involved in the degradation of the AFB 1 solution. The results of this study indicate that the property value of the acetonitrile solution of AFB 1 can be well retained when it is stored at temperatures lower than 60 °C, and the exposure to UV light irradiation is avoided.