Determination of Aflatoxins in Peanut Oil by One-Step Solid-Phase Extraction with Metal-Organic Framework MIL-101 (Cr) Filled Syringe Filter and HPLC-MS/MS

A simple, rapid and sensitive method for the determination of aflatoxins in peanut oil was developed using MIL-101(Cr) material filled syringe filter for one-step solid-phase extraction (SPE) with high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) detection. The MIL-101(Cr) sorbent was characterized and its mass, the loading solution, and the eluent were optimized; under these conditions, a matrix matching internal standard method was developed. The linear range was from 0.1 to 20 ng/mL with correlation coefficient (r) exceeding 0.9998. The recoveries were between 94.7% and 105.9% with relative standard deviations from 2.02% 6.88%. The recoveries of inter-day and intra-day measurements were from 93.0% to 98.5% and 97.6% to 100.7%. The precision values for inter-day and intra-day analyses were from 6.09% to 7.68% and 2.56% to 4.30%, respectively. The pretreatment efficiency of the developed method was superior to literature procedures and used to determine aflatoxins in 126 peanut oil samples from local markets. 38 samples had positive results and 1 sample exceeded the allowable limit. Hence, the developed protocol was suitable for the determination of aflatoxins in peanut oil.