Ion source component development for ambient mass spectrometry-based mycotoxin detection in ready-to-eat corn

A rapid hydrophilic covalent organic frameworks coated steel substrate (HCOFCS) was developed for the simultaneous determination of 9 mycotoxins in ready-to-eat corn using ambient mass spectrometry (AMS). The HCOFCS platform efficiently combines solid-phase extraction with electrospray ionization mass spectrometry. The established HCOFCS-ESI-MS method was employed to detect a variety of mycotoxins in ready-to-eat corn, including aflatoxin B₁ (AFB₁), aflatoxin B₂ (AFB₂), aflatoxin G₁ (AFG₁), aflatoxin G₂ (AFG₂), Zearalenone (ZEN), Zearalanone (ZAN), Zearalenol (ZEL), Zearalanol (ZAL) and ochratoxin A (OTA). After the extraction process, HCOFCS was subjected to high voltage for ESI-MS, with a detection time of approximately 1 min. The method demonstrated a coefficient of determination (R²) exceeding 0.99 over a concentration range 0.1-100 μg/L. Limits of detection (LODs) and limits of quantitation (LOQs) ranged from 0.01-0.12 µg/kg to 0.1-0.7 μg/kg, respectively. The results indicated that the developed HCOFCS-ESI-MS method enables rapid and sensitive detection of multiple mycotoxins in ready-to-eat corn samples. Recoveries for the mycotoxins ranged from 83.62% to 96.97%, with relative standard deviations (RSDs) below 11.53%. Moreover, HCOFCS exhibited excellent inter-day and intra-day RSDs ranges, and the material could be reused at least six times without significant loss of adsorption efficiency.