Development and optimization of a method based on dispersive solid phase extraction followed by ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry for simultaneous determination of 30 mycotoxins in Citrus products.

Abstract

Citrus, a raw material widely used in food and medicine, is susceptible to fungal infection and its metabolites during growth, transportation, and storage. Thus, monitoring the residual levels of various mycotoxins in Citrus traditional Chinese medicines and related products is crucial. This study described a simple, reliable, and sensitive method for simultaneous identification and quantification of 30 mycotoxins in Citrus products. The method is based on modified quick, easy, cheap, effective, rugged, and safe extraction and purification followed by ultra-high-performance liquid chromatography-quadrupole/orbitrap high-resolution mass spectrometry. The limit of detection ranged from 0.10 to 1.50μg/kg, and the quantification ranged from 0.25 to 5.00μg/kg. The recoveries at three spiked levels were 64.90-99.72% and the relative standard deviation was less than 12%. The method was applied to 55 Citrus samples. The detection rates of tentoxin and mycophenolic acid were the highest, reaching 22.7% and with concentration ranges of 0.33-1.03 and 0.57-2.09μg/kg, respectively. All contamination levels were below the maximum residue limits recommended by the European Commission and China. These results could be used to establish guidelines for screening mycotoxins in Citrus products and the limits of acceptable levels.