Rapid analysis and identification of multi-class mycotoxins in Morinda officinalis by UFLC-ESI-MS/MS

Abstract

A simple, rapid and cost-effective analytical method based on dilute-and-shoot pretreatment coupled with ultra fast liquid chromatography-tandem mass spectrometry (DAS-UFLC-MS/MS) has been developed for simultaneous quantification and identification of multi-class mycotoxins in Morinda officinalis, using a hybrid triple quadrupole linear ion trap mass spectrometer (QTRAP®). Mycotoxins were extracted with a methanol/water/formic acid mixture and directly injected into the chromatographic system after a one-fold dilution with the initial mobile phase. One precursor ion and two product ions of all analytes were simultaneously characterized and quantified based on the scheduled multiple reaction monitoring-information-dependent acquisition-enhanced product ion (sMRM-IDA-EPI) mode with a turbo ion spray interface simultaneously operated in both positive and negative modes in one chromatographic run within 10 min. Matrix-matched calibration is recommended for reliable quantitation, with zearalanone as the internal standard. After careful optimization of the corresponding parameters, the DAS-UFLC-ESI-MS/MS method was validated to express satisfactory linearity (r > 0.9900), sensitivity (limits of detection, 0.02 and 4.00 ng mL⁻¹ and limits of quantification, 0.06–10 ng mL⁻¹), precision (intra-day and inter-day precision, <15%), stability (4.12–14.10%), repeatability (5.45–15.56%) and spiked recoveries (63.63–119.44%). The proposed method was applied for 40 M. officinalis samples, and two samples were detected with five classes of mycotoxins with concentrations below the regulatory maximum residue limits. This study highlighted the occurrence of multi-class mycotoxins in M. officinalis, which should be under safety control.