Sixty mycotoxins in nuts and dried fruits simultaneously detected by QuEChERS combined with UPLC-Orbitrap/MS

Abstract

ObjectiveA qualitative and quantitative method was established for the simultaneous detection of 60 mycotoxins in nuts and dried fruits.MethodsPeanuts and raisins， two typical food substrates rich in fat and sugar， were pre-processed by QuEChERS technique （900 mg MgSO4， 150 mg PSA， 150 mg C18）， and analyzed by ultra-high performance liquid chromatography-high resolution mass spectrometry （UPLC-Orbitrap/MS） with full scan and data-dependent scanning （dd-MS2） mode. It was qualitatively determined by the retention time and accurate mass of mycotoxins， the chromatographic peak area was quantified， and the fragment ion information was used for confirmation.ResultsThe results showed that the pH value of the extraction solution significantly affected the dissociation state of mycotoxins， which in turn affected the recovery rate. The interference of components such as carbohydrates and lipids in the sample was effectively removed by QuEChERS purification， and the accuracy of qualitative and quantitative analysis was improved. A blank matrix-matched standard curve was used for calibration to reduce the matrix effect and meet the quantitative analysis requirements. The mycotoxins had a good linear relationship within their respective mass concentration ranges （correlation coefficient R2>0.95）， and the recoveries were 60%-120% with relative standard deviation less than 20%. The other seven mycotoxins with R2 less than 0.95 can be qualitatively analyzed.ConclusionCompared with the detection method based on triple quadrupole mass spectrometry， the high-resolution mass spectrometry method is easier to quantify， and there is no need to optimize the parent ion， product ion and collision energy for the target one by one，which can effectively reduce the difficulty and time consuming for multi-target analysis. The method has high sensitivity， accuracy and reliable results， and is suitable for the qualitative and quantitative analysis of 60 mycotoxins in nuts and dried fruits.

Keywords

• mycotoxins
• nuts
• dried fruits
• uplc-orbitrap/ms
• quechers