Development, validation, and application of a multi-method for the determination of mycotoxins, plant growth regulators, tropane alkaloids, and pesticides in cereals by two-dimensional liquid chromatography\xa0tandem mass spectrometry

Ann-Kristin Rausch,Ann-Kristin Rausch,Robert Brockmeyer,Tanja Schwerdtle,Tanja Schwerdtle

doi:10.1007/s00216-021-03239-1

Ann-Kristin Rausch, Ann-Kristin Rausch + Show 3 more

Open Access

https://doi.org/10.1007/s00216-021-03239-1

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Abstract

Mycotoxins and pesticides regularly co-occur in agricultural products worldwide. Thus, humans can be exposed to both toxic contaminants and pesticides simultaneously, and multi-methods assessing the occurrence of various food contaminants and residues in a single method are necessary. A two-dimensional high performance liquid chromatography tandem mass spectrometry method for the analysis of 40 (modified) mycotoxins, two plant growth regulators, two tropane alkaloids, and 334 pesticides in cereals was developed. After an acetonitrile/water/formic acid (79:20:1, v/v/v) multi-analyte extraction procedure, extracts were injected into the two-dimensional setup, and an online clean-up was performed. The method was validated according to Commission Decision (EC) no. 657/2002 and document N° SANTE/12682/2019. Good linearity (R2 > 0.96), recovery data between 70-120%, repeatability and reproducibility values < 20%, and expanded measurement uncertainties < 50% were obtained for a wide range of analytes, including very polar substances like deoxynivalenol-3-glucoside and methamidophos. However, results for fumonisins, zearalenone-14,16-disulfate, acid-labile pesticides, and carbamates were unsatisfying. Limits of quantification meeting maximum (residue) limits were achieved for most analytes. Matrix effects varied highly (−85 to +1574%) and were mainly observed for analytes eluting in the first dimension and early-eluting analytes in the second dimension. The application of the method demonstrated the co-occurrence of different types of cereals with 28 toxins and pesticides. Overall, 86% of the samples showed positive findings with at least one mycotoxin, plant growth regulator, or pesticide.Graphical abstract

Highlights

Cereal crops are major staple foods, while wheat accounts for more than half of the cereal production in the European Union (EU) [1]
A 2D-liquid chromatography (LC)-Tandem mass spectrometry (MS/MS) system was installed since the study aimed to analyze pesticides and mycotoxins in one chromatographic run without classical clean-up steps in sample preparation
A One-dimensional liquid chromatography (1D-LC) method would not have provided a sufficient resolution for all analytes resulting in coelution and unresolved peaks

Summary

Introduction

Cereal crops are major staple foods, while wheat accounts for more than half of the cereal production in the European Union (EU) [1]. To obtain a high yield, crops are often treated with pesticides and fertilizers. Due to their plant protection ability, they defend against crop losses, e.g., due to fungi, weeds, or insects [2]. Crops can be contaminated with toxic compounds. Under humid conditions, cereals are often infected with fungi, which can produce mycotoxins as toxic secondary products [3]. Further contamination sources represent plant growth regulators and tropane alkaloids. The latter contaminate cereals by co-harvested undesired weeds [4]

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