@article{RauschBrockmeyerSchwerdtle2021,
  author    = {Rausch, Ann-Kristin and Brockmeyer, Robert and Schwerdtle, Tanja},
  title     = {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 tandem mass spectrometry},
  series = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica},
  volume    = {413},
  journal   = {Analytical \& bioanalytical chemistry : a merger of Fresenius' journal of analytical chemistry, Analusis and Quimica analitica},
  number    = {11},
  publisher = {Springer},
  address   = {Berlin},
  issn      = {1618-2650},
  doi       = {10.1007/s00216-021-03239-1},
  pages     = {3041 -- 3054},
  year      = {2021},
  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.},
  language  = {en}
}
@misc{RauschBrockmeyerSchwerdtle2021,
  author    = {Rausch, Ann-Kristin and Brockmeyer, Robert and Schwerdtle, Tanja},
  title     = {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 tandem mass spectrometry},
  series = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  journal   = {Zweitver{\"o}ffentlichungen der Universit{\"a}t Potsdam : Mathematisch-Naturwissenschaftliche Reihe},
  number    = {143},
  issn      = {1866-8372},
  doi       = {10.25932/publishup-51479},
  url       = {http://nbn-resolving.de/urn:nbn:de:kobv:517-opus4-514795},
  pages     = {16},
  year      = {2021},
  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.},
  language  = {en}
}
@phdthesis{Rausch2021,
  author    = {Rausch, Ann-Kristin},
  title     = {Development of LC-MS/MS Multi-Methods for the Analysis of Contaminants and Residues},
  school      = {Universit{\"a}t Potsdam},
  pages     = {IX, 234, v},
  year      = {2021},
  abstract  = {Mycotoxins are secondary metabolites produced by several filamentous fungal species, thus occurring ubiquitously in the environment and food. While the heterogeneous group shows differences in their bioavailability and toxicity, the low-molecular-weight xenobiotics are capable of impacting human and animal health acutely and chronically. Therefore, maximum levels for the major mycotoxins in food and feed are regulated in the current European legislation. Besides free mycotoxins, naturally occurring modified mycotoxins are gaining more attention in recent years. Modified mycotoxins constitute toxins altered by plants, microorganisms, and living organisms in different metabolic pathways or food processing steps. The toxicological relevant compounds often co-occur with their free forms in infested food and feed. Thus, the toxins may contribute to the overall toxicity of mycotoxins, wherefore their presence and toxicity should be considered in risk assessment. Until now, however, there are no regulated limits for modified mycotoxins within the European Union. In this thesis, rapid, sensitive, and robust methods for the analysis of mycotoxins and their modified forms were developed and validated using state-of-the-art high performance liquid chromatography tandem mass spectrometry (LC-MS/MS) systems. Firstly, two analytical methods for determining 38 mycotoxins in cereals and 41 mycotoxins in beer were established since agricultural products count as the primary source of mycotoxin contamination. For the analysis of cereal samples, a QuEChERS- based extraction approach was pursued, while analytes from beer samples were extracted using an acetonitrile precipitation scheme. Validation in cereals, namely wheat, corn, rice, and barley, as well as in beer, demonstrated satisfactory results. To obtain information regarding the natural occurrence of mycotoxins in food products, the developed methods were applied to the analysis of several commercial samples partly produced worldwide. The Fusarium toxins deoxynivalenol and its conjugated metabolite deoxynivalenol-3-glucoside turned out to be the most abundant toxins. None of the other modified mycotoxins were quantified in the samples. However, one cereal sample showed traces of zearalenone- 14-sulfate below the limit of quantification. Moreover, pesticides, plant growth regulators, and tropane alkaloids were investigated in this thesis. Pesticides present biologically highly effective compounds applied in the environment to protect humans from the hazardous effects of pests. While plant growth regulators show similar functions, mainly improving agricultural production, tropane alkaloids are naturally occurring secondary metabolites mainly in the species of Solanaceae that may pose unintended poisoning of humans. The third part of the present thesis aimed to analyze cereal-relevant compounds simultaneously, wherefore a multi-method for the analysis of (modified) mycotoxins, pesticides, plant growth regulators, and tropane alkaloids was established. After processing the samples, this should be done in a single extraction step with subsequent one-time measurements. Various sample preparation procedures were compared, whereby an approach based on an acidified acetonitrile/water extraction, followed by an online clean-up, was finally chosen. The simultaneous determination of more than 350 analytes required an analytical tool that offered an increased resolving power, represented as an enhanced peak capacity, and the possibility of analyzing a broad polarity range. Thus, a two-dimensional LC-MS/MS system based on two different separation mechanisms that performed orthogonal to one another was used for the analysis. Validation of the developed method revealed good performance characteristics for most analytes, while subsequent application showed that 86\% of the samples were contaminated with at least one compound. In summary, this thesis provides novel insights into the analysis of food-relevant (modified) mycotoxins. Different sample preparation and LC-MS/MS approaches were introduced, resulting in the development of three new analytical methods. For the first time, such a high number of modified mycotoxins was included in multi-mycotoxin methods and a multi-method ranging both contaminants and residues. Although first steps towards the analysis of modified mycotoxins have been made, further research is needed to elucidate their (co-) occurrence and toxicological behavior in order to understand their relevance to human health in the future.},
  language  = {en}
}