TY - JOUR A1 - Kotthoff, Lisa A1 - O’Callaghan, S.-L. A1 - Lisec, Jan A1 - Schwerdtle, T. A1 - Koch, Matthias T1 - Structural annotation of electro- and photochemically generated transformation products of moxidectin using high-resolution mass spectrometry N2 - Moxidectin (MOX) is a widely used anthelmintic drug for the treatment of internal and external parasites in food-producing and companion animals. Transformation products (TPs) of MOX, formed through metabolic degradation or acid hydrolysis, May pose a potential environmental risk, but only few were identified so far. In this study, we therefore systematically characterized electro- and photochemically generatedMOX TPs using high-resolution mass spectrometry (HRMS). Oxidative electrochemical (EC) TPs were generated in an electrochemical reactor and photochemical (PC) TPs by irradiation with UV-C light. Subsequent HRMS measurements were performed to identify accuratemasses and deduce occurring modification reactions of derived TPs in a suspected target analysis. In total, 26 EC TPs and 59 PC TPs were found. The main modification reactions were hydroxylation, (de-)hydration, and derivative formation with methanol for EC experiments and isomeric changes, (de-)hydration, and changes at the methoxime moiety for PC experiments. In addition, several combinations of different modification reactions were identified. For 17 TPs, we could predict chemical structures through interpretation of acquired MS/MS data. Most modifications could be linked to two specific regions of MOX. Some previously described metabolic reactions like hydroxylation or O-demethylation were confirmed in our EC and PC experiments as reaction type, but the corresponding TPs were not identical to known metabolites or degradation products. The obtained knowledge regarding novel TPs and reactions will aid to elucidate the degradation pathway of MOX which is currently unknown. KW - Moxidectin KW - Transformation products KW - Electrochemical Reactor PY - 2020 DO - https://doi.org/10.1007/s00216-020-02572-1 VL - 412 IS - 13 SP - 3141 EP - 3152 PB - Springer AN - OPUS4-50721 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Bliesener, Lilly A1 - Weiss, Tilman A1 - Koch, Matthias T1 - Marker Substances in the Aroma of Truffles N2 - The aim of this study was to identify specific truffle marker substances within the truffle aroma. The aroma profile of different truffle species was analyzed using static headspace sampling with gas chromatography mass spectrometry analysis (SHS/GC-MS). Possible marker substances were identified, taking the additional literature into account. The selected marker substances were tested in an experiment with 19 truffle dogs. The hypothesis “If trained truffle dogs recognize the substances as supposed truffles in the context of an experiment, they can be regarded as specific” was made. As it would be nearly impossible to investigate every other possible emitter of the same compounds to determine their specificity, this hypothesis was a reasonable approximation. We were interested in the question of what it is the dogs actually search for on a chemical level and whether we can link their ability to find truffles to one or more specific marker substances. The results of the dog experiment are not as unambiguous as could have been expected based on the SHS/GC-MS measurements. Presumably, the truffle aroma is mainly characterized and perceived by dogs by dimethyl sulfide and dimethyl disulfide. However, as dogs are living beings and not analytical instruments, it seems unavoidable that one must live with some degree of uncertainty regarding these results. KW - Truffle KW - Volatile organic compounds; KW - Gas chromatography KW - Mass spectrometry KW - Canine olfactometry PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-556116 DO - https://doi.org/10.3390/molecules27165169 SN - 1420-3049 VL - 27 IS - 16 SP - 1 EP - 19 PB - MDPI CY - Basel AN - OPUS4-55611 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Koch, Matthias T1 - On-Site Detection of Volatile Organic Compounds (VOCs) N2 - Volatile organic compounds (VOCs) are of interest in many different fields. Among them are food and fragrance analysis, environmental and atmospheric research, industrial applications, security or medical and life science. In the past, the characterization of these compounds was mostly performed via sample collection and off-site analysis with gas chromatography coupled to mass spectrometry (GC-MS) as the gold standard. While powerful, this method also has several drawbacks such as being slow, expensive, and demanding on the user. For decades, intense research has been dedicated to find methods for fast VOC analysis on-site with time and spatial resolution. We present the working principles of the most important, utilized, and researched technologies for this purpose and highlight important publications from the last five years. In this overview, non-selective gas sensors, electronic noses, spectroscopic methods, miniaturized gas chromatography, ion mobility spectrometry and direct injection mass spectrometry are covered. The advantages and limitations of the different methods are compared. Finally, we give our outlook into the future progression of this field of research. KW - Volatile organic compounds KW - On-site detection KW - Mobile analytics KW - Sensors PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-570885 DO - https://doi.org/10.3390/molecules28041598 VL - 28 IS - 4 SP - 1 EP - 19 PB - MDPI CY - Basel, Switzerland AN - OPUS4-57088 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knoche, Lisa A1 - Lisec, Jan A1 - Koch, Matthias T1 - Analysis of electrochemical and liver microsomal transformation products of lasalocid by LC/HRMS N2 - Rationale: Lasalocid (LAS), an ionophore, is used in cattle and poultry farming as feed additive for its antibiotic and growth-promoting properties. Literature on transformation products (TP) resulting from LAS degradation is limited. So far, only hydroxylation is found to occur as the metabolic reaction during the LAS degradation. To investigate potential TPs of LAS, we used electrochemistry (EC) and liver microsome (LM) assays to synthesize TPs, which were identified using liquid chromatography high-resolution mass spectrometry (LC/HRMS). Methods: Electrochemically produced TPs were analyzed online by direct coupling of the electrochemical cell to the electrospray ionization (ESI) source of a Sciex Triple-TOF high resolution mass spectrometer. Then, EC-treated LAS solution was collected and analyzed offline using LC/HRMS to confirm stable TPs and improve their annotation with a chemical structure due to informative MS/MS spectra. In a complementary approach, TPs formed by rat and human microsomal incubation were investigated using LC/HRMS. The resulting data were used to investigate LAS modification reactions and elucidate the chemical structure of obtained TPs. Results: The online measurements identified a broad variety of TPs, resulting from modification reactions like (de-)hydrogenation, hydration, methylation, oxidation as well as adduct formation with methanol. We consistently observed different ion complexations of LAS and LAS-TPs (Na+; 2Na+ K+; NaNH4 +; KNH4 +). Two stable methylated EC-TPs were found, structurally annotated, and assigned to a likely modification reaction. Using LM incubation, seven TPs were formed, mostly by oxidation/hydroxylation. After the identification of LM-TPs as Na+-complexes, we identified LM-TPs as K+-complexes. Conclusion: We identified and characterized TPs of LAS using EC- and LM-based methods. Moreover, we found different ion complexes of LAS-based TPs. This knowledge, especially the different ion complexes, may help elucidate the metabolic and environmental degradation pathways of LAS. KW - Mass Spectrometry KW - Electrochemistry KW - ECR KW - Lasalocid KW - Ionophore KW - Transformation products PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-553919 DO - https://doi.org/10.1002/rcm.9349 VL - 36 IS - 18 SP - 1 EP - 10 PB - Wiley online library AN - OPUS4-55391 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Koch, Matthias A1 - Mauch, Tatjana A1 - Riedel, Juliane T1 - Development of a Hydrazine-Based Solid-Phase Extraction and Clean-Up Method for Highly Selective Quantification of Zearalenone in Edible Vegetable Oils by HPLC-FLD N2 - Rapid, cost-efficient, and eco-friendly methods are desired today for routine analysis of the Fusarium mycotoxin zearalenone (ZEN) in edible vegetable oils. Liquid chromatography with fluorescence detection (HPLC-FLD) is commonly used to reliably control the specified ZEN maximum levels, which requires efficient sample clean-up to avoid matrix interferences. Therefore, a highly selective extraction and clean-up method based on reversible covalent hydrazine chemistry (RCHC) using hydrazine-functionalized silica was developed. This efficient solid-phase extraction (SPE) involves reversible hydrazone formation of ZEN with the hydrazine moiety covalently bound to a solid phase. Optimal conditions were achieved with 1 mL SPE cartridges filled with 400 mg of hydrazine-functionalized silica. The developed RCHC-SPE method was validated in an interlaboratory comparison study (ILC) with twelve participants analyzing six edible vegetable oils with a focus on maize oils. The derived method parameters (ZEN recovery 83%, repeatability 7.0%, and reproducibility 18%) meet the performance criteria of Commission Regulation (EC) No 401/2006. The developed RCHC-SPE-based HPLC-FLD method allows the reliable quantification of ZEN in the range of 47–494 μg/kg for different types of edible vegetable oils, also for matrix-reach native oils. Due to the high efficiency, the significantly reduced matrix load helps to extend the lifetime of analytical equipment. Furthermore, the re-useability of the RCHC-SPE cartridges contributes to an eco-friendly approach and reduced analysis costs. To our knowledge, this is the first report on ZEN quantification in edible vegetable oils based on manual RCHC-SPE cartridges. Due to its high performance, the developed RCHC-SPE method is a promising alternative to the current European standard method EN 16924:2017 (HPLC-FLD part). KW - Mycotoxin KW - Food KW - Reversible covalent hydrazine chemistry (RCHC) KW - Quantitative determination PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-554812 DO - https://doi.org/10.3390/toxins14080549 VL - 14 IS - 8 PB - MDPI CY - Basel AN - OPUS4-55481 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Epping, Ruben A1 - Lisec, Jan A1 - Koch, Matthias T1 - Changes in Black Truffle (Tuber melanosporum) Aroma during Storage under Different Conditions N2 - The enticing aroma of truffles is a key factor for their culinary value. Although all truffle species tend to be pricy, the most intensely aromatic species are the most sought after. Research into the aroma of truffles encompasses various disciplines including chemistry, biology, and sensory science. This study focusses on the chemical composition of the aroma of black truffles (Tuber melanosporum) and the changes occurring under different storage conditions. For this, truffle samples were stored under different treatments, at different temperatures, and measured over a total storage time of 12 days. Measurements of the truffle aroma profiles were taken with SPME/GC–MS at regular intervals. To handle the ample data collected, a systematic approach utilizing multivariate data analysis techniques was taken. This approach led to a vast amount of data which we made publicly available for future exploration. Results reveal the complexity of aroma changes, with 695 compounds identified, highlighting the need for a comprehensive understanding. Principal component analyses offer initial insights into truffle composition, while individual compounds may serve as markers for age (formic acid, 1-methylpropyl ester), freshness (2-Methyl-1-propanal; 1-(methylthio)-propane), freezing (tetrahydrofuran), salt treatment (1-chloropentane), or heat exposure (4-hydroxy-3-methyl-2-butanone). This research suggests that heat treatment or salt contact significantly affects truffle aroma, while freezing and cutting have less pronounced effects in comparison. The enrichment of compounds showing significant changes during storage was investigated with a metabolomic pathway analysis. The involvement of some of the enriched compounds on the pyruvate/glycolysis and sulfur pathways was shown. KW - Mass Spectrometry KW - Metabolomics KW - Tuber melanosporum KW - Truffle Aroma PY - 2024 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-601731 DO - https://doi.org/10.3390/jof10050354 VL - 10 IS - 5 SP - 1 EP - 22 PB - MDPI AN - OPUS4-60173 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Herter, Sven-Oliver A1 - Haase, Hajo A1 - Koch, Matthias T1 - Semisynthesis of Stable Isotope-Labeled Ergot Alkaloids for HPLC-MS/MS Analysis N2 - Ergot alkaloids (EAs) are prevalent food contaminants affecting cereals, such as rye, wheat, and barley worldwide. To ensure EU safety standards, the six most common EAs: ergometrine, ergotamine, ergosine, ergocornine, ergocristine, and ergocryptine, and their epimers, are quantified using HPLC-MS/MS, as described in the European Standard Method EN 17425:2021. However, this can be challenging and time-consuming in food matrices without appropriate internal standards and highlights the need for more robust and precise analytical tools to support their monitoring. The development of isotope-labeled EAs directly addresses this gap, offering improved accuracy and leading to more consistency across laboratories and consequently to more consumer safety. Therefore, we developed a semisynthetic approach, building upon our previous work where native ergotamine was N6-demethylated to norergotamine and subsequently remethylated using iodomethane (13CD3-I). Herein, we are now able to present the successful synthesis of all of the isotopically labeled priority EAs. These isotope-labeled standards were tested against their native counterparts using HPLC coupled with HR-MS/MS. The chromatographic and mass spectrometric properties of the unlabeled and isotopically labeled EAs match exactly, confirming their successful synthesis and structure. These standards can now be utilized to enhance the accuracy and reliability of EA quantification in food and feed. KW - Reference Material KW - HPLC-MS/MS KW - Mycotoxins KW - Ergot Alkaloids KW - Stable Isotope Dilution Analysis KW - Semisynthesis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-639692 DO - https://doi.org/10.1021/acs.jafc.5c03345 SN - 0021-8561 VL - 73 IS - 29 SP - 18412 EP - 18419 PB - American Chemical Society (ACS) AN - OPUS4-63969 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Knoche, Lisa A1 - Lisec, Jan A1 - Schwerdtle, T. A1 - Koch, Matthias T1 - LC-HRMS-Based Identification of Transformation Products of the Drug Salinomycin Generated by Electrochemistry and Liver Microsome N2 - The drug salinomycin (SAL) is a polyether antibiotic and used in veterinary Medicine as coccidiostat and growth promoter. Recently, SAL was suggested as a potential anticancer drug. However, transformation products (TPs) resulting from metabolic and environmental degradation of SAL are incompletely known and structural information is missing. In this study, we therefore systematically investigated the formation and identification of SAL derived TPs using electrochemistry (EC) in an electrochemical reactor and rat and human liver microsome incubation (RLM and HLM) as TP generating methods. Liquid chromatography (LC) coupled to high-resolution mass spectrometry (HRMS) was applied to determine accurate masses in a suspected target analysis to identify TPs and to deduce occurring modification reactions of derived TPs. A total of 14 new, structurally different TPs were found (two EC-TPs, five RLM-TPs, and 11 HLM-TPs). The main modification reactions are decarbonylation for EC-TPs and oxidation (hydroxylation) for RLM/HLM-TPs. Of particular interest are potassium-based TPs identified after liver microsome incubation because these might have been overlooked or declared as oxidated sodium adducts in previous, non-HRMS-based studies due to the small mass difference between K and O + Na of 21 mDa. The MS fragmentation pattern of TPs was used to predict the position of identified modifications in the SAL molecule. The obtained knowledge regarding transformation reactions and novel TPs of SAL will contribute to elucidate SAL-metabolites with regards to structural prediction. KW - Salinomycin KW - Ionophore antibiotics KW - Transformation product KW - Electrochemistry KW - Rat/human liver microsomes KW - HRMS PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-542543 DO - https://doi.org/10.3390/antibiotics11020155 SN - 2079-6382 VL - 11 IS - 2 SP - 155 PB - MDPI CY - Basel AN - OPUS4-54254 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuner, Maximilian A1 - Lisec, Jan A1 - Picher, Marie-Idrissa A1 - Rigo, Massimo A1 - Konetzki, Jörg A1 - Haase, Hajo A1 - Koch, Matthias T1 - Development and Application of Isotope Labelled Internal Standards in a Sum Parameter Method for Ergot Alkaloid Screening of Food N2 - Ergot alkaloids are a group of toxic compounds, formed by fungi on infested grasses. In 2022, the European Commission set into effect maximum levels for the sum of the twelve major ergot alkaloids in multiple foods. To facilitate the laborious and costly individual quantification of the twelve major ergot alkaloids by HPLC–MS/MS or -FLD, we recently reported a sum parameter method (SPM) for ergot alkaloid quantification. Here, derivatization to lysergic acid hydrazide—a derivative of the mutual ergoline backbone in all ergot alkaloids—allowed simplified determination of all ergot alkaloids in flour via HPLC-FLD. For the measurement of more complex matrices like processed foods, we now developed a MS/MS-based SPM. Two internal standards (IS), isotopically labelled at different positions of the molecule, were synthesized and employed in the MS/MS-measurements. Method performance using either the 13CD3-labelled or the 15N2-labelled IS was evaluated on naturally contaminated rye and wheat flour samples as well as on processed food matrices. Employing the 13CD3-labelled IS leads to lower variances and better consistency with the reference data (obtained by the FLD-based SPM) in flour samples compared to the 15N2-labelled IS. The novel method significantly improves the measurement of ergot alkaloids in complex food matrices, due to their increased selectivity and thus lower interferences. Furthermore, the application of isotope labelled IS obviates the need for time-consuming steps like the determination of recovery rate based, matrix specific correction factors as described in the MS/MS-based European standard method for ergot alkaloid quantification (EN 17425). KW - Mycotoxins KW - Sum Parameter Method KW - Isotope Labelling KW - HPLC-MS/MS KW - Analytical Chemistry KW - Lysergic acid hydrazide PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-588582 DO - https://doi.org/10.1007/s12161-023-02553-x SN - 1936-976X VL - 17 IS - 1 SP - 119 EP - 128 PB - Springer CY - New York, NY AN - OPUS4-58858 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuner, Maximilian A1 - Lisec, Jan A1 - Mauch, Tatjana A1 - Konetzki, J. A1 - Haase, H. A1 - Koch, Matthias T1 - Quantification of Ergot Alkaloids via Lysergic Acid Hydrazide—Development and Comparison of a Sum Parameter Screening Method N2 - Ergot alkaloids are a group of mycotoxins occurring in products derived from various grasses (e.g., rye) and have been regulated in the EU recently. The new maximum levels refer to the sum of the six most common ergot alkaloids in their two stereoisomeric forms in different food matrices. Typically, these twelve compounds are individually quantified via HPLC-MS/MS or -FLD and subsequently summed up to evaluate food safety in a time-consuming process. Since all these structures share the same ergoline backbone, we developed a novel sum parameter method (SPM) targeting all ergot alkaloids simultaneously via lysergic acid hydrazide. After extraction and clean-up, in analogy to the current European standard method EN 17425 (ESM) for ergot alkaloid quantitation, the samples were derivatized by an optimized hydrazinolysis protocol, which allowed quantitative conversion after 20 min at 100 °C. The new SPM was evaluated against another established HPLC-FLD-based method (LFGB) and the HPLC-MS/MS-based ESM using six naturally contaminated rye and wheat matrix reference materials. While the SPM provided comparable values to the ESM, LFGB showed deviating results. Determined recovery rates, limits of detection and quantification of all three employed methods confirm that the new SPM is a promising alternative to the classical approaches for ergot alkaloid screening in food. KW - Ergot alkaloids KW - Sum Parameter KW - Mycotoxins KW - Derivatization KW - Hydrazinolysis PY - 2023 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-573968 DO - https://doi.org/10.3390/molecules28093701 SN - 0015-2684 VL - 28 IS - 9 SP - 3701 PB - MDPI CY - Basel AN - OPUS4-57396 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Li, X.M. A1 - Li, H.M. A1 - Zhang, Q.H. A1 - Lu, X.H. A1 - Li, S.Q. A1 - Koch, Matthias A1 - Polzer, J. A1 - Hackenber, R. A1 - Moniruzzaman, M. A1 - Khan, M. A1 - Kakoulides, E. A1 - Pak-Wing, K. A1 - Richy, A1 - Chi-Shing, N. A1 - Lu, T. A1 - Gui, E.M. A1 - Cheow, P.S. A1 - Teo, T.L. A1 - Rego, E. A1 - Garrido, B. A1 - Carvalho, L. A1 - Leal, R. A1 - Violante, F. A1 - Baek, S.Y. A1 - Lee, S. A1 - Choi, K. A1 - Kim, B. A1 - Bucar-Miklavcic, M. A1 - Hopley, C. A1 - Nammoonnoy, J. A1 - Murray, J. A1 - Wilson, W. A1 - Toman, B. A1 - Itoh, N. A1 - Gokcen, T. A1 - Krylov, A. A1 - Mikheeva, A. T1 - CCQM-K146 low-polarity analyte in high fat food: benzo a pyrene in olive oil N2 - The demonstration of competency and equivalence for the assessment of levels of contaminants and nutrients in primary foodstuffs is a priority within the 10-year strategy for the OAWG Track A core comparisons. The measurements are core challenges for reference material producers and providers of calibration Services. This key comparison related to low polarity analytes in a high fat, low protein, low carbohydrate food matrix and Benzo[a]pyrene in edible oil was the model System selected to align with this class within the OAWG strategy. Evidence of successful participation in formal, relevant international comparisons is needed to document measurement capability claims (CMCs) made by national metrology institutes (NMIs) and designated institutes (Dis). 16 National Metrology Institutions participated in the Track A Key Comparison CCQM-K146 Low-Polarity Analyte in high fat food: Benzo[a]pyrene in Olive Oil. Participants were requested to evaluate the mass fractions, expressed in µg/kg, of Benzo[a]pyrene in the olive oil material. The KCRV was determined from the results of all NMIs/DIs participating in the key comparison that used appropriately validated methods with demonstrated metrological traceability. Different methods such as liquid-liquid extraction, GPC and SPE were applied in the sample pretreatment and HPLC-FLD, HPLC-MS/MS, and GC-MS or GC-MS/MS were applied for detection by the participants. The mass fractions for BaP were in the range of (1.78 to 3.09) µg/kg with Standard uncertainties of (0.026 to 0.54) µg/kg, with corresponding relative Standard uncertainties from 0.9% to 21%. Five labs withdrew their result from the Statistical evaluation of the KCRV for technical reasons. One lab was excluded from the KCRV evaluation, as they did not meet the CIPM metrological traceability requirements. A Hierarchical Bayes option was selected for the KCRV value, which was determined as 2.74 µg/kg with a Standard uncertainty of 0.03 µg/kg. The 10 institutes those were included in the calculation of the consensus KCRV all agreed within their Standard uncertainties. Successful participation in CCQM-K146 demonstrates the measurement capabilities in determining mass fraction of organic compounds, with molecular mass of 100 g/mol to 500 g/mol, having low polarity pKow < -2, in mass fraction range from 0.1 µg/kg to 1000 µg/kg in a high fat, low protein, low carbohydrate food matrix. KW - Metrology KW - CCQM KW - Food KW - PAH PY - 2020 DO - https://doi.org/10.1088/0026-1394/57/1a/08017 VL - 57 IS - 1a SP - 08017 AN - OPUS4-52435 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hoffmann, A. A1 - Lischeid, G. A1 - Koch, Matthias A1 - Lentzsch, P. A1 - Sommerfeld, Thomas A1 - Müller, M.H. T1 - Co-Cultivation of Fusarium, Alternaria, and Pseudomonas on Wheat-Ears Affects Microbial Growth and Mycotoxin Production N2 - Mycotoxigenic fungal pathogens Fusarium and Alternaria are a leading cause of loss in cereal production. On wheat-ears, they are confronted by bacterial antagonists such as pseudomonads. Studies on these groups’ interactions often neglect the infection process’s temporal aspects and the associated priority effects. In the present study, the focus was on how the first colonizer affects the subsequent ones. In a climate chamber experiment, wheat-ears were successively inoculated with two different strains (Alternaria enuissima At625, Fusarium graminearum Fg23, or Pseudomonas simiae Ps9). Over three weeks, microbial abundances and mycotoxin concentrations were analyzed and visualized via Self Organizing Maps with Sammon Mapping (SOM-SM). All three strains revealed different characteristics and strategies to deal with co-inoculation: Fg23, as the first colonizer, suppressed the establishment of At625 and Ps9. Nevertheless, primary inoculation of At625 reduced all of the Fusarium toxins and stopped Ps9 from establishing. Ps9 showed priority effects in delaying and blocking the production of the fungal mycotoxins. The SOM-SM analysis visualized the competitive strengths: Fg23 ranked first, At625 second, Ps9 third. Our findings of species-specific priority effects in a natural environment and the role of the mycotoxins involved are relevant for developing biocontrol strategies. KW - Antagonists KW - Microbe interactions KW - Mycotoxins KW - Priority effect KW - SOM-SM PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-521554 DO - https://doi.org/10.3390/microorganisms9020443 VL - 9 IS - 2 SP - 443 PB - MDPI AN - OPUS4-52155 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Riedel, Juliane A1 - Recknagel, Sebastian A1 - Sassenroth, Diana A1 - Mauch, Tatjana A1 - Buttler, Sabine A1 - Sommerfeld, Thomas A1 - Penk, Sibylle A1 - Koch, Matthias T1 - Development and certification of a reference material for zearalenone in maize germ oil N2 - Zearalenone (ZEN), an estrogenic mycotoxin produced by several species of Fusarium fungi, is a common contaminant of cereal-based food worldwide. Due to frequent occurrences associated with high levels of ZEN, maize oil is a particular source of exposure. Although a European maximumlevel for ZEN in maize oil exists according to Commission Regulation (EC) No. 1126/2007 along with a newly developed international standard method for analysis, certified reference materials (CRM) are still not available. To overcome this lack, the first CRM for the determination of ZEN in contaminated maize germ oil (ERM®-BC715) was developed in the frame of a European Reference Materials (ERM®) project according to the requirements of ISO Guide 35. The whole process of CRM development including preparation, homogeneity and stability studies, and value assignment is presented. The assignment of the certified mass fraction was based upon an in-house study using high-performance liquid chromatography isotope dilution tandem mass spectrometry. Simultaneously, to support the in-house certification study, an interlaboratory comparison study was conducted with 13 expert laboratories using different analytical methods. The certified mass fraction and expanded uncertainty (k=2) of ERM®-BC715 (362± 22) μg kg−1 ZEN are traceable to the SI. This reference material is intended for analytical quality control and contributes to the improvement of consumer protection and food safety. KW - Fusarium mycotoxin KW - Vegetable edible oil KW - Food analysis KW - European Reference Material KW - Quality assurance PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-531831 DO - https://doi.org/10.1007/s00216-021-03532-z SN - 1618-2642 SN - 1618-2650 VL - 413 IS - 21 SP - 5483 EP - 5491 PB - Springer CY - Berlin AN - OPUS4-53183 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kuner, Maximilian A1 - Kühn, S. A1 - Haase, H. A1 - Meyer, Klas A1 - Koch, Matthias T1 - Cleaving Ergot Alkaloids by Hydrazinolysis - A Promising Approach for a Sum Parameter Screening Method N2 - Ergot alkaloids are mycotoxins formed by fungi of the Claviceps genus, which are some of the most common contaminants of food and feed worldwide. These toxins are a structurally heterogeneous group of compounds, sharing an ergoline backbone. Six structures and their corresponding stereoisomers are typically quantified by either HPLC-FLD or HPLC-MS/MS and the values subsequently summed up to determine the total ergot alkaloid content. For the development of a screening method targeting all ergot alkaloids simultaneously, the alkaloids need to be transferred to one homogeneous structure: a lysergic acid derivative. In this study, two promising cleaving methods—acidic esterification and hydrazinolysis—are compared, using dihydroergocristine as a model compound. While the acidic esterification proved to be unsuitable, due to long reaction times and oxidation sensitivity, hydrazinolysis reached a quantitative yield in 40-60 min. Parallel workup of several samples is possible. An increasing effect on the reaction rate by the addition of ammonium iodide was demonstrated. Application of hydrazinolysis to a major ergot alkaloid mix solution showed that all ergopeptines were cleaved, but ergometrine/-inine was barely affected. Still, hydrazinolysis is a suitable tool for the development of a sum parameter screening method for ergot alkaloids in food and feed. KW - Ergot alkaloids KW - Sum parameter method KW - Hydrazinolysis KW - Esterification PY - 2021 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-527508 DO - https://doi.org/10.3390/toxins13050342 VL - 13 IS - 5 SP - 342 PB - MDPI CY - Basel, Switzerland AN - OPUS4-52750 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tjaden, B. A1 - Lisec, Jan A1 - Schramm, A. T1 - N-Myc-induced metabolic rewiring creates novel therapeutic vulnerabilities in neuroblastoma N2 - N-Myc is a transcription factor that is aberrantly expressed in many tumor types and is often correlated with poor patient prognosis. Recently, several lines of evidence pointed to the fact that oncogenic activation of Myc family proteins is concomitant with reprogramming of tumor cells to cope with an enhanced need for metabolites during cell growth. These adaptions are driven by the ability of Myc proteins to act as transcriptional amplifiers in a tissue-of-origin specific manner. Here, we describe the effects of N-Myc overexpression on metabolic reprogramming in neuroblastoma cells. Ectopic expression of N-Myc induced a glycolytic switch that was concomitant with enhanced sensitivity towards 2-deoxyglucose, an inhibitor of glycolysis. Moreover, global metabolic profiling revealed extensive alterations in the cellular metabolome resulting from overexpression of N-Myc. Limited supply with either of the two main carbon sources, glucose or glutamine, resulted in distinct shifts in steady-state metabolite levels and significant changes in glutathione metabolism. Interestingly, interference with glutamine-glutamate conversion preferentially blocked proliferation of N-Myc overexpressing cells, when glutamine levels were reduced. Thus, our study uncovered N-Myc induction and nutrient levels as important metabolic master switches in neuroblastoma cells and identified critical nodes that restrict tumor cell proliferation. KW - Mass-Spectrometry KW - Cancer KW - MYCN PY - 2020 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-507193 DO - https://doi.org/10.1038/s41598-020-64040-1 VL - 10 IS - 1 SP - 7157 AN - OPUS4-50719 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Noureen, N. A1 - Shah, F. A. A1 - Lisec, Jan A1 - Usman, H. A1 - Khalid, M. A1 - Munir, R. A1 - Zaidi, N. T1 - Revisiting the Association between Human Leukocyte Antigen and End-Stage Renal Disease N2 - Multiple works have studied possible associations between human leukocyte antigen (HLA) alleles and end stage renal disease (ESRD). However, there are several contradictions in these previous works and no consistent HLA associations with ESRD itself have been identified. Most of these works have several limitations, for instance, the population size was too small, or only limited HLA loci were studied. The presented work aims to revisit the association between ESRD and HLA antigens while taking in to account the previously overlooked limitations. Here, we compared the HLA polymorphism (at HLA-A, -B, -C, -DRB1, -DQB1 and DQA1 loci) in ESRD patients (n=497) and controls (n=672). Our data identified several HLA alleles that displayed a significant positive or negative association with ESRD. We also determined whether heterozygosity or homozygosity of the ESRD-associated HLA alleles at different loci could modify the prevalence of the disease. Few HLA allele combinations displayed significant associations with ESRD among which HLA-A*3 –HLA-A*26 combination showed the highest strength of association (OR= 4.488, P≤ 0.05) with ESRD. However, the age of ESRD onset was not affected by HLA allele combinations at different loci. Most of the previous works have studied the association of HLA with ESRD in homogeneous ethnic groups and have interpreted their data accordingly. Here, we also performed an extensive literature analysis to determine whether the association of HLA to ESRD can be similar across different ethnic groups. This analysis showed that at least for certain alleles, the association of HLA to ESRD can be similar in different ethnic groups. For instance, HLA-A*11, HLA-DRB1*11, and HLA-DRB1*4 all showed significant positive associations with ESRD in different ethnic groups. The findings of our study will help in determining possible protective or susceptible roles of various HLA alleles in ESRD. KW - Mass-Spectrometry KW - HLA KW - Renal disease PY - 2020 DO - https://doi.org/10.1101/2020.03.18.996330 SP - 1 EP - 23 AN - OPUS4-50720 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Meermann, Björn A1 - Lisec, Jan A1 - Jaeger, Carsten A1 - Saatz, Jessica A1 - Traub, Heike A1 - von der Au, Marcus T1 - Mehr Analyten, kleinere Proben N2 - Molekülmassenspektrometrie entwickelt sich weg von klassischer Target- hin zu Nontarget-Analytik. Elementmassenspektrometrie liefert hohe Ortsauflösung beim Element-Imaging und analysiert einzelne Zellen. Aufgrund der Fortschritte bei den Geräten für Timeof-Flight-Massenspektrometrie mit induktiv gekoppeltem Plasma (ICPToF-MS) lässt sich das gesamte Periodensystem der Elemente in kurzen transienten Signalen quasi-simultan massenspektrometrisch erfassen. KW - Massenspektrometrie KW - Non-target KW - ICP-ToF-MS KW - Laser Ablation/Imaging PY - 2021 VL - 69 IS - Juni SP - 64 EP - 67 PB - Wiley-VCH AN - OPUS4-52800 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Dorgerloh, Ute A1 - Gökçe, Emine A1 - Freeling, Finnian T1 - Monitoring von Trifluoressigsäure (TFA) im Wasser: Neue DIN-Norm bringt Klarheit bei der Analytik N2 - Um eine zuverlässige und vergleichbare Messung von TFA in verschiedenen Wasserarten zu ermöglichen, wurde im DIN-Normenausschuss Wasserwesen (NAW) ein standardisiertes analytisches Verfahren entwickelt. Der im Dezember 2024 veröffentlichte Normentwurf DIN 38407-53 beschreibt ein LC-MS/MS-Verfahren zur Bestimmung von TFA mittels Direktinjektion. Die Norm adressiert den wachsenden Bedarf an einheitlichen Messstandards im Umweltmonitoring – mit Potenzial für den Einsatz in Überwachungsprogrammen, Laboratorien und Fachbehörden. KW - Trifluoressigsäure TFA KW - Validierungsringversuch PY - 2025 IS - 07 SP - 94 EP - 97 PB - DIN AN - OPUS4-64537 LA - deu AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Sebald, M. A1 - Gebauer, J. A1 - Koch, Matthias T1 - Concise Synthesis of Alternariol and Alternariol-9-monomethyl ether as well as their D3-Isotopologues N2 - Abstract Alternariol (AOH) and alternariol-9-monomethyl ether (AME) are two secondary metabolites of Alternaria fungi which can be found in various foodstuff like tomatoes, nuts, and grains. Due to their toxicity and potential mutagenic activity the need for the development of high-throughput methods for the supervision of AOH- and AME-levels is of increasing interest. As the availability of both native and labeled AOH and AME analytical standards is very limited we herein wish to present a novel concise approach towards their synthesis employing a ruthenium-catalyzed ortho-arylation as the key step. Finally, we demonstrate their suitability as internal standards in stable-isotope dilution assay (SIDA)-HPLC-MS/MS analysis commonly used for the quantification of the natural products in food and feed. KW - Mycotoxins KW - Food Analysis KW - Emerging contaminants PY - 2021 DO - https://doi.org/10.1055/a-1698-8328 SN - 0039-7881 VL - 54 IS - 19 SP - 4285 EP - 4293 PB - Thieme AN - OPUS4-53994 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Matiushkina, Anna A1 - Abram, Sarah-Luise A1 - Tavernaro, Isabella A1 - Richstein, R. A1 - Reithofer, M. R. A1 - Andresen, Elina A1 - Michaelis, Matthias A1 - Koch, Matthias A1 - Resch-Genger, Ute T1 - Quantifying Citrate Surface Ligands on Iron Oxide Nanoparticles with TGA, CHN Analysis, NMR, and RP-HPLC with UV Detection N2 - Although citrate is frequently used as a surface ligand for nanomaterials (NMs) such as metal, metal oxide, and lanthanide-based NMs in hydrophilic environments due to its biocompatibility and simple replacement by other more strongly binding ligands in postsynthetic surface modification reactions, its quantification on NM surfaces has rarely been addressed. Here, we present a multimethod approach for citrate quantification on iron oxide nanoparticles (IONPs) broadly applied in the life and material sciences. Methods explored include thermogravimetric (TGA) and elemental (CHN) analysis, providing citrate-nonspecific information on the IONP coating, simple photometry, and citrate-selective reversed-phase high-performance liquid chromatography (RP-HPLC) with absorption (UV) detection and quantitative nuclear magnetic resonance spectroscopy (qNMR). Challenges originating from the strongly absorbing magnetic NM and paramagnetic iron species interfering with optical and NMR Methods were overcome by suitable sample preparation workflows. Our multimethod approach to citrate quantification highlights the advantages of combining specific and unspecific methods for characterizing NM Surface chemistry and method cross-validation. It also demonstrates that chemically nonselective measurements can favor an overestimation of the amount of a specific surface ligand by signal contributions from molecules remaining on the NM surface, e.g., from particle synthesis, such as initially employed ligands and/or surfactants. Our results emphasize the potential of underexplored selective RPHPLC for quantifying ligands on NMs, which does not require a multistep sample preparation workflow such as qNMR for many NMs and provides a higher sensitivity. These findings can pave the road to future applications of versatile HPLC methods in NM characterization. KW - Advanced material KW - Functional group KW - Iron oxide KW - Ligand KW - Nano KW - Particle KW - Quantification KW - Surface analysis PY - 2025 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-648632 DO - https://doi.org/10.1021/acs.analchem.5c03024 SN - 0003-2700 VL - 97 IS - 36 SP - 19627 EP - 19634 PB - American Chemical Society (ACS) CY - Washington, DC AN - OPUS4-64863 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -