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 -