TY - JOUR A1 - Kunc, F. A1 - Nirmalananthan-Budau, Nithiya A1 - Rühle, Bastian A1 - Sung, Y. A1 - Johnston, L.J. A1 - Resch-Genger, Ute T1 - Interlaboratory Comparison on the Quantification of Total and Accessible Amine Groups on Silica Nanoparticles with qNMR and Optical Assays JF - Analytical chemistry N2 - Risk assessment of nanomaterials requires not only standardized toxicity studies but also validated methods for nanomaterial surface characterization with known uncertainties. In this context, a first bilateral interlaboratory comparison on Surface group quantification of nanomaterials is presented that assesses different reporter-free and labeling methods for the quantification of the total and accessible number of amine functionalities on commercially available silica nanoparticles that are widely used in the life sciences. The overall goal of this comparison is the identification of optimum methods as well as achievable measurement uncertainties and the comparability of the results across laboratories. We also examined the robustness and ease of implementation of the applied analytical methods and discussed method-inherent limitations. In summary, this comparison presents a first step toward the eventually required standardization of methods for surface group quantification. KW - Nano KW - Nanomaterial KW - Surface KW - Method KW - QNMR KW - Quantification KW - Comparison KW - Quality assurance KW - Optical probe KW - Sensor KW - Interlabority comparison KW - Standardization KW - Optical assay KW - Functional group analysis KW - Silica KW - Particle KW - Safety KW - Environment PY - 2021 DO - https://doi.org/10.1021/acs.analchem.1c02162 SN - 1520-6882 VL - 93 IS - 46 SP - 15271 EP - 15278 PB - ASC Publications AN - OPUS4-53818 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Radnik, Jörg A1 - Reed, B. A1 - Shard, A. T1 - Elemental composition of an ionic liquid surface N2 - (1) First results show the suitability of IL as reference for quantification of XPS (at least for organic materials). (2) Different quantification methods lead to similar results (with a slight advantage for “background method”). (3)Promising reference material for a better understanding and traceable protocols for the quantification of organic materials with XPS. T2 - BIPM / SAWG Spring Meeting CY - Online meeting DA - 12.05.2021 KW - Ionic liquid KW - X-ray photoelectron spectroscopy KW - Quantification PY - 2021 AN - OPUS4-52688 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Given, Joseph A1 - Lehleitner, Johannes T1 - First insights into the human-related risks of tunnel inspection N2 - Whereas human factors (HF) in the non-destructive testing (NDT) of metallic components are a poorly investigated topic (in comparison to other industrial fields such as aviation), HF in the inspection of concrete components are even less known. Studies have shown that there is always some variability between individuals in their inspection results and that HF affect the reliability of NDT inspections. The aim of the ongoing WIPANO project is to draft a standard for a holistic reliability assessment, with concrete inspection as one case study. This includes also the HF. A human-oriented Failure Modes and Effects Analysis (FMEA) was carried out to do the following: a) identify possible human-related risks in tunnel inspection processes using a laser scan method (including data collection,evaluation, and assessment of tunnel damage) and b) evaluate these human-related risks as regards their possible causes, consequences and probability of occurrence – in addition with respect to existing and possible preventive measures. The results show that the causes for possible failures can lie within people, the physical environment, technology, organisation, and extra-organisational environment. Whereas current preventive measures rely mostly on the individual and quality management practices, there is potential for even larger improvement at the organisational and extra-organisational level. The FMEA results were also used to develop a quantification method to further understand the HF in tunnel inspection, which could possibly be included in the information into the overall reliability assessment. The usage of qualitative and quantitative data collected through the human-FMEA within the proposed quantification method shows promise that HF can be quantified and could offer broader understanding of HF influences on inspection in various industries. T2 - NDT-CE 2022 CY - Zurich, Switzerland DA - 16.08.2022 KW - Human Factors KW - Failure Modes and Effects Analysis KW - FMEA KW - Tunnel Inspection KW - NDT Reliability KW - Quantification PY - 2022 AN - OPUS4-56015 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Bertovic, Marija A1 - Given, Joseph A1 - Lehleitner, Johannes T1 - First insights into the human-related risks of tunnel inspection T2 - NDT-CE 2022 N2 - Whereas human factors (HF) in the non-destructive testing (NDT) of metallic components are a poorly investigated topic (in comparison to other industrial fields such as aviation), HF in the inspection of concrete components are even less known. Studies have shown that there is always some variability between individuals in their inspection results and that HF affect the reliability of NDT inspections. The aim of the ongoing WIPANO project is to draft a standard for a holistic reliability assessment, with concrete inspection as one case study. This includes also the HF. A human-oriented Failure Modes and Effects Analysis (FMEA) was carried out to do the following: a) identify possible human-related risks in tunnel inspection processes using a laser scan method (including data collection,evaluation, and assessment of tunnel damage) and b) evaluate these human-related risks as regards their possible causes, consequences and probability of occurrence – in addition with respect to existing and possible preventive measures. The results show that the causes for possible failures can lie within people, the physical environment, technology, organisation, and extra-organisational environment. Whereas current preventive measures rely mostly on the individual and quality management practices, there is potential for even larger improvement at the organisational and extra-organisational level. The FMEA results were also used to develop a quantification method to further understand the HF in tunnel inspection, which could possibly be included in the information into the overall reliability assessment. The usage of qualitative and quantitative data collected through the human-FMEA within the proposed quantification method shows promise that HF can be quantified and could offer broader understanding of HF influences on inspection in various industries T2 - The International Symposium on Nondestructive Testing in Civil Engineering CY - Zurich, Switzerland DA - 16.08.2022 KW - Human Factors KW - Failure Modes and Effects Analysis KW - FMEA KW - Tunnel Inspection KW - NDT Reliability KW - Quantification PY - 2022 UR - https://nbn-resolving.org/urn:nbn:de:kobv:b43-560138 SP - 1 EP - 5 AN - OPUS4-56013 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Geißler, Daniel A1 - Nirmalananthan-Budau, Nithiya A1 - Moser, Marko A1 - Resch-Genger, Ute T1 - Synthesis of polymeric nanobeads with different surface group densities and their charaterization using multimodal cleavable reporters and lanthanide tags N2 - Polymeric nanoparticles (NP) are of increasing importance for a wide range of applications in the material and life sciences, including their use as drug carriers, fluorescent sensors and multimodal reporters in a large variety of bioassays and bioimaging studies. Application-relevant properties of NP include their size (and size distribution), shape, optical properties, and ease of subsequent functionalization, e.g. with linkers, sensor molecules, and bioligands. In this respect, knowledge of the chemical nature, the total number of surface groups and the number of groups accessible for subsequent coupling reactions is mandatory.1 Commercially available polystyrene NP often contain different additives like stabilizers, radical starters and crosslinkers, which can influence the quantification of surface functionalities. Moreover, they often have unknown surface group densities that may vary from batch to batch, which complicates or even hampers their reliable use in many (bio)applications. To circumvent these issues, we synthesized amino- and carboxy-functionalized, monodisperse 100 nm polystyrene NP with three different, well-defined surface group densities. Using a recently developed approach for the quantification of functional groups on nano- and microparticles with cleavable reporters,2 we quantified the assessible functional groups on the self-synthesised PS particles via optical spectroscopy (photometry) and inductively coupled optical emission spectrometry (32S ICP-OES). In addition, we developed a fluorimetric approach for the quantification of surface functional groups on nanoparticles based on the labelling with luminescent lanthanide complexes (LLC). In contrast to common organic dyes, LLC are not prone to photo¬luminescence quenching arising from reabsorption or dye aggregation, and thus, enable a reliable fluorometric quantification of the assessible functional groups on NP surfaces. Moreover, lanthanide tags can be detected with high specificity and sensitivity with analytical techniques such as XPS and ICP-MS, which allow for the multimodal validation of the fluorometric quantification approach. T2 - RSC-NPL Symposium "Nanoparticle concentration – critical needs and state-of-the-art measurement" and EMPIR 14IND12 Innanopart Open Day CY - London, UK DA - 24.05.2018 KW - Nanoparticle KW - Functional group KW - Quantification PY - 2018 N1 - Geburtsname von Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. - Birth name of Nirmalananthan-Budau, Nithiya: Nirmalananthan, N. AN - OPUS4-44836 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Hoffmann, Katrin A1 - Wegmann, Marc A1 - Hannemann, Mandy A1 - Somma, Valentina A1 - Jochum, Tobias A1 - Niehaus, Jan A1 - Roggenbuck, Dirk A1 - Resch-Genger, Ute T1 - NanoGenotox - Automatable determination of genotoxicity of nanoparticles with DNA-based optical assays N2 - The overall interest in nanotoxicity, triggered by the increasing use of nanomaterials in the material and life sciences, and the synthesis of an ever increasing number of new functional nanoparticles calls for standardized test procedures and for efficient approaches to screen the potential genotoxicity of these materials. Aiming at the development of fast and easy to use, automated microscopic methods for the determination of the genotoxicity of different types of nanoparticles, we assess the potential of the fluorometric γH2AX assay for this purpose. This assay, which can be run on an automated microscopic detection system, relies on the detection of DNA double strand breaks (DSB) as a sign for genotoxicity. Here, we provide first results obtained with broadly used nanomaterials like CdSe/CdS and InP/ZnS quantum dots as well as iron oxide, gold, and polymer particles of different surface chemistry with previously tested colloidal stability and different cell lines like Hep-2 and 8E11 cells, which reveal a dependence of the genotoxicity on the chemical composition as well as the surface chemistry of these nanomaterials. These studies will be also used to establish nanomaterials as positive and negative genotoxicity controls or standards for assay performance validation for users of this fluorometric genotoxicity assay. In the future, after proper validation, this microscopic platform technology will be expanded to other typical toxicity assays. T2 - Nanoworkshop 2018 CY - PTB Berlin-Adlershof, Germany DA - 14.05.2018 KW - Qdots KW - Surface functions KW - Quantification KW - Nanogenotoxicity PY - 2018 AN - OPUS4-45126 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute T1 - Introduction to Fluorescence Spectroscopy N2 - A brief introduction to fluorescence spectroscopy will be provided, ranging from typically measured fluorescence quantities over instrument-specific contributions to measured fluorescence signals to selected applications. In this context, an overview of the photoluminescence properties of molecular and nanoscale luminescence reporters will be given including a brief insight into their photophysics and fluorescence standards designed by division Biophotonics for the calibration and instrument performance validation of fluorescence measuring devices will be presented. T2 - Analytical Academy BAM CY - Online meeting DA - 17.11.2020 KW - Fluorescence KW - Quality assurance KW - Quantification KW - Linearity KW - Measurement uncertainty KW - Method KW - Nano particle KW - Dye PY - 2020 AN - OPUS4-51619 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Moraleja, I. A1 - Mena, M. L. A1 - Lázaro, A. A1 - Neumann, B. A1 - Tejedor, A. A1 - Jakubowski, Norbert A1 - Gómez-Gómez, M. M. A1 - Esteban-Fernández, D. T1 - An approach for quantification of platinum distribution in tissues by LA-ICP-MS imaging using isotope dilution analysis JF - Talanta N2 - Laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) has been revealed as a convenient technique for trace elemental imaging in tissue sections, providing elemental 2D distribution at a quantitative level. For quantification purposes, in the last years several approaches have been proposed in the literature such as the use of CRMs or matrix matched standards. The use of Isotope Dilution (ID) for quantification by LA-ICP-MS has been also described, being mainly useful for bulk analysis but not feasible for spatial measurements so far. In this work, a quantification method based on ID analysis was developed by printing isotope-enriched inks onto kidney slices from rats treated with antitumoral Pt-based drugs using a commercial ink-jet device, in order to perform an elemental quantification in different areas from bio-images. For the ID experiments ¹⁹⁴Pt enriched platinum was used. The methodology was validated by deposition of natural Pt standard droplets with a known amount of Pt onto the surface of a control tissue, where could be quantified even 50 pg of Pt, with recoveries higher than 90%. The amount of Pt present in the whole kidney slices was quantified for cisplatin, carboplatin and oxaliplatin-treated rats. The results obtained were in accordance with those previously reported. The amount of Pt distributed between the medullar and cortical areas was also quantified, observing different behavior for the three drugs. KW - Isotopic dilution KW - LA-ICP-MS KW - Quantification KW - Imaging KW - Kidney KW - Pt-based drugs PY - 2018 DO - https://doi.org/10.1016/j.talanta.2017.09.031 SN - 0039-9140 VL - 178 SP - 166 EP - 171 PB - Elsevier AN - OPUS4-43627 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Millar, Steven A1 - Kruschwitz, Sabine A1 - Wilsch, Gerd T1 - Determination of total chloride content in cement pastes with laser-induced breakdown spectroscopy (LIBS) JF - Cement and Concrete Research N2 - The presented work discusses the accuracy of Laser Induced Breakdown Spectroscopy (LIBS) in determining the total chloride content in cement pastes. LIBS as an emission spectroscopy method is used to detect simultaneously several elements present in cement-based materials. By scanning surfaces the variability in the spatial distribution of elements can be visualised. However, for a quantification of the results, studies are necessary to characterise possible influences due to the wide variation of the chemical compositions in which cement can occur. It is shown how the calibration can be done, how the calibration samples were produced, and which statistical parameters are necessary to describe the precision of the regression. The performance of LIBS is estimated by detecting chloride in validation samples. Therefore, 55 samples and 7 ets with changing mix ompositions were produced. The presented study deals with possible influences of different mix compositions, ncluding different cations of chloride, varying w/c-ratios and the artial replacement of Portland cement with last furnace slag (50% BFS) and limestone (30% LS). Comparing the LIBS results with otentiometric titration, n accuracy of±0.05 wt%/total has been determined. KW - Spectroscopy KW - LIBS KW - Chloride KW - Quantification KW - Cement PY - 2019 DO - https://doi.org/10.1016/j.cemconres.2018.12.001 SN - 0008-8846 VL - 117 IS - March SP - 16 EP - 22 PB - Elsevier CY - Amsterdam AN - OPUS4-47059 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Resch-Genger, Ute A1 - Nirmalanthan-Budau, Nithiya A1 - Moser, Marko A1 - Roloff, Alexander A1 - Moldenhauer, Daniel T1 - Quantification of Surface Groups on Nanomaterials with Simple Optical Methods N2 - Surface functionalization of nanomaterials is nowadays at the core of many applications of functional materials in the life and material sciences. Examples range from membranes and microarrays over bead-based assays, and next generation sequencing to nanometer-sized optical reporters, nanosensors, and magnetic and optical contrast agents. Typical function-nalization steps include silanization and grafting reactions with reactive monomers to introduce functional groups like amino or carboxylic acid groups or the attachment of ligands like polyethylene glycol (PEG) molecules and biomolecules. [1-3] This enables to tune e.g., dis-persibility, hydrophilicity and biocompatibility, minimize unspecific interactions, improve biofunctionalization efficiencies, and enhance blood circulation times and allows for the use of nanomaterials as reporters in assays or the design of targeted probes for bioimaging. At the core of all functionalization strategies are reliable and validated methods for surface group and ligand quantification that can be preferably performed with routine laboratory instrumentation, require only small amounts of substances, and are suitable for many different types of nanomaterials. [3] There is meanwhile a considerable need to make these methods traceable. We present here versatile and simple concepts for the quantification of common functional groups, ligands, and biomolecules on different types of organic and inorganic nanomaterials, using conventional and newly developed cleavable and multimodal reporters, that can be detected with optical spectroscopy. [4-7] These reporters are chosen to enable method validation with the aid of method comparisons and mass balances. Also, strategies how to make these simple assays traceable to SI units using quantitative nuclear resonance spectroscopy (qNMR) and X-ray photoelectron spectroscopy (XPS) are derived. T2 - JRC-NIST Workshop CY - Ispra, Italy DA - 04.12.2018 KW - Nanoparticle KW - Nanocrystal KW - Absolute fluorometry KW - Fluorescence KW - Surface chemistry KW - Assay KW - Cleavable probe KW - Conductometry KW - Quantification KW - Functional group PY - 2018 AN - OPUS4-46950 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -