TY - JOUR A1 - Rosenkranz, Daniel A1 - Kriegel, F. L. A1 - Mavrakis, E. A1 - Pergantis, S. A. A1 - Reichardt, Ph. A1 - Tentschert, J. A1 - Jakubowski, Norbert A1 - Laux, P. A1 - Panne, Ulrich T1 - Improved validation for single particle ICP-MS analysis using a pneumatic nebulizer / microdroplet generator sample introduction system for multi-mode nanoparticle determination N2 - This study reports on the development of a single-particle (sp) inductively coupled plasma mass spectrometry (ICP-MS) technique suitable for the multi-mode determination of nanoparticle (NP) metal mass fraction and number concentration. The described technique, which is based on a dual inlet System consisting of a pneumatic nebulizer (PN) and a microdroplet generator (MDG), allows for the sequential introduction of ionic metal calibrant solutions and nanoparticle suspensions via all combinations of the two inlets; thus allowing for a combination of three independent modes of analysis. A novel interface, assembled using standard analytical components (a demountable quartz ICP-MS torch, flexible nonconducting silicon tubing and various connectors), was used to interface the dual inlet system to an ICP-MS. The interface provided improved functionality, compared to a previous design. It is now possible to conveniently exchange and introduce standard solutions and samples via all inlet combinations, analyze them, and also wash the sample inlet systems while the whole setup is still connected to an operating ICP-MS. This setup provided seamless and robust operation in a total of three analysis modes, i.e. three ways to independently determine the metal mass fraction and NP number concentration. All three analyses modes could be carried out within a single analytical run lasting approximately 20 min. The unique feature of the described approach is that each analysis mode is based on a different. KW - Nanomaterials KW - Nanoparticles KW - Single particle ICP-MS KW - Microdroplet generator PY - 2020 U6 - https://doi.org/10.1016/j.aca.2019.11.043 VL - 1099 SP - 16 EP - 25 PB - Elsevier B.V. AN - OPUS4-50361 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Rosenkranz, D. A1 - Kriegel, F. L. A1 - Mavrakis, E. A1 - Pergantis, S. A. A1 - Reichardt, P. A1 - Tentschert, J. A1 - Jakubowski, N. A1 - Laux, P. A1 - Panne, Ulrich A1 - Luch, A. T1 - Versatile dual-inlet sample introduction system for multi-mode single particle inductively coupled plasma mass spectrometry N2 - Metal-containing nanoparticles (NP) can be characterized with inductively coupled plasma mass spectrometers (ICP-MS) in terms of their size and number concentration by using the single-particle mode of the instrument (spICP-MS). The accuracy of measurement depends on the setup, operational conditions of the instrument and specific parameters that are set by the user. The transport efficiency of the ICP-MS is crucial for the quantification of the NP and usually requires a reference material with homogenous size distribution and a known particle number concentration. Currently, NP reference materials are available for only a few metals and in limited sizes. If particles are characterized without a reference standard, the results of both size and particle number may be biased. Therefore, a dual-inlet Setup for characterizing nanoparticles with spICP-MS was developed to overcome this problem. This setup is based on a conventional introduction system consisting of a pneumatic nebulizer (PN) for nanoparticle solutions and a microdroplet Generator (μDG) for ionic calibration solutions. A new and flexible interface was developed to facilitate the coupling of μDG, PN and the ICP-MS system. The interface consists of available laboratory components and allows for the calibration, nanoparticle (NP) characterization and cleaning of the arrangement, while the ICP-MS instrument is still running. Three independent analysis modes are available for determining particle size and number concentration. Each mode is based on a different calibration principle. While mode I (counting) and mode III (μDG) are known from the literature, mode II (sensitivity), is used to determine the transport efficiency by inorganic ionic Standard solutions only. It is independent of NP reference materials. The μDG based inlet system described here guarantees superior analyte sensitivities and, therefore, lower detection limits (LOD). The size dependent LODs achieved are less than 15 nm for all NP (Au, Ag, CeO2) investigated. KW - Spectrometer KW - Reference KW - Calibration PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-536121 SN - 1940-087X IS - 163 SP - 1 EP - 19 PB - MyJoVE Corporation CY - Cambridge, MA, USA AN - OPUS4-53612 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Laux, P. A1 - Tentschert, J. A1 - Riebeling, Ch. A1 - Braeuning, A. A1 - Creutzenberg, O. A1 - Epp, A. A1 - Fessard, V. A1 - Haas, K.-H. A1 - Haase, A. A1 - Hund-Rinke, K. A1 - Jakubowski, Norbert A1 - Kearns, P. A1 - Lampen, A. A1 - Rauscher, H. A1 - Schoonjans, R. A1 - Störmer, A. A1 - Thielmann, A. A1 - Mühle, U. A1 - Luch, A. T1 - Nanomaterials: certain aspects of application, risk assessment and risk communication N2 - Development and market introduction of new nanomaterials trigger the need for an adequate risk assessment of such products alongside suitable risk communication measures. Current application of classical and new nanomaterials is analyzed in context of regulatory requirements and standardization for chemicals, food and consumer products. The challenges of nanomaterial characterization as the main bottleneck of risk assessment and regulation are presented. In some areas, e.g., quantification of nanomaterials within complex matrices, the establishment and adaptation of analytical techniques such as laser ablation inductively coupled plasma mass spectrometry and others are potentially suited to meet the requirements. As an example, we here provide an approach for the reliable characterization of human exposure to nanomaterials resulting from food packaging. Furthermore, results of nanomaterial toxicity and ecotoxicity testing are discussed, with concluding key criteria such as solubility and fiber rigidity as important parameters to be considered in material development and regulation. Although an analysis of the public opinion has revealed a distinguished rating depending on the particular field of application, a rather positive perception of nanotechnology could be ascertained for the German public in general. An improvement of material characterization in both toxicological testing as well as end-product control was concluded as being the main obstacle to ensure not only safe use of materials, but also wide acceptance of this and any novel technology in the general public. KW - Nanomaterials KW - Toxicity KW - Ecotoxicity KW - Standardization KW - Exposure PY - 2018 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-441096 VL - 92 IS - 1 SP - 121 EP - 141 PB - Springer AN - OPUS4-44109 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kromer, Ch. A1 - Schwibbert, K. A1 - Gadicherla, A. K. A1 - Thiele, D. A1 - Nirmalananthan-Budau, Nithiya A1 - Laux, P. A1 - Resch-Genger, Ute A1 - Luch, A. A1 - Tschiche, H. R. T1 - Monitoring and imaging pH in biofilms utilizing a fluorescent polymeric nanosensor N2 - Biofilms are ubiquitous in nature and in the man-made environment. Given their harmful effects on human health, an in-depth understanding of biofilms and the monitoring of their formation and growth are important. Particularly relevant for many metabolic processes and survival strategies of biofilms is their extracellular pH. However, most conventional techniques are not suited for minimally invasive pH measurements of living biofilms. Here, a fluorescent nanosensor is presented for ratiometric measurements of pH in biofilms in the range of pH 4.5–9.5 using confocal laser scanning microscopy. The nanosensor consists of biocompatible polystyrene nanoparticles loaded with pH-inert dye Nile Red and is surface functionalized with a pH-responsive fluorescein dye. Its performance was validated by fluorometrically monitoring the time-dependent changes in pH in E. coli biofilms after glucose inoculation at 37 °C and 4 °C. This revealed a temperature-dependent decrease in pH over a 4-h period caused by the acidifying glucose metabolism of E. coli. These studies demonstrate the applicability of this nanosensor to characterize the chemical microenvironment in biofilms with fluorescence methods. KW - Dye KW - Fluorescence KW - Signal enhancement KW - Sensor KW - Quantum yield KW - Synthesis KW - Nanoparticle KW - Nano KW - Polymer KW - Ph KW - Biofilm KW - MIC KW - Corrosion KW - Microorganism KW - Bacteria PY - 2022 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-550751 SN - 2045-2322 VL - 12 IS - 1 SP - 1 EP - 10 PB - Nature Publishing Group CY - London AN - OPUS4-55075 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Hachenberger, Y. U. A1 - Rosenkranz, D. A1 - Kriegel, Fabian L. A1 - Krause, B. A1 - Matschaß, René A1 - Reichardt, P. A1 - Tentschert, J. A1 - Laux, P. A1 - Jakubowski, Norbert A1 - Panne, Ulrich A1 - Luch, A. T1 - Tackling Complex Analytical Tasks: An ISO/TS-Based Validation Approach for Hydrodynamic Chromatography Single Particle Inductively Coupled Plasma Mass Spectrometry N2 - Nano-carrier systems such as liposomes have promising biomedical applications. Nevertheless, characterization of these complex samples is a challenging analytical task. In this study a coupled hydrodynamic chromatography-single particle-inductively coupled plasma mass spectrometry (HDC-spICP-MS) approach was validated based on the technical specification (TS) 19590:2017 of the international organization for standardization (ISO). The TS has been adapted to the hyphenated setup. The quality criteria (QC), e.g., linearity of the calibration, transport efficiency, were investigated. Furthermore, a cross calibration of the particle size was performed with values from dynamic light scattering (DLS) and transmission electron microscopy (TEM). Due to an additional Y-piece, an online-calibration routine was implemented. This approach allows the calibration of the ICP-MS during the dead time of the chromatography run, to reduce the required time and enhance the robustness of the results. The optimized method was tested with different gold nanoparticle (Au-NP) mixtures to investigate the characterization properties of HDC separations for samples with increasing complexity. Additionally, the technique was successfully applied to simultaneously determine both the hydrodynamic radius and the Au-NP content in liposomes. With the established hyphenated setup, it was possible to distinguish between different subpopulations with various NP loads and different hydrodynamic diameters inside the liposome carriers. KW - Single particle ICP-MS KW - Nanoparticle characterization KW - Nano-carrier KW - Iposomes KW - Hydrodynamic chromatography (HDC) KW - Validation PY - 2020 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:b43-506609 VL - 13 IS - 6 SP - 1 EP - 14 CY - Basel, Switzerland AN - OPUS4-50660 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -