TY - JOUR A1 - Tentschert, Jutta A1 - Jungnickel, Harald A1 - Reichardt, Philipp A1 - Leube, Peter A1 - Kretzschmar, Bernd A1 - Taubert, Andreas A1 - Luch, A. T1 - Identification of nano clay in composite polymers JF - Surface and interface analysis : an international journal devoted to the development and application of techniques for the analysis surfaces, interfaces and thin films N2 - Industrialized food production is in urgent search for alternative packaging materials, which can serve the requirements of a globalized world in terms of longer product shelf lives, reduced freight weight to decrease transport costs, and better barrier functionality to preserve its freshness. Polymer materials containing organically modified nano clay particles as additives are one example for a new generation of packaging materials with specific barrier functionality to actually hit the market. Clay types used for these applications are aluminosilicates, which belong to the mineral group of phyllosilicates. These consist of nano-scaled thin platelets, which are organically modified with quaternary ammonium compounds acting as spacers between the different clay layers, thereby increasing the hydrophobicity of the mineral additive. A variety of different organically modified clays are already available, and the use as additive for food packaging materials is one important application. To ensure valid risk assessments of emerging nano composite polymers used in the food packaging industry, exact analytical characterization of the organically modified clay within the polymer matrix is of paramount importance. Time-of-flight SIMS in combination with multivariate statistical analysis was used to differentiate modified clay reference materials from another. Time-of-flight SIMS spectra of a reference polymer plate, which contained one specific nano clay composite, were acquired. For each modified clay additive, a set of characteristic diagnostic ions could be identified, which then was used to successfully assign unknown clay additives to the corresponding reference material. Thus, the described methodology could be used to define and characterize nano clay within polymer matrices. Copyright (c) 2014 John Wiley & Sons, Ltd. KW - ToF-SIMS KW - nanoparticles KW - nano clay KW - polymer KW - food contact material Y1 - 2014 U6 - https://doi.org/10.1002/sia.5546 SN - 0142-2421 SN - 1096-9918 VL - 46 SP - 334 EP - 336 PB - Wiley-Blackwell CY - Hoboken ER - TY - JOUR A1 - Haase, Andrea A1 - Arlinghaus, Heinrich F. A1 - Tentschert, Jutta A1 - Jungnickel, Harald A1 - Graf, Philipp A1 - Mantion, Alexandre A1 - Draude, Felix A1 - Galla, Sebastian A1 - Plendl, Johanna A1 - Goetz, Mario E. A1 - Masic, Admir A1 - Meier, Wolfgang P. A1 - Thuenemann, Andreas F. A1 - Taubert, Andreas A1 - Luch, Andreas T1 - Application of Laser Postionization Secondary Neutral Mass Spectrometry/Time-of-Flight Secondary Ion Mass Spectrometry in Nanotoxicology: Visualization of Nanosilver in Human Macrophages and Cellular Responses JF - ACS nano N2 - Silver nanoparticles (SNP) are the subject of worldwide commercialization because of their antimicrobial effects. Yet only little data on their mode of action exist. Further, only few techniques allow for visualization and quantification of unlabeled nanoparticles inside cells. To study SNP of different sizes and coatings within human macrophages, we introduce a novel laser postionization secondary neutral mass spectrometry (Laser-SNMS) approach and prove this method superior to the widely applied confocal Raman and transmission electron microscopy. With time-of-flight secondary ion mass spectrometry (TOF-SIMS) we further demonstrate characteristic fingerprints in the lipid pattern of the cellular membrane indicative of oxidative stress and membrane fluidity changes. Increases of protein carbonyl and heme oxygenase-1 levels in treated cells confirm the presence of oxidative stress biochemically. Intriguingly, affected phagocytosis reveals as highly sensitive end point of SNP-mediated adversity In macrophages. The cellular responses monitored are. hierarchically linked, but follow individual kinetics and are partially reversible. KW - nanosilver KW - Laser-SNMS KW - TOF-SIMS KW - confocal Raman microscopy KW - oxidative stress KW - protein carbonyls Y1 - 2011 U6 - https://doi.org/10.1021/nn200163w SN - 1936-0851 VL - 5 IS - 4 SP - 3059 EP - 3068 PB - American Chemical Society CY - Washington ER -