Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Type of Medium
Language
Year
  • 1
    Language: English
    In: PLoS ONE, 2011, Vol.6(5), p.e20112
    Description: The production and use of nanoparticles (NP) has steadily increased within the last decade; however, knowledge about risks of NP to human health and ecosystems is still scarce. Common knowledge concerning NP effects on freshwater organisms is largely limited to standard short-term (≤48 h) toxicity tests, which lack both NP fate characterization and an understanding of the mechanisms underlying toxicity. Employing slightly longer exposure times (72 to 96 h), we found that suspensions of nanosized (∼100 nm initial mean diameter) titanium dioxide (nTiO 2 ) led to toxicity in Daphnia magna at nominal concentrations of 3.8 (72-h EC 50 ) and 0.73 mg/L (96-h EC 50 ). However, nTiO 2 disappeared quickly from the ISO-medium water phase, resulting in toxicity levels as low as 0.24 mg/L (96-h EC 50 ) based on measured concentrations. Moreover, we showed that nTiO 2 (∼100 nm) is significantly more toxic than non-nanosized TiO 2 (∼200 nm) prepared from the same stock suspension. Most importantly, we hypothesized a mechanistic chain of events for nTiO 2 toxicity in D. magna that involves the coating of the organism surface with nTiO 2 combined with a molting disruption. Neonate D. magna (≤6 h) exposed to 2 mg/L nTiO 2 exhibited a “biological surface coating” that disappeared within 36 h, during which the first molting was successfully managed by 100% of the exposed organisms. Continued exposure up to 96 h led to a renewed formation of the surface coating and significantly reduced the molting rate to 10%, resulting in 90% mortality. Because coating of aquatic organisms by manmade NP might be ubiquitous in nature, this form of physical NP toxicity might result in widespread negative impacts on environmental health.
    Keywords: Research Article ; Biology ; Chemistry ; Earth Sciences ; Materials Science ; Medicine ; Chemistry ; Public Health And Epidemiology ; Marine And Aquatic Sciences ; Ecology ; Critical Care And Emergency Medicine ; Science Policy ; Biochemistry ; Non-clinical Medicine
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: Chemosphere, July 2017, Vol.179, pp.185-193
    Description: In an exemplary incubation study with an anaerobic sediment sampled at an oxbow of the river Lahn in Germany (50°18′56.87″N; 7°37′41.25″E) and contaminated by former mining activity, a novel meso profiling and sampling system ( ) is presented. enables a low invasive, automated sampling of pore water profiles across the sediment water interface (SWI), down to ∼20 cm depth with a spacial resolution of 1 cm. In parallel to the pore water sampling it measures physicochemical sediment parameters such as redox potential and pH value. In an incubation experiment of 151 days the ability of the setup was proven to address several different aspects relevant for fresh water and marine sediment studies: (i) The influence of mechanical disturbance and oxygen induced acidification on the mobility of 13 metals and metalloids (Cd, Co, Cu, Fe, Mn, Mo, Ni, Sb, U, V, Zn) was quantified based on 11 profiles. The analytes were quantified by inductively coupled plasma-mass spectrometry. Three groups of elements were identified with respect to the release into the pore water and the overlying water under different experimental conditions. (ii) The capability to investigate the impacts of changing physicochemical sediment properties on arsenic and antimony (III/V) speciation is shown. (iii) An approach to obtain information on size fractionation effects and to address the colloidal pore water fractions (0.45 μm–16 μm) was successfully conducted for the elements Ag, As, Cu, Fe and Mn.
    Keywords: Sediment Pore Water ; Depth Profile ; Sediment Water Interface ; Profiling ; Metals ; Chemistry ; Ecology
    ISSN: 0045-6535
    E-ISSN: 1879-1298
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Analytical and Bioanalytical Chemistry, 2014, Vol.406(2), pp.467-479
    Description: Validated and easily applicable analytical tools are required to develop and implement regulatory frameworks and an appropriate risk assessment for engineered nanoparticles (ENPs). Concerning metal-based ENPs, two main aspects are the quantification of the absolute mass concentration and of the “dissolved” fraction in, e.g., (eco)toxicity and environmental studies. To provide information on preparative aspects and on potential uncertainties, preferably simple off-line methods were compared to determine (1) the total concentration of suspensions of five metal-based ENP materials (Ag, TiO 2 , CeO 2 , ZnO, and Au; two sizes), and (2) six methods to quantify the “dissolved” fraction of an Ag ENP suspension. Focusing on inductively coupled plasma–mass spectrometry, the total concentration of the ENP suspensions was determined by direct measurement, after acidification and after microwave-assisted digestion. Except for Au 10 nm, the total concentrations determined by direct measurements were clearly lower than those measured after digestion (between 61.1 % for Au 200 nm and 93.7 % for ZnO). In general, acidified suspensions delivered better recoveries from 89.3 % (ZnO) to 99.3 % (Ag). For the quantification of dissolved fractions two filtration methods (ultrafiltration and tangential flow filtration), centrifugation and ion selective electrode were mainly appropriate with certain limitations, while dialysis and cloud point extraction cannot be recommended. With respect to precision, time consumption, applicability, as well as to economic demands, ultrafiltration in combination with microwave digestion was identified as best practice. Figure A Multi-method approach to identify best practice for ICP-MS based off-line characterization of ENP suspensions.
    Keywords: Nanoparticle quantification ; Total concentration analyses ; Off-line fractionation ; Sample preparation ; Dissolved fraction ; ICP-MS
    ISSN: 1618-2642
    E-ISSN: 1618-2650
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: PLoS ONE, 01 January 2017, Vol.12(1), p.e0168926
    Description: Today, basic requirements for construction works include the protection of human health and of the environment. In the tension area between economic demands, circular flow economy and environmental safety, a link between the results from standardized leaching tests and the respective environmental quality standards must be created. To derive maximum release limits of metals and metalloids for armourstones in hydraulic engineering, this link is accomplished via a simple model approach. By treating natural materials and industrial by-products the same way, the article delivers an overview on the recent regulative situation in Europe as well as describes and discusses an innovative approach to derive maximum release limits for monolithic construction products in hydraulic engineering on a conceptual level. On a practical level, a list of test parameters is derived by connecting an extensive dataset (seven armourstone materials with five repetitions and 31 elements tested with the worldwide applied dynamic surface leaching test) with surface water quality standards and predicted no effect concentrations. Finally, the leaching tests results are compared with the envisaged maximum release limits, offering a direct comparison between natural materials and industrial by-products.
    Keywords: Sciences (General)
    E-ISSN: 1932-6203
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Analytical and Bioanalytical Chemistry, 2016, Vol.408(27), pp.7551-7557
    Description: Coacervate-based techniques are intensively used in environmental analytical chemistry to enrich and extract different kinds of analytes. Most methods focus on the total content or the speciation of inorganic and organic substances. Size fractionation is less commonly addressed. Within coacervate-based techniques, cloud point extraction (CPE) is characterized by a phase separation of non-ionic surfactants dispersed in an aqueous solution when the respective cloud point temperature is exceeded. In this context, the feature article raises the following question: May CPE in future studies serve as a key tool (i) to enrich and extract nanoparticles (NPs) from complex environmental matrices prior to analyses and (ii) to preserve the colloidal status of unstable environmental samples? With respect to engineered NPs, a significant gap between environmental concentrations and size- and element-specific analytical capabilities is still visible. CPE may support efforts to overcome this “concentration gap” via the analyte enrichment. In addition, most environmental colloidal systems are known to be unstable, dynamic, and sensitive to changes of the environmental conditions during sampling and sample preparation. This delivers a so far unsolved “sample preparation dilemma” in the analytical process. The authors are of the opinion that CPE-based methods have the potential to preserve the colloidal status of these instable samples. Focusing on NPs, this feature article aims to support the discussion on the creation of a convention called the “CPE extractable fraction” by connecting current knowledge on CPE mechanisms and on available applications, via the uncertainties visible and modeling approaches available, with potential future benefits from CPE protocols.
    Keywords: Nanoparticles ; Cloud point extraction ; Colloids ; Coacervate-based techniques ; Enrichment ; Sample preservation
    ISSN: 1618-2642
    E-ISSN: 1618-2650
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    In: Journal of Analytical Atomic Spectrometry, 2014, Vol.29(2), pp.287-296
    Description: Engineered nanoparticles (ENPs) show new and interesting properties leading to an increased use in various application fields and have entered our daily environment ( e.g. , functionalized clothing, cosmetics, food, medicine). Though on the one hand nanotechnology plays a substantial role in societies' daily life, on the other the presence and behavior of ENPs in organisms and the environment is still unclear to a large extent. Furthermore, comprehensive legislative regulation is still missing. For adequate regulation a clear definition of ENPs is needed. A definition recommendation was released in 2011 by the European Commission (EC) on the basis of size and number of ENPs present within a defined size range. However, straightforward analytical techniques which easily provide information allowing for a decision (based on the EC definition) on the presence and concentration of ENPs in a given sample do not exist yet. A promising tool, offering fraction-related size information on the one hand and allowing for element-specific detection on the other is the coupling of asymmetric flow-field-flow-fractionation (AF4) with inductively coupled plasma-mass spectrometry (ICP-MS). In this work, a new strategy for quantifying silver nanoparticle (AgNP) size fractions (30 nm 2.1 nm, 75 nm 3.9 nm) after base-line AF4 separation relying on on-line ICP-MS detection combined with post-channel species-unspecific on-line isotope dilution (on-line ID) was successfully developed. A limit of detection (LOD) of 0.5 g Ag L 1 and a limit of quantification (LOQ) of 1.6 g Ag L 1 were achieved by the approach applied. The recovery values for the smaller size-fraction (30 nm) were in the range of 3141% while for the larger size-fraction (75 nm) in the range of 7578%. The overall reproducibility (RSDs, peak areas) was in between 3.45.4%. Validation of the on-line ID approach was achieved via off-line fraction collection and total silver determination afterwards; a bias of 2.916.4% between both approaches was observed indicating that the on-line ID approach is working properly. To the best of the authors' knowledge, this is the first time that species-unspecific (post-channel) on-line ID was combined with AF4/ICP-SF-MS for fraction-related quantification of AgNPs.
    ISSN: 0267-9477
    E-ISSN: 1364-5544
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    In: Journal of Environmental Monitoring, 2011, Vol.13(5), pp.1204-1211
    Description: The pore water transport of antimony and titanium, applied as nanoparticles (NPs), was studied by spiking stable suspensions of two different nanomaterials on the surface of an undisturbed floodplain soil. For preparation of stable dispersions, two different strategies were followed. (i) Comparable to those used in industrial applications: titanium dioxide nanoparticles, with an average diameter of 99 nm, were prepared by high-energy ball milling in water, whereas for (ii) antimony trioxide (Sb 2 O 3 ; average diameter 121 nm) a dispersing agent (sodium salt of poly[(naphthaleneformaldehyde)sulfonate] (pNFS) in water) was used. The upper 17 cm of a floodplain soil (river Rhine, Germany) was sampled using the minimally invasive sediment or fauna incubation experiment (SOFIE® two compartment cell; 3 l volume each), which preserved the pore system of the soil. The cells were equipped with 450 and 100 nm filter probes at different depths providing a non-invasive sampling of the pore water. The pore water was sampled at different times ( T = 0, 24, 48, 96 and 196 h) and analysed by inductively coupled plasma quadrupole mass spectrometry (ICP-QMS). Sb and Ti were transported via the pore water of the floodplain soil to a depth of 14 cm, corresponding to the maximum cell depth. The highest Sb concentration in the pore water was detected after 24 h at a depth of 5.5–8 cm. Although the spiked concentration was higher for Ti than for Sb, the total Ti concentration in the pore water of the spiked cell was lower. This indicates a stronger agglomeration of TiO 2 NPs or a more intensive interaction of Ti with the solid matrix and a faster transport of Sb towards deeper soil layers. The results show that metal(loid)s from metal oxide NPs are transported in the soil pore water and, hence, have the potential to act as the source of contamination of deeper soil layers after soil surface contamination.
    Keywords: Environmental Monitoring ; Flood Plains ; Mass Spectrometry ; Nanoparticles ; Sodium ; Soil ; Soil Depth ; Metals ; Pore Water ; Titanium Dioxide ; Antimony ; Flood Plains ; Nanotechnology ; Germany ; Europe, Rhine R. ; Freshwater Pollution ; Environment ; Renewable Resources-Terrestrial ; Instruments (551.508);
    ISSN: 1464-0325
    E-ISSN: 1464-0333
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Critical Reviews in Environmental Science and Technology, 16 February 2016, Vol.46(4), pp.434-437
    Keywords: Engineering ; Environmental Sciences
    ISSN: 1064-3389
    E-ISSN: 1547-6537
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Environmental science & technology, 06 September 2016, Vol.50(17), pp.9506-14
    Description: Sediment water interfaces (SWIs) are often characterized by steep biogeochemical gradients determining the fate of inorganic and organic substances. Important transport processes at the SWI are sedimentation and resuspension of particulate matter and fluxes of dissolved materials. A microprofiling and micro sampling system (missy), enabling high resolution measurements of sediment parameters in parallel to a direct sampling of sediment pore waters (SPWs), was combined with two fractionation approaches (ultrafiltration (UF) and cloud point extraction (CPE)) to differentiate between colloidal and dissolved fractions at a millimeter scale. An inductively coupled plasma-quadrupole mass spectrometry method established for volumes of 300 μL enabled the combination of the high resolution fractionation with multi-element analyzes. UF and CPE comparably indicated that manganese is predominantly present in dissolved fractions of SPW profiles. Differences found for cobalt and iron showed that the results obtained by size-dependent UF and micelle-mediated CPE do not necessarily coincide, probably due to different fractionation mechanisms. Both methods were identified as suitable for investigating fraction-related element concentrations in SPW along sediment depth profiles at a millimeter scale. The two approaches are discussed with regard to their advantages, limitations, potential sources of errors, further improvements, and potential future applications.
    Keywords: Metals ; Water
    ISSN: 0013936X
    E-ISSN: 1520-5851
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    In: Journal of Analytical Atomic Spectrometry, 2011, Vol.26(2), pp.450-455
    Description: The demand to quantify the elemental composition of very small sample amounts and/or of samples which form artefacts during conventional sample preparations is increasing. Example applications are the quantification of engineered metal(loid) based nanomaterials in environmental samples, e.g. (i) the direct analyses of engineered nanoparticle (ENP) suspensions showing broad particle size distributions which are not suitable to be applied via the spray chamber in ICP-MS analyses, (ii) measurements of single invertebrates and tissue of selected organs which were exposed to ENPs, and (iii) whole plants or plant parts e.g. from Lemna sp. The use of imaging based high resolution methods like atomic force microscopy or environmental scanning electron microscopy creates the need to quantify the elemental composition of the visualised objects as directly and exactly as possible, at very low limits of detection. With this study the authors present a method/concept for the multi-element quantification of analytes from ENPs in complex matrices with different degrees of complexity by graphite furnace electrothermal vaporisation coupled to inductively coupled plasma quadrupole mass spectrometry equipped with collision/reaction cell (GF-ETV-ICP-QMS).
    Keywords: Demand ; Imaging ; Invertebrates ; Mathematical Analysis ; Matrices ; Matrix Methods ; Nanomaterials ; Nanoparticles ; Instruments and Measurements (So);
    ISSN: 0267-9477
    E-ISSN: 1364-5544
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages