Multiple search fields may be used to refine results. Most recent publications appear first.


ZSM-5 catalyzed fast pyrolysis of biomass

ID: 1703
Year: 2017
Authors: Hoff, TC;
Products: PFA-100
Journal: Thesis
Volume: 1  -  Pages: 1-189

Zeolite catalyzed fast pyrolysis offers a simple and robust approach to convert lignocellulosic biomass to aromatic hydrocarbons. During catalytic fast pyrolysis (CFP), cellulose, hemicellulose, and lignin are first thermally decomposed to bio-oil vapors that are further converted to aromatics in the presence of a ZSM-5 zeolite catalyst. The high temperatures required for CFP also favor coke formation, an undesired byproduct, through condensation of the oxygenated intermediates on ZSM-5's outer surface and/or secondary reactions inside its micropores. Introducing mesopores through desilication represents a possible strategy to enhance mass transport and favor aromatic production over undesired coke formation. The effect of desilication on the structure, acidity, and performance of aluminum-rich ZSM-5 was studied and a detailed characterization of the structure obtained. Results indicate that mild desilication conditions do not significantly affect the elemental composition, crystallographic structure, microporosity, or distribution of aluminum atoms in framework and extraframework sites. However, the number of accessible Brønsted acid sites increased considerably (ca. 50%) as a result of the enhanced mesoporosity. Aromatic yields for desilicated samples were found to increase by 17% in the pyrolysis of red oak compared to the parent zeolite. The interplay of structural parameters under reaction conditions was also investigated with the objective to identify relationships that would facilitate further catalyst design. Here, we studied commercial and laboratory synthesized ZSM-5 zeolites and combined data from ten complementary characterization techniques in an attempt to identify parameters common to high-performance catalysts. Crystallinity and framework aluminum site accessibility were found to be critical to achieve high aromatic yields. These findings enabled us to synthesize a ZSM-5 catalyst with enhanced activity, offering the highest aromatic hydrocarbon yield reported to date. To clarify how mesoporous and highly crystalline zeolites decrease coke formation, the role of internal micropore diffusion and external mass transfer in the deposition of carbon was studied. Here, we decoupled the contributions of these parameters through the comparison of conventional in-situ experiments (biomass/catalyst physical mixtures) to zeolites with model compounds pre-adsorbed in the porous structure. Experimental results, diffusion measurements, and the calculation of the mass transfer Biot number point to micropore diffusion as the dominant cause of coke formation. Specifically, the presence of defects in the zeolite's micropores was found to actively contribute to this undesired side reaction. Conversely, external surface barriers appear to play a minimal role in coking. In addition to catalyst optimization, the stability of ZSM-5 was studied to gain insights into the dynamic phenomena that may alter the catalyst structure under reaction conditions. Our results suggest high-aluminum content zeolites thermally degrade within hours above 600 °C, emphasizing the importance of operating conditions on long-term catalyst performance. Detailed characterization of the thermally treated zeolites indicated that they retained the desired MFI crystallographic structure but displayed significant changes in Brønsted and Lewis acid site densities due to extensive dealumination. Depending on temperature, up to 50% of the aluminum initially present in the zeolite structure was lost to form extra-framework species that restrict the diffusion of reactants and products inside the catalyst particles. These alterations led to a 70% drop in performance for the catalyzed fast pyrolysis of cellulose. Low aluminum content ZSM-5 zeolites were more stable, suggesting a compromise must be found between reaction temperature and catalyst features to achieve high activity and long-term stability.


ID: 1702
Year: 2017
Authors: Mamani, G;Judith, M;
Products: 12009 Analytical West
Journal: Thesis
Volume: 1  -  Pages: 31048

It was observed that the modification of the concentration of nitric acid (HNO3), from 2% to 6%, in presence of thiocarbamide (CH4N2S) for the probe washing solution (known as rinse), increases the quantification limit of strontium (Sr), during the quantitative measurement (analysis) of samples with possible content of rare-earth element (REE), by ICP-MS. For optimizing the method of preparing probe washing solution (rinse). First of all, concentrations 2%, 4%, y 6% of nitric acid (HNO3) were evaluated, in order to find the most effective, which should be demonstrated, by evaluation before and after the equipment ICP-MS is analyzing the samples, for long periods of time; finally relation between concentration 0%, 0,125%, 0,250%, 0,375%, y 0,5% of thiocarbamide (CH4N2S) and the intensity of strontium (Sr); was evaluated by Pearson test. Concluding that the concentration that shows greater efficacy to maintain the optimal value of quantification limit of strontium (Sr); before and after the equipment ICP-MS is analyzing for long times periods is 4% of HNO3, without thiocarbamide (CH4N2S), because is directly proportional, to strontium (Sr) intensities.

Comparison of the analytical methods used to determine natural and artificial radionuclides from environmental samples by gamma, alpha and beta spectrometry Final Report from the NKS-B CAMNAR activity

ID: 1701
Year: 2017
Authors: Pöllänen, R;Virtanen, S;Kämäräinen, M;Kaipiainen, M;Hou, X;Roos, P;Eriksson, M;Ehrs, S;Nalbandyan, A;Møller, B;Jonsson, S;Lagerkvist, P;Tovedal, A;
Products: SC-4 DX FAST
Journal: Technical University of Denmark
Volume: 1  -  Pages: 43128

In CAMNAR, an extensive interlaboratory exercise on the analytical methods used to determine several radionuclides present in the environmental samples was organized. Activity concentration of different natural radionuclides, such as Rn-222, Pb-210, Po-210, K-40, Ra-226, Ra-228 and isotopes of uranium, in addition to artificial Cs-137 and Am-241 were analysed from lake sediment samples and drinking water. The measurement techniques were gamma-ray spectrometry, alpha spectrometry, liquid scintillation counting and inductively coupled plasma mass spectrometry. Twenty six laboratories from nine Nordic and European countries participated in the intercomparison. Extraordinary variation between the results reported by different laboratories were revealed for some radionuclides indicating the need of future intercomparisons especially in the case of natural water samples.

Trace metals in Arctic fast ice

ID: 1700
Year: 2017
Authors: Domena, V;
Products: ow flow (100 µL/min) self-aspirating nebulizer
Journal: Thesis
Volume: 1  -  Pages: 16072

Trace metals in the marine environment are found in trace amounts, but are important tracers of oceanographic processes, and bioactive trace metals can impact ocean biogeochemistry through their nutrient or toxic influence of microbial populations. Sea ice is an intrinsic feature of the Arctic Ocean that likely plays a key role in the cycling of trace metals, given that this substrate can concentrate, alter, and transport these elements. Warming conditions in the Arctic have decreased sea ice cover over the past decades and the loss of sea ice threatens to drastically change the Arctic ecosystem, but the implications are not entirely understood. The scarcity of studies on Arctic sea ice entrained trace metals is due in part to the lack of commercially available sampling equipment capable of collecting sea ice without introducing contamination, and in part to the logistic and economic difficulties in accessing remote Arctic sea ice sites. Natural heterogeneity related to large sediment loads incorporated in uneven patches across Arctic fast ice poses a challenge when designing observational studies of trace metals in sea ice. The scope of this thesis is on the study of trace metals in Alaskan Beaufort Sea fast ice environment. The study includes snow, sea ice and seawater under the ice. Analysis of dissolved (Mn, Fe, Cu and Zn) and particulate (Al, Mn, Fe, Cu and Zn) phases was carried out from 50 ice cores collected with a trace metal clean ice corer developed at the University of Alaska Fairbanks. The results of this study indicated that the ice corer developed at UAF was able to collect uncontaminated samples. Highly variable and elevated concentrations of particulate (> 0.2 µm) trace elements were observed due to the notable variability in the amount of sediment incorporated within ice cores, but surprisingly dissolved (< 0.2 µm) metal concentrations were relatively low and consistent. The observed low dissolved metal concentrations, along with low bulk salinity and low percent leachable particulate trace metal fractions, suggest that desalination removed reactive metals from the ice matrix prior to sampling. Spatial variability of dissolved and particulate trace metals was statistically analyzed and indicated generally negligible variability on the meter scale, but significant variability on the kilometer scale, for both size classes. These results emphasize that future studies of trace metals in sea ice should include temporal and spatial considerations.

Use of an Inline Autodilution Method to Eliminate Species Interconversion for LC-ICPMS with Elemental Scientific's prepFAST IC

ID: 1699
Year: 2018
Authors: Quarles Jr, CD;Sullivan, P;Field, MP;Kim, H;
Products: Elemental Scientific's prepFAST IC
Journal: Journal of Analytical Atomic Spectroscopy
Volume: 33  -  Pages: 745-751

Trace element analysis is vital for industrial, government, and academic communities. Knowing the total concentration of an element in a given sample is important, but it does not tell the whole story. The chemical species (e.g., As (III), As (V), or AsCH5 O3 ) plays an important part in understanding how it can affect the environment, its bioavailability, or its toxicity. For example, inorganic arsenic (As (III)) is more toxic than organic arsenic (monomethylarsonic acid), whereas organic mercury (methylmercury) is more toxic than its inorganic form (Hg (II)).

Analyses of Engineered Nanoparticles and Colloids at Sediment Water Interfaces

ID: 1698
Year: 2017
Authors: und Gutachter, G;
Products: ICP-SF-MS
Journal: Thesis
Volume: 1  -  Pages: 1-169

Within aquatic environments sediment water interfaces (SWIs) are the most important areas concerning exchange processes between the water body and the sediment. These spatially restricted regions are characterized by steep biogeochemical gradients that determine the speciation and fate of natural or artificial substances. Apart from biological mediated processes (e.g., burrowing organisms, photosynthesis) the determining exchange processes are diffusion or a colloid-mediated transport. Hence, methods are required enabling to capture the fine scale structures at the boundary layer and to distinguish between the different transport pathways. Regarding emerging substances that will probably reach the aquatic environment engineered nanomaterials (ENMs) are of great concern due to their increased use in many products and applications. Since they are determined based on their size (< 1 µm) including natural nanomaterials. With regard to existing methodological gaps concerning the characterization of ENMs (as emerging substances) and the investigation of SWIs (as receiving environmental compartments), the aim of this thesis was to develop, validate and apply suitable analytical tools. The challenges were to i) develop methods that enable a high resolution and low-invasive sampling of sediment pore water. To ii) develop routine-suitable methods for the characterization of metal-based engineered nanoparticles and iii) to adopt and optimize size-fractionation approaches for pore water samples of sediment depth profiles to obtain size-related information on element distributions at SWIs. Within the first part, an available microprofiling system was combined with a novel micro sampling system equipped with newly developed sample filtration-probes. The system was thoroughly validated and applied to a freshwater sediment proving the applicability for an automatic sampling of sediment pore waters in parallel to microsensor measurements. Thereby, for the first time multi-element information for sediment depth profiles were obtained at a millimeter scale that could directly be related to simultaneously measured sediment parameters.

Sampling and Sample-handling Protocols for GEOTRACES Cruises. Version 3, August 2017.

ID: 1697
Year: 2017
Authors: Cutter, G;Casciotti, K;Croot, P;Geibert, W;
Products: offline seaFAST system
Journal: Book
Volume: 1  -  Pages: 1-178

The GEOTRACES Standards and Intercalibration (S&I) Committee is charged with ensuring that the data generated during GEOTRACES are as precise and accurate as possible, which includes all the steps from sampling to analysis. Thus, sampling methods for dissolved and particulate constituents must take a representative (of the water depth/water mass) and uncontaminated sample, the samples must be stored (or immediately analyzed) in a fashion that preserves the concentrations (activities) and chemical speciation, and the analyses of these samples must yield accurate data (concentration, activity, isotopic composition, and chemical speciation). To this end, experiences from the 2008-2010 GEOTRACES Intercalibration Program, actual GEOTRACES cruises from 2010-2017, and other related intercalibration efforts, helped to create the protocols in this document. However, methods continually evolve and the GEOTRACES S&I Committee will monitor these advances as validated by intercalibrations and modify the methods as warranted. The protocols here are divided into trace element and isotope groups: Hydrography and Ancillary Parameters, Radioactive Isotopes, Radiogenic Isotopes, Trace Elements, Nutrient Isotopes, Optics, and BioGEOTRACES parameters. Those who contributed to preparing these protocols are listed in Appendix 1 and are sincerely thanked for their efforts in helping GEOTRACES and the worldwide TEI community.

Validation of inductively-coupled plasma mass spectrometer instruments for analysis of trace metals in unfiltered-water and filtered-water samples

ID: 1696
Year: 2017
Authors: Stetson, SJ;Miller, H;
Products: Elemental Scientific Prepfast autosampler
Volume: 1  -  Pages: 1-115

This memorandum documents method performance of recently acquired inductively-coupled plasma mass spectrometer (ICP-MS) instrumentation and method quality, including variability, bias, interferences, and detection limits (DLs) for trace metals in unfiltered and filtered-water measured by inductively-coupled plasma mass spectrometry at the National Water Quality Laboratory (NWQL). Out-of-date instruments used to make these measurements have been replaced, and optimized method parameters as well as validation data are reported here.

An inter-comparison exercise on the application of ICP-MS techniques for measurement of long-lived radionuclides

ID: 1695
Year: 2018
Authors: Qiao, J;Lagerkvist, P;Rodushkin, I;Salminen-Paatero, S;Roos, P;Lierhagen, S;Jensen, KA;Engstrom, E;Skipperud, L;
Products: SC2 DX auto sampler
Journal: Nordic nuclear safety research
Volume: 1  -  Pages: 12785

Inductively coupled plasma (ICP) spectrometry techniques are widely used in the fields related to environmental monitoring, nuclear waste disposal and management, radioecology and tracer studies, as well as nuclear forensics and nuclear emergency preparedness. Especially ICP mass spectrometry (ICP-MS) is playing an important role for determination of low-level long-lived radionuclides and their isotopic ratios. ICP optical emission spectrometry (ICP-OES) is commonly used for determining stable elements (Al, Fe, Ca, etc.) and cannot perform isotopic ratio measurement with desirable precision and at low analyte concentrations. Therefore ICP-OES is often used as a supplementary technique to ICP-MS in the analysis, for instance, to screen the matrix composition of a sample, or to determine Sr and Y chemical yield in the Sr-90 analysis, etc. Among the Nordic countries, there are probably less than 20 ICP-MS instruments which are currently applied in the nuclear field for the measurement of radionuclides and their isotopic ratios. Due to different application purposes and technical background of the analysts, each ICP lab has different set-ups and experiences in running these instruments. More efficient application of ICP-MS will be achieved when these experiences are well shared among these labs. Also, for newly established ICP labs or scientists/students in the Nordic countries to quickly build up the competence in operating their instruments in practice, hands-on experience is very valuable. Therefore, within the Nordic-ICP project, an inter-comparison exercise was performed during 2016, which was focused on the measurement of uranium and plutonium isotopes in certified reference material by ICP-MS in combination with radiochemical separation. This report summarizes the results and conclusions obtained base on this inter-comparison exercise.

Pathways of Siberian freshwater and sea ice in the Arctic Ocean traced with radiogenic neodymium isotopes and rare earth elements

ID: 1694
Year: 2017
Authors: Laukert, G;Frank, M;Hathorne, EC;Krumpen, T;
Products: seaFAST system
Journal: Polarforschung
Volume: 87  -  Pages: 43172
DOI: 10.2312/polarforschung.87.1.3

Freshwater and sea ice in the Arctic Ocean (AO) both respond to climate forcing but changes in their distribution may in turn also significantly affect Northern Hemisphere climate. The exact mechanisms controlling their transport are, however, still subject of ongoing research. Radiogenic neodymium (Nd) isotopes (expressed as εNd) and rare earth elements (REEs) have successfully been used to trace ocean circulation in the AO and can provide valuable information on the origin, transport and fate of Arctic freshwater and drifting sea ice. Here, we present first sea-ice data and discuss the applicability of these tracers to determine the pathways of Siberian freshwater and the source areas of Arctic sea ice within the Eurasian Basin. Freshwaters originating from various Siberian rivers are well mixed and diluted prior to their advection to the central AO and the Fram Strait, thereby inhibiting the assessment of the individual contributions of the different rivers for these regions. Recent investigations of seawater Nd isotope and REE distributions on the Siberian shelves now allow for a more detailed determination of the sources of transpolar freshwater transport, and suggest that freshwater from the Lena River can at least be qualitatively traced further away from the shelves. In addition, sea ice has the potential to preserve marine and riverine εNd and REE signatures of the Siberian shelf source waters transported across the AO to the Fram Strait thereby avoiding the effects of mixing. Here, we test this potential for the first time by comparing εNd and REE signatures determined from unfiltered but essentially sediment-free sea-ice samples recovered in the Eurasian Basin of the central AO in 2012 with corresponding signatures of surface seawater in the formation regions of the ice. The sampled sea ice is dominantly characterized by εNd values near -8, in agreement with the incorporation of radiogenic freshwater (εNd = -6) from the Yenisei and Ob rivers and its formation east of Vilkitsky Strait as identified by a backtracking approach based on satellite-derived ice drift and concentration data. The latter also indicates that sea ice with a less radiogenic εNd signature near -11 formed north of the Laptev Sea, in agreement with mixed contributions of radiogenic waters from the Kara Sea and northward flowing highly unradiogenic Lena River water (εNd ≤ -15). Compared to the REE concentrations in Siberian shelf waters, those in the sea ice are depleted, indicating rejection of REEs together with salt during sea-ice formation. Despite potential modifications during incorporation into sea ice, its REE distribution patterns indicate a predictable relationship to those of the source waters, thus in addition supporting preservation of at least some of the marine and riverine REE characteristics during sea-ice formation and transport.

Trace Elements in the General Population and Their Possible Role in Type 2 Diabetes-the Third Nord-Trøndelag Health Survey (HUNT3)

ID: 1693
Year: 2017
Authors: Simic, A;
Products: 2.5 mm injector
Journal: Thesis
Volume: 1  -  Pages: 1-133

Access to reliable information on the elemental contents of the human body is crucial to understand the roles these elements may have in the maintenance of human health. Establishing trace element blood levels in a general population can help elucidate potential causes of diseases related to natural and anthropogenic sources of these elements; it can also provide a baseline for potential future biomonitoring that could assess and evaluate temporal changes in the trace element status in populations. For the toxic elements such population studies can provide an important source for considering the total exposure of such elements through food, water and air, and may thus warn us on potentially dangerous exposure or contamination. Several epidemiological studies have indicated that a number of trace elements may play a role in type 2 diabetes (T2D). To address the question on when anomalous levels of trace elements begin to appear in T2D development, one could measure trace elements levels in the different stages of the disease in cross-sectional studies. In the present dissertation, whole blood samples and data collected in the third wave of the population-based Nord-Trøndelag Health Survey (HUNT3) were used in cross-sectional studies to investigate: 1) the background levels of 28 trace elements in the population of Nord-Trøndelag County and possible regional differences in the trace element levels; 2) potential relations between trace element blood levels and T2D in two case-control studies, one in persons who did not have a T2D diagnosis when blood samples were drawn, and the other in persons with an established T2D diagnosis. The whole blood concentrations of 28 trace elements in this Norwegian population were found to be well within reference levels, suggesting low exposure to toxic elements in the residents of Nord-Trøndelag County. Our results imply that geographical area, lifestyle, and several socio-demographic characteristics markedly influence the blood concentrations of several trace elements in humans, particularly for the elements arsenic, mercury, bromine, boron and selenium, for which the marine environment may be an important source of exposure. Our studies on trace element blood levels in T2D showed significant associations of lower indium, lead and magnesium, but higher boron, calcium and silver levels with prevalent T2D, and lower bromine, but higher chromium, iron, nickel, silver and zinc levels in the early phase of T2D. Increasing blood levels of calcium were associated with diabetes duration, which suggest that calcium might be linked to disease progression or antidiabetic treatment. In future studies of trace elements in the general population, emphasis should be placed on well-characterized prospectively followed population-based cohorts (such as the HUNT population), where detailed information is available on a wide range of socio-demographic and lifestyle characteristics, paying particular attention to nutritional factors. Future studies on trace elements in T2D should focus on changes in trace element levels over longer periods (including samples collected before the disease is manifest); on the speciation of trace elements in different intracellular and extracellular compartments, and on how particular glucose-lowering drugs may affect levels of especially essential trace elements in diabetic patients.

Evaluating the ability of microsatellite DNA markers and otolith microchemistry to distinguish spatially separated populations and identify recruitment sites of common carp (Cyprinus carpio) in interconnected lake systems of the North American Midwest

ID: 1692
Year: 2017
Authors: Swanson, R;
Products: low flow (100 µL/min) self-aspirating nebulizer
Journal: Thesis
Volume: 1  -  Pages: 1-218

The common carp (Cyprinus carpio) is an invasive fish whose populations have grown to ecologically damaging levels in the North American Midwest and many areas throughout the world. Recent research has shown that abundance of this species in areas of the North American Midwest is driven by its propensity to use shallow basins as productive nursery habitats. The ability of managers to discriminate which shallow basins are producing carp across a large sub-watershed of interconnected lakes has the potential to increase the efficacy of management practices which are aimed at the disruption of successful recruitment (i.e. surviving to join adult population). This study assessed whether carp nurseries could be distinguished based on differences in 12 microsatellite DNA markers in carp across the twin cities metropolitan area (n=1023) and the concentrations of 11 trace elements measured in carp otoliths collected in the Six-Mile Creek sub-watershed, Minnesota, USA (n=157). I found that genetic assessment could separate carp populations at a regional scale, but not between individual putative nurseries. Microchemical otolith analysis revealed that it is feasible to classify carp to their capture locations, discriminate between nursery and non-nursery habitat types, and distinguish juvenile carp from individual nursery sites. Elemental signatures of otoliths were obtained from laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Ratios of aluminum (Al), barium (Ba), copper (Cu), iron (Fe), potassium (K), lithium (Li), magnesium (Mg), sodium (Na), phosphorus (P), and strontium (Sr) to calcium (Ca) in otolith edges differed significantly among carp from all eight capture sites in a 70 km2 watershed. Ratios of Ba, Fe, Li, manganese (Mn), and P to Ca differed significantly among juvenile carp from three nursery basins. Ratios of Al, Ba, Cu, Fe, Li, K, Na, P, and Sr to Ca were significantly different between nursery and non-nursery habitat types. Quadratic discriminant analysis (QDA) could accurately classify otoliths to collection site (total accuracy 54%). QDA had increased accuracy when restricted to juvenile carp (76%) and classifying carp to nursery and non-nursery habitat types (87%) in contrast to individual sites. Further evaluation of differences between elemental signatures of the core and edge region (i.e. recent and natal signatures) and water samples from multiple years suggests that elemental parameters in otoliths and water are changing across time preventing identification of past recruitment sources. Identification of past natal origins of carp in these systems using otolith microchemistry will require obtaining continuous signatures across larger spatial and temporal scales.

Organic Aerosol Source Apportionment on Long-Term, Spatially-Dense Observation Networks Using Novel Mass Spectrometry Techniques

ID: 1691
Year: 2017
Authors: Dallenbach, KR;
Products: customized Apex Q nebulizer
Journal: Thesis
Volume: 1  -  Pages: 1-224

Particulate matter (PM), liquid or solid particles suspended in the atmosphere, contributes significantly to air pollution. Besides negative acute and long-term health effects, PM also affects the Earth's climate by scattering and absorbing solar radiation and also by changing cloud properties. A large part of PM consists of organic aerosol (OA) which is a complex mixture of compounds. OA can be emitted directly as particleswhich is called primary OA (POA) or can be formed as secondary OA (SOA) through atmospheric aging of initially emitted volatile organic compounds (VOCs). Important OA sources are traffic, cooking, combustion of biomass or fossil fuels but also biogenic VOC emissions from terrestrial and marine ecosystems. For understanding the many processes involved, measurements with high temporal resolution are necessary. Similarly, for establishing mitigation goals and strategies also long-term analyses in spatially dense observation networks are crucial. In this dissertation, we used two mass spectrometers in a new way for long-term analyses of OA in order to obtain a deeper understanding of its chemical composition and the different contributing sources. The Aerodyne aerosol mass spectrometer (AMS) is designed and used for short-term online measurement campaigns in order to determine the contribution of the different OA sources. However, the complex maintenance and the instrument cost hinder long-term and multi-site deployments. In comparison, collecting PM on filters is easier and is routinely performed for determining PM concentrations worldwide. In a first study, we developed an analytical technique, based on analyzing the organic mass spectral signatures of water extracted filter samples by AMS (termed offline AMS). By comparing offline AMS results to reference methods like online deployments of AMS or the more robust aerosol chemical speciation monitor (ACSM), we showed that the analyzed water-soluble OA (WSOA) covers a large part of OA and also exhibits similar signatures as total OA. While highly oxygenated organic compound classes seemed to be well represented, hydrocarbons are strongly underestimated. A statistical source apportionment (SA) analysis pointed out the value of such offline AMS data. In comparison to SA results from online ACSM x analysis, we determined what proportion of the different OA sources was represented in the offline AMS SA. In a second study, we determined the contributions of different relevant OA sources using the offline AMS technique. Thereby, we separated the influence of POA sources in terms of traffic (HOA), cooking (COA), and biomass burning (BBOA) as well as secondary OA categories and then validated our results by comparing them to established state-of-the-art measurements. Moreover also a factor explaining organic sulfur fragments of yet unknown origin was resolved. This factor is hypothesized to be related to traffic activity. This dataset of source contributions is unique in its coverage, both temporal and spatial (covering the entire year 2013 at 9 sites in central Europe). Our results showed that the influence of BBOA was higher in winter than in summer and exhibited enhanced concentrations at southern alpine valley sites than the sites in northern Switzerland (no valley sites). The SOA was separated seasonally in a component dominant in summer (summer oxygenated organic aerosol, SOOA) and another component dominant in winter (WOOA). SOOA concentrations increased more than linearly with rising temperatures, similar to biogenic VOC emissions and biogenic SOA concentrations in other studies. This suggests that SOOA is strongly influenced by biogenic emissions. In contrary, WOOA concentrations evolved similarly to anthropogenically influenced inorganic compounds like ammonium (and also sulfate and nitrate) suggesting a considerable anthropogenic influence on WOOA.

Multi-dimensional hydroxyapatite microspheres as a filling material of minicolumns for effective removal at trace level of noble and non-noble metals from aqueous solutions

ID: 1690
Year: 2018
Authors: Silina, Y;Koch, M;Herbeck-Engel, P;Fink-Straube, C;
Products: auto sampler SC-E2 DX
Journal: Journal of Environmental Chemical Engineering
Volume: 6  -  Pages: 1886-1897
DOI: 10.1016/j.jece.2018.02.044

In contrast, ICP-MS, SEM, XRD, TEM/EDX and RAMAN investigations independently revealed that the adsorption of Pb(II) onto the minicolumns was complete over the entire pH range and did not significantly depend on the medium acidity/basicity. The formation of a hydroxylpyromorphite phase with a general formula of Pb5-x/Cax(PO4)3OH onto the calcium MD-HAp-Ms minicolumns during Pb(II) uptake regardless from the used pH range was detected.

Some Aspects of Regulatory Criteria for Metal-ligand Homeostasis in Epidermal Cells

ID: 1689
Year: 2018
Authors: Petukhov, V;Dmitriev, ;Baumane, L;Skalny, A;.Lobanova, Y;Grabeklis, A;
Products: ESI SC-2 DX4 autosampler
Journal: JAA
Volume: 1  -  Pages: 22-32
DOI: 10.14302/issn.2471-2140.jaa-17-1927

The work is dedicated to the problem of the norm in the quantitative evaluation of metal content in the epidermal cells (hair) obtained by the method of spectrometry. Authors have analyzed the hair samples for Zn, Cu, and Fe content, which were obtained from 10000 healthy subjects (5000 males and 5000 females aged 20 to 45). The definition of the norm, in the authors' opinion, is closely related to the basic positions of the theory of self-organized criticality (SC). The observed shifts in the homeostasis of essential metals are local and therefore cannot serve as a criterion of sufficient (or insufficient) metal content throughout the body.

The marine biogeochemistry of chromium isotopes

ID: 1688
Year: 2018
Authors: Moos, S;
Products: heated Spiro desolvating membrane
Journal: Thesis
Volume: 1  -  Pages: 1-135
DOI: 10.1575/1912/9489

In the ocean, chromium (Cr) is a redox-sensitive trace metal. The reduction of Cr(VI) to Cr(III) occurs in oxygen deficient zones (ODZs), and Cr reduction in general has been identified as a significant Cr isotope fractionation mechanism. This thesis presents the first Cr isotope variations (d53Cr) in ODZs of the ocean and adds to the sparse Cr isotope data published for modern seawater. I developed a precise and accurate Cr isotope method for seawater samples. Seawater acidification converts total Cr to Cr(III) which is preconcentrated by Mg(OH)2 coprecipitation. A three-column anion exchange chromatography scheme separates Cr from isobaric and polyatomic interferences present in the seawater and reagent matrixes. Isotope analysis is performed on a MC-ICP-MS IsoProbe. The addition of a 50Cr-54Cr double spike allows for accurate correction of procedural and instrumental Cr mass fractionations. The first Cr isotope ratio data for a full water column profile in the Pacific Ocean is presented. This station serves as a fully oxic counterpart to stations located within the ODZ of the Eastern Tropical North Pacific. At one station, Cr concentrations are lower and d53Cr values are heavier within the ODZ. This is consistent with Cr reduction resulting in isotopically lighter, particlereactive Cr(III), which is scavenged and exported from the water column. A strong correlation of d53Cr and d15NNO3- at this station suggests that Cr reduction may be microbially mediated instead of simply being a product of thermodynamic equilibrium. Alternatively, Cr may be reduced by Fe(II). In the anoxic bottom waters of the Santa Barbara Basin a strong Cr reduction signal (lower [Cr], heavier d53Cr) is observed, which may result from the same aforementioned Cr reduction mechanisms. A shift to the heaviest seawater Cr isotope signatures yet observed was detected in the oxic bottom waters of the shallow Arctic Chukchi shelf, while Cr concentrations decreased. This extreme isotope signal may result from Cr reduction by a reduced species (e.g. Fe(II)), which was released from the underlying anoxic shelf sediments. Cr in the Atlantic layer and in the bottom water of a central Arctic station appears to be shaped by a novel, unidentified process.

The Influence of Basaltic Islands on the Oceanic REE Distribution: A Case Study From the Tropical South Pacific

ID: 1687
Year: 2018
Authors: Molina-Kescher, M;Hathorne, E;Osborne, A;Behrens, M;Kölling, M;Pahnke, K;Frank, M;
Products: seaFAST online pre-concentration system
Journal: Front. Mar. Sci.
Volume: 5  -  Pages: 50
DOI: 10.3389/fmars.2018.00050

The Rare Earth Elements (REEs) have been widely used to investigate marine biogeochemical processes as well as the sources and mixing of water masses. However, there are still important uncertainties about the global aqueous REE cycle with respect to the contributions of highly reactive basaltic minerals originating from volcanic islands and the role of Submarine Groundwater Discharge (SGD). Here we present dissolved REE concentrations obtained from waters at the island-ocean interface (including SGD, river, lagoon and coastal waters) from the island of Tahiti and from three detailed open ocean profiles on the Manihiki Plateau (including neodymium (Nd) isotope compositions), which are located in ocean currents downstream of Tahiti. Tahitian fresh waters have highly variable REE concentrations that likely result from variable water–rock interaction and removal by secondary minerals. In contrast to studies on other islands, the SGD samples do not exhibit elevated REE concentrations but have distinctive REE distributions and Y/Ho ratios. The basaltic Tahitian rocks impart a REE pattern to the waters characterized by a middle REE enrichment, with a peak at europium similar to groundwaters and coastal waters of other volcanic islands in the Pacific. However, the basaltic island REE characteristics (with the exception of elevated Y/Ho ratios) are lost during transport to the Manihiki Plateau within surface waters that also exhibit highly radiogenic Nd isotope signatures. Our new data demonstrate that REE concentrations are enriched in Tahitian coastal water, but without multidimensional sampling, basaltic island Nd flux estimates range over orders of magnitude from relatively small to globally significant. Antarctic Intermediate Water (AAIW) loses its characteristic Nd isotopic signature (-6 to -9) around the Manihiki Plateau as a consequence of mixing with South Equatorial Pacific Intermediate Water (SEqPIW), which shows more positive values (-1 to -2). However, an additional Nd input/exchange along the pathway of AAIW, eventually originating from the volcanic Society, Tuamotu and Tubuai Islands (including Tahiti), is indicated by an offset from the mixing array of AAIW and SEqPIW to more radiogenic Nd isotope compositions.

Distinct Siderophores Contribute to Iron Cycling in the Mesopelagic at Station ALOHA

ID: 1686
Year: 2018
Authors: Bundy, R;Boiteau, R;McLean, C;Turk-Kubo, K;McIlvin, M;Saito, M;Van Mooy, B;Repeta, D;
Products: PFA-ST
Journal: Front. Mar. Sci.
Volume: 5  -  Pages: 61
DOI: 10.3389/fmars.2018.00061

The distribution of dissolved iron (Fe), total organic Fe-binding ligands, and siderophores were measured between the surface and 400 m at Station ALOHA, a long term ecological study site in the North Pacific Subtropical Gyre. Dissolved Fe concentrations were low throughout the water column and strong organic Fe-binding ligands exceeded dissolved Fe at all depths; varying from 0.9 nmol L−1 in the surface to 1.6 nmol L-1 below 150 m. Although Fe does not appear to limit microbial production, we nevertheless found siderophores at nearly all depths, indicating some populations of microbes were responding to Fe stress. Ferrioxamine siderophores were most abundant in the upper water column, with concentrations between 0.1 and 2 pmol L−1, while a suite of amphibactins were found below 200 m with concentrations between 0.8 and 11 pmol L−1. The distinct vertical distribution of ferrioxamines and amphibactins may indicate disparate strategies for acquiring Fe from dust in the upper water column and recycled organic matter in the lower water column. Amphibactins were found to have conditional stability constants (log KcondFeL1,Fe′) ranging from 12.0 to 12.5, while ferrioxamines had much stronger conditional stability constants ranging from 14.0 to 14.4, within the range of observed L1 ligands by voltammetry. We used our data to calculate equilibrium Fe speciation at Station ALOHA to compare the relative concentration of inorganic and siderophore complexed Fe. The results indicate that the concentration of Fe bound to siderophores was up to two orders of magnitude higher than inorganic Fe, suggesting that even if less bioavailable, siderophores were nevertheless a viable pathway for Fe acquisition by microbes at our study site. Finally, we observed rapid production of ferrioxamine E by particle-associated bacteria during incubation of freshly collected sinking organic matter. Fe-limitation may therefore be a factor in regulating carbon metabolism and nutrient regeneration in the mesopelagic.

Advanced source apportionment of carbonaceous aerosols by coupling offline AMS and radiocarbon size segregated measurements over a nearly two-year period

ID: 1685
Year: 2017
Authors: Vlachou, A;Daellenbach, K;Bozzetti, C;Chazeau, B;Salazar, G;Szidat, S;Jaffrezo, J;Hueglin, C;Baltensperger, U;El Haddad, I;Prévôt, A;
Products: Apex Q nebulizer
Journal: Atmos. Chem. Phys. Discuss.
Volume:   -  Pages: 43125
DOI: 10.5194/acp-2017-1102

Carbonaceous aerosols are related to adverse human health effects. Therefore, identification of their sources and analysis of their chemical composition is important. The offline AMS technique offers quantitative separation of organic aerosol (OA) factors that can be related to major OA sources either primary or secondary. 20 While primary OA can be more clearly separated into sources, secondary (SOA) source apportionment is more challenging because different sources - anthropogenic or natural, fossil or non-fossil - can yield similar highly oxygenated mass spectra. Radiocarbon measurements provide unequivocal separation between fossil and nonfossil sources of carbon. Here we coupled these two offline methods and analysed the OA and organic carbon (OC) of different size fractions (particulate matter below 10 and 2.5µm – PM10 and PM2.5, respectively) from the 25 Alpine valley of Magadino (Switzerland) during the years 2013 and 2014 (219 samples). The combination of the techniques gave further insights into the characteristics of secondary OC (SOC) which was rather based on the type of SOC precursor and not on the volatility or the oxidation state of OC, as typically considered. Out of the primary sources separated in this study, biomass burning OC was the dominant one in winter with average concentrations of 5.36±2.64 µg m-3 for PM10 and 3.83±1.81 µg m-3 for PM2.5, indicating that wood combustion 30 particles were predominantly generated in the fine mode. The additional information from the size segregated measurements revealed a primary sulphur containing factor, mainly fossil, detected in the coarse size fraction and related to non-exhaust traffic emissions with average yearly PM10 (PM2.5) concentration of 0.20±0.24 µg m-3 (0.05±0.04 µg m-3 ). A primary biological OC was also detected in the coarse mode peaking in spring and summer with yearly average concentrations for PM10 (PM2.5) 0.79±0.31 µg m-3 (0.24±0.20 µg m-3 ). The 35 secondary OC was separated into two oxygenated, non-fossil OC factors which were identified based on their seasonal variability (i.e. summer and winter OOC) and a third fossil OOC factor which correlated with fossil OC mainly peaking in winter and spring with PM10 (PM2.5) contributing on average 13%±7% (10%±9%) to the total OC. The winter OOC was connected to anthropogenic sources, with PM10 (PM2.5) contributing on average 13%±13% (6%±6%) to the total OC. The summer OOC, stemming from oxidation of biogenic emissions was 40 more pronounced in the fine mode with PM10 (PM2.5) contributing on average 43%±12% (75%±44%) to the total OC. In total the non-fossil OC far dominated the fossil OC throughout all seasons, by contributing on average 75%±24% to the total OC. The results also suggested that during the cold period the prevailing source was residential biomass burning while during the warm period primary biological sources and secondary organic aerosol from the oxidation of biogenic emissions became important. However, SOC was also formed by aged fossil fuel combustion emissions not only in summer but also during the rest of the year.

No role for industrial black carbon in forcing 19th century glacierretreat in the Alps

ID: 1684
Year: 2018
Authors: Sigl, M;Abram, N;Gabrieli, J;Jenk, T;Osmont, D;Schwikowski, M;
Products: APEX-Q
Journal: The Cryosphere Discuss.
Volume:   -  Pages: 12420
DOI: 10.5194/tc-2018-22

Light absorbing aerosols in the atmosphere and cryosphere play an important role in the climate system. Their presence in ambient air and snow changes radiative properties of these media, thus contributing to increased atmospheric warming and snowmelt. High spatio-temporal variability of aerosol concentrations and a shortage of long-term observations contribute to large uncertainties in properly assigning the climate effects of aerosols through time.<br><br> Starting around 1860 AD, many glaciers in the European Alps began to retreat from their maximum mid-19th century terminus positions, thereby visualizing the end of the Little Ice Age in Europe. Radiative forcing by increasing deposition of industrial black carbon to snow has been suggested as the main driver of the abrupt glacier retreats in the Alps. Basis for this hypothesis were model simulations using elemental carbon concentrations at low temporal resolution from two ice cores in the Alps. <br><br> Here we present sub-annually resolved, well-replicated concentration records of refractory black carbon (rBC; using soot photometry) as well as distinctive tracers for mineral dust, biomass burning and industrial pollution from the Colle Gnifetti ice core in the Alps from 1741&amp;ndash;2015 AD. These records allow precise assessment of a potential relation between the timing of observed acceleration of glacier melt in the mid-19th century with an increase of rBC deposition on the glacier caused by the industrialization of Western Europe. Our study reveals that in 1875 AD, the time when European rBC emission rates started to significantly increase, the majority of Alpine glaciers had already experienced more than 80&amp;thinsp;% of their total 19th century length reduction. Industrial BC emissions can, therefore, not been considered as the primary forcing for the rapid deglaciation at the end of the Little Ice Age in the Alps. BC records from the Alps and Greenland also reveal the limitations of bottom-up emission inventories to represent a realistic evolution of anthropogenic BC emissions since preindustrial times.

Biology of Vascular Endothelial Growth Factor C in the Morphogenesis of Lymphatic Vessels

ID: 1683
Year: 2018
Authors: Rauniyar, K;Jha, SK;Jeltsch, M;
Products: ICP-SF-MS
Journal: Front Bioeng Biotechnol
Volume: 6  -  Pages: 7
DOI: 10.3389/fbioe.2018.00007

Because virtually all tissues contain blood vessels, the importance of hemevascularization has been long recognized in regenerative medicine and tissue engineering. However, the lymphatic vasculature has only recently become a subject of interest. Central to the task of growing a lymphatic network are lymphatic endothelial cells (LECs), which constitute the innermost layer of all lymphatic vessels. The central molecule that directs proliferation and migration of LECs during embryogenesis is vascular endothelial growth factor C (VEGF-C). VEGF-C is therefore an important ingredient for LEC culture and attempts to (re)generate lymphatic vessels and networks. During its biosynthesis VEGF-C undergoes a stepwise proteolytic processing, during which its properties and affinities for its interaction partners change. Many of these fundamental aspects of VEGF-C biosynthesis have only recently been uncovered. So far, most-if not all-applications of VEGF-C do not discriminate between different forms of VEGF-C. However, for lymphatic regeneration and engineering purposes, it appears mandatory to understand these differences, since they relate, e.g., to important aspects such as biodistribution and receptor activation potential. In this review, we discuss the molecular biology of VEGF-C as it relates to the growth of LECs and lymphatic vessels. However, the properties of VEGF-C are similarly relevant for the cardiovascular system, since both old and recent data show that VEGF-C can have a profound effect on the blood vasculature.

Quantification of Zinc in Thermally Conducting Polycarbonate Containing Fiber-type SiO2 Fillers

ID: 1682
Year: 2018
Authors: Kim, E;Lim, H;
Products: autosampler
Journal: Bull. Korean Chem. Soc.
Volume: 39  -  Pages: 341-346
DOI: 10.1002/bkcs.11392

In this work, a new analytical method based on dry ashing followed by Si removal was developed for the determination of Zn in polycarbonate (PC)-conducting polymers containing fiber-type SiO2 fillers. Since major matrices of the polymers, i.e., PC and SiO2 fibers, were removed during the treatment, low interference and reproducible result were achieved in inductively coupled plasma-mass spectrometry (ICP-MS). When the developed method was applied to PC polymers used for electrical appliances, the recovery was obtained in the range of 103.5% to 108.8% with relative standard deviations of <12.1%. Furthermore, the determined polymers were used as reference materials for laser‐ablation ICP‐MS (LA‐ICP‐MS) and laser induced‐breakdown spectroscopy (LIBS) in order to test the feasibility of screening and quality control. Although the mapping images of LIBS showed severe inhomogeneity, the averaged intensities of LIBS and LA‐ICP‐MS displayed reasonable correlations with the determined concentrations of Zn. The result indicates that both methods have a potential for screening and quantitative analysis of the conducting polymers used in manufacturing process, even if fiber‐type SiO2 fillers were embedded.

Assessment of Ground-Based and Aerial Cloud Seeding Using Trace Chemistry

ID: 1681
Year: 2018
Authors: Fisher, J;Lytle, M;Kunkel, M;Blestrud, D;Dawson, N;Parkinson, S;Edwards, R;Benner, S;
Products: polyethylene sample rack
Journal: Advances in Meteorology
Volume: 2018  -  Pages: 43115
DOI: 10.1155/2018/7293987

Targeting seedable clouds with silver iodide in complex terrain adds considerable uncertainty in weather modification studies. This study explores the geographic and temporal distribution of silver iodide associated with an active cloud seeding program in central Idaho snowpack using trace chemistry. Over 4,000 snow samples were analyzed for the presence of a cloud seeding silver iodide (AgI) signature over two winter seasons. The results indicate the following. (1) At sites within 70 km of AgI sources, silver enrichments were detected at 88% of cases involving seeding efforts from ground generators, but none from aircraft seeded cases. (2) Real-time snow collection methods were replicable within 0.41 ppt and confirmed seeding signatures for the entire duration of a seeded storm (n=3). (3) Sites sampled beyond 70 km of AgI sources (n=13) lacked detectable seeding signatures in snow. The results of this study demonstrate some of the strengths and limitations of chemical tracers to evaluate cloud seeding operations and provide observational data that can inform numerical simulations of these processes. The results also indicate that this chemical approach can be used to help constrain the spatiotemporal distribution of silver from cloud seeding efforts.

On the application of ICP-MS techniques for measuring uranium and plutonium: a Nordic inter-laboratory comparison exercise

ID: 1680
Year: 2018
Authors: Qiao, J;Lagerkvist, P;Rodushkin, I;Salminen-Paatero, S;Roos, P;Lierhagen, S;Jensen, K;Engstrom, E;Lahaye, Y;Skipperud, L;
Products: SC2 DX auto sampler
Journal: J Radioanal Nucl Chem
Volume: 315  -  Pages: 565-580
DOI: 10.1007/s10967-018-5697-4

Inductively coupled plasma mass spectrometry (ICP-MS) techniques are widely used for determination of long-lived radionuclides and their isotopic ratios in the nuclear fields. Uranium (U) and Plutonium (Pu) isotopes have been determined by many researchers with ICP-MS due to its relatively high sensitivity and short measurement time. In this work, an inter-laboratory comparison exercise among the Nordic countries was performed, focusing on the measurement of U and Pu isotopes in certified reference materials by ICP-MS. The performance and characters of different ICP-MS instruments are evaluated and discussed in this paper.

Comparisons of soil pretreatment methods for SF-ICP-MS determination of ultra-trace level plutonium in water soluble and exchangeable fractions

ID: 1679
Year: 2018
Authors: Ni, Y;Zheng, J;Guo, Q;Wang, H;Tagami, K;Uchida, S;
Products: APEX-Q
Journal: J Radioanal Nucl Chem
Volume: 315  -  Pages: 643-651
DOI: 10.1007/s10967-018-5700-0

In this study, we developed a method to evaluate the potentially bioavailable fraction of Pu in agricultural soils by determining their water soluble and exchangeable fractions. Three commonly used pretreatment methods were compared for their ability and performances to process the extracted solutions. Results showed that these three methods were able to obtain consistent Pu concentration results; however, based on the experimental performance factors, we considered that wet-ashing followed by Fe(OH)3 co-precipitation was the best pretreatment method, with which high 242Pu recoveries for the overall process were realized for the water soluble fraction (69.8%) and the exchangeable fraction (70.6%).

A simple distillation method to extract bromine from natural water and salt samples for isotope analysis by multi-collector inductively coupled plasma mass spectrometry

ID: 1678
Year: 2018
Authors: Eggenkamp, HGM;Louvat, P;
Products: PFA nebulizer
Journal: Rapid Commun. Mass Spectrom.
Volume: 32  -  Pages: 612-618
DOI: 10.1002/rcm.8080

In natural samples bromine is present in trace amounts, and measurement of stable Br isotopes necessitates its separation from the matrix. Most methods described previously need large samples or samples with high Br/Cl ratios. The use of metals as reagents, proposed in previous Br distillation methods, must be avoided for multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) analyses, because of risk of cross-contamination, since the instrument is also used to measure stable isotopes of metals. Dedicated to water and evaporite samples with low Br/Cl ratios, the proposed method is a simple distillation that separates bromide from chloride for isotopic analyses by MC-ICP-MS. It is based on the difference in oxidation potential between chloride and bromide in the presence of nitric acid. The sample is mixed with dilute (1:5) nitric acid in a distillation flask and heated over a candle flame for 10 min. The distillate (bromine) is trapped in an ammonia solution and reduced to bromide. Chloride is only distilled to a very small extent. The obtained solution can be measured directly by MC-ICP-MS for stable Br isotopes. The method was tested for a variety of volumes, ammonia concentrations, pH values and distillation times and compared with the classic ion-exchange chromatography method. The method more efficiently separates Br from Cl, so that samples with lower Br/Cl ratios can be analysed, with Br isotope data in agreement with those obtained by previous methods. Unlike other Br extraction methods based on oxidation, the distillation method presented here does not use any metallic ion for redox reactions that could contaminate the mass spectrometer. It is efficient in separating Br from samples with low Br/Cl ratios. The method ensures reproducible recovery yields and a long-term reproducibility of ±0.11‰ (1 standard deviation). The distillation method was successfully applied to samples with low Br/Cl ratios and low Br amounts (down to 20 µg).

Hair Trace Elements in Overweight and Obese Adults in Association with Metabolic Parameters

ID: 1677
Year: 2018
Authors: Skalnaya, MG;Skalny, AV;Grabeklis, AR;Serebryansky, EP;Demidov, VA;Tinkov, AA;
Products: ESI SC-2 DX4
Journal: Biol Trace Elem Res
Volume:   -  Pages: 43109
DOI: 10.1007/s12011-018-1282-5

The objective of the present study was to investigate the level of toxic and essential trace elements in hair of adult overweight and obese persons as well as its association with metabolic parameters. Hair trace element levels were assessed using inductively coupled plasma mass-spectrometry in 112 overweight and obese patients and 106 lean controls. Serum total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), triglycerides (TG), glucose, uric acid (UA) levels, and cholinesterase (CE) and gamma-glutamyltransferase (GGT) activity were also assessed. Excessive body weight significantly affected hair trace element levels. In particular, hair Co (33%), Cu (13%), I (30%), Mg (2-fold), Mn (25%), Zn (17%), and Ni (21%) levels were lower, whereas Al (14%) and As levels were higher in comparison to those in the control group. Correlation analysis demonstrated the most significant correlations for hair Mg with body weight, BMI, systolic and diastolic blood pressure, and UA, and for hair Al with body weight, BMI, TC, glucose, TG, CE, GGT, and UA. Multiple regression analysis demonstrated that trace elements were not associated with TC and LDL-C levels neither in crude nor in adjusted models. In turn, crude and adjusted models accounted for 25 and 43% of serum TG variance. The most significant associations were observed for hair Al, Fe, Si, and V in adjusted model. The obtained data demonstrate that obesity-related metabolic disorders may be at least partially mediated by altered trace element and mineral levels.

Ultra-trace analysis of silver and platinum in seawater by ICP-SFMS after off-line matrix separation and pre-concentration

ID: 1676
Year: 2018
Authors: Fischer, L;Smith, G;Hann, S;Bruland, K;
Products: PFA ST nebulizer
Journal: Marine Chemistry
Volume: 199  -  Pages: 44-52
DOI: 10.1016/j.marchem.2018.01.006

Precise and accurate quantification of Ag and platinum group elements in marine, estuarine and riverine waters is challenging due to the complex matrices and ultra-low concentrations in the pmol kg-1 and fmol kg-1 range. A methodological approach has been developed for the analysis of Ag and Pt in seawater based on the extraction of their anionic chloro-complexes utilizing the strong anion exchange resin Dowex™ 1-נ8 in an off-line matrix separation and pre-concentration approach prior to determination by ICP-SFMS. The method allows simultaneous processing of four 100 mL samples at a flow rate of up to 2 mL min-1 in an ultra-clean manifold. Enrichment factors of 40 could be achieved with elution into 2.5 g of a mixture of HNO3/HCl, yielding adequately low detection limits to obtain open ocean profiles. Quantification was performed by matrix-matched calibration and internal standardization. To validate the accuracy of this approach, isotope dilution analysis was also used. The applicability of the method was demonstrated on a suite of reference samples and depth profiles collected during the 2009 2nd U.S. GEOTRACES Intercalibration cruise in the eastern North Pacific.

Potential of insect-based diets for Atlantic salmon ( Salmo salar )

ID: 1675
Year: 2018
Authors: Belghit, I;Liland, N;Waagbø, R;Biancarosa, I;Pelusio, N;Li, Y;Krogdahl, ;Lock, E;
Products: FAST SC-4Q DX
Journal: Aquaculture
Volume: 491  -  Pages: 72-81
DOI: 10.1016/j.aquaculture.2018.03.016

In the present study, we aimed to assess the effect of dietary insect meal (IM) and insect oil (IO) on growth performance, body composition and nutrient digestibility of freshwater reared Atlantic salmon. The IM and IO were produced from black soldier fly larvae (Hermetia illucens, L.; BSF) that had been grown on (1) media containing organic waste streams, or on (2) media partially containing seaweed (Ascophyllum nodosum). The feeding trial of the current study followed a factorial 2 x 3 way-ANOVA experimental design with six dietary groups of Atlantic salmon fed diets with insect-derived ingredients for 8 weeks. A typical industrial diet, with protein from fish meal and soy protein concentrate (SPC) (50:50) and lipids from fish oil and vegetable oil (33:66), was fed to a positive control group. Five experimental diets were formulated, where 85% of the dietary protein was replaced by IM and/or all the vegetable oil was replaced by IO (IM from insects grown on media 1, IO from insects grown on either media 1 (IO1) or media 2 (IO2)). Replacing the dietary fish meal and SPC with insect protein significantly reduced the apparent digestibility coefficients (ADC) of protein, lipid and all amino acids investigated, though remained highly digestible. There were, however, only small differences due to protein or lipid source in growth performance, and no effects of insect ingredients on feed intake or feed conversion ratio. Inclusion of IM-based diets significantly increased both hepatosomatic index and visceral somatic index of Atlantic salmon. Proteinase activity in the intestine was not affected by dietary inclusion of BSF larvae meal, while leucine aminopeptidase activity was lower in fish fed with insect ingredients than the control group. Whole-body protein, lipid, amino acids and minerals contents were not affected by protein or lipid source. In general, this study showed that protein meal and oil from BSF larvae hold a great potential as a source of nutrients for Atlantic salmon.

The gold of the Carambolo Treasure: New data on its origin by elemental (LA-ICP-MS) and lead isotope (MC-ICP-MS) analysis

ID: 1674
Year: 2018
Authors: Nocete, F;Sáez, R;Navarro, A;San Martin, C;Gil-Ibarguchi, J;
Products: Apex IR inlet system
Journal: Journal of Archaeological Science
Volume: 92  -  Pages: 87-102
DOI: 10.1016/j.jas.2018.02.011

The Carambolo Treasure (Seville, Spain), is a key collection of materials from the 1st Millennium BC Mediterranean. Besides the uniqueness, technical complexity and beauty of this assemblage of gold associated with the mythical name of Tartessos, the treasure has been at the epicentre of debates over the last 50 years regarding the Phoenician presence in the west and the origin of the first great western civilization. However, the absence of a precise archaeological context and systematic analyses aimed at identifying the source of the supply of gold have led to diverse and conflicting interpretations in terms of its functionality (ritual from a Phoenician temple versus ostentation of a palatial royalty), and origin (Atlantic vs Eastern Mediterranean).


^ top of page