The large-scale distribution of Cu and Zn in sub- and topsoil: Separating topsoil bioaccumulation and natural matrix effects from diffuse and regional contamination

2019 ◽  
Vol 655 ◽  
pp. 730-740 ◽  
Author(s):  
Clemens Reimann ◽  
Karl Fabian ◽  
Belinda Flem ◽  
Peter Englmaier
Keyword(s):  
Large Scale ◽  
Matrix Effects ◽  
Regional Contamination ◽  
Cu And Zn

scholarly journals Study of Δ9-tetrahydrocannabinol (THC) and cannabidiol (CBD) extraction FROM dried oral fluid spots (DOFS) and LC–MS/MS detection

2021 ◽  
Vol 3 (1) ◽  
Author(s):  
Roberta Gorziza ◽  
Joseph Cox ◽  
Renata Pereira Limberger ◽  
Luis E. Arroyo-Mora
Keyword(s):  
Method Validation ◽  
Qualitative Method ◽  
Large Scale ◽  
Oral Fluid ◽  
Drugs Of Abuse ◽  
Matrix Effects ◽  
Low Cost ◽  
Sampling Strategy ◽  
Sampling Technique ◽  
Process Efficiency

Abstract Background Oral fluid is a widely studied matrix able to isolate the primary Cannabis constituent THC, facilitating its detection via mass spectrometry, and in most cases link these findings to recent drug use. As an alternative to liquid oral fluid, dried oral fluid spots (DOFS) is a simple and a low-cost sampling technique. It has shown improved stability compared to liquid samples, allowing for the possibility to preserve the specimens under various temperature and humidity conditions. The sampling strategy is straightforward and involves the application of a small quantity of oral fluid aliquot to a paper substrate that is set to air dry allowing for on-site collection at a large-scale demand. The goal of this study is to study THC and CBD extraction from DOFS, applying a previous established protocol for a LC–MS/MS qualitative method validation. Although other drugs of abuse have been included in DOFS methods, this is the first method validation including cannabinoids. An alternative oral fluid extraction method (WAX-S tips) is demonstrated to improve the recovery of the analytes. Methods A pool of blank oral fluid was used to prepare THC and CBD spiked DOFS samples for method validation and application. Spiked oral fluid was used to demonstrate WAX-S tips THC and CBD extraction. All samples were analyzed on a LC–MS/MS instrument. Results The qualitative method validation for THC and CBD confirmation in DOFS included method selectivity, matrix effects (< 20%), recovery (average of 25%), process efficiency (average of 21%), LOD (2 ng/mL for THC and 4 ng/mL for CBD), absence of carryover, and DOFS stability (70% in 35 days) as figures of merit. The method application in blindly prepared samples demonstrated the method capability to identify THC and CBD. WAX-S tips extraction showed an average of 91% recovery of THC and CBD from liquid oral fluid. Conclusions THC and CBD extraction from DOFS showed low recoveries. However, the LC–MS/MS qualitative confirmation of THC and CBD in DOFS could improve cannabinoids screening in oral fluid, as it shows adequate LOD and stability over time. This method has potential for assisting the screening of drivers under possible drug influence by facilitating sample transportation and temporary storage in dried spot form. Additional research is suggested for WAX-S tips extraction and quantitative method validation.

scholarly journals Polar Lipids in Starch-Rich Commodities to be Analyzed with LC-MS-Based Metabolomics—Optimization of Ionization Parameters and High-Throughput Extraction Protocols

Metabolites ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 167 ◽  
Author(s):  
Christin Claassen ◽  
Jürgen Kuballa ◽  
Sascha Rohn
Keyword(s):  
High Performance ◽  
Large Scale ◽  
Matrix Effects ◽  
Polar Lipids ◽  
Ionization Source ◽  
Long Term Stability ◽  
Folch Method ◽  
Ion Mobility Spectroscopy ◽  
Targeted Approach

Metabolomics-based approaches are still receiving growing attention with regard to food authenticity testing. Such studies require enormous sample numbers with negligible experimental or analytical variations to obtain statistically reliable results. In this context, an extraction protocol in line with optimized ionization parameters was developed in consideration of potential starch-derived matrix effects focusing on the polar lipids of potatoes. Therefore, well-known extractions (Bligh and Dyer, Folch, Matyash, and a n-hexane-based procedure) were compared in a non-targeted and a targeted approach regarding the extractability of their lipids such as phosphatidylcholines, phosphatidylethanolamines, galacto- and glucocerebrosides, di- and triglycerides, and acylated steryl glucosides. The selected Folch method was also scrutinized in view of its ability to remove the matrix’s starch and consequently improved by substituting trichlormethane with ethyl acetate as a “greener” Folch approach. Moreover, the challenge of starch-derived contamination and imminent ion suppression in the electrospray ionization source (ESI) was addressed by an optimization of ionization parameters varying desolvation settings, removing injection peaks, and increasing the angles and distances of the ESI-device. Long-term stability tests over five days were performed successfully with a combination of appropriate extraction and decreased desolvation settings during ionization. In conclusion, the present methodology provided the basis for on-going large-scale metabolomic studies with respect to the botanical origin of potatoes using UPLC-IMS-QToF (ultra-high performance liquid chromatography ion mobility spectroscopy quadrupole-time of flight mass spectrometer).

The Removal of Heavy Metals by the Three Aquatic Macrophytes

2013 ◽  
Vol 401-403 ◽  
pp. 2088-2091
Author(s):  
Yuan Qing Zhou ◽  
Shu Ying Li ◽  
Wei Lv ◽  
Yan Chen ◽  
Guang Hua He ◽  
...  
Keyword(s):  
Waste Water ◽  
Heavy Metals ◽  
Comparative Evaluation ◽  
Aquatic Macrophytes ◽  
Large Scale ◽  
Myriophyllum Spicatum ◽  
Scale Removal ◽  
Removal Of Heavy Metals ◽  
Sagittaria Sagittifolia ◽  
Cu And Zn

The present study deals with comparative evaluation of three different aquatic macrophytes, i.e. Myriophyllum spicatum, Sagittaria sagittifolia and Pistia stratiote planted at three different concentrations (1.0, 3.0 and 5.0 mg/L) of metals in laboratory experiment for Cd, Cu and Zn removal from aqueous solution. Result revealed high removal (>90%) of different metals during 15 days experiment. Highest removal was observed on 13th day of experiment, thereafter it decreased. Results revealed Pistia stratiote as the most efficient for the removal of selected heavy metal followed by Sagittaria sagittifolia and Myriophyllum spicatum. Selected plants can be used for large scale removal of Cd, Cu and Zn from waste water.

scholarly journals Disentangling urban habitat and matrix effects on wild bee species

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e2729 ◽  
Author(s):  
Leonie K. Fischer ◽  
Julia Eichfeld ◽  
Ingo Kowarik ◽  
Sascha Buchholz
Keyword(s):  
Urban Areas ◽  
Large Scale ◽  
Matrix Effects ◽  
Urban Environments ◽  
Urban Habitat ◽  
Anthropogenic Pressure ◽  
Wild Bees ◽  
Study Region ◽  
Rural Landscapes ◽  
Wild Bee

In face of a dramatic decline of wild bee species in many rural landscapes, potential conservation functions of urban areas gain importance. Yet effects of urbanization on pollinators, and in particular on wild bees, remain ambiguous and not comprehensively understood. This is especially true for amenity grassland and extensively managed wastelands within large-scale residential housing areas. Using Berlin as a study region, we aimed to investigate (a) if these greenspaces are accepted by wild bee assemblages as foraging habitats; (b) how assemblage structure of bees and individual bee species are affected by different habitat (e.g., management, flower density) and urban matrix variables (e.g., isolation, urbanization); and (c) to what extent grassland restoration can promote bees in urban environments. In summer 2012, we collected 62 bee species belonging to more than 20% of the taxa known for Berlin. Urbanization significantly affected species composition of bees; 18 species were affiliated to different levels of urbanization. Most bee species were not affected by any of the environmental variables tested, and urbanization had a negative effect only for one bee species. Further, we determined that restoration of diverse grasslands positively affected bee species richnesss in urban environments. We conclude that differently structured and managed greenspaces in large-scale housing areas can provide additional foraging habitats and refuges for pollinators. This supports approaches towards a biodiversity friendly management within urban regions and may be of particular importance given that anthropogenic pressure is increasing in many rural landscapes.

Heavy Metal Pollution of Farmland Soils Surrounding Large-Scale Pig Farms

2013 ◽  
Vol 781-784 ◽  
pp. 2133-2137
Author(s):  
Qiu Gen Zhang ◽  
Su Qin Wang ◽  
Li An Wei
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Pollution ◽  
Heavy Metal Pollution ◽  
Large Scale ◽  
Pollution Index ◽  
Comprehensive Index ◽  
Pig Farms ◽  
Farmland Soils ◽  
Cu And Zn

The seven typical plots were sampled and the contents of As, Cd, Cr, Cu, Ni, Pb and Zn were analyzed in order to investigate the heavy metal pollution of farmland soils surrounding scale pig farms in Nanchang. The heavy metal pollution was evaluated by using single pollution index and comprehensive index methods. The results were addressed that Cd and Pb were the major two pollutants in the farmland soils. The sequence of single pollution index was Cd, Pb, Ni, Cu, Zn, As and Cr. The competitive pollution index was 1.55, and the farmland soils were a slightly polluted grade. The correlation among heavy metals As, Cd, Pb, Cu and Zn were highly significant or significant, but the correlation among Cr, Ni and other heavy metals were not relevant.

Some comments about observations and image processing of comet 29P/Schwassmann-Wachmann 1

1999 ◽  
Vol 173 ◽  
pp. 243-248
Author(s):  
D. Kubáček ◽  
A. Galád ◽  
A. Pravda
Keyword(s):  
Image Processing ◽  
Large Scale ◽  
Harvard College ◽  
Oak Ridge ◽  
Large Scale Structures ◽  
Short Period Comet ◽  
Short Period ◽  
Scale Structures ◽  
Harvard College Observatory ◽  
Period Comet

AbstractUnusual short-period comet 29P/Schwassmann-Wachmann 1 inspired many observers to explain its unpredictable outbursts. In this paper large scale structures and features from the inner part of the coma in time periods around outbursts are studied. CCD images were taken at Whipple Observatory, Mt. Hopkins, in 1989 and at Astronomical Observatory, Modra, from 1995 to 1998. Photographic plates of the comet were taken at Harvard College Observatory, Oak Ridge, from 1974 to 1982. The latter were digitized at first to apply the same techniques of image processing for optimizing the visibility of features in the coma during outbursts. Outbursts and coma structures show various shapes.

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Large-scale Motion of Solar Filaments

2000 ◽  
Vol 179 ◽  
pp. 205-208
Author(s):  
Pavel Ambrož ◽  
Alfred Schroll
Keyword(s):  
Magnetic Flux ◽  
Proper Motion ◽  
Time Scale ◽  
Large Scale ◽  
Accuracy Of Measurements ◽  
Solar Filaments ◽  
General Movement ◽  
Scale Motion ◽  
Velocity Scatter

AbstractPrecise measurements of heliographic position of solar filaments were used for determination of the proper motion of solar filaments on the time-scale of days. The filaments have a tendency to make a shaking or waving of the external structure and to make a general movement of whole filament body, coinciding with the transport of the magnetic flux in the photosphere. The velocity scatter of individual measured points is about one order higher than the accuracy of measurements.

Some applications of electron beam microanalysis techniques in VLSI process evaluation

1983 ◽  
Vol 41 ◽  
pp. 160-161
Author(s):  
Simon Thomas
Keyword(s):  
Integrated Circuits ◽  
Process Evaluation ◽  
Large Scale ◽  
Technology Development ◽  
Analytical Techniques ◽  
Successful Implementation ◽  
Analysis Of Failures ◽  
Characterization Of Materials ◽  
Circuits Vlsi

Trends in the technology development of very large scale integrated circuits (VLSI) have been in the direction of higher density of components with smaller dimensions. The scaling down of device dimensions has been not only laterally but also in depth. Such efforts in miniaturization bring with them new developments in materials and processing. Successful implementation of these efforts is, to a large extent, dependent on the proper understanding of the material properties, process technologies and reliability issues, through adequate analytical studies. The analytical instrumentation technology has, fortunately, kept pace with the basic requirements of devices with lateral dimensions in the micron/ submicron range and depths of the order of nonometers. Often, newer analytical techniques have emerged or the more conventional techniques have been adapted to meet the more stringent requirements. As such, a variety of analytical techniques are available today to aid an analyst in the efforts of VLSI process evaluation. Generally such analytical efforts are divided into the characterization of materials, evaluation of processing steps and the analysis of failures.

Electron microscopy study of reactively sputter-deposited Ti/N films on silicon

1992 ◽  
Vol 50 (2) ◽  
pp. 1362-1363
Author(s):  
V. C. Kannan ◽  
A. K. Singh ◽  
R. B. Irwin ◽  
S. Chittipeddi ◽  
F. D. Nkansah ◽  
...  
Keyword(s):  
Integrated Circuits ◽  
Large Scale ◽  
Hexagonal Phase ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Process Conditions ◽  
Tin Films ◽  
Wide Range ◽  
Fcc Phase ◽  
Circuits Vlsi

Titanium nitride (TiN) films have historically been used as diffusion barrier between silicon and aluminum, as an adhesion layer for tungsten deposition and as an interconnect material etc. Recently, the role of TiN films as contact barriers in very large scale silicon integrated circuits (VLSI) has been extensively studied. TiN films have resistivities on the order of 20μ Ω-cm which is much lower than that of titanium (nearly 66μ Ω-cm). Deposited TiN films show resistivities which vary from 20 to 100μ Ω-cm depending upon the type of deposition and process conditions. TiNx is known to have a NaCl type crystal structure for a wide range of compositions. Change in color from metallic luster to gold reflects the stabilization of the TiNx (FCC) phase over the close packed Ti(N) hexagonal phase. It was found that TiN (1:1) ideal composition with the FCC (NaCl-type) structure gives the best electrical property.

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