Determination of minor and trace elements in aromatic spices by micro-wave assisted digestion and inductively coupled plasma-mass spectrometry.

PubMed

Khan, Naeem; Choi, Ji Yeon; Nho, Eun Yeong; Jamila, Nargis; Habte, Girum; Hong, Joon Ho; Hwang, In Min; Kim, Kyong Su

2014-09-01

This study aimed at analyzing the concentrations of 23 minor and trace elements in aromatic spices by inductively coupled plasma-mass spectrometry (ICP-MS), after wet digestion by microwave system. The analytical method was validated by linearity, detection limits, precision, accuracy and recovery experiments, obtaining satisfactory values in all cases. Results indicated the presence of variable amounts of both minor and trace elements in the selected aromatic spices. Manganese was high in cinnamon (879.8 μg/g) followed by cardamom (758.1 μg/g) and clove (649.9 μg/g), strontium and zinc were high in ajwain (489.9 μg/g and 84.95 μg/g, respectively), while copper was high in mango powder (77.68 μg/g). On the whole some of the minor and essential trace elements were found to have good nutritional contribution in accordance to RDA. The levels of toxic trace elements, including As, Cd, and Pb were very low and did not found to pose any threat to consumers. Copyright © 2014 Elsevier Ltd. All rights reserved.

Concentration comparison of selected constituents between groundwater samples collected within the Missouri River alluvial aquifer using purge and pump and grab-sampling methods, near the city of Independence, Missouri, 2013

USGS Publications Warehouse

Krempa, Heather M.

2015-10-29

Relative percent differences between methods were greater than 10 percent for most analyzed trace elements. Barium, cobalt, manganese, and boron had concentrations that were significantly different between sampling methods. Barium, molybdenum, boron, and uranium method concentrations indicate a close association between pump and grab samples based on bivariate plots and simple linear regressions. Grab sample concentrations were generally larger than pump concentrations for these elements and may be because of using a larger pore sized filter for grab samples. Analysis of zinc blank samples suggests zinc contamination in filtered grab samples. Variations of analyzed trace elements between pump and grab samples could reduce the ability to monitor temporal changes and potential groundwater contamination threats. The degree of precision necessary for monitoring potential groundwater threats and application objectives need to be considered when determining acceptable variation amounts.

Solid phase extraction of trace amounts of cadmium(II) ions in water and food samples using iron magnetite nanoparticles modified by sodium dodecyl sulfate and 2-mercaptobenzothiazole.

PubMed

Abbasi, Shahriar; ShanbehDehbalai, Mehdi; Khani, Hossein

2017-03-01

A new, simple and rapid method for solid phase extraction and preconcentration of trace amounts of cadmium ions using 2-mercaptobenzothiazole/sodium dodecyl sulfate immobilized on magnetite nanoparticles (MBT-SDS-MNPs) was proposed. The method is based on the extraction of cadmium ions via complexation with MBT immobilized on SDS-coated MNPs and their determination by flame atomic absorption spectrometry. The effects of different parameters - pH; eluent type, concentration and volume; amounts of salt and adsorbent; contact time and interfering ions - on the adsorption of cadmium ions were studied. Under optimized conditions, the calibration curve was linear in the range of 10-5,000 μg L -1 . Detection limit and relative standard deviation of the proposed method were 0.009 μg L -1 and 2.2%, respectively. The adsorption data were analyzed by Langmuir and Freundlich isotherm models and a maximum adsorption amount of 24.80 mg g -1 , a Langmuir adsorption equilibrium constant (b) of 4.62 and Freundlich constants K f and n of 6.075 mg 1-1/n L 1/n g -1 and 2.391, respectively, were obtained. Finally, this adsorbent was successfully used for extraction of cadmium from water and food samples.

Rapid screening of heavy metals and trace elements in environmental samples using portable X-ray fluorescence spectrometer, A comparative study

PubMed Central

McComb, Jacqueline Q.; Rogers, Christian; Han, Fengxiang X.; Tchounwou, Paul B.

2014-01-01

With industrialization, great amounts of trace elements and heavy metals have been excavated and released on the surface of the earth and dissipated into the environments. Rapid screening technology for detecting major and trace elements as well as heavy metals in variety of environmental samples is most desired. The objectives of this study were to determine the detection limits, accuracy, repeatability and efficiency of a X-ray fluorescence spectrometer (Niton XRF analyzer) in comparison with the traditional analytical methods, inductively coupled plasma optical emission spectrometer (ICP-OES) and inductively coupled plasma optical emission spectrometer (ICP-MS) in screening of major and trace elements of environmental samples including estuary soils and sediments, contaminated soils, and biological samples. XRF is a fast and non-destructive method in measuring the total concentration of multi--elements simultaneously. Contrary to ICP-OES and ICP-MS, XRF analyzer is characterized by the limited preparation required for solid samples, non-destructive analysis, increased total speed and high throughout, the decreased production of hazardous waste and the low running costs as well as multi-elemental determination and portability in the fields. The current comparative study demonstrates that XRF is a good rapid non-destructive method for contaminated soils, sediments and biological samples containing higher concentrations of major and trace elements. Unfortunately, XRF does not have sensitive detection limits of most major and trace elements as ICP-OES or ICP-MS but it may serve as a rapid screening tool for locating hot spots of uncontaminated field soils and sediments. PMID:25861136

Determination of trace amounts of tin in geological materials by atomic absorption spectrometry

USGS Publications Warehouse

Welsch, E.P.; Chao, T.T.

1976-01-01

An atomic absorption method is described for the determination of traces of tin in rocks, soils, and stream sediments. A dried mixture of the sample and ammonium iodide is heated to volatilize tin tetraiodide -which is then dissolved in 5 % hydrochloric acid, extracted into TOPO-MIBK, and aspirated into a nitrous oxide-acetylene flame. The limit of determination is 2 p.p.m. tin and the relative standard deviation ranges from 2 to 14 %. Up to 20 % iron and 1000 p.p.m. Cu, Pb, Zn, Mn, Hg, Mo, V, or W in the sample do not interfere. As many as 50 samples can be easily analyzed per man-day. ?? 1976.

Simultaneous spectrophotometric determination of trace amounts of uranium, thorium, and zirconium using the partial least squares method after their preconcentration by alpha-benzoin oxime modified Amberlite XAD-2000 resin.

PubMed

Ghasemi, Jahan B; Zolfonoun, E

2010-01-15

A new solid phase extraction method for separation and preconcentration of trace amounts of uranium, thorium, and zirconium in water samples is proposed. The procedure is based on the adsorption of U(VI), Th(IV) and Zr(IV) ions on a column of Amberlite XAD-2000 resin loaded with alpha-benzoin oxime prior to their simultaneous spectrophotometric determination with Arsenazo III using orthogonal signal correction partial least squares method. The enrichment factor for preconcentration of uranium, thorium, and zirconium was found to be 100. The detection limits for U(VI), Th(IV) and Zr(IV) were 0.50, 0.54, and 0.48microgL(-1), respectively. The precision of the method, evaluated as the relative standard deviation obtained by analyzing a series of 10 replicates, was below 4% for all elements. The practical applicability of the developed sorbent was examined using synthetic seawater, natural waters and ceramic samples.

Problems associated with using filtration to define dissolved trace element concentrations in natural water samples

USGS Publications Warehouse

Horowitz, A.J.; Lum, K.R.; Garbarino, J.R.; Hall, G.E.M.; Lemieux, C.; Demas, C.R.

1996-01-01

Field and laboratory experiments indicate that a number of factors associated with filtration other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample) can produce significant variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. The bulk of these variations result from the inclusion/exclusion of colloidally associated trace elements in the filtrate, although dilution and sorption/desorption from filters also may be factors. Thus, dissolved trace element concentrations quantitated by analyzing filtrates generated by processing whole water through similar pore-sized filters may not be equal or comparable. As such, simple filtration of unspecified volumes of natural water through unspecified 0.45-??m membrane filters may no longer represent an acceptable operational definition for a number of dissolved chemical constituents.

Atmospheric Deposition of Trace Elements in Ombrotrophic Peat as a Result of Anthropic Activities

NASA Astrophysics Data System (ADS)

Fabio Lourençato, Lucio; Cabral Teixeira, Daniel; Vieira Silva-Filho, Emmanoel

2014-05-01

Ombrotrophic peat can be defined as a soil rich in organic matter, formed from the partial decomposition of vegetable organic material in a humid and anoxic environment, where the accumulation of material is necessarily faster than the decomposition. From the physical-chemical point of view, it is a porous and highly polar material with high adsorption capacity and cation exchange. The high ability of trace elements to undergo complexation by humic substances happens due to the presence of large amounts of oxygenated functional groups in these substances. Since the beginning of industrialization human activities have scattered a large amount of trace elements in the environment. Soil contamination by atmospheric deposition can be expressed as a sum of site contamination by past/present human activities and atmospheric long-range transport of trace elements. Ombrotrophic peat records can provide valuable information about the entries of trace metals into the atmosphere and that are subsequently deposited on the soil. These trace elements are toxic, non-biodegradable and accumulate in the food chain, even in relatively low quantities. Thus studies on the increase of trace elements in the environment due to human activities are necessary, particularly in the southern hemisphere, where these data are scarce. The aims of this study is to evaluate the concentrations of mercury in ombrotrophic peat altomontanas coming from atmospheric deposition. The study is conducted in the Itatiaia National Park, Brazilian conservation unit, situated between the southeastern state of Rio de Janeiro, São Paulo and Minas Gerais. An ombrotrophic peat core is being sampled in altitude (1980m), to measure the trace elements concentrations of this material. As it is conservation area, the trace elements found in the samples is mainly from atmospheric deposition, since in Brazil don't exist significant lithology of trace elements. The samples are characterized by organic matter content which is determined by calcination and pH. For the determination of mercury, an aliquot of 10 mL of sample with 5 mL of the reducing agent 2 % SnCl2, purged with air by atomic absorption spectrophotometry by cold vapor, EAAVF is being used. The determination of other trace elements (Zn, Cd and Pb) is analyzed by flame atomic absorption spectroscopy (FAAS).

Contamination Analyzer

NASA Technical Reports Server (NTRS)

1994-01-01

Measurement of the total organic carbon content in water is important in assessing contamination levels in high purity water for power generation, pharmaceutical production and electronics manufacture. Even trace levels of organic compounds can cause defects in manufactured products. The Sievers Model 800 Total Organic Carbon (TOC) Analyzer, based on technology developed for the Space Station, uses a strong chemical oxidizing agent and ultraviolet light to convert organic compounds in water to carbon dioxide. After ionizing the carbon dioxide, the amount of ions is determined by measuring the conductivity of the deionized water. The new technique is highly sensitive, does not require compressed gas, and maintenance is minimal.

High-resolution mass spectrometry of nitrogenous compounds of the Colorado Green River formation oil shale.

NASA Technical Reports Server (NTRS)

Simoneit, B. R.; Schnoes, H. K.; Haug, P.; Burlingame, A. L.

1971-01-01

Basic nitrogenous compounds isolated from extracts of Green River Formation oil shale were analyzed. The major homologous constituents found were the compositional types - namely, quinolines, tetrahydrequinolines with minor amounts of pyridines and indoles series and traces of more aromatized nitrogen compounds. These results are correlated with nitrogen compounds isolated from Green River Formation retort oil and are a survey of the unaltered nitrogen compounds indigeneous to the shale.

Development of a selective and sensitive flotation method for determination of trace amounts of cobalt, nickel, copper and iron in environmental samples.

PubMed

Karimi, H; Ghaedi, M; Shokrollahi, A; Rajabi, H R; Soylak, M; Karami, B

2008-02-28

A simple, selective and rapid flotation method for the separation-preconcentration of trace amounts of cobalt, nickel, iron and copper ions using phenyl 2-pyridyl ketone oxime (PPKO) has been developed prior to their flame atomic absorption spectrometric determinations. The influence of pH, amount of PPKO as collector, type and amount of eluting agent, type and amount of surfactant as floating agent and ionic strength was evaluated on the recoveries of analytes. The influences of the concomitant ions on the recoveries of the analyte ions were also examined. The enrichment factor was 93. The detection limits based on 3 sigma for Cu, Ni, Co and Fe were 0.7, 0.7, 0.8, and 0.7 ng mL(-1), respectively. The method has been successfully applied for determination of trace amounts of ions in various real samples.

Occurrence of trace elements and antibiotics in manure-based fertilizers from the Zhejiang Province of China.

PubMed

Qian, Mingrong; Wu, Huizhen; Wang, Jianmei; Zhang, Hu; Zhang, Zulin; Zhang, Yongzhi; Lin, Hui; Ma, Junwei

2016-07-15

The occurrence of seven trace elements and forty three antibiotics was investigated in manure-based fertilizers from the Zhejiang province of China. These trace elements included copper, zinc, arsenic, chromium, mercury, lead and cadmium. The targeted antibiotics included four groups: sulfonamides, tetracyclines, fluoroquinolones and chloramphenicols. The median amounts of copper, zinc, arsenic, chromium, mercury, lead and cadmium in the analyzed samples were 160, 465, 7.9, 21.2, 0.3, 8.1 and 0.6mg·kg(-1), respectively. Seventeen antibiotics were detected. Enrofloxacin was the most frequently detected compound, with a detection rate of 39.3% and concentrations ranging from 6.7μg·kg(-1) to 4091μg·kg(-1). Based on the referred loading rates in agricultural soil, 10% of the collected manure-based fertilizer samples might pose a high potential ecological risk due to the presence of antibiotics. Copyright © 2016. Published by Elsevier B.V.

Variations in the chemical properties of landfill leachate

NASA Astrophysics Data System (ADS)

Chu, L. M.; Cheung, K. C.; Wong, M. H.

1994-01-01

Landfill leachates were collected and their chemical properties analyzed once every two months over a ten-month period from the Gin Drinkers' Bay (GDB) and Junk Bay (JB) landfills. The contents of solids, and inorganic and organic components fluctuated considerably with time. In general, the chemical properties of the two leachates correlated negatively ( P<0.05) with the amounts of rainfall prior to the sampling periods. However, magnesium and pH of the leachates remained relatively constant with respect to sampling time. The JB leachate contained higher average contents of solids and inorganic and organic matter than those of GDB with the exception of trace metals. Trace metals were present in the two leachates in trace quantities (<1.0 mg/liter). The concentrations of average ammoniacal nitrogen were 1040 and 549 mg/liter, while chemical oxygen demand (COD) values were 767 and 695 mg/liter for JB and GDB leachates, respectively. These results suggest that the leachates need further treatment before they can be discharged to the coastal waters.

Constructing Space-Time Views from Fixed Size Statistical Data: Getting the Best of both Worlds

NASA Technical Reports Server (NTRS)

Schmidt, Melisa; Yan, Jerry C.

1997-01-01

Many performance monitoring tools are currently available to the super-computing community. The performance data gathered and analyzed by these tools fall under two categories: statistics and event traces. Statistical data is much more compact but lacks the probative power event traces offer. Event traces, on the other hand, can easily fill up the entire file system during execution such that the instrumented execution may have to be terminated half way through. In this paper, we propose an innovative methodology for performance data gathering and representation that offers a middle ground. The user can trade-off tracing overhead, trace data size vs. data quality incrementally. In other words, the user will be able to limit the amount of trace collected and, at the same time, carry out some of the analysis event traces offer using space-time views for the entire execution. Two basic ideas arc employed: the use of averages to replace recording data for each instance and formulae to represent sequences associated with communication and control flow. With the help of a few simple examples, we illustrate the use of these techniques in performance tuning and compare the quality of the traces we collected vs. event traces. We found that the trace files thus obtained are, in deed, small, bounded and predictable before program execution and that the quality of the space time views generated from these statistical data are excellent. Furthermore, experimental results showed that the formulae proposed were able to capture 100% of all the sequences associated with 11 of the 15 applications tested. The performance of the formulae can be incrementally improved by allocating more memory at run-time to learn longer sequences.

Constructing Space-Time Views from Fixed Size Statistical Data: Getting the Best of Both Worlds

NASA Technical Reports Server (NTRS)

Schmidt, Melisa; Yan, Jerry C.; Bailey, David (Technical Monitor)

1996-01-01

Many performance monitoring tools are currently available to the super-computing community. The performance data gathered and analyzed by these tools fall under two categories: statistics and event traces. Statistical data is much more compact but lacks the probative power event traces offer. Event traces, on the other hand, can easily fill up the entire file system during execution such that the instrumented execution may have to be terminated half way through. In this paper, we propose an innovative methodology for performance data gathering and representation that offers a middle ground. The user can trade-off tracing overhead, trace data size vs. data quality incrementally. In other words, the user will be able to limit the amount of trace collected and, at the same time, carry out some of the analysis event traces offer using spacetime views for the entire execution. Two basic ideas are employed: the use of averages to replace recording data for each instance and "formulae" to represent sequences associated with communication and control flow. With the help of a few simple examples, we illustrate the use of these techniques in performance tuning and compare the quality of the traces we collected vs. event traces. We found that the trace files thus obtained are, in deed, small, bounded and predictable before program execution and that the quality of the space time views generated from these statistical data are excellent. Furthermore, experimental results showed that the formulae proposed were able to capture 100% of all the sequences associated with 11 of the 15 applications tested. The performance of the formulae can be incrementally improved by allocating more memory at run-time to learn longer sequences.

Reversal electron attachment ionizer for detection of trace species

NASA Technical Reports Server (NTRS)

Bernius, Mark T. (Inventor); Chutjian, Ara (Inventor)

1990-01-01

An in-line reversal electron, high-current ionizer capable of focusing a beam of electrons to a reversal region and executing a reversal of said electrons, such that the electrons possess zero kinetic energy at the point of reversal, may be used to produce both negative and positive ions. A sample gas is introduced at the point of electron reversal for low energy electron-(sample gas) molecule attachment with high efficiency. The attachment process produces negative ions from the sample gas, which includes species present in trace (minute) amounts. These ions are extracted efficiently and directed to a mass analyzer where they may be detected and identified. The generation and detection of positive ions is accomplished in a similar fashion with minimal adjustment to potentials applied to the apparatus.

Reversal electron attachment ionizer for detection of trace species

NASA Technical Reports Server (NTRS)

Bernius, Mark T. (Inventor); Chutjian, Ara (Inventor)

1989-01-01

An in-line reversal electron, high-current ionizer capable of focusing a beam of electrons to a reversal region and executing a reversal of the electrons, such that the electrons possess zero kinetic energy at the point of reversal, may be used to produce both negative and positive ions. A sample gas is introduced at the point of electron reversal for low energy electron-(sample gas) molecule attachment with high efficiency. The attachment process produces negative ions from the sample gas, which includes species present in trace (minute) amounts. These ions are extracted efficiently and directed to a mass analyzer where they may be detected and identified. The generation and detection of positive ions is accomplished in a similar fashion with minimal adjustment to potentials applied to the apparatus.

Pollution Detection Devices

NASA Technical Reports Server (NTRS)

1980-01-01

Barringer Research, Inc.'s COSPEC IVB (correlation spectrometer) can sense from a considerable distance emissions from a volcanic eruption. Remote sensor is capable of measuring sulfur dioxide and nitrogen dioxide in the atmosphere. An associated product, GASPEC, a compression of Non-dispersive Gas Filter Spectrometer, is an infrared/ultraviolet gas analyzer which can be used as either a ground based detector or in aircraft/spacecraft applications. Extremely sensitive, it is useful in air pollution investigations for detecting a variety of trace elements, vapors, which exist in the atmosphere in small amounts.

Flame atomic absorption spectrometric determination of trace amounts of nickel after extraction and preconcentration onto natural modified analcime zeolite loaded with 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol.

PubMed

Afzali, Darush; Taher, Mohammad Ali; Mostafavi, Ali; Mahani, Mohammad Khayatzadeh

2005-01-01

Nickel is a moderately toxic element compared with other transition metals. However, inhalation of nickel and its compounds leads to serious problems, including cancer of the respiratory system and a skin disorder, nickel-eczema. Thus, attention has focused on the toxicity of nickel at low concentrations, and the development of reliable, analytical approaches for the determination of trace amounts of nickel is needed. This paper describes a simple, rapid, and sensitive flame atomic absorption spectrometric method for the determination of trace amounts of nickel in various samples after adsorption of its 2-(5-bromo-2-pyridylazo)-5-diethylaminophenol complex on a modified Analcime column in the pH range of 7.5-10.5. The retained analyte on the Analcime is recovered with 5.0 mL 2 M nitric acid and determined by flame atomic absorption spectrometry. The detection limit is 20 ng/mL, and the calibration curve is linear for analyte concentrations in the range of 0.1-8 microg/mL final solution, with a correlation coefficient of 0.9993. Eight replicate determinations of nickel at 2 microg/mL in the final solution gave an absorbance of 0.1222, with a relative standard deviation (RSD) of +/-1.2%. The interference of a large number of anions and cations was studied, and the proposed method was used for the determination of nickel in various standard reference samples. The accuracy of the proposed method was evaluated by analyzing standard reference samples, and the results were satisfactory (recoveries of >96%; RSD of <3.5%).

Determination and stereochemistry of proteinogenic and non-proteinogenic amino acids in Saudi Arabian date fruits.

PubMed

Ali, Hatem Salama Mohamed; Alhaj, Omar Amin; Al-Khalifa, Abdulrahman Saleh; Brückner, Hans

2014-09-01

Whereas an abundance of literature is available on the occurrence of common proteinogenic amino acids (AAs) in edible fruits of the date palm (Phoenix dactylifera L.), recent reports on non-proteinogenic (non-coded) AAs and amino components are scarce. With emphasis on these components we have analyzed total hydrolysates of twelve cultivars of date fruits using automated ion-exchange chromatography, HPLC employing a fluorescent aminoquinolyl label, and GC-MS of total hydrolysates using the chiral stationary phases Chirasil(®)-L-Val and Lipodex(®) E. Besides common proteinogenic AAs, relatively large amounts of the following non-proteinogenic amino acids were detected: (2S,5R)-5-hydroxypipecolic acid (1.4-4.0 g/kg dry matter, DM), 1-aminocyclopropane-1-carboxylic acid (1.3-2.6 g/kg DM), γ-amino-n-butyric acid (0.5-1.2 g/kg DM), (2S,4R)-4-hydroxyproline (130-230 mg/kg DM), L-pipecolic acid (40-140 mg/kg DM), and 2-aminoethanol (40-160 mg/kg DM) as well as low or trace amounts (<70 mg/kg DM) of L-ornithine, 5-hydroxylysine, β-alanine, and in some samples (<20 mg/kg DM) of (S)-β-aminoisobutyric acid and (<10 mg/kg DM) L-allo-isoleucine. In one date fruit, traces of α-aminoadipic acid could be determined. Enantiomeric analysis of 6 M DCl/D2O hydrolysates of AAs using chiral capillary gas chromatography-mass spectrometry revealed the presence of very low amounts of D-Ala, D-Asp, D-Glu, D-Ser and D-Phe (1.2-0.4%, relative to the corresponding L-enantiomers), besides traces (0.2-1%) of other D-AAs. The possible relevance of non-proteinogenic amino acids in date fruits is briefly addressed.

Trace element analysis of human urine collected after administration of Gd-based MRI contrast agents: characterizing spectral interferences using inorganic mass spectrometry

PubMed Central

Steuerwald, Amy J.; Parsons, Patrick J.; Arnason, John G.; Chen, Zhen; Peterson, C. Matthew; Louis, Germaine M. Buck

2013-01-01

Analysis of human urine is commonly used in biomonitoring studies to assess exposure to essential (e.g., Cu, Zn, Se) and non-essential (Pb, Cd, Pt) trace elements. These data are also used in epidemiological studies to evaluate potential associations between trace element exposure and various health outcomes within a population. Today most trace element analyses are typically performed using quadrupole-based inductively coupled plasma mass spectrometry (Q-ICP-MS). However, there is always the potential for spectral interferences with Q-ICP-MS instrumentation, especially when analyzing human specimens that may contain medications and other exogenous substances. Moreover, such xenobiotics may be unknown to the investigators. In a recent study focusing on environmental exposures and endometriosis: Endometriosis: Natural History, Diagnosis, and Outcomes (ENDO Study), urine specimens (n=619) were collected from participating women upon enrollment into the study or prior to surgery or pelvic magnetic resonance imaging (MRI), and analyzed for 21 trace elements by Q-ICP-MS. Here we report on some anomalous results observed for Se and Pt with elevated concentrations up to several orders of magnitude greater than what might be expected based on established reference intervals. Further investigations using Sector Field (SF-) ICP-MS instrumentation led to identification of doubly charged and polyatomic gadolinium (Gd) species traced to a Gd-based contrast agent that was administered to some subjects just prior to urine collection. Specifically, interferences from Gd2+ and several minor polyatomics were identified as interferences on all of the major isotopes of Se including 74Se, 76Se, 77Se, 78Se, 80Se, and 82Se. While trace amounts of Pt were present in the urine, a number of Gd-containing polyatomic species were also evident as major interferences on all isotopes of Pt (190Pt, 192Pt, 194Pt, 195Pt, 196Pt, and 198Pt), including Gd-chlorides, Gd-argides, and Gd-oxides. These observations underscore the importance of considering potential isobaric interferences when interpreting unusual trace element results for clinical specimens. PMID:27397951

Hydrocyclone/Filter for Concentrating Biomarkers from Soil

NASA Technical Reports Server (NTRS)

Ponce, Adrian; Obenhuber, Donald

2008-01-01

The hydrocyclone-filtration extractor (HFE), now undergoing development, is a simple, robust apparatus for processing large amounts of soil to extract trace amounts of microorganisms, soluble organic compounds, and other biomarkers from soil and to concentrate the extracts in amounts sufficient to enable such traditional assays as cell culturing, deoxyribonucleic acid (DNA) analysis, and isotope analysis. Originally intended for incorporation into a suite of instruments for detecting signs of life on Mars, the HFE could also be used on Earth for similar purposes, including detecting trace amounts of biomarkers or chemical wastes in soils.

Organochlorine compounds and trace elements in fish tissue and streambed sediment in the Mobile River Basin, Alabama, Mississippi, and Georgia, 1998

USGS Publications Warehouse

Zappia, Humbert

2002-01-01

During the summer of 1998, as part of the National Water-Quality Assessment Program, a survey was conducted to determine which organochlorine compounds and trace elements occur in fish tissues and streambed sediments in the Mobile River Basin, which includes parts of Alabama, Mississippi, Georgia, and Tennessee. The data collected were compared to guidelines related to wildlife, land use, and to 1991 and 1994 National Water-Quality Assessment Program Study-Unit data.Twenty-one sites were sampled in subbasins of the Mobile River Basin. The subbasins ranged in size from about 9 to 22,000 square miles and were dominated by either a single land use or a combination of land uses. The major land-use categories were urban, agriculture, and forest.Organochlorine compounds were widespread spatially in the Mobile River Basin. At least one organochlorine compound was reported at the majority of sampling sites (84 percent) and in a majority of whole-fish (80 percent) and streambed-sediment (52 percent) samples. Multiple organochlorine compounds were reported at 75 percent of the sites where fish tissues were collected and were reported at many of the streambed-sediment sampling sites (45 percent). The majority of concentrations reported, however, were less than 5 micrograms per kilogram in fish-tissue samples and less than 1 microgram per kilogram in streambed-sediment samples.The majority of trace elements analyzed in fish-liver tissue (86 percent) and streambed-sediment (98 percent) samples were reported during this study. Multiple trace elements were reported in all samples and at all sites.Based on comparisons of concentrations of organochlorine compounds and trace elements in fish-tissue and streambed-sediment samples in relation to National Academy of Science and National Academy of Engineering and Canadian tissue guidelines, probable-effects concentrations, and mean probable-effects concentration quotients for streambed sediment, the potential exists for adverse effects to wildlife at 15 (72 percent) of the sites sampled. The potential for adverse effects at these sites is because of the presence of residues or breakdown products related to polychlorinated biphenyls (PCB?s), chlordane, dichlorodiphenyltrichloroethane (DDT), chromium, lead, and zinc.The majority of compounds reported (65 percent) were chlordane, DDT, and PCB?s, or their breakdown products. Concentrations of chlordane and heptachlor epoxide in whole-fish tissue were positively correlated to the amount of urban land use in a basin. Total DDT concentrations in whole-fish tissues were positively correlated to agriculture.The relation of trace elements to land use is not as clear as the relation of organochlorine compounds to land use. This lack of clarity may be due to the possibility of geologic sources of trace elements in the Mobile River Basin and to the ubiquitous nature of many of these trace elements. However, there may be a correlation between the amount of urban land use and concentrations of antimony, cadmium, lead, and zinc in streambed-sediment samples from the Mobile River Basin.Fewer organochlorine compounds and trace elements were reported in samples from the Mobile River Basin than in samples collected during the 1991 and 1994 National Water-Quality Assessment Program studies. Of the organochlorine compounds analyzed nationally, 57 percent were reported in whole-fish tissue samples collected locally and 41 percent were reported in streambed-sediment samples collected locally, whereas 96 percent and 86 percent, respectively, were reported nationally. Of trace elements analyzed nationally, 86 percent were reported in fish-liver tissue locally and 95 percent were reported in streambed-sediment samples locally, whereas 95 percent and 98 percent, respectively, were reported nationally.In general, concentrations of organochlorine compounds and trace elements and the frequency with which they were reported in the Mobile River Basin are similar to or less than t

Oil and gas exploration system and method for detecting trace amounts of hydrocarbon gases in the atmosphere

DOEpatents

Wamsley, Paula R.; Weimer, Carl S.; Nelson, Loren D.; O'Brien, Martin J.

2003-01-01

An oil and gas exploration system and method for land and airborne operations, the system and method used for locating subsurface hydrocarbon deposits based upon a remote detection of trace amounts of gases in the atmosphere. The detection of one or more target gases in the atmosphere is used to indicate a possible subsurface oil and gas deposit. By mapping a plurality of gas targets over a selected survey area, the survey area can be analyzed for measurable concentration anomalies. The anomalies are interpreted along with other exploration data to evaluate the value of an underground deposit. The system includes a differential absorption lidar (DIAL) system with a spectroscopic grade laser light and a light detector. The laser light is continuously tunable in a mid-infrared range, 2 to 5 micrometers, for choosing appropriate wavelengths to measure different gases and avoid absorption bands of interference gases. The laser light has sufficient optical energy to measure atmospheric concentrations of a gas over a path as long as a mile and greater. The detection of the gas is based on optical absorption measurements at specific wavelengths in the open atmosphere. Light that is detected using the light detector contains an absorption signature acquired as the light travels through the atmosphere from the laser source and back to the light detector. The absorption signature of each gas is processed and then analyzed to determine if a potential anomaly exists.

The Trace Element Composition of Plankton and Dust in the Qatari EEZ

NASA Astrophysics Data System (ADS)

Turner, J.; Murray, J. W.; Yigiterhan, O.; Al-Ansari, I. S.; Al-Ansi, M.; Abdel-Moati, M.; Paul, B.; Nelson, A.

2015-12-01

We present data on elemental concentrations of plankton net tow samples from the Exclusive Economic Zone (EEZ) of Qatar in the Arabian Gulf as part of a broader study of biogenic and lithogenic influences on particulate trace metal concentrations in the surface ocean. There are relatively few analyses of planktonic trace metals and their associated role in the biogeochemical system. We had the opportunity to investigate the composition of plankton in a region heavily affected by dust, a significant factor for phytoplankton growth. Our samples were collected from 2012 to 2015 using trace metal clean net tows with mesh sizes of 50 and 200 microns for measurements of phytoplankton and zooplankton, respectively. Samples were totally digested and analyzed by inductively coupled plasma-mass spectroscopy (ICP-MS). The biogenic portion was determined by subtracting the lithogenic portion from the total concentration. The lithogenic fraction was defined as the concentration of aluminum in the sample multiplied by a [Me]/Al ratio. Using average Qatari dust for these ratios generated a significant amount of overcorrection, so ratios were established using average upper continental crust (UCC). This method still caused some overcorrection for the lithogenic portion resulting in negative excess values for barium, molybdenum, and lead. These same elements showed the least consistency between measurements. For the other elements, a relative stoichiometry for plankton was determined as Fe > Cu ≈ Zn > As ≈ Cr ≈ Mn ≈ Ni ≈ V > Cd ≈ Co. We also found a significant near shore enrichment for 9 out of 13 elements analyzed, indicative of a possible influence of coastal processes.

Rapid detection of trace amounts of surfactants using nanoparticles in fluorometric assays

NASA Astrophysics Data System (ADS)

Härmä, Harri; Laakso, Susana; Pihlasalo, Sari; Hänninen, Pekka; Faure, Bertrand; Rana, Subhasis; Bergström, Lennart

2010-01-01

Rapid microtiter assays that utilize the time-resolved fluorescence resonance energy transfer or quenching of dye-labeled proteins adsorbed onto the surfaces of polystyrene or maghemite nanoparticles have been developed for the detection and quantification of trace amounts of surfactants at concentrations down to 10 nM.Rapid microtiter assays that utilize the time-resolved fluorescence resonance energy transfer or quenching of dye-labeled proteins adsorbed onto the surfaces of polystyrene or maghemite nanoparticles have been developed for the detection and quantification of trace amounts of surfactants at concentrations down to 10 nM. Electronic supplementary information (ESI) available: Experimental details and Fig. S1 and S2. See DOI: 10.1039/b9nr00172g

Chemical fingerprinting of valeriana species: simultaneous determination of valerenic acids, flavonoids, and phenylpropanoids using liquid chromatography with ultraviolet detection.

PubMed

Navarrete, Andres; Avula, Bharathi; Choi, Young-Whan; Khan, Ikhlas A

2006-01-01

The roots and rhizomes of various valeriana species are currently used as a sleeping aid or mild sedative. A liquid chromatography method has been developed that permits the analysis of chlorogenic acid, lignans, flavonoids, valerenic acids, and valpotrates in various valerian samples. The best results were obtained with a Phenomenex Luna C18(2) column using gradient elution with a mobile phase consisting of water and 0.05% phosphoric acid and 2-100% acetonitrile-methanol (1 + 1) with 0.05% phosphoric acid. The flow rate was 0.8 mL/min and ultraviolet detection was at 207, 225, 254, 280, and 325 nm. Different valerian species and commercial products showed remarkable quantitative variations. Chlorogenic acid (0.2-1.2%), 3 lignans, linarin (0.002-0.24%), and valepotriates were detected in all the valeriana species analyzed. Highest amounts of valerenic acids were detected in V. officinalis L., trace amounts in V. sitchensis, and none in the other species analyzed.

Mapping Fifteen Trace Elements in Human Seminal Plasma and Sperm DNA.

PubMed

Ali, Sazan; Chaspoul, Florence; Anderson, Loundou; Bergé-Lefranc, David; Achard, Vincent; Perrin, Jeanne; Gallice, Philippe; Guichaoua, Marie

2017-02-01

Studies suggest a relationship between semen quality and the concentration of trace elements in serum or seminal plasma. However, trace elements may be linked to DNA and capable of altering the gene expression patterns. Thus, trace element interactions with DNA may contribute to the mechanisms for a trans-generational reproductive effect. We developed an analytical method to determine the amount of trace elements bound to the sperm DNA, and to estimate their affinity for the sperm DNA by the ratio: R = Log [metal concentration in the sperm DNA/metal concentration in seminal plasma]. We then analyzed the concentrations of 15 trace elements (Al, Cd, Cr, Cu, Hg, Mn, Mo, Ni, Pb, Ti, V, Zn, As, Sb, and Se) in the seminal plasma and the sperm DNA in 64 normal and 30 abnormal semen specimens with Inductively Coupled Plasma/Mass Spectrometry (ICP-MS). This study showed all trace elements were detected in the seminal plasma and only metals were detected in the sperm DNA. There was no correlation between the metals' concentrations in the seminal plasma and the sperm DNA. Al had the highest affinity for DNA followed by Pb and Cd. This strong affinity is consistent with the known mutagenic effects of these metals. The lowest affinity was observed for Zn and Ti. We observed a significant increase of Al linked to the sperm DNA of patients with oligozoospermia and teratozoospermia. Al's reproductive toxicity might be due to Al linked to DNA, by altering spermatogenesis and expression patterns of genes involved in the function of reproduction.

Quality of ground water in Clark County, Washington, 1988

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turney, G.L.

1990-01-01

Water samples were collected from 76 wells throughout Clark County, in southwest Washington, during April and May 1988, and were analyzed from concentrations of major ions, silica, nitrate, phosphorus, aluminum, manganese, radon, and bacteria. Samples from 20 wells were analyzed for concentrations of trace elements and organic compounds, including most of those on the US Environmental Protection Agency (USEPA) priority pollutant list. Dissolved solids concentrations range from 12 to 245 mg/L, with a median concentration of 132 mg/L. The major dissolved constituents are calcium, bicarbonate, and silica, and, in some samples, sodium. Nitrate concentrations exceeded 1.0 mg/L throughout the Vancouvermore » urban area, and were as large as 6.7 mg/L. Comparison with limited historical data indicates that nitrate concentrations were somewhat correlated, possibly indicating similar sources. Volatile organic compound, including tetrachloroethane and 1,1,1-trichloroethane, were detected in samples from three wells in the Vancouver area. Trace amounts of volatile organic compounds were reported in samples from several other wells, but at concentrations too close to analytical detection limits to ascertain that they were in the groundwater. Trace elements and radiochemical constituents were present at small levels indicating natural sources for these constituents. Only pH, turbidity, iron, manganese, and total coliform bacteria had values that did not meet USEPA Drinking Water Standards.« less

Baseline study on essential and trace elements in polished rice from South Korea.

PubMed

Jung, Myung Chae; Yun, Seong-Taek; Lee, Jin-Soo; Lee, Jong-Un

2005-09-01

In 2000, 63 (polished) white rice samples were collected in eight administrative areas all over South Korea and analyzed for 16 elements by inductively coupled plasma atomic emission spectrometry (ICP-AES). Potassium had the highest content, next to Mg, Ca, Si, Zn, Na, Al and Fe. Most of the samples contained worldwide average concentrations of essential and trace elements in rice grains reported by various researches. For inter-area differences in those elements in the rice, the statistical analysis showed no significant differences (p > 0.05) among the eight administrative areas, suggesting that inter-area differences were not substantial in most cases. Thus, the present data can be used as national background levels of elements in rice produced in South Korea. Using the published data on daily consumption of rice in South Korea, it was possible to estimate the daily intake of As, Cd, Cu, Pb and Zn via rice. The results showed that a regular consumption of rice produced in Korea plays an important role in accumulation of essential and trace elements in Korean, especially for farm-households consuming relatively large amounts of rice.

Aerogel volatiles concentrator and analyzer (AVCA) - Collection and concentration of trace volatile organics in aerogel for spectroscopic detection

NASA Astrophysics Data System (ADS)

Tsapin, A.; Jones, S.; Petkov, M.; Borchardt, D.; Anderson, M.

2017-03-01

A study was conducted to determine the efficacy of using silica aerogel to collect and concentrate ambient trace organics for spectroscopic analysis. Silica aerogel was exposed to atmospheres containing trace amounts of polycyclic aromatic and aliphatic hydrocarbons. The organics present were concentrated in the aerogels by factors varying from 10 to more than 1000 over the levels found in the atmospheres, depending on the specific organic present. Since silica aerogel is transparent over a wide range of optical and near infrared wavelengths, UV-induced fluorescence, Raman and infrared spectroscopies were used to detect and identify the organics collected by the aerogel. Measurements were conducted to determine the sensitivity of these spectroscopic methods for determining organics concentrated by aerogels and the effectiveness of this method for identifying systems containing multiple organic species. Polycyclic aromatic hydrocarbons (PAHs) were added to simulated Mars regolith and then vaporized by modest heating in the presence of aerogel. The aerogels adsorbed and concentrated the PAHs, which were detected by induced fluorescence and Raman and FTIR spectroscopies.

Organic cloud condensation nuclei: the effect of phase, surface tension, trace soluble species, and oxidative processing on particle activation.

NASA Astrophysics Data System (ADS)

Broekhuizen, K. E.; Thornberry, T.; Abbatt, J. P.

2003-12-01

The ability of organic aerosols to act as cloud condensation nuclei (CCN) will be discussed. A variety of laboratory experiments will be presented which address several key questions concerning organic particle activation. Does the particle phase impact activation? How does surface tension play a role and can a trace amount of a surface active species impact activation? Does a trace amount of a highly soluble species impact the activation of organic particles of moderate to low solubility? Can the activation properties of organic aerosols be enhanced through oxidative processing? To systematically address these issues, the CCN activity of various diacids such as oxalic, malonic, succinic, adipic and azelaic acid have been studied, as well as the addition of trace amounts of nonanoic acid and ammonium sulfate to examine the roles of surface active and soluble species, respectively. The first examination of the role of oxidative processing on CCN activity has involved investigating the effect of ozone oxidation on the activity of oleic acid particles.

Vitamin A and carotene contents of some wildlife foods

USGS Publications Warehouse

Nestler, R.B.; Derby, J.V.; DeWitt, J.B.

1949-01-01

In order to determine possible sources of vitamin A for quail, 37 species of insects and other invertebrates were analyzed for vitamin A and for carotene, and 26 species of seeds and fruits were assayed for carotene. The invertebrates showed no trace of vitamin A; but 8 herbivorous invertebrates and the praying mantis contained carotene. Most of the plants contained carotene--some of them a lot (dotted smartweed, some legumes, sumac, roses, bittersweet, etc.). The amount of carotene varied among plants of the same species and even among fruits on the same plant.

Food of the American smelt in Saginaw Bay, Lake Huron

USGS Publications Warehouse

Gordon, William G.

1961-01-01

In order to determine possible sources of vitamin A for quail, 37 species of insects and other invertebrates were analyzed for vitamin A and for carotene, and 26 species of seeds and fruits were assayed for carotene. The invertebrates showed no trace of vitamin A; but 8 herbivorous invertebrates and the praying mantis contained carotene. Most of the plants contained carotene--some of them a lot (dotted smartweed, some legumes, sumac, roses, bittersweet, etc.). The amount of carotene varied among plants of the same species and even among fruits on the same plant.

Development of a primary diffusion source of organic vapors for gas analyzer calibration

NASA Astrophysics Data System (ADS)

Lecuna, M.; Demichelis, A.; Sassi, G.; Sassi, M. P.

2018-03-01

The generation of reference mixtures of volatile organic compounds (VOCs) at trace levels (10 ppt-10 ppb) is a challenge for both environmental and clinical measurements. The calibration of gas analyzers for trace VOC measurements requires a stable and accurate source of the compound of interest. The dynamic preparation of gas mixtures by diffusion is a suitable method for fulfilling these requirements. The estimation of the uncertainty of the molar fraction of the VOC in the mixture is a key step in the metrological characterization of a dynamic generator. The performance of a dynamic generator was monitored over a wide range of operating conditions. The generation system was simulated by a model developed with computational fluid dynamics and validated against experimental data. The vapor pressure of the VOC was found to be one of the main contributors to the uncertainty of the diffusion rate and its influence at 10-70 kPa was analyzed and discussed. The air buoyancy effect and perturbations due to the weighing duration were studied. The gas carrier flow rate and the amount of liquid in the vial were found to play a role in limiting the diffusion rate. The results of sensitivity analyses were reported through an uncertainty budget for the diffusion rate. The roles of each influence quantity were discussed. A set of criteria to minimize the uncertainty contribution to the primary diffusion source (25 µg min-1) were estimated: carrier gas flow rate higher than 37.7 sml min-1, a maximum VOC liquid mass decrease in the vial of 4.8 g, a minimum residual mass of 1 g and vial weighing times of 1-3 min. With this procedure a limit uncertainty of 0.5% in the diffusion rate can be obtained for VOC mixtures at trace levels (10 ppt-10 ppb), making the developed diffusion vials a primary diffusion source with potential to become a new reference material for trace VOC analysis.

Solid-phase extraction of some heavy metal ions on a double-walled carbon nanotube disk and determination by flame atomic absorption spectrometry.

PubMed

Karatepe, Aslihan; Soylak, Mustafa; Elçi, Latif

2011-01-01

A new preconcentration method was developed for the determination of trace amounts of Cu(II), Fe(III), Pb(II), Ni(II), and Cd(II) on a double-walled carbon nanotube disk. 4-(2-Thiazolylazo) resorcinol was used as a complexing reagent. The effects of parameters, including pH of the solutions, amounts of complexing reagent, eluent type, sample volume, flow rates of solutions, and matrix ions were examined for quantitative recoveries of the studied analyte ions. The retained metal ions were eluted by 2 M HNO3. The LOD values for the analytes were in the range of 0.7-4.4 microg/mL. Natural water samples and standard reference materials were analyzed by the presented method.

A dynamic gravimetric standard for trace water.

PubMed

Brewer, P J; Goody, B A; Woods, P T; Milton, M J T

2011-10-01

A system for generating traceable reference standards of water vapor at trace levels between 5 and 2000 nmol/mol has been developed. It can provide different amount fractions of trace water vapor by using continuous accurate measurements of mass loss from a permeation device coupled with a dilution system based on an array of critical flow orifices. An estimated relative expanded uncertainty of ±2% has been achieved for most amount fractions generated. The system has been used in an international comparison and demonstrates excellent comparability with National Metrology Institutes maintaining standards of water vapor in this range using other methods.

Forensic trace DNA: a review

PubMed Central

2010-01-01

DNA analysis is frequently used to acquire information from biological material to aid enquiries associated with criminal offences, disaster victim identification and missing persons investigations. As the relevance and value of DNA profiling to forensic investigations has increased, so too has the desire to generate this information from smaller amounts of DNA. Trace DNA samples may be defined as any sample which falls below recommended thresholds at any stage of the analysis, from sample detection through to profile interpretation, and can not be defined by a precise picogram amount. Here we review aspects associated with the collection, DNA extraction, amplification, profiling and interpretation of trace DNA samples. Contamination and transfer issues are also briefly discussed within the context of trace DNA analysis. Whilst several methodological changes have facilitated profiling from trace samples in recent years it is also clear that many opportunities exist for further improvements. PMID:21122102

Monitoring of chlorsulfuron in biological fluids and water samples by molecular fluorescence using rhodamine B as fluorophore.

PubMed

Alesso, Magdalena; Escudero, Luis A; Talio, María Carolina; Fernández, Liliana P

2016-11-01

A new simple methodology is proposed for chlorsufuron (CS) traces quantification based upon enhancement of rhodamine B (RhB) fluorescent signal. Experimental variables that influence fluorimetric sensitivity have been studied and optimized. The zeroth order regression calibration was linear from 0.866 to 35.800µgL(-1) CS, with a correlation coefficient of 0.99. At optimal experimental conditions, a limit of detection of 0.259µgL(-1) and a limit of quantification of 0.866µgL(-1) were obtained. The method showed good sensitivity and adequate selectivity and was applied to the determination of trace amounts of CS in plasma, serum and water samples with satisfactory results analyzed by ANOVA test. The proposed methodology represents an alternative to traditional chromatographic techniques for CS monitoring in complex samples, using an accessible instrument in control laboratories. Copyright © 2016 Elsevier B.V. All rights reserved.

The effect of membrane filtration on dissolved trace element concentrations

USGS Publications Warehouse

Horowitz, A.J.; Lum, K.R.; Garbarino, J.R.; Hall, G.E.M.; Lemieux, C.; Demas, C.R.

1996-01-01

The almost universally accepted operational definition for dissolved constituents is based on processing whole-water samples through a 0.45-??m membrane filter. Results from field and laboratory experiments indicate that a number of factors associated with filtration, other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample), can produce substantial variations in the 'dissolved' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. These variations result from the inclusion/exclusion of colloidally- associated trace elements. Thus, 'dissolved' concentrations quantitated by analyzing filtrates generated by processing whole-water through similar pore- sized membrane filters may not be equal/comparable. As such, simple filtration through a 0.45-??m membrane filter may no longer represent an acceptable operational definition for dissolved chemical constituents. This conclusion may have important implications for environmental studies and regulatory agencies.

A Proof of the Occupancy Principle and the Mean-Transit-Time Theorem for Compartmental Models

PubMed Central

RAMAKRISHNAN, RAJASEKHAR; LEONARD, EDWARD F.; DELL, RALPH B.

2012-01-01

The occupancy principle and the mean-transit-time theorem are derived for the passage of a tracer through a system that can be described by a general pool model. It is proved, using matrix theory, that if (and only if) tracer entering the system labels equally all tracee fluxes into the system, then the integral of the tracer concentration is the same in all the pools. It is also proved that if, in addition, all flow out of the system is through the observation point, the first moment of the tracer concentration at the observation point can be used to calculate the total amount of trace in the system. The necessity of this condition is analyzed. Examples are given of models in which the occupancy principle and the mean-transit-time theorem hold or do not hold. PMID:22328793

The spatial distribution of major and trace elements in the surface sediments from the northeastern Beibu Gulf, South China Sea

NASA Astrophysics Data System (ADS)

Ge, Q.; Xue, Z. G.

2017-12-01

Major and trace elements contents and grain size were analyzed for surface sediments retrieved from the northeastern Beibu (Tonkin) Gulf. The study area was divided into four zones: Zone I locates in the northeastern coastal area of the gulf, which received large amount of the fluvial materials from local rivers; Zone II locates in the center of the study area, where surface sediments is from multiple sources; Zone III locates in the Qiongzhou Strait, which is dominated by material from the Pearl River and Hainan Island; Zone IV locates in the southwest of the study area, and the sediments mainly originated from the Red River. Statistical analyses of sediment geochemical characteristics reveal that grain size is the leading factor for elementary distribution, which is also influenced by hydrodynamics, mineral composition of terrigenous sediments, anthropogenic activity, and authigenic components.

Method for removing trace pollutants from aqueous solutions

DOEpatents

Silver, G.L.

A method of substantially removing a trace metallic contaminant from a liquid containing the same comprises: adding an oxidizing agent to a liquid containing a trace amount of a metallic contaminant of a concentration of up to about 0.1 ppM, and separating the homogeneously precipitated product from the liquid.

Immunoaffinity column as clean-up tool for determination of trace amounts of microcystins in tap water.

PubMed

Tsutsumi, T; Nagata, S; Hasegawa, A; Ueno, Y

2000-07-01

Trace amounts of microcystins (MCs) in drinking water should be monitored because of their potential hazard for human health as an environmental tumor promoter. We describe here a new clean-up tool with immunoaffinity column (IAC) for determination of trace amounts of MCs (from pg to microg/litre) in tap water. The water samples were concentrated with IAC clean-up and MCs levels were determined by HPLC with UV detection or enzyme-linked immunosorbent assay (ELISA). In the combination with HPLC analysis, mean recovery of microcystin-LR (MCLR),-RR and-YR spiked to tap water were 91.8%, 77.3% and 86.4%, respectively, in the range 2.5-100 microg/litre. The chromatogram of MCs-spiked tap water sample cleaned up with IAC showed effective elimination of the impurities compared to that with octadecyl silanized cartridge, which had been cleaned up with a conventional method. Also, in the combination with highly sensitive ELISA, mean recovery of MCLR spiked to tap water was 80% in the range 0.1-1000 ng/litre. The combined methods developed here can detect pg to microg/litre of MCs in tap water. The overall results indicated that IAC will be suitable as a clean-up tool for trace amounts of MCs in tap water.

Distribution of trace levels of therapeutic gallium in bone as mapped by synchrotron x-ray microscopy.

PubMed Central

Bockman, R S; Repo, M A; Warrell, R P; Pounds, J G; Schidlovsky, G; Gordon, B M; Jones, K W

1990-01-01

Gallium nitrate, a drug that inhibits calcium release from bone, has been proven a safe and effective treatment for the accelerated bone resorption associated with cancer. Though bone is a target organ for gallium, the kinetics, sites, and effects of gallium accumulation in bone are not known. We have used synchrotron x-ray microscopy to map the distribution of trace levels of gallium in bone. After short-term in vivo administration of gallium nitrate to rats, trace (nanogram) amounts of gallium preferentially localized to the metabolically active regions in the metaphysis as well as the endosteal and periosteal surfaces of diaphyseal bone, regions where new bone formation and modeling were occurring. The amounts measured were well below the levels known to be cytotoxic. Iron and zinc, trace elements normally found in bone, were decreased in amount after in vivo administration of gallium. These studies represent a first step toward understanding the mechanism(s) of action of gallium in bone by suggesting the possible cellular, structural, and elemental "targets" of gallium. Images PMID:2349224

Stand-off imaging Raman spectroscopy for forensic analysis of post-blast scenes: trace detection of ammonium nitrate and 2,4,6-trinitrotoluene

NASA Astrophysics Data System (ADS)

Ceco, Ema; Önnerud, Hans; Menning, Dennis; Gilljam, John L.; Bââth, Petra; Östmark, Henric

2014-05-01

The following paper presents a realistic forensic capability test of an imaging Raman spectroscopy based demonstrator system, developed at FOI, the Swedish Defence Research Agency. The system uses a 532 nm laser to irradiate a surface of 25×25mm. The backscattered radiation from the surface is collected by an 8" telescope with subsequent optical system, and is finally imaged onto an ICCD camera. We present here an explosives trace analysis study of samples collected from a realistic scenario after a detonation. A left-behind 5 kg IED, based on ammonium nitrate with a TNT (2,4,6-trinitrotoluene) booster, was detonated in a plastic garbage bin. Aluminum sample plates were mounted vertically on a holder approximately 6 m from the point of detonation. Minutes after the detonation, the samples were analyzed with stand-off imaging Raman spectroscopy from a distance of 10 m. Trace amounts could be detected from the secondary explosive (ammonium nitrate with an analysis time of 1 min. Measurement results also indicated detection of residues from the booster (TNT). The sample plates were subsequently swabbed and analyzed with HPLC and GC-MS analyses to confirm the results from the stand-off imaging Raman system. The presented findings indicate that it is possible to determine the type of explosive used in an IED from a distance, within minutes after the attack, and without tampering with physical evidence at the crime scene.

A first proposal for a general description model of forensic traces

NASA Astrophysics Data System (ADS)

Lindauer, Ina; Schäler, Martin; Vielhauer, Claus; Saake, Gunter; Hildebrandt, Mario

2012-06-01

In recent years, the amount of digitally captured traces at crime scenes increased rapidly. There are various kinds of such traces, like pick marks on locks, latent fingerprints on various surfaces as well as different micro traces. Those traces are different from each other not only in kind but also in which information they provide. Every kind of trace has its own properties (e.g., minutiae for fingerprints, or raking traces for locks) but there are also large amounts of metadata which all traces have in common like location, time and other additional information in relation to crime scenes. For selected types of crime scene traces, type-specific databases already exist, such as the ViCLAS for sexual offences, the IBIS for ballistic forensics or the AFIS for fingerprints. These existing forensic databases strongly differ in the trace description models. For forensic experts it would be beneficial to work with only one database capable of handling all possible forensic traces acquired at a crime scene. This is especially the case when different kinds of traces are interrelated (e.g., fingerprints and ballistic marks on a bullet casing). Unfortunately, current research on interrelated traces as well as general forensic data models and structures is not mature enough to build such an encompassing forensic database. Nevertheless, recent advances in the field of contact-less scanning make it possible to acquire different kinds of traces with the same device. Therefore the data of these traces is structured similarly what simplifies the design of a general forensic data model for different kinds of traces. In this paper we introduce a first common description model for different forensic trace types. Furthermore, we apply for selected trace types from the well established database schema development process the phases of transferring expert knowledge in the corresponding forensic fields into an extendible, database-driven, generalised forensic description model. The trace types considered here are fingerprint traces, traces at locks, micro traces and ballistic traces. Based on these basic trace types, also combined traces (multiple or overlapped fingerprints, fingerprints on bullet casings, etc) and partial traces are considered.

Homologous Recombination and Translesion DNA Synthesis Play Critical Roles on Tolerating DNA Damage Caused by Trace Levels of Hexavalent Chromium

PubMed Central

Chen, Youjun; Zhou, Yi-Hui; Neo, Dayna; Clement, Jean; Takata, Minoru; Takeda, Shunichi; Sale, Julian; Wright, Fred A.; Swenberg, James A.; Nakamura, Jun

2016-01-01

Contamination of potentially carcinogenic hexavalent chromium (Cr(VI)) in the drinking water is a major public health concern worldwide. However, little information is available regarding the biological effects of a nanomoler amount of Cr(VI). Here, we investigated the genotoxic effects of Cr(VI) at nanomoler levels and their repair pathways. We found that DNA damage response analyzed based on differential toxicity of isogenic cells deficient in various DNA repair proteins is observed after a three-day incubation with K2CrO4 in REV1-deficient DT40 cells at 19.2 μg/L or higher as well as in TK6 cells deficient in polymerase delta subunit 3 (POLD3) at 9.8 μg/L or higher. The genotoxicity of Cr(VI) decreased ~3000 times when the incubation time was reduced from three days to ten minutes. TK mutation rate also significantly decreased from 6 day to 1 day exposure to Cr(VI). The DNA damage response analysis suggest that DNA repair pathways, including the homologous recombination and REV1- and POLD3-mediated error-prone translesion synthesis pathways, are critical for the cells to tolerate to DNA damage caused by trace amount of Cr(VI). PMID:27907204

Determination of trace amount of formaldehyde base on a bromate-Malachite Green system.

PubMed

Tang, Yufang; Chen, Hao; Weng, Chao; Tang, Xiaohui; Zhang, Miaoling; Hu, Tao

2015-01-25

A novel catalytic kinetic spectrophotometric method for determination of trace amount of formaldehyde (FA) has been established, based on catalytic effect of trace amount of FA on the oxidation of Malachite Green (MG) by potassium bromate in presence of sulfuric acid medium, and was reported for the first time. The method was monitored by measuring the decrease in absorbance of MG at 617 nm and allowed a precise determination of FA in the range of 0.003-0.08 μg mL(-1), with a limit of detection down to 1 ng mL(-1). The relative standard deviation of 10 replicate measurements was 1.63%. The method developed was approved to be sensitive, selective and accurate, and adopted to determinate free FA in samples directly with good accuracy and reproducibility. Copyright © 2014 Elsevier B.V. All rights reserved.

Dosimetry analyses of the Ringhals 3 and 4 reactor pressure vessels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kulesza, J.A.; Fero, A.H.; Rouden, J.

2011-07-01

A comprehensive series of neutron dosimetry measurements consisting of surveillance capsules, reactor pressure vessel cladding samples, and ex-vessel neutron dosimetry has been analyzed and compared to the results of three-dimensional, cycle-specific neutron transport calculations for the Ringhals Unit 3 and Unit 4 reactors in Sweden. The comparisons show excellent agreement between calculations and measurements. The measurements also demonstrate that it is possible to perform retrospective dosimetry measurements using the {sup 93}Nb (n,n') {sup 93m}Nb reaction on samples of 18-8 austenitic stainless steel with only trace amounts of elemental niobium. (authors)

Organochlorine-induced mortality and residues in long-billed curlews from Oregon

USGS Publications Warehouse

Blus, L.J.; Henny, Charles J.; Krynitsky, A.J.

1985-01-01

In order to determine possible sources of vitamin A for quail, 37 species of insects and other invertebrates were analyzed for vitamin A and for carotene, and 26 species of seeds and fruits were assayed for carotene. The invertebrates showed no trace of vitamin A; but 8 herbivorous invertebrates and the praying mantis contained carotene. Most of the plants contained carotene--some of them a lot (dotted smartweed, some legumes, sumac, roses, bittersweet, etc.). The amount of carotene varied among plants of the same species and even among fruits on the same plant.

Inert Reassessment Document for Ethylenediaminetetracetric acid (EDTA)

EPA Pesticide Factsheets

EDTA is a chelating agent. Its ability to bind heavy metal ions can be used to sequester these trace metals. However, trace amounts of various metals are necessary for the proper functioning of the body.

Steam stable mesoporous silica MCM-41 stabilized by trace amounts of Al.

PubMed

Tompkins, Jordan T; Mokaya, Robert

2014-02-12

Evaluation of low and ultralow Al content (Si/Al between 50 and 412) aluminosilicate Al-MCM-41 materials synthesized via three contrasting alumination routes, namely, direct mixed-gel synthesis, post-synthesis wet grafting, and post-synthesis dry grafting, indicates that trace amounts of Al introduced via dry grafting can stabilize mesoporous silica MCM-41 to steaming at 900 °C for 4 h. It was found that trace amounts of Al (Si/Al > 400) introduced via so-called dry grafting of Al stabilize the virtually purely siliceous MCM-41 to steaming, whereas Al incorporated via other methods that involve aqueous media such as direct mixed gel synthesis or wet grafting of Al offer only limited protection at low Al content. It is particularly remarkable that a post-synthesis dry grafted Al-MCM-41 material possessing trace amounts of Al (i.e., Si/Al ratio of 412) and surface area and pore volume of 1112 m(2)/g and 1.20 cm(3)/g, respectively, retains 90% (998 m(2)/g) of the surface area and 85% (1.03 cm(3)/g) of the pore volume after exposure to steaming at 900 °C for 4 h. Under similar steam treatment conditions, the mesostructure of pure silica Si-MCM-41 is virtually destroyed and undergoes a 93% reduction in surface area (958 m(2)/g to 69 m(2)/g) and 88% decrease in pore volume (0.97 cm(3)/g to 0.12 cm(3)/g). The steam stable ultralow (i.e., trace) Al containing MCM-41 materials is found to be virtually similar to mesoporous pure silica Si-MCM-41 with hardly any detectable acidity. The improvement in steam stability arises from not only the presence of trace amounts of Al, but also from an apparent increase in the level of silica condensation that is specific to dry grafted alluminosilicate MCM-41 materials. The more highly condensed framework has fewer silanol groups and therefore is more resistant to hydrolysis under steaming conditions.

Early Diagenesis of Trace Elements in Modern Fjord Sediments of the High Arctic

NASA Astrophysics Data System (ADS)

Herbert, L.; Riedinger, N.; Aller, R. C.; Jørgensen, B. B.; Wehrmann, L.

2017-12-01

Marine sediments are critical repositories for elements that are only available at trace concentrations in seawater, such as Fe, Mn, Co, Ni, As, Mo, and U. The behavior of these trace elements in the sediment is governed by a dynamic interplay of diagenetic reactions involving organic carbon, Fe and Mn oxides, and sulfur phases. In the Arctic fjords of Svalbard, glacial meltwater delivers large amounts of reactive Fe and Mn oxides to the sediment, while organic carbon is deposited episodically and diluted by lithogenic material. These conditions result in pronounced Fe and Mn cycling, which in turn drives other diagenetic processes such as rapid sulfide oxidation. These conditions make the Svalbard fjords ideal sites for investigating trace element diagenesis because they allow resolution of the interconnections between Fe and Mn dynamics and trace element cycling. In August 2016, we collected sediment cores from three Svalbard fjords and analyzed trace elements in the pore water and solid sediment over the top meter. Initial results reveal the dynamic nature of these fjords, which are dominated by non-steady state processes and episodic events such as meltwater pulses and phytoplankton blooms. Within this system, the distribution of As appears to be strongly linked to the Fe cycle, while Co and Ni follow Mn; thus, these three elements may be released from the sediment through diffusion and bioturbation along with Fe and Mn. The pore water profiles of U and Mo indicate removal processes that are independent from Fe or Mn, and which are rather unexpected given the apparent diagenetic conditions. Our results will help elucidate the processes controlling trace element cycling in a dynamic, glacially impacted environment and will ultimately contribute to our understanding of the role of fjords in the biogeochemical cycling of trace elements in a rapidly changing Arctic Ocean.

Context-sensitive trace inlining for Java.

PubMed

Häubl, Christian; Wimmer, Christian; Mössenböck, Hanspeter

2013-12-01

Method inlining is one of the most important optimizations in method-based just-in-time (JIT) compilers. It widens the compilation scope and therefore allows optimizing multiple methods as a whole, which increases the performance. However, if method inlining is used too frequently, the compilation time increases and too much machine code is generated. This has negative effects on the performance. Trace-based JIT compilers only compile frequently executed paths, so-called traces, instead of whole methods. This may result in faster compilation, less generated machine code, and better optimized machine code. In the previous work, we implemented a trace recording infrastructure and a trace-based compiler for [Formula: see text], by modifying the Java HotSpot VM. Based on this work, we evaluate the effect of trace inlining on the performance and the amount of generated machine code. Trace inlining has several major advantages when compared to method inlining. First, trace inlining is more selective than method inlining, because only frequently executed paths are inlined. Second, the recorded traces may capture information about virtual calls, which simplify inlining. A third advantage is that trace information is context sensitive so that different method parts can be inlined depending on the specific call site. These advantages allow more aggressive inlining while the amount of generated machine code is still reasonable. We evaluate several inlining heuristics on the benchmark suites DaCapo 9.12 Bach, SPECjbb2005, and SPECjvm2008 and show that our trace-based compiler achieves an up to 51% higher peak performance than the method-based Java HotSpot client compiler. Furthermore, we show that the large compilation scope of our trace-based compiler has a positive effect on other compiler optimizations such as constant folding or null check elimination.

The Influence of New Technologies on the Visual Attention of CSIs Performing a Crime Scene Investigation.

PubMed

de Gruijter, Madeleine; de Poot, Christianne J; Elffers, Henk

2016-01-01

Currently, a series of promising new tools are under development that will enable crime scene investigators (CSIs) to analyze traces in situ during the crime scene investigation or enable them to detect blood and provide information on the age of blood. An experiment is conducted with thirty CSIs investigating a violent robbery at a mock crime scene to study the influence of such technologies on the perception and interpretation of traces during the first phase of the investigation. Results show that in their search for traces, CSIs are not directed by the availability of technologies, which is a reassuring finding. Qualitative findings suggest that CSIs are generally more focused on analyzing perpetrator traces than on reconstructing the event. A focus on perpetrator traces might become a risk when other crime-related traces are overlooked, and when analyzed traces are in fact not crime-related and in consequence lead to the identification of innocent suspects. © 2015 American Academy of Forensic Sciences.

Determination of the Tribological Fundamentals of Solid Lubricated Ceramics. Volume 3. Appendices P through II

DTIC Science & Technology

1991-09-01

9H and tungsten silicides may also be present in the microstructure. The non-SiC eiemental concentrations for NC-203 would not be expected to exceed...lesser amounts of yttrium silicate and tungsten silicide . Trace amounts of a-Si 3N4 , silicon oxynitride, tungsten-iron- silicide , and yttrium silicon...SiC ESK On this sample, we detect Silicon, Carbon, and also Oxygen and Nitrogen, as well as Calcium and Sodium traces. After ionic etching up to about

[Evaluation of nutritional characteristics of commercial canned cat diets].

PubMed

Rückert, Cornelia; Braun, Conny; Vervuert, Ingrid

2017-08-10

To evaluate commercial complete canned cat foods according to their composition, labeling and nutritional characteristics. A total of 21 commercial complete canned compound feeds for adult cats were analyzed for crude nutrients, minerals, vitamins, selected amino acids and taurine. The analyzed parameters were compared to the internal set of standards of the European Pet Food Industry Federation (FEDIAF). The energy content was calculated and compared with the labeled recommendations regarding the amounts of diet that should be fed. Analyzed nutrients were compared with the labeled nutrients according to the regulations of the EU food and feed law (directive EU regulation 767/2009). In many cases, the labeled feeding protocols did not match the calculated daily energy requirements. In eight complete foods, the recommended daily feed amounts were underestimated and four recommendations exceeded energy requirements of adult cats. In 12 complete foods, the calcium and phosphorus contents were threefold higher than the respective requirement. In 16 of 21 complete foods, substantial discrepancies were observed between the recommendations and the analyzed trace elements. In particular, selenium contents exceeded the selenium requirement more than threefold. The vitamin, arginine and taurine contents showed no significant discrepancies to the recommendations. With respect to the labeled nutrients, there were only minor deviations from the regulations of the European law. In general, healthy adult cats are adequately supplied with energy and nutrients when feeding commercial canned complete diets for cats. In cases of body weight loss or gain, the labelled feed amounts should be questioned. The high phosphorus contents are an issue of concern, because a high phosphorus intake can potentially increase the risk for urinary stones and particularly for older cats the risk for renal insufficiency. Furthermore, it is recommended to decrease the high selenium levels by the reduction of selenium-rich feed materials such as offal.

Graphene/dodecanol floating solidification microextraction for the preconcentration of trace levels of cinnamic acid derivatives in traditional Chinese medicines.

PubMed

Hu, Shuang; Yang, Xiao; Xue, Jiao; Chen, Xuan; Bai, Xiao-Hong; Yu, Zhi-Hui

2017-07-01

A novel graphene/dodecanol floating solidification microextraction followed by HPLC with diode-array detection has been developed to extract trace levels of four cinnamic acid derivatives in traditional Chinese medicines. Several parameters affecting the performance were investigated and optimized. Also, possible microextraction mechanism was analyzed and discussed. Under the optimum conditions (amount of graphene in dodecanol: 0.25 mg/mL; volume of extraction phase: 70 μL; pH of sample phase: 3; extraction time: 30   min; stirring rate: 1000 rpm; salt amount: 26.5% NaCl; volume of sample phase: 10 mL, and without dispersant addition), the enrichment factors of four cinnamic acid derivatives ranged from 26 to 112, the linear ranges were 1.0 × 10 -2 -10.0 μg/mL for caffeic acid, 1.3 × 10 -3 -1.9 μg/mL for p-hydroxycinnamic acid, 2.8 × 10 -3 -4.1 μg/mL for ferulic acid, and 2.7 × 10 -3 -4.1 μg/mL for cinnamic acid, with r 2 ≥ 0.9993. The detection limits were found to be in the range of 0.1-1.0 ng/mL, and satisfactory recoveries (92.5-111.2%) and precisions (RSDs 1.1-9.5%) were also achieved. The results showed that the approach is simple, effective and sensitive for the preconcentration and determination of trace levels of cinnamic acid derivatives in Chinese medicines. The proposed method was compared with conventional dodecanol floating solidification microextraction and other extraction methods. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Using the full IASI spectrum for the physical retrieval of temperature, H2O, HDO, O3, minor and trace gases

NASA Astrophysics Data System (ADS)

Serio, C.; Blasi, M. G.; Liuzzi, G.; Masiello, G.; Venafra, S.

2017-02-01

IASI (Infrared Atmospheric Sounder Interferometer) is flying on the European MetOp series of weather satellites. Besides acquiring temperature and humidity data, IASI also observes the infrared emission of the main minor and trace atmospheric components with high precision. The retrieval of these gases would be highly beneficial to the efforts of scientists monitoring Earths climate. IASI retrieval capability and algorithms have been mostly driven by Numerical Weather Prediction centers, whose limited resources for data transmission and computing is hampering the full exploitation of IASI information content. The quest for real or nearly real time processing has affected the precision of the estimation of minor and trace gases, which are normally retrieved on a very coarse spatial grid. The paper presents the very first retrieval of the complete suite of IASI target parameters by exploiting all its 8461 channels. The analysis has been exemplified for sea surface and the target parameters will include sea surface temperature, temperature profile, water vapour and HDO profiles, ozone profile, total column amount of CO, CO2, CH4, N2O, SO2, HNO3, NH3, OCS and CF4. Concerning CO2, CH4 and N2O, it will be shown that their colum amount can be obtained for each single IASI IFOV (Instantaneous Field of View) with a precision better than 1-2%, which opens the possibility to analyze, e.g., the formation of regional patterns of greenhouse gases. To assess the quality of the retrieval, a case study has been set up which considers two years of IASI soundings over the Hawaii, Manua Loa validation station.

Carcinogenic agents in snuff.

PubMed

Hoffmann, D; Harley, N H; Fisenne, I; Adams, J D; Brunnemann, K D

1986-03-01

The oral use of snuff has been associated with an increased-risk for cancer of the oral cavity and pharynx. The five most popular U.S. snuff brands were analyzed for alkaloids, volatile and tobacco-specific N-nitrosamines (TSNA), benzo[a]pyrene (CAS: 50-32-8), and polonium-210. The carcinogenic TSNA in the five snuff brands ranged from 9,600 to 289,000 ppb. These concentrations exceed the nitrosamine concentrations of other consumer products by at least 2 orders of magnitude. Polonium amounted to 0.16-1.22 pCi/g dry snuff. Trace amounts of benzo[a]pyrene (0.1-63 ppb) were indicative of contamination of the tobacco with thermal degradation products, probably due to fire curing or flue curing. The findings from this study, the biologic activity of snuff in animal models, and the epidemiologic studies on snuff use and oral cancer strongly suggest the need for reduction of carcinogens and especially of nitrosamines and polonium-210 in snuff.

Ecotoxicological assessment of diamondback terrapin (Malaclemys terrapin) pond habitat, prey and eggs in Bermuda.

PubMed

Outerbridge, Mark E; O'Riordan, Ruth; Fort, Douglas J; Davenport, John

2016-01-15

Total petroleum hydrocarbons, PAH and various trace metal residues were extracted and analyzed from fresh whole diamondback terrapin (Malaclemys terrapin) eggs, whole brackish-water gastropods (terrapin prey) and benthic sediment from anchialine pond environments in Bermuda inhabited by terrapins. Gastropods and terrapin eggs showed higher concentrations of trace metals and organic contaminants than sediments. Conversely, PAHs were mostly found within the sediment and smaller amounts detected in gastropods and terrapin eggs. Results indicated that contaminants in prey were transferred to terrapin eggs, and that concentrations of several contaminants exceeded potentially toxic concentrations for aquatic vertebrates. Necropsy of unhatched eggs from nests that had yielded viable hatchlings showed significantly compromised embryonic development. Bermudian diamondback terrapins reside and feed in brackish wetland habitats characterized by widespread, multifactorial contamination. This study suggests that environmental contamination plays a role in the recorded low hatching success in terrapin eggs in Bermuda. Copyright © 2015 Elsevier Ltd. All rights reserved.

Detection of titanium in human tissues after craniofacial surgery.

PubMed

Jorgenson, D S; Mayer, M H; Ellenbogen, R G; Centeno, J A; Johnson, F B; Mullick, F G; Manson, P N

1997-04-01

Generally, titanium fixation plates are not removed after osteosynthesis, because they have high biocompatability and high corrosion resistance characteristics. Experiments with laboratory animals, and limited studies of analyses of human tissues, have reported evidence of titanium release into local and distant tissues. This study summarizes our results of the analysis of soft tissues for titanium in four patients with titanium microfixation plates. Energy dispersive x-ray analysis, scanning electron microscopy, and electrothermal atomic absorption spectrophotometry were used to detect trace amounts of titanium in surrounding soft tissues. A single metal inclusion was detected by scanning electron microscopy and energy dispersive x-ray analysis in one patient, whereas, electrothermal atomic absorption spectrophotometry analyses revealed titanium present in three of four specimens in levels ranging from 7.92 to 31.8 micrograms/gm of dry tissue. Results from this study revealed trace amounts of titanium in tissues surrounding craniofacial plates. At the atomic level, electrothermal atomic absorption spectrophotometry appears to be a sensitive tool to quantitatively detect ultra-trace amounts of metal in human tissue.

In vitro study of role of trace amount of Cu release from Cu-bearing stainless steel targeting for reduction of in-stent restenosis.

PubMed

Ren, Ling; Xu, Lu; Feng, Jingwen; Zhang, Yang; Yang, Ke

2012-05-01

A novel 316L type Cu-bearing stainless steel was developed in present work, aiming at reducing the occurrence of the in-stent restenosis after implantations of coronary stents, through trace amount of Cu release from surface of the steel in body fluid. It was found that there was a trace amount of Cu released from the Cu-bearing steel in a simulated body fluid, with no cytotoxicity. All the in vitro experimental results proved that this Cu-bearing steel could not only inhibit the proliferation of vascular smooth muscle cells, reducing the formation of thrombosis, which are the main reasons for happening of the in-stent restenosis, but also promote the proliferation of vascular endothelial cells needed for the revascularization, showing that this novel steel is prospective to be a new material for manufacturing coronary stents with function of reducing the in-stent restenosis.

The Environmental Measurements Laboratory's Stratospheric Radionuclide (RANDAB) and Trace Gas (TRACDAB) Databases

DOE Data Explorer

Leifer, Robert [Environmental Measurements Lab. (EML), New York, NY (United States); Chan, Nita [Environmental Measurements Lab. (EML), New York, NY (United States)

1997-01-01

RANDAB represents the worlds largest collection of stratospheric and upper tropospheric radionuclide data. The database contains results of measurements made from 1957 to 1983 during the ASHCAN, STARDUST, AIRSTREAM, and High Altitude Sampling Program (HASP) projects. More than 20,000 filters were collected during this period and analyzed for approximately 40 different radionuclides. All of the available data characterizing each filter are included in RANDAB. RANDAB offers gas samples characterizing the tritium, radon and 14CO2 concentration in stratospheric air. Only a limited amount of data is available for radon because of analytical and sampling problems. The tritium data were provided graciously by Dr. Allen Mason of Los Alamos Laboratory and Dr. H. G. Oslund of the Tritium Laboratory, University of Miami. The second database, TRACDAB, contains more than 1000 stratospheric trace gas measurements for the period 1974 to 1983. These samples were collected during Project AIRSTREAM. During the years 1974 to 1976, the samples were analyzed at EML. Subsequently, Washington State University (1976-1979) and the Oregon Graduate Institute for Science & Technology (formerly the Oregon Graduate Center 1980-1983) were under contract to EML to analyze AIRSTREAM gas samples. During the period 1974-1983, 980 gas samples were analyzed for one or more of the following gases CCl3F, CCl2F2, CCl4, CH3CCl3, SF6, N20, CO2, CH4, and carbonyl sulfide (COS). To learn more about the naming of halocarbons (CFCs, HFCs, HCFCs, and halons), go to http://cdiac.ess-dive.lbl.gov/pns/cfcinfo.html.

Infrared measurements of atmospheric gases above Mauna Loa, Hawaii, in February 1987

NASA Technical Reports Server (NTRS)

Rinsland, C. P.; Goldman, A.; Murcray, F. J.; Murcray, F. H.; Blatherwick, R. D.

1988-01-01

The IR absorptions spectra of 13 minor and trace atmospheric gases, recorded by the NOAA's Geophysical Monitoring for Climate Change (GMCC) program station at Mauna Loa, Hawaii, for four days in February 1987, were analyzed to determine simultaneous total vertical column amounts for these gases. Comparisons with other data indicate that the NOAA GMCC surface volume mixing ratios are good measures of the mean volume mixing ratios of these gases in the troposphere and that Mauna Loa is a favorable site for IR monitoring of atmospheric gases. The ozone total columns deduced from the IR spectra agreed with the correlative Umkehr observations.

Some thoughts on problems associated with various sampling media used for environmental monitoring

USGS Publications Warehouse

Horowitz, A.J.

1997-01-01

Modern analytical instrumentation is capable of measuring a variety of trace elements at concentrations down into the single or double digit parts-per-trillion (ng l-1) range. This holds for the three most common sample media currently used in environmental monitoring programs: filtered water, whole-water and separated suspended sediment. Unfortunately, current analytical capabilities have exceeded the current capacity to collect both uncontaminated and representative environmental samples. The success of any trace element monitoring program requires that this issue be both understood and addressed. The environmental monitoring of trace elements requires the collection of calendar- and event-based dissolved and suspended sediment samples. There are unique problems associated with the collection and chemical analyses of both types of sample media. Over the past 10 years, reported ambient dissolved trace element concentrations have declined. Generally, these decreases do not reflect better water quality, but rather improvements in the procedures used to collect, process, preserve and analyze these samples without contaminating them during these steps. Further, recent studies have shown that the currently accepted operational definition of dissolved constituents (material passing a 0.45 ??m membrane filter) is inadequat owing to sampling and processing artifacts. The existence of these artifacts raises questions about the generation of accurate, precise and comparable 'dissolved' trace element data. Suspended sediment and associated trace elements can display marked short- and long-term spatial and temporal variability. This implies that spatially representative samples only can be obtained by generating composites using depth- and width-integrated sampling techniques. Additionally, temporal variations have led to the view that the determination of annual trace element fluxes may require nearly constant (e.g., high-frequency) sampling and subsequent chemical analyses. Ultimately, sampling frequency for flux estimates becomes dependent on the time period of concern (daily, weekly, monthly, yearly) and the amount of acceptable error associated with these estimates.

Development and Commissioning of an External Beam Facility in the Union College Ion Beam Analysis Laboratory

NASA Astrophysics Data System (ADS)

Yoskowitz, Joshua; Clark, Morgan; Labrake, Scott; Vineyard, Michael

2015-10-01

We have developed an external beam facility for the 1.1-MV tandem Pelletron accelerator in the Union College Ion Beam Analysis Laboratory. The beam is extracted from an aluminum pipe through a 1 / 4 ' ' diameter window with a 7.5- μm thick Kapton foil. This external beam facility allows us to perform ion beam analysis on samples that cannot be put under vacuum, including wet samples and samples too large to fit into the scattering chamber. We have commissioned the new facility by performing proton induced X-ray emission (PIXE) analysis of several samples of environmental interest. These include samples of artificial turf, running tracks, and a human tooth with an amalgam filling. A 1.7-MeV external proton beam was incident on the samples positioned 2 cm from the window. The resulting X-rays were measured using a silicon drift detector and were analyzed using GUPIX software to determine the concentrations of elements in the samples. The results on the human tooth indicate that while significant concentrations of Hg, Ag, and Sn are present in the amalgam filling, only trace amounts of Hg appear to have leached into the tooth. The artificial turf and running tracks show rather large concentrations of a broad range of elements and trace amounts of Pb in the turf infill.

Assessment of heavy metals in Averrhoa bilimbi and A. carambola fruit samples at two developmental stages.

PubMed

Soumya, S L; Nair, Bindu R

2016-05-01

Though the fruits of Averrhoa bilimbi and A. carambola are economically and medicinally important, they remain underutilized. The present study reports heavy metal quantitation in the fruit samples of A. bilimbi and A. carambola (Oxalidaceae), collected at two stages of maturity. Heavy metals are known to interfere with the functioning of vital cellular components. Although toxic, some elements are considered essential for human health, in trace quantities. Heavy metals such as Cr, Mn, Co, Cu, Zn, As, Se, Pb, and Cd were analyzed by atomic absorption spectroscopy (AAS). The samples under investigation included, A. bilimbi unripe (BU) and ripe (BR), A. carambola sour unripe (CSU) and ripe (CSR), and A. carambola sweet unripe (CTU) and ripe (CTR). Heavy metal analysis showed that relatively higher level of heavy metals was present in BR samples compared to the rest of the samples. The highest amount of As and Se were recorded in BU samples while Mn content was highest in CSU samples and Co in CSR. Least amounts of Cr, Zn, Se, Cd, and Pb were noted in CTU while, Mn, Cu, and As were least in CTR. Thus, the sweet types of A. carambola (CTU, CTR) had comparatively lower heavy metal content. There appears to be no reason for concern since different fruit samples of Averrhoa studied presently showed the presence of various heavy metals in trace quantities.

Petrographic and geochemical contrasts and environmentally significant trace elements in marine-influenced coal seams, Yanzhou mining area, China

USGS Publications Warehouse

Liu, Gaisheng; Yang, P.; Peng, Z.; Chou, C.-L.

2004-01-01

The Yanzhou mining area in west Shandong Province, China contains coals of Permian and Carboniferous age. The 31 and 32 seams of the Permian Shanxi Formation and seams 6, 15-17 of the Carboniferous Taiyuan Formation were analyzed for coal petrology, mineralogy and geochemical parameters. The parameters indicate that the coal is high volatile bituminous in rank. The coal is characterized by high vitrinite and low to medium inertinite and liptinite contents. These properties may be related to evolution of the coal forming environment from more reducing conditions in a marine influenced lower delta plain environment for the early Taiyuan coals to more oxidizing paleoenvironments in an upper delta plain for the upper Shanxi coal seams. The major mineral phases present in the coal are quartz, kaolinite, pyrite and calcite. Sulfur is one of the hazardous elements in coal. The major forms of sulfur in coal are pyritic, organic and sulfate sulfur. Pyritic and organic sulfur generally account for the bulk of the sulfur in coal. Elemental sulfur also occurs in coal, but only in trace to minor amounts. In this paper, the distribution and concentration of sulfur in the Yanzhou mining district are analyzed, and the forms of sulfur are studied. The sulfur content of the Taiyuan coal seams is considerably higher than that of the Shanxi coals. Organic sulfur content is positively correlated to total and pyritic sulfur. The vertical variation of Cu, Zn, Pb, As, Th, U and sulfur contents in coal seam 3 of the Shanxi Formation in the Xinglongzhuang mine show that all these trace elements, with the exception of Th, are enriched in the top and bottom plies of the seam, and that their concentrations are also relatively high in the dirt bands within the seam. The pyritic sulfur is positively correlated with total sulfur, and both are enriched in the top, bottom and parting plies of the seam. The concentrations of the trace elements are closely related to sulfur and ash contents. Most of the trace elements are correlated with the ash content, and may be associated with the mineral matter in the coal. ?? 2004 Elsevier Ltd. All rights reserved.

X-radiography of trace fossils in limestones and dolostones from the Jurassic Smackover Formation, south Alabama

DOE Office of Scientific and Technical Information (OSTI.GOV)

Esposito, R.A.; Castleman, S.P.; King, D.T. Jr.

X-radiography has been useful in studying biogenic sedimentary structures in unconsolidated sediments but the technique has not been applied often to the study of hard carbonate rock. The authors have applied x-radiography to the study of the lower part of the Smackover to enhance the complete petrologic description of the rock. The lower Smackover has many dense micrite intervals and intervals of monotonous, thin graded beds. Parts of the lower Smackover is also dolomitized. None of the above rocks contains significant amount of skeletal debris and trace fossils are not generally obvious in an etched slab of core. In limestone,more » they have detected well-preserved trace fossils by x-radiography, however. The dolostones show no traces using our method. In limestones, the traces are marked by minute amounts of finely divided iron sulfides. This causes a slight density difference resulting in greater x-ray absorption. They recognize two main trace-fossil types: a Thalassinoides best seen in slabs cut parallel to bedding and a Zoophycos best seen in slabs cut perpendicular to bedding. The technique requires a slab cut 8 mm thick with parallel flat surfaces and a medical x-ray unit using accelerating voltages of 66 kV and 10 mas. Traces are most successfully imaged on industrial-quality films.« less

Quercetin as colorimetric reagent for determination of zirconium

USGS Publications Warehouse

Grimaldi, F.S.; White, C.E.

1953-01-01

Methods described in the literature for the determination of zirconium are generally designed for relatively large amounts of this element. A good procedure using colorimetric reagent for the determination of trace amounts is desirable. Quercetin has been found to yield a sensitive color reaction with zirconium suitable for the determination of from 0.1 to 50?? of zirconium dioxide. The procedure developed involves the separation of zirconium from interfering elements by precipitation with p-dimethylaminoazophenylarsonic acid prior to its estimation with quercetin. The quercetin reaction is carried out in 0.5N hydrochloric acid solution. Under the operating conditions it is indicated that quercetin forms a 2 to 1 complex with zirconium; however, a 2 to 1 and a 1 to 1 complex can coexist under special conditions. Approximate values for the equilibrium constants of the complexes are K1 = 0.33 ?? 10-5 and K2 = 1.3 ?? 10-9. Seven Bureau of Standards samples of glass sands and refractories were analyzed with excellent results. The method described should find considerable application in the analysis of minerals and other materials for macro as well as micro amounts of zirconium.

Ultra high performance liquid chromatography tandem mass spectrometry for rapid analysis of trace organic contaminants in water

PubMed Central

2013-01-01

Background The widespread utilization of organic compounds in modern society and their dispersion through wastewater have resulted in extensive contamination of source and drinking waters. The vast majority of these compounds are not regulated in wastewater outfalls or in drinking water while trace amounts of certain compounds can impact aquatic wildlife. Hence it is prudent to monitor these contaminants in water sources until sufficient toxicological data relevant to humans becomes available. A method was developed for the analysis of 36 trace organic contaminants (TOrCs) including pharmaceuticals, pesticides, steroid hormones (androgens, progestins, and glucocorticoids), personal care products and polyfluorinated compounds (PFCs) using a single solid phase extraction (SPE) technique with ultra-high performance liquid chromatography coupled to tandem mass spectrometry (UHPLC-MS/MS). The method was applied to a variety of water matrices to demonstrate method performance and reliability. Results UHPLC-MS/MS in both positive and negative electrospray ionization (ESI) modes was employed to achieve optimum sensitivity while reducing sample analysis time (<20 min) compared with previously published methods. The detection limits for most compounds was lower than 1.0 picogram on the column while reporting limits in water ranged from 0.1 to 15 ng/L based on the extraction of a 1 L sample and concentration to 1 mL. Recoveries in ultrapure water for most compounds were between 90-110%, while recoveries in surface water and wastewater were in the range of 39-121% and 38-141% respectively. The analytical method was successfully applied to analyze samples across several different water matrices including wastewater, groundwater, surface water and drinking water at different stages of the treatment. Among several compounds detected in wastewater, sucralose and TCPP showed the highest concentrations. Conclusion The proposed method is sensitive, rapid and robust; hence it can be used to analyze a large variety of trace organic compounds in different water matrixes. PMID:23777604

An exploratory investigation of polar organic compounds in waters from a lead–zinc mine and mill complex

USGS Publications Warehouse

Rostad, Colleen E.; Schmitt, Christopher J.; Schumacher, John G.; Leiker, Thomas J.

2011-01-01

Surface water samples were collected in 2006 from a lead mine-mill complex in Missouri to investigate possible organic compounds coming from the milling process. Water samples contained relatively high concentrations of dissolved organic carbon (DOC; greater than 20 mg/l) for surface waters but were colorless, implying a lack of naturally occurring aquatic humic or fulvic acids. Samples were extracted by three different types of solid-phase extraction and analyzed by electrospray ionization/mass spectrometry. Because large amounts of xanthate complexation reagents are used in the milling process, techniques were developed to extract and analyze for sodium isopropyl xanthate and sodium ethyl xanthate. Although these xanthate reagents were not found, trace amounts of the degradates, isopropyl xanthyl thiosulfonate and isopropyl xanthyl sulfonate, were found in most locations sampled, including the tailings pond downstream. Dioctyl sulfosuccinate, a surfactant and process filtering aid, was found at concentrations estimated at 350 μg/l at one mill outlet, but not downstream. Release of these organic compounds downstream from lead-zinc mine and milling areas has not previously been reported. A majority of the DOC remains unidentified.

Iron active electrode and method of making same

DOEpatents

Jackovitz, John F.; Seidel, Joseph; Pantier, Earl A.

1982-10-26

An iron active electrode and method of preparing same in which iron sulfate is calcined in an oxidizing atmosphere at a temperature in the range of from about 600.degree. C. to about 850.degree. C. for a time sufficient to produce an iron oxide with a trace amount of sulfate. The calcined material is loaded into an electrically conductive support and then heated in a reducing atmosphere at an elevated temperature to produce activated iron having a trace amount of sulfide which is formed into an electrode plate.

Immunosensors using a quartz crystal microbalance

NASA Astrophysics Data System (ADS)

Kurosawa, Shigeru; Aizawa, Hidenobu; Tozuka, Mitsuhiro; Nakamura, Miki; Park, Jong-Won

2003-11-01

Better analytical technology has been demanded for accurate and rapid determination of trace amounts of chemical compounds, such as marker proteins for disease or endocrine disrupters like dioxin, which might be contained in blood, food and the environment. The study of immunosensors using a quartz crystal microbalance (QCM) has recently focused on conventional detection methods for the determination of chemical compounds together with the development of reagents and processes. This paper introduces the principle of the detection method of QCM immunosensors developed at AIST and its application to the detection of trace amounts of chemical compounds.

Trace determination of zinc by substoichiometric isotope dilution analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandhya, D.; Priya, S.; Subramanian, M.O.S.

1996-09-01

A radiometric method based on substoichiometric isotope dilution analysis using 1,10-phenanthroline and a substoichiometric amount of eosin was developed for determining trace amounts of zinc. Evaluation of various metal ion interferences shows that as little as 0.2 {mu}g Zn could be determined in an aqueous-phase volume of 60 mL. The method has been successfully applied to the determination of Zn in city waste incineration ash, cadmium metal, Fourts-B tablets, Boro-plus ointment, and magnesium alloy samples. 12 refs., 3 figs., 3 tabs.

Estimation of trace amounts of benzene in solvent-extracted vegetable oils and oil seed cakes.

PubMed

Masohan, A; Parsad, G; Khanna, M K; Chopra, S K; Rawat, B S; Garg, M O

2000-09-01

A new method is presented for the qualitative and quantitative estimation of trace amounts (up to 0.15 ppm) of benzene in crude as well as refined vegetable oils obtained by extraction with food grade hexane (FGH), and in the oil seed cakes left after extraction. The method involves the selection of two solvents; cyclohexanol, for thinning of viscous vegetable oil, and heptane, for azeotroping out trace benzene as a concentrate from the resulting mixture. Benzene is then estimated in the resulting azeotrope either by UV spectroscopy or by GC-MS subject to availability and cost effectiveness of the latter. Repeatability and reproducibility of the method is within 1-3% error. This method is suitable for estimating benzene in vegetable oils and oil seed cakes.

Water Contents of the Mantle Beneath the Rio Grande Rift: FTIR Analysis of Kilbourne Hole Peridotite Xenoliths

NASA Technical Reports Server (NTRS)

Schaffer, Lillian A.; Peslier, Anne; Brandon, Alan

2013-01-01

Although nominally anhydrous mantle minerals contain only trace amounts of water, they are the main reservoir of water in the mantle. Added up at the scale of the Earth's mantle, these trace amounts of water represent oceans worth in mass]. Mantle xenoliths from Kilbourne Hole in southern New Mexico are ideal to study mantle water distribution in a rift tectonic setting as they come from a recently-erupted maar in the middle of the Rio Grande Rift. Eleven lherzolites, one harzburgite, and one dunite are being analyzed for water contents by FTIR. The xenoliths will also be analyzed for major and trace element composition, Fe3+/Summation (Fe) ratios, and characterized petrologically. Olivines exhibit variable water contents with less water at the rims compared to the cores. This is probably due to H loss during decompression and xenolith transport by the host magma. Mantle water contents appear to have been primarily preserved in the core of the olivines, based on diffusion modeling of the typically plateau-shaped water content profiles across these grains. Water concentrations are in equilibrium between clino- and orthopyroxene, but olivine concentrations are typically not in equilibrium with those of either pyroxene. Lherzolites analyzed so far have water contents of 2-12 ppm H2O in olivines, 125-165 ppm H2O in orthopyroxenes, and 328-447 ppm H2O in clinopyroxenes. These water contents are similar to, but with a narrower range, than those for the respective minerals in other continental peridotite xenoliths. The lherzolites have bulk-rock (BR) Al2O3 contents that range between 3.17 and 3.78 wt%, indicating similar degrees of partial melting, which could explain the narrow range of their pyroxene water contents. Primitive mantle normalized rare earth element (REE) profiles of the bulk lherzolites vary from light REE depleted to flat, with no significant differences between, nor relation to, their mineral water contents. Consequently, the metasomatic agents that enriched LREEs in these lherzolites were most likely water-poor. The harzburgite and the dunite have lower weight percent Al2O3 compared to the lherzolites (2.11% and 0.34% respectively) indicating higher degrees of melting. Their olivine water contents, however, are similar to those of the lherzolites. Moreover, no correlations are observed between pyroxene water contents and indices of melting or metasomatism between the lherzolite group, the harzburgite, and the dunite, although the latter has the lowest pyroxene water contents. More samples will be analyzed to determine if the water contents are controlled by melting, metasomatism, or a combination of the two in the Kilbourne Hole mantle.

Method for remote detection of trace contaminants

DOEpatents

Simonson, Robert J.; Hance, Bradley G.

2003-09-09

A method for remote detection of trace contaminants in a target area comprises applying sensor particles that preconcentrate the trace contaminant to the target area and detecting the contaminant-sensitive fluorescence from the sensor particles. The sensor particles can have contaminant-sensitive and contaminant-insensitive fluorescent compounds to enable the determination of the amount of trace contaminant present in the target are by relative comparison of the emission of the fluorescent compounds by a local or remote fluorescence detector. The method can be used to remotely detect buried minefields.

Impact of Drainage Networks on Cholera Outbreaks in Lusaka, Zambia

PubMed Central

Suzuki, Hiroshi; Fujino, Yasuyuki; Kimura, Yoshinari; Cheelo, Meetwell

2009-01-01

Objectives. We investigated the association between precipitation patterns and cholera outbreaks and the preventative roles of drainage networks against outbreaks in Lusaka, Zambia. Methods. We collected data on 6542 registered cholera patients in the 2003–2004 outbreak season and on 6045 cholera patients in the 2005–2006 season. Correlations between monthly cholera incidences and amount of precipitation were examined. The distribution pattern of the disease was analyzed by a kriging spatial analysis method. We analyzed cholera case distribution and spatiotemporal cluster by using 2590 cholera cases traced with a global positioning system in the 2005–2006 season. The association between drainage networks and cholera cases was analyzed with regression analysis. Results. Increased precipitation was associated with the occurrence of cholera outbreaks, and insufficient drainage networks were statistically associated with cholera incidences. Conclusions. Insufficient coverage of drainage networks elevated the risk of cholera outbreaks. Integrated development is required to upgrade high-risk areas with sufficient infrastructure for a long-term cholera prevention strategy. PMID:19762668

Application of Box-Behnken experimental design to optimize the extraction of insecticidal Cry1Ac from soil.

PubMed

Li, Yan-Liang; Fang, Zhi-Xiang; You, Jing

2013-02-20

A validated method for analyzing Cry proteins is a premise to study the fate and ecological effects of contaminants associated with genetically engineered Bacillus thuringiensis crops. The current study has optimized the extraction method to analyze Cry1Ac protein in soil using a response surface methodology with a three-level-three-factor Box-Behnken experimental design (BBD). The optimum extraction conditions were at 21 °C and 630 rpm for 2 h. Regression analysis showed a good fit of the experimental data to the second-order polynomial model with a coefficient of determination of 0.96. The method was sensitive and precise with a method detection limit of 0.8 ng/g dry weight and relative standard deviations at 7.3%. Finally, the established method was applied for analyzing Cry1Ac protein residues in field-collected soil samples. Trace amounts of Cry1Ac protein were detected in the soils where transgenic crops have been planted for 8 and 12 years.

Trace Metals Derived from Electronic Cigarette (ECIG) Generated Aerosol: Potential Problem of ECIG Devices That Contain Nickel

PubMed Central

Palazzolo, Dominic L.; Crow, Andrew P.; Nelson, John M.; Johnson, Robert A.

2017-01-01

Introduction: ECIGs are currently under scrutiny concerning their safety, particularly in reference to the impact ECIG liquids (E-liquids) have on human health. One concern is that aerosolized E-liquids contain trace metals that could become trapped in respiratory tissues and induce pathology. Methods: To mimic this trapping, peristaltic pumps were used to generate and transport aerosol onto mixed cellulose ester (MCE) membranes where aluminum (Al), arsenic (As), cadmium (Cd), copper (Cu), iron (Fe), manganese (Mn), nickel (Ni), lead (Pb), and zinc (Zn) were subsequently captured and quantified. The presence of trace metals on unexposed MCE membranes and on MCE membranes exposed to mainstream smoke served as control and comparison, respectively. The presence of these metals was also determined from the E-liquid before aerosolization and untouched by the ECIG device. All metals were quantified using ICP-MS. The ECIG core assembly was analyzed using scanning electron microscopy with elemental analysis capability. Results: The contents (μg) of Al, As, Cd, Cu, Fe, Mn, Ni, Pb, and Zn on control MCE membranes were 1.2 ± 0.2, 0.050 ± 0.002, 0.047 ± 0.003, 0.05 ± 0.01, 0.001 ± 0.001, 0.16 ± 0.04, 0.005 ± 0.003, 0.014 ± 0.006, and 0.09 ± 0.02, respectively. The contents of all trace metals on MCE membranes exposed to aerosol were similar to controls, except Ni which was significantly (p < 0.01) higher (0.024 ± 0.004 μg). In contrast, contents of Al, As, Fe, Mn, and Zn on MCE membranes exposed to smoke were significantly higher (p < 0.05) than controls. The contents of Al, As, Cu, Fe, and Mn on smoke-exposed MCE membranes were also significantly higher (p < 0.05) than their content on aerosol-exposed membranes. The contents per cigarette equivalent of metals in E-liquid before aerosolization were negligible compared to amounts of aerosolized E-liquid, except for Fe (0.002 μg before and 0.001 μg after). Elemental analysis of the core assembly reveals the presence of several of these trace metals, especially Al, Fe, Ni, and Zn. Conclusions: In general, from the single ECIG-device/E-liquid combination used, the amount of trace metals from ECIG-generated aerosol are lower than in traditional mainstream smoke, Only Ni in the ECIG-generated aerosol was higher than control. The most probable source of Ni in this aerosol is the core assembly. PMID:28119618

Simultaneous Measurement of Zinc, Copper, Lead and Cadmium in Baby Weaning Food and Powder Milk by DPASV.

PubMed

Sadeghi, Naficeh; Oveisi, Mohammad Reza; Jannat, Behrooz; Hajimahmoodi, Mannan; Behfar, Abdolazim; Behzad, Masoomeh; Norouzi, Narges; Oveisi, Morvarid; Jannat, Behzad

2014-01-01

Apart from the breast milk, infant formula and baby weaning food have a special role in infant diet. Infants and young children are very susceptible to amount of trace elements. Copper and zinc are two elements that add in infant food. Lead and cadmium are heavy metals that enter to food chain unavoidably. DPASV is a benefit and applicable method for measurement of trace elements in food products. In this study, concentration of zinc, copper, lead and cadmium in four brands of baby food (rice and wheat based) and powder milk was analyzed with DPASV and polarograph set. Total Mean ± SE of zinc, copper, lead and cadmium in baby foods (n = 240) were 11.86 ± 1.474 mg/100g, 508.197 ± 83.154 μg/100g, 0.445 ± 0.006, 0.050 ± 0.005 mg/Kg respectively. Also these amount in powder milk (n = 240) were 3.621± 0.529 mg/100g, 403.822 ± 133.953 μg/100g, 0.007 ± 0.003, 0.060 ± 0.040 mg/Kg respectively. Zinc level in baby food type I was higher than lablled value (P = 0.030), but in other brands was not difference. Concentration of copper in all of samples was in labeled range (P > 0.05). In each four products, level of lead and cadmium were lower than the standard limit (P < 0.05). Amount of zinc and lead in baby food I, had difference versus other products. Concentration of zinc, camium in baby food type I, was higher than type II (P = 0.043, 0.001 respectively). Concentration of lead and cadmium in baby food type II, was higher than infant formulas, but are in standard limit.

Simultaneous visualization of the subfemtomolar expression of microRNA and microRNA target gene using HILO microscopy.

PubMed

Lin, Yi-Zhen; Ou, Da-Liang; Chang, Hsin-Yuan; Lin, Wei-Yu; Hsu, Chiun; Chang, Po-Ling

2017-09-01

The family of microRNAs (miRNAs) not only plays an important role in gene regulation but is also useful for the diagnosis of diseases. A reliable method with high sensitivity may allow researchers to detect slight fluctuations in ultra-trace amounts of miRNA. In this study, we propose a sensitive imaging method for the direct probing of miR-10b (miR-10b-3p, also called miR-10b*) and its target ( HOXD10 mRNA) in fixed cells based on the specific recognition of molecular beacons combined with highly inclined and laminated optical sheet (HILO) fluorescence microscopy. The designed dye-quencher-labelled molecular beacons offer excellent efficiencies of fluorescence resonance energy transfer that allow us to detect miRNA and the target mRNA simultaneously in hepatocellular carcinoma cells using HILO fluorescence microscopy. Not only can the basal trace amount of miRNA be observed in each individual cell, but the obtained images also indicate that this method is useful for monitoring the fluctuations in ultra-trace amounts of miRNA when the cells are transfected with a miRNA precursor or a miRNA inhibitor (anti-miR). Furthermore, a reasonable causal relation between the miR-10b and HOXD10 expression levels was observed in miR-10b* precursor-transfected cells and miR-10b* inhibitor-transfected cells. The trends of the miRNA alterations obtained using HILO microscopy completely matched the RT-qPCR data and showed remarkable reproducibility (the coefficient of variation [CV] = 0.86%) and sensitivity (<1.0 fM). This proposed imaging method appears to be useful for the simultaneous visualisation of ultra-trace amounts of miRNA and target mRNA and excludes the procedures for RNA extraction and amplification. Therefore, the visualisation of miRNA and the target mRNA should facilitate the exploration of the functions of ultra-trace amounts of miRNA in fixed cells in biological studies and may serve as a powerful tool for diagnoses based on circulating cancer cells.

ENHANCED FORMATION OF DIOXINS AND FURANS FROM COMBUSTION DEVICES BY ADDITION OF TRACE QUANTITIES OF BROMINE

EPA Science Inventory

Past pilot-scale experimental studies have shown a dramatic increase in the formation of certain chlorinated products of incomplete combustion (PICs) caused by the addition of trace amounts of bromine (Br). Emissions of trichloroethylene and tetrachloorethylene, generated as PICs...

Development of an Assay for the Detection of PrPres in Blood and Urine Based on PMCA Assay and ELISA Methods

DTIC Science & Technology

2008-09-01

the Origen Analyzer (BioVeris), the DELFIA (Wallac/PE) and the MPD ELISA ( BioTraces ). BioTraces had the most sensitive assay in which 125I was used...investigations we decided to abandon the BioTraces assay and focused on a more practical and also sensitive assay provided by the Origen Analyzer

Should bioactive trace elements not recognized as essential, but with beneficial health effects, have intake recommendations.

PubMed

Nielsen, Forrest H

2014-10-01

Today, most nutritionists do not consider a trace element essential unless it has a defined biochemical function in higher animals or humans. As a result, even though it has been found that trace elements such as boron and silicon have beneficial bioactivity in higher animals and humans, they generally receive limited attention or mention when dietary guidelines or intake recommendations are formulated. Recently, the possibility of providing dietary intake recommendations such as an adequate intake (AI) for some bioactive food components (e.g., flavonoids) has been discussed. Boron, chromium, nickel, and silicon are bioactive food components that provide beneficial health effects by plausible mechanisms of action in nutritional and supra nutritional amounts, and thus should be included in the discussions. Although the science base may not be considered adequate for establishing AIs, a significant number of findings suggest that statements about these trace elements should be included when dietary intake guidance is formulated. An appropriate recommendation may be that diets should include foods that would provide trace elements not currently recognized as essential in amounts shown to reduce the risk of chronic disease and/or promote health and well-being. Published by Elsevier GmbH.

Stable isotope (2H, 17O, 18O) and hydro chemical patterns of precipitation collected in weekly resolution at Hannover, Germany

NASA Astrophysics Data System (ADS)

Koeniger, Paul; Himmelsbach, Thomas

2016-04-01

Long-term observations of stable isotopes (δ18O and δ2H) in precipitation were initiated in May 2008 at the Federal Institute of Geosciences and Natural Resources (BGR) in Hannover, Germany. In 2014 all precipitation samples were re-analyzed because a purchase of a new laser spectrometer (Picarro L2140-i) now allowed measurements of δ17O and a calculation of the 17O-excess parameter. Starting in October 2015 a routine analysis of hydro chemical parameters was added whenever enough sample aliquot was available (major ions, trace elements). A discussion of the stable isotope data of the seven year series of weekly precipitation samples (n = 370) will be presented. Beneath general patterns (seasonality and trends) we also focus on importance of amount weighing procedures, corrections for minor rain amounts, aspects of sample storage and re-analyzes, as well as impacts through changes in analytical equipment (IRMS, CRD spectroscopy) which is visible from the data. For stable isotopes a Thermo Fisher delta plus IRMS (Gasbench and H-Device) was used until 2011 and from 2012 on a Picarro L2120-i water vapor analyzer with long-term accuracies for quality check samples better than 0.2‰ and 0.8‰ for δ18O and δ2H, respectively.

An analysis of fracture trace patterns in areas of flat-lying sedimentary rocks for the detection of buried geologic structure. [Kansas and Texas

NASA Technical Reports Server (NTRS)

Podwysocki, M. H.

1974-01-01

Two study areas in a cratonic platform underlain by flat-lying sedimentary rocks were analyzed to determine if a quantitative relationship exists between fracture trace patterns and their frequency distributions and subsurface structural closures which might contain petroleum. Fracture trace lengths and frequency (number of fracture traces per unit area) were analyzed by trend surface analysis and length frequency distributions also were compared to a standard Gaussian distribution. Composite rose diagrams of fracture traces were analyzed using a multivariate analysis method which grouped or clustered the rose diagrams and their respective areas on the basis of the behavior of the rays of the rose diagram. Analysis indicates that the lengths of fracture traces are log-normally distributed according to the mapping technique used. Fracture trace frequency appeared higher on the flanks of active structures and lower around passive reef structures. Fracture trace log-mean lengths were shorter over several types of structures, perhaps due to increased fracturing and subsequent erosion. Analysis of rose diagrams using a multivariate technique indicated lithology as the primary control for the lower grouping levels. Groupings at higher levels indicated that areas overlying active structures may be isolated from their neighbors by this technique while passive structures showed no differences which could be isolated.

Elemental Geochemistry of Samples From Fault Segments of the San Andreas Fault Observatory at Depth (SAFOD) Drill Hole

NASA Astrophysics Data System (ADS)

Tourscher, S. N.; Schleicher, A. M.; van der Pluijm, B. A.; Warr, L. N.

2006-12-01

Elemental geochemistry of mudrock samples from phase 2 drilling of the San Andreas Fault Observatory at Depth (SAFOD) is presented from bore hole depths of 3066 m to 3169 m and from 3292 m to 3368 m, which contain a creeping section and main trace of the fault, respectively. In addition to preparation and analysis of whole rock sample, fault grains with neomineralized, polished surfaces were hand picked from well-washed whole rock samples, minimizing the potential contamination from drilling mud and steel shavings. The separated fractions were washed in deionized water, powdered using a mortar and pestle, and analyzed using an Inductively Coupled Plasma- Optical Emission Spectrometer for major and minor elements. Based on oxide data results, systematic differences in element concentrations are observed between the whole rock and fault rock. Two groupings of data points are distinguishable in the regions containing the main trace of the fault, a shallow part (3292- 3316 m) and a deeper section (3320-3368 m). Applying the isocon method, assuming Zr and Ti to be immobile elements in these samples, indicates a volume loss of more than 30 percent in the shallow part and about 23 percent in the deep part of the main trace. These changes are minimum estimates of fault-related volume loss, because the whole rock from drilling samples contains variable amount of fault rock as well. Minimum estimates for volume loss in the creeping section of the fault are more than 50 percent when using the isocon method, comparing whole rock to plucked fault rock. The majority of the volume loss in the fault rocks is due to the dissolution and loss of silica, potassium, aluminum, sodium and calcium, whereas (based on oxide data) the mineralized surfaces of fractures appear to be enriched in Fe and Mg. The large amount of element mobility within these fault traces suggests extensive circulation of hydrous fluids along fractures that was responsible for progressive dissolution and leaching of the wall rock during faulting.

Physiological Effects of Trace Elements and Chemicals in Water

ERIC Educational Resources Information Center

Varma, M. M.; And Others

1976-01-01

The physiological effects on humans and animals of trace amounts of organic and unorganic pollutants in natural and waste waters are examined. The sensitivity of particular organs and species is emphasized. Substances reviewed include mercury, arsenic, cadmium, lead, chromium, fluorides, nitrates and organics, including polychlounated biphenyls.…

Micro-polarimeter for high performance liquid chromatography

DOEpatents

Yeung, Edward E.; Steenhoek, Larry E.; Woodruff, Steven D.; Kuo, Jeng-Chung

1985-01-01

A micro-polarimeter interfaced with a system for high performance liquid chromatography, for quantitatively analyzing micro and trace amounts of optically active organic molecules, particularly carbohydrates. A flow cell with a narrow bore is connected to a high performance liquid chromatography system. Thin, low birefringence cell windows cover opposite ends of the bore. A focused and polarized laser beam is directed along the longitudinal axis of the bore as an eluent containing the organic molecules is pumped through the cell. The beam is modulated by air gap Faraday rotators for phase sensitive detection to enhance the signal to noise ratio. An analyzer records the beams's direction of polarization after it passes through the cell. Calibration of the liquid chromatography system allows determination of the quantity of organic molecules present from a determination of the degree to which the polarized beam is rotated when it passes through the eluent.

PM2.5 aerosols collected in the Antarctic Peninsula with a solar powered sampler during austral summer periods

NASA Astrophysics Data System (ADS)

Préndez, M.; Wachter, J.; Vega, C.; Flocchini, R. G.; Wakayabashi, P.; Morales, J. R.

Collection of PM2.5 particles was carried out in Antarctica in the summer periods of years 2006 and 2007 using solar panels to operate the sampling unit. The unit was installed 2.5 km from the B. O'Higgins Chilean base to avoid possible air contamination from oil or gas burning electric power stations. The aerosols were analyzed by XRF identifying twenty elements between Na and Sr. Results showed the presence of elements of typical Earth crust and seawater origins. In addition, considerable amounts of non-sea sulfur together with traces of Pb and Se from probable long distant anthropogenic activities were observed.

The use of hydroxyacids as geochemical indicators

NASA Technical Reports Server (NTRS)

Cardoso, J. N.; Eglinton, G.

1983-01-01

The distributions of hydroxyacids in a variety of recent and ancient sediments have been determined by gas chromatography-mass spectrometry. A lacustrine sediment (Rostherne Mere, U.K.) and two marine situations (Cariaco Trench, Black Sea) were analyzed as examples of recent depositional environments. Beta-hydroxyacids occurred in all of the recent sediments, consistent with their presumed microbial origin, whereas di- and trihydroxyacids were present in the sediments with a significant higher plant input (Black Sea and Rostherne Mere sediments). The two ancient (Eocene) sediments examined, viz, the Greene River (U.S.) and Messel (Germany) oil shales, contained only trace amounts of hydroxyacids. These results provide evidence that hydroxyacids are in general not well preserved over geological time.

Remediation using trace element humate surfactant

DOEpatents

Riddle, Catherine Lynn; Taylor, Steven Cheney; Bruhn, Debra Fox

2016-08-30

A method of remediation at a remediation site having one or more undesirable conditions in which one or more soil characteristics, preferably soil pH and/or elemental concentrations, are measured at a remediation site. A trace element humate surfactant composition is prepared comprising a humate solution, element solution and at least one surfactant. The prepared trace element humate surfactant composition is then dispensed onto the remediation site whereby the trace element humate surfactant composition will reduce the amount of undesirable compounds by promoting growth of native species activity. By promoting native species activity, remediation occurs quickly and environmental impact is minimal.

Ordering Traces Logically to Identify Lateness in Message Passing Programs

DOE PAGES

Isaacs, Katherine E.; Gamblin, Todd; Bhatele, Abhinav; ...

2015-03-30

Event traces are valuable for understanding the behavior of parallel programs. However, automatically analyzing a large parallel trace is difficult, especially without a specific objective. We aid this endeavor by extracting a trace's logical structure, an ordering of trace events derived from happened-before relationships, while taking into account developer intent. Using this structure, we can calculate an operation's delay relative to its peers on other processes. The logical structure also serves as a platform for comparing and clustering processes as well as highlighting communication patterns in a trace visualization. We present an algorithm for determining this idealized logical structure frommore » traces of message passing programs, and we develop metrics to quantify delays and differences among processes. We implement our techniques in Ravel, a parallel trace visualization tool that displays both logical and physical timelines. Rather than showing the duration of each operation, we display where delays begin and end, and how they propagate. As a result, we apply our approach to the traces of several message passing applications, demonstrating the accuracy of our extracted structure and its utility in analyzing these codes.« less

Ray Tracing with Virtual Objects.

ERIC Educational Resources Information Center

Leinoff, Stuart

1991-01-01

Introduces the method of ray tracing to analyze the refraction or reflection of real or virtual images from multiple optical devices. Discusses ray-tracing techniques for locating images using convex and concave lenses or mirrors. (MDH)

The challenges of analysing blood stains with hyperspectral imaging

NASA Astrophysics Data System (ADS)

Kuula, J.; Puupponen, H.-H.; Rinta, H.; Pölönen, I.

2014-06-01

Hyperspectral imaging is a potential noninvasive technology for detecting, separating and identifying various substances. In the forensic and military medicine and other CBRNE related use it could be a potential method for analyzing blood and for scanning other human based fluids. For example, it would be valuable to easily detect whether some traces of blood are from one or more persons or if there are some irrelevant substances or anomalies in the blood. This article represents an experiment of separating four persons' blood stains on a white cotton fabric with a SWIR hyperspectral camera and FT-NIR spectrometer. Each tested sample includes standardized 75 _l of 100 % blood. The results suggest that on the basis of the amount of erythrocytes in the blood, different people's blood might be separable by hyperspectral analysis. And, referring to the indication given by erythrocytes, there might be a possibility to find some other traces in the blood as well. However, these assumptions need to be verified with wider tests, as the number of samples in the study was small. According to the study there also seems to be several biological, chemical and physical factors which affect alone and together on the hyperspectral analyzing results of blood on fabric textures, and these factors need to be considered before making any further conclusions on the analysis of blood on various materials.

The differentiation of eucrites: The role of in situ crystallization

NASA Astrophysics Data System (ADS)

Barrat, J. A.; Blichert-Toft, J.; Gillet, Ph.; Keller, F.

2000-09-01

We report on major and trace element analyses of 17 eucrites, including three cumulate eucrites (Binda, Moore County, and Serra de Magé), determined by, respectively, ICP-AES and ICP-MS. The results obtained for Binda and Moore County are consistent with the model of Treiman (1997) for the formation of cumulate eucrites, which holds that these meteorites were produced from a eucritic melt. Our sample of Serra de Magé contains unusually large amounts of pyroxene and probably an accessory phase rich in HREEs and is therefore not representative of this eucrite as known from literature data. Our results for the noncumulate eucrites Bereba, Bouvante, Cachari, Caldera, Camel Donga, Ibitira, Jonzac, Juvinas, Lakangaon, Millbillillie, Padvarninkai, Pasamonte, Sioux County and Stannern are in good agreement with literature data. The observed decoupling between major and trace elements for noncumulate eucrites can be explained by in-situ crystallization during the differentiation of an asteroidal magma ocean. This model can further account for both the Nuevo Laredo and the Stannern trends but has as a consequence that none of the analyzed eucrites represents a primary melt.

Nociceptive role of substance-P in the knee joint of a patient with congenital insensitivity to pain.

PubMed

Derwin, K A; Glover, R A; Wojtys, E M

1994-01-01

This case report describes the immunocytochemical examination of tissue from a 9-year-old black child diagnosed with congenital insensitivity to pain at age 5. A recent fall and resulting patella fracture required surgical treatment. Biopsies of the distal pole and surrounding soft tissue, as well as a sample of his patellofemoral joint fluid, were taken at the time of partial patellectomy and analyzed for substance-P (SP). Morphologic staining of the patella showed a grossly degenerated patellofemoral articular surface. Examination of tissue sections stained either immunocytochemically with diaminobenzidine DAB or by a rhodamine fluorescent labeling technique showed no evidence of SP-positive nerve fibers. Furthermore, only a trace amount of SP (7.29 pg/ml) was detected in a sample of the patient's knee joint synovial fluid. This patient's absence of pain sensation in conjunction with the absence of SP nerve fibers in stained patella sections and identification of only trace levels of SP in his synovial fluid, further implicates this neuropeptide in nociceptive innervation of diarthrodial joints.

Functionalized dithiocarbamate chelating resin for the removal of Co2+ from simulated wastewater

NASA Astrophysics Data System (ADS)

Shi, Xuewei; Fu, Linwei; Wu, Yanyang; Zhao, Huiling; Zhao, Shuangliang; Xu, Shouhong

2017-12-01

Industrial wastewater that contains trace amounts of heavy metal ions is often seen in petrochemical industry. While this wastewater can not be directly discharged, it is difficult to treat due to the low concentration of metal ions. Introducing chelating reagents into this wastewater for selective ion adsorption, followed by a mechanical separation process, provides an appealing solution. Toward the success of this technology, the development of effective chelating resins is of key importance. In the present work, a chelating resin containing amino and dithiocarbamate groups was reported for the removal of Co(II) metal ions in trace concentrations from simulated wastewater. By investigating the adsorption performance of the chelating resin at different solution pH values, adsorbent dosages, contact time, initial ion concentrations, and adsorption temperatures, the maximum adsorption capacity of the resin for Co(II) was identified to be 24.89 mg g-1 for a 2 g L-1 adsorbent dosage and a pH value of 5. After four adsorption-desorption cycles, 97% of the adsorption capacity of the resin was maintained. The adsorption kinetics and thermodynamics were analyzed and discussed as well.

Reconnaissance of water-quality characteristics of streams in the City of Charlotte and Mecklenburg County, North Carolina

USGS Publications Warehouse

Eddins, W.H.; Crawford, J.K.

1984-01-01

In 1979-81, water samples were collected from 119 sites on streams throughout the City of Charlotte and Mecklenburg County, North Carolina, and were analyzed for specific conductance, dissolved chloride, hardness, pH, total alkalinity, total phosphorus, trace elements, arsenic, cadmium, chromium, copper, iron, lead, manganese, mercury, silver, and zinc and biological measures including dissolved oxygen, biochemical oxygen demand, fecal coliform bacteria, and fecal streptococcus bacteria. Sampling was conducted during both low flow (base flow) and high flow. Several water-quality measures including pH, total arsenic, total cadmium, total chromium, total copper, total iron, total lead, total manganese, total mercury, total silver, total zinc, dissolved oxygen, and fecal coliform bacteria at times exceeded North Carolina water-quality standards in various streams. Runoff from non-point sources appears to contribute more to the deterioration of streams in Charlotte and Mecklenburg County than point-source effluents. Urban and industrial areas contribute various trace elements. Residential and rural areas and municipal waste-water treatment plants contribute high amounts of phosphorus.

Tracing the trajectory of skill learning with a very large sample of online game players.

PubMed

Stafford, Tom; Dewar, Michael

2014-02-01

In the present study, we analyzed data from a very large sample (N = 854,064) of players of an online game involving rapid perception, decision making, and motor responding. Use of game data allowed us to connect, for the first time, rich details of training history with measures of performance from participants engaged for a sustained amount of time in effortful practice. We showed that lawful relations exist between practice amount and subsequent performance, and between practice spacing and subsequent performance. Our methodology allowed an in situ confirmation of results long established in the experimental literature on skill acquisition. Additionally, we showed that greater initial variation in performance is linked to higher subsequent performance, a result we link to the exploration/exploitation trade-off from the computational framework of reinforcement learning. We discuss the benefits and opportunities of behavioral data sets with very large sample sizes and suggest that this approach could be particularly fecund for studies of skill acquisition.

Studies on the content of heavy metals in Aries River using ICP-MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voica, Cezara, E-mail: Cezara.Voica@itim-cj.ro; Kovacs, Melinda, E-mail: Cezara.Voica@itim-cj.ro; Feher, Ioana, E-mail: Cezara.Voica@itim-cj.ro

2013-11-13

Among the industrial branches, the mining industry has always been an important source of environmental pollution, both aesthetically and chemically. Through this paper results of ICP-MS characterization of Aries River Basin are reported. Mining activities from this area has resulted in contamination of environment and its surrounding biota. This is clearly evidenced in analyzed water samples, especially from Baia de Aries site where increased amount of trace elements as Cr, Zn, As, Se, Cd, Pb and U were founded. Also in this site greater amount of rare earth elements was evidenced also. Through monitoring of Aries River from other non-miningmore » area it was observed that the quantitative content of heavy metals was below the maximum permissible levels which made us to conclude that the water table wasn't seriously affected (which possibly might be attributed to the cessation of mining activities in this area from a few years ago)« less

Direct analysis of organic priority pollutants by IMS

NASA Technical Reports Server (NTRS)

Giam, C. S.; Reed, G. E.; Holliday, T. L.; Chang, L.; Rhodes, B. J.

1995-01-01

Many routine methods for monitoring of trace amounts of atmospheric organic pollutants consist of several steps. Typical steps are: (1) collection of the air sample; (2) trapping of organics from the sample; (3) extraction of the trapped organics; and (4) identification of the organics in the extract by GC (gas chromatography), HPLC (High Performance Liquid Chromatography), or MS (Mass Spectrometry). These methods are often cumbersome and time consuming. A simple and fast method for monitoring atmospheric organics using an IMS (Ion Mobility Spectrometer) is proposed. This method has a short sampling time and does not require extraction of the organics since the sample is placed directly in the IMS. The purpose of this study was to determine the responses in the IMS to organic 'priority pollutants'. Priority pollutants including representative polycyclic aromatic hydrocarbons (PAHs), phthalates, phenols, chlorinated pesticides, and polychlorinated biphenyls (PCB's) were analyzed in both the positive and negative detection mode at ambient atmospheric pressure. Detection mode and amount detected are presented.

Stability of hydrophilic vitamins mixtures in the presence of electrolytes and trace elements for parenteral nutrition: a nuclear magnetic resonance spectroscopy investigation.

PubMed

Uccello-Barretta, Gloria; Balzano, Federica; Aiello, Federica; Falugiani, Niccolò; Desideri, Ielizza

2015-03-25

In total parenteral nutrition (TPN), especially in the case of preterm infants, simultaneous administration of vitamins and trace elements is still a problematic issue: guidelines put in evidence the lack of specific documentation. In this work NMR spectroscopy was applied to the study of vitamins (pyridoxine hydrochloride, thiamine nitrate, riboflavin-5'-phosphate and nicotinamide) stability in presence of salts and trace elements. Vitamins in D2O were first analyzed by (1)H NMR spectroscopy in absence of salts and trace elements; changes in chemical shifts or in diffusion coefficients, measured by NMR DOSY technique, were analyzed. The effects of salts and trace elements on single vitamins and on their admixtures were then investigated by performing quantitative analyses during 48h. Selected vitamins are subject to intermolecular interactions. No degradative effects were observed in presence of salts and trace elements. Only riboflavin-5'-phosphate is subject to precipitation in presence of divalent cations; however, at low concentration and in presence of other vitamins this effect was not observed. Solutions analyzed, in the condition of this study, are stable for at least 48h and vitamins and trace elements can be administered together in TPN. Copyright © 2014 Elsevier B.V. All rights reserved.

Determination of trace amounts of chemical warfare agent degradation products in decontamination solutions with NMR spectroscopy.

PubMed

Koskela, Harri; Rapinoja, Marja-Leena; Kuitunen, Marja-Leena; Vanninen, Paula

2007-12-01

Decontamination solutions are used for an efficient detoxification of chemical warfare agents (CWAs). As these solutions can be composed of strong alkaline chemicals with hydrolyzing and oxidizing properties, the analysis of CWA degradation products in trace levels from these solutions imposes a challenge for any analytical technique. Here, we present results of application of nuclear magnetic resonance spectroscopy for analysis of trace amounts of CWA degradation products in several untreated decontamination solutions. Degradation products of the nerve agents sarin, soman, and VX were selectively monitored with substantially reduced interference of background signals by 1D 1H-31P heteronuclear single quantum coherence (HSQC) spectrometry. The detection limit of the chemicals was at the low part-per-million level (2-10 microg/mL) in all studied solutions. In addition, the concentration of the degradation products was obtained with sufficient confidence with external standards.

Trace elements content in the selected medicinal plants traditionally used for curing skin diseases by the natives of Mizoram, India.

PubMed

Rajan, Jay Prakash; Singh, Kshetrimayum Birla; Kumar, Sanjiv; Mishra, Raj Kumar

2014-09-01

To determine the trace elements content in the selected medicinal plants, namely, Eryngium foetidum L., Mimosa pudica L., Polygonum plebeium, and Prunus cerasoides D. Don traditionally used by the natives of the Mizoram, one of the north eastern states in India as their folklore medicines for curing skin diseases like eczema, leg and fingers infection, swelling and wound. A 3 MeV proton beam of proton induced X-ray emission technique, one of the most powerful techniques for its quick multi elemental trace analysis capability and high sensitivity was used to detect and characterized for trace elements. The studies revealed that six trace elements, namely, Fe, Zn, Cu, Mn, V, and Co detected in mg/L unit were present in varying concentrations in the selected medicinal plants with high and notable concentration of Fe, Zn, Mn and appreciable amount of the Cu, Co and V in all the plants. The results of the present study support the therapeutic usage of these medicinal plants in the traditional practices for curing skin diseases since they are found to contain appreciable amount of the Fe, Zn, Cu, Mn, V and Co. Copyright © 2014 Hainan Medical College. Published by Elsevier B.V. All rights reserved.

Privacy Vulnerability of Published Anonymous Mobility Traces

DOE PAGES

Ma, Chris Y. T.; Yau, David K. Y.; Yip, Nung Kwan; ...

2013-06-01

Mobility traces of people and vehicles have been collected and published to assist the design and evaluation of mobile networks, such as large-scale urban sensing networks. Although the published traces are often made anonymous in that the true identities of nodes are replaced by random identifiers, the privacy concern remains. This is because in real life, nodes are open to observations in public spaces, or they may voluntarily or inadvertently disclose partial knowledge of their whereabouts. Thus, snapshots of nodes’ location information can be learned by interested third parties, e.g., directly through chance/engineered meetings between the nodes and their observers,more » or indirectly through casual conversations or other information sources about people. In this paper, we investigate how an adversary, when equipped with a small amount of the snapshot information termed as side information, can infer an extended view of the whereabouts of a victim node appearing in an anonymous trace. Our results quantify the loss of victim nodes’ privacy as a function of the nodal mobility, the inference strategies of adversaries, and any noise that may appear in the trace or the side information. Generally, our results indicate that the privacy concern is significant in that a relatively small amount of side information is sufficient for the adversary to infer the true identity (either uniquely or with high probability) of a victim in a set of anonymous traces. For instance, an adversary is able to identify the trace of 30%-50% of the victims when she has collected 10 pieces of side information about a victim.« less

Trace elements in hazardous mineral fibres.

PubMed

Bloise, Andrea; Barca, Donatella; Gualtieri, Alessandro Francesco; Pollastri, Simone; Belluso, Elena

2016-09-01

Both occupational and environmental exposure to asbestos-mineral fibres can be associated with lung diseases. The pathogenic effects are related to the dimension, biopersistence and chemical composition of the fibres. In addition to the major mineral elements, mineral fibres contain trace elements and their content may play a role in fibre toxicity. To shed light on the role of trace elements in asbestos carcinogenesis, knowledge on their concentration in asbestos-mineral fibres is mandatory. It is possible that trace elements play a synergetic factor in the pathogenesis of diseases caused by the inhalation of mineral fibres. In this paper, the concentration levels of trace elements from three chrysotile samples, four amphibole asbestos samples (UICC amosite, UICC anthophyllite, UICC crocidolite and tremolite) and fibrous erionite from Jersey, Nevada (USA) were determined using inductively coupled plasma mass spectrometry (ICP-MS). For all samples, the following trace elements were measured: Li, Be, Sc, V, Cr, Mn, Co, Ni, Cu, Zn, As, Rb, Sr, Y, Sb, Cs, Ba, La, Pb, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Th, U. Their distribution in the various mineral species is thoroughly discussed. The obtained results indicate that the amount of trace metals such as Mn, Cr, Co, Ni, Cu and Zn is higher in anthophyllite and chrysotile samples, whereas the amount of rare earth elements (REE) is higher in erionite and tremolite samples. The results of this work can be useful to the pathologists and biochemists who use asbestos minerals and fibrous erionite in-vitro studies as positive cyto- and geno-toxic standard references. Copyright © 2016 Elsevier Ltd. All rights reserved.

CaSO4 Scale Inhibition by a Trace Amount of Zinc Ion in Piping System

NASA Astrophysics Data System (ADS)

Mangestiyono, W.; Sutrisno

2017-05-01

Usually, a small steam generator is not complemented by equipment such as demineralization and chlorination process apparatus since the economic aspect was a precedence. Such phenomenon was uncovered in a case study of green tea industrial process in which the boiler capacity was not more than 1 ton/hour. The operation of the small boiler affected the scaling process in its piping system. In a year operation, there was already a large scale of calcium attached to the inner surface of the pipe. Such large scale formed a layer and decreased the overall heat transfer coefficient, prolonged the process time and decreased the production. The aim of the current research was to solve the problem through a laboratory research to inhibit the CaSO4 scale formation by the addition of trace amounts of zinc ion. This research was conducted through a built in-house experimental rig which consisted of a dosing pump for controlling the flow rate and a thermocouple to control the temperature. Synthesis solution was prepared with 3,500 ppm concentration of CaCl2 and Na2SO4. The concentration of zinc was set at 0.00; 5.00 and 10.00 ppm. The data found were characterized by scanning electron microscopy (SEM) to analyze crystal polymorph as the influence of zinc ion addition. The induction time was also investigated to analyze the nucleation time, and it was found on the 9th, 13th, and 19th minute of the zinc ion addition of 0.00, 5.00 and 10.00 ppm. After running for a four-hour duration, the scale grow-rate was found to be 5.799; 5.501 and 4.950 × 10-3 gr/min for 0.00; 5.00 and 10.00 ppm of zinc addition at 50 °C.

Sensitive trace enrichment of environmental andiandrogen vinclozolin from natural waters and sediment samples using hollow-fiber liquid-phase microextraction.

PubMed

Lambropoulou, Dimitra A; Albanis, Triantafyllos A

2004-12-17

The presence of vinclozolin in the environment as far as the endocrine disruption effects in biota are concerned has raised interest in the environmental fate of this compound. In this respect, the present study attempts to investigate the feasibility of applying a novel quantitative method, liquid-phase microextraction (LPME), so as to determine this environmental andiandrogen in environmental samples such as water and sediment samples. The technique involved the use of a small amount (3 microL) of organic solvent impregnated in a hollow fiber membrane, which was attached to the needle of a conventional GC syringe. The extracted samples were analyzed by gas chromatography coupled with electron-capture detection. Experimental LPME conditions such as extraction solvent, stirring rate, content of NaCl and pH were tested. Once LPME was optimized, the performance of the proposed technique was evaluated for the determination of vinclozolin in different types of natural water samples. The recovery of spiked water samples was from 80 to 99%. The procedure was adequate for quantification of vinclozolin in waters at levels of 0.010 to 50 microg/L (r> 0.994) with a detection limit of 0.001 microg/L (S/N= 3). Natural sediment samples from the Aliakmonas River area (Macedonia, Greece) spiked with the target andiandrogen compound were liquid-liquid extracted and analyzed by the methodology developed in this work. No significant interferences from the samples matrix were noticed, indicating that the reported methodology is an innovative tactic for sample preparation in sediment analysis, with a considerable improvement in the achieved detection limits. The results demonstrated that apart from analyte enrichment, the proposed LPME procedure also serves as clean-up method and could be successfully performed to determine trace amounts of vinclozolin in water and sediment samples.

Comparison of Decontamination Efficacy of Cleaning Solutions on a Biological Safety Cabinet Workbench Contaminated by Cyclophosphamide

PubMed Central

Adé, Apolline; Chauchat, Laure; Frève, Johann-François Ouellette; Gagné, Sébastien; Caron, Nicolas; Bussières, Jean-François

2017-01-01

Background Several studies have compared cleaning procedures for decontaminating surfaces exposed to antineoplastic drugs. All of the cleaning products tested were successful in reducing most of the antineoplastic drug quantities spilled on surfaces, but none of them completely removed residual traces. Objective To assess the efficacy of various cleaning solutions for decontaminating a biological safety cabinet workbench exposed to a defined amount of cyclophosphamide. Methods In this pilot study, specific areas of 2 biological safety cabinets (class II, type B2) were deliberately contaminated with a defined quantity of cyclophosphamide (10 μg or 107 pg). Three cleaning solutions were tested: quaternary ammonium, sodium hypochlorite 0.02%, and sodium hypochlorite 2%. After cleaning, the cyclophosphamide remaining on the areas was quantified by wipe sampling. Each cleaning solution was tested 3 times, with cleaning and wipe sampling being performed 5 times for each test. Results A total of 57 wipe samples were collected and analyzed. The average recovery efficiency was 121.690% (standard deviation 5.058%). The decontamination efficacy increased with the number of successive cleaning sessions: from 98.710% after session 1 to 99.997% after session 5 for quaternary ammonium; from 97.027% to 99.997% for sodium hypochlorite 0.02%; and from 98.008% to 100% for sodium hypochlorite 2%. Five additional cleaning sessions performed after the main study (with detergent and sodium hypochlorite 2%) were effective to complete the decontamination, leaving no detectable traces of the drug. Conclusions All of the cleaning solutions reduced contamination of biological safety cabinet workbenches exposed to a defined amount of cyclophosphamide. Quaternary ammonium and sodium hypochlorite (0.02% and 2%) had mean efficacy greater than 97% for removal of the initial quantity of the drug (107 pg) after the first cleaning session. When sodium hypochlorite 2% was used, fewer cleaning sessions were required to complete decontamination. Further studies should be conducted to identify optimal cleaning strategies to fully eliminate traces of hazardous drugs. PMID:29298999

BIOLOGICAL MONITORING OF TOXIC TRACE METALS. VOLUME 2. TOXIC TRACE METALS IN PLANTS AND ANIMALS OF THE WORLD. PART II

EPA Science Inventory

The needs and priorities in using biological accumulator organisms for monitoring toxic trace metals in plants and animals are analyzed. The toxic trace metals selected for study are antimony, arsenic, beryllium, boron, cadmium, chromium, cobalt, copper, lead, mercury, nickel, se...

BIOLOGICAL MONITORING OF TOXIC TRACE METALS. VOLUME 2. TOXIC TRACE METALS IN PLANTS AND ANIMALS OF THE WORLD. PART I

EPA Science Inventory

The needs and priorities in using biological accumulator organisms for monitoring toxic trace metals in plants and animals are analyzed. The toxic trace metals selected for study are antimony, arsenic, beryllium, boron, cadmium, chromium, cobalt, copper, lead, mercury, nickel, se...

Convective-diffusion-based fluorescence correlation spectroscopy for detection of a trace amount of E. coli in water.

PubMed

Qing, De-Kui; Mengüç, M Pinar; Payne, Fred A; Danao, Mary-Grace C

2003-06-01

Fluorescence correlation spectroscopy (FCS) is adapted for a new procedure to detect trace amounts of Escherichia coli in water. The present concept is based on convective diffusion rather than Brownian diffusion and employs confocal microscopy as in traditional FCS. With this system it is possible to detect concentrations as small as 1.5 x 10(5) E. coli per milliliter (2.5 x 10(-16) M). This concentration corresponds to an approximately 1.0-nM level of Rhodamine 6G dyes. A detailed analysis of the optical system is presented, and further improvements for the procedure are discussed.

Cause and Effects of Fluorocarbon Degradation in Electronics and Opto-Electronic Systems

NASA Technical Reports Server (NTRS)

Predmore, Roamer E.; Canham, John S.

2002-01-01

Trace degradation of fluorocarbon or halocarbon materials must be addressed in their application in sensitive systems. As the dimensions and/or tolerances of components in a system decrease, the sensitivity of the system to trace fluorocarbon or halocarbon degradation products increases. Trace quantities of highly reactive degradation products from fluorocarbons have caused a number of failures of flight hardware. It is of utmost importance that the risk of system failure, resulting from trace amounts of reactive fluorocarbon degradation products be addressed in designs containing fluorocarbon or halocarbon materials. Thermal, electrical, and mechanical energy input into the system can multiply the risk of failure.

Selective and sensitized spectrophotometric determination of trace amounts of Ni(II) ion using α-benzyl dioxime in surfactant media

NASA Astrophysics Data System (ADS)

Ghaedi, Mehrorang

2007-02-01

Highly sensitive and interference-free sensitized spectrophotometric method for the determination of Ni(II) ions is described. The method is based on the reaction between Ni(II) ion and benzyl dioxime in micellar media in the presence of sodium dodecyl sulfate (SDS). The absorbance is linear from 0.1 up to 25.0 μg mL -1 in aqueous solution with repeatability (RSD) of 1.0% at a concentration of 1 μg mL -1 and a detection limit of 0.12 ng mL -1 and molar absorption coefficient of 68,600 L mol -1 cm -1. The influence of reaction variables including type and amount of surfactant, pH, and amount of ligand and complexation time and the effect of interfering ions are investigated. The proposed procedure was applied to the determination of trace amounts of Ni(II) ion in tap water, river water, chocolate and vegetable without separation or organic solvent extraction.

Does Time-on-Task Estimation Matter? Implications for the Validity of Learning Analytics Findings

ERIC Educational Resources Information Center

Kovanovic, Vitomir; Gaševic, Dragan; Dawson, Shane; Joksimovic, Srecko; Baker, Ryan S.; Hatala, Marek

2015-01-01

With\twidespread adoption of Learning Management Systems (LMS) and other learning technology, large amounts of data--commonly known as trace data--are readily accessible to researchers. Trace data has been extensively used to calculate time that students spend on different learning activities--typically referred to as time-on-task. These measures…

Identification of water-quality trends using sediment cores from Dillon Reservoir, Summit County, Colorado

USGS Publications Warehouse

Greve, Adrienne I.; Spahr, Norman E.; Van Metre, Peter C.; Wilson, Jennifer T.

2001-01-01

Since the construction of Dillon Reservoir, in Summit County, Colorado, in 1963, its drainage area has been the site of rapid urban development and the continued influence of historical mining. In an effort to assess changes in water quality within the drainage area, sediment cores were collected from Dillon Reservoir in 1997. The sediment cores were analyzed for pesticides, polychlorinated biphenyls (PCBs), polycyclic aromatic hydrocarbons (PAHs), and trace elements. Pesticides, PCBs, and PAHs were used to determine the effects of urban development, and trace elements were used to identify mining contributions. Water-quality and streambed-sediment samples, collected at the mouth of three streams that drain into Dillon Reservoir, were analyzed for trace elements. Of the 14 pesticides and 3 PCBs for which the sediment samples were analyzed, only 2 pesticides were detected. Low amounts of dichloro-diphenyldichloroethylene (DDE) and dichloro-diphenyldichloroethane (DDD), metabolites of dichlorodiphenyltrichloroethane (DDT), were found at core depths of 5 centimeters and below 15 centimeters in a core collected near the dam. The longest core, which was collected near the dam, spanned the entire sedimentation history of the reservoir. Concentrations of total combustion PAH and the ratio of fluoranthene to pyrene in the core sample decreased with core depth and increased over time. This relation is likely due to growth in residential and tourist populations in the region. Comparisons between core samples gathered in each arm of the reservoir showed the highest PAH concentrations were found in the Tenmile Creek arm, the only arm that has an urban area on its shores, the town of Frisco. All PAH concentrations, except the pyrene concentration in one segment in the core near the dam and acenaphthylene concentrations in the tops of three cores taken in the reservoir arms, were below Canadian interim freshwater sediment-quality guidelines. Concentrations of arsenic, cadmium, chromium, copper, lead, and zinc in sediment samples from Dillon Reservoir exceeded the Canadian interim freshwater sediment-quality guidelines. Copper, iron, lithium, nickel, scandium, titanium, and vanadium concentrations in sediment samples decreased over time. Other elements, while no trend was evident, displayed concentration spikes in the down-core profiles, indicating loads entering the reservoir may have been larger than they were in 1997. The highest concentrations of copper, lead, manganese, mercury, and zinc were detected during the late 1970's and early 1980's. Elevated concentrations of trace elements in sediment in Dillon Reservoir likely resulted from historical mining in the drainage area. The downward trend identified for copper, iron, lithium, nickel, scandium, titanium, and vanadium may be due in part to restoration efforts in mining-affected areas and a decrease in active mining in the Dillon Reservoir watershed. Although many trace-element core-sediment concentrations exceeded the Canadian probable effect level for freshwater lakes, under current limnological conditions, the high core-sediment concentrations do not adversely affect water quality in Dillon Reservoir. The trace-element concentrations in the reservoir water column meet the standards established by the Colorado Water Quality Control Commission. Although many trace-element core-sediment concentrations exceeded the Canadian probable effect level for freshwater lakes, under current limnological conditions, the high core-sediment concentrations do not adversely affect water quality in Dillon Reservoir. The trace-element concentrations in the reservoir water column meet the standards established by the Colorado Water Quality Control Commission.

Application of SERS spectroscopy for detection of trace components in urinary deposits

NASA Astrophysics Data System (ADS)

Pucetaite, Milda; Velicka, Martynas; Tamosaityte, Sandra; Sablinskas, Valdas

2014-03-01

Surface-enhanced Raman scattering (SERS) spectroscopy can be a useful tool in regard to disease diagnosis and prevention. Advantage of SERS over conventional Raman spectroscopy is its significantly increased signal (up to factor of 106-108) which allows detection of trace amounts of substances in the sample. So far, this technique is successfully used for analysis of food, pieces of art and various biochemical/biomedical samples. In this work, we survey the possibility of applying SERS spectroscopy for detection of trace components in urinary deposits. Early discovery together with the identification of the exact chemical composition of urinary sediments could be crucial for taking appropriate preventive measures that inhibit kidney stone formation or growth processes. In this initial study, SERS spectra (excitation wavelength - 1064 nm) of main components of urinary deposits (calcium oxalate, uric acid, cystine, etc.) were recorded by using silver (Ag) colloid. Spectra of 10-3-10-5 M solutions were obtained. While no/small Raman signal was detected without the Ag colloid, characteristic peaks of the substances could be clearly separated in the SERS spectra. This suggests that even small amounts of the components could be detected and taken into account while determining the type of kidney stone forming in the urinary system. We found for the first time that trace amounts of components constituting urinary deposits could be detected by SERS spectroscopy. In the future study, the analysis of centrifuged urine samples will be carried out.

[Determination of Alternaria mycotoxins in selected raw and processed fruit and vegetable products].

PubMed

Giryn, H; Szteke, B

1995-01-01

The purpose of the study was the assessment of Alternaria-mycotoxins contamination in some raw and processed plant products. The analytical method for detection of alternariol (AOH) and alternariol methyl ether (AME) is described. After extraction and purification of sample crude extracts by column chromatography on silica gel, the qualitative and quantitative analyses were carried out by two-dimensional TLC. There were 110 samples analyzed -44 (included 32 moulded) raw plant samples and 56 processed plant products. Levels of alternaria-mycotoxins found in fruits and tomatoes visibly decayed ranged between 3 to 420 micrograms/kg for AOH and 10 to 100 micrograms/kg for AME. Trace amounts of AOH were detected in 3 samples of processed products.

Chemical characterization of seven Large Area Collector particles by SXRF. [cosmic dust composition

NASA Technical Reports Server (NTRS)

Flynn, G. J.; Sutton, S. R.

1991-01-01

Optical microscopy and synchrotron X-ray fluorescence (SXRF) are used to analyze the chemical composition of seven dark-appearing cosmic-dust particles obtained in the stratosphere during NASA Johnson Large Area Collector flights. The experimental setup and procedures are outlined, and the results are presented in extensive tables. Three of the particles had abundances similar to those of chondrites (except for low Ca values in one particle); two had a metallic appearance and spectra dominated by Fe and Zn; one contained Cu and Cr plus small amounts of Fe and Zn; and one had igneous-type abundances of minor and trace elements while containing all of the elements seen in chondritic particles, suggesting it may be of extraterrestrial origin.

Proton-transfer-reaction/ion-mobility-spectrometer and method of using the same

NASA Technical Reports Server (NTRS)

Kanik, Isik (Inventor); Beegle, Luther W. (Inventor)

2004-01-01

A high-pressure hollow cathode ionizer is combined with an ion-mobility-spectrometer (IMS) for the detection of trace amounts of organic compounds in gas. The ionizer uses H.sub.3 0.sup.+, ions which do not react with air to ionize the organic compounds and the organic compounds are soft ionized. The ionized organic compounds are detected in the IMS at levels of parts per billion and identified using calibrated reference tables. Applications include but are not limited to the fields of: (1) medicine as a breath analyzer for detection of lung cancer, diabetes, liver cirrhosis, (2) law enforcement in drug interdiction and explosives detection, (3) food monitoring and control, (4) environmental monitoring and (5) space applications.

Method for removing trace pollutants from aqueous solutions

DOEpatents

Silver, Gary L.

1986-01-01

A method of substantially removing a trace metallic contaminant from a liquid containing the same comprises, adding an oxidizing agent to a liquid containing a trace amount of a metallic contaminant of a concentration of up to about 10.sup.-1 ppm, the oxidizing agent being one which oxidizes the contaminant to form an oxidized product which is insoluble in the liquid and precipitates therefrom, and the conditions of the addition being selected to ensure that the precipitation of the oxidized product is homogeneous, and separating the homogeneously precipitated product from the liquid.

Parallel program debugging with flowback analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Choi, Jongdeok.

1989-01-01

This thesis describes the design and implementation of an integrated debugging system for parallel programs running on shared memory multi-processors. The goal of the debugging system is to present to the programmer a graphical view of the dynamic program dependences while keeping the execution-time overhead low. The author first describes the use of flowback analysis to provide information on causal relationship between events in a programs' execution without re-executing the program for debugging. Execution time overhead is kept low by recording only a small amount of trace during a program's execution. He uses semantic analysis and a technique called incrementalmore » tracing to keep the time and space overhead low. As part of the semantic analysis, he uses a static program dependence graph structure that reduces the amount of work done at compile time and takes advantage of the dynamic information produced during execution time. The cornerstone of the incremental tracing concept is to generate a coarse trace during execution and fill incrementally, during the interactive portion of the debugging session, the gap between the information gathered in the coarse trace and the information needed to do the flowback analysis using the coarse trace. Then, he describes how to extend the flowback analysis to parallel programs. The flowback analysis can span process boundaries; i.e., the most recent modification to a shared variable might be traced to a different process than the one that contains the current reference. The static and dynamic program dependence graphs of the individual processes are tied together with synchronization and data dependence information to form complete graphs that represent the entire program.« less

Trace-fiber color discrimination by electrospray ionization mass spectrometry: a tool for the analysis of dyes extracted from submillimeter nylon fibers.

PubMed

Tuinman, Albert A; Lewis, Linda A; Lewis, Samuel A

2003-06-01

The application of electrospray ionization mass spectrometry (ESI-MS) to trace-fiber color analysis is explored using acidic dyes commonly employed to color nylon-based fibers, as well as extracts from dyed nylon fibers. Qualitative information about constituent dyes and quantitative information about the relative amounts of those dyes present on a single fiber become readily available using this technique. Sample requirements for establishing the color identity of different samples (i.e., comparative trace-fiber analysis) are shown to be submillimeter. Absolute verification of dye mixture identity (beyond the comparison of molecular weights derived from ESI-MS) can be obtained by expanding the technique to include tandem mass spectrometry (ESI-MS/MS). For dyes of unknown origin, the ESI-MS/MS analyses may offer insights into the chemical structure of the compound-information not available from chromatographic techniques alone. This research demonstrates that ESI-MS is viable as a sensitive technique for distinguishing dye constituents extracted from a minute amount of trace-fiber evidence. A protocol is suggested to establish/refute the proposition that two fibers--one of which is available in minute quantity only--are of the same origin.

A Forensic Experiment: The Case of the Crime at the Cinema

ERIC Educational Resources Information Center

Valente Nabais, J. M.; Costa, Sara D.

2017-01-01

This paper reports an experimental activity where students have to carefully analyze the evidence collected at the crime scene, namely fibers and lipstick traces. The fibers are analyzed by infrared spectroscopy, solubility tests, and optical microscopy, while in turn the lipstick traces are investigated by thin layer chromatography. Students also…

Automatic Whistler Detector and Analyzer system: Implementation of the analyzer algorithm

NASA Astrophysics Data System (ADS)

Lichtenberger, JáNos; Ferencz, Csaba; Hamar, Daniel; Steinbach, Peter; Rodger, Craig J.; Clilverd, Mark A.; Collier, Andrew B.

2010-12-01

The full potential of whistlers for monitoring plasmaspheric electron density variations has not yet been realized. The primary reason is the vast human effort required for the analysis of whistler traces. Recently, the first part of a complete whistler analysis procedure was successfully automated, i.e., the automatic detection of whistler traces from the raw broadband VLF signal was achieved. This study describes a new algorithm developed to determine plasmaspheric electron density measurements from whistler traces, based on a Virtual (Whistler) Trace Transformation, using a 2-D fast Fourier transform transformation. This algorithm can be automated and can thus form the final step to complete an Automatic Whistler Detector and Analyzer (AWDA) system. In this second AWDA paper, the practical implementation of the Automatic Whistler Analyzer (AWA) algorithm is discussed and a feasible solution is presented. The practical implementation of the algorithm is able to track the variations of plasmasphere in quasi real time on a PC cluster with 100 CPU cores. The electron densities obtained by the AWA method can be used in investigations such as plasmasphere dynamics, ionosphere-plasmasphere coupling, or in space weather models.

A simplified soil extraction sequence to monitor the main and trace element speciation in soil after compost and mineral fertilizer additions upon the composition of wheat grains

NASA Astrophysics Data System (ADS)

Sager, Manfred; Erhart, Eva

2016-04-01

High quality biological waste treatment aims at producing compost in order to maintain a clean environment and to sustain soil organic carbon levels. Fertilization with compost as a source of organic carbon, nutrients, and accessory elements, as well as fertilization with mineral N- and PK fertilizer have been tested in a field experiment on a calcaric Fluvisol in the Danube wetlands, at 4 levels each. Yields of wheat were recorded, and grains and soils were sampled from each treatment, and analyzed for main and trace element composition. The corresponding soils were characterized by mobile phases, obtained by leaching with 0,16M acetic acid to cover exchangeables plus carbonates, and subsequently by 0,1M oxalate buffer pH 3 to dissolve the pedogenic oxides. Total amounts were obtained from digests with perchloric- nitric-hydrofluoric acid. For quasi-total amounts, aqua regia was replaced by pressure decomposition with KClO3 in dilute nitric acid. The proposed extraction sequence permits to analyze and interpret soil for main elements, trace elements, nutrients and anions simultaneously. Factor analyses of soil extracts obtained from dilute acetic acid revealed Ba-Be-Cd-Cu-Li-S (traces), Ca-Mg-Mn (main carbonates), Al-Fe-B, Y, and P-K (nutrients) as chemically feasible principal components. Subsequent soil extracts from oxalate contained Al-B-Co-K-Na-Pb-Si-V-S (maybe acid silicate weathering), Cr-Li-Ni-Sr-Ti (maybe basic silicate weathering), Be-Cu-Fe-P, Co-Mg-Mn-Zn (Mn-oxides) and Ba-Sc as principal components. Factor analyses of total element data distinguished the principal components Ce-La-Li-Sc-Y-P (rare earths), Al-Ca-Fe-K-Mg-Na-P (main elements), Cd-Co-Cr-Cu-Ni-Zn (trace elements), As-Pb (contaminants), Ba-Mn-Sr, and Ti, which looks chemically feasible also. Factor analyses of those soil fractions which presumably form the main fractions of exchangeables, carbonates, pedogenic oxides and silicates, showed no cross connections, except for P. Oxalate-soluble Fe together with P and S was independent from oxalate-soluble Al-Mn-Si. In the crops, all element levels were within a non-contaminated and non-deficient range, therefore correlations with concentrations as well as loads in the wheat grains where largely not pronounced. Maximum correlations between plant and soil data were obtained with Li and Be. The load data (concentration times yield, given in g/ha) were much more intercorrelated than the concentrations. Regarding the same element, correlation coefficients between loads and respective concentrations were larger than 0,800 for Al, Ba, Cd, Co, Cr, Li, Mo, Na, Ni, Se, and Sr, which means the transfer remained independent from the load. In case of Ca, Mg, P, S, Zn, however, correlation coefficients between loads and concentrations were < 0,500, thus the transfer was not constant because of obvious metabolic influences. The proposed method of soil characterization was applied at a field trial here for the first time, and offers new possibilities of intercorrelations between plant uptake and geochemical soil fractions.

Microgravimetric Analysis Method for Activation-Energy Extraction from Trace-Amount Molecule Adsorption.

PubMed

Xu, Pengcheng; Yu, Haitao; Li, Xinxin

2016-05-03

Activation-energy (Ea) value for trace-amount adsorption of gas molecules on material is rapidly and inexpensively obtained, for the first time, from a microgravimetric analysis experiment. With the material loaded, a resonant microcantilever is used to record in real time the adsorption process at two temperatures. The kinetic parameter Ea is thereby extracted by solving the Arrhenius equation. As an example, two CO2 capture nanomaterials are examined by the Ea extracting method for evaluation/optimization and, thereby, demonstrating the applicability of the microgravimetric analysis method. The achievement helps to solve the absence in rapid quantitative characterization of sorption kinetics and opens a new route to investigate molecule adsorption processes and materials.

Artificial Neural Network as the FPGA Trigger in the Cyclone V based Front-End for a Detection of Neutrino-Origin Showers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szadkowski, Zbigniew; Glas, Dariusz; Pytel, Krzysztof

Neutrinos play a fundamental role in the understanding of the origin of ultra-high-energy cosmic rays. They interact through charged and neutral currents in the atmosphere generating extensive air showers. However, their a very low rate of events potentially generated by neutrinos is a significant challenge for a detection technique and requires both sophisticated algorithms and high-resolution hardware. A trigger based on a artificial neural network was implemented into the Cyclone{sup R} V E FPGA 5CEFA9F31I7 - the heart of the prototype Front-End boards developed for tests of new algorithms in the Pierre Auger surface detectors. Showers for muon and taumore » neutrino initiating particles on various altitudes, angles and energies were simulated in CORSICA and Offline platforms giving pattern of ADC traces in Auger water Cherenkov detectors. The 3-layer 12-8-1 neural network was taught in MATLAB by simulated ADC traces according the Levenberg-Marquardt algorithm. Results show that a probability of a ADC traces generation is very low due to a small neutrino cross-section. Nevertheless, ADC traces, if occur, for 1-10 EeV showers are relatively short and can be analyzed by 16-point input algorithm. We optimized the coefficients from MATLAB to get a maximal range of potentially registered events and for fixed-point FPGA processing to minimize calculation errors. New sophisticated triggers implemented in Cyclone{sup R} V E FPGAs with large amount of DSP blocks, embedded memory running with 120 - 160 MHz sampling may support a discovery of neutrino events in the Pierre Auger Observatory. (authors)« less

Preparation of styrene-co-4-vinylpyridine magnetic polymer beads by microwave irradiation for analysis of trace 24-epibrassinolide in plant samples using high performance liquid chromatography.

PubMed

Zhang, Zhuomin; Zhang, Yi; Tan, Wei; Li, Gongke; Hu, Yuling

2010-10-15

In the study, a kind of novel styrene-co-4-vinylpyridine (St-co-4-VP) porous magnetic polymer beads was prepared by microwave irradiation using suspension polymerization. Microwave heating preparation greatly reduced the polymerization time to 1h. Physical characteristic tests suggested that these beads were cross-linking and possessed spherical shape, good magnetic response and porous morphologies with a narrow diameter distribution of 70-180 μm. Therefore, these beads displayed the long-term stability after undergoing 100-time extractions. Then, an analytical method for the determination of trace 24-epiBR in plant samples was developed by magnetic polymer bead extraction coupled with high performance liquid chromatography-fluorescence detection. St-co-4-VP magnetic polymer beads demonstrated the higher extraction selectivity for 24-epiBR than other reference compounds. Linear range was 10.00-100.0 μg/L with a relative standard deviation (RSD) of 6.7%, and the detection limit was 6.5 μg/kg. This analytical method was successfully applied to analyze the trace 24-epiBR in cole and breaking-wall rape pollen samples with recoveries of 77.2-90.0% and 72.3-83.4%, respectively, and RSDs were less than 4.1%. The amount of 24-epiBR in real breaking-wall rape pollen samples was found to be 26.2 μg/kg finally. This work proposed a sensitive, rapid, reliable and convenient analytical method for the determination of trace brassinosteroids in complicated plant samples by the use of St-co-4-VP magnetic polymer bead extraction coupled with chromatographic method. Copyright © 2010 Elsevier B.V. All rights reserved.

Reactivation of the chloroplast CF1-ATPase beta subunit by trace amounts of the CF1 alpha subunit suggests a chaperonin-like activity for CF1 alpha.

PubMed

Avni, A; Avital, S; Gromet-Elhanan, Z

1991-04-25

Incubation of tobacco and lettuce thylakoids with 2 M LiCl in the presence of MgATP removes the beta subunit from their CF1-ATPase (CF1 beta) together with varying amounts of the CF1 alpha subunit (CF1 alpha). These 2 M LiCl extracts, as with the one obtained from spinach thylakoids (Avital, S., and Gromet-Elhanan, Z. (1991) J. Biol. Chem. 266, 7067-7072), could form active hybrid ATPases when reconstituted into inactive beta-less Rhodospirillum rubrum chromatophores. Pure CF1 beta fractions that have been isolated from these extracts could not form such active hybrids by themselves, but could do so when supplemented with trace amounts (less than 5%) of CF1 alpha. A mitochondrial F1-ATPase alpha subunit was recently reported to be a heat-shock protein, having two amino acid sequences that show a highly conserved identity with sequences found in molecular chaperones (Luis, A. M., Alconada, A., and Cuezva, J. M. (1990) J. Biol. Chem. 265, 7713-7716). These sequences are also conserved in CF1 alpha isolated from various plants, but not in F1 beta subunits. The above described reactivation of CF1 beta by trace amounts of CF1 alpha could thus be due to a chaperonin-like function of CF1 alpha, which involves the correct, active folding of isolated pure CF1 beta.

Scalable Performance Measurement and Analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gamblin, Todd

2009-01-01

Concurrency levels in large-scale, distributed-memory supercomputers are rising exponentially. Modern machines may contain 100,000 or more microprocessor cores, and the largest of these, IBM's Blue Gene/L, contains over 200,000 cores. Future systems are expected to support millions of concurrent tasks. In this dissertation, we focus on efficient techniques for measuring and analyzing the performance of applications running on very large parallel machines. Tuning the performance of large-scale applications can be a subtle and time-consuming task because application developers must measure and interpret data from many independent processes. While the volume of the raw data scales linearly with the number ofmore » tasks in the running system, the number of tasks is growing exponentially, and data for even small systems quickly becomes unmanageable. Transporting performance data from so many processes over a network can perturb application performance and make measurements inaccurate, and storing such data would require a prohibitive amount of space. Moreover, even if it were stored, analyzing the data would be extremely time-consuming. In this dissertation, we present novel methods for reducing performance data volume. The first draws on multi-scale wavelet techniques from signal processing to compress systemwide, time-varying load-balance data. The second uses statistical sampling to select a small subset of running processes to generate low-volume traces. A third approach combines sampling and wavelet compression to stratify performance data adaptively at run-time and to reduce further the cost of sampled tracing. We have integrated these approaches into Libra, a toolset for scalable load-balance analysis. We present Libra and show how it can be used to analyze data from large scientific applications scalably.« less

Determination of macro and trace elements in multivitamin dietary supplements by high-resolution continuum source graphite furnace atomic absorption spectrometry with slurry sampling.

PubMed

Krawczyk, Magdalena

2014-01-01

In this research, three different commercially available multivitamin dietary supplements were analyzed by high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GFAAS) with slurry sampling. The concentrations of Cr, Cu, Fe, Mn, and Se were determined and compared to the amounts stated by producers. The safety of multivitamin dietary supplements depends on various factors including the manufacturing process and the purity and origins of the raw ingredients. For this reason, this research determined concentrations of several toxic elements (As, Cd, and Pb). Microwave-assisted high pressure Teflon bomb digestion was used to determine total amounts of elements in samples. Samples were prepared as slurries at a concentration of 0.1% (m/v) for macro elements (Cr, Cu, Fe, Mn, and Se) and at a concentration of % (m/v) for trace elements (As, Cd, and Pb) in acidic media (3M HNO3). The influence of acid concentration, Triton X-100 addition, sonication time, and sonication power on absorbance was investigated. The accuracy of this method was validated by analyses of NRCC LUTS-1 (Lobster hepatopancreas), NRCC DORM-1 (Dogfish Muscle), NRCC DOLT-2 (Dogfish Liver), NBS SRM 1570 (Spinach Leaves) and NBS SRM 1573 (Tomato Leaves) certified reference materials. The measured elements contents in these reference materials (except NRCC DOLT-2) were in satisfactory agreement with the certified values according to the t-test for a 95% confidence level. Copyright © 2013 Elsevier B.V. All rights reserved.

Separation of bismuth from gram amounts of thallium and silver by cation-exchange chromatography in nitric acid.

PubMed

Meintjies, E; Strelow, F W; Victor, A H

1987-04-01

Traces and small amounts of bismuth can be separated from gram amounts of thallium and silver by successively eluting these elements with 0.3M and 0.6M nitric acid from a column containing 13 ml (3 g) of AG50W-X4, a cation-exchanger (100-200 mesh particle size) with low cross-linking. Bismuth is retained and can be eluted with 0.2M hydrobromic acid containing 20% v/v acetone, leaving many other trace elements absorbed. Elution of thallium is quite sharp, but silver shows a small amount of tailing (less than 1 gmg/ml silver in the eluate) when gram amounts are present, between 20 and 80 mug of silver appearing in the bismuth fraction. Relevant elution curves and results for the analysis of synthetic mixtures containing between 50 mug and 10 mg of bismuth and up to more than 1 g of thallium and silver are presented, as well as results for bismuth in a sample of thallium metal and in Merck thallium(I) carbonate. As little as 0.01 ppm of bismuth can be determined when the separation is combined with electrothermal atomic-absorption spectrometry.

Isotope-Labeled Composition B for Tracing Detonation Signatures

NASA Astrophysics Data System (ADS)

Manner, Virginia; Podlesak, David; Huber, Rachel; Amato, Ronald; Giambra, Anna; Bowden, Patrick; Hartline, Ernest; Dattelbaum, Dana

2017-06-01

To better understand how solid carbon forms and evolves during detonation, we have prepared Composition B with 13 C and 15 N-labeled 1,3,5-trinitro-1,3,5-triazacyclohexane (RDX) and 2,4,6-trinitrotoluene (TNT) in order to trace the formation of soot from the carbon and nitrogen atoms in these explosives. Isotope-labeling of explosives has been performed in the recent past for a variety of reasons, including environmental remediation and reaction mechanism studies. Because it is expensive and time consuming to prepare these materials, and our detection equipment only requires trace amounts of isotopes, we have prepared fully-labeled materials and substituted them into unlabeled RDX and TNT at less than the 1% level. We will discuss the preparation and full characterization of this labeled Composition B, the detonation tests performed, along with the results of the post-detonation soot analysis. Various detonation models predict differing amounts and forms of carbon and nitrogen; these isotopically-labeled precursors have allowed these models to be tested.

Ten Thousand Years of Environment Assessment Using Synchrotron Radiation Micro Beam

NASA Astrophysics Data System (ADS)

Shirasawa, K.; Ide-Ektessabi, A.; Koizumi, A.; Azechi, M.

2003-08-01

The environment surrounding human has changed through civilization and industrialization, and through these developments, problems including the pollution from heavy metals such as lead and mercury have arisen. In this study, we analyzed major and trace elements in modern and prehistoric teeth by x-ray fluorescence (XRF) analysis using synchrotron radiation micro beam, in order to assess the changes of the environment through the civilization and the industrialization and their affects to the human. It is suggested that teeth accumulate elements in the mineral phase, hydroxiapatite, during their formation, and because there are no significant turnovers, teeth are concerned to be indicators of the environment of the donor. We first analyzed the elements on the surface of tooth from modern individual and tooth from human remains of Jomon period to assess the heavy metal concentration and effect of the diagenesis. The adhering ground elements on the prehistoric teeth showed high amount of Ti, Fe, Mn and other metallic elements.

The extraction of negative carbon ions from a volume cusp ion source

NASA Astrophysics Data System (ADS)

Melanson, Stephane; Dehnel, Morgan; Potkins, Dave; McDonald, Hamish; Hollinger, Craig; Theroux, Joseph; Martin, Jeff; Stewart, Thomas; Jackle, Philip; Philpott, Chris; Jones, Tobin; Kalvas, Taneli; Tarvainen, Olli

2017-08-01

Acetylene and carbon dioxide gases are used in a filament-powered volume-cusp ion source to produce negative carbon ions for the purpose of carbon implantation for gettering applications. The beam was extracted to an energy of 25 keV and the composition was analyzed with a spectrometer system consisting of a 90° dipole magnet and a pair of slits. It is found that acetylene produces mostly C2- ions (up to 92 µA), while carbon dioxide produces mostly O- with only trace amounts of C-. Maximum C2- current was achieved with 400 W of arc power and, the beam current and composition were found to be highly dependent on the pressure in the source. The beam properties as a function of source settings are analyzed, and plasma properties are measured with a Langmuir probe. Finally, we describe testing of a new RF H- ion source, found to produce more than 6 mA of CW H- beam.

Capillary zone electrophoresis-tandem mass spectrometry detects low concentration host cell impurities in monoclonal antibodies

PubMed Central

Zhu, Guijie; Sun, Liangliang; Heidbrink-Thompson, Jennifer; Kuntumalla, Srilatha; Lin, Hung-yu; Larkin, Christopher J.; McGivney, James B.; Dovichi, Norman J.

2016-01-01

We have evaluated capillary zone electrophoresis-electrospray ionization-tandem mass spectrometry (CZE-ESI-MS/MS) for detection of trace amounts of host cell protein impurities in recombinant therapeutics. Compared to previously published procedures, we have optimized the buffer pH used in the formation of a pH junction to increase injection volume. We also prepared a five-point calibration curve by spiking twelve standard proteins into a solution of a human monoclonal antibody. A custom CZE-MS/MS system was used to analyze the tryptic digest of this mixture without depletion of the antibody. CZE generated a ~70 min separation window (~90 min total analysis duration) and ~300 peak capacity. We also analyzed the sample using ultra-performance liquid chromatography (UPLC)-MS/MS. CZE-MS/MS generated ~five times higher base peak intensity and more peptide identifications for low-level spiked proteins. Both methods detected all proteins spiked at the ~100 ppm level with respect to the antibody. PMID:26530276

A novel technology for the detection, enrichment, and separation of trace amounts of target DNA based on amino-modified fluorescent magnetic composite nanoparticles.

PubMed

Wang, Guannan; Su, Xingguang

2010-06-01

A novel, highly sensitive technology for the detection, enrichment, and separation of trace amounts of target DNA was developed on the basis of amino-modified fluorescent magnetic composite nanoparticles (AFMN). In this study, the positively charged amino-modified composite nanoparticles conjugate with the negatively charged capture DNA through electrostatic binding. The optimal combination of AFMN and capture DNA was measured by dynamic light scattering (DLS) and UV-vis absorption spectroscopy. The highly sensitive detection of trace amounts of target DNA was achieved through enrichment by means of AFMN. The detection limit for target DNA is 0.4 pM, which could be further improved by using a more powerful magnet. Because of their different melting temperatures, single-base mismatched target DNA could be separated from perfectly complementary target DNA. In addition, the photoluminescence (PL) signals of perfectly complementary target DNA and single-base mismatched DNA as well as the hybridization kinetics of different concentrations of target DNA at different reaction times have also been studied. Most importantly, the detection, enrichment, and separation ability of AFMN was further verified with milk. Simple and satisfactory results were obtained, which show the great potential in the fields of mutation identification and clinical diagnosis.

"Dilute & shoot" approach for rapid determination of trace amounts of nicotine in zero-level e-liquids by reversed phase liquid chromatography and hydrophilic interactions liquid chromatography coupled with tandem mass spectrometry-electrospray ionization.

PubMed

Kubica, Paweł; Kot-Wasik, Agata; Wasik, Andrzej; Namieśnik, Jacek

2013-05-10

Two analytical procedures are proposed where HILIC and RPLC techniques are coupled with tandem mass spectrometry detection for rapid determination of trace amounts of nicotine in zero-level liquids for electronic cigarettes. Samples are prepared on the basis of the approach "dilute & shoot" which makes this important step quick and not complicated. The chromatographic separation was carried out on a Zorbax XDB column (RPLC method) and Ascentis Si column (HILIC mode). Within-run precisions (CVs) measured at three concentration levels were as follows: 0.73%, 0.98% and 1.44% for RPLC method and 1.39%, 1.44% and 0.57% (HILIC mode). Between-run CVs were as follows: 1.94%, 1.02% and 1.22% for RPLC mode and 1.49%, 1.20% and 1.22% for HILIC mode. The detection limits of RPLC and HILIC modes were 4.08 and 3.90 ng/mL respectively. The proposed procedures are rapid, not complicated, sensitive and are suitable for fast determination of trace amounts of nicotine in zero-level liquids for electronic cigarettes. Copyright © 2013 Elsevier B.V. All rights reserved.

Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems

PubMed Central

2018-01-01

Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P < 0.05. Polymers identified in field samples in order of abundance were; PVC (39), LDPE (28), PS (18), polyethylene (PE, 9), PP (8), nylon (8), high density polyethylene (HDPE, 7), polycarbonate (PC, 6), PET (6), polyurethane (PUR, 3) and polyoxymethylene (POM, 2). PVC and LDPE accounted for 46% of all samples. Field samples of PVC, HDPE and LDPE had significantly greater amounts of acid extracted copper and HDPE, LDPE and PUR significantly greater amounts of acid extracted zinc. PVC and LDPE had significantly greater amounts of acid extracted cadmium and PVC tended to have greater levels of acid extracted lead, significantly so for HDPE. Five of the collected items demonstrated extreme levels of acid extracted metal; greatest concentrations were 188, 6667, 698,000 and 930 μgg-1 of copper, zinc, lead and cadmium respectively recovered from an unidentified object comprised of PVC. Comparison of recently manufactured versus field samples indicated that recently manufactured samples had significantly greater amounts of acid extracted cadmium and zinc and field samples significantly greater amounts of acid extracted copper and lead which was primarily attributed to metal extracted from field samples of PVC. Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the “inherent” load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals. PMID:29444103

Macro and micro plastics sorb and desorb metals and act as a point source of trace metals to coastal ecosystems.

PubMed

Munier, B; Bendell, L I

2018-01-01

Nine urban intertidal regions in Burrard Inlet, Vancouver, British Columbia, Canada, were sampled for plastic debris. Debris included macro and micro plastics and originated from a wide diversity of uses ranging from personal hygiene to solar cells. Debris was characterized for its polymer through standard physiochemical characteristics, then subject to a weak acid extraction to remove the metals, zinc, copper, cadmium and lead from the polymer. Recently manufactured low density polyethylene (LDPE), nylon, polyethylene terephthalate (PET), polypropylene (PP), polystyrene (PS) and polyvinyl chloride (PVC) were subject to the same extraction. Data was statistically analyzed by appropriate parametric and non-parametric tests when needed with significance set at P < 0.05. Polymers identified in field samples in order of abundance were; PVC (39), LDPE (28), PS (18), polyethylene (PE, 9), PP (8), nylon (8), high density polyethylene (HDPE, 7), polycarbonate (PC, 6), PET (6), polyurethane (PUR, 3) and polyoxymethylene (POM, 2). PVC and LDPE accounted for 46% of all samples. Field samples of PVC, HDPE and LDPE had significantly greater amounts of acid extracted copper and HDPE, LDPE and PUR significantly greater amounts of acid extracted zinc. PVC and LDPE had significantly greater amounts of acid extracted cadmium and PVC tended to have greater levels of acid extracted lead, significantly so for HDPE. Five of the collected items demonstrated extreme levels of acid extracted metal; greatest concentrations were 188, 6667, 698,000 and 930 μgg-1 of copper, zinc, lead and cadmium respectively recovered from an unidentified object comprised of PVC. Comparison of recently manufactured versus field samples indicated that recently manufactured samples had significantly greater amounts of acid extracted cadmium and zinc and field samples significantly greater amounts of acid extracted copper and lead which was primarily attributed to metal extracted from field samples of PVC. Plastic debris will affect metals within coastal ecosystems by; 1) providing a sorption site (copper and lead), notably for PVC 2) desorption from the plastic i.e., the "inherent" load (cadmium and zinc) and 3) serving as a point source of acute trace metal exposure to coastal ecosystems. All three mechanisms will put coastal ecosystems at risk to the toxic effects of these metals.

Acute Stress Facilitates Trace Eyeblink Conditioning in C57BL/6 Male Mice and Increases the Excitability of Their CA1 Pyramidal Neurons

ERIC Educational Resources Information Center

Weiss, Craig; Sametsky, Evgeny; Sasse, Astrid; Spiess, Joachim; Disterhoft, John F.

2005-01-01

The effects of stress (restraint plus tail shock) on hippocampus-dependent trace eyeblink conditioning and hippocampal excitability were examined in C57BL/6 male mice. The results indicate that the stressor significantly increased the concentration of circulating corticosterone, the amount and rate of learning relative to nonstressed conditioned…

Study of the Effect of Trace Mg Additions on Carbides in Die Steel H13

NASA Astrophysics Data System (ADS)

Li, Ji; Li, Jing; Wang, Liang-liang; Zhu, Qin-tian

2016-09-01

Carbides in annealed steel H13 without magnesium and with a micro-addition of magnesium (0.0010%) are studied. Trace amounts of magnesium strengthen carbide segregation and reduce their size. Carbides phases M7C3, M6 C, and M(C, N) are detected in steel H13, and this agrees with results of thermodynamic calculations.

Turbine Chemistry Modeling

NASA Technical Reports Server (NTRS)

Liu, Nan-Suey; Wey, Thomas

2001-01-01

Many of the engine exhaust species resulting in significant environmental impact exist in trace amounts. Recent research, e.g., conducted at MIT-AM, has pointed to the intra-engine environment as a possible site for important trace chemistry activity. In addition, the key processes affecting the trace species activity occurring downstream in the air passages of the turbine and exhaust nozzle are not well understood. Most recently, an effort has been initiated at NASA Glenn Research Center under the UEET Program to evaluate and further develop CFD-based technology for modeling and simulation of intra-engine trace chemical changes relevant to atmospheric effects of pollutant emissions from aircraft engines. This presentation will describe the current effort conducted at Glenn; some preliminary results relevant to the trace species chemistry in a turbine passage will also be presented to indicate the progress to date.

Vertical nutrient and trace element migration in cambisoils after application of residues from anaerobic digestion of pig manure

NASA Astrophysics Data System (ADS)

Sager, Manfred; Unterfrauner, Hans

2013-04-01

Cambisols sampled in alpine pastures were packed into soil columns in order to monitor downward migration of nutrient and trace elements, applied within the residue from anaerobic digestion of a pig manure. 2 rain events per week were simulated. The manure added substantial amounts of K, ammonium, Na, Ca, P, S, Cl, B, Zn and Cu to the soil, whereas Mg, Mn, Ni, Cr, Pb, Cd and V were at the same level. In the eluates, total elemental composition as well as nitrate and ammonium were monitored. Addition of soluble Fe (at 1000 mg/l as FeCl3) decreased the release of soluble sulphate, but had no significant effect on the release of Fe and P. During subsequent rain events, exchangeable K remained enriched in the topsoil, wheras total sulfur moved to deeper layers. After 8 weeks, the columns were dismantled and analyzed for quasi-total and mobile fractions. Both in topsoils and subsoils, manure addition finally increased soil pH in case of low P soils, but decreased soil pH in case of high pH soils. Effects of manure applications on groundwater formation processes will be discussed.

Major and trace element chemistry of separated fragments from a hibonite-bearing Allende inclusion

NASA Technical Reports Server (NTRS)

Davis, A. M.; Grossman, L.; Allen, J. M.

1978-01-01

The major and trace elements of separated fragments and a bulk sample from CG-11, a hibonite-bearing inclusion in the Allende meteorite, were analyzed. Major element abundances were used to determine the minerology of separated fragments. The high degree of correlation between Eu/Sm ratios and Lu/Yb ratios for the samples studied indicates that their rare earth element (REE) distributions are governed by two components. One, Lu-, Eu-rich, is probably hibonite; the other, depleted in these elements, seems to be associated with the secondary alteration phases, grossular, nepheline and anorthite. The REE distribution in CG-11 precludes melting events after formation of the secondary alteration phases, but a melting event involving the primary minerals cannot be excluded. The enrichment of Lu with respect to other measured REE in hibonite can be explained by present REE condensation models. Two Hf-bearing components, most likely hibonite and perovskite, are necessary to account for variations in Sc/Hf ratios in the fragments studied. The lithophile volatiles Na, Mn, Fe, Zn, and probably Cr increase in the same order as the amount of secondary alteration minerals; the volatile siderophile elements Co and Au, however, do not.

Gas chromatography/trace analysis of derivatized azelaic acid as a stability marker.

PubMed

Alzweiri, Muhammed; Tarawneh, Ruba; Khanfar, Mohammad A

2013-10-01

Azelaic acid, a naturally occurring saturated dicarboxylic acid, is found in many topical formulations for its various medical benefits or as a byproduct of the oxidative decomposition of unsaturated fatty acids. The poor volatility of azelaic acid hinders its applicability in GC analysis. Therefore, azelaic acid was derivatized by methylation and silylation procedures to enhance its volatility for GC analysis. Accordingly, dimethyl azelate (DMA) and di(trimethylsilyl) azelate were synthesized and characterized by GC-MS. Subsequently, a GC with flame ionization detection method was developed and validated to analyze trace amounts of azelaic acid in some marketed skin creams. Unlike DMA, di(trimethylsilyl) azelate was chemically unstable and degraded within few hours. Nonane was used as a stable internal standard. Variability due to derivatization and extraction was controlled by a standard addition procedure. DMA analysis was linear in a wide concentration range (100 ng/mL to 100 mg/mL). Moreover, the method was accurate (96.4-103.4%) and precise with inter- and intraday variability <2.0% and LOQ and LOD of 100 and 10 ng/mL, respectively. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Lower- and higher-order aberrations predicted by an optomechanical model of arcuate keratotomy for astigmatism.

PubMed

Navarro, Rafael; Palos, Fernando; Lanchares, Elena; Calvo, Begoña; Cristóbal, José A

2009-01-01

To develop a realistic model of the optomechanical behavior of the cornea after curved relaxing incisions to simulate the induced astigmatic change and predict the optical aberrations produced by the incisions. ICMA Consejo Superior de Investigaciones Científicas and Universidad de Zaragoza, Zaragoza, Spain. A 3-dimensional finite element model of the anterior hemisphere of the ocular surface was used. The corneal tissue was modeled as a quasi-incompressible, anisotropic hyperelastic constitutive behavior strongly dependent on the physiological collagen fibril distribution. Similar behaviors were assigned to the limbus and sclera. With this model, some corneal incisions were computer simulated after the Lindstrom nomogram. The resulting geometry of the biomechanical simulation was analyzed in the optical zone, and finite ray tracing was performed to compute refractive power and higher-order aberrations (HOAs). The finite-element simulation provided new geometry of the corneal surfaces, from which elevation topographies were obtained. The surgically induced astigmatism (SIA) of the simulated incisions according to the Lindstrom nomogram was computed by finite ray tracing. However, paraxial computations would yield slightly different results (undercorrection of astigmatism). In addition, arcuate incisions would induce significant amounts of HOAs. Finite-element models, together with finite ray-tracing computations, yielded realistic simulations of the biomechanical and optical changes induced by relaxing incisions. The model reproduced the SIA indicated by the Lindstrom nomogram for the simulated incisions and predicted a significant increase in optical aberrations induced by arcuate keratotomy.

Retrieval of Vertical Aerosol and Trace Gas Distributions from Polarization Sensitive Multi-Axis Differential Optical Absorption Spectroscopy (MAX-DOAS)

NASA Astrophysics Data System (ADS)

Tirpitz, Jan-Lukas; Friess, Udo; Platt, Ulrich

2017-04-01

An accurate knowledge of the vertical distribution of trace gases and aerosols is crucial for our understanding of the chemical and dynamical processes in the lower troposphere. Their accurate determination is typically only possible by means of laborious and expensive airborne in-situ measurements but in the recent decades, numerous promising ground-based remote sensing approaches have been developed. One of them is to infer vertical distributions from "Differential Optical Absorption Spectroscopy" (DOAS) measurements. DOAS is a technique to analyze UV- and visible radiation spectra of direct or scattered sunlight, which delivers information on different atmospheric parameters, integrated over the light path from space to the instrument. An appropriate set of DOAS measurements, recorded under different viewing directions (Multi-Axis DOAS) and thus different light path geometries, provides information on the atmospheric state. The vertical profiles of aerosol properties and trace gas concentrations can be retrieved from such a set by numerical inversion techniques, incorporating radiative transfer models. The information content of measured data is rarely sufficient for a well-constrained retrieval, particularly for atmospheric layers above 1 km. We showed in first simulations that, apart from spectral properties, the polarization state of skylight is likely to provide a significant amount of additional information on the atmospheric state and thus to enhance retrieval quality. We present first simulations, expectations and ideas on how to implement and characterize a polarization sensitive Multi-Axis DOAS instrument and a corresponding profile retrieval algorithm.

Real-time trace ambient ammonia monitor for haze prevention

NASA Astrophysics Data System (ADS)

Nishimura, Katsumi; Sakaguchi, Yuhei; Crosson, Eric; Wahl, Edward; Rella, Chris

2007-05-01

In photolithography, haze prevention is of critical importance to integrated circuit chip manufacturers. Numerous studies have established that the presence of ammonia in the photolithography tool can cause haze to form on optical surfaces resulting in permanent damage to costly deep ultra-violet optics. Ammonia is emitted into wafer fab air by various semiconductor processes including coating steps in the track and CMP. The workers in the clean room also emit a significant amount of ammonia. Chemical filters are typically used to remove airborne contamination from critical locations but their lifetime and coverage cannot offer complete protection. Therefore, constant or periodic monitoring of airborne ammonia at parts-per-trillion (ppt) levels is critical to insure the integrity of the lithography process. Real time monitoring can insure that an accidental ammonia release in the clean room is detected before any optics is damaged. We have developed a transportable, highly accurate, highly specific, real-time trace gas monitor that detects ammonia using Cavity Ring-Down Spectroscopy (CRDS). The trace gas monitor requires no calibration gas standards, and can measure ammonia with 200 ppt sensitivity in five minutes with little or no baseline drift. In addition, the high spectral resolution of CRDS makes the analyzer less susceptible to interference from other gases when compared to other detection methods. In this paper we describe the monitor, focus on its performance, discuss the results of a careful comparison with ion chromatography (IC), and present field data measured inside the aligner and the reticule stocker at a semiconductor fab.

On the Information Content of Program Traces

NASA Technical Reports Server (NTRS)

Frumkin, Michael; Hood, Robert; Yan, Jerry; Saini, Subhash (Technical Monitor)

1998-01-01

Program traces are used for analysis of program performance, memory utilization, and communications as well as for program debugging. The trace contains records of execution events generated by monitoring units inserted into the program. The trace size limits the resolution of execution events and restricts the user's ability to analyze the program execution. We present a study of the information content of program traces and develop a coding scheme which reduces the trace size to the limit given by the trace entropy. We apply the coding to the traces of AIMS instrumented programs executed on the IBM SPA and the SCSI Power Challenge and compare it with other coding methods. Our technique shows size of the trace can be reduced by more than a factor of 5.

Research on Pin Tumbler Locks and the Characteristics of Surface Traces Formed by Unlocking Guns

NASA Astrophysics Data System (ADS)

Yi, Gao; Yifeng, Jin; Yanping, Bai; Hongcheng, Mei; Zhen, Xu

2018-02-01

In this paper, taking the structure of the pin tumbler locks and the principle of opening and closing locks as breakthrough point, we have studied the machining traces of pin tumbler components and trace characters of pin surface during normal operating. At the same time, taking the unlocking gun as an example, the paper analyzes the unlocking technology and the formation of traces, and summarizes the changing rules of the surface traces of elastic bead locks by comparing the positions and the characteristics of the traces, which provides technical support for the future study of traces of pin tumbler locks.

Greenhouse effects due to man-made perturbations of trace gases

NASA Technical Reports Server (NTRS)

Wang, W. C.; Yung, Y. L.; Lacis, A. A.; Mo, T.; Hansen, J. E.

1976-01-01

Nitrous oxide, methane, ammonia, and a number of other trace constituents of the earth's atmosphere have infrared absorption bands in the spectral range from 7 to 14 microns. Despite their small amounts, these gases can have a significant effect on the thermal structure of the atmosphere by transmitting most of the thermal radiation from the earth's surface to the lower atmosphere. In the present paper, this greenhouse effect is computed for a number of trace gases. The nature and climatic implications of possible changes in the concentrations of N2O, CH4, NH3, and HNO3 are discussed.

The SNPforID Assay as a Supplementary Method in Kinship and Trace Analysis

PubMed Central

Schwark, Thorsten; Meyer, Patrick; Harder, Melanie; Modrow, Jan-Hendrick; von Wurmb-Schwark, Nicole

2012-01-01

Objective Short tandem repeat (STR) analysis using commercial multiplex PCR kits is the method of choice for kinship testing and trace analysis. However, under certain circumstances (deficiency testing, mutations, minute DNA amounts), STRs alone may not suffice. Methods We present a 50-plex single nucleotide polymorphism (SNP) assay based on the SNPs chosen by the SNPforID consortium as an additional method for paternity and for trace analysis. The new assay was applied to selected routine paternity and trace cases from our laboratory. Results and Conclusions Our investigation shows that the new SNP multiplex assay is a valuable method to supplement STR analysis, and is a powerful means to solve complicated genetic analyses. PMID:22851934

Morphology, composition, and mixing state of primary particles from combustion sources - crop residue, wood, and solid waste.

PubMed

Liu, Lei; Kong, Shaofei; Zhang, Yinxiao; Wang, Yuanyuan; Xu, Liang; Yan, Qin; Lingaswamy, A P; Shi, Zongbo; Lv, Senlin; Niu, Hongya; Shao, Longyi; Hu, Min; Zhang, Daizhou; Chen, Jianmin; Zhang, Xiaoye; Li, Weijun

2017-07-11

Morphology, composition, and mixing state of individual particles emitted from crop residue, wood, and solid waste combustion in a residential stove were analyzed using transmission electron microscopy (TEM). Our study showed that particles from crop residue and apple wood combustion were mainly organic matter (OM) in smoldering phase, whereas soot-OM internally mixed with K in flaming phase. Wild grass combustion in flaming phase released some Cl-rich-OM/soot particles and cardboard combustion released OM and S-rich particles. Interestingly, particles from hardwood (pear wood and bamboo) and softwood (cypress and pine wood) combustion were mainly soot and OM in the flaming phase, respectively. The combustion of foam boxes, rubber tires, and plastic bottles/bags in the flaming phase released large amounts of soot internally mixed with a small amount of OM, whereas the combustion of printed circuit boards and copper-core cables emitted large amounts of OM with Br-rich inclusions. In addition, the printed circuit board combustion released toxic metals containing Pb, Zn, Sn, and Sb. The results are important to document properties of primary particles from combustion sources, which can be used to trace the sources of ambient particles and to know their potential impacts in human health and radiative forcing in the air.

Bioaccumulation and distribution of selenium in Enterococcus durans.

PubMed

Pieniz, Simone; Andreazza, Robson; Mann, Michele Bertoni; Camargo, Flávio; Brandelli, Adriano

2017-03-01

Selenium is an essential nutrient for all living organisms. Under appropriate conditions lactic acid bacteria (LAB) are capable for accumulating large amounts of trace elements, such as selenium, and incorporating them into organic compounds. In this study, the capacity of selenium bioaccumulation by Enterococcus durans LAB18s was evaluated. The distribution of organic selenium in selenium-enriched E. durans LAB18s biomass was analyzed, and the highest percentage of organic selenium was found in the fraction of total protein, followed by the fractions of polysaccharides and nucleic acids. When the protein fraction was obtained by different extractions (water, NaCl, ethanol and NaOH) it was demonstrated that alkali-soluble protein showed the higher Selenium content. Analysis of protein fractions by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed that selenium was present in the proteins ranging from 23 to 100kDa. The cells were analyzed by scanning electron microscopy (SEM); scanning electron microscopy/energy dispersive spectrometry (SEM/EDS) and transmission electron microscopy (TEM). SEM, TEM and SEM/EDS showed the morphology, the selenium particles bioaccumulated into and on the cells and the amounts of selenium present into the cells, respectively. Thus, the isolate E. durans LAB18s can be a promising probiotic to be used as selenium-enriched biomass in feed trials. Copyright © 2016 Elsevier GmbH. All rights reserved.

Serum Concentrations of Trace Elements in Patients with Tuberculosis and Its Association with Treatment Outcome

PubMed Central

Choi, Rihwa; Kim, Hyoung-Tae; Lim, Yaeji; Kim, Min-Ji; Kwon, O Jung; Jeon, Kyeongman; Park, Hye Yun; Jeong, Byeong-Ho; Koh, Won-Jung; Lee, Soo-Youn

2015-01-01

Deficiencies in essential trace elements are associated with impaired immunity in tuberculosis infection. However, the trace element concentrations in the serum of Korean patients with tuberculosis have not yet been investigated. This study aimed to compare the serum trace element concentrations of Korean adult patients with tuberculosis with noninfected controls and to assess the impact of serum trace element concentration on clinical outcome after antituberculosis treatment. The serum concentrations of four trace elements in 141 consecutively recruited patients with tuberculosis and 79 controls were analyzed by inductively coupled plasma-mass spectrometry. Demographic characteristics were also analyzed. Serum cobalt and copper concentrations were significantly higher in patients with tuberculosis compared with controls, while zinc and selenium concentrations were significantly lower (p < 0.01). Moreover, serum selenium and zinc concentrations were positively correlated (ρ = 0.41, p < 0.05). A high serum copper concentration was associated with a worse clinical outcome, as assessed after one month of antituberculosis therapy. Specifically, culture-positive patients had higher serum copper concentrations than culture-negative patients (p < 0.05). Patients with tuberculosis had altered serum trace element concentrations. Further research is needed to elucidate the roles of individual trace elements and to determine their clinical impact on patients with tuberculosis. PMID:26197334

Photoacoustic Effect of Ethene: Sound Generation due to Plant Hormone Gases.

NASA Astrophysics Data System (ADS)

Park, Han Jung; Ide, David; University of Tennessee at Chattanooga Team

2017-01-01

Ethene, which is produced in plants as they mature, was used to study its photoacoustic properties using photoacoustic spectroscopy. Detection of trace amounts, with N2 gas, of the ethylene gas were also applied. The gas was tested in various conditions: temperature, concentration of the gas, gas cell length, and power of the laser, were varied to determine their effect on the photoacoustic signal, the ideal conditions to detect trace gas amounts, and concentration of ethylene produced by an avocado and banana. A detection limit of 10 ppm was determined for pure C2H4. A detection of 5% and 13% (by volume) concentration of ethylene were produced for a ripening avocado and banana, respectively, in closed space.

Micro-quantity tissue digestion for metal measurements by use of a microwave acid-digestion bomb.

PubMed

Nicholson, J R; Savory, M G; Savory, J; Wills, M R

1989-03-01

We describe a simple and convenient method for processing small amounts of tissue samples for trace-metal measurements by atomic absorption spectrometry, by use of a modified Parr microwave digestion bomb. Digestion proceeds rapidly (less than or equal to 90 s) in a sealed Teflon-lined vessel that eliminates contamination or loss from volatilization. Small quantities of tissue (5-100 mg dry weight) are digested in high-purity nitric acid, yielding concentrations of analyte that can be measured directly without further sample manipulation. We analyzed National Institute of Standards and Technology bovine liver Standard Reference Material to verify the accuracy of the technique. We assessed the applicability of the technique to analysis for aluminum in bone by comparison with a dry ashing procedure.

Core-Shell Columns in High-Performance Liquid Chromatography: Food Analysis Applications

PubMed Central

Preti, Raffaella

2016-01-01

The increased separation efficiency provided by the new technology of column packed with core-shell particles in high-performance liquid chromatography (HPLC) has resulted in their widespread diffusion in several analytical fields: from pharmaceutical, biological, environmental, and toxicological. The present paper presents their most recent applications in food analysis. Their use has proved to be particularly advantageous for the determination of compounds at trace levels or when a large amount of samples must be analyzed fast using reliable and solvent-saving apparatus. The literature hereby described shows how the outstanding performances provided by core-shell particles column on a traditional HPLC instruments are comparable to those obtained with a costly UHPLC instrumentation, making this novel column a promising key tool in food analysis. PMID:27143972

Characterization of biogenic elements in interplanetary dust particles

NASA Technical Reports Server (NTRS)

Bunch, T. E.

1986-01-01

Those particles that were designated cometary are aggregates of amorphous materials including carbon, iron-magnesium silicates, sulfides, metal and trace amounts of unusual phases. Most aggregates are carbon-rich with major and minor element abundances similar to a fine grained matrix of carbonaceous chondrites. Several particles were analyzed by a laser microprobe. The negative ionic species identified to date include carbon clusters, protonated carbon clusters, CN-, HCN-, CNO-, PO2-, PO3-, S-, S2- asnd OH-. These species are similar to those observed in cometary spectra and they support the assumption that organic materials are present. The occurance of phosphate ions suggests the presence of apatite or whitlockite. Cometary particle characteristics may indicate that the component grains represent primitive unaltered dust whose overall properties are extremely similar to altered primitive dust in carbonaceous chondrites.

In Situ Trace Element Analysis of an Allende Type B1 CAI: EK-459-5-1

NASA Technical Reports Server (NTRS)

Jeffcoat, C. R.; Kerekgyarto, A.; Lapen, T. J.; Andreasen, R.; Righter, M.; Ross, D. K.

2014-01-01

Variations in refractory major and trace element composition of calcium, aluminum-rich inclusions (CAIs) provide constraints on physical and chemical conditions and processes in the earliest stages of the Solar System. Previous work indicates that CAIs have experienced complex histories involving, in many cases, multiple episodes of condensation, evaporation, and partial melting. We have analyzed major and trace element abundances in two core to rim transects of the melilite mantle as well as interior major phases of a Type B1 CAI (EK-459-5-1) from Allende by electron probe micro-analyzer (EPMA) and laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to investigate the behavior of key trace elements with a primary focus on the REEs Tm and Yb.

Liquid Chromatographic Analysis of Hydraulic Fluids.

DTIC Science & Technology

1979-11-01

chemical mixtures of a petroleum- or nonpetroleum-base stock component formulated with various additives which may be present in trace amounts or...absorb UV radiation near the monitoring wavelength may swamp the detector signal and therefore should be avoided in 1JV detection. The recorder trace of...Also, organic phosphites , thiophosphates, and sulfides are used to inhibit oxidative catalysis by metal ions. The oxidation inhibitor in 6083D-0 is BPC

Consumer-producer relationships for trace metals in Chorthippus brunneus (Thunberg. )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, M.S.

1986-08-01

The behavior of trace metals in terrestrial food chains is a subject of ecological interest, particularly in polluted environments where the potential exists for bioconcentration of metals known to be essential in trace amounts for normal plant and animal metabolism, as well as those with no known metabolic function but recognized toxicological properties. Laboratory studies of food chain relationships afford a means by which direct comparisons can be made between trace metals as a basis for interpretation of data collected from wild plant and animal populations. This study compares the behavior of three trace elements, copper, zinc and cadmium, inmore » terms of their assimilation under experimental conditions by the herbivorous common field grasshopper, Chorthippus brunneus (Thunberg.). This voracious orthopteran is widely distributed in Britain and is particularly prominent in the restricted invertebrate community of some metal smelter-affected grasslands where it forms important seasonal prey for insectivorous small mammals.« less

Reconnaissance of Soil, Ground Water, and Plant Contamination at an Abandoned Oilfield-Service Site near Shawnee, Oklahoma, 2005-2006

USGS Publications Warehouse

Mashburn, Shana L.; Smith, S. Jerrod

2007-01-01

The U.S. Geological Survey, in cooperation with the Absentee Shawnee Tribe of Oklahoma, began a reconnaissance study of a site in Pottawatomie County, Oklahoma, in 2005 by testing soil, shallow ground water, and plant material for the presence of trace elements and semivolatile organic compounds. Chemical analysis of plant material at the site was investigated as a preliminary tool to determine the extent of contamination at the site. Thirty soil samples were collected from 15 soil cores during October 2005 and analyzed for trace elements and semivolatile organic compounds. Five small-diameter, polyvinyl-chloride-cased wells were installed and ground-water samples were collected during December 2005 and May 2006 and analyzed for trace elements and semivolatile organic compounds. Thirty Johnsongrass samples and 16 Coralberry samples were collected during September 2005 and analyzed for 53 constituents, including trace elements. Results of the soil, ground-water, and plant data indicate that the areas of trace element and semivolatile organic compound contamination are located in the shallow (A-horizon) soils near the threading barn. Most of the trace-element concentrations in the soils on the study site were either similar to or less than trace-element concentrations in background soils. Several trace elements and semivolatile organic compounds exceeded the U.S. Environmental Protection Agency, Region 6, Human Health Medium-Specific Screening Levels 2007 for Tap Water, Residential Soils, Industrial Indoor Soils, and Industrial Outdoor Soils. There was little or no correlation between the plant and soil sample concentrations and the plant and ground-water concentrations based on the current sample size and study design. The lack of correlation between trace-element concentrations in plants and soils, and plants and ground water indicate that plant sampling was not useful as a preliminary tool to assess contamination at the study site.

Water-quality assessment of the Rio Grande Valley, Colorado, New Mexico and Texas; organic compounds and trace elements in bed sediment and fish tissue, 1992-93

USGS Publications Warehouse

Carter, L.F.; Anderholm, S.K.

1997-01-01

The occurrence and distribution of contaminants in aquatic systems are major components of the National Water-Quality Assessment (NAWQA) Program. Bed-sediment samples were collected at 18 sites in the Rio Grande Valley study unit between September 1992 and March 1993 to characterize the geographic distribution of organic compounds, including chlorinated insecticides, polychlorinated biphenyls (PCB's), and other chlorinated hydrocarbons, and also trace elements. Two-millimeter-size- fraction sediment was analyzed for organic compounds and less than 63-micron-size-fraction sediment was analyzed for trace elements. Concentrations of p,p'-DDE were detected in 33 percent of the bed-sediment samples. With the exception of DDT-related compounds, no other organochlorine insecticides or polychlorinated biphenyls were detected in samples of bed sediment. Whole-body fish samples were collected at 11 of the bed- sediment sites and analyzed for organic compounds. Organic compounds were reported more frequently in samples of fish, and more types of organic compounds were found in whole-body fish samples than in bed-sediment samples. Concentrations of p,p'-DDE were detected in 91 percent of whole-body fish samples. Polychlorinated biphenyls, cis-chlordane, trans-chlordane, trans- nonachlor, and hexachlorobenzene were other organic compounds detected in whole-body samples of fish from at least one site. Because of the extent of mineralized areas in the Rio Grande Basin arsenic, cadmium, copper, lead, mercury, selenium, and zinc concentrations in bed-sediment samples could represent natural conditions at most sites. However, a combination of natural conditions and human activities appears to be associated with elevated trace-element concentrations in the bed-sediment sample from the site Rio Grande near Creede, Colorado, because this sample exceeded the background trace-element concentrations calculated for this study. Fish-liver samples were collected at 12 of the bed-sediment sites and analyzed for trace elements. Certain trace elements were detected at higher concentrations in fish-liver samples than in bed-sediment samples from the same site. Both bed-sediment and fish-tissue samples are necessary for a complete environmental assessment of the occurrence and distribution of trace elements.

A Method for Assessing the Retention of Trace Elements in Human Body Using Neural Network Technology

PubMed Central

Ragimov, Aligejdar; Faizullin, Rashat; Valiev, Vsevolod

2017-01-01

Models that describe the trace element status formation in the human organism are essential for a correction of micromineral (trace elements) deficiency. A direct trace element retention assessment in the body is difficult due to the many internal mechanisms. The trace element retention is determined by the amount and the ratio of incoming and excreted substance. So, the concentration of trace elements in drinking water characterizes the intake, whereas the element concentration in urine characterizes the excretion. This system can be interpreted as three interrelated elements that are in equilibrium. Since many relationships in the system are not known, the use of standard mathematical models is difficult. The artificial neural network use is suitable for constructing a model in the best way because it can take into account all dependencies in the system implicitly and process inaccurate and incomplete data. We created several neural network models to describe the retentions of trace elements in the human body. On the model basis, we can calculate the microelement levels in the body, knowing the trace element levels in drinking water and urine. These results can be used in health care to provide the population with safe drinking water. PMID:29065586

[Determination of trace amounts of zinc in nickel electrolyte by flow injection on-line enrichment].

PubMed

Zhou, Z; Wang, Y; Dong, Z; Tong, K; Guo, X; Guo, X

1999-10-01

A method for the determination of trace amount of zinc in nickel electrolyte utilizing the flow injection on-line enrichment technique is reported in this paper. Atomic absorption spectrometer was used as detector. Zinc was separated from large amounts of nickel andother components in the electrolyte by absorption its chlorocomplex on a mini-column packed with strongly basic anion exchangers. It was found that sodium chloride containing in the electrolyte offered a sufficient chloride concentration needed for the formation of the zinc chlorocomplex and thus no additional reagent was required for the determination. The throughput of the method is 30 determinations per hour. The detection limit of the method is 0.002 microg x mL(-1) and the precision is 1.9% (RSD). The proposed method is rapid and cost-effective. It has been used for almost three years in the quality control of the electrolyte in the factory with great success.

Ray Tracing Through Non-Imaging Concentrators

NASA Astrophysics Data System (ADS)

Greynolds, Alan W.

1984-01-01

A generalized algorithm for tracing rays through both imaging and non-imaging radiation collectors is presented. A computer program based on the algorithm is then applied to analyzing various two-stage Winston concentrators.

Micovascular integration into porous polyHEMA scaffold

NASA Astrophysics Data System (ADS)

Cho, Eugenia H.; Boico, Alina; Wisniewski, Natalie A.; Gant, Rebecca; Helton, Kristen L.; Brown, Nga L.; Register, Janna K.; Vo-Dinh, Tuan; Schroeder, Thies; Klitzman, Bruce

2014-03-01

Surface-enhanced Raman scattering (SERS) spectroscopy can be a useful tool in regard to disease diagnosis and prevention. Advantage of SERS over conventional Raman spectroscopy is its significantly increased signal (up to factor of 106-108) which allows detection of trace amounts of substances in the sample. So far, this technique is successfully used for analysis of food, pieces of art and various biochemical/biomedical samples. In this work, we survey the possibility of applying SERS spectroscopy for detection of trace components in urinary deposits. Early discovery together with the identification of the exact chemical composition of urinary sediments could be crucial for taking appropriate preventive measures that inhibit kidney stone formation or growth processes. In this initial study, SERS spectra (excitation wavelength - 1064 nm) of main components of urinary deposits (calcium oxalate, uric acid, cystine, etc.) were recorded by using silver (Ag) colloid. Spectra of 10-3-10-5 M solutions were obtained. While no/small Raman signal was detected without the Ag colloid, characteristic peaks of the substances could be clearly separated in the SERS spectra. This suggests that even small amounts of the components could be detected and taken into account while determining the type of kidney stone forming in the urinary system. We found for the first time that trace amounts of components constituting urinary deposits could be detected by SERS spectroscopy. In the future study, the analysis of centrifuged urine samples will be carried out.

The repair of low dose UV light-induced damage to human skin DNA in condition of trace amount Mg 2+

NASA Astrophysics Data System (ADS)

Gao, Fang; Guo, Zhouyi; Zheng, Changchun; Wang, Rui; Liu, Zhiming; Meng, Pei; Zhai, Juan

2008-12-01

Ultraviolet light-induced damage to human skin DNA was widely investigated. The primary mechanism of this damage contributed to form cyclobutane pyrimidine dimmers (CPDs). Although the distribution of UV light-induced CPDs within a defined sequence is similar, the damage in cellular environment which shields the nuclear DNA was higher than that in organism in apparent dose. So we use low UVB light as main study agent. Low dose UV-irradiated HDF-a cells (Human Dermal Fibroblasts-adult cells) which is weaker than epidermic cells were cultured with DMEM at different trace amount of Mg2+ (0mmol/L , 0.1mmol/L , 0.2mmol/L, 0.4mmol/L, 0.8mmol/L, 1.2mmol/L) free-serum DMEM and the repair of DNA strands injured were observed. Treat these cells with DNA strand breaks detection, photoproducts detection and the repair of photoproducts detection. Then quantitate the role of trace amount Mg2+ in repair of UV light-induced damage to human skin. The experiment results indicated that epidermic cells have capability of resistance to UV-radiation at a certain extent. And Mg2+ can regulate the UV-induced damage repair and relative vitality. It can offer a rationale and experiment data to relieve UV light-induced skin disease.

Determination of trace elements in dairy milk collected from the environment of coal-fired power plant.

PubMed

Ramamurthy, N; Thillaivelavan, K

2005-01-01

In the present study the environmental effects on herbivores mammals in and around Coal-fired power plant were studied by collecting the various milk samples of Cow and Buffalo in clean polyethylene bottles. Milk samples collected at five different locations along the banks of the Paravanaru river in and around Neyveli area. These samples were prepared for trace metal determination. The concentration of trace metals (Cu, Zn, Ni, Cd, Cr, Mn, Co and Hg) were determined by Inductively Coupled Plasma-Atomic Emission Spectrometry (ICP-AES) and Cold Vapour Atomic Absorption Spectrometry (CVAAS). It is observed that the samples contain greater amounts of trace metals than that in the unexposed areas. Obviously the milk samples are contaminated with these metals due to fly ash released in such environment.

Analysis of memory use for improved design and compile-time allocation of local memory

NASA Technical Reports Server (NTRS)

Mcniven, Geoffrey D.; Davidson, Edward S.

1986-01-01

Trace analysis techniques are used to study memory referencing behavior for the purpose of designing local memories and determining how to allocate them for data and instructions. In an attempt to assess the inherent behavior of the source code, the trace analysis system described here reduced the effects of the compiler and host architecture on the trace by using a technical called flattening. The variables in the trace, their associated single-assignment values, and references are histogrammed on the basis of various parameters describing memory referencing behavior. Bounds are developed specifying the amount of memory space required to store all live values in a particular histogram class. The reduction achieved in main memory traffic by allocating local memory is specified for each class.

Leveraging First Response Time into the Knowledge Tracing Model

ERIC Educational Resources Information Center

Wang, Yutao; Heffernan, Neil T.

2012-01-01

The field of educational data mining has been using the Knowledge Tracing model, which only look at the correctness of student first response, for tracking student knowledge. Recently, lots of other features are studied to extend the Knowledge Tracing model to better model student knowledge. The goal of this paper is to analyze whether or not the…

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kooperman, Gabriel J.; Pritchard, Michael S.; Burt, Melissa A.

Changes in the character of rainfall are assessed using a holistic set of statistics based on rainfall frequency and amount distributions in climate change experiments with three conventional and superparameterized versions of the Community Atmosphere Model (CAM and SPCAM). Previous work has shown that high-order statistics of present-day rainfall intensity are significantly improved with superparameterization, especially in regions of tropical convection. Globally, the two modeling approaches project a similar future increase in mean rainfall, especially across the Inter-Tropical Convergence Zone (ITCZ) and at high latitudes, but over land, SPCAM predicts a smaller mean change than CAM. Changes in high-order statisticsmore » are similar at high latitudes in the two models but diverge at lower latitudes. In the tropics, SPCAM projects a large intensification of moderate and extreme rain rates in regions of organized convection associated with the Madden Julian Oscillation, ITCZ, monsoons, and tropical waves. In contrast, this signal is missing in all versions of CAM, which are found to be prone to predicting increases in the amount but not intensity of moderate rates. Predictions from SPCAM exhibit a scale-insensitive behavior with little dependence on horizontal resolution for extreme rates, while lower resolution (~2°) versions of CAM are not able to capture the response simulated with higher resolution (~1°). Furthermore, moderate rain rates analyzed by the “amount mode” and “amount median” are found to be especially telling as a diagnostic for evaluating climate model performance and tracing future changes in rainfall statistics to tropical wave modes in SPCAM.« less

Discrimination of microbiological samples using femtosecond laser-induced breakdown spectroscopy

NASA Astrophysics Data System (ADS)

Baudelet, Matthieu; Yu, Jin; Bossu, Myriam; Jovelet, Julien; Wolf, Jean-Pierre; Amodeo, Tanguy; Fréjafon, Emeric; Laloi, Patrick

2006-10-01

Using femtosecond laser-induced breakdown spectroscopy, the authors have analyzed five different species of bacterium. Line emissions from six trace mineral elements, Na, Mg, P, K, Ca, and Fe, have been clearly detected. Their intensities correspond to relative concentrations of these elements contained in the analyzed samples. The authors demonstrate that the concentration profile of trace elements allows unambiguous discrimination of different bacteria. Quantitative differentiation has been made by representing bacteria in a six-dimension hyperspace with each of its axis representing a detected trace element. In such hyperspace, representative points of different species of bacterium are gathered in different and distinct volumes.

Particulate and trace gas emissions from prescribed burns in southeastern U.S. fuel types: Summary of a 5-year project

Treesearch

David R. Weise; Timothy J. Johnson; James Reardon

2015-01-01

Management of smoke from prescribed fires requires knowledge of fuel quantity and the amount and composition of the smoke produced by the fire to minimize adverse impacts on human health. A five-year study produced new emissions information for more than 100 trace gases and particulate matter in smoke for fuel types found in the southern United States of America using...

Elimination of cadmium trace contaminations from drinking water.

PubMed

Zhao, Xuan; Höll, Wolfgang H; Yun, Guichun

2002-02-01

Raw waters polluted with trace heavy metals present serious problems to the part of the Chinese water supply. One of the important contaminants is cadmium. Removal of trace amounts of heavy metals can be achieved by means of selective sorption processes. One of the possibilities is the application of weak base anion exchangers. LEWIS-base/acid interactions lead to an exclusive sorption of heavy metal cations and an equivalent amount of anions of strong acids. The respective elimination of cadmium from pure solutions and spiked natural water and the regeneration of the exhausted exchanger has been investigated. The results demonstrate a very efficient elimination. The standards for drinking water are met for a very large relative volume of treated water. In addition, even a considerable share of dissolved organic matter is adsorbed. Regeneration requires a first step with sulfuric acid to remove the metals and a second one with sodium hydroxide to neutralize the exchanger and to displace the DOC adsorbed. The heavy metals can be concentrated in a small volume which facilitates the discharge of the waste.

Is violence in part a lithium deficiency state?

PubMed

Goldstein, Mark R; Mascitelli, Luca

2016-04-01

Violence, particularly firearm violence, leading to suicide and homicide is a significant problem worldwide. A majority of suicidal and homicidal violence involves males; homicidal violence is prevalent among young men and suicide is the leading cause of violence worldwide. Lithium, in pharmacological doses, has been used successfully for decades in treating bipolar disorders, and has been shown to decrease violent crime in this situation. Interestingly, lithium, in trace amounts, as occurs in some drinking water, has been inversely related to aggression, and suicidal and homicidal violence. Lithium is naturally found in vegetables, grains and drinking water, and dietary intake varies from nearly zero to 3mg daily. Elemental lithium, in trace doses, has been shown to improve mood in weeks. Moreover, lithium, in trace amounts, has no toxicity. In order to ensure adequate dietary intakes of elemental lithium daily for the purpose of decreasing aggression and violence, we propose considering the fortification of cereal grain products with lithium and also the addition of lithium to vitamin preparations for adults. Importantly, randomized trials in various populations are needed to test this hypothesis. Copyright © 2016 Elsevier Ltd. All rights reserved.

Trace metal levels, sources, and ecological risk assessment in a densely agricultural area from Saudi Arabia.

PubMed

Al-Wabel, Mohammad I; Sallam, Abd El-Azeem S; Usman, Adel R A; Ahmad, Mahtab; El-Naggar, Ahmed Hamdy; El-Saeid, Mohammed Hamza; Al-Faraj, Abdulelah; El-Enazi, Khaled; Al-Romian, Fahad A

2017-06-01

The present study was conducted in one of the most densely cultivated area of Al-Qassim region in Kingdom of Saudi Arabia to (i) monitor trace metal (Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb, and Zn) contents in surface and subsurface soils, (ii) assess the pollution and potential ecological risk levels of trace metals, and (iii) identify trace metal sources using enrichment factor (EF), correlation matrix, and principal component analysis (PCA). The pollution levels of the analyzed trace metals calculated by the geoaccumulation index (I geo ) and contamination factor (C f ) suggested that the soils were highly contaminated with Cd and moderately contaminated with Pb. Based on the average values of EF, soil samples were found to present extremely high enrichment for Cd, significant enrichment for Pb, moderate enrichment for Zn, and deficient to minimal enrichment for other trace metals. Among the analyzed trace metals, a very high ecological risk was observed only in the case of Cd at some sampling sites. Meanwhile, other investigated trace metals had a low ecological risk. The results of PCA combined with correlation matrix suggested that Fe, Mn, Zn, Cu, Cr Ni, Cu, and Co represent natural abundance in soil, but Cd, Pb, and Cu are of anthropogenic inputs, mainly due to agrochemical and fertilizer applications. It could be generally concluded that the obtained results can be useful for assessing and conducting a future program for trace metal monitoring in agricultural areas of Saudi Arabia.

Trace-metal accumulation, distribution, and fluxes in forests of the northeastern United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Friedland, A.J.

1985-01-01

Forest floor was sampled at 78 sites in nine northeastern states in the USA and analyzed for Cu, Zn, Ni, and Cd. Higher levels of trace metals occurred in the southern half of the study region. Earlier work identified that Pb accumulated in the forest floor of the high-elevation regions of New England. The distribution of Pb, Cu, Zn, Ni, and Cd within the forest floor was studied at three different forested states in New England. The greatest concentration of Pb, Cu, Zn, Ni, and Cd occurred in the Oe horizon of the forest floor in all three forests. Thismore » is the zone of greatest biological activity in the forest floor. Because it receives relatively high rates of atmospheric deposition, Camels Hump in northern Vermont was studied in greater detail. Lead concentration and amount in the forest floor increased between 550 and 1160 m elevation. Comparisons with 1966 and 1977 samples from the same stands showed that Pb, Cu, and Zn concentrations increased by as much as 148% in the intervening 14 years. Estimated deposition rates of Pb, Cu, and Zn based on accumulation rates agreed with regional deposition rates reported in the literature. Lead concentrations were an order of magnitude lower in mineral soil and vegetation than in forest floor. Thus the most likely source of forest floor Pb is the atmosphere. Lead was strongly retained by the forest floor and approximately 3% of the current Pb content of the forest floor is added each year by atmospheric deposition. At the current accumulation rates, the amount of Pb in the forest floor will double in three to four decades.« less

Determination of uranium in zircon

USGS Publications Warehouse

Cuttitta, F.; Daniels, G.J.

1959-01-01

A routine fluorimetric procedure is described for the determination of trace amounts of uranium in zircon. It employs the direct extraction of uranyl nitrate with ethyl acetate using phosphate as a retainer for zirconium. Submicrogram amounts or uranium are separated in the presence of 100,000 times the amount of zirconium. The modified procedure has been worked out using synthetic mixtures of known composition and zircon. Results of analyses have an accuracy of 97-98% of the contained uranium and a standard deviation of less than 2.5%. ?? 1959.

Investigating landfill leachate as a source of trace organic pollutants.

PubMed

Clarke, Bradley O; Anumol, Tarun; Barlaz, Morton; Snyder, Shane A

2015-05-01

Landfill leachate samples (n=11) were collected from five USA municipal solid waste (MSW) landfills and analyzed for ten trace organic pollutants that are commonly detected in surface and municipal wastewater effluents (viz., carbamazepine, DEET, fluoxetine, gemfibrozil, PFOA, PFOS, primidone, sucralose, sulfamethoxazole and trimethoprim). Carbamazepine, DEET, PFOA and primidone were detected in all leachate samples analyzed and gemfibrozil was detected in samples from four of the five-landfill sites. The contaminants found in the highest concentrations were DEET (6900-143000 ng L(-1)) and sucralose (<10-621000 ng L(-1)). Several compounds were not detected (fluoxetine) or detected infrequently (sulfamethoxazole, trimethoprim and PFOS). Using the average mass of DEET in leachate amongst the five landfills and scaling the mass release from the five test landfills to the USA population of landfills, an order of magnitude estimate is that over 10000 kg DEET yr(-1) may be released in leachate. Some pharmaceuticals have similar annual mean discharges to one another, with the estimated annual discharge of carbamazepine, gemfibrozil, primidone equating to 53, 151 and 128 kg year(-1). To the authors knowledge, this is the first time that primidone has been included in a landfill leachate study. While the estimates developed in this study are order of magnitude, the values do suggest the need for further research to better quantify the amount of chemicals sent to wastewater treatment facilities with landfill leachate, potential impacts on treatment processes and the significance of landfill leachate as a source of surface water contamination. Copyright © 2015. Published by Elsevier Ltd.

Polonium (²¹⁰Po), uranium (²³⁴U, ²³⁸U) isotopes and trace metals in mosses from Sobieszewo Island, northern Poland.

PubMed

Boryło, Alicja; Nowicki, Waldemar; Olszewski, Grzegorz; Skwarzec, Bogdan

2012-01-01

The activity of polonium (210)Po and uranium (234)U, (238)U radionuclides, as well as trace metals in mosses, collected from Sobieszewo Island area (northern Poland), were determined using the alpha spectrometry, AAS (atomic absorption spectrometry) and OES-ICP (atomic emission spectrometry with inductively coupled plasma). The concentrations of mercury (directly from the solid sample) were determined by the cold vapor technique of CV AAS. The obtained results revealed that the concentrations of (210)Po, (234)U, and (238)U in the two analyzed kinds of mosses: schrebers big red stem moss (Pleurozium schreberi) and broom moss (Dicranum scoparium) were similar. The higher polonium concentrations were found in broom moss (Dicranum scoparium), but uranium concentrations were relatively low for both species of analyzed mosses. Among the analyzed trace metals the highest concentration in mosses was recorded for iron, while the lowest for nickel, cadmium and mercury. The obtained studies showed that the sources of polonium and uranium isotopes, as well as trace metals in analyzed mosses are air city contaminations transported from Gdańsk and from existing in the vicinity the phosphogypsum waste heap in Wiślinka (near Gdańsk).

NARSTO EPA SS ST LOUIS AIR CHEM PM MET DATA

Atmospheric Science Data Center

2018-04-09

... Winds Precipitation Amount Surface Pressure Solar Radiation Surface Air Temperature Particulates Trace Metals ... Earth Related Data:  Environmental Protection Agency Supersites St. Louis SCAR-B Block:  ...

Trace metal dynamics in floodplain soils of the river Elbe: a review.

PubMed

Schulz-Zunkel, Christiane; Krueger, Frank

2009-01-01

This paper reviews trace metal dynamics in floodplain soils using the Elbe floodplains in Germany as an example of extraordinary importance because of the pollution level of its sediments and soils. Trace metal dynamics are determined by processes of retention and release, which are influenced by a number of soil properties including pH value, redox potential, organic matter, type and amount of clay minerals, iron-, manganese- and aluminum-oxides. Today floodplains act as important sinks for contaminants but under changing hydraulic and geochemical conditions they may also act as sources for pollutants. In floodplains such changes may be extremes in flooding or dry periods that particularly lead to altered redox potentials and that in turn influence the pH value, the mineralization of organic matter as well as the charge of the pedogenic oxides. Such reactions may affect the bioavailability of trace metals in soils and it can be clearly seen that the bioavailability of metals is an important factor for estimating trace metal remobilization in floodplain soils. However as bioavailability is not a constant factor, there is still a lack of quantification of metal mobilization particularly on the basis of changing geochemical conditions. Moreover, mobile amounts of metals in the soil solution do not indicate to which extent remobilized metals will be transported to water bodies or plants and therefore potentially have toxicological effects. Consequently, floodplain areas still need to be taken into consideration when studying the role and behavior of sediments and soils for transporting pollutants within river systems, particularly concerning the Water Framework Directive.

Composition of minerals and trace elements at Mamasani thermal source: A possible preventive treatment for some skin diseases.

PubMed

Hamidizadeh, Nasrin; Simaeetabar, Shima; Handjani, Farhad; Ranjbar, Sara; Moghadam, Mohammad Gohari; Parvizi, Mohammad Mahdi

2017-01-01

Some skin diseases are incurable and modern medicine can only control them. In addition, alternative treatment remedies including balneotherapy can be effective in improving skin conditions. However, there are only a limited number of studies on particular mineral or trace elements of mineral sources that have been identified in Iran. In this respect, the amount of minerals and trace elements in Mamasani thermal source, Fars Province, Iran, was measured using electrochemical, titration, and spectrophotometric methods and evaluated. The amount of minerals and trace elements in Mamasani thermal source, Fars Province, Iran, was measured using electrochemical, titration, and spectrophotometric methods. The concentrations of natural gases such as H 2 S and NO 3 in Mamasani thermal source were measured to be 22.10 mg/L and 42.79 mg/L, respectively. The source also contained major ions such as chloride, sulfate, sodium, calcium, magnesium, potassium, and carbonate. Due to the high concentration of chloride, sulfate, and sodium ions in comparison with other major ions, the water source is also classified as sulfide water. The existing trace elements in this thermal water source are iron, zinc, copper, selenium, cobalt, chromium, boron, silisium, aluminum, magnesium, and molybdenum. We concluded that bathing in this source could be beneficial. As nitrate concentration is close to the highest standard concentration for drinking water, it can be used in chronic dermatitis, psoriasis, burns, and allergy. Furthermore, the antibacterial and antifungal effects of sulfur-containing water in this source can be helpful in the treatment of leg ulcers, tinea versicolor, tinea corporis, and tinea capitis.

Trace elements geochemistry of fractured basement aquifer in southern Malawi: A case of Blantyre rural

NASA Astrophysics Data System (ADS)

Mapoma, Harold Wilson Tumwitike; Xie, Xianjun; Nyirenda, Mathews Tananga; Zhang, Liping; Kaonga, Chikumbusko Chiziwa; Mbewe, Rex

2017-07-01

In this study, twenty one (21) trace elements in the basement complex groundwater of Blantyre district, Malawi were analyzed. The majority of the analyzed trace elements in the water were within the standards set by World Health Organization (WHO) and Malawi Standards Board (MSB). But, iron (Fe) (BH16 and 21), manganese (Mn) (BH01) and selenium (Se) (BH02, 13, 18, 19 and 20) were higher than the WHO and MSB standards. Factor analysis (FA) revealed up to five significant factors which accounted for 87.4% of the variance. Factor 1, 2 and 3 suggest evaporite dissolution and silicate weathering processes while the fourth factor may explain carbonate dissolution and pH influence on trace element geochemistry of the studied groundwater samples. According to PHREEQC computed saturation indices, dissolution, precipitation and rock-water-interaction control the levels of trace elements in this aquifer. Elevated concentrations of Fe, Mn and Se in certain boreholes are due to the geology of the aquifer and probable redox status of groundwater. From PHREEQC speciation results, variations in trace element species were observed. Based on this study, boreholes need constant monitoring and assessment for human consumption to avoid health related issues.

Chemical characterization of ambient aerosol collected during the northeast monsoon season over the Arabian Sea: Labile-Fe(II) and other trace metals

NASA Astrophysics Data System (ADS)

Johansen, Anne M.; Hoffmann, Michael R.

2003-07-01

Ambient aerosol samples were collected over the Arabian Sea during the month of March of 1997, aboard the German R/V Sonne, as part of the German Joint Global Ocean Flux Study (JGOFS) project. This is the third study in a series of analogous measurements taken over the Arabian Sea during different seasons of the monsoon. Dichotomous high-volume collector samples were analyzed for ferrous iron immediately after collection, while trace metals, anions, and cations were determined upon return to the laboratory. The main crustal component was geochemically well represented by the average crustal composition and amounted to 5.94 ± 3.08 μg m-3. An additional crustal constituent of clay-like character, rich in water-soluble Ca and Mg, was seen in the fine fraction in air masses of Arabian origin. Total ferrous iron concentrations varied from 3.9 to 17.2 ng m-3 and averaged 9.8 ± 3.4 ng m-3, with 87.2% of Fe(II) present in the fine aerosol fraction. Fe(II) concentrations accounted for on average 1.3 ± 0.5% of the total Fe. While ferrous iron in the coarse fraction appeared to be correlated with the main crustal component, the fine Fe(II) fraction exhibited a more complex behavior. The anthropogenic contribution to the aerosol, as traced by Pb, Zn, and some anions and cations, was found to be considerably larger, especially during the first 10 days of this cruise, than in previously collected samples from the inter-monsoon and southwest monsoon of 1995.

Molybdenite Mineral Evolution: A Study Of Trace Elements Through Time

NASA Astrophysics Data System (ADS)

McMillan, M. M.; Downs, R. T.; Stein, H. J.; Zimmerman, A.; Beitscher, B. A.; Sverjensky, D. A.; Papineau, D.; Armstrong, J. T.; Hazen, R. M.

2010-12-01

Mineral evolution explores changes through time in Earth’s near-surface mineralogy, including diversity of species, relative abundances of species, and compositional ranges of major, minor and trace elements. Such studies elucidate the co-evolution of the geosphere and biosphere. Accordingly, we investigated trace and minor elements in molybdenite (MoS2) with known ages from 3 billion years to recent. Molybdenite, the commonest mineral of Mo, may prove to be a useful case study as a consequence of its presence in Earth’s early history, the effects of oxidation on Mo mobility, and the possible role of Mo mineral coevolution with biology via its role in the nitrogen fixation enzyme nitrogenase. We employed ICPMS, SEM and electron microprobe analyses to detect trace and minor elements. We detected significant amounts of Mn and Cu (~100 ppm) and greater amounts of Fe, W, and Re (to ~4000 ppm). Molybdenites commonly contain micro inclusions, resulting in local concentrations in otherwise homogeneous samples. Inhomogeneities in Fe, Zn and Sn concentrations, for example, point to the presence of pyrite, sphalerite and cassiterite inclusions, respectively. Analyses examined as a function of time reveal that samples containing significant concentrations (>200 ppm, compared to average values < 100 ppm) of W and Re formed primarily within the last billion years. These trends may reflect changes in the mobility of W and Re in oxic hydrothermal fluids at shallow crustal conditions following the Great Oxidation Event.

National Trends in Trace Metals Concentrations in Ambient Particulate Matter

NASA Astrophysics Data System (ADS)

McCarthy, M. C.; Hafner, H. R.; Charrier, J. G.

2007-12-01

Ambient measurements of trace metals identified as hazardous air pollutants (HAPs, air toxics) collected in the United States from 1990 to 2006 were analyzed for long-term trends. Trace metals analyzed include lead, manganese, arsenic, chromium, nickel, cadmium, and selenium. Visual and statistical analyses were used to identify and quantify temporal variations in air toxics at national and regional levels. Trend periods were required to be at least five years. Lead particles decreased in concentration at most monitoring sites, but trends in other metals were not consistent over time or spatially. In addition, routine ambient monitoring methods had method detection limits (MDLs) too high to adequately measure concentrations for trends analysis. Differences between measurement methods at urban and rural sites also confound trends analyses. Improvements in MDLs, and a better understanding of comparability between networks, are needed to better quantify trends in trace metal concentrations in the future.

Concentrations of selected trace elements in mineral and spring bottled waters on the Serbian market.

PubMed

Ristić, M; Popović, I; Pocajt, V; Antanasijević, D; Perić-Grujić, A

2011-01-01

Eight selected trace elements, which are generally included in regulations, were analyzed in 23 types of bottled waters. Ten mineral and seven spring bottled waters were from the Serbian market and six mineral bottled waters were obtained in different EU countries. For the purpose of comparison, selected tap waters were also analyzed. Inductively coupled plasma mass spectrometry (ICP-MS) was used for the analysis of trace elements (arsenic, cadmium, copper, manganese, nickel, lead and antimony). Results were compared with the Serbian regulations for bottled water, EU regulations and guideline values set by the World Health Organization for drinking water. With few exceptions, the trace element levels of most bottled waters were below the guideline values. However, a higher content of antimony was observed in waters from polyethylene terephthalate (PET) containers, indicating a potential leaching of this element from the plastic packaging.

Trace element release from estuarine sediments of South Mosquito Lagoon near Kennedy Space Center

NASA Technical Reports Server (NTRS)

Menon, M. P.; Ghuman, G. S.; Emeh, C. O.

1979-01-01

Analytical partitioning of four trace metals in estuarine sediments collected from eight sites in South Mosquito Lagoon near Kennedy Space Center, in terms of four different categories was accomplished using four different extraction techniques. The concentrations of the four trace metals, Zn, Mn, Cd, and Cu, released in interstitial water extract, 1 N ammonium acetate extract, conc. HCl extract and fusion extract of sediments as well as their concentrations in water samples collected from the same location were determined using flame atomic absorption technique. From the analytical results the percentages of total amount of each metal distributed among four different categories, interstitial water phase, acetate extractable, acid extractable and detrital crystalline material, were determined. Our results suggest that analytical partitioning of trace metals in estuarine sediments may be used to study the mechanism of incorporation of trace metals with sediments from natural waters. A correlation between the seasonal variation in the concentration of acetate extractable trace metals in the sediment and similar variation in their concentration in water was observed. A mechanism for the release of trace metals from estuarine sediments to natural water is also suggested.

New insights into trace element wet deposition in the Himalayas: amounts, seasonal patterns, and implications.

PubMed

Cong, Zhiyuan; Kang, Shichang; Zhang, Yulan; Gao, Shaopeng; Wang, Zhongyan; Liu, Bin; Wan, Xin

2015-02-01

Our research provides the first complete year-long dataset of wet deposition of trace elements in the high Himalayas based on a total of 42 wet deposition events on the northern slope of Mt. Qomolangma (Everest). Except for typical crustal elements (Al, Fe, and Mn), the concentration level of most trace elements (Sc, V, Cr, Co, Ni, Cu, Zn, As, Mo, Cd, Sn, Cs, Pb, Bi, and U) are generally comparable to those preserved in snow pits and ice cores from the nearby East Rongbuk Glacier. Cadmium was the element most affected by anthropogenic emissions. No pronounced seasonal variations are observed for most trace elements despite different transport pathways. In our study, the composition of wet precipitation reflects a regional background condition and is not clearly related to specific source regions. For the trace element record from ice cores and snow pits in the Himalayas, it could be deduced that the pronounced seasonal patterns were caused by the dry deposition of trace elements (aerosols) during their long exposure to the atmosphere after precipitation events. Our findings are of value for the understanding of the trace element deposition mechanisms in the Himalayas.

Ray tracing: Experience at SRC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Severson, M.

1996-09-01

SHADOW [B. Lai and F. Cerrina, Nucl. Instrum. Methods A {bold 246}, 337 (1986)] is the primary ray-tracing program used at SRC. Ray tracing provides a tremendous amount of information regarding beamline layout, mirror sizes, resolution, alignment tolerances, and beam size at various locations. It also provides a way to check the beamline design for errors. Two recent designs have been ray traced extensively: an undulator-based, 4-meter, normal-incidence monochromator (NIM) [R. Reininger, M.C. Severson, R.W.C. Hansen, W.R. Winter, M.A. Green, and W.S. Trzeciak, Rev. Sci. Instrum. {bold 66}, 2194 (1995)] and an undulator-based, plane-grating monochromator (PGM) [R. Reininger, S.L. Crossley,more » M.A. Lagergren, M.C. Severson, and R.W.C. Hansen, Nucl. Instrum. Methods A {bold 347}, 304 (1994)]. {copyright} {ital 1996 American Institute of Physics.}« less

On-Line Analyzer For Monitoring Trace Amounts Of Oil In Turbid Waters

NASA Astrophysics Data System (ADS)

Niemela, P.; Jaatinen, J.

1986-05-01

This report presents an automated analyzer which continuously monitors oil content of a sample water stream that flows through the analyzer. The measuring principle is based on the absorption of infrared radiation by oil molecules contained in the sample water. The wavelength band that is used in the measurement is at 3.4 μm, where different types of oils show nearly equal absorption. Another wavelength band of 3.6 μm, where oil has no absorption, is used to compensate the effect of turbidity, which is due to solid particles and oil droplets contained in the sample water. Before entering the analyzer the sample water flow is properly homogenized. To compensate the strong absorption by water molecules in these wavelength bands the sample water is compared with reference water. This is done by directing them alternately through the same measuring cell. The reference water is obtained from the sample water by ultrafiltration and it determines the base line for the contaminated sample water. To ensure the stability of the base line, temperature and pressure differences of the two waters are kept within adequate ranges. Areas of application of the analyzer are wide ranging i.a. from ships' discharge waters to waste waters of industrial processes. The first application of the analyzer is on board oil tankers to control the discharge process of bilge and ballast waters. The analyzer is the first that fully corresponds to the stringent regulations for oil content monitors by the International Maritime Organization (IMO). Pilot installations of the analyzer are made on industrial plants.

Assessment of the risk of pollution by sulfur compounds and heavy metals in soils located in the proximity of a disused for 20 years sulfur mine (SE Poland).

PubMed

Sołek-Podwika, Katarzyna; Ciarkowska, Krystyna; Kaleta, Dorota

2016-09-15

The study assessed the long-term effects of anthropogenic pressure of the sulfur industry on turf-covered soils located in the vicinity of the sulfur mine Grzybów. The study assumes that 20 years which elapsed since the end of the exploitation of sulfur is a period sufficiently long for the content of sulfur compounds in soils not to exceed the permissible level and that soil of the region can be classified as not contaminated. A part of the study involved identification of changes in the contents Stot. and SSO4(2-) in soils collected in the 1970s and early twenty-first century. It was also traced the relationship between the content of sulfur compounds and selected soil properties and estimated risk of soil environment pollution by heavy metals. Mean contents of trace elements studied amounted to 10.2-10.8 mg kg(-1) for Pb, 14.3-39.4 mg kg(-1) for Zn, 0.2-0.4 mg kg(-1) for Cd, 3.8-32.2 mg kg(-1) for Cr, 2.7-15.1 mg kg(-1) for Cu and 2.9-18.7 mg kg(-1) for Ni. Based on the results of SSO4(2-) content in soils collected at a distance of 1 km from the mine, it was found out that despite the passage of years, the amount of this type of sulfur still is increased and exceeds 0.14 g kg(-1). As the distance from the mine grew lower (from 0.017 to 0.03 g kg(-1)) average content of the sulfur form was observed. In the studied soil material we found generally positive, strong correlation between the Stot. and SSO4(2-) content and analyzed trace elements. The degree of contamination of examined soils with heavy metals was estimated on the basis of the integrated pollution index, which pointed to a moderate and low level of antropogenization of this area. In addition, the relationship between the determined characteristics of soils (Corg. contents, the fraction <0.002 mm and pH) and heavy metals confirms that the trace elements present in soils do not occur in mobile forms in the soil solution. Copyright © 2016 Elsevier Ltd. All rights reserved.

Integration of Ground-Based Solar FT-IR Absorption Spectroscopy and Open-Path Systems for Atmospheric Analysis

NASA Astrophysics Data System (ADS)

Steill, J. D.; Hager, J. S.; Compton, R. N.

2005-12-01

Air quality issues in the Knoxville and East Tennessee region are of great concern, particularly as regards the nearby Great Smoky Mountains National Park. Integration of a Bomem DA8 FT-IR spectrometer with rooftop sun-tracking optics and an open-path system provides a unique opportunity to analyze the local atmospheric chemical composition. Many trace atmospheric constituents are open to this analysis, such as O3, CO, CH4, and N2O. Boundary layer concentrations as well as total column abundances and vertical concentration profiles are derived. Vertical concentration profiles are determined by fitting solar absorbance lines with the SFIT2 algorithm. Improved fitting of solar spectra has been demonstrated by incorporating the tropospheric concentrations as determined by open-path measurements. In addition to providing a means to improve the analysis of solar spectra, the open-path data is useful for elucidation of diurnal trends in the trace gas concentrations. Anthropogenic influences are of special interest, and seasonal and daily trends in amounts of tropospheric pollutants such as ozone correlate with other sources such as the EPA. Although obviously limited by weather considerations, the technique is suited to the regional climate and a body of data of more than two years extent is available for analysis.

The “Dark Side” of Food Stuff Proteomics: The CPLL-Marshals Investigate

PubMed Central

Righetti, Pier Giorgio; Fasoli, Elisa; D’Amato, Alfonsina; Boschetti, Egisto

2014-01-01

The present review deals with analysis of the proteome of animal and plant-derived food stuff, as well as of non-alcoholic and alcoholic beverages. The survey is limited to those systems investigated with the help of combinatorial peptide ligand libraries, a most powerful technique allowing access to low- to very-low-abundance proteins, i.e., to those proteins that might characterize univocally a given biological system and, in the case of commercial food preparations, attest their genuineness or adulteration. Among animal foods the analysis of cow’s and donkey’s milk is reported, together with the proteomic composition of egg white and yolk, as well as of honey, considered as a hybrid between floral and animal origin. In terms of plant and fruits, a survey is offered of spinach, artichoke, banana, avocado, mango and lemon proteomics, considered as recalcitrant tissues in that small amounts of proteins are dispersed into a large body of plant polymers and metabolites. As examples of non-alcoholic beverages, ginger ale, coconut milk, a cola drink, almond milk and orgeat syrup are analyzed. Finally, the trace proteome of white and red wines, beer and aperitifs is reported, with the aim of tracing the industrial manipulations and herbal usage prior to their commercialization. PMID:28234315

[Trace analysis of aristolochic acid A].

PubMed

Liu, Yalin; Gao, Huimin; Wang, Zhimin; Zhang, Qiwei

2010-12-01

A HPLC method for limit detection of aristolochic acid A in the Chinese herbs containing aristolochic acid or suspected-containing aristolochic acid and their preparations was established. The samples were analyzed on an Alltima C18 column eluted with methanol-water-acetic acid (68:32:1.5) as the mobile phase. Flow rate was at 1.0 mL x min(-1) and the detection wavelength was at 390 nm. The calibration curve was linear over the range from 0.016 to 0.51 g (r = 0.9993) and LOD was 4 ng. The average recovery was 101.2% with RSD of 2.01%. The procedures of sample preparation were systematically investigated. The contents of aristolochic acid A in Radix et Rhizoma Asari bought from market or drugstore were fluctuated from 3.1 to 26.6 microg x g(-1) and 3 of 11 samples accorded with the quality requirement of current Chinese Pharmacopoeia. Among 15 batches samples of Chinese medicaments, only one sample was found to contain aristolochic acid A. The present investigation shows that the method is sensitive and repeatable and it could be used for the limit detection of aristolochic acid A in the Chinese herbal medicines containing trace amount of aristolochic acid A or suspected-containing aristolochic acid A and their preparations.

Determination of trace amounts of rare-earth elements in highly pure neodymium oxide by sector field inductively coupled plasma mass spectrometry (ICP-SFMS) and high-performance liquid chromatography (HPLC) techniques

NASA Astrophysics Data System (ADS)

Pedreira, W. R.; Sarkis, J. E. S.; da Silva Queiroz, C. A.; Rodrigues, C.; Tomiyoshi, I. A.; Abrão, A.

2003-02-01

Recently rare-earth elements (REE) have received much attention in fields of geochemistry and industry. Rapid and accurate determinations of them are increasingly required as industrial demands expand. Sector field inductively coupled plasma mass spectrometry (ICP-SFMS) with high-performance liquid chromatography (HPLC) has been applied to the determination of REE. HR ICP-MS was used as an element-selective detector for HPLC in highly pure materials. The separation of REE with HPLC helped to avoid erroneous analytical results due to spectral interferences. Sixteen elements (Sc, Y and 14 lanthanides) were determined selectively with the HPLC/ICP-SFMS system using a concentration gradient methods. The detection limits with the HPLC/ICP-SFMS system were about 0.5-10 pg mL-1. The percentage recovery ranged from 90% to 100% for different REE. The %RSD of the methods varying between 2.5% and 4.5% for a set of five (n=5) replicates was found for the IPEN's material and for the certificate reference sample. Determination of trace REEs in two highly pure neodymium oxides samples (IPEN and Johnson Matthey Company) were performed. In short, the IPEN's materials which are highly pure (>99.9%) were successfully analyzed without spectral interferences.

Chiral pharmaceuticals: A review on their environmental occurrence and fate processes.

PubMed

Sanganyado, Edmond; Lu, Zhijiang; Fu, Qiuguo; Schlenk, Daniel; Gan, Jay

2017-11-01

More than 50% of pharmaceuticals in current use are chiral compounds. Enantiomers of the same pharmaceutical have identical physicochemical properties, but may exhibit differences in pharmacokinetics, pharmacodynamics and toxicity. The advancement in separation and detection methods has made it possible to analyze trace amounts of chiral compounds in environmental media. As a result, interest on chiral analysis and evaluation of stereoselectivity in environmental occurrence, phase distribution and degradation of chiral pharmaceuticals has grown substantially in recent years. Here we review recent studies on the analysis, occurrence, and fate of chiral pharmaceuticals in engineered and natural environments. Monitoring studies have shown ubiquitous presence of chiral pharmaceuticals in wastewater, surface waters, sediments, and sludge, particularly β-receptor antagonists, analgesics, antifungals, and antidepressants. Selective sorption and microbial degradation have been demonstrated to result in enrichment of one enantiomer over the other. The changes in enantiomer composition may also be caused by biologically catalyzed chiral inversion. However, accurate evaluation of chiral pharmaceuticals as trace environmental pollutants is often hampered by the lack of identification of the stereoconfiguration of enantiomers. Furthermore, a systematic approach including occurrence, fate and transport in various environmental matrices is needed to minimize uncertainties in risk assessment of chiral pharmaceuticals as emerging environmental contaminants. Copyright © 2017 Elsevier Ltd. All rights reserved.

Chemical elements in Mediterranean macroalgae. A review.

PubMed

Bonanno, Giuseppe; Orlando-Bonaca, Martina

2018-02-01

This review analyzes the state of knowledge on the capacity of Mediterranean macroalgae to accumulate, tolerate and biomonitor macro- and micro-elements present in seawater and sediments. The results show that the investigated macroalgal species amount to c. 5.0% of all Mediterranean native Rhodophyta, Chlorophyta and Ochrophyta. The most commonly analyzed elements in algae were Pb, Cd, Zn and Cu, whereas very few studies were available for macroelements such as Ca and K. Uptake mechanisms and the factors influencing accumulation are overall well known, but the available studies are restricted to a limited number of chemical elements and algal species. This review also shows that macroalgae can accumulate and tolerate high concentrations of chemical elements, and can act as effective bioindicators of marine pollution. Phytotoxic limits for algal species are not clearly identified by the available studies and require further investigation. Future research should focus on the development of protocols for long-term biomonitoring programmes through the use of macroalgae. Future studies also need to investigate the biomagnification of toxic trace elements in macroalgae-based food webs. Copyright © 2017 Elsevier Inc. All rights reserved.

Using laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) to characterize copper, zinc and mercury along grizzly bear hair providing estimate of diet.

PubMed

Noël, Marie; Christensen, Jennie R; Spence, Jody; Robbins, Charles T

2015-10-01

We enhanced an existing technique, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), to function as a non-lethal tool in the temporal characterization of trace element exposure in wild mammals. Mercury (Hg), copper (Cu), cadmium (Cd), lead (Pb), iron (Fe) and zinc (Zn) were analyzed along the hair of captive and wild grizzly bears (Ursus arctos horribilis). Laser parameters were optimized (consecutive 2000 μm line scans along the middle line of the hair at a speed of 50 μm/s; spot size=30 μm) for consistent ablation of the hair. A pressed pellet of reference material DOLT-2 and sulfur were used as external and internal standards, respectively. Our newly adapted method passed the quality control tests with strong correlations between trace element concentrations obtained using LA-ICP-MS and those obtained with regular solution-ICP-MS (r(2)=0.92, 0.98, 0.63, 0.57, 0.99 and 0.90 for Hg, Fe, Cu, Zn, Cd and Pb, respectively). Cross-correlation analyses revealed good reproducibility between trace element patterns obtained from hair collected from the same bear. One exception was Cd for which external contamination was observed resulting in poor reproducibility. In order to validate the method, we used LA-ICP-MS on the hair of five captive grizzly bears fed known and varying amounts of cutthroat trout over a period of 33 days. Trace element patterns along the hair revealed strong Hg, Cu and Zn signals coinciding with fish consumption. Accordingly, significant correlations between Hg, Cu, and Zn in the hair and Hg, Cu, and Zn intake were evident and we were able to develop accumulation models for each of these elements. While the use of LA-ICP-MS for the monitoring of trace elements in wildlife is in its infancy, this study highlights the robustness and applicability of this newly adapted method. Copyright © 2015 Elsevier B.V. All rights reserved.

An optimization of the FPGA trigger based on the artificial neural network for a detection of neutrino-origin showers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Szadkowski, Zbigniew; Glas, Dariusz; Pytel, Krzysztof

Observations of ultra-high energy neutrinos became a priority in experimental astro-particle physics. Up to now, the Pierre Auger Observatory did not find any candidate on a neutrino event. This imposes competitive limits to the diffuse flux of ultra-high energy neutrinos in the EeV range and above. A very low rate of events potentially generated by neutrinos is a significant challenge for a detection technique and requires both sophisticated algorithms and high-resolution hardware. A trigger based on a artificial neural network was implemented into the Cyclone{sup R} V E FPGA 5CEFA9F31I7. The prototype Front-End boards for Auger-Beyond-2015 with Cyclone{sup R} Vmore » E can test the neural network algorithm in real pampas conditions in 2015. Showers for muon and tau neutrino initiating particles on various altitudes, angles and energies were simulated in CORSICA and Offline platforms giving pattern of ADC traces in Auger water Cherenkov detectors. The 3-layer 12-10-1 neural network was taught in MATLAB by simulated ADC traces according the Levenberg-Marquardt algorithm. Results show that a probability of a ADC traces generation is very low due to a small neutrino cross-section. Nevertheless, ADC traces, if occur, for 1-10 EeV showers are relatively short and can be analyzed by 16-point input algorithm. For 100 EeV range traces are much longer, but with significantly higher amplitudes, which can be detected by standard threshold algorithms. We optimized the coefficients from MATLAB to get a maximal range of potentially registered events and for fixed-point FPGA processing to minimize calculation errors. Currently used Front-End boards based on no-more produced ACEXR PLDs and obsolete Cyclone{sup R} FPGAs allow an implementation of relatively simple threshold algorithms for triggers. New sophisticated trigger implemented in Cyclone{sup R} V E FPGAs with large amount of DSP blocks, embedded memory running with 120 - 160 MHz sampling may support to discover neutrino events in the Pierre Auger Observatory. (authors)« less

Determination of mineral, trace element, and pesticide levels in honey samples originating from different regions of Malaysia compared to manuka honey.

PubMed

Moniruzzaman, Mohammed; Chowdhury, Muhammed Alamgir Zaman; Rahman, Mohammad Abdur; Sulaiman, Siti Amrah; Gan, Siew Hua

2014-01-01

The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination.

Determination of Mineral, Trace Element, and Pesticide Levels in Honey Samples Originating from Different Regions of Malaysia Compared to Manuka Honey

PubMed Central

Moniruzzaman, Mohammed; Chowdhury, Muhammed Alamgir Zaman; Rahman, Mohammad Abdur; Sulaiman, Siti Amrah; Gan, Siew Hua

2014-01-01

The present study was undertaken to determine the content of six minerals, five trace elements, and ten pesticide residues in honeys originating from different regions of Malaysia. Calcium (Ca), magnesium (Mg), iron (Fe), and zinc (Zn) were analyzed by flame atomic absorption spectrometry (FAAS), while sodium (Na) and potassium (K) were analyzed by flame emission spectrometry (FAES). Trace elements such as arsenic (As), lead (Pb), cadmium (Cd), copper (Cu), and cobalt (Co) were analyzed by graphite furnace atomic absorption spectrometry (GFAAS) following the microwave digestion of honey. High mineral contents were observed in the investigated honeys with K, Na, Ca, and Fe being the most abundant elements (mean concentrations of 1349.34, 236.80, 183.67, and 162.31 mg/kg, resp.). The concentrations of the trace elements were within the recommended limits, indicating that the honeys were of good quality. Principal component analysis reveals good discrimination between the different honey samples. The pesticide analysis for the presence of organophosphorus and carbamates was performed by high performance liquid chromatography (HPLC). No pesticide residues were detected in any of the investigated honey samples, indicating that the honeys were pure. Our study reveals that Malaysian honeys are rich sources of minerals with trace elements present within permissible limits and that they are free from pesticide contamination. PMID:24982869

Blood-collection device for trace and ultra-trace metal specimens evaluated.

PubMed

Moyer, T P; Mussmann, G V; Nixon, D E

1991-05-01

We evaluated the evacuated phlebotomy tube designed specifically for trace metal analysis by Sherwood Medical Co. Pools of human serum containing known concentrations of aluminum, arsenic, calcium, cadmium, copper, chromium, iron, lead, magnesium, manganese, mercury, selenium, and zinc were exposed to the tube and rubber stopper for defined periods ranging from 5 min to 24 h. Analysis for each element was performed in a randomized fashion under rigidly controlled conditions by use of standard electrothermal atomization atomic absorption spectroscopy, inductively coupled plasma atomic emission spectroscopy, and cold vapor atomic absorption spectrometry. In addition, for comparative purposes, we collected blood samples from normal volunteers by use of ultra-clean polystyrene phlebotomy syringes as well as standard evacuated phlebotomy tubes. We conclude that, except for lead, there was no significant contribution of any trace element studied from the evaluated tube and stopper to the serum. Because whole blood is the usual specimen for lead testing, the observation of a trace amount of lead in this tube designed for serum collection is trivial.

Variation in Macro and Trace Elements in Progression of Type 2 Diabetes

PubMed Central

2014-01-01

Macro elements are the minerals of which the body needs more amounts and are more important than any other elements. Trace elements constitute a minute part of the living tissues and have various metabolic characteristics and functions. Trace elements participate in tissue and cellular and subcellular functions; these include immune regulation by humoral and cellular mechanisms, nerve conduction, muscle contractions, membrane potential regulations, and mitochondrial activity and enzyme reactions. The status of micronutrients such as iron and vanadium is higher in type 2 diabetes. The calcium, magnesium, sodium, chromium, cobalt, iodine, iron, selenium, manganese, and zinc seem to be low in type 2 diabetes while elements such as potassium and copper have no effect. In this review, we emphasized the status of macro and trace elements in type 2 diabetes and its advantages or disadvantages; this helps to understand the mechanism, progression, and prevention of type 2 diabetes due to the lack and deficiency of different macro and trace elements. PMID:25162051

Analysis of Cloud-Based Database Systems

DTIC Science & Technology

2015-06-01

EU) citizens under the Patriot Act [3]. Unforeseen virtualization bugs have caused wide-reaching outages [4], leaving customers helpless to assist...collected from SQL Server Profiler traces. We analyze the trace results captured from our test bed both before and after increasing system resources...cloud test- bed . A. DATA COLLECTION, PARSING, AND ORGANIZATION Once we finished collecting the trace data, we knew we needed to have as close a

PRESERVATION OF TRACE METALS IN WATER SAMPLES

EPA Science Inventory

Questions about trace metal preservation are resurfacing because the health effect risks associated with certain metals continue to drive the required reporting limits lower. Inductively coupled plasma-mass spectrometry was used in this study to analyze preservation of samples co...

Modeling ECM fiber formation: structure information extracted by analysis of 2D and 3D image sets

NASA Astrophysics Data System (ADS)

Wu, Jun; Voytik-Harbin, Sherry L.; Filmer, David L.; Hoffman, Christoph M.; Yuan, Bo; Chiang, Ching-Shoei; Sturgis, Jennis; Robinson, Joseph P.

2002-05-01

Recent evidence supports the notion that biological functions of extracellular matrix (ECM) are highly correlated to its structure. Understanding this fibrous structure is very crucial in tissue engineering to develop the next generation of biomaterials for restoration of tissues and organs. In this paper, we integrate confocal microscopy imaging and image-processing techniques to analyze the structural properties of ECM. We describe a 2D fiber middle-line tracing algorithm and apply it via Euclidean distance maps (EDM) to extract accurate fibrous structure information, such as fiber diameter, length, orientation, and density, from single slices. Based on a 2D tracing algorithm, we extend our analysis to 3D tracing via Euclidean distance maps to extract 3D fibrous structure information. We use computer simulation to construct the 3D fibrous structure which is subsequently used to test our tracing algorithms. After further image processing, these models are then applied to a variety of ECM constructions from which results of 2D and 3D traces are statistically analyzed.

Ancient Oceans Had Less Oxygen

ERIC Educational Resources Information Center

King, Angela G.

2004-01-01

The amount of dissolved oxygen in the oceans in the mid-Proterozoic period has evolutionary implications since essential trace metals are redox sensitive. The findings suggest that there is global lack of oxygen in seawater.

Premature Craniosynostosis: A Complication of Thyroid Replacement Therapy

ERIC Educational Resources Information Center

Penfold, James L.; Simpson, Donald A.

1975-01-01

Presented are case studies of 3 children, infancy to 9-years-old, whose premature skull ossification (craniosynostosis) is traced to iatrogenic hyperthyroidism from the administration of excessive amounts of thyroid hormone. (CL)

Electrochemical Impedance Sensors for Monitoring Trace Amounts of NO3 in Selected Growing Media.

PubMed

Ghaffari, Seyed Alireza; Caron, William-O; Loubier, Mathilde; Normandeau, Charles-O; Viens, Jeff; Lamhamedi, Mohammed S; Gosselin, Benoit; Messaddeq, Younes

2015-07-21

With the advent of smart cities and big data, precision agriculture allows the feeding of sensor data into online databases for continuous crop monitoring, production optimization, and data storage. This paper describes a low-cost, compact, and scalable nitrate sensor based on electrochemical impedance spectroscopy for monitoring trace amounts of NO3- in selected growing media. The nitrate sensor can be integrated to conventional microelectronics to perform online nitrate sensing continuously over a wide concentration range from 0.1 ppm to 100 ppm, with a response time of about 1 min, and feed data into a database for storage and analysis. The paper describes the structural design, the Nyquist impedance response, the measurement sensitivity and accuracy, and the field testing of the nitrate sensor performed within tree nursery settings under ISO/IEC 17025 certifications.

Electrochemical Impedance Sensors for Monitoring Trace Amounts of NO3 in Selected Growing Media

PubMed Central

Ghaffari, Seyed Alireza; Caron, William-O.; Loubier, Mathilde; Normandeau, Charles-O.; Viens, Jeff; Lamhamedi, Mohammed S.; Gosselin, Benoit; Messaddeq, Younes

2015-01-01

With the advent of smart cities and big data, precision agriculture allows the feeding of sensor data into online databases for continuous crop monitoring, production optimization, and data storage. This paper describes a low-cost, compact, and scalable nitrate sensor based on electrochemical impedance spectroscopy for monitoring trace amounts of NO3− in selected growing media. The nitrate sensor can be integrated to conventional microelectronics to perform online nitrate sensing continuously over a wide concentration range from 0.1 ppm to 100 ppm, with a response time of about 1 min, and feed data into a database for storage and analysis. The paper describes the structural design, the Nyquist impedance response, the measurement sensitivity and accuracy, and the field testing of the nitrate sensor performed within tree nursery settings under ISO/IEC 17025 certifications. PMID:26197322

Solid phase extraction of trace amounts of Ag, Cd, Cu, and Zn in environmental samples using magnetic nanoparticles coated by 3-(trimethoxysilyl)-1-propantiol and modified with 2-amino-5-mercapto-1,3,4-thiadiazole and their determination by ICP-OES.

PubMed

Mashhadizadeh, Mohammad Hossein; Karami, Zahra

2011-06-15

A fast, sensitive, and simple method using magnetic nanoparticles (MNPs) coated by 3-(trimethoxysilyl)-1-propantiol and modified with 2-amino-5-mercapto-1,3,4-thiadiazole, as an adsorbent has been successfully developed for extraction, preconcentration, and determination of trace amounts of Ag, Cd, Cu, and Zn from environmental samples. The prepared nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). These magnetic nanoparticles can be easily dispersed in aqueous samples and retrieved by the application of external magnetic field via a piece of permanent magnet. The main factors affecting the extraction efficiency such as pH value, sample volume, eluent concentration and volume, ultrasonication time, and coexisting ions have been investigated and established. Under the optimal conditions, high concentration factors (194, 190, 170, and 182) were achieved for Ag, Cd, Cu, and Zn with relative standard deviations of 5.31%, 4.03%, 3.62%, and 4.20%, respectively. The limits of detection for Ag, Cd, Cu, and Zn were as low as 0.12, 0.12, 0.13 and 0.11 ng mL(-1). The prepared sorbent was applied for preconcentration of trace amounts of Ag, Cd, Cu, and Zn in the various water samples with satisfactory results. Copyright © 2011 Elsevier B.V. All rights reserved.

Organic Elemental Analysis.

ERIC Educational Resources Information Center

Ma, T. S.; Wang, C. Y.

1984-01-01

Presents a literature review on methods used to analyze organic elements. Topic areas include methods for: (1) analyzing carbon, hydrogen, and nitrogen; (2) analyzing oxygen, sulfur, and halogens; (3) analyzing other elements; (4) simultaneously determining several elements; and (5) determing trace elements. (JN)

Experimental Constraints on Iron Mobilization into Biomass Burning Aerosols

NASA Astrophysics Data System (ADS)

Sherry, A. M.; Romaniello, S. J.; Herckes, P.; Anbar, A. D.

2017-12-01

Atmospheric deposition of iron (Fe) can limit marine primary productivity and, therefore, carbon dioxide uptake. Recent modeling studies suggest that biomass burning aerosols may contribute a significant amount of soluble Fe to the surface ocean. To address this hypothesis, we collected foliage samples from species representative of several biomes impacted by severe fire events. Existing studies of burn-induced trace element mobilization have often collected both entrained soil particles along with material from burning biomass, making it difficult to determine the actual source of aerosolized trace metals. In order to better constrain the importance of biomass vs. entrained soil as a source of trace metals in burn aerosols, we conducted burn experiments using soil-free foliage representative of a variety of fire-impacted ecosystems. The resulting burn aerosols were collected in two stages (PM > 2.5 μm and PM < 2.5 μm) on cellulose filters using a high-volume air sampler equipped an all-Teflon impactor. Unburned foliage and burn aerosols were analyzed for Fe and other trace metals using inductively coupled plasma mass spectrometry (ICP-MS). Our results show that 0.06-0.86 % of Fe in plant biomass is likely mobilized as atmospheric aerosols during biomass burning events, depending on the type of foliage. We used these results and estimates of annual global wildfire area to estimate the impact of biomass burning aerosols on total atmospheric Fe flux to the ocean. We estimate that biomass-derived Fe likely contributes 3% of the total soluble Fe flux from aerosols. Prior studies, which implicitly included both biomass and soil-derived Fe, concluded that biomass burning contributed as much as 7% of the total marine soluble Fe flux from aerosols. Together, these studies suggest that biomass and fire-entrained soil probably contribute equally to the total fire-derived Fe aerosol flux. Further study of solubility differences between plant- and soil-derived Fe is needed to improve estimates of the soluble Fe contribution from biomass burning to the marine soluble Fe flux.

Ion chromatography in the manufacture of multilayer circuit boards

NASA Astrophysics Data System (ADS)

Smith, R. E.

1987-10-01

Ion chromatography (IC) has proven useful in analyzing chemical solutions used in the manufacture of multilayer circuit boards. IC provides results on ions not expected in the production solutions. Thus, solution contamination and breakdown products can be monitored in every phase of the circuit board manufacturing. During the first phase, epoxy laminates experience an etchback, first in chromic acid, which can be analyzed for trace chloride and sulfate, then in ammonium bifluoride/HCl, which can be analyzed for fluoride and chloride. Following a wet blasting to roughen up the surface, 20 mu in. of copper are deposited using an electroless bath. Again, IC is applicable for monitoring formate, tartarate, and sulfate levels. Next, an acid copper bath is used to electroplate the through holes with 0.001 in. of ductile copper. This bath is analyzed for trace chloride. Photoimaging is then performed, and the organic solvents used can be assayed for trace ionic chloride. Finally, a fluoroboric acid-based tin-lead bath is used to deposit a solderable alloy. This bath is analyzed for total fluoroborate, tin, and lead. In addition, mobile phase ion chromatography (MPIC) is used to monitor the nonionic organic brighteners in the baths.

Ion chromatography in the manufacture of multilayer circuit boards

NASA Astrophysics Data System (ADS)

Smith, Robert E.

1990-01-01

Ion chromatography (IC) has proven useful in analyzing chemical solutions used in the manufacture of multilayer circuit boards. Unlike other chemical quantification techniques, IC provides results on ions not expected in the production solutions. Thus, solution contamination and break-down products can be monitored in every phase of the circuit board manufacturing. During the first phase, epoxy laminates experience an etchback, first in chromic acid, which can be analyzed for trace chloride and sulfate, then in ammonium bifluoride/HCl, which can be analyzed for fluoride and chloride. Following a wet-blasting to roughen up the surface, 20 microinches of copper are deposited using an electroless bath. Again, IC is applicable for monitoring formate, tartarate, and sulfate levels. Next, an acid copper bath is used to electroplate the through holes with 0.001 inches of ductile copper. This bath is analyzed for trace chloride. Photoimaging is then performed, and the organic solvents used can be assayed for trace ionic chloride. Finally, a fluoroboric acid-based tin-lead bath is used to deposit a solderable alloy. This bath is analyzed for fluoroborate, tin, and lead. In addition, mobile phase ion chromatography (MPIC) is used to monitor the nonionic organic brighteners in the baths.

Performance Data Gathering and Representation from Fixed-Size Statistical Data

NASA Technical Reports Server (NTRS)

Yan, Jerry C.; Jin, Haoqiang H.; Schmidt, Melisa A.; Kutler, Paul (Technical Monitor)

1997-01-01

The two commonly-used performance data types in the super-computing community, statistics and event traces, are discussed and compared. Statistical data are much more compact but lack the probative power event traces offer. Event traces, on the other hand, are unbounded and can easily fill up the entire file system during program execution. In this paper, we propose an innovative methodology for performance data gathering and representation that offers a middle ground. Two basic ideas are employed: the use of averages to replace recording data for each instance and 'formulae' to represent sequences associated with communication and control flow. The user can trade off tracing overhead, trace data size with data quality incrementally. In other words, the user will be able to limit the amount of trace data collected and, at the same time, carry out some of the analysis event traces offer using space-time views. With the help of a few simple examples, we illustrate the use of these techniques in performance tuning and compare the quality of the traces we collected with event traces. We found that the trace files thus obtained are, indeed, small, bounded and predictable before program execution, and that the quality of the space-time views generated from these statistical data are excellent. Furthermore, experimental results showed that the formulae proposed were able to capture all the sequences associated with 11 of the 15 applications tested. The performance of the formulae can be incrementally improved by allocating more memory at runtime to learn longer sequences.

Metallic contamination of food during preparation and storage: development of methods and some preliminary results.

PubMed

Samsahl, K; Wester, P O

1977-09-01

A chemical procedure for studying trace metals leached from metallic cooking utensils and preserving cans used in the preparation and storage of food has been developed. The method consists in the destruction of the major part of organic matter with HNO3-vapour followed by a complete mineralization of residues with small amounts of HNO3 in Teflon bombs at 150-160 degrees C under a pressure of 3-12 kg/cm2, depending on the amount and composition of the samples. Subsequently, an ion-exchange step removes major components and concentrates the trace elements in a dilute HNO3-solution, suitable for analysis. The ion-exchange separation, which is performed with an automatic ion-exchange separator, is practically free from blank level problems, e.g., typically a mean of less than 2 per cent of the sample levels of the elements being determined. Preliminary results show that large amounts of aluminium are released from vessels to the water during boiling at the same pH-range which exist for most drinking water in Sweden.

Grain-size distribution and selected major and trace element concentrations in bed-sediment cores from the Lower Granite Reservoir and Snake and Clearwater Rivers, eastern Washington and northern Idaho, 2010

USGS Publications Warehouse

Braun, Christopher L.; Wilson, Jennifer T.; Van Metre, Peter C.; Weakland, Rhonda J.; Fosness, Ryan L.; Williams, Marshall L.

2012-01-01

Fifty subsamples from 15 cores were analyzed for major and trace elements. Concentrations of trace elements were low, with respect to sediment quality guidelines, in most cores. Typically, major and trace element concentrations were lower in the subsamples collected from the Snake River compared to those collected from the Clearwater River, the confluence of the Snake and Clearwater Rivers, and Lower Granite Reservoir. Generally, lower concentrations of major and trace elements were associated with coarser sediments (larger than 0.0625 millimeter) and higher concentrations of major and trace elements were associated with finer sediments (smaller than 0.0625 millimeter).

Bread enriched in lycopene and other bioactive compounds by addition of dry tomato waste.

PubMed

Nour, Violeta; Ionica, Mira Elena; Trandafir, Ion

2015-12-01

The tomato processing industry generates high amounts of waste, mainly tomato skins and seeds, which create environmental problems. These residues are attractive sources of valuable bioactive components and pigments. A relatively simple recovery technology could consist of production of powders to be directly incorporated into foods. Tomato waste coming from a Romanian tomato processing unit were analyzed for the content of several bioactive compounds like ascorbic acid, β-carotene, lycopene, total phenolics, mineral and trace elements. In addition, its antioxidant capacity was assayed. Results revealed that tomato waste (skins and seeds) could be successfully utilized as functional ingredient for the formulation of antioxidant rich functional foods. Dry tomato processing waste were used to supplement wheat flour at 6 and 10 % levels (w/w flour basis) and the effects on the bread's physicochemical, baking and sensorial characteristics were studied. The following changes were observed: increase in moisture content, titratable acidity and bread crumb elasticity, reduction in specific volume and bread crumb porosity. The addition of dry tomato waste at 6 % resulted in bread with good sensory characteristics and overall acceptability but as the amount of dry tomato waste increased to 10 %, bread was less acceptable.

Hydrogen ions associated with the dry deposition of pollen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Noll, K.E.; Khalili, E.K.

The data provided in this paper demonstrates that pollen can generate significant amounts of hydrogen ions when added to water and that the deposition of tree pollen in forested areas represents a significant hydrogen ion source. Measurements of dry deposition of pollen were made during the months of May and June, 1987 in Northern Wisconsin, using a smooth surrogate surface. Rain samples were also collected. Deposited particles were weighed to determine mass fluxes, then washed and ion chromatographed for SO {sub 4} = and NO {sub 3} {minus} analysis. Species of pollen collected from different types of trees during themore » sampling period were analyzed for SO{sub 4} = NO {sub 3} and other trace constituents. The micrograms of hydrogen ions (protons) generated per gram for different types of pollen added to water, were measured. From 56 to 566 gm were generated per gram or pollen added. The amount generated varied with pollen type. Based on this information, the equivalent protons from the dry deposition of pollen were calculated and compared with the wet deposition proton data. The sulfate, nitrate, and protons associated with dry deposition were of a magnitude comparable with wet deposition.« less

Plutonium oxalate precipitation for trace elemental determination in plutonium materials

DOE PAGES

Xu, Ning; Gallimore, David; Lujan, Elmer; ...

2015-05-26

In this study, an analytical chemistry method has been developed that removes the plutonium (Pu) matrix from the dissolved Pu metal or oxide solution prior to the determination of trace impurities that are present in the metal or oxide. In this study, a Pu oxalate approach was employed to separate Pu from trace impurities. After Pu(III) was precipitated with oxalic acid and separated by centrifugation, trace elemental constituents in the supernatant were analyzed by inductively coupled plasma-optical emission spectroscopy with minimized spectral interferences from the sample matrix.

Progress of pharmacogenomic research related to minerals and trace elements.

PubMed

Zeng, Mei-Zi; Tang, Jie; Liu, Zhao-Qian; Zhou, Hong-Hao; Zhang, Wei

2015-10-01

Pharmacogenomics explores the variations in both the benefits and the adverse effects of a drug among patients in a target population by analyzing genomic profiles of individual patients. Minerals and trace elements, which can be found in human tissues and maintain normal physiological functions, are also in the focus of pharmacogenomic research. Single-nucleotide polymorphisms (SNPs) affect the metabolism, disposition and efficacy of minerals and trace elements in humans, resulting in changes of body function. This review describes some of the recent progress in pharmacogenomic research related to minerals and trace elements.

Trace element contamination in feather and tissue samples from Anna’s hummingbirds

USGS Publications Warehouse

Mikoni, Nicole A.; Poppenga, Robert H.; Ackerman, Joshua T.; Foley, Janet E.; Hazlehurst, Jenny; Purdin, Güthrum; Aston, Linda; Hargrave, Sabine; Jelks, Karen; Tell, Lisa A.

2017-01-01

Trace element contamination (17 elements; Be, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Mo, Cd, Ba, Hg, Tl, and Pb) of live (feather samples only) and deceased (feather and tissue samples) Anna's hummingbirds (Calypte anna) was evaluated. Samples were analyzed using inductively coupled plasma-mass spectrometry (ICP-MS; 17 elements) and atomic absorption spectrophotometry (Hg only). Mean plus one standard deviation (SD) was considered the benchmark, and concentrations above the mean + 1 SD were considered elevated above normal. Contour feathers were sampled from live birds of varying age, sex, and California locations. In order to reduce thermal impacts, minimal feathers were taken from live birds, therefore a novel method was developed for preparation of low mass feather samples for ICP-MS analysis. The study found that the novel feather preparation method enabled small mass feather samples to be analyzed for trace elements using ICP-MS. For feather samples from live birds, all trace elements, with the exception of beryllium, had concentrations above the mean + 1 SD. Important risk factors for elevated trace element concentrations in feathers of live birds were age for iron, zinc, and arsenic, and location for iron, manganese, zinc, and selenium. For samples from deceased birds, ICP-MS results from body and tail feathers were correlated for Fe, Zn, and Pb, and feather concentrations were correlated with renal (Fe, Zn, Pb) or hepatic (Hg) tissue concentrations. Results for AA spectrophotometry analyzed samples from deceased birds further supported the ICP-MS findings where a strong correlation between mercury concentrations in feather and tissue (pectoral muscle) samples was found. These study results support that sampling feathers from live free-ranging hummingbirds might be a useful, non-lethal sampling method for evaluating trace element exposure and provides a sampling alternative since their small body size limits traditional sampling of blood and tissues. The results from this study provide a benchmark for the distribution of trace element concentrations in feather and tissue samples from hummingbirds and suggests a reference mark for exceeding normal. Lastly, pollinating avian species are minimally represented in the literature as bioindicators for environmental trace element contamination. Given that trace elements can move through food chains by a variety of routes, our study indicates that hummingbirds are possible bioindicators of environmental trace element contamination.

How Markovian is exciton dynamics in purple bacteria?

NASA Astrophysics Data System (ADS)

Vaughan, Felix; Linden, Noah; Manby, Frederick R.

2017-03-01

We investigate the extent to which the dynamics of excitons in the light-harvesting complex LH2 of purple bacteria can be described using a Markovian approximation. To analyse the degree of non-Markovianity in these systems, we introduce a measure based on fitting Lindblad dynamics, as well as employing a recently introduced trace-distance measure. We apply these measures to a chromophore-dimer model of exciton dynamics and use the hierarchical equation-of-motion method to take into account the broad, low-frequency phonon bath. With a smooth phonon bath, small amounts of non-Markovianity are present according to the trace-distance measure, but the dynamics is poorly described by a Lindblad master equation unless the excitonic dimer coupling strength is modified. Inclusion of underdamped, high-frequency modes leads to significant deviations from Markovian evolution in both measures. In particular, we find that modes that are nearly resonant with gaps in the excitonic spectrum produce dynamics that deviate most strongly from the Lindblad approximation, despite the trace distance measuring larger amounts of non-Markovianity for higher frequency modes. Overall we find that the detailed structure in the high-frequency region of the spectral density has a significant impact on the nature of the dynamics of excitons.

Multielemental analysis in vegetable edible oils by inductively coupled plasma mass spectrometry after solubilisation with tetramethylammonium hydroxide.

PubMed

Savio, Marianela; Ortiz, María S; Almeida, César A; Olsina, Roberto A; Martinez, Luis D; Gil, Raúl A

2014-09-15

Trace metals have negative effects on the oxidative stability of edible oils and they are important because of possibility for oils characterisation. A single-step procedure for trace elemental analysis of edible oils is presented. To this aim, a solubilisation with tetramethylammonium hydroxide (TMAH) was assayed prior to inductively coupled plasma mass spectrometry detection. Small amounts of TMAH were used, resulting in high elemental concentrations. This method was applied to edible oils commercially available in Argentine. Elements present in small amounts (Cu, Ge, Mn, Mo, Ni, Sb, Sr, Ti, and V) were determined in olive, corn, almond and sunflower oils. The limits of detection were between 0.004 μg g(-1) for Mn and Sr, and 0.32 μg g(-1) for Sb. Principal components analysis was used to correlate the content of trace metals with the type of oils. The two first principal components retained 91.6% of the variability of the system. This is a relatively simple and safe procedure, and could be an attractive alternative for quality control, traceability and routine analysis of edible oils. Copyright © 2014 Elsevier Ltd. All rights reserved.

Trace Elements in Bed Sediments and Biota from Streams in the Santee River Basin and Coastal Drainages, North and South Carolina, 1995-97

Treesearch

Thomas A. Abrahamsen

1999-01-01

Bed-sediment and tissue samples were collected and analyzed for the presence of trace elements from 25 sites in the Santee River Basin and coastal drainages study area during 1995-97 as part of the U.S. Geological Survey's National Water-Quality Assessment Program, Sediment trace-element priority-pollutant concentrations were compared among streams draining water-...

Composition of minerals and trace elements at Mamasani thermal source: A possible preventive treatment for some skin diseases

PubMed Central

Hamidizadeh, Nasrin; Simaeetabar, Shima; Handjani, Farhad; Ranjbar, Sara; Moghadam, Mohammad Gohari; Parvizi, Mohammad Mahdi

2017-01-01

INTRODUCTION: Some skin diseases are incurable and modern medicine can only control them. In addition, alternative treatment remedies including balneotherapy can be effective in improving skin conditions. However, there are only a limited number of studies on particular mineral or trace elements of mineral sources that have been identified in Iran. In this respect, the amount of minerals and trace elements in Mamasani thermal source, Fars Province, Iran, was measured using electrochemical, titration, and spectrophotometric methods and evaluated. MATERIALS AND METHODS: The amount of minerals and trace elements in Mamasani thermal source, Fars Province, Iran, was measured using electrochemical, titration, and spectrophotometric methods. RESULTS: The concentrations of natural gases such as H2S and NO3 in Mamasani thermal source were measured to be 22.10 mg/L and 42.79 mg/L, respectively. The source also contained major ions such as chloride, sulfate, sodium, calcium, magnesium, potassium, and carbonate. Due to the high concentration of chloride, sulfate, and sodium ions in comparison with other major ions, the water source is also classified as sulfide water. The existing trace elements in this thermal water source are iron, zinc, copper, selenium, cobalt, chromium, boron, silisium, aluminum, magnesium, and molybdenum. CONCLUSION: We concluded that bathing in this source could be beneficial. As nitrate concentration is close to the highest standard concentration for drinking water, it can be used in chronic dermatitis, psoriasis, burns, and allergy. Furthermore, the antibacterial and antifungal effects of sulfur-containing water in this source can be helpful in the treatment of leg ulcers, tinea versicolor, tinea corporis, and tinea capitis. PMID:29296611

Geomorphological assessment of sediment contamination in an urban stream system

USGS Publications Warehouse

Rhoads, B.L.; Cahill, R.A.

1999-01-01

Little is known about the influence of fluvial-geomorphological features on the dispersal of sediment-related contaminants in urban drainage systems. This study investigates the relation between reach-scale geomorphological conditions and network-scale patterns of trace-element concentrations in a partially urbanized stream system in East-Central Illinois, USA Robust statistical analysis of bulk sediment samples reveals levels of Cr, Cu, Pb, Ni, and Zn exceed contamination thresholds in the portion of the watershed in close proximity to potential sources of pollution-in this case storm-sewer outfalls. Although trace-element concentrations decrease rapidly downstream from these sources, substantial local variability in metal levels exists within contaminated reaches. This local variability is related to reach-scale variation in fluvial-geomorphic conditions, which in turn produces variation in the degree of sorting and organic-matter content of bed material. Metal concentrations at contaminated sites also exhibit considerable variability over time. Analytical tests on specific size fractions of material collected at a highly contaminated site indicate that Cr and Ni are concentrated in the 0.063 to 0.250 mm fraction of the sediment. This fraction also has elevated concentration of Zr. SEM analysis shows that the fine sand fraction contains shards of stainless steel within a matrix of zircon sand, an industrial material associated with a nearby alloy casting operation. Samples of suspended load and bedload at the contaminated site also have elevated amounts of trace metals, but concentrations of Ni and Cr in the bedload are less than concentrations in the bed material, suggesting that these trace elements are relatively immobile. Off the other hand, amounts of CU and Zn in the bedload exceed concentrations in the bed material, implying that these trace metals are preferentially mobilized during transport events.

Movement of Trace Elements During Residence in the Antarctic Ice: a Laboratory Simulation

NASA Technical Reports Server (NTRS)

Strait, Melissa M.

1991-01-01

Recent work has determined that differences in the trace element distribution between Antarctic eucrites and non-Antarctic eucrites may be due to weathering during residence in the ice, and samples that demonstrate trace element disturbances do not necessarily correspond to eucrites that appear badly weathered to the naked eye. This study constitutes a preliminary test of the idea that long-term residence in the ice is the cause of the trace element disturbances observed in the eucrites. Samples of a non-Antarctic eucrite were leached in water at room temperature conditions. Liquid samples were analyzed for rare earth element abundances using ion chromatography. The results for the short-term study showed little or no evidence that leaching had occurred. However, there were tantalizing hints that something may be happening. The residual solid samples are currently being analyzed for the unleached trace metals using instrumental neutron activation analysis and should show evidence of disturbance if the chromatography clues were real. In addition, another set of samples continues to be intermittently sampled for later analysis. The results should give us information about the movement of trace elements under our conditions and allow us to make some tentative extrapolations to what we observe in actual Antarctic eucrite samples.

Trace Elements Characteristic Based on ICP-AES and the Correlation of Flavonoids from Sparganii rhizoma.

PubMed

Wang, Xinsheng; Wu, Yanfang; Wu, Chengying; Wu, Qinan; Niu, Qingshan

2018-04-01

The aim of the present work was to investigate the trace elements and the correlation with flavonoids from Sparganii rhizoma. The ICP-AES and ultraviolet-visible spectroscopy were employed to analyze trace elements and flavonoids. The concentrations of trace elements and flavonoids were calculated using standard curve. The content of flavonoids was expressed as rutin equivalents. The cluster analysis was applied to evaluate geographical features of S. rhizoma from different geographical regions. The correlation analysis was used to obtain the relationship between the trace elements and flavonoids. The results indicated that the 15 trace elements were measured and the K, Ca, Mg, Na, Mn, Al, Cu, and Zn are rich in Sparganii rhizome. The different producing regions samples were classified into four groups. There was a weak relationship between trace elements and flavonoids.

TENORM: Wastewater Treatment Residuals

EPA Pesticide Factsheets

Water and wastes which have been discharged into municipal sewers are treated at wastewater treatment plants. These may contain trace amounts of both man-made and naturally occurring radionuclides which can accumulate in the treatment plant and residuals.

76 FR 65749 - Importer of Controlled Substances; Notice of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

... treatment of wounds which contains trace amounts of the controlled substances normally found in poppy straw... the company's compliance with state and local laws, and a review of the company's background and...

27 CFR 5.23 - Alteration of class and type.

Code of Federal Regulations, 2014 CFR

2014-04-01

... trace amount of citric acid. (b) Extractions. The removal from any distilled spirits of any constituents... than 15 percent of the fixed acids, or volatile acids, or esters, or soluble solids, or higher alcohols...

27 CFR 5.23 - Alteration of class and type.

Code of Federal Regulations, 2012 CFR

2012-04-01

... trace amount of citric acid. (b) Extractions. The removal from any distilled spirits of any constituents... than 15 percent of the fixed acids, or volatile acids, or esters, or soluble solids, or higher alcohols...

27 CFR 5.23 - Alteration of class and type.

Code of Federal Regulations, 2013 CFR

2013-04-01

... trace amount of citric acid. (b) Extractions. The removal from any distilled spirits of any constituents... than 15 percent of the fixed acids, or volatile acids, or esters, or soluble solids, or higher alcohols...

26 CFR 301.6362-5 - Qualified nonresident tax.

Code of Federal Regulations, 2010 CFR

2010-04-01

... which bears the same ratio to such sum as the amount described in subdivision (i) of this subparagraph... tracing of the profitability of each phase and aspect of the partnership's operations, and shows the State...

Spectroscopic characterization of digestates obtained from sludge mixed to increasing amounts of fruit and vegetable wastes

NASA Astrophysics Data System (ADS)

Provenzano, Maria Rosaria; Cavallo, Ornella; Malerba, Anna Daniela; Di Maria, Francesco; Ricci, Anna; Gigliotti, Giovanni

2015-04-01

Anaerobic digestion (AD) represents an efficient waste-treatment technology during which microorganisms break down biodegradable material in absence of oxygen yielding a biogas containing methane. The aim of this work was to investigate the transformations occurring in the organic matter during the co-digestion of waste mixed sludge (WMS) with an increasing amount of fruit and vegetable wastes (FVW) in a pilot scale apparatus reproducing a full-scale digester in an existing wastewater treatment plant. Samples comprised: sludge, FVW, sludge mixed with 10-20-30-40% FVW. Ingestates and digestates were analyzed by means of emission fluorescence spectroscopy and FTIR associated to Fourier self deconvolution (FSD) of spectra. With increasing the amount of FVW from 10% to 20% at which percentage biogas production reached the maximum value, FTIR spectra and FSD traces of digestates exhibited a decrease of intensity of peaks assigned to polysaccharides and aliphatics and an increase of peak assigned to aromatics as a result of the biodegradation of rapidly degradable materials and concentration of aromatic recalcitrant compounds. Digestates with 30 and 40% FVW exhibited a relative increase of intensity of peaks assigned to aliphatics likely as a result of the increasing amount of rapidly degradable materials and the consequent reduction of the hydraulic retention time. This may cause inhibition of methanogenesis and accumulation of volatile fatty acids. The highest emission fluorescence intensity was observed for the digestate with 20% FVW confirming the concentration of aromatic recalcitrant compounds in the substrate obtained at the highest biogas production.

Analysis of Trace Gas Mixtures Using an External Cavity Quantum Cascade Laser Sensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, Mark C.; Taubman, Matthew S.; Brumfield, Brian E.

2015-07-01

We measure and analyze mixtures of trace gases at ppb-ppm levels using an external cavity quantum cascade laser sensor with a 1-second response time. Accurate spectral fits are obtained in the presence of overlapping spectra.

Sediment-quality assessment of Franklin D. Roosevelt Lake and the upstream reach of the Columbia River, Washington, 1992

USGS Publications Warehouse

Bortleson, Gilbert Carl; Cox, S.E.; Munn, M.D.; Schumaker, R.J.; Block, E.K.

2001-01-01

Elevated concentrations of trace elements were found in bed sediment of Lake Roosevelt and the Columbia River, its principal source of inflow. Trace-element concentrations in whole water samples did not exceed criteria for freshwater organisms. Bed sediments of Lake Roosevelt were analyzed for organic compounds associated with wood-pulp waste. Dioxins and furans were found in suspended sediment and water of the Columbia River. Abundance and diversity of benthic invertebrate communities were analyzed.

The effect of pasteurization on trace elements in donor breast milk.

PubMed

Mohd-Taufek, N; Cartwright, D; Davies, M; Hewavitharana, A K; Koorts, P; McConachy, H; Shaw, P N; Sumner, R; Whitfield, K

2016-10-01

Premature infants often receive pasteurized donor human milk when mothers are unable to provide their own milk. This study aims to establish the effect of the pasteurization process on a range of trace elements in donor milk. Breast milk was collected from 16 mothers donating to the milk bank at the Royal Brisbane and Women's Hospital. Samples were divided into pre- and post-pasteurization aliquots and were Holder pasteurized. Inductively coupled plasma mass spectrometry was used to analyze the trace elements zinc (Zn), copper (Cu), selenium (Se), manganese (Mn), iodine (I), iron (Fe), molybdenum (Mo) and bromine (Br). Differences in trace elements pre- and post-pasteurization were analyzed. No significant differences were found between the trace elements tested pre- and post-pasteurization, except for Fe (P<0.05). The median (interquartile range, 25 to 75%; μg l(-1)) of trace elements for pre- and post- pasteurization aliquots were-Zn: 1639 (888-4508), 1743 (878-4143), Cu: 360 (258-571), 367 (253-531), Se: 12.34 (11.73-17.60), 12.62 (11.94-16.64), Mn: (1.48 (1.01-1.75), 1.49 (1.11-1.75), I (153 (94-189), 158 (93-183), Fe (211 (171-277), 194 (153-253), Mo (1.46 (0.37-2.99), 1.42 (0.29-3.73) and Br (1066 (834-1443), 989 (902-1396). Pasteurization had minimal effect on several trace elements in donor breast milk but high levels of inter-donor variability of trace elements were observed. The observed decrease in the iron content of pasteurized donor milk is, however, unlikely to be clinically relevant.

Continuous monitoring of enzymatic activity within native electrophoresis gels: Application to mitochondrial oxidative phosphorylation complexes

PubMed Central

Covian, Raul; Chess, David; Balaban, Robert S.

2012-01-01

Native gel electrophoresis allows the separation of very small amounts of protein complexes while retaining aspects of their activity. In-gel enzymatic assays are usually performed by using reaction-dependent deposition of chromophores or light scattering precipitates quantified at fixed time points after gel removal and fixation, limiting the ability to analyze enzyme reaction kinetics. Herein, we describe a custom reaction chamber with reaction media recirculation and filtering and an imaging system that permits the continuous monitoring of in-gel enzymatic activity even in the presence of turbidity. Images were continuously collected using time-lapse high resolution digital imaging, and processing routines were developed to obtain kinetic traces of the in-gel activities and analyze reaction time courses. This system also permitted the evaluation of enzymatic activity topology within the protein bands of the gel. This approach was used to analyze the reaction kinetics of two mitochondrial complexes in native gels. Complex IV kinetics showed a short initial linear phase where catalytic rates could be calculated, whereas Complex V activity revealed a significant lag phase followed by two linear phases. The utility of monitoring the entire kinetic behavior of these reactions in native gels, as well as the general application of this approach, is discussed. PMID:22975200

Enhanced amine and amino acid analysis using Pacific Blue and the Mars Organic Analyzer microchip capillary electrophoresis system.

PubMed

Chiesl, Thomas N; Chu, Wai K; Stockton, Amanda M; Amashukeli, Xenia; Grunthaner, Frank; Mathies, Richard A

2009-04-01

The fluorescent amine reactive probe Pacific Blue succinimidyl ester (PB) is used for the detection of trace amounts of amines and amino acids by microchip capillary electrophoresis on the Mars Organic Analyzer (MOA). The spectral and chemical properties of PB provide a 200-fold increase in sensitivity and improved resolution compared to fluorescamine derivatization. With the use of cross injection and PB labeling, the MOA detected amino acids at concentrations as low as 75 pM (sub-parts-per-trillion). Micellar electrokinetic chromatography (MEKC) which separates PB-labeled amino acids by their hydrophobicity is also demonstrated. The optimized MEKC conditions (45 mM CHAPSO, pH 6 at 5 degrees C) effectively separated amines and 25 amino acids with enantiomeric resolution of alanine, serine, and citrulline. Samples from the Yungay Hills region in the Atacama Desert, Chile, and from the Murchison meteorite are successfully analyzed using both techniques, and amino acids are found in the parts-per-billion range. Abiotic amino acids such as beta-alanine and epsilon-aminocaprioc acid are detected along with several neutral and acidic amino acids in the Murchison sample. The Atacama Desert sample is found to contain homochiral L-alanine and L-serine indicating the presence of extant or recently extinct life.

Effect of dactyloscopic powders on DNA profiling from enhanced fingerprints: results from an experimental study.

PubMed

Tozzo, Pamela; Giuliodori, Alice; Rodriguez, Daniele; Caenazzo, Luciana

2014-03-01

We conducted a study on the effect of fingerprint enhancement methods on subsequent short tandem repeat profiling. First, we performed a study typing blood traces deposited on 5 different surfaces, treated with 8 types of dactyloscopic powders. Three different DNA extraction methods were used. Subsequently, we analyzed latent fingerprints on the same 5 surfaces enhanced with the 8 different powders used in the first part of the study. This study has demonstrated that DNA profiling can be performed on fingerprints left on different substrates, and the substrate will affect the amount of DNA that can be recovered for DNA typing. In the first phase of the study, a profile was obtained in 92% of the 120 samples analyzed; in the second part, in 55% of the 80 samples analyzed, we obtained a profile complete in 32.5% of the cases. From the results obtained, it seems that the powders used in latent fingerprints enhancement, rather than having a direct inhibitory effect on extraction and amplification of DNA, may cause partial degradation of DNA, reducing the efficiency of amplification reaction. It should not be forgotten that these results were obtained under laboratory conditions, and in real caseworks, there may still be different problems involved.

Continuous monitoring of enzymatic activity within native electrophoresis gels: application to mitochondrial oxidative phosphorylation complexes.

PubMed

Covian, Raul; Chess, David; Balaban, Robert S

2012-12-01

Native gel electrophoresis allows the separation of very small amounts of protein complexes while retaining aspects of their activity. In-gel enzymatic assays are usually performed by using reaction-dependent deposition of chromophores or light-scattering precipitates quantified at fixed time points after gel removal and fixation, limiting the ability to analyze the enzyme reaction kinetics. Herein, we describe a custom reaction chamber with reaction medium recirculation and filtering and an imaging system that permits the continuous monitoring of in-gel enzymatic activity even in the presence of turbidity. Images were continuously collected using time-lapse high-resolution digital imaging, and processing routines were developed to obtain kinetic traces of the in-gel activities and analyze reaction time courses. This system also permitted the evaluation of enzymatic activity topology within the protein bands of the gel. This approach was used to analyze the reaction kinetics of two mitochondrial complexes in native gels. Complex IV kinetics showed a short initial linear phase in which catalytic rates could be calculated, whereas Complex V activity revealed a significant lag phase followed by two linear phases. The utility of monitoring the entire kinetic behavior of these reactions in native gels, as well as the general application of this approach, is discussed. Published by Elsevier Inc.

Simultaneous visualization of the subfemtomolar expression of microRNA and microRNA target gene using HILO microscopy† †Electronic supplementary information (ESI) available: The LED device for the sample photobleaching, a schematic presentation of HILO microscopy, fluorescence spectra and hybridization curves of the molecular beacons, the linear correlation between the miRNA fluorescence intensity and the miRNA copy number, a validation of the miRNA adsorption and miRNA target gene expression via RT-qPCR, a validation of RT-qPCR using capillary electrophoresis, the reproducibility of RT-qPCR and Poisson distribution of the miRNA pipetting as well as a complete list of the oligonucleotides used in this study. See DOI: 10.1039/c7sc02701j Click here for additional data file.

PubMed Central

Lin, Yi-Zhen; Ou, Da-Liang; Chang, Hsin-Yuan; Lin, Wei-Yu; Hsu, Chiun

2017-01-01

The family of microRNAs (miRNAs) not only plays an important role in gene regulation but is also useful for the diagnosis of diseases. A reliable method with high sensitivity may allow researchers to detect slight fluctuations in ultra-trace amounts of miRNA. In this study, we propose a sensitive imaging method for the direct probing of miR-10b (miR-10b-3p, also called miR-10b*) and its target (HOXD10 mRNA) in fixed cells based on the specific recognition of molecular beacons combined with highly inclined and laminated optical sheet (HILO) fluorescence microscopy. The designed dye-quencher-labelled molecular beacons offer excellent efficiencies of fluorescence resonance energy transfer that allow us to detect miRNA and the target mRNA simultaneously in hepatocellular carcinoma cells using HILO fluorescence microscopy. Not only can the basal trace amount of miRNA be observed in each individual cell, but the obtained images also indicate that this method is useful for monitoring the fluctuations in ultra-trace amounts of miRNA when the cells are transfected with a miRNA precursor or a miRNA inhibitor (anti-miR). Furthermore, a reasonable causal relation between the miR-10b and HOXD10 expression levels was observed in miR-10b* precursor-transfected cells and miR-10b* inhibitor-transfected cells. The trends of the miRNA alterations obtained using HILO microscopy completely matched the RT-qPCR data and showed remarkable reproducibility (the coefficient of variation [CV] = 0.86%) and sensitivity (<1.0 fM). This proposed imaging method appears to be useful for the simultaneous visualisation of ultra-trace amounts of miRNA and target mRNA and excludes the procedures for RNA extraction and amplification. Therefore, the visualisation of miRNA and the target mRNA should facilitate the exploration of the functions of ultra-trace amounts of miRNA in fixed cells in biological studies and may serve as a powerful tool for diagnoses based on circulating cancer cells. PMID:28989695

Trace analysis of energetic materials via direct analyte-probed nanoextraction coupled to direct analysis in real time mass spectrometry.

PubMed

Clemons, Kristina; Dake, Jeffrey; Sisco, Edward; Verbeck, Guido F

2013-09-10

Direct analysis in real time mass spectrometry (DART-MS) has proven to be a useful forensic tool for the trace analysis of energetic materials. While other techniques for detecting trace amounts of explosives involve extraction, derivatization, solvent exchange, or sample clean-up, DART-MS requires none of these. Typical DART-MS analyses directly from a solid sample or from a swab have been quite successful; however, these methods may not always be an optimal sampling technique in a forensic setting. For example, if the sample were only located in an area which included a latent fingerprint of interest, direct DART-MS analysis or the use of a swab would almost certainly destroy the print. To avoid ruining such potentially invaluable evidence, another method has been developed which will leave the fingerprint virtually untouched. Direct analyte-probed nanoextraction coupled to nanospray ionization-mass spectrometry (DAPNe-NSI-MS) has demonstrated excellent sensitivity and repeatability in forensic analyses of trace amounts of illicit drugs from various types of surfaces. This technique employs a nanomanipulator in conjunction with bright-field microscopy to extract single particles from a surface of interest and has provided a limit of detection of 300 attograms for caffeine. Combining DAPNe with DART-MS provides another level of flexibility in forensic analysis, and has proven to be a sufficient detection method for trinitrotoluene (TNT), RDX, and 1-methylaminoanthraquinone (MAAQ). Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Trace detection of perchlorate in industrial-grade emulsion explosive with portable surface-enhanced Raman spectroscopy.

PubMed

Nuntawong, N; Eiamchai, P; Limwichean, S; Wong-ek, B; Horprathum, M; Patthanasettakul, V; Leelapojanaporn, A; Nakngoenthong, S; Chindaudom, P

2013-12-10

Recent analyses by ion-exchange chromatography (IC) showed that, beside nitrate, the majority of the industrial-grade emulsion explosives, extensively used by most separatists in the southern Thailand insurgency, contained small traces of perchlorate anions. In demand for the faster, reliable, and simple detection methods, the portable detection of nitrate and perchlorate became the great interest for the forensic and field-investigators. This work proposed a unique method to detect the trace amount of perchlorate in seven industrial-grade emulsion explosives under the field tests. We utilized the combination of the portable Raman spectroscope, the developed surfaced-enhanced Raman substrates, and the sample preparation procedures. The portable Raman spectroscope with a laser diode of 785 nm for excitation and a thermoelectric-cooled CCD spectrometer for detection was commercially available. The SERS substrates, with uniformly distributed nanostructured silver nanorods, were fabricated by the DC magnetron sputtering system, based on the oblique-angle deposition technique. The sample preparation procedures were proposed based on (1) pentane extraction technique and (2) combustion technique, prior to being dissolved in the purified water. In comparison to the ion chromatography and the conventional Raman measurements, our proposed methods successfully demonstrated the highly sensitive detectability of the minimal trace amount of perchlorate from five of the explosives with minimal operating time. This work was therefore highly practical to the development for the forensic analyses of the post-blast explosive residues under the field-investigations. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Removal of trace organic chemical contaminants by a membrane bioreactor.

PubMed

Trinh, T; van den Akker, B; Stuetz, R M; Coleman, H M; Le-Clech, P; Khan, S J

2012-01-01

Emerging wastewater treatment processes such as membrane bioreactors (MBRs) have attracted a significant amount of interest internationally due to their ability to produce high quality effluent suitable for water recycling. It is therefore important that their efficiency in removing hazardous trace organic contaminants be assessed. Accordingly, this study investigated the removal of trace organic chemical contaminants through a full-scale, package MBR in New South Wales, Australia. This study was unique in the context of MBR research because it characterised the removal of 48 trace organic chemical contaminants, which included steroidal hormones, xenoestrogens, pesticides, caffeine, pharmaceuticals and personal care products (PPCPs). Results showed that the removal of most trace organic chemical contaminants through the MBR was high (above 90%). However, amitriptyline, carbamazepine, diazepam, diclofenac, fluoxetine, gemfibrozil, omeprazole, sulphamethoxazole and trimethoprim were only partially removed through the MBR with the removal efficiencies of 24-68%. These are potential indicators for assessing MBR performance as these chemicals are usually sensitive to changes in the treatment systems. The trace organic chemical contaminants detected in the MBR permeate were 1 to 6 orders of magnitude lower than guideline values reported in the Australian Guidelines for Water Recycling. The outcomes of this study enhanced our understanding of the levels and removal of trace organic contaminants by MBRs.

Trace metal concentrations in tropical mangrove sediments, NE Brazil.

PubMed

Miola, Brígida; Morais, Jáder Onofre de; Pinheiro, Lidriana de Souza

2016-01-15

Sediment cores were taken from the mangroves of the Coreaú River estuary off the northeast coast of Brazil. They were analyzed for grain size, CaCO3, organic matter, and trace metal (Cd, Pb, Zn, Cu, Al, and Fe) contents. Mud texture was the predominant texture. Levels of trace metals in surface sediments indicated strong influence of anthropogenic processes, and diagenetic processes controlled the trace metal enrichment of core sediments of this estuary. The positive relationships between trace metals and Al and Fe indicate that Cu, Zn, Pb, and Cd concentrations are associated mainly with Al and Fe oxy-hydroxides and have natural sources. Copyright © 2015 Elsevier Ltd. All rights reserved.

Reactor for removing ammonia

DOEpatents

Luo, Weifang [Livermore, CA; Stewart, Kenneth D [Valley Springs, CA

2009-11-17

Disclosed is a device for removing trace amounts of ammonia from a stream of gas, particularly hydrogen gas, prepared by a reformation apparatus. The apparatus is used to prevent PEM "poisoning" in a fuel cell receiving the incoming hydrogen stream.

76 FR 30969 - Importer of Controlled Substances; Notice of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2011-05-27

... treatment of wounds which contain trace amounts of the controlled substances normally found in poppy straw... company's background and history. Therefore, pursuant to 21 U.S.C. 952(a) and 958(a), and in accordance...

75 FR 9614 - Importer of Controlled Substances; Notice of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

... an ointment for the treatment of wounds which contains trace amounts of controlled substances... background and history. Therefore, pursuant to 21 U.S.C. 952(a) and Sec. 958(a), and in accordance with 21...

Dangerous Elements.

ERIC Educational Resources Information Center

Pinkham, Jim

1994-01-01

Discusses legislation currently under consideration that sets standards for the amount of radon, aluminum, and arsenic allowable in drinking water. Considers the economic impact of the legislation and traces the status of the Safe Drinking Water Act Regulations from 1989-92. (MDH)

Long-term Operation of an External Cavity Quantum Cascade Laser-based Trace-gas Sensor for Building Air Monitoring

DOE Office of Scientific and Technical Information (OSTI.GOV)

Phillips, Mark C.; Craig, Ian M.

2013-11-03

We analyze the long-term performance and stability of a trace-gas sensor based on an external cavity quantum cascade laser using data collected over a one-year period in a building air monitoring application.

Remote Sensing of Tropospheric Pollution from Space

NASA Technical Reports Server (NTRS)

Fishman, Jack; Bowman, Kevin W.; Burrows, John P.; Chance, Kelly V.; Edwards, David P.; Martin, Randall V.; Morris, Gary A.; Pierce, R. Bradley; Ziemke, Jerald R.; Al-Saadi, Jassim A.;

Trace element biomonitoring using mosses in urban areas affected by mud volcanoes around Mt. Etna. The case of the Salinelle, Italy.

PubMed

Bonanno, Giuseppe; Lo Giudice, Rosa; Pavone, Pietro

2012-08-01

Trace element impact was assessed using mosses in a densely inhabited area affected by mud volcanoes. Such volcanoes, locally called Salinelle, are phenomena that occur around Mt. Etna (Sicily, Italy) and are interpreted as the surface outflow of a hydrothermal system located below Mt. Etna, releasing sedimentary fluids (hydrocarbons and NaCl brines) along with magmatic gases (mainly CO(2) and He). To date, scarce data are available about the presence of trace elements, and no biomonitoring campaigns are reported about the cumulative effects of such emissions. In this study, concentrations of Al, As, Cd, Cr, Cu, Hg, Mn, Ni, Pb, V, and Zn were detected in the moss Bryum argenteum, in soil and water. Results showed that the trace element contribution of the Salinelle to the general pollution was significant for Al, Mn, Ni, and Zn. The comparison of trace concentrations in mosses from Salinelle and Etna showed that the mud volcanoes release a greater amount of Al and Mn, whereas similar values of Ni were found. Natural emissions of trace elements could be hazardous in human settlements, in particular, the Salinelle seem to play an important role in environmental pollution.

The numerical simulation based on CFD of hydraulic turbine pump

NASA Astrophysics Data System (ADS)

Duan, X. H.; Kong, F. Y.; Liu, Y. Y.; Zhao, R. J.; Hu, Q. L.

2016-05-01

As the functions of hydraulic turbine pump including self-adjusting and compensation with each other, it is far-reaching to analyze its internal flow by the numerical simulation based on CFD, mainly including the pressure field and the velocity field in hydraulic turbine and pump.The three-dimensional models of hydraulic turbine pump are made by Pro/Engineer software;the internal flow fields in hydraulic turbine and pump are simulated numerically by CFX ANSYS software. According to the results of the numerical simulation in design condition, the pressure field and the velocity field in hydraulic turbine and pump are analyzed respectively .The findings show that the static pressure decreases systematically and the pressure gradient is obvious in flow area of hydraulic turbine; the static pressure increases gradually in pump. The flow trace is regular in suction chamber and flume without spiral trace. However, there are irregular traces in the turbine runner channels which contrary to that in flow area of impeller. Most of traces in the flow area of draft tube are spiral.

Method for quantitative determination and separation of trace amounts of chemical elements in the presence of large quantities of other elements having the same atomic mass

DOEpatents

Miller, C.M.; Nogar, N.S.

1982-09-02

Photoionization via autoionizing atomic levels combined with conventional mass spectroscopy provides a technique for quantitative analysis of trace quantities of chemical elements in the presence of much larger amounts of other elements with substantially the same atomic mass. Ytterbium samples smaller than 10 ng have been detected using an ArF* excimer laser which provides the atomic ions for a time-of-flight mass spectrometer. Elemental selectivity of greater than 5:1 with respect to lutetium impurity has been obtained. Autoionization via a single photon process permits greater photon utilization efficiency because of its greater absorption cross section than bound-free transitions, while maintaining sufficient spectroscopic structure to allow significant photoionization selectivity between different atomic species. Separation of atomic species from others of substantially the same atomic mass is also described.

PIXE analysis of tumors and localization behavior of a lanthanide in nude mice

NASA Astrophysics Data System (ADS)

Chang, Pei-Jiun; Yang, Czau-Siung; Chou, Ming-Ji; Wei, Chau-Chin; Hsu, Chu-Chung; Wang, Chia-Yu

1984-04-01

We have used particle induced X-ray emission (PIXE) to analyze the elemental compositions and uptakes of a lanthanide, yttrium in this report, in tumors and normal tissues of nude mice. A small amount of yttrium nitrate was injected into nude mice with tumors. Samples of normal and malignant tissues taken from these mice were bombarded by the 2 MeV proton beam from a 3 MeV Van de Graaff accelerator with a Ge detector system to determine the relative elemental compositions of tissues and the relative concentrations of yttrium taken up by these tissues. We found that the uptakes of yttrium by tumors were at least five times more than those by normal tissues. Substantial differences were often observed between the trace element weight (or concentration) pattern of the cancerous and normal tissues. The present result is compared with human tissues.

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Astrophysics Data System (ADS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-09-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Additional studies for the spectrophotometric measurement of iodine in water

NASA Technical Reports Server (NTRS)

1972-01-01

Previous work in iodine spectroscopy is briefly reviewed. Continued studies of the direct spectrophotometric determination of aqueous iodine complexed with potassium iodide show that free iodine is optimally determined at the isosbestic point for these solutions. The effects on iodine determinations of turbidity and chemical substances (in trace amounts) is discussed and illustrated. At the levels tested, iodine measurements are not significantly altered by such substances. A preliminary design for an on-line, automated iodine monitor with eventual capability of operating also as a controller was analyzed and developed in detail with respect single beam colorimeter operating at two wavelengths (using a rotating filter wheel). A flow-through sample cell allows the instrument to operate continuously, except for momentary stop flow when measurements are made. The timed automatic cycling of the system may be interrupted whenever desired, for manual operation. An analog output signal permits controlling an iodine generator.

Graphene supported heterogeneous catalysts for Li-O2 batteries

NASA Astrophysics Data System (ADS)

Alaf, M.; Tocoglu, U.; Kartal, M.; Akbulut, H.

2016-09-01

In this study production and characterization of free-standing and flexible (i) graphene, (ii) α-MnO2/graphene, (iii) Pt/graphene (iv) α-MnO2/Pt/graphene composite cathodes for Li-air batteries were reported. Graphene supported heterogeneous catalysts were produced by a facile method. In order to prevent aggregation of graphene sheets and increase not only interlayer distance but also surface area, a trace amount multi-wall carbon nano tube (MWCNT) was introduced to the composite structure. The obtained composite catalysts were characterized by SEM, X-ray diffraction, N2 adsorption-desorption analyze and Raman spectroscopy. The electrochemical characterization tests including galvanostatic charge/discharge and electrochemical impedance spectroscopy (EIS) measurement of catalyst were carried out by using an ECC-Air test cell. These highly active graphene supported heterogeneous composite catalysts provide competitive properties relative to other catalyst materials for Li-air batteries.

A rapid and definitive diagnosis of kerosene dermatitis by an analysis of detached lesional epidermis using gas chromatography-mass spectrometry.

PubMed

Tsujino, Yoshio; Hieda, Yoko; Morita, Eishin

2005-08-01

A 73-year-old woman, who suffered from erythema with bullae and pustules on her abdomen and anterior right thigh, visited our hospital without an awareness of the causative agents. The lesions appeared like first and second degree burns. The small amount of detached roof of bulla was sampled without skin biopsy before the ointment treatment. The sample was sonicated in an ultrasonic bath for 1 min in n-pentane, and then 1 mul of the extract was analyzed by gas chromatography-mass spectrometry (GC-MS). The causative agent was determined to be kerosene. An examination of blood samples collected at the first visit failed to detect kerosene, though traces of trimethylbenzene were detected. A GC-MS analysis of the small sample of lesional epidermis was very useful to identify kerosene as a causative agent.

Ion chromatographic determination of lithium at trace level concentrations. Application to a tracer experiment in a high-mountain lake.

PubMed

Nickus, U; Thies, H

2001-06-22

The water residence time of a high-mountain seepage lake in the Austrian Alps was derived from the flushing rate of a tracer substance. A diluted lithium chloride solution was injected into the lake during holomictic conditions in order to favour the homogeneous distribution of the tracer. The exponential decline of the mass of lithium in the lake revealed a water residence time of 1.5 to 3 months for summer and almost no lake water exchange during winter. Lithium concentrations ranged from background values of 0.06 microg l(-1) to about 3 microg l(-1) immediately after the tracer injection. Lake water samples were analyzed with ion-exchange chromatography using a Dionex device with a CS 12A separation column. The method detection limit determined according to the definition of the US Envirinmental Protection Agency amounted to 0.009 microg l(-1).

Chemical composition of HAL, an isotopically-unusual Allende inclusion

NASA Technical Reports Server (NTRS)

Davis, A. M.; Tanaka, T.; Grossman, L.; Lee, T.; Wasserburg, G. J.

1982-01-01

Samples of hibonite, black rim, and portions of friable rim from an unusual Allende inclusion, named HAL, were analyzed by INAA and RNAA for 37 major, minor, and trace elements. An unusually low amount of Ce was found in HAL, although it otherwise was highly enriched in REE compared to C1 chondrites. HAL is also depleted in Sr, Ba, U, V, Ru, Os, and Ir relative to other refractory elements. It is concluded that the distribution of REE between hibonite and rims was established when hibonite and other refractory minerals were removed at slightly different temperatures from a hot, oxidizing gas in which they previously coexisted as separate grains. Possible locations for the chemical and mass dependent isotopic fractionation are considered to be in ejecta from the low temperature helium-burning zone of a supernova and in the locally oxidizing environment generated by evaporation of interstellar grains of near-chondritic chemical composition.

Rock fracture skeleton tracing by image processing and quantitative analysis by geometry features

NASA Astrophysics Data System (ADS)

Liang, Yanjie

2016-06-01

In rock engineering, fracture measurement is important for many applications. This paper proposes a novel method for rock fracture skeleton tracing and analyzing. As for skeleton localizing, the curvilinear fractures are multiscale enhanced based on a Hessian matrix, after image binarization, and clutters are post-processed by image analysis; subsequently, the fracture skeleton is extracted via ridge detection combined with a distance transform and thinning algorithm, after which gap sewing and burrs removal repair the skeleton. In regard to skeleton analyzing, the roughness and distribution of a fracture network are respectively described by the fractal dimensions D s and D b; the intersection and fragmentation of a fracture network are respectively characterized by the average number of ends and junctions per fracture N average and the average length per fracture L average. Three rock fracture surfaces are analyzed for experiments and the results verify that both the fracture tracing accuracy and the analysis feasibility are satisfactory using the new method.

The use of surface-enhanced Raman scattering for detecting molecular evidence of life in rocks, sediments, and sedimentary deposits.

PubMed

Bowden, Stephen A; Wilson, Rab; Cooper, Jonathan M; Parnell, John

2010-01-01

Raman spectroscopy is a versatile analytical technique capable of characterizing the composition of both inorganic and organic materials. Consequently, it is frequently suggested as a payload on many planetary landers. Only approximately 1 in every 10(6) photons are Raman scattered; therefore, the detection of trace quantities of an analyte dispersed in a sample matrix can be much harder to achieve. To overcome this, surface-enhanced Raman scattering (SERS) and surface-enhanced resonance Raman scattering (SERRS) both provide greatly enhanced signals (enhancements between 10(5) and 10(9)) through the analyte's interaction with the locally generated surface plasmons, which occur at a "roughened" or nanostructured metallic surface (e.g., Cu, Au, and Ag). Both SERS and SERRS may therefore provide a viable technique for trace analysis of samples. In this paper, we describe the development of SERS assays for analyzing trace amounts of compounds present in the solvent extracts of sedimentary deposits. These assays were used to detect biological pigments present in an Arctic microoasis (a small locale of elevated biological productivity) and its detrital regolith, characterize the pigmentation of microbial mats around hydrothermal springs, and detect fossil organic matter in hydrothermal deposits. These field study examples demonstrate that SERS technology is sufficiently mature to be applied to many astrobiological analog studies on Earth. Many current and proposed imaging systems intended for remote deployment already posses the instrumental components needed for SERS. The addition of wet chemistry sample processing facilities to these instruments could yield field-deployable analytical instruments with a broadened analytical window for detecting organic compounds with a biological or geological origin.

Trace-element concentrations and water-soluble ions in size-segregated dust-borne and soil samples in Sistan, southeast Iran

NASA Astrophysics Data System (ADS)

Behrooz, Reza Dahmardeh; Esmaili-Sari, Abbas; Bahramifar, Nader; Kaskaoutis, D. G.; Saeb, Keivan; Rajaei, Fatemeh

2017-04-01

This study analyzes the chemical composition (water-soluble ions and trace elements) of the total suspended particles (TSP) and particulate matter less than 10 and 2.5 μm (PM10 and PM2.5) in the Sistan basin, southeast Iran during the dusty and windy period June - October 2014. Extreme TSP, PM10 and PM2.5 concentrations, means of 1624.8, 433.4 and 320.8 μgm-3, respectively, were recorded in the Zabol sampling site, while the examined water-soluble ions and trace metals constitute small fractions (∼4.1%-17.7%) of the particulate masses. Intense winds on the dust-storm days result in weathering of soil crust and deflation of evaporate minerals from the dried Hamoun lake beds in the Sistan basin. The soil samples are rich in Ca2+, SO42-, Na+ and Cl- revealing the existence of non-sea salts, as well as in Al, Fe and Mg, while the similarity in the chemical composition between soil and airborne samples indicates that the dust events over Sistan are local in origin. In contrast, low concentrations of secondary ions (i.e., nitrate) and heavy metals (i.e., Pb, Cr, Ni, Cu) indicate less anthropogenic and industrial emissions. Enrichment Factor analysis for TSP, PM10 and PM2.5 reveals that the anthropogenic sources contribute a substantial amount in the heavy metals rather than soil crust, while Al, Fe, Sn, Mg are mostly of crustal origin. The results provide essential knowledge in atmospheric chemistry over Sistan and in establishing mitigation strategies for air pollution control.

Analysis of trace metals in water by inductively coupled plasma emission spectrometry using sodium dibenzyldithiocarbamate for preconcentration

USGS Publications Warehouse

Smith, C.L.; Motooka, J.M.; Willson, W.R.

1984-01-01

Since concentrations of trace elements in most natural waters seldom exceed the ??g/L level, analysis of trace elements in natural waters by inductively coupled plasma emission spectrometry (ICP) requires a preconcentration procedure. The elements Ag, Bi, Cd, Co, Cu, Fe, Mo, Ni, Pb, Sn, V, W, and Zn were separated and concentrated from 500 mL of water by coprecipitating them with sodium dibenzyldithiocarbamate (NaDBDTC) using nickel or silver as a carrier. The precipitated trace elements were collected on a membrane filter, redissolved from the filter with hot nitric and hydrochloric acids, and analyzed using ICP. Recoveries for all the trace elements except tungsten exceeded 80%. Coprecipitation of trace elements with NaDBDTC eliminated the use of difficult-to-inject organic solvents, and NaDBDTC coprecipitated a wider array of trace elements than ammoniumpyrrolidinedithiocarbamate (APDC), another commonly used coprecipitate.

Water-quality assessment of part of the Upper Mississippi River Basin, Minnesota and Wisconsin: Trace elements in streambed sediment and fish livers, 1995-96

USGS Publications Warehouse

Kroening, Sharon E.; Fallon, James D.; Lee, Kathy E.

2000-01-01

In fish livers, all of the trace elements analyzed were detected except antimony, beryllium, cobalt, and uranium. Trace element concentrations in fish livers generally did not show any pronounced patterns. Ranges for concentrations of arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc were similar to those measured in 20 other NAWQA studies across the United States. Cadmium concentrations in fish livers were moderately correlated to fish length and weight. There were no relations between trace element concentrations in fish livers and streambed sediment.

Global sensing of gaseous and aerosol trace species using automated instrumentation on 747 airliners

NASA Technical Reports Server (NTRS)

Perkins, P. J.; Papathakos, L. C.

1978-01-01

The Global Atmospheric Sampling Program (GASP) is collecting and analyzing data on gaseous and aerosol trace contaminants in the upper troposphere and lower stratosphere. Measurements are obtained from automated systems installed on four 747 airliners flying global air routes. Improved instruments and analysis techniques are providing an expanding data base for trace species including ozone, carbon monoxide, water vapor, condensation nuclei, and mass concentration of sulfates and nitrates. Simultaneous measurements of several trace species obtained frequently can be used to identify the source of the air mass as being typically tropospheric or stratospheric.

Trace element composition of Luna 24 Crisium VLT basalt

NASA Technical Reports Server (NTRS)

Haskin, L. A.

1978-01-01

The origins of the individual particles analyzed from the Luna 24 core and the information they provide on the trace-element composition of Mare Crisium basalt are considered. Previous analyses of several Luna 24 soil fragments are reviewed. It is concluded that: (1) the average trace-element concentrations for 12 VLT basalt fragments are the best available estimates for bulk samples of Crisium VLT basalt; (2) there is weak evidence that the average Crisium basalt might have a small positive Eu anomaly relative to chondritic matter; (3) the soils contain components from sources other than the Crisium VLT basalt; and (4) there is no convincing information in concentrations of rare-earth elements, Co, Sc, FeO, or Na2O among the analyzed fragments to indicate more than one parent basalt.

Water-quality data for selected stations in the East Everglades, Florida

USGS Publications Warehouse

Waller, Bradley G.

1981-01-01

The results of water-quality samples collected from April 1978 through April 1980 from three canal stations, four marsh stations, and two ground-water stations within the East Everglades, Dade County, Florida, are tabulated in 37 tables. The major categories of parameters analyzed are field measurements, physical characteristics, macronutrients (carbon, nitrogen, and phosphorus), major ions, trace elements, and algae. Chemical data for bulk-precipitation stations within and adjacent to the East Everglades are also given. The parameters analyzed include macronutrients, major ions, and trace elements. The period of record for these stations is October 1977 through April 1980. Bottom material at the canal and marsh stations was collected twice during the investigation. These data include analyses for macronutrients, trace elements, and chlorinated-hydrocarbon insecticides. (USGS)

Experimental investigations about the effect of trace amount of propane on the formation of mixed hydrates of methane and propane

NASA Astrophysics Data System (ADS)

Cai, W.; Lu, H.; Huang, X.

2016-12-01

In natural gas hydrates, some heavy hydrocarbons are always detected in addition to methane. However, it is still not well understood how the trace amount of heavy gas affect the hydrate properties. Intensive studies have been carried out to study the thermodynamic properties and structure types of mixed gases hydrates, but comparatively few investigations have been carried out on the cage occupancies of guest molecules in mixed gases hydrates. For understanding how trace amount of propane affects the formation of mixed methane-propane hydrates, X-ray diffraction, Raman spectroscopy, and gas chromatography were applied to the synthesized mixed methane-propane hydrate specimens, to get their structural characteristics (structure type, structural parameters, cage occupancy, etc.) and gas compositions. The mixed methane-propane hydrates were prepared by reacting fine ice powders with various gas mixtures of methane and propane. When the propane content was below 0.4%, the hydrates synthesized were found containing both sI methane hydrate and sII methane-propane hydrate; while the hydrates were found always sII when propane was over certain content. Detail studies about the cage occupancies of propane and methane in sII hydrate revealed that: 1) with the increase in propane content of methane-propane mixture, the occupancy of propane in large cage increased as accompanied with the decrease in methane occupancy in large cage, however the occupancy of methane in small cage didn't experience significant change; 2) temperature and pressure seemed no obvious influence on cage occupancy.

Application of cotton as a solid phase extraction sorbent for on-line preconcentration of copper in water samples prior to inductively coupled plasma optical emission spectrometry determination.

PubMed

Faraji, Mohammad; Yamini, Yadollah; Shariati, Shahab

2009-07-30

Copper, as a heavy metal, is toxic for many biological systems. Thus, the determination of trace amounts of copper in environmental samples is of great importance. In the present work, a new method was developed for the determination of trace amounts of copper in water samples. The method is based on the formation of ternary Cu(II)-CAS-CTAB ion-pair and adsorption of it into a mini-column packed with cotton prior applying inductively coupled plasma optical emission spectrometry (ICP-OES). The experimental parameters that affected the extraction efficiency of the method such as pH, flow rate and volume of the sample solution, concentration of chromazurol S (CAS) and cethyltrimethylammonium bromide (CTAB) as well as type and concentration of eluent were investigated and optimized. The ion-pair (Cu(II)-CAS-CTAB) was quantitatively retained on the cotton under the optimum conditions, then eluted completely using a solution of 25% (v/v) 1-propanol in 0.5 mol L(-1) HNO(3) and directly introduced into the nebulizer of the ICP-OES. The detection limit (DL) of the method for copper was 40 ng L(-1) (V(sample)=100mL) and the relative standard deviation (R.S.D.) for the determination of copper at 10 microg L(-1) level was found to be 1.3%. The method was successfully applied to determine the trace amounts of copper in tap water, deep well water, seawater and two different mineral waters, and suitable recoveries were obtained (92-106%).

A solid-phase extraction method using Transcarpathian clinoptilolite for preconcentration of trace amounts of terbium in water samples.

PubMed

Vasylechko, Volodymyr O; Gryshchouk, Galyna V; Zakordonskiy, Victor P; Vyviurska, Olga; Pashuk, Andriy V

2015-01-01

In spite of the fact that terbium is one of the rarest elements in the Earth's crust, it is frequently used for the production of high technological materials. At the result, an effective combination of sample preparation procedure and detection method for terbium ions in different matrices is highly required. The solid-phase extraction procedure with natural Transcarpathian clinoptilolite thermally activated at 350 °C was used to preconcentrate trace amounts of terbium ions in aqueous solutions for a final spectrophotometric determination with arsenazo III. Thermogravimetric investigations confirmed the existence of relations between changes that appeared during dehydratation of calcined zeolite and its sorption affinity. Since the maximum of sorption capacity towards terbium was observed at pH 8.25, a borate buffer medium (2.5 · 10(-4) М) was used to maintain ionic force and solution acidity. Terbium was quantitatively removed from the solid-phase extraction column with a 1.0 M solution of sodium chloride (pH 2.5). The linearity of the proposed method was evaluated in the range of 2.5-200 ng · mL(-1) with detection limit 0.75 ng · mL(-1). Due to acceptable recoveries (93.3-102.0 %) and RSD values (6-7.1) from spiked tap water, the developed method can be successfully applied for the determination of trace amounts of terbium ions in the presence of major components of water. Graphical abstractSorption of terbium(III) ions on clinoptilolite.

Infrared trace element detection system

DOEpatents

Bien, F.; Bernstein, L.S.; Matthew, M.W.

1988-11-15

An infrared trace element detection system includes an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined. 11 figs.

Infrared trace element detection system

DOEpatents

Bien, Fritz; Bernstein, Lawrence S.; Matthew, Michael W.

1988-01-01

An infrared trace element detection system including an optical cell into which the sample fluid to be examined is introduced and removed. Also introduced into the optical cell is a sample beam of infrared radiation in a first wavelength band which is significantly absorbed by the trace element and a second wavelength band which is not significantly absorbed by the trace element for passage through the optical cell through the sample fluid. The output intensities of the sample beam of radiation are selectively detected in the first and second wavelength bands. The intensities of a reference beam of the radiation are similarly detected in the first and second wavelength bands. The sensed output intensity of the sample beam in one of the first and second wavelength bands is normalized with respect to the other and similarly, the intensity of the reference beam of radiation in one of the first and second wavelength bands is normalized with respect to the other. The normalized sample beam intensity and normalized reference beam intensity are then compared to provide a signal from which the amount of trace element in the sample fluid can be determined.

Sediment and water chemistry of the San Juan River and Escalante River deltas of Lake Powell, Utah, 2010-2011

USGS Publications Warehouse

Hornewer, Nancy J.

2014-01-01

Recent studies have documented the presence of trace elements, organic compounds including polycyclic aromatic hydrocarbons, and radionuclides in sediment from the Colorado River delta and from sediment in some side canyons in Lake Powell, Utah and Arizona. The fate of many of these contaminants is of significant concern to the resource managers of the National Park Service Glen Canyon National Recreation Area because of potential health impacts to humans and aquatic and terrestrial species. In 2010, the U.S. Geological Survey began a sediment-core sampling and analysis program in the San Juan River and Escalante River deltas in Lake Powell, Utah, to help the National Park Service further document the presence or absence of contaminants in deltaic sediment. Three sediment cores were collected from the San Juan River delta in August 2010 and three sediment cores and an additional replicate core were collected from the Escalante River delta in September 2011. Sediment from the cores was subsampled and composited for analysis of major and trace elements. Fifty-five major and trace elements were analyzed in 116 subsamples and 7 composited samples for the San Juan River delta cores, and in 75 subsamples and 9 composited samples for the Escalante River delta cores. Six composited sediment samples from the San Juan River delta cores and eight from the Escalante River delta cores also were analyzed for 55 low-level organochlorine pesticides and polychlorinated biphenyls, 61 polycyclic aromatic hydrocarbon compounds, gross alpha and gross beta radionuclides, and sediment-particle size. Additionally, water samples were collected from the sediment-water interface overlying each of the three cores collected from the San Juan River and Escalante River deltas. Each water sample was analyzed for 57 major and trace elements. Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for the sediment-core subsamples and composited samples. Low-level organochlorine pesticides and polychlorinated biphenyls were not detected in any of the samples. Only one polycyclic aromatic hydrocarbon compound was detected at a concentration greater than the reporting level for one San Juan composited sample. Gross alpha and gross beta radionuclides were detected at concentrations greater than reporting levels for all samples. Most of the major and trace elements analyzed were detected at concentrations greater than reporting levels for water samples.

Optimal conditions for elution of hepatitis B antigen after absorption onto colloidal silica.

PubMed Central

Pillot, J; Goueffon, S; Keros, R G

1976-01-01

Hepatitis B surface antigen (HBSAg) adsorbed from sera onto colloidal silica could be completely eluted through the use of 0.25% sodium deoxycholate in 0.01 M borax, pH 9.3, at 56 degrees C. The HBSAg recovered in the eluate represented 100% of that present in the original serum, and it was contaminated by only trace amounts of serum proteins (in decreasing amounts: beta-lipoprotein, immunoglobulin G, albumin). This preliminary step greatly facilitates purification of large amounts of HBSAg and provides small volumes of highly concentrated material for subsequent purification by density gradient centrifugation. PMID:9423

78 FR 39338 - Importer of Controlled Substances; Notice of Registration; Catalent CTS., Inc.

Federal Register 2010, 2011, 2012, 2013, 2014

2013-07-01

... plans to import an ointment for the treatment of wounds, which contains trace amounts of the controlled..., verification of the company's compliance with state and local laws, and a review of the company's background...

75 FR 9613 - Importer of Controlled Substances; Notice of Registration

Federal Register 2010, 2011, 2012, 2013, 2014

2010-03-03

... for the treatment of wounds which contain trace amounts of the controlled substance normally found in..., and a review of the company's background and history. Therefore, pursuant to 21 U.S.C. 952(a) and 958...

Helium Find Thaws the Cold Fusion Trail.

ERIC Educational Resources Information Center

Pennisi, E.

1991-01-01

Reported is a study of cold fusion in which trace amounts of helium, possible evidence of an actual fusion reaction, were found. Research methodology is detailed. The controversy over the validity of experimental results with cold fusion are reviewed. (CW)

Changes in Trace Gas Nitrogen Emissions as a Response to Ecosystem Type Conversion in a Semi-Arid Climate.

NASA Astrophysics Data System (ADS)

Andrews, H.; Eberwein, J. R.; Jenerette, D.

2016-12-01

As humans continue to introduce exotic plants and to alter climate and fire regimes in semi-arid ecosystems, many plant communities have begun to shift from perennial forbs and shrubs to annual grasses with different functional traits. Shifts in plant types are also associated with shifts in microclimate, microbial activity, and litter inputs, all of which contribute to the efficiency of nitrogen processing and the magnitude of trace gas emissions (NOx and N2O), which are increasingly important fluxes in water-limited systems. Here, we explored how changes in plant litter impact trace gas emissions, asking the question: How does conversion from a native shrubland to exotic grassland ecosystem alter NOx and N2O fluxes in a semi-arid climate? We posed two hypotheses to explain the impacts of different types of litter on soils disturbed by exotic grasses and those that were still considered shrublands: 1.) Soils that have undergone conversion by exotic grasses release higher amounts of NOx and N2O than do those of unconverted shrublands, due to disruptions of native plant and soil processes by exotic grasses, and 2.) Because litter of exotic grasses has lower C:N than that of shrubs, litter inputs from exotic grasses will increase NOx and N2O emissions from soils more than will litter inputs from shrubs. As a preliminary study, we experimentally wetted mesocosms in a laboratory incubation containing converted and unconverted soils that had been mixed with no litter or either exotic grass or coastal sage scrub (CSS) litter. We measured N2O fluxes from mesocosms over a 48-hour period. 24 hours after wetting, samples with grass litter produced higher amounts of N2O than those with CSS litter; similarly, converted soils produced higher amounts of N2O than unconverted soils. These two effects combined resulted in exotic grassland conditions (converted soils with exotic grass litter) producing 10 times the amount of N2O as those containing native shrubland conditions (unconverted soils with CSS litter). Additionally, soils with no litter peaked in N2O emissions earlier than those with litter (12 hours after wetting compared to 24 hours after wetting). Following preliminary results, we suggest that differences in plant traits, such as litter, play a significant role in the magnitude and timing of trace gas nitrogen emissions.

Effect of copper chloride on the emissions of PCDD/Fs and PAHs from PVC combustion.

PubMed

Wang, Dongli; Xu, Xiaobai; Zheng, Minghui; Chiu, Chung H

2002-09-01

The influences of temperature, air flow and the amount of copper chloride upon the types and amount of the toxic emissions such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) and polycyclic aromatic hydrocarbons (PAHs) during combustion of polyvinyl chloride (PVC) were investigated. The mechanism concerning the effect of temperature and copper chloride on the PCDD/Fs and PAHs formation was discussed. The results shown that without copper chloride, trace amounts of PCDD/Fs and large amounts of PAHs were found in the emissions from the pure PVC combustion under various combustion conditions. The addition of copper chloride enhanced PCDD/Fs formation, but it seems that the formation of PAHs decreased with increasing amount of copper chloride, and greater total amount of PAHs were produced at the higher temperature under our experimental conditions.

Concentrations of selected trace elements in fish tissue and streambed sediment in the Clark Fork-Pend Oreille and Spokane River basins, Washington, Idaho, and Montana, 1998

USGS Publications Warehouse

Maret, Terry R.; Skinner, K.D.

2000-01-01

Fish tissue and bed sediment samples were collected from 16 stream sites in the Northern Rockies Intermontane Basins study area in 1998 as part of the U.S. Geological Survey National Water-Quality Assessment Program. Bed sediment samples were analyzed for 45 trace elements, and fish livers and sportfish fillets were analyzed for 22 elements to characterize the occurrence and distribution of these elements in relation to stream characteristics and land use activities. Nine trace elements of environmental concern—arsenic, cadmium, chromium, copper, lead, mercury, nickel, selenium, and zinc—were detected in bed sediment, but not all of these elements were detected in fish tissue. Trace-element concentrations were highest in bed sediment samples collected at sites downstream from significant natural mineral deposits and (or) mining activities. Arsenic, cadmium, copper, lead, mercury, and zinc in bed sediment at some sites were elevated relative to national median concentrations, and some concentrations were at levels that can adversely affect aquatic biota. Although trace-element concentrations in bed sediment exceeded various guidelines, no concentrations in sportfish fillets exceeded U.S. Environmental Protection Agency screening values for the protection of human health. Correlations between most trace-element concentrations in bed sediment and fish tissue (liver and fillet) were not significant (r0.05). Concentrations of arsenic, cadmium, copper, lead, mercury, nickel, selenium, and zinc in bed sediment were significantly correlated (r=0.53 to 0.88, p2=0.95 and 0.99, p<0.001) that corresponded to trace-element enrichment categories. These strong relations warrant further study using mine density as an explanatory variable to predict trace-element concentrations in bed sediment.

Results of chemical and isotopic analyses of sediment and water from alluvium of the Canadian River near a closed municipal landfill, Norman, Oklahoma

USGS Publications Warehouse

Breit, George N.; Tuttle, Michele L.W.; Cozzarelli, Isabelle M.; Christenson, Scott C.; Jaeschke, Jeanne B.; Fey, David L.; Berry, Cyrus J.

2005-01-01

Results of physical and chemical analyses of sediment and water collected near a closed municipal landfill at Norman, Oklahoma are presented in this report. Sediment analyses are from 40 samples obtained by freeze-shoe coring at 5 sites, and 14 shallow (depth <1.3 m) sediment samples. The sediment was analyzed to determine grain size, the abundance of extractable iron species and the abundances and isotopic compositions of forms of sulfur. Water samples included pore water from the freeze-shoe core, ground water, and surface water. Pore water from 23 intervals of the core was collected and analyzed for major and trace dissolved species. Thirteen ground-water samples obtained from wells within a few meters of the freeze-shoe core sites and one from the landfill were analyzed for major and trace elements as well as the sulfur and oxygen isotope composition of dissolved sulfate. Samples of surface water were collected at 10 sites along the Canadian River from New Mexico to central Oklahoma. These river-water samples were analyzed for major elements, trace elements, and the isotopic composition of dissolved sulfate.

Analysis of trace impurities in neon by a customized gas chromatography.

PubMed

Yin, Min Kyo; Lim, Jeong Sik; Moon, Dong Min; Lee, Gae Ho; Lee, Jeongsoon

2016-09-09

Excimer lasers, widely used in the semiconductor industry, are crucial for analyzing the purity of premix laser gases for the purpose of controlling stable laser output power. In this study, we designed a system for analyzing impurities in pure neon (Ne) base gas by customized GC. Impurities in pure neon (H2 and He), which cannot be analyzed at the sub-μmol/mol level using commercial GC detectors, were analyzed by a customized pulsed-discharge Ne ionization detector (PDNeD) and a pressurized injection thermal conductivity detector using Ne as the carrier gas (Pres. Inj. Ne-TCD). From the results, trace species in Ne were identified with the following detection limits: H2, 0.378μmol/mol; O2, 0.119μmol/mol; CH4, 0.880μmol/mol; CO, 0.263μmol/mol; CO2, 0.162μmol/mol (PDNeD); and He, 0.190μmol/mol (Pres. Inj. Ne-TCD). This PDNeD and pressurized injection Ne-TCD technique thus developed permit the quantification of trace impurities present in high-purity Ne. Copyright © 2016. Published by Elsevier B.V.

Neutron activation analyses and half-life measurements at the usgs triga reactor

NASA Astrophysics Data System (ADS)

Larson, Robert E.

Neutron activation of materials followed by gamma spectroscopy using high-purity germanium detectors is an effective method for making measurements of nuclear beta decay half-lives and for detecting trace amounts of elements present in materials. This research explores applications of neutron activation analysis (NAA) in two parts. Part 1. High Precision Methods for Measuring Decay Half-Lives, Chapters 1 through 8 Part one develops research methods and data analysis techniques for making high precision measurements of nuclear beta decay half-lives. The change in the electron capture half-life of 51Cr in pure chromium versus chromium mixed in a gold lattice structure is explored, and the 97Ru electron capture decay half-life are compared for ruthenium in a pure crystal versus ruthenium in a rutile oxide state, RuO2. In addition, the beta-minus decay half-life of 71mZn is measured and compared with new high precision findings. Density Functional Theory is used to explain the measured magnitude of changes in electron capture half-life from changes in the surrounding lattice electron configuration. Part 2. Debris Collection Nuclear Diagnostic at the National Ignition Facility, Chapters 9 through 11 Part two explores the design and development of a solid debris collector for use as a diagnostic tool at the National Ignition Facility (NIF). NAA measurements are performed on NIF post-shot debris collected on witness plates in the NIF chamber. In this application NAA is used to detect and quantify the amount of trace amounts of gold from the hohlraum and germanium from the pellet present in the debris collected after a NIF shot. The design of a solid debris collector based on material x-ray ablation properties is given, and calculations are done to predict performance and results for the collection and measurements of trace amounts of gold and germanium from dissociated hohlraum debris.

Quantifying Trace Amounts of Aggregates in Biopharmaceuticals Using Analytical Ultracentrifugation Sedimentation Velocity: Bayesian Analyses and F Statistics.

PubMed

Wafer, Lucas; Kloczewiak, Marek; Luo, Yin

2016-07-01

Analytical ultracentrifugation-sedimentation velocity (AUC-SV) is often used to quantify high molar mass species (HMMS) present in biopharmaceuticals. Although these species are often present in trace quantities, they have received significant attention due to their potential immunogenicity. Commonly, AUC-SV data is analyzed as a diffusion-corrected, sedimentation coefficient distribution, or c(s), using SEDFIT to numerically solve Lamm-type equations. SEDFIT also utilizes maximum entropy or Tikhonov-Phillips regularization to further allow the user to determine relevant sample information, including the number of species present, their sedimentation coefficients, and their relative abundance. However, this methodology has several, often unstated, limitations, which may impact the final analysis of protein therapeutics. These include regularization-specific effects, artificial "ripple peaks," and spurious shifts in the sedimentation coefficients. In this investigation, we experimentally verified that an explicit Bayesian approach, as implemented in SEDFIT, can largely correct for these effects. Clear guidelines on how to implement this technique and interpret the resulting data, especially for samples containing micro-heterogeneity (e.g., differential glycosylation), are also provided. In addition, we demonstrated how the Bayesian approach can be combined with F statistics to draw more accurate conclusions and rigorously exclude artifactual peaks. Numerous examples with an antibody and an antibody-drug conjugate were used to illustrate the strengths and drawbacks of each technique.

Preparation and characterization of magnetic nanocomposite of Schiff base/silica/magnetite as a preconcentration phase for the trace determination of heavy metal ions in water, food and biological samples using atomic absorption spectrometry.

PubMed

Bagheri, Hasan; Afkhami, Abbas; Saber-Tehrani, Mohammad; Khoshsafar, Hosein

2012-08-15

A versatile and robust solid phase with both magnetic property and a very high adsorption capacity is presented on the basis of modification of iron oxide-silica magnetic particles with a newly synthesized Schiff base (Fe(3)O(4)/SiO(2)/L). The structure of the resulting product was confirmed by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) spectrometry and transmission electron microscopy (TEM). We developed an efficient and cost-effective method for the preconcentration of trace amounts of Pb(II), Cd(II) and Cu(II) in environmental and biological samples using this novel magnetic solid phase. Prepared magnetic solid phase is an ideal support because it has a large surface area, good selectivity and can be easily retrieved from large volumes of aqueous solutions. The possible parameters affecting the enrichment were optimized. Under the optimal conditions, the method detection limit was 0.14, 0.19 and 0.12 μg L(-1) for Pb(II), Cd(II) and Cu(II) ions, respectively. The established method has been successfully applied to analyze real samples, and satisfactory results were obtained. All these indicated that this magnetic phase had a great potential in environmental and biological fields. Copyright © 2012 Elsevier B.V. All rights reserved.

Determination of trace endocrine active phenolic compounds by GC/MS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gang Sun; Geno, P.W.

1997-12-31

4-Nonylphenol ethoxylates (NPEOs) and 4-octylphenol ethoxylates (OPEOs) are widely used as nonionic surfactants, Due to the potential estrogenic properties of these compounds and their biodegradation products, there is increasing concern about their presence in ground and drinking water. To assess their prevalence in drinking and ground water, a simple, highly sensitive and accurate analytical method for determination of trace amounts of 4-nonylphenol, 4-nonylphenol monoethoxylate (NP1EO), 4-nonylphenol diethoxylate (NP2EO), 4-nonylphenol monoethoxycarboxylate (NP1EC), 4-octylphenol, 4-octylphenol monoethoxylate (OP1EO), 4-octylphenol diethoxylate (OP2EO), and other 15 phenolic compounds has been developed and validated. One liter of drinking water sample was extracted and concentrated into dichloromethane.more » The analytes in the extracts were converted to their trimethylsilyl derivatives by reacting with N,O-bis(trimethylsilyl) trifluoroacetamine (BSTFA) and 10 % trimethylchlorosilane (TMCS) at 90{degrees}C. The derivatized extracts were then directly analyzed by gas chromatography-mass spectrometry operating in a selected-ion monitoring mode (GUMS-SIM). Method detection limits (MDLs) were 0.01 to 0.02 {mu}g/L for 4-nonylphenol, NP1EO, 2PNEO; 0.064 {mu}g/L for NP1EC; 0.005 to 0.02 {mu}g/L for 4-octylphenol, OP1EO, OP2EO; and 0.001 to 0.003 {mu}g/L, for other 15 phenolic compounds.« less

A study of the impact of moist-heat and dry-heat treatment processes on hazardous trace elements migration in food waste.

PubMed

Chen, Ting; Jin, Yiying; Qiu, Xiaopeng; Chen, Xin

2015-03-01

Using laboratory experiments, the authors investigated the impact of dry-heat and moist-heat treatment processes on hazardous trace elements (As, Hg, Cd, Cr, and Pb) in food waste and explored their distribution patterns for three waste components: oil, aqueous, and solid components. The results indicated that an insignificant reduction of hazardous trace elements in heat-treated waste-0.61-14.29% after moist-heat treatment and 4.53-12.25% after dry-heat treatment-and a significant reduction in hazardous trace elements (except for Hg without external addition) after centrifugal dehydration (P < 0.5). Moreover, after heat treatment, over 90% of the hazardous trace elements in the waste were detected in the aqueous and solid components, whereas only a trace amount of hazardous trace elements was detected in the oil component (<0.01%). In addition, results indicated that heat treatment process did not significantly reduce the concentration of hazardous trace elements in food waste, but the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk considerably. Finally, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment on the removal of external water-soluble ionic hazardous trace elements. An insignificant reduction of hazardous trace elements in heat-treated waste showed that heat treatment does not reduce trace elements contamination in food waste considerably, whereas the separation process for solid and aqueous components, such as centrifugal dehydration, could reduce the risk significantly. Moreover, combined with the separation technology for solid and liquid components, dry-heat treatment is superior to moist-heat treatment for the removal of external water-soluble ionic hazardous trace elements, by exploring distribution patterns of trace elements in three waste components: oil, aqueous, and solid components.

Geochemical distribution of major and trace elements in agricultural soils of Castilla-La Mancha (central Spain): finding criteria for baselines and delimiting regional anomalies.

PubMed

Bravo, Sandra; García-Ordiales, Efrén; García-Navarro, Francisco Jesús; Amorós, José Ángel; Pérez-de-Los-Reyes, Caridad; Jiménez-Ballesta, Raimundo; Esbrí, José María; García-Noguero, Eva María; Higueras, Pablo

2017-09-07

Castilla-La Mancha (central Spain) is a region characterized by significant agricultural production aimed at high-quality food products such as wine and olive oil. The quality of agricultural products depends directly on the soil quality. Soil geochemistry, including dispersion maps and the recognition of baselines and anomalies of various origins, is the most important tool to assess soil quality. With this objective, 200 soil samples were taken from agricultural areas distributed among the different geological domains present in the region. Analysis of these samples included evaluation of edaphological parameters (reactivity, electrical conductivity, organic matter content) and the geochemistry of major and trace elements by X-ray fluorescence. The dataset obtained was statistically analyzed for major elements and, in the case of trace elements, was normalized with respect to Al and analyzed using the relative cumulative frequency (RCF) distribution method. Furthermore, the geographic distribution of analytical data was characterized and analyzed using the kriging technique, with a correspondence found between major and trace elements in the different geologic domains of the region as well as with the most important mining areas. The results show an influence of the clay fraction present in the soil, which acts as a repository for trace elements. On the basis of the results, of the possible elements related with clay that could be used for normalization, Al was selected as the most suitable, followed by Fe, Mn, and Ti. Reference values estimated using this methodology were lower than those estimated in previous studies.

Amplification of trace amounts of nucleic acids

DOEpatents

Church, George M [Brookline, MA; Zhang, Kun [Brighton, MA

2008-06-17

Methods of reducing background during amplification of small amounts of nucleic acids employ careful analysis of sources of low level contamination. Ultraviolet light can be used to reduce nucleic acid contaminants in reagents and equipment. "Primer-dimer" background can be reduced by judicious design of primers. We have shown clean signal-to-noise with as little as starting material as one single human cell (.about.6 picogram), E. coli cell (.about.5 femtogram) or Prochlorococcus cell (.about.3 femtogram).

Quantification of fluorine traces in solid samples using CaF molecular emission bands in atmospheric air Laser-Induced Breakdown Spectroscopy

NASA Astrophysics Data System (ADS)

Alvarez-Llamas, C.; Pisonero, J.; Bordel, N.

2016-09-01

Direct solid determination of trace amounts of fluorine using Laser-Induced Breakdown Spectroscopy (LIBS) is a challenging task due to the low excitation efficiency of this element. Several strategies have been developed to improve the detection capabilities, including the use of LIBS in a He atmosphere to enhance the signal to background ratios of F atomic emission lines. An alternative method is based on the detection of the molecular compounds that are formed with fluorine in the LIBS plasma. In this work, the detection of CaF molecular emission bands is investigated to improve the analytical capabilities of atmospheric air LIBS for the determination of fluorine traces in solid samples. In particular, Cu matrix samples containing different fluorine concentration (between 50 and 600 μg/g), and variable amounts of Ca, are used to demonstrate the linear relationships between CaF emission signal and F concentration. Limits of detection for fluorine are improved by more than 1 order of magnitude using CaF emission bands versus F atomic lines, in atmospheric-air LIBS. Furthermore, a toothpaste powder sample is used to validate this analytical method. Good agreement is observed between the nominal and the predicted fluorine mass-content.

Construction of uniformly sized pseudo template imprinted polymers coupled with HPLC-UV for the selective extraction and determination of trace estrogens in chicken tissue samples.

PubMed

Wang, Shu; Li, Yun; Wu, Xiaoli; Ding, Meijuan; Yuan, Lihua; Wang, Ruoyu; Wen, Tingting; Zhang, Jun; Chen, Lina; Zhou, Xuemin; Li, Fei

2011-02-28

To assess the potential risks associated with the environmental exposure of steroid estrogens, a novel highly efficient and selective estrogen enrichment procedure based on the use of molecularly imprinted polymer has been developed and evaluated. Herein, analogue of estrogens, namely 17-ethyl estradiol (EE(2)) was used as the pseudo template, to avoid the leakage of a trace amount of the target analytes. The resulting pseudo molecularly imprinted polymers (PMIPs) showed large sorption capacity, high recognition ability and fast binding kinetics for estrogens. Moreover, using these imprinted particles as dispersive solid-phase extraction (DSPE) materials, the amounts of three estrogens (E(1), E(2) and E(3)) which were detected by HPLC-UV from the chicken tissue samples were 0.28, 0.31 and 0.17 μg g(-1), and the recoveries were 72.5-78.7%, 90.3-95.2% and 80.5-83.6% in spiked chicken tissue samples with RSD <7%, respectively. All these results reveal that EE(2)-PMIPs as DSPE materials coupled with HPLC-UV could be applied to the highly selective separation and sensitive determination of trace estrogens in chicken tissue samples. Copyright © 2010 Elsevier B.V. All rights reserved.

Variable thickness double-refracting plate

DOEpatents

Hadeishi, Tetsuo

1976-01-01

This invention provides an A.C., cyclic, current-controlled, phase retardation plate that uses a magnetic clamp to produce stress birefringence. It was developed for an Isotope-Zeeman Atomic Absorption Spectrometer that uses polarization modulation to effect automatic background correction in atomic absorption trace-element measurements. To this end, the phase retardation plate of the invention is a variable thickness, photoelastic, double-refracting plate that is alternately stressed and released by the magnetic clamp selectively to modulate specific components selected from the group consisting of circularly and plane polarized Zeeman components that are produced in a dc magnetic field so that they correspond respectively to Zeeman reference and transmission-probe absorption components. The polarization modulation changes the phase of these polarized Zeeman components, designated as .sigma. reference and .pi. absorption components, so that every half cycle the components change from a transmission mode to a mode in which the .pi. component is blocked and the .sigma. components are transmitted. Thus, the Zeeman absorption component, which corresponds in amplitude to the amount of the trace element to be measured in a sample, is alternately transmitted and blocked by a linear polarizer, while the circularly polarized reference components are continuously transmitted thereby. The result is a sinusoidally varying output light amplitude whose average corresponds to the amount of the trace element present in the sample.

Preparation of modified magnetic nanoparticles as a sorbent for the preconcentration and determination of cadmium ions in food and environmental water samples prior to flame atomic absorption spectrometry

NASA Astrophysics Data System (ADS)

Mirabi, Ali; Dalirandeh, Zeinab; Rad, Ali Shokuhi

2015-05-01

A new method has been developed for the separation/preconcentration of trace level cadmium ions using diphenyl carbazone/sodium dodecyl sulfate immobilized on magnetic nanoparticle Fe3O4 as a new sorbent SPE and their determination by flame atomic absorption spectrometry (FAAS). Synthesized nanoparticle was characterized by scanning electron microscope (SEM) and transmission electron microscope (TEM). Various influencing parameters on the separation and preconcentration of trace level cadmium ions such as, pH value, amount of nanoparticles, amount of diphenyl carbazone, condition of eluting solution, the effects of matrix ions were examined. The cadmium ions can be eluted from the modified magnetic nanoparticle using 1 mol L-1 HCl as a desorption reagent. The detection limit of this method for cadmium was 3.71 ng ml-1 and the R.S.D. was 0.503% (n=6). The advantages of this new method include rapidity, easy preparation of sorbents and a high concentration factor. The proposed method has been applied to the determination of Cd ions at trace levels in real samples such as, green tea, rice, tobacco, carrot, lettuce, ginseng, spice, tap water, river water, sea water with satisfactory results.

78 FR 69131 - Importer of Controlled Substances; Notice of Registration; Catalent CTS, LLC

Federal Register 2010, 2011, 2012, 2013, 2014

2013-11-18

... treatment of wounds which contains trace amounts of the controlled substances normally found in poppy straw... company's background and history. Therefore, pursuant to 21 U.S.C. 952(a) and 958(a), and in accordance...

RELATIONSHIPS BETWEEN LABORATORY AND PILOT-SCALE COMBUSTION OF SOME CHLORINATED HYDROCARBONS

EPA Science Inventory

Factors governing the occurence of trace amounts of residual organic substance emmissions (ROSEs) in full-scale incierators are not fully understood. Pilot-scale spray combustion expereiments involving some liquid chlorinated hydrocarbons (CHCs) and their dilute mixtures with hy...

Collaborative Study of Analysis of High Resolution Infrared Atmospheric Spectra Between NASA Langley Research Center and the University of Denver

NASA Technical Reports Server (NTRS)

Goldman, Aaron

1999-01-01

The Langley-D.U. collaboration on the analysis of high resolution infrared atmospheric spectra covered a number of important studies of trace gases identification and quantification from field spectra, and spectral line parameters analysis. The collaborative work included: Quantification and monitoring of trace gases from ground-based spectra available from various locations and seasons and from balloon flights. Studies toward identification and quantification of isotopic species, mostly oxygen and Sulfur isotopes. Search for new species on the available spectra. Update of spectroscopic line parameters, by combining laboratory and atmospheric spectra with theoretical spectroscopy methods. Study of trends of atmosphere trace constituents. Algorithms developments, retrievals intercomparisons and automatization of the analysis of NDSC spectra, for both column amounts and vertical profiles.

Trace element distribution in waters of the northern catchment area of Lake Linneret, northern Israel

NASA Astrophysics Data System (ADS)

Sandler, A.; Brenner, I. B.; Halicz, L.

1988-02-01

Waters of the northern watershed of Lake Kineret, sampled during the period 1978 1983, were analyzed for their major and trace element contents. The trace element concentrations of the major water sources of the watershed (the Dan and Banias springs) represent background values. After emergence, the waters are subjected to human activity. In crossing the populated and cultivated Hula Basin in man-made canals, the major and trace element contents increase. In comparison to the trace element concentrations, those of the major elements have narrow ranges and small temporal fluctuations. Trace element concentrations varied by 3 orders of magnitude, and temporal variations were large but not neccessarily seasonal. Point sources of trace elements were urban effluents, fish pond wastes, and peat soil drainage. The trace element concentrations decrease in the waters of the last segment of the Jordan River. All measured trace elements were below the criteria levels established by regulatory agencies. Several, however, were of the same order of magnitude. Addition of wastes from enhanced recycling, and morphologic modification of the final course of the Jordan River could result in increase in the trace element concentrations in the water.

An information transfer based novel framework for fault root cause tracing of complex electromechanical systems in the processing industry

NASA Astrophysics Data System (ADS)

Wang, Rongxi; Gao, Xu; Gao, Jianmin; Gao, Zhiyong; Kang, Jiani

2018-02-01

As one of the most important approaches for analyzing the mechanism of fault pervasion, fault root cause tracing is a powerful and useful tool for detecting the fundamental causes of faults so as to prevent any further propagation and amplification. Focused on the problems arising from the lack of systematic and comprehensive integration, an information transfer-based novel data-driven framework for fault root cause tracing of complex electromechanical systems in the processing industry was proposed, taking into consideration the experience and qualitative analysis of conventional fault root cause tracing methods. Firstly, an improved symbolic transfer entropy method was presented to construct a directed-weighted information model for a specific complex electromechanical system based on the information flow. Secondly, considering the feedback mechanisms in the complex electromechanical systems, a method for determining the threshold values of weights was developed to explore the disciplines of fault propagation. Lastly, an iterative method was introduced to identify the fault development process. The fault root cause was traced by analyzing the changes in information transfer between the nodes along with the fault propagation pathway. An actual fault root cause tracing application of a complex electromechanical system is used to verify the effectiveness of the proposed framework. A unique fault root cause is obtained regardless of the choice of the initial variable. Thus, the proposed framework can be flexibly and effectively used in fault root cause tracing for complex electromechanical systems in the processing industry, and formulate the foundation of system vulnerability analysis and condition prediction, as well as other engineering applications.

Gaseous trace impurity analyzer and method

DOEpatents

Edwards, Jr., David; Schneider, William

1980-01-01

Simple apparatus for analyzing trace impurities in a gas, such as helium or hydrogen, comprises means for drawing a measured volume of the gas as sample into a heated zone. A segregable portion of the zone is then chilled to condense trace impurities in the gas in the chilled portion. The gas sample is evacuated from the heated zone including the chilled portion. Finally, the chilled portion is warmed to vaporize the condensed impurities in the order of their boiling points. As the temperature of the chilled portion rises, pressure will develop in the evacuated, heated zone by the vaporization of an impurity. The temperature at which the pressure increase occurs identifies that impurity and the pressure increase attained until the vaporization of the next impurity causes a further pressure increase is a measure of the quantity of the preceding impurity.

Dating and Tracing Groundwater and Ice with 81Kr and 85Kr

NASA Astrophysics Data System (ADS)

Yang, Guomin; Tong, Amin; Dong, Xize; Gu, Jiqiang; Hu, Shuiming; Jiang, Wei; Lu, Zhengtian; Ritterbusch, Florian

2017-04-01

81Kr (half-life 229kyr) is an ideal tracer for old groundwater and ice in the age range of 105 - 106 years. To meet the increasing demands from the earth science community, a new and improved Atom Trap Trace Analysis (ATTA) apparatus is developed at the University of Science and Technology of China (USTC). This instrument is capable of analyzing over 300 samples per year. Each measurement requirs 1-2 uL STP of krypton gas, which can be extracted from 20-40 kg of water. New sampling and purification systems have also been developed at USTC. With the new portable sampling system, the time for on-site sampling is typically less than one hour. The same sampling and atom-trap apparatuses are also used to analyze 85Kr (half-life 11 yr) to trace young groundwater.

Impacts of cloud superparameterization on projected daily rainfall intensity climate changes in multiple versions of the Community Earth System Model

DOE PAGES

Kooperman, Gabriel J.; Pritchard, Michael S.; Burt, Melissa A.; ...

2016-09-26

Changes in the character of rainfall are assessed using a holistic set of statistics based on rainfall frequency and amount distributions in climate change experiments with three conventional and superparameterized versions of the Community Atmosphere Model (CAM and SPCAM). Previous work has shown that high-order statistics of present-day rainfall intensity are significantly improved with superparameterization, especially in regions of tropical convection. Globally, the two modeling approaches project a similar future increase in mean rainfall, especially across the Inter-Tropical Convergence Zone (ITCZ) and at high latitudes, but over land, SPCAM predicts a smaller mean change than CAM. Changes in high-order statisticsmore » are similar at high latitudes in the two models but diverge at lower latitudes. In the tropics, SPCAM projects a large intensification of moderate and extreme rain rates in regions of organized convection associated with the Madden Julian Oscillation, ITCZ, monsoons, and tropical waves. In contrast, this signal is missing in all versions of CAM, which are found to be prone to predicting increases in the amount but not intensity of moderate rates. Predictions from SPCAM exhibit a scale-insensitive behavior with little dependence on horizontal resolution for extreme rates, while lower resolution (~2°) versions of CAM are not able to capture the response simulated with higher resolution (~1°). Furthermore, moderate rain rates analyzed by the “amount mode” and “amount median” are found to be especially telling as a diagnostic for evaluating climate model performance and tracing future changes in rainfall statistics to tropical wave modes in SPCAM.« less

Forensic DNA methylation profiling from minimal traces: How low can we go?

PubMed

Naue, Jana; Hoefsloot, Huub C J; Kloosterman, Ate D; Verschure, Pernette J

2018-03-01

Analysis of human DNA methylation (DNAm) can provide additional investigative leads in crime cases, e.g. the type of tissue or body fluid, the chronological age of an individual, and differentiation between identical twins. In contrast to the genetic profile, the DNAm level is not the same in every cell. At the single cell level, DNAm represents a binary event at a defined CpG site (methylated versus non-methylated). The DNAm level from a DNA extract however represents the average level of methylation of the CpG of interest of all molecules in the forensic sample. The variance of DNAm levels between replicates is often attributed to technological issues, i.e. degradation of DNA due to bisulfite treatment, preferential amplification of DNA, and amplification failure. On the other hand, we show that stochastic variations can lead to gross fluctuation in the analysis of methylation levels in samples with low DNA levels. This stochasticity in DNAm results is relevant since low DNA amounts (1pg - 1ng) is rather the norm than the exception when analyzing forensic DNA samples. This study describes a conceptual analysis of DNAm profiling and its dependence on the amount of input DNA. We took a close look at the variation of DNAm analysis due to DNA input and its consequences for different DNAm-based forensic applications. As can be expected, the 95%-confidence interval of measured DNAm becomes narrower with increasing amounts of DNA. We compared this aspect for two different DNAm-based forensic applications: body fluid identification and chronological age determination. Our study shows that DNA amount should be well considered when using DNAm for forensic applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Paper-based SERS swab for rapid trace detection on real-world surfaces.

PubMed

Lee, Chang H; Tian, Limei; Singamaneni, Srikanth

2010-12-01

One of the important but often overlooked considerations in the design of surface-enhanced Raman scattering (SERS) substrates for trace detection is the efficiency of sample collection. Conventional designs based on rigid substrates such as silicon, alumina, and glass resist conformal contact with the surface under investigation, making the sample collection inefficient. We demonstrate a novel SERS substrate based on common filter paper adsorbed with gold nanorods, which allows conformal contact with real-world surfaces, thus dramatically enhancing the sample collection efficiency compared to conventional rigid substrates. We demonstrate the detection of trace amounts of analyte (140 pg spread over 4 cm2) by simply swabbing the surface under investigation with the novel SERS substrate. The hierarchical fibrous structure of paper serves as a 3D vasculature for easy uptake and transport of the analytes to the electromagnetic hot spots in the paper. Simple yet highly efficient and cost-effective SERS substrate demonstrated here brings SERS-based trace detection closer to real-world applications.

Effects of reaction conditions on the emission behaviors of arsenic, cadmium and lead during sewage sludge pyrolysis.

PubMed

Han, Hengda; Hu, Song; Syed-Hassan, Syed Shatir A; Xiao, Yiming; Wang, Yi; Xu, Jun; Jiang, Long; Su, Sheng; Xiang, Jun

2017-07-01

Sewage sludge is an important class of bioresources whose energy content could be exploited using pyrolysis technology. However, some harmful trace elements in sewage sludge can escape easily to the gas phase during pyrolysis, increasing the potential of carcinogenic material emissions to the atmosphere. This study investigates emission characteristics of arsenic, cadmium and lead under different pyrolysis conditions for three different sewage sludge samples. The increased temperature (within 723-1123K) significantly promoted the cadmium and lead emissions, but its influence on arsenic emission was not pronounced. The releasing rate order of the three trace elements is volatile arsenic compounds>cadmium>lead in the beginning of pyrolysis. Fast heating rates promoted the emission of trace elements for the sludge containing the highest amount of ash, but exhibited an opposite effect for other studied samples. Overall, the high ash sludge released the least trace elements almost under all reaction conditions. Copyright © 2017 Elsevier Ltd. All rights reserved.

Muscarinic receptors in amygdala control trace fear conditioning.

PubMed

Baysinger, Amber N; Kent, Brianne A; Brown, Thomas H

2012-01-01

Intelligent behavior requires transient memory, which entails the ability to retain information over short time periods. A newly-emerging hypothesis posits that endogenous persistent firing (EPF) is the neurophysiological foundation for aspects or types of transient memory. EPF is enabled by the activation of muscarinic acetylcholine receptors (mAChRs) and is triggered by suprathreshold stimulation. EPF occurs in several brain regions, including the lateral amygdala (LA). The present study examined the role of amygdalar mAChRs in trace fear conditioning, a paradigm that requires transient memory. If mAChR-dependent EPF selectively supports transient memory, then blocking amygdalar mAChRs should impair trace conditioning, while sparing delay and context conditioning, which presumably do not rely upon transient memory. To test the EPF hypothesis, LA was bilaterally infused, prior to trace or delay conditioning, with either a mAChR antagonist (scopolamine) or saline. Computerized video analysis quantified the amount of freezing elicited by the cue and by the training context. Scopolamine infusion profoundly reduced freezing in the trace conditioning group but had no significant effect on delay or context conditioning. This pattern of results was uniquely anticipated by the EPF hypothesis. The present findings are discussed in terms of a systems-level theory of how EPF in LA and several other brain regions might help support trace fear conditioning.

Trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations: A review.

PubMed

Olafisoye, O B; Oguntibeju, O O; Osibote, O A

2017-05-03

Oil palm (Elaeisguineensis) is one of the most productive oil producing plant in the world. Crude palm oil is composed of triglycerides supplying the world's need of edible oils and fats. Palm oil also provides essential elements and antioxidants that are potential mediators of cellular functions. Experimental studies have demonstrated the toxicity of the accumulation of significant amounts of nonessential trace elements and radionuclides in palm oil that affects the health of consumers. It has been reported that uptake of trace elements and radionuclides from the oil palm tree may be from water and soil on the palm plantations. In the present review, an attempt was made to revise and access knowledge on the presence of some selected trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations based on the available facts and data. Existing reports show that the presence of nonessential trace elements and radionuclides in palm oil may be from natural or anthropogenic sources in the environment. However, the available literature is limited and further research need to be channeled to the investigation of trace elements and radionuclides in soil, water, leaves, and palm oil from oil palm plantations around the globe.

Above detection limits - Prebiotic organics in comets and carbonaceous meteorites

NASA Astrophysics Data System (ADS)

Stern, J. C.; Elsila, J. E.; Callahan, M. P.; Glavin, D. P.; Martin, M. G.; Dworkin, J. P.

2009-12-01

The delivery of organic compounds such as amino acids and nucleobases by comets, asteroids, and their fragments may have contributed feedstock for prebiotic chemistry leading to the first self-replicating systems of the early Earth. In order to determine the isotopic composition, distribution, and abundance of prebiotic organic compounds in extraterrestrial samples we have recently optimized a highly sensitive liquid chromatography tandem quadupole mass spectrometer (LC-QqQ-MS) and a gas chromatography mass spectrometer coupled with an isotope ratio mass spectrometer (GC-MS/IRMS). This suite of instruments not only allows us to identify and quantify extremely trace amounts of organics of astrobiological interest, but also to confirm their extraterrestrial origins by stable isotopic measurements. The amino acid glycine was detected upon preliminary examinations of foils from NASA’s Stardust mission, which returned cometary material from comet 81P/Wild 2. To rule out the possibility of terrestrial contamination as the source of the glycine, the carbon isotopic ratio was measured. The δ13C value for glycine was determined to be +29 ± 6‰, well outside the terrestrial range for organic carbon of +6 ‰ to -40 ‰. The Stardust glycine δ13C value falls in the range previously reported for glycine (+22‰ to +41‰) in the carbonaceous meteorites Murchison and Orgueil. This represents the first detection of glycine or any other amino acid in a comet. Recent investigations of carbonaceous meteorite organic matter have revealed the presence of several nucleobases in the Murchison meteorite and several Antarctic CR meteorites never before analyzed for nucleobases using LC-QqQ-MS. This analytical tool is a sensitive and highly selective method for measuring the trace amounts of these organics in meteorites. In particular, the unusual Antarctic C2 meteorite, LON 94102, shows high abundances of guanine, hypoxanthine, and xanthine with concentrations ranging from 70 to 200 ppb. Nitrogen isotopic measurements will be made to determine the origin (extraterrestrial or terrestrial) of these compounds.

INAA Application for Trace Element Determination in Biological Reference Material

NASA Astrophysics Data System (ADS)

Atmodjo, D. P. D.; Kurniawati, S.; Lestiani, D. D.; Adventini, N.

2017-06-01

Trace element determination in biological samples is often used in the study of health and toxicology. Determination change to its essentiality and toxicity of trace element require an accurate determination method, which implies that a good Quality Control (QC) procedure should be performed. In this study, QC for trace element determination in biological samples was applied by analyzing the Standard Reference Material (SRM) Bovine muscle 8414 NIST using Instrumental Neutron Activation Analysis (INAA). Three selected trace element such as Fe, Zn, and Se were determined. Accuracy of the elements showed as %recovery and precision as %coefficient of variance (%CV). The result showed that %recovery of Fe, Zn, and Se were in the range between 99.4-107%, 92.7-103%, and 91.9-112%, respectively, whereas %CV were 2.92, 3.70, and 5.37%, respectively. These results showed that INAA method is precise and accurate for trace element determination in biological matrices.

TRANSPORT AND FATE OF AMMONIUM AND ITS IMPACT ON URANIUM AND OTHER TRACE ELEMENTS AT A FORMER URANIUM MILL TAILING SITE

PubMed Central

Miao, Ziheng; Nihat, Hakan; McMillan, Andrew Lee; Brusseau, Mark L.

2013-01-01

The remediation of ammonium-containing groundwater discharged from uranium mill tailing sites is a difficult problem facing the mining industry. The Monument Valley site is a former uranium mining site in the southwest US with both ammonium and nitrate contamination of groundwater. In this study, samples collected from 14 selected wells were analyzed for major cations and anions, trace elements, and isotopic composition of ammonium and nitrate. In addition, geochemical data from the U.S. Department of Energy (DOE) database were analyzed. Results showing oxic redox conditions and correspondence of isotopic compositions of ammonium and nitrate confirmed the natural attenuation of ammonium via nitrification. Moreover, it was observed that ammonium concentration within the plume area is closely related to concentrations of uranium and a series of other trace elements including chromium, selenium, vanadium, iron, and manganese. It is hypothesized that ammonium-nitrate transformation processes influence the disposition of the trace elements through mediation of redox potential, pH, and possibly aqueous complexation and solid-phase sorption. Despite the generally relatively low concentrations of trace elements present in groundwater, their transport and fate may be influenced by remediation of ammonium or nitrate at the site. PMID:24357895

Concentration of trace elements on branded cigarette in Malaysia

NASA Astrophysics Data System (ADS)

Azman, Muhammad Azfar; Yasir, Muhamad Samudi; Rahman, Irman Abdul; Hamzah, Suhaimi; Rahman, Shamsiah Abdul; Elias, Md Suhaimi; Abdullah, Nazaratul Ashifa; Hashim, Azian; Shukor, Shakirah Abd

2016-01-01

Tobacco is a plant that is used as a recreational drug since the beginning of its use by the Native Americans. Now with the development of the tobacco industry, smoking has become a norm for the public in Malaysia. Trace elements in plants are mostly due to the uptake processes from the soils into the roots of the plants. The concentration of the elements may also be influenced by the elements contained in the water and also fertilizers. This paper aim to analyze the concentration of the trace elements contained in the branded cigarettes sold in Malaysia by utilizing the neutron activation analysis. The tobaccos were taken out from the cigarettes. The collected samples were air dried and passed through 2 mm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia Triga Mark II reactor with a neutron flux of 2.0 x 1012 n cm-2 s-1. The samples then were analyzed using ORTEC Gamma Spectrometer a co-axial n-type HPGe detector with resolution of 2.0 keV at 1332 keV and relative efficiency of 20%. The data obtained could help in assessing the concentration of the trace elements that complying with the standard limitation dose proposed by World Health Organization (WHO).

Study of V-OTDR stability for dynamic strain measurement in piezoelectric vibration

NASA Astrophysics Data System (ADS)

Ren, Meiqi; Lu, Ping; Chen, Liang; Bao, Xiaoyi

2016-09-01

In a phase-sensitive optical-time domain reflectometry (Φ-OTDR) system, the challenge for dynamic strain measurement lies in large intensity fluctuations from trace to trace. The intensity fluctuation caused by stochastic characteristics of Rayleigh backscattering sets detection limit for the minimum strength of vibration measurement and causes the large measurement uncertainty. Thus, a trace-to-trace correlation coefficient is introduced to quantify intensity fluctuation of Φ-OTDR traces and stability of the sensor system theoretically and experimentally. A novel approach of measuring dynamic strain induced by various driving voltages of lead zirconate titanate (PZT) in Φ-OTDR is also demonstrated. Piezoelectric vibration signals are evaluated through analyzing peak values of fast Fourier transform spectra at the fundamental frequency and high-order harmonics based on Bessel functions. High trace-to-trace correlation coefficients varying from 0.824 to 0.967 among 100 measurements are obtained in experimental results, showing the good stability of our sensor system, as well as small uncertainty of measured peak values.

Seasonal investigation of trace element contents in commercially valuable fish species from the Black sea, Turkey.

PubMed

Mendil, Durali; Demirci, Zafer; Tuzen, Mustafa; Soylak, Mustafa

2010-03-01

Fish species (Sarda sarda, Mulus barbatus ponticus, Trachurus trachurus and Merlangius merlangus) were collected from the Black sea, Turkey between 2008 and 2009 (spring, summer, autumn and winter). The samples were analyzed using flame and graphite furnace atomic absorption spectrometry after microwave digestion. The maximum metal concentrations were found to be as 25.5-41.4 microg/g (Fe), 17.8-25.7 microg/g (Zn), 0.28-0.64 microg/g (Pb), 0.64-0.99 microg/g (Cr), 1.3-3.6 microg/g (Mn), 1.4-1.9 microg/g (Cu), 0.18-0.35 microg/g (Cd) and 0.25-0.42 microg/g (Co) for fish species. The concentration of trace metals in samples is depended on fish species. Some species is accumulated trace metals at high ratio. Trace element levels in analyzed fish species were acceptable to human consumption at nutritional and toxic levels. The levels of lead and cadmium in fish samples were higher than the recommended legal limits. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

Effect of parameters in moving average method for event detection enhancement using phase sensitive OTDR

NASA Astrophysics Data System (ADS)

Kwon, Yong-Seok; Naeem, Khurram; Jeon, Min Yong; Kwon, Il-bum

2017-04-01

We analyze the relations of parameters in moving average method to enhance the event detectability of phase sensitive optical time domain reflectometer (OTDR). If the external events have unique frequency of vibration, then the control parameters of moving average method should be optimized in order to detect these events efficiently. A phase sensitive OTDR was implemented by a pulsed light source, which is composed of a laser diode, a semiconductor optical amplifier, an erbium-doped fiber amplifier, a fiber Bragg grating filter, and a light receiving part, which has a photo-detector and high speed data acquisition system. The moving average method is operated with the control parameters: total number of raw traces, M, number of averaged traces, N, and step size of moving, n. The raw traces are obtained by the phase sensitive OTDR with sound signals generated by a speaker. Using these trace data, the relation of the control parameters is analyzed. In the result, if the event signal has one frequency, then the optimal values of N, n are existed to detect the event efficiently.

DNA in the Criminal Justice System: The DNA Success Story in Perspective.

PubMed

Mapes, Anna A; Kloosterman, Ate D; de Poot, Christianne J

2015-07-01

Current figures on the efficiency of DNA as an investigative tool in criminal investigations only tell part of the story. To get the DNA success story in the right perspective, we examined all forensic reports from serious (N = 116) and high-volume crime cases (N = 2791) over the year 2011 from one police region in the Netherlands. These data show that 38% of analyzed serious crime traces (N = 384) and 17% of analyzed high-volume crime traces (N = 386) did not result in a DNA profile. Turnaround times (from crime scene to DNA report) were 66 days for traces from serious crimes and 44 days for traces from high-volume crimes. Suspects were truly identified through a match with the Offender DNA database of the Netherlands in 3% of the serious crime cases and in 1% of the high-volume crime cases. These data are important for both the forensic laboratory and the professionals in the criminal justice system to further optimize forensic DNA testing as an investigative tool. © 2015 American Academy of Forensic Sciences.

Differential-optoacoustic absorption detector

NASA Technical Reports Server (NTRS)

Shumate, M. S.

1977-01-01

Two-cell spectrophone detects trace amounts of atmospheric pollutants by measuring absorption coefficients of gases with various laser sources. Device measures pressure difference between two tapered cells with differential manometer. Background signal is reduced by balanced window heating and balanced carrier gas absorption in two cells.

Lead Speciation And Bioavailability In Apatite-Amended Sediments

EPA Science Inventory

The in situ sequestration of lead (Pb) in sediment with a phosphate amendment was investigated by Pb speciation and bioavailability. Sediment Pb in preamendment samples was identified as galena (PbS) with trace amounts of absorbed Pb. Sediment exposed to atmospheric conditions ...

Detection of Staphylococcal Enterotoxin in Food

PubMed Central

Casman, Ezra P.; Bennett, Reginald W.

1965-01-01

Methods are described for the extraction and serological detection of trace amounts of enterotoxins A and B in foods incriminated in outbreaks of staphylococcal food poisoning. Evidence is presented for the probable applicability of the methods for the detection of unidentified enterotoxins. PMID:14325876

Acrylamide in processed potato products

USDA-ARS?s Scientific Manuscript database

Trace amounts of acrylamide are found in many foods cooked at high temperatures. Acrylamide in processed potato products is formed from reducing sugars and asparagine and is a product of the Maillard reaction. Processed potato products including fries and chips are relatively high in acrylamide comp...

Multidimensional Raman spectroscopic signatures as a tool for forensic identification of body fluid traces: a review.

PubMed

Sikirzhytski, Vitali; Sikirzhytskaya, Aliaksandra; Lednev, Igor K

2011-11-01

The analysis of body fluid traces during forensic investigations is a critical step in determining the key details of a crime. Several confirmatory and presumptive biochemical tests are currently utilized. However, these tests are all destructive, and no single method can be used to analyze all body fluids. This review outlines recent progress in the development of a novel universal approach for the nondestructive, confirmatory identification of body fluid traces using Raman spectroscopy. The method is based on the use of multidimensional spectroscopic signatures of body fluids and accounts for the intrinsic heterogeneity of dry traces and donor variation. The results presented here demonstrate that Raman spectroscopy has potential for identifying traces of semen, blood, saliva, sweat, and vaginal fluid with high confidence.

Release of plutonium isotopes into the environment from the Fukushima Daiichi Nuclear Power Plant accident: what is known and what needs to be known.

PubMed

Zheng, Jian; Tagami, Keiko; Uchida, Shigeo

2013-09-03

The Fukushima Daiichi Nuclear Power Plant (FDNPP) accident has caused serious contamination in the environment. The release of Pu isotopes renewed considerable public concern because they present a large risk for internal radiation exposure. In this Critical Review, we summarize and analyze published studies related to the release of Pu from the FDNPP accident based on environmental sample analyses and the ORIGEN model simulations. Our analysis emphasizes the environmental distribution of released Pu isotopes, information on Pu isotopic composition for source identification of Pu releases in the FDNPP-damaged reactors or spent fuel pools, and estimation of the amounts of Pu isotopes released from the FDNPP accident. Our analysis indicates that a trace amount of Pu isotopes (∼2 × 10(-5)% of core inventory) was released into the environment from the damaged reactors but not from the spent fuel pools located in the reactor buildings. Regarding the possible Pu contamination in the marine environment, limited studies suggest that no extra Pu input from the FDNPP accident could be detected in the western North Pacific 30 km off the Fukushima coast. Finally, we identified knowledge gaps remained on the release of Pu into the environment and recommended issues for future studies.

Anthropogenic Enrichment of Heavy Metals in Urban Dust and Possible Corresponding Sources

NASA Astrophysics Data System (ADS)

van Laaten, Neele; Merten, Dirk; Pirrung, Michael

2017-04-01

Atmospheric dust (particulate matter, PM) is regarded as a crucial factor for human health and a major environmental problem in densely populated areas. Due to anthropogenic processes like traffic, waste incineration and industry increased amounts of PM can be detected in those areas. To reduce the amounts detailed knowledge on both the composition of PM and the source contribution in a target area is needed. The latter has, to our knowledge, rarely been regarded in central Europe. Within this study, spider webs from various locations in the city of Jena (Germany), that act as natural trappers of PM, were analyzed for the contents of 27 trace elements using aqua regia digestion followed by ICP-OES and ICP-MS determinations. Aerosol-crust enrichment factors were calculated for selected elements and both a cluster analysis and a factor analysis were executed to identify sources of PM. High values for the enrichment factors clearly show an anthropogenic influence. In addition, the cluster analysis leads to a grouping of the sampling points mainly depending on the kind and volume of traffic at the corresponding locations. Five different possible sources of PM can be found by the factor analysis: Soil erosion (41% of variance), abrasion of rails (16%), tyre and break wear (16%), charcoal combustion (8%) and oil combustion (7%).

Transferring pharmaceuticals into the gas phase

NASA Astrophysics Data System (ADS)

Christen, Wolfgang; Krause, Tim; Rademann, Klaus

2008-11-01

The dissolution of molecules of biological interest in supercritical carbon dioxide is investigated using pulsed molecular beam mass spectrometry. Due to the mild processing temperatures of most supercritical fluids, their adiabatic expansion into vacuum permits to transfer even thermally very sensitive substances into the gas phase, which is particularly attractive for pharmaceutical and biomedical applications. In addition, supercritical CO2constitutes a chemically inert solvent that is compatible with hydrocarbon-free ultrahigh vacuum conditions. Here, we report on the dissolution and pulsed supersonic jet expansion of caffeine (C8H10N4O2), the provitamin menadione (C11H8O2), and the amino acid derivative l-phenylalanine tert-butyl ester hydrochloride (C6H5CH2CH(NH2)COOC(CH3)3[dot operator]HCl), into vacuum. An on-axis residual gas analyzer is used to monitor the relative amounts of solute and solvent in the molecular beam as a function of solvent densityE The excellent selectivity and sensitivity provided by mass spectrometry permits to probe even trace amounts of solutes. The strong density variation of CO2 close to the critical point results in a pronounced pressure dependence of the relative ion currents of solute and solvent molecules, reflecting a substantial change in solubility.

Discussion on 'characteristics of fly ashes from full-scale coal-fired power plants and their relationship to mercury adsorption' by Lu et al.

DOE Office of Scientific and Technical Information (OSTI.GOV)

James C. Hower; Bruno Valentim; Irena J. Kostova

2008-03-15

Mercury capture by coal-combustion fly ash is a function of the amount of Hg in the feed coal, the amount of carbon in the fly ash, the type of carbon in the fly ash (including variables introduced by the rank of the feed coal), and the flue gas temperature at the point of ash collection. In their discussion of fly ash and Hg adsorption, Lu et al. (Energy Fuels 2007, 21, 2112-2120) had some fundamental flaws in their techniques, which, in turn, impact the validity of analyzed parameters. First, they used mechanical sieving to segregate fly ash size fractions. Mechanicalmore » sieving does not produce representative size fractions, particularly for the finest sizes. If the study samples were not obtained correctly, the subsequent analyses of fly ash carbon and Hg cannot accurately represent the size fractions. In the analysis of carbon forms, it is not possible to accurately determine the forms with scanning electron microscopy. The complexity of the whole particles is overlooked when just examining the outer particle surface. Examination of elements such as Hg, present in very trace quantities in most fly ashes, requires careful attention to the analytical techniques. 36 refs., 3 figs., 1 tab.« less

Flavonol Glycosides in Currant Leaves and Variation with Growth Season, Growth Location, and Leaf Position.

PubMed

Yang, Wei; Alanne, Aino-Liisa; Liu, Pengzhan; Kallio, Heikki; Yang, Baoru

2015-10-28

Flavonol glycosides (FG) were analyzed in the leaves of six currant cultivars (Ribes spp.) with HPLC-DAD, HPLC-MS/MS, and NMR. The average amounts of the 12 major, identified FG constituted 86-93% (9.6-14.1 mg/g DW) of the total of 27 FG found. Quercetin and kaempferol were the major aglycones with trace amounts of myricetin. Quercetin-3-O-(2,6-α-dirhamnopyranosyl-β-glucopyranoside), quercetin-3-O-(2-β-xylopyranosyl-6-α-rhamnopyranosyl-β-glucopyranoside), and kaempferol-3-O-(3,6-α-dirhamnopyranosyl-β-glucopyranoside) were identified for the first time in currant leaves and existed in a white currant cultivar 'White Dutch' only. Kaempferol-3-O-β-(6'-malonyl)glucopyranoside was also a new compound existing in abundance in five cultivars but not in the white one. The results show the primary importance of the genetic background of the cultivars. The content of malonylated FG of special importance in cardiovascular health decreased regularly during summer. Time of collection and leaf position were more prominent factors affecting the composition than were the year of harvest or the growth latitude. Randomly collected leaves differed in their FG profiles from those collected from the middle position of new branches.

Chemical quality of depositional sediments and associated soils in New Orleans and the Louisiana peninsula following Hurricane Katrina

USGS Publications Warehouse

Adams, C.; Witt, E.C.; Wang, Jingyuan; Shaver, D.K.; Summers, D.; Filali-Meknassi, Y.; Shi, H.; Luna, R.; Anderson, N.

2007-01-01

Hurricane Katrina made landfall on the Louisiana peninsula south of New Orleans on Aug 29, 2005. The resulting storm surge caused numerous levy breaches in the parishes of New Orleans as well as on the Louisiana peninsula. This study was conducted to determine the concentrations of inorganic and organic constituents in sediments and associated soils in New Orleans parishes and the Louisiana peninsula after the floodwaters had been removed and/or receded following Hurricane Katrina. A total of 46 sediment and soil samples were analyzed that were collected throughout New Orleans and the Louisiana peninsula. Approximately 20% of the sediment samples were analyzed, including shallow sediment samples from locations that included the top and beneath automobiles, in residential and commercial areas, and near refineries. Gasoline constituents, pesticides, and leachable heavy metals were analyzed using headspace gas chromatography/mass spectrometry (GC/MS), organic extraction GC/MS, and inductively coupled plasma/mass spectrometry, respectively. A significant number of samples had leachable As and Pb concentrations in excess of drinking water standards. The remaining metals analyzed (i.e., Cd, Cr, Cu, Hg, and V) generally had much lower leachable levels. Of the gasoline constituents, only benzene was observed above the limit of detection (of 5 ??g/kg), with no samples observed as being above the method detection limits of 10 ??g/kg. For the 18 pesticides analyzed, most were in the nondetectable range and all were in trace amounts that were orders of magnitude below regulatory guidelines. ?? 2007 American Chemical Society.

Development of Proxies for Vent Fluid Trace Metal Concentrations and pH through Study of Sulfide Chimney Linings

NASA Astrophysics Data System (ADS)

Evans, G. N.; Tivey, M. K.; Seewald, J.; Rouxel, O. J.; Monteleone, B.

2016-12-01

Analyses of trace elements (Ag, As, Co, Mn, and Zn) hosted in the chalcopyrite linings of `black smoker' chimneys using secondary ion mass spectrometry (SIMS) have been combined with data for trace metal concentrations in corresponding vent fluids to investigate fluid-mineral partitioning of trace elements. Goals of this research include development of proxies for fluid chemistry based on mineral trace element content. The use of SIMS allows for the measurement of trace elements below the detection limits of electron microprobe and at the necessary spatial resolution (20 microns) to examine fine-grained and mixed-mineral samples. Results indicate that the chalcopyrite linings of many `black smoker' chimneys are homogeneous with respect to Ag, Mn, Co, and Zn. Minerals picked from samples exhibiting homogeneity with respect to specific elements were dissolved and analyzed by solution inductively coupled plasma mass spectrometry (ICP-MS) for use as working standards. Results also document a strong correlation between the Ag content of chalcopyrite and the Ag:Cu ratio of the corresponding hydrothermal fluid. This supports systematic partitioning of Ag into chalcopyrite as a substitute for Cu, providing a proxy for fluid Ag concentration. Additionally, the Ag content of chalcopyrite correlates with fluid pH, particularly at pH>3, and thus represents an effective proxy for fluid pH. Application of these proxies to chimney samples provides an opportunity to better identify hydrothermal conditions even when fluids have not been sampled, or not fully analyzed.

Standoff detection of trace amounts of solids by nonlinear Raman spectroscopy using shaped femtosecond pulses

NASA Astrophysics Data System (ADS)

Katz, O.; Natan, A.; Silberberg, Y.; Rosenwaks, S.

2008-04-01

We demonstrate a single-beam, standoff (>10m) detection and identification of various materials including minute amounts of explosives under ambient light conditions. This is obtained by multiplex coherent anti-Stokes Raman scattering spectroscopy (CARS) using a single femtosecond phase-shaped laser pulse. We exploit the strong nonresonant background for amplification of the backscattered resonant CARS signals by employing a homodyne detection scheme. The simple and highly sensitive spectroscopic technique has a potential for hazardous materials standoff detection applications.

Can Dynamic Bubble Templating Play a Role in Corrosion Product Morphology?

DTIC Science & Technology

2012-02-01

FeOOH (goethite) with moderate amounts of metallic luster Fe304 (magnetite), and trace amounts of CaC03 (calcite). In addition, the core was marbled ...cathodically produced gas bubbles (i.e., H2). By physically separating the anode and cathode. Stone and Goldstein26 generated tubular structures electro...D.A. Stone , RE. Goldstein. Proc. MatL Acad. Set U.S-A. 101 (2004): p. 11537. G. Butler, H.C.K. Ison, Nature 182 (1958): p. 1229. B. McEnaney. D.C

Effect of doping in the Bi-Sr-Ca-Cu-O superconductor

NASA Technical Reports Server (NTRS)

Akbar, S. A.; Wong, M. S.; Botelho, M. J.; Sung, Y. M.; Alauddin, M.; Drummer, C. E.; Fair, M. J.

1991-01-01

The results of the effect of doping on the superconducting transition in the Bi-Sr-Ca-Cu-O system are reported. Samples were prepared under identical conditions with varying types (Pb, Sb, Sn, Nb) and amounts of dopants. All samples consisted of multiple phases, and showed stable and reproducible superconducting transitions. Stabilization of the well known 110 K phase depends on both the type and amount of dopant. No trace of superconducting phase of 150 K and above was observed.

Glow discharge detector

DOEpatents

Koo, Jackson C.; Yu, Conrad M.

2002-01-01

A highly sensitive electronic ion cell for the measurement of trace elements in He carrier gas which involves glow discharge. A constant wave (CW) glow discharge detector which is controlled through a biased resistor, can detect the change of electron density caused by impurities in the He carrier gas by many orders of magnitude larger than that caused by direct ionization or electron capture. The glow discharge detector utilizes a floating pseudo-electrode to form a probe in or near the plasma. By using this probe, the large variation of electron density due to trace amounts of impurities can be directly measured.

Compton scattering artifacts in electron excited X-ray spectra measured with a silicon drift detector.

PubMed

Ritchie, Nicholas W M; Newbury, Dale E; Lindstrom, Abigail P

2011-12-01

Artifacts are the nemesis of trace element analysis in electron-excited energy dispersive X-ray spectrometry. Peaks that result from nonideal behavior in the detector or sample can fool even an experienced microanalyst into believing that they have trace amounts of an element that is not present. Many artifacts, such as the Si escape peak, absorption edges, and coincidence peaks, can be traced to the detector. Others, such as secondary fluorescence peaks and scatter peaks, can be traced to the sample. We have identified a new sample-dependent artifact that we attribute to Compton scattering of energetic X-rays generated in a small feature and subsequently scattered from a low atomic number matrix. It seems likely that this artifact has not previously been reported because it only occurs under specific conditions and represents a relatively small signal. However, with the advent of silicon drift detectors and their utility for trace element analysis, we anticipate that more people will observe it and possibly misidentify it. Though small, the artifact is not inconsequential. Under some conditions, it is possible to mistakenly identify the Compton scatter artifact as approximately 1% of an element that is not present.

Seasonal variations of trace elements in precipitation at the largest city in Tibet, Lhasa

NASA Astrophysics Data System (ADS)

Guo, Junming; Kang, Shichang; Huang, Jie; Zhang, Qianggong; Tripathee, Lekhendra; Sillanpää, Mika

2015-02-01

Precipitation samples were collected from March 2010 to August 2012 at an urban site in Lhasa, the capital and largest city of Tibet. The volume weighted mean (VWM) concentrations of 17 trace elements in precipitation were higher during the non-monsoon season than in the monsoon season, but inverse seasonal variations occurred for wet deposition fluxes of most of the trace elements. Concentrations for most of trace elements were negatively correlated with precipitation amount, indicating that below-cloud scavenging of trace elements was an important mechanism contributing to wet deposition of these elements. The elements Al, Sc, V, Cr, Mn, Fe, Mn, Ni, and U displayed low crustal enrichment factors (EFs), whereas Co, Cu, Zn, As, Cd Sn, Pb, and Bi showed high EF values in precipitation, suggesting that anthropogenic activities might be important contributors of these elements at Lhasa. However, this present work indicates a much lower anthropogenic emission at Lhasa than in seriously polluted regions. Our study will not only provide insights for assessing the current status of the atmospheric environment in Lhasa but also enhance our understanding for updating the baseline for environmental protection over the Tibetan Plateau.

Trace Gas Analyzer (TGA) program

NASA Technical Reports Server (NTRS)

1977-01-01

The design, fabrication, and test of a breadboard trace gas analyzer (TGA) is documented. The TGA is a gas chromatograph/mass spectrometer system. The gas chromatograph subsystem employs a recirculating hydrogen carrier gas. The recirculation feature minimizes the requirement for transport and storage of large volumes of carrier gas during a mission. The silver-palladium hydrogen separator which permits the removal of the carrier gas and its reuse also decreases vacuum requirements for the mass spectrometer since the mass spectrometer vacuum system need handle only the very low sample pressure, not sample plus carrier. System performance was evaluated with a representative group of compounds.

Car MAX-DOAS measurements of the tropospheric Formaldehyde (HCHO) column around Bucharest (Romania) and in the Rhein-Main area (Germany)

NASA Astrophysics Data System (ADS)

Donner, Sebastian; Shaiganfar, Reza; Riffel, Katharina; Dörner, Steffen; Lampel, Johannes; Remmers, Julia; Wagner, Thomas

2016-04-01

The DOAS (differential optical absorption spectroscopy)-method analyses the absorptions of atmospheric trace gases in spectra of scattered sun light. It is an excellent way to determine the concentrations of different trace gases (e.g. NO2, SO2, HCHO…) simultaneously. MAX (Multi-AXis)-DOAS measurements observe scattered sun light under different elevation angles. From such measurements tropospheric vertical column densities (VCDs) or even vertical profiles of the measured trace gases and aerosols can be determined. We performed mobile MAX-DOAS measurements using two instruments on the roof of a car in summer 2015 in Romania during the AROMAT2 campaign and in the Winter/Spring 2016 in the Rhein-Main area (Germany). The latter is one of the densest populated areas in Germany. One instrument is a commercial Mini-MAX-DOAS instrument from the Hoffmann company, the other a self-built instrument using an AVANTES spectrometer with better optical characteristics. The instruments were looking in two different directions (one forward and one backward). Mobile MAX-DOAS measurements cover a quite large area in a short period of time. This enables to map existing gradients of concentrations of tropospheric trace gases, e.g. NO2 and HCHO. The results of those measurements then can be used to validate satellite measurements or can be compared to model results. In this study we focus on formaldehyde (HCHO). In small amounts it is emitted directly by industries and other anthropogenic and biogenic activities. Large amounts are mostly secondary produced. As it is an intermediate product of basic oxidation cycles of other hydrocarbons its concentrations are determined by the abundances of other hydrocarbons. Therefore it can be used as an indicator for volatile organic compounds (VOCs). Furthermore HCHO plays an important role in photochemical smog chemistry and tropospheric O3 chemistry. In this work we present the measurement setup and preliminary HCHO results of the AROMAT2 campaign and first results of the measurements in the Rhein-Main area. We characterize the amounts, spatial gradients and identify potential emission sources of HCHO.

Predicting Water Quality Problems Associated with Coal Fly Ash Disposal Facilities Using a Trace Element Partitioning Study

NASA Astrophysics Data System (ADS)

Bhattacharyya, S.; Donahoe, R. J.; Graham, E. Y.

2006-12-01

For much of the U.S., coal-fired power plants are the most important source of electricity for domestic and industrial use. Large quantities of fly ash and other coal combustion by-products are produced every year, the majority of which is impounded in lagoons and landfills located throughout the country. Many older fly ash disposal facilities are unlined and have been closed for decades. Fly ash often contains high concentrations of toxic trace elements such as arsenic, boron, chromium, molybdenum, nickel, selenium, lead, strontium and vanadium. Trace elements present in coal fly ash are of potential concern due to their toxicity, high mobility in the environment and low drinking water MCL values. Concern about the potential release of these toxic elements into the environment due to leaching of fly ash by acid rain, groundwater or acid mine drainage has prompted the EPA to develop national standards under the subtitle D of the Resource Conservation and Recovery Act (RCRA) to regulate ash disposal in landfills and surface impoundments. An attempt is made to predict the leaching of toxic elements into the environment by studying trace element partitioning in coal fly ash. A seven step sequential chemical extraction procedure (SCEP) modified from Filgueiras et al. (2002) is used to determine the trace element partitioning in seven coal fly ash samples collected directly from electric power plants. Five fly ash samples were derived from Eastern Bituminous coal, one derived from Western Sub-bituminous coal and the other derived from Northern Lignite. The sequential chemical extraction procedure gives valuable information on the association of trace elements: 1) soluble fraction, 2) exchangeable fraction, 3) acid soluble fraction, 4) easily reducible fraction, 5) moderately reducible fraction, 6) poorly reducible fraction and 7) oxidizable organics/sulfide fraction. The trace element partitioning varies with the composition of coal fly ash which is influenced by the type of coal burned. Preliminary studies show that in some fly ash samples, significant amounts of As, B, Mo, Se, Sr and V are associated with the soluble and exchangeable fraction, and thus would be highly mobile in the environment. Lead, on the other hand, is mainly associated with the amorphous Fe and Mn oxide fractions and would be highly immobile in oxidizing conditions, but mobile in reducing conditions. Ni and Cr show different associations in different fly ash samples. In most fly ash samples, significant amounts of the trace elements are associated with more stable fractions that do not threaten the environment. The study of trace element partitioning in coal fly ash thus helps us to predict their leaching behavior under various conditions.

AIR EMISSIONS FROM LASER DRILLING OF PRINTED WIRING BOARD MATERIALS

EPA Science Inventory

The paper gives results of a study to characterize gases generated during laser drilling of printed wiring board (PWB) material and identifies the pollutants and generation rates found during the drilling process. Typically found in the missions stream were trace amounts of carbo...

GENERATION AND CONTROL OF AIR POLLUTANTS FROM ORIMULSION (R) COMBUSTION

EPA Science Inventory

The paper discusses a study requested in 1997 by the U.S. Congress to provide technical information regarding Orimulsion (R) and its environmental impacts. (NOTE: Orimulsion is an emulsified fuel, composed of approximately 70% Venezuelan bitumen, 30% water, and trace amounts of ...

Lighting for Our Schools.

ERIC Educational Resources Information Center

Rankin, John C.

In this speech, the author traces the history of lighting in schools, discusses the variables affecting the amount of illuminance needed, and provides a table of illuminances recommended for Ontario schools. Other factors that affect vision--glare, veiling reflection, color, and brightness balance--are outlined. Planners are admonished to…

Measuring protein isoelectric points by AFM-based force spectroscopy using trace amounts of sample

NASA Astrophysics Data System (ADS)

Guo, Shifeng; Zhu, Xiaoying; Jańczewski, Dominik; Lee, Serina Siew Chen; He, Tao; Teo, Serena Lay Ming; Vancso, G. Julius

2016-09-01

Protein charge at various pH and isoelectric point (pI) values is important in understanding protein function. However, often only trace amounts of unknown proteins are available and pI measurements cannot be obtained using conventional methods. Here, we show a method based on the atomic force microscope (AFM) to determine pI using minute quantities of proteins. The protein of interest is immobilized on AFM colloidal probes and the adhesion force of the protein is measured against a positively and a negatively charged substrate made by layer-by-layer deposition of polyelectrolytes. From the AFM force-distance curves, pI values with an estimated accuracy of ±0.25 were obtained for bovine serum albumin, myoglobin, fibrinogen and ribonuclease A over a range of 4.7-9.8. Using this method, we show that the pI of the ‘footprint’ of the temporary adhesive proteins secreted by the barnacle cyprid larvae of Amphibalanus amphitrite is in the range 9.6-9.7.

Flotation-separation and ICP-AES determination of ultra trace amounts of copper, cadmium, nickel and cobalt using 2-aminocyclopentene-1-dithiocarboxylic acid.

PubMed

Shamsipur, Mojtaba; Hashemi, Omid Reza; Safavi, Afsaneh

2005-09-01

A rapid flotation method for separation and enrichment of ultra trace amounts of copper(II), cadmium(II), nickel(II) and cobalt(II) ions from water samples is established. At pH 6.5 and with sodium dodecylsulfate used as a foaming reagent, Cu2+, Cd2+, Ni2+ and Co2+ were separated simultaneously with 2-aminocyclopentene-1-dithiocarboxylic acid (ACDA) added to 1 l of aqueous solution. The proposed procedure of preconcentration is applied prior to the determination of these four analytes using inductivity coupled plasma-atomic emission spectrometry (ICP-AES). The effects of pH, concentration of ACDA, applicability of different surfactants and foreign ions on the separation efficiency were investigated. The preconcentration factor of the method is 1000 and the detection limits of copper(II), cadmium(II), nickel(II) and cobalt(II) ions are 0.078, 0.075, 0.072 and 0.080 ng ml(-1), respectively.

Integrated Utilization of Sewage Sludge and Coal Gangue for Cement Clinker Products: Promoting Tricalcium Silicate Formation and Trace Elements Immobilization

PubMed Central

Yang, Zhenzhou; Zhang, Yingyi; Liu, Lili; Seetharaman, Seshadri; Wang, Xidong; Zhang, Zuotai

2016-01-01

The present study firstly proposed a method of integrated utilization of sewage sludge (SS) and coal gangue (CG), two waste products, for cement clinker products with the aim of heat recovery and environment protection. The results demonstrated that the incremental amounts of SS and CG addition was favorable for the formation of tricalcium silicate (C3S) during the calcinations, but excess amount of SS addition could cause the impediment effect on C3S formation. Furthermore, it was also observed that the C3S polymorphs showed the transition from rhombohedral to monoclinic structure as SS addition was increased to 15 wt %. During the calcinations, most of trace elements could be immobilized especially Zn and cannot be easily leached out. Given the encouraging results in the present study, the co-process of sewage sludge and coal gangue in the cement kiln can be expected with a higher quality of cement products and minimum pollution to the environment. PMID:28773400

Highly sensitive spectrofluorimetric determination of trace amounts NADP using Europium ion-doxycycline complex probe

NASA Astrophysics Data System (ADS)

Peng, Qian; Hou, Faju; Jiang, Chongqiu

2006-09-01

A new spectrofluorimetric method was developed for determination of trace amount of Coenzyme II (NADP). Using europium ion-doxycycline (DC) as a fluorescent probe, in the buffer solution of pH 8.44, NADP can remarkably enhance the fluorescence intensity of the Eu 3+-DC complex at λ = 612 nm and the enhanced fluorescence intensity is in proportion to the concentration of NADP. Optimum conditions for the determination of NADP were also investigated. The dynamic range for the determination of NADP is 3.3 × 10 -7 to 6.1 × 10 -6 mol l -1 with detection limit of 6.8 × 10 -8 mol l -1. This method is simple, practical and relatively free interference from coexisting substances and can be successfully applied to determination of NADP in synthetic water samples and in serum samples. Moreover, the enhancement mechanisms of the fluorescence intensity in the Eu 3+-DC system and the Eu 3+-DC-NADP system have been also discussed.

Measurement of trace impurities in ultra pure hydrogen and deuterium at the parts-per-billion level using gas chromatography

NASA Astrophysics Data System (ADS)

Ganzha, V.; Ivshin, K.; Kammel, P.; Kravchenko, P.; Kravtsov, P.; Petitjean, C.; Trofimov, V.; Vasilyev, A.; Vorobyov, A.; Vznuzdaev, M.; Wauters, F.

2018-02-01

A series of muon experiments at the Paul Scherrer Institute in Switzerland deploy ultra-pure hydrogen active targets. A new gas impurity analysis technique was developed, based on conventional gas chromatography, with the capability to measure part-per-billion (ppb) traces of nitrogen and oxygen in hydrogen and deuterium. Key ingredients are a cryogenic admixture accumulation, a directly connected sampling system and a dedicated calibration setup. The dependence of the measured concentration on the sample volume was investigated, confirming that all impurities from the sample gas are collected in the accumulation column and measured with the gas chromatograph. The system was calibrated utilizing dynamic dilution of admixtures into the gas flow down to sub-ppb level concentrations. The total amount of impurities accumulated in the purification system during a three month long experimental run was measured and agreed well with the calculated amount based on the measured concentrations in the flow.

Solidified Floating Organic Drop Microextraction for the Detection of Trace Amount of Lead in Various Samples by Electrothermal Atomic Absorption Spectrometry.

PubMed

Aydın Urucu, Oya; Dönmez, Şeyda; Kök Yetimoğlu, Ece

2017-01-01

A novel method was developed for determination of trace amounts of lead in water and food samples. Solidified floating organic drop microextraction was used to preconcentrate the lead ion. After the analyte was complexed with 1-(2-pyridylazo)-2-naphthol, undecanol and acetonitrile were added as extraction and dispersive solvent, respectively. Variables such as pH, volumes of extraction and dispersive solvents, and concentration of chelating agent were optimized. Under the optimum conditions, the detection limit of Pb (II) was determined as 0.042  µ g L -1 with an enrichment factor of 300. The relative standard deviation is <10%. Accuracy of the developed procedure was evaluated by the analysis of certified reference material of human hair (NCS DC 73347) and wastewater (SPS-WW2) with satisfactory results. The developed procedure was then successfully applied to biscuit and water samples for detection of Pb (II) ions.

Applications of organo-silica nanocomposites for SPNE of Hg(II)

NASA Astrophysics Data System (ADS)

Kaur, Anupreet

2016-02-01

An analytical method using modified SiO2 nanoparticles as solid-phase extractant has been developed for the preconcentration of trace amounts of Hg(II) in different water samples. Conditions of the analysis such as preconcentration factor, effect of pH, sample volume, shaking time, elution conditions and effects of interfering ions for the recovery of analyte were investigated. The adsorption capacity of nanometer SiO2-APTMS was found to be 181.42 µmol g-1 at optimum pH and the detection limit (3σ) was 0.45 µg L-1. The extractant showed rapid kinetic sorption. The adsorption equilibrium of Hg(II) on nanometer SiO2-APTMS was achieved just in 15 min. Adsorbed Hg(II) was easily eluted with 4 mL of 2.0 M hydrochloric acid. The maximum preconcentration factor was 75. The method was applied for the determination of trace amounts of Hg(II) in various synthetic samples and water samples.

Comparison of activated carbon and oxidized multiwalled carbon nanotubes modified with bis(3-nitrobenzylidene)-1,2-ethanediamine for enrichment of trace amounts of some metal ions.

PubMed

Ghaedi, Mehrorang; Montazerozohori, Mortaza; Tabatabie, Maryam; Noormohamadi, Hamid; Haghighi, Alireza Borhan

2012-01-01

The efficiency of modified activated carbon (AC) and multiwalled carbon nanotubes (MWCNTs) for the separation/preconcentration and determination of Co, Cd, Pb, Zn, and Cu following their complexation by bis(3-nitrobenzylidene)-1,2-ethanediamine has been described and compared. A one-at-a-time optimization method investigated the influence of various parameters that significantly influence the recoveries of the studied metal ions. At the optimum values of all variables, the response was linear over the range of 0.01-0.3 microg/mL, and detection limit (3 SDb/m, n = 10) was between 1.41-2.05 ng/mL for both sorbents while the preconcentration factor was 100 for AC and 500 for MWCNTs. The method was successfully applied for preconcentration and determination of trace amount of the aforementioned ions in various real samples such as orange, lettuce, bread, and pear.

Novel fluorimetric assay of trace analysis of epinephrine in human serum

NASA Astrophysics Data System (ADS)

Adeniyi, William K.; Wright, Ashleigh R.

2009-12-01

A simple, rapid, and sensitive spectrofluorimetric technique for the microdetermination of epinephrine in human serum is described. The investigation shows that trace amounts of epinephrine, antidepressant of clinical importance, can be determined without the conventional derivatization or use of fluorophores by diazotization. The method is based on the optimization of experimental parameters, such as pH, temperature, careful selection of excitation and emission wavelengths and on the use of anionic surfactant, sodium dodecyl sulfate (SDS), to enhance sensitivity. The measurement was carried out at 360 nm with excitation at 286 nm. Under the optimum conditions, a linear relationship was obtained between the fluorescence intensity and epinephrine concentration in the range of 0.10 and 1.0 μg/mL; the correlation coefficient and detection limit are 0.9953 and 0.05 μg/mL, respectively. Recovery tests indicated an efficiency of 95.5-98.7% by using known amounts of epinephrine spiked with human serum.

Biotinylated dextran amine anterograde tracing of the canine corticospinal tract.

PubMed

Han, Xiao; Lv, Guangming; Wu, Huiqun; Ji, Dafeng; Sun, Zhou; Li, Yaofu; Tang, Lemin

2012-04-15

In this study, biotinylated dextran amine (BDA) was microinjected into the left cortical motor area of the canine brain. Fluorescence microscopy results showed that a large amount of BDA-labeled pyramidal cells were visible in the left cortical motor area after injection. In the left medulla oblongata, the BDA-labeled corticospinal tract was evenly distributed, with green fluorescence that had a clear boundary with the surrounding tissue. The BDA-positive corticospinal tract entered into the right lateral funiculus of the spinal cord and descended into the posterior part of the right lateral funiculus, close to the posterior horn, from cervical to sacral segments. There was a small amount of green fluorescence in the sacral segment. The distribution of BDA labeling in the canine central nervous system was consistent with the course of the corticospinal tract. Fluorescence labeling for BDA gradually diminished with time after injection. Our findings indicate that the BDA anterograde tracing technique can be used to visualize the localization and trajectory of the corticospinal tract in the canine central nervous system.

Preparation of Some Homologous TEMPO Nitroxides and Oxoammonium Salts; Notes on the NMR Spectroscopy of Nitroxide Free Radicals; Observed Radical Nature of Oxoammonium Salt Solutions Containing Trace Amounts of Corresponding Nitroxides in an Equilibrium Relationship.

PubMed

Bobbitt, James M; Eddy, Nicholas A; Cady, Clyde X; Jin, Jing; Gascon, Jose A; Gelpí-Dominguez, Svetlana; Zakrzewski, Jerzy; Morton, Martha D

2017-09-15

Three new homologous TEMPO oxoammonium salts and three homologous nitroxide radicals have been prepared and characterized. The oxidation properties of the salts have been explored. The direct 13 C NMR and EPR spectra of the nitroxide free radicals and the oxoammonium salts, along with TEMPO and its oxoammonium salt, have been successfully measured with little peak broadening of the NMR signals. In the spectra of all ten compounds (nitroxides and corresponding oxoammonium salts), the carbons in the 2,2,6,6-tetramethylpiperidine core do not appear, implying paramagnetic properties. This unpredicted overall paramagnetism in the oxoammonium salt solutions is explained by a redox equilibrium as shown between oxoammonium salts and trace amounts of corresponding nitroxide. This equilibrium is confirmed by electron interchange reactions between nitroxides with an N-acetyl substituent and oxoammonium salts with longer acyl side chains.

Electron-rich triphenylamine-based sensors for picric acid detection.

PubMed

Chowdhury, Aniket; Mukherjee, Partha Sarathi

2015-04-17

This paper demonstrates the role of solvent in selectivity and sensitivity of a series of electron-rich compounds for the detection of trace amounts of picric acid. Two new electron-rich fluorescent esters (6, 7) containing a triphenylamine backbone as well as their analogous carboxylic acids (8, 9) have been synthesized and characterized. Fluorescent triphenylamine coupled with an ethynyl moiety constitutes π-electron-rich selective and sensitive probes for electron-deficient picric acid (PA). In solution, the high sensitivity of all the sensors toward PA can be attributed to a combined effect of the ground-state charge-transfer complex formation and resonance energy transfer between the sensor and analyte. The acids 8 and 9 also showed enhanced sensitivity for nitroaromatics in the solid state, and their enhanced sensitivity could be attributed to exciton migration due to close proximity of the neighboring acid molecules, as evident from the X-ray diffraction study. The compounds were found to be quite sensitive for the detection of trace amount of nitroaromatics in solution, solid, and contact mode.

Presence and risk assessment of pharmaceuticals in surface water and drinking water.

PubMed

Sanderson, Hans

2011-01-01

Trace amounts of pharmaceuticals have been detected in surface waters in the nano- to microgram per liter range, and in drinking water in the nanogram/L range. The environmental risks of pharmaceuticals in surface waters have been evaluated and generally found to be low if the wastewater is treated before release to the environment. The human health risks of trace amounts of pharmaceuticals in drinking water have however not been evaluated in any great depth. Preliminary screening level assessments suggest risk to be low--but the public and decision-makers are concerned and would like the matter investigated more thoroughly, especially with regards to mixture effects, chronic long-term effects and sensitive sub-populations. The World Health Organization is currently evaluating the need for credible health based guidance associated with low concentrations of pharmaceuticals in drinking water. The aim of this paper is to summarize the state-of-the-science and the ongoing international debate on the topic.

Trace metals in Bermuda rainwater

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jickells, T.D.; Knap, A.H.; Church, T.M.

1984-02-20

The concentration of Cd, Cu, Fe, Mn, Ni, Pb, and Zn have been measured in Bermuda rainwater. Factor analysis indicates that Fe, Mn, and Pb have similar to acidic components derived from North America. The other metals all behave simiarly but differently to the acides. Sea salt, even after allowances for fractionation, apparently contributes minor amounts of Cu, Pb, and Zn and uncertain amounts of Fe, Mn, and Cd to Atlantic Ocean precipitation. Wash out ratios, calculated from this data along with earlier measurements of atmospheric trace metal concentration on Bermuda, are of the same order as those reported frommore » other remote ocean areas. The wet depositional fluxes of Cu, Ni, Pb, and Zn to the western Atlantic Ocean are significant compared to measured oceanic flux rates. However, the wet depositional fluxes of Fe and Mn to this area are relatively small, suggesting additional inputs, while an excess wet depositional flux of Cd suggests large-scale atmospheric recycling of this element.« less

Traceability of sulfonamide antibiotic treatment by immunochemical analysis of farm animal hair samples.

PubMed

Adrian, Javier; Gratacós-Cubarsí, Marta; Sánchez-Baeza, Francisco; Garcia Regueiro, Jose-Antonio; Castellari, Massimo; Marco, M-Pilar

2009-10-01

The use of hair to trace use of unauthorized substances, therapeutic agents, or their misuse is becoming very attractive since residues can be detected for a long time after treatment. For this purpose, an indirect enzyme-linked immunosorbent assay (ELISA) has been evaluated for its capability to trace sulfonamide antibiotic treatment by analyzing cattle and pig hair samples. Pigmented and nonpigmented hair samples from control and sulfamethazine (SMZ)-treated pigs and calves were collected, extracted under different alkaline conditions, and analyzed by ELISA after just diluting the extracts with the assay buffer. Data analysis following the European recommendations for screening methods demonstrates that the ELISA can detect SMZ in hair samples with a limit of detection (90% of the zero dose (IC(90))) between 30 and 75 ng g(-1). The same samples have been analyzed by HPLC after a dual solid-phase extraction. The ELISA results matched very well those obtained by the chromatographic method, demonstrating that the immunochemical method can be used as a screening tool to trace animal treatments. Between the benefits of this method are the possibility to directly analyze hair extracts with sufficient detectability and its high-throughput capability. Preliminary validation data are reported using an experimental approach inspired on the Commission Decision 2002/657/EC criteria for screening methods.

Trace metal analysis by laser ablation-inductively coupled plasmamass spectrometry and x-ray K-edge densitometry of forensic samples

DOE Office of Scientific and Technical Information (OSTI.GOV)

Berry, Jonna Elizabeth

This dissertation describes a variety of studies on the determination of trace elements in samples with forensic importance. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used to determine the trace element composition of numerous lipstick samples. Lipstick samples were determined to be homogeneous. Most lipstick samples of similar colors were readily distinguishable at a 95% confidence interval based on trace element composition. Numerous strands of a multi-strand speaker cable were analyzed by LA-ICP-MS. The strands in this study are spatially heterogeneous in trace element composition. In actual forensic applications, the possibility of spatial heterogeneity must be considered, especially in casesmore » where only small samples (e.g., copper wire fragments after an explosion) are available. The effects of many unpredictable variables, such as weather, temperature, and human activity, on the retention of gunshot residue (GSR) around projectile wounds were assessed with LAICP- MS. Skin samples around gunshot and stab wounds and larvae feeding in and around the wounds on decomposing pig carcasses were analyzed for elements consistent with GSR (Sb, Pb, Ba, and Cu). These elements were detected at higher levels in skin and larvae samples around the gunshot wounds compared to the stab wounds for an extended period of time throughout decomposition in both a winter and summer study. After decomposition, radiographic images of the pig bones containing possible damage from bullets revealed metallic particles embedded within a number of bones. Metallic particles within the bones were analyzed with x-ray, K-edge densitometry and determined to contain lead, indicating that bullet residue can be retained throughout decomposition and detected within bones containing projectile trauma.« less

Heavy metals and manganese oxides in the genesee watershed, New York state: effects of geology and land use

USGS Publications Warehouse

Whitney, P.R.

1981-01-01

Manganese oxide coatings on gravels from 255 sites on tributary streams in the Genesee River Watershed were analyzed for Mn, Fe, Zn, Cd, Co, Ni, Pb, and Cu. The results were compared with data on bedrock geology, surficial geology and land use, using factor analysis and stepwise multiple regression. All metals except Pb show strong positive correlation with Mn. This association results from the well-known tendency of Mn oxide precipitates to adsorb and incorporate dissolved trace metals. Pb may be present in a separate phase on the gravel surfaces; alternatively Pb abundance may be so strongly influenced by environmental factors that the effect of varying abundance of the carrier phase becomes relatively unimportant. When the effects of varying Mn abundance are allowed for, Pb and to a lesser extent Zn and Cu abundances are seen to be related to commercial, industrial and residential land use. In addition to this pollution effect, all the trace metals, Cd and Ni most strongly, tend to be more abundant in oxide coatings from streams in the forested uplands in the southern part of the area. This probably reflects increased geochemical mobility of the metals in the more acid soils and groundwater of the southern region. A strong Zn anomaly is present in streams draining areas underlain by the Lockport Formation. Oxide coatings in these streams contain up to 5% Zn, originating from disseminated sphalerite in the Lockport and secondary Zn concentrations in the overlying muck soils. The same group of metals, plus calcium and loss on ignition, were determined in the silt and clay (minus 230 mesh) fraction of stream sediments from 129 of the same sites, using a hot nitric acid leach. The amounts of manganese in the sediments are low (average 1020 ppm) and manganese oxides are, at most, of relatively minor significance in the trace-metal geochemistry of these sediments. The bulk of the trace metals in sediment appears to be associated with iron oxides, clays and organic matter. ?? 1981.

Microbial bioreporters of trace explosives.

PubMed

Shemer, Benjamin; Koshet, Ori; Yagur-Kroll, Sharon; Belkin, Shimshon

2017-06-01

Since its introduction as an explosive in the late 19th century, 2,4,6-trinitrotoluene (TNT), along with other explosive compounds, has left numerous environmental marks. One of these is widespread soil and water pollution by trace explosives in military proving grounds, manufacturing facilities, or actual battlefields. Another dramatic impact is that exerted by the millions of landmines and other explosive devices buried in large parts of the world, causing extensive loss of life, injuries, and economical damage. In this review we highlight recent advances in the design and construction of microbial bioreporters, molecularly engineered to generate a quantifiable dose-dependent signal in the presence of trace amounts of explosives. Such sensor strains may be employed for monitoring environmental pollution as well as for the remote detection of buried landmines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Bags with oven-dried moss for the active monitoring of airborne trace elements in urban areas.

PubMed

Giordano, S; Adamo, P; Monaci, F; Pittao, E; Tretiach, M; Bargagli, R

2009-10-01

To define a harmonized methodology for the use of moss and lichen bags as active monitoring devices of airborne trace elements in urban areas, we evaluated the element accumulation in bags exposed in Naples in different spring weather conditions for 6- and 12-weeks. Three different pre-exposure treatments were applied to moss and lichen materials: water-washing, acid-washing and oven-drying. During the different exposure periods in the Naples urban environment the moss accumulated always higher amounts of elements (except Hg) than lichens and the element accumulation increased during wetter weather and higher PM(10) conditions. The oven pre-treatment did not substantially modify the morphology and element composition of moss and the exposure in bags of this material for 6-weeks was sufficient to detect the pattern of airborne trace elements.

Trace Elements and Carbon and Nitrogen Stable Isotopes in Organisms from a Tropical Coastal Lagoon

PubMed Central

van Hattum, B.; de Boer, J.; van Bodegom, P. M.; Rezende, C. E.; Salomons, W.

2010-01-01

Trace elements (Fe, Mn, Al, Zn, Cr, Cu, Ni, Pb, Cd, Hg, and As) and stable isotope ratios (δ13C and δ15N) were analyzed in sediments, invertebrates, and fishes from a tropical coastal lagoon influenced by iron ore mining and processing activities to assess the differences in trace element accumulation patterns among species and to investigate relations with trophic levels of the organisms involved. Overall significant negative relations between trophic level (given by 15N) and trace element concentrations in gastropods and crustaceans showed differences in internal controls of trace element accumulation among the species of different trophic positions, leading to trace element dilution. Generally, no significant relation between δ15N and trace element concentrations was observed among fish species, probably due to omnivory in a number of species as well as fast growth. Trace element accumulation was observed in the fish tissues, with higher levels of most trace elements found in liver compared with muscle and gill. Levels of Fe, Mn, Al, and Hg in invertebrates, and Fe and Cu in fish livers, were comparable with levels in organisms and tissues from other contaminated areas. Trace element levels in fish muscle were below the international safety baseline standards for human consumption. PMID:20217062

Trace elements and carbon and nitrogen stable isotopes in organisms from a tropical coastal lagoon.

PubMed

Pereira, A A; van Hattum, B; de Boer, J; van Bodegom, P M; Rezende, C E; Salomons, W

2010-10-01

Trace elements (Fe, Mn, Al, Zn, Cr, Cu, Ni, Pb, Cd, Hg, and As) and stable isotope ratios (delta(13)C and delta(15)N) were analyzed in sediments, invertebrates, and fishes from a tropical coastal lagoon influenced by iron ore mining and processing activities to assess the differences in trace element accumulation patterns among species and to investigate relations with trophic levels of the organisms involved. Overall significant negative relations between trophic level (given by (15)N) and trace element concentrations in gastropods and crustaceans showed differences in internal controls of trace element accumulation among the species of different trophic positions, leading to trace element dilution. Generally, no significant relation between delta(15)N and trace element concentrations was observed among fish species, probably due to omnivory in a number of species as well as fast growth. Trace element accumulation was observed in the fish tissues, with higher levels of most trace elements found in liver compared with muscle and gill. Levels of Fe, Mn, Al, and Hg in invertebrates, and Fe and Cu in fish livers, were comparable with levels in organisms and tissues from other contaminated areas. Trace element levels in fish muscle were below the international safety baseline standards for human consumption.

[Determination of Trace Elements in Marine Cetaceans by ICP-MS and Health Risk Assessment].

PubMed

Ding, Yu-long; Ning, Xi; Gui, Duan; Mo, Hui; Li, Yu-sen; Wu, Yu-ping

2015-09-01

The liver, kidney and muscle samples from seven cetaceans were digested by microwave digestion, and trace elements amounts of V, Cd, Cu, Zn, As, Cr, Ni, Mn, Se, Hg and Pb were determined by inductively coupled plasma mass spectrometry (ICP-MS), and the health risk assessment for Zn, Cu, Cd, Hg, Se in the liver was conducted. The results of international lobster hepatopancreas standard (TORT-2) showed acceptable agreement with the certified values, and the relative standard deviation (RSD) of eleven kinds of trace elements were less than 3.54%, showing that the method is suitable for the determination of trace elements in cetaceans. The experimental results indicated that different tissues and organs of the dolphins had different trace elements, presenting the tissue specificity. There is a certain inter-species difference among different dolphins about the bioaccumulation ability of the trace elements. The distribution of trace elements in whales presented a certain regularity: the contents of most elements in liver, kidney were much higher than the contents of muscle tissues, Cu, Mn, Hg, Se, and Zn exhibit the higher concentrations in liver, while Cd was mainly accumulated in kidney. And according to the health risk assessment in liver, the exceeding standardrate of selenium and copper in seven kinds of whales was 100%, suggesting that these whales were suffering the contamination of trace elements. The experimental results is instructive to the study of trace elements in cetaceans, while this is the first report for the concentrations in organs of Striped dolphin, Bottlenose dolphin, Fraser's Dolphin and Risso's dolphin in China, it may provide us valuable data for the conservation of cetaceans.

An animal model of fetal alcohol spectrum disorder: Trace conditioning as a window to inform memory deficits and intervention tactics.

PubMed

Hunt, Pamela S; Barnet, Robert C

2015-09-01

Animal models of Fetal Alcohol Spectrum Disorders (FASD) afford the unique capacity to precisely control timing of alcohol exposure and alcohol exposure amounts in the developing animal. These models have powerfully informed neurophysiological alterations associated with fetal and perinatal alcohol. In two experiments presented here we expand use of the Pavlovian Trace Conditioning procedure to examine cognitive deficits and intervention strategies in a rat model of FASD. Rat pups were exposed to 5g/kg/day ethanol on postnatal days (PD) 4-9, simulating alcohol exposure in the third trimester in humans. During early adolescence, approximately PD 30, the rats were trained in the trace conditioning task in which a light conditioned stimulus (CS) and shock unconditioned stimulus (US) were paired but separated by a 10-s stimulus free trace interval. Learning was assessed in freezing behavior during shock-free tests. Experiment 1 revealed that neonatal ethanol exposure significantly impaired hippocampus-dependent trace conditioning relative to controls. In Experiment 2 a serial compound conditioning procedure known as 'gap filling' completely reversed the ethanol-induced deficit in trace conditioning. We also discuss prior data regarding the beneficial effects of supplemental choline and novel preliminary data regarding the pharmacological cognitive enhancer physostigmine, both of which mitigate the alcohol-induced cognitive deficit otherwise seen in trace conditioning controls. We suggest trace conditioning as a useful tool for characterizing some of the core cognitive deficits seen in FASD, and as a model for developing effective environmental as well as nutritional and pharmacological interventions. Copyright © 2014 Elsevier Inc. All rights reserved.

An Animal Model of Fetal Alcohol Spectrum Disorder: Trace Conditioning as a Window to Inform Memory Deficits and Intervention Tactics

PubMed Central

Hunt, Pamela S.; Barnet, Robert C.

2014-01-01

Animal models of Fetal Alcohol Spectrum Disorders (FASD) afford the unique capacity to precisely control timing of alcohol exposure and alcohol exposure amounts in the developing animal. These models have powerfully informed neurophysiological alterations associated with fetal and perinatal alcohol. In two experiments presented here we expand use of the Pavlovian Trace Conditioning procedure to examine cognitive deficits and intervention strategies in a rat model of FASD. Rat pups were exposed to 5 g/kg/day ethanol on postnatal days (PD) 4–9, simulating alcohol exposure in the third trimester in humans. During early adolescence, approximately PD 30, the rats were trained in the trace conditioning task in which a light conditioned stimulus (CS) and shock unconditioned stimulus (US) were paired but separated by a 10-s stimulus free trace interval. Learning was assessed in freezing behavior during shock-free tests. Experiment 1 revealed that neonatal ethanol exposure significantly impaired hippocampus-dependent trace conditioning relative to controls. In Experiment 2 a serial compound conditioning procedure known as ‘gap filling’ completely reversed the ethanol-induced deficit in trace conditioning. We also discuss prior data regarding the beneficial effects of supplemental choline and novel preliminary data regarding the pharmacological cognitive enhancer physostigmine, both of which mitigate the alcohol-induced cognitive deficit otherwise seen in trace conditioning controls. We suggest trace conditioning as a useful tool for characterizing some of the core cognitive deficits seen in FASD, and as a model for developing effective environmental as well as nutritional and pharmacological interventions. PMID:25477227

Cognitive Demand of Model Tracing Tutor Tasks: Conceptualizing and Predicting How Deeply Students Engage

ERIC Educational Resources Information Center

Kessler, Aaron M.; Stein, Mary Kay; Schunn, Christian D.

2015-01-01

Model tracing tutors represent a technology designed to mimic key elements of one-on-one human tutoring. We examine the situations in which such supportive computer technologies may devolve into mindless student work with little conceptual understanding or student development. To analyze the support of student intellectual work in the model…

Absorption of N-phenylpropenoyl-L-amino acids in healthy humans by oral administration of cocoa (Theobroma cacao).

PubMed

Stark, Timo; Lang, Roman; Keller, Daniela; Hensel, Andreas; Hofmann, Thomas

2008-10-01

Besides flavan-3-ols, a family of N-phenylpropenoyl-L-amino acids (NPAs) has been recently identified as polyphenol/amino acid conjugates in the seeds of Theobroma cacao as well as in a variety of herbal drugs. Stimulated by reports on their biological activity, the purpose of this study was to investigate if these amides are absorbed by healthy volunteers after administration of a cocoa drink. For the first time, 12 NPAs were quantified in human urine by means of a stable isotope dilution analysis with LC-MS/MS (MRM) detection. A maximum amount was found in the urine taken 2 h after the cocoa consumption. The highest absolute amount of NPAs excreted with the urine was found for N-[4'-hydroxy-(E)-cinnamoyl]-L-aspartic acid (5), but the highest recovery rate (57.3 and 22.8%), that means the percentage amount of ingested amides excreted with the urine, were determined for N-[4'-hydroxy-(E)-cinnamoyl]-L-glutamic acid (6) and N-[4'-hydroxy-3'-methoxy-(E)-cinnamoyl]-L-tyrosine (13). In order to gain first insights into the NPA metabolism in vivo, urine samples were analyzed by LC-MS/MS before and after beta-glucuronidase/sulfatase treatment. As independent of the enzyme treatment the same NPA amounts were found in urine, there is strong evidence that these amides are metabolized neither via their O-glucuronides nor their O-sulfates. In order to screen for caffeic acid O-glucuronides as potential NPA metabolites, urine samples were screened by means of LC-MS/MS for caffeic acid 3-O-beta-D-glucuronide and 4-O-beta-D-glucuronide. But not even trace amounts of one of these glucuronides were detectable, thus excluding them as major NPA metabolites and underlining the importance of future investigations on a potential O-methylation or reduction of the N-phenylpropenoyl moiety in NPAs.

Practical applications of trace minerals for dairy cattle.

PubMed

Overton, T R; Yasui, T

2014-02-01

Trace minerals have critical roles in the key interrelated systems of immune function, oxidative metabolism, and energy metabolism in ruminants. To date, the primary trace elements of interest in diets for dairy cattle have included Zn, Cu, Mn, and Se although data also support potentially important roles of Cr, Co, and Fe in diets. Trace minerals such as Zn, Cu, Mn, and Se are essential with classically defined roles as components of key antioxidant enzymes and proteins. Available evidence indicates that these trace minerals can modulate aspects of oxidative metabolism and immune function in dairy cattle, particularly during the transition period and early lactation. Chromium has been shown to influence both immune function and energy metabolism of cattle; dairy cows fed Cr during the transition period and early lactation have evidence of improved immune function, increased milk production, and decreased cytological endometritis. Factors that complicate trace mineral nutrition at the farm level include the existence of a large number of antagonisms affecting bioavailability of individual trace minerals and uncertainty in terms of requirements under all physiological and management conditions; therefore, determining the optimum level and source of trace minerals under each specific situation continues to be a challenge. Typical factorial approaches to determine requirements for dairy cattle do not account for nuances in biological function observed with supplementation with various forms and amounts of trace minerals. Trace mineral nutrition modulates production, health, and reproduction in cattle although both formal meta-analysis and informal survey of the literature reveal substantial heterogeneity of response in these outcome variables. The industry has largely moved away from oxide-based programs toward sulfate-based programs; however, some evidence favors shifting supplementation strategies further toward more bioavailable forms of inorganic and organic trace minerals. Furthermore, opportunities for specific modulation of aspects of health, milk production, and reproduction through supplementation strategies for diets of transition dairy cows are attractive because of the known dynamics of energy metabolism, immune function, and oxidative metabolism during this timeframe.

Petroleum formation during serpentinization: the evidence of trace elements

NASA Astrophysics Data System (ADS)

Szatmari, P.; Fonseca, T. C.; Miekeley, N. F.

2002-05-01

An organic source of petroleum formation is well attested by many biomarkers. This need not, however, exclude contribution from inorganic sources. During serpentinization, in the absence of free oxygen, oxidation of bivalent Fe to magnetite breaks up the water molecule, generating hydrogen and creating one of the most reducing environments near the Earth's surface (Janecky & Seyfried, 1986). Szatmari (1989) proposed that some petroleum forms at plate boundaries by Fischer-Tropsch-type synthesis over serpentinizing peridotites and suggested that Ni, an element rare in the continental crust but important in both petroleum and the mantle, may be indicative of such a source. Recently, Holm and Charlou (2001) observed hydrocarbon formation by Fischer-Tropsch-type synthesis over serpentinizing peridotites of the Mid-Atlantic Ridge. To test whether the relative amounts of other trace elements in petroleum are in agreement with a serpentinizing source, we analyzed by internally coupled plasma-mass spectroscopy (ICP-MS) 22 trace elements in 68 oils sampled in seven sedimentary basins throughout Brazil. We found that trace elements in the oils correlate well with mantle peridotites and reflects the process of hydrothermal serpentinization during continental breakup. Four groups may be distinguished. In serpentinites, trace elements of the first group, Ti, Cr, Mn, and Fe, are largely retained in low-solubility magnetite and other spinels formed during serpentinization or inherited from the original peridotites. In the oils, when normalized to mantle peridotites, these elements are at relatively low levels, about 10,000 times less than their abundances in mantle peridotites, reflecting their low availability from stable minerals. In contrast, trace elements of the second group, which includes V, Co, Ni, Cu, Zn, Ga, Rb, Sr, Y, Ba, La, Ce, and Nd, pass during serpentinization mostly into serpentine minerals or solution. In the oils, when normalized to mantle peridotites, these elements are at higher levels than those of the first group, about 300 times less than their abundances in mantle peridotites, reflecting their higher availability during serpentinization. Within both groups, trace metal ratios and A/(A+B) type proportionalities in the oils are close to mantle peridotites. V behaves somewhat differently: in lacustrine sequences V contents in the oils are low and the ratios of V to other elements of the second group are mantle-like, whereas in marine sequences V and its ratios to other trace elements rise by orders of magnitude. Trace elements commonly enriched in formation fluids and hydrothermal brines (Rb, Sr, Ba, Cu, Zn), when normalized to mantle peridotites, are enriched in the oils by about 0.5 order of magnitude relative to other elements of the second group. The third group of elements includes S, Mo, and As. These elements occur in the oils at abundances similar to sea water and are, when normalized to mantle peridotites and Ni, enriched in the oils by several orders of magnitude, indicating sea water reacting with peridotites during sepentinization as their possible source. Finally trace elements of the fourth group, such as Pb and Ag, are enriched in the oils by several orders of magnitude relative to both mantle peridotites and sea water and were presumably mobilized from shales by hydrothermal fluids. References:Holm, N.G. and Charlou, J.L., 2001, EPSL 191, 1-8. Janecky, D.R. and Seyfried, W.E., 1986, Geochim. Cosmochim. Acta 50, 1357-1378. Szatmari, P., 1989, AAPG Bull. 73, 989-998.

Extraction of CO2 from air samples for isotopic analysis and limits to ultra high precision delta18O determination in CO2 gas.

PubMed

Werner, R A; Rothe, M; Brand, W A

2001-01-01

The determination of delta18O values in CO2 at a precision level of +/-0.02 per thousand (delta-notation) has always been a challenging, if not impossible, analytical task. Here, we demonstrate that beyond the usually assumed major cause of uncertainty - water contamination - there are other, hitherto underestimated sources of contamination and processes which can alter the oxygen isotope composition of CO2. Active surfaces in the preparation line with which CO2 comes into contact, as well as traces of air in the sample, can alter the apparent delta18O value both temporarily and permanently. We investigated the effects of different surface materials including electropolished stainless steel, Duran glass, gold and quartz, the latter both untreated and silanized. CO2 frozen with liquid nitrogen showed a transient alteration of the 18O/16O ratio on all surfaces tested. The time to recover from the alteration as well as the size of the alteration varied with surface type. Quartz that had been ultrasonically cleaned for several hours with high purity water (0.05 microS) exhibited the smallest effect on the measured oxygen isotopic composition of CO2 before and after freezing. However, quartz proved to be mechanically unstable with time when subjected to repeated large temperature changes during operation. After several days of operation the gas released from the freezing step contained progressively increasing trace amounts of O2 probably originating from inclusions within the quartz, which precludes the use of quartz for cryogenically trapping CO2. Stainless steel or gold proved to be suitable materials after proper pre-treatment. To ensure a high trapping efficiency of CO2 from a flow of gas, a cold trap design was chosen comprising a thin wall 1/4" outer tube and a 1/8" inner tube, made respectively from electropolished stainless steel and gold. Due to a considerable 18O specific isotope effect during the release of CO2 from the cold surface, the thawing time had to be as long as 20 min for high precision delta18O measurements. The presence of traces of air in almost all CO2 gases that we analyzed was another major source of error. Nitrogen and oxygen in the ion source of our mass spectrometer (MAT 252, Finnigan MAT, Bremen, Germany) give rise to the production of NO2 at the hot tungsten filament. NO2+ is isobaric with C16O18O+ (m/z 46) and interferes with the delta18O measurement. Trace amounts of air are present in CO2 extracted cryogenically from air at -196 degrees C. This air, trapped at the cold surface, cannot be pumped away quantitatively. The amount of air present depends on the surface structure and, hence, the alteration of the measured delta18O value varies with the surface conditions. For automated high precision measurement of the isotopic composition of CO2 of air samples stored in glass flasks an extraction interface ('BGC-AirTrap') was developed which allows 18 analyses (including standards) per day to be made. For our reference CO2-in-air, stored in high pressure cylinders, the long term (>9 months) single sample precision was 0.012 per thousand for delta13C and 0.019 per thousand for delta18O. Copyright 2001 John Wiley & Sons, Ltd.

IDENTIFICATION OF POLLUTANTS IN A MUNICIPAL WELL USING HIGH RESOLUTION MASS SPECTROMETRY

EPA Science Inventory

An elevated incidence of childhood cancer was observed near a contaminated site. Trace amounts of several isomeric compounds were detected by gas chromatography/mass spectrometry (GC/MS) in a concentrated extract of municipal well water. No matching library mass spectra were foun...

Ammonia emissions from cattle feeding operations.

USDA-ARS?s Scientific Manuscript database

Ammonia is a colorless gas with an pungent odor that occurs naturally in trace amounts in the atmosphere, where it is the dominant base. Ammonia is produced during the decomposition of livestock manure. There is concern about atmospheric ammonia because of its potential effects on air quality, wat...

Differentiation of farmed and wild turbot (Psetta maxima): proximate chemical composition, fatty acid profile, trace minerals and antimicrobial resistance of contaminant bacteria.

PubMed

Martínez, B; Miranda, J M; Nebot, C; Rodriguez, J L; Cepeda, A; Franco, C M

2010-10-01

The proximate, cholesterol, fatty acid and trace mineral compositions in the flesh of farmed and wild turbot (Psetta maxima) were evaluated. Additionally, the potential influence of the use of antimicrobial agents in the bacteria carried by farmed turbot was investigated. For this purpose, a total of 144 Pseudomonas spp. and 127 Aeromonas spp. were isolated and tested for their susceptibility to 12 antimicrobials by a disk diffusion method. Farmed turbot contained higher fat, cholesterol and calories as well as lower moisture content than its wild counterpart. The fatty acid profile of farmed turbot included higher levels of myristic, pentadecanoic, palmitoleic, gadoleic, cetoleic, linoleic, linolenic, stearidonic, eicosadienoic and eicosapentaenoic acids, and lower levels of stearic, arachidonic, docosapentaenoic and docosahexaenoic acids than its wild counterpart. The proportions of polyunsaturated fatty acids and n-3/n-6 ratios were higher in wild turbot than in farmed turbot. With respect to trace minerals, no toxic levels were found, and higher amounts of Cd, Co, Cu, Fe, Mn, Pb and Zn, as well as lower amounts of Cr, were found in farmed turbot relative to wild turbot. The antimicrobial resistance of Pseudomonas spp. and Aeromonas spp. were quite similar, with only the trimethoprim-sulfamethoxazole resistance of Aeromonas spp. isolated from farmed turbot being higher than those isolated from wild turbot. In the case of ampicillin, Pseudomonas spp. isolated from wild turbot showed higher resistance levels than those of their counterparts isolated from farmed turbot. In conclusion, the nutritional parameters of wild turbot are more adequate with respect to nutritional recommendations, while no differences were observed in food safety derived from trace mineral concentrations or the antimicrobial resistance of bacteria isolated from wild and farmed turbot.

Organic Compounds, Trace Elements, Suspended Sediment, and Field Characteristics at the Heads-of-Tide of the Raritan, Passaic, Hackensack, Rahway, and Elizabeth Rivers, New Jersey, 2000-03

USGS Publications Warehouse

Bonin, Jennifer L.; Wilson, Timothy P.

2006-01-01

Concentrations of suspended sediment, particulate and dissolved organic carbon, trace elements, and organic compounds were measured in samples from the heads-of-tide of the five tributaries to the Newark and Raritan Bays during June 2000 to June 2003. The samples were collected as part of the New Jersey Department of Environmental Protection Toxics Reduction Workplan/Contaminant Assessment Reduction Program. Samples of streamwater were collected at water-quality sampling stations constructed near U.S. Geological Survey gaging stations on the Raritan, Passaic, Hackensack, Rahway, and Elizabeth Rivers. Sampling was conducted during base-flow conditions and storms. Constituent concentrations were measured to determine the water quality and to calculate the load of sediment and contaminants contributed to the bays from upstream sources. Water samples were analyzed for suspended sediment, dissolved organic carbon, particulate organic carbon, and specific conductance. Samples of suspended sediment and water were analyzed for 98 distinct polychlorinated biphenyl congeners, 7 dioxins, 10 furans, 27 pesticides, 26 polycyclic aromatic hydrocarbons, and the trace elements cadmium, lead, mercury, and methyl-mercury. Measurements of ultra-low concentrations of organic compounds in sediment and water were obtained by collecting 1 to 3 grams of suspended sediment on glass fiber filters and by passing at least 20 liters of filtered water through XAD-2 resin. The extracted sediment and XAD-2 resin were analyzed for organic compounds by high- and low-resolution gas chromatography mass-spectrometry that uses isotope dilution procedures. Trace elements in filtered and unfiltered samples were analyzed for cadmium, lead, mercury, and methyl-mercury by inductively coupled charged plasma and mass-spectrometry. All constituent concentrations are raw data. Interpretation of the data will be completed in the second phase of the study.

[Coal fineness effect on primary particulate matter features during pulverized coal combustion].

PubMed

Lü, Jian-yi; Li, Ding-kai

2007-09-01

Three kinds of coal differed from fineness were burned in a laboratory-scale drop tube furnace for combustion test, and an 8-stage Andersen particle impactor was employed for sampling the primary particulate matter (PM), in order to study coal fineness effect on primary PM features during pulverized coal combustion. It has been shown that the finer the coal was, the finer the PM produced. PM, emission amount augmented with coal fineness decreased, and the amount of PM10 increased from 13 mg/g to 21 mg/g respectively generated by coarse coal and fine coal. The amount of PM2.5 increased from 2 mg/g to 8 mg/g at the same condition. Constituents and content in bulk ash varied little after three different fineness coal combustion, while the appearance of grading PM differed visibly. The value of R(EE) increased while the coal fineness deceased. The volatility of trace elements which were investigated was Pb > Cr > Zn > Cu > Ni in turn. The concentration of poisonous trace elements was higher which generated from fine coal combustion. The volatilization capacity was influenced little by coal fineness, but the volatilization extent was influenced differently by coal fineness. Fine coal combustion affects worse environment than coarse coal does.

Ultrasound-Assisted Emulsification Microextraction Based on Solidification Floating Organic Drop Trace Amounts of Manganese Prior to Graphite Furnace Atomic Absorption Spectrometry Determination

PubMed Central

Mohadesi, Alireza; Falahnejad, Masoumeh

2012-01-01

In the present study, an ultrasound-assisted emulsification microextraction based on solidification floating organic drop method is described for preconcentration of trace amounts of Mn (II). 2-(5-Bromo-2-pyridylazo)-5 diethylaminophenol was added to a solution of Mn+2 at ph = 10.0. After this, 1-undecanol was added to the solution as an extraction solvent, and solution was stirred. Several factors influencing the microextraction efficiency, such as pH, the amount of chelating agent, nature and volume of extraction solvent, the volume of sample solution, stirring rate, and extraction time were investigated and optimized. Then sample vial was cooled by inserting into an ice bath, and the solidified was transferred into a suitable vial for immediate melting. Finally the sample was injected into a graphite furnace atomic absorption spectrometry. Under the optimum condition the linear dynamic range was 0.50–10.0 ng mL−1 with a correlation coefficient of 0.9926, and the detection limit of 0.3 ng mL−1 was obtained. The enrichment factor was 160. The proposed method was successfully applied for separation and determination of manganese in sea, rain, tap, and river water samples. PMID:22645504

Impregnated multiwalled carbon nanotubes as efficient sorbent for the solid phase extraction of trace amounts of heavy metal ions in food and water samples.

PubMed

Gouda, Ayman A; Al Ghannam, Sheikha M

2016-07-01

A new, sensitive and simple solid phase extraction (SPE), separation and preconcentration method of some heavy metal ions, Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) at trace levels using multiwalled carbon nanotubes (MWCNTs) impregnated with 2-(2-benzothiazolylazo)orcinol (BTAO) from food and water samples were investigated. The effect of analytical parameters was examined. The metals retained on the nanotubes at pH 7.0 were eluted by 5.0mL HNO3 (2.0molL(-1)). The influence of matrix ions on the proposed method was evaluated. The preconcentration factor was calculated and found to be 100. The detection limits (LODs) for Cd(II), Cu(II), Ni(II), Pb(II) and Zn(II) were found at 0.70, 1.2, 0.80, 2.6 and 2.2μgL(-1), respectively. The relative standard deviation (RSD) and the recoveries of the standard addition method were lower than 5.0% and 95-102%, respectively. The new procedure was successfully applied to the determination of trace amounts of the studied metal ions in various food and water samples and validated using certified reference materials SRM 1570A (spinach leaves) with satisfactory and compatible results. Copyright © 2016 Elsevier Ltd. All rights reserved.

Preparation of dummy template imprinted polymers at surface of silica microparticles for the selective extraction of trace bisphenol A from water samples.

PubMed

Zhao, Wenhui; Sheng, Na; Zhu, Rong; Wei, Fangdi; Cai, Zheng; Zhai, Meijuan; Du, Shuhu; Hu, Qin

2010-07-15

Molecularly imprinted polymers for bisphenol A (BPA) were prepared by using surface molecular imprinting technique. Analogues of BPA, namely 4,4'-dihydroxybiphenyl and 3,3',5,5'-tetrabromobisphenol A, were used as the dummy templates instead of BPA, to avoid the leakage of a trace amount of the target analyte (BPA). The resulting dummy molecularly imprinted polymers (DMIPs) showed the large sorption capacity, high recognition ability and fast binding kinetics for BPA. The maximal sorption capacity was up to 958 micromol g(-1), and it only took 40 min for DMIPs to achieve the sorption equilibrium. The DMIPs were successfully applied to the solid-phase extraction coupled with HPLC/UV for the determination of BPA in water samples. The calibration graph of the analytical method was linear with a correlation coefficient more than 0.999 in the concentration range of 0.0760-0.912 ng mL(-1) of BPA. The limit of detection was 15.2 pg mL(-1) (S/N=3). Recoveries were in the range of 92.9-102% with relative standard deviation (RSD) less than 11%. The trace amounts of BPA in tap water, drinking water, rain and leachate of one-off tableware were determined by the method built, and the satisfactory results were obtained. 2010 Elsevier B.V. All rights reserved.

Synthesis of Fe3O4@CuS@Ni2P-CNTs magnetic nanocomposite for sonochemical-assisted sorption and pre-concentration of trace Allura Red from aqueous samples prior to HPLC-UV detection: CCD-RSM design.

PubMed

Asfaram, Arash; Ghaedi, Mehrorang; Abidi, Hassan; Javadian, Hamedreza; Zoladl, Mohammad; Sadeghfar, Fardin

2018-06-01

A simple procedure based on ultrasound-assisted (UA) dispersive micro solid phase extraction (D-μ-SPE) was applied for sorption of trace amount Allura Red (AR) in fruit juice and water samples. After loading process by UA-D-μ-SPE, the concentrated AR was eluted and monitored using high-performance liquid chromatography-ultraviolet -visible detector (HPLC-UV). The best operational conditions were obtained as follows: pH = 3.0, 8 mg of the sorbent, sonication time of 4.5 min and 0.16 mL of THF as elution solvent. Under the optimum operational conditions, the present method was acceptable for AR quantification in the range of 1.0-5000 ng mL -1 . The repeatability based on RSD with the amount of 1.67-3.18%, low LOD (0.198 ng mL -1 ) and LOQ (0.659 ng mL -1 ) were obtained. The UA-D-μ-SPE-HPLC-UV method was successfully applied for trace quantification of AR from water and commercial fruit juice samples supplied from local supermarkets, and acceptable relative recoveries over the range of 97.7-105.4% with RSDs ≤5.50% were obtained. Copyright © 2018 Elsevier B.V. All rights reserved.

Concentration of trace elements on branded cigarette in Malaysia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Azman, Muhammad Azfar, E-mail: m-azfar@nuclearmalaysia.gov.my; Hamzah, Suhaimi; Rahman, Shamsiah Abdul

Tobacco is a plant that is used as a recreational drug since the beginning of its use by the Native Americans. Now with the development of the tobacco industry, smoking has become a norm for the public in Malaysia. Trace elements in plants are mostly due to the uptake processes from the soils into the roots of the plants. The concentration of the elements may also be influenced by the elements contained in the water and also fertilizers. This paper aim to analyze the concentration of the trace elements contained in the branded cigarettes sold in Malaysia by utilizing themore » neutron activation analysis. The tobaccos were taken out from the cigarettes. The collected samples were air dried and passed through 2 mm sieve. Instrumental Neutron Activation Analysis (NAA) has been used for the determination of trace elements. Samples were activated in the Nuclear Malaysia Triga Mark II reactor with a neutron flux of 2.0 x 10{sup 12} n cm{sup -2} s{sup -1}. The samples then were analyzed using ORTEC Gamma Spectrometer a co-axial n-type HPGe detector with resolution of 2.0 keV at 1332 keV and relative efficiency of 20%. The data obtained could help in assessing the concentration of the trace elements that complying with the standard limitation dose proposed by World Health Organization (WHO)« less

Numerical simulation of trace element transport on subsurface environment pollution in coal mine spoil.

PubMed

Qiang, Xue; Bing, Liang; Hui-yun, Wang; Lei, Liu

2006-01-01

An understanding of the dynamic behavior of trace elements leaching from coal mine spoil is important in predicting the groundwater quality. The relationship between trace element concentrations and leaching times, pH values of the media is studied. Column leaching tests conducted in the laboratory showed that there was a close correlation between pH value and trace element concentrations. The longer the leaching time, the higher the trace element concentrations. Different trace elements are differently affected by pH values of leaching media. A numerical model for water flow and trace element transport has been developed based on analyzing the characteristics of migration and transformation of trace elements leached from coal mine spoil. Solutions to the coupled model are accomplished by Eulerian-Lagrangian localized adjoint method. Numerical simulation shows that rainfall intensity determined maximum leaching depth. As rainfall intensity is 3.6ml/s, the outflow concentrations indicate a breakthrough of trace elements beyond the column base, with peak concentration at 90cm depth. And the subsurface pollution range has a trend of increase with time. The model simulations are compared to experimental results of trace element concentrations, with reasonable agreement between them. The analysis and modeling of trace elements suggested that the infiltration of rainwater through the mine spoil might lead to potential groundwater pollution. It provides theoretical evidence for quantitative assessment soil-water quality of trace element transport on environment pollution.

Predicting Individual Characteristics from Digital Traces on Social Media: A Meta-Analysis.

PubMed

Settanni, Michele; Azucar, Danny; Marengo, Davide

2018-04-01

The increasing utilization of social media provides a vast and new source of user-generated ecological data (digital traces), which can be automatically collected for research purposes. The availability of these data sets, combined with the convergence between social and computer sciences, has led researchers to develop automated methods to extract digital traces from social media and use them to predict individual psychological characteristics and behaviors. In this article, we reviewed the literature on this topic and conducted a series of meta-analyses to determine the strength of associations between digital traces and specific individual characteristics; personality, psychological well-being, and intelligence. Potential moderator effects were analyzed with respect to type of social media platform, type of digital traces examined, and study quality. Our findings indicate that digital traces from social media can be studied to assess and predict theoretically distant psychosocial characteristics with remarkable accuracy. Analysis of moderators indicated that the collection of specific types of information (i.e., user demographics), and the inclusion of different types of digital traces, could help improve the accuracy of predictions.

Trace Water as Prominent Factor to Induce Peptide Self-Assembly: Dynamic Evolution and Governing Interactions in Ionic Liquids.

PubMed

Wang, Juan; Yuan, Chengqian; Han, Yuchun; Wang, Yilin; Liu, Xiaomin; Zhang, Suojiang; Yan, Xuehai

2017-11-01

The interaction between water and biomolecules including peptides is of critical importance for forming high-level architectures and triggering life's functions. However, the bulk aqueous environment has limitations in detecting the kinetics and mechanisms of peptide self-assembly, especially relating to interactions of trace water. With ionic liquids (ILs) as a nonconventional medium, herein, it is discovered that trace amounts of water play a decisive role in triggering self-assembly of a biologically derived dipeptide. ILs provide a suitable nonaqueous environment, enabling us to mediate water content and follow the dynamic evolution of peptide self-assembly. The trace water is found to be involved in the assembly process of dipeptide, especially leading to the formation of stable noncovalent dipeptide oligomers in the early stage of nucleation, as evident by both experimental studies and theoretical simulations. The thermodynamics of the growth process is mainly governed by a synergistic effect of hydrophobic interaction and hydrogen bonds. Each step of assembly presents a different trend in thermodynamic energy. The dynamic evolution of assembly process can be efficiently mediated by changing trace water content. The decisive role of trace water in triggering and mediating self-assembly of biomolecules provides a new perspective in understanding supramolecular chemistry and molecular self-organization in biology. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Improving Biomethane Production and Mass Bioconversion of Corn Stover Anaerobic Digestion by Adding NaOH Pretreatment and Trace Elements

PubMed Central

Liu, ChunMei; Yuan, HaiRong; Zou, DeXun; Liu, YanPing; Zhu, BaoNing; Li, XiuJin

2015-01-01

This research applied sodium hydroxide (NaOH) pretreatment and trace elements to improve biomethane production when using corn stover for anaerobic digestion. Full-factor experimental tests identified the best combination of trace elements with the NaOH pretreatment, indicating that the best combination was with 1.0, 0.4, and 0.4 mg·L−1·d−1 of elements Fe, Co, and Ni, respectively. The cumulative biomethane production adding NaOH pretreatment and trace elements was 11,367 mL; total solid bioconversion rate was 55.7%, which was 41.8%–62.2% higher than with NaOH-pretreatment alone and 22.2%–56.3% higher than with untreated corn stover. The best combination was obtained 5–9 days shorter than T90 and maintained good system operation stability. Only a fraction of the trace elements in the best combination was present in the resulting solution; more than 85% of the total amounts added were transferred into the solid fraction. Adding 0.897 g of Fe, 0.389 g of Co, and 0.349 g of Ni satisfied anaerobic digestion needs and enhanced biological activity at the beginning of the operation. The results showed that NaOH pretreatment and adding trace elements improve corn stover biodegradability and enhance biomethane production. PMID:26137469

Retrieval of trace gas concentrations over Summit Station, Greenland using moderate-resolution spectral infrared radiances

NASA Astrophysics Data System (ADS)

Bahramvash Shams, S.; Walden, V. P.; Turner, D. D.

2017-12-01

Measurements of trace gases at high temporal resolution are important for understanding variations and trends at high latitudes. Trace gases over Greenland can be influenced by both long-range transport from pollution sources as well as local chemical processes. Satellite retrievals are an important data source in the polar regions, but accurate ground-based measurements are needed for proper validation, especially in data sparse regions. A moderate-resolution (0.5 cm-1) Fourier transform infrared spectrometer (FTIR), the Polar Atmospheric Emitted Radiance Interferometer (P-AERI), has been operated at Summit Station, Greenland as part of the ICECAPS project since 2010. In this study, trace gas concentrations, including ozone, nitrous oxide, and methane are retrieved using different optimal estimation retrieval codes. We first present results of retrieved gases using synthetic spectra (from a radiative transfer model) that mimic P-AERI measurements to evaluate systematic errors in the inverse models. We also retrieve time series of trace gas concentrations during periods of clear skies over Summit. We investigate the amount of vertical information that can be obtained with moderate resolution spectra for each of the trace gases, and also the impact of the seasonal variation of atmospheric water vapor on the retrievals. Data from surface observations and ozonesondes obtained by the NOAA Global Monitoring Division are used to improve the retrievals and as validation.

Simultaneously combining AOD and multiple trace gas measurements to identify decadal changes in urban and biomass burning aerosols

NASA Astrophysics Data System (ADS)

Cohen, Jason

2017-04-01

This work presents a methodology by which to comprehensively analyze simultaneous tropospheric measurements of AOD and associated trace gasses. It then applies this methodology by focusing over the past 11 years (2006-2016) on one of the most rapidly changing regions of the troposphere: Eastern and Southeastern Asia. The specific work presented incorporates measurements of both aerosol and related gas phase tropospheric measurements across different spectral, spatial, temporal, and passive/active sensors and properties, including: MODIS, MISR, OMI, CALIOP, and others. This new characterization reveals a trio of new information, including a time-invariant urban signal, slowly-time-varying new-urbanization signal, and a rapidly time-varying biomass burning signal. Additionally, due to the different chemical properties of the various species analyzed, analyzing the different spatial domains of the resulting products allows for further information in terms of the amounts of aerosols produced both through primary emissions as well as secondary processing. The end result is a new characterization, in space, time, and magnitude, of both anthropogenic and biomass burning aerosols. These results are then used to drive an advanced modeling system including aerosol chemistry, physics, optics, and transport, and employing an aerosol routine based on multi-modal and both externally mixed and core-shell mixing. The resulting characterization in space, time, and quantity is analyzed and compared against AERONET, NOAA, and other ground networks, with the results comparing consistently to or better than present approaches which set up net emissions separately from urban and biomass burning products. Scientifically, new source regions of emissions are identified, some of which were previously non-urbanized or found to not contain any fire hotspots. This new approach is consistent with the underlying economic and development pathways of expanding urban areas and rapid economic growth throughout Southeast and East Asia. Furthermore, findings are made which are consistent with many individual previous studies, such as the significance of vertical transport and subsequent long-range transport throughout the Northern Hemisphere, and the intra-annual and inter-annual variations in fires due to El-Nino. Such knowledge can allow us to better understand the consequences and impacts of the rapid ongoing changes occurring in these regions.

Skeleton-based tracing of curved fibers from 3D X-ray microtomographic imaging

NASA Astrophysics Data System (ADS)

Huang, Xiang; Wen, Donghui; Zhao, Yanwei; Wang, Qinghui; Zhou, Wei; Deng, Daxiang

A skeleton-based fiber tracing algorithm is described and applied on a specific fibrous material, porous metal fiber sintered sheet (PMFSS), featuring high porosity and curved fibers. The skeleton segments are firstly categorized according to the connectivity of the skeleton paths. Spurious segments like fiber bonds are detected making extensive use of the distance transform (DT) values. Single fibers are then traced and reconstructed by consecutively choosing the connecting skeleton segment pairs that show the most similar orientations and radius. Moreover, to reduce the misconnection due to the tracing orders, a multilevel tracing strategy is proposed. The fibrous network is finally reconstructed by dilating single fibers according to the DT values. Based on the traced single fibers, various morphology information regarding fiber length, radius, orientation, and tortuosity are quantitatively analyzed and compared with our previous results (Wang et al., 2013). Moreover, the number of bonds per fibers are firstly accessed. The methodology described in this paper can be expanded to other fibrous materials with adapted parameters.

Instrumental and statistical methods for the comparison of class evidence

NASA Astrophysics Data System (ADS)

Liszewski, Elisa Anne

Trace evidence is a major field within forensic science. Association of trace evidence samples can be problematic due to sample heterogeneity and a lack of quantitative criteria for comparing spectra or chromatograms. The aim of this study is to evaluate different types of instrumentation for their ability to discriminate among samples of various types of trace evidence. Chemometric analysis, including techniques such as Agglomerative Hierarchical Clustering, Principal Components Analysis, and Discriminant Analysis, was employed to evaluate instrumental data. First, automotive clear coats were analyzed by using microspectrophotometry to collect UV absorption data. In total, 71 samples were analyzed with classification accuracy of 91.61%. An external validation was performed, resulting in a prediction accuracy of 81.11%. Next, fiber dyes were analyzed using UV-Visible microspectrophotometry. While several physical characteristics of cotton fiber can be identified and compared, fiber color is considered to be an excellent source of variation, and thus was examined in this study. Twelve dyes were employed, some being visually indistinguishable. Several different analyses and comparisons were done, including an inter-laboratory comparison and external validations. Lastly, common plastic samples and other polymers were analyzed using pyrolysis-gas chromatography/mass spectrometry, and their pyrolysis products were then analyzed using multivariate statistics. The classification accuracy varied dependent upon the number of classes chosen, but the plastics were grouped based on composition. The polymers were used as an external validation and misclassifications occurred with chlorinated samples all being placed into the category containing PVC.

Local Semantic Trace: A Method to Analyze Very Small and Unstructured Texts for Propositional Knowledge

ERIC Educational Resources Information Center

Pirnay-Dummer, Pablo

2015-01-01

A local semantic trace is a certain quasi-propositional structure that can still be reconstructed from written content that is incomplete or does not follow a proper grammar. It can also retrace bits of knowledge from text containing only very few words, making the microstructure of these artifacts of knowledge externalization available for…

Observing and Understanding an On-Line Learning Activity: A Model-Based Approach for Activity Indicator Engineering

ERIC Educational Resources Information Center

Djouad, Tarek; Mille, Alain

2018-01-01

Although learning indicators are now properly studied and published, it is still very difficult to manage them freely within most distance learning platforms. As all activity indicators need to collect and analyze properly traces of the learning activity, we propose to use these traces as a starting point for a platform independent Trace…

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE--COMPENDIUM OF METHODS FOR ANALYSIS OF TRACE METALS AND PESTICIDES IN DIETARY SAMPLES USING TOTAL DIET STUDY PROCEDURES (FDA-COMPENDIUM)

EPA Science Inventory

This compendium contains seven SOPs developed by Food and Drug Administration (FDA) laboratories for methods of analyzing trace metals in dietary samples collected using Total Diet study procedures. The SOPs include the following: (1) Quality Control for Analysis of NHEXAS Food o...

Drill core major, trace and rare earth element anlayses from wells RN-17B and RN-30, Reykjanes, Iceland

DOE Data Explorer

Andrew Fowler

2015-04-01

Analytical results for X-ray fluorescence (XRF) and inductively coupled plasma mass spectrometry (ICP-MS) measurement of major, trace and rare earth elements in drill core from geothermal wells in Reykjanes, Iceland. Total Fe was analyzed as FeO, therefore is not included under the Fe2O3 column.

Drill cutting and core major, trace and rare earth element anlayses from wells RN-17B and RN-30, Reykjanes, Iceland

DOE Data Explorer

Andrew Fowler

2015-05-01

Analytical results for x-ray fluorescence (XRF) and Inductively Couple Plasma Mass Spectrometry (ICP-MS) measurement of major, trace and rare earth elements in drill cuttings from geothermal wells in Reykjanes, Iceland. Total Fe was analyzed as FeO, therefore is not included under the Fe2O3 column.

Selective hydrodechlorination of 1,2-dichloroethane catalyzed by trace Pd decorated Ag/Al2O3 catalysts prepared by galvanic replacement

NASA Astrophysics Data System (ADS)

Sun, Jingya; Han, Yuxiang; Fu, Heyun; Wan, Haiqin; Xu, Zhaoyi; Zheng, Shourong

2018-01-01

Ag catalysts decorated by trace Pd supported on γ-Al2O3 with different structure and chemical properties were prepared using a combined impregnation and galvanic replacement method. For comparison, monometallic Ag/γ-Al2O3 and Pd/γ-Al2O3 catalysts were prepared using the impregnation method. Gas-phase catalytic hydrodechlorination of 1,2-dichloroethane to ethylene was investigated on those catalysts. The structures and chemical compositions of bimetallic Pd-Ag particles in the catalysts were controlled by adjusting Pd replacement amount. The as-prepared catalysts were characterized by X-ray diffraction, transmission electron microscopy, UV-vis diffuse reflectance spectroscopy, X-ray photoelectron spectroscopy, and in-situ FTIR spectroscopy of CO adsorption. The results demonstrated that contiguous Pd sites dominated in the monometallic Pd/γ-Al2O3 catalyst, while Pd atoms were separately decorated on the surface of Ag particles in the bimetallic Pd-Ag/γ-Al2O3 catalysts when Pd replacement amount was below 0.30 wt.%. At Pd replacement amount of 0.30 wt.%, Pd ensembles with contiguous Pd sites developed in the bimetallic catalyst. Thus, monometallic Pd/γ-Al2O3 catalyst displayed negligible ethylene selectivity toward the catalytic hydrodechlorination of 1,2-dichloroethane, while bimetallic Pd-Ag/γ-Al2O3 catalyst with a Pd replacement amount of 0.13 wt.% exhibited 94.6% of ethylene selectivity. Furthermore, selectivity to incompletely dechlorinated byproduct chloroethylene decreased with Pd replacement amount, due to the enhanced decoration effect of Pd on large Ag ensembles. Findings in this work provide a promising bimetallic catalyst prepared by galvanic replacement for the selective catalytic hydrodechlorination of 1,2-dichloroethane.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; preparation procedure for aquatic biological material determined for trace metals

USGS Publications Warehouse

Hoffman, Gerald L.

1996-01-01

A method for the chemical preparation of tissue samples that are subsequently analyzed for 22 trace metals is described. The tissue-preparation procedure was tested with three National Institute of Standards and Technology biological standard reference materials and two National Water Quality Laboratory homogenized biological materials. A low-temperature (85 degrees Celsius) nitric acid digestion followed by the careful addition of hydrogen peroxide (30-percent solution) is used to decompose the biological material. The solutions are evaporated to incipient dryness, reconstituted with 5 percent nitric acid, and filtered. After filtration the solutions were diluted to a known volume and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), and cold vapor-atomic absorption spectrophotometry (CV-AAS). Many of the metals were determined by both ICP-MS and ICP-AES. This report does not provide a detailed description of the instrumental procedures and conditions used with the three types of instrumentation for the quantitation of trace metals determined in this study. Statistical data regarding recovery, accuracy, and precision for individual trace metals determined in the biological material tested are summarized.

Analysis of the Effect of Electron Density Perturbations Generated by Gravity Waves on HF Communication Links

NASA Astrophysics Data System (ADS)

Fagre, M.; Elias, A. G.; Chum, J.; Cabrera, M. A.

2017-12-01

In the present work, ray tracing of high frequency (HF) signals in ionospheric disturbed conditions is analyzed, particularly in the presence of electron density perturbations generated by gravity waves (GWs). The three-dimensional numerical ray tracing code by Jones and Stephenson, based on Hamilton's equations, which is commonly used to study radio propagation through the ionosphere, is used. An electron density perturbation model is implemented to this code based upon the consideration of atmospheric GWs generated at a height of 150 km in the thermosphere and propagating up into the ionosphere. The motion of the neutral gas at these altitudes induces disturbances in the background plasma which affects HF signals propagation. To obtain a realistic model of GWs in order to analyze the propagation and dispersion characteristics, a GW ray tracing method with kinematic viscosity and thermal diffusivity was applied. The IRI-2012, HWM14 and NRLMSISE-00 models were incorporated to assess electron density, wind velocities, neutral temperature and total mass density needed for the ray tracing codes. Preliminary results of gravity wave effects on ground range and reflection height are presented for low-mid latitude ionosphere.

Combined micro-droplet and thin-film-assisted pre-concentration of lead traces for on-line monitoring using anodic stripping voltammetry.

PubMed

Belostotsky, Inessa; Gridin, Vladimir V; Schechter, Israel; Yarnitzky, Chaim N

2003-02-01

An improved analytical method for airborne lead traces is reported. It is based on using a Venturi scrubber sampling device for simultaneous thin-film stripping and droplet entrapment of aerosol influxes. At least threefold enhancement of the lead-trace pre-concentration is achieved. The sampled traces are analyzed by square-wave anodic stripping voltammetry. The method was tested by a series of pilot experiments. These were performed using contaminant-controlled air intakes. Reproducible calibration plots were obtained. The data were validated by traditional analysis using filter sampling. LODs are comparable with the conventional techniques. The method was successfully applied to on-line and in situ environmental monitoring of lead.

[Remote sensing of atmospheric trace gas by airborne passive FTIR].

PubMed

Gao, Min-quang; Liu, Wen-qing; Zhang, Tian-shu; Liu, Jian-guo; Lu, Yi-huai; Wang, Ya-ping; Xu, Liang; Zhu, Jun; Chen, Jun

2006-12-01

The present article describes the details of aviatic measurement for remote sensing trace gases in atmosphere under various surface backgrounds with airborne passive FTIR. The passive down viewing and remote sensing technique used in the experiment is discussed. The method of acquiring atmospheric trace gases infrared characteristic spectra in complicated background and the algorithm of concentration retrieval are discussed. The concentrations of CO and N2O of boundary-layer atmosphere in experimental region below 1000 m are analyzed quantitatively. This measurement technique and the data analysis method, which does not require a previously measured background spectrum, allow fast and mobile remote detection and identification of atmosphere trace gas in large area, and also can be used for urgent monitoring of pollution accidental breakout.

Digital Geodata Traces--New Challenges for Geographic Education

ERIC Educational Resources Information Center

Hohnle, Steffen; Michel, Boris; Glasze, Georg; Uphues, Rainer

2013-01-01

Young people in modern societies consciously (e.g. Facebook) or unconsciously (e.g. some Google services) produce a vast amount of geodata. Using relational databases, private companies are capable of creating very precise profiles of the individual user and his/her spatial practices from this data. This almost inevitably prompts questions…

Speciation, Characterization, And Mobility Of As, Se and Hg In Flue Gas Desulphurization Residues

EPA Science Inventory

Flue gas from coal combustion contains significant amounts of volatile toxic trace elements such as arsenic (As), selenium (Se) and mercury (Hg). The capture of these elements in the flue gas desulphurization (FGD) scrubber unit has resulted in generation of a metal-laden residue...

Advancing Explosives Detection Capabilities: Vapor Detection

ScienceCinema

Atkinson, David

2018-05-11

A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

Reconnaissance geology of the Al Ba'ayith quadrangle, sheet 26/41 D, Kingdom of Saudi Arabia

USGS Publications Warehouse

Williams, P.L.; Simonds, F.W.; Turner, J.D.

1985-01-01

Gold-bearing quartz veins occur associated with small plutons of the Idah suite in the southeastern part of the quadrangle, and have been mined in the past. Ironstones, near Murran in the center of the quadrangle contain trace amounts of silver and gold.

Alternative technologies for water quality management

Treesearch

Mandla A. Tshabalala

2002-01-01

Cranberry growers are concerned about the quality of water discharged from cranberry bogs into receiving surface waters. These water discharges may contain traces of pesticides arising from herbicide, insecticide or fungicide applications. They may also contain excess phosphorus from fertilizer application. Some cranberry farms have holding ponds to reduce the amount...

Advancing Explosives Detection Capabilities: Vapor Detection

DOE Office of Scientific and Technical Information (OSTI.GOV)

Atkinson, David

2012-10-15

A new, PNNL-developed method provides direct, real-time detection of trace amounts of explosives such as RDX, PETN and C-4. The method selectively ionizes a sample before passing the sample through a mass spectrometer to detect explosive vapors. The method could be used at airports to improve aviation security.

Selenium cycling across soil-plant atmosphere interfaces: a critical review

USDA-ARS?s Scientific Manuscript database

Selenium (Se) is an essential element for humans and animals, which occurs ubiquitously in the environment. It is present in trace amounts in both organic and inorganic forms in marine and freshwater systems, soils, biomass, and in the atmosphere. Low Se levels in certain terrestrial environments ha...

POM-assisted electrochemical delignification and bleaching of chemical pulp

Treesearch

Helene Laroche; Mohini Sain; Carl Houtman; Claude Daneault

2001-01-01

A polyoxometalate-catalyzed electrochemical process has shown good selectivity in delignifying pulp. This breakthrough in redox catalysis shows promise for the development of a new environmentally benign technology for pulp bleaching. The electrochemical process, applied with a mildly alkaline electrolyte solution containing trace amounts of a vanadium-based...

Fate of the CHBrsub2O radical in air

NASA Technical Reports Server (NTRS)

Bayes, K. D.; Friedl, R. F.

2003-01-01

Trace amounts of bromoform in air have been photolyzed at 266 and 303 nm to form Br atoms and CHBr2 radicals. The Br concentration as a funtion of time is followed by resonance fluorescence. The CHBr2 radicals react with O2 in the air to form peroxy radicals.

Compounds that Inhibit Insect Host-Seeking Ability

USDA-ARS?s Scientific Manuscript database

Humans release hundreds of volatile compounds from their skin. Some of these compounds are used by mosquitoes and other insects to locate the host (kairomones) while a few compounds are found in trace amounts that tend to produce anosmia in these insects. The net result of this anosmic action on th...

Trace Norm Regularized CANDECOMP/PARAFAC Decomposition With Missing Data.

PubMed

Liu, Yuanyuan; Shang, Fanhua; Jiao, Licheng; Cheng, James; Cheng, Hong

2015-11-01

In recent years, low-rank tensor completion (LRTC) problems have received a significant amount of attention in computer vision, data mining, and signal processing. The existing trace norm minimization algorithms for iteratively solving LRTC problems involve multiple singular value decompositions of very large matrices at each iteration. Therefore, they suffer from high computational cost. In this paper, we propose a novel trace norm regularized CANDECOMP/PARAFAC decomposition (TNCP) method for simultaneous tensor decomposition and completion. We first formulate a factor matrix rank minimization model by deducing the relation between the rank of each factor matrix and the mode- n rank of a tensor. Then, we introduce a tractable relaxation of our rank function, and then achieve a convex combination problem of much smaller-scale matrix trace norm minimization. Finally, we develop an efficient algorithm based on alternating direction method of multipliers to solve our problem. The promising experimental results on synthetic and real-world data validate the effectiveness of our TNCP method. Moreover, TNCP is significantly faster than the state-of-the-art methods and scales to larger problems.

Paper based Flexible and Conformal SERS Substrate for Rapid Trace Detection on Real-world Surfaces

NASA Astrophysics Data System (ADS)

Singamaneni, Srikanth; Lee, Chang; Tian, Limei

2011-03-01

One of the important but often overlooked considerations in the design of surface enhanced Raman scattering (SERS) substrates for trace detection is the efficiency of sample collection. Conventional designs based on rigid substrates such as silicon, alumina, and glass resist conformal contact with the surface under investigation, making the sample collection inefficient. We demonstrate a novel SERS substrate based on common filter paper adsorbed with gold nanorods, which allows conformal contact with real-world surfaces, thus dramatically enhancing the sample collection efficiency compared to conventional rigid substrates. We demonstrate the detection of trace amounts of analyte (140 pg spread over 4 cm2) by simply swabbing the surface under investigation with the novel SERS substrate. The hierarchical fibrous structure of paper serves as a 3D vasculature for easy uptake and transport of the analytes to the electromagnetic hot spots in the paper. Simple yet highly efficient and cost effective SERS substrate demonstrated here brings SERS based trace detection closer to real-world applications. We acknowledge the financial support from Center for Materials Innovation at Washington University.

Gold nanochestnut arrays as ultra-sensitive SERS substrate for detecting trace pesticide residue.

PubMed

Geng, Fei; Zhao, Huaping; Fu, Qun; Mi, Yan; Miao, Likun; Li, Wei; Dong, Yulian; Wu, Minghong; Lei, Yong

2018-07-20

In comparison to conventional spectroscopic techniques based on chromatography, surface-enhanced Raman spectroscopy (SERS) enables the rapid identification and detection of trace pesticide residues present in trace amounts in the environment and foods. Herein, a facile approach to fabricate unique gold nanochestnuts (GNCs) as an ultra-sensitive SERS substrate for detecting trace pesticide residues has been developed based on anodic aluminum oxide (AAO) templates. The GNCs are synthesized through the galvanic replacement of Ag on the top of Ni nanorod arrays. The as-prepared GNCs have well-controlled structural parameters, and importantly have unique anisotropic morphologies that benefit the enhancement in SERS performance. As a result, rhodamine 6 G (R6G) can be efficiently detected with GNCs as the SERS substrate even with a concentration of only 10 -12 M, and the Raman enhancement factor reaches up to 5.4 × 10 9 at this concentration. Further SERS measurement of thiram indicates a remarkable SERS-active sensitivity of the as-prepared GNCs with a detection limit of thiram up to 10 -14 M. The GNCs also exhibit a high signal-to-noise ratio.

Trace-Element Analysis by Use of PIXE Technique on Agricultural Products

NASA Astrophysics Data System (ADS)

Takagi, A.; Yokoyama, R.; Makisaka, K.; Kisamori, K.; Kuwada, Y.; Nishimura, D.; Matsumiya, R.; Fujita, Y.; Mihara, M.; Matsuta, K.; Fukuda, M.

2009-10-01

In order to examine whether a trace-element analysis by PIXE (Particle Induced X-ray Emission) gives a clue to identify production area of agricultural products, we carried out a study on soy beans as an example. In the present study, a proton beam at the energy of 2.3MeV was provided by Van de Graaff accelerator at Osaka University. We used a Ge detector with Be window to measure X-ray spectra. We prepared sample soy beans from China, Thailand, Taiwan, and 7 different areas in Japan. As a result of PIXE analysis, 5 elements, potassium, iron, zinc, arsenic and rubidium, have been identified. There are clear differences in relative amount of trace-elements between samples from different international regions. Chinese beans contain much more Rb than the others, while there are significant differences in Fe and Zn between beans of Thailand and Taiwan. There are relatively smaller differences among Japanese beans. This result shows that trace-elements bring us some practical information of the region where the product grown.

An innovative method for nondestructive analysis of cast iron artifacts at Hopewell Furnace National Historic Site, Pennsylvania

USGS Publications Warehouse

Sloto, R.A.; Helmke, M.F.

2011-01-01

Iron ore containing elevated concentrations of trace metals was smelted at Hopewell Furnace during its 113 years of operation (1771-1883). For this study, we sampled iron ore, cast iron furnace products, slag, soil, groundwater, streamflow, and streambed sediment to determine the fate of trace metals released into the environment during the iron-smelting process. Standard techniques were used to sample and analyze all media except cast iron. We analyzed the trace-metal content of the cast iron using a portable X-ray fluorescence spectrometer, which provided rapid, on-site, nondestructive analyses for 23 elements. The artifacts analyzed included eight cast iron stoves, a footed pot, and a kettle in the Hopewell Furnace museum. We measured elevated concentrations of arsenic, copper, lead, and zinc in the cast iron. Lead concentrations as great as 3,150 parts per million were measured in the stoves. Cobalt was detectable but not quantifiable because of interference with iron. Our study found that arsenic, cobalt, and lead were not released to soil or slag, which could pose a significant health risk to visitors and employees. Instead, our study demonstrates these heavy metals remained with the cast iron and were removed from the site.

HF propagation results from the Metal Oxide Space Cloud (MOSC) experiment

NASA Astrophysics Data System (ADS)

Joshi, Dev; Groves, Keith M.; McNeil, William; Carrano, Charles; Caton, Ronald G.; Parris, Richard T.; Pederson, Todd R.; Cannon, Paul S.; Angling, Matthew; Jackson-Booth, Natasha

2017-06-01

With support from the NASA sounding rocket program, the Air Force Research Laboratory launched two sounding rockets in the Kwajalein Atoll, Marshall Islands in May 2013 known as the Metal Oxide Space Cloud experiment. The rockets released samarium metal vapor at preselected altitudes in the lower F region that ionized forming a plasma cloud. Data from Advanced Research Project Agency Long-range Tracking and Identification Radar incoherent scatter radar and high-frequency (HF) radio links have been analyzed to understand the impacts of the artificial ionization on radio wave propagation. The HF radio wave ray-tracing toolbox PHaRLAP along with ionospheric models constrained by electron density profiles measured with the ALTAIR radar have been used to successfully model the effects of the cloud on HF propagation. Up to three new propagation paths were created by the artificial plasma injections. Observations and modeling confirm that the small amounts of ionized material injected in the lower F region resulted in significant changes to the natural HF propagation environment.

Isolation and Identification of Three γ-Glutamyl Tripeptides and Their Putative Production Mechanism in Aged Garlic Extract.

PubMed

Nakamoto, Masashi; Fujii, Takuto; Matsutomo, Toshiaki; Kodera, Yukihiro

2018-03-21

We analyzed aged garlic extract (AGE) to understand its complex sulfur chemistry using post-column high-performance liquid chromatography with an iodoplatinate reagent and liquid chromatography high resolution mass spectrometry (LC-MS). We observed unidentified peaks of putative sulfur compounds. Three compounds were isolated and identified as γ-glutamyl-γ-glutamyl- S-methylcysteine, γ-glutamyl-γ-glutamyl- S-allylcysteine (GGSAC) and γ-glutamyl-γ-glutamyl- S-1-propenyl-cysteine (GGS1PC) by nuclear magnetic resonance and LC-MS analysis based on comparisons with chemically synthesized reference compounds. GGSAC and GGS1PC were novel compounds. Trace amounts of these compounds were detected in raw garlic, but the contents of these compounds increased during the aging process. Production of these compounds was inhibited using a γ-glutamyl transpeptidase (GGT) inhibitor in the model reaction mixtures. These findings suggest that γ-glutamyl tripeptides in AGE are produced by GGT during the aging process.

Concentration method for the spectrochemical determination of seventeen minor elements in natural water

USGS Publications Warehouse

Silvey, W.D.; Brennan, R.

1962-01-01

A method for the quantitative spectrochemical determination of microgram amounts of 17 minor elements in water is given. The chelating reagents 8-quinolinol, tannic acid, and thionalide are utilized to concentrate traces (1 to 500 ??g.) of aluminum, cobalt, chromium, copper, iron, gallium, germanium, manganese, nickel, titanium, vanadium, bismuth, lead, molybdenum, cadmium, zinc, and beryllium. Indium is added as a buffer, and palladium is used as an internal standard. The ashed oxides of these 17 metals are subsequently subjected to direct current arcing conditions during spectrum analysis. The method can be used to analyze waters with dissolved solids ranging from less than 100 to more than 100,000 p.p.m. There is no limiting concentration range for the determination of the heavy metals since any volume of sample can be used that will contain a heavy metal concentration within the analytical range of the method. Both the chemical and spectrographic procedures are described, and precision and accuracy data are given.

Research of stimulants and anabolic steroids in dietary supplements.

PubMed

Baume, N; Mahler, N; Kamber, M; Mangin, P; Saugy, M

2006-02-01

The purpose of this study was to analyze the composition of 103 dietary supplements bought on the internet. The supplements were dispatched in four different categories according to their announced contents [creatine, prohormones, "mental enhancers" and branched chain amino acids (BCAA)]. All the supplements were screened for the presence of stimulants and main anabolic steroids parent compounds. At the same time, the research was focused on the precursors and metabolites of testosterone and nandrolone. The study pointed out three products containing an anabolic steroid, metandienone, in a very high amount. The ingestion of such products induced a high quantity of metandienone metabolites in urines that would be considered as a positive antidoping test. The results have also shown that one creatine product and three "mental enhancers" contained traces of hormones or prohormones not claimed on the labels and 14 prohormone products contained substances other than those indicated by the manufacturer. The oral intake of the creatine product revealed the presence of the two main nandrolone metabolites (19-norandrosterone and 19-noretiocholanolone) in urine.

Application of a computerized vibroacoustic data bank for random vibration criteria development

NASA Technical Reports Server (NTRS)

Ferebee, R. C.

1982-01-01

A computerized data bank system was developed for utilization of large amounts of vibration and acoustic data to formulate component random vibration design and test criteria. This system consists of a computer, graphics tablets, and a dry silver hard copier which are all desk top type hardware and occupy minimal space. Currently, the data bank contains data from the Saturn 5 and Titan 3 flight and static test programs. The vibration and acoustic data are stored in the form of power spectral density and one third octave band plots over the frequency range from 20 to 2000 Hz. The data were stored by digitizing each spectral plot by tracing with the graphics tablet. The digitized data were statistically analyzed, and the resulting 97.5 percent confidence levels were stored on tape along with the appropriate structural parameters. Standard extrapolation procedures were programmed for prediction of component random vibration test criteria for new launch vehicle and payload configurations. A user's manual is included to guide potential users through the programs.

Copper and boron fixation in wood by pyrolytic resins.

PubMed

Mourant, Daniel; Yang, Dian-Qing; Lu, Xiao; Riedl, Bernard; Roy, Christian

2009-02-01

A phenol-formaldehyde (PF)-resin designed to penetrate wood and immobilize copper and boron in wood cells for protection against decay was investigated. The phenol portion of the PF-resin was partially substituted with pyrolysis oil derived from softwood bark. The objective was to reduce the environmental impact associated with the production of petroleum-borne phenol, as well as to improve the product economics. Leaching tests were conducted with three different formulas of resins containing 50%, 75% or 85% by weight of pyrolytic oil on a total phenol basis. The leachates were analyzed for the presence of copper by atomic absorption spectroscopy while inductively coupled plasma spectroscopy was used for boron detection. Copper leaching was reduced up to 18 times when comparing the treatments with and without the resin. Preservative leaching varied between wood species as well as between the resins containing different concentrations of pyrolytic oil. The organic leachates were measured using gas chromatography and mass spectroscopy. Trace amounts of organics, mostly acetic acid, were found in the leachates.

The monitoring of pesticides and alkylphenols in selected rivers in the State of Selangor, Malaysia.

PubMed

Tan, B L L; Mustafa, A M

2004-01-01

Alkylphenols and most pesticides, especially organochlorine pesticides are endocrine-disrupting chemicals and they usually mimic the female hormone, estrogen. Using these chemicals in our environment would eventually lead us to consume them somehow in the food web. Several rivers in the State of Selangor, Malaysia were selected to monitor the level of alkylphenols and pesticides contamination for several months. The compounds were extracted from the water samples using liquid-liquid extraction method with dichloromethane and ethyl acetate as the extracting solvents. The alkylphenols and pesticides were analyzed by selected ion monitoring (SIM) mode using the quadrapole detector in Shimadzu QP-5000 gas chromatograph-mass spectrometer (GCMS). Recovery of most alkylphenols and pesticides were in the range of 50% to 120%. Trace amounts of the compounds were detected in the river water samples, mainly in the range of parts per trillion. This technique of monitoring the levels of endocrine-disruptors in river water is consistent and cost effective.

Sequence of Tissue Responses in the Early Stages of Experimental Allergic Encephalomyelitis (EAE): Immunohistochemical, Light Microscopic, and Ultrastructural Observations in the Spinal Cord

NASA Technical Reports Server (NTRS)

DAmelio, Fernando E.; Smith, Marion E.; Eng, Lawrence F.

1990-01-01

Experimental allergic encephalomyelitis (EAE) was induced in adult Lewis rats with purified guinea pig CNS myelin and Freund's adjuvant. As soon as the very earliest clinical signs appeared the animals were perfused with fixatives and the spinal cord analyzed by electron microscopy, silver methods, and immunocytochemistry. Our findings suggest that in the early stages of EAE a sequence of events can be traced, although these events frequently overlap. The earliest morphological change appears to be astrocytic edema in both the cell body and processes. Increased amounts of glycogen particles and dispersion of glial filaments are prominent. These changes seem to occur just prior to the time when inflammatory cells begin to penetrate the capillary walls. Invasion of the neuropil mainly by macrophages and lymphocytes closely follows. Both macrophages and microglia seem to participate in phagocytosis of oligodendrocytes and myelin. Demyelination, however, is not a prominent feature at this early stage.

Systematic Destruction of Electronic Parts for Aid in Electronic Failure Analysis

NASA Technical Reports Server (NTRS)

Decker, S. E.; Rolin, T. D.; McManus, P. D.

2012-01-01

NASA analyzes electrical, electronic, and electromechanical (EEE) parts used in space vehicles to understand failure modes of these components. Operational amplifiers and transistors are two examples of EEE parts critical to NASA missions that can fail due to electrical overstress (EOS). EOS is the result of voltage or current over time conditions that exceeds a component s specification limit. The objective of this study was to provide known voltage pulses over well-defined time intervals to determine the type and extent of damage imparted to the device. The amount of current was not controlled but measured so that pulse energy was determined. The damage was ascertained electrically using curve trace plots and optically using various metallographic techniques. The resulting data can be used to build a database of physical evidence to compare to damaged components removed from flight avionics. The comparison will provide the avionics failure analyst necessary information about voltage and times that caused flight or test failures when no other electrical data is available.

Natural selection in the colloid world: active chiral spirals.

PubMed

Zhang, Jie; Granick, Steve

2016-10-06

We present a model system in which to study natural selection in the colloid world. In the assembly of active Janus particles into rotating pinwheels when mixed with trace amounts of homogeneous colloids in the presence of an AC electric field, broken symmetry in the rotation direction produces spiral, chiral shapes. Locked into a central rotation point by the centre particle, the spiral arms are found to trail rotation of the overall cluster. To achieve a steady state, the spiral arms undergo an evolutionary process to coordinate their motion. Because all the particles as segments of the pinwheel arms are self-propelled, asymmetric arm lengths are tolerated. Reconfiguration of these structures can happen in various ways and various mechanisms of this directed structural change are analyzed in detail. We introduce the concept of VIP (very important particles) to express that sustainability of active structures is most sensitive to only a few particles at strategic locations in the moving self-assembled structures.

Evaluation of aquifer environment under Hazaribagh leather processing zone of Dhaka city

NASA Astrophysics Data System (ADS)

Zahid, Anwar; Balke, K.-D.; Hassan, M. Qumrul; Flegr, Matthias

2006-07-01

Hazaribagh is a densely populated area of Dhaka city where about 185 leather processing industries have been operating and discharging solid and liquid wastes directly to the low-lying areas, river and natural canals without proper treatment. The area is covered by alluvial deposits of Holocene age and is underlain by Pleistocene Madhupur clay. The Dupi Tila Formation of Mio-Pliocene age underlain by this yellowish gray to brick red clay bed serves as the main water-bearing aquifer of Dhaka city. To assess the environmental degradation as well as the groundwater environment, major anions, cations and heavy metals of water samples, heavy metals and organic carbon content of sediment samples were analyzed in this study. Analyses of tannery effluent detect high concentration of Na+, Mg2+, Cl- and SO{4/2-} followed by Ca2+, NH{4/+} and K+ with remarkable contents of some trace elements, mainly Cr, Fe, Mn, S, Ni and Pb. Higher accumulations of Cr, Al and Fe are observed in topsoil samples with significant amounts of Mn, Zn, Ni and Cu. Concentrations of ions and all the investigated trace elements of sampled groundwater were within the maximum allowable limit for drinking water of the Department of Environment, Bangladesh (DoE), and World Health Organization (WHO). However, excessive concentrations of Cr, Pb, etc., have already been reported in the shallow groundwater (10-20 m) of the area. Due to excessive withdrawal the vulnerability of groundwater contamination in deeper parts cannot be avoided for the future.

Menthol and geraniol biotransformation and glycosylation capacity of Levisticum officinale hairy roots.

PubMed

Nunes, Inês S; Faria, Jorge M S; Figueiredo, A Cristina; Pedro, Luis G; Trindade, Helena; Barroso, José G

2009-03-01

The biotransformation capacity of Levisticum officinale W.D.J. Koch hairy root cultures was studied by evaluating the effect of the addition of 25 mg/L menthol or geraniol on morphology, growth, and volatiles production. L. officinale hairy root cultures were maintained for 7 weeks in SH medium, in darkness at 24 degrees C and 80 r.p.m., and the substrates were added 15 days after inoculation. Growth was evaluated by measuring fresh and dry weight and by using the dissimilation method. Volatiles composition was analyzed by GC and GC-MS. Hairy roots morphology and growth were not influenced by substrate addition. No new volatiles were detected after menthol addition and, as was also the case with the control cultures, volatiles of these hairy roots were dominated by (Z)-falcarinol (1-45%), N-octanal (3-8%), palmitic acid (3-10%), and (Z)-ligustilide (2-9%). The addition of geraniol induced the production of six new volatiles: nerol/citronellol/neral (traces-15%), alpha-terpineol (0.2-3%), linalool (0.1-1.2%), and geranyl acetate (traces-2%). The relative amounts of the substrates and some of their biotransformation products decreased during the course of the experiment. Following the addition of beta-glycosidase to the remaining distillation water, analysis of the extracted volatiles showed that lovage hairy roots were able to convert both substrates and their biotransformation products into glycosidic forms. GC:gas chromatography GC-MS:gas chromatography-mass spectrometry SH:Schenk and Hildebrandt (1972) culture medium.

Electrochemical quantum tunneling for electronic detection and characterization of biological toxins

NASA Astrophysics Data System (ADS)

Gupta, Chaitanya; Walker, Ross M.; Gharpuray, Rishi; Shulaker, Max M.; Zhang, Zhiyong; Javanmard, Mehdi; Davis, Ronald W.; Murmann, Boris; Howe, Roger T.

2012-06-01

This paper introduces a label-free, electronic biomolecular sensing platform for the detection and characterization of trace amounts of biological toxins within a complex background matrix. The mechanism for signal transduction is the electrostatic coupling of molecule bond vibrations to charge transport across an insulated electrode-electrolyte interface. The current resulting from the interface charge flow has long been regarded as an experimental artifact of little interest in the development of traditional charge based biosensors like the ISFET, and has been referred to in the literature as a "leakage current". However, we demonstrate by experimental measurements and theoretical modeling that this current has a component that arises from the rate-limiting transition of a quantum mechanical electronic relaxation event, wherein the electronic tunneling process between a hydrated proton in the electrolyte and the metallic electrode is closely coupled to the bond vibrations of molecular species in the electrolyte. Different strategies to minimize the effect of quantum decoherence in the quantized exchange of energy between the molecular vibrations and electron energy will be discussed, as well as the experimental implications of such strategies. Since the mechanism for the transduction of chemical information is purely electronic and does not require labels or tags or optical transduction, the proposed platform is scalable. Furthermore, it can achieve the chemical specificity typically associated with traditional micro-array or mass spectrometry-based platforms that are used currently to analyze complex biological fluids for trace levels of toxins or pathogen markers.

Real-time explosive particle detection using a cyclone particle concentrator.

PubMed

Hashimoto, Yuichiro; Nagano, Hisashi; Takada, Yasuaki; Kashima, Hideo; Sugaya, Masakazu; Terada, Koichi; Sakairi, Minoru

2014-06-30

There is a need for more rapid methods for the detection of explosive particles. We have developed a novel real-time analysis technique for explosive particles that uses a cyclone particle concentrator. This technique can analyze sample surfaces for the presence of particles from explosives such as TNT and RDX within 3 s, which is much faster than is possible by conventional methods. Particles are detached from the sample surface with air jet pulses, and then introduced into a cyclone particle concentrator with a high pumping speed of about 80 L/min. A vaporizer placed at the bottom of the cyclone particle concentrator immediately converts the particles into a vapor. The vapor is then ionized in the atmospheric pressure chemical ionization (APCI) source of a linear ion trap mass spectrometer. An online connection between the vaporizer and a mass spectrometer enables high-speed detection within a few seconds, compared with the conventional off-line heating method that takes more than 10 s to raise the temperature of a sample filter unit. Since the configuration enriched the number density of explosive particles by about 80 times compared with that without the concentrator, a sub-ng amount of TNT particles on a surface was detectable. The detection limit of our technique is comparable with that of an explosives trace detector using ion mobility spectrometry. The technique will be beneficial for trace detection in security applications, because it detects explosive particles on the surface more speedily than conventional methods. Copyright © 2014 John Wiley & Sons, Ltd.

Improved predictive modeling of white LEDs with accurate luminescence simulation and practical inputs with TracePro opto-mechanical design software

NASA Astrophysics Data System (ADS)

Tsao, Chao-hsi; Freniere, Edward R.; Smith, Linda

2009-02-01

The use of white LEDs for solid-state lighting to address applications in the automotive, architectural and general illumination markets is just emerging. LEDs promise greater energy efficiency and lower maintenance costs. However, there is a significant amount of design and cost optimization to be done while companies continue to improve semiconductor manufacturing processes and begin to apply more efficient and better color rendering luminescent materials such as phosphor and quantum dot nanomaterials. In the last decade, accurate and predictive opto-mechanical software modeling has enabled adherence to performance, consistency, cost, and aesthetic criteria without the cost and time associated with iterative hardware prototyping. More sophisticated models that include simulation of optical phenomenon, such as luminescence, promise to yield designs that are more predictive - giving design engineers and materials scientists more control over the design process to quickly reach optimum performance, manufacturability, and cost criteria. A design case study is presented where first, a phosphor formulation and excitation source are optimized for a white light. The phosphor formulation, the excitation source and other LED components are optically and mechanically modeled and ray traced. Finally, its performance is analyzed. A blue LED source is characterized by its relative spectral power distribution and angular intensity distribution. YAG:Ce phosphor is characterized by relative absorption, excitation and emission spectra, quantum efficiency and bulk absorption coefficient. Bulk scatter properties are characterized by wavelength dependent scatter coefficients, anisotropy and bulk absorption coefficient.

Incidence of mycoflora and mycotoxins in some edible fruits and seeds of forest origin.

PubMed

Singh, P K; Khan, S; Harsh, N; Pandey, R

2001-06-01

Twelve fungi namelyAlternaria alternata, Aspergillus flavus, A niger, A ochraceus, Actinomucor repens, Capnodoium spp., Curvularia lunata, Fusarium pallidoroseum, F solani, F verticillioides, Penicillium citrinum and Rhizopus stolonifer were recorded from samples ofAegle marmelos, Aesculus indica, Buchanania lanzan andPinus gerardiana. In case ofPrunus amygdalus only Rstolonifer was recorded. A significant variation in pattern of mycoflora incidence was observed in terms of source and season. Fungal infestation in most of the substrates was found to be highest during monsoon. Aflatoxins were the most common mycotoxins elaborated by different isolates ofA flavus obtained fromA marmelos, B lanzan andP gerardiana. The amount of aflatoxins produced by the toxigenic isolates ofA flavus was in the range of traces to 0.9-26.0 μg/ml inA marmelos, 0.8-17.5 μg/ml inP gerardiana and 0.65-13.2 μg/ml inB lanzan. The percentage toxigenicity was comparatively lower in the isolates of other mycotoxigenic fungi. Aflatoxins were detected almost in all the samples analyzed for mycotoxin contamination. However, traces of zearalenone were detected inA marmelos. The concentration of aflatoxin B1 was in the range of 0.13-0.75 μg/g inA marmelos, 0.09-0.60 μg/g inP gerardiana and 0.01-0.20 ug/g inB lanzan. Mycotoxins were not detected inAesculus indica andPrunus amygdalus.

Eddy covariance fluxes of the NO-NO2-O3 triad above a spruce forest canopy in south-eastern Germany.

NASA Astrophysics Data System (ADS)

Tsokankunku, A.; Zhu, Z.; Meixner, F. X.; Foken, T.; Andreae, M. O.

2009-04-01

We investigated the diel variability of the eddy covariance fluxes of the NO-NO2-O3 triad above a spruce forest canopy at the "Weidenbrunnen" research site (Fichtelgebirge, Germany). Measurements were part of the EGER project (ExchanGE processes in mountainous Regions), which focuses on the role of process interactions among the different scales of soil, in-canopy and atmospheric exchange processes of reactive and non-reactive trace gases and energy. The eddy covariance platform was at the top of a 32 m high tower (50˚ 08'31" N, 11˚ 52'1"E, elevation 755 m.a.s.l). The eddy covariance system consisted of a CSAT3 sonic anemometer and a high speed, high resolution NO-NO2two channel chemiluminescence analyzer (Ecophysics CLD 790 SR2). A solid-state blue-light photolytic converter was connected to the NO2 channel of the analyzer just behind the sample inlet. Ambient NO and NO2 mixing ratios were sampled via 52 m long tubes with the instrument itself located in a temperature-controlled container at the ground. The NO-NO2 analyzer was operated at 5 Hz. Additionally we measured eddy covariance fluxes of CO2 and H2O. An infrared absorption-based analyzer (LI-7000) was used to sample CO2 and H2O mixing ratios, and a fast solid-phase chemiluminescence ozone analyzer (GFAS) was deployed to measure O3 mixing ratios. All trace gas inlets were situated at 32.5 m, 20 cm below the path of the sonic anemometer. The 32m inlet of an independent NO, NO2, and O3 concentration profile measuring system was used as the calibration source for the fast ozone analyzer and the two channel NO-NO2chemiluminescence analyzer. Preliminary results show that NO and NO2advection plays a big role in the magnitude and direction of the fluxes at the site. The main source of the advection is a busy country road situated about 2 km west of the site. CO2 fluxes were also influenced by advection. Extended periods of stationarity usually occurred on Sundays when the amount of traffic was significantly lower. During the "golden days period" (29 June - 3 July 2008), there was mainly downward directed NO fluxes (within the margin of error). However there is also evidence of NO leaving the canopy in some instances. NO and NO2 fluxes ranged between +1.5 and -1.5 nmol m-2 s-1 (±45 ngNO m-2 s-1 and ±70 ngNO2 m-2 s-1).

Screening for trace explosives by AccuTOF™-DART®: an in-depth validation study.

PubMed

Sisco, Edward; Dake, Jeffrey; Bridge, Candice

2013-10-10

Ambient ionization mass spectrometry is finding increasing utility as a rapid analysis technique in a number of fields. In forensic science specifically, analysis of many types of samples, including drugs, explosives, inks, bank dye, and lotions, has been shown to be possible using these techniques [1]. This paper focuses on one type of ambient ionization mass spectrometry, Direct Analysis in Real Time Mass Spectrometry (DART-MS or DART), and its viability as a screening tool for trace explosives analysis. In order to assess viability, a validation study was completed which focused on the analysis of trace amounts of nitro and peroxide based explosives. Topics which were studied, and are discussed, include method optimization, reproducibility, sensitivity, development of a search library, discrimination of mixtures, and blind sampling. Advantages and disadvantages of this technique over other similar screening techniques are also discussed. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Removal and recovery of mercury(II) from hazardous wastes using 1-(2-thiazolylazo)-2-naphthol functionalized activated carbon as solid phase extractant.

PubMed

Starvin, A M; Rao, T Prasada

2004-09-10

As a part of removal of toxic heavy metals from hazardous wastes, solid phase extraction (SPE) of mercury(II) at trace and ultra trace levels was studied using 1-(2-thiazolylazo)-2-naphthol (TAN) functionalized activated carbon (AC). The SPE material removes traces of mercury(II) quantitatively in the pH range 6.0 +/- 0.2. Other parameters that influence quantitative recovery of mercury(II), viz. percent concentration of TAN in AC, amount of TAN-AC, preconcentration time and volume of aqueous phase were varied and optimized. The possible means of removal of Hg(II) from other metal ions that are likely to be present in the wastes of the chloroalkali industry is discussed. The potential of TAN-functionalized AC SPE material for decontaminating mercury from the brine sludge and cell house effluent of a chloralkali plant has been evaluated.

Collaborative Study for Analysis of High Resolution Infrared Atmospheric Spectra Between NASA Langley Research Center and the University of Denver

NASA Technical Reports Server (NTRS)

Goldman, A.

2002-01-01

The Langley-D.U. collaboration on the analysis of high resolultion infrared atmospheric spectra covered a number of important studies of trace gases identification and quantification from field spectra, and spectral line parameters analysis. The collaborative work included: 1) Quantification and monitoring of trace gases from ground-based spectra available from various locations and seasons and from balloon flights; 2) Identification and preliminary quantification of several isotopic species, including oxygen and Sulfur isotopes; 3) Search for new species on the available spectra, including the use of selective coadding of ground-based spectra for high signal to noise; 4) Update of spectroscopic line parameters, by combining laboratory and atmospheric spectra with theoretical spectroscopy methods; 5) Study of trends and correlations of atmosphere trace constituents; and 6) Algorithms developments, retrievals intercomparisons and automatization of the analysis of NDSC spectra, for both column amounts and vertical profiles.

Hydrogeochemical survey of groundwater for selected areas in the Arabian Shield and in cover rocks, Kingdom of Saudi Arabia

USGS Publications Warehouse

McHugh, John B.; Miller, W. Roger

1989-01-01

In the spring of 1984, a hydrogeochemical survey was conducted in the Kingdom of Saudi Arabia to test ground water as a sampling medium in exploration for mineral deposits. Eighty-one water samples (mostly from wells) were collected. The samples were analysed for the presence and concentration of major cations and anions, as well as a suite of trace elements. Most of the water samples contained high concentrations of dissolved salts. The majority of the samples showed no significant amounts of the trace elements. A few well-water samples contained moderately anomalous concentrations of zinc, molybdenum, and uranium. These anomalies could be due to salinity effects, contamination, or the proximity of mineral sources. This survey has established some baseline water-chemistry data, especially for the trace metals, which to date have not been reported in ground water in the Kingdom of Saudi Arabia.

Testing Linear Temporal Logic Formulae on Finite Execution Traces

NASA Technical Reports Server (NTRS)

Havelund, Klaus; Rosu, Grigore; Norvig, Peter (Technical Monitor)

2001-01-01

We present an algorithm for efficiently testing Linear Temporal Logic (LTL) formulae on finite execution traces. The standard models of LTL are infinite traces, reflecting the behavior of reactive and concurrent systems which conceptually may be continuously alive. In most past applications of LTL. theorem provers and model checkers have been used to formally prove that down-scaled models satisfy such LTL specifications. Our goal is instead to use LTL for up-scaled testing of real software applications. Such tests correspond to analyzing the conformance of finite traces against LTL formulae. We first describe what it means for a finite trace to satisfy an LTL property. We then suggest an optimized algorithm based on transforming LTL formulae. The work is done using the Maude rewriting system. which turns out to provide a perfect notation and an efficient rewriting engine for performing these experiments.

Benthic foraminifera as bio-indicators of trace element pollution in the heavily contaminated Santa Gilla lagoon (Cagliari, Italy).

PubMed

Frontalini, Fabrizio; Buosi, Carla; Da Pelo, Stefania; Coccioni, Rodolfo; Cherchi, Antonietta; Bucci, Carla

2009-06-01

In order to assess the response of benthic foraminifera to trace element pollution, a study of benthic foraminiferal assemblages was carried out into sediment samples collected from the Santa Gilla lagoon (Sardinia, Italy). The lagoon has been contaminated by industrial waste, mainly trace elements, as well as by agricultural and domestic effluent. The analysis of surficial sediment shows enrichment in trace elements, including Cr, Cu, Hg, Ni, Pb and Zn. Biotic and abiotic data, analyzed with multivariate techniques of statistical analysis, reveal a distinct separation of both the highly polluted and less polluted sampling sites. The innermost part of the lagoon, comprising the industrial complex at Macchiareddu, is exposed to a high load of trace elements which are probably enhanced by their accumulation in the finer sediment fraction. This area reveals lower diversity and higher percentages of abnormalities when compared to the outermost part of the lagoon.

TRACE ELEMENT ANALYSES OF URANIUM MATERIALS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beals, D; Charles Shick, C

The Savannah River National Laboratory (SRNL) has developed an analytical method to measure many trace elements in a variety of uranium materials at the high part-per-billion (ppb) to low part-per-million (ppm) levels using matrix removal and analysis by quadrapole ICP-MS. Over 35 elements were measured in uranium oxides, acetate, ore and metal. Replicate analyses of samples did provide precise results however none of the materials was certified for trace element content thus no measure of the accuracy could be made. The DOE New Brunswick Laboratory (NBL) does provide a Certified Reference Material (CRM) that has provisional values for a seriesmore » of trace elements. The NBL CRM were purchased and analyzed to determine the accuracy of the method for the analysis of trace elements in uranium oxide. These results are presented and discussed in the following paper.« less

Sea Slugs, Subliminal Pictures, and Vegetative State Patients: Boundaries of Consciousness in Classical Conditioning

PubMed Central

Bekinschtein, Tristan A.; Peeters, Moos; Shalom, Diego; Sigman, Mariano

2011-01-01

Classical (trace) conditioning is a specific variant of associative learning in which a neutral stimulus leads to the subsequent prediction of an emotionally charged or noxious stimulus after a temporal gap. When conditioning is concurrent with a distraction task, only participants who can report the relationship (the contingency) between stimuli explicitly show associative learning. This suggests that consciousness is a prerequisite for trace conditioning. We review and question three main controversies concerning this view. Firstly, virtually all animals, even invertebrate sea slugs, show this type of learning; secondly, unconsciously perceived stimuli may elicit trace conditioning; and thirdly, some vegetative state patients show trace learning. We discuss and analyze these seemingly contradictory arguments to find the theoretical boundaries of consciousness in classical conditioning. We conclude that trace conditioning remains one of the best measures to test conscious processing in the absence of explicit reports. PMID:22164148

WGA-Alexa conjugates for axonal tracing

PubMed Central

Levy, Sabrina L.; White, Joshua J.; Lackey, Elizabeth P.; Schwartz, Lindsey; Sillitoe, Roy V.

2017-01-01

Anatomical labeling approaches are essential for understanding brain organization. Among these approaches are various methods of performing tract tracing. However, a major hurdle to overcome when marking neurons in vivo is visibility. Poor visibility makes it challenging to image a desired neuronal pathway so that it can be easily differentiated from a closely neighboring pathway. As a result, it becomes impossible to analyze individual projections or their connections. The tracer that is chosen for a given purpose has a major influence on the quality of the tracing. Here, we describe the wheat germ agglutinin (WGA) tracer conjugated to Alexa fluorophores for reliable high-resolution tracing of central nervous system projections. Using the mouse cerebellum as a model system, we implement WGA-Alexa tracing for marking and mapping neural circuits that control motor function. We also show its utility for marking localized regions of the cerebellum after performing single-unit extracellular recordings in vivo. PMID:28398642

A mechanism for efficient debugging of parallel programs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, B.P.; Choi, J.D.

1988-01-01

This paper addresses the design and implementation of an integrated debugging system for parallel programs running on shared memory multi-processors (SMMP). The authors describe the use of flowback analysis to provide information on causal relationships between events in a program's execution without re-executing the program for debugging. The authors introduce a mechanism called incremental tracing that, by using semantic analyses of the debugged program, makes the flowback analysis practical with only a small amount of trace generated during execution. The extend flowback analysis to apply to parallel programs and describe a method to detect race conditions in the interactions ofmore » the co-operating processes.« less

On-site Determination of Trace Arsenic by Reflection-Absorption Colorimetry of Molybdenum Blue Collected on a Membrane Filter.

PubMed

Hasegawa, Yuya; Suzuki, Yasutada; Kawakubo, Susumu

2017-01-01

An on-site determination method for trace arsenic has been developed by collecting it as molybdenum blue (MB) in the presence of tetradecyldimethylbenzylammonium chloride on a mixed cellulose ester membrane filter and by measuring reflection absorbance (RA) of MB on the filter using a laboratory-made palm-top size reflection-absorbance colorimeter with a red light-emitting diode. The value of RA was proportional to the amount of arsenic up to 0.5 μg with a detection limit of 0.01 μg. The proposed method was successfully applied to soil extract and hot-spring water samples.

Mesoporous Silica Nanoparticles as an Adsorbent for Preconcentration and Determination of Trace Amount of Nickel in Environmental Samples by Atom Trap Flame Atomic Absorption Spectrometry

NASA Astrophysics Data System (ADS)

Shirkhanloo, H.; Falahnejad, M.; Zavvar Mousavi, H.

2016-01-01

A rapid enrichment method based on solid-phase extraction (SPE) has been established for preconcentration and separation of trace Ni(II) ions in water samples prior to their determination by atom trap flame atomic absorption spectrometry. A column filled with bulky NH2-UVM7 was used as the novel adsorbent. Under optimal conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were 3-92 μg/L, 0.8 μg/L, and 100, respectively. The validity of the method was checked by the standard reference material.

Derivatization in gas chromatographic determination of phenol and aniline traces in aqueous media

NASA Astrophysics Data System (ADS)

Gruzdev, I. V.; Zenkevich, I. G.; Kondratenok, B. M.

2015-06-01

Substituted anilines and phenols are the most common hydrophilic organic environmental toxicants. The principles of gas chromatographic determination of trace amounts of these compounds in aqueous media at concentrations <=0.1 μg litre-1 based on synthesis of their derivatives (derivatization) directly in the aqueous phase are considered. Conversion of relatively hydrophilic analytes into more hydrophobic derivatives makes it possible to achieve such low detection limits and optimize the protocols of extractive preconcentration and selective chromatographic detection. Among the known reactions, this condition is best met by electrophilic halogenation of compounds at the aromatic moiety. The bibliography includes 177 references.

The global consequences of increasing tropospheric ozone concentrations

NASA Technical Reports Server (NTRS)

Fishman, Jack

1989-01-01

Recent analyses of long term records of tropospheric ozone measurements in the Northern Hemisphere suggest that it is increasing at a rate of 1 to 2 percent per year. Because of this, it is argued that the amount of atmospheric warming due to increasing tropospheric ozone is comparable to, or possibly even greater than, the amount of warming due to the increase of carbon dioxide. Unlike all other climatically important trace gases, ozone is toxic, and increases in its concentration will result in serious environmental damage, as well as impairment of human health.

Impact of trace metal concentrations on coccolithophore growth and morphology: species-specific responses in past and present ocean

NASA Astrophysics Data System (ADS)

Faucher, Giulia; Hoffmann, Linn; Bach, Lennart Thomas; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

2017-04-01

The Cretaceous witnessed intervals of profound perturbation named "Oceanic Anoxic Events (OAEs)" characterized by volcanic injection of large amounts of CO2, ocean anoxia, eutrophication, and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a number of nannofossil species. To detect the cause/s of such changes in the fossil record is challenging. Evidence of a correspondence between intervals of high trace metals concentrations and nannofossil dwarfism may be suggestive for a negative effect of these elements on nannoplankton biocalcification process. In order to verify the hypothesis that anomalously high quantities of essential and/or toxic metals were the cause of coccolith dwarfism, we explored the toxicities of a mixture of trace metals on four living coccolithophores species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The trace metals tested were chosen based upon concentration peaks identified in the geological record and upon known trace metal interaction with living coccolithophores algae. Our results demonstrate a species-specific response to trace metal enrichment in living coccolithophores: E. huxleyi, G. oceanica and C. pelagicus showed a decrease in their growth rate with progressively and exponentially increased trace metal concentrations, while P. carterae is unresponsive to trace metal content. Furthermore, E. huxleyi, G. oceanica and C. pelagicus evidenced a decrease in the cell diameter. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccolith of G. oceanica showed a decrease in size only at the highest trace metal concentrations tested. P. carterae size was unresponsive for changing trace metal concentration. Our results on living coccolithophore algae, demonstrate that elevated trace metal concentrations not only affect growth but also coccolith size and/or weight and that there are large differences between different species. These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions. Following the laboratory experiment results, elevated trace metal conditions in the past oceans could have caused at least part of the observed morphological changes detected during some Mesozoic OAEs.

Silurian trace fossils in carbonate turbidites from the Alexander Arc of southeastern Alaska

DOE Office of Scientific and Technical Information (OSTI.GOV)

Soja, C.M.

Early to Late Silurian (Wenlock-Ludlow) body and trace fossils from the Heceta Formation are preserved in the oldest widespread carbonates in the Alexander terrane of southeastern Alaska. They represent the earliest shelly benthos to inhabit a diversity of marine environments and are important indicators of the early stages in benthic community development within this ancient island arc. The trace fossils are significant because they add to a small but growing body of knowledge about ichnofaunas in deep-water Paleozoic carbonates. Proximal to medial carbonate turbidites yield a low-diversity suite of trace fossils that comprises five distinct types of biogenic structures. Beddingmore » planes reveal simple epichnial burrows (Planolites), cross-cutting burrows (Fucusopsis), and tiny cylindrical burrows. These and other casts, including chondrites( )-like burrow clusters, represent the feeding activities (fodinichnia) of preturbidite animals. Hypichnial burrows and rare endichnial traces reflect the activities of postturbidite animals. Broken and offset traces indicate that infaunal biota commenced burrowing before slumping and subsequent soft-sediment deformation. The abundance and density of trace fossils increases offshore in the medial turbidites associated with a decrease in the size and amount of coarse particles and with an increase in mud and preserved organic material. Although diversity levels are similar in the proximal and medial turbidite facies, they are much lower than in Paleozoic siliciclastic turbidites. This may reflect unfavorable environmental conditions for infaunal biota or paleobiogeographic isolation of the Alexander terrane during the Silurian. A greater use of trace fossils in terrane analysis will help to resolve this issue and should provide new data for reconstructing the paleogeography of circum-Pacific terranes.« less

Optimizing detector geometry for trace element mapping by X-ray fluorescence.

PubMed

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris; Kirz, Janos; Vogt, Stefan

2015-05-01

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersive detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples. Copyright © 2015. Published by Elsevier B.V.

Optimizing detector geometry for trace element mapping by X-ray fluorescence

PubMed Central

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris; Kirz, Janos; Vogt, Stefan

2016-01-01

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersive detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples. PMID:25600825

Optimizing detector geometry for trace element mapping by X-ray fluorescence

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sun, Yue; Gleber, Sophie-Charlotte; Jacobsen, Chris

Trace metals play critical roles in a variety of systems, ranging from cells to photovoltaics. X-Ray Fluorescence (XRF) microscopy using X-ray excitation provides one of the highest sensitivities available for imaging the distribution of trace metals at sub-100 nm resolution. With the growing availability and increasing performance of synchrotron light source based instruments and X-ray nanofocusing optics, and with improvements in energy-dispersive XRF detectors, what are the factors that limit trace element detectability? To address this question, we describe an analytical model for the total signal incident on XRF detectors with various geometries, including the spectral response of energy dispersivemore » detectors. This model agrees well with experimentally recorded X-ray fluorescence spectra, and involves much shorter calculation times than with Monte Carlo simulations. With such a model, one can estimate the signal when a trace element is illuminated with an X-ray beam, and when just the surrounding non-fluorescent material is illuminated. From this signal difference, a contrast parameter can be calculated and this can in turn be used to calculate the signal-to-noise ratio (S/N) for detecting a certain elemental concentration. We apply this model to the detection of trace amounts of zinc in biological materials, and to the detection of small quantities of arsenic in semiconductors. We conclude that increased detector collection solid angle is (nearly) always advantageous even when considering the scattered signal. However, given the choice between a smaller detector at 90° to the beam versus a larger detector at 180° (in a backscatter-like geometry), the 90° detector is better for trace element detection in thick samples, while the larger detector in 180° geometry is better suited to trace element detection in thin samples.« less

Do trace metals (chromium, copper, and nickel) influence toxicity of diesel fuel for free-living marine nematodes?

PubMed

Hedfi, Amor; Boufahja, Fehmi; Ben Ali, Manel; Aïssa, Patricia; Mahmoudi, Ezzeddine; Beyrem, Hamouda

2013-06-01

The objective of this study was to test the hypotheses that (1) free-living marine nematodes respond in a differential way to diesel fuel if it is combined with three trace metals (chromium, copper, and nickel) used as smoke suppressants and that (2) the magnitude of toxicity of diesel fuel differs according to the level of trace metal mixture added. Nematodes from Sidi Salem beach (Tunisia) were subjected separately for 30 days to three doses of diesel fuel and three others of a trace metals mixture. Simultaneously, low-dose diesel was combined with three amounts of a trace metal mixture. Results from univariate and multivariate methods of data evaluation generally support our initial hypothesis that nematode assemblages exhibit various characteristic changes when exposed to different types of disturbances; the low dose of diesel fuel, discernibly non-toxic alone, became toxic when trace metals were added. For all types of treatments, biological disturbance caused severe specific changes in assemblage structure. For diesel fuel-treated microcosms, Marylynnia bellula and Chromaspirinia pontica were the best positive indicative species; their remarkable presence in given ecosystem may predict unsafe seafood. The powerful toxicity of the combination between diesel fuel and trace metals was expressed with only negative bioindicators, namely Trichotheristus mirabilis, Pomponema multipapillatum, Ditlevsenella murmanica, Desmodora longiseta, and Bathylaimus capacosus. Assemblages with high abundances of these species should be an index of healthy seafood. When nematodes were exposed to only trace metals, their response looks special with a distinction of a different list of indicative species; the high presence of seven species (T. mirabilis, P. multipapillatum, Leptonemella aphanothecae, D. murmanica, Viscosia cobbi, Gammanema conicauda, and Viscosia glabra) could indicate a good quality of seafood and that of another species (Oncholaimellus mediterraneus) appeared an index of the opposite situation.

Impact of trace metal concentrations on coccolithophore growth and morphology: laboratory simulations of Cretaceous stress

NASA Astrophysics Data System (ADS)

Faucher, Giulia; Hoffmann, Linn; Bach, Lennart T.; Bottini, Cinzia; Erba, Elisabetta; Riebesell, Ulf

2017-07-01

The Cretaceous ocean witnessed intervals of profound perturbations such as volcanic input of large amounts of CO2, anoxia, eutrophication and introduction of biologically relevant metals. Some of these extreme events were characterized by size reduction and/or morphological changes of a few calcareous nannofossil species. The correspondence between intervals of high trace metal concentrations and coccolith dwarfism suggests a negative effect of these elements on nannoplankton biocalcification processes in past oceans. In order to test this hypothesis, we explored the potential effect of a mixture of trace metals on growth and morphology of four living coccolithophore species, namely Emiliania huxleyi, Gephyrocapsa oceanica, Pleurochrysis carterae and Coccolithus pelagicus. The phylogenetic history of coccolithophores shows that the selected living species are linked to Mesozoic species showing dwarfism under excess metal concentrations. The trace metals tested were chosen to simulate the environmental stress identified in the geological record and upon known trace metal interactions with living coccolithophore algae.Our laboratory experiments demonstrated that elevated trace metal concentrations, similarly to the fossil record, affect coccolithophore algae size and/or weight. Smaller coccoliths were detected in E. huxleyi and C. pelagicus, while coccoliths of G. oceanica showed a decrease in size only at the highest trace metal concentrations. P. carterae coccolith size was unresponsive to changing trace metal concentrations. These differences among species allow discriminating the most- (P. carterae), intermediate- (E. huxleyi and G. oceanica) and least-tolerant (C. pelagicus) taxa. The fossil record and the experimental results converge on a selective response of coccolithophores to metal availability.These species-specific differences must be considered before morphological features of coccoliths are used to reconstruct paleo-chemical conditions.

Ar39 Detection at the 10-16 Isotopic Abundance Level with Atom Trap Trace Analysis

NASA Astrophysics Data System (ADS)

Jiang, W.; Williams, W.; Bailey, K.; Davis, A. M.; Hu, S.-M.; Lu, Z.-T.; O'Connor, T. P.; Purtschert, R.; Sturchio, N. C.; Sun, Y. R.; Mueller, P.

2011-03-01

Atom trap trace analysis, a laser-based atom counting method, has been applied to analyze atmospheric Ar39 (half-life=269yr), a cosmogenic isotope with an isotopic abundance of 8×10-16. In addition to the superior selectivity demonstrated in this work, the counting rate and efficiency of atom trap trace analysis have been improved by 2 orders of magnitude over prior results. The significant applications of this new analytical capability lie in radioisotope dating of ice and water samples and in the development of dark matter detectors.

Application of RFID in the area of agricultural products quality traceability and tracking and the anti-collision algorithm

NASA Astrophysics Data System (ADS)

Wang, Zu-liang; Zhang, Ting; Xie, Shi-yang

2017-01-01

In order to improve the agricultural tracing efficiency and reduce tracking and monitoring cost, agricultural products quality tracking and tracing based on Radio-Frequency Identification(RFID) technology is studied, then tracing and tracking model is set up. Three-layer structure model is established to realize the high quality of agricultural products traceability and tracking. To solve the collision problems between multiple RFID tags and improve the identification efficiency a new reservation slot allocation mechanism is proposed. And then we analyze and optimize the parameter by numerical simulation method.

Assessing trace element diffusion models in fossil and sub-fossil bone

NASA Astrophysics Data System (ADS)

Suarez, C. A.; Kohn, M. J.

2012-12-01

Three different diffusion models have been proposed to explain trace element uptake during fossilization of bone: diffusion-adsorption (DA), diffusion-recrystallization (DR), and double-medium diffusion (DMD). Theoretically, differences in trace element profiles, particularly the rare earth elements (REE) and U, can discriminate among these possibilities. In this study, we tested which model best explains natural samples by analyzing trace element profiles in natural bone using laser-ablation inductively-coupled plasma mass spectrometry (LA-ICP-MS). Fossil bones ranging in age from a few ka to over 100 Ma were analyzed along traverses from the outer cortical edge to the inner marrow cavity margin. Forty major, minor and trace elements were analyzed, notably Ca, P, transition metals, Sr, Ba, REE, U, Th and Pb. Spatial and analytical resolutions were ~10 μm and ~100 ppb respectively. Many specimens show commonly observed exponential decreases in REE from the outer edge and marrow cavity, with relatively homogeneous U distributions. Yet, most significantly, specimens from American Falls (last interglacial) and Duck Point (last glacial maximum) show distinctive U plateaus adjacent to the outer and inner cortical bone margins. Whereas exponential profiles can be produced by different uptake processes, such plateaus are diagnostic of a DR mechanism. Our work is consistent with recent investigation of trace element diffusivities in modern fresh and deproteinated bone. These studies show similar diffusion rates for REE and U, so the profound disparity in U vs. REE profiles in most fossils cannot result solely from differences in volume diffusion within the context of DA and DMD. Rather, as a recrystallization front propagates into bone, the bone appears to encode changing soil water compositions with earlier vs. later compositions reflected in the bone margin vs. interior. Soil water U concentrations apparently remain nearly fixed during fossilization, whereas REE are rapidly stripped from the surrounding matrix, leading to nearly homogeneous U vs. steep REE profiles. However in our Pleistocene bones (American Falls and Duck Point), changes to U concentrations on the bone margin reveal more complex changes to boundary compositions, and eliminate both DA and DMD (alone) as the dominant mechanisms of trace element uptake. Our work reconciles disparate zoning patterns observed in fossil bone, and simplifies interpretations of soil or sediment water chemistry, but complicates U-series dating of fossils.

Nanoporous impedemetric biosensor for detection of trace atrazine from water samples.

PubMed

Pichetsurnthorn, Pie; Vattipalli, Krishna; Prasad, Shalini

2012-02-15

Trace contamination of ground water sources has been a problem ever since the introduction of high-soil-mobility pesticides, one such example is atrazine. In this paper we present a novel nanoporous portable bio-sensing device that can identify trace contamination of atrazine through a label-free assay. We have designed a pesticide sensor comprising of a nanoporous alumina membrane integrated with printed circuit board platform. Nanoporous alumina in the biosensor device generates a high density array of nanoscale confined spaces. By leveraging the size based immobilization of atrazine small molecules we have designed electrochemical impedance spectroscopy based biosensor to detect trace amounts of atrazine. We have calibrated the sensor using phosphate buffered saline and demonstrated trace detection from river and bottled drinking water samples. The limit of detection in all the three cases was in the femtogram/mL (fg/mL) (parts-per-trillion) regime with a dynamic range of detection spanning from 10 fg/mL to 1 ng/mL (0.01 ppt to 1 ppm). The selectivity of the device was tested using a competing pesticide; malathion and selectivity in detection was observed in the fg/mL regime in all the three cases. Copyright © 2011 Elsevier B.V. All rights reserved.

Vitamin and trace element supplementation in grazing dairy ewe during the dry season: effect on milk yield, composition, and clotting aptitude.

PubMed

Tufarelli, Vincenzo; Petrera, F; Khan, R U; Laudadio, Vito

2011-06-01

A study was carried out to evaluate the influence of vitamin and trace mineral supplementation on milk production and composition in grazing dairy ewes during the dry season. Ewes (n = 50) were assigned at weaning to blocks and treatments. Ewes were daily conducted (8 h/day) on a pasture based on Italian ryegrass (Lolium multiflorum). At fold, ewes received a basal diet composed by ad libitum oat hay and a definite amount of a pelleted concentrate. Dietary treatments included: (1) the control concentrate containing background of vitamin and trace mineral only, and (2) the experimental concentrate containing the premix supplement (10 g/kg of dry matter). Vitamin and trace mineral supplementation did not affect ewes' body weight. Milk, fat- and protein-corrected milk, fat percentage, and clotting properties were improved in ewes fed supplemented concentrate. There was a week × treatment interaction (P < 0.05) for yield of milk and corrected milk that was greatest at peak production in ewes fed the premix. Our findings indicate that in grazing dairy ewe, the dietary vitamin and trace mineral supplementation during dry season led to an increase of milk production and quality, with positive improvement in milk clotting aptitude.

Examination of the Behavior of Bismuth in Shallow-Level Hydrothermal Ore Systems: Constraints Based on Hydrothermal Experiments at 800°C and 100 MPa

NASA Astrophysics Data System (ADS)

Wilmot, M. S.; Candela, P. A.; Piccoli, P. M.; Simon, A. C.; McDonough, W. F.

2006-05-01

The partitioning of ore metals between melt and crystals affects the concentrations of these metals in an evolving ore fluid, and therefore the efficiency of their removal from the magma by hydrothermal processes. Some porphyry-type W-Mo deposits contain recoverable amounts of Bi, whereas others contain only trace amounts. In order to determine the magmatic controls on the ratio of Bi to other commodities in these and other deposits, we examined the partitioning behavior of bismuth between melt, minerals and aqueous phases. Hydrothermal experiments were performed by using externally heated cold seal vessels and employing a double capsule technique. Experiments contained 40 mg of Bishop Tuff glass (SiO2 = 74% ) and 40 mg of either magnetite or pyrrhotite. Bi was added as elemental Bi (< 1 mg). Two different aqueous solutions were used. Initially, the added aqueous phase comprised the solutes HCl, KCl and NaCl in a molar1:1:1 ratio, with a bulk salinity of 10 wt % NaCl eq. The aqueous phase for later experiments contained only the solutes KCl and NaCl in a 1:1 molar ratio. Pre-fractured quartz was added to the experiments to trap fluid inclusions at run PTX conditions. Experiments were performed in Au or Pt capsules held inside Rene 41 cold-seal vessels at 800°C and 100 MPa for durations of up to 36 hours. Analytical data have been collected from the run product solids by using an electron probe microanalyzer (major and trace elements) and laser ablation inductively coupled plasma mass spectrometry (trace elements). Bi in Mt is found in concentrations up to 100 ppm, with higher concentrations in runs where Po decomposed to form magnetite. The Bi concentration in the glass ranges up to 100 ppm. In the Po-bearing runs, data were only collected from Po grains in the experiments containing the HCl-free aqueous solution (the Po grains in the other experiments were too small to analyze). Pyrrhotite contained 10-20 ppm Bi, whereas the glass contained 5-10 ppm. Preliminary Nernst- type partition coefficients for Bi between Mt and melt and Po and melt are approximately 5 and 2, respectively. These data reveal that Bi is only slightly compatible in Mt and Po, and that the Po/melt partition coefficient for Bi is much lower than for Cu, Ag and Au, and is comparable to Mn and Zn. Additional experiments are in progress to more compare the partitioning of Bi with that of W and Mo.

Analysis of trace halocarbon contaminants in ultra high purity helium

NASA Technical Reports Server (NTRS)

Fewell, Larry L.

1994-01-01

This study describes the analysis of ultra high purity helium. Purification studies were conducted and containment removal was effected by the utilization of solid adsorbent purge-trap systems at cryogenic temperatures. Volatile organic compounds in ultra high purity helium were adsorbed on a solid adsorbent-cryogenic trap, and thermally desorbed trace halocarbon and other contaminants were analyzed by combined gas chromatography-mass spectrometry.

Environmental impact of volcanic emissions at Nyiragongo (DRC)

NASA Astrophysics Data System (ADS)

Scaglione, Sarah; Calabrese, Sergio; Bobrowski, Nicole; Giuffrida, Giovanni; D'Alessandro, Walter; Brusca, Lorenzo; Bellomo, Sergio; Liotta, Marcello; Minani, Abel; Shamavu, Patient; Pandolfo, Francesco; Tedesco, Dario

2015-04-01

The large amount of trace elements emitted from volcanoes has a strong impact on the close surrounding areas. Nyiragongo Volcano (Democratic Republic of Congo) belongs to the Virunga volcanic chain and is one of the most active volcanoes in Africa. It is characterized by the presence of an active and permanent lava lake with a persistent degassing activity. During a field trip in October-November 2014, we investigated the impact of the volcanogenic deposition in the surrounding of the crater by using different sampling techniques. Rain-gauges were used to collect atmospheric bulk deposition. Active and passive biomonitoring techniques (moss-bags and leaves of endemic plants - Senecio spp. and Amarantus viridis) were applied in order to investigate the dispersion of volcanic gas and particle emissions. We collected daily rainfall events at various sites: seven samples at the crater rim (on the western and southern side, 3470 m a.s.l.), one sample at the village Kibati (south-eastern flank, 1955 m a.s.l.) located at the up-wind base of the volcano (representing the local background), and four samples in the city of Goma (southern flank of the volcano, 1500 m a.s.l.). In order to implement our dataset, several samples of rainwater, amaranth leaves, soils and atmospheric depositions (by moss-bags and filters exposition) were sampled after the field trip by the researchers of the Goma Volcano Observatory (GVO). Since, the prevalent wind direction was blowing the plume in westerly or southwesterly direction, we exposed the raingauges in the villages of Bulengo, Rusayo and Kingi in the southwestern side respect to the volcano, and Kibumba in the southesthern as a background site, at increasing distance from the rim. In the same sites, leaves of Amarantus viridis, which is one of the principal vegetables eaten by the local population, were collected. Rainwater, moss bags and plant samples were analyzed for major and trace elements by IC, ICP-OES and ICP-MS. The large amount of emitted volcanic gases and particles includes sulfur, halogens and trace elements, that strongly affect rainwater chemistry and have a widespread impact on the surrounding vegetation of the volcano. Indeed, rainwater samples collected at the rim of the crater have low pH values (≈ 3), high concentration of F- and Cl- (up to 12.0 and 12.8 mg/l, respectively) and dissolved toxic elements (such as Al, As, Cd, Cu, Fe and Pb), whereas samples from the city of Goma have pH values above 5 and the same elements show orders of magnitude lower concentrations. The biomonitoring results highlight that bioaccumulation of trace elements is extremely high in the proximity of the crater rim and decreases with the distance from the active craters. The data will be compared to earlier measurements taken in December 2011 and the impact of a slightly decreasing gas emission on the vegetation will be discussed.

Selected trace metals and organic compounds and bioavailability of selected organic compounds in soils, Hackberry Flat, Tillman County, Oklahoma, 1994-95

USGS Publications Warehouse

Becker, M.F.

1997-01-01

In 1995 the Oklahoma Department of Wildlife Conservation acquired a drained wetland in southwest Oklahoma known as Hackberry Flat. Following restoration by Wildlife Conservation the wetland will be used by migratory birds and waterfowl. If naturally occurring trace metals and residual organic compounds from agriculture and industry were present, they may have posed a potential biohazard and were a concern for Wildlife Conservation. The U. S. Geological Survey, in cooperation with Wildlife Conservation and the Oklahoma Geological Survey, examined the soils of Hackberry Flat to determine trace metal concentrations, presence of selected organic compounds, and the bioavailability of selected organic compounds in the soils. The purpose of this report is to present the data that establish the baseline concentrations of selected trace metals and organic compounds in the soils of Hackberry Flat prior to wetland restoration. Sampling and analysis were performed using two approaches. One was to collect soil samples and analyze the composition with standard laboratory practices. The second exposed composite soils samples to organic-free water and a semipermeable membrane device that mimics an organism and then analyzed the device. Ten soil samples were collected in 1994 to be analyzed for trace metals, organochlorine pesticides, and polychlorinated biphenyls. Soil samples tested for bioavailability of selected organic compounds were collected in 1995. Most of the 182 soil samples collected were from the center of every 40-acre quarter-quarter section owned by the Wildlife Conservation. The samples were grouped by geographical area with a maximum of 16 sample sites per group. Concentrations of most selected trace metals measured from soils in Hackberry Flat are within the range of mean concentrations measured in cultivated soils within the United States. Organochlorine pesticides, polychlorinated biphenyls, and polyaromatic hydrocarbons were not found at concentrations above the analytical detection levels and, if present, in the soil samples are at concentrations below the detection level of the analytical method used. Organochlorine pesticides, total polychlorinated biphenyls, and polyaromatic hydrocarbons were not detected in any of the semipermeable membrane devices at the analytical detection levels.

Proton-transfer reaction mass spectrometry (PTRMS) in combination with thermal desorption (TD) for sensitive off-line analysis of volatiles.

PubMed

Crespo, Elena; Devasena, Samudrala; Sikkens, Cor; Centeno, Raymund; Cristescu, Simona M; Harren, Frans J M

2012-04-30

When performing trace gas analysis, it is not always possible to bring the source of volatiles and the gas analyzer together. In these cases, volatile storage containers, such as thermal desorption (TD) tubes, can be used for off-line measurement. TD is routinely combined with gas chromatography/mass spectrometry (GC/MS), but so far not with proton-transfer reaction mass spectrometry (PTRMS), which has a faster response. A PTR-quadrupole-MS instrument and a PTR-ion-trap-MS instrument were separately coupled to a TD unit for off-line analysis of trace volatiles in air. Carbograph 1TD/Carbopack X sorbent tubes were filled with different concentrations of a trace gas mixture containing low molecular weight volatiles (32 g/mol up to 136 g/mol) and measured with the above-mentioned combinations. The carrier gas in the TD unit was changed from helium to nitrogen to be able to combine this instrument with the mass spectrometer. Good linearity and reproducibility with the amount of gas stored were obtained. The storage capacity over time (up to 14 days) showed larger variability (<11% for all compounds, except for acetone 27%). Several tubes were filled with breath of different persons, and the breath of a smoker showed increased levels of acetonitrile and benzene. The combination of the PTR ion-trap instrument with the TD unit was also investigated. Due to its higher sampling rate, the ion-trap system showed higher throughput capabilities than the quadrupole system. The combination of TD with PTRMS using both a quadrupole and an ion trap for off-line volatile analysis has been validated. TD tubes can be a robust and compact volatile storage method when the mass spectrometry and the sampling cannot be performed in the same place, for example in large screening studies. In addition, a higher measurement throughput than with GC/MS could be obtained. Copyright © 2012 John Wiley & Sons, Ltd.

Associations between toxic metals in follicular fluid and in vitro fertilization (IVF) outcomes.

PubMed

Bloom, Michael S; Kim, Keewan; Kruger, Pamela C; Parsons, Patrick J; Arnason, John G; Steuerwald, Amy J; Fujimoto, Victor Y

2012-12-01

We previously reported associations between trace concentrations of Hg, Cd and Pb in blood and urine and reproductive outcomes for women undergoing in-vitro fertilization (IVF). Here we assess measurements in single follicular fluid (FF) specimens from 46 women as a presumably more relevant marker of dose for reproductive toxicity. FF specimens were analyzed for Hg, Cd and Pb using sector field-inductively coupled plasma-mass spectrometry (SF-ICP-MS). Variability sources were assessed by nested ANOVA. Multivariable regression was used to evaluate associations for square root transformed metals with IVF outcomes, adjusting for confounders. An inverse association is detected for FF Pb and fertilization (relative risk (RR) = 0.68, P = 0.026), although positive for Cd (RR = 9.05, P = 0.025). While no other statistically significant associations are detected, odds ratios (OR) are increased for embryo cleavage with Hg (OR = 3.83, P = 0.264) and Cd (OR = 3.18, P = 0.644), and for embryo fragmentation with Cd (OR = 4.08, P = 0.586) and Pb (OR = 2.22, P = 0.220). Positive estimates are observed for Cd with biochemical (RR = 19.02, P = 0.286) and clinical pregnancies (RR = 38.80, P = 0.212), yet with very low precision. We have identified associations between trace amounts of Pb and Cd in FF from a single follicle, and oocyte fertilization. Yet, the likelihood of biological variation in trace element concentrations within and between follicles, coupled with levels that are near the limits of detection suggest that future work should examine multiple follicles using a 'one follicle-one oocyte/embryo' approach. A larger study is merited to assess more definitively the role that these environmental factors could play with respect to egg quality in IVF programs.

The Mars Organic Analyzer: Instrumentation and Methods for Detecting Trace Organic Molecules in our Solar System

NASA Astrophysics Data System (ADS)

Stockton, A. M.; Kim, J.; Willis, P. A.; Lillis, R.; Amundson, R.; Beegle, L.; Butterworth, A.; Curtis, D.; Ehrenfreund, P.; Grunthaner, F.; Hazen, R.; Kaiser, R.; Ludlam, M.; Mora, M. F.; Scherer, J.; Turin, P.; Welten, K.; Williford, K.; Mathies, R. A.

2014-07-01

Mars Organic Analyzer was designed to give the Mars 2020 Mission capability to look for organic molecules, including amines, aldehydes, ketones, organic acids, thiols and polycyclic aromatic hydrocarbons, in martian samples with sub-ppb sensitivity.

Emissions of volatile organic compounds and particulate matter from small-scale peat fires

NASA Astrophysics Data System (ADS)

George, I. J.; Black, R.; Walker, J. T.; Hays, M. D.; Tabor, D.; Gullett, B.

2013-12-01

Air pollution emitted from peat fires can negatively impact regional air quality, visibility, climate, and human health. Peat fires can smolder over long periods of time and, therefore, can release significantly greater amounts of carbon into the atmosphere per unit area compared to burning of other types of biomass. However, few studies have characterized the gas and particulate emissions from peat burning. To assess the atmospheric impact of peat fires, particulate matter (PM) and volatile organic compounds (VOCs) were quantified from controlled small-scale peat fire experiments. Major carbon emissions (i.e. CO2, CO, methane and total hydrocarbons) were measured during the peat burn experiments. Speciated PM mass was also determined from the peat burns from filter and polyurethane foam samples. Whole air samples were taken in SUMMA canisters and analyzed by gas chromatography-mass spectrometry to measure 82 trace VOCs. Additional gaseous carbonyl species were measured by sampling with dinitrophenylhydrazine-coated cartridges and analyzed with high performance liquid chromatography. VOCs with highest observed concentrations measured from the peat burns were propylene, benzene, chloromethane and toluene. Gas-phase carbonyls with highest observed concentrations included acetaldehyde, formaldehyde and acetone. Emission factors of major pollutants will be compared with recommended values for peat and other biomass burning.

The crash of Colgan Air flight 3407: Advanced techniques in victim identification.

PubMed

Bush, Mary; Miller, Raymond

2011-12-01

Identifying disaster victims by means of dental records is a well-established technique. In cases in which high temperatures are involved, destruction of the structural relationship of the dentition necessitates that adjunctive aids be used in the identification process. Analysis of tooth fragments by means of scanning electron microscopy with energy dispersive x-ray spectroscopy can reveal evidence of restorative procedures, as well as trace amounts of dental materials remaining on tooth surfaces. In addition, dental materials can be analyzed and identified according to brand, even if the materials have been cremated. The authors describe the identification of three victims from the crash of Colgan Air flight 3407, a commuter airplane flying between Newark, N.J., and Buffalo, N.Y. The crash involved a fire, and a portion of the airplane burned for nearly 11 hours. Dental fragments that had restorative material adhering to them were recovered and analyzed. These fragments contained corroborative information that helped confirm the identity of the victims. Detailed record keeping is part of clinical practice. The level of detail present in dental records can affect the ability of forensic odontologists to determine the identity of a victim's remains. Documenting the brand names of dental materials used in restorative procedures can make the difference between identifying and not identifying a victim's remains.

Fatty acid anilides: in vivo formation and relevance to toxic oil syndrome.

PubMed

Kaphalia, B S; Khan, M F; Ansari, G A

1999-01-01

Toxic oil syndrome (TOS), a multisystemic epidemic outbreak in 1981 in Spain, was caused by the ingestion of a cooking oil mixture containing rapeseed oil denatured with aniline. The mechanisms and causative agents responsible for the TOS are still not known. Although primary lesions observed in TOS patients could not be reproduced experimentally, the levels of fatty acid anilides (FAAs) and aniline in TOS-related cooking oil were considered proximate markers of TOS. Aniline, available from free aniline and FAAs ingested with TOS-related cooking oil, and its reconjugation with endogenous fatty acids could be an early event leading to TOS. Therefore, the present study was undertaken to determine the formation of FAAs following an oral dose of 2 mmol/kg aniline hydrochloride (AH) via gavage in rats. Here, 16:0, 18:0, 18:1, 18:2, 18:3, and 20:4 FAAs were analyzed in the whole blood, brown fat, liver, and pancreas at 0 (control), 0.25, 0.5, 1, 3, 6, 12, 24, and 48 hours. Generally, 16:0 and 18:1 FAAs were detected in the whole blood, brown fat, and liver of AH-treated rats with highest mean levels at 0.25 or 0.5 hour, except 3 hours for the whole blood. Only 16:0 FAA was detectable in the pancreas of AH-treated animals. The 18:0 FAA was also detected frequently in the liver while other FAAs were either in trace amounts or not detectable in the tissues analyzed in the present study. Overall, highest formation of the 16:0 FAA was found in the liver followed by pancreas and of 18:1 FAA in the whole blood and brown fat. These results indicate a rapid formation and further metabolism and disposition of FAAs in rat model and support our previous findings that 18:1 and 16:0 fatty acids are better substrates for the conjugation with aniline. Surprisingly, a small or trace amount of a few FAAs also detected in the tissues of control rats indicates their endogenous biosynthesis and/or presence. Results of 18:1 fatty acid incubation and aniline in the presence of fatty acid ethyl ester synthase, purified to homogeneity from rat liver microsome, suggest that formation of FAAs is catalyzed by an enzyme involved in the conjugation of fatty acids with xenobiotic alcohols. Because the FAAs are known to exert a wide range of toxicity in experimental animals and primary cell cultures, in vivo formation of FAAs could be an early event leading to TOS.