Relevant bibliographies by topics / Organic analytes

Contents

  1. Journal articles
  2. Dissertations / Theses
  3. Books
  4. Book chapters
  5. Conference papers
  6. Reports

Academic literature on the topic 'Organic analytes'

Author: Grafiati
Published: 4 June 2021
Last updated: 2 February 2022

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'Organic analytes.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "Organic analytes"

1

Müller, Karl-Heinz, Nereus Patel, Lee J. Hubble, James S. Cooper, and Edith Chow. "Strong enhancement of gold nanoparticle chemiresistor response to low-partitioning organic analytes induced by pre-exposure to high partitioning organics." Physical Chemistry Chemical Physics 22, no. 16 (2020): 9117–23. http://dx.doi.org/10.1039/c9cp06849j.

Full text
Abstract:
A method to enhance the gold nanoparticle sensor response to weak analytes is demonstrated by pre-exposing the sensor to an analyte which elicits a strong response. This weak analyte effectively reduces the strong analyte interaction with the sensor.
APA, Harvard, Vancouver, ISO, and other styles
2

Huckins, James N., Mark W. Tubergen, Jon A. Lebo, Robert W. Gale, and Ted R. Schwartz. "Polymeric Film Dialysis in Organic Solvent Media for Cleanup of Organic Contaminants." Journal of AOAC INTERNATIONAL 73, no. 2 (1990): 290–93. http://dx.doi.org/10.1093/jaoac/73.2.290.

Full text
Abstract:
Abstract Dialytic enrichment, using a nonpolar polymeric film or membrane, is proposed as a new approach for the separation of organic contaminants from fish lipid. Nonpolar organochlorine analytes diffuse from the fish lipid through a polyethylene membrane into cyclopentane. Separations of 48 h or less in duration afforded excellent recoveries for all analytes tested and removed 93% of the fish oil. Kinetics of membrane diffusion and possible controlling factors are elucidated for selected analytes and model compounds. Potential advantages of this technique over conventional lipld-removal methods such as gel permeation chromatography include simplicity, large sample capacity, reduced solvent requirements, and amenability to interfacing in-line with other enrichment modules.
APA, Harvard, Vancouver, ISO, and other styles
3

Dąbrowski, Łukasz. "Evaluation of Solvents Used as Keepers in the Determination of Organic Pollutants by GC/MS." Molecules 25, no. 19 (2020): 4419. http://dx.doi.org/10.3390/molecules25194419.

Full text
Abstract:
Solvent evaporation is often used in the sample preparation procedure for the determination of organic pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and organic pesticides. Because of the loss of analyte during this step, a high-boiling solvent, i.e., a keeper, is often added to the extract before evaporation. However, there are almost no basic studies found in the literature on the selection of keepers for the appropriate type of analytes (keepers are usually selected only on the basis of information provided by various recommendations). In this work, the effect of several keepers (isooctane, toluene, nonane, octanol, dodecane) on the recovery of various analytes (PAHs, PCBs, organic pesticides) was evaluated (during evaporation in a stream of nitrogen, at 40 °C). The analysis of the results obtained for the tested compounds shows that 1-octanol is a universal keeper for compounds with low volatility, i.e., PCBs (average recovery: 97.6%), organochlorine pesticides (average recovery: 95.0%), organophosphorus pesticides (OPPs; average recovery: 99.7%) and higher mass PAHs (average recovery: 91.9%). The use of isooctane as a keeper yields high recoveries for PAHs, regardless of their volatility (average recovery: 95.5%). When using 1-octanol or dodecane as a keeper, the reversed solvent effect (during GC analysis) was noted in relation to volatile analytes causing the distortion of their peaks. Additionally, the phenomenon of loss of some analytes (e.g., OPPs) was observed during evaporation without heating the vials. However, in the case of PCBs, organochlorine pesticides (OCPs) and o-hydroxybiphenyl, evaporation under such conditions yields recoveries greater than or equal to 90.0%. The results presented in this work can help in finding a suitable keeper for a specific group of analytes or an alternative to the commonly used one, especially in the case of recovery problems.
APA, Harvard, Vancouver, ISO, and other styles
4

Aborkhees, Ghada, Renata Raina-Fulton, and Ondiveerapan Thirunavokkarasu. "Determination of Endocrine Disrupting Chemicals in Water and Wastewater Samples by Liquid Chromatography-Negative Ion Electrospray Ionization-Tandem Mass Spectrometry." Molecules 25, no. 17 (2020): 3906. http://dx.doi.org/10.3390/molecules25173906.

Full text
Abstract:
A liquid chromatography-negative ion electrospray ionization-tandem mass spectrometry method was developed for the simultaneous analysis of bisphenol A, 4-octylphenol, 4-nonylphenol, diethylstilbestrol, 17β-estradiol, estriol, estrone, 17α-ethinylestradiol, prednisone, and prednisolone. This method used solid-phase extraction with an elution solvent of acetonitrile to improve the stability of the analytes. To maintain the stability of analytes analyses were completed within five days. The recoveries ranged from 84 to 112% and the relative standard deviation of analysis of duplicate samples was <10%. The limits of quantitation were 1–10 ng/L. Surface water and wastewater were obtained from five wastewater treatment plants in Saskatchewan. Matrix effects were moderate to severe. Using standard addition calibration, all analytes except diethylstilbestrol and 17α-ethinyl estradiol were detected. There was a low frequency of detection of the target analytes in upstream and downstream water, indicating good removal efficiency during the wastewater treatment process. Bisphenol A and 4-nonylphenol were the only analytes detected downstream. Bisphenol A was the most frequently detected in raw wastewater (133 to 403 ng/L). Estriol was detected more often in raw wastewater than estrone or 17β-estradiol. This is the first Canadian study with the detection of prednisone and prednisolone with concentrations at 198–350 ng/L in raw wastewater at 60% of the wastewater treatment plants.
APA, Harvard, Vancouver, ISO, and other styles
5

Hu, Mao-Lin, Sayed Ali Akbar Razavi, Maryam Piroozzadeh, and Ali Morsali. "Sensing organic analytes by metal–organic frameworks: a new way of considering the topic." Inorganic Chemistry Frontiers 7, no. 7 (2020): 1598–632. http://dx.doi.org/10.1039/c9qi01617a.

Full text
Abstract:
In this review, our goal is comparison of advantageous and disadvantageous of MOFs about signal-transduction in different instrumental methods for detection of different categories of organic analytes.
APA, Harvard, Vancouver, ISO, and other styles
6

Jarouche, Suresh, Low, Xu, and Khoo. "Quality Control and Variability Assessment of an Eight‐Herb Formulation for Hypertension Using Method Validation and Statistical Analysis." Molecules 24, no. 8 (2019): 1520. http://dx.doi.org/10.3390/molecules24081520.

Full text
Abstract:
Background—The quality control (QC) for commercial herbal formulations is sparse due to a lack of well-developed HPLC-ESI-MS/MS methods. Objective—This study reports the quantification of nine selected analytes for a commercial eight-herb formulation known as Qi Ju Di Huang Wan (QJDHW) used to relieve hypertension. Methods—An HPLC-ESI/MS method for the quantitation of analytes selected using the Herbal Chemical Marker Ranking System (Herb MaRS) was developed. The Herb MaRS ranking system which takes into account bioavailability, bioactivity, and physiological action related to its intended use and the commercial availability of the standard. After a method optimization, seven analytes were found to be ideal for quantitation. Results—The target analytes were identified using an electrospray ionization-tandem MS molecular breakdown comparison between the herbal peak and the commercial standard. The quantitative aspect of analyte variability of eleven samples was studied using fold variation. The fold variation of selected analytes among eleven samples ranged from 1.5 to 28.9. The qualitative aspect of variability was studied using principal component analysis (PCA) and hierarchical cluster analysis (HCA). Conclusions—There is a great degree of chemical variability in herbal formulations which are due to raw material harvesting times, storage techniques, and plant subspecies variability. Highlights—Commercial QJDHW formulations need to be standardised using HPLC-ESI-MS/MS to ensure better product quality control (QC) and product efficacy for the consumer.
APA, Harvard, Vancouver, ISO, and other styles
7

Amarandei, Cornelia, Romeo Iulian Olariu, and Cecilia Arsene. "Implications of Matrix Effects in Quantitative HPLC/ESI-ToF-MS Analyses of Atmospheric Organic Aerosols." Proceedings 55, no. 1 (2020): 6. http://dx.doi.org/10.3390/proceedings2020055006.

Full text
Abstract:
Matrix-induced signal suppression or enhancements are known phenomena in electrospray ionization mass spectrometry. Very few studies report on method development for organic aerosols analyses with the evaluation of the matrix effects. The matrix effects lead to errors in the quantification of the analytes and affect the detection capability, precision, and accuracy of an analysis method. The present study reports on the matrix effects in the analysis of organic chemical compounds present in atmospheric aerosol particles collected on quartz filters. A total number of 19 analytes, including different classes of organic compounds, such as monoaromatic phenols and derivatives (e.g., catechol, 4-methylcatechol, 3-methoxycatechol, 4-nitrocatechol, 4-nitrophenol, 2,4-dinitrophenol, 2,6-dimethyl-4-nitrophenol), carboxylic acids (terebic acid, adipic acid, pimelic acid, phthalic acid, vanillic acid), and sulfonic acids (e.g., camphor-10-sulfonic acid), was investigated by high-performance liquid chromatography coupled to electrospray ionization time-of-flight mass spectrometry (HPLC/ESI-ToF-MS). The HPLC and ESI set-up parameters used in this study were previously optimized for the investigated compounds. Different volumes of a standard mixture were added to sample extracts, with final solutions concentrations in the 50–1500 μg L−1 range. For the investigated concentration range, the observed matrix effect was independent of the standard concentration level. For quartz filter extracts, the average matrix effect determined on a concentration-based method was 109.5 ± 6.1%. Both signal suppression and enhancement effects were observed for different compounds. For other analytes, the influence of the matrix effect is variable, suggesting that the use of an internal standard is not sufficient for the matrix effects correction. Competition between analyte ions and matrix components in the gas-phase ionization processes occurring in electrospray might explain signal suppression while generated coeluted isobaric compounds might induce signal enhancement.
APA, Harvard, Vancouver, ISO, and other styles
8

Westgate, John N., Uwayemi M. Sofowote, Pat Roach, et al. "In search of potential source regions of semi-volatile organic contaminants in air in the Yukon Territory, Canada from 2007 to 2009 using hybrid receptor models." Environmental Chemistry 10, no. 1 (2013): 22. http://dx.doi.org/10.1071/en12164.

Full text
Abstract:
Environmental context Some long-lived organic contaminants, such as chlorinated organics, brominated flame retardants and polycyclic aromatic hydrocarbons, can undergo transport through the atmosphere to remote regions. A series of measurements of these compounds taken over almost 3 years in the air at a remote location was combined with meteorological data to try to reveal potential source areas. After adjusting several parameters to optimise the method’s ability to identify sources it was found that for most contaminants no definitive sources are revealed. Abstract A suite of brominated flame retardants, chlorinated organic pesticides and some metabolites thereof were analysed in week-long and day-long air samples collected at Little Fox Lake in Canada’s Yukon Territory from 2007 to 2009. Several trajectory-based methods for source region identification were applied to this dataset, as well as to polycyclic aromatic hydrocarbon (PAH) concentrations in those same samples reported previously. A type of concentration weighted trajectory (CWT) analysis, using a modified grid to avoid difficulties near the Earth’s poles, and removing trajectory endpoints at altitudes greater than 700m did not identify distinct source regions for most analytes. Decreasing the spatial resolution of the grid made interpretation simpler but reinforced patterns that may have stemmed from single trajectories. The potential source contribution function (PSCF) is similar to CWT but treats the concentration data categorically, rather than numerically. PSCF provides more distinct results, highlighting the Arctic Ocean as a potential source of para,para′-dichlorodiphenyldichloroethene and both northern Siberia and Canada’s Yukon and Northwest Territories as potential sources of PAHs. To simulate the uncertainty associated with individual trajectories, a set of trajectories was also generated for six points surrounding the sampling station and included in the trajectory analyses. This had the effect of smoothing the CWT and PSCF values for those analytes with no clearly definable sources, and highlighting the source regions for the two that did. For the bulk of the analytes discussed here, Little Fox Lake is well positioned to act as a background monitoring site.
APA, Harvard, Vancouver, ISO, and other styles
9

Janicki, Wacław, Wojciech Chrzanowski, Andrzej Wasik, Elżbieta Przyk, and Jacek Namieśnik. "Automated analyser for monitoring trace amounts of volatile chloro-organic compounds in recirculated industrial water." Journal of Automated Methods and Management in Chemistry 24, no. 1 (2002): 9–16. http://dx.doi.org/10.1155/s1463924602000020.

Full text
Abstract:
An automated analyser of volatile chloro-organic compounds in water was constructed and tested using standard mixtures of dichloromethane and dichloroethane. It was based on continuous, countercurrent gas stripping of the liquid sample followed by periodic trapping of the analytes on two traps alternately connected to the bubbler outlet, and thermal desorption. When one trap performed adsorption, the other underwent desorption and cooling. Analytes were detected by an ECD detector. Integration, calibration, calculations and overall operating cycle control was performed by a microcomputer. The instrument guarantees a 0.02 ppm Cl (w/w) detection limit, a 0—2 ppm detection range and 2 months of autonomous operation. Results are reported every 13 min.
APA, Harvard, Vancouver, ISO, and other styles
10

Eichler, P., M. Müller, B. D'Anna, and A. Wisthaler. "A novel inlet system for on-line chemical analysis of semi-volatile submicron particulate matter." Atmospheric Measurement Techniques Discussions 7, no. 9 (2014): 10109–30. http://dx.doi.org/10.5194/amtd-7-10109-2014.

Full text
Abstract:
Abstract. We herein present the concept of a novel modular inlet system that allows using gas-phase analyzers for on-line chemical characterization of semi-volatile submicron particles. The "chemical analysis of aerosol on-line" (CHARON) inlet consists of a gas-phase denuder for stripping off gas-phase analytes, an aerodynamic lens for particle enrichment in the sampling flow and a thermo-desorption unit for particle volatilization prior to chemical analysis. We coupled the CHARON inlet to a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS) which quantitatively detects most organic analytes and ammonia. The combined set-up measures submicron organic and ammonium nitrate/sulfate particles online. Two proof-of-principle studies were carried out for demonstrating the analytical power of the new set-up in analyzing primarily emitted and secondarily generated particles. Oxygenated organics and their partitioning between the gas and the particulate phase were observed from the reaction of limonene with ozone. Abundant quasi-molecular ions of organic particulate constituents were observed when submicron particles were sampled from diluted mainstream cigarette smoke.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Dissertations / Theses on the topic "Organic analytes"

1

Panagiotopoulou, Maria. "Organic-inorganic composite materials for specific recognition and optical detection of environmental, food and biomedical analytes." Thesis, Compiègne, 2016. http://www.theses.fr/2016COMP2315/document.

Full text
Abstract:
Cette thèse décrit l'état de l'art des sondes et nanoparticules fluorescents traditionnels utilisés en imagerie de fluorescence ainsi que le développement de nouveaux nanomatériaux à base de polymère à empreinte moléculaire, aussi dénommé ‘anticorps plastique’, pour le ciblage et la bioimagerie. En biologie et en médecine, il y a un besoin constant de diagnostiquer diverses maladies pour leur éventuel traitement et prévention. Une distribution anormale et un taux élévé de glycosylation (e.g. acides hyaluronique et sialique) à la surface ou dans les cellules sont indicateurs d’une infection ou d’un cancer. Généralement, l’imagerie par fluorescence permet de visualiser, localiser et quantifier les biomarqueurs de pathologie mais à l’heure actuelle, il n’existe pas d’outil analytique fiable pour cibler spécifiquement les molécules de glycosylation car les anticorps et les lectines vendus dans le commerce ont une faible affinité et sélectivité vis-à-vis de ces cibles. Dans ce contexte, les polymères à empreintes moléculaires (MIPs) pourraient apporter une solution. Les MIPs sont des récepteurs synthétiques possédant des affinités et sélectivités comparables à ceux des anticorps, mais exhibant une stabilité physique, thermique et chimique bien plus accrue. De plus, leur fabrication est peu coûteuse et ne nécessite pas de tuer des animaux comme pour l’obtention des anticorps biologiques. Dans cette thèse, nous avons optimisé et synthétisé des MIPs biocompatibles pour leur utilisation en bioimagerie afin de détecter et quantifier l’acide hyaluronique et l’acide sialique sur les cellules et les tissus de peau humaine. L’acide glucuronique, une composante de l’acide hyaluronique et l’acide N-acétylneuraminique, l’acide sialique le plus commun, ont été utilisés comme molécules ‘patron’, générant des MIPs très sélectifs envers leur cible en milieu aqueux. Deux types de nanoparticules de MIPs fluorescents ont été synthétisés: (1) en incorporant un colorant rhodamine polymérisable dans la solution de pré-polymérisation et (2) en encapsulant des boîtes quantiques InP/ZnS générant ainsi des MIPs de type cœur-coquille. Pour cela, nous avons adopté une stratégie innovante qui consiste à synthétiser les coquilles de MIPs directement autour des boîtes quantiques en utilisant l’énergie de l’onde fluorescente émise par l’excitation des points quantiques, pour initier la polymérisation. Un protocole d'immunocoloration standard a ensuite été optimisé afin d’imager des kératinocytes humains fixés et vivants ainsi que des tissus de peau, par microscopie à épifluorescence et confocale. Les résultats étaient similaires à ceux obtenus par la méthode de référence utilisant une protéine biotinylée reconnaissant l'acide hyaluronique. L'imagerie multiplex en combinant deux MIPs couplés à deux couleurs de boîtes quantiques et l’imagerie des cellules cancéreuses ont également été démontrées. Bien que les MIPs n’étaient pas cytotoxiques aux concentrations utilisées pour la bioimagerie, la toxicité des différentes composantes du MIP pourrait être un frein à leur utilisation dans le domaine biomédical. Afin de rendre ces MIPs plus ‘inoffensifs’, nous avons supprimé l’amorceur de polymérisation, une molécule considérée comme toxique. Les MIPs ont été synthétisés en employant des monomères qui s’auto-initient sous l’effet de l’UV ou de la chaleur. La spécificité et la sélectivité des MIPs obtenus étaient similaires à ceux préparés avec des amorceurs. En conclusion, cette thèse décrit la première utilisation des MIPs comme anticorps synthétique pour la bioimagerie de fluorescence. Ce travail ouvre la voie à de nouvelles applications en détection, diagnostique et thérapie par des MIPs<br>This thesis describes the state of the art in nanomaterials-based targeted bioimaging and introduces molecularly imprinted polymers, also termed ‘plastic antibodies’ as novel biorecognition agents for labeling and imaging of cells and tissues. In fundamental biology and medical diagnostics, there is a constant need to localize and quantify specific molecular targets. Abnormal glycosylation levels or distributions of hyaluronan or sialic acids on cells are indicators of infection or malignancy. In general, bioimaging with fluorescent probes enables the localization and qualitative or quantitative determination of these pathological biomarkers. However, no reliable tools for the recognition of glycosylation sites on proteins exist, because the commercially available antibodies or lectins have poor affinity and selectivity for these targets. In this context, tailor-made molecularly imprinted polymers (MIPs) are promising synthetic receptor materials since they present a series of advantages over their natural counterparts such as the ease and low cost of preparation and their physical and chemical stability. Thus, MIPs could provide a robust and specific imaging tool for revealing the location/distribution, time of appearance and structure of glycosylation sites on/in cells, which would lead to a better insight of the tremendously diverse biological processes in which these molecules are involved. Herein, we describe the synthesis of water-compatible MIPs for the molecular imaging of hyaluronan and sialylation sites on cells and tissues. Since molecular imprinting of entire biomacromolecules like oligosaccharides is challenging, we opted for what is commonly called the ‘epitope approach’, which was inspired by nature. The monosaccharides, glucuronic acid and N-acetylneuraminic acid were imprinted, and the resulting MIPs were able to bind these molecules when present and accessible on the terminal unit of hyaluronan and sialylation sites. Fluorescent MIPs were synthesized as rhodamine-labeled nanoparticles and as MIP-coated InP/ZnS core-shell quantum dot (QD) particles. For the coating of the QDs, a novel versatile solubilization and functionalization strategy was proposed, which consists of creating polymer shells directly on QDs by photopolymerization using the particles as individual internal light sources. A standard immunostaining protocol was then successfully adapted for the application of the fluorescently labeled MIPs to image fixed and living human keratinocytes and skin tissues, by epifluorescence and confocal fluorescence microscopy. The results were comparable to those obtained with a reference method where staining was done with a biotinylated hyaluronic acid binding protein. Multiplexed and cancer cell imaging were also performed, demonstrating the potential of molecularly imprinted polymers as a versatile biolabeling and bioimaging tool. Although the MIPs were not cytotoxic at the concentrations used for bioimaging, in order to render them generally applicable in biomedicine, where toxicity of the polymerization precursors is a matter of concern, we suppressed the initiator, a toxic chemical. Initiator-free MIPs were thus synthesized by using monomers that can self-initiate under UV irradiation or heat. The specificity and selectivity of the obtained MIPs were as good as the ones prepared with initiators. In conclusion, we have demonstrated for the first time the great potential of MIPs as synthetic antibody mimics for bioimaging. The possibility to associate other functionalities such as QDs and additionally attach drugs to the same material appears rather straightforward due to the synthetic polymeric nature of MIPs, which paves the way to new potential applications in theranostics
APA, Harvard, Vancouver, ISO, and other styles
2

Fuligni, Matteo. "PEDOT:PSS-based conductive Textile for simultaneous detection of sweat analytes." Bachelor's thesis, Alma Mater Studiorum - Università di Bologna, 2020. http://amslaurea.unibo.it/21204/.

Full text
Abstract:
This thesis is part of the wearable electronic field, and in particular of the Organic BioElecteonic Sensors that have the in-situ real-time monitoring of the health and performance status of the subject as the main goals. With this purpose, textile-based wearable sensors for continuous and simultaneous detection of [Cl–] and pH level have been developed. PEDOT:PSS is the intrinsic conductive polymer used to make the commercial yarns conductive. The coated threads have been functionalized with Ag/AgCl NPs and BTB to make them able to detect [Cl–] and pH level, respectively. The developed sensors end up to be easy-to-make, reproducible with excellent sensitivity and stability both in single and multiple configurations without any interference. The results achieved in this work allow future improvements to develop a new textile-based device that can be easily integrated into clothing, allowing worn it in dealy life.
APA, Harvard, Vancouver, ISO, and other styles
3

Perez, Gregory Paul. "Chemically sensitive polymer-mediated nanoporous alumina SAW sensors for the detection of vapor-phase analytes." Texas A&M University, 2003. http://hdl.handle.net/1969.1/2202.

Full text
Abstract:
We have investigated the chemical sensitivity of nanoporous (NP) alumina-coated surface acoustic wave (SAW) devices that have been surface-modified with polymeric mediating films. The research in this dissertation covers the refinement of the NP alumina coating, development of dendrimer and/or polymer surface modifications, design of composite ultrathin vapor-phase analyte gates, and preparation of selectively permeable, polymeric films that mediate analyte transport. Nanoporous alumina SAW devices were fabricated from planar Al SAW devices using an anodization process that yields a high-surface-area transduction platform. Refinement of the anodization process results in a homogeneously porous substrate capable of ~40 times the analyte sensitivity of conventional planar SAW devices. Attempts to directly impart selective gas-phase analyte permeation with monolayers of amine-terminated, poly(amidoamine) (PAMAM) dendrimer films were investigated with and without secondary functionalization. We also prepared and characterized pore-bridging polymeric composite ultrathin films (~12 nm) of PAMAM dendrimers and poly(maleic anhydride)-c-poly(methyl vinylether) (Gantrez). Access to the underlying pores of the NP alumina coating can be modulated through the sequential deposition of the composite film. These tailorable ultrathin films result in impermeable surface- modifications which fully gate the analyte response without filling the porous structure. Thin spin-cast films (40 nm) of polydimethylsiloxane (PDMS) were developed to simultaneously provide selective sorption and permeation characteristics towards vapor-phase analytes. The porous nature of the underlying alumina coating provides for this real-time evaluation of sorption and permeation. The results suggest that the thin films offer preferential sorption of non-polar organics and selective permeability towards water vapor.
APA, Harvard, Vancouver, ISO, and other styles
4

Al-Karawi, Dheyaa Hussein. "The Investigation of The Electrical Control of Hemimicelles and Admicelles on Gold for Analyte Preconcentration." TopSCHOLAR®, 2016. http://digitalcommons.wku.edu/theses/1732.

Full text
Abstract:
Hemimicelles and admicelles are well-investigated wonders in modern science; they are surfactant monolayers and surface adsorbed micelles, respectively. Capacitance measurements for monitoring the formation of dodecyl sulfate (DS) surfactant monolayer on positively charged gold substrates (planar gold) and the adsorbance of 2-naphthol onto DS surfactant monolayer were performed. The investigation of the electrical control of DS at various concentrations (4, 6, 16, and 32 mM) below and above the critical micelle concentration (CMC= 8 mM) on gold surfaces for analyte preconcentration, prior to chromatographic analysis, is presented. Charged ionic surfactants, such as DS, drawn to a surface of opposite charge (porous nickel substrates coated with gold) serve as a stationary phase to trap organic analytes. It is believed that these DS assemblies gain stability through surfactant chain–chain interactions. The attachment and the removal of the surfactant are controlled using an electric field. Due to the fact that the surfactantanalyte association is released by electrical control, organic solvents, which are used in conventional solid phase extraction, are not required, making this procedure environmentally friendly. Electrical Impedance Spectroscopy was used to investigate the formation of the DS layer and the preconcentration of 2-naphthol in the presence of an applied electric field. High performance liquid chromatography was used to determine 2- naphthol concentrations. Anthracene and 9-anthracenecarboxylic acid were substituted as additional test molecules as well. Presented are the results of the preconcentration of 2-naphthol, anthracene and 9-anthracenecarboxylic acid using the DS layer with various concentrations of sodium dodecyl sulfate on a gold electrode surface.
APA, Harvard, Vancouver, ISO, and other styles
5

Heiman, Ross D. "Analyses of organic grain prices." Thesis, Manhattan, Kan. : Kansas State University, 2006. http://hdl.handle.net/2097/176.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

McKay, Sarah Michele. "Understanding Organic Prices: An Analysis of Organic Price Risk and Premiums." Thesis, Virginia Tech, 2016. http://hdl.handle.net/10919/71677.

Full text
Abstract:
Organic food products are produced without synthetic chemicals, including herbicides, pesticides, and fertilizers. Food grown in organic systems that are certified organic by the United States Department of Agriculture command a price premium, whether it is direct to consumer via farmers markets or in conventional grocery stores. Organic food and food products are representing a relatively larger portion of overall food sales in recent years, and the demand for organic meat has also increased. However, there is a lack of available U.S.-grown organic grains and soybeans to feed the growing number of organic certified livestock to produce organic meat to meet this demand. This shortage results from many factors, yet is primarily due to organic production requirements for significantly more land and operating capital when compared to conventionally grown counterparts. There is a lack of information detailing the relative costs and returns of organic grain production, and, limited understanding of organic premiums. The overall goal of this study is to examine differences in price levels between organic and conventional corn, soybeans, wheat, oats, and barley between 2007 and 2015, as well as factors that may affect the organic premium. For organic grain and soybean producers, study findings reveal that the least risky organic commodities to grow include corn and soybeans, especially if sold in the cash market. However, the author suggests that growers may consider growing wheat, barley, and oats if they have a buyer willing to contract in advance to ensure a premium and reduce price risk. For purchasers of organic grains and soybeans, including major food companies as well as livestock producers, it is recommended they continue to study developments in organic grain supplies as producers continue to consider adoption of organic production methods.<br>Master of Science
APA, Harvard, Vancouver, ISO, and other styles
7

Mogemark, Mickael. "Solid-phase glycoconjugate synthesis : on-resin analysis with gel-phase ¹9F NMR spectroscopy." Doctoral thesis, Umeå University, Chemistry, 2005. http://urn.kb.se/resolve?urn=urn:nbn:se:umu:diva-438.

Full text
Abstract:
<p>An efficient and versatile non-destructive method to analyze the progress of solid-phase glycoconjugate synthesis with gel-phase <sup>19</sup>F NMR spectroscopy is described. The method relies on use of fluorinated linkers and building blocks carrying fluorinated protective groups. Commercially available fluorinated reagents have been utilized to attach the protective groups. </p><p>The influence of resin structures for seven commercial resins upon resolution of gel-phase <sup>19</sup>F NMR spectra was investigated. Two different linkers for oligosaccharide synthesis were also developed and successfully employed in preparation of α-Gal trisaccharides and a n-pentenyl glycoside. Finally, reaction conditions for solid-phase peptide glycosylations were established.</p>
APA, Harvard, Vancouver, ISO, and other styles
8

Skinner, Diane Elizabeth. "Organising organic : a Foucauldian analysis of the regulation of organic food production." Thesis, University of Warwick, 2007. http://wrap.warwick.ac.uk/2850/.

Full text
Abstract:
Early in the life of this thesis, Britain became the world's third largest consumer of organic produce with sales of organic food exceeding one billion pounds. Drawing on a conceptual framework based on Foucault's texts, the research investigates this little word "organic" and asks how organic food production is regulated. The empirical study begins with a genealogy/archaeology of organic farming regulation, including very recent history in the making during the research period. Using Foucault's concepts of code- and ethics-oriented morality and focusing on self-regulation, the study considers commitment to organic farming by producers as ethical subjects. An ethnography carried out within a self-managing cooperative organic farming community shifts the research to a local level. The research investigates the various organic truths produced by individuals through subjectivisation-objectivisation interplay. The code-oriented morality of the Soil Association is an absent presence that is at variance with a looser set of values and rules associated with the self-sufficiency movement and handed down as an oral tradition. Within a heterogeneity of organic, the care of the self practice parrhesia is used to analyse how community members establish collective organic farming practices through decision-making practices. The research uncovers the hidden complexities and ambiguities embedded in organic food production. The thesis reveals too how power relations are at play within the context of equality in a headless organisation. The thesis addresses the under-researched area of agriculture within business schools. Moreover, the thesis provides a comprehensive and accessible working example of Foucault's main themes and contributes to an emerging body of work based on the interplay of subjectivisation and objectivisation. Finally, the thesis contributes an empirical study of self-management to the emerging research field within Critical Management Studies of alternative organisational forms.
APA, Harvard, Vancouver, ISO, and other styles
9

Ndlovu, Bongani. "Kimberlite weathering : effects of organic reagents." Diss., University of Pretoria, 2013. http://hdl.handle.net/2263/33354.

Full text
Abstract:
Diamonds are commonly present in an ore called kimberlite. Kimberlites vary extensively in mineralogy and therefore can complicate the processing and the extraction of diamonds. Weathering of kimberlite was investigated in this study and refers to the rapid physical breakdown of the kimberlite material. Kimberlite weathering by organic molecule adsorption was investigated utilising organic solutions; ethanol, formamide, n-hexane, oxalic acid, urea, pentanoic acid and acetic acid, was investigated. The extent of weathering was measured by XRD, TGA and FTIR analysis as well as by evaluating changes in the particle size distribution. The idea to predict the susceptibility of weathering of kimberlite based on TGA analysis was discredited as it was found that there was no correlation between the smectite content and the % weight loss from TGA analysis. In XRD analysis studies to relate the d-spacing to the extent of weathering, it was found that the technique was not sensitive enough to enable direct prediction of weathering behaviour. Organic solutions at 0.5 M generally did not significantly alter the d-spacing. In the case of utilising pure organic solutions, it was observed that switching from diluted to pure organic solutions did not increase the d-spacings but rather lowers the space. Cation pretreatment prior to organic weathering resulted in d-spacings up to 2 water layers (12.6 Å being equal to 1 water layer, 15.6 Å equal to 2 layers and 18.6 Å equal to 3 layer). The general trend was that the divalent cations Mg2+ and Ca2+ increased the d-spacings whereas monovalent cations Na+ and K+ decreased the spacing. In the case of pre-organic treatment prior to organic weathering, it was observed that the resulting d-spacing increased to 2 and 3 water layers. TGA analysis confirmed that the kimberlite structure did absorb organic reagents during weathering. It was observed that the amount of organic reagents adsorbed decrease in the following order: oxalic acid > urea > pentanoic acid > formamide > ethanol > n-hexane > acetic acid, with oxalic acid having been adsorbed the greatest. In addition, it was also shown that the extent of inorganic cation adsorption was more than that of organic solutions. The analysis also showed that organic pretreatments yielded promising results and the order followed was dimethyldioctadecylammonium chloride > cetylpyridium chloride > dodecylamine > pyridine in encouraging subsequent organic adsorption. FTIR analysis results indicated the mechanism by which organic molucules attached onto the mineral surface. It was observed that there was a disturbance of the bond between water in the interlayer and the silicate structure by a stronger H-bond gained through organic molecule attachment. Oxalic acid was observed to cause a structural change due to proton attack of the silicate structure. It was found that kimberlite weathering, in essence, occurred in the first 24 hours of contact with the solution. Oxalic acid was found to be the most effective weathering agent compared to the rest of the tested organic solutions. The effect of the tested solutions, at 0.5 M concentration, on kimberlite weathering followed the series Cu2+ > oxalic acid > ethanol > acetic acid > formamide > n-hexane > distilled water. This study therefore showed that the accelerated weathering of kimberlite utilising organic solutions was not as efficient as the Cu2+ solution. Comparing Cu2+ and oxalic acid treatments, results showed that 67 % of the particles passed 12 mm screen size due to Cu2+ weathering as opposed to 48 % in oxalic acid. In investigating the effects of variables, it was found that time of exposure had a small effect in the weathering of kimberlite. Increasing the organic concentration from 0.025 M to 0.5 M saw an increase in the amount of particles passing the 12 mm screen size by~20 %. There was however no improved weathering when the solution temperature was increased from approximately 25 °C to 40 °C. In the study of kinetics involved during organic weathering utilising oxalic acid and comparing with Cu2+ medium, a high mineral dissolution was observed in the first 24 hours of contact with the weathering solution. However, different weathering mechanisms were observed between Cu2+ and oxalic acid. Inorganic solutions foster weathering by interlayer cation exchange which results in the reduction of the surface energy and this encourages further crack propagation. Oxalic acid weathering mechanism was by proton attack of the structural cations which was then limited thereafter by oxalate salts precipitation. Al3+ and Mg2+ were the dominant cations in solution during weathering (reaching 40 mmol/L) at higher oxalic acid concentration. This indicated that the dissolution of the clay‟s octahedral structure occurred, making oxalic acid a more effective agent than the rest of the tested organic solutions. An alternative method to transform non-swelling clay minerals to swelling in kimberlites was highlighted. It was observed that cation exchange treatment in conjunction with acid and oxidation treatments on kimberlites containing non-swelling minerals: mica or forsterite that are at least 30 % in quantity may result in the presence of swelling clays after these treatments. Kimberlite that contained serpentine minerals was more resistant to alteration under these conditions.<br>Dissertation (MEng)--University of Pretoria, 2013.<br>gm2014<br>Materials Science and Metallurgical Engineering<br>UPonly
APA, Harvard, Vancouver, ISO, and other styles
10

Rugunanan, Rajan Anil. "Intersolid pyrotechnic reactions of silicon." Thesis, Rhodes University, 1992. http://hdl.handle.net/10962/d1015571.

Full text
Abstract:
A study of the role of different oxidants with silicon as the fuel in simple binary pyrotechnic compositions is reported. Several oxidants were examined, but only three (Sb₂0₃, Fe₂0₃ and Sn0₂) satisfied the restrictions that the combustion temperatures should be below the melting point of platinum/rhodium thermocouples (1760°C), that burning rates should not exceed the response of the thermocouples, and that burning should occur without significant mass-transport. A fourth oxidant, KN0₃, was selected on account of its low melting point and general importance as a pyrotechnic oxidant. The oxidation of silicon in the presence of either Sb₂0₃ or KN0₃ could be identified from thermal analysis curves. No thermal events were noted when Si/Sn0₂ and SiFe₂0₃ compositions were heated under similar conditions. The oxidation of Si powder in oxygen was also studied. All four binary systems sustained burning over a reasonably wide range of compositions. The range of burning rates measured (2 to 35 mm s⁻¹) depended on the oxidant used. Fe₂0₃ and Sb₂0₃ gave slow burning mixtures compared to Sn0₂ and to KN0₃ compositions with a high Si content. Burning rates generally increased with increasing specific surface area of silicon, but decreased in the presence of inert diluents and moisture. The burning rates of the Si/Fe₂0₃ and Si/Sn0₂ systems increased with increasing compaction of the samples. Kinetic parameters derived from the temperature proftles recorded during combustion were generally low (6 to 37 kJ mol⁻¹). This is in keeping with proposals that burning is diffusion controlled. The values of kinetic parameters derived from thermal analysis curves were considerably greater ( > 250 kJ mol⁻¹). Two other fuels, FeSi₇ and CaSi₂, gave similar thermal analysis curves when used instead of silicon. There were considerable differences in the burning rates for binary mixtures of these fuels compared to silicon. Ternary systems with two fuels or two oxidants showed that only limited interaction occurs during thermal analysis. The use of a second fuel or oxidant did, however, modify the burning behaviour considerably. Other techniques used in this study to probe the details of the reaction processes included bomb calorimetry, measurement of thermal conductivities, infrared spectroscopy, X-ray diffraction and scanning electron micoscropy.
APA, Harvard, Vancouver, ISO, and other styles
More sources

Books on the topic "Organic analytes"

1

Self, Ron. Extraction of organic analytes from foods: A manual of methods. Royal Society of Chemistry, 2005.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
2

Self, Ron. Extraction of organic analytes from foods: A manual of methods. Royal Society of Chemistry, 2005.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
3

Organic spectroscopy. 3rd ed. Macmillan Education, 1991.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
4

J, Bendell David, Groundwater Paul W, and Royal Society of Chemistry (Great Britain), eds. Organic spectroscopic analysis. Royal Society of Chemistry, 2004.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
5

1963-, Rodríguez Jaime, and Jaspars Marcel 1966-, eds. Organic structure analysis. Oxford University Press, 1998.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
6

Crews, Phillip. Organic structure analysis. 2nd ed. Oxford University Press, 2010.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
7

1963-, Rodríguez Jaime, and Jaspars Marcel 1966-, eds. Organic structure analysis. 2nd ed. Oxford University Press, 2010.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
8

Qualitative organic analysis: Spectrochemical techniques. 2nd ed. McGraw-Hill, 1986.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
9

Organic structural spectroscopy. 2nd ed. Pearson Prentice Hall, 2011.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
10

Brown, D. W. Organic spectroscopy. J. Wiley, 1988.

Find full text
APA, Harvard, Vancouver, ISO, and other styles
More sources

Book chapters on the topic "Organic analytes"

1

Zuin, Vânia Gomes, and Cíntia Alessandra Matiucci Pereira. "Green Sample Preparation Focusing on Organic Analytes in Complex Matrices." In Green Chromatographic Techniques. Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7735-4_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Smyth, W. Franklin. "Selected Analytical Problems Involving Organic Analytes which are Major or Minor Organic Constituents of a Sample." In Analytical Chemistry of Complex Matrices. Vieweg+Teubner Verlag, 1996. http://dx.doi.org/10.1007/978-3-322-87182-4_6.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Smyth, W. Franklin. "Organic Trace Analysis of Low Molecular Weight Analytes in Environmental Samples and Biological Materials." In Analytical Chemistry of Complex Matrices. Vieweg+Teubner Verlag, 1996. http://dx.doi.org/10.1007/978-3-322-87182-4_7.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Bügler, Jürgen H., Menno de Jong, Johan F. J. Engbersen, and David N. Reinhoudt. "Functionalized Cyclodextrin-Calix[4]Arene Host Molecules for Detection of Organic Analytes." In Sensor Technology in the Netherlands: State of the Art. Springer Netherlands, 1998. http://dx.doi.org/10.1007/978-94-011-5010-1_49.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Datta, Sriparna, Runa Ghosh Auddy, and Amit De. "Supercritical Fluid Chromatography: A Green Approach for Separation and Purification of Organic and Inorganic Analytes." In Green Chromatographic Techniques. Springer Netherlands, 2013. http://dx.doi.org/10.1007/978-94-007-7735-4_3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Wetzel, Robert G., and Gene E. Likens. "Organic Matter." In Limnological Analyses. Springer New York, 2000. http://dx.doi.org/10.1007/978-1-4757-3250-4_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

Wetzel, Robert G., and Gene E. Likens. "Organic Matter." In Limnological Analyses. Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4757-4098-1_9.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

Fresenius, Wilhelm, Karl Ernst Quentin, and Wilhelm Schneider. "Organic Parameters." In Water Analysis. Springer Berlin Heidelberg, 1988. http://dx.doi.org/10.1007/978-3-642-72610-1_4.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Wetzel, Robert G., and Gene E. Likens. "Decomposition: Particulate Organic Matter." In Limnological Analyses. Springer New York, 1991. http://dx.doi.org/10.1007/978-1-4757-4098-1_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Wetzel, Robert G., and Gene E. Likens. "Decomposition: Particulate Organic Matter." In Limnological Analyses. Springer New York, 2000. http://dx.doi.org/10.1007/978-1-4757-3250-4_21.

Full text
APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "Organic analytes"

1

Bose, Indranil, Anna Ohlander, Matthias I. J. Stich, et al. "Polymer opto-chemical-electronic based module as a detection system for volatile analytes on a foil substrate." In SPIE Organic Photonics + Electronics, edited by Ruth Shinar and Ioannis Kymissis. SPIE, 2012. http://dx.doi.org/10.1117/12.929821.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Khurana, Tarun K., and Juan G. Santiago. "On-Chip Indirect Detection of Non-Fluorescent Analytes Using Fluorescent Spacers." In ASME 2007 International Mechanical Engineering Congress and Exposition. ASMEDC, 2007. http://dx.doi.org/10.1115/imece2007-42261.

Full text
Abstract:
We present a technique that accomplishes on-chip preconcentration, separation and indirect detection of nonfluorescent analytes by leveraging isotachophoresis (ITP) and a set of fluorescent species termed spacers. The non-fluorescent analyte zones are detected as dark zones/gaps between fluorescent spacer zones. The length of this gap quantifies the initial concentration of the non-fluorescent analyte and mobilities of the fluorescent spacers on either side provide the upper and lower bound for the analyte mobility. We have successfully demonstrated separation and detection of amino acids, serine and phenylalanine, as well as other organic acids, acetic acid and phenylpropionic acid with this technique. Using three fluorescent spacers, we were able to detect ∼10 μM concentration of non-fluorescent analytes.
APA, Harvard, Vancouver, ISO, and other styles
3

Khurana, Tarun K., Moran Bercovici, and Juan G. Santiago. "Indirect Fluorescence Detection of Non Fluorescent Analytes Using Isotachophoretic Mobility Markers." In ASME 2008 6th International Conference on Nanochannels, Microchannels, and Minichannels. ASMEDC, 2008. http://dx.doi.org/10.1115/icnmm2008-62027.

Full text
Abstract:
We have developed a method to detect non-fluorescent analytes on standard microfluidic chip platforms equipped with fluorescence detection. We leverage isotachophoresis (ITP) to electrophoretically segregate both analytes and fluorescent species termed mobility markers into distinct zones. The fluorescent marker zones bound analyte zones, so that gaps in the fluorescent signal indicate the presence and concentration of analytes. We here demonstrate separation and indirect detection of amino acids, serine and phenylalanine and organic acids, acetic acid and phenylpropionic acid (∼10 μM) using this technique. We also present an indirect detection of the environmental toxin phenol [1][2] (∼10 μM) using two mobility markers. We show preliminary numerical simulation results that provide useful guidelines in design and optimization of our indirect detection assay.
APA, Harvard, Vancouver, ISO, and other styles
4

Burge, Scott R. "Automated Analysis of Trichloroethene and Chloroform." In ASME 2003 9th International Conference on Radioactive Waste Management and Environmental Remediation. ASMEDC, 2003. http://dx.doi.org/10.1115/icem2003-4648.

Full text
Abstract:
Chloroform and trichloroethene (TCE) are two organic contaminants commonly encountered in ground water. TCE, formerly a common cleaning solvent, is usually associated with contaminated aquifers. Chloroform is usually associated with the chlorination of municipal water. The remediation level for TCE in aquifers is typically 5 ppb, therefore, the analytical method employed for monitoring these analytes must be capable of detecting and quantifying the analytes in the low ppb concentration range. The most common analytical methodology for the determination of TCE or chloroform in water is a purge and trap technique for sample introduction into a gas chromatographic system equipped with electroconductivity or mass spectroscopy detector. The instrumentation has a method limit of detection (LOD) of less than 0.5 ppb for TCE and chloroform, however, the expense, size and complexity of the gas chromatographic techniques limit its use outside the laboratory environment. An alternative to the gas chromatographic method for the analysis of select volatile chlorinated compounds in the low concentration range is an analytical instrument based on a halocarbon-specific optrode. The principle of detection is a quantitative, irreversible chemical reaction (modified Fujiwara reaction) that forms visible light-absorbing products. The operational basis of the optrode is the measure of the time history of the development of the colored (red) product formed by the reaction of the target analytes. The optrode has the selectivity and sensitivity for monitoring TCE and chloroform at the low ppb concentration range in the presence of other volatile chlorinated contaminants. The low-power requirements and simplicity of design make it a good choice for remote operations. This paper presents the analytical results (January 2002, to December 2002) of a panel-mounted instrument used to monitor the influent and effluent water of a TCE treatment facility located in Scottsdale, Arizona, and the analytical results of a well-mounted instrument used to monitor ground water (May 2002, to August 2002) at Edwards Air Force Base, California.
APA, Harvard, Vancouver, ISO, and other styles
5

Esmaeilzadeh, Hamed, George Cernigliaro, Junwei Su, et al. "The Effects of Material Properties on Pillar-Based QCM Sensors." In ASME 2015 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/imece2015-52533.

Full text
Abstract:
Quartz crystal microbalance (QCM) device is a highly sensitive mass sensor (sensitivity: 0.5 ng/cm2) with a wide range of applications including biosensing, thin film deposition, surface chemistry, volatile organic compounds (VOC) and gaseous analytes detection. A recent study shows that several orders of magnitude improvement in sensitivity can be achieved by attaching microscale Polymethyl methacrylate (PMMA) pillars onto the surface of the QCM (QCM-P) to form a two-degree of freedom coupled resonant system. In this research, the effects of residual layer from the nanoimprinting process of micro-pillars and polydispersity index (Pd) of PMMA molecules on the sensitivity of QCM-P devices are investigated both experimentally and theoretically. The results show the residual layer behaves as an additional mass and significantly reduces the frequency shift of QCM-P sensor while a low polydispersity of PMMA improves the sensor responses. The outcome of this research leads to an in-depth understanding of the effects of material and fabrication process on QCM-P sensors which will build a solid foundation for the further improvement of QCM-P devices for a variety of applications such as protein binding measurement in drug discovery, gas detection for environmental monitoring and protection.
APA, Harvard, Vancouver, ISO, and other styles
6

Yang, Se Young, Christy Petruczok, Hyungryul Johnny Choi, Ayse Asatekin, George Barbastathis, and Karen K. Gleason. "Nano Fracture Chemical Sensor for Explosives Detection." In ASME 2010 International Mechanical Engineering Congress and Exposition. ASMEDC, 2010. http://dx.doi.org/10.1115/imece2010-37802.

Full text
Abstract:
Selective detection of explosive compounds is critical for national defense and homeland security. In this paper we describe the fabrication and demonstration of a chemical sensor capable of detecting nitroaromatic explosives in air. The device has the unique features of nano-scale dimensions, simple and inexpensive fabrication, and low power consumption. It consists of a nano-patterned conductive metal line placed on top of a patterned responsive polymer, poly(4-vinylpyridine) (P4VP). Due to polymer-solvent interactions, P4VP swells when it encounters the target analyte, producing a large stress. Detection takes place by monitoring the change in device resistance as the metal nano line deforms or fractures when P4VP swells and transfers mechanical stress. The sensors would be ideal for discreet, wide-scale deployment over large areas. It is also important to note that device sensitivity can be readily enhanced by scaling down the feature size of the metal line or adjusting the material properties of both the metal and polymer. The fabrication process is readily transferrable to a variety of organic and metal materials, improving the versatility of the sensors. The resulting devices may provide new ways to detect security threats and complement existing complex methods to increase the probability of detection and to reduce false alarms. The same approach may also be applicable outside the military/security domain, for example, for pollution monitoring, for factory safety and operational monitoring, or for food quality inspection; all these applications are contingent upon finding the appropriate polymers for the respective analytes.
APA, Harvard, Vancouver, ISO, and other styles
7

ŠILEIKIENĖ, Daiva, Laima ČESONIENĖ, and Aurelija PAULAUSKIENĖ. "PRICE DYNAMICS IN THE ASSORTMENT OF VEGETABLES OF ORGANIC AGRICULTURAL PRODUCTION IN 2014–2016." In RURAL DEVELOPMENT. Aleksandras Stulginskis University, 2018. http://dx.doi.org/10.15544/rd.2017.065.

Full text
Abstract:
The article analyzes the price dynamics of organic vegetables in Lithuania during the period of 2014 - 2016. A comparative analysis of the prices of organic vegetables (potatoes, carrots, onions) was carried out as well as a comparative analysis of Lithuanian and imported vegetables, the trends of organic potato and vegetable price dynamics were estimated. The research carried out has revealed that lowest price of organic potato during the research period was in spring and winter. Potatoes of new harvest during summer (1.23 EUR/kg) and autumn (1.25 EUR/kg) seasons are higher. Price difference between Lithuanian and imported organic carrots and potatoes during different seasons is insignificant; significant fluctuations have been recorded only in Lithuanian and imported carrots in all period and potatoes in 2015. The most expensive vegetables were organic carrots, the average price of which in 2014 was 1.38 EUR/kg. During the research period the average price of organic potatoes was 1.21 EUR/kg, i.e. 2.5 of times more than the conventional carrots (0.47 EUR/kg). Prices of the imported vegetables were higher than the prices of Lithuanian ones. In the analysed period the price of imported carrots (1.98 EUR/kg) was on average 1.5 times higher than the price of Lithuanian carrots (1.31 EUR/kg), imported organic onions (2.33 EUR/kg) were up to 57% more expensive than Lithuanian onions (1.33 EUR/kg). Germany has a wider supply of organic products. The price of potatoes in Germany using the analyzed period has risen in 51%. In 2016, the price of potatoes in Germany was 34% higher than in Lithuania. During the entire research period the price of organic carrots in Lithuania was higher than in Germany. In 2016, onions in Germany were 16% more expensive.
APA, Harvard, Vancouver, ISO, and other styles
8

Yacoubian, Araz, Vadim Chuyanov, Sean M. Garner, et al. "Acoustic spectrum analysis using polymer integrated optics." In Organic Thin Films. OSA, 1999. http://dx.doi.org/10.1364/otf.1999.sad2.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

Berkovic, Garry, G. Meshulam, and Z. Kotler. "Molecular hyperpolarizablilty in the two-photon resonance regime: Measurement and analysis." In Organic Thin Films. OSA, 1999. http://dx.doi.org/10.1364/otf.1999.sub3.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Anderson, Jay, Mustafa Kansiz, Michael Lo, and Curtis Marcott. "Submicron Simultaneous IR and Raman Spectroscopy (IR+Raman): Breakthrough Developments in Optical Photothermal IR (O-PTIR) Combined for Enhanced Failure Analysis." In ISTFA 2019. ASM International, 2019. http://dx.doi.org/10.31399/asm.cp.istfa2019p0292.

Full text
Abstract:
Abstract Failure analysis of organics at the microscopic scale is an increasingly important requirement, with traditional analytical tools such as FTIR and Raman microscopy, having significant limitations in either spatial resolution or data quality. We introduce here a new method of obtaining Infrared microspectroscopic information, at the submicron level in reflection (far-field) mode, called Optical-Photothermal Infrared (O-PTIR) spectroscopy, that can also generate simultaneous Raman spectra, from the same spot, at the same time and with the same spatial resolution. This novel combination of these two correlative techniques can be considered to be complimentary and confirmatory, in which the IR confirms the Raman result and vice-versa, to yield more accurate and therefore more confident organic unknowns analysis.
APA, Harvard, Vancouver, ISO, and other styles

Reports on the topic "Organic analytes"

1

Clauss, S. A., and R. M. Bean. A literature review of methods of analysis of organic analytes in radioactive wastes with an emphasis on sources from the United Kingdom. Office of Scientific and Technical Information (OSTI), 1993. http://dx.doi.org/10.2172/10187846.

Full text
APA, Harvard, Vancouver, ISO, and other styles
2

Clauss, S. A., K. E. Grant, V. Hoopes, et al. Organic analysis progress report FY 1997. Office of Scientific and Technical Information (OSTI), 1998. http://dx.doi.org/10.2172/671918.

Full text
APA, Harvard, Vancouver, ISO, and other styles
3

Evans, John C., James A. Campbell, Francis V. Hoopes, et al. Organic Analysis of C-104 Tank Waste. Office of Scientific and Technical Information (OSTI), 2001. http://dx.doi.org/10.2172/15011290.

Full text
APA, Harvard, Vancouver, ISO, and other styles
4

Jones, Frank E. Collection and analysis of organic compounds in air :. National Bureau of Standards, 1987. http://dx.doi.org/10.6028/nbs.ir.87-3527.

Full text
APA, Harvard, Vancouver, ISO, and other styles
5

Clarkson, R. B. VHF EPR analysis of organic sulfur in coal. Office of Scientific and Technical Information (OSTI), 1991. http://dx.doi.org/10.2172/5791531.

Full text
APA, Harvard, Vancouver, ISO, and other styles
6

Wahl, K. L., J. A. Campbell, and S. A. Clauss. Advanced organic analysis and analytical methods development: FY 1995 progress report. Waste Tank Organic Safety Program. Office of Scientific and Technical Information (OSTI), 1995. http://dx.doi.org/10.2172/109515.

Full text
APA, Harvard, Vancouver, ISO, and other styles
7

FOWLER, K. D. Organic end state analysis of tank 241-S-102. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/782402.

Full text
APA, Harvard, Vancouver, ISO, and other styles
8

FOWLER, K. D. Organic end state analysis of tank 241-S-106. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/782415.

Full text
APA, Harvard, Vancouver, ISO, and other styles
9

FOWLER, K. D. Organic end state analysis of tank 241-S-103. Office of Scientific and Technical Information (OSTI), 1999. http://dx.doi.org/10.2172/782418.

Full text
APA, Harvard, Vancouver, ISO, and other styles
10

Manqun, Lin, Shen Meiqing, Jia Bin, et al. Organic Compound Exhaust Analysis from Ethanol-Gasoline Fueled Motorcycle. SAE International, 2005. http://dx.doi.org/10.4271/2005-32-0055.

Full text
APA, Harvard, Vancouver, ISO, and other styles
You might also be interested in the extended bibliographies on the topic 'Organic analytes' for particular source types:
Journal articles Dissertations / Theses Books
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography