A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis

PubMed Central

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described. PMID:28542338

A technique for setting analytical thresholds in massively parallel sequencing-based forensic DNA analysis.

PubMed

Young, Brian; King, Jonathan L; Budowle, Bruce; Armogida, Luigi

2017-01-01

Amplicon (targeted) sequencing by massively parallel sequencing (PCR-MPS) is a potential method for use in forensic DNA analyses. In this application, PCR-MPS may supplement or replace other instrumental analysis methods such as capillary electrophoresis and Sanger sequencing for STR and mitochondrial DNA typing, respectively. PCR-MPS also may enable the expansion of forensic DNA analysis methods to include new marker systems such as single nucleotide polymorphisms (SNPs) and insertion/deletions (indels) that currently are assayable using various instrumental analysis methods including microarray and quantitative PCR. Acceptance of PCR-MPS as a forensic method will depend in part upon developing protocols and criteria that define the limitations of a method, including a defensible analytical threshold or method detection limit. This paper describes an approach to establish objective analytical thresholds suitable for multiplexed PCR-MPS methods. A definition is proposed for PCR-MPS method background noise, and an analytical threshold based on background noise is described.

Sensitivity, Specificity, and Receiver Operating Characteristics: A Primer for Neuroscience Nurses.

PubMed

McNett, Molly; Amato, Shelly; Olson, DaiWai M

2017-04-01

It is important for neuroscience nurses to have a solid understanding of the instruments they use in clinical practice. Specifically, when reviewing reports of research instruments, nurses should be knowledgeable of analytical terms when determining the applicability of instruments for use in clinical practice. The purpose of this article is to review 3 such analytical terms: sensitivity, specificity, and receiver operating characteristic curves. Examples of how these terms are used in the neuroscience literature highlight the relevance of these terms to neuroscience nursing practice. As the role of the nurse continues to expand, it is important not to simply accept all instruments as valid but to be able to critically evaluate their properties for applicability to nursing practice and evidence-based care of our patients.

Microfluidic-Based sample chips for radioactive solutions

DOE PAGES

Tripp, J. L.; Law, J. D.; Smith, T. E.; ...

2015-01-01

Historical nuclear fuel cycle process sampling techniques required sample volumes ranging in the tens of milliliters. The radiation levels experienced by analytical personnel and equipment, in addition to the waste volumes generated from analysis of these samples, have been significant. These sample volumes also impacted accountability inventories of required analytes during process operations. To mitigate radiation dose and other issues associated with the historically larger sample volumes, a microcapillary sample chip was chosen for further investigation. The ability to obtain microliter volume samples coupled with a remote automated means of sample loading, tracking, and transporting to the analytical instrument wouldmore » greatly improve analytical efficiency while reducing both personnel exposure and radioactive waste volumes. Sample chip testing was completed to determine the accuracy, repeatability, and issues associated with the use of microfluidic sample chips used to supply µL sample volumes of lanthanide analytes dissolved in nitric acid for introduction to an analytical instrument for elemental analysis.« less

Quantitative Analysis of Heavy Metals in Children's Toys and Jewelry: A Multi-Instrument, Multitechnique Exercise in Analytical Chemistry and Public Health

ERIC Educational Resources Information Center

Finch, Lauren E.; Hillyer, Margot M.; Leopold, Michael C.

2015-01-01

For most chemistry curricula, laboratory-based activities in quantitative and instrumental analysis continue to be an important aspect of student development/training, one that can be more effective if conceptual understanding is delivered through an inquiry-based process relating the material to relevant issues of public interest and student…

Complexometric Determination of Mercury Based on a Selective Masking Reaction

ERIC Educational Resources Information Center

Romero, Mercedes; Guidi, Veronica; Ibarrolaza, Agustin; Castells, Cecilia

2009-01-01

In the first analytical chemistry course, students are introduced to the concepts of equilibrium in water solutions and classical (non-instrumental) analytical methods. Our teaching experience shows that "real samples" stimulate students' enthusiasm for the laboratory work. From this diagnostic, we implemented an optional activity at the end of…

Microprocessor Based Temperature Control of Liquid Delivery with Flow Disturbances.

ERIC Educational Resources Information Center

Kaya, Azmi

1982-01-01

Discusses analytical design and experimental verification of a PID control value for a temperature controlled liquid delivery system, demonstrating that the analytical design techniques can be experimentally verified by using digital controls as a tool. Digital control instrumentation and implementation are also demonstrated and documented for…

Evaluation of a reconfigurable portable instrument for copper determination based on luminescent carbon dots.

PubMed

Salinas-Castillo, Alfonso; Morales, Diego P; Lapresta-Fernández, Alejandro; Ariza-Avidad, María; Castillo, Encarnación; Martínez-Olmos, Antonio; Palma, Alberto J; Capitan-Vallvey, Luis Fermin

2016-04-01

A portable reconfigurable platform for copper (Cu(II)) determination based on luminescent carbon dot (Cdots) quenching is described. The electronic setup consists of a light-emitting diode (LED) as the carbon dot optical exciter and a photodiode as a light-to-current converter integrated in the same instrument. Moreover, the overall analog conditioning is simply performed with one integrated solution, a field-programmable analog array (FPAA), which makes it possible to reconfigure the filter and gain stages in real time. This feature provides adaptability to use the platform as an analytical probe for carbon dots coming from different batches with some variations in luminescence characteristics. The calibration functions obtained that fit a modified Stern-Volmer equation were obtained using luminescence signals from Cdots quenching by Cu(II). The analytical applicability of the reconfigurable portable instrument for Cu(II) using Cdots has been successfully demonstrated in tap water analysis.

Aerosol-based detectors for liquid chromatography.

PubMed

Magnusson, Lars-Erik; Risley, Donald S; Koropchak, John A

2015-11-20

Aerosol-based detectors developed within the last few decades have increasingly addressed the need for sensitive, universal liquid chromatography detection in a wide variety of applications. Herein, we review the operating principles, instrumentation, analytical characteristics, and recent applications of the three general types of such detectors: evaporative light scattering detection (ELSD), condensation nucleation light scattering detection (CNLSD); commercially known as the nano-quantity analyte detector (NQAD), and charged aerosol detection (CAD). Included is a comparative evaluation of the operational and analytical characteristics of these detectors. Copyright © 2015 Elsevier B.V. All rights reserved.

A Laboratory-Based System for Managing and Distributing Publically Funded Geochemical Data in a Collaborative Environment

NASA Astrophysics Data System (ADS)

McInnes, B.; Brown, A.; Liffers, M.

2015-12-01

Publically funded laboratories have a responsibility to generate, archive and disseminate analytical data to the research community. Laboratory managers know however, that a long tail of analytical effort never escapes researchers' thumb drives once they leave the lab. This work reports on a research data management project (Digital Mineralogy Library) where integrated hardware and software systems automatically archive and deliver analytical data and metadata to institutional and community data portals. The scientific objective of the DML project was to quantify the modal abundance of heavy minerals extracted from key lithological units in Western Australia. The selected analytical platform was a TESCAN Integrated Mineral Analyser (TIMA) that uses EDS-based mineral classification software to image and quantify mineral abundance and grain size at micron scale resolution. The analytical workflow used a bespoke laboratory information management system (LIMS) to orchestrate: (1) the preparation of grain mounts with embedded QR codes that serve as enduring links between physical samples and analytical data, (2) the assignment of an International Geo Sample Number (IGSN) and Digital Object Identifier (DOI) to each grain mount via the System for Earth Sample Registry (SESAR), (3) the assignment of a DOI to instrument metadata via Research Data Australia, (4) the delivery of TIMA analytical outputs, including spatially registered mineralogy images and mineral abundance data, to an institutionally-based data management server, and (5) the downstream delivery of a final data product via a Google Maps interface such as the AuScope Discovery Portal. The modular design of the system permits the networking of multiple instruments within a single site or multiple collaborating research institutions. Although sharing analytical data does provide new opportunities for the geochemistry community, the creation of an open data network requires: (1) adopting open data reporting standards and conventions, (2) requiring instrument manufacturers and software developers to deliver and process data in formats compatible with open standards, and (3) public funding agencies to incentivise researchers, laboratories and institutions to make their data open and accessible to consumers.

Promoting Active Learning by Practicing the "Self-Assembly" of Model Analytical Instruments

ERIC Educational Resources Information Center

Algar, W. Russ; Krull, Ulrich J.

2010-01-01

In our upper-year instrumental analytical chemistry course, we have developed "cut-and-paste" exercises where students "build" models of analytical instruments from individual schematic images of components. These exercises encourage active learning by students. Instead of trying to memorize diagrams, students are required to think deeply about…

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

none, none; Tuchman, Nancy

The U.S. Department of Energy awarded Loyola University Chicago and the Institute of Environmental Sustainability (IES) $486,000.00 for the proposal entitled “Chicago clean air, clean water project: Environmental monitoring for a healthy, sustainable urban future.” The project supported the purchase of analytical instruments for the development of an environmental analytical laboratory. The analytical laboratory is designed to support the testing of field water and soil samples for nutrients, industrial pollutants, heavy metals, and agricultural toxins, with special emphasis on testing Chicago regional soils and water affected by coal-based industry. Since the award was made in 2010, the IES has beenmore » launched (fall 2013), and the IES acquired a new state-of-the-art research and education facility on Loyola University Chicago’s Lakeshore campus. Two labs were included in the research and education facility. The second floor lab is the Ecology Laboratory where lab experiments and analyses are conducted on soil, plant, and water samples. The third floor lab is the Environmental Toxicology Lab where lab experiments on environmental toxins are conducted, as well as analytical tests conducted on water, soil, and plants. On the south end of the Environmental Toxicology Lab is the analytical instrumentation collection purchased from the present DOE grant, which is overseen by a full time Analytical Chemist (hired January 2016), who maintains the instruments, conducts analyses on samples, and helps to train faculty and undergraduate and graduate student researchers.« less

Rumsey and Walker_AMT_2016_Table 1

EPA Pesticide Factsheets

Table summarizes instrument analytical detection limits, including liquid and equivalent air concentrations.This dataset is associated with the following publication:Rumsey, I. Application of an online ion chromatography-based instrument for gradient flux measurements of speciated nitrogen and sulfur. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 9(6): 2581-2592, (2016).

Real-Time Data Warehousing and On-Line Analytical Processing at Aberdeen Test Center’s Distributed Center

DTIC Science & Technology

2005-12-01

data collected via on-board instrumentation -VxWorks based computer. Each instrument produces a continuous time history record of up to 250...data in multidimensional hierarchies and views. UGC 2005 Institute a high performance data warehouse • PostgreSQL 7.4 installed on dedicated filesystem

Carbon Nanotube-Based Chemical Sensors.

PubMed

Meyyappan, M

2016-04-27

The need to sense gases and vapors arises in numerous scenarios in industrial, environmental, security and medical applications. Traditionally, this activity has utilized bulky instruments to obtain both qualitative and quantitative information on the constituents of the gas mixture. It is ideal to use sensors for this purpose since they are smaller in size and less expensive; however, their performance in the field must match that of established analytical instruments in order to gain acceptance. In this regard, nanomaterials as sensing media offer advantages in sensitivity, preparation of chip-based sensors and construction of electronic nose for selective detection of analytes of interest. This article provides a review of the use of carbon nanotubes in gas and vapor sensing. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The Effect of Emulsion Intensity on Selected Sensory and Instrumental Texture Properties of Full-Fat Mayonnaise

PubMed Central

Olsson, Viktoria; Håkansson, Andreas

2018-01-01

Varying processing conditions can strongly affect the microstructure of mayonnaise, opening up new applications for the creation of products tailored to meet different consumer preferences. The aim of the study was to evaluate the effect of emulsification intensity on sensory and instrumental characteristics of full-fat mayonnaise. Mayonnaise, based on a standard recipe, was processed at low and high emulsification intensities, with selected sensory and instrumental properties then evaluated using an analytical panel and a back extrusion method. The evaluation also included a commercial reference mayonnaise. The overall effects of a higher emulsification intensity on the sensory and instrumental characteristics of full-fat mayonnaise were limited. However, texture was affected, with a more intense emulsification resulting in a firmer mayonnaise according to both back extrusion data and the analytical sensory panel. Appearance, taste and flavor attributes were not affected by processing. PMID:29342128

Career Decision Statuses among Portuguese Secondary School Students: A Cluster Analytical Approach

ERIC Educational Resources Information Center

Santos, Paulo Jorge; Ferreira, Joaquim Armando

2012-01-01

Career indecision is a complex phenomenon and an increasing number of authors have proposed that undecided individuals do not form a group with homogeneous characteristics. This study examines career decision statuses among a sample of 362 12th-grade Portuguese students. A cluster-analytical procedure, based on a battery of instruments designed to…

Microfabricated field calibration assembly for analytical instruments

DOEpatents

Robinson, Alex L [Albuquerque, NM; Manginell, Ronald P [Albuquerque, NM; Moorman, Matthew W [Albuquerque, NM; Rodacy, Philip J [Albuquerque, NM; Simonson, Robert J [Cedar Crest, NM

2011-03-29

A microfabricated field calibration assembly for use in calibrating analytical instruments and sensor systems. The assembly comprises a circuit board comprising one or more resistively heatable microbridge elements, an interface device that enables addressable heating of the microbridge elements, and, in some embodiments, a means for positioning the circuit board within an inlet structure of an analytical instrument or sensor system.

Exploratory Analysis of Supply Chains in the Defense Industrial Base

DTIC Science & Technology

2012-04-01

Instruments Industry Group 382: Laboratory Apparatus and Analytical, Optical, Measuring, and Controlling Instruments 3821 Laboratory Apparatus and Furniture ...I N S T I T U T E F O R D E F E N S E A N A LY S E S Exploratory Analysis of Supply Chains in the Defense Industrial Base James R. Dominy...contract DASW01-04-C-0003, AH-7-3315, “Exploratory Analysis of Supply Chains in the Defense Industrial Base,” for the Director, Industrial Policy. The

Pre-concentration technique for reduction in "Analytical instrument requirement and analysis"

NASA Astrophysics Data System (ADS)

Pal, Sangita; Singha, Mousumi; Meena, Sher Singh

2018-04-01

Availability of analytical instruments for a methodical detection of known and unknown effluents imposes a serious hindrance in qualification and quantification. Several analytical instruments such as Elemental analyzer, ICP-MS, ICP-AES, EDXRF, ion chromatography, Electro-analytical instruments which are not only expensive but also time consuming, required maintenance, damaged essential parts replacement which are of serious concern. Move over for field study and instant detection installation of these instruments are not convenient to each and every place. Therefore, technique such as pre-concentration of metal ions especially for lean stream elaborated and justified. Chelation/sequestration is the key of immobilization technique which is simple, user friendly, most effective, least expensive, time efficient; easy to carry (10g - 20g vial) to experimental field/site has been demonstrated.

Characterizing nonconstant instrumental variance in emerging miniaturized analytical techniques.

PubMed

Noblitt, Scott D; Berg, Kathleen E; Cate, David M; Henry, Charles S

2016-04-07

Measurement variance is a crucial aspect of quantitative chemical analysis. Variance directly affects important analytical figures of merit, including detection limit, quantitation limit, and confidence intervals. Most reported analyses for emerging analytical techniques implicitly assume constant variance (homoskedasticity) by using unweighted regression calibrations. Despite the assumption of constant variance, it is known that most instruments exhibit heteroskedasticity, where variance changes with signal intensity. Ignoring nonconstant variance results in suboptimal calibrations, invalid uncertainty estimates, and incorrect detection limits. Three techniques where homoskedasticity is often assumed were covered in this work to evaluate if heteroskedasticity had a significant quantitative impact-naked-eye, distance-based detection using paper-based analytical devices (PADs), cathodic stripping voltammetry (CSV) with disposable carbon-ink electrode devices, and microchip electrophoresis (MCE) with conductivity detection. Despite these techniques representing a wide range of chemistries and precision, heteroskedastic behavior was confirmed for each. The general variance forms were analyzed, and recommendations for accounting for nonconstant variance discussed. Monte Carlo simulations of instrument responses were performed to quantify the benefits of weighted regression, and the sensitivity to uncertainty in the variance function was tested. Results show that heteroskedasticity should be considered during development of new techniques; even moderate uncertainty (30%) in the variance function still results in weighted regression outperforming unweighted regressions. We recommend utilizing the power model of variance because it is easy to apply, requires little additional experimentation, and produces higher-precision results and more reliable uncertainty estimates than assuming homoskedasticity. Copyright © 2016 Elsevier B.V. All rights reserved.

Utilizing global data to estimate analytical performance on the Sigma scale: A global comparative analysis of methods, instruments, and manufacturers through external quality assurance and proficiency testing programs.

PubMed

Westgard, Sten A

2016-06-01

To assess the analytical performance of instruments and methods through external quality assessment and proficiency testing data on the Sigma scale. A representative report from five different EQA/PT programs around the world (2 US, 1 Canadian, 1 UK, and 1 Australasian) was accessed. The instrument group standard deviations were used as surrogate estimates of instrument imprecision. Performance specifications from the US CLIA proficiency testing criteria were used to establish a common quality goal. Then Sigma-metrics were calculated to grade the analytical performance. Different methods have different Sigma-metrics for each analyte reviewed. Summary Sigma-metrics estimate the percentage of the chemistry analytes that are expected to perform above Five Sigma, which is where optimized QC design can be implemented. The range of performance varies from 37% to 88%, exhibiting significant differentiation between instruments and manufacturers. Median Sigmas for the different manufacturers in three analytes (albumin, glucose, sodium) showed significant differentiation. Chemistry tests are not commodities. Quality varies significantly from manufacturer to manufacturer, instrument to instrument, and method to method. The Sigma-assessments from multiple EQA/PT programs provide more insight into the performance of methods and instruments than any single program by itself. It is possible to produce a ranking of performance by manufacturer, instrument and individual method. Laboratories seeking optimal instrumentation would do well to consult this data as part of their decision-making process. To confirm that these assessments are stable and reliable, a longer term study should be conducted that examines more results over a longer time period. Copyright © 2016 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Developing automated analytical methods for scientific environments using LabVIEW.

PubMed

Wagner, Christoph; Armenta, Sergio; Lendl, Bernhard

2010-01-15

The development of new analytical techniques often requires the building of specially designed devices, each requiring its own dedicated control software. Especially in the research and development phase, LabVIEW has proven to be one highly useful tool for developing this software. Yet, it is still common practice to develop individual solutions for different instruments. In contrast to this, we present here a single LabVIEW-based program that can be directly applied to various analytical tasks without having to change the program code. Driven by a set of simple script commands, it can control a whole range of instruments, from valves and pumps to full-scale spectrometers. Fluid sample (pre-)treatment and separation procedures can thus be flexibly coupled to a wide range of analytical detection methods. Here, the capabilities of the program have been demonstrated by using it for the control of both a sequential injection analysis - capillary electrophoresis (SIA-CE) system with UV detection, and an analytical setup for studying the inhibition of enzymatic reactions using a SIA system with FTIR detection.

Air Pollution Instrumentation: A Trend toward Physical Methods

ERIC Educational Resources Information Center

Maugh, Thomas H., II

1972-01-01

Reviews reasons for the trend from wet chemical'' analytic techniques for measuring air pollutants toward physical methods based upon chemiluminescence, electrochemical transduction, flame ionization coupled with gas chromotography, and spectroscopy. (AL)

Analytic Method for Computing Instrument Pointing Jitter

NASA Technical Reports Server (NTRS)

Bayard, David

2003-01-01

A new method of calculating the root-mean-square (rms) pointing jitter of a scientific instrument (e.g., a camera, radar antenna, or telescope) is introduced based on a state-space concept. In comparison with the prior method of calculating the rms pointing jitter, the present method involves significantly less computation. The rms pointing jitter of an instrument (the square root of the jitter variance shown in the figure) is an important physical quantity which impacts the design of the instrument, its actuators, controls, sensory components, and sensor- output-sampling circuitry. Using the Sirlin, San Martin, and Lucke definition of pointing jitter, the prior method of computing the rms pointing jitter involves a frequency-domain integral of a rational polynomial multiplied by a transcendental weighting function, necessitating the use of numerical-integration techniques. In practice, numerical integration complicates the problem of calculating the rms pointing error. In contrast, the state-space method provides exact analytic expressions that can be evaluated without numerical integration.

Correlation between polymerization shrinkage stress and C-factor depends upon cavity compliance.

PubMed

Wang, Zhengzhi; Chiang, Martin Y M

2016-03-01

The literature reports inconsistent results regarding using configuration factor (C-factor) as an indicator to reflect the generation of polymerization shrinkage stress (PS) from dental restorative composites due to the constraint of cavity configuration. The current study aimed at unraveling the complex effects of C-factor on PS based on analytical and experimental approaches together, such that the reported inconsistency can be explained and a significance of C-factor in clinic can be comprehensively provided. Analytical models based on linear elasticity were established to predict PS measured in instruments (testing systems) with different compliances, and complex effects of C-factor on PS were derived. The analyses were validated by experiments using a cantilever beam-based instrument and systematic variation of instrumental compliance. For a general trend, PS decreased with increasing C-factor when measured by instruments with high compliance. However, this trend gradually diminished and eventually reversed (PS became increased with increasing C-factor) by decreasing the system compliance. Our study indicates that the correlation between PS and C-factor are highly dependent on the compliance of testing instrument for PS measurement. This suggests that the current concept on the role of C-factor in the stress development and transmission to tooth structures, higher C-factor produces higher PS due to reduced flow capacity of more confined materials, can be misleading. Thus, the compliance of the prepared tooth (cavity) structure should also be considered in the effect of C-factor on PS. Published by Elsevier Ltd.

Instrumentation '79.

ERIC Educational Resources Information Center

Chemical and Engineering News, 1979

1979-01-01

Surveys the state of commerical development of analytical instrumentation as reflected by the Pittsburgh Conference on Analytical Chemistry and Applied Spectroscopy. Includes optical spectroscopy, liquid chromatography, magnetic spectrometers, and x-ray. (Author/MA)

Analytical Chemistry in Russia.

PubMed

Zolotov, Yuri

2016-09-06

Research in Russian analytical chemistry (AC) is carried out on a significant scale, and the analytical service solves practical tasks of geological survey, environmental protection, medicine, industry, agriculture, etc. The education system trains highly skilled professionals in AC. The development and especially manufacturing of analytical instruments should be improved; in spite of this, there are several good domestic instruments and other satisfy some requirements. Russian AC has rather good historical roots.

Art, Meet Chemistry; Chemistry, Meet Art: Case Studies, Current Literature, and Instrumental Methods Combined to Create a Hands-On Experience for Nonmajors and Instrumental Analysis Students

ERIC Educational Resources Information Center

Nivens, Delana A.; Padgett, Clifford W.; Chase, Jeffery M.; Verges, Katie J.; Jamieson, Deborah S.

2010-01-01

Case studies and current literature are combined with spectroscopic analysis to provide a unique chemistry experience for art history students and to provide a unique inquiry-based laboratory experiment for analytical chemistry students. The XRF analysis method was used to demonstrate to nonscience majors (art history students) a powerful…

Technical Note: Intercomparison of formaldehyde measurements at the atmosphere simulation chamber SAPHIR

NASA Astrophysics Data System (ADS)

Wisthaler, A.; Apel, E. C.; Bossmeyer, J.; Hansel, A.; Junkermann, W.; Koppmann, R.; Meier, R.; Müller, K.; Solomon, S. J.; Steinbrecher, R.; Tillmann, R.; Brauers, T.

2008-04-01

The atmosphere simulation chamber SAPHIR at the Research Centre Jülich was used to test the suitability of state-of-the-art analytical instruments for the measurement of gas-phase formaldehyde (HCHO) in air. Five analyzers based on four different sensing principles were deployed: a differential optical absorption spectrometer (DOAS), cartridges for 2,4-dinitrophenylhydrazine (DNPH) derivatization followed by off-line high pressure liquid chromatography (HPLC) analysis, two different types of commercially available wet chemical sensors based on Hantzsch fluorimetry, and a proton-transfer-reaction mass spectrometer (PTR-MS). A new optimized mode of operation was used for the PTR-MS instrument which significantly enhanced its performance for online HCHO detection at low absolute humidities. The instruments were challenged with typical ambient levels of HCHO ranging from zero to several ppb. Synthetic air of high purity and particulate-filtered ambient air were used as sample matrices in the atmosphere simulation chamber onto which HCHO was spiked under varying levels of humidity and ozone. Measurements were compared to mixing ratios calculated from the chamber volume and the known amount of HCHO injected into the chamber; measurements were also compared between the different instruments. The formal and blind intercomparison exercise was conducted under the control of an independent referee. A number of analytical problems associated with the experimental set-up and with individual instruments were identified, the overall agreement between the methods was fair.

Biological Matrix Effects in Quantitative Tandem Mass Spectrometry-Based Analytical Methods: Advancing Biomonitoring

PubMed Central

Panuwet, Parinya; Hunter, Ronald E.; D’Souza, Priya E.; Chen, Xianyu; Radford, Samantha A.; Cohen, Jordan R.; Marder, M. Elizabeth; Kartavenka, Kostya; Ryan, P. Barry; Barr, Dana Boyd

2015-01-01

The ability to quantify levels of target analytes in biological samples accurately and precisely, in biomonitoring, involves the use of highly sensitive and selective instrumentation such as tandem mass spectrometers and a thorough understanding of highly variable matrix effects. Typically, matrix effects are caused by co-eluting matrix components that alter the ionization of target analytes as well as the chromatographic response of target analytes, leading to reduced or increased sensitivity of the analysis. Thus, before the desired accuracy and precision standards of laboratory data are achieved, these effects must be characterized and controlled. Here we present our review and observations of matrix effects encountered during the validation and implementation of tandem mass spectrometry-based analytical methods. We also provide systematic, comprehensive laboratory strategies needed to control challenges posed by matrix effects in order to ensure delivery of the most accurate data for biomonitoring studies assessing exposure to environmental toxicants. PMID:25562585

Moving your laboratories to the field – Advantages and limitations of the use of field portable instruments in environmental sample analysis

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

Gałuszka, Agnieszka, E-mail: Agnieszka.Galuszka@ujk.edu.pl; Migaszewski, Zdzisław M.; Namieśnik, Jacek

The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector),more » ultraviolet–visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities. - Highlights: • Field portable instruments are widely used in environmental sample analysis. • Field portable instruments are indispensable for analysis in emergency response. • Miniaturization of field portable instruments reduces resource consumption. • In situ analysis is in agreement with green analytical chemistry principles. • Performance requirements in field analysis stimulate technological progress.« less

Low-Cost Method for Quantifying Sodium in Coconut Water and Seawater for the Undergraduate Analytical Chemistry Laboratory: Flame Test, a Mobile Phone Camera, and Image Processing

ERIC Educational Resources Information Center

Moraes, Edgar P.; da Silva, Nilbert S. A.; de Morais, Camilo de L. M.; das Neves, Luiz S.; de Lima, Kassio M. G.

2014-01-01

The flame test is a classical analytical method that is often used to teach students how to identify specific metals. However, some universities in developing countries have difficulties acquiring the sophisticated instrumentation needed to demonstrate how to identify and quantify metals. In this context, a method was developed based on the flame…

Toward high value sensing: monolayer-protected metal nanoparticles in multivariable gas and vapor sensors.

PubMed

Potyrailo, Radislav A

2017-08-29

For detection of gases and vapors in complex backgrounds, "classic" analytical instruments are an unavoidable alternative to existing sensors. Recently a new generation of sensors, known as multivariable sensors, emerged with a fundamentally different perspective for sensing to eliminate limitations of existing sensors. In multivariable sensors, a sensing material is designed to have diverse responses to different gases and vapors and is coupled to a multivariable transducer that provides independent outputs to recognize these diverse responses. Data analytics tools provide rejection of interferences and multi-analyte quantitation. This review critically analyses advances of multivariable sensors based on ligand-functionalized metal nanoparticles also known as monolayer-protected nanoparticles (MPNs). These MPN sensing materials distinctively stand out from other sensing materials for multivariable sensors due to their diversity of gas- and vapor-response mechanisms as provided by organic and biological ligands, applicability of these sensing materials for broad classes of gas-phase compounds such as condensable vapors and non-condensable gases, and for several principles of signal transduction in multivariable sensors that result in non-resonant and resonant electrical sensors as well as material- and structure-based photonic sensors. Such features should allow MPN multivariable sensors to be an attractive high value addition to existing analytical instrumentation.

Paper-based analytical devices for environmental analysis.

PubMed

Meredith, Nathan A; Quinn, Casey; Cate, David M; Reilly, Thomas H; Volckens, John; Henry, Charles S

2016-03-21

The field of paper-based microfluidics has experienced rapid growth over the past decade. Microfluidic paper-based analytical devices (μPADs), originally developed for point-of-care medical diagnostics in resource-limited settings, are now being applied in new areas, such as environmental analyses. Low-cost paper sensors show great promise for on-site environmental analysis; the theme of ongoing research complements existing instrumental techniques by providing high spatial and temporal resolution for environmental monitoring. This review highlights recent applications of μPADs for environmental analysis along with technical advances that may enable μPADs to be more widely implemented in field testing.

State-of-the-art Instruments for Detecting Extraterrestrial Life

NASA Technical Reports Server (NTRS)

Bada, Jeffrey L.

2003-01-01

In the coming decades, state-of-the-art spacecraft-based instruments that can detect key components associated with life as we know it on Earth will directly search for extinct or extant extraterrestrial life in our solar system. Advances in our analytical and detection capabilities, especially those based on microscale technologies, will be important in enhancing the abilities of these instruments. Remote sensing investigations of the atmospheres of extrasolar planets could provide evidence of photosynthetic-based life outside our solar system, although less advanced life will remain undetectable by these methods. Finding evidence of extraterrestrial life would have profound consequences both with respect to our understanding of chemical and biological evolution, and whether the biochemistry on Earth is unique in the universe.

Data Acquisition Programming (LabVIEW): An Aid to Teaching Instrumental Analytical Chemistry.

ERIC Educational Resources Information Center

Gostowski, Rudy

A course was developed at Austin Peay State University (Tennessee) which offered an opportunity for hands-on experience with the essential components of modern analytical instruments. The course aimed to provide college students with the skills necessary to construct a simple model instrument, including the design and fabrication of electronic…

Chemical Detection and Identification Techniques for Exobiology Flight Experiments

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Sheverev, Valery A.; Khromov, Nikolai A.

2002-01-01

Exobiology flight experiments require highly sensitive instrumentation for in situ analysis of the volatile chemical species that occur in the atmospheres and surfaces of various bodies within the solar system. The complex mixtures encountered place a heavy burden on the analytical Instrumentation to detect and identify all species present. The minimal resources available onboard for such missions mandate that the instruments provide maximum analytical capabilities with minimal requirements of volume, weight and consumables. Advances in technology may be achieved by increasing the amount of information acquired by a given technique with greater analytical capabilities and miniaturization of proven terrestrial technology. We describe here methods to develop analytical instruments for the detection and identification of a wide range of chemical species using Gas Chromatography. These efforts to expand the analytical capabilities of GC technology are focused on the development of detectors for the GC which provide sample identification independent of the GC retention time data. A novel new approach employs Penning Ionization Electron Spectroscopy (PIES).

Recent developments and future trends in solid phase microextraction techniques towards green analytical chemistry.

PubMed

Spietelun, Agata; Marcinkowski, Łukasz; de la Guardia, Miguel; Namieśnik, Jacek

2013-12-20

Solid phase microextraction find increasing applications in the sample preparation step before chromatographic determination of analytes in samples with a complex composition. These techniques allow for integrating several operations, such as sample collection, extraction, analyte enrichment above the detection limit of a given measuring instrument and the isolation of analytes from sample matrix. In this work the information about novel methodological and instrumental solutions in relation to different variants of solid phase extraction techniques, solid-phase microextraction (SPME), stir bar sorptive extraction (SBSE) and magnetic solid phase extraction (MSPE) is presented, including practical applications of these techniques and a critical discussion about their advantages and disadvantages. The proposed solutions fulfill the requirements resulting from the concept of sustainable development, and specifically from the implementation of green chemistry principles in analytical laboratories. Therefore, particular attention was paid to the description of possible uses of novel, selective stationary phases in extraction techniques, inter alia, polymeric ionic liquids, carbon nanotubes, and silica- and carbon-based sorbents. The methodological solutions, together with properly matched sampling devices for collecting analytes from samples with varying matrix composition, enable us to reduce the number of errors during the sample preparation prior to chromatographic analysis as well as to limit the negative impact of this analytical step on the natural environment and the health of laboratory employees. Copyright © 2013 Elsevier B.V. All rights reserved.

The Open AUC Project.

PubMed

Cölfen, Helmut; Laue, Thomas M; Wohlleben, Wendel; Schilling, Kristian; Karabudak, Engin; Langhorst, Bradley W; Brookes, Emre; Dubbs, Bruce; Zollars, Dan; Rocco, Mattia; Demeler, Borries

2010-02-01

Progress in analytical ultracentrifugation (AUC) has been hindered by obstructions to hardware innovation and by software incompatibility. In this paper, we announce and outline the Open AUC Project. The goals of the Open AUC Project are to stimulate AUC innovation by improving instrumentation, detectors, acquisition and analysis software, and collaborative tools. These improvements are needed for the next generation of AUC-based research. The Open AUC Project combines on-going work from several different groups. A new base instrument is described, one that is designed from the ground up to be an analytical ultracentrifuge. This machine offers an open architecture, hardware standards, and application programming interfaces for detector developers. All software will use the GNU Public License to assure that intellectual property is available in open source format. The Open AUC strategy facilitates collaborations, encourages sharing, and eliminates the chronic impediments that have plagued AUC innovation for the last 20 years. This ultracentrifuge will be equipped with multiple and interchangeable optical tracks so that state-of-the-art electronics and improved detectors will be available for a variety of optical systems. The instrument will be complemented by a new rotor, enhanced data acquisition and analysis software, as well as collaboration software. Described here are the instrument, the modular software components, and a standardized database that will encourage and ease integration of data analysis and interpretation software.

Analytical Electrochemistry: Theory and Instrumentation of Dynamic Techniques.

ERIC Educational Resources Information Center

Johnson, Dennis C.

1980-01-01

Emphasizes trends in the development of six topics concerning analytical electrochemistry, including books and reviews (34 references cited), mass transfer (59), charge transfer (25), surface effects (33), homogeneous reactions (21), and instrumentation (31). (CS)

[Survey of analytical works for drugs at emergency and critical care centers with high-performance instruments provided by the Ministry of Health and Welfare (at present: Ministry of Health, Labour, and Welfare) in fiscal 1998--continuation of survey with 2008 survey results as point of reference].

PubMed

Saito, Takeshi; Tominaga, Aya; Nozawa, Mayu; Unei, Hiroko; Hatano, Yayoi; Fujita, Yuji; Iseki, Ken; Hori, Yasushi

2013-09-01

In a 2008 survey of the 73 emergency and critical care centers around the nation that were equipped with the drug and chemical analytical instrument provided by the Ministry of Welfare (currently the Ministry of Health, Labour, and Welfare) in 1998, 36 of those facilities were using the analytical instruments. Of these 36 facilities, a follow-up survey of the 17 facilities that recorded 50 or analyses per year. Responses were gained from 16 of the facilities and we learned that of those, 14 facilities (87.5%) were conducting analyses using the instrument. There was a positive mutual correlation between the annual number of cases of the 14 facilities conducting analyses with the instrument and the number of work hours. Depending on the instrument in use, average analytical instrument parts and maintenance expenses were roughly three million yen and consumables required a maximum three million yen for analysis of 51-200 cases per year. From this, we calculate that such expenses can be covered under the allowed budget for advanced emergency and critical care centers of 5,000 NHI points (1 point = 10 yen). We found there were few facilities using the instrument for all 15 of the toxic substances recommended for testing by the Japanese Society for Clinical Toxicology. There tended to be no use of the analytical instrument for compounds with no toxicology cases. However, flexible responses were noted at each facility in relation to frequently analyzed compounds. It is thought that a reevaluation of compounds subject to analysis is required.

Accommodating subject and instrument variations in spectroscopic determinations

DOEpatents

Haas, Michael J [Albuquerque, NM; Rowe, Robert K [Corrales, NM; Thomas, Edward V [Albuquerque, NM

2006-08-29

A method and apparatus for measuring a biological attribute, such as the concentration of an analyte, particularly a blood analyte in tissue such as glucose. The method utilizes spectrographic techniques in conjunction with an improved instrument-tailored or subject-tailored calibration model. In a calibration phase, calibration model data is modified to reduce or eliminate instrument-specific attributes, resulting in a calibration data set modeling intra-instrument or intra-subject variation. In a prediction phase, the prediction process is tailored for each target instrument separately using a minimal number of spectral measurements from each instrument or subject.

Instrumentation development for drug detection on the breath

DOT National Transportation Integrated Search

1972-09-01

Based on a survey of candidate analytical methods, mass spectrometry was identified as a promising technique for drug detection on the breath. To demonstrate its capabilities, an existing laboratory mass spectrometer was modified by the addition of a...

Mars Methane Analogue Mission (M3): Analytical Techniques and Operations

NASA Astrophysics Data System (ADS)

Cloutis, E.; Vrionis, H.; Qadi, A.; Bell, J. F.; Berard, G.; Boivin, A.; Ellery, A.; Jamroz, W.; Kruzelecky, R.; Mann, P.; Samson, C.; Stromberg, J.; Strong, K.; Tremblay, A.; Whyte, L.; Wing, B.

2011-03-01

The Mars Methane Analogue Mission (M3) project is designed to simulate a rover-based search for, and analysis of, methane sources on Mars at a serpentinite open pit mine in Quebec, using a variety of instruments.

A computer-based maintenance reminder and record-keeping system for clinical laboratories.

PubMed

Roberts, B I; Mathews, C L; Walton, C J; Frazier, G

1982-09-01

"Maintenance" is all the activity an organization devotes to keeping instruments within performance specifications to assure accurate and precise operation. The increasing use of complex analytical instruments as "workhorses" in clinical laboratories requires more maintenance awareness by laboratory personnel. Record-keeping systems that document maintenance completion and that should prompt the continued performance of maintenance tasks have not kept up with instrumentation development. We report here a computer-based record-keeping and reminder system that lists weekly the maintenance items due for each work station in the laboratory, including the time required to complete each item. Written in BASIC, the system uses a DATABOSS data base management system running on a time-shared Digital Equipment Corporation PDP 11/60 computer with a RSTS V 7.0 operating system.

Thermoelectrically cooled water trap

DOEpatents

Micheels, Ronald H [Concord, MA

2006-02-21

A water trap system based on a thermoelectric cooling device is employed to remove a major fraction of the water from air samples, prior to analysis of these samples for chemical composition, by a variety of analytical techniques where water vapor interferes with the measurement process. These analytical techniques include infrared spectroscopy, mass spectrometry, ion mobility spectrometry and gas chromatography. The thermoelectric system for trapping water present in air samples can substantially improve detection sensitivity in these analytical techniques when it is necessary to measure trace analytes with concentrations in the ppm (parts per million) or ppb (parts per billion) partial pressure range. The thermoelectric trap design is compact and amenable to use in a portable gas monitoring instrumentation.

Method and apparatus for continuous fluid leak monitoring and detection in analytical instruments and instrument systems

DOEpatents

Weitz, Karl K [Pasco, WA; Moore, Ronald J [West Richland, WA

2010-07-13

A method and device are disclosed that provide for detection of fluid leaks in analytical instruments and instrument systems. The leak detection device includes a collection tube, a fluid absorbing material, and a circuit that electrically couples to an indicator device. When assembled, the leak detection device detects and monitors for fluid leaks, providing a preselected response in conjunction with the indicator device when contacted by a fluid.

Advanced Analytical Methodologies Based on Raman Spectroscopy to Detect Prebiotic and Biotic Molecules: Applicability in the Study of the Martian Nakhlite NWA 6148 Meteorite

NASA Astrophysics Data System (ADS)

Madariaga, J. M.; Torre-Fdez, I.; Ruiz-Galende, P.; Aramendia, J.; Gomez-Nubla, L.; Fdez-Ortiz de Vallejuelo, S.; Maguregui, M.; Castro, K.; Arana, G.

2018-04-01

Advanced methodologies based on Raman spectroscopy are proposed to detect prebiotic and biotic molecules in returned samples from Mars: (a) optical microscopy with confocal micro-Raman, (b) the SCA instrument, (c) Raman Imaging. Examples for NWA 6148.

Analytical display design for flight tasks conducted under instrument meteorological conditions. [human factors engineering of pilot performance for display device design in instrument landing systems

NASA Technical Reports Server (NTRS)

Hess, R. A.

1976-01-01

Paramount to proper utilization of electronic displays is a method for determining pilot-centered display requirements. Display design should be viewed fundamentally as a guidance and control problem which has interactions with the designer's knowledge of human psychomotor activity. From this standpoint, reliable analytical models of human pilots as information processors and controllers can provide valuable insight into the display design process. A relatively straightforward, nearly algorithmic procedure for deriving model-based, pilot-centered display requirements was developed and is presented. The optimal or control theoretic pilot model serves as the backbone of the design methodology, which is specifically directed toward the synthesis of head-down, electronic, cockpit display formats. Some novel applications of the optimal pilot model are discussed. An analytical design example is offered which defines a format for the electronic display to be used in a UH-1H helicopter in a landing approach task involving longitudinal and lateral degrees of freedom.

Comparison of thermal analytic model with experimental test results for 30-sentimeter-diameter engineering model mercury ion thruster

NASA Technical Reports Server (NTRS)

Oglebay, J. C.

1977-01-01

A thermal analytic model for a 30-cm engineering model mercury-ion thruster was developed and calibrated using the experimental test results of tests of a pre-engineering model 30-cm thruster. A series of tests, performed later, simulated a wide range of thermal environments on an operating 30-cm engineering model thruster, which was instrumented to measure the temperature distribution within it. The modified analytic model is described and analytic and experimental results compared for various operating conditions. Based on the comparisons, it is concluded that the analytic model can be used as a preliminary design tool to predict thruster steady-state temperature distributions for stage and mission studies and to define the thermal interface bewteen the thruster and other elements of a spacecraft.

Stable oxygen and hydrogen isotopes of brines - comparing isotope ratio mass spectrometry and isotope ratio infrared spectroscopy

NASA Astrophysics Data System (ADS)

Ahrens, Christian; Koeniger, Paul; van Geldern, Robert; Stadler, Susanne

2013-04-01

Today's standard analytical methods for high precision stable isotope analysis of fluids are gas-water equilibration and high temperature pyrolysis coupled to isotope ratio mass spectrometers (IRMS). In recent years, relatively new laser-based analytical instruments entered the market that are said to allow high isotope precision data on nearly every media. This optical technique is referred to as isotope ratio infrared spectroscopy (IRIS). The objective of this study is to evaluate the capability of this new instrument type for highly saline solutions and a comparison of the analytical results with traditional IRMS analysis. It has been shown for the equilibration method that the presence of salts influences the measured isotope values depending on the salt concentration (see Lécuyer et al, 2009; Martineau, 2012). This so-called 'isotope salt effect' depends on the salt type and salt concentration. These factors change the activity in the fluid and therefore shift the isotope ratios measured by the equilibration method. Consequently, correction factors have to be applied to these analytical data. Direct conversion techniques like pyrolysis or the new laser instruments allow the measurement of the water molecule from the sample directly and should therefore not suffer from the salt effect, i.e. no corrections of raw values are necessary. However, due to high salt concentrations this might cause technical problems with the analytical hardware and may require labor-intensive sample preparation (e.g. vacuum distillation). This study evaluates the salt isotope effect for the IRMS equilibration technique (Thermo Gasbench II coupled to Delta Plus XP) and the laser-based IRIS instruments with liquid injection (Picarro L2120-i). Synthetic salt solutions (NaCl, KCl, CaCl2, MgCl2, MgSO4, CaSO4) and natural brines collected from the Stassfurt Salt Anticline (Germany; Stadler et al., 2012) were analysed with both techniques. Salt concentrations ranged from seawater salinity up to full saturation. References Lécuyer, C. et al. (2009). Chem. Geol., 264, 122-126. [doi:10.1016/j.chemgeo.2009.02.017] Martineau, F. et al. (2012). Chem. Geol., 291, 236-240. [doi:10.1016/j.chemgeo.2011.10.017] Stadler, S. et al. (2012). Chem. Geol., 294-295, 226-242. [doi:10.1016/j.chemgeo.2011.12.006

International Space Station Model Correlation Analysis

NASA Technical Reports Server (NTRS)

Laible, Michael R.; Fitzpatrick, Kristin; Hodge, Jennifer; Grygier, Michael

2018-01-01

This paper summarizes the on-orbit structural dynamic data and the related modal analysis, model validation and correlation performed for the International Space Station (ISS) configuration ISS Stage ULF7, 2015 Dedicated Thruster Firing (DTF). The objective of this analysis is to validate and correlate the analytical models used to calculate the ISS internal dynamic loads and compare the 2015 DTF with previous tests. During the ISS configurations under consideration, on-orbit dynamic measurements were collected using the three main ISS instrumentation systems; Internal Wireless Instrumentation System (IWIS), External Wireless Instrumentation System (EWIS) and the Structural Dynamic Measurement System (SDMS). The measurements were recorded during several nominal on-orbit DTF tests on August 18, 2015. Experimental modal analyses were performed on the measured data to extract modal parameters including frequency, damping, and mode shape information. Correlation and comparisons between test and analytical frequencies and mode shapes were performed to assess the accuracy of the analytical models for the configurations under consideration. These mode shapes were also compared to earlier tests. Based on the frequency comparisons, the accuracy of the mathematical models is assessed and model refinement recommendations are given. In particular, results of the first fundamental mode will be discussed, nonlinear results will be shown, and accelerometer placement will be assessed.

Time-resolved fluorescence spectroscopy for chemical sensors

NASA Astrophysics Data System (ADS)

Draxler, Sonja; Lippitsch, Max E.

1996-07-01

A family of sensors is presented with fluorescence decay-time measurements used as the sensing technique. The concept is to take a single fluorophore with a suitably long fluorescence decay time as the basic building block for numerous different sensors. Analyte recognition can be performed by different functional groups that are necessary for selective interaction with the analyte. To achieve this, the principle of excited-state electron transfer is applied with pyrene as the fluorophore. Therefore the same instrumentation based on a small, ambient air-nitrogen laser and solid-state electronics can be used to measure different analytes, for example, oxygen, pH, carbon dioxide, potassium, ammonium, lead, cadmium, zinc, and phosphate.

Vortex Advisory System Safety Analysis : Volume 1. Analytical Model

DOT National Transportation Integrated Search

1978-09-01

The Vortex Advisory System (VAS) is based on wind criterion--when the wind near the runway end is outside of the criterion, all interarrival Instrument Flight Rules (IFR) aircraft separations can be set at 3 nautical miles. Five years of wind data ha...

Microfluidic-Based Robotic Sampling System for Radioactive Solutions

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

Jack D. Law; Julia L. Tripp; Tara E. Smith

A novel microfluidic based robotic sampling system has been developed for sampling and analysis of liquid solutions in nuclear processes. This system couples the use of a microfluidic sample chip with a robotic system designed to allow remote, automated sampling of process solutions in-cell and facilitates direct coupling of the microfluidic sample chip with analytical instrumentation. This system provides the capability for near real time analysis, reduces analytical waste, and minimizes the potential for personnel exposure associated with traditional sampling methods. A prototype sampling system was designed, built and tested. System testing demonstrated operability of the microfluidic based sample systemmore » and identified system modifications to optimize performance.« less

Development of Processing Techniques for Advanced Thermal Protection Materials

NASA Technical Reports Server (NTRS)

Selvaduray, Guna; Cox, Michael; Srinivasan, Vijayakumar

1997-01-01

Thermal Protection Materials Branch (TPMB) has been involved in various research programs to improve the properties and structural integrity of the existing aerospace high temperature materials. Specimens from various research programs were brought into the analytical laboratory for the purpose of obtaining and refining the material characterization. The analytical laboratory in TPMB has many different instruments which were utilized to determine the physical and chemical characteristics of materials. Some of the instruments that were utilized by the SJSU students are: Scanning Electron Microscopy (SEM), Energy Dispersive X-ray analysis (EDX), X-ray Diffraction Spectrometer (XRD), Fourier Transform-Infrared Spectroscopy (FTIR), Ultra Violet Spectroscopy/Visible Spectroscopy (UV/VIS), Particle Size Analyzer (PSA), and Inductively Coupled Plasma Atomic Emission Spectrometer (ICP-AES). The above mentioned analytical instruments were utilized in the material characterization process of the specimens from research programs such as: aerogel ceramics (I) and (II), X-33 Blankets, ARC-Jet specimens, QUICFIX specimens and gas permeability of lightweight ceramic ablators. In addition to analytical instruments in the analytical laboratory at TPMB, there are several on-going experiments. One particular experiment allows the measurement of permeability of ceramic ablators. From these measurements, physical characteristics of the ceramic ablators can be derived.

A Helium GC/IMS for the Analysis of Extraterrestrial Volatiles in Exobiology Flight Experiments

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Carle, Glenn C.; Humphry, Donald E.; Shao, Maxine; Takeuchi, Nori

1995-01-01

For exobiology experiments on board spacecraft or space probes, a wide range of chemical species often must be detected and identified. The limited amount of power and space available for flight instruments severely limits the number of instruments that can be flown on any given mission. It is important then, that these experiments utilize instrumentation with universal response, so that all species of interest can be analyzed. Instrumentation to fulfill the analytical requirements of exobiology experiments has been developed utilizing Gas Chromatography - Ion Mobility Spectrometry. The Gas Chromatograph (GC) combines columns developed specifically for the complex mixtures anticipated with highly sensitive Metastable Ionization Detectors (a type of Helium Ionization Detector). To satisfy the limitations placed on resources, the Ion Mobility Spectrometer (IMS) uses the same ultra high purity helium as the GC. This GC-MS provides the analytical capability to fulfill a wide range of exobiology flight experiment applications and has been included on a proposed Discovery Mission and proposals for both Lander and Orbiter of the European Space Agency's Rosetta Comet Mission. A data base of helium IMS spectra is now being built for these future applications.

Modern Instrumental Methods in Forensic Toxicology*

PubMed Central

Smith, Michael L.; Vorce, Shawn P.; Holler, Justin M.; Shimomura, Eric; Magluilo, Joe; Jacobs, Aaron J.; Huestis, Marilyn A.

2009-01-01

This article reviews modern analytical instrumentation in forensic toxicology for identification and quantification of drugs and toxins in biological fluids and tissues. A brief description of the theory and inherent strengths and limitations of each methodology is included. The focus is on new technologies that address current analytical limitations. A goal of this review is to encourage innovations to improve our technological capabilities and to encourage use of these analytical techniques in forensic toxicology practice. PMID:17579968

Analytical Chemistry Laboratory Progress Report for FY 1994

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

Green, D.W.; Boparai, A.S.; Bowers, D.L.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1994 (October 1993 through September 1994). This annual report is the eleventh for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has a research program inmore » analytical chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require significant development of methods and adaption of techniques to obtain useful analytical data. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis -- which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL. The Chemical Analysis Group uses wet- chemical and instrumental methods for elemental, compositional, and isotopic determinations in solid, liquid, and gaseous samples and provides specialized analytical services. Major instruments in this group include an ion chromatograph (IC), an inductively coupled plasma/atomic emission spectrometer (ICP/AES), spectrophotometers, mass spectrometers (including gas-analysis and thermal-ionization mass spectrometers), emission spectrographs, autotitrators, sulfur and carbon determinators, and a kinetic phosphorescence uranium analyzer.« less

The rise of environmental analytical chemistry as an interdisciplinary activity.

PubMed

Brown, Richard

2009-07-01

Modern scientific endeavour is increasingly delivered within an interdisciplinary framework. Analytical environmental chemistry is a long-standing example of an interdisciplinary approach to scientific research where value is added by the close cooperation of different disciplines. This editorial piece discusses the rise of environmental analytical chemistry as an interdisciplinary activity and outlines the scope of the Analytical Chemistry and the Environmental Chemistry domains of TheScientificWorldJOURNAL (TSWJ), and the appropriateness of TSWJ's domain format in covering interdisciplinary research. All contributions of new data, methods, case studies, and instrumentation, or new interpretations and developments of existing data, case studies, methods, and instrumentation, relating to analytical and/or environmental chemistry, to the Analytical and Environmental Chemistry domains, are welcome and will be considered equally.

Low level measurements of atmospheric DMS, H2S, and SO2 for GTE/CITE-3

NASA Technical Reports Server (NTRS)

Saltzman, Eric; Cooper, David

1991-01-01

This project involved the measurement of atmospheric dimethylsulfide (DMS) and hydrogen sulfide (H2S) as part of the GTE/CITE-3 instrument intercomparison program. The two instruments were adapted for use on the NASA Electra aircraft and participated in all phases of the mission. This included ground-based measurements of NIST-provided standard gases and a series of airborne missions over the Western Atlantic Ocean. Analytical techniques used are described and the results are summarized.

Analytical methods for dating modern writing instrument inks on paper.

PubMed

Ezcurra, Magdalena; Góngora, Juan M G; Maguregui, Itxaso; Alonso, Rosa

2010-04-15

This work reviews the different analytical methods that have been proposed in the field of forensic dating of inks from different modern writing instruments. The reported works have been classified according to the writing instrument studied and the ink component analyzed in relation to aging. The study, done chronologically, shows the advances experienced in the ink dating field in the last decades. Copyright 2009 Elsevier Ireland Ltd. All rights reserved.

JPRS Report, Science & Technology, USSR: Engineering & Equipment

DTIC Science & Technology

1987-08-05

working successfully in the " Veda " PO and at the analytical instruments plant. Characteristically, it was these very enterprises which were on top in...the 1985 review: the analytical instruments plant collective came in first, the " Veda " PO collective came in second, and the "Elektronmash" PO

Analytical and pre-analytical performance characteristics of a novel cartridge-type blood gas analyzer for point-of-care and laboratory testing.

PubMed

Oyaert, Matthijs; Van Maerken, Tom; Bridts, Silke; Van Loon, Silvi; Laverge, Heleen; Stove, Veronique

2018-03-01

Point-of-care blood gas test results may benefit therapeutic decision making by their immediate impact on patient care. We evaluated the (pre-)analytical performance of a novel cartridge-type blood gas analyzer, the GEM Premier 5000 (Werfen), for the determination of pH, partial carbon dioxide pressure (pCO 2 ), partial oxygen pressure (pO 2 ), sodium (Na + ), potassium (K + ), chloride (Cl - ), ionized calcium ( i Ca 2+ ), glucose, lactate, and total hemoglobin (tHb). Total imprecision was estimated according to the CLSI EP5-A2 protocol. The estimated total error was calculated based on the mean of the range claimed by the manufacturer. Based on the CLSI EP9-A2 evaluation protocol, a method comparison with the Siemens RapidPoint 500 and Abbott i-STAT CG8+ was performed. Obtained data were compared against preset quality specifications. Interference of potential pre-analytical confounders on co-oximetry and electrolyte concentrations were studied. The analytical performance was acceptable for all parameters tested. Method comparison demonstrated good agreement to the RapidPoint 500 and i-STAT CG8+, except for some parameters (RapidPoint 500: pCO 2 , K + , lactate and tHb; i-STAT CG8+: pO 2 , Na + , i Ca 2+ and tHb) for which significant differences between analyzers were recorded. No interference of lipemia or methylene blue on CO-oximetry results was found. On the contrary, significant interference for benzalkonium and hemolysis on electrolyte measurements were found, for which the user is notified by an interferent specific flag. Identification of sample errors from pre-analytical sources, such as interferences and automatic corrective actions, along with the analytical performance, ease of use and low maintenance time of the instrument, makes the evaluated instrument a suitable blood gas analyzer for both POCT and laboratory use. Copyright © 2018 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

Method of assessing a lipid-related health risk based on ion mobility analysis of lipoproteins

DOEpatents

Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

2010-12-14

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Application of the correlation constrained multivariate curve resolution alternating least-squares method for analyte quantitation in the presence of unexpected interferences using first-order instrumental data.

PubMed

Goicoechea, Héctor C; Olivieri, Alejandro C; Tauler, Romà

2010-03-01

Correlation constrained multivariate curve resolution-alternating least-squares is shown to be a feasible method for processing first-order instrumental data and achieve analyte quantitation in the presence of unexpected interferences. Both for simulated and experimental data sets, the proposed method could correctly retrieve the analyte and interference spectral profiles and perform accurate estimations of analyte concentrations in test samples. Since no information concerning the interferences was present in calibration samples, the proposed multivariate calibration approach including the correlation constraint facilitates the achievement of the so-called second-order advantage for the analyte of interest, which is known to be present for more complex higher-order richer instrumental data. The proposed method is tested using a simulated data set and two experimental data systems, one for the determination of ascorbic acid in powder juices using UV-visible absorption spectral data, and another for the determination of tetracycline in serum samples using fluorescence emission spectroscopy.

Moving your laboratories to the field--Advantages and limitations of the use of field portable instruments in environmental sample analysis.

PubMed

Gałuszka, Agnieszka; Migaszewski, Zdzisław M; Namieśnik, Jacek

2015-07-01

The recent rapid progress in technology of field portable instruments has increased their applications in environmental sample analysis. These instruments offer a possibility of cost-effective, non-destructive, real-time, direct, on-site measurements of a wide range of both inorganic and organic analytes in gaseous, liquid and solid samples. Some of them do not require the use of reagents and do not produce any analytical waste. All these features contribute to the greenness of field portable techniques. Several stationary analytical instruments have their portable versions. The most popular ones include: gas chromatographs with different detectors (mass spectrometer (MS), flame ionization detector, photoionization detector), ultraviolet-visible and near-infrared spectrophotometers, X-ray fluorescence spectrometers, ion mobility spectrometers, electronic noses and electronic tongues. The use of portable instruments in environmental sample analysis gives a possibility of on-site screening and a subsequent selection of samples for routine laboratory analyses. They are also very useful in situations that require an emergency response and for process monitoring applications. However, quantification of results is still problematic in many cases. The other disadvantages include: higher detection limits and lower sensitivity than these obtained in laboratory conditions, a strong influence of environmental factors on the instrument performance and a high possibility of sample contamination in the field. This paper reviews recent applications of field portable instruments in environmental sample analysis and discusses their analytical capabilities. Copyright © 2015 Elsevier Inc. All rights reserved.

Thermo Scientific Ozone Analyzer Instrument Handbook

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

Springston, S. R.

The primary measurement output from the Thermo Scientific Ozone Analyzer is the concentration of the analyte (O3) reported at 1-s resolution in units of ppbv in ambient air. Note that because of internal pneumatic switching limitations the instrument only makes an independent measurement every 4 seconds. Thus, the same concentration number is repeated roughly 4 times at the uniform, monotonic 1-s time base used in the AOS systems. Accompanying instrument outputs include sample temperatures, flows, chamber pressure, lamp intensities and a multiplicity of housekeeping information. There is also a field for operator comments made at any time while data ismore » being collected.« less

Assessment regarding the use of the computer aided analytical models in the calculus of the general strength of a ship hull

NASA Astrophysics Data System (ADS)

Hreniuc, V.; Hreniuc, A.; Pescaru, A.

2017-08-01

Solving a general strength problem of a ship hull may be done using analytical approaches which are useful to deduce the buoyancy forces distribution, the weighting forces distribution along the hull and the geometrical characteristics of the sections. These data are used to draw the free body diagrams and to compute the stresses. The general strength problems require a large amount of calculi, therefore it is interesting how a computer may be used to solve such problems. Using computer programming an engineer may conceive software instruments based on analytical approaches. However, before developing the computer code the research topic must be thoroughly analysed, in this way being reached a meta-level of understanding of the problem. The following stage is to conceive an appropriate development strategy of the original software instruments useful for the rapid development of computer aided analytical models. The geometrical characteristics of the sections may be computed using a bool algebra that operates with ‘simple’ geometrical shapes. By ‘simple’ we mean that for the according shapes we have direct calculus relations. In the set of ‘simple’ shapes we also have geometrical entities bounded by curves approximated as spline functions or as polygons. To conclude, computer programming offers the necessary support to solve general strength ship hull problems using analytical methods.

Using chromatography – desorption method of manufacturing gas mixtures for analytical instruments calibration

NASA Astrophysics Data System (ADS)

Platonov, I. A.; Kolesnichenko, I. N.; Lange, P. K.

2018-05-01

In this paper, the chromatography desorption method of obtaining gas mixtures of known compositions stable for a time sufficient to calibrate analytical instruments is considered. The comparative analysis results of the preparation accuracy of gas mixtures with volatile organic compounds using diffusion, polyabarbotage and chromatography desorption methods are presented. It is shown that the application of chromatography desorption devices allows one to obtain gas mixtures that are stable for 10...60 hours in a dynamic condition. These gas mixtures contain volatile aliphatic and aromatic hydrocarbons with a concentration error of no more than 7%. It is shown that it is expedient to use such gas mixtures for analytical instruments calibration (chromatographs, spectrophotometers, etc.)

Estimation of the limit of detection using information theory measures.

PubMed

Fonollosa, Jordi; Vergara, Alexander; Huerta, Ramón; Marco, Santiago

2014-01-31

Definitions of the limit of detection (LOD) based on the probability of false positive and/or false negative errors have been proposed over the past years. Although such definitions are straightforward and valid for any kind of analytical system, proposed methodologies to estimate the LOD are usually simplified to signals with Gaussian noise. Additionally, there is a general misconception that two systems with the same LOD provide the same amount of information on the source regardless of the prior probability of presenting a blank/analyte sample. Based upon an analogy between an analytical system and a binary communication channel, in this paper we show that the amount of information that can be extracted from an analytical system depends on the probability of presenting the two different possible states. We propose a new definition of LOD utilizing information theory tools that deals with noise of any kind and allows the introduction of prior knowledge easily. Unlike most traditional LOD estimation approaches, the proposed definition is based on the amount of information that the chemical instrumentation system provides on the chemical information source. Our findings indicate that the benchmark of analytical systems based on the ability to provide information about the presence/absence of the analyte (our proposed approach) is a more general and proper framework, while converging to the usual values when dealing with Gaussian noise. Copyright © 2013 Elsevier B.V. All rights reserved.

Hyphenated analytical techniques for materials characterisation

NASA Astrophysics Data System (ADS)

Armstrong, Gordon; Kailas, Lekshmi

2017-09-01

This topical review will provide a survey of the current state of the art in ‘hyphenated’ techniques for characterisation of bulk materials, surface, and interfaces, whereby two or more analytical methods investigating different properties are applied simultaneously to the same sample to better characterise the sample than can be achieved by conducting separate analyses in series using different instruments. It is intended for final year undergraduates and recent graduates, who may have some background knowledge of standard analytical techniques, but are not familiar with ‘hyphenated’ techniques or hybrid instrumentation. The review will begin by defining ‘complementary’, ‘hybrid’ and ‘hyphenated’ techniques, as there is not a broad consensus among analytical scientists as to what each term means. The motivating factors driving increased development of hyphenated analytical methods will also be discussed. This introduction will conclude with a brief discussion of gas chromatography-mass spectroscopy and energy dispersive x-ray analysis in electron microscopy as two examples, in the context that combining complementary techniques for chemical analysis were among the earliest examples of hyphenated characterisation methods. The emphasis of the main review will be on techniques which are sufficiently well-established that the instrumentation is commercially available, to examine physical properties including physical, mechanical, electrical and thermal, in addition to variations in composition, rather than methods solely to identify and quantify chemical species. Therefore, the proposed topical review will address three broad categories of techniques that the reader may expect to encounter in a well-equipped materials characterisation laboratory: microscopy based techniques, scanning probe-based techniques, and thermal analysis based techniques. Examples drawn from recent literature, and a concluding case study, will be used to explain the practical issues that arise in combining different techniques. We will consider how the complementary and varied information obtained by combining these techniques may be interpreted together to better understand the sample in greater detail than that was possible before, and also how combining different techniques can simplify sample preparation and ensure reliable comparisons are made between multiple analyses on the same samples—a topic of particular importance as nanoscale technologies become more prevalent in applied and industrial research and development (R&D). The review will conclude with a brief outline of the emerging state of the art in the research laboratory, and a suggested approach to using hyphenated techniques, whether in the teaching, quality control or R&D laboratory.

Developments in the Identification of Glycan Biomarkers for the Detection of Cancer

PubMed Central

Ruhaak, L. Renee; Miyamoto, Suzanne; Lebrilla, Carlito B.

2013-01-01

Changes in glycosylation readily occur in cancer and other disease states. Thanks to recent advances in the development of analytical techniques and instrumentation, especially in mass spectrometry, it is now possible to identify blood-derived glycan-based biomarkers using glycomics strategies. This review is an overview of the developments made in the search for glycan-based cancer biomarkers and the technologies currently in use. It is anticipated that the progressing instrumental and bioinformatics developments will allow the identification of relevant glycan biomarkers for the diagnosis, early detection, and monitoring of cancer treatment with sufficient sensitivity and specificity for clinical use. PMID:23365456

Data Filtering in Instrumental Analyses with Applications to Optical Spectroscopy and Chemical Imaging

ERIC Educational Resources Information Center

Vogt, Frank

2011-01-01

Most measurement techniques have some limitations imposed by a sensor's signal-to-noise ratio (SNR). Thus, in analytical chemistry, methods for enhancing the SNR are of crucial importance and can be ensured experimentally or established via pre-treatment of digitized data. In many analytical curricula, instrumental techniques are given preference…

Automation, consolidation, and integration in autoimmune diagnostics.

PubMed

Tozzoli, Renato; D'Aurizio, Federica; Villalta, Danilo; Bizzaro, Nicola

2015-08-01

Over the past two decades, we have witnessed an extraordinary change in autoimmune diagnostics, characterized by the progressive evolution of analytical technologies, the availability of new tests, and the explosive growth of molecular biology and proteomics. Aside from these huge improvements, organizational changes have also occurred which brought about a more modern vision of the autoimmune laboratory. The introduction of automation (for harmonization of testing, reduction of human error, reduction of handling steps, increase of productivity, decrease of turnaround time, improvement of safety), consolidation (combining different analytical technologies or strategies on one instrument or on one group of connected instruments) and integration (linking analytical instruments or group of instruments with pre- and post-analytical devices) opened a new era in immunodiagnostics. In this article, we review the most important changes that have occurred in autoimmune diagnostics and present some models related to the introduction of automation in the autoimmunology laboratory, such as automated indirect immunofluorescence and changes in the two-step strategy for detection of autoantibodies; automated monoplex immunoassays and reduction of turnaround time; and automated multiplex immunoassays for autoantibody profiling.

The development of an integrated assessment instrument for measuring analytical thinking and science process skills

NASA Astrophysics Data System (ADS)

Irwanto, Rohaeti, Eli; LFX, Endang Widjajanti; Suyanta

2017-05-01

This research aims to develop instrument and determine the characteristics of an integrated assessment instrument. This research uses 4-D model, which includes define, design, develop, and disseminate. The primary product is validated by expert judgment, tested it's readability by students, and assessed it's feasibility by chemistry teachers. This research involved 246 students of grade XI of four senior high schools in Yogyakarta, Indonesia. Data collection techniques include interview, questionnaire, and test. Data collection instruments include interview guideline, item validation sheet, users' response questionnaire, instrument readability questionnaire, and essay test. The results show that the integrated assessment instrument has Aiken validity value of 0.95. Item reliability was 0.99 and person reliability was 0.69. Teachers' response to the integrated assessment instrument is very good. Therefore, the integrated assessment instrument is feasible to be applied to measure the students' analytical thinking and science process skills.

Cloud point extraction thermospray flame quartz furnace atomic absorption spectrometry for determination of ultratrace cadmium in water and urine

NASA Astrophysics Data System (ADS)

Wu, Peng; Zhang, Yunchang; Lv, Yi; Hou, Xiandeng

2006-12-01

A simple, low cost and highly sensitive method based on cloud point extraction (CPE) for separation/preconcentration and thermospray flame quartz furnace atomic absorption spectrometry was proposed for the determination of ultratrace cadmium in water and urine samples. The analytical procedure involved the formation of analyte-entrapped surfactant micelles by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution and a Triton X-114 solution. When the temperature of the system was higher than the cloud point of Triton X-114, the complex of cadmium-PDC entered the surfactant-rich phase and thus separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, the limit of detection was 0.04 μg/L for cadmium with a sample volume of 10 mL. The analytical results of cadmium in water and urine samples agreed well with those by ICP-MS.

Dreams In Jungian Psychology: The use of Dreams as an Instrument For Research, Diagnosis and Treatment of Social Phobia.

PubMed

Khodarahimi, Siamak

2009-10-01

The significance of dreams has been explained in psychoanalysis, depth psychology and gestalt therapy. There are many guidelines in analytic psychology for dream interpretation and integration in clinical practice. The present study, based on the Jungian analytic model, incorporated dreams as an instrument for assessment of aetiology, the psychotherapy process and the outcome of treatment for social phobia within a clinical case study. This case study describes the use of dream analysis in treating a female youth with social phobia. The present findings supported the three stage paradigm efficiency in the Jungian model for dream working within a clinical setting, i.e. written details, reassembly with amplification and assimilation. It was indicated that childhood and infantile traumatic events, psychosexual development malfunctions, and inefficient coping skills for solving current life events were expressed in the patient's dreams. Dreams can reflect a patient's aetiology, needs, illness prognosis and psychotherapy outcome. Dreams are an instrument for the diagnosis, research and treatment of mental disturbances in a clinical setting.

Seeing the light: The SpecUP educational spectrophotometer

NASA Astrophysics Data System (ADS)

Forbes, P. B. C.

2016-09-01

Spectrophotometry is a cross-cutting analytical technique, which finds use in disciplines ranging from chemistry to pharmacy, biochemistry, food science and physics. The SpecUP (Spectrophotometer of the University of Pretoria) is an educational spectrophotometer which was developed so that students could build their own instruments from components in a kit, and then utilise it to generate analytically useful results. This initiative allows for institutions to have more spectroscopy equipment available, as the SpecUP costs less than 40 as opposed to 2 000 which is the cost of an entry-level commercial instrument. This is of particular importance in a developing country context, where student numbers are typically high and resources are scarce. In addition, the SpecUP has moving parts and an open design which allows users to understand what is inside the "black box" of commercial instruments and to discover what happens when they adjust components, allowing for active, inquiry-based learning. The SpecUP user network currently spans South Africa, Tunisia, Namibia, Lesotho, Botswana, Kenya, Swaziland, Zimbabwe, Zambia, Ivory Coast, Egypt, Turkey and Italy.

Dreams In Jungian Psychology: The use of Dreams as an Instrument For Research, Diagnosis and Treatment of Social Phobia

PubMed Central

Khodarahimi, Siamak

2009-01-01

Background: The significance of dreams has been explained in psychoanalysis, depth psychology and gestalt therapy. There are many guidelines in analytic psychology for dream interpretation and integration in clinical practice. The present study, based on the Jungian analytic model, incorporated dreams as an instrument for assessment of aetiology, the psychotherapy process and the outcome of treatment for social phobia within a clinical case study. Method: This case study describes the use of dream analysis in treating a female youth with social phobia. Results: The present findings supported the three stage paradigm efficiency in the Jungian model for dream working within a clinical setting, i.e. written details, reassembly with amplification and assimilation. It was indicated that childhood and infantile traumatic events, psychosexual development malfunctions, and inefficient coping skills for solving current life events were expressed in the patient’s dreams. Conclusion: Dreams can reflect a patient’s aetiology, needs, illness prognosis and psychotherapy outcome. Dreams are an instrument for the diagnosis, research and treatment of mental disturbances in a clinical setting. PMID:22135511

Development of inquiry-based learning activities integrated with the local learning resource to promote learning achievement and analytical thinking ability of Mathayomsuksa 3 student

NASA Astrophysics Data System (ADS)

Sukji, Paweena; Wichaidit, Pacharee Rompayom; Wichaidit, Sittichai

2018-01-01

The objectives of this study were to: 1) compare learning achievement and analytical thinking ability of Mathayomsuksa 3 students before and after learning through inquiry-based learning activities integrated with the local learning resource, and 2) compare average post-test score of learning achievement and analytical thinking ability to its cutting score. The target of this study was 23 Mathayomsuksa 3 students who were studying in the second semester of 2016 academic year from Banchatfang School, Chainat Province. Research instruments composed of: 1) 6 lesson plans of Environment and Natural Resources, 2) the learning achievement test, and 3) analytical thinking ability test. The results showed that 1) student' learning achievement and analytical thinking ability after learning were higher than that of before at the level of .05 statistical significance, and 2) average posttest score of student' learning achievement and analytical thinking ability were higher than its cutting score at the level of .05 statistical significance. The implication of this research is for science teachers and curriculum developers to design inquiry activities that relate to student's context.

Design, Implementation, and Operational Methodologies for Sub-arcsecond Attitude Determination, Control, and Stabilization of the Super-pressure Balloon-Borne Imaging Telescope (SuperBIT)

NASA Astrophysics Data System (ADS)

Javier Romualdez, Luis

Scientific balloon-borne instrumentation offers an attractive, competitive, and effective alternative to space-borne missions when considering the overall scope, cost, and development timescale required to design and launch scientific instruments. In particular, the balloon-borne environment provides a near-space regime that is suitable for a number of modern astronomical and cosmological experiments, where the atmospheric interference suffered by ground-based instrumentation is negligible at stratospheric altitudes. This work is centered around the analytical strategies and implementation considerations for the attitude determination and control of SuperBIT, a scientific balloon-borne payload capable of meeting the strict sub-arcsecond pointing and image stability requirements demanded by modern cosmological experiments. Broadly speaking, the designed stability specifications of SuperBIT coupled with its observational efficiency, image quality, and accessibility rivals state-of-the-art astronomical observatories such as the Hubble Space Telescope. To this end, this work presents an end-to-end design methodology for precision pointing balloon-borne payloads such as SuperBIT within an analytical yet implementationally grounded context. Simulation models of SuperBIT are analytically derived to aid in pre-assembly trade-off and case studies that are pertinent to the dynamic balloon-borne environment. From these results, state estimation techniques and control methodologies are extensively developed, leveraging the analytical framework of simulation models and design studies. This pre-assembly design phase is physically validated during assembly, integration, and testing through implementation in real-time hardware and software, which bridges the gap between analytical results and practical application. SuperBIT attitude determination and control is demonstrated throughout two engineering test flights that verify pointing and image stability requirements in flight, where the post-flight results close the overall design loop by suggesting practical improvements to pre-design methodologies. Overall, the analytical and practical results presented in this work, though centered around the SuperBIT project, provide generically useful and implementationally viable methodologies for high precision balloon-borne instrumentation, all of which are validated, justified, and improved both theoretically and practically. As such, the continuing development of SuperBIT, built from the work presented in this thesis, strives to further the potential for scientific balloon-borne astronomy in the near future.

Scribed transparency microplates mounted on a modified standard microplate.

PubMed

Cheong, Brandon Huey-Ping; Chua, Wei Seong; Liew, Oi Wah; Ng, Tuck Wah

2014-08-01

The immense cost effectiveness of using transparencies as analyte handling implements in microplate instrumentation offers the possibility of application even in resource-limited laboratories. In this work, a standard microplate was adapted to serve as the permanent base for disposable scribed transparencies. The approach is shown to ameliorate evaporation, which can affect assay accuracy when analytes need to be incubated for some time. It also offers assurance against fluorescence measurement errors due to the cross-talk of samples from adjacent wells. Copyright © 2014 Elsevier Inc. All rights reserved.

Ion beam analysis in cultural heritage studies: Milestones and perspectives

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

Dran, Jean-Claude; Calligaro, Thomas

2013-07-18

For three decades, ion beam analysis (IBA) in external mode was considered as the best choice for the characterisation of cultural heritage materials, as it combines excellent analytical performance and non-invasive character. However, in recent years, other analytical techniques arose as serious competitors, such as those based on synchrotron radiation (X-ray absorption, fluorescence or diffraction) or those using portable instruments (XRF, micro-Raman). It is shown that nevertheless IBA remains unmatched thanks to two unique features, namely the analysis of light elements and the high-resolution 3D chemical imaging.

Analytical techniques and instrumentation: A compilation

NASA Technical Reports Server (NTRS)

1974-01-01

Technical information on developments in instrumentation is arranged into four sections: (1) instrumentation for analysis; (2) analysis of matter; (3) analysis of electrical and mechanical phenomena; and (4) structural analysis. Patent information for two of the instruments described is presented.

Development of collaborative-creative learning model using virtual laboratory media for instrumental analytical chemistry lectures

NASA Astrophysics Data System (ADS)

Zurweni, Wibawa, Basuki; Erwin, Tuti Nurian

2017-08-01

The framework for teaching and learning in the 21st century was prepared with 4Cs criteria. Learning providing opportunity for the development of students' optimal creative skills is by implementing collaborative learning. Learners are challenged to be able to compete, work independently to bring either individual or group excellence and master the learning material. Virtual laboratory is used for the media of Instrumental Analytical Chemistry (Vis, UV-Vis-AAS etc) lectures through simulations computer application and used as a substitution for the laboratory if the equipment and instruments are not available. This research aims to design and develop collaborative-creative learning model using virtual laboratory media for Instrumental Analytical Chemistry lectures, to know the effectiveness of this design model adapting the Dick & Carey's model and Hannafin & Peck's model. The development steps of this model are: needs analyze, design collaborative-creative learning, virtual laboratory media using macromedia flash, formative evaluation and test of learning model effectiveness. While, the development stages of collaborative-creative learning model are: apperception, exploration, collaboration, creation, evaluation, feedback. Development of collaborative-creative learning model using virtual laboratory media can be used to improve the quality learning in the classroom, overcome the limitation of lab instruments for the real instrumental analysis. Formative test results show that the Collaborative-Creative Learning Model developed meets the requirements. The effectiveness test of students' pretest and posttest proves significant at 95% confidence level, t-test higher than t-table. It can be concluded that this learning model is effective to use for Instrumental Analytical Chemistry lectures.

Interactive Physical Simulation of Catheter Motion within Mayor Vessel Structures and Cavities for ASD/VSD Treatment

NASA Astrophysics Data System (ADS)

Becherer, Nico; Hesser, Jürgen; Kornmesser, Ulrike; Schranz, Dietmar; Männer, Reinhard

2007-03-01

Simulation systems are becoming increasingly essential in medical education. Hereby, capturing the physical behaviour of the real world requires a sophisticated modelling of instruments within the virtual environment. Most models currently used are not capable of user interactive simulations due to the computation of the complex underlying analytical equations. Alternatives are often based on simplifying mass-spring systems, being able to deliver high update rates that come at the cost of less realistic motion. In addition, most techniques are limited to narrow and tubular vessel structures or restrict shape alterations to two degrees of freedom, not allowing instrument deformations like torsion. In contrast, our approach combines high update rates with highly realistic motion and can in addition be used with respect to arbitrary structures like vessels or cavities (e.g. atrium, ventricle) without limiting the degrees of freedom. Based on energy minimization, bending energies and vessel structures are considered as linear elastic elements; energies are evaluated at regularly spaced points on the instrument, while the distance of the points is fixed, i.e. we simulate an articulated structure of joints with fixed connections between them. Arbitrary tissue structures are modeled through adaptive distance fields and are connected by nodes via an undirected graph system. The instrument points are linked to nodes by a system of rules. Energy minimization uses a Quasi Newton method without preconditioning and, hereby, gradients are estimated using a combination of analytical and numerical terms. Results show a high quality in motion simulation when compared to a phantom model. The approach is also robust and fast. Simulating an instrument with 100 joints runs at 100 Hz on a 3 GHz PC.

Automated novel high-accuracy miniaturized positioning system for use in analytical instrumentation

NASA Astrophysics Data System (ADS)

Siomos, Konstadinos; Kaliakatsos, John; Apostolakis, Manolis; Lianakis, John; Duenow, Peter

1996-01-01

The development of three-dimensional automotive devices (micro-robots) for applications in analytical instrumentation, clinical chemical diagnostics and advanced laser optics, depends strongly on the ability of such a device: firstly to be positioned with high accuracy, reliability, and automatically, by means of user friendly interface techniques; secondly to be compact; and thirdly to operate under vacuum conditions, free of most of the problems connected with conventional micropositioners using stepping-motor gear techniques. The objective of this paper is to develop and construct a mechanically compact computer-based micropositioning system for coordinated motion in the X-Y-Z directions with: (1) a positioning accuracy of less than 1 micrometer, (the accuracy of the end-position of the system is controlled by a hard/software assembly using a self-constructed optical encoder); (2) a heat-free propulsion mechanism for vacuum operation; and (3) synchronized X-Y motion.

Field-deployable sniffer for 2,4-dinitrotoluene detection.

PubMed

Albert, K J; Myrick, M L; Brown, S B; James, D L; Milanovich, F P; Walt, D R

2001-08-01

A field-deployable instrument has been developed to detect low-level 2,4-dinitrotoluene (2,4-DNT) vapors. The system is based on previously developed artificial nose technology and employs an array of sensory materials attached to the distal tips of an optical fiber bundle. Both semiselective and nonspecific, cross-reactive sensors were employed. Each sensor within the array responds differentially to vapor exposure so the array's fluorescence response patterns are unique for each analyte. The instrument is computationally "trained" to discriminate target response patterns from nontarget and background environments. This detection system has been applied to detect 2,4-DNT, an analyte commonly detected on the soil surface above buried 2,4,6-trinitrotoluene (TNT) land mines, in spiked soil and aqueous and ground samples. The system has been characterized and demonstrated the ability to detect 120 ppb 2,4-DNT vapor in blind (unknown) humidified samples during a supervised field test.

Cross-instrument Analysis Correlation Software

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

McJunkin, Timothy R.

This program has been designed to assist with the tracking of a sample from one analytical instrument to another such as SEM, microscopes, micro x-ray diffraction and other instruments where particular positions/locations on the sample are examined, photographed, etc. The software is designed to easily enter the position of fiducials and locations of interest such that in a future session in the same of different instrument the positions of interest can be re-found through using the known location fiducials in the current and reference session to transform the point into the current sessions coordinate system. The software is dialog boxmore » driven guiding the user through the necessary data entry and program choices. Information is stored in a series of text based extensible markup language (XML) files.« less

Median of patient results as a tool for assessment of analytical stability.

PubMed

Jørgensen, Lars Mønster; Hansen, Steen Ingemann; Petersen, Per Hyltoft; Sölétormos, György

2015-06-15

In spite of the well-established external quality assessment and proficiency testing surveys of analytical quality performance in laboratory medicine, a simple tool to monitor the long-term analytical stability as a supplement to the internal control procedures is often needed. Patient data from daily internal control schemes was used for monthly appraisal of the analytical stability. This was accomplished by using the monthly medians of patient results to disclose deviations from analytical stability, and by comparing divergences with the quality specifications for allowable analytical bias based on biological variation. Seventy five percent of the twenty analytes achieved on two COBASs INTEGRA 800 instruments performed in accordance with the optimum and with the desirable specifications for bias. Patient results applied in analytical quality performance control procedures are the most reliable sources of material as they represent the genuine substance of the measurements and therefore circumvent the problems associated with non-commutable materials in external assessment. Patient medians in the monthly monitoring of analytical stability in laboratory medicine are an inexpensive, simple and reliable tool to monitor the steadiness of the analytical practice. Copyright © 2015 Elsevier B.V. All rights reserved.

GENES AS INSTRUMENTS FOR STUDYING RISK BEHAVIOR EFFECTS: AN APPLICATION TO MATERNAL SMOKING AND OROFACIAL CLEFTS

PubMed Central

Jugessur, Astanand; Murray, Jeffrey C.; Moreno, Lina; Wilcox, Allen; Lie, Rolv T.

2011-01-01

This study uses instrumental variable (IV) models with genetic instruments to assess the effects of maternal smoking on the child’s risk of orofacial clefts (OFC), a common birth defect. The study uses genotypic variants in neurotransmitter and detoxification genes relateded to smoking as instruments for cigarette smoking before and during pregnancy. Conditional maximum likelihood and two-stage IV probit models are used to estimate the IV model. The data are from a population-level sample of affected and unaffected children in Norway. The selected genetic instruments generally fit the IV assumptions but may be considered “weak” in predicting cigarette smoking. We find that smoking before and during pregnancy increases OFC risk substantially under the IV model (by about 4–5 times at the sample average smoking rate). This effect is greater than that found with classical analytic models. This may be because the usual models are not able to consider self-selection into smoking based on unobserved confounders, or it may to some degree reflect limitations of the instruments. Inference based on weak-instrument robust confidence bounds is consistent with standard inference. Genetic instruments may provide a valuable approach to estimate the “causal” effects of risk behaviors with genetic-predisposing factors (such as smoking) on health and socioeconomic outcomes. PMID:22102793

40 CFR 1066.130 - Measurement instrument calibrations and verifications.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 40 Protection of Environment 33 2014-07-01 2014-07-01 false Measurement instrument calibrations... (CONTINUED) AIR POLLUTION CONTROLS VEHICLE-TESTING PROCEDURES Equipment, Measurement Instruments, Fuel, and Analytical Gas Specifications § 1066.130 Measurement instrument calibrations and verifications. The...

Development of a canopy Solar-induced chlorophyll fluorescence measurement instrument

NASA Astrophysics Data System (ADS)

Sun, G.; Wang, X.; Niu, Zh; Chen, F.

2014-02-01

A portable solar-induced chlorophyll fluorescence detecting instrument based on Fraunhofer line principle was designed and tested. The instrument has a valid survey area of 1.3 × 1.3 meter when the height was fixed to 1.3 meter. The instrument uses sunlight as its light source. The instrument is quipped with two sets of special photoelectrical detectors with the centre wavelength at 760 nm and 771 nm respectively and bandwidth less than 1nm. Both sets of detectors are composed of an upper detector which are used for detecting incidence sunlight and a bottom detector which are used for detecting reflex light from the canopy of crop. This instrument includes photoelectric detector module, signal process module, A/D convert module, the data storage and upload module and human-machine interface module. The microprocessor calculates solar-induced fluorescence value based on the A/D values get from detectors. And the value can be displayed on the instrument's LCD, stored in the flash memory of instrument and can also be uploaded to PC through the PC's serial interface. The prototype was tested in the crop field and the results demonstrate that the instrument can measure the solar-induced chlorophyll value exactly with the correlation coefficients was 0.9 compared to the values got from Analytical Spectral Devices FieldSpec Pro spectrometer. This instrument can diagnose the plant growth status by the acquired spectral response.

Using In Silico Fragmentation to Improve Routine Residue Screening in Complex Matrices.

PubMed

Kaufmann, Anton; Butcher, Patrick; Maden, Kathryn; Walker, Stephan; Widmer, Mirjam

2017-12-01

Targeted residue screening requires the use of reference substances in order to identify potential residues. This becomes a difficult issue when using multi-residue methods capable of analyzing several hundreds of analytes. Therefore, the capability of in silico fragmentation based on a structure database ("suspect screening") instead of physical reference substances for routine targeted residue screening was investigated. The detection of fragment ions that can be predicted or explained by in silico software was utilized to reduce the number of false positives. These "proof of principle" experiments were done with a tool that is integrated into a commercial MS vendor instrument operating software (UNIFI) as well as with a platform-independent MS tool (Mass Frontier). A total of 97 analytes belonging to different chemical families were separated by reversed phase liquid chromatography and detected in a data-independent acquisition (DIA) mode using ion mobility hyphenated with quadrupole time of flight mass spectrometry. The instrument was operated in the MS E mode with alternating low and high energy traces. The fragments observed from product ion spectra were investigated using a "chopping" bond disconnection algorithm and a rule-based algorithm. The bond disconnection algorithm clearly explained more analyte product ions and a greater percentage of the spectral abundance than the rule-based software (92 out of the 97 compounds produced ≥1 explainable fragment ions). On the other hand, tests with a complex blank matrix (bovine liver extract) indicated that the chopping algorithm reports significantly more false positive fragments than the rule based software. Graphical Abstract.

Using In Silico Fragmentation to Improve Routine Residue Screening in Complex Matrices

NASA Astrophysics Data System (ADS)

Kaufmann, Anton; Butcher, Patrick; Maden, Kathryn; Walker, Stephan; Widmer, Mirjam

2017-12-01

Targeted residue screening requires the use of reference substances in order to identify potential residues. This becomes a difficult issue when using multi-residue methods capable of analyzing several hundreds of analytes. Therefore, the capability of in silico fragmentation based on a structure database ("suspect screening") instead of physical reference substances for routine targeted residue screening was investigated. The detection of fragment ions that can be predicted or explained by in silico software was utilized to reduce the number of false positives. These "proof of principle" experiments were done with a tool that is integrated into a commercial MS vendor instrument operating software (UNIFI) as well as with a platform-independent MS tool (Mass Frontier). A total of 97 analytes belonging to different chemical families were separated by reversed phase liquid chromatography and detected in a data-independent acquisition (DIA) mode using ion mobility hyphenated with quadrupole time of flight mass spectrometry. The instrument was operated in the MSE mode with alternating low and high energy traces. The fragments observed from product ion spectra were investigated using a "chopping" bond disconnection algorithm and a rule-based algorithm. The bond disconnection algorithm clearly explained more analyte product ions and a greater percentage of the spectral abundance than the rule-based software (92 out of the 97 compounds produced ≥1 explainable fragment ions). On the other hand, tests with a complex blank matrix (bovine liver extract) indicated that the chopping algorithm reports significantly more false positive fragments than the rule based software. [Figure not available: see fulltext.

Convergence of Scores on the Interview and Questionnaire Versions of the Eating Disorder Examination: A Meta-Analytic Review

ERIC Educational Resources Information Center

Berg, Kelly C.; Peterson, Carol B.; Frazier, Patricia; Crow, Scott J.

2011-01-01

Significant discrepancies have been found between interview- and questionnaire-based assessments of psychopathology; however, these studies have typically compared instruments with unmatched item content. The Eating Disorder Examination (EDE), a structured interview, and the questionnaire version of the EDE (EDE-Q) are considered the preeminent…

Applicability of market-based instruments for safeguarding water quality in coastal waterways: Case study for Darwin Harbour, Australia

NASA Astrophysics Data System (ADS)

Greiner, Romy

2014-02-01

Water pollution of coastal waterways is a complex problem due to the cocktail of pollutants and multiplicity of polluters involved and pollution characteristics. Pollution control therefore requires a combination of policy instruments. This paper examines the applicability of market-based instruments to achieve effective and efficient water quality management in Darwin Harbour, Northern Territory, Australia. Potential applicability of instruments is examined in the context of biophysical and economic pollution characteristics, and experience with instruments elsewhere. The paper concludes that there is potential for inclusion of market-based instruments as part of an instrument mix to safeguard water quality in Darwin Harbour. It recommends, in particular, expanding the existing licencing system to include quantitative pollution limits for all significant point polluters; comprehensive and independent pollution monitoring across Darwin Harbour; public disclosure of water quality and emissions data; positive incentives for landholders in the Darwin Harbour catchment to improve land management practices; a stormwater offset program for greenfield urban developments; adoption of performance bonds for developments and operations which pose a substantial risk to water quality, including port expansion and dredging; and detailed consideration of a bubble licensing scheme for nutrient pollution. The paper offers an analytical framework for policy makers and resource managers tasked with water quality management in coastal waterways elsewhere in Australia and globally, and helps to scan for MBIs suitable in any given environmental management situation.

Analytical instrumentation infrastructure for combinatorial and high-throughput development of formulated discrete and gradient polymeric sensor materials arrays

NASA Astrophysics Data System (ADS)

Potyrailo, Radislav A.; Hassib, Lamyaa

2005-06-01

Multicomponent polymer-based formulations of optical sensor materials are difficult and time consuming to optimize using conventional approaches. To address these challenges, our long-term goal is to determine relationships between sensor formulation and sensor response parameters using new scientific methodologies. As the first step, we have designed and implemented an automated analytical instrumentation infrastructure for combinatorial and high-throughput development of polymeric sensor materials for optical sensors. Our approach is based on the fabrication and performance screening of discrete and gradient sensor arrays. Simultaneous formation of multiple sensor coatings into discrete 4×6, 6×8, and 8×12 element arrays (3-15μL volume per element) and their screening provides not only a well-recognized acceleration in the screening rate, but also considerably reduces or even eliminates sources of variability, which are randomly affecting sensors response during a conventional one-at-a-time sensor coating evaluation. The application of gradient sensor arrays provides additional capabilities for rapid finding of the optimal formulation parameters.

Ion Chromatography-on-a-chip for Water Quality Analysis

NASA Technical Reports Server (NTRS)

Kidd, R. D.; Noell, A.; Kazarians, G.; Aubrey, A. D.; Scianmarello, N.; Tai, Y.-C.

2015-01-01

We report progress towards developing a Micro-Electro-Mechanical Systems (MEMS)- based ion chromatograph (IC) for crewed spacecraft water analysis. This IC-chip is an offshoot of a NASA-funded effort to produce a high performance liquid chromatograph (HPLC)-chip. This HPLC-chip system would require a desalting (i.e. ion chromatography) step. The complete HPLC instrument consists of the Jet Propulsion Labortory's (JPL's) quadrupole ion trap mass spectrometer integrated with a state-of-the-art MEMS liquid chromatograph (LC) system developed by the California Institute of Technology's (Caltech's) Micromachining Laboratory. The IC version of the chip consist of an electrolysis-based injector, a separation column, two electrolysis pumps for gradient generation, mixer, and a built-in conductivity detector. The HPLC version of the chip also includes a nanospray tip. The low instrument mass, coupled with its high analytical capabilities, makes the LC chip ideally suitable for wide range of applications such as trace contaminant, inorganic analytical science and, when coupled to a mass spectrometer, a macromolecular detection system for either crewed space exploration vehicles or robotic planetary missions.

A novel non-imaging optics based Raman spectroscopy device for transdermal blood analyte measurement

PubMed Central

Kong, Chae-Ryon; Barman, Ishan; Dingari, Narahara Chari; Kang, Jeon Woong; Galindo, Luis; Dasari, Ramachandra R.; Feld, Michael S.

2011-01-01

Due to its high chemical specificity, Raman spectroscopy has been considered to be a promising technique for non-invasive disease diagnosis. However, during Raman excitation, less than one out of a million photons undergo spontaneous Raman scattering and such weakness in Raman scattered light often require highly efficient collection of Raman scattered light for the analysis of biological tissues. We present a novel non-imaging optics based portable Raman spectroscopy instrument designed for enhanced light collection. While the instrument was demonstrated on transdermal blood glucose measurement, it can also be used for detection of other clinically relevant blood analytes such as creatinine, urea and cholesterol, as well as other tissue diagnosis applications. For enhanced light collection, a non-imaging optical element called compound hyperbolic concentrator (CHC) converts the wide angular range of scattered photons (numerical aperture (NA) of 1.0) from the tissue into a limited range of angles accommodated by the acceptance angles of the collection system (e.g., an optical fiber with NA of 0.22). A CHC enables collimation of scattered light directions to within extremely narrow range of angles while also maintaining practical physical dimensions. Such a design allows for the development of a very efficient and compact spectroscopy system for analyzing highly scattering biological tissues. Using the CHC-based portable Raman instrument in a clinical research setting, we demonstrate successful transdermal blood glucose predictions in human subjects undergoing oral glucose tolerance tests. PMID:22125761

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

Song, Ehwang; Gao, Yuqian; Wu, Chaochao

Here, mass spectrometry (MS) based targeted proteomic methods such as selected reaction monitoring (SRM) are becoming the method of choice for preclinical verification of candidate protein biomarkers. The Clinical Proteomic Tumor Analysis Consortium (CPTAC) of the National Cancer Institute has investigated the standardization and analytical validation of the SRM assays and demonstrated robust analytical performance on different instruments across different laboratories. An Assay Portal has also been established by CPTAC to provide the research community a resource consisting of large set of targeted MS-based assays, and a depository to share assays publicly, providing that assays meet the guidelines proposed bymore » CPTAC. Herein, we report 98 SRM assays covering 70 candidate protein biomarkers previously reported as associated with ovarian cancer that have been thoroughly characterized according to the CPTAC Assay Characterization Guidance Document. The experiments, methods and results for characterizing these SRM assays for their MS response, repeatability, selectivity, stability, and reproducible detection of endogenous analytes are described in detail.« less

Analytical balance-based Faraday magnetometer

NASA Astrophysics Data System (ADS)

Riminucci, Alberto; Uhlarz, Marc; De Santis, Roberto; Herrmannsdörfer, Thomas

2017-03-01

We introduce a Faraday magnetometer based on an analytical balance in which we were able to apply magnetic fields up to 0.14 T. We calibrated it with a 1 mm Ni sphere previously characterized in a superconducting quantum interference device (SQUID) magnetometer. The proposed magnetometer reached a theoretical sensitivity of 3 × 10-8 A m2. We demonstrated its operation on magnetic composite scaffolds made of poly(ɛ-caprolactone)/iron-doped hydroxyapatite. To confirm the validity of the method, we measured the same scaffold properties in a SQUID magnetometer. The agreement between the two measurements was within 5% at 0.127 T and 12% at 24 mT. With the addition, for a small cost, of a permanent magnet and computer controlled linear translators, we were thus able to assemble a Faraday magnetometer based on an analytical balance, which is a virtually ubiquitous instrument. This will make simple but effective magnetometry easily accessible to most laboratories, in particular, to life sciences ones, which are increasingly interested in magnetic materials.

Multiplexed Paper Analytical Device for Quantification of Metals using Distance-Based Detection

PubMed Central

Cate, David M.; Noblitt, Scott D.; Volckens, John; Henry, Charles S.

2015-01-01

Exposure to metal-containing aerosols has been linked with adverse health outcomes for almost every organ in the human body. Commercially available techniques for quantifying particulate metals are time-intensive, laborious, and expensive; often sample analysis exceeds $100. We report a simple technique, based upon a distance-based detection motif, for quantifying metal concentrations of Ni, Cu, and Fe in airborne particulate matter using microfluidic paper-based analytical devices. Paper substrates are used to create sensors that are self-contained, self-timing, and require only a drop of sample for operation. Unlike other colorimetric approaches in paper microfluidics that rely on optical instrumentation for analysis, with distance-based detection, analyte is quantified visually based on the distance of a colorimetric reaction, similar to reading temperature on a thermometer. To demonstrate the effectiveness of this approach, Ni, Cu, and Fe were measured individually in single-channel devices; detection limits as low as 0.1, 0.1, and 0.05 µg were reported for Ni, Cu, and Fe. Multiplexed analysis of all three metals was achieved with detection limits of 1, 5, and 1 µg for Ni, Cu, and Fe. We also extended the dynamic range for multi-analyte detection by printing concentration gradients of colorimetric reagents using an off the shelf inkjet printer. Analyte selectivity was demonstrated for common interferences. To demonstrate utility of the method, Ni, Cu, and Fe were measured from samples of certified welding fume; levels measured with paper sensors matched known values determined gravimetrically. PMID:26009988

Capillary waveguide optrodes: an approach to optical sensing in medical diagnostics

NASA Astrophysics Data System (ADS)

Lippitsch, Max E.; Draxler, Sonja; Kieslinger, Dietmar; Lehmann, Hartmut; Weigl, Bernhard H.

1996-07-01

Glass capillaries with a chemically sensitive coating on the inner surface are used as optical sensors for medical diagnostics. A capillary simultaneously serves as a sample compartment, a sensor element, and an inhomogeneous optical waveguide. Various detection schemes based on absorption, fluorescence intensity, or fluorescence lifetime are described. In absorption-based capillary waveguide optrodes the absorption in the sensor layer is analyte dependent; hence light transmission along the inhomogeneous waveguiding structure formed by the capillary wall and the sensing layer is a function of the analyte concentration. Similarly, in fluorescence-based capillary optrodes the fluorescence intensity or the fluorescence lifetime of an indicator dye fixed in the sensing layer is analyte dependent; thus the specific property of fluorescent light excited in the sensing layer and thereafter guided along the inhomogeneous waveguiding structure is a function of the analyte concentration. Both schemes are experimentally demonstrated, one with carbon dioxide as the analyte and the other one with oxygen. The device combines optical sensors with the standard glass capillaries usually applied to gather blood drops from fingertips, to yield a versatile diagnostic instrument, integrating the sample compartment, the optical sensor, and the light-collecting optics into a single piece. This ensures enhanced sensor performance as well as improved handling compared with other sensors. waveguide, blood gases, medical diagnostics.

Towards autonomous environmental monitoring systems.

PubMed

Sequeira, Margaret; Bowden, Michaela; Minogue, Edel; Diamond, Dermot

2002-02-11

The concept of micro total analysis systems (muTAS) or Lab-on-a-chip is based on the twin strategies of integration and miniaturisation that have been so successful in the electronics industry. This paper will look at the materials issues, particularly with respect to the new polymeric materials that are becoming available, and strategies for integrating optical (colorimetric) detection. The influence of breakthroughs in apparently unrelated areas on the range of chemistries that can be applied will be illustrated. For environmental monitoring, the further integration of wireless communications with micro-dimensioned analytical instruments and sensors will become the ultimate driving force. The emergence of these compact, self-sustaining, networked instruments will have enormous impact on all field-based environmental measurements.

Systematic comparison of static and dynamic headspace sampling techniques for gas chromatography.

PubMed

Kremser, Andreas; Jochmann, Maik A; Schmidt, Torsten C

2016-09-01

Six automated, headspace-based sample preparation techniques were used to extract volatile analytes from water with the goal of establishing a systematic comparison between commonly available instrumental alternatives. To that end, these six techniques were used in conjunction with the same gas chromatography instrument for analysis of a common set of volatile organic carbon (VOC) analytes. The methods were thereby divided into three classes: static sampling (by syringe or loop), static enrichment (SPME and PAL SPME Arrow), and dynamic enrichment (ITEX and trap sampling). For PAL SPME Arrow, different sorption phase materials were also included in the evaluation. To enable an effective comparison, method detection limits (MDLs), relative standard deviations (RSDs), and extraction yields were determined and are discussed for all techniques. While static sampling techniques exhibited sufficient extraction yields (approx. 10-20 %) to be reliably used down to approx. 100 ng L(-1), enrichment techniques displayed extraction yields of up to 80 %, resulting in MDLs down to the picogram per liter range. RSDs for all techniques were below 27 %. The choice on one of the different instrumental modes of operation (aforementioned classes) was thereby the most influential parameter in terms of extraction yields and MDLs. Individual methods inside each class showed smaller deviations, and the least influences were observed when evaluating different sorption phase materials for the individual enrichment techniques. The option of selecting specialized sorption phase materials may, however, be more important when analyzing analytes with different properties such as high polarity or the capability of specific molecular interactions. Graphical Abstract PAL SPME Arrow during the extraction of volatile analytes from the headspace of an aqueous sample.

A versatile, refrigerant- and cryogen-free cryofocusing-thermodesorption unit for preconcentration of traces gases in air

NASA Astrophysics Data System (ADS)

Obersteiner, Florian; Bönisch, Harald; Keber, Timo; O'Doherty, Simon; Engel, Andreas

2016-10-01

We present a compact and versatile cryofocusing-thermodesorption unit, which we developed for quantitative analysis of halogenated trace gases in ambient air. Possible applications include aircraft-based in situ measurements, in situ monitoring and laboratory operation for the analysis of flask samples. Analytes are trapped on adsorptive material cooled by a Stirling cooler to low temperatures (e.g. -80 °C) and subsequently desorbed by rapid heating of the adsorptive material (e.g. +200 °C). The set-up involves neither the exchange of adsorption tubes nor any further condensation or refocusing steps. No moving parts are used that would require vacuum insulation. This allows for a simple and robust design. Reliable operation is ensured by the Stirling cooler, which neither contains a liquid refrigerant nor requires refilling a cryogen. At the same time, it allows for significantly lower adsorption temperatures compared to commonly used Peltier elements. We use gas chromatography - mass spectrometry (GC-MS) for separation and detection of the preconcentrated analytes after splitless injection. A substance boiling point range of approximately -80 to +150 °C and a substance mixing ratio range of less than 1 ppt (pmol mol-1) to more than 500 ppt in preconcentrated sample volumes of 0.1 to 10 L of ambient air is covered, depending on the application and its analytical demands. We present the instrumental design of the preconcentration unit and demonstrate capabilities and performance through the examination of analyte breakthrough during adsorption, repeatability of desorption and analyte residues in blank tests. Examples of application are taken from the analysis of flask samples collected at Mace Head Atmospheric Research Station in Ireland using our laboratory GC-MS instruments and by data obtained during a research flight with our in situ aircraft instrument GhOST-MS (Gas chromatograph for the Observation of Tracers - coupled with a Mass Spectrometer).

Preparations for ExoMars: Learning Lessons from Curiosity

NASA Astrophysics Data System (ADS)

Edwards, Peter Henry; Hutchinson, Ian; Morgan, Sally; McHugh, Melissa; Malherbe, Cedric; Lerman, Hannah; INGLEY, Richard

2016-10-01

In 2020, the European Space Agency will launch its first Mars rover mission, ExoMars. The rover will use a drill to obtain samples from up to 2m below the Martian surface that will then be analysed using a variety of analytical instruments, including the Raman Laser Spectrometer (RLS), which will be the first Raman spectrometer to be used on a planetary mission.To prepare for ExoMars RLS operations, we report on a series of experiments that have been performed in order to investigate the response of a representative Raman instrument to a number of analogue samples (selected based on the types of material known to be important, following investigations performed by NASA's Mars Science Laboratory, MSL, on the Curiosity rover). Raman spectroscopy will provide molecular and mineralogical information about the samples obtained from the drill cores on ExoMars. MSL acquires similar information using the CheMin XRD instrument which analyses samples acquired from drill holes several centimetres deep. Like Raman spectroscopy, XRD also provides information on the mineralogical makeup of the analysed samples.The samples in our study were selected based on CheMin data obtained from drill sites at Yellowknife Bay, one of the first locations visited by Curiosity (supplemented with additional fine scale elemental information obtained with the ChemCam LIBS laser instrument). Once selected (or produced), the samples were characterised using standard laboratory XRD and XRF instruments (in order to compare with the data obtained by CheMin) and a standard, laboratory based LIBS system (in order to compare with the ChemCam data). This characterisation provides confirmation that the analogue samples are representative of the materials likely to be encountered on Mars by the ExoMars rover.A representative, miniaturised Raman spectrometer was used to analyse the samples, using acquisition strategies and operating modes similar to those expected for the ExoMars instrument. The type of minerals detected are identified and compared to the information typically acquired using other analytical science techniques investigating in order to highlight the benefits and drawbacks of using Raman spectroscopy for planetary science applications.

Integrating laboratory robots with analytical instruments--must it really be so difficult?

PubMed

Kramer, G W

1990-09-01

Creating a reliable system from discrete laboratory instruments is often a task fraught with difficulties. While many modern analytical instruments are marvels of detection and data handling, attempts to create automated analytical systems incorporating such instruments are often frustrated by their human-oriented control structures and their egocentricity. The laboratory robot, while fully susceptible to these problems, extends such compatibility issues to the physical dimensions involving sample interchange, manipulation, and event timing. The workcell concept was conceived to describe the procedure and equipment necessary to carry out a single task during sample preparation. This notion can be extended to organize all operations in an automated system. Each workcell, no matter how complex its local repertoire of functions, must be minimally capable of accepting information (commands, data), returning information on demand (status, results), and being started, stopped, and reset by a higher level device. Even the system controller should have a mode where it can be directed by instructions from a higher level.

How to change environmental conditions for health.

PubMed

Commers, Matthew J; Gottlieb, Nell; Kok, Gerjo

2007-03-01

Since the Lalonde report, contemporary public-health theory has given steadily more attention to the role of environments in influencing health status. Environments, both social and physical, influence health directly or through complex interactions with behavior, genetics and health-care systems. They are also important for public-health because environments are the complex systems through which people are both empowered and exercise their empowerment. If public-health professionals are to play a significant role in influencing environments for health, they need analytical instruments that enable them to link specific environmental conditions with the actions necessary to improve them. These instruments must also enable public-health professionals to identify points of leverage for stimulating key actors to take the actions necessary to make environments more promoting of health. This article first presents one such analytical instrument. Then, building on examples relating to socio-economic health inequities, the analytical instrument is applied to reveal how it can add value to health professionals' effectiveness in planning interventions for more health-promoting environments.

The Raman Laser Spectrometer for the ExoMars Rover Mission to Mars

NASA Astrophysics Data System (ADS)

Rull, Fernando; Maurice, Sylvestre; Hutchinson, Ian; Moral, Andoni; Perez, Carlos; Diaz, Carlos; Colombo, Maria; Belenguer, Tomas; Lopez-Reyes, Guillermo; Sansano, Antonio; Forni, Olivier; Parot, Yann; Striebig, Nicolas; Woodward, Simon; Howe, Chris; Tarcea, Nicolau; Rodriguez, Pablo; Seoane, Laura; Santiago, Amaia; Rodriguez-Prieto, Jose A.; Medina, Jesús; Gallego, Paloma; Canchal, Rosario; Santamaría, Pilar; Ramos, Gonzalo; Vago, Jorge L.; RLS Team

2017-07-01

The Raman Laser Spectrometer (RLS) on board the ESA/Roscosmos ExoMars 2020 mission will provide precise identification of the mineral phases and the possibility to detect organics on the Red Planet. The RLS will work on the powdered samples prepared inside the Pasteur analytical suite and collected on the surface and subsurface by a drill system. Raman spectroscopy is a well-known analytical technique based on the inelastic scattering by matter of incident monochromatic light (the Raman effect) that has many applications in laboratory and industry, yet to be used in space applications. Raman spectrometers will be included in two Mars rovers scheduled to be launched in 2020. The Raman instrument for ExoMars 2020 consists of three main units: (1) a transmission spectrograph coupled to a CCD detector; (2) an electronics box, including the excitation laser that controls the instrument functions; and (3) an optical head with an autofocus mechanism illuminating and collecting the scattered light from the spot under investigation. The optical head is connected to the excitation laser and the spectrometer by optical fibers. The instrument also has two targets positioned inside the rover analytical laboratory for onboard Raman spectral calibration. The aim of this article was to present a detailed description of the RLS instrument, including its operation on Mars. To verify RLS operation before launch and to prepare science scenarios for the mission, a simulator of the sample analysis chain has been developed by the team. The results obtained are also discussed. Finally, the potential of the Raman instrument for use in field conditions is addressed. By using a ruggedized prototype, also developed by our team, a wide range of terrestrial analog sites across the world have been studied. These investigations allowed preparing a large collection of real, in situ spectra of samples from different geological processes and periods of Earth evolution. On this basis, we are working to develop models for interpreting analog processes on Mars during the mission.

Selected Analytical Methods for Environmental Remediation and Recovery (SAM) - Home

EPA Pesticide Factsheets

The SAM Home page provides access to all information provided in EPA's Selected Analytical Methods for Environmental Remediation and Recovery (SAM), and includes a query function allowing users to search methods by analyte, sample type and instrumentation.

Analyzing chromatographic data using multilevel modeling.

PubMed

Wiczling, Paweł

2018-06-01

It is relatively easy to collect chromatographic measurements for a large number of analytes, especially with gradient chromatographic methods coupled with mass spectrometry detection. Such data often have a hierarchical or clustered structure. For example, analytes with similar hydrophobicity and dissociation constant tend to be more alike in their retention than a randomly chosen set of analytes. Multilevel models recognize the existence of such data structures by assigning a model for each parameter, with its parameters also estimated from data. In this work, a multilevel model is proposed to describe retention time data obtained from a series of wide linear organic modifier gradients of different gradient duration and different mobile phase pH for a large set of acids and bases. The multilevel model consists of (1) the same deterministic equation describing the relationship between retention time and analyte-specific and instrument-specific parameters, (2) covariance relationships relating various physicochemical properties of the analyte to chromatographically specific parameters through quantitative structure-retention relationship based equations, and (3) stochastic components of intra-analyte and interanalyte variability. The model was implemented in Stan, which provides full Bayesian inference for continuous-variable models through Markov chain Monte Carlo methods. Graphical abstract Relationships between log k and MeOH content for acidic, basic, and neutral compounds with different log P. CI credible interval, PSA polar surface area.

Analytical design and performance studies of nuclear furnace tests of small nuclear light bulb models

NASA Technical Reports Server (NTRS)

Latham, T. S.; Rodgers, R. J.

1972-01-01

Analytical studies were continued to identify the design and performance characteristics of a small-scale model of a nuclear light bulb unit cell suitable for testing in a nuclear furnace reactor. Emphasis was placed on calculating performance characteristics based on detailed radiant heat transfer analyses, on designing the test assembly for ease of insertion, connection, and withdrawal at the reactor test cell, and on determining instrumentation and test effluent handling requirements. In addition, a review of candidate test reactors for future nuclear light bulb in-reactor tests was conducted.

MEMS-Based Micro Instruments for In-Situ Planetary Exploration

NASA Technical Reports Server (NTRS)

George, Thomas; Urgiles, Eduardo R; Toda, Risaku; Wilcox, Jaroslava Z.; Douglas, Susanne; Lee, C-S.; Son, Kyung-Ah; Miller, D.; Myung, N.; Madsen, L.;

Smaller to larger biomolecule detection using a lab-built surface plasmon resonance based instrument

NASA Astrophysics Data System (ADS)

Lukose, J.; Kulal, V.; Chidangil, S.; Sinha, R. K.

2016-10-01

We have developed a low-cost surface plasmon resonance (SPR) instrument based on the Kretschmann configuration for biosensing applications. The fabricated instrument is capable of operating in both angular and intensity interrogation schemes. The proposed sensor has proved enormously versatile by detecting a range of analytes with low to high molecular weights. The refractive index based sensor has been used for detecting the variation in the concentration of the aqueous solution of glucose and glycerine. Real time immobilization of protein molecules, bovine serum albumin on a gold (Au) film surface, has also been detected using the SPR imaging technique. Alkanethiol functionalization of the Au surface was performed, and bovine serum albumin was immobilized onto the carboxyl functionalized surface using amine reactive cross linker chemistry. In future, the present approach can also be utilized for the selective detection of a wide range of target biomolecules with the help of specific capture probes, as well as for monitoring protein-drug interactions.

Instrumental Analysis in Environmental Chemistry - Gas Phase Detection Systems

ERIC Educational Resources Information Center

Stedman, Donald H.; Meyers, Philip A.

1974-01-01

Discusses advances made in chemical analysis instrumentation used in environmental monitoring. This first of two articles is concerned with analytical instrumentation in which detection and dispersion depend ultimately on the properties of gaseous molecules. (JR)

Validation of a Four-Factor Model of Career Indecision

ERIC Educational Resources Information Center

Brown, Steven D.; Hacker, Jason; Abrams, Matthew; Carr, Andrea; Rector, Christopher; Lamp, Kristen; Telander, Kyle; Siena, Anne

2012-01-01

Two studies were designed to explore whether a meta-analytically derived four-factor model of career indecision (Brown & Rector, 2008) could be replicated at the primary and secondary data levels. In the first study, an initial pool of 167 items was written based on 35 different instruments whose scores had loaded saliently on at least one…

A Complex Systems Investigation of Group Work Dynamics in L2 Interactive Tasks

ERIC Educational Resources Information Center

Poupore, Glen

2018-01-01

Working with Korean university-level learners of English, this study provides a detailed analytical comparison of 2 task work groups that were video-recorded, with 1 group scoring very high and the other relatively low based on the results of a Group Work Dynamic (GWD) measuring instrument. Adopting a complexity theory (CT) perspective and…

USDA-ARS GRACEnet Project Protocols, Chapter 3. Chamber-based trace gas flux measurements4

USDA-ARS?s Scientific Manuscript database

This protocol addresses N2O, CO2 and CH4 flux measurement by soil chamber methodology. The reactivities of other gasses of interest such as NOx O3, CO, and NH3 will require different chambers and associated instrumentation. Carbon dioxide is included as an analyte with this protocol; however, when p...

Science Update: Analytical Chemistry.

ERIC Educational Resources Information Center

Worthy, Ward

1980-01-01

Briefly discusses new instrumentation in the field of analytical chemistry. Advances in liquid chromatography, photoacoustic spectroscopy, the use of lasers, and mass spectrometry are also discussed. (CS)

Assessment of Raman spectroscopy as a tool for the non-destructive identification of organic minerals and biomolecules for Mars studies

NASA Astrophysics Data System (ADS)

Jehlička, J.; Edwards, H. G. M.; Vítek, P.

2009-05-01

Several characteristic geological features found on the surface of Mars by planetary rovers suggest that a possible extinct biosphere could exist based on similar sources of energy as occurred on Earth. For this reason, analytical instrumental protocols for the detection of biomarkers in suitable geological matrices unequivocally have to be elaborated for future unmanned explorations including the forthcoming ESA ExoMars mission. As part of the Pasteur suite of analytical instrumentation on ExoMars, the Raman/LIBS instrument will seek elemental and molecular information about geological, biological and biogeological markers in the Martian record. A key series of experiments on terrestrial Mars analogues, of which this paper addresses a particularly important series of compounds, is required to obtain the Raman spectra of key molecules and crystals, which are characteristic for each biomarker. Here, we present Raman spectra of several examples of organic compounds which have been recorded non-destructively - higher n-alkanes, polycyclic aromatic hydrocarbons, carotenoids, salts of organic acids, pure crystalline terpenes as well as oxygen-containing organic compounds. In addition, the lower limit of β-carotene detection in sulphate matrices using Raman microspectroscopy was estimated.

Flow chemistry vs. flow analysis.

PubMed

Trojanowicz, Marek

2016-01-01

The flow mode of conducting chemical syntheses facilitates chemical processes through the use of on-line analytical monitoring of occurring reactions, the application of solid-supported reagents to minimize downstream processing and computerized control systems to perform multi-step sequences. They are exactly the same attributes as those of flow analysis, which has solid place in modern analytical chemistry in several last decades. The following review paper, based on 131 references to original papers as well as pre-selected reviews, presents basic aspects, selected instrumental achievements and developmental directions of a rapidly growing field of continuous flow chemical synthesis. Interestingly, many of them might be potentially employed in the development of new methods in flow analysis too. In this paper, examples of application of flow analytical measurements for on-line monitoring of flow syntheses have been indicated and perspectives for a wider application of real-time analytical measurements have been discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Responsivity-based criterion for accurate calibration of FTIR emission spectra: theoretical development and bandwidth estimation.

PubMed

Rowe, Penny M; Neshyba, Steven P; Walden, Von P

2011-03-14

An analytical expression for the variance of the radiance measured by Fourier-transform infrared (FTIR) emission spectrometers exists only in the limit of low noise. Outside this limit, the variance needs to be calculated numerically. In addition, a criterion for low noise is needed to identify properly calibrated radiances and optimize the instrument bandwidth. In this work, the variance and the magnitude of a noise-dependent spectral bias are calculated as a function of the system responsivity (r) and the noise level in its estimate (σr). The criterion σr/r<0.3, applied to downwelling and upwelling FTIR emission spectra, shows that the instrument bandwidth is specified properly for one instrument but needs to be restricted for another.

A simple analytical platform based on thin-layer chromatography coupled with paper-based analytical device for determination of total capsaicinoids in chilli samples.

PubMed

Dawan, Phanphruk; Satarpai, Thiphol; Tuchinda, Patoomratana; Shiowatana, Juwadee; Siripinyanond, Atitaya

2017-01-01

A new analytical platform based on the use of thin-layer chromatography (TLC) coupled with paper-based analytical device (PAD) was developed for the determination of total capsaicinoids in chilli samples. This newly developed TLC-PAD is simple and low-cost without any requirement of special instrument or skillful person. The analysis consisted of two steps, i.e., extraction of capsaicinoids from chilli samples by using ethanol as solvent and separation of capsaicinoids by thin-layer chromatography (TLC) and elution of capsaicinoids from the TLC plate with in situ colorimetric detection of capsaicinoids on the PAD. For colorimetric detection, Folin-Ciocalteu reagent was used to detect phenolic functional group of capsaicinoids yielding the blue color. The blue color on the PAD was imaged by a scanner followed by evaluation of its grayscale intensity value by ImageJ program. This newly developed TLC-PAD method provided a linear range from 50 to 1000mgL -1 capsaicinoids with the limit of detection as low as 50mgL -1 capsaicinoids. The proposed method was applied to determine capsaicinoids in dried chilli and seasoning powder samples and the results were in good agreement with those obtained by HPLC method. Copyright © 2016 Elsevier B.V. All rights reserved.

Transmission versus reflectance spectroscopy for quantitation.

PubMed

Gardner, Craig M

2018-01-01

The objective of this work was to compare the accuracy of analyte concentration estimation when using transmission versus diffuse reflectance spectroscopy of a scattering medium. Monte Carlo ray tracing of light through the medium was used in conjunction with pure component absorption spectra and Beer-Lambert absorption along each ray's pathlength to generate matched sets of pseudoabsorbance spectra, containing water and six analytes present in skin. PLS regression models revealed an improvement in accuracy when using transmission compared to reflectance for a range of medium thicknesses and instrument noise levels. An analytical expression revealed the source of the accuracy degradation with reflectance was due both to the reduced collection efficiency for a fixed instrument etendue and to the broad pathlength distribution that detected light travels in the medium before exiting from the incident side. (2018) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE).

A Toolbox of Metrology-Based Techniques for Optical System Alignment

NASA Technical Reports Server (NTRS)

Coulter, Phillip; Ohl, Raymond G.; Blake, Peter N.; Bos, Brent J.; Casto, Gordon V.; Eichhorn, William L.; Gum, Jeffrey S.; Hadjimichael, Theodore J.; Hagopian, John G.; Hayden, Joseph E.;

A Toolbox of Metrology-Based Techniques for Optical System Alignment

NASA Technical Reports Server (NTRS)

Coulter, Phillip; Ohl, Raymond G.; Blake, Peter N.; Bos, Brent J.; Eichhorn, William L.; Gum, Jeffrey S.; Hadjimichael, Theodore J.; Hagopian, John G.; Hayden, Joseph E.; Hetherington, Samuel E.;

Evaluation Criteria for Micro-CAI: A Psychometric Approach

PubMed Central

Wallace, Douglas; Slichter, Mark; Bolwell, Christine

1985-01-01

The increased use of microcomputer-based instructional programs has resulted in a greater need for third-party evaluation of the software. This in turn has prompted the development of micro-CAI evaluation tools. The present project sought to develop a prototype instrument to assess the impact of CAI program presentation characteristics on students. Data analysis and scale construction was conducted using standard item reliability analyses and factor analytic techniques. Adequate subscale reliabilities and factor structures were found, suggesting that a psychometric approach to CAI evaluation may possess some merit. Efforts to assess the utility of the resultant instrument are currently underway.

Generation and analysis of chemical compound libraries

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

Gregoire, John M.; Jin, Jian; Kan, Kevin S.

2017-10-03

Various samples are generated on a substrate. The samples each includes or consists of one or more analytes. In some instances, the samples are generated through the use of gels or through vapor deposition techniques. The samples are used in an instrument for screening large numbers of analytes by locating the samples between a working electrode and a counter electrode assembly. The instrument also includes one or more light sources for illuminating each of the samples. The instrument is configured to measure the photocurrent formed through a sample as a result of the illumination of the sample.

Raman Spectrometry.

ERIC Educational Resources Information Center

Gardiner, Derek J.

1980-01-01

Reviews mainly quantitative analytical applications in the field of Raman spectrometry. Includes references to other reviews, new and analytically untested techniques, and novel sampling and instrument designs. Cites 184 references. (CS)

Ab initio simulation of diffractometer instrumental function for high-resolution X-ray diffraction1

PubMed Central

Mikhalychev, Alexander; Benediktovitch, Andrei; Ulyanenkova, Tatjana; Ulyanenkov, Alex

2015-01-01

Modeling of the X-ray diffractometer instrumental function for a given optics configuration is important both for planning experiments and for the analysis of measured data. A fast and universal method for instrumental function simulation, suitable for fully automated computer realization and describing both coplanar and noncoplanar measurement geometries for any combination of X-ray optical elements, is proposed. The method can be identified as semi-analytical backward ray tracing and is based on the calculation of a detected signal as an integral of X-ray intensities for all the rays reaching the detector. The high speed of calculation is provided by the expressions for analytical integration over the spatial coordinates that describe the detection point. Consideration of the three-dimensional propagation of rays without restriction to the diffraction plane provides the applicability of the method for noncoplanar geometry and the accuracy for characterization of the signal from a two-dimensional detector. The correctness of the simulation algorithm is checked in the following two ways: by verifying the consistency of the calculated data with the patterns expected for certain simple limiting cases and by comparing measured reciprocal-space maps with the corresponding maps simulated by the proposed method for the same diffractometer configurations. Both kinds of tests demonstrate the agreement of the simulated instrumental function shape with the measured data. PMID:26089760

Analysis of Observational Studies in the Presence of Treatment Selection Bias: Effects of Invasive Cardiac Management on AMI Survival Using Propensity Score and Instrumental Variable Methods

PubMed Central

Stukel, Thérèse A.; Fisher, Elliott S; Wennberg, David E.; Alter, David A.; Gottlieb, Daniel J.; Vermeulen, Marian J.

2007-01-01

Context Comparisons of outcomes between patients treated and untreated in observational studies may be biased due to differences in patient prognosis between groups, often because of unobserved treatment selection biases. Objective To compare 4 analytic methods for removing the effects of selection bias in observational studies: multivariable model risk adjustment, propensity score risk adjustment, propensity-based matching, and instrumental variable analysis. Design, Setting, and Patients A national cohort of 122 124 patients who were elderly (aged 65–84 years), receiving Medicare, and hospitalized with acute myocardial infarction (AMI) in 1994–1995, and who were eligible for cardiac catheterization. Baseline chart reviews were taken from the Cooperative Cardiovascular Project and linked to Medicare health administrative data to provide a rich set of prognostic variables. Patients were followed up for 7 years through December 31, 2001, to assess the association between long-term survival and cardiac catheterization within 30 days of hospital admission. Main Outcome Measure Risk-adjusted relative mortality rate using each of the analytic methods. Results Patients who received cardiac catheterization (n=73 238) were younger and had lower AMI severity than those who did not. After adjustment for prognostic factors by using standard statistical risk-adjustment methods, cardiac catheterization was associated with a 50% relative decrease in mortality (for multivariable model risk adjustment: adjusted relative risk [RR], 0.51; 95% confidence interval [CI], 0.50–0.52; for propensity score risk adjustment: adjusted RR, 0.54; 95% CI, 0.53–0.55; and for propensity-based matching: adjusted RR, 0.54; 95% CI, 0.52–0.56). Using regional catheterization rate as an instrument, instrumental variable analysis showed a 16% relative decrease in mortality (adjusted RR, 0.84; 95% CI, 0.79–0.90). The survival benefits of routine invasive care from randomized clinical trials are between 8% and 21 %. Conclusions Estimates of the observational association of cardiac catheterization with long-term AMI mortality are highly sensitive to analytic method. All standard risk-adjustment methods have the same limitations regarding removal of unmeasured treatment selection biases. Compared with standard modeling, instrumental variable analysis may produce less biased estimates of treatment effects, but is more suited to answering policy questions than specific clinical questions. PMID:17227979

Introduction of organic/hydro-organic matrices in inductively coupled plasma optical emission spectrometry and mass spectrometry: a tutorial review. Part I. Theoretical considerations.

PubMed

Leclercq, Amélie; Nonell, Anthony; Todolí Torró, José Luis; Bresson, Carole; Vio, Laurent; Vercouter, Thomas; Chartier, Frédéric

2015-07-23

Due to their outstanding analytical performances, inductively coupled plasma optical emission spectrometry (ICP-OES) and mass spectrometry (ICP-MS) are widely used for multi-elemental measurements and also for isotopic characterization in the case of ICP-MS. While most studies are carried out in aqueous matrices, applications involving organic/hydro-organic matrices become increasingly widespread. This kind of matrices is introduced in ICP based instruments when classical "matrix removal" approaches such as acid digestion or extraction procedures cannot be implemented. Due to the physico-chemical properties of organic/hydro-organic matrices and their associated effects on instrumentation and analytical performances, their introduction into ICP sources is particularly challenging and has become a full topic. In this framework, numerous theoretical and phenomenological studies of these effects have been performed in the past, mainly by ICP-OES, while recent literature is more focused on applications and associated instrumental developments. This tutorial review, divided in two parts, explores the rich literature related to the introduction of organic/hydro-organic matrices in ICP-OES and ICP-MS. The present Part I, provides theoretical considerations in connection with the physico-chemical properties of organic/hydro-organic matrices, in order to better understand the induced phenomena. This focal point is divided in four chapters highlighting: (i) the impact of organic/hydro-organic matrices from aerosol generation to atomization/excitation/ionization processes; (ii) the production of carbon molecular constituents and their spatial distribution in the plasma with respect to analytes repartition; (iii) the subsequent modifications of plasma fundamental properties; and (iv) the resulting spectroscopic and non spectroscopic interferences. This first part of this tutorial review is addressed either to beginners or to more experienced scientists who are interested in the analysis of organic/hydro-organic matrices by ICP sources and would like to consider the theoretical background of effects induced by such matrices. The second part of this tutorial review will be dedicated to more practical consideration on instrumentation, such as adapted introductions devices, as well as instrumental and operating parameters optimization. The analytical strategies for elemental quantification in such matrices will also be addressed. Copyright © 2015 Elsevier B.V. All rights reserved.

Detection of heavy metal by paper-based microfluidics.

PubMed

Lin, Yang; Gritsenko, Dmitry; Feng, Shaolong; Teh, Yi Chen; Lu, Xiaonan; Xu, Jie

2016-09-15

Heavy metal pollution has shown great threat to the environment and public health worldwide. Current methods for the detection of heavy metals require expensive instrumentation and laborious operation, which can only be accomplished in centralized laboratories. Various microfluidic paper-based analytical devices have been developed recently as simple, cheap and disposable alternatives to conventional ones for on-site detection of heavy metals. In this review, we first summarize current development of paper-based analytical devices and discuss the selection of paper substrates, methods of device fabrication, and relevant theories in these devices. We then compare and categorize recent reports on detection of heavy metals using paper-based microfluidic devices on the basis of various detection mechanisms, such as colorimetric, fluorescent, and electrochemical methods. To finalize, the future development and trend in this field are discussed. Copyright © 2016 Elsevier B.V. All rights reserved.

Post-analytical Issues in Hemostasis and Thrombosis Testing.

PubMed

Favaloro, Emmanuel J; Lippi, Giuseppe

2017-01-01

Analytical concerns within hemostasis and thrombosis testing are continuously decreasing. This is essentially attributable to modern instrumentation, improvements in test performance and reliability, as well as the application of appropriate internal quality control and external quality assurance measures. Pre-analytical issues are also being dealt with in some newer instrumentation, which are able to detect hemolysis, icteria and lipemia, and, in some cases, other issues related to sample collection such as tube under-filling. Post-analytical issues are generally related to appropriate reporting and interpretation of test results, and these are the focus of the current overview, which provides a brief description of these events, as well as guidance for their prevention or minimization. In particular, we propose several strategies for improved post-analytical reporting of hemostasis assays and advise that this may provide the final opportunity to prevent serious clinical errors in diagnosis.

Dynamic mechanical analysis and organization/storage of data for polymetric materials

NASA Technical Reports Server (NTRS)

Rosenberg, M.; Buckley, W.

1982-01-01

Dynamic mechanical analysis was performed on a variety of temperature resistant polymers and composite resin matrices. Data on glass transition temperatures and degree of cure attained were derived. In addition a laboratory based computer system was installed and data base set up to allow entry of composite data. The laboratory CPU termed TYCHO is based on a DEC PDP 11/44 CPU with a Datatrieve relational data base. The function of TYCHO is integration of chemical laboratory analytical instrumentation and storage of chemical structures for modeling of new polymeric structures and compounds

Fractionation of persistent organic pollutants in fish oil by high-performance liquid chromatography on a 2-(1-pyrenyl)ethyl silica column.

PubMed

Ortiz, X; Martí, R; Montaña, M J; Gasser, M; Margarit, L; Broto, F; Díaz-Ferrero, J

2010-09-01

The analysis of persistent organic pollutants in foodstuffs has become necessary for control of their levels in products for human and animal consumption. These analytical procedures usually require a fractionation step in order to separate the different families of pollutants to avoid interferences during the instrumental determination. In this study the separation was carried out on a 2-(1-pyrenyl)ethyl silica column, where analyte fractionation was based on differences in planarity and aromaticity. The fractionation of several types of persistent organic pollutants found in fish oil samples was studied; the pollutants included polychlorinated dibenzo-p-dioxins and dibenzofurans, polychlorinated biphenyls, polybrominated diphenyl ethers, and some organochlorine pesticides. Fractions were analyzed by high-resolution gas chromatography with electron-capture detection and high-resolution gas chromatography-high resolution mass spectroscopy. Finally, the whole method (including the purification, fractionation, and instrumental determination steps) was validated and successfully applied to the analysis of several samples of fish oil.

Proposed techniques for launching instrumented balloons into tornadoes

NASA Technical Reports Server (NTRS)

Grant, F. C.

1971-01-01

A method is proposed to introduce instrumented balloons into tornadoes by means of the radial pressure gradient, which supplies a buoyancy force driving to the center. Presented are analytical expressions, verified by computer calculations, which show the possibility of introducing instrumented balloons into tornadoes at or below the cloud base. The times required to reach the center are small enough that a large fraction of tornadoes are suitable for the technique. An experimental procedure is outlined in which a research airplane puts an instrumented, self-inflating balloon on the track ahead of the tornado. The uninflated balloon waits until the tornado closes to, typically, 750 meters; then it quickly inflates and spirals up and into the core, taking roughly 3 minutes. Since the drive to the center is automatically produced by the radial pressure gradient, a proper launch radius is the only guidance requirement.

Evaluation of portable Raman spectrometer with 1064 nm excitation for geological and forensic applications.

PubMed

Vítek, Petr; Ali, Esam M A; Edwards, Howell G M; Jehlička, Jan; Cox, Rick; Page, Kristian

2012-02-01

The development of miniaturized Raman instrumentation is in demand for applications relevant to forensic, pharmaceutical and art analyses, as well as geosciences, and planetary exploration. In this study we report on evaluation of a portable dispersive Raman spectrometer equipped with 1064 nm laser excitation. Selected samples from geological, geobiological and forensic areas of interest have been studied from which the advantages, disadvantages and the analytical potential of the instrument are assessed based on a comparison with bench instrumentation and other portable Raman spectrometers using 785 nm excitation. It is demonstrated that the instrument operating with 1064 nm excitation has potential for expanding the number and types of samples that can be measured by miniaturized Raman spectroscopy without interfering fluorescence background emission. It includes inorganic and organic minerals, biomolecules within living lichen and endolithic cyanobacteria as well as drugs of abuse and explosives. Copyright © 2011 Elsevier B.V. All rights reserved.

Evaluation of portable Raman spectrometer with 1064 nm excitation for geological and forensic applications

NASA Astrophysics Data System (ADS)

Vítek, Petr; Ali, Esam M. A.; Edwards, Howell G. M.; Jehlička, Jan; Cox, Rick; Page, Kristian

2012-02-01

The development of miniaturized Raman instrumentation is in demand for applications relevant to forensic, pharmaceutical and art analyses, as well as geosciences, and planetary exploration. In this study we report on evaluation of a portable dispersive Raman spectrometer equipped with 1064 nm laser excitation. Selected samples from geological, geobiological and forensic areas of interest have been studied from which the advantages, disadvantages and the analytical potential of the instrument are assessed based on a comparison with bench instrumentation and other portable Raman spectrometers using 785 nm excitation. It is demonstrated that the instrument operating with 1064 nm excitation has potential for expanding the number and types of samples that can be measured by miniaturized Raman spectroscopy without interfering fluorescence background emission. It includes inorganic and organic minerals, biomolecules within living lichen and endolithic cyanobacteria as well as drugs of abuse and explosives.

Development of an UPLC-MS/MS Sulfonamide Multi-residue Method and It's Application to Water, Manure Slurry, and Soils from Swine Rearing Facilities

USDA-ARS?s Scientific Manuscript database

An analytical method was developed using ultra performance liquid chromatography-triple quadrupole-tandem mass spectrophotometry (UPLC-TQ-MS/MS) to simultaneously analyze 14 sulfonamides (SA) in six minutes. The instrumental detection limit based on signal-to-noise ratio (S/N) > 3, was below 1 pg/µL...

Determining the Antifungal Agent Clioquinol by HPLC, the Not so Pure Preparation: A Laboratory-Based Case Study for an Instrumental Analytical Chemistry Course

ERIC Educational Resources Information Center

Schaber, Peter M.; Hobika, Geoffrey

2018-01-01

The case study approach provides students with a better appreciation of how scientists solve problems and conduct themselves in the "real world". When applied to the undergraduate chemistry laboratory, this approach also challenges critical thinking skills and creativity in ways "cook book" experiments very often do not. This…

A method of mounting multiple otoliths for beam-based microchemical analyses

USGS Publications Warehouse

Donohoe, C.J.; Zimmerman, C.E.

2010-01-01

Beam-based analytical methods are widely used to measure the concentrations of elements and isotopes in otoliths. These methods usually require that otoliths be individually mounted and prepared to properly expose the desired growth region to the analytical beam. Most analytical instruments, such as LA-ICPMS and ion and electron microprobes, have sample holders that will accept only one to six slides or mounts at a time. We describe a method of mounting otoliths that allows for easy transfer of many otoliths to a single mount after they have been prepared. Such an approach increases the number of otoliths that can be analyzed in a single session by reducing the need open the sample chamber to exchange slides-a particularly time consuming step on instruments that operate under vacuum. For ion and electron microprobes, the method also greatly reduces the number of slides that must be coated with an electrical conductor prior to analysis. In this method, a narrow strip of cover glass is first glued at one end to a standard microscope slide. The otolith is then mounted in thermoplastic resin on the opposite, free end of the strip. The otolith can then be ground and flipped, if needed, by reheating the mounting medium. After otolith preparation is complete, the cover glass is cut with a scribe to free the otolith and up to 20 small otoliths can be arranged on a single petrographic slide. ?? 2010 The Author(s).

Trends in Analytical Scale Separations.

ERIC Educational Resources Information Center

Jorgenson, James W.

1984-01-01

Discusses recent developments in the instrumentation and practice of analytical scale operations. Emphasizes detection devices and procedures in gas chromatography, liquid chromatography, electrophoresis, supercritical fluid chromatography, and field-flow fractionation. (JN)

Laboratory and field based evaluation of chromatography ...

EPA Pesticide Factsheets

The Monitor for AeRosols and GAses in ambient air (MARGA) is an on-line ion-chromatography-based instrument designed for speciation of the inorganic gas and aerosol ammonium-nitrate-sulfate system. Previous work to characterize the performance of the MARGA has been primarily based on field comparison to other measurement methods to evaluate accuracy. While such studies are useful, the underlying reasons for disagreement among methods are not always clear. This study examines aspects of MARGA accuracy and precision specifically related to automated chromatography analysis. Using laboratory standards, analytical accuracy, precision, and method detection limits derived from the MARGA chromatography software are compared to an alternative software package (Chromeleon, Thermo Scientific Dionex). Field measurements are used to further evaluate instrument performance, including the MARGA’s use of an internal LiBr standard to control accuracy. Using gas/aerosol ratios and aerosol neutralization state as a case study, the impact of chromatography on measurement error is assessed. The new generation of on-line chromatography-based gas and particle measurement systems have many advantages, including simultaneous analysis of multiple pollutants. The Monitor for Aerosols and Gases in Ambient Air (MARGA) is such an instrument that is used in North America, Europe, and Asia for atmospheric process studies as well as routine monitoring. While the instrument has been evaluat

FieldSpec: A field portable mass spectrometer prototype for high frequency measurements of δ (2) H and δ (18) O ratios in water

NASA Astrophysics Data System (ADS)

López Días, Veneranda; Quang Hoang, Hung; Martínez-Carreras, Núria; Barnich, François; Wirtz, Tom; Pfister, Laurent; McDonnell, Jeffrey

2016-04-01

Hydrological studies relying on stable water isotopes to better understand water sources, flowpaths and transit times are currently limited by the coarse temporal resolution of sampling and analysis protocols. At present, two kinds of lab-based instruments are used : (i) the standard isotope ratio mass spectrometers (IRMS) [1] and (ii) the laser-based instruments [2, 3]. In both cases, samples need to be collected in the field and then transferred to the laboratory for the water isotopic ratio measurements (even further complex sample preparation is required for the IRMS). Hence, past and ongoing research targets the development of field deployable instruments for measuring stable water isotopes at high temporal frequencies. While recent studies have demonstrated that laser-based instruments may be taken to the field [4, 5], their size and power consumption still restrict their use to sites equipped with mains power or generators. Here, we present progress on the development of a field portable mass spectrometer (FieldSpec) for direct high frequency measurements of δ2H and δ18O ratios in water. The FieldSpec instrument is based upon the use of a double focusing magnetic sector mass spectrometer in combination with an electron impact ion source and a membrane dual inlet system. The instrument directly collects liquid water samples in the field, which are then converted into water vapour before being injected into the mass spectrometer for the stable isotope analysis. δ2H and δ18O are derived from the measured mass spectra. All the components are arranged in a vacuum case having a suit case type dimension with portable electronics and battery. Proof-of-concept experiments have been carried out to characterize the instrument. The results show that the FieldSpec instrument has good linearity (R2 = 0.99). The reproducibility of the instrument ranges between 1 and 4 ‰ for δ2H and between 0.1 and 0.4 ‰ for δ18O isotopic ratio measurements. A measurement frequency of less than 60 minutes per sample has been achieved. We intend to further increase the measurement frequency in the near future. In this presentation, we will describe the instrument, present experimental data reflecting its performance and discuss applications. [1] de Groot, P.A., 2004. Handbook of Stable Isotope Analytical Techniques, Vol.1. Elsevier, Amsterdam, 1234 pp [2] Lis, G., Wassenaar, L.I., Hendry, M.J., 2008. Analytical Chemistry 80 (1), 287-293. [3] Brand, W.A., Geilmann, H., Crosson, E.R., Rella, C.W., 2009. Rapid Communications in Mass Spectrometry 23, 1879-1884. [4] Berman, E.S.F., Gupta, M., Gabrielli, C., Garland, T., McDonnell, J.J., 2009. Water Resources Research 45 W1020, 1-7. [5] Munksgaard, N.C., Wurster, C.M., Bird, M.I., 2011. Rapid Communication Mass Spectrometry 25, 3706-3712.

Recent Advances in Analytical Pyrolysis to Investigate Organic Materials in Heritage Science.

PubMed

Degano, Ilaria; Modugno, Francesca; Bonaduce, Ilaria; Ribechini, Erika; Colombini, Maria Perla

2018-06-18

The molecular characterization of organic materials in samples from artworks and historical objects traditionally entailed qualitative and quantitative analyses by HPLC and GC. Today innovative approaches based on analytical pyrolysis enable samples to be analysed without any chemical pre-treatment. Pyrolysis, which is often considered as a screening technique, shows previously unexplored potential thanks to recent instrumental developments. Organic materials that are macromolecular in nature, or undergo polymerization upon curing and ageing can now be better investigated. Most constituents of paint layers and archaeological organic substances contain major insoluble and chemically non-hydrolysable fractions that are inaccessible to GC or HPLC. To date, molecular scientific investigations of the organic constituents of artworks and historical objects have mostly focused on the minor constituents of the sample. This review presents recent advances in the qualitative and semi-quantitative analyses of organic materials in heritage objects based on analytical pyrolysis coupled with mass spectrometry. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Targeted proteomic assays for quantitation of proteins identified by proteogenomic analysis of ovarian cancer

DOE PAGES

Song, Ehwang; Gao, Yuqian; Wu, Chaochao; ...

2017-07-19

Here, mass spectrometry (MS) based targeted proteomic methods such as selected reaction monitoring (SRM) are becoming the method of choice for preclinical verification of candidate protein biomarkers. The Clinical Proteomic Tumor Analysis Consortium (CPTAC) of the National Cancer Institute has investigated the standardization and analytical validation of the SRM assays and demonstrated robust analytical performance on different instruments across different laboratories. An Assay Portal has also been established by CPTAC to provide the research community a resource consisting of large set of targeted MS-based assays, and a depository to share assays publicly, providing that assays meet the guidelines proposed bymore » CPTAC. Herein, we report 98 SRM assays covering 70 candidate protein biomarkers previously reported as associated with ovarian cancer that have been thoroughly characterized according to the CPTAC Assay Characterization Guidance Document. The experiments, methods and results for characterizing these SRM assays for their MS response, repeatability, selectivity, stability, and reproducible detection of endogenous analytes are described in detail.« less

Improvement of analytical capabilities of neutron activation analysis laboratory at the Colombian Geological Survey

NASA Astrophysics Data System (ADS)

Parrado, G.; Cañón, Y.; Peña, M.; Sierra, O.; Porras, A.; Alonso, D.; Herrera, D. C.; Orozco, J.

2016-07-01

The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes with medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.

Alternatives to current flow cytometry data analysis for clinical and research studies.

PubMed

Gondhalekar, Carmen; Rajwa, Bartek; Patsekin, Valery; Ragheb, Kathy; Sturgis, Jennifer; Robinson, J Paul

2018-02-01

Flow cytometry has well-established methods for data analysis based on traditional data collection techniques. These techniques typically involved manual insertion of tube samples into an instrument that, historically, could only measure 1-3 colors. The field has since evolved to incorporate new technologies for faster and highly automated sample preparation and data collection. For example, the use of microwell plates on benchtop instruments is now a standard on virtually every new instrument, and so users can easily accumulate multiple data sets quickly. Further, because the user must carefully define the layout of the plate, this information is already defined when considering the analytical process, expanding the opportunities for automated analysis. Advances in multi-parametric data collection, as demonstrated by the development of hyperspectral flow-cytometry, 20-40 color polychromatic flow cytometry, and mass cytometry (CyTOF), are game-changing. As data and assay complexity increase, so too does the complexity of data analysis. Complex data analysis is already a challenge to traditional flow cytometry software. New methods for reviewing large and complex data sets can provide rapid insight into processes difficult to define without more advanced analytical tools. In settings such as clinical labs where rapid and accurate data analysis is a priority, rapid, efficient and intuitive software is needed. This paper outlines opportunities for analysis of complex data sets using examples of multiplexed bead-based assays, drug screens and cell cycle analysis - any of which could become integrated into the clinical environment. Copyright © 2017. Published by Elsevier Inc.

Major advances in testing of dairy products: milk component and dairy product attribute testing.

PubMed

Barbano, D M; Lynch, J M

2006-04-01

Milk component analysis is relatively unusual in the field of quantitative analytical chemistry because an analytical test result determines the allocation of very large amounts of money between buyers and sellers of milk. Therefore, there is high incentive to develop and refine these methods to achieve a level of analytical performance rarely demanded of most methods or laboratory staff working in analytical chemistry. In the last 25 yr, well-defined statistical methods to characterize and validate analytical method performance combined with significant improvements in both the chemical and instrumental methods have allowed achievement of improved analytical performance for payment testing. A shift from marketing commodity dairy products to the development, manufacture, and marketing of value added dairy foods for specific market segments has created a need for instrumental and sensory approaches and quantitative data to support product development and marketing. Bringing together sensory data from quantitative descriptive analysis and analytical data from gas chromatography olfactometry for identification of odor-active compounds in complex natural dairy foods has enabled the sensory scientist and analytical chemist to work together to improve the consistency and quality of dairy food flavors.

Positive lists of cosmetic ingredients: Analytical methodology for regulatory and safety controls - A review.

PubMed

Lores, Marta; Llompart, Maria; Alvarez-Rivera, Gerardo; Guerra, Eugenia; Vila, Marlene; Celeiro, Maria; Lamas, J Pablo; Garcia-Jares, Carmen

2016-04-07

Cosmetic products placed on the market and their ingredients, must be safe under reasonable conditions of use, in accordance to the current legislation. Therefore, regulated and allowed chemical substances must meet the regulatory criteria to be used as ingredients in cosmetics and personal care products, and adequate analytical methodology is needed to evaluate the degree of compliance. This article reviews the most recent methods (2005-2015) used for the extraction and the analytical determination of the ingredients included in the positive lists of the European Regulation of Cosmetic Products (EC 1223/2009): comprising colorants, preservatives and UV filters. It summarizes the analytical properties of the most relevant analytical methods along with the possibilities of fulfilment of the current regulatory issues. The cosmetic legislation is frequently being updated; consequently, the analytical methodology must be constantly revised and improved to meet safety requirements. The article highlights the most important advances in analytical methodology for cosmetics control, both in relation to the sample pretreatment and extraction and the different instrumental approaches developed to solve this challenge. Cosmetics are complex samples, and most of them require a sample pretreatment before analysis. In the last times, the research conducted covering this aspect, tended to the use of green extraction and microextraction techniques. Analytical methods were generally based on liquid chromatography with UV detection, and gas and liquid chromatographic techniques hyphenated with single or tandem mass spectrometry; but some interesting proposals based on electrophoresis have also been reported, together with some electroanalytical approaches. Regarding the number of ingredients considered for analytical control, single analyte methods have been proposed, although the most useful ones in the real life cosmetic analysis are the multianalyte approaches. Copyright © 2016 Elsevier B.V. All rights reserved.

An Integrated Hot-Stage Microscope-Direct Analysis in Real Time-Mass Spectrometry System for Studying the Thermal Behavior of Materials.

PubMed

Ashton, Gage P; Harding, Lindsay P; Parkes, Gareth M B

2017-12-19

This paper describes a new analytical instrument that combines a precisely temperature-controlled hot-stage with digital microscopy and Direct Analysis in Real Time-mass spectrometry (DART-MS) detection. The novelty of the instrument lies in its ability to monitor processes as a function of temperature through the simultaneous recording of images, quantitative color changes, and mass spectra. The capability of the instrument was demonstrated through successful application to four very varied systems including profiling an organic reaction, decomposition of silicone polymers, and the desorption of rhodamine B from an alumina surface. The multidimensional, real-time analytical data provided by this instrument allow for a much greater insight into thermal processes than could be achieved previously.

On-Chip Microfluidic Components for In Situ Analysis, Separation, and Detection of Amino Acids

NASA Technical Reports Server (NTRS)

Zheng, Yun; Getty, Stephanie; Dworkin, Jason; Balvin, Manuel; Kotecki, Carl

2013-01-01

The Astrobiology Analytical Laboratory at GSFC has identified amino acids in meteorites and returned cometary samples by using liquid chromatography-electrospray ionization time-of-flight mass spectrometry (LCMS). These organic species are key markers for life, having the property of chirality that can be used to distinguish biological from non-biological amino acids. One of the critical components in the benchtop instrument is liquid chromatography (LC) analytical column. The commercial LC analytical column is an over- 250-mm-long and 4.6-mm-diameter stainless steel tube filled with functionized microbeads as stationary phase to separate the molecular species based on their chemistry. Miniaturization of this technique for spaceflight is compelling for future payloads for landed missions targeting astrobiology objectives. A commercial liquid chromatography analytical column consists of an inert cylindrical tube filled with a stationary phase, i.e., microbeads, that has been functionalized with a targeted chemistry. When analyte is sent through the column by a pressurized carrier fluid (typically a methanol/ water mixture), compounds are separated in time due to differences in chemical interactions with the stationary phase. Different species of analyte molecules will interact more strongly with the column chemistry, and will therefore take longer to traverse the column. In this way, the column will separate molecular species based on their chemistry. A lab-on-chip liquid analysis tool was developed. The microfluidic analytical column is capable of chromatographically separating biologically relevant classes of molecules based on their chemistry. For this analytical column, fabrication, low leak rate, and stationary phase incorporation of a serpentine microchannel were demonstrated that mimic the dimensions of a commercial LC column within a 5 10 1 mm chip. The microchannel in the chip has a 75- micrometer-diameter oval-shaped cross section. The serpentine microchannel has four different lengths: 40, 60, 80, and 100 mm. Functionized microbeads were filled inside the microchannel to separate molecular species based on their chemistry.

Potential sources of analytical bias and error in selected trace element data-quality analyses

USGS Publications Warehouse

Paul, Angela P.; Garbarino, John R.; Olsen, Lisa D.; Rosen, Michael R.; Mebane, Christopher A.; Struzeski, Tedmund M.

2016-09-28

Potential sources of analytical bias and error associated with laboratory analyses for selected trace elements where concentrations were greater in filtered samples than in paired unfiltered samples were evaluated by U.S. Geological Survey (USGS) Water Quality Specialists in collaboration with the USGS National Water Quality Laboratory (NWQL) and the Branch of Quality Systems (BQS).Causes for trace-element concentrations in filtered samples to exceed those in associated unfiltered samples have been attributed to variability in analytical measurements, analytical bias, sample contamination either in the field or laboratory, and (or) sample-matrix chemistry. These issues have not only been attributed to data generated by the USGS NWQL but have been observed in data generated by other laboratories. This study continues the evaluation of potential analytical bias and error resulting from matrix chemistry and instrument variability by evaluating the performance of seven selected trace elements in paired filtered and unfiltered surface-water and groundwater samples collected from 23 sampling sites of varying chemistries from six States, matrix spike recoveries, and standard reference materials.Filtered and unfiltered samples have been routinely analyzed on separate inductively coupled plasma-mass spectrometry instruments. Unfiltered samples are treated with hydrochloric acid (HCl) during an in-bottle digestion procedure; filtered samples are not routinely treated with HCl as part of the laboratory analytical procedure. To evaluate the influence of HCl on different sample matrices, an aliquot of the filtered samples was treated with HCl. The addition of HCl did little to differentiate the analytical results between filtered samples treated with HCl from those samples left untreated; however, there was a small, but noticeable, decrease in the number of instances where a particular trace-element concentration was greater in a filtered sample than in the associated unfiltered sample for all trace elements except selenium. Accounting for the small dilution effect (2 percent) from the addition of HCl, as required for the in-bottle digestion procedure for unfiltered samples, may be one step toward decreasing the number of instances where trace-element concentrations are greater in filtered samples than in paired unfiltered samples.The laboratory analyses of arsenic, cadmium, lead, and zinc did not appear to be influenced by instrument biases. These trace elements showed similar results on both instruments used to analyze filtered and unfiltered samples. The results for aluminum and molybdenum tended to be higher on the instrument designated to analyze unfiltered samples; the results for selenium tended to be lower. The matrices used to prepare calibration standards were different for the two instruments. The instrument designated for the analysis of unfiltered samples was calibrated using standards prepared in a nitric:hydrochloric acid (HNO3:HCl) matrix. The instrument designated for the analysis of filtered samples was calibrated using standards prepared in a matrix acidified only with HNO3. Matrix chemistry may have influenced the responses of aluminum, molybdenum, and selenium on the two instruments. The best analytical practice is to calibrate instruments using calibration standards prepared in matrices that reasonably match those of the samples being analyzed.Filtered and unfiltered samples were spiked over a range of trace-element concentrations from less than 1 to 58 times ambient concentrations. The greater the magnitude of the trace-element spike concentration relative to the ambient concentration, the greater the likelihood spike recoveries will be within data control guidelines (80–120 percent). Greater variability in spike recoveries occurred when trace elements were spiked at concentrations less than 10 times the ambient concentration. Spike recoveries that were considerably lower than 90 percent often were associated with spiked concentrations substantially lower than what was present in the ambient sample. Because the main purpose of spiking natural water samples with known quantities of a particular analyte is to assess possible matrix effects on analytical results, the results of this study stress the importance of spiking samples at concentrations that are reasonably close to what is expected but sufficiently high to exceed analytical variability. Generally, differences in spike recovery results between paired filtered and unfiltered samples were minimal when samples were analyzed on the same instrument.Analytical results for trace-element concentrations in ambient filtered and unfiltered samples greater than 10 and 40 μg/L, respectively, were within the data-quality objective for precision of ±25 percent. Ambient trace-element concentrations in filtered samples greater than the long-term method detection limits but less than 10 μg/L failed to meet the data-quality objective for precision for at least one trace element in about 54 percent of the samples. Similarly, trace-element concentrations in unfiltered samples greater than the long-term method detection limits but less than 40 μg/L failed to meet this data-quality objective for at least one trace-element analysis in about 58 percent of the samples. Although, aluminum and zinc were particularly problematic, limited re-analyses of filtered and unfiltered samples appeared to improve otherwise failed analytical precision.The evaluation of analytical bias using standard reference materials indicate a slight low bias for results for arsenic, cadmium, selenium, and zinc. Aluminum and molybdenum show signs of high bias. There was no observed bias, as determined using the standard reference materials, during the analysis of lead.

Two stage algorithm vs commonly used approaches for the suspect screening of complex environmental samples analyzed via liquid chromatography high resolution time of flight mass spectroscopy: A test study.

PubMed

Samanipour, Saer; Baz-Lomba, Jose A; Alygizakis, Nikiforos A; Reid, Malcolm J; Thomaidis, Nikolaos S; Thomas, Kevin V

2017-06-09

LC-HR-QTOF-MS recently has become a commonly used approach for the analysis of complex samples. However, identification of small organic molecules in complex samples with the highest level of confidence is a challenging task. Here we report on the implementation of a two stage algorithm for LC-HR-QTOF-MS datasets. We compared the performances of the two stage algorithm, implemented via NIVA_MZ_Analyzer™, with two commonly used approaches (i.e. feature detection and XIC peak picking, implemented via UNIFI by Waters and TASQ by Bruker, respectively) for the suspect analysis of four influent wastewater samples. We first evaluated the cross platform compatibility of LC-HR-QTOF-MS datasets generated via instruments from two different manufacturers (i.e. Waters and Bruker). Our data showed that with an appropriate spectral weighting function the spectra recorded by the two tested instruments are comparable for our analytes. As a consequence, we were able to perform full spectral comparison between the data generated via the two studied instruments. Four extracts of wastewater influent were analyzed for 89 analytes, thus 356 detection cases. The analytes were divided into 158 detection cases of artificial suspect analytes (i.e. verified by target analysis) and 198 true suspects. The two stage algorithm resulted in a zero rate of false positive detection, based on the artificial suspect analytes while producing a rate of false negative detection of 0.12. For the conventional approaches, the rates of false positive detection varied between 0.06 for UNIFI and 0.15 for TASQ. The rates of false negative detection for these methods ranged between 0.07 for TASQ and 0.09 for UNIFI. The effect of background signal complexity on the two stage algorithm was evaluated through the generation of a synthetic signal. We further discuss the boundaries of applicability of the two stage algorithm. The importance of background knowledge and experience in evaluating the reliability of results during the suspect screening was evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Tile-Based Fisher Ratio Analysis of Comprehensive Two-Dimensional Gas Chromatography Time-of-Flight Mass Spectrometry (GC × GC – TOFMS) Data using a Null Distribution Approach

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

Parsons, Brendon A.; Marney, Luke C.; Siegler, William C.

Multi-dimensional chromatographic instrumentation produces information-rich, and chemically complex data containing meaningful chemical signals and/or chemical patterns. Two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (GC × GC – TOFMS) is a prominent instrumental platform that has been applied extensively for discovery-based experimentation, where samples are sufficiently volatile or amenable to derivatization. Use of GC × GC – TOFMS and associated data analysis strategies aim to uncover meaningful chemical signals or chemical patterns. However, for complex samples, meaningful chemical information is often buried in a background of less meaningful chemical signal and noise. In this report, we utilize the tile-based F-ratiomore » software in concert with the standard addition method by spiking non-native chemicals into a diesel fuel matrix at low concentrations. While the previous work studied the concentration range of 100-1000 ppm, the current study focuses on the 0 ppm to 100 ppm analyte spike range. This study demonstrates the sensitivity and selectivity of the tile-based F-ratio software for discovery of true positives in the non-targeted analysis of a chemically complex and analytically challenging sample matrix. By exploring the low concentration spike levels, we gain a better understanding of the limit of detection (LOD) of the tile-based F-ratio software with GC × GC – TOFMS data.« less

Building the analytical response in frequency domain of AC biased bolometers. Application to Planck/HFI

NASA Astrophysics Data System (ADS)

Sauvé, Alexandre; Montier, Ludovic

2016-12-01

Context: Bolometers are high sensitivity detector commonly used in Infrared astronomy. The HFI instrument of the Planck satellite makes extensive use of them, but after the satellite launch two electronic related problems revealed critical. First an unexpected excess response of detectors at low optical excitation frequency for ν < 1 Hz, and secondly the Analog To digital Converter (ADC) component had been insufficiently characterized on-ground. These two problems require an exquisite knowledge of detector response. However bolometers have highly nonlinear characteristics, coming from their electrical and thermal coupling making them very difficult to model. Goal: We present a method to build the analytical transfer function in frequency domain which describe the voltage response of an Alternative Current (AC) biased bolometer to optical excitation, based on the standard bolometer model. This model is built using the setup of the Planck/HFI instrument and offers the major improvement of being based on a physical model rather than the currently in use had-hoc model based on Direct Current (DC) bolometer theory. Method: The analytical transfer function expression will be presented in matrix form. For this purpose, we build linearized versions of the bolometer electro thermal equilibrium. A custom description of signals in frequency is used to solve the problem with linear algebra. The model performances is validated using time domain simulations. Results: The provided expression is suitable for calibration and data processing. It can also be used to provide constraints for fitting optical transfer function using real data from steady state electronic response and optical response. The accurate description of electronic response can also be used to improve the ADC nonlinearity correction for quickly varying optical signals.

What's the Bottom Line

EPA Science Inventory

Advances in analytical instrumentation have not only increased the number and types of chemicals measured, but reduced the quantitation limits, allowing these chemicals to be detected at progressively lower concentrations in various environmental matrices. Such analytical advanc...

Accurate mass measurements and their appropriate use for reliable analyte identification.

PubMed

Godfrey, A Ruth; Brenton, A Gareth

2012-09-01

Accurate mass instrumentation is becoming increasingly available to non-expert users. This data can be mis-used, particularly for analyte identification. Current best practice in assigning potential elemental formula for reliable analyte identification has been described with modern informatic approaches to analyte elucidation, including chemometric characterisation, data processing and searching using facilities such as the Chemical Abstracts Service (CAS) Registry and Chemspider.

Multi-species trace gas sensing with dual-wavelength QCLs

NASA Astrophysics Data System (ADS)

Hundt, P. Morten; Tuzson, Béla; Aseev, Oleg; Liu, Chang; Scheidegger, Philipp; Looser, Herbert; Kapsalidis, Filippos; Shahmohammadi, Mehran; Faist, Jérôme; Emmenegger, Lukas

2018-06-01

Instrumentation for environmental monitoring of gaseous pollutants and greenhouse gases tends to be complex, expensive, and energy demanding, because every compound measured relies on a specific analytical technique. This work demonstrates an alternative approach based on mid-infrared laser absorption spectroscopy with dual-wavelength quantum cascade lasers (QCLs). The combination of two dual- and one single-DFB QCL yields high-precision measurements of CO (0.08 ppb), CO2 (100 ppb), NH3 (0.02 ppb), NO (0.4 ppb), NO2 (0.1 ppb), N2O (0.045 ppb), and O3 (0.11 ppb) simultaneously in a compact setup (45 × 45 cm2). The lasers are driven time-multiplexed in intermittent continuous wave mode with a repetition rate of 1 kHz. The individual spectra are real-time averaged (1 s) by an FPGA-based data acquisition system. The instrument was assessed for environmental monitoring and benchmarked with reference instrumentation to demonstrate its potential for compact multi-species trace gas sensing.

Evaluation of the Current Status of the Combinatorial Approach for the Study of Phase Diagrams

PubMed Central

Wong-Ng, W.

2012-01-01

This paper provides an evaluation of the effectiveness of using the high throughput combinatorial approach for preparing phase diagrams of thin film and bulk materials. Our evaluation is based primarily on examples of combinatorial phase diagrams that have been reported in the literature as well as based on our own laboratory experiments. Various factors that affect the construction of these phase diagrams are examined. Instrumentation and analytical approaches needed to improve data acquisition and data analysis are summarized. PMID:26900530

Implementation of picoSpin Benchtop NMR Instruments into Organic Chemistry Teaching Laboratories through Spectral Analysis of Fischer Esterification Products

ERIC Educational Resources Information Center

Yearty, Kasey L.; Sharp, Joseph T.; Meehan, Emma K.; Wallace, Doyle R.; Jackson, Douglas M.; Morrison, Richard W.

2017-01-01

[Superscript 1]H NMR analysis is an important analytical technique presented in introductory organic chemistry courses. NMR instrument access is limited for undergraduate organic chemistry students due to the size of the instrument, price of NMR solvents, and the maintenance level required for instrument upkeep. The University of Georgia Chemistry…

Mars Analytical Microimager

NASA Astrophysics Data System (ADS)

Batory, Krzysztof J.; Govindjee; Andersen, Dale; Presley, John; Lucas, John M.; Sears, S. Kelly; Vali, Hojatollah

Unambiguous detection of extraterrestrial nitrogenous hydrocarbon microbiology requires an instrument both to recognize potential biogenic specimens and to successfully discriminate them from geochemical settings. Such detection should ideally be in-situ and not jeopardize other experiments by altering samples. Taken individually most biomarkers are inconclusive. For example, since amino acids can be synthesized abiotically they are not always considered reliable biomarkers. An enantiomeric imbalance, which is characteristic of all terrestrial life, may be questioned because chirality can also be altered abiotically. However, current scientific understanding holds that aggregates of identical proteins or proteinaceous complexes, with their well-defined amino acid residue sequences, are indisputable biomarkers. Our paper describes the Mars Analytical Microimager, an instrument for the simultaneous imaging of generic autofluorescent biomarkers and overall morphology. Autofluorescence from ultraviolet to near-infrared is emitted by all known terrestrial biology, and often as consistent complex bands uncharacteristic of abiotic mineral luminescence. The MAM acquires morphology, and even sub-micron morphogenesis, at a 3-centimeter working distance with resolution approaching a laser scanning microscope. Luminescence is simultaneously collected via a 2.5-micron aperture, thereby permitting accurate correlation of multi-dimensional optical behavior with specimen morphology. A variable wavelength excitation source and photospectrometer serve to obtain steady-state and excitation spectra of biotic and luminescent abiotic sources. We believe this is the first time instrumentation for detecting hydrated or desiccated microbiology non-destructively in-situ has been demonstrated. We have obtained excellent preliminary detection of biota and inorganic matrix discrimination from terrestrial polar analogues, and perimetric morphology of individual magnetotactic bacteria. Proposed analytical components for enhanced detection are: fluorescence anisotropy which analyzes chromophore-based proteins, anisotropy depletion to detect the presence of a fluid environment, anisotropy excitation spectrum for augmented characterization, and fluorescence-detected circular dichroism. Because all its analytical components are independent of chirality and amino acid types, life detection ability of the MAM is not limited to the terrestrial core biomolecular subsets.

42 CFR 493.1252 - Standard: Test systems, equipment, instruments, reagents, materials, and supplies.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 42 Public Health 5 2010-10-01 2010-10-01 false Standard: Test systems, equipment, instruments... REQUIREMENTS Quality System for Nonwaived Testing Analytic Systems § 493.1252 Standard: Test systems, equipment...) Temperature. (3) Humidity. (4) Protection of equipment and instruments from fluctuations and interruptions in...

Serendipity: Genesis of the Electrochemical Instrumentation at Princeton Applied Research Corporation

ERIC Educational Resources Information Center

Flato, J. B.

2007-01-01

Princeton Applied Research Corporation (PAR) was a small electronic instrument company in early 1960s but once they entered electrochemistry they were very successful. Since then they have developed and designed successful instruments with their tremendous knowledge and have made great contribution to the field of analytical chemistry.

Emission quantification using the tracer gas dispersion method: The influence of instrument, tracer gas species and source simulation.

PubMed

Delre, Antonio; Mønster, Jacob; Samuelsson, Jerker; Fredenslund, Anders M; Scheutz, Charlotte

2018-09-01

The tracer gas dispersion method (TDM) is a remote sensing method used for quantifying fugitive emissions by relying on the controlled release of a tracer gas at the source, combined with concentration measurements of the tracer and target gas plumes. The TDM was tested at a wastewater treatment plant for plant-integrated methane emission quantification, using four analytical instruments simultaneously and four different tracer gases. Measurements performed using a combination of an analytical instrument and a tracer gas, with a high ratio between the tracer gas release rate and instrument precision (a high release-precision ratio), resulted in well-defined plumes with a high signal-to-noise ratio and a high methane-to-tracer gas correlation factor. Measured methane emission rates differed by up to 18% from the mean value when measurements were performed using seven different instrument and tracer gas combinations. Analytical instruments with a high detection frequency and good precision were established as the most suitable for successful TDM application. The application of an instrument with a poor precision could only to some extent be overcome by applying a higher tracer gas release rate. A sideward misplacement of the tracer gas release point of about 250m resulted in an emission rate comparable to those obtained using a tracer gas correctly simulating the methane emission. Conversely, an upwind misplacement of about 150m resulted in an emission rate overestimation of almost 50%, showing the importance of proper emission source simulation when applying the TDM. Copyright © 2018 Elsevier B.V. All rights reserved.

Modeling the frequency response of microwave radiometers with QUCS

NASA Astrophysics Data System (ADS)

Zonca, A.; Roucaries, B.; Williams, B.; Rubin, I.; D'Arcangelo, O.; Meinhold, P.; Lubin, P.; Franceschet, C.; Jahn, S.; Mennella, A.; Bersanelli, M.

2010-12-01

Characterization of the frequency response of coherent radiometric receivers is a key element in estimating the flux of astrophysical emissions, since the measured signal depends on the convolution of the source spectral emission with the instrument band shape. Laboratory Radio Frequency (RF) measurements of the instrument bandpass often require complex test setups and are subject to a number of systematic effects driven by thermal issues and impedance matching, particularly if cryogenic operation is involved. In this paper we present an approach to modeling radiometers bandpasses by integrating simulations and RF measurements of individual components. This method is based on QUCS (Quasi Universal Circuit Simulator), an open-source circuit simulator, which gives the flexibility of choosing among the available devices, implementing new analytical software models or using measured S-parameters. Therefore an independent estimate of the instrument bandpass is achieved using standard individual component measurements and validated analytical simulations. In order to automate the process of preparing input data, running simulations and exporting results we developed the Python package python-qucs and released it under GNU Public License. We discuss, as working cases, bandpass response modeling of the COFE and Planck Low Frequency Instrument (LFI) radiometers and compare results obtained with QUCS and with a commercial circuit simulator software. The main purpose of bandpass modeling in COFE is to optimize component matching, while in LFI they represent the best estimation of frequency response, since end-to-end measurements were strongly affected by systematic effects.

Quantitative structure-retention relationships applied to development of liquid chromatography gradient-elution method for the separation of sartans.

PubMed

Golubović, Jelena; Protić, Ana; Otašević, Biljana; Zečević, Mira

2016-04-01

QSRR are mathematically derived relationships between the chromatographic parameters determined for a representative series of analytes in given separation systems and the molecular descriptors accounting for the structural differences among the investigated analytes. Artificial neural network is a technique of data analysis, which sets out to emulate the human brain's way of working. The aim of the present work was to optimize separation of six angiotensin receptor antagonists, so-called sartans: losartan, valsartan, irbesartan, telmisartan, candesartan cilexetil and eprosartan in a gradient-elution HPLC method. For this purpose, ANN as a mathematical tool was used for establishing a QSRR model based on molecular descriptors of sartans and varied instrumental conditions. The optimized model can be further used for prediction of an external congener of sartans and analysis of the influence of the analyte structure, represented through molecular descriptors, on retention behaviour. Molecular descriptors included in modelling were electrostatic, geometrical and quantum-chemical descriptors: connolly solvent excluded volume non-1,4 van der Waals energy, octanol/water distribution coefficient, polarizability, number of proton-donor sites and number of proton-acceptor sites. Varied instrumental conditions were gradient time, buffer pH and buffer molarity. High prediction ability of the optimized network enabled complete separation of the analytes within the run time of 15.5 min under following conditions: gradient time of 12.5 min, buffer pH of 3.95 and buffer molarity of 25 mM. Applied methodology showed the potential to predict retention behaviour of an external analyte with the properties within the training space. Connolly solvent excluded volume, polarizability and number of proton-acceptor sites appeared to be most influential paramateres on retention behaviour of the sartans. Copyright © 2015 Elsevier B.V. All rights reserved.

Reflectance Infrared Spectroscopy on Operating Surface Acoustic Wave Chemical Sensors During Exposure to Gas-Phase Analytes

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

Hierlemann, A.; Hill, M.; Ricco, A.J.

We have developed instrumentation to enable the combination of surface acoustic wave (SAW) sensor measurements with direct, in-situ molecular spectroscopic measurements to understand the response of the SAW sensors with respect to the interfacial chemistry of surface-confined sensing films interacting with gas-phase analytes. Specifically, the instrumentation and software was developed to perform in-situ Fourier-transform infrared external-reflectance spectroscopy (FTIR-ERS) on operating SAW devices during dosing of their chemically modified surfaces with analytes. By probing the surface with IR spectroscopy during gas exposure, it is possible to understand in unprecedented detail the interaction processes between the sorptive SAW coatings and the gaseousmore » analyte molecules. In this report, we provide details of this measurement system, and also demonstrate the utility of these combined measurements by characterizing the SAW and FTIR-ERS responses of organic thin-film sensor coatings interacting with gas-phase analytes.« less

Moving from ethnography to epidemiology: lessons learned in Appalachia

PubMed Central

Kuzara, Jennifer; Copeland, William E.; Costello, E. Jane; Angold, Adrian; Worthman, Carol M.

2009-01-01

Background Anthropologists are beginning to translate insights from ethnography into tools for population studies that assess the role of culture in human behavior, biology, and health. Aim We describe several lessons learned in the creation and administration of an ethnographically-based instrument to assess the life course perspectives of Appalachian youth, the Life Trajectory Interview for Youth (LTI-Y). Then, we explore the utility of the LTI-Y in predicting depressive affect, controlling for prior depressed mood and severe negative life events throughout the life course. Subjects and methods In a sample of 319 youth (190 White, 129 Cherokee), we tested the association between depressive affect and two domains of the LTI-Y - life course barriers and milestones. Longitudinal data on previous depressed mood and negative life events were included in the model. Results The ethnographically-based scales of life course barriers and milestones were associated with unique variance in depressed mood, together accounting for 11% of the variance in this outcome. Conclusion When creating ethnographically-based instruments, it is important to strike a balance between detailed, participant-driven procedures and the analytic needs of hypothesis testing. Ethnographically-based instruments have utility for predicting health outcomes in longitudinal studies. PMID:19353406

Final Report on Jobin Yvon Contained Inductively Coupled Plasma Emission Spectrometer

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

Pennebaker, F.M.

2003-03-17

A new Inductively Coupled Plasma -- Emission Spectrometer (ICP-ES) was recently purchased and installed in Lab B-147/151 at SRTC. The contained JY Model Ultima 170-C ICP-ES has been tested and compared to current ADS ICP-ES instrumentation. The testing has included both performance tests to evaluate instrumental ability, and the measurement of matrix standards commonly analyzed by ICP-ES at Savannah River. In developing operating procedures for this instrument, we have implemented the use of internal standards and off-peak background subtraction. Both of these techniques are recommended by EPA SW-846 ICP-ES methods and are common to current ICP-ES operations. Based on themore » testing and changes, the JY Model Ultima 170-C ICP-ES provides improved performance for elemental analysis of radioactive samples in the Analytical Development Section.« less

Shipboard Analytical Capabilities on the Renovated JOIDES Resolution, IODP Riserless Drilling Vessel

NASA Astrophysics Data System (ADS)

Blum, P.; Foster, P.; Houpt, D.; Bennight, C.; Brandt, L.; Cobine, T.; Crawford, W.; Fackler, D.; Fujine, K.; Hastedt, M.; Hornbacher, D.; Mateo, Z.; Moortgat, E.; Vasilyev, M.; Vasilyeva, Y.; Zeliadt, S.; Zhao, J.

2008-12-01

The JOIDES Resolution (JR) has conducted 121 scientific drilling expeditions during the Ocean Drilling Program (ODP) and the first phase of the Integrated Ocean Drilling Program (IODP) (1983-2006). The vessel and scientific systems have just completed an NSF-sponsored renovation (2005-2008). Shipboard analytical systems have been upgraded, within funding constraints imposed by market driven vessel conversion cost increases, to include: (1) enhanced shipboard analytical services including instruments and software for sampling and the capture of chemistry, physical properties, and geological data; (2) new data management capabilities built around a laboratory information management system (LIMS), digital asset management system, and web services; (3) operations data services with enhanced access to navigation and rig instrumentation data; and (4) a combination of commercial and home-made user applications for workflow- specific data extractions, generic and customized data reporting, and data visualization within a shipboard production environment. The instrumented data capture systems include a new set of core loggers for rapid and non-destructive acquisition of images and other physical properties data from drill cores. Line-scan imaging and natural gamma ray loggers capture data at unprecedented quality due to new and innovative designs. Many instruments used to characterize chemical compounds of rocks, sediments, and interstitial fluids were upgraded with the latest technology. The shipboard analytical environment features a new and innovative framework (DESCinfo) and application (DESClogik) for capturing descriptive and interpretive data from geological sub-domains such as sedimentology, petrology, paleontology, structural geology, stratigraphy, etc. This system fills a long-standing gap by providing a global database, controlled vocabularies and taxa name lists with version control, a highly configurable spreadsheet environment for data capture, and visualization of context data collected with the shipboard core loggers and other instruments.

A model of the demand for Islamic banks debt-based financing instrument

NASA Astrophysics Data System (ADS)

Jusoh, Mansor; Khalid, Norlin

2013-04-01

This paper presents a theoretical analysis of the demand for debt-based financing instruments of the Islamic banks. Debt-based financing, such as through baibithamanajil and al-murabahah, is by far the most prominent of the Islamic bank financing and yet it has been largely ignored in Islamic economics literature. Most studies instead have been focusing on equity-based financing of al-mudharabah and al-musyarakah. Islamic bank offers debt-based financing through various instruments derived under the principle of exchange (ukud al-mu'awadhat) or more specifically, the contract of deferred sale. Under such arrangement, Islamic debt is created when goods are purchased and the payments are deferred. Thus, unlike debt of the conventional bank which is a form of financial loan contract to facilitate demand for liquid assets, this Islamic debt is created in response to the demand to purchase goods by deferred payment. In this paper we set an analytical framework that is based on an infinitely lived representative agent model (ILRA model) to analyze the demand for goods to be purchased by deferred payment. The resulting demand will then be used to derive the demand for Islamic debt. We also investigate theoretically, factors that may have an impact on the demand for Islamic debt.

Multivariate figures of merit (FOM) investigation on the effect of instrument parameters on a Fourier transform-near infrared spectroscopy (FT-NIRS) based content uniformity method on core tablets.

PubMed

Doddridge, Greg D; Shi, Zhenqi

2015-01-01

Since near infrared spectroscopy (NIRS) was introduced to the pharmaceutical industry, efforts have been spent to leverage the power of chemometrics to extract out the best possible signal to correlate with the analyte of the interest. In contrast, only a few studies addressed the potential impact of instrument parameters, such as resolution and co-adds (i.e., the number of averaged replicate spectra), on the method performance of error statistics. In this study, a holistic approach was used to evaluate the effect of the instrument parameters of a FT-NIR spectrometer on the performance of a content uniformity method with respect to a list of figures of merit. The figures of merit included error statistics, signal-to-noise ratio (S/N), sensitivity, analytical sensitivity, effective resolution, selectivity, limit of detection (LOD), and noise. A Bruker MPA FT-NIR spectrometer was used for the investigation of an experimental design in terms of resolution (4 cm(-1) and 32 cm(-1)) and co-adds (256 and 16) plus a center point at 8 cm(-1) and 32 co-adds. Given the balance among underlying chemistry, instrument parameters, chemometrics, and measurement time, 8 cm(-1) and 32 co-adds in combination with appropriate 2nd derivative preprocessing was found to fit best for the intended purpose as a content uniformity method. The considerations for optimizing both instrument parameters and chemometrics were proposed and discussed in order to maximize the method performance for its intended purpose for future NIRS method development in R&D. Copyright © 2014 Elsevier B.V. All rights reserved.

[The water content reference material of water saturated octanol].

PubMed

Wang, Haifeng; Ma, Kang; Zhang, Wei; Li, Zhanyuan

2011-03-01

The national standards of biofuels specify the technique specification and analytical methods. A water content certified reference material based on the water saturated octanol was developed in order to satisfy the needs of the instrument calibration and the methods validation, assure the accuracy and consistency of results in water content measurements of biofuels. Three analytical methods based on different theories were employed to certify the water content of the reference material, including Karl Fischer coulometric titration, Karl Fischer volumetric titration and quantitative nuclear magnetic resonance. The consistency of coulometric and volumetric titration was achieved through the improvement of methods. The accuracy of the certified result was improved by the introduction of the new method of quantitative nuclear magnetic resonance. Finally, the certified value of reference material is 4.76% with an expanded uncertainty of 0.09%.

Instrumental Analysis in Environmental Chemistry - Liquid and Solid Phase Detection Systems

ERIC Educational Resources Information Center

Stedman, Donald H.; Meyers, Philip A.

1974-01-01

This is the second of two reviews dealing with analytical methods applicable to environmental chemistry. Methods are discussed under gas, liquid, or solid depending upon the state of the analyte during detection. (RH)

Digital Education Governance: Data Visualization, Predictive Analytics, and "Real-Time" Policy Instruments

ERIC Educational Resources Information Center

Williamson, Ben

2016-01-01

Educational institutions and governing practices are increasingly augmented with digital database technologies that function as new kinds of policy instruments. This article surveys and maps the landscape of digital policy instrumentation in education and provides two detailed case studies of new digital data systems. The Learning Curve is a…

Pods: a Powder Delivery System for Mars In-situ Organic, Mineralogic and Isotopic Analysis Instruments

NASA Technical Reports Server (NTRS)

Saha, C. P.; Bryson, C. E.; Sarrazin, P.; Blake, D. F.

2005-01-01

Many Mars in situ instruments require fine-grained high-fidelity samples of rocks or soil. Included are instruments for the determination of mineralogy as well as organic and isotopic chemistry. Powder can be obtained as a primary objective of a sample collection system (e.g., by collecting powder as a surface is abraded by a rotary abrasion tool (RAT)), or as a secondary objective (e.g, by collecting drill powder as a core is drilled). In the latter case, a properly designed system could be used to monitor drilling in real time as well as to deliver powder to analytical instruments which would perform complementary analyses to those later performed on the intact core. In addition, once a core or other sample is collected, a system that could transfer intelligently collected subsamples of power from the intact core to a suite of analytical instruments would be highly desirable. We have conceptualized, developed and tested a breadboard Powder Delivery System (PoDS) intended to satisfy the collection, processing and distribution requirements of powder samples for Mars in-situ mineralogic, organic and isotopic measurement instruments.

Analytical techniques for retrieval of atmospheric composition with the quadrupole mass spectrometer of the Sample Analysis at Mars instrument suite on Mars Science Laboratory

NASA Astrophysics Data System (ADS)

B. Franz, Heather; G. Trainer, Melissa; H. Wong, Michael; L. K. Manning, Heidi; C. Stern, Jennifer; R. Mahaffy, Paul; K. Atreya, Sushil; Benna, Mehdi; G. Conrad, Pamela; N. Harpold, Dan; A. Leshin, Laurie; A. Malespin, Charles; P. McKay, Christopher; Thomas Nolan, J.; Raaen, Eric

2014-06-01

The Sample Analysis at Mars (SAM) instrument suite is the largest scientific payload on the Mars Science Laboratory (MSL) Curiosity rover, which landed in Mars' Gale Crater in August 2012. As a miniature geochemical laboratory, SAM is well-equipped to address multiple aspects of MSL's primary science goal, characterizing the potential past or present habitability of Gale Crater. Atmospheric measurements support this goal through compositional investigations relevant to martian climate evolution. SAM instruments include a quadrupole mass spectrometer, a tunable laser spectrometer, and a gas chromatograph that are used to analyze martian atmospheric gases as well as volatiles released by pyrolysis of solid surface materials (Mahaffy et al., 2012). This report presents analytical methods for retrieving the chemical and isotopic composition of Mars' atmosphere from measurements obtained with SAM's quadrupole mass spectrometer. It provides empirical calibration constants for computing volume mixing ratios of the most abundant atmospheric species and analytical functions to correct for instrument artifacts and to characterize measurement uncertainties. Finally, we discuss differences in volume mixing ratios of the martian atmosphere as determined by SAM (Mahaffy et al., 2013) and Viking (Owen et al., 1977; Oyama and Berdahl, 1977) from an analytical perspective. Although the focus of this paper is atmospheric observations, much of the material concerning corrections for instrumental effects also applies to reduction of data acquired with SAM from analysis of solid samples. The Sample Analysis at Mars (SAM) instrument measures the composition of the martian atmosphere. Rigorous calibration of SAM's mass spectrometer was performed with relevant gas mixtures. Calibration included derivation of a new model to correct for electron multiplier effects. Volume mixing ratios for Ar and N2 obtained with SAM differ from those obtained with Viking. Differences between SAM and Viking volume mixing ratios are under investigation.

Analytical interference of drugs in clinical chemistry: I--Study of twenty drugs on seven different instruments.

PubMed

Letellier, G; Desjarlais, F

1985-12-01

We have investigated the effect of 20 drugs on the accuracy of results obtained from seven instruments now widely used in clinical biochemistry laboratories: Abbott VP, aca II, Cobas Bio, Ektachem 400, Hitachi 705, KDA and SMAC. Eleven to 18 constituents were analysed on each instrument. Our results lead us to the following conclusions: (1) only rarely does drug interference with a method lead to a clinically significant change in a measured value; (2) the magnitude of the change may relate linearly or non-linearly to the drug concentration but is usually independent of the target analyte concentration; (3) interference with a chemical reaction on one instrument does not always mean that the same reaction will be altered in the same way on other instruments; (4) no interferences were found for drugs with therapeutic levels in the low micro-molar range; (5) in most cases the interference could not be predicted from the chemical nature of drug.

Creating New Technologists of Research in the 1960s: The Case of the Reproduction of Automated Chromatography Specialists and Practitioners

NASA Astrophysics Data System (ADS)

Gerontas, Apostolos

2014-08-01

Chromatographic instrumentation has been really influential in shaping the modern chemical practice, and yet it has been largely overlooked by history of science.Gas chromatography in the 1960s was considered the analytical technique closer to becoming dominant, and being the first automated chromatography set the standards that all the subsequent chromatographic instrumentation had to fulfill. Networks of specialists, groups of actors, corporate strategies and the analytical practice itself, were all affected and in many ways because of the entrance of gas chromatography in the chemical laboratory and in the instrumentation market. This paper gives a view of the early history of the gas chromatography instrumentation, relates it to the broader research-technology phenomenon and discusses issues of education and group reproduction in the case of the groups of technologists of the era. The chaotic elements of knowledge transfer during the instrumentation revolution in chemistry are being highlighted and they are being connected to the observable radical innovation of the period.

Analytical capabilities and services of Lawrence Livermore Laboratory's General Chemistry Division. [Methods available at Lawrence Livermore

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

Gutmacher, R.; Crawford, R.

This comprehensive guide to the analytical capabilities of Lawrence Livermore Laboratory's General Chemistry Division describes each analytical method in terms of its principle, field of application, and qualitative and quantitative uses. Also described are the state and quantity of sample required for analysis, processing time, available instrumentation, and responsible personnel.

Scoping study to expedite development of a field deployable and portable instrument for UF6 enrichment assay

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

Chan, George; Valentine, John D.; Russo, Richard E.

The primary objective of the present study is to identity the most promising, viable technologies that are likely to culminate in an expedited development of the next-generation, field-deployable instrument for providing rapid, accurate, and precise enrichment assay of uranium hexafluoride (UF6). UF6 is typically involved, and is arguably the most important uranium compound, in uranium enrichment processes. As the first line of defense against proliferation, accurate analytical techniques to determine the uranium isotopic distribution in UF6 are critical for materials verification, accounting, and safeguards at enrichment plants. As nuclear fuel cycle technology becomes more prevalent around the world, international nuclearmore » safeguards and interest in UF6 enrichment assay has been growing. At present, laboratory-based mass spectrometry (MS), which offers the highest attainable analytical accuracy and precision, is the technique of choice for the analysis of stable and long-lived isotopes. Currently, the International Atomic Energy Agency (IAEA) monitors the production of enriched UF6 at declared facilities by collecting a small amount (between 1 to 10 g) of gaseous UF6 into a sample bottle, which is then shipped under chain of custody to a central laboratory (IAEA’s Nuclear Materials Analysis Laboratory) for high-precision isotopic assay by MS. The logistics are cumbersome and new shipping regulations are making it more difficult to transport UF6. Furthermore, the analysis is costly, and results are not available for some time after sample collection. Hence, the IAEA is challenged to develop effective safeguards approaches at enrichment plants. In-field isotopic analysis of UF6 has the potential to substantially reduce the time, logistics and expense of sample handling. However, current laboratory-based MS techniques require too much infrastructure and operator expertise for field deployment and operation. As outlined in the IAEA Department of Safeguards Long-Term R&D Plan, 2012–2023, one of the IAEA long-term R&D needs is to “develop tools and techniques to enable timely, potentially real-time, detection of HEU (Highly Enriched Uranium) production in LEU (Lowly Enriched Uranium) enrichment facilities” (Milestone 5.2). Because it is common that the next generation of analytical instruments is driven by technologies that are either currently available or just now emerging, one reasonable and practical approach to project the next generation of chemical instrumentation is to track the recent trends and to extrapolate them. This study adopted a similar approach, and an extensive literature review on existing and emerging technologies for UF6 enrichment assay was performed. The competitive advantages and current limitations of different analytical techniques for in-field UF6 enrichment assay were then compared, and the main gaps between needs and capabilities for their field use were examined. Subsequently, based on these results, technologies for the next-generation field-deployable instrument for UF6 enrichment assay were recommended. The study was organized in a way that a suite of assessment metric was first identified. Criteria used in this evaluation are presented in Section 1 of this report, and the most important ones are described briefly in the next few paragraphs. Because one driving force for in-field UF6 enrichment assay is related to the demanding transportation regulation for gaseous UF6, Section 2 contains a review of solid sorbents that convert and immobilized gaseous UF6 to a solid state, which is regarded as more transportation friendly and is less regulated. Furthermore, candidate solid sorbents, which show promise in mating with existing and emerging assay technologies, also factor into technology recommendations. Extensive literature reviews on existing and emerging technologies for UF6 enrichment assay, covering their scientific principles, instrument options, and current limitations are detailed in Sections 3 and 4, respectively. In Section 5, the technological gaps as well as start-of-the-art and commercial off-the-shelf components that can be adopted to expedite the development of a fieldable or portable UF6 enrichment-assay instrument are identified and discussed. Finally, based on the results of the review, requirements and recommendations for developing the next-generation field-deployable instrument for UF6 enrichment assay are presented in Section 6.« less

Rumsey and Walker_AMT_2016_Figure 2.xlsx

EPA Pesticide Factsheets

Figure summarizes uncertainty (error) in hourly gradient flux measurements by individual analyte. Flux uncertainty is derived from estimates of uncertainty in chemical gradients and turbulent transfer velocity.This dataset is associated with the following publication:Rumsey, I. Application of an online ion chromatography-based instrument for gradient flux measurements of speciated nitrogen and sulfur. ENVIRONMENTAL SCIENCE & TECHNOLOGY. American Chemical Society, Washington, DC, USA, 9(6): 2581-2592, (2016).

Potential of dynamically harmonized Fourier transform ion cyclotron resonance cell for high-throughput metabolomics fingerprinting: control of data quality.

PubMed

Habchi, Baninia; Alves, Sandra; Jouan-Rimbaud Bouveresse, Delphine; Appenzeller, Brice; Paris, Alain; Rutledge, Douglas N; Rathahao-Paris, Estelle

2018-01-01

Due to the presence of pollutants in the environment and food, the assessment of human exposure is required. This necessitates high-throughput approaches enabling large-scale analysis and, as a consequence, the use of high-performance analytical instruments to obtain highly informative metabolomic profiles. In this study, direct introduction mass spectrometry (DIMS) was performed using a Fourier transform ion cyclotron resonance (FT-ICR) instrument equipped with a dynamically harmonized cell. Data quality was evaluated based on mass resolving power (RP), mass measurement accuracy, and ion intensity drifts from the repeated injections of quality control sample (QC) along the analytical process. The large DIMS data size entails the use of bioinformatic tools for the automatic selection of common ions found in all QC injections and for robustness assessment and correction of eventual technical drifts. RP values greater than 10 6 and mass measurement accuracy of lower than 1 ppm were obtained using broadband mode resulting in the detection of isotopic fine structure. Hence, a very accurate relative isotopic mass defect (RΔm) value was calculated. This reduces significantly the number of elemental composition (EC) candidates and greatly improves compound annotation. A very satisfactory estimate of repeatability of both peak intensity and mass measurement was demonstrated. Although, a non negligible ion intensity drift was observed for negative ion mode data, a normalization procedure was easily applied to correct this phenomenon. This study illustrates the performance and robustness of the dynamically harmonized FT-ICR cell to perform large-scale high-throughput metabolomic analyses in routine conditions. Graphical abstract Analytical performance of FT-ICR instrument equipped with a dynamically harmonized cell.

The relative responsiveness of test instruments can be estimated using a meta-analytic approach: an illustration with treatments for depression.

PubMed

Kounali, Daphne Z; Button, Katherine S; Lewis, Glyn; Ades, Anthony E

2016-09-01

We present a meta-analytic method that combines information on treatment effects from different instruments from a network of randomized trials to estimate instrument relative responsiveness. Five depression-test instruments [Beck Depression Inventory (BDI I/II), Patient Health Questionnaire (PHQ9), Hamilton Rating for Depression 17 and 24 items, Montgomery-Asberg Depression Rating] and three generic quality of life measures [EuroQoL (EQ-5D), SF36 mental component summary (SF36 MCS), and physical component summary (SF36 PCS)] were compared. Randomized trials of treatments for depression reporting outcomes on any two or more of these instruments were identified. Information on the within-trial ratios of standardized treatment effects was pooled across the studies to estimate relative responsiveness. The between-instrument ratios of standardized treatment effects vary across trials, with a coefficient of variation of 13% (95% credible interval: 6%, 25%). There were important differences between the depression measures, with PHQ9 being the most responsive instrument and BDI the least. Responsiveness of the EQ-5D and SF36 PCS was poor. SF36 MCS performed similarly to depression instruments. Information on relative responsiveness of several test instruments can be pooled across networks of trials reporting at least two outcomes, allowing comparison and ranking of test instruments that may never have been compared directly. Copyright © 2016 Elsevier Inc. All rights reserved.

Development of diagnostic SPR based biosensor for the detection of pharmaceutical compounds in saliva

NASA Astrophysics Data System (ADS)

Sonny, Susanna; Sesay, Adama M.; Virtanen, Vesa

2010-11-01

The aim of the study is to develop diagnostic tests for the detection of pharmaceutical compounds in saliva. Oral fluid is increasingly being considered as an ideal sample matrix. It can be collected non-invasively and causes less stress to the person being tested. The detection of pharmaceutical compounds and drugs in saliva can give valuable information on individual bases on dose response, usage, characterization and clinical diagnostics. Surface plasmon resonance (SPR) is a highly sensitive, fast and label free analytical technique for the detection of molecular interactions. The specific binding of measured analyte onto the active gold sensing surface of the SPR device induces a refractive index change that can be monitored. To monitor these pharmaceutical compounds in saliva the immunoassays were developed using a SPR instrument. The instrument is equipped with a 670nm laser diode and has two sensing channels. Monoclonal antibodies against the pharmaceutical compounds were used to specifically recognise and capture the compounds which intern will have an effect of the refractive index monitored. Preliminary results show that the immunoassays for cocaine and MDMA (3,4-methylenedioxymethamphetamine) are very sensitive and have linear ranges of 0.01 pg/ml - 1 ng/ml and 0.1 pg/ml - 100 ng/ml, respectively.

Blade loss transient dynamics analysis, volume 2. Task 2: Theoretical and analytical development. Task 3: Experimental verification

NASA Technical Reports Server (NTRS)

Gallardo, V. C.; Storace, A. S.; Gaffney, E. F.; Bach, L. J.; Stallone, M. J.

1981-01-01

The component element method was used to develop a transient dynamic analysis computer program which is essentially based on modal synthesis combined with a central, finite difference, numerical integration scheme. The methodology leads to a modular or building-block technique that is amenable to computer programming. To verify the analytical method, turbine engine transient response analysis (TETRA), was applied to two blade-out test vehicles that had been previously instrumented and tested. Comparison of the time dependent test data with those predicted by TETRA led to recommendations for refinement or extension of the analytical method to improve its accuracy and overcome its shortcomings. The development of working equations, their discretization, numerical solution scheme, the modular concept of engine modelling, the program logical structure and some illustrated results are discussed. The blade-loss test vehicles (rig full engine), the type of measured data, and the engine structural model are described.

State of the art of environmentally friendly sample preparation approaches for determination of PBDEs and metabolites in environmental and biological samples: A critical review.

PubMed

Berton, Paula; Lana, Nerina B; Ríos, Juan M; García-Reyes, Juan F; Altamirano, Jorgelina C

2016-01-28

Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Better by design: business preferences for environmental regulatory reform.

PubMed

Taylor, Christopher M; Pollard, Simon J T; Rocks, Sophie A; Angus, Andrew J

2015-04-15

We present the preferences for environmental regulatory reform expressed by 30 UK businesses and industry bodies from 5 sectors. While five strongly preferred voluntary regulation, seven expressed doubts about its effectiveness, and 18 expressed no general preference between instrument types. Voluntary approaches were valued for flexibility and lower burdens, but direct regulation offered stability and a level playing field. Respondents sought regulatory frameworks that: are coherent; balance clarity, prescription and flexibility; are enabled by positive regulatory relationships; administratively efficient; targeted according to risk magnitude and character; evidence-based and that deliver long-term market stability for regulatees. Anticipated differences in performance between types of instrument can be undermined by poor implementation. Results underline the need for policy makers and regulators to tailor an effective mix of instruments for a given sector, and to overcome analytical, institutional and political barriers to greater coherence, to better coordinate existing instruments and tackle new environmental challenges as they emerge. Copyright © 2015 Elsevier B.V. All rights reserved.

Supercritical Fluid Chromatography--Theoretical Background and Applications on Natural Products.

PubMed

Hartmann, Anja; Ganzera, Markus

2015-11-01

The use of supercritical fluid chromatography for natural product analysis as well as underlying theoretical mechanisms and instrumental requirements are summarized in this review. A short introduction focusing on the historical development of this interesting separation technique is followed by remarks on the current instrumental design, also describing possible detection modes and useable stationary phases. The overview on relevant applications is grouped based on their basic intention, may it be (semi)preparative or purely analytical. They indicate that supercritical fluid chromatography is still primarily considered for the analysis of nonpolar analytes like carotenoids, fatty acids, or terpenes. The low polarity of supercritical carbon dioxide, which is used with modifiers almost exclusively as a mobile phase today, combined with high efficiency and fast separations might explain the popularity of supercritical fluid chromatography for the analysis of these compounds. Yet, it has been shown that more polar natural products (e.g., xanthones, flavonoids, alkaloids) are separable too, with the same (if not superior) selectivity and reproducibility than established approaches like HPLC or GC. Georg Thieme Verlag KG Stuttgart · New York.

Technologies for autonomous integrated lab-on-chip systems for space missions

NASA Astrophysics Data System (ADS)

Nascetti, A.; Caputo, D.; Scipinotti, R.; de Cesare, G.

2016-11-01

Lab-on-chip devices are ideal candidates for use in space missions where experiment automation, system compactness, limited weight and low sample and reagent consumption are required. Currently, however, most microfluidic systems require external desktop instrumentation to operate and interrogate the chip, thus strongly limiting their use as stand-alone systems. In order to overcome the above-mentioned limitations our research group is currently working on the design and fabrication of "true" lab-on-chip systems that integrate in a single device all the analytical steps from the sample preparation to the detection without the need for bulky external components such as pumps, syringes, radiation sources or optical detection systems. Three critical points can be identified to achieve 'true' lab-on-chip devices: sample handling, analytical detection and signal transduction. For each critical point, feasible solutions are presented and evaluated. Proposed microfluidic actuation and control is based on electrowetting on dielectrics, autonomous capillary networks and active valves. Analytical detection based on highly specific chemiluminescent reactions is used to avoid external radiation sources. Finally, the integration on the same chip of thin film sensors based on hydrogenated amorphous silicon is discussed showing practical results achieved in different sensing tasks.

Laser Time-of-Flight Mass Spectrometry for Future In Situ Planetary Missions

NASA Technical Reports Server (NTRS)

Getty, S. A.; Brinckerhoff, W. B.; Cornish, T.; Ecelberger, S. A.; Li, X.; Floyd, M. A. Merrill; Chanover, N.; Uckert, K.; Voelz, D.; Xiao, X.;

Analytical Chemistry and the Microchip.

ERIC Educational Resources Information Center

Lowry, Robert K.

1986-01-01

Analytical techniques used at various points in making microchips are described. They include: Fourier transform infrared spectrometry (silicon purity); optical emission spectroscopy (quantitative thin-film composition); X-ray photoelectron spectroscopy (chemical changes in thin films); wet chemistry, instrumental analysis (process chemicals);…

VISAGE Visualization for Integrated Satellite, Airborne and Ground-Based Data Exploration

NASA Technical Reports Server (NTRS)

Conover, Helen; Berendes, Todd; Naeger, Aaron; Maskey, Manil; Gatlin, Patrick; Wingo, Stephanie; Kulkarni, Ajinkya; Gupta, Shivangi; Nagaraj, Sriraksha; Wolff, David;

Characterization of a turbomolecular-pumped magnetic sector mass spectrometer

NASA Technical Reports Server (NTRS)

Mehta, Narinder K.

1988-01-01

A Perkin Elmer MGA-1200, turbomolecular-pumped, magnetic sector, multiple gas analyzer mass spectrometer with modified inlet for fast response was characterized for the analysis of hydrogen, helium, oxygen and argon in nitrogen and helium background gases. This instrument was specially modified for the Vanderberg AFB SLC-6 Hydrogen Disposal Test Program, as a part of the Hydrogen Sampling System (H2S2). Linearity, precision, drift, detection limits and accuracy among other analytical parameters for each of the background gas were studied to evaluate the performance of the instrument. The result demonstrates that H2S2 mass spectrometer is a stable instrument and can be utilized for the quantitative analytical determination of hydrogen, helium, oxygen and argon in nitrogen and helium background gases.

Diode laser-based cavity ring-down instrument for NO3, N2O5, NO, NO2 and O3 from aircraft

NASA Astrophysics Data System (ADS)

Wagner, N. L.; Dubé, W. P.; Washenfelder, R. A.; Young, C. J.; Pollack, I. B.; Ryerson, T. B.; Brown, S. S.

2011-06-01

This article presents a diode laser-based, cavity ring-down spectrometer for simultaneous in situ measurements of four nitrogen oxide species, NO3, N2O5, NO, NO2, as well as O3, designed for deployment on aircraft. The instrument measures NO3 and NO2 by optical extinction at 662 nm and 405 nm, respectively; N2O5 is measured by thermal conversion to NO3, while NO and O3 are measured by chemical conversion to NO2. The instrument has several advantages over previous instruments developed by our group for measurement of NO2, NO3 and N2O5 alone, based on a pulsed Nd:YAG and dye laser. First, the use of continuous wave diode lasers reduces the requirements for power and weight and eliminates hazardous materials. Second, detection of NO2 at 405 nm is more sensitive than our previously reported 532 nm instrument, and does not have a measurable interference from O3. Third, the instrument includes chemical conversion of NO and O3 to NO2 to provide measurements of total NOx (= NO + NO2) and Ox (= NO2 + O3) on two separate channels; mixing ratios of NO and O3 are determined by subtraction of NO2. Finally, all five species are calibrated against a single standard based on 254 nm O3 absorption to provide high accuracy. Disadvantages include an increased sensitivity to water vapor on the 662 nm NO3 and N2O5 channels and a modest reduction in sensitivity for these species compared to the pulsed laser instrument. The in-flight detection limit for both NO3 and N2O5 is 3 pptv (2 σ, 1 s) and for NO, NO2 and O3 is 140, 90, and 120 pptv (2 σ, 1 s) respectively. Demonstrated performance of the instrument in a laboratory/ground based environment is better by approximately a factor of 2-3. The NO and NO2 measurements are less precise than research-grade chemiluminescence instruments. However, the combination of these five species in a single instrument, calibrated to a single analytical standard, provides a complete and accurate picture of nighttime nitrogen oxide chemistry. The instrument performance is demonstrated using data acquired during a recent field campaign in California.

Man vs. Machine: A Junior-level Laboratory Exercise Comparing Human and Instrumental Detection Limits

ERIC Educational Resources Information Center

Elias, Ryan J.; Hopfer, Helene; Hofstaedter, Amanda N.; Hayes, John E.

2017-01-01

The human nose is a very sensitive detector and is able to detect potent aroma compounds down to low ng/L levels. These levels are often below detection limits of analytical instrumentation. The following laboratory exercise is designed to compare instrumental and human methods for the detection of volatile odor active compounds. Reference…

Jonathan W. Amy and the Amy Facility for Instrumentation Development.

PubMed

Cooks, R Graham

2017-05-16

This Perspective describes the unique Jonathan Amy Facility for Chemical Instrumentation in the Department of Chemistry at Purdue University, tracing its history and mode of operation. It also describes aspects of the career of its namesake and some of his insights which have been central to analytical instrumentation development, improvement, and utilization, both at Purdue and nationally.

Assessing the impact of natural policy experiments on socioeconomic inequalities in health: how to apply commonly used quantitative analytical methods?

PubMed

Hu, Yannan; van Lenthe, Frank J; Hoffmann, Rasmus; van Hedel, Karen; Mackenbach, Johan P

2017-04-20

The scientific evidence-base for policies to tackle health inequalities is limited. Natural policy experiments (NPE) have drawn increasing attention as a means to evaluating the effects of policies on health. Several analytical methods can be used to evaluate the outcomes of NPEs in terms of average population health, but it is unclear whether they can also be used to assess the outcomes of NPEs in terms of health inequalities. The aim of this study therefore was to assess whether, and to demonstrate how, a number of commonly used analytical methods for the evaluation of NPEs can be applied to quantify the effect of policies on health inequalities. We identified seven quantitative analytical methods for the evaluation of NPEs: regression adjustment, propensity score matching, difference-in-differences analysis, fixed effects analysis, instrumental variable analysis, regression discontinuity and interrupted time-series. We assessed whether these methods can be used to quantify the effect of policies on the magnitude of health inequalities either by conducting a stratified analysis or by including an interaction term, and illustrated both approaches in a fictitious numerical example. All seven methods can be used to quantify the equity impact of policies on absolute and relative inequalities in health by conducting an analysis stratified by socioeconomic position, and all but one (propensity score matching) can be used to quantify equity impacts by inclusion of an interaction term between socioeconomic position and policy exposure. Methods commonly used in economics and econometrics for the evaluation of NPEs can also be applied to assess the equity impact of policies, and our illustrations provide guidance on how to do this appropriately. The low external validity of results from instrumental variable analysis and regression discontinuity makes these methods less desirable for assessing policy effects on population-level health inequalities. Increased use of the methods in social epidemiology will help to build an evidence base to support policy making in the area of health inequalities.

Recognizing and Reducing Analytical Errors and Sources of Variation in Clinical Pathology Data in Safety Assessment Studies.

PubMed

Schultze, A E; Irizarry, A R

2017-02-01

Veterinary clinical pathologists are well positioned via education and training to assist in investigations of unexpected results or increased variation in clinical pathology data. Errors in testing and unexpected variability in clinical pathology data are sometimes referred to as "laboratory errors." These alterations may occur in the preanalytical, analytical, or postanalytical phases of studies. Most of the errors or variability in clinical pathology data occur in the preanalytical or postanalytical phases. True analytical errors occur within the laboratory and are usually the result of operator or instrument error. Analytical errors are often ≤10% of all errors in diagnostic testing, and the frequency of these types of errors has decreased in the last decade. Analytical errors and increased data variability may result from instrument malfunctions, inability to follow proper procedures, undetected failures in quality control, sample misidentification, and/or test interference. This article (1) illustrates several different types of analytical errors and situations within laboratories that may result in increased variability in data, (2) provides recommendations regarding prevention of testing errors and techniques to control variation, and (3) provides a list of references that describe and advise how to deal with increased data variability.

Laboratory evaluation of alcohol safety interlock systems. Volume 2 : instrument screening experiments

DOT National Transportation Integrated Search

1974-01-01

The report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were developed...

Engineering Rugged Field Assays to Detect Hazardous Chemicals Using Spore-Based Bacterial Biosensors.

PubMed

Wynn, Daniel; Deo, Sapna; Daunert, Sylvia

2017-01-01

Bacterial whole cell-based biosensors have been genetically engineered to achieve selective and reliable detection of a wide range of hazardous chemicals. Although whole-cell biosensors demonstrate many advantages for field-based detection of target analytes, there are still some challenges that need to be addressed. Most notably, their often modest shelf life and need for special handling and storage make them challenging to use in situations where access to reagents, instrumentation, and expertise are limited. These problems can be circumvented by developing biosensors in Bacillus spores, which can be engineered to address all of these concerns. In its sporulated state, a whole cell-based biosensor has a remarkably long life span and is exceptionally resistant to environmental insult. When these spores are germinated for use in analytical techniques, they show no loss in performance, even after long periods of storage under harsh conditions. In this chapter, we will discuss the development and use of whole cell-based sensors, their adaptation to spore-based biosensors, their current applications, and future directions in the field. © 2017 Elsevier Inc. All rights reserved.

40 CFR 1066.101 - Overview.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROCEDURES Equipment, Measurement Instruments, Fuel, and Analytical Gas Specifications § 1066.101 Overview. (a) This subpart addresses equipment related to emission testing, as well as test fuels and... specifications for fuels, engine fluids, and analytical gases; these specifications apply for testing under this...

Analytical Chemistry of Surfaces: Part II. Electron Spectroscopy.

ERIC Educational Resources Information Center

Hercules, David M.; Hercules, Shirley H.

1984-01-01

Discusses two surface techniques: X-ray photoelectron spectroscopy (ESCA) and Auger electron spectroscopy (AES). Focuses on fundamental aspects of each technique, important features of instrumentation, and some examples of how ESCA and AES have been applied to analytical surface problems. (JN)

Recommended Inorganic Chemicals for Calibration.

ERIC Educational Resources Information Center

Moody, John R.; And Others

1988-01-01

All analytical techniques depend on the use of calibration chemicals to relate analyte concentration to instrumental parameters. Discusses the preparation of standard solutions and provides a critical evaluation of available materials. Lists elements by group and discusses the purity and uses of each. (MVL)

Analytical Chemistry Laboratory

NASA Technical Reports Server (NTRS)

Anderson, Mark

2013-01-01

The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

The Hessdalen Luminous Phenomenon: A Data Analysis

NASA Astrophysics Data System (ADS)

Teodorani, M.; Strand, E. P.

1998-08-01

In the period 21 January - 26 February 1984, a group of research engineers belonging to "Project Hessdalen", carried out instrumental investigations on a luminous atmospheric phenomenon occurring with strong recurrence in the area of Hessdalen in Norway. Several multi-mode instruments were used in order to monitor the phenomenon. In the present work, an analytical attempt, based on the data achieved during the 1984 investigation period, has been done in order to explain such a phenomenon. The following main results are presented: (1) the luminous phenomenon occurs with a periodicity of about one day and is approximately coincident with some peculiar magnetic pulsations and, more scarcely, with some components of radio emission; (2) magnetometric data, radar data and some components of radiometric data show some slight correlation with daily solar activity. Hypothesis regarding formation of solar-driven plasmoids acquiring self-governing EM and magnetic fields, is further ventured and discussed. Technical requirements for future instrumental research are presented as well.

Application of kernel principal component analysis and computational machine learning to exploration of metabolites strongly associated with diet.

PubMed

Shiokawa, Yuka; Date, Yasuhiro; Kikuchi, Jun

2018-02-21

Computer-based technological innovation provides advancements in sophisticated and diverse analytical instruments, enabling massive amounts of data collection with relative ease. This is accompanied by a fast-growing demand for technological progress in data mining methods for analysis of big data derived from chemical and biological systems. From this perspective, use of a general "linear" multivariate analysis alone limits interpretations due to "non-linear" variations in metabolic data from living organisms. Here we describe a kernel principal component analysis (KPCA)-incorporated analytical approach for extracting useful information from metabolic profiling data. To overcome the limitation of important variable (metabolite) determinations, we incorporated a random forest conditional variable importance measure into our KPCA-based analytical approach to demonstrate the relative importance of metabolites. Using a market basket analysis, hippurate, the most important variable detected in the importance measure, was associated with high levels of some vitamins and minerals present in foods eaten the previous day, suggesting a relationship between increased hippurate and intake of a wide variety of vegetables and fruits. Therefore, the KPCA-incorporated analytical approach described herein enabled us to capture input-output responses, and should be useful not only for metabolic profiling but also for profiling in other areas of biological and environmental systems.

Integrating exhaled breath diagnostics by disease-sniffing dogs with instrumental laboratory analysis.

PubMed

Pleil, Joachim; Giese, Roger

2017-09-07

Dogs have been studied for many years as a medical diagnostic tool to detect a pre-clinical disease state by sniffing emissions directly from a human or an in vitro biological sample. Some of the studies report high sensitivity and specificity in blinded case-control studies. However, in these studies it is completely unknown as to which suites of chemicals the dogs detect and how they ultimately interpret this information amidst confounding background odors. Herein, we consider the advantages and challenges of canine olfaction for early (meaningful) detection of cancer, and propose an experimental concept to narrow the molecular signals used by the dog for sample classification to laboratory-based instrumental analysis. This serves two purposes; first, in contrast to dogs, analytical methods could be quickly up-scaled for high throughput sampling. Second, the knowledge gained from identifying probative chemicals could be helpful in learning more about biochemical pathways and disease progression. We focus on exhaled breath aerosol, arguing that the semi-volatile fraction should be given more attention. Ultimately, we conclude that the interaction between dog-based and instrument-based research will be mutually beneficial and accelerate progress towards early detection of cancer by breath analysis.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of selected carbamate pesticides in water by high-performance liquid chromatography

USGS Publications Warehouse

Werner, S.L.; Johnson, S.M.

1994-01-01

As part of its primary responsibility concerning water as a national resource, the U.S. Geological Survey collects and analyzes samples of ground water and surface water to determine water quality. This report describes the method used since June 1987 to determine selected total-recoverable carbamate pesticides present in water samples. High- performance liquid chromatography is used to separate N-methyl carbamates, N-methyl carbamoyloximes, and an N-phenyl carbamate which have been extracted from water and concentrated in dichloromethane. Analytes, surrogate compounds, and reference compounds are eluted from the analytical column within 25 minutes. Two modes of analyte detection are used: (1) a photodiode-array detector measures and records ultraviolet-absorbance profiles, and (2) a fluorescence detector measures and records fluorescence from an analyte derivative produced when analyte hydrolysis is combined with chemical derivatization. Analytes are identified and confirmed in a three-stage process by use of chromatographic retention time, ultraviolet (UV) spectral comparison, and derivatization/fluorescence detection. Quantitative results are based on the integration of single-wavelength UV-absorbance chromatograms and on comparison with calibration curves derived from external analyte standards that are run with samples as part of an instrumental analytical sequence. Estimated method detection limits vary for each analyte, depending on the sample matrix conditions, and range from 0.5 microgram per liter to as low as 0.01 microgram per liter. Reporting levels for all analytes have been set at 0.5 microgram per liter for this method. Corrections on the basis of percentage recoveries of analytes spiked into distilled water are not applied to values calculated for analyte concentration in samples. These values for analyte concentrations instead indicate the quantities recovered by the method from a particular sample matrix.

A Unifying Review of Bioassay-Guided Fractionation, Effect-Directed Analysis and Related Techniques

PubMed Central

Weller, Michael G.

2012-01-01

The success of modern methods in analytical chemistry sometimes obscures the problem that the ever increasing amount of analytical data does not necessarily give more insight of practical relevance. As alternative approaches, toxicity- and bioactivity-based assays can deliver valuable information about biological effects of complex materials in humans, other species or even ecosystems. However, the observed effects often cannot be clearly assigned to specific chemical compounds. In these cases, the establishment of an unambiguous cause-effect relationship is not possible. Effect-directed analysis tries to interconnect instrumental analytical techniques with a biological/biochemical entity, which identifies or isolates substances of biological relevance. Successful application has been demonstrated in many fields, either as proof-of-principle studies or even for complex samples. This review discusses the different approaches, advantages and limitations and finally shows some practical examples. The broad emergence of effect-directed analytical concepts might lead to a true paradigm shift in analytical chemistry, away from ever growing lists of chemical compounds. The connection of biological effects with the identification and quantification of molecular entities leads to relevant answers to many real life questions. PMID:23012539

Transmission versus reflectance spectroscopy for quantitation

NASA Astrophysics Data System (ADS)

Gardner, Craig M.

2018-01-01

The objective of this work was to compare the accuracy of analyte concentration estimation when using transmission versus diffuse reflectance spectroscopy of a scattering medium. Monte Carlo ray tracing of light through the medium was used in conjunction with pure component absorption spectra and Beer-Lambert absorption along each ray's pathlength to generate matched sets of pseudoabsorbance spectra, containing water and six analytes present in skin. PLS regression models revealed an improvement in accuracy when using transmission compared to reflectance for a range of medium thicknesses and instrument noise levels. An analytical expression revealed the source of the accuracy degradation with reflectance was due both to the reduced collection efficiency for a fixed instrument etendue and to the broad pathlength distribution that detected light travels in the medium before exiting from the incident side.

Tunable lasers and their application in analytical chemistry

NASA Technical Reports Server (NTRS)

Steinfeld, J. I.

1975-01-01

The impact that laser techniques might have in chemical analysis is examined. Absorption, scattering, and heterodyne detection is considered. Particular emphasis is placed on the advantages of using frequency-tunable sources, and dye solution lasers are regarded as the outstanding example of this type of laser. Types of spectroscopy that can be carried out with lasers are discussed along with the ultimate sensitivity or minimum detectable concentration of molecules that can be achieved with each method. Analytical applications include laser microprobe analysis, remote sensing and instrumental methods such as laser-Raman spectroscopy, atomic absorption/fluorescence spectrometry, fluorescence assay techniques, optoacoustic spectroscopy, and polarization measurements. The application of lasers to spectroscopic methods of analysis would seem to be a rewarding field both for research in analytical chemistry and for investments in instrument manufacturing.

Laboratory evaluation of alcohol safety interlock systems. Volume 3 : instrument performance at high BAL

DOT National Transportation Integrated Search

1974-01-01

This report contains the results of an experimental and analytical evaluation of instruments and techniques designed to prevent an intoxicated driver from operating his automobile. The prototype 'Alcohol Safety Interlock Systems' tested were develope...

Contributions of Analytical Chemistry to the Clinical Laboratory.

ERIC Educational Resources Information Center

Skogerboe, Kristen J.

1988-01-01

Highlights several analytical techniques that are being used in state-of-the-art clinical labs. Illustrates how other advances in instrumentation may contribute to clinical chemistry in the future. Topics include: biosensors, polarization spectroscopy, chemiluminescence, fluorescence, photothermal deflection, and chromatography in clinical…

Normal incidence X-ray mirror for chemical microanalysis

DOEpatents

Carr, Martin J.; Romig, Jr., Alton D.

1990-01-01

A non-planar, focusing mirror, to be utilized in both electron column instruments and micro-x-ray fluorescence instruments for performing chemical microanalysis on a sample, comprises a concave, generally spherical base substrate and a predetermined number of alternating layers of high atomic number material and low atomic number material contiguously formed on the base substrate. The thickness of each layer is an integral multiple of the wavelength being reflected and may vary non-uniformly according to a predetermined design. The chemical analytical instruments in which the mirror is used also include a predetermined energy source for directing energy onto the sample and a detector for receiving and detecting the x-rays emitted from the sample; the non-planar mirror is located between the sample and detector and collects the x-rays emitted from the sample at a large solid angle and focuses the collected x-rays to the sample. For electron column instruments, the wavelengths of interest lie above 1.5 nm, while for x-ray fluorescence instruments, the range of interest is below 0.2 nm. Also, x-ray fluorescence instruments include an additional non-planar focusing mirror, formed in the same manner as the previously described m The invention described herein was made in the performance of work under contract with the Department of Energy, Contract No. DE-AC04-76DP00789, and the United States Government has rights in the invention pursuant to this contract.

Spectral radiation analyses of the GOES solar illuminated hexagonal cell scan mirror back

NASA Technical Reports Server (NTRS)

Fantano, Louis G.

1993-01-01

A ray tracing analytical tool has been developed for the simulation of spectral radiation exchange in complex systems. Algorithms are used to account for heat source spectral energy, surface directional radiation properties, and surface spectral absorptivity properties. This tool has been used to calculate the effective solar absorptivity of the geostationary operational environmental satellites (GOES) scan mirror in the calibration position. The development and design of Sounder and Imager instruments on board GOES is reviewed and the problem of calculating the effective solar absorptivity associated with the GOES hexagonal cell configuration is presented. The analytical methodology based on the Monte Carlo ray tracing technique is described and results are presented and verified by experimental measurements for selected solar incidence angles.

Cartilage analysis by reflection spectroscopy

NASA Astrophysics Data System (ADS)

Laun, T.; Muenzer, M.; Wenzel, U.; Princz, S.; Hessling, M.

2015-07-01

A cartilage bioreactor with analytical functions for cartilage quality monitoring is being developed. For determining cartilage composition, reflection spectroscopy in the visible (VIS) and near infrared (NIR) spectral region is evaluated. Main goal is the determination of the most abundant cartilage compounds water, collagen I and collagen II. Therefore VIS and NIR reflection spectra of different cartilage samples of cow, pig and lamb are recorded. Due to missing analytical instrumentation for identifying the cartilage composition of these samples, typical literature concentration values are used for the development of chemometric models. In spite of these limitations the chemometric models provide good cross correlation results for the prediction of collagen I and II and water concentration based on the visible and the NIR reflection spectra.

High performance liquid chromatography column efficiency enhancement by zero dead volume recycling and practical approach using park and recycle arrangement.

PubMed

Minarik, Marek; Franc, Martin; Minarik, Milan

2018-06-15

A new instrumental approach to recycling HPLC is described. The concept is based on fast reintroduction of incremental peak sections back onto the separation column. The re-circulation is performed within a closed loop containing only the column and two synchronized switching valves. By having HPLC pump out of the cycle, the method minimizes peak broadening due to dead volume. As a result the efficiency is dramatically increased allowing for the most demanding analytical applications. In addition, a parking loop is employed for temporary storage of analytes from the middle section of the separated mixture prior to their recycling. Copyright © 2018 Elsevier B.V. All rights reserved.

Characterization and measurement of natural gas trace constituents. Volume 1. Arsenic. Final report, June 1989-October 1993

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

Chao, S.S.; Attari, A.

1995-01-01

The discovery of arsenic compounds, as alkylarsines, in natural gas prompted this research program to develop reliable measurement techniques needed to assess the efficiency of removal processes for these environmentally sensitive substances. These techniques include sampling, speciation, quantitation and on-line instrumental methods for monitoring the total arsenic concentration. The current program has yielded many products, including calibration standards, arsenic-specific sorbents, sensitive analytical methods and instrumentation. Four laboratory analytical methods have been developed and successfully employed for arsenic determination in natural gas. These methods use GC-AED and GC-MS instruments to speciate alkylarsines, and peroxydisulfate extraction with FIAS, special carbon sorbent withmore » XRF and an IGT developed sorbent with GFAA for total arsenic measurement.« less

Propellant injection systems and processes

NASA Technical Reports Server (NTRS)

Ito, Jackson I.

1995-01-01

The previous 'Art of Injector Design' is maturing and merging with the more systematic 'Science of Combustion Device Analysis.' This technology can be based upon observation, correlation, experimentation and ultimately analytical modeling based upon basic engineering principles. This methodology is more systematic and far superior to the historical injector design process of 'Trial and Error' or blindly 'Copying Past Successes.' The benefit of such an approach is to be able to rank candidate design concepts for relative probability of success or technical risk in all the important combustion device design requirements and combustion process development risk categories before committing to an engine development program. Even if a single analytical design concept cannot be developed to predict satisfying all requirements simultaneously, a series of risk mitigation key enabling technologies can be identified for early resolution. Lower cost subscale or laboratory experimentation to demonstrate proof of principle, critical instrumentation requirements, and design discriminating test plans can be developed based on the physical insight provided by these analyses.

Evaporative concentration on a paper-based device to concentrate analytes in a biological fluid.

PubMed

Wong, Sharon Y; Cabodi, Mario; Rolland, Jason; Klapperich, Catherine M

2014-12-16

We report the first demonstration of using heat on a paper device to rapidly concentrate a clinically relevant analyte of interest from a biological fluid. Our technology relies on the application of localized heat to a paper strip to evaporate off hundreds of microliters of liquid to concentrate the target analyte. This method can be used to enrich for a target analyte that is present at low concentrations within a biological fluid to enhance the sensitivity of downstream detection methods. We demonstrate our method by concentrating the tuberculosis-specific glycolipid, lipoarabinomannan (LAM), a promising urinary biomarker for the detection and diagnosis of tuberculosis. We show that the heat does not compromise the subsequent immunodetectability of LAM, and in 20 min, the tuberculosis biomarker was concentrated by nearly 20-fold in simulated urine. Our method requires only 500 mW of power, and sample flow is self-driven via capillary action. As such, our technology can be readily integrated into portable, battery-powered, instrument-free diagnostic devices intended for use in low-resource settings.

Method for reduction of selected ion intensities in confined ion beams

DOEpatents

Eiden, Gregory C.; Barinaga, Charles J.; Koppenaal, David W.

1998-01-01

A method for producing an ion beam having an increased proportion of analyte ions compared to carrier gas ions is disclosed. Specifically, the method has the step of addition of a charge transfer gas to the carrier analyte combination that accepts charge from the carrier gas ions yet minimally accepts charge from the analyte ions thereby selectively neutralizing the carrier gas ions. Also disclosed is the method as employed in various analytical instruments including an inductively coupled plasma mass spectrometer.

Method for reduction of selected ion intensities in confined ion beams

DOEpatents

Eiden, G.C.; Barinaga, C.J.; Koppenaal, D.W.

1998-06-16

A method for producing an ion beam having an increased proportion of analyte ions compared to carrier gas ions is disclosed. Specifically, the method has the step of addition of a charge transfer gas to the carrier analyte combination that accepts charge from the carrier gas ions yet minimally accepts charge from the analyte ions thereby selectively neutralizing the carrier gas ions. Also disclosed is the method as employed in various analytical instruments including an inductively coupled plasma mass spectrometer. 7 figs.

Atomic spectrometry and trends in clinical laboratory medicine

NASA Astrophysics Data System (ADS)

Parsons, Patrick J.; Barbosa, Fernando

2007-09-01

Increasing numbers of clinical laboratories are transitioning away from flame and electrothermal AAS methods to those based on ICP-MS. Still, for many laboratories, the choice of instrumentation is based upon (a) the element(s) to be determined, (b) the matrix/matrices to be analyzed, and (c) the expected concentration(s) of the analytes in the matrix. Most clinical laboratories specialize in measuring Se, Zn, Cu, and Al in serum, and/or Pb, Cd, Hg, As, and Cr in blood and/or urine, while other trace elements (e.g., Pt, Au etc.) are measured for therapeutic purposes. Quantitative measurement of elemental species is becoming more widely accepted for nutritional and/or toxicological screening purposes, and ICP-MS interfaced with separation techniques, such as liquid chromatography or capillary electrophoresis, offers the advantage of on-line species determination coupled with very low detection limits. Polyatomic interferences for some key elements such as Se, As, and Cr require instrumentation equipped with dynamic reaction cell or collision cell technologies, or might even necessitate the use of sector field ICP-MS, to assure accurate results. Nonetheless, whatever analytical method is selected for the task, careful consideration must be given both to specimen collection procedures and to the control of pre-analytical variables. Finally, all methods benefit from access to reliable certified reference materials (CRMs). While a variety of reference materials (RMs) are available for trace element measurements in clinical matrices, not all can be classified as CRMs. The major metrological organizations (e.g., NIST, IRMM, NIES) provide a limited number of clinical CRMs, however, secondary reference materials are readily available from commercial organizations and organizers of external quality assessment schemes.

40 CFR 92.102 - Definitions and abbreviations.

Code of Federal Regulations, 2011 CFR

2011-07-01

... engineering practice. Calibration means the act of calibrating an analytical instrument using known standards... be consistent with scientific and engineering principles. Hang-up refers to the process of... reaching the instrument detector. It also refers to any subsequent desorption of the molecules into the...

Introduction to Instrumental Analysis of Water Pollutants. Training Manual.

ERIC Educational Resources Information Center

Office of Water Program Operations (EPA), Cincinnati, OH. National Training and Operational Technology Center.

This course is designed for those requiring an introduction to instruments commonly used in water pollution analyses. Examples are: pH, conductivity, dissolved oxygen meters, spectrophotometers, turbidimeters, carbon analyzer, and gas chromatographs. Students should have a basic knowledge of analytical chemistry. (CO)

ANALYTICAL METHOD COMPARISONS BY ESTIMATES OF PRECISION AND LOWER DETECTION LIMIT

EPA Science Inventory

The paper describes the use of principal component analysis to estimate the operating precision of several different analytical instruments or methods simultaneously measuring a common sample of a material whose actual value is unknown. This approach is advantageous when none of ...

Comparison of soil pollution concentrations determined using AAS and portable XRF techniques.

PubMed

Radu, Tanja; Diamond, Dermot

2009-11-15

Past mining activities in the area of Silvermines, Ireland, have resulted in heavily polluted soils. The possibility of spreading pollution to the surrounding areas through dust blow-offs poses a potential threat for the local communities. Conventional environmental soil and dust analysis techniques are very slow and laborious and consequently there is a need for fast and accurate analytical methods, which can provide real-time in situ pollution mapping. Laboratory-based aqua regia acid digestion of the soil samples collected in the area followed by the atomic absorption spectrophotometry (AAS) analysis confirmed very high pollution, especially by Pb, As, Cu, and Zn. In parallel, samples were analyzed using portable X-ray fluorescence radioisotope and miniature tube powered (XRF) NITON instruments and their performance was compared. Overall, the portable XRF instrument gave excellent correlation with the laboratory-based reference AAS method.

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

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for fiscal year 1988 (October 1987 through September 1988). The Analytical Chemistry Laboratory is a full-cost recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routinemore » standard analyses to unique problems that require significant development of methods and techniques.« less

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

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1989 (October 1988 through September 1989). The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standardmore » analyses to unique problems that require significant development of methods and techniques.« less

Performance of the MOMA Gas Chromatograph-Mass Spectrometer onboard the 2018 ExoMars Mission

NASA Astrophysics Data System (ADS)

Buch, Arnaud; Pinnick, Veronica; Szopa, Cyril; Grand, Noël; Freissinet, Caroline; Danell, Ryan; van Ameron, Friso; Arevalo, Ricardo; Brinckerhoff, William; Raulin, François; Mahaffy, Paul; Goesmann, Fred

2015-04-01

The Mars Organic Molecule Analyzer (MOMA) is a dual ion source linear ion trap mass spectrometer that was designed for the 2018 joint ESA-Roscosmos mission to Mars. The main scientific aim of the mission is to search for signs of extant or extinct life in the near subsurface of Mars by acquir-ing samples from as deep as 2 m below the surface. MOMA will be a key analytical tool in providing chemical (molecular) information from the solid samples, with particular focus on the characterization of organic content. The MOMA instrument, itself, is a joint venture for NASA and ESA to develop a mass spectrometer capable of analyzing samples from pyrolysis gas chromatograph (GC) as well as ambient pressure laser desorption ionization (LDI). The combination of the two analytical techniques allows for the chemical characterization of a broad range of compounds, including volatile and non-volatile species. Generally, MOMA can provide in-formation on elemental and molecular makeup, po-larity, chirality and isotopic patterns of analyte spe-cies. Here we report on the current performance of the MOMA prototype instruments, specifically the demonstration of the gas chromatography-mass spec-trometry (GC-MS) mode of operation. Both instruments have been tested separately first and have been coupled in order to test the efficiency of the future MOMA GC-MS instrument. The main objective of the second step has been to test the quantitative response of both instruments while they are coupled and to characterize the combined instrument detection limit for several compounds. A final experiment has been done in order to test the feasibility of the separation and detection of a mixture contained in a soil sample introduced in the MOMA oven.

Laboratory Methods for the Measurement of Pollutants in Water and Waste Effluents

NASA Technical Reports Server (NTRS)

Ballinger, Dwight G.

1971-01-01

The requirement for accurate, precise, and rapid analytical procedures for the examination of water and waste samples requires the use of a variety of instruments. The instrumentation in water laboratories includes atomic absorption, UV-visible. and infrared spectrophotometers, automatic colorimetric analyzers, gas chromatographs and mass spectrometers. Because of the emphasis on regulatory action, attention is being directed toward quality control of analytical results. Among the challenging problems are the differentiation of metallic species in water at nanogram concentrations, rapid measurement of free cyanide and free ammonia, more sensitive methods for arsenic and selenium and improved characterization of organic contaminants.

Development of TPS flight test and operational instrumentation

NASA Technical Reports Server (NTRS)

Carnahan, K. R.; Hartman, G. J.; Neuner, G. J.

1975-01-01

Thermal and flow sensor instrumentation was developed for use as an integral part of the space shuttle orbiter reusable thermal protection system. The effort was performed in three tasks: a study to determine the optimum instruments and instrument installations for the space shuttle orbiter RSI and RCC TPS; tests and/or analysis to determine the instrument installations to minimize measurement errors; and analysis using data from the test program for comparison to analytical methods. A detailed review of existing state of the art instrumentation in industry was performed to determine the baseline for the departure of the research effort. From this information, detailed criteria for thermal protection system instrumentation were developed.

Integrated fiducial sample mount and software for correlated microscopy

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

Timothy R McJunkin; Jill R. Scott; Tammy L. Trowbridge

2014-02-01

A novel design sample mount with integrated fiducials and software for assisting operators in easily and efficiently locating points of interest established in previous analytical sessions is described. The sample holder and software were evaluated with experiments to demonstrate the utility and ease of finding the same points of interest in two different microscopy instruments. Also, numerical analysis of expected errors in determining the same position with errors unbiased by a human operator was performed. Based on the results, issues related to acquiring reproducibility and best practices for using the sample mount and software were identified. Overall, the sample mountmore » methodology allows data to be efficiently and easily collected on different instruments for the same sample location.« less

Strategies to avoid false negative findings in residue analysis using liquid chromatography coupled to time-of-flight mass spectrometry.

PubMed

Kaufmann, Anton; Butcher, Patrick

2006-01-01

Liquid chromatography coupled to orthogonal acceleration time-of-flight mass spectrometry (LC/TOF) provides an attractive alternative to liquid chromatography coupled to triple quadrupole mass spectrometry (LC/MS/MS) in the field of multiresidue analysis. The sensitivity and selectivity of LC/TOF approach those of LC/MS/MS. TOF provides accurate mass information and a significantly higher mass resolution than quadrupole analyzers. The available mass resolution of commercial TOF instruments ranging from 10 000 to 18 000 full width at half maximum (FWHM) is not, however, sufficient to completely exclude the problem of isobaric interferences (co-elution of analyte ions with matrix compounds of very similar mass). Due to the required data storage capacity, TOF raw data is commonly centroided before being electronically stored. However, centroiding can lead to a loss of data quality. The co-elution of a low intensity analyte peak with an isobaric, high intensity matrix compound can cause problems. Some centroiding algorithms might not be capable of deconvoluting such partially merged signals, leading to incorrect centroids.Co-elution of isobaric compounds has been deliberately simulated by injecting diluted binary mixtures of isobaric model substances at various relative intensities. Depending on the mass differences between the two isobaric compounds and the resolution provided by the TOF instrument, significant deviations in exact mass measurements and signal intensities were observed. The extraction of a reconstructed ion chromatogram based on very narrow mass windows can even result in the complete loss of the analyte signal. Guidelines have been proposed to avoid such problems. The use of sub-2 microm HPLC packing materials is recommended to improve chromatographic resolution and to reduce the risk of co-elution. The width of the extraction mass windows for reconstructed ion chromatograms should be defined according to the resolution of the TOF instrument. Alternative approaches include the spiking of the sample with appropriate analyte concentrations. Furthermore, enhanced software, capable of deconvoluting partially merged mass peaks, may become available. Copyright (c) 2006 John Wiley & Sons, Ltd.

Development and application of GC-MS method for monitoring of long-term exposure to the pesticide cypermethrin.

PubMed

Kavvalakis, Matthaios P; Tzatzarakis, Manolis N; Alegakis, Athanasios K; Vynias, Dionysios; Tsakalof, Andreas K; Tsatsakis, Aristidis M

2014-06-01

Cypermethrin (CPMN) is a synthetic pyrethroid used as an insecticide in large-scale commercial agricultural applications as well as for domestic purposes. In the present study a gas chromatography-mass spectrometry (GC-MS) based method was developed and validated for the quantitation of CPMN metabolites, 3-phenoxybenzoic acid (3-PBA) and cis- and trans- 3-(2,2-dichlorovinyl)-2,2-dimethyl-1-cyclopropane (cis- and trans- Cl2 CA). The developed method was applied for the monitoring of CPMN metabolites in hair of laboratory animals (rabbits) intentionally exposed per os to CPMN at 40 (low dose) and 80 (high dose) mg/kg weight/day for 16 weeks. The analytical method comprises three main steps: isolation of analytes from hair, analytes derivatization, and subsequent instrumental analysis by GC-MS. The limits of detection ensured by the method are 4.0, 3.9 and 1.0 pg/mg hair for cis-Cl2 CA, trans-Cl2 CA and 3-PBA, respectively. The instrument responce is linear (r(2)  > 0.99) in the investigated concentrations range from 25 to 1000 pg/mg. With and between-run precision as well as accuracy were estimated and found satisfactory. Analytes were efficiently isolated by solid-liquid extraction from hair with recoveries greater than 84.8% for cis-Cl2 CA, 87.2% for trans-Cl2 CA and 96.4% for 3-PBA. Rabbit's hair showed increasing levels for all metabolites (metabolites accumulation in a time and dose dependent manner) over time and in a dose-dependent manner. The developed experimental procedure could be used for biomonitoring of population exposure to CPMN. Copyright © 2014 John Wiley & Sons, Ltd.

The role of light microscopy in aerospace analytical laboratories

NASA Technical Reports Server (NTRS)

Crutcher, E. R.

1977-01-01

Light microscopy has greatly reduced analytical flow time and added new dimensions to laboratory capability. Aerospace analytical laboratories are often confronted with problems involving contamination, wear, or material inhomogeneity. The detection of potential problems and the solution of those that develop necessitate the most sensitive and selective applications of sophisticated analytical techniques and instrumentation. This inevitably involves light microscopy. The microscope can characterize and often identify the cause of a problem in 5-15 minutes with confirmatory tests generally less than one hour. Light microscopy has and will make a very significant contribution to the analytical capabilities of aerospace laboratories.

Instrumental Surveillance of Water Quality.

ERIC Educational Resources Information Center

Miller, J. A.; And Others

The role analytical instrumentation performs in the surveillance and control of the quality of water resources is reviewed. Commonly performed analyses may range from simple tests for physical parameters to more highly sophisticated radiological or spectrophotometric methods. This publication explores many of these types of water quality analyses…

The Microcomputer as an Educational Laboratory Workstation.

ERIC Educational Resources Information Center

Ciociolo, James M.

1983-01-01

Describes laboratory workstations which provide direct connection for monitoring and control of analytical instruments such as pH meters, spectrophotometers, temperature, and chromatographic instruments. This is accomplished through analog/digital and digital/analog converters for analog signals and input/output devices for on/off signals.…

Black Boxes in Analytical Chemistry: University Students' Misconceptions of Instrumental Analysis

ERIC Educational Resources Information Center

Carbo, Antonio Domenech; Adelantado, Jose Vicente Gimeno; Reig, Francisco Bosch

2010-01-01

Misconceptions of chemistry and chemical engineering university students concerning instrumental analysis have been established from coordinated tests, tutorial interviews and laboratory lessons. Misconceptions can be divided into: (1) formal, involving specific concepts and formulations within the general frame of chemistry; (2)…

Opening Remarks for "Analytical Chemistry, Monitoring, and Environmental Fate and Transport" Session at Fluoros 2015

EPA Science Inventory

There have been a number of revolutionary developments during the past decade that have led to a much more comprehensive understanding of per- and polyfluoroalkyl substances (PFASs) in the environment. Improvements in analytical instrumentation have made liquid chromatography tri...

Biochemical Applications in the Analytical Chemistry Lab

ERIC Educational Resources Information Center

Strong, Cynthia; Ruttencutter, Jeffrey

2004-01-01

An HPLC and a UV-visible spectrophotometer are identified as instruments that helps to incorporate more biologically-relevant experiments into the course, in order to increase the students understanding of selected biochemistry topics and enhances their ability to apply an analytical approach to biochemical problems. The experiment teaches…

Mars Geochemical Instrument (MarGI): An instrument for the analysis of the Martian surface and the search for evidence of life

NASA Technical Reports Server (NTRS)

Kojiro, Daniel R.; Mancinelli, Rocco; Martin, Joe; Holland, Paul M.; Stimac, Robert M.; Kaye, William J.

2005-01-01

The Mars Geochemical Instrument, MarGI, was developed to provide a comprehensive analysis of the rocks and surface material on Mars. The instrument combines Differential Thermal Analysis (DTA) with miniature Gas Chromatography-Ion Mobility Spectrometry (GC-IMS) to identify minerals, the presence and state of water, and organic compounds. Miniature pyrolysis ovens are used to both, conduct DTA analysis of soil or crushed rocks samples, and pyrolyze the samples at temperatures up to 1000 degrees C for GC-IMS analysis of the released gases. This combination of analytical processes and techniques, which can characterize the mineralogy of the rocks and soil, and identify and quantify volatiles released during pyrolysis, has applications across a wide range of target sites including comets, planets, asteroids, and moons such as Titan and Europa. The MarGI analytical approach evolved from the Cometary Ice and Dust Experiment (CIDEX) selected to fly on the Comet Rendezvous Asteroid Flyby Mission (CRAF).

Predicting Team Performance through Human Behavioral Sensing and Quantitative Workflow Instrumentation

DTIC Science & Technology

2016-07-27

make risk-informed decisions during serious games . Statistical models of intra- game performance were developed to determine whether behaviors in...specific facets of the gameplay workflow were predictive of analytical performance and games outcomes. A study of over seventy instrumented teams revealed...more accurate game decisions. 2 Keywords: Humatics · Serious Games · Human-System Interaction · Instrumentation · Teamwork · Communication Analysis

Liquid-to-gel transition for visual and tactile detection of biological analytes.

PubMed

Fedotova, Tatiana A; Kolpashchikov, Dmitry M

2017-11-23

So far all visual and instrument-free methods have been based on a color change. However, colorimetric assays cannot be used by blind or color-blind people. Here we introduce a liquid-to-gel transition as a general output platform. The signal output (a piece of gel) can be unambiguously distinguished from liquid both visually and by touch. This approach promises to contribute to the development of an accessible environment for visually impaired persons.

Ultrasensitive detection of target analyte-induced aggregation of gold nanoparticles using laser-induced nanoparticle Rayleigh scattering.

PubMed

Lin, Jia-Hui; Tseng, Wei-Lung

2015-01-01

Detection of salt- and analyte-induced aggregation of gold nanoparticles (AuNPs) mostly relies on costly and bulky analytical instruments. To response this drawback, a portable, miniaturized, sensitive, and cost-effective detection technique is urgently required for rapid field detection and monitoring of target analyte via the use of AuNP-based sensor. This study combined a miniaturized spectrometer with a 532-nm laser to develop a laser-induced Rayleigh scattering technique, allowing the sensitive and selective detection of Rayleigh scattering from the aggregated AuNPs. Three AuNP-based sensing systems, including salt-, thiol- and metal ion-induced aggregation of the AuNPs, were performed to examine the sensitivity of laser-induced Rayleigh scattering technique. Salt-, thiol-, and metal ion-promoted NP aggregation were exemplified by the use of aptamer-adsorbed, fluorosurfactant-stabilized, and gallic acid-capped AuNPs for probing K(+), S-adenosylhomocysteine hydrolase-induced hydrolysis of S-adenosylhomocysteine, and Pb(2+), in sequence. Compared to the reported methods for monitoring the aggregated AuNPs, the proposed system provided distinct advantages of sensitivity. Laser-induced Rayleigh scattering technique was improved to be convenient, cheap, and portable by replacing a diode laser and a miniaturized spectrometer with a laser pointer and a smart-phone. Using this smart-phone-based detection platform, we can determine whether or not the Pb(2+) concentration exceed the maximum allowable level of Pb(2+) in drinking water. Copyright © 2014 Elsevier B.V. All rights reserved.

Self-Sealing Wet Chemistry Cell for Field Analysis

NASA Technical Reports Server (NTRS)

Beegle, Luther W.; Soto, Juancarlos; Lasnik, James; Roark, Shane

2012-01-01

In most analytical investigations, there is a need to process complex field samples for the unique detection of analytes, especially when detecting low concentration organic molecules that may identify extraterrestrial life. Wet chemistry based instruments are the techniques of choice for most laboratory- based analysis of organic molecules due to several factors including less fragmentation of fragile biomarkers, and ability to concentrate target species resulting in much lower limits of detection. Development of an automated wet chemistry preparation system that can operate autonomously on Earth and is also designed to operate under Martian ambient conditions will demonstrate the technical feasibility of including wet chemistry on future missions. An Automated Sample Processing System (ASPS) has recently been developed that receives fines, extracts organics through solvent extraction, processes the extract by removing non-organic soluble species, and delivers sample to multiple instruments for analysis (including for non-organic soluble species). The key to this system is a sample cell that can autonomously function under field conditions. As a result, a self-sealing sample cell was developed that can autonomously hermetically seal fines and powder into a container, regardless of orientation of the apparatus. The cap is designed with a beveled edge, which allows the cap to be self-righted as the capping motor engages. Each cap consists of a C-clip lock ring below a crucible O-ring that is placed into a groove cut into the sample cap.

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

Green, D.W.; Heinrich, R.R.; Jensen, K.J.

Technical and administrative activities of the Analytical Chemistry Laboratory (ACL) are reported for fiscal year 1984. The ACL is a full-cost-recovery service center, with the primary mission of providing a broad range of technical support services to the scientific and engineering programs at ANL. In addition, ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL is administratively within the Chemical Technology Division, the principal user, but provides technical support for all of the technical divisions and programs at ANL. The ACL has threemore » technical groups - Chemical Analysis, Instrumental Analysis, and Organic Analysis. Under technical activities 26 projects are briefly described. Under professional activities, a list is presented for publications and reports, oral presentations, awards and meetings attended. 6 figs., 2 tabs.« less

Electrochemical Microsensors for the Detection of Cadmium(II) and Lead(II) Ions in Plants

PubMed Central

Krystofova, Olga; Trnkova, Libuse; Adam, Vojtech; Zehnalek, Josef; Hubalek, Jaromir; Babula, Petr; Kizek, Rene

2010-01-01

Routine determination of trace metals in complex media is still a difficult task for many analytical instruments. The aim of this work was to compare three electro-chemical instruments [a standard potentiostat (Autolab), a commercially available miniaturized potentiostat (PalmSens) and a homemade micropotentiostat] for easy-to-use and sensitive determination of cadmium(II) and lead(II) ions. The lowest detection limits (hundreds of pM) for both metals was achieved by using of the standard potentiostat, followed by the miniaturized potentiostat (tens of nM) and the homemade instrument (hundreds of nM). Nevertheless, all potentiostats were sensitive enough to evaluate contamination of the environment, because the environmental limits for both metals are higher than detection limits of the instruments. Further, we tested all used potentiostats and working electrodes on analysis of environmental samples (rainwater, flour and plant extract) with artificially added cadmium(II) and lead(II). Based on the similar results obtained for all potentiostats we choose a homemade instrument with a carbon tip working electrode for our subsequent environmental experiments, in which we analyzed maize and sunflower seedlings and rainwater obtained from various sites in the Czech Republic. PMID:22219663

The Pavlovian analysis of instrumental conditioning.

PubMed

Gormezano, I; Tait, R W

1976-01-01

An account was given of the development within the Russian literature of a uniprocess formulation of classical and instrumental conditioning, known as the bidirectional conditioning hypothesis. The hypothesis purports to offer a single set of Pavlovian principles to account for both paradigms, based upon a neural model which assumes that bidirectional (forward and backward) connections are formed in both calssical and instrumental conditioning situations. In instrumental conditioning, the bidirectional connections are hypothesized to be simply more complex than those in classical conditioning, and any differences in empirical functions are presumed to lie not in difference in mechanism, but in the strength of the forward and backward connections. Although bidirectional connections are assumed to develop in instrumental conditioning, the experimental investigation of the bidirectional conditioning hypothesis has been essentially restricted to the classical conditioning operations of pairing two CSs (sensory preconditioning training), a US followed by a CS (backward conditioning training) and two USs. However, the paradigm involving the pairing of two USs, because of theoretical and analytical considerations, is the one most commonly employed by Russian investigators. The results of an initial experiment involving the pairing of two USs, and reference to the results of a more extensive investigation, leads us to tentatively question the validity of the bidirectional conditioning account of instrumental conditioning.

The Analog Revolution and Its On-Going Role in Modern Analytical Measurements.

PubMed

Enke, Christie G

2015-12-15

The electronic revolution in analytical instrumentation began when we first exceeded the two-digit resolution of panel meters and chart recorders and then took the first steps into automated control. It started with the first uses of operational amplifiers (op amps) in the analog domain 20 years before the digital computer entered the analytical lab. Their application greatly increased both accuracy and precision in chemical measurement and they provided an elegant means for the electronic control of experimental quantities. Later, laboratory and personal computers provided an unlimited readout resolution and enabled programmable control of instrument parameters as well as storage and computation of acquired data. However, digital computers did not replace the op amp's critical role of converting the analog sensor's output to a robust and accurate voltage. Rather it added a new role: converting that voltage into a number. These analog operations are generally the limiting portions of our computerized instrumentation systems. Operational amplifier performance in gain, input current and resistance, offset voltage, and rise time have improved by a remarkable 3-4 orders of magnitude since their first implementations. Each 10-fold improvement has opened the doors for the development of new techniques in all areas of chemical analysis. Along with some interesting history, the multiple roles op amps play in modern instrumentation are described along with a number of examples of new areas of analysis that have been enabled by their improvements.

Keeping It Simple: Can We Estimate Malting Quality Potential Using an Isothermal Mashing Protocol and Common Laboratory Instrumentation?

USDA-ARS?s Scientific Manuscript database

Current methods for generating malting quality metrics have been developed largely to support commercial malting and brewing operations, providing accurate, reproducible analytical data to guide malting and brewing production. Infrastructure to support these analytical operations often involves sub...

Combining data visualization and statistical approaches for interpreting measurements and meta-data: Integrating heatmaps, variable clustering, and mixed regression models

EPA Science Inventory

The advent of new higher throughput analytical instrumentation has put a strain on interpreting and explaining the results from complex studies. Contemporary human, environmental, and biomonitoring data sets are comprised of tens or hundreds of analytes, multiple repeat measures...

Social Learning Analytics: Navigating the Changing Settings of Higher Education

ERIC Educational Resources Information Center

de Laat, Maarten; Prinsen, Fleur R.

2014-01-01

Current trends and challenges in higher education (HE) require a reorientation towards openness, technology use and active student participation. In this article we will introduce Social Learning Analytics (SLA) as instrumental in formative assessment practices, aimed at supporting and strengthening students as active learners in increasingly open…

Instrumentation: Photodiode Array Detectors in UV-VIS Spectroscopy. Part II.

ERIC Educational Resources Information Center

Jones, Dianna G.

1985-01-01

A previous part (Analytical Chemistry; v57 n9 p1057A) discussed the theoretical aspects of diode ultraviolet-visual (UV-VIS) spectroscopy. This part describes the applications of diode arrays in analytical chemistry, also considering spectroelectrochemistry, high performance liquid chromatography (HPLC), HPLC data processing, stopped flow, and…

Automated Flow-Injection Instrument for Chemiluminescence Detection Using a Low-Cost Photodiode Detector

ERIC Educational Resources Information Center

Economou, A.; Papargyris, D.; Stratis, J.

2004-01-01

The development of an FI analyzer for chemiluminescence detection using a low-cost photoiodide is presented. The experiment clearly demonstrates in a single interdisciplinary project the way in which different aspects in chemical instrumentation fit together to produce a working analytical system.

Selecting Suicide Ideation Assessment Instruments: A Meta-Analytic Review

ERIC Educational Resources Information Center

Erford, Bradley T.; Jackson, Jessica; Bardhoshi, Gerta; Duncan, Kelly; Atalay, Zumra

2018-01-01

Psychometric meta-analyses and reviews were provided for four commonly used suicidal ideation instruments: the Beck Scale for Suicide Ideation, the Suicide Ideation Questionnaire, the Suicide Probability Scale, and Columbia--Suicide Severity Rating Scale. Practical and technical issues and best use recommendations for screening and outcome…

Report on Cosmic Dust Capture Research and Development for the Exobiology Program

NASA Technical Reports Server (NTRS)

Nishioka, Kenji

1997-01-01

Collaboration with Ames' personnel was in: 1) grant administration, 2) intellectual science support, 3) collaboration with the University of Paris for the Mir flight experiment, and 4) arranging scanning and X-ray probe analytical support from UCB and SUNYP. LNIMS provided access to: 1) analytical research instruments, 2) chemical analyses support, 3) cleanroom facilities, and 4) design and fabrication expertise of hardware and electronics. They also supported the hypervelocity testing along with test data acquisition and its reduction for the breadboard instrument. A&M Associates provided technical expertise and support on determining the expected charges on orbital particles and a conceptual design for a breadboard particle charge detection sensor. University of California provided analytical support for the recovered Mir flight modules using their unique scanning capability to detect particle tracks in the aerogel. SUNYP, along with help from the University of Chicago, analyzed particle tracks found in the aerogel for biogenic compounds using an x-ray probe instrument. Dr. Schultz provided access to his experiments and the benefits of his considerable hyper-velocity testing expertise at the Ames hypervelocity gun facility, and this proved beneficial to our development testing, significantly reducing the test time and cost for the breadboard instrument development testing. The participants in this activity acknowledge and thank the National Aeronautics and Space Administration and its Ames Research Center for providing the necessary support and resources to conduct this investigation on instrument technology for exobiology application and being able to acquire some interesting results. Primarily, the newly identified technology problems for future research are the important results of this research.

Point-of-care urine albumin in general practice offices: effect of participation in an external quality assurance scheme.

PubMed

Bukve, Tone; Røraas, Thomas; Riksheim, Berit Oddny; Christensen, Nina Gade; Sandberg, Sverre

2015-01-01

The Norwegian Quality Improvement of Primary Care Laboratories (Noklus) offers external quality assurance (EQA) schemes (EQASs) for urine albumin (UA) annually. This study analyzed the EQA results to determine how the analytical quality of UA analysis in general practice (GP) offices developed between 1998 (n=473) and 2012 (n=1160). Two EQA urine samples were distributed yearly to the participants by mail. The participants measured the UA of each sample and returned the results together with information about their instrument, the profession and number of employees at the office, frequency of internal quality control (IQC), and number of analyses per month. In the feedback report, they received an assessment of their analytical performance. The number of years that the GP office had participated in Noklus was inversely related to the percentage of "poor" results for quantitative but not semiquantitative instruments. The analytical quality improved for participants using quantitative instruments who received an initial assessment of "poor" and who subsequently changed their instrument. Participants using reagents that had expired or were within 3 months of the expiration date performed worse than those using reagents that were expiring in more than 3 months. Continuous participation in the Noklus program improved the performance of quantitative UA analyses at GP offices. This is probably in part attributable to the complete Noklus quality system, whereby in addition to participating in EQAS, participants are visited by laboratory consultants who examine their procedures and provide practical advice and education regarding the use of different instruments.

A multilaboratory comparison of calibration accuracy and the performance of external references in analytical ultracentrifugation.

PubMed

Zhao, Huaying; Ghirlando, Rodolfo; Alfonso, Carlos; Arisaka, Fumio; Attali, Ilan; Bain, David L; Bakhtina, Marina M; Becker, Donald F; Bedwell, Gregory J; Bekdemir, Ahmet; Besong, Tabot M D; Birck, Catherine; Brautigam, Chad A; Brennerman, William; Byron, Olwyn; Bzowska, Agnieszka; Chaires, Jonathan B; Chaton, Catherine T; Cölfen, Helmut; Connaghan, Keith D; Crowley, Kimberly A; Curth, Ute; Daviter, Tina; Dean, William L; Díez, Ana I; Ebel, Christine; Eckert, Debra M; Eisele, Leslie E; Eisenstein, Edward; England, Patrick; Escalante, Carlos; Fagan, Jeffrey A; Fairman, Robert; Finn, Ron M; Fischle, Wolfgang; de la Torre, José García; Gor, Jayesh; Gustafsson, Henning; Hall, Damien; Harding, Stephen E; Cifre, José G Hernández; Herr, Andrew B; Howell, Elizabeth E; Isaac, Richard S; Jao, Shu-Chuan; Jose, Davis; Kim, Soon-Jong; Kokona, Bashkim; Kornblatt, Jack A; Kosek, Dalibor; Krayukhina, Elena; Krzizike, Daniel; Kusznir, Eric A; Kwon, Hyewon; Larson, Adam; Laue, Thomas M; Le Roy, Aline; Leech, Andrew P; Lilie, Hauke; Luger, Karolin; Luque-Ortega, Juan R; Ma, Jia; May, Carrie A; Maynard, Ernest L; Modrak-Wojcik, Anna; Mok, Yee-Foong; Mücke, Norbert; Nagel-Steger, Luitgard; Narlikar, Geeta J; Noda, Masanori; Nourse, Amanda; Obsil, Tomas; Park, Chad K; Park, Jin-Ku; Pawelek, Peter D; Perdue, Erby E; Perkins, Stephen J; Perugini, Matthew A; Peterson, Craig L; Peverelli, Martin G; Piszczek, Grzegorz; Prag, Gali; Prevelige, Peter E; Raynal, Bertrand D E; Rezabkova, Lenka; Richter, Klaus; Ringel, Alison E; Rosenberg, Rose; Rowe, Arthur J; Rufer, Arne C; Scott, David J; Seravalli, Javier G; Solovyova, Alexandra S; Song, Renjie; Staunton, David; Stoddard, Caitlin; Stott, Katherine; Strauss, Holger M; Streicher, Werner W; Sumida, John P; Swygert, Sarah G; Szczepanowski, Roman H; Tessmer, Ingrid; Toth, Ronald T; Tripathy, Ashutosh; Uchiyama, Susumu; Uebel, Stephan F W; Unzai, Satoru; Gruber, Anna Vitlin; von Hippel, Peter H; Wandrey, Christine; Wang, Szu-Huan; Weitzel, Steven E; Wielgus-Kutrowska, Beata; Wolberger, Cynthia; Wolff, Martin; Wright, Edward; Wu, Yu-Sung; Wubben, Jacinta M; Schuck, Peter

2015-01-01

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies.

A Multilaboratory Comparison of Calibration Accuracy and the Performance of External References in Analytical Ultracentrifugation

PubMed Central

Zhao, Huaying; Ghirlando, Rodolfo; Alfonso, Carlos; Arisaka, Fumio; Attali, Ilan; Bain, David L.; Bakhtina, Marina M.; Becker, Donald F.; Bedwell, Gregory J.; Bekdemir, Ahmet; Besong, Tabot M. D.; Birck, Catherine; Brautigam, Chad A.; Brennerman, William; Byron, Olwyn; Bzowska, Agnieszka; Chaires, Jonathan B.; Chaton, Catherine T.; Cölfen, Helmut; Connaghan, Keith D.; Crowley, Kimberly A.; Curth, Ute; Daviter, Tina; Dean, William L.; Díez, Ana I.; Ebel, Christine; Eckert, Debra M.; Eisele, Leslie E.; Eisenstein, Edward; England, Patrick; Escalante, Carlos; Fagan, Jeffrey A.; Fairman, Robert; Finn, Ron M.; Fischle, Wolfgang; de la Torre, José García; Gor, Jayesh; Gustafsson, Henning; Hall, Damien; Harding, Stephen E.; Cifre, José G. Hernández; Herr, Andrew B.; Howell, Elizabeth E.; Isaac, Richard S.; Jao, Shu-Chuan; Jose, Davis; Kim, Soon-Jong; Kokona, Bashkim; Kornblatt, Jack A.; Kosek, Dalibor; Krayukhina, Elena; Krzizike, Daniel; Kusznir, Eric A.; Kwon, Hyewon; Larson, Adam; Laue, Thomas M.; Le Roy, Aline; Leech, Andrew P.; Lilie, Hauke; Luger, Karolin; Luque-Ortega, Juan R.; Ma, Jia; May, Carrie A.; Maynard, Ernest L.; Modrak-Wojcik, Anna; Mok, Yee-Foong; Mücke, Norbert; Nagel-Steger, Luitgard; Narlikar, Geeta J.; Noda, Masanori; Nourse, Amanda; Obsil, Tomas; Park, Chad K.; Park, Jin-Ku; Pawelek, Peter D.; Perdue, Erby E.; Perkins, Stephen J.; Perugini, Matthew A.; Peterson, Craig L.; Peverelli, Martin G.; Piszczek, Grzegorz; Prag, Gali; Prevelige, Peter E.; Raynal, Bertrand D. E.; Rezabkova, Lenka; Richter, Klaus; Ringel, Alison E.; Rosenberg, Rose; Rowe, Arthur J.; Rufer, Arne C.; Scott, David J.; Seravalli, Javier G.; Solovyova, Alexandra S.; Song, Renjie; Staunton, David; Stoddard, Caitlin; Stott, Katherine; Strauss, Holger M.; Streicher, Werner W.; Sumida, John P.; Swygert, Sarah G.; Szczepanowski, Roman H.; Tessmer, Ingrid; Toth, Ronald T.; Tripathy, Ashutosh; Uchiyama, Susumu; Uebel, Stephan F. W.; Unzai, Satoru; Gruber, Anna Vitlin; von Hippel, Peter H.; Wandrey, Christine; Wang, Szu-Huan; Weitzel, Steven E.; Wielgus-Kutrowska, Beata; Wolberger, Cynthia; Wolff, Martin; Wright, Edward; Wu, Yu-Sung; Wubben, Jacinta M.; Schuck, Peter

2015-01-01

Analytical ultracentrifugation (AUC) is a first principles based method to determine absolute sedimentation coefficients and buoyant molar masses of macromolecules and their complexes, reporting on their size and shape in free solution. The purpose of this multi-laboratory study was to establish the precision and accuracy of basic data dimensions in AUC and validate previously proposed calibration techniques. Three kits of AUC cell assemblies containing radial and temperature calibration tools and a bovine serum albumin (BSA) reference sample were shared among 67 laboratories, generating 129 comprehensive data sets. These allowed for an assessment of many parameters of instrument performance, including accuracy of the reported scan time after the start of centrifugation, the accuracy of the temperature calibration, and the accuracy of the radial magnification. The range of sedimentation coefficients obtained for BSA monomer in different instruments and using different optical systems was from 3.655 S to 4.949 S, with a mean and standard deviation of (4.304 ± 0.188) S (4.4%). After the combined application of correction factors derived from the external calibration references for elapsed time, scan velocity, temperature, and radial magnification, the range of s-values was reduced 7-fold with a mean of 4.325 S and a 6-fold reduced standard deviation of ± 0.030 S (0.7%). In addition, the large data set provided an opportunity to determine the instrument-to-instrument variation of the absolute radial positions reported in the scan files, the precision of photometric or refractometric signal magnitudes, and the precision of the calculated apparent molar mass of BSA monomer and the fraction of BSA dimers. These results highlight the necessity and effectiveness of independent calibration of basic AUC data dimensions for reliable quantitative studies. PMID:25997164

High throughput liquid absorption preconcentrator sampling instrument

DOEpatents

Zaromb, Solomon; Bozen, Ralph M.

1992-01-01

A system for detecting trace concentrations of an analyte in air includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container comprising a wettable material. The wettable material is continuously wetted with an analyte-sorbing liquid which flows from one part of the container to a lower end. Sampled air flows through the container in contact with the wetted material with a swirling motion which results in efficient transfer of analyte vapors or aerosol particles to the sorbing liquid and preconcentration of traces of analyte in the liquid. The preconcentrated traces of analyte may be either detected within the container or removed therefrom for injection into a separate detection means or for subsequent analysis.

High throughput liquid absorption preconcentrator sampling instrument

DOEpatents

Zaromb, S.; Bozen, R.M.

1992-12-22

A system for detecting trace concentrations of an analyte in air includes a preconcentrator for the analyte and an analyte detector. The preconcentrator includes an elongated tubular container comprising a wettable material. The wettable material is continuously wetted with an analyte-sorbing liquid which flows from one part of the container to a lower end. Sampled air flows through the container in contact with the wetted material with a swirling motion which results in efficient transfer of analyte vapors or aerosol particles to the sorbing liquid and preconcentration of traces of analyte in the liquid. The preconcentrated traces of analyte may be either detected within the container or removed therefrom for injection into a separate detection means or for subsequent analysis. 12 figs.

'Aussie normals': an a priori study to develop clinical chemistry reference intervals in a healthy Australian population.

PubMed

Koerbin, G; Cavanaugh, J A; Potter, J M; Abhayaratna, W P; West, N P; Glasgow, N; Hawkins, C; Armbruster, D; Oakman, C; Hickman, P E

2015-02-01

Development of reference intervals is difficult, time consuming, expensive and beyond the scope of most laboratories. The Aussie Normals study is a direct a priori study to determine reference intervals in healthy Australian adults. All volunteers completed a health and lifestyle questionnaire and exclusion was based on conditions such as pregnancy, diabetes, renal or cardiovascular disease. Up to 91 biochemical analyses were undertaken on a variety of analytical platforms using serum samples collected from 1856 volunteers. We report on our findings for 40 of these analytes and two calculated parameters performed on the Abbott ARCHITECTci8200/ci16200 analysers. Not all samples were analysed for all assays due to volume requirements or assay/instrument availability. Results with elevated interference indices and those deemed unsuitable after clinical evaluation were removed from the database. Reference intervals were partitioned based on the method of Harris and Boyd into three scenarios, combined gender, males and females and age and gender. We have performed a detailed reference interval study on a healthy Australian population considering the effects of sex, age and body mass. These reference intervals may be adapted to other manufacturer's analytical methods using method transference.

Analytical performance of the various acquisition modes in Orbitrap MS and MS/MS.

PubMed

Kaufmann, Anton

2018-04-30

Quadrupole Orbitrap instruments (Q Orbitrap) permit high-resolution mass spectrometry (HRMS)-based full scan acquisitions and have a number of acquisition modes where the quadrupole isolates a particular mass range prior to a possible fragmentation and HRMS-based acquisition. Selecting the proper acquisition mode(s) is essential if trace analytes are to be quantified in complex matrix extracts. Depending on the particular requirements, such as sensitivity, selectivity of detection, linear dynamic range, and speed of analysis, different acquisition modes may have to be chosen. This is particularly important in the field of multi-residue analysis (e.g., pesticides or veterinary drugs in food samples) where a large number of analytes within a complex matrix have to be detected and reliably quantified. Meeting the specific detection and quantification performance criteria for every targeted compound may be challenging. It is the aim of this paper to describe the strengths and the limitations of the currently available Q Orbitrap acquisition modes. In addition, the incorporation of targeted acquisitions between full scan experiments is discussed. This approach is intended to integrate compounds that require an additional degree of sensitivity or selectivity into multi-residue methods. This article is protected by copyright. All rights reserved.

Diode laser-based cavity ring-down instrument for NO3, N2O5, NO, NO2 and O3 from aircraft

NASA Astrophysics Data System (ADS)

Wagner, N. L.; Dubé, W. P.; Washenfelder, R. A.; Young, C. J.; Pollack, I. B.; Ryerson, T. B.; Brown, S. S.

2011-03-01

This article presents a diode laser based, cavity ring-down spectrometer for simultaneous in situ measurements of four nitrogen oxide species, NO3, N2O5, NO, NO2, as well as O3, designed for deployment on aircraft. The instrument measures NO3 and NO2 by optical extinction at 662 nm and 405 nm, respectively; N2O5 is measured by thermal conversion to NO3, while NO and O3 are measured by chemical conversion to NO2. The instrument has several advantages over previous instruments developed by our group for measurement of NO2, NO3 and N2O5 alone, based on a pulsed Nd:YAG and dye laser. First, the use of continuous wave diode lasers reduces the requirements for power and weight and eliminates hazardous materials. Second, detection of NO2 at 405 nm is more sensitive than our previously reported 532 nm instrument, and does not have a measurable interference from O3. Third, the instrument includes chemical conversion of NO and O3 to NO2 to provide measurements of total NOx (= NO + NO2) and Ox (= NO2 + O3) on two separate channels; mixing ratios of NO and O3 are determined by subtraction of NO2. Finally, all five species are calibrated against a single standard based on 254 nm O3 absorption to provide high accuracy. Disadvantages include an increased sensitivity to water vapor on the 662 nm NO3 and N2O5 channels and a modest reduction in sensitivity for these species compared to the pulsed laser instrument. The measurement precision for both NO3 and N2O5 is below 1 pptv (2σ, 1 s) and for NO, NO2 and O3 is 170, 46, and 56 pptv (2σ, 1 s) respectively. The NO and NO2 measurements are less precise than research-grade chemiluminescence instruments. However, the combination of these five species in a single instrument, calibrated to a single analytical standard, provides a complete and accurate picture of nighttime nitrogen oxide chemistry. The instrument performance is demonstrated using data acquired during a recent field campaign in California.

Advances in the analysis of biological samples using ionic liquids.

PubMed

Clark, Kevin D; Trujillo-Rodríguez, María J; Anderson, Jared L

2018-02-12

Ionic liquids are a class of solvents and materials that hold great promise in bioanalytical chemistry. Task-specific ionic liquids have recently been designed for the selective extraction, separation, and detection of proteins, peptides, nucleic acids, and other physiologically relevant analytes from complex biological samples. To facilitate rapid bioanalysis, ionic liquids have been integrated in miniaturized and automated procedures. Bioanalytical separations have also benefited from the modification of nonspecific magnetic materials with ionic liquids or the implementation of ionic liquids with inherent magnetic properties. Furthermore, the direct detection of the extracted molecules in the analytical instrument has been demonstrated with structurally tuned ionic liquids and magnetic ionic liquids, providing a significant advantage in the analysis of low-abundance analytes. This article gives an overview of these advances that involve the application of ionic liquids and derivatives in bioanalysis. Graphical abstract Ionic liquids, magnetic ionic liquids, and ionic liquid-based sorbents are increasing the speed, selectivity, and sensitivity in the analysis of biological samples.

Analytical surveillance of emerging drugs of abuse and drug formulations

PubMed Central

Thomas, Brian F.; Pollard, Gerald T.; Grabenauer, Megan

2012-01-01

Uncontrolled recreational drugs are proliferating in number and variety. Effects of long-term use are unknown, and regulation is problematic, as efforts to control one chemical often lead to several other structural analogs. Advanced analytical instrumentation and methods are continuing to be developed to identify drugs, chemical constituents of products, and drug substances and metabolites in biological fluids. Several mass spectrometry based approaches appear promising, particularly those that involve high resolution chromatographic and mass spectrometric methods that allow unbiased data acquisition and sophisticated data interrogation. Several of these techniques are shown to facilitate both targeted and broad spectrum analysis, which is often of particular benefit when dealing with misleadingly labeled products or assessing a biological matrix for illicit drugs and metabolites. The development and application of novel analytical approaches such as these will help to assess the nature and degree of exposure and risk and, where necessary, inform forensics and facilitate implementation of specific regulation and control measures. PMID:23154240

[Developments in preparation and experimental method of solid phase microextraction fibers].

PubMed

Yi, Xu; Fu, Yujie

2004-09-01

Solid phase microextraction (SPME) is a simple and effective adsorption and desorption technique, which concentrates volatile or nonvolatile compounds from liquid samples or headspace of samples. SPME is compatible with analyte separation and detection by gas chromatography, high performance liquid chromatography, and other instrumental methods. It can provide many advantages, such as wide linear scale, low solvent and sample consumption, short analytical times, low detection limits, simple apparatus, and so on. The theory of SPME is introduced, which includes equilibrium theory and non-equilibrium theory. The novel development of fiber preparation methods and relative experimental techniques are discussed. In addition to commercial fiber preparation, different newly developed fabrication techniques, such as sol-gel, electronic deposition, carbon-base adsorption, high-temperature epoxy immobilization, are presented. Effects of extraction modes, selection of fiber coating, optimization of operating conditions, method sensitivity and precision, and systematical automation, are taken into considerations in the analytical process of SPME. A simple perspective of SPME is proposed at last.

Solvent microextraction-flame atomic absorption spectrometry (SME-FAAS) for determination of ultratrace amounts of cadmium in meat and fish samples.

PubMed

Goudarzi, Nasser

2009-02-11

A simple, low cost and highly sensitive method based on solvent microextraction (SME) for separation/preconcentration and flame atomic absorption spectrometry (FAAS) was proposed for the determination of ultratrace amounts of cadmium in meat and fish samples. The analytical procedure involved the formation of a hydrophobic complex by mixing the analyte solution with an ammonium pyrrolidinedithiocarbamate (APDC) solution. In suitable conditions, the complex of cadmium-APDC entered the micro organic phase, and thus, separation of the analyte from the matrix was achieved. Under optimal chemical and instrumental conditions, a detection limit (3 sigma) of 0.8 ng L(-1) and an enrichment factor of 93 were achieved. The relative standard deviation for the method was found to be 2.2% for Cd. The interference effects of some anions and cations were also investigated. The developed method has been applied to the determination of trace Cd in meat and fish samples.

Annual banned-substance review: analytical approaches in human sports drug testing.

PubMed

Thevis, Mario; Kuuranne, Tiia; Geyer, Hans; Schänzer, Wilhelm

2015-01-01

Within the mosaic display of international anti-doping efforts, analytical strategies based on up-to-date instrumentation as well as most recent information about physiology, pharmacology, metabolism, etc., of prohibited substances and methods of doping are indispensable. The continuous emergence of new chemical entities and the identification of arguably beneficial effects of established or even obsolete drugs on endurance, strength, and regeneration, necessitate frequent and adequate adaptations of sports drug testing procedures. These largely rely on exploiting new technologies, extending the substance coverage of existing test protocols, and generating new insights into metabolism, distribution, and elimination of compounds prohibited by the World Anti-Doping Agency (WADA). In reference of the content of the 2014 Prohibited List, literature concerning human sports drug testing that was published between October 2013 and September 2014 is summarized and reviewed in this annual banned-substance review, with particular emphasis on analytical approaches and their contribution to enhanced doping controls. Copyright © 2014 John Wiley & Sons, Ltd.

A microfluidic device integrating dual CMOS polysilicon nanowire sensors for on-chip whole blood processing and simultaneous detection of multiple analytes.

PubMed

Kuan, Da-Han; Wang, I-Shun; Lin, Jiun-Rue; Yang, Chao-Han; Huang, Chi-Hsien; Lin, Yen-Hung; Lin, Chih-Ting; Huang, Nien-Tsu

2016-08-02

The hemoglobin-A1c test, measuring the ratio of glycated hemoglobin (HbA1c) to hemoglobin (Hb) levels, has been a standard assay in diabetes diagnosis that removes the day-to-day glucose level variation. Currently, the HbA1c test is restricted to hospitals and central laboratories due to the laborious, time-consuming whole blood processing and bulky instruments. In this paper, we have developed a microfluidic device integrating dual CMOS polysilicon nanowire sensors (MINS) for on-chip whole blood processing and simultaneous detection of multiple analytes. The micromachined polymethylmethacrylate (PMMA) microfluidic device consisted of a serpentine microchannel with multiple dam structures designed for non-lysed cells or debris trapping, uniform plasma/buffer mixing and dilution. The CMOS-fabricated polysilicon nanowire sensors integrated with the microfluidic device were designed for the simultaneous, label-free electrical detection of multiple analytes. Our study first measured the Hb and HbA1c levels in 11 clinical samples via these nanowire sensors. The results were compared with those of standard Hb and HbA1c measurement methods (Hb: the sodium lauryl sulfate hemoglobin detection method; HbA1c: cation-exchange high-performance liquid chromatography) and showed comparable outcomes. Finally, we successfully demonstrated the efficacy of the MINS device's on-chip whole blood processing followed by simultaneous Hb and HbA1c measurement in a clinical sample. Compared to current Hb and HbA1c sensing instruments, the MINS platform is compact and can simultaneously detect two analytes with only 5 μL of whole blood, which corresponds to a 300-fold blood volume reduction. The total assay time, including the in situ sample processing and analyte detection, was just 30 minutes. Based on its on-chip whole blood processing and simultaneous multiple analyte detection functionalities with a lower sample volume requirement and shorter process time, the MINS device can be effectively applied to real-time diabetes diagnostics and monitoring in point-of-care settings.

Analytical characterization of a new mobile X-ray fluorescence and X-ray diffraction instrument combined with a pigment identification case study

NASA Astrophysics Data System (ADS)

Van de Voorde, Lien; Vekemans, Bart; Verhaeven, Eddy; Tack, Pieter; De Wolf, Robin; Garrevoet, Jan; Vandenabeele, Peter; Vincze, Laszlo

2015-08-01

A new, commercially available, mobile system combining X-ray diffraction and X-ray fluorescence has been evaluated which enables both elemental analysis and phase identification simultaneously. The instrument makes use of a copper or molybdenum based miniature X-ray tube and a silicon-Pin diode energy-dispersive detector to count the photons originating from the samples. The X-ray tube and detector are both mounted on an X-ray diffraction protractor in a Bragg-Brentano θ:θ geometry. The mobile instrument is one of the lightest and most compact instruments of its kind (3.5 kg) and it is thus very useful for in situ purposes such as the direct (non-destructive) analysis of cultural heritage objects which need to be analyzed on site without any displacement. The supplied software allows both the operation of the instrument for data collection and in-depth data analysis using the International Centre for Diffraction Data database. This paper focuses on the characterization of the instrument, combined with a case study on pigment identification and an illustrative example for the analysis of lead alloyed printing letters. The results show that this commercially available light-weight instrument is able to identify the main crystalline phases non-destructively, present in a variety of samples, with a high degree of flexibility regarding sample size and position.

Construction of a Chemical Sensor/Instrumentation Package Using Fiber Optic and Miniaturization Technology

NASA Technical Reports Server (NTRS)

Newton, R. L.

1999-01-01

The objective of this research was to construct a chemical sensor/instrumentation package that was smaller in weight and volume than conventional instrumentation. This reduction in weight and volume is needed to assist in further reducing the cost of launching payloads into space. To accomplish this, fiber optic sensors, miniaturized spectrometers, and wireless modems were employed. The system was evaluated using iodine as a calibration analyte.

Modeling surface topography of state-of-the-art x-ray mirrors as a result of stochastic polishing process: recent developments

NASA Astrophysics Data System (ADS)

Yashchuk, Valeriy V.; Centers, Gary; Tyurin, Yuri N.; Tyurina, Anastasia

2016-09-01

Recently, an original method for the statistical modeling of surface topography of state-of-the-art mirrors for usage in xray optical systems at light source facilities and for astronomical telescopes [Opt. Eng. 51(4), 046501, 2012; ibid. 53(8), 084102 (2014); and ibid. 55(7), 074106 (2016)] has been developed. In modeling, the mirror surface topography is considered to be a result of a stationary uniform stochastic polishing process and the best fit time-invariant linear filter (TILF) that optimally parameterizes, with limited number of parameters, the polishing process is determined. The TILF model allows the surface slope profile of an optic with a newly desired specification to be reliably forecast before fabrication. With the forecast data, representative numerical evaluations of expected performance of the prospective mirrors in optical systems under development become possible [Opt. Eng., 54(2), 025108 (2015)]. Here, we suggest and demonstrate an analytical approach for accounting the imperfections of the used metrology instruments, which are described by the instrumental point spread function, in the TILF modeling. The efficacy of the approach is demonstrated with numerical simulations for correction of measurements performed with an autocollimator based surface slope profiler. Besides solving this major metrological problem, the results of the present work open an avenue for developing analytical and computational tools for stitching data in the statistical domain, obtained using multiple metrology instruments measuring significantly different bandwidths of spatial wavelengths.

Analytical improvements of hybrid LC-MS/MS techniques for the efficient evaluation of emerging contaminants in river waters: a case study of the Henares River (Madrid, Spain).

PubMed

Pérez-Parada, Andrés; Gómez-Ramos, María del Mar; Martínez Bueno, María Jesús; Uclés, Samanta; Uclés, Ana; Fernández-Alba, Amadeo R

2012-02-01

Instrumental capabilities and software tools of modern hybrid mass spectrometry (MS) instruments such as high-resolution mass spectrometry (HRMS), quadrupole time-of-flight (QTOF), and quadrupole linear ion trap (QLIT) were experimentally investigated for the study of emerging contaminants in Henares River water samples. Automated screening and confirmatory capabilities of QTOF working in full-scan MS and tandem MS (MS/MS) were explored when dealing with real samples. Investigations on the effect of sensitivity and resolution power influence on mass accuracy were studied for the correct assignment of the amoxicillin transformation product 5(R) amoxicillin-diketopiperazine-2',5' as an example of a nontarget compound. On the other hand, a comparison of quantitative and qualitative strategies based on direct injection analysis and off-line solid-phase extraction sample treatment were assayed using two different QLIT instruments for a selected group of emerging contaminants when operating in selected reaction monitoring (SRM) and information-dependent acquisition (IDA) modes. Software-aided screening usually needs a further confirmatory step. Resolving power and MS/MS feature of QTOF showed to confirm/reject most findings in river water, although sensitivity-related limitations are usually found. Superior sensitivity of modern QLIT-MS/MS offered the possibility of direct injection analysis for proper quantitative study of a variety of contaminants, while it simultaneously reduced the matrix effect and increased the reliability of the results. Confirmation of ethylamphetamine, which lacks on a second SRM transition, was accomplished by using the IDA feature. Hybrid MS instruments equipped with high resolution and high sensitivity contributes to enlarge the scope of targeted analytes in river waters. However, in the tested instruments, there is a margin of improvement principally in required sensitivity and data treatment software tools devoted to reliable confirmation and improved automated data processing.

Analytical approaches for the characterization and quantification of nanoparticles in food and beverages.

PubMed

Mattarozzi, Monica; Suman, Michele; Cascio, Claudia; Calestani, Davide; Weigel, Stefan; Undas, Anna; Peters, Ruud

2017-01-01

Estimating consumer exposure to nanomaterials (NMs) in food products and predicting their toxicological properties are necessary steps in the assessment of the risks of this technology. To this end, analytical methods have to be available to detect, characterize and quantify NMs in food and materials related to food, e.g. food packaging and biological samples following metabolization of food. The challenge for the analytical sciences is that the characterization of NMs requires chemical as well as physical information. This article offers a comprehensive analysis of methods available for the detection and characterization of NMs in food and related products. Special attention was paid to the crucial role of sample preparation methods since these have been partially neglected in the scientific literature so far. The currently available instrumental methods are grouped as fractionation, counting and ensemble methods, and their advantages and limitations are discussed. We conclude that much progress has been made over the last 5 years but that many challenges still exist. Future perspectives and priority research needs are pointed out. Graphical Abstract Two possible analytical strategies for the sizing and quantification of Nanoparticles: Asymmetric Flow Field-Flow Fractionation with multiple detectors (allows the determination of true size and mass-based particle size distribution); Single Particle Inductively Coupled Plasma Mass Spectrometry (allows the determination of a spherical equivalent diameter of the particle and a number-based particle size distribution).

INVESTIGATION OF RESPONSE DIFFERENCES BETWEEN DIFFERENT TYPES OF TOTAL ORGANIC CARBON (TOC) ANALYTICAL INSTRUMENT SYSTEMS

EPA Science Inventory

Total organic carbon (TOC) and dissolved organic carbon (DOC) have long been used to estimate the amount of natural organic matter (NOM) found in raw and finished drinking water. In recent years, computer automation and improved instrumental analysis technologies have created a ...

Existential Measurement: A Factor Analytic Study of Some Current Psychometric Instruments.

ERIC Educational Resources Information Center

Thauberger, Patrick C.; And Others

1982-01-01

Research in existentialism and ontology has given rise to several psychometric instruments. Used both exploratory and confirmatory principal-factor analyses to study relationships among 16 existential scales. Exploratory factor analysis provided some support of the theory that the avoidance of existential confrontation is a central function of…

THE COST-EFFECTIVENESS OF ALTERNATIVE INSTRUMENTS FOR ENVIRONMENTAL PROTECTION IN A SECOND-BEST SETTING. (R825313)

EPA Science Inventory

Abstract

This paper employs analytical and numerical general equilibrium models to examine the significance of pre-existing factor taxes for the costs of pollution reduction under a wide range of environmental policy instruments. Pre-existing taxes imply significantly ...

Life cycle management of analytical methods.

PubMed

Parr, Maria Kristina; Schmidt, Alexander H

2018-01-05

In modern process management, the life cycle concept gains more and more importance. It focusses on the total costs of the process from invest to operation and finally retirement. Also for analytical procedures an increasing interest for this concept exists in the recent years. The life cycle of an analytical method consists of design, development, validation (including instrumental qualification, continuous method performance verification and method transfer) and finally retirement of the method. It appears, that also regulatory bodies have increased their awareness on life cycle management for analytical methods. Thus, the International Council for Harmonisation of Technical Requirements for Pharmaceuticals for Human Use (ICH), as well as the United States Pharmacopeial Forum discuss the enrollment of new guidelines that include life cycle management of analytical methods. The US Pharmacopeia (USP) Validation and Verification expert panel already proposed a new General Chapter 〈1220〉 "The Analytical Procedure Lifecycle" for integration into USP. Furthermore, also in the non-regulated environment a growing interest on life cycle management is seen. Quality-by-design based method development results in increased method robustness. Thereby a decreased effort is needed for method performance verification, and post-approval changes as well as minimized risk of method related out-of-specification results. This strongly contributes to reduced costs of the method during its life cycle. Copyright © 2017 Elsevier B.V. All rights reserved.

Simultaneous analysis of multiple classes of antimicrobials in environmental water samples using SPE coupled with UHPLC-ESI-MS/MS and isotope dilution.

PubMed

Tran, Ngoc Han; Chen, Hongjie; Do, Thanh Van; Reinhard, Martin; Ngo, Huu Hao; He, Yiliang; Gin, Karina Yew-Hoong

2016-10-01

A robust and sensitive analytical method was developed for the simultaneous analysis of 21 target antimicrobials in different environmental water samples. Both single SPE and tandem SPE cartridge systems were investigated to simultaneously extract multiple classes of antimicrobials. Experimental results showed that good extraction efficiencies (84.5-105.6%) were observed for the vast majority of the target analytes when extraction was performed using the tandem SPE cartridge (SB+HR-X) system under an extraction pH of 3.0. HPLC-MS/MS parameters were optimized for simultaneous analysis of all the target analytes in a single injection. Quantification of target antimicrobials in water samples was accomplished using 15 isotopically labeled internal standards (ILISs), which allowed the efficient compensation of the losses of target analytes during sample preparation and correction of matrix effects during UHPLC-MS/MS as well as instrument fluctuations in MS/MS signal intensity. Method quantification limit (MQL) for most target analytes based on SPE was below 5ng/L for surface waters, 10ng/L for treated wastewater effluents, and 15ng/L for raw wastewater. The method was successfully applied to detect and quantify the occurrence of the target analytes in raw influent, treated effluent and surface water samples. Copyright © 2016 Elsevier B.V. All rights reserved.

QCloud: A cloud-based quality control system for mass spectrometry-based proteomics laboratories

PubMed Central

Chiva, Cristina; Olivella, Roger; Borràs, Eva; Espadas, Guadalupe; Pastor, Olga; Solé, Amanda

2018-01-01

The increasing number of biomedical and translational applications in mass spectrometry-based proteomics poses new analytical challenges and raises the need for automated quality control systems. Despite previous efforts to set standard file formats, data processing workflows and key evaluation parameters for quality control, automated quality control systems are not yet widespread among proteomics laboratories, which limits the acquisition of high-quality results, inter-laboratory comparisons and the assessment of variability of instrumental platforms. Here we present QCloud, a cloud-based system to support proteomics laboratories in daily quality assessment using a user-friendly interface, easy setup, automated data processing and archiving, and unbiased instrument evaluation. QCloud supports the most common targeted and untargeted proteomics workflows, it accepts data formats from different vendors and it enables the annotation of acquired data and reporting incidences. A complete version of the QCloud system has successfully been developed and it is now open to the proteomics community (http://qcloud.crg.eu). QCloud system is an open source project, publicly available under a Creative Commons License Attribution-ShareAlike 4.0. PMID:29324744

VALIDATION OF ANALYTICAL METHODS AND INSTRUMENTATION FOR BERYLLIUM MEASUREMENT: REVIEW AND SUMMARY OF AVAILABLE GUIDES, PROCEDURES, AND PROTOCOLS

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

Ekechukwu, A.

This document proposes to provide a listing of available sources which can be used to validate analytical methods and/or instrumentation for beryllium determination. A literature review was conducted of available standard methods and publications used for method validation and/or quality control. A comprehensive listing of the articles, papers, and books reviewed is given in Appendix 1. Available validation documents and guides are listed in the appendix; each has a brief description of application and use. In the referenced sources, there are varying approaches to validation and varying descriptions of validation at different stages in method development. This discussion focuses onmore » validation and verification of fully developed methods and instrumentation that have been offered up for use or approval by other laboratories or official consensus bodies such as ASTM International, the International Standards Organization (ISO) and the Association of Official Analytical Chemists (AOAC). This review was conducted as part of a collaborative effort to investigate and improve the state of validation for measuring beryllium in the workplace and the environment. Documents and publications from the United States and Europe are included. Unless otherwise specified, all documents were published in English.« less

Insights into the varnishes of historical musical instruments using synchrotron micro-analytical methods

NASA Astrophysics Data System (ADS)

Echard, J.-P.; Cotte, M.; Dooryhee, E.; Bertrand, L.

2008-07-01

Though ancient violins and other stringed instruments are often revered for the beauty of their varnishes, the varnishing techniques are not much known. In particular, very few detailed varnish analyses have been published so far. Since 2002, a research program at the Musée de la musique (Paris) is dedicated to a detailed description of varnishes on famous ancient musical instruments using a series of novel analytical methods. For the first time, results are presented on the study of the varnish from a late 16th century Venetian lute, using synchrotron micro-analytical methods. Identification of both organic and inorganic compounds distributed within the individual layers of a varnish microsample has been performed using spatially resolved synchrotron Fourier transform infrared microscopy. The univocal identification of the mineral phases is obtained through synchrotron powder X-ray diffraction. The materials identified may be of utmost importance to understand the varnishing process and its similarities with some painting techniques. In particular, the proteinaceous binding medium and the calcium sulfate components (bassanite and anhydrite) that have been identified in the lower layers of the varnish microsample could be related, to a certain extent, to the ground materials of earlier Italian paintings.

The impact of modelling errors on interferometer calibration for 21 cm power spectra

NASA Astrophysics Data System (ADS)

Ewall-Wice, Aaron; Dillon, Joshua S.; Liu, Adrian; Hewitt, Jacqueline

2017-09-01

We study the impact of sky-based calibration errors from source mismodelling on 21 cm power spectrum measurements with an interferometer and propose a method for suppressing their effects. While emission from faint sources that are not accounted for in calibration catalogues is believed to be spectrally smooth, deviations of true visibilities from model visibilities are not, due to the inherent chromaticity of the interferometer's sky response (the 'wedge'). Thus, unmodelled foregrounds, below the confusion limit of many instruments, introduce frequency structure into gain solutions on the same line-of-sight scales on which we hope to observe the cosmological signal. We derive analytic expressions describing these errors using linearized approximations of the calibration equations and estimate the impact of this bias on measurements of the 21 cm power spectrum during the epoch of reionization. Given our current precision in primary beam and foreground modelling, this noise will significantly impact the sensitivity of existing experiments that rely on sky-based calibration. Our formalism describes the scaling of calibration with array and sky-model parameters and can be used to guide future instrument design and calibration strategy. We find that sky-based calibration that downweights long baselines can eliminate contamination in most of the region outside of the wedge with only a modest increase in instrumental noise.

The parameterization of microchannel-plate-based detection systems

NASA Astrophysics Data System (ADS)

Gershman, Daniel J.; Gliese, Ulrik; Dorelli, John C.; Avanov, Levon A.; Barrie, Alexander C.; Chornay, Dennis J.; MacDonald, Elizabeth A.; Holland, Matthew P.; Giles, Barbara L.; Pollock, Craig J.

2016-10-01

The most common instrument for low-energy plasmas consists of a top-hat electrostatic analyzer (ESA) geometry coupled with a microchannel-plate-based (MCP-based) detection system. While the electrostatic optics for such sensors are readily simulated and parameterized during the laboratory calibration process, the detection system is often less well characterized. Here we develop a comprehensive mathematical description of particle detection systems. As a function of instrument azimuthal angle, we parameterize (1) particle scattering within the ESA and at the surface of the MCP, (2) the probability distribution of MCP gain for an incident particle, (3) electron charge cloud spreading between the MCP and anode board, and (4) capacitive coupling between adjacent discrete anodes. Using the Dual Electron Spectrometers on the Fast Plasma Investigation on NASA's Magnetospheric Multiscale mission as an example, we demonstrate a method for extracting these fundamental detection system parameters from laboratory calibration. We further show that parameters that will evolve in flight, namely, MCP gain, can be determined through application of this model to specifically tailored in-flight calibration activities. This methodology provides a robust characterization of sensor suite performance throughout mission lifetime. The model developed in this work is not only applicable to existing sensors but also can be used as an analytical design tool for future particle instrumentation.

Gain Switching for a Detection System to Accommodate a Newly Developed MALDI-Based Quantification Method

NASA Astrophysics Data System (ADS)

Ahn, Sung Hee; Hyeon, Taeghwan; Kim, Myung Soo; Moon, Jeong Hee

2017-09-01

In matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF), matrix-derived ions are routinely deflected away to avoid problems with ion detection. This, however, limits the use of a quantification method that utilizes the analyte-to-matrix ion abundance ratio. In this work, we will show that it is possible to measure this ratio by a minor instrumental modification of a simple form of MALDI-TOF. This involves detector gain switching. [Figure not available: see fulltext.

Status and Needs Research for On-line Monitoring of VOCs Emissions from Stationary Sources

NASA Astrophysics Data System (ADS)

Zhou, Gang; Wang, Qiang; Zhong, Qi; Zhao, Jinbao; Yang, Kai

2018-01-01

Based on atmospheric volatile organic compounds (VOCs) pollution control requirements during the twelfth-five year plan and the current status of monitoring and management at home and abroad, instrumental architecture and technical characteristics of continuous emission monitoring systems (CEMS) for VOCs emission from stationary sources are investigated and researched. Technological development needs of VOCs emission on-line monitoring techniques for stationary sources in china are proposed from the system sampling pretreatment technology and analytical measurement techniques.

Detecting Learning Strategies with Analytics: Links with Self-Reported Measures and Academic Performance

ERIC Educational Resources Information Center

Gaševic, Dragan; Jovanovic, Jelena; Pardo, Abelardo; Dawson, Shane

2017-01-01

The use of analytic methods for extracting learning strategies from trace data has attracted considerable attention in the literature. However, there is a paucity of research examining any association between learning strategies extracted from trace data and responses to well-established self-report instruments and performance scores. This paper…

Instrumental Analysis of Biodiesel Content in Commercial Diesel Blends: An Experiment for Undergraduate Analytical Chemistry

ERIC Educational Resources Information Center

Feng, Z. Vivian; Buchman, Joseph T.

2012-01-01

The potential of replacing petroleum fuels with renewable biofuels has drawn significant public interest. Many states have imposed biodiesel mandates or incentives to use commercial biodiesel blends. We present an inquiry-driven experiment where students are given the tasks to gather samples, develop analytical methods using various instrumental…

40 CFR Appendix B to Part 136 - Definition and Procedure for the Determination of the Method Detection Limit-Revision 1.11

Code of Federal Regulations, 2012 CFR

2012-07-01

... ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES... to a wide variety of sample types ranging from reagent (blank) water containing analyte to wastewater... times the standard deviation of replicate instrumental measurements of the analyte in reagent water. (c...

A paralleled readout system for an electrical DNA-hybridization assay based on a microstructured electrode array

NASA Astrophysics Data System (ADS)

Urban, Matthias; Möller, Robert; Fritzsche, Wolfgang

2003-02-01

DNA analytics is a growing field based on the increasing knowledge about the genome with special implications for the understanding of molecular bases for diseases. Driven by the need for cost-effective and high-throughput methods for molecular detection, DNA chips are an interesting alternative to more traditional analytical methods in this field. The standard readout principle for DNA chips is fluorescence based. Fluorescence is highly sensitive and broadly established, but shows limitations regarding quantification (due to signal and/or dye instability) and the need for sophisticated (and therefore high-cost) equipment. This article introduces a readout system for an alternative detection scheme based on electrical detection of nanoparticle-labeled DNA. If labeled DNA is present in the analyte solution, it will bind on complementary capture DNA immobilized in a microelectrode gap. A subsequent metal enhancement step leads to a deposition of conductive material on the nanoparticles, and finally an electrical contact between the electrodes. This detection scheme offers the potential for a simple (low-cost as well as robust) and highly miniaturizable method, which could be well-suited for point-of-care applications in the context of lab-on-a-chip technologies. The demonstrated apparatus allows a parallel readout of an entire array of microstructured measurement sites. The readout is combined with data-processing by an embedded personal computer, resulting in an autonomous instrument that measures and presents the results. The design and realization of such a system is described, and first measurements are presented.

An expert system/ion trap mass spectrometry approach for life support systems monitoring

NASA Technical Reports Server (NTRS)

Palmer, Peter T.; Wong, Carla M.; Yost, Richard A.; Johnson, Jodie V.; Yates, Nathan A.; Story, Michael

1992-01-01

Efforts to develop sensor and control system technology to monitor air quality for life support have resulted in the development and preliminary testing of a concept based on expert systems and ion trap mass spectrometry (ITMS). An ITMS instrument provides the capability to identify and quantitate a large number of suspected contaminants at trace levels through the use of a variety of multidimensional experiments. An expert system provides specialized knowledge for control, analysis, and decision making. The system is intended for real-time, on-line, autonomous monitoring of air quality. The key characteristics of the system, performance data and analytical capabilities of the ITMS instrument, the design and operation of the expert system, and results from preliminary testing of the system for trace contaminant monitoring are described.

Turbine blade and vane heat flux sensor development, phase 2

NASA Technical Reports Server (NTRS)

Atkinson, W. H.; Cyr, M. A.; Strange, R. R.

1985-01-01

The development of heat flux sensors for gas turbine blades and vanes and the demonstration of heat transfer measurement methods are reported. The performance of the heat flux sensors was evaluated in a cylinder in cross flow experiment and compared with two other heat flux measurement methods, the slug calorimeter and a dynamic method based on fluctuating gas and surface temperature. Two cylinders, each instrumented with an embedded thermocouple sensor, a Gardon gauge, and a slug calorimeter, were fabricated. Each sensor type was calibrated using a quartz lamp bank facility. The instrumented cylinders were then tested in an atmospheric pressure combustor rig at conditions up to gas stream temperatures of 1700K and velocities to Mach 0.74. The test data are compared to other measurements and analytical prediction.

A new spectrometer concept for Mars exploration

NASA Astrophysics Data System (ADS)

Rull, F.; Sansano, A.; Díaz, E.; Colombo, M.; Belenguer, T.; Fernández, M.; Guembe, V.; Canchal, R.; Dávila, B.; Sánchez, A.; Laguna, H.; Ramos, G.; González, C.; Fraga, D.; Gallego, P.; Hutchinson, I.; Ingley, R.; Sánchez, J.; Canora, C. P.; Moral, A. G.; Ibarmia, S.; Prieto, J. A. R.; Manfredi, J. A. R.; Cabo, P.; Díaz, C.; Jiménez, A.; Pla, J.; Margoillés, R.

2011-10-01

The Raman Laser Spectrometer instrument is included in ExoMars program Pasteur payload and it is focused on the Mars samples analytical analysis of the geochemistry content and elemental composition of the observed crushed samples obtained by the Rover. One of the most critical Units of the RLS is the Spectrometer unit (SPU) that performs Raman spectroscopy technique and operates in a very demanding environment (operative temperature: from -40 ºC to 6 ºC) with very restrictive design constraints. It is a very small optical instrument capable to cope with 0.09 nm/pixel of resolution. The selected solution is based on a single transmisive holographic grating. At this stage of the project SPU Team is preparing the Conceptual Design Review that will take place at the end of October 2011.

The modern rotor aerodynamic limits survey: A report and data survey

NASA Technical Reports Server (NTRS)

Cross, J.; Brilla, J.; Kufeld, R.; Balough, D.

1993-01-01

The first phase of the Modern Technology Rotor Program, the Modern Rotor Aerodynamic Limits Survey, was a flight test conducted by the United States Army Aviation Engineering Flight Activity for NASA Ames Research Center. The test was performed using a United States Army UH-60A Black Hawk aircraft and the United States Air Force HH-60A Night Hawk instrumented main-rotor blade. The primary purpose of this test was to gather high-speed, steady-state, and maneuvering data suitable for correlation purposes with analytical prediction tools. All aspects of the data base, flight-test instrumentation, and test procedures are presented and analyzed. Because of the high volume of data, only select data points are presented. However, access to the entire data set is available upon request.

Novel immunoassay formats for integrated microfluidic circuits: diffusion immunoassays (DIA)

NASA Astrophysics Data System (ADS)

Weigl, Bernhard H.; Hatch, Anson; Kamholz, Andrew E.; Yager, Paul

2000-03-01

Novel designs of integrated fluidic microchips allow separations, chemical reactions, and calibration-free analytical measurements to be performed directly in very small quantities of complex samples such as whole blood and contaminated environmental samples. This technology lends itself to applications such as clinical diagnostics, including tumor marker screening, and environmental sensing in remote locations. Lab-on-a-Chip based systems offer many *advantages over traditional analytical devices: They consume extremely low volumes of both samples and reagents. Each chip is inexpensive and small. The sampling-to-result time is extremely short. They perform all analytical functions, including sampling, sample pretreatment, separation, dilution, and mixing steps, chemical reactions, and detection in an integrated microfluidic circuit. Lab-on-a-Chip systems enable the design of small, portable, rugged, low-cost, easy to use, yet extremely versatile and capable diagnostic instruments. In addition, fluids flowing in microchannels exhibit unique characteristics ('microfluidics'), which allow the design of analytical devices and assay formats that would not function on a macroscale. Existing Lab-on-a-chip technologies work very well for highly predictable and homogeneous samples common in genetic testing and drug discovery processes. One of the biggest challenges for current Labs-on-a-chip, however, is to perform analysis in the presence of the complexity and heterogeneity of actual samples such as whole blood or contaminated environmental samples. Micronics has developed a variety of Lab-on-a-Chip assays that can overcome those shortcomings. We will now present various types of novel Lab- on-a-Chip-based immunoassays, including the so-called Diffusion Immunoassays (DIA) that are based on the competitive laminar diffusion of analyte molecules and tracer molecules into a region of the chip containing antibodies that target the analyte molecules. Advantages of this technique are a reduction in reagents, higher sensitivity, minimal preparation of complex samples such as blood, real-time calibration, and extremely rapid analysis.

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

Not Available

This purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1990. The ACL has four technical groups -- Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis. The Chemical Analysis Group uses wet-chemical and instrumental methods for elemental, compositional, and isotopic analyses of solid, liquid, and gaseous samples and provides specialized analytical services. The Instrumental Analysis Group uses nuclear counting techniques in radiochemical analyses over a wide range of sample types from low-level environmental samples to samples of high radioactivity. The Organic Analysis Group uses amore » number of complementary techniques to separate and to quantitatively and qualitatively analyze complex organic mixtures and compounds at the trace level, including synthetic fuels, toxic substances, fossil-fuel residues and emissions, pollutants, biologically active compounds, pesticides, and drugs. The Environmental Analysis Group performs analyses of inorganic environmental and hazardous waste and coal samples.« less

Clinically relevant advances in on-chip affinity-based electrophoresis and electrochromatography.

PubMed

Hou, Chenlu; Herr, Amy E

2008-08-01

Clinical and point-of-care disease diagnostics promise to play an important role in personalized medicine, new approaches to global health, and health monitoring. Emerging instrument platforms based on lab-on-a-chip technology can confer performance advantages successfully exploited in electrophoresis and electrochromatography to affinity-based electrokinetic separations. This review surveys lab-on-a-chip diagnostic developments in affinity-based electrokinetic separations for quantitation of proteins, integration of preparatory functions needed for subsequent analysis of diverse biological samples, and initial forays into multiplexed analyses. The technologies detailed here underpin new clinical and point-of-care diagnostic strategies. The techniques and devices promise to advance translation of until now laboratory-based sample preparation and analytical assays to near-patient settings.

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.

Considerations in detecting CDC select agents under field conditions

NASA Astrophysics Data System (ADS)

Spinelli, Charles; Soelberg, Scott; Swanson, Nathaneal; Furlong, Clement; Baker, Paul

2008-04-01

Surface Plasmon Resonance (SPR) has become a widely accepted technique for real-time detection of interactions between receptor molecules and ligands. Antibody may serve as receptor and can be attached to the gold surface of the SPR device, while candidate analyte fluids contact the detecting antibody. Minute, but detectable, changes in refractive indices (RI) indicate that analyte has bound to the antibody. A decade ago, an inexpensive, robust, miniature and fully integrated SPR chip, called SPREETA, was developed. University of Washington (UW) researchers subsequently developed a portable, temperature-regulated instrument, called SPIRIT, to simultaneously use eight of these three-channel SPREETA chips. A SPIRIT prototype instrument was tested in the field, coupled to a remote reporting system on a surrogate unmanned aerial vehicle (UAV). Two target protein analytes were released sequentially as aerosols with low analyte concentration during each of three flights and were successfully detected and verified. Laboratory experimentation with a more advanced SPIRIT instrument demonstrated detection of very low levels of several select biological agents that might be employed by bioterrorists. Agent detection under field-like conditions is more challenging, especially as analyte concentrations are reduced and complex matricies are introduced. Two different sample preconditioning protocols have been developed for select agents in complex matrices. Use of these preconditioning techniques has allowed laboratory detection in spiked heavy mud of Francisella tularensis at 10 3 CFU/ml, Bacillus anthracis spores at 10 3 CFU/ml, Staphylococcal enterotoxin B (SEB) at 1 ng/ml, and Vaccinia virus (a smallpox simulant) at 10 5 PFU/ml. Ongoing experiments are aimed at simultaneous detection of multiple agents in spiked heavy mud, using a multiplex preconditioning protocol.

Improving the efficiency of quantitative (1)H NMR: an innovative external standard-internal reference approach.

PubMed

Huang, Yande; Su, Bao-Ning; Ye, Qingmei; Palaniswamy, Venkatapuram A; Bolgar, Mark S; Raglione, Thomas V

2014-01-01

The classical internal standard quantitative NMR (qNMR) method determines the purity of an analyte by the determination of a solution containing the analyte and a standard. Therefore, the standard must meet the requirements of chemical compatibility and lack of resonance interference with the analyte as well as a known purity. The identification of such a standard can be time consuming and must be repeated for each analyte. In contrast, the external standard qNMR method utilizes a standard with a known purity to calibrate the NMR instrument. The external standard and the analyte are measured separately, thereby eliminating the matter of chemical compatibility and resonance interference between the standard and the analyte. However, the instrumental factors, including the quality of NMR tubes, must be kept the same. Any deviations will compromise the accuracy of the results. An innovative qNMR method reported herein utilizes an internal reference substance along with an external standard to assume the role of the standard used in the traditional internal standard qNMR method. In this new method, the internal reference substance must only be chemically compatible and be free of resonance-interference with the analyte or external standard whereas the external standard must only be of a known purity. The exact purity or concentration of the internal reference substance is not required as long as the same quantity is added to the external standard and the analyte. The new method reduces the burden of searching for an appropriate standard for each analyte significantly. Therefore the efficiency of the qNMR purity assay increases while the precision of the internal standard method is retained. Copyright © 2013 Elsevier B.V. All rights reserved.

Paper-based microfluidic devices on the crime scene: A simple tool for rapid estimation of post-mortem interval using vitreous humour.

PubMed

Garcia, Paulo T; Gabriel, Ellen F M; Pessôa, Gustavo S; Santos Júnior, Júlio C; Mollo Filho, Pedro C; Guidugli, Ruggero B F; Höehr, Nelci F; Arruda, Marco A Z; Coltro, Wendell K T

2017-06-29

This paper describes for the first time the use of paper-based analytical devices at crime scenes to estimate the post-mortem interval (PMI), based on the colorimetric determination of Fe 2+ in vitreous humour (VH) samples. Experimental parameters such as the paper substrate, the microzone diameter, the sample volume and the 1,10-phenanthroline (o-phen) concentration were optimised in order to ensure the best analytical performance. Grade 1 CHR paper, microzone with diameter of 5 mm, a sample volume of 4 μL and an o-phen concentration of 0.05 mol/L were chosen as the optimum experimental conditions. A good linear response was observed for a concentration range of Fe 2+ between 2 and 10 mg/L and the calculated values for the limit of detection (LOD) and limit of quantification (LOQ) were 0.3 and 0.9 mg/L, respectively. The specificity of the Fe 2+ colorimetric response was tested in the presence of the main interfering agents and no significant differences were found. After selecting the ideal experimental conditions, four HV samples were investigated on paper-based devices. The concentration levels of Fe 2+ achieved for samples #1, #2, #3 and #4 were 0.5 ± 0.1, 0.7 ± 0.1, 1.2 ± 0.1 and 15.1 ± 0.1 mg/L, respectively. These values are in good agreement with those calculated by ICP-MS. It important to note that the concentration levels measured using both techniques are proportional to the PMI. The limitation of the proposed analytical device is that it is restricted to a PMI greater than 1 day. The capability of providing an immediate answer about the PMI on the crime scene without any sophisticated instrumentation is a great achievement in modern instrumentation for forensic chemistry. The strategy proposed in this study could be helpful in many criminal investigations. Copyright © 2017 Elsevier B.V. All rights reserved.

Computer-Based Readability Testing of Information Booklets for German Cancer Patients.

PubMed

Keinki, Christian; Zowalla, Richard; Pobiruchin, Monika; Huebner, Jutta; Wiesner, Martin

2018-04-12

Understandable health information is essential for treatment adherence and improved health outcomes. For readability testing, several instruments analyze the complexity of sentence structures, e.g., Flesch-Reading Ease (FRE) or Vienna-Formula (WSTF). Moreover, the vocabulary is of high relevance for readers. The aim of this study is to investigate the agreement of sentence structure and vocabulary-based (SVM) instruments. A total of 52 freely available German patient information booklets on cancer were collected from the Internet. The mean understandability level L was computed for 51 booklets. The resulting values of FRE, WSTF, and SVM were assessed pairwise for agreement with Bland-Altman plots and two-sided, paired t tests. For the pairwise comparison, the mean L values are L FRE  = 6.81, L WSTF  = 7.39, L SVM  = 5.09. The sentence structure-based metrics gave significantly different scores (P < 0.001) for all assessed booklets, confirmed by the Bland-Altman analysis. The study findings suggest that vocabulary-based instruments cannot be interchanged with FRE/WSTF. However, both analytical aspects should be considered and checked by authors to linguistically refine texts with respect to the individual target group. Authors of health information can be supported by automated readability analysis. Health professionals can benefit by direct booklet comparisons allowing for time-effective selection of suitable booklets for patients.

Separation of musical instruments based on amplitude and frequency comodulation

NASA Astrophysics Data System (ADS)

Jacobson, Barry D.; Cauwenberghs, Gert; Quatieri, Thomas F.

2002-05-01

In previous work, amplitude comodulation was investigated as a basis for monaural source separation. Amplitude comodulation refers to similarities in amplitude envelopes of individual spectral components emitted by particular types of sources. In many types of musical instruments, amplitudes of all resonant modes rise/fall, and start/stop together during the course of normal playing. We found that under certain well-defined conditions, a mixture of constant frequency, amplitude comodulated sources can unambiguously be decomposed into its constituents on the basis of these similarities. In this work, system performance was improved by relaxing the constant frequency requirement. String instruments, for example, which are normally played with vibrato, are both amplitude and frequency comodulated sources, and could not be properly tracked under the constant frequency assumption upon which our original algorithm was based. Frequency comodulation refers to similarities in frequency variations of individual harmonics emitted by these types of sources. The analytical difficulty is in defining a representation of the source which properly tracks frequency varying components. A simple, fixed filter bank can only track an individual spectral component for the duration in which it is within the passband of one of the filters. Alternatives are therefore explored which are amenable to real-time implementation.

PTSD-8: A Short PTSD Inventory

PubMed Central

Hansen, Maj; Andersen, Tonny Elmose; Armour, Cherie; Elklit, Ask; Palic, Sabina; Mackrill, Thomas

2010-01-01

Traumatic events pose great challenges on mental health services in scarcity of specialist trauma clinicians and services. Simple short screening instruments for detecting adverse psychological responses are needed. Several brief screening instruments have been developed. However, some are limited, especially in relation to reflecting the posttraumatic stress disorder (PTSD) diagnosis. Recently, several studies have challenged pre-existing ideas about PTSD’s latent structure. Factor analytic research currently supports two four factor models. One particular model contains a dysphoria factor which has been associated with depression and anxiety. The symptoms in this factor have been hailed as less specific to PTSD. The scope of this article is therefore to present a short screening instrument, based on this research; Posttraumatic Stress Disorder (PTSD) – 8 items. The PTSD-8 is shown to have good psychometric properties in three independent samples of whiplash patients (n=1710), rape victims (n=305), and disaster victims (n=516). Good test-rest reliability is also shown in a pilot study of young adults from families with alcohol problems (n=56). PMID:21253461

PTSD-8: A Short PTSD Inventory.

PubMed

Hansen, Maj; Andersen, Tonny Elmose; Armour, Cherie; Elklit, Ask; Palic, Sabina; Mackrill, Thomas

2010-09-28

Traumatic events pose great challenges on mental health services in scarcity of specialist trauma clinicians and services. Simple short screening instruments for detecting adverse psychological responses are needed. Several brief screening instruments have been developed. However, some are limited, especially in relation to reflecting the posttraumatic stress disorder (PTSD) diagnosis. Recently, several studies have challenged pre-existing ideas about PTSD's latent structure. Factor analytic research currently supports two four factor models. One particular model contains a dysphoria factor which has been associated with depression and anxiety. The symptoms in this factor have been hailed as less specific to PTSD. The scope of this article is therefore to present a short screening instrument, based on this research; Posttraumatic Stress Disorder (PTSD) - 8 items. The PTSD-8 is shown to have good psychometric properties in three independent samples of whiplash patients (n=1710), rape victims (n=305), and disaster victims (n=516). Good test-rest reliability is also shown in a pilot study of young adults from families with alcohol problems (n=56).

A new software for dimensional measurements in 3D endodontic root canal instrumentation.

PubMed

Sinibaldi, Raffaele; Pecci, Raffaella; Somma, Francesco; Della Penna, Stefania; Bedini, Rossella

2012-01-01

The main issue to be faced to get size estimates of 3D modification of the dental canal after endodontic treatment is the co-registration of the image stacks obtained through micro computed tomography (micro-CT) scans before and after treatment. Here quantitative analysis of micro-CT images have been performed by means of new dedicated software targeted to the analysis of root canal after endodontic instrumentation. This software analytically calculates the best superposition between the pre and post structures using the inertia tensor of the tooth. This strategy avoid minimization procedures, which can be user dependent, and time consuming. Once the co-registration have been achieved dimensional measurements have then been performed by contemporary evaluation of quantitative parameters over the two superimposed stacks of micro-CT images. The software automatically calculated the changes of volume, surface and symmetry axes in 3D occurring after the instrumentation. The calculation is based on direct comparison of the canal and canal branches selected by the user on the pre treatment image stack.

Apparatus for reduction of selected ion intensities in confined ion beams

DOEpatents

Eiden, Gregory C.; Barinaga, Charles J.; Koppenaal, David W.

2001-01-01

An apparatus for producing an ion beam having an increased proportion of analyte ions compared to carrier gas ions is disclosed. Specifically, the apparatus has an ion trap or a collision cell containing a reagent gas wherein the reagent gas accepts charge from the analyte ions thereby selectively neutralizing the carrier gas ions. Also disclosed is the collision cell as employed in various locations within analytical instruments including an inductively coupled plasma mass spectrometer.

MARA (Multimode Airborne Radar Altimeter) system documentation. Volume 1: MARA system requirements document

NASA Technical Reports Server (NTRS)

Parsons, C. L. (Editor)

1989-01-01

The Multimode Airborne Radar Altimeter (MARA), a flexible airborne radar remote sensing facility developed by NASA's Goddard Space Flight Center, is discussed. This volume describes the scientific justification for the development of the instrument and the translation of these scientific requirements into instrument design goals. Values for key instrument parameters are derived to accommodate these goals, and simulations and analytical models are used to estimate the developed system's performance.

Specifying and calibrating instrumentations for wideband electronic power measurements. [in switching circuits

NASA Technical Reports Server (NTRS)

Lesco, D. J.; Weikle, D. H.

1980-01-01

The wideband electric power measurement related topics of electronic wattmeter calibration and specification are discussed. Tested calibration techniques are described in detail. Analytical methods used to determine the bandwidth requirements of instrumentation for switching circuit waveforms are presented and illustrated with examples from electric vehicle type applications. Analog multiplier wattmeters, digital wattmeters and calculating digital oscilloscopes are compared. The instrumentation characteristics which are critical to accurate wideband power measurement are described.

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

Not Available

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year (FY) 1993 (October 1992 through September 1993). This annual report is the tenth for the ACL and describes continuing effort on projects, work on new projects, and contributions of the ACL staff to various programs at ANL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. The ACL also has research programs in analyticalmore » chemistry, conducts instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems. Some routine or standard analyses are done, but it is common for the Argonne programs to generate unique problems that require development or modification of methods and adaption of techniques to obtain useful analytical data. The ACL is administratively within the Chemical Technology Division (CMT), its principal ANL client, but provides technical support for many of the technical divisions and programs at ANL. The ACL has four technical groups--Chemical Analysis, Instrumental Analysis, Organic Analysis, and Environmental Analysis--which together include about 45 technical staff members. Talents and interests of staff members cross the group lines, as do many projects within the ACL.« less

Instrument Attitude Precision Control

NASA Technical Reports Server (NTRS)

Juang, Jer-Nan

2004-01-01

A novel approach is presented in this paper to analyze attitude precision and control for an instrument gimbaled to a spacecraft subject to an internal disturbance caused by a moving component inside the instrument. Nonlinear differential equations of motion for some sample cases are derived and solved analytically to gain insight into the influence of the disturbance on the attitude pointing error. A simple control law is developed to eliminate the instrument pointing error caused by the internal disturbance. Several cases are presented to demonstrate and verify the concept presented in this paper.

The Mars Organic Molecule Analyzer (MOMA) Instrument: Characterization of Organic Material in Martian Sediments

PubMed Central

Goesmann, Fred; Brinckerhoff, William B.; Raulin, François; Danell, Ryan M.; Getty, Stephanie A.; Siljeström, Sandra; Mißbach, Helge; Steininger, Harald; Arevalo, Ricardo D.; Buch, Arnaud; Freissinet, Caroline; Grubisic, Andrej; Meierhenrich, Uwe J.; Pinnick, Veronica T.; Stalport, Fabien; Szopa, Cyril; Vago, Jorge L.; Lindner, Robert; Schulte, Mitchell D.; Brucato, John Robert; Glavin, Daniel P.; Grand, Noel; Li, Xiang; van Amerom, Friso H. W.

2017-01-01

Abstract The Mars Organic Molecule Analyzer (MOMA) instrument onboard the ESA/Roscosmos ExoMars rover (to launch in July, 2020) will analyze volatile and refractory organic compounds in martian surface and subsurface sediments. In this study, we describe the design, current status of development, and analytical capabilities of the instrument. Data acquired on preliminary MOMA flight-like hardware and experimental setups are also presented, illustrating their contribution to the overall science return of the mission. Key Words: Mars—Mass spectrometry—Life detection—Planetary instrumentation. Astrobiology 17, 655–685.

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

Green, D.W.; Heinrich, R.R.; Graczyk, D.G.

The purpose of this report is to summarize the activities of the Analytical Chemistry Laboratory (ACL) at Argonne National Laboratory (ANL) for Fiscal Year 1991 (October 1990 through September 1991). This is the eighth annual report for the ACL. The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of analytical chemistry support services to the scientific and engineering programs at ANL. In addition, the ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handlesmore » a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques.« less

Application of conductive polymer analysis for wood and woody plant identifications

Treesearch

A. Dan Wilson; D.G. Lester; Charisse S. Oberle

2005-01-01

An electronic aroma detection (EAD) technology known as conductive polymer analysis (CPA) was evaluated as a means of identifying and discriminating woody samples of angiosperms and gymnosperms using an analytical instrument (electronic nose) that characterizes the aroma profiles of volatiles released from excised wood into sampled headspace. The instrument measures...

Walking towards Instrumental Appropriation of Mobile Devices. A Comparison of Studies

ERIC Educational Resources Information Center

Hernandez Serrano, Maria José; Yang, Lingling

2013-01-01

The study of instrumental appropriation is considered a relevant outstanding and productive perspective in the arena of Mobile ICT and learning. This paper seeks for the consolidation of this perspective at a theoretical and analytical level. Regarding the theoretical level, two characteristics of mobile devices--flexibility and mobility--are…

The Kohn Social Competence Scale and Kohn Symptom Checklist for the Preschool Child: A Follow-Up Report

ERIC Educational Resources Information Center

Kohn, Martin

1977-01-01

The paper focuses on two research instruments, the Kohn Social Competence Scale and the Kohn Symptom Checklist, designed to assess the behavior of children in a preschool setting as well as on two factor-analytically derived dimensions of social-emotional functioning which the instruments measure. (SBH)

Using a Systematic Approach to Develop a Chemistry Course Introducing Students to Instrumental Analysis

ERIC Educational Resources Information Center

Shen, Hao-Yu; Shen, Bo; Hardacre, Christopher

2013-01-01

A systematic approach to develop the teaching of instrumental analytical chemistry is discussed, as well as a conceptual framework for organizing and executing lectures and a laboratory course. Three main components are used in this course: theoretical knowledge developed in the classroom, simulations via a virtual laboratory, and practical…

Build Your Own Photometer: A Guided-Inquiry Experiment to Introduce Analytical Instrumentation

ERIC Educational Resources Information Center

Wang, Jessie J.; Nun´ez, Jose´ R. Rodríguez; Maxwell, E. Jane; Algar, W. Russ

2016-01-01

A guided-inquiry project designed to teach students the basics of spectrophotometric instrumentation at the second year level is presented. Students design, build, program, and test their own single-wavelength, submersible photometer using low-cost light-emitting diodes (LEDs) and inexpensive household items. A series of structured prelaboratory…

Academic Research Equipment and Equipment Needs in Selected Science and Engineering Fields: 1989-90.

ERIC Educational Resources Information Center

Westat, Inc., Rockville, MD.

This monograph is one in a series of analytical reports presenting findings from the National Science Foundation's 1989-90 National Survey of Academic Research Instruments and Instrumentation Needs. This report documents current status and recent trends in the amounts, costs, and kinds of academic research equipment in seven major…

40 CFR 86.111-90 - Exhaust gas analytical system.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., or indicating silica gel to remove water vapor and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

40 CFR 86.111-90 - Exhaust gas analytical system.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., or indicating silica gel to remove water vapor and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

Construct Validity Examination of Critical Thinking Dispositions for Undergraduate Students in University Putra Malaysia

ERIC Educational Resources Information Center

Ghadi, Ibrahim; Alwi, Nor Hayati; Bakar, Kamariah Abu; Talib, Othman

2012-01-01

This research aims to evaluate the psychology properties of the construct validity for the Critical Thinking Disposition (CTD) instrument. The CTD instrument consists of 39 Likert-type items measuring seven dispositions, namely analyticity, open-mind, truth-seeking, systematicity, self-confidence inquisitiveness and maturity. The study involves…

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

Parrado, G., E-mail: gparrado@sgc.gov.co; Cañón, Y.; Peña, M., E-mail: mlpena@sgc.gov.co

The Neutron Activation Analysis (NAA) laboratory at the Colombian Geological Survey has developed a technique for multi-elemental analysis of soil and plant matrices, based on Instrumental Neutron Activation Analysis (INAA) using the comparator method. In order to evaluate the analytical capabilities of the technique, the laboratory has been participating in inter-comparison tests organized by Wepal (Wageningen Evaluating Programs for Analytical Laboratories). In this work, the experimental procedure and results for the multi-elemental analysis of four soil and four plant samples during participation in the first round on 2015 of Wepal proficiency test are presented. Only elements with radioactive isotopes withmore » medium and long half-lives have been evaluated, 15 elements for soils (As, Ce, Co, Cr, Cs, Fe, K, La, Na, Rb, Sb, Sc, Th, U and Zn) and 7 elements for plants (Br, Co, Cr, Fe, K, Na and Zn). The performance assessment by Wepal based on Z-score distributions showed that most results obtained |Z-scores| ≤ 3.« less

Standardization of Nanoparticle Characterization: Methods for Testing Properties, Stability, and Functionality of Edible Nanoparticles.

PubMed

McClements, Jake; McClements, David Julian

2016-06-10

There has been a rapid increase in the fabrication of various kinds of edible nanoparticles for oral delivery of bioactive agents, such as those constructed from proteins, carbohydrates, lipids, and/or minerals. It is currently difficult to compare the relative advantages and disadvantages of different kinds of nanoparticle-based delivery systems because researchers use different analytical instruments and protocols to characterize them. In this paper, we briefly review the various analytical methods available for characterizing the properties of edible nanoparticles, such as composition, morphology, size, charge, physical state, and stability. This information is then used to propose a number of standardized protocols for characterizing nanoparticle properties, for evaluating their stability to environmental stresses, and for predicting their biological fate. Implementation of these protocols would facilitate comparison of the performance of nanoparticles under standardized conditions, which would facilitate the rational selection of nanoparticle-based delivery systems for different applications in the food, health care, and pharmaceutical industries.

Measuring the Chemical Potential of the Martian Regolith to Generate and Sustain Life

NASA Technical Reports Server (NTRS)

Kounaves, S. P.; Buehler, M. G.; Kuhlman, K. R.

1999-01-01

A critical component for identifying chemical biosignatures is the ability to assess in-situ the potential of an aqueous geochemical environment to generate and sustain life. On Mars or other solar bodies, in-situ chemical characterization could provide evidence as to whether the chemical composition of the regolith or evaporites in suspected ancient water bodies have been biologically influenced or possess the chemical parameters within which life may have existed, or may still exist. A variety of analytical techniques have been proposed for use in detecting and identify signatures of past or present life. These techniques fall into two groups; visual observation with instruments such as cameras or optical/atomic-force microscopes; or elemental chemical analysis with such instruments as X-ray fluorescence (XRF) and diffraction (XRD), a-proton backscatter (APX), y-ray, Mossbauer, Raman, IR, UV/VIS spectroscopies, gas chromatography (GC), or mass spectrometry (MS). Direct observation of an identifiable lifeform by the first set of instruments in a single sample is highly unlikely, especially for extinct organisms or on the surface. The later instruments can provide vital data as to the elemental mineralogy and geological history of the planet, but are highly inadequate for understanding the chemistry of the planet in terms of indigenous life or interactions with human explorers. Techniques such as XRD, XRF, and APX, provide elemental composition at high limits of detection. Some of this data can be extrapolated or interpolated to provide chemical parameters such as oxidation state or composition. Gas chromatography (GC) without standards and non-specific detectors, has little chance of identifying a mixture of unknown components. Combined with GC or by itself, mass spectrometry (MS) can provide identification of compounds, but in both cases the sample must be appropriately prepared for accurate and reliable analysis. Life as we know it, and probably identify it as such, requires an aqueous environment. Deciphering die chemical speciation of this aqueous environment is the key to recognizing therein the biosignatures of any extinct or present life forms. Identifying the soluble (ionic and nonionic) components by reacting a currently dormant environment can provide a "picture" of the thermodynamics and chemical components of a possibly bioactive environment. The only devices which can provide such information are electrochemical sensors based on the potentiometric ion selective electrodes (ISEs) and on dynamic techniques such as cyclic voltammetry (CV) and stripping voltammetry (SV). Such an array of devices can provide not only the chemical composition of a water-soluble Martian soil sample, but also several other vital chemical parameters such as pH, conductivity, redox potential, and dissolved gases. To address these issues we have been investigating the possible use of an electrochemically-based ion sensor array as a new integrated approach to quantitative analytical and chemometric electrochemical measurements. The sensor array will consist of specific and semispecific ion selective and amperometric transducers, which can simultaneously and continuously identify and semiquantitatively determine over 50 organic and inorganic analytes in water-based environments. Several individual sensors, based on the same principle, have been flight-tested and have been installed as part of the MECA instrumentation on the Mars 2001 Lander for in-situ analyses. However, the microfabrication, integration and multiplexing of such a large number of these sensors on a single substrate have not been previously attempted.

Monte Carlo simulations of neutron-scattering instruments using McStas

NASA Astrophysics Data System (ADS)

Nielsen, K.; Lefmann, K.

2000-06-01

Monte Carlo simulations have become an essential tool for improving the performance of neutron-scattering instruments, since the level of sophistication in the design of instruments is defeating purely analytical methods. The program McStas, being developed at Risø National Laboratory, includes an extension language that makes it easy to adapt it to the particular requirements of individual instruments, and thus provides a powerful and flexible tool for constructing such simulations. McStas has been successfully applied in such areas as neutron guide design, flux optimization, non-Gaussian resolution functions of triple-axis spectrometers, and time-focusing in time-of-flight instruments.

The Quantitative Resolution of a Mixture of Group II Metal Ions by Thermometric Titration with EDTA. An Analytical Chemistry Experiment.

ERIC Educational Resources Information Center

Smith, Robert L.; Popham, Ronald E.

1983-01-01

Presents an experiment in thermometric titration used in an analytic chemistry-chemical instrumentation course, consisting of two titrations, one a mixture of calcium and magnesium, the other of calcium, magnesium, and barium ions. Provides equipment and solutions list/specifications, graphs, and discussion of results. (JM)

Impulsive-Analytic Disposition in Mathematical Problem Solving: A Survey and a Mathematics Test

ERIC Educational Resources Information Center

Lim, Kien H.; Wagler, Amy

2012-01-01

The Likelihood-to-Act (LtA) survey and a mathematics test were used in this study to assess students' impulsive-analytic disposition in the context of mathematical problem solving. The results obtained from these two instruments were compared to those obtained using two widely-used scales: Need for Cognition (NFC) and Barratt Impulsivity Scale…

Gas-analytic measurement complexes of Baikal atmospheric-limnological observatory

NASA Astrophysics Data System (ADS)

Pestunov, D. A.; Shamrin, A. M.; Shmargunov, V. P.; Panchenko, M. V.

2015-11-01

The paper presents the present-day structure of stationary and mobile hardware-software gas-analytical complexes of Baikal atmospheric-limnological observatory (BALO) Siberian Branch Russian Academy of Sciences (SB RAS), designed to study the processes of gas exchange of carbon-containing gases in the "atmosphere-water" system, which are constantly updated to include new measuring and auxiliary instrumentation.

Application of Steinberg vibration fatigue model for structural verification of space instruments

NASA Astrophysics Data System (ADS)

García, Andrés; Sorribes-Palmer, Félix; Alonso, Gustavo

2018-01-01

Electronic components in spaceships are subjected to vibration loads during the ascent phase of the launcher. It is important to verify by tests and analysis that all parts can survive in the most severe load cases. The purpose of this paper is to present the methodology and results of the application of the Steinberg's fatigue model to estimate the life of electronic components of the EPT-HET instrument for the Solar Orbiter space mission. A Nastran finite element model (FEM) of the EPT-HET instrument was created and used for the structural analysis. The methodology is based on the use of the FEM of the entire instrument to calculate the relative displacement RDSD and RMS values of the PCBs from random vibration analysis. These values are used to estimate the fatigue life of the most susceptible electronic components with the Steinberg's fatigue damage equation and the Miner's cumulative fatigue index. The estimations are calculated for two different configurations of the instrument and three different inputs in order to support the redesign process. Finally, these analytical results are contrasted with the inspections and the functional tests made after the vibration tests, concluding that this methodology can adequately predict the fatigue damage or survival of the electronic components.

A qualitative approach to assessing work ability.

PubMed

Tengland, Per-Anders

2013-01-01

We often need to be able to assess the extent to which individuals have or lack work ability. For this we need instruments. Most of the instruments available have flaws. They either lack validity or they use roundabout methods when collecting information about the individual's work ability. The aim of this paper is to present a conceptual model for constructing a questionnaire that can be used for assessing work ability. The methods used are philosophical, i.e. analytical and deductive. A conceptual theory is provided, and based on the resulting definition of the concept of "work ability" conclusions are drawn regarding how to assess work ability. When constructing quantitative instruments, we can increase validity through using a more strict definition of work ability. However, such an approach will only solve some of the problems noted above. The proposal is, instead, to create a qualitative questionnaire, founded on a definition of "work ability", which focuses on the concrete problems concerning the work ability of the individual. Finally, a sketch of such an instrument is provided, with questions covering all the relevant aspects of work ability. The qualitative questionnaire proposed is believed to be superior to more traditional (quantitative) instruments for assessing a person's work ability, as well as for finding solutions to her problems concerning work ability.

In-house-made capillary electrophoresis instruments coupled with contactless conductivity detection as a simple and inexpensive solution for water analysis: a case study in Vietnam.

PubMed

Duong, Hong Anh; Le, Minh Duc; Nguyen, Kim Diem Mai; Hauser, Peter C; Pham, Hung Viet; Mai, Thanh Duc

2015-11-01

A simple and inexpensive method for the determination of various ionic species in different water matrices is discussed in this study. The approach is based on the employment of in-house-made capillary electrophoresis (CE) instruments with capacitively coupled contactless conductivity detection (C(4)D), which can be realized even when only a modest financial budget and limited expertise are available. Advantageous features and considerations of these instruments are detailed following their pilot deployment in Vietnam. Different categories of ionic species, namely major inorganic cations (K(+), Na(+), Ca(2+), Mg(2+), and NH4(+)) and major inorganic anions (Cl(-), NO3(-), NO2(-), SO4(2-), and phosphate), in different water matrices in Vietnam were determined using these in-house fabricated instruments. Inorganic trivalent arsenic (As(iii)), which is the most abundant form of arsenic in reducing groundwater, was determined by CE-C(4)D. The effect of some interfering ions in groundwater on the analytical performance was investigated and is highlighted. The results from in-house-made CE-C(4)D-instruments were cross-checked with those obtained using the standard methods (AAS, AES, UV and IC), with correlation coefficients r(2) ≥ 0.9 and deviations from the referenced results less than 15%.

Focused Ion Beam Recovery and Analysis of Interplanetary Dust Particles (IDPs) and Stardust Analogues

NASA Technical Reports Server (NTRS)

Graham, G. A.; Bradley, J. P.; Bernas, M.; Stroud, R. M.; Dai, Z. R.; Floss, C.; Stadermann, F. J.; Snead, C. J.; Westphal, A. J.

2004-01-01

Meteoritics research is a major beneficiary of recent developments in analytical instrumentation [1,2]. Integrated studies in which multiple analytical techniques are applied to the same specimen are providing new insight about the nature of IDPs [1]. Such studies are dependent on the ability to prepare specimens that can be analyzed in multiple instruments. Focused ion beam (FIB) microscopy has revolutionized specimen preparation in materials science [3]. Although FIB has successfully been used for a few IDP and meteorite studies [1,4-6], it has yet to be widely utilized in meteoritics. We are using FIB for integrated TEM/NanoSIMS/synchrotron infrared (IR) studies [1].

When can social media lead financial markets?

PubMed

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-02-27

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes.

When Can Social Media Lead Financial Markets?

NASA Astrophysics Data System (ADS)

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-02-01

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes.

When Can Social Media Lead Financial Markets?

PubMed Central

Zheludev, Ilya; Smith, Robert; Aste, Tomaso

2014-01-01

Social media analytics is showing promise for the prediction of financial markets. However, the true value of such data for trading is unclear due to a lack of consensus on which instruments can be predicted and how. Current approaches are based on the evaluation of message volumes and are typically assessed via retrospective (ex-post facto) evaluation of trading strategy returns. In this paper, we present instead a sentiment analysis methodology to quantify and statistically validate which assets could qualify for trading from social media analytics in an ex-ante configuration. We use sentiment analysis techniques and Information Theory measures to demonstrate that social media message sentiment can contain statistically-significant ex-ante information on the future prices of the S&P500 index and a limited set of stocks, in excess of what is achievable using solely message volumes. PMID:24572909

Studies on transmitted beam modulation effect from laser induced damage on fused silica optics.

PubMed

Zheng, Yi; Ma, Ping; Li, Haibo; Liu, Zhichao; Chen, Songlin

2013-07-15

UV laser induced damage (LID) on exit surface of fused silica could cause modulation effect to transmitted beam and further influence downstream propagation properties. This paper presents our experimental and analytical studies on this topic. In experiment, a series of measurement instruments are applied, including beam profiler, interferometer, microscope, and optical coherent tomography (OCT). Creating and characterizing of LID on fused silica sample have been implemented. Morphological features are studied based on their particular modulation effects on transmitted beam. In theoretical investigation, analytical modeling and numerical simulation are performed. Modulation effects from amplitude, phase, and size factors are analyzed respectively. Furthermore, we have novelly designed a simplified polygon model to simulate actual damage site with multiform modulation features, and the simulation results demonstrate that the modeling is usable and representative.

Population-based pediatric reference intervals for general clinical chemistry analytes on the Abbott Architect ci8200 instrument.

PubMed

Ridefelt, Peter; Aldrimer, Mattias; Rödöö, Per-Olof; Niklasson, Frank; Jansson, Leif; Gustafsson, Jan; Hellberg, Dan

2012-02-29

Reference intervals are crucial decision-making tools aiding clinicians in differentiating between healthy and diseased populations. However, for children such values often are lacking or incomplete. Blood samples were obtained from 692 healthy children, aged 6 months to 18 years, recruited in daycare centers and schools. Twelve common general clinical chemistry analytes were measured on the Abbott Architect ci8200 platform; sodium, potassium, chloride, calcium, albumin-adjusted calcium, phosphate, magnesium, creatinine (Jaffe and enzymatic), cystatin C, urea and uric acid. Age- and gender specific pediatric reference intervals were defined by calculating the 2.5th and 97.5th percentiles. The data generated is primarily applicable to a Caucasian population when using the Abbott Architect platform, but could be used by any laboratory if validated for the local patient population.

Simulation of 2D Waves in Circular Membrane Using Excel Spreadsheet with Visual Basic for Teaching Activity

NASA Astrophysics Data System (ADS)

Eso, R.; Safiuddin, L. O.; Agusu, L.; Arfa, L. M. R. F.

2018-04-01

We propose a teaching instrument demonstrating the circular membrane waves using the excel interactive spreadsheets with the Visual Basic for Application (VBA) programming. It is based on the analytic solution of circular membrane waves involving Bessel function. The vibration modes and frequencies are determined by using Bessel approximation and initial conditions. The 3D perspective based on the spreadsheets functions and facilities has been explored to show the 3D moving objects in transitional or rotational processes. This instrument is very useful both in teaching activity and learning process of wave physics. Visualizing of the vibration of waves in the circular membrane which is showing a very clear manner of m and n vibration modes of the wave in a certain frequency has been compared and matched to the experimental result using resonance method. The peak of deflection varies in time if the initial condition was working and have the same pattern with matlab simulation in zero initial velocity

A Simple, Inexpensive Device for Nucleic Acid Amplification without Electricity—Toward Instrument-Free Molecular Diagnostics in Low-Resource Settings

PubMed Central

LaBarre, Paul; Hawkins, Kenneth R.; Gerlach, Jay; Wilmoth, Jared; Beddoe, Andrew; Singleton, Jered; Boyle, David; Weigl, Bernhard

2011-01-01

Background Molecular assays targeted to nucleic acid (NA) markers are becoming increasingly important to medical diagnostics. However, these are typically confined to wealthy, developed countries; or, to the national reference laboratories of developing-world countries. There are many infectious diseases that are endemic in low-resource settings (LRS) where the lack of simple, instrument-free, NA diagnostic tests is a critical barrier to timely treatment. One of the primary barriers to the practicality and availability of NA assays in LRS has been the complexity and power requirements of polymerase chain reaction (PCR) instrumentation (another is sample preparation). Methodology/Principal Findings In this article, we investigate the hypothesis that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays. We assess the heater's equivalence to commercially available PCR instruments through the characterization of the temperature profiles produced, and a minimal method comparison. Versions of the prototype for several different isothermal techniques are presented. Conclusions/Significance We demonstrate that an electricity-free heater based on exothermic chemical reactions and engineered phase change materials can successfully incubate isothermal NA amplification assays, and that the results of those assays are not significantly different from ones incubated in parallel in commercially available PCR instruments. These results clearly suggest the potential of the non-instrumented nucleic acid amplification (NINA) heater for molecular diagnostics in LRS. When combined with other innovations in development that eliminate power requirements for sample preparation, cold reagent storage, and readout, the NINA heater will comprise part of a kit that should enable electricity-free NA testing for many important analytes. PMID:21573065

ARM Mentor Selection Process

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

Sisterson, D. L.

2015-10-01

The Atmospheric Radiation Measurement (ARM) Program was created in 1989 with funding from the U.S. Department of Energy (DOE) to develop several highly instrumented ground stations to study cloud formation processes and their influence on radiative transfer. In 2003, the ARM Program became a national scientific user facility, known as the ARM Climate Research Facility. This scientific infrastructure provides for fixed sites, mobile facilities, an aerial facility, and a data archive available for use by scientists worldwide through the ARM Climate Research Facility—a scientific user facility. The ARM Climate Research Facility currently operates more than 300 instrument systems that providemore » ground-based observations of the atmospheric column. To keep ARM at the forefront of climate observations, the ARM infrastructure depends heavily on instrument scientists and engineers, also known as lead mentors. Lead mentors must have an excellent understanding of in situ and remote-sensing instrumentation theory and operation and have comprehensive knowledge of critical scale-dependent atmospheric processes. They must also possess the technical and analytical skills to develop new data retrievals that provide innovative approaches for creating research-quality data sets. The ARM Climate Research Facility is seeking the best overall qualified candidate who can fulfill lead mentor requirements in a timely manner.« less

Subminiaturization for ERAST instrumentation (Environmental Research Aircraft and Sensor Technology)

NASA Technical Reports Server (NTRS)

Madou, Marc; Lowenstein, Max; Wegener, Steven

1995-01-01

We are focusing on the Argus as an example to demonstrate our philosophy on miniaturization of airborne analytical instruments for the study of atmospheric chemistry. Argus is a two channel, tunable-diode laser absorption spectrometer developed at NASA for the measurement of nitrogen dioxide (N2O) (4.5 micrometers) and ammonia (CH3) (3.3 micrometers) at the 0.1 parts per billion (ppb) level from the Perseus aircraft platform at altitudes up to 30 km. Although Argus' mass is down to 23 kg from the 197 kg Atlas, its predecessor, our goal is to design a next-generation subminiaturized instrument weighing less than 1 kg, measuring a few cm(exp 3) and able to eliminate dewars for cooling. Current designs enable use to make a small,inexpensive, monolithic spectrometer without the required sensitivity range. Further work is on its way to increase sensitivity. We are continuing to zero-base the technical approach in terms of the specifications for the given instrument. We are establishing a check list of questions to hone into the best micromachining approach and to superpose on the answers insights in scaling laws and flexible engineering designs to enable more relaxed tolerances for the smallest of the components.

Time-of-flights and traps: from the Histone Code to Mars.

PubMed

Cotter, Robert J; Swatkoski, Stepehen; Becker, Luann; Evans-Nguyen, Theresa

2010-01-01

Two very different analytical instruments are featured in this perspective paper on mass spectrometer design and development. The first instrument, based upon the curved-field reflectron developed in the Johns Hopkins Middle Atlantic Mass Spectrometry Laboratory, is a tandem time-of-flight mass spectrometer whose performance and practicality are illustrated by applications to a series of research projects addressing the acetylation, deacetylation and ADP-ribosylation of histone proteins. The chemical derivatization of lysine-rich, hyperacetylated histones as their deuteroacetylated analogs enables one to obtain an accurate quantitative assessment of the extent of acetylation at each site. Chemical acetylation of histone mixtures is also used to determine the lysine targets of sirtuins, an important class of histone deacetylases (HDACs), by replacing the deacetylated residues with biotin. Histone deacetylation by sirtuins requires the co-factor NAD+, as does the attachment of ADP-ribose. The second instrument, a low voltage and low power ion trap mass spectrometer known as the Mars Organic Mass Analyzer (MOMA), is a prototype for an instrument expected to be launched in 2018. Like the tandem mass spectrometer, it is also expected to have applicability to environmental and biological analyses and, ultimately, to clinical care.

Time-of-flights and traps: from the Histone Code to Mars*

PubMed Central

Swatkoski, Stephen; Becker, Luann; Evans-Nguyen, Theresa

2011-01-01

Two very different analytical instruments are featured in this perspective paper on mass spectrometer design and development. The first instrument, based upon the curved-field reflectron developed in the Johns Hopkins Middle Atlantic Mass Spectrometry Laboratory, is a tandem time-of-flight mass spectrometer whose performance and practicality are illustrated by applications to a series of research projects addressing the acetylation, deacetylation and ADP-ribosylation of histone proteins. The chemical derivatization of lysine-rich, hyperacetylated histones as their deuteroacetylated analogs enables one to obtain an accurate quantitative assessment of the extent of acetylation at each site. Chemical acetylation of histone mixtures is also used to determine the lysine targets of sirtuins, an important class of histone deacetylases (HDACs), by replacing the deacetylated residues with biotin. Histone deacetylation by sirtuins requires the co-factor NAD+, as does the attachment of ADP-ribose. The second instrument, a low voltage and low power ion trap mass spectrometer known as the Mars Organic Mass Analyzer (MOMA), is a prototype for an instrument expected to be launched in 2018. Like the tandem mass spectrometer, it is also expected to have applicability to environmental and biological analyses and, ultimately, to clinical care. PMID:20530839

Theoretical and practical considerations for teaching diagnostic electronic-nose technologies to clinical laboratory technicians

Treesearch

Alphus D. Wilson

2012-01-01

The rapid development of new electronic technologies and instruments, utilized to perform many current clinical operations in the biomedical field, is changing the way medical health care is delivered to patients. The majority of test results from laboratory analyses, performed with these analytical instruments often prior to clinical examinations, are frequently used...

Assessment of Symptoms in Adult Survivors of Incest: A Factor Analytic Study of the Responses to Childhood Incest Questionnaire.

ERIC Educational Resources Information Center

Edwards, Patrick W.; Donaldson, Mary Ann

1989-01-01

A study of the construction and factor validity of the Response to Child Incest Questionnaire, a self-report instrument for assessing commonly reported symptoms of adult survivors of incest, is reported. The instrument's usefulness as a pre- and post-treatment measure and further research needs are discussed. (MSE)

Evaluating Effective Teaching in College Level Economics Using Student Ratings of Instruction: A Factor Analytic Approach

ERIC Educational Resources Information Center

Agbetsiafa, Douglas

2010-01-01

This paper explores the factors that affect students' evaluation of economic instruction using a sample of 1300 completed rating instruments at a comprehensive four-year mid-western public university. The study uses factor analysis to determine the validity and reliability of the evaluation instrument in assessing instructor or course…

40 CFR 86.1311-94 - Exhaust gas analytical system; CVS bag sample.

Code of Federal Regulations, 2011 CFR

2011-07-01

... desiccating silica gel to remove water vapor, and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments are used which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

40 CFR 86.1311-94 - Exhaust gas analytical system; CVS bag sample.

Code of Federal Regulations, 2012 CFR

2012-07-01

... desiccating silica gel to remove water vapor, and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments are used which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

40 CFR 86.1311-94 - Exhaust gas analytical system; CVS bag sample.

Code of Federal Regulations, 2010 CFR

2010-07-01

... desiccating silica gel to remove water vapor, and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments are used which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

40 CFR 86.1311-94 - Exhaust gas analytical system; CVS bag sample.

Code of Federal Regulations, 2013 CFR

2013-07-01

... desiccating silica gel to remove water vapor, and containing ascarite to remove carbon dioxide from the CO analysis stream. (i) If CO instruments are used which are essentially free of CO2 and water vapor... instrument will be considered to be essentially free of CO2 and water vapor interference if its response to a...

Assuring the Quality of Test Results in the Field of Nuclear Techniques and Ionizing Radiation. The Practical Implementation of Section 5.9 of the EN ISO/IEC 17025 Standard

NASA Astrophysics Data System (ADS)

Cucu, Daniela; Woods, Mike

2008-08-01

The paper aims to present a practical approach for testing laboratories to ensure the quality of their test results. It is based on the experience gained in assessing a large number of testing laboratories, discussing with management and staff, reviewing results obtained in national and international PTs and ILCs and exchanging information in the EA laboratory committee. According to EN ISO/IEC 17025, an accredited laboratory has to implement a programme to ensure the quality of its test results for each measurand. Pre-analytical, analytical and post-analytical measures shall be applied in a systematic manner. They shall include both quality control and quality assurance measures. When designing the quality assurance programme a laboratory should consider pre-analytical activities (like personnel training, selection and validation of test methods, qualifying equipment), analytical activities ranging from sampling, sample preparation, instrumental analysis and post-analytical activities (like decoding, calculation, use of statistical tests or packages, management of results). Designed on different levels (analyst, quality manager and technical manager), including a variety of measures, the programme shall ensure the validity and accuracy of test results, the adequacy of the management system, prove the laboratory's competence in performing tests under accreditation and last but not least show the comparability of test results. Laboratory management should establish performance targets and review periodically QC/QA results against them, implementing appropriate measures in case of non-compliance.

Non-destructive in situ study of "Mad Meg" by Pieter Bruegel the Elder using mobile X-ray fluorescence, X-ray diffraction and Raman spectrometers

NASA Astrophysics Data System (ADS)

Van de Voorde, Lien; Van Pevenage, Jolien; De Langhe, Kaat; De Wolf, Robin; Vekemans, Bart; Vincze, Laszlo; Vandenabeele, Peter; Martens, Maximiliaan P. J.

2014-07-01

"Mad Meg", a figure of Flemish folklore, is the subject of a famous oil-on-panel painting by the Flemish renaissance artist Pieter Bruegel the Elder, exhibited in the Museum Mayer van den Bergh (Antwerp, Belgium). This article reports on the in situ chemical characterization of this masterpiece by using currently available state-of-the-art portable analytical instruments. The applied non-destructive analytical approach involved the use of a) handheld X-ray fluorescence instrumentation for retrieving elemental information and b) portable X-ray fluorescence/X-ray diffraction instrumentation and laser-based Raman spectrometers for obtaining structural/molecular information. Next to material characterization of the used pigments and of the different preparation layers of the painting, also the verification of two important historical iconographic hypotheses is performed concerning the economic way of painting by Brueghel, and whether or not he used blue smalt pigment for painting the boat that appears towards the top of the painting. The pigments identified are smalt pigment (65% SiO2 + 15% K2O + 10% CoO + 5% Al2O3) for the blue color present in all blue areas of the painting, probably copper resinate for the green colors, vermillion (HgS) as red pigment and lead white is used to form different colors. The comparison of blue pigments used on different areas of the painting gives no differences in the elemental fingerprint which confirms the existing hypothesis concerning the economic painting method by Bruegel.

The cobas p 630 instrument: a dedicated pre-analytic solution to optimize COBAS® AmpliPrep/COBAS® TaqMan® system workflow and turn-around-time.

PubMed

Vallefuoco, L; Sorrentino, R; Spalletti Cernia, D; Colucci, G; Portella, G

2012-12-01

The cobas p 630, a fully automated pre-analytical instrument for primary tube handling recently introduced to complete the Cobas(®) TaqMan systems portfolio, was evaluated in conjunction with: the COBAS(®) AmpliPrep/COBAS(®) TaqMan HBV Test, v2.0, COBAS(®) AmpliPrep/COBAS(®) TaqMan HCV Test, v1.0 and COBAS(®) AmpliPrep/COBAS(®) TaqMan HIV Test, v2.0. The instrument performance in transferring samples from primary to secondary tubes, its impact in improving COBAS(®) AmpliPrep/COBAS(®) TaqMan workflow and hands-on reduction and the risk of possible cross-contamination were assessed. Samples from 42 HBsAg positive, 42 HCV and 42 HIV antibody (Ab) positive patients as well as 21 healthy blood donors were processed with or without automated primary tubes. HIV, HCV and HBsAg positive samples showed a correlation index of 0.999, 0.987 and of 0.994, respectively. To assess for cross-contamination, high titer HBV DNA positive samples, HCV RNA and HIV RNA positive samples were distributed in the cobas p 630 in alternate tube positions, adjacent to negative control samples within the same rack. None of the healthy donor samples showed any reactivity. Based on these results, the cobas p 630 can improve workflow and sample tracing in laboratories performing molecular tests, and reduce turnaround time, errors, and risks. Copyright © 2012 Elsevier B.V. All rights reserved.

Smartphone Analytics: Mobilizing the Lab into the Cloud for Omic-Scale Analyses.

PubMed

Montenegro-Burke, J Rafael; Phommavongsay, Thiery; Aisporna, Aries E; Huan, Tao; Rinehart, Duane; Forsberg, Erica; Poole, Farris L; Thorgersen, Michael P; Adams, Michael W W; Krantz, Gregory; Fields, Matthew W; Northen, Trent R; Robbins, Paul D; Niedernhofer, Laura J; Lairson, Luke; Benton, H Paul; Siuzdak, Gary

2016-10-04

Active data screening is an integral part of many scientific activities, and mobile technologies have greatly facilitated this process by minimizing the reliance on large hardware instrumentation. In order to meet with the increasingly growing field of metabolomics and heavy workload of data processing, we designed the first remote metabolomic data screening platform for mobile devices. Two mobile applications (apps), XCMS Mobile and METLIN Mobile, facilitate access to XCMS and METLIN, which are the most important components in the computer-based XCMS Online platforms. These mobile apps allow for the visualization and analysis of metabolic data throughout the entire analytical process. Specifically, XCMS Mobile and METLIN Mobile provide the capabilities for remote monitoring of data processing, real time notifications for the data processing, visualization and interactive analysis of processed data (e.g., cloud plots, principle component analysis, box-plots, extracted ion chromatograms, and hierarchical cluster analysis), and database searching for metabolite identification. These apps, available on Apple iOS and Google Android operating systems, allow for the migration of metabolomic research onto mobile devices for better accessibility beyond direct instrument operation. The utility of XCMS Mobile and METLIN Mobile functionalities was developed and is demonstrated here through the metabolomic LC-MS analyses of stem cells, colon cancer, aging, and bacterial metabolism.

Tandem Laser Induced Breakdown Spectroscopy (LIBS), Laser Ablation Inductively Coupled Plasma Mass Spectroscopy (LA-ICP-MS) and/or Laser Ablation Inductively Coupled Plasma Optical Emission Spectroscopy (LA-ICP-OES) for the analysis of samples of geological interest

NASA Astrophysics Data System (ADS)

Oropeza, D.

2016-12-01

A highly innovative laser ablation sampling instrument (J200 Tandem LA - LIBS) that combines the capabilities and analytical benefits of LIBS, LA-ICP-MS and LA-ICP-OES was used for micrometer-scale, spatially-resolved, elemental analysis of a wide variety of samples of geological interest. Data collected using ablation systems consisted of nanosecond (Nd:YAG operated 266nm) and femtosecond lasers (1030 and 343nm). An ICCD LIBS detector and Quadrupole based mass spectrometer were selected for LIBS and ICP-MS detection, respectively. This tandem instrument allows simultaneous determination of major and minor elements (for example, Si, Ca, Na, and Al, and trace elements such as Li, Ce, Cr, Sr, Y, Zn, Zr among others). The research also focused on elemental mapping and calibration strategies, specifically the use of emission and mass spectra for multivariate data analysis. Partial Least Square Regression (PLSR) is shown to minimize and compensate for matrix effects in the emission and mass spectra improving quantitative analysis by LIBS and LA-ICP-MS, respectively. The study provides a benchmark to evaluate analytical results for more complex geological sample matrices.

Smartphone Analytics: Mobilizing the Lab into the Cloud for Omic-Scale Analyses

PubMed Central

2016-01-01

Active data screening is an integral part of many scientific activities, and mobile technologies have greatly facilitated this process by minimizing the reliance on large hardware instrumentation. In order to meet with the increasingly growing field of metabolomics and heavy workload of data processing, we designed the first remote metabolomic data screening platform for mobile devices. Two mobile applications (apps), XCMS Mobile and METLIN Mobile, facilitate access to XCMS and METLIN, which are the most important components in the computer-based XCMS Online platforms. These mobile apps allow for the visualization and analysis of metabolic data throughout the entire analytical process. Specifically, XCMS Mobile and METLIN Mobile provide the capabilities for remote monitoring of data processing, real time notifications for the data processing, visualization and interactive analysis of processed data (e.g., cloud plots, principle component analysis, box-plots, extracted ion chromatograms, and hierarchical cluster analysis), and database searching for metabolite identification. These apps, available on Apple iOS and Google Android operating systems, allow for the migration of metabolomic research onto mobile devices for better accessibility beyond direct instrument operation. The utility of XCMS Mobile and METLIN Mobile functionalities was developed and is demonstrated here through the metabolomic LC-MS analyses of stem cells, colon cancer, aging, and bacterial metabolism. PMID:27560777

Comparison of mid-infrared transmission spectroscopy with biochemical methods for the determination of macronutrients in human milk.

PubMed

Silvestre, Dolores; Fraga, Miriam; Gormaz, María; Torres, Ester; Vento, Máximo

2014-07-01

The variability of human milk (HM) composition renders analysis of its components essential for optimal nutrition of preterm fed either with donor's or own mother's milk. To fulfil this requirement, various analytical instruments have been subjected to scientific and clinical evaluation. The objective of this study was to evaluate the suitability of a rapid method for the analysis of macronutrients in HM as compared with the analytical methods applied by cow's milk industry. Mature milk from 39 donors was analysed using an infrared human milk analyser (HMA) and compared with biochemical reference laboratory methods. The statistical analysis was based on the use of paired data tests. The use of an infrared HMA for the analysis of lipids, proteins and lactose in HM proved satisfactory as regards the rapidity, simplicity and the required sample volume. The instrument afforded good linearity and precision in application to all three nutrients. However, accuracy was not acceptable when compared with the reference methods, with overestimation of the lipid content and underestimation of the amount of proteins and lactose contents. The use of mid-infrared HMA might become the standard for rapid analysis of HM once standardisation and rigorous and systematic calibration is provided. © 2012 John Wiley & Sons Ltd.

Smartphone Analytics: Mobilizing the Lab into the Cloud for Omic-Scale Analyses

DOE PAGES

Montenegro-Burke, J. Rafael; Phommavongsay, Thiery; Aisporna, Aries E.; ...

2016-08-25

Active data screening is an integral part of many scientific activities, and mobile technologies have greatly facilitated this process by minimizing the reliance on large hardware instrumentation. In order to meet with the increasingly growing field of metabolomics and heavy workload of data processing, we designed the first remote metabolomic data screening platform for mobile devices. Two mobile applications (apps), XCMS Mobile and METLIN Mobile, facilitate access to XCMS and METLIN, which are the most important components in the computer-based XCMS Online platforms. These mobile apps allow for the visualization and analysis of metabolic data throughout the entire analytical process.more » Specifically, XCMS Mobile and METLIN Mobile provide the capabilities for remote monitoring of data processing, real time notifications for the data processing, visualization and interactive analysis of processed data (e.g., cloud plots, principle component analysis, box-plots, extracted ion chromatograms, and hierarchical cluster analysis), and database searching for metabolite identification. These apps, available on Apple iOS and Google Android operating systems, allow for the migration of metabolomic research onto mobile devices for better accessibility beyond direct instrument operation. The utility of XCMS Mobile and METLIN Mobile functionalities was developed and is demonstrated here through the metabolomic LC-MS analyses of stem cells, colon cancer, aging, and bacterial metabolism.« less

Smartphone Analytics: Mobilizing the Lab into the Cloud for Omic-Scale Analyses

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

Montenegro-Burke, J. Rafael; Phommavongsay, Thiery; Aisporna, Aries E.

Active data screening is an integral part of many scientific activities, and mobile technologies have greatly facilitated this process by minimizing the reliance on large hardware instrumentation. In order to meet with the increasingly growing field of metabolomics and heavy workload of data processing, we designed the first remote metabolomic data screening platform for mobile devices. Two mobile applications (apps), XCMS Mobile and METLIN Mobile, facilitate access to XCMS and METLIN, which are the most important components in the computer-based XCMS Online platforms. These mobile apps allow for the visualization and analysis of metabolic data throughout the entire analytical process.more » Specifically, XCMS Mobile and METLIN Mobile provide the capabilities for remote monitoring of data processing, real time notifications for the data processing, visualization and interactive analysis of processed data (e.g., cloud plots, principle component analysis, box-plots, extracted ion chromatograms, and hierarchical cluster analysis), and database searching for metabolite identification. These apps, available on Apple iOS and Google Android operating systems, allow for the migration of metabolomic research onto mobile devices for better accessibility beyond direct instrument operation. The utility of XCMS Mobile and METLIN Mobile functionalities was developed and is demonstrated here through the metabolomic LC-MS analyses of stem cells, colon cancer, aging, and bacterial metabolism.« less

Concentration Gradient Immunoassay I. A Rapid Immunoassay Based on Interdiffusion and Surface Binding in a Microchannel

PubMed Central

Nelson, Kjell E.; Foley, Jennifer O.; Yager, Paul

2008-01-01

We describe a novel microfluidic immunoassay method based on the diffusion of a small molecule analyte into a parallel-flowing stream containing cognate antibody. This interdiffusion results in a steady-state gradient of antibody binding site occupancy transverse to convective flow. In contrast to the diffusion immunoassay (Hatch et al. Nature Biotechnology,19:461−465 (2001)), this antibody occupancy gradient is interrogated by a sensor surface coated with a functional analog of the analyte. Antibodies with at least one unoccupied binding site may specifically bind to this functionalized surface, leading to a quantifiable change in surface coverage by the antibody. SPR imaging is used to probe the spatial distribution of antibody binding to the surface and, therefore, the outcome of the assay. We show that the pattern of antibody binding to the SPR sensing surface correlates with the concentration of a model analyte (phenytoin) in the sample stream. Using an inexpensive disposable microfluidic device, we demonstrate assays for phenytoin ranging in concentration from 75 to 1000 nM in phosphate buffer. At a total volumetric flow rate of 90 nL/sec, the assays are complete within 10 minutes. Inclusion of an additional flow stream on the side of the antibody stream opposite to that of the sample enables simultaneous calibration of the assay. This assay method is suitable for rapid quantitative detection of low-molecular weight analytes for point-of-care diagnostic instrumentation. PMID:17437332

Measurement instruments for automatically monitoring the water chemistry of reactor coolant at nuclear power stations equipped with VVER reactors. Selection of measurement instruments and experience gained from their operation at Russian and foreign NPSs

NASA Astrophysics Data System (ADS)

Ivanov, Yu. A.

2007-12-01

An analytical review is given of Russian and foreign measurement instruments employed in a system for automatically monitoring the water chemistry of the reactor coolant circuit and used in the development of projects of nuclear power stations equipped with VVER-1000 reactors and the nuclear station project AES 2006. The results of experience gained from the use of such measurement instruments at nuclear power stations operating in Russia and abroad are presented.

ExoMars Raman laser spectrometer overview

NASA Astrophysics Data System (ADS)

Rull, F.; Sansano, A.; Díaz, E.; Canora, C. P.; Moral, A. G.; Tato, C.; Colombo, M.; Belenguer, T.; Fernández, M.; Manfredi, J. A. R.; Canchal, R.; Dávila, B.; Jiménez, A.; Gallego, P.; Ibarmia, S.; Prieto, J. A. R.; Santiago, A.; Pla, J.; Ramos, G.; González, C.

2010-09-01

The Raman Laser Spectrometer (RLS) is one of the Pasteur Payload instruments, within the ESA's Aurora Exploration Programme, ExoMars mission. The RLS Instrument will perform Raman spectroscopy on crushed powered samples deposited on a small container after crushing the cores obtained by the Rover's drill system. This is the first time that a Raman spectrometer will be launched in an out planetary mission. The Instrument will be accommodated and operate inside the Rover's ALD (Analytical Laboratory Drawer), complying with COSPAR (Committee on Space Research) Planetary Protection requirements. The RLS Instrument is composed by the following units: SPU (Spectrometer Unit); iOH: (Internal Optical Head); ICEU (Instrument Control and Excitation Unit). Other instrument units are EH (Electrical Harness), OH (Optical Harness) and RLS SW On-Board.

Instrumental background in balloon-borne gamma-ray spectrometers and techniques for its reduction

NASA Technical Reports Server (NTRS)

Gehrels, N.

1985-01-01

Instrumental background in balloon-borne gamma-ray spectrometers is presented. The calculations are based on newly available interaction cross sections and new analytic techniques, and are the most detailed and accurate published to date. Results compare well with measurements made in the 20 keV to 10 MeV energy range by the Goddard Low Energy Gamma-ray Spectrometer (LEGS). The principal components of the continuum background in spectrometers with GE detectors and thick active shields are: (1) elastic neutron scattering of atmospheric neutrons on the Ge nuclei; (2) aperture flux of atmospheric and cosmic gamma rays; (3) beta decays of unstable nuclides produced by nuclear interactions of atmospheric protons and neutrons with Ge nuclei; and (4) shield leakage of atmospheric gamma rays. The improved understanding of these components leads to several recommended techniques for reducing the background.

A Comparison of the OSHA Modified NIOSH Physical and Chemical Analytical Method (P and CAM) 304 and the Dust Trak Photometric Aerosol Sampler for 0-Chlorobenzylidine Malonitrile

DTIC Science & Technology

2013-04-02

photometric particle counting instrument, DustTrak, to the established OSHA modified NIOSH P&CAM 304 method to determine correlation between the two...study compared the non-specific, rapid photometric particle counting instrument, DustTrak, to the established OSHA modified NIOSH P&CAM 304 method...mask confidence training (27) . This study will compare a direct reading, non-specific photometric particle count instrument (DustTrak TSI Model

Instrumental variable applications using nursing home prescribing preferences in comparative effectiveness research.

PubMed

Huybrechts, Krista F; Gerhard, Tobias; Franklin, Jessica M; Levin, Raisa; Crystal, Stephen; Schneeweiss, Sebastian

2014-08-01

Nursing home residents are of particular interest for comparative effectiveness research given their susceptibility to adverse treatment effects and systematic exclusion from trials. However, the risk of residual confounding because of unmeasured markers of declining health using conventional analytic methods is high. We evaluated the validity of instrumental variable (IV) methods based on nursing home prescribing preference to mitigate such confounding, using psychotropic medications to manage behavioral problems in dementia as a case study. A cohort using linked data from Medicaid, Medicare, Minimum Data Set, and Online Survey, Certification and Reporting for 2001-2004 was established. Dual-eligible patients ≥65 years who initiated psychotropic medication use after admission were selected. Nursing home prescribing preference was characterized using mixed-effects logistic regression models. The plausibility of IV assumptions was explored, and the association between psychotropic medication class and 180-day mortality was estimated. High-prescribing and low-prescribing nursing homes differed by a factor of 2. Each preference-based IV measure described a substantial proportion of variation in psychotropic medication choice (β(IV → treatment): 0.22-0.36). Measured patient characteristics were well balanced across patient groups based on instrument status (52% average reduction in Mahalanobis distance). There was no evidence that instrument status was associated with markers of nursing home quality of care. Findings indicate that IV analyses using nursing home prescribing preference may be a useful approach in comparative effectiveness studies, and should extend naturally to analyses including untreated comparison groups, which are of great scientific interest but subject to even stronger confounding. Copyright © 2014 John Wiley & Sons, Ltd.

Application of surface plasmon resonance for the detection of carbohydrates, glycoconjugates, and measurement of the carbohydrate-specific interactions: a comparison with conventional analytical techniques. A critical review.

PubMed

Safina, Gulnara

2012-01-27

Carbohydrates (glycans) and their conjugates with proteins and lipids contribute significantly to many biological processes. That makes these compounds important targets to be detected, monitored and identified. The identification of the carbohydrate content in their conjugates with proteins and lipids (glycoforms) is often a challenging task. Most of the conventional instrumental analytical techniques are time-consuming and require tedious sample pretreatment and utilising various labeling agents. Surface plasmon resonance (SPR) has been intensively developed during last two decades and has received the increasing attention for different applications, from the real-time monitoring of affinity bindings to biosensors. SPR does not require any labels and is capable of direct measurement of biospecific interaction occurring on the sensing surface. This review provides a critical comparison of modern analytical instrumental techniques with SPR in terms of their analytical capabilities to detect carbohydrates, their conjugates with proteins and lipids and to study the carbohydrate-specific bindings. A few selected examples of the SPR approaches developed during 2004-2011 for the biosensing of glycoforms and for glycan-protein affinity studies are comprehensively discussed. Copyright © 2011 Elsevier B.V. All rights reserved.

Implementation and application of moving average as continuous analytical quality control instrument demonstrated for 24 routine chemistry assays.

PubMed

Rossum, Huub H van; Kemperman, Hans

2017-07-26

General application of a moving average (MA) as continuous analytical quality control (QC) for routine chemistry assays has failed due to lack of a simple method that allows optimization of MAs. A new method was applied to optimize the MA for routine chemistry and was evaluated in daily practice as continuous analytical QC instrument. MA procedures were optimized using an MA bias detection simulation procedure. Optimization was graphically supported by bias detection curves. Next, all optimal MA procedures that contributed to the quality assurance were run for 100 consecutive days and MA alarms generated during working hours were investigated. Optimized MA procedures were applied for 24 chemistry assays. During this evaluation, 303,871 MA values and 76 MA alarms were generated. Of all alarms, 54 (71%) were generated during office hours. Of these, 41 were further investigated and were caused by ion selective electrode (ISE) failure (1), calibration failure not detected by QC due to improper QC settings (1), possible bias (significant difference with the other analyzer) (10), non-human materials analyzed (2), extreme result(s) of a single patient (2), pre-analytical error (1), no cause identified (20), and no conclusion possible (4). MA was implemented in daily practice as a continuous QC instrument for 24 routine chemistry assays. In our setup when an MA alarm required follow-up, a manageable number of MA alarms was generated that resulted in valuable MA alarms. For the management of MA alarms, several applications/requirements in the MA management software will simplify the use of MA procedures.

Construction Method of Analytical Solutions to the Mathematical Physics Boundary Problems for Non-Canonical Domains

NASA Astrophysics Data System (ADS)

Mobarakeh, Pouyan Shakeri; Grinchenko, Victor T.

2015-06-01

The majority of practical cases of acoustics problems requires solving the boundary problems in non-canonical domains. Therefore construction of analytical solutions of mathematical physics boundary problems for non-canonical domains is both lucrative from the academic viewpoint, and very instrumental for elaboration of efficient algorithms of quantitative estimation of the field characteristics under study. One of the main solving ideologies for such problems is based on the superposition method that allows one to analyze a wide class of specific problems with domains which can be constructed as the union of canonically-shaped subdomains. It is also assumed that an analytical solution (or quasi-solution) can be constructed for each subdomain in one form or another. However, this case implies some difficulties in the construction of calculation algorithms, insofar as the boundary conditions are incompletely defined in the intervals, where the functions appearing in the general solution are orthogonal to each other. We discuss several typical examples of problems with such difficulties, we study their nature and identify the optimal methods to overcome them.

A Review of Current Methods for Analysis of Mycotoxins in Herbal Medicines

PubMed Central

Zhang, Lei; Dou, Xiao-Wen; Zhang, Cheng; Logrieco, Antonio F.; Yang, Mei-Hua

2018-01-01

The presence of mycotoxins in herbal medicines is an established problem throughout the entire world. The sensitive and accurate analysis of mycotoxin in complicated matrices (e.g., herbs) typically involves challenging sample pretreatment procedures and an efficient detection instrument. However, although numerous reviews have been published regarding the occurrence of mycotoxins in herbal medicines, few of them provided a detailed summary of related analytical methods for mycotoxin determination. This review focuses on analytical techniques including sampling, extraction, cleanup, and detection for mycotoxin determination in herbal medicines established within the past ten years. Dedicated sections of this article address the significant developments in sample preparation, and highlight the importance of this procedure in the analytical technology. This review also summarizes conventional chromatographic techniques for mycotoxin qualification or quantitation, as well as recent studies regarding the development and application of screening assays such as enzyme-linked immunosorbent assays, lateral flow immunoassays, aptamer-based lateral flow assays, and cytometric bead arrays. The present work provides a good insight regarding the advanced research that has been done and closes with an indication of future demand for the emerging technologies. PMID:29393905

Real-Time Monitoring of Cellular Bioenergetics with a Multi-Analyte Screen-Printed Electrode

PubMed Central

McKenzie, Jennifer R.; Cognata, Andrew C.; Davis, Anna N.; Wikswo, John P.; Cliffel, David E.

2016-01-01

Real-time monitoring of changes to cellular bioenergetics can provide new insights into mechanisms of action for disease and toxicity. This work describes the development of a multi-analyte screen-printed electrode for the detection of analytes central to cellular bioenergetics: glucose, lactate, oxygen, and pH. Platinum screen-printed electrodes were designed in-house and printed by Pine Research Instrumentation. Electrochemical plating techniques were used to form quasi-reference and pH electrodes. A Dimatix materials inkjet printer was used to deposit enzyme and polymer films to form sensors for glucose, lactate, and oxygen. These sensors were evaluated in bulk solution and microfluidic environments, and found to behave reproducibly and possess a lifetime of up to six weeks. Linear ranges and limits of detection for enzyme-based sensors were found to have an inverse relationship with enzyme loading, and iridium oxide pH sensors were found to have super-Nernstian responses. Preliminary measurements where the sensor was enclosed within a microfluidic channel with RAW 264.7 macrophages were performed to demonstrate the sensors’ capabilities for performing real-time microphysiometry measurements. PMID:26125545

Comparison of functional group selective ion-molecule reactions of trimethyl borate in different ion trap mass spectrometers

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

Habicht, S C; Vinueza, Nelson R; Amundson, Lucas M

2011-02-01

We report here a comparison of the use of diagnostic ion–molecule reactions for the identification of oxygen-containing functional groups in Fourier-transform ion cyclotron resonance (FTICR) and linear quadrupole ion trap (LQIT) mass spectrometers. The ultimate goal of this research is to be able to identify functionalities in previously unknown analytes by using many different types of mass spectrometers. Previous work has focused on the reactions of various boron reagents with protonated oxygen-containing analytes in FTICR mass spectrometers. By using a LQIT modified to allow the introduction of neutral reagents into the helium buffer gas, this methodology has been successfully implementedmore » to this type of an ion trap instrument. The products obtained from the reactions of trimethyl borate (TMB) with various protonated analytes are compared for the two instruments. Finally, the ability to integrate these reactions into LC-MS experiments on the LQIT is demonstrated.« less

Nanometrology and its perspectives in environmental research.

PubMed

Kim, Hyun-A; Seo, Jung-Kwan; Kim, Taksoo; Lee, Byung-Tae

2014-01-01

Rapid increase in engineered nanoparticles (ENPs) in many goods has raised significant concern about their environmental safety. Proper methodologies are therefore needed to conduct toxicity and exposure assessment of nanoparticles in the environment. This study reviews several analytical techniques for nanoparticles and summarizes their principles, advantages and disadvantages, reviews the state of the art, and offers the perspectives of nanometrology in relation to ENP studies. Nanometrology is divided into five techniques with regard to the instrumental principle: microscopy, light scattering, spectroscopy, separation, and single particle inductively coupled plasma-mass spectrometry. Each analytical method has its own drawbacks, such as detection limit, ability to quantify or qualify ENPs, and matrix effects. More than two different analytical methods should be used to better characterize ENPs. In characterizing ENPs, the researchers should understand the nanometrology and its demerits, as well as its merits, to properly interpret their experimental results. Challenges lie in the nanometrology and pretreatment of ENPs from various matrices; in the extraction without dissolution or aggregation, and concentration of ENPs to satisfy the instrumental detection limit.

Acquisition of a High Resolution Field Emission Scanning Electron Microscope for the Analysis of Returned Samples

NASA Technical Reports Server (NTRS)

Nittler, Larry R.

2003-01-01

This grant furnished funds to purchase a state-of-the-art scanning electron microscope (SEM) to support our analytical facilities for extraterrestrial samples. After evaluating several instruments, we purchased a JEOL 6500F thermal field emission SEM with the following analytical accessories: EDAX energy-dispersive x-ray analysis system with fully automated control of instrument and sample stage; EDAX LEXS wavelength-dispersive x-ray spectrometer for high sensitivity light-element analysis; EDAX/TSL electron backscatter diffraction (EBSD) system with software for phase identification and crystal orientation mapping; Robinson backscatter electron detector; and an in situ micro-manipulator (Kleindiek). The total price was $550,000 (with $150,000 of the purchase supported by Carnegie institution matching funds). The microscope was delivered in October 2002, and most of the analytical accessories were installed by January 2003. With the exception of the wavelength spectrometer (which has been undergoing design changes) everything is working well and the SEM is in routine use in our laboratory.

Process for analyzing CO.sub.2 in seawater

DOEpatents

Atwater, James E.; Akse, James R.; DeHart, Jeffrey

1997-01-01

The process of this invention comprises providing a membrane for separating CO.sub.2 into a first CO.sub.2 sample phase and a second CO.sub.2 analyte phase. CO.sub.2 is then transported through the membrane thereby separating the CO.sub.2 with the membrane into a first CO.sub.2 sample phase and a second CO.sub.2 analyte liquid phase including an ionized, conductive, dissociated CO.sub.2 species. Next, the concentration of the ionized, conductive, dissociated CO.sub.2 species in the second CO.sub.2 analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO.sub.2 to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO.sub.2 in the first CO.sub.2 sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO.sub.2 species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO.sub.2 species are detected using the conductivity measuring instrument.

Dissecting the human immunologic memory for pathogens.

PubMed

Zielinski, Christina E; Corti, Davide; Mele, Federico; Pinto, Dora; Lanzavecchia, Antonio; Sallusto, Federica

2011-03-01

Studies on immunologic memory in animal models and especially in the human system are instrumental to identify mechanisms and correlates of protection necessary for vaccine development. In this article, we provide an overview of the cellular basis of immunologic memory. We also describe experimental approaches based on high throughput cell cultures, which we have developed to interrogate human memory T cells, B cells, and plasma cells. We discuss how these approaches can provide new tools and information for vaccine design, in a process that we define as 'analytic vaccinology'. © 2011 John Wiley & Sons A/S.

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

Green, D.W.; Heinrich, R.R.; Jensen, K.J.

The Analytical Chemistry Laboratory is a full-cost-recovery service center, with the primary mission of providing a broad range of technical support services to the scientific and engineering programs at ANL. In addition, ACL conducts a research program in analytical chemistry, works on instrumental and methods development, and provides analytical services for governmental, educational, and industrial organizations. The ACL handles a wide range of analytical problems, from routine standard analyses to unique problems that require significant development of methods and techniques. The purpose of this report is to summarize the technical and administrative activities of the Analytical Chemistry Laboratory (ACL) atmore » Argonne National Laboratory (ANL) for Fiscal Year 1985 (October 1984 through September 1985). This is the second annual report for the ACL. 4 figs., 1 tab.« less

System compliance dictates the effect of composite filler content on polymerization shrinkage stress.

PubMed

Wang, Zhengzhi; Chiang, Martin Y M

2016-04-01

The effect of filler content in dental restorative composites on the polymerization shrinkage stress (PS) is not straightforward and has caused much debate in the literature. Our objective in this study was to clarify the PS/filler content relationship based on analytical and experimental approaches, so that guidelines for materials comparison in terms of PS and clinical selection of dental composites with various filler content can be provided. Analytically, a simplified model based on linear elasticity was utilized to predict PS as a function of filler content under various compliances of the testing system, a cantilever beam-based instrument used in this study. The predictions were validated by measuring PS of composites synthesized using 50/50 mixtures of two common dimethacrylate resins with a variety of filler contents. Both experiments and predictions indicated that the influence of filler content on the PS highly depended on the compliance of the testing system. Within the clinic-relevant range of compliances and for the specific sample configuration tested, the PS increased with increasing filler content at low compliance of instrument, while increasing the compliance caused the effect of filler content on the PS to gradually diminish. Eventually, at high compliance, the PS inverted and decreased with increasing filler content. This compliance-dependent effect of filler content on PS suggests: (1) for materials comparison in terms of PS, the specific compliance at which the comparison being done should always be reported and (2) clinically, composites with relatively lower filler content could be selected for such cavities with relatively lower compliance (e.g. a Class-I cavity with thick tooth walls or the basal part in a cavity) and vice versa in order to reduce the final PS. Published by Elsevier Ltd.

Comparison of the analytical capabilities of the BAC Datamaster and Datamaster DMT forensic breath testing devices.

PubMed

Glinn, Michele; Adatsi, Felix; Curtis, Perry

2011-11-01

The State of Michigan uses the Datamaster as an evidential breath testing device. The newest version, the DMT, will replace current instruments in the field as they are retired from service. The Michigan State Police conducted comparison studies to test the analytical properties of the new instrument and to evaluate its response to conditions commonly cited in court defenses. The effects of mouth alcohol, objects in the mouth, and radiofrequency interference on paired samples from drinking subjects were assessed on the DMT. The effects of sample duration and chemical interferents were assessed on both instruments, using drinking subjects and wet-bath simulators, respectively. Our testing shows that Datamaster and DMT results are essentially identical; the DMT gave accurate readings as compared with measurements made using simulators containing standard ethanol solutions and that the DMT did not give falsely elevated breath alcohol results from any of the influences tested. © 2011 American Academy of Forensic Sciences.

Ion mobility analysis of lipoproteins

DOEpatents

Benner, W Henry [Danville, CA; Krauss, Ronald M [Berkeley, CA; Blanche, Patricia J [Berkeley, CA

2007-08-21

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Aerosol preparation of intact lipoproteins

DOEpatents

Benner, W Henry [Danville, CA; Krauss, Ronald M [Berkeley, CA; Blanche, Patricia J [Berkeley, CA

2012-01-17

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Two-dimensional convolute integers for analytical instrumentation

NASA Technical Reports Server (NTRS)

Edwards, T. R.

1982-01-01

As new analytical instruments and techniques emerge with increased dimensionality, a corresponding need is seen for data processing logic which can appropriately address the data. Two-dimensional measurements reveal enhanced unknown mixture analysis capability as a result of the greater spectral information content over two one-dimensional methods taken separately. It is noted that two-dimensional convolute integers are merely an extension of the work by Savitzky and Golay (1964). It is shown that these low-pass, high-pass and band-pass digital filters are truly two-dimensional and that they can be applied in a manner identical with their one-dimensional counterpart, that is, a weighted nearest-neighbor, moving average with zero phase shifting, convoluted integer (universal number) weighting coefficients.

Auditing of chromatographic data.

PubMed

Mabie, J T

1998-01-01

During a data audit, it is important to ensure that there is clear documentation and an audit trail. The Quality Assurance Unit should review all areas, including the laboratory, during the conduct of the sample analyses. The analytical methodology that is developed should be documented prior to sample analyses. This is an important document for the auditor, as it is the instrumental piece used by the laboratory personnel to maintain integrity throughout the process. It is expected that this document will give insight into the sample analysis, run controls, run sequencing, instrument parameters, and acceptance criteria for the samples. The sample analysis and all supporting documentation should be audited in conjunction with this written analytical method and any supporting Standard Operating Procedures to ensure the quality and integrity of the data.

Optimization and Design of an Absorbance Spectrometer Controlled Using a Raspberry Pi to Improve Analytical Skills

ERIC Educational Resources Information Center

Bougot-Robin, Kristelle; Paget, Jack; Atkins, Stephen C.; Edel, Joshua B.

2016-01-01

It is not uncommon for students to view laboratory instruments as black boxes. Unfortunately, this can often result in poor experimental results and interpretation. To tackle this issue, a laboratory course was designed to enable students not only to critically think about operating principles of the instrument but also to improve interpretation…

A Factor Analytic Investigation of the BASC-2 Behavioral and Emotional Screening System Parent Form: Psychometric Properties, Practical Implications, and Future Directions

ERIC Educational Resources Information Center

Dowdy, Erin; Chin, Jenna K.; Twyford, Jennifer M.; Dever, Bridget V.

2011-01-01

The Behavior Assessment System for Children, Second Edition (BASC-2) Behavioral and Emotional Screening System Parent Form (BESS Parent; Kamphaus & Reynolds, 2007) is a recently developed instrument designed to identify behavioral and emotional risk in students. To describe the underlying factor structure for this instrument, exploratory (EFA)…

An Automated Analyzer System to Strengthen Teaching and Research Infrastructure at West Virginia State University

DTIC Science & Technology

2015-08-18

SECURITY CLASSIFICATION OF: Arena 60 Discrete Photometric Analyzer System and ancillary instrumentation were acquired to increase our analytical...Infrastructure at West Virginia State University Report Title Arena 60 Discrete Photometric Analyzer System and ancillary instrumentation were acquired...Progress Principal Accomplishments: a. One Postdoctoral fellow was trained using the automated Arena 60 Discrete Photometric Analyzer and

Validating Affordances as an Instrument for Design and a Priori Analysis of Didactical Situations in Mathematics

ERIC Educational Resources Information Center

Sollervall, Håkan; Stadler, Erika

2015-01-01

The aim of the presented case study is to investigate how coherent analytical instruments may guide the a priori and a posteriori analyses of a didactical situation. In the a priori analysis we draw on the notion of affordances, as artefact-mediated opportunities for action, to construct hypothetical trajectories of goal-oriented actions that have…

Novel approaches to the construction of miniaturized analytical instrumentation

NASA Technical Reports Server (NTRS)

Porter, Marc D.; Otoole, Ronald P.; Coldiron, Shelley J.; Deninger, William D.; Deinhammer, Randall S.; Burns, Stanley G.; Bastiaans, Glenn J.; Braymen, Steve D.; Shanks, Howard R.

1992-01-01

This paper focuses on the design, construction, preliminary testing, and potential applications of three forms of miniaturized analytical instrumentation. The first is an optical fiber instrument for monitoring pH and other cations in aqueous solutions. The instrument couples chemically selective indicators that were immobilized at porous polymeric films with a hardware package that provides the excitation light source, required optical components, and detection and data processing hardware. The second is a new form of a piezoelectric mass sensor. The sensor was fabricated by the deposition of a thin (5.5 micron) film of piezoelectric aluminum nitride (AIN). The completed deposition process yields a thin film resonator (TFR) that is shaped as a 400 micron square and supports a standing bulk acoustic wave in a longitudinal mode at frequencies of approx. 1 GHz. Various deposition and vapor sorption studies indicate that the mass sensitivity of the TFR's rival those of the most sensitive mass sensors currently available, though offering such performance in a markedly smaller device. The third couples a novel form of liquid chromatography with microlithographic miniaturization techniques. The status of the miniaturization effort, the goal of which is to achieve chip-scale separations, is briefly discussed.

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

Koester, C J; Moulik, A

This article discusses developments in environmental analytical chemistry that occurred in the years of 2003 and 2004. References were found by searching the ''Science Citation Index and Current Contents''. As in our review of two years ago (A1), techniques are highlighted that represent current trends and state-of-the-art technologies in the sampling, extraction, separation, and detection of trace concentrations, low-part-per-billion and less, of organic, inorganic, and organometallic contaminants in environmental samples. New analytes of interest are also reviewed, the detections of which are made possible by recently developed analytical instruments and methods.

A bioanalytical platform for simultaneous detection and quantification of biological toxins.

PubMed

Weingart, Oliver G; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin's identity and concentration. The system's performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5-1 ng · mL(-1) in buffer or in raw milk.

A Bioanalytical Platform for Simultaneous Detection and Quantification of Biological Toxins

PubMed Central

Weingart, Oliver G.; Gao, Hui; Crevoisier, François; Heitger, Friedrich; Avondet, Marc-André; Sigrist, Hans

2012-01-01

Prevalent incidents support the notion that toxins, produced by bacteria, fungi, plants or animals are increasingly responsible for food poisoning or intoxication. Owing to their high toxicity some toxins are also regarded as potential biological warfare agents. Accordingly, control, detection and neutralization of toxic substances are a considerable economic burden to food safety, health care and military biodefense. The present contribution describes a new versatile instrument and related procedures for array-based simultaneous detection of bacterial and plant toxins using a bioanalytical platform which combines the specificity of covalently immobilized capture probes with a dedicated instrumentation and immuno-based microarray analytics. The bioanalytical platform consists of a microstructured polymer slide serving both as support of printed arrays and as incubation chamber. The platform further includes an easy-to-operate instrument for simultaneous slide processing at selectable assay temperature. Cy5 coupled streptavidin is used as unifying fluorescent tracer. Fluorescence image analysis and signal quantitation allow determination of the toxin’s identity and concentration. The system’s performance has been investigated by immunological detection of Botulinum Neurotoxin type A (BoNT/A), Staphylococcal enterotoxin B (SEB), and the plant toxin ricin. Toxins were detectable at levels as low as 0.5–1 ng·mL−1 in buffer or in raw milk. PMID:22438766

Development and validation of an UHPLC-MS/MS method for β2-agonists quantification in human urine and application to clinical samples.

PubMed

Bozzolino, Cristina; Leporati, Marta; Gani, Federica; Ferrero, Cinzia; Vincenti, Marco

2018-02-20

A fast analytical method for the simultaneous detection of 24 β 2 -agonists in human urine was developed and validated. The method covers the therapeutic drugs most commonly administered, but also potentially abused β 2 -agonists. The procedure is based on enzymatic deconjugation with β-glucuronidase followed by SPE clean up using mixed-phase cartridges with both ion-exchange and lipophilic properties. Instrumental analysis conducted by UHPLC-MS/MS allowed high peak resolution and rapid chromatographic separation, with reduced time and costs. The method was fully validated according ISO 17025:2005 principles. The following parameters were determined for each analyte: specificity, selectivity, linearity, limit of detection, limit of quantification, precision, accuracy, matrix effect, recovery and carry-over. The method was tested on real samples obtained from patients subjected to clinical treatment under chronic or acute therapy with either formoterol, indacaterol, salbutamol, or salmeterol. The drugs were administered using pressurized metered dose inhalers. All β 2 -agonists administered to the patients were detected in the real samples. The method proved adequate to accurately measure the concentration of these analytes in the real samples. The observed analytical data are discussed with reference to the administered dose and the duration of the therapy. Copyright © 2017 Elsevier B.V. All rights reserved.

Blood analysis by Raman spectroscopy.

PubMed

Enejder, Annika M K; Koo, Tae-Woong; Oh, Jeankun; Hunter, Martin; Sasic, Slobodan; Feld, Michael S; Horowitz, Gary L

2002-11-15

Concentrations of multiple analytes were simultaneously measured in whole blood with clinical accuracy, without sample processing, using near-infrared Raman spectroscopy. Spectra were acquired with an instrument employing nonimaging optics, designed using Monte Carlo simulations of the influence of light-scattering-absorbing blood cells on the excitation and emission of Raman light in turbid medium. Raman spectra were collected from whole blood drawn from 31 individuals. Quantitative predictions of glucose, urea, total protein, albumin, triglycerides, hematocrit, and hemoglobin were made by means of partial least-squares (PLS) analysis with clinically relevant precision (r(2) values >0.93). The similarity of the features of the PLS calibration spectra to those of the respective analyte spectra illustrates that the predictions are based on molecular information carried by the Raman light. This demonstrates the feasibility of using Raman spectroscopy for quantitative measurements of biomolecular contents in highly light-scattering and absorbing media.

Fast and accurate detection of cancer cell using a versatile three-channel plasmonic sensor

NASA Astrophysics Data System (ADS)

Hoseinian, M.; Ahmadi, A. R.; Bolorizadeh, M. A.

2016-09-01

Surface Plasmon Resonance (SPR) optical fiber sensors can be used as cost-effective small sized biosensors that are relatively simple to operate. Additionally, these instruments are label-free, hence rendering them highly sensitive to biological measurements. In this study, a three-channel microstructure optical fiber plasmonic-based portable biosensor is designed and analyzed using Finite Element Method. The proposed system is capable of determining changes in sample's refractive index with precision of order one thousandth. The biosensor measures three absorption resonance wavelengths of the analytes simultaneously. This property is one of the main advantages of the proposed biosensor since it reduces the error in the measured wavelength and enhances the accuracy of the results up to 10-5 m/RIU by reducing noise. In this paper, Jurkat cell, an indicator cell for leukemia cancer, is considered as the analyte; and its absorption resonance wavelengths as well as sensitivity in each channel are determined.

Nuclear analytical techniques in medicine

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

Cesareo, R.

1988-01-01

This book acquaints one with the fundamental principles and the instrumentation relevant to analytical technique based on atomic and nuclear physics, as well as present and future biomedical applications. Besides providing a theoretical description of the physical phenomena, a large part of the book is devoted to applications in the medical and biological field, particularly in hematology, forensic medicine and environmental science. This volume reviews methods such as the possibility of carrying out rapid multi-element analysis of trace elements on biomedical samples, in vitro and in vivo, by XRF-analysis; the ability of the PIXE-microprobe to analyze in detail and tomore » map trace elements in fragments of biomedical samples or inside the cells; the potentiality of in vivo nuclear activation analysis for diagnostic purposes. Finally, techniques are described such as radiation scattering (elastic and inelastic scattering) and attenuation measurements which will undoubtedly see great development in the immediate future.« less

Analytic evaluation of the weighting functions for remote sensing of blackbody planetary atmospheres : the case of limb viewing geometry

NASA Technical Reports Server (NTRS)

Ustinov, Eugene A.

2006-01-01

In a recent publication (Ustinov, 2002), we proposed an analytic approach to evaluation of radiative and geophysical weighting functions for remote sensing of a blackbody planetary atmosphere, based on general linearization approach applied to the case of nadir viewing geometry. In this presentation, the general linearization approach is applied to the limb viewing geometry. The expressions, similar to those obtained in (Ustinov, 2002), are obtained for weighting functions with respect to the distance along the line of sight. Further on, these expressions are converted to the expressions for weighting functions with respect to the vertical coordinate in the atmosphere. Finally, the numerical representation of weighting functions in the form of matrices of partial derivatives of grid limb radiances with respect to the grid values of atmospheric parameters is used for a convolution with the finite field of view of the instrument.

Plasmonic ELISA for the ultrasensitive detection of disease biomarkers with the naked eye

NASA Astrophysics Data System (ADS)

de La Rica, Roberto; Stevens, Molly M.

2012-12-01

In resource-constrained countries, affordable methodologies for the detection of disease biomarkers at ultralow concentrations can potentially improve the standard of living. However, current strategies for ultrasensitive detection often require sophisticated instruments that may not be available in laboratories with fewer resources. Here, we circumvent this problem by introducing a signal generation mechanism for biosensing that enables the detection of a few molecules of analyte with the naked eye. The enzyme label of an enzyme-linked immunosorbent assay (ELISA) controls the growth of gold nanoparticles and generates coloured solutions with distinct tonality when the analyte is present. Prostate specific antigen (PSA) and HIV-1 capsid antigen p24 were detected in whole serum at the ultralow concentration of 1 × 10-18 g ml-1. p24 was also detected with the naked eye in the sera of HIV-infected patients showing viral loads undetectable by a gold standard nucleic acid-based test.

NIR and UV-vis spectroscopy, artificial nose and tongue: comparison of four fingerprinting techniques for the characterisation of Italian red wines.

PubMed

Casale, M; Oliveri, P; Armanino, C; Lanteri, S; Forina, M

2010-06-04

Four rapid and low-cost vanguard analytical systems (NIR and UV-vis spectroscopy, a headspace-mass based artificial nose and a voltammetric artificial tongue), together with chemometric pattern recognition techniques, were applied and compared in addressing a food authentication problem: the distinction between wine samples from the same Italian oenological region, according to the grape variety. Specifically, 59 certified samples belonging to the Barbera d'Alba and Dolcetto d'Alba appellations and collected from the same vintage (2007) were analysed. The instrumental responses, after proper data pre-processing, were used as fingerprints of the characteristics of the samples: the results from principal component analysis and linear discriminant analysis were discussed, comparing the capability of the four analytical strategies in addressing the problem studied. Copyright 2010 Elsevier B.V. All rights reserved.

International Space Station Modal Correction Analysis

NASA Technical Reports Server (NTRS)

Fotz[atrocl. Lrostom; Grugoer. < ocjae; Laible, Michael; Sugavanam, Sujatha

2012-01-01

This paper summarizes the on-orbit modal test and the related modal analysis, model validation and correlation performed for the ISS Stage ULF4, DTF S4-1A, October 11,2010, GMT 284/06:13:00.00. The objective of this analysis is to validate and correlate analytical models with the intent to verify the ISS critical interface dynamic loads and improve fatigue life prediction. For the ISS configurations under consideration, on-orbit dynamic responses were collected with Russian vehicles attached and without the Orbiter attached to the ISS. ISS instrumentation systems that were used to collect the dynamic responses during the DTF S4-1A included the Internal Wireless Instrumentation System (IWIS), External Wireless Instrumentation System (EWIS), Structural Dynamic Measurement System (SDMS), Space Acceleration Measurement System (SAMS), Inertial Measurement Unit (IMU) and ISS External Cameras. Experimental modal analyses were performed on the measured data to extract modal parameters including frequency, damping and mode shape information. Correlation and comparisons between test and analytical modal parameters were performed to assess the accuracy of models for the ISS configuration under consideration. Based on the frequency comparisons, the accuracy of the mathematical models is assessed and model refinement recommendations are given. Section 2.0 of this report presents the math model used in the analysis. This section also describes the ISS configuration under consideration and summarizes the associated primary modes of interest along with the fundamental appendage modes. Section 3.0 discusses the details of the ISS Stage ULF4 DTF S4-1A test. Section 4.0 discusses the on-orbit instrumentation systems that were used in the collection of the data analyzed in this paper. The modal analysis approach and results used in the analysis of the collected data are summarized in Section 5.0. The model correlation and validation effort is reported in Section 6.0. Conclusions and recommendations drawn from this analysis are included in Section 7.0.

Intercomparison of OH and OH reactivity measurements in a high isoprene and low NO environment during the Southern Oxidant and Aerosol Study (SOAS)

NASA Astrophysics Data System (ADS)

Sanchez, Dianne; Jeong, Daun; Seco, Roger; Wrangham, Ian; Park, Jeong-Hoo; Brune, William H.; Koss, Abigail; Gilman, Jessica; de Gouw, Joost; Misztal, Pawel; Goldstein, Allen; Baumann, Karsten; Wennberg, Paul O.; Keutsch, Frank N.; Guenther, Alex; Kim, Saewung

2018-02-01

We intercompare OH and OH reactivity datasets from two different techniques, chemical ionization mass spectrometry (CIMS) and laser-induced fluorescence (LIF) in a high isoprene and low NO environment in a southeastern US forest during the Southern Oxidant and Aerosol Study (SOAS). An LIF instrument measured OH and OH reactivity at the top of a tower, a CIMS instrument measured OH at the top of the tower, and a CIMS based comparative reactivity method (CRM-CIMS) instrument deployed at the base of the tower measured OH reactivity. Averaged diel variations of OH and OH reactivity from these datasets agree within analytical uncertainty and correlations of LIF versus CIMS for OH and OH reactivity have slopes of 0.65 and 0.97, respectively. However, there are systematic differences between the measurement datasets. The CRM-CIMS measurements of OH reactivity were ∼16% lower than those by the LIF technique in the late afternoon. We speculate that it is caused by losses in the sampling line down to the CRM-CIMS instrument. On the other hand, we could not come up with a reasonable explanation for the difference in the LIF and CIMS OH datasets for early morning and late afternoon when OH is below 1 × 106 molecules cm-3. Nonetheless, results of this intercomparison exercise strengthen previous publications from the field site on OH concentrations and atmospheric reactivity.

Image simulation and surface reconstruction of undercut features in atomic force microscopy

NASA Astrophysics Data System (ADS)

Qian, Xiaoping; Villarrubia, John; Tian, Fenglei; Dixson, Ronald

2007-03-01

CD-AFMs (critical dimension atomic force microscopes) are instruments with servo-control of the tip in more than one direction. With appropriately "boot-shaped" or flared tips, such instruments can image vertical or even undercut features. As with any AFM, the image is a dilation of the sample shape with the tip shape. Accurate extraction of the CD requires a correction for the tip effect. Analytical methods to correct images for the tip shape have been available for some time for the traditional (vertical feedback only) AFMs, but were until recently unavailable for instruments with multi-dimensional feedback. Dahlen et al. [J. Vac. Sci. Technol. B23, pp. 2297-2303, (2005)] recently introduced a swept-volume approach, implemented for 2-dimensional (2D) feedback. It permits image simulation and sample reconstruction, techniques previously developed for the traditional instruments, to be extended for the newer tools. We have introduced [X. Qian and J. S. Villarrubia, Ultramicroscopy, in press] an alternative dexel-based method, that does the same in either 2D or 3D. This paper describes the application of this method to sample shapes of interest in semiconductor manufacturing. When the tip shape is known (e.g., by prior measurement using a tip characterizer) a 3D sample surface may be reconstructed from its 3D image. Basing the CD measurement upon such a reconstruction is shown here to remove some measurement artifacts that are not removed (or are incompletely removed) by the existing measurement procedures.

Demonstration of the ExoMars sample preparation and distribution system jointly with an optical instrument head

NASA Astrophysics Data System (ADS)

Schulte, Wolfgang; Thiele, Hans; Hofmann, Peter; Baglioni, Pietro

The ExoMars program will search for past and present life on Mars. ExoMars will address important scientific goals and demonstrate key in-situ enabling technologies. Among such technologies are the acquisition, preparation, distribution and analysis of samples from Mars surface rocks and from the subsurface. The 2018 mission will land an ESA rover on Mars which carries a sample preparation and distribution system (SPDS) and a suite of analytical instruments, the Pasteur Payload with its Analytical Laboratory Drawer (ALD). Kayser-Threde GmbH (Germany) will be responsible for the SPDS as a subcontractor under the mission prime Thales Alenia Space. The SPDS comprises a number of complex mechanisms and mechanical devices designed to transport drill core samples within the rover analytical laboratory, to crush them to powder with a fine grain size, to portion discrete amounts of powdered sample material, to distribute and fill the material into sample containers and to prepare flat sample surfaces for scientific analysis. Breadboards of the crushing mechanism, the dosing mechanism and a distribution carousel with sample containers and a powder sample surface flattening mechanism were built and tested. Kayser-Threde, as a member of the Spanish led ExoMars Raman Instrument team, is also responsible for development of the Raman optical head, which will be mounted inside ALD and will inspect the crushed samples, when they are presented to the instrument by the distribution carousel. Within this activity, which is performed under contract with the Institute of Physical Chemistry of the University of Jena (Germany) and funded by the German DLR, Kayser-Threde can demonstrate Raman measurements with the optical head and a COTS laser and spectrometer and thus simulate the full Raman instrument optical path. An autofocus system with actuator and feedback optics is also part of this activity, which allows focusing the 50 m Raman spot on the surface of the powdered sample. Availability of both, the SPDS mechanisms and the Raman Spectrometer optical head at Kayser-Threde facilities allowed to demonstrate for the first time a sample preparation chain with a joint operation of the optical head. Mineral samples were crushed, dosed into sample containers on the carousel, flattened and then inspected by the Raman optical head. The samples were provided by the University of Jena, a member of the ExoMars Raman science team. This paper will give an overview of the breadboards developed so far for the ExoMars SPDS and the Raman optical head and illustrate the joint demonstration test setup of the SPDS with the instrument. The different behavior of different sample materials will be highlighted and first conclusions will be drawn on what could be learned from test setups combining the ExoMars SPDS and analytical instruments.

Commentary on "Theory-Led Design of Instruments and Representations in Learning Analytics: Developing a Novel Tool for Orchestration of Online Collaborative Learning"

ERIC Educational Resources Information Center

Teplovs, Chris

2015-01-01

This commentary reflects on the contributions to learning analytics and theory by a paper that describes how multiple theoretical frameworks were woven together to inform the creation of a new, automated discourse analysis tool. The commentary highlights the contributions of the original paper, provides some alternative approaches, and touches on…

[Examination of analytical method for triphenyltin (TPT) and tributyltin (TBT) to revise the official methods based on "Act on the Control of Household Products Containing Harmful Substances"].

PubMed

Kawakami, Tsuyoshi; Isama, Kazuo; Nakashima, Harunobu; Yoshida, Jin; Ooshima, Tomoko; Ohno, Hiroyuki; Uemura, Hitoshi; Shioda, Hiroko; Kikuchi, Yoko; Matsuoka, Atsuko; Nishimura, Tetsuji

2012-01-01

The use of triphenyltin (TPT) and tributyltin (TBT) in some household products is banned by "Act on the Control of Household Products Containing Harmful Substances" in Japan. To revise the official analytical method, the method for detecting these organotin compounds was examined in six laboratories using a textile product, water-based adhesive, oil-based paint, which contained known amounts of TPT and TBT (0.1, 1.0, 10 μg/g). TPT and TBT were measured by GC-MS after ethyl-derivation with sodium tetraethylborate. The TBT recoveries in the samples were 70-120%. The TPT recoveries in the water-based adhesive samples were 80-110%, while its concentrations in the textile product and oil-based paint samples decreased because of dephenylation during storage. However, the precision of the method examined was satisfactory because most coefficients of variation for TPT and TBT in the samples were less than 10%. Furthermore, the revised method was able to detect concentrations lower than the officially regulated value. However, the sample matrix and the condition of analytical instrument might affect the estimated TPT and TBT concentrations. Therefore, the revised method may not be suitable for quantitative tests; rather, it can be employed to judge the acceptable levels of these organotin compounds by comparing the values of control sample containing regulated amounts of TPT and TBT with those for an unknown sample, with deuterated TPT and TBT as surrogate substances. It is desirable that TPT in textile and oil-based paint samples are analyzed immediately after the samples obtained because of the decomposition of TPT.

Instrumentation and methodology for quantifying GFP fluorescence in intact plant organs

NASA Technical Reports Server (NTRS)

Millwood, R. J.; Halfhill, M. D.; Harkins, D.; Russotti, R.; Stewart, C. N. Jr

2003-01-01

The General Fluorescence Plant Meter (GFP-Meter) is a portable spectrofluorometer that utilizes a fiber-optic cable and a leaf clip to gather spectrofluorescence data. In contrast to traditional analytical systems, this instrument allows for the rapid detection and fluorescence measurement of proteins under field conditions with no damage to plant tissue. Here we discuss the methodology of gathering and standardizing spectrofluorescence data from tobacco and canola plants expressing GFP. Furthermore, we demonstrate the accuracy and effectiveness of the GFP-Meter. We first compared GFP fluorescence measurements taken by the GFP-Meter to those taken by a standard laboratory-based spectrofluorometer, the FluoroMax-2. Spectrofluorescence measurements were taken from the same location on intact leaves. When these measurements were tested by simple linear regression analysis, we found that there was a positive functional relationship between instruments. Finally, to exhibit that the GFP-Meter recorded accurate measurements over a span of time, we completed a time-course analysis of GFP fluorescence measurements. We found that only initial measurements were accurate; however, subsequent measurements could be used for qualitative purposes.

Laboratory Scale X-ray Fluorescence Tomography: Instrument Characterization and Application in Earth and Environmental Science.

PubMed

Laforce, Brecht; Vermeulen, Bram; Garrevoet, Jan; Vekemans, Bart; Van Hoorebeke, Luc; Janssen, Colin; Vincze, Laszlo

2016-03-15

A new laboratory scale X-ray fluorescence (XRF) imaging instrument, based on an X-ray microfocus tube equipped with a monocapillary optic, has been developed to perform XRF computed tomography experiments with both higher spatial resolution (20 μm) and a better energy resolution (130 eV @Mn-K(α)) than has been achieved up-to-now. This instrument opens a new range of possible applications for XRF-CT. Next to the analytical characterization of the setup by using well-defined model/reference samples, demonstrating its capabilities for tomographic imaging, the XRF-CT microprobe has been used to image the interior of an ecotoxicological model organism, Americamysis bahia. This had been exposed to elevated metal (Cu and Ni) concentrations. The technique allowed the visualization of the accumulation sites of copper, clearly indicating the affected organs, i.e. either the gastric system or the hepatopancreas. As another illustrative application, the scanner has been employed to investigate goethite spherules from the Cretaceous-Paleogene boundary, revealing the internal elemental distribution of these valuable distal ejecta layer particles.

Particle shape accounts for instrumental discrepancy in ice core dust size distributions

NASA Astrophysics Data System (ADS)

Folden Simonsen, Marius; Cremonesi, Llorenç; Baccolo, Giovanni; Bosch, Samuel; Delmonte, Barbara; Erhardt, Tobias; Kjær, Helle Astrid; Potenza, Marco; Svensson, Anders; Vallelonga, Paul

2018-05-01

The Klotz Abakus laser sensor and the Coulter counter are both used for measuring the size distribution of insoluble mineral dust particles in ice cores. While the Coulter counter measures particle volume accurately, the equivalent Abakus instrument measurement deviates substantially from the Coulter counter. We show that the difference between the Abakus and the Coulter counter measurements is mainly caused by the irregular shape of dust particles in ice core samples. The irregular shape means that a new calibration routine based on standard spheres is necessary for obtaining fully comparable data. This new calibration routine gives an increased accuracy to Abakus measurements, which may improve future ice core record intercomparisons. We derived an analytical model for extracting the aspect ratio of dust particles from the difference between Abakus and Coulter counter data. For verification, we measured the aspect ratio of the same samples directly using a single-particle extinction and scattering instrument. The results demonstrate that the model is accurate enough to discern between samples of aspect ratio 0.3 and 0.4 using only the comparison of Abakus and Coulter counter data.

The role of multi-target policy instruments in agri-environmental policy mixes.

PubMed

Schader, Christian; Lampkin, Nicholas; Muller, Adrian; Stolze, Matthias

2014-12-01

The Tinbergen Rule has been used to criticise multi-target policy instruments for being inefficient. The aim of this paper is to clarify the role of multi-target policy instruments using the case of agri-environmental policy. Employing an analytical linear optimisation model, this paper demonstrates that there is no general contradiction between multi-target policy instruments and the Tinbergen Rule, if multi-target policy instruments are embedded in a policy-mix with a sufficient number of targeted instruments. We show that the relation between cost-effectiveness of the instruments, related to all policy targets, is the key determinant for an economically sound choice of policy instruments. If economies of scope with respect to achieving policy targets are realised, a higher cost-effectiveness of multi-target policy instruments can be achieved. Using the example of organic farming support policy, we discuss several reasons why economies of scope could be realised by multi-target agri-environmental policy instruments. Copyright © 2014 Elsevier Ltd. All rights reserved.

Foundations of measurement and instrumentation

NASA Technical Reports Server (NTRS)

Warshawsky, Isidore

1990-01-01

The user of instrumentation has provided an understanding of the factors that influence instrument performance, selection, and application, and of the methods of interpreting and presenting the results of measurements. Such understanding is prerequisite to the successful attainment of the best compromise among reliability, accuracy, speed, cost, and importance of the measurement operation in achieving the ultimate goal of a project. Some subjects covered are dimensions; units; sources of measurement error; methods of describing and estimating accuracy; deduction and presentation of results through empirical equations, including the method of least squares; experimental and analytical methods of determining the static and dynamic behavior of instrumentation systems, including the use of analogs.

Instrumental images: the visual rhetoric of self-presentation in Hevelius's Machina Coelestis.

PubMed

Vertesi, Janet

2010-06-01

This article places the famous images of Johannes Hevelius's instruments in his Machina Coelestis (1673) in the context of Hevelius's contested cometary observations and his debate with Hooke over telescopic sights. Seen thus, the images promote a crafted vision of Hevelius's astronomical practice and skills, constituting a careful self-presentation to his distant professional network and a claim as to which instrumental techniques guarantee accurate observations. Reviewing the reception of the images, the article explores how visual rhetoric may be invoked and challenged in the context of controversy, and suggests renewed analytical attention to the role of laboratory imagery in instrumental cultures in the history of science.

New-generation bar adsorptive microextraction (BAμE) devices for a better eco-user-friendly analytical approach-Application for the determination of antidepressant pharmaceuticals in biological fluids.

PubMed

Ide, A H; Nogueira, J M F

2018-05-10

The present contribution aims to design new-generation bar adsorptive microextraction (BAμE) devices that promote an innovative and much better user-friendly analytical approach. The novel BAμE devices were lab-made prepared having smaller dimensions by using flexible nylon-based supports (7.5 × 1.0 mm) coated with convenient sorbents (≈ 0.5 mg). This novel advance allows effective microextraction and back-extraction ('only single liquid desorption step') stages as well as interfacing enhancement with the instrumental systems dedicated for routine analysis. To evaluate the achievements of these improvements, four antidepressant agents (bupropion, citalopram, amitriptyline and trazodone) were used as model compounds in aqueous media combined with liquid chromatography (LC) systems. By using an N-vinylpyrrolidone based-polymer phase good selectivity and efficiency were obtained. Assays performed on 25 mL spiked aqueous samples, yielded average recoveries in between 67.8 ± 12.4% (bupropion) and 88.3 ± 12.1% (citalopram), under optimized experimental conditions. The analytical performance also showed convenient precision (RSD < 12%) and detection limits (50 ng L -1 ), as well as linear dynamic ranges (160-2000 ng L -1 ) with suitable determination coefficients (r 2  > 0.9820). The application of the proposed analytical approach on biological fluids showed negligible matrix effects by using the standard addition methodology. From the data obtained, the new-generation BAμE devices presented herein provide an innovative and robust analytical cycle, are simple to prepare, cost-effective, user-friendly and compatible with the current LC autosampler systems. Furthermore, the novel devices were designed to be disposable and used together with negligible amounts of organic solvents (100 μL) during back-extraction, in compliance with the green analytical chemistry principles. In short, the new-generation BAμE devices showed to be an eco-user-friendly approach for trace analysis of priority compounds in biological fluids and a versatile alternative over other well-stablished sorption-based microextraction techniques. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of a micro-X-ray fluorescence system based on polycapillary X-ray optics for non-destructive analysis of archaeological objects

NASA Astrophysics Data System (ADS)

Cheng, Lin; Ding, Xunliang; Liu, Zhiguo; Pan, Qiuli; Chu, Xuelian

2007-08-01

A new micro-X-ray fluorescence (micro-XRF) system based on rotating anode X-ray generator and polycapillary X-ray optics has been set up in XOL Lab, BNU, China, in order to be used for analysis of archaeological objects. The polycapillary X-ray optics used here can focus the primary X-ray beam down to tens of micrometers in diameter that allows for non-destructive and local analysis of sub-mm samples with minor/trace level sensitivity. The analytical characteristics and potential of this micro-XRF system in archaeological research are discussed. Some described uses of this instrument include studying Chinese ancient porcelain.

Polyacrylonitrile Nanofiber-Based Quartz Crystal Microbalance for Sensitive Detection of Safrole

PubMed Central

Julian, Trisna; Hidayat, Shidiq Nur; Suyono, Eko Agus

2018-01-01

Safrole is the main precursor for producing the amphetamine-type stimulant (ATS) drug, N-methyl-3,4-methylenedioxyamphetamine (MDMA), also known as ecstasy. We devise a polyacrylonitrile (PAN) nanofiber-based quartz crystal microbalance (QCM) for detecting safrole. The PAN nanofibers were fabricated by direct electrospinning to modify the QCM chips. The PAN nanofiber on the QCM chips has a diameter of 240 ± 10 nm. The sensing of safrole by QCM modified with PAN nanofiber shows good reversibility and an apparent sensitivity of 4.6 Hz·L/mg. The proposed method is simple, inexpensive, and convenient for detecting safrole, and can be an alternative to conventional instrumental analytical methods for general volatile compounds. PMID:29642565

Concomitant Ion Effects on Isotope Ratio Measurements with Liquid Sampling – Atmospheric Pressure Glow Discharge Ion Source Orbitrap Mass Spectrometry

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

Hoegg, Edward D.; Marcus, R. Kenneth; Hager, Georg

2018-02-28

In an effort to understand and improve the accuracy and precision of the liquid sampling- atmospheric pressure glow discharge (LS-APGD)/Orbitrap system, effects of concomitant ions on the acquired mass spectra are examined and presented. The LS-APGD/ Orbitrap instrument system is capable of high quality isotope ratio measurements, which are of high analytical interest for nuclear non-proliferation detection applications. The presence of background and concomitant ions (water clusters, matrix, and other analytes) has presented limitations in earlier studies. In order to mitigate these effects, an alternative quadrupole-Orbitrap hybrid mass spectrometer was employed in this study. This instrument configuration has a quadrupolemore » mass filter preceding the Orbitrap to filter-out undesired non-analyte ions. Results are presented for the analysis of U in the presence of Rb, Ag, Ba, and Pb as concomitants, each present at 5 µg/mL concentration. Progressive filtering of each concomitant ion shows steadily improved U isotope ratio performance. Ultimately, a 235U/238U ratio of 0.007133, with a relative accuracy of -2.1% and a relative standard deviation of 0.087% was achieved using this system, along with improved calibration linearity and lowered limits of detection. The resultant performance compares very favorably with other commonly accepted isotope ratio measurement platforms - surprisingly so for an ion trap type mass spectrometry instrument.« less

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

NASA Technical Reports Server (NTRS)

Woronowicz, Michael; Abel, Joshua; Autrey, David; Blackmon, Rebecca; Bond, Tim; Brown, Martin; Buffington, Jesse; Cheng, Edward; DeLatte, Danielle; Garcia, Kelvin;

Analytical and Experimental Studies of Leak Location and Environment Characterization for the International Space Station

NASA Technical Reports Server (NTRS)

Woronowicz, Michael S.; Abel, Joshua C.; Autrey, David; Blackmon, Rebecca; Bond, Tim; Brown, Martin; Buffington, Jesse; Cheng, Edward; DeLatte, Danielle; Garcia, Kelvin;

Quantitative analysis of flavanones from citrus fruits by using mesoporous molecular sieve-based miniaturized solid phase extraction coupled to ultrahigh-performance liquid chromatography and quadrupole time-of-flight mass spectrometry.

PubMed

Cao, Wan; Ye, Li-Hong; Cao, Jun; Xu, Jing-Jing; Peng, Li-Qing; Zhu, Qiong-Yao; Zhang, Qian-Yun; Hu, Shuai-Shuai

2015-08-07

An analytical procedure based on miniaturized solid phase extraction (SPE) and ultrahigh-performance liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry was developed and validated for determination of six flavanones in Citrus fruits. The mesoporous molecular sieve SBA-15 as a solid sorbent was characterised by Fourier transform-infrared spectroscopy and scanning electron microscopy. Additionally, compared with reported extraction techniques, the mesoporous SBA-15 based SPE method possessed the advantages of shorter analysis time and higher sensitivity. Furthermore, considering the different nature of the tested compounds, all of the parameters, including the SBA-15 amount, solution pH, elution solvent, and the sorbent type, were investigated in detail. Under the optimum condition, the instrumental detection and quantitation limits calculated were less than 4.26 and 14.29ngmL(-1), respectively. The recoveries obtained for all the analytes were ranging from 89.22% to 103.46%. The experimental results suggested that SBA-15 was a promising material for the purification and enrichment of target flavanones from complex citrus fruit samples. Copyright © 2015 Elsevier B.V. All rights reserved.

Systems and methods for laser assisted sample transfer to solution for chemical analysis

DOEpatents

Van Berkel, Gary J.; Kertesz, Vilmos; Ovchinnikova, Olga S.

2014-06-03

Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

Systems and methods for laser assisted sample transfer to solution for chemical analysis

DOEpatents

Van Berkel, Gary J.; Kertesz, Vilmos; Ovchinnikova, Olga S.

2015-09-29

Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

Systems and methods for laser assisted sample transfer to solution for chemical analysis

DOEpatents

Van Berkel, Gary J; Kertesz, Vilmos; Ovchinnikova, Olga S

2013-08-27

Systems and methods are described for laser ablation of an analyte from a specimen and capturing of the analyte in a dispensed solvent to form a testing solution. A solvent dispensing and extraction system can form a liquid microjunction with the specimen. The solvent dispensing and extraction system can include a surface sampling probe. The laser beam can be directed through the surface sampling probe. The surface sampling probe can also serve as an atomic force microscopy probe. The surface sampling probe can form a seal with the specimen. The testing solution including the analyte can then be analyzed using an analytical instrument or undergo further processing.

Expanding the Use of Online Remote Electron Microscopy in the Classroom to Transform Undergraduate Geoscience Education: Successes and Strategies for Increasing Student and Faculty Engagement

NASA Astrophysics Data System (ADS)

Hickey-Vargas, R.; Holbik, S. P.; Ryan, J. G.; MacDonald, J. H., Jr.; Beck, M.

2015-12-01

Geoscience faculty at the University of South Florida (USF), Florida Gulf Coast University (FCGU), Valencia College (VC) and Florida International University (FIU) have teamed to construct, test and disseminate geoscience curricula in which microbeam analytical instruments are operated by undergraduates, with data gathered in the classroom in real-time over the internet. Activities have been developed for courses Physical Geology, Oceanography, Earth Materials, Mineralogy/Petrology and Stratigraphy using the Scanning Electron Microscope (SEM) and Electron Probe Microanalyzer (EPMA) housed in the Florida Center for Analytical Electron Microscopy (FCAEM; https://fcaem.fiu.edu) at FIU. Students and faculty send research materials such as polished rock sections and microfossil mounts to FCAEM to be examined during their scheduled class and lab periods. Student control of both decision-making and selection of analytical targets is encouraged. The objective of these activities is to move students from passive learning to active, self-directed inquiry at an early stage in their undergraduate career, while providing access to advanced instruments that are not available at USF, FGCU and VC. These strategies strongly facilitate student interest in undergraduate research making use of these instruments and one positive outcome to date is an increased number of students undertaking independent research projects. Prior research by USF PI Jeff Ryan indicated that various barriers related to instrument access and use hindered interested geoscience faculty in making use of these tools and strategies. In the current project, post-doctoral researcher Dr. Sven Holbik acts as a facilitator, working directly with faculty from other institutions one-on-one to provide initial training and support, including on-site visits to field check classroom technology when needed. Several new educators and institutions will initiate classroom activities using FCAEM instrumentation this Fall.

Laboratory technology and cosmochemistry

PubMed Central

Zinner, Ernst K.; Moynier, Frederic; Stroud, Rhonda M.

2011-01-01

Recent developments in analytical instrumentation have led to revolutionary discoveries in cosmochemistry. Instrumental advances have been made along two lines: (i) increase in spatial resolution and sensitivity of detection, allowing for the study of increasingly smaller samples, and (ii) increase in the precision of isotopic analysis that allows more precise dating, the study of isotopic heterogeneity in the Solar System, and other studies. A variety of instrumental techniques are discussed, and important examples of discoveries are listed. Instrumental techniques and instruments include the ion microprobe, laser ablation gas MS, Auger EM, resonance ionization MS, accelerator MS, transmission EM, focused ion-beam microscopy, atom probe tomography, X-ray absorption near-edge structure/electron loss near-edge spectroscopy, Raman microprobe, NMR spectroscopy, and inductively coupled plasma MS. PMID:21498689

Massive stellar systems: observational challenges and perspectives in the E-ELT era

NASA Astrophysics Data System (ADS)

Bono, G.; Braga, V. F.; Ferraro, I.; Fiorentino, G.; Gilmozzi, R.; Iannicola, G.; Magurno, D.; Matsunaga, N.; Monelli, M.; Rastello, S.

2017-03-01

We introduce the empirical framework concerning optical and near-infrared (NIR) photometry of crowded stellar fields. In particular, we address the impact that linear detectors and analytical PSF played in improving the accuracy and the precision of multi-band color-magnitude diagrams (CMDs). We focus our attention on recent findings based on deep NIR images collected with Adaptive Optics (AO) systems at the 8-10m class telescopes and discuss pros and cons of the different approaches. We also discuss the estimate of the absolute age of globular clusters using a well defined knee along the lower main sequence. We mention the role which the current AO-assisted instruments will have in addressing longstanding astrophysical problems of the Galactic center. Finally, we outline the role of first generation of E-ELT instruments upon photometry and spectroscopy of crowded stellar fields.

Development and Evaluation of Event-Specific Quantitative PCR Method for Genetically Modified Soybean MON87701.

PubMed

Tsukahara, Keita; Takabatake, Reona; Masubuchi, Tomoko; Futo, Satoshi; Minegishi, Yasutaka; Noguchi, Akio; Kondo, Kazunari; Nishimaki-Mogami, Tomoko; Kurashima, Takeyo; Mano, Junichi; Kitta, Kazumi

2016-01-01

A real-time PCR-based analytical method was developed for the event-specific quantification of a genetically modified (GM) soybean event, MON87701. First, a standard plasmid for MON87701 quantification was constructed. The conversion factor (C f ) required to calculate the amount of genetically modified organism (GMO) was experimentally determined for a real-time PCR instrument. The determined C f for the real-time PCR instrument was 1.24. For the evaluation of the developed method, a blind test was carried out in an inter-laboratory trial. The trueness and precision were evaluated as the bias and reproducibility of relative standard deviation (RSDr), respectively. The determined biases and the RSDr values were less than 30 and 13%, respectively, at all evaluated concentrations. The limit of quantitation of the method was 0.5%, and the developed method would thus be applicable for practical analyses for the detection and quantification of MON87701.

Evolution of Orbitrap Mass Spectrometry Instrumentation

NASA Astrophysics Data System (ADS)

Eliuk, Shannon; Makarov, Alexander

2015-07-01

We discuss the evolution of OrbitrapTM mass spectrometry (MS) from its birth in the late 1990s to its current role as one of the most prominent techniques for MS. The Orbitrap mass analyzer is the first high-performance mass analyzer that employs trapping of ions in electrostatic fields. Tight integration with the ion injection process enables the high-resolution, mass accuracy, and sensitivity that have become essential for addressing analytical needs in numerous areas of research, as well as in routine analysis. We examine three major families of instruments (related to the LTQ Orbitrap, Q Exactive, and Orbitrap Fusion mass spectrometers) in the context of their historical development over the past ten eventful years. We discuss as well future trends and perspectives of Orbitrap MS. We illustrate the compelling potential of Orbitrap-based mass spectrometers as (ultra) high-resolution platforms, not only for high-end proteomic applications, but also for routine targeted analysis.

Analysis of Soft Drinks: UV Spectrophotometry, Liquid Chromatography, and Capillary Electrophoresis

NASA Astrophysics Data System (ADS)

McDevitt, Valerie L.; Rodriguez, Alejandra; Williams, Kathryn R.

1998-05-01

Instrumental analysis students analyze commercial soft drinks in three successive laboratory experiments. First, UV multicomponent analysis is used to determine caffeine and benzoic acid in Mello YelloTM using the spectrophotometer's software and manually by the simultaneous equations method. The following week, caffeine, benzoic acid and aspartame are determined in a variety of soft drinks by reversed-phase liquid chromatography using 45% methanol/55% aqueous phosphate, pH 3.0, as the mobile phase. In the third experiment, the same samples are analyzed by capillary electrophoresis using a pH 9.4 borate buffer. Students also determine the minimum detection limits for all three compounds by both LC and CE. The experiments demonstrate the analytical use and limitations of the three instruments. The reports and prelab quizzes also stress the importance of the chemistry of the three compounds, especially the relationships of acid/base behavior and polarity to the LC and CE separations.

Instrumentation for optimizing an underground coal-gasification process

NASA Astrophysics Data System (ADS)

Seabaugh, W.; Zielinski, R. E.

1982-06-01

While the United States has a coal resource base of 6.4 trillion tons, only seven percent is presently recoverable by mining. The process of in-situ gasification can recover another twenty-eight percent of the vast resource, however, viable technology must be developed for effective in-situ recovery. The key to this technology is system that can optimize and control the process in real-time. An instrumentation system is described that optimizes the composition of the injection gas, controls the in-situ process and conditions the product gas for maximum utilization. The key elements of this system are Monsanto PRISM Systems, a real-time analytical system, and a real-time data acquisition and control system. This system provides from complete automation of the process but can easily be overridden by manual control. The use of this cost effective system can provide process optimization and is an effective element in developing a viable in-situ technology.

A broadband cavity enhanced absorption spectrometer for aircraft measurements of glyoxal, methylglyoxal, nitrous acid, nitrogen dioxide, and water vapor

NASA Astrophysics Data System (ADS)

Min, K.-E.; Washenfelder, R. A.; Dubé, W. P.; Langford, A. O.; Edwards, P. M.; Zarzana, K. J.; Stutz, J.; Lu, K.; Rohrer, F.; Zhang, Y.; Brown, S. S.

2015-10-01

We describe a two-channel broadband cavity enhanced absorption spectrometer (BBCEAS) for aircraft measurements of glyoxal (CHOCHO), methylglyoxal (CH3COCHO), nitrous acid (HONO), nitrogen dioxide (NO2), and water (H2O). The instrument spans 361-389 and 438-468 nm, using two light emitting diodes (LEDs) and a grating spectrometer with a charge-coupled device (CCD) detector. Robust performance is achieved using a custom optical mounting system, high power LEDs with electronic on/off modulation, state-of-the-art cavity mirrors, and materials that minimize analyte surface losses. We have successfully deployed this instrument during two aircraft and two ground-based field campaigns to date. The demonstrated precision (2σ) for retrievals of CHOCHO, HONO and NO2 are 34, 350 and 80 pptv in 5 s. The accuracy is 5.8, 9.0 and 5.0 % limited mainly by the available absorption cross sections.

Fabricating a UV-Vis and Raman Spectroscopy Immunoassay Platform.

PubMed

Hanson, Cynthia; Israelsen, Nathan D; Sieverts, Michael; Vargis, Elizabeth

2016-11-10

Immunoassays are used to detect proteins based on the presence of associated antibodies. Because of their extensive use in research and clinical settings, a large infrastructure of immunoassay instruments and materials can be found. For example, 96- and 384-well polystyrene plates are available commercially and have a standard design to accommodate ultraviolet-visible (UV-Vis) spectroscopy machines from various manufacturers. In addition, a wide variety of immunoglobulins, detection tags, and blocking agents for customized immunoassay designs such as enzyme-linked immunosorbent assays (ELISA) are available. Despite the existing infrastructure, standard ELISA kits do not meet all research needs, requiring individualized immunoassay development, which can be expensive and time-consuming. For example, ELISA kits have low multiplexing (detection of more than one analyte at a time) capabilities as they usually depend on fluorescence or colorimetric methods for detection. Colorimetric and fluorescent-based analyses have limited multiplexing capabilities due to broad spectral peaks. In contrast, Raman spectroscopy-based methods have a much greater capability for multiplexing due to narrow emission peaks. Another advantage of Raman spectroscopy is that Raman reporters experience significantly less photobleaching than fluorescent tags 1 . Despite the advantages that Raman reporters have over fluorescent and colorimetric tags, protocols to fabricate Raman-based immunoassays are limited. The purpose of this paper is to provide a protocol to prepare functionalized probes to use in conjunction with polystyrene plates for direct detection of analytes by UV-Vis analysis and Raman spectroscopy. This protocol will allow researchers to take a do-it-yourself approach for future multi-analyte detection while capitalizing on pre-established infrastructure.

Measurement of Henry's Law Constants Using Internal Standards: A Quantitative GC Experiment for the Instrumental Analysis or Environmental Chemistry Laboratory

ERIC Educational Resources Information Center

Ji, Chang; Boisvert, Susanne M.; Arida, Ann-Marie C.; Day, Shannon E.

2008-01-01

An internal standard method applicable to undergraduate instrumental analysis or environmental chemistry laboratory has been designed and tested to determine the Henry's law constants for a series of alkyl nitriles. In this method, a mixture of the analytes and an internal standard is prepared and used to make a standard solution (organic solvent)…

Rapid and automatic chemical identification of the medicinal flower buds of Lonicera plants by the benchtop and hand-held Fourier transform infrared spectroscopy

NASA Astrophysics Data System (ADS)

Chen, Jianbo; Guo, Baolin; Yan, Rui; Sun, Suqin; Zhou, Qun

2017-07-01

With the utilization of the hand-held equipment, Fourier transform infrared (FT-IR) spectroscopy is a promising analytical technique to minimize the time cost for the chemical identification of herbal materials. This research examines the feasibility of the hand-held FT-IR spectrometer for the on-site testing of herbal materials, using Lonicerae Japonicae Flos (LJF) and Lonicerae Flos (LF) as examples. Correlation-based linear discriminant models for LJF and LF are established based on the benchtop and hand-held FT-IR instruments. The benchtop FT-IR models can exactly recognize all articles of LJF and LF. Although a few LF articles are misjudged at the sub-class level, the hand-held FT-IR models are able to exactly discriminate LJF and LF. As a direct and label-free analytical technique, FT-IR spectroscopy has great potential in the rapid and automatic chemical identification of herbal materials either in laboratories or in fields. This is helpful to prevent the spread and use of adulterated herbal materials in time.

Selective Sampling with Direct Ion Mobility Spectrometric Detection for Explosives Analysis

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

Harvey, Scott D; Ewing, Robert G; Waltman, Melanie J

2009-06-29

This study investigates the potential and limitations of a streamlined, field-deployable analytical approach that involves selective capture of explosive materials with direct analysis by ion mobility spectrometry (IMS). Selective capture of explosives was performed on deactivated quartz fiber filters impregnated with metal β-diketonate polymers. These Lewis acidic polymers selectively interact with Lewis base analytes such as explosives. The filter coupons could be directly inserted into an IMS instrument for analysis. The uptake kinetics of 2,4,6-trinitrotoluene (TNT) from a saturated atmosphere were characterized, and based on these studies, passive equilibrium sampling was applied to estimate the TNT concentration within an ammunitionmore » magazine that contained bulk TNT. Hexahydro-1,3,5-trinitro-1,3,5-triazine (RDX) uptake from a saturated environment also was examined over a one-month period. Each incremental sampling period showed increasing quantities of RDX culminating with collection of approximately 5 ng of RDX on the coupon at the end of one month. This is the first time that gas-phase uptake of RDX has been demonstrated.« less

Line-Focused Optical Excitation of Parallel Acoustic Focused Sample Streams for High Volumetric and Analytical Rate Flow Cytometry.

PubMed

Kalb, Daniel M; Fencl, Frank A; Woods, Travis A; Swanson, August; Maestas, Gian C; Juárez, Jaime J; Edwards, Bruce S; Shreve, Andrew P; Graves, Steven W

2017-09-19

Flow cytometry provides highly sensitive multiparameter analysis of cells and particles but has been largely limited to the use of a single focused sample stream. This limits the analytical rate to ∼50K particles/s and the volumetric rate to ∼250 μL/min. Despite the analytical prowess of flow cytometry, there are applications where these rates are insufficient, such as rare cell analysis in high cellular backgrounds (e.g., circulating tumor cells and fetal cells in maternal blood), detection of cells/particles in large dilute samples (e.g., water quality, urine analysis), or high-throughput screening applications. Here we report a highly parallel acoustic flow cytometer that uses an acoustic standing wave to focus particles into 16 parallel analysis points across a 2.3 mm wide optical flow cell. A line-focused laser and wide-field collection optics are used to excite and collect the fluorescence emission of these parallel streams onto a high-speed camera for analysis. With this instrument format and fluorescent microsphere standards, we obtain analysis rates of 100K/s and flow rates of 10 mL/min, while maintaining optical performance comparable to that of a commercial flow cytometer. The results with our initial prototype instrument demonstrate that the integration of key parallelizable components, including the line-focused laser, particle focusing using multinode acoustic standing waves, and a spatially arrayed detector, can increase analytical and volumetric throughputs by orders of magnitude in a compact, simple, and cost-effective platform. Such instruments will be of great value to applications in need of high-throughput yet sensitive flow cytometry analysis.

VALIDATION OF ANALYTICAL METHODS AND INSTRUMENTATION FOR BERYLLIUM MEASUREMENT: REVIEW AND SUMMARY OF AVAILABLE GUIDES, PROCEDURES, AND PROTOCOLS

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

Ekechukwu, A

Method validation is the process of evaluating whether an analytical method is acceptable for its intended purpose. For pharmaceutical methods, guidelines from the United States Pharmacopeia (USP), International Conference on Harmonisation (ICH), and the United States Food and Drug Administration (USFDA) provide a framework for performing such valications. In general, methods for regulatory compliance must include studies on specificity, linearity, accuracy, precision, range, detection limit, quantitation limit, and robustness. Elements of these guidelines are readily adapted to the issue of validation for beryllium sampling and analysis. This document provides a listing of available sources which can be used to validatemore » analytical methods and/or instrumentation for beryllium determination. A literature review was conducted of available standard methods and publications used for method validation and/or quality control. A comprehensive listing of the articles, papers and books reviewed is given in the Appendix. Available validation documents and guides are listed therein; each has a brief description of application and use. In the referenced sources, there are varying approches to validation and varying descriptions of the valication process at different stages in method development. This discussion focuses on valication and verification of fully developed methods and instrumentation that have been offered up for use or approval by other laboratories or official consensus bodies such as ASTM International, the International Standards Organization (ISO) and the Association of Official Analytical Chemists (AOAC). This review was conducted as part of a collaborative effort to investigate and improve the state of validation for measuring beryllium in the workplace and the environment. Documents and publications from the United States and Europe are included. Unless otherwise specified, all referenced documents were published in English.« less

LIBS-LIF-Raman: a new tool for the future E-RIHS

NASA Astrophysics Data System (ADS)

Detalle, Vincent; Bai, Xueshi; Bourguignon, Elsa; Menu, Michel; Pallot-Frossard, Isabelle

2017-07-01

France is one of the countries involved in the future E-RIHS - European Research Infrastructure for Heritage Science. The research infrastructure dedicated to the study of materials of cultural and natural heritage will provide transnational access to state-of-the-art technologies (synchrotron, ion beams, lasers, portable methods, etc.) and scientific archives. E-RIHS addresses the experimental problems of knowledge and conservation of heritage materials (collections of art and natural museums, monuments, archaeological sites, archives, libraries, etc.). The cultural artefacts are characterized by complementary methods at multi-scales. The variety and the hybrid are specific of these artefacts and induce complex problems that are not expected in traditional Natural Science: paints, ceramics and glasses, metals, palaeontological specimens, lithic materials, graphic documents, etc. E-RIHS develops in that purpose transnational access to distributed platforms in many European countries. Five complementary accesses are in this way available: FIXLAB (access to fixed platforms for synchrotron, neutrons, ion beams, lasers, etc.), MOLAB (access to mobile examination and analytical methods to study the works in situ), ARCHLAB (access to scientific archives kept in the cultural institutions), DIGILAB (access to a digital infrastructure for the processing of quantitative data, implementing a policy on (re)use of data, choice of data formats, etc.) and finally EXPERTLAB (panels of experts for the implementation of collaborative and multidisciplinary projects for the study, the analysis and the conservation of heritage works).Thus E-RIHS is specifically involved in complex studies for the development of advanced high-resolution analytical and imaging tools. The privileged field of intervention of the infrastructure is that of the study of large corpora, collections and architectural ensembles. Based on previous I3 European program, and especially IPERION-CH program that support the creation of new mobile instrumentation, the French institutions are involved in the development of LIBS/LIF/RAMAN portable instrumentation. After a presentation of the challenge and the multiple advantages in building the European Infrastructure and of the French E-RIHS hub, the major interests of associating the three lasers based on analytical methods for a more global and precise characterization of the heritage objects taking into account their precious characters and their specific constraints. Lastly some preliminary results will be presented in order to give a first idea of the power of this analytical tool.

Ammonium hydroxide enhancing electrospray response and boosting sensitivity of bisphenol A and its analogs.

PubMed

Tan, Dongqin; Jin, Jing; Wang, Longxing; Zhao, Xueqin; Guo, Cuicui; Sun, Xiaoli; Dhanjai; Lu, Xianbo; Chen, Jiping

2018-05-15

As one of the most important analytical techniques for accurate quantification of bisphenol compounds, liquid chromatography coupled to online electrospray ionization (ESI) tandem mass spectrometry exhibits relative weak ESI response in negative mode, which greatly reduces their sensitivity and limits their detection at trace levels, especially in complex samples such as blood. Based on the facilitated deprotonation of bisphenol molecule under alkaline condition, post-column injection of ammonium hydroxide (NH 3 ·H 2 O) to mass spectrometer was explored to enhance the ionization efficiency of BPA and its eight analogs and improve their analytical sensitivity. Parameters effecting response intensity and stability were investigated, including mass concentration and flow rate of NH 3 ·H 2 O. Under the optimal conditions with the addition of 2% (w/w) of NH 3 ·H 2 O at 4 μL min -1 , the instrument detection limits for bisphenol compounds were greatly lowered to 0.001-0.04 ng mL -1 , which were 2-28.6 times lower than the result obtained without injecting NH 3 ·H 2 O, except TBBPA (0.03 ng mL -1 in either case). The relative standard deviations (RSDs) for instrument repeatability of BPA and its analogs at three different concentration levels were in a range of 1.2-20%. Furthermore, a decreased matrix effects (90-111%) for bisphenols (except TBBPA) analysis in serum extracts were found compared with the result obtained without NH 3 ·H 2 O injection (43-111%). The results demonstrated that the improved instrumental method coupled with suitable pretreatment techniques is more feasible to analyze bisphenol compounds in complex bio-samples. Copyright © 2018 Elsevier B.V. All rights reserved.

Determining the risk of cardiovascular disease using ion mobility of lipoproteins

DOEpatents

Benner, W. Henry; Krauss, Ronald M.; Blanche, Patricia J.

2010-05-11

A medical diagnostic method and instrumentation system for analyzing noncovalently bonded agglomerated biological particles is described. The method and system comprises: a method of preparation for the biological particles; an electrospray generator; an alpha particle radiation source; a differential mobility analyzer; a particle counter; and data acquisition and analysis means. The medical device is useful for the assessment of human diseases, such as cardiac disease risk and hyperlipidemia, by rapid quantitative analysis of lipoprotein fraction densities. Initially, purification procedures are described to reduce an initial blood sample to an analytical input to the instrument. The measured sizes from the analytical sample are correlated with densities, resulting in a spectrum of lipoprotein densities. The lipoprotein density distribution can then be used to characterize cardiac and other lipid-related health risks.

Establishment of gold-quartz standard GQS-1

USGS Publications Warehouse

Millard, Hugh T.; Marinenko, John; McLane, John E.

1969-01-01

A homogeneous gold-quartz standard, GQS-1, was prepared from a heterogeneous gold-bearing quartz by chemical treatment. The concentration of gold in GQS-1 was determined by both instrumental neutron activation analysis and radioisotope dilution analysis to be 2.61?0.10 parts per million. Analysis of 10 samples of the standard by both instrumental neutron activation analysis and radioisotope dilution analysis failed to reveal heterogeneity within the standard. The precision of the analytical methods, expressed as standard error, was approximately 0.1 part per million. The analytical data were also used to estimate the average size of gold particles. The chemical treatment apparently reduced the average diameter of the gold particles by at least an order of magnitude and increased the concentration of gold grains by a factor of at least 4,000.

Hydrothermal Alteration Mineralogy Characterized Through Multiple Analytical Methods: Implications for Mars

NASA Astrophysics Data System (ADS)

Black, S.; Hynek, B. M.; Kierein-Young, K. S.; Avard, G.; Alvarado-Induni, G.

2015-12-01

Proper characterization of mineralogy is an essential part of geologic interpretation. This process becomes even more critical when attempting to interpret the history of a region remotely, via satellites and/or landed spacecraft. Orbiters and landed missions to Mars carry with them a wide range of analytical tools to aid in the interpretation of Mars' geologic history. However, many instruments make a single type of measurement (e.g., APXS: elemental chemistry; XRD: mineralogy), and multiple data sets must be utilized to develop a comprehensive understanding of a sample. Hydrothermal alteration products often exist in intimate mixtures, and vary widely across a site due to changing pH, temperature, and fluid/gas chemistries. These characteristics require that we develop a detailed understanding regarding the possible mineral mixtures that may exist, and their detectability in different instrument data sets. This comparative analysis study utilized several analytical methods on existing or planned Mars rovers (XRD Raman, LIBS, Mössbauer, and APXS) combined with additional characterization (thin section, VNIR, XRF, SEM-EMP) to develop a comprehensive suite of data for hydrothermal alteration products collected from Poás and Turrialba volcanoes in Costa Rica. Analyzing the same samples across a wide range of instruments allows for direct comparisons of results, and identification of instrumentation "blind spots." This provides insight into the ability of in-situ analyses to comprehensively characterize sites on Mars exhibiting putative hydrothermal characteristics, such as the silica and sulfate deposits at Gusev crater [eg: Squyres et al., 2008], as well as valuable information for future mission planning and data interpretation. References: Squyres et al. (2008), Detection of Silica-Rich Deposits on Mars, Science, 320, 1063-1067, doi:10.1126/science.1155429.

Analytical evaluation of the automated galectin-3 assay on the Abbott ARCHITECT immunoassay instruments.

PubMed

Gaze, David C; Prante, Christian; Dreier, Jens; Knabbe, Cornelius; Collet, Corinne; Launay, Jean-Marie; Franekova, Janka; Jabor, Antonin; Lennartz, Lieselotte; Shih, Jessie; del Rey, Jose Manuel; Zaninotto, Martina; Plebani, Mario; Collinson, Paul O

2014-06-01

Galectin-3 is secreted from macrophages and binds and activates fibroblasts forming collagen. Tissue fibrosis is central to the progression of chronic heart failure (CHF). We performed a European multicentered evaluation of the analytical performance of the two-step routine and Short Turn-Around-Time (STAT) galectin-3 immunoassay on the ARCHITECT i1000SR, i2000SR, and i4000SR (Abbott Laboratories). We evaluated the assay precision and dilution linearity for both routine and STAT assays and compared serum and plasma, and fresh vs. frozen samples. The reference interval and biological variability were also assessed. Measurable samples were compared between ARCHITECT instruments and between the routine and STAT assays and also to a galectin-3 ELISA (BG Medicine). The total assay coefficient of variation (CV%) was 2.3%-6.2% and 1.7%-7.4% for the routine and STAT assays, respectively. Both assays demonstrated linearity up to 120 ng/mL. Galectin-3 concentrations were higher in plasma samples than in serum samples and correlated well between fresh and frozen samples (R=0.997), between the routine and STAT assays, between the ARCHITECT i1000 and i2000 instruments and with the galectin-3 ELISA. The reference interval on 627 apparently healthy individuals (53% male) yielded upper 95th and 97.5th percentiles of 25.2 and 28.4 ng/mL, respectively. Values were significantly lower in subjects younger than 50 years. The galectin-3 routine and STAT assays on the Abbott ARCHITECT instruments demonstrated good analytical performance. Further clinical studies are required to demonstrate the diagnostic and prognostic potential of this novel marker in patients with CHF.

Chandra ACIS-I particle background: an analytical model

NASA Astrophysics Data System (ADS)

Bartalucci, I.; Mazzotta, P.; Bourdin, H.; Vikhlinin, A.

2014-06-01

Aims: Imaging and spectroscopy of X-ray extended sources require a proper characterisation of a spatially unresolved background signal. This background includes sky and instrumental components, each of which are characterised by its proper spatial and spectral behaviour. While the X-ray sky background has been extensively studied in previous work, here we analyse and model the instrumental background of the ACIS-I detector on board the Chandra X-ray observatory in very faint mode. Methods: Caused by interaction of highly energetic particles with the detector, the ACIS-I instrumental background is spectrally characterised by the superimposition of several fluorescence emission lines onto a continuum. To isolate its flux from any sky component, we fitted an analytical model of the continuum to observations performed in very faint mode with the detector in the stowed position shielded from the sky, and gathered over the eight-year period starting in 2001. The remaining emission lines were fitted to blank-sky observations of the same period. We found 11 emission lines. Analysing the spatial variation of the amplitude, energy and width of these lines has further allowed us to infer that three lines of these are presumably due to an energy correction artefact produced in the frame store. Results: We provide an analytical model that predicts the instrumental background with a precision of 2% in the continuum and 5% in the lines. We use this model to measure the flux of the unresolved cosmic X-ray background in the Chandra deep field south. We obtain a flux of 10.2+0.5-0.4 × 10-13 erg cm-2 deg-2 s-1 for the [1-2] keV band and (3.8 ± 0.2) × 10-12 erg cm-2 deg-2 s-1 for the [2-8] keV band.

Low-Level Analytical Methodology Updates to Support Decontaminant Performance Evaluations

DTIC Science & Technology

2011-06-01

from EPDM and tire rubber coupon materials that were spiked with a known amount of the chemical agent VX, treated with bleach decontaminant, and...to evaluate the performance of bleach decontaminant on EPDM and tire rubber coupons. Dose-confirmation or Tool samples were collected by delivering...components • An aging or damaged analytical column • Dirty detector • Other factors related to general instrument and/or sample analysis performance

ANALYTICAL CHEMISTRY DIVISION ANNUAL PROGRESS REPORT FOR PERIOD ENDING DECEMBER 31, 1961

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

None

1962-02-01

Research and development progress is reported on analytlcal instrumentation, dlssolver-solution analyses, special research problems, reactor projects analyses, x-ray and spectrochemical analyses, mass spectrometry, optical and electron microscopy, radiochemical analyses, nuclear analyses, inorganic preparations, organic preparations, ionic analyses, infrared spectral studies, anodization of sector coils for the Analog II Cyclotron, quality control, process analyses, and the Thermal Breeder Reactor Projects Analytical Chemistry Laboratory. (M.C.G.)

Theory-Led Design of Instruments and Representations in Learning Analytics: Developing a Novel Tool for Orchestration of Online Collaborative Learning

ERIC Educational Resources Information Center

Kelly, Nick; Thompson, Kate; Yeoman, Pippa

2015-01-01

This paper describes theory-led design as a way of developing novel tools for learning analytics (LA). It focuses upon the domain of automated discourse analysis (ADA) of group learning activities to help an instructor to orchestrate online groups in real-time. The paper outlines the literature on the development of LA tools within the domain of…

Static Load Test on Instrumented Pile - Field Data and Numerical Simulations

NASA Astrophysics Data System (ADS)

Krasiński, Adam; Wiszniewski, Mateusz

2017-09-01

Static load tests on foundation piles are generally carried out in order to determine load - the displacement characteristic of the pile head. For standard (basic) engineering practices this type of test usually provides enough information. However, the knowledge of force distribution along the pile core and its division into the friction along the shaft and the resistance under the base can be very useful. Such information can be obtained by strain gage pile instrumentation [1]. Significant investigations have been completed on this technology, proving its utility and correctness [8], [10], [12]. The results of static tests on instrumented piles are not easy to interpret. There are many factors and processes affecting the final outcome. In order to understand better the whole testing process and soil-structure behavior some investigations and numerical analyses were done. In the paper, real data from a field load test on instrumented piles is discussed and compared with numerical simulation of such a test in similar conditions. Differences and difficulties in the results interpretation with their possible reasons are discussed. Moreover, the authors used their own analytical solution for more reliable determination of force distribution along the pile. The work was presented at the XVII French-Polish Colloquium of Soil and Rock Mechanics, Łódź, 28-30 November 2016.

Measuring nursing competencies in the operating theatre: instrument development and psychometric analysis using Item Response Theory.

PubMed

Nicholson, Patricia; Griffin, Patrick; Gillis, Shelley; Wu, Margaret; Dunning, Trisha

2013-09-01

Concern about the process of identifying underlying competencies that contribute to effective nursing performance has been debated with a lack of consensus surrounding an approved measurement instrument for assessing clinical performance. Although a number of methodologies are noted in the development of competency-based assessment measures, these studies are not without criticism. The primary aim of the study was to develop and validate a Performance Based Scoring Rubric, which included both analytical and holistic scales. The aim included examining the validity and reliability of the rubric, which was designed to measure clinical competencies in the operating theatre. The fieldwork observations of 32 nurse educators and preceptors assessing the performance of 95 instrument nurses in the operating theatre were used in the calibration of the rubric. The Rasch model, a particular model among Item Response Models, was used in the calibration of each item in the rubric in an attempt at improving the measurement properties of the scale. This is done by establishing the 'fit' of the data to the conditions demanded by the Rasch model. Acceptable reliability estimates, specifically a high Cronbach's alpha reliability coefficient (0.940), as well as empirical support for construct and criterion validity for the rubric were achieved. Calibration of the Performance Based Scoring Rubric using Rasch model revealed that the fit statistics for most items were acceptable. The use of the Rasch model offers a number of features in developing and refining healthcare competency-based assessments, improving confidence in measuring clinical performance. The Rasch model was shown to be useful in developing and validating a competency-based assessment for measuring the competence of the instrument nurse in the operating theatre with implications for use in other areas of nursing practice. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

An investigation of soil-structure interaction effects observed at the MIT Green Building

USGS Publications Warehouse

Taciroglu, Ertugrul; Çelebi, Mehmet; Ghahari, S. Farid; Abazarsa, Fariba

2016-01-01

The soil-foundation impedance function of the MIT Green Building is identified from its response signals recorded during an earthquake. Estimation of foundation impedance functions from seismic response signals is a challenging task, because: (1) the foundation input motions (FIMs) are not directly measurable, (2) the as-built properties of the super-structure are only approximately known, and (3) the soil-foundation impedance functions are inherently frequency-dependent. In the present study, aforementioned difficulties are circumvented by using, in succession, a blind modal identification (BMID) method, a simplified Timoshenko beam model (TBM), and a parametric updating of transfer functions (TFs). First, the flexible-base modal properties of the building are identified from response signals using the BMID method. Then, a flexible-base TBM is updated using the identified modal data. Finally, the frequency-dependent soil-foundation impedance function is estimated by minimizing the discrepancy between TFs (of pairs instrumented floors) that are (1) obtained experimentally from earthquake data and (2) analytically from the updated TBM. Using the fully identified flexible-base TBM, the FIMs as well as building responses at locations without instruments can be predicted, as demonstrated in the present study.

Characterization of air pollution in Mexico City by remote sensing

NASA Astrophysics Data System (ADS)

Grutter, Michel; Arellano, Josue; Bezanilla, Alejandro; Friedrich, Martina; Plaza, Eddy; Rivera, Claudia; Stremme, Wolfgang

2014-05-01

Megacities, like the Mexico City Metropolitan Area, are home to a large fraction of the population of the world and a consequence is that they are one of the biggest sources of contaminants and greenhouse gases emitted to the atmosphere. The pollution is visible form space through remote sensing instruments, however, satellite observations like those with NADIR viewing geometries have decreased sensitivity near the Earth's surface and the analytical algorithms are in generally optimized to detect pollution plumes in the free troposphere or above. Ground-based observations are thus necessary in order to reduce uncertainties from satellite products. As we will show, Mexico City and its surroundings is well characterized by ground-based remote sensing measurements like from two stations with solar-absorption FTIR spectrometers and a newly formed network of MAX-DOAS and LIDAR instruments. Examples will be provided of how the evolution of the mixing-layer height is characterized and the vertical column densities and profiles of gases in and outside the urban area are continuously monitored. The combination of ground-based and space-borne measurements are used to improve the current knowledge in the spatial and temporal distribution of key pollutants from this megacity.

TOPLEX: Teleoperated Lunar Explorer. Instruments and Operational Concepts for an Unmanned Lunar Rover

NASA Technical Reports Server (NTRS)

Blacic, James D.

1992-01-01

A Teleoperated Lunar Explorer, or TOPLEX, consisting of a lunar lander payload in which a small, instrument-carrying lunar surface rover is robotically landed and teleoperated from Earth to perform extended lunar geoscience and resource evaluation traverses is proposed. The rover vehicle would mass about 100 kg and carry approximately 100 kg of analytic instruments. Four instruments are envisioned: (1) a Laser-Induced Breakdown Spectrometer (LIBS) for geochemical analysis at ranges up to 100 m, capable of operating in three different modes; (2) a combined x-ray fluorescence and x-ray diffraction (XRF/XRD) instrument for elemental and mineralogic analysis of acquired samples; (3) a mass spectrometer system for stepwise heating analysis of gases released from acquired samples; and (4) a geophysical instrument package for subsurface mapping of structures such as lava tubes.

New algorithms for motion error detection of numerical control machine tool by laser tracking measurement on the basis of GPS principle.

PubMed

Wang, Jindong; Chen, Peng; Deng, Yufen; Guo, Junjie

2018-01-01

As a three-dimensional measuring instrument, the laser tracker is widely used in industrial measurement. To avoid the influence of angle measurement error on the overall measurement accuracy, the multi-station and time-sharing measurement with a laser tracker is introduced on the basis of the global positioning system (GPS) principle in this paper. For the proposed method, how to accurately determine the coordinates of each measuring point by using a large amount of measured data is a critical issue. Taking detecting motion error of a numerical control machine tool, for example, the corresponding measurement algorithms are investigated thoroughly. By establishing the mathematical model of detecting motion error of a machine tool with this method, the analytical algorithm concerning on base station calibration and measuring point determination is deduced without selecting the initial iterative value in calculation. However, when the motion area of the machine tool is in a 2D plane, the coefficient matrix of base station calibration is singular, which generates a distortion result. In order to overcome the limitation of the original algorithm, an improved analytical algorithm is also derived. Meanwhile, the calibration accuracy of the base station with the improved algorithm is compared with that with the original analytical algorithm and some iterative algorithms, such as the Gauss-Newton algorithm and Levenberg-Marquardt algorithm. The experiment further verifies the feasibility and effectiveness of the improved algorithm. In addition, the different motion areas of the machine tool have certain influence on the calibration accuracy of the base station, and the corresponding influence of measurement error on the calibration result of the base station depending on the condition number of coefficient matrix are analyzed.

New algorithms for motion error detection of numerical control machine tool by laser tracking measurement on the basis of GPS principle

NASA Astrophysics Data System (ADS)

Wang, Jindong; Chen, Peng; Deng, Yufen; Guo, Junjie

2018-01-01

As a three-dimensional measuring instrument, the laser tracker is widely used in industrial measurement. To avoid the influence of angle measurement error on the overall measurement accuracy, the multi-station and time-sharing measurement with a laser tracker is introduced on the basis of the global positioning system (GPS) principle in this paper. For the proposed method, how to accurately determine the coordinates of each measuring point by using a large amount of measured data is a critical issue. Taking detecting motion error of a numerical control machine tool, for example, the corresponding measurement algorithms are investigated thoroughly. By establishing the mathematical model of detecting motion error of a machine tool with this method, the analytical algorithm concerning on base station calibration and measuring point determination is deduced without selecting the initial iterative value in calculation. However, when the motion area of the machine tool is in a 2D plane, the coefficient matrix of base station calibration is singular, which generates a distortion result. In order to overcome the limitation of the original algorithm, an improved analytical algorithm is also derived. Meanwhile, the calibration accuracy of the base station with the improved algorithm is compared with that with the original analytical algorithm and some iterative algorithms, such as the Gauss-Newton algorithm and Levenberg-Marquardt algorithm. The experiment further verifies the feasibility and effectiveness of the improved algorithm. In addition, the different motion areas of the machine tool have certain influence on the calibration accuracy of the base station, and the corresponding influence of measurement error on the calibration result of the base station depending on the condition number of coefficient matrix are analyzed.

Quality Assurance of RNA Expression Profiling in Clinical Laboratories

PubMed Central

Tang, Weihua; Hu, Zhiyuan; Muallem, Hind; Gulley, Margaret L.

2012-01-01

RNA expression profiles are increasingly used to diagnose and classify disease, based on expression patterns of as many as several thousand RNAs. To ensure quality of expression profiling services in clinical settings, a standard operating procedure incorporates multiple quality indicators and controls, beginning with preanalytic specimen preparation and proceeding thorough analysis, interpretation, and reporting. Before testing, histopathological examination of each cellular specimen, along with optional cell enrichment procedures, ensures adequacy of the input tissue. Other tactics include endogenous controls to evaluate adequacy of RNA and exogenous or spiked controls to evaluate run- and patient-specific performance of the test system, respectively. Unique aspects of quality assurance for array-based tests include controls for the pertinent outcome signatures that often supersede controls for each individual analyte, built-in redundancy for critical analytes or biochemical pathways, and software-supported scrutiny of abundant data by a laboratory physician who interprets the findings in a manner facilitating appropriate medical intervention. Access to high-quality reagents, instruments, and software from commercial sources promotes standardization and adoption in clinical settings, once an assay is vetted in validation studies as being analytically sound and clinically useful. Careful attention to the well-honed principles of laboratory medicine, along with guidance from government and professional groups on strategies to preserve RNA and manage large data sets, promotes clinical-grade assay performance. PMID:22020152

A catalytic beacon sensor for uranium with parts-per-trillion sensitivity and millionfold selectivity.

PubMed

Liu, Juewen; Brown, Andrea K; Meng, Xiangli; Cropek, Donald M; Istok, Jonathan D; Watson, David B; Lu, Yi

2007-02-13

Here, we report a catalytic beacon sensor for uranyl (UO2(2+)) based on an in vitro-selected UO2(2+)-specific DNAzyme. The sensor consists of a DNA enzyme strand with a 3' quencher and a DNA substrate with a ribonucleotide adenosine (rA) in the middle and a fluorophore and a quencher at the 5' and 3' ends, respectively. The presence of UO2(2+) causes catalytic cleavage of the DNA substrate strand at the rA position and release of the fluorophore and thus dramatic increase of fluorescence intensity. The sensor has a detection limit of 11 parts per trillion (45 pM), a dynamic range up to 400 nM, and selectivity of >1-million-fold over other metal ions. The most interfering metal ion, Th(IV), interacts with the fluorescein fluorophore, causing slightly enhanced fluorescence intensity, with an apparent dissociation constant of approximately 230 microM. This sensor rivals the most sensitive analytical instruments for uranium detection, and its application in detecting uranium in contaminated soil samples is also demonstrated. This work shows that simple, cost-effective, and portable metal sensors can be obtained with similar sensitivity and selectivity as much more expensive and sophisticated analytical instruments. Such a sensor will play an important role in environmental remediation of radionuclides such as uranium.

A catalytic beacon sensor for uranium with parts-per-trillion sensitivity and millionfold selectivity

PubMed Central

Liu, Juewen; Brown, Andrea K.; Meng, Xiangli; Cropek, Donald M.; Istok, Jonathan D.; Watson, David B.; Lu, Yi

2007-01-01

Here, we report a catalytic beacon sensor for uranyl (UO22+) based on an in vitro-selected UO22+-specific DNAzyme. The sensor consists of a DNA enzyme strand with a 3′ quencher and a DNA substrate with a ribonucleotide adenosine (rA) in the middle and a fluorophore and a quencher at the 5′ and 3′ ends, respectively. The presence of UO22+ causes catalytic cleavage of the DNA substrate strand at the rA position and release of the fluorophore and thus dramatic increase of fluorescence intensity. The sensor has a detection limit of 11 parts per trillion (45 pM), a dynamic range up to 400 nM, and selectivity of >1-million-fold over other metal ions. The most interfering metal ion, Th(IV), interacts with the fluorescein fluorophore, causing slightly enhanced fluorescence intensity, with an apparent dissociation constant of ≈230 μM. This sensor rivals the most sensitive analytical instruments for uranium detection, and its application in detecting uranium in contaminated soil samples is also demonstrated. This work shows that simple, cost-effective, and portable metal sensors can be obtained with similar sensitivity and selectivity as much more expensive and sophisticated analytical instruments. Such a sensor will play an important role in environmental remediation of radionuclides such as uranium. PMID:17284609

The HARPS-N archive through a Cassandra, NoSQL database suite?

NASA Astrophysics Data System (ADS)

Molinari, Emilio; Guerra, Jose; Harutyunyan, Avet; Lodi, Marcello; Martin, Adrian

2016-07-01

The TNG-INAF is developing the science archive for the WEAVE instrument. The underlying architecture of the archive is based on a non relational database, more precisely, on Apache Cassandra cluster, which uses a NoSQL technology. In order to test and validate the use of this architecture, we created a local archive which we populated with all the HARPSN spectra collected at the TNG since the instrument's start of operations in mid-2012, as well as developed tools for the analysis of this data set. The HARPS-N data set is two orders of magnitude smaller than WEAVE, but we want to demonstrate the ability to walk through a complete data set and produce scientific output, as valuable as that produced by an ordinary pipeline, though without accessing directly the FITS files. The analytics is done by Apache Solr and Spark and on a relational PostgreSQL database. As an example, we produce observables like metallicity indexes for the targets in the archive and compare the results with the ones coming from the HARPS-N regular data reduction software. The aim of this experiment is to explore the viability of a high availability cluster and distributed NoSQL database as a platform for complex scientific analytics on a large data set, which will then be ported to the WEAVE Archive System (WAS) which we are developing for the WEAVE multi object, fiber spectrograph.

Photoacoustic detection of CO2 based on LABVIEW at 10.303 μm.

PubMed

Zhao, Junjuan; Zhao, Zhan; Du, Lidong; Geng, Daoqu; Wu, Shaohua

2011-04-01

A detailed study on a photoacoustic carbon dioxide detection system, through sound card based on virtual instrument, is presented in this paper. In this system, the CO(2) concentration was measured with the non-resonant photoacoustic cell technique through measuring the photoacoustic signal caused by the CO(2). In order to obtain small photoacoustic signals buried in noise, a measurement software was designed with LABVIEW. It has functions of Lock-in Amplifier, digital filter, and signal generator; can also be used to achieve spectrum analysis and signal recovery; has been provided with powerful function for data processing and communication with other measuring instrument. The test results show that the entire system has an outstanding measuring performance with the sensitivity of 10 μv between 10-44 KHz. The non-resonance test of the trace gas analyte CO(2) conducted at 100 Hz demonstrated large signals (15.89 mV) for CO(2) concentrations at 600 ppm and high signal-to-noise values (∼85:1). © 2011 American Institute of Physics

Training analysis and reanalysis in the development of the psychoanalyst.

PubMed

Meyer, Jon K

2007-01-01

A psychoanalyst faces the extraordinary demand of becoming instrumental in the psychoanalytic process. In the candidate's attempt to rise to that expectation, the first step is the training analysis. As the center-piece of psychoanalytic education, it is no ordinary analysis and bears special burdens intrinsic to its multiple functions and institutionalization. Recognizing the difficulties of both analytic education and analytic practice, Freud suggested that the analyst be periodically reanalyzed; for many, reanalysis is integral to their analytic development. Indeed, an analyst is actually never "made" but is always "in the making," developing and maturing in life and in practice. Reanalysis serves to focus elements of transference and resistance, rework defenses, facilitate more extensive regression in the service of the ego, deepen emotional integration, rework those elements of psychoanalysis itself that have been incorporated into defensive structure, and further the maturation of the analyzing instrument. If analysis is our most powerful mode of initial education, reanalysis is the most powerful form of continuing education. That remarkably little attention has been paid to reanalysis is testimony to the infantile fantasies that remain invested in our personal analyses.

Process for analyzing CO[sub 2] in air and in water

DOEpatents

Atwater, J.E.; Akse, J.R.; DeHart, J.

1999-06-08

The process of this invention comprises providing a membrane for separating CO[sub 2] into a first CO[sub 2] sample phase and a second CO[sub 2] analyte phase. CO[sub 2] is then transported through the membrane thereby separating the CO[sub 2] with the membrane into a first CO[sub 2] sample phase and a second CO[sub 2] analyte liquid phase including an ionized, conductive, dissociated CO[sub 2] species. Next, the concentration of the ionized, conductive, dissociated CO[sub 2] species in the second CO[sub 2] analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO[sub 2] to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO[sub 2] in the first CO[sub 2] sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO[sub 2] species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO[sub 2] species are detected using the conductivity measuring instrument. 43 figs.

Process for analyzing CO.sub.2 in air and in water

DOEpatents

Atwater, James E.; Akse, James R.; DeHart, Jeffrey

1999-01-01

The process of this invention comprises providing a membrane for separating CO.sub.2 into a first CO.sub.2 sample phase and a second CO.sub.2 analyte phase. CO.sub.2 is then transported through the membrane thereby separating the CO.sub.2 with the membrane into a first CO.sub.2 sample phase and a second CO.sub.2 analyte liquid phase including an ionized, conductive, dissociated CO.sub.2 species. Next, the concentration of the ionized, conductive, dissociated CO.sub.2 species in the second CO.sub.2 analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO.sub.2 to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO.sub.2 in the first CO.sub.2 sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO.sub.2 species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO.sub.2 species are detected using the conductivity measuring instrument.

Process for analyzing CO{sub 2} in seawater

DOEpatents

Atwater, J.E.; Akse, J.R.; DeHart, J.

1997-07-01

The process of this invention comprises providing a membrane for separating CO{sub 2} into a first CO{sub 2} sample phase and a second CO{sub 2} analyte phase. CO{sub 2} is then transported through the membrane thereby separating the CO{sub 2} with the membrane into a first CO{sub 2} sample phase and a second CO{sub 2} analyte liquid phase including an ionized, conductive, dissociated CO{sub 2} species. Next, the concentration of the ionized, conductive, dissociated CO{sub 2} species in the second CO{sub 2} analyte liquid phase is chemically amplified using a water-soluble chemical reagent which reversibly reacts with undissociated CO{sub 2} to produce conductivity changes therein corresponding to fluctuations in the partial pressure of CO{sub 2} in the first CO{sub 2} sample phase. Finally, the chemically amplified, ionized, conductive, dissociated CO{sub 2} species is introduced to a conductivity measuring instrument. Conductivity changes in the chemically amplified, ionized, conductive, dissociated CO{sub 2} species are detected using the conductivity measuring instrument. 43 figs.

Model uncertainty of various settlement estimation methods in shallow tunnels excavation; case study: Qom subway tunnel

NASA Astrophysics Data System (ADS)

Khademian, Amir; Abdollahipour, Hamed; Bagherpour, Raheb; Faramarzi, Lohrasb

2017-10-01

In addition to the numerous planning and executive challenges, underground excavation in urban areas is always followed by certain destructive effects especially on the ground surface; ground settlement is the most important of these effects for which estimation there exist different empirical, analytical and numerical methods. Since geotechnical models are associated with considerable model uncertainty, this study characterized the model uncertainty of settlement estimation models through a systematic comparison between model predictions and past performance data derived from instrumentation. To do so, the amount of surface settlement induced by excavation of the Qom subway tunnel was estimated via empirical (Peck), analytical (Loganathan and Poulos) and numerical (FDM) methods; the resulting maximum settlement value of each model were 1.86, 2.02 and 1.52 cm, respectively. The comparison of these predicted amounts with the actual data from instrumentation was employed to specify the uncertainty of each model. The numerical model outcomes, with a relative error of 3.8%, best matched the reality and the analytical method, with a relative error of 27.8%, yielded the highest level of model uncertainty.

Chemical Analysis through CL-Detection Assisted by Periodate Oxidation

PubMed Central

Evmiridis, Nicholaos P.; Vlessidis, Athanasios G.; Thanasoulias, Nicholas C.

2007-01-01

The progress of the research work of the author and his colleagues on the field of CL-emission generated by pyrogallol oxidation and further application for the direct determination of periodate and indirect or direct determination of other compounds through flow-injection manifold/CL-detection set up is described. The instrumentation used for these studies was a simple flow-injection manifold that provides good reproducibility, coupled to a red sensitive photomultiplier that gives sensitive CL-detection. In addition, recent reports on studies and analytical methods based on CL-emission generated by periodate oxidation by other authors are included. PMID:17611611

Fast, cheap and in control: spectral imaging with handheld devices

NASA Astrophysics Data System (ADS)

Gooding, Edward A.; Deutsch, Erik R.; Huehnerhoff, Joseph; Hajian, Arsen R.

2017-05-01

Remote sensing has moved out of the laboratory and into the real world. Instruments using reflection or Raman imaging modalities become faster, cheaper and more powerful annually. Enabling technologies include virtual slit spectrometer design, high power multimode diode lasers, fast open-loop scanning systems, low-noise IR-sensitive array detectors and low-cost computers with touchscreen interfaces. High-volume manufacturing assembles these components into inexpensive portable or handheld devices that make possible sophisticated decision-making based on robust data analytics. Examples include threat, hazmat and narcotics detection; remote gas sensing; biophotonic screening; environmental remediation and a host of other applications.

40 CFR 141.74 - Analytical and monitoring requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

..., Volume 54, p. 3197, December, 1988), may be obtained from the American Water Works Association Research... method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision...

40 CFR 141.74 - Analytical and monitoring requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

..., Volume 54, p. 3197, December, 1988), may be obtained from the American Water Works Association Research... method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision...

40 CFR 141.74 - Analytical and monitoring requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

..., Volume 54, p. 3197, December, 1988), may be obtained from the American Water Works Association Research... method for use with a continuous monitoring instrument provided the chemistry, accuracy, and precision...

Integrated Response Time Evaluation Methodology for the Nuclear Safety Instrumentation System

NASA Astrophysics Data System (ADS)

Lee, Chang Jae; Yun, Jae Hee

2017-06-01

Safety analysis for a nuclear power plant establishes not only an analytical limit (AL) in terms of a measured or calculated variable but also an analytical response time (ART) required to complete protective action after the AL is reached. If the two constraints are met, the safety limit selected to maintain the integrity of physical barriers used for preventing uncontrolled radioactivity release will not be exceeded during anticipated operational occurrences and postulated accidents. Setpoint determination methodologies have actively been developed to ensure that the protective action is initiated before the process conditions reach the AL. However, regarding the ART for a nuclear safety instrumentation system, an integrated evaluation methodology considering the whole design process has not been systematically studied. In order to assure the safety of nuclear power plants, this paper proposes a systematic and integrated response time evaluation methodology that covers safety analyses, system designs, response time analyses, and response time tests. This methodology is applied to safety instrumentation systems for the advanced power reactor 1400 and the optimized power reactor 1000 nuclear power plants in South Korea. The quantitative evaluation results are provided herein. The evaluation results using the proposed methodology demonstrate that the nuclear safety instrumentation systems fully satisfy corresponding requirements of the ART.

Caesium sputter ion source compatible with commercial SIMS instruments

NASA Astrophysics Data System (ADS)

Belykh, S. F.; Palitsin, V. V.; Veryovkin, I. V.; Kovarsky, A. P.; Chang, R. J. H.; Adriaens, A.; Dowsett, M.; Adams, F.

2006-07-01

A simple design for a caesium sputter cluster ion source compatible with commercially available secondary ion mass spectrometers is reported. This source has been tested with the Cameca IMS 4f instrument using the cluster Si n- and Cu n- ions, and will shortly be retrofitted to the floating low energy ion gun (FLIG) of the type used on the Cameca 4500/4550 quadruple instruments. Our experiments with surface characterization and depth profiling conducted to date demonstrate improvements of analytical capabilities of the SIMS instrument due to the non-additive enhancement of secondary ion emission and shorter ion ranges of polyatomic projectiles compared to atomic ions with the same impact energy.

Development of an Atmospheric Pressure Ionization Mass Spectrometer

NASA Technical Reports Server (NTRS)

1998-01-01

A commercial atmospheric pressure ionization mass spectrometer (APIMS) was purchased from EXTREL Mass Spectrometry, Inc. (Pittsburgh, PA). Our research objectives were to adapt this instrument and develop techniques for real-time determinations of the concentrations of trace species in the atmosphere. The prototype instrument is capable of making high frequency measurements with no sample preconcentrations. Isotopically labeled standards are used as an internal standard to obtain high precision and to compensate for changes in instrument sensitivity and analyte losses in the sampling manifold as described by Bandy and coworkers. The prototype instrument is capable of being deployed on NASA C130, Electra, P3, and DC8 aircraft. After purchasing and taking delivery by June 1994, we assembled the mass spectrometer, data acquisition, and manifold flow control instrumentation in electronic racks and performed tests.

Research highlights: increasing paper possibilities.

PubMed

Wu, Chueh-Yu; Adeyiga, Oladunni; Lin, Jonathan; Di Carlo, Dino

2014-09-07

In this issue we highlight three recent papers that demonstrate new strategies to extend the capabilities of paper microfluidics. Paper (a mesh of porous fibers) has a long history as a substrate to perform biomolecular assays. Traditional lateral flow immunoassays (LFAs) are widely used for rapid diagnostic tests, and perform well when a yes or no answer is required and the analyte of interest is at relatively high concentrations. High concentrations are required because usually only a small volume of analyte-containing fluid flows past the detection region, leading to a limited signal. Further, the small pores within paper matrices prevent the use of paper to control the flow of larger particles and cells, limiting the use of paper microfluidics for cell-based diagnostics. The work we highlight addresses these important unmet challenges in paper microfluidics: enriching low concentration analytes to a higher concentration in a smaller volume that can be processed effectively, and using paper to pump flows in larger channels amenable to cells. Applying these new approaches may allow diagnosis of disease states currently technically unachievable using current LFA systems, while maintaining many of the "un-instrumented" advantages of an assay on self-wicking paper.

Mass Spectrometry Parameters Optimization for the 46 Multiclass Pesticides Determination in Strawberries with Gas Chromatography Ion-Trap Tandem Mass Spectrometry

NASA Astrophysics Data System (ADS)

Fernandes, Virgínia C.; Vera, Jose L.; Domingues, Valentina F.; Silva, Luís M. S.; Mateus, Nuno; Delerue-Matos, Cristina

2012-12-01

Multiclass analysis method was optimized in order to analyze pesticides traces by gas chromatography with ion-trap and tandem mass spectrometry (GC-MS/MS). The influence of some analytical parameters on pesticide signal response was explored. Five ion trap mass spectrometry (IT-MS) operating parameters, including isolation time (IT), excitation voltage (EV), excitation time (ET), maximum excitation energy or " q" value (q), and isolation mass window (IMW) were numerically tested in order to maximize the instrument analytical signal response. For this, multiple linear regression was used in data analysis to evaluate the influence of the five parameters on the analytical response in the ion trap mass spectrometer and to predict its response. The assessment of the five parameters based on the regression equations substantially increased the sensitivity of IT-MS/MS in the MS/MS mode. The results obtained show that for most of the pesticides, these parameters have a strong influence on both signal response and detection limit. Using the optimized method, a multiclass pesticide analysis was performed for 46 pesticides in a strawberry matrix. Levels higher than the limit established for strawberries by the European Union were found in some samples.