EPA Contract Laboratory Program Statement of Work for Inorganic Superfund Methods Multi-Media, Multi-Concentration ISM02.4

EPA Pesticide Factsheets

This document contains analytical methods for the analysis of metals and cyanide in environmental samples. It also contains contractual requirements for laboratories participating in Superfund's Contract Laboratory Program.

Chapter A5. Section 6.1.F. Wastewater, Pharmaceutical, and Antibiotic Compounds

USGS Publications Warehouse

Lewis, Michael Edward; Zaugg, Steven D.

2003-01-01

The USGS differentiates between samples collected for analysis of wastewater compounds and those collected for analysis of pharmaceutical and antibiotic compounds, based on the analytical schedule for the laboratory method. Currently, only the wastewater laboratory method for field-filtered samples (SH1433) is an approved, routine (production) method. (The unfiltered wastewater method LC 8033 also is available but requires a proposal for custom analysis.) At this time, analysis of samples for pharmaceutical and antibiotic compounds is confined to research studies and is available only on a custom basis.

A round robin approach to the analysis of bisphenol a (BPA) in human blood samples

PubMed Central

2014-01-01

Background Human exposure to bisphenol A (BPA) is ubiquitous, yet there are concerns about whether BPA can be measured in human blood. This Round Robin was designed to address this concern through three goals: 1) to identify collection materials, reagents and detection apparatuses that do not contribute BPA to serum; 2) to identify sensitive and precise methods to accurately measure unconjugated BPA (uBPA) and BPA-glucuronide (BPA-G), a metabolite, in serum; and 3) to evaluate whether inadvertent hydrolysis of BPA-G occurs during sample handling and processing. Methods Four laboratories participated in this Round Robin. Laboratories screened materials to identify BPA contamination in collection and analysis materials. Serum was spiked with concentrations of uBPA and/or BPA-G ranging from 0.09-19.5 (uBPA) and 0.5-32 (BPA-G) ng/mL. Additional samples were preserved unspiked as ‘environmental’ samples. Blinded samples were provided to laboratories that used LC/MSMS to simultaneously quantify uBPA and BPA-G. To determine whether inadvertent hydrolysis of BPA metabolites occurred, samples spiked with only BPA-G were analyzed for the presence of uBPA. Finally, three laboratories compared direct and indirect methods of quantifying BPA-G. Results We identified collection materials and reagents that did not introduce BPA contamination. In the blinded spiked sample analysis, all laboratories were able to distinguish low from high values of uBPA and BPA-G, for the whole spiked sample range and for those samples spiked with the three lowest concentrations (0.5-3.1 ng/ml). By completion of the Round Robin, three laboratories had verified methods for the analysis of uBPA and two verified for the analysis of BPA-G (verification determined by: 4 of 5 samples within 20% of spiked concentrations). In the analysis of BPA-G only spiked samples, all laboratories reported BPA-G was the majority of BPA detected (92.2 – 100%). Finally, laboratories were more likely to be verified using direct methods than indirect ones using enzymatic hydrolysis. Conclusions Sensitive and accurate methods for the direct quantification of uBPA and BPA-G were developed in multiple laboratories and can be used for the analysis of human serum samples. BPA contamination can be controlled during sample collection and inadvertent hydrolysis of BPA conjugates can be avoided during sample handling. PMID:24690217

Results of the first provisional technical secretariat interlaboratory comparison test

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

Stuff, J.R.; Hoffland, L.

1995-06-01

The principal task of this laboratory in the first Provisional Technical Secretariat (PTS) Interlaboratory Comparison Test was to verify and test the extraction and preparation procedures outlined in the Recommended Operating Procedures for Sampling and Analysis in the Verification of Chemical Disarmament in addition to our laboratory extraction methods and our laboratory analysis methods. Sample preparation began on 16 May 1994 and analysis was completed on 12 June 1994. The analytical methods used included NMR ({sup 1}H and {sup 31}P) GC/AED, GC/MS (EI and methane CI), GC/IRD, HPLC/IC, HPLC/TSP/MS, MS/MS(Electrospray), and CZE.

Reliability on intra-laboratory and inter-laboratory data of hair mineral analysis comparing with blood analysis.

PubMed

Namkoong, Sun; Hong, Seung Phil; Kim, Myung Hwa; Park, Byung Cheol

2013-02-01

Nowadays, although its clinical value remains controversial institutions utilize hair mineral analysis. Arguments about the reliability of hair mineral analysis persist, and there have been evaluations of commercial laboratories performing hair mineral analysis. The objective of this study was to assess the reliability of intra-laboratory and inter-laboratory data at three commercial laboratories conducting hair mineral analysis, compared to serum mineral analysis. Two divided hair samples taken from near the scalp were submitted for analysis at the same time, to all laboratories, from one healthy volunteer. Each laboratory sent a report consisting of quantitative results and their interpretation of health implications. Differences among intra-laboratory and interlaboratory data were analyzed using SPSS version 12.0 (SPSS Inc., USA). All the laboratories used identical methods for quantitative analysis, and they generated consistent numerical results according to Friedman analysis of variance. However, the normal reference ranges of each laboratory varied. As such, each laboratory interpreted the patient's health differently. On intra-laboratory data, Wilcoxon analysis suggested they generated relatively coherent data, but laboratory B could not in one element, so its reliability was doubtful. In comparison with the blood test, laboratory C generated identical results, but not laboratory A and B. Hair mineral analysis has its limitations, considering the reliability of inter and intra laboratory analysis comparing with blood analysis. As such, clinicians should be cautious when applying hair mineral analysis as an ancillary tool. Each laboratory included in this study requires continuous refinement from now on for inducing standardized normal reference levels.

Laboratory theory and methods for sediment analysis

USGS Publications Warehouse

Guy, Harold P.

1969-01-01

The diverse character of fluvial sediments makes the choice of laboratory analysis somewhat arbitrary and the pressing of sediment samples difficult. This report presents some theories and methods used by the Water Resources Division for analysis of fluvial sediments to determine the concentration of suspended-sediment samples and the particle-size distribution of both suspended-sediment and bed-material samples. Other analyses related to these determinations may include particle shape, mineral content, and specific gravity, the organic matter and dissolved solids of samples, and the specific weight of soils. The merits and techniques of both the evaporation and filtration methods for concentration analysis are discussed. Methods used for particle-size analysis of suspended-sediment samples may include the sieve pipet, the VA tube-pipet, or the BW tube-VA tube depending on the equipment available, the concentration and approximate size of sediment in the sample, and the settling medium used. The choice of method for most bed-material samples is usually limited to procedures suitable for sand or to some type of visual analysis for large sizes. Several tested forms are presented to help insure a well-ordered system in the laboratory to handle the samples, to help determine the kind of analysis required for each, to conduct the required processes, and to assist in the required computations. Use of the manual should further 'standardize' methods of fluvial sediment analysis among the many laboratories and thereby help to achieve uniformity and precision of the data.

A Lean Six Sigma approach to the improvement of the selenium analysis method.

PubMed

Cloete, Bronwyn C; Bester, André

2012-11-02

Reliable results represent the pinnacle assessment of quality of an analytical laboratory, and therefore variability is considered to be a critical quality problem associated with the selenium analysis method executed at Western Cape Provincial Veterinary Laboratory (WCPVL). The elimination and control of variability is undoubtedly of significant importance because of the narrow margin of safety between toxic and deficient doses of the trace element for good animal health. A quality methodology known as Lean Six Sigma was believed to present the most feasible solution for overcoming the adverse effect of variation, through steps towards analytical process improvement. Lean Six Sigma represents a form of scientific method type, which is empirical, inductive and deductive, and systematic, which relies on data, and is fact-based. The Lean Six Sigma methodology comprises five macro-phases, namely Define, Measure, Analyse, Improve and Control (DMAIC). Both qualitative and quantitative laboratory data were collected in terms of these phases. Qualitative data were collected by using quality-tools, namely an Ishikawa diagram, a Pareto chart, Kaizen analysis and a Failure Mode Effect analysis tool. Quantitative laboratory data, based on the analytical chemistry test method, were collected through a controlled experiment. The controlled experiment entailed 13 replicated runs of the selenium test method, whereby 11 samples were repetitively analysed, whilst Certified Reference Material (CRM) was also included in 6 of the runs. Laboratory results obtained from the controlled experiment was analysed by using statistical methods, commonly associated with quality validation of chemistry procedures. Analysis of both sets of data yielded an improved selenium analysis method, believed to provide greater reliability of results, in addition to a greatly reduced cycle time and superior control features. Lean Six Sigma may therefore be regarded as a valuable tool in any laboratory, and represents both a management discipline, and a standardised approach to problem solving and process optimisation.

Comparison of multianalyte proficiency test results by sum of ranking differences, principal component analysis, and hierarchical cluster analysis.

PubMed

Škrbić, Biljana; Héberger, Károly; Durišić-Mladenović, Nataša

2013-10-01

Sum of ranking differences (SRD) was applied for comparing multianalyte results obtained by several analytical methods used in one or in different laboratories, i.e., for ranking the overall performances of the methods (or laboratories) in simultaneous determination of the same set of analytes. The data sets for testing of the SRD applicability contained the results reported during one of the proficiency tests (PTs) organized by EU Reference Laboratory for Polycyclic Aromatic Hydrocarbons (EU-RL-PAH). In this way, the SRD was also tested as a discriminant method alternative to existing average performance scores used to compare mutlianalyte PT results. SRD should be used along with the z scores--the most commonly used PT performance statistics. SRD was further developed to handle the same rankings (ties) among laboratories. Two benchmark concentration series were selected as reference: (a) the assigned PAH concentrations (determined precisely beforehand by the EU-RL-PAH) and (b) the averages of all individual PAH concentrations determined by each laboratory. Ranking relative to the assigned values and also to the average (or median) values pointed to the laboratories with the most extreme results, as well as revealed groups of laboratories with similar overall performances. SRD reveals differences between methods or laboratories even if classical test(s) cannot. The ranking was validated using comparison of ranks by random numbers (a randomization test) and using seven folds cross-validation, which highlighted the similarities among the (methods used in) laboratories. Principal component analysis and hierarchical cluster analysis justified the findings based on SRD ranking/grouping. If the PAH-concentrations are row-scaled, (i.e., z scores are analyzed as input for ranking) SRD can still be used for checking the normality of errors. Moreover, cross-validation of SRD on z scores groups the laboratories similarly. The SRD technique is general in nature, i.e., it can be applied to any experimental problem in which multianalyte results obtained either by several analytical procedures, analysts, instruments, or laboratories need to be compared.

Interlaboratory comparison for the determination of the soluble fraction of metals in welding fume samples.

PubMed

Berlinger, Balazs; Harper, Martin

2018-02-01

There is interest in the bioaccessible metal components of aerosols, but this has been minimally studied because standardized sampling and analytical methods have not yet been developed. An interlaboratory study (ILS) has been carried out to evaluate a method for determining the water-soluble component of realistic welding fume (WF) air samples. Replicate samples were generated in the laboratory and distributed to participating laboratories to be analyzed according to a standardized procedure. Within-laboratory precision of replicate sample analysis (repeatability) was very good. Reproducibility between laboratories was not as good, but within limits of acceptability for the analysis of typical aerosol samples. These results can be used to support the development of a standardized test method.

Evaluation of the annual Canadian biodosimetry network intercomparisons

PubMed Central

Wilkins, Ruth C.; Beaton-Green, Lindsay A.; Lachapelle, Sylvie; Kutzner, Barbara C.; Ferrarotto, Catherine; Chauhan, Vinita; Marro, Leonora; Livingston, Gordon K.; Boulay Greene, Hillary; Flegal, Farrah N.

2015-01-01

Abstract Purpose: To evaluate the importance of annual intercomparisons for maintaining the capacity and capabilities of a well-established biodosimetry network in conjunction with assessing efficient and effective analysis methods for emergency response. Materials and methods: Annual intercomparisons were conducted between laboratories in the Canadian National Biological Dosimetry Response Plan. Intercomparisons were performed over a six-year period and comprised of the shipment of 10–12 irradiated, blinded blood samples for analysis by each of the participating laboratories. Dose estimates were determined by each laboratory using the dicentric chromosome assay (conventional and QuickScan scoring) and where possible the cytokinesis block micronucleus (CBMN) assay. Dose estimates were returned to the lead laboratory for evaluation and comparison. Results: Individual laboratories performed comparably from year to year with only slight fluctuations in performance. Dose estimates using the dicentric chromosome assay were accurate about 80% of the time and the QuickScan method for scoring the dicentric chromosome assay was proven to reduce the time of analysis without having a significant effect on the dose estimates. Although analysis with the CBMN assay was comparable to QuickScan scoring with respect to speed, the accuracy of the dose estimates was greatly reduced. Conclusions: Annual intercomparisons are necessary to maintain a network of laboratories for emergency response biodosimetry as they evoke confidence in their capabilities. PMID:25670072

Data Analysis and Graphing in an Introductory Physics Laboratory: Spreadsheet versus Statistics Suite

ERIC Educational Resources Information Center

Peterlin, Primoz

2010-01-01

Two methods of data analysis are compared: spreadsheet software and a statistics software suite. Their use is compared analysing data collected in three selected experiments taken from an introductory physics laboratory, which include a linear dependence, a nonlinear dependence and a histogram. The merits of each method are compared. (Contains 7…

Sediment laboratory quality-assurance project: studies of methods and materials

USGS Publications Warehouse

Gordon, J.D.; Newland, C.A.; Gray, J.R.

2001-01-01

In August 1996 the U.S. Geological Survey initiated the Sediment Laboratory Quality-Assurance project. The Sediment Laboratory Quality Assurance project is part of the National Sediment Laboratory Quality-Assurance program. This paper addresses the fmdings of the sand/fme separation analysis completed for the single-blind reference sediment-sample project and differences in reported results between two different analytical procedures. From the results it is evident that an incomplete separation of fme- and sand-size material commonly occurs resulting in the classification of some of the fme-size material as sand-size material. Electron microscopy analysis supported the hypothesis that the negative bias for fme-size material and the positive bias for sand-size material is largely due to aggregation of some of the fine-size material into sand-size particles and adherence of fine-size material to the sand-size grains. Electron microscopy analysis showed that preserved river water, which was low in dissolved solids, specific conductance, and neutral pH, showed less aggregation and adhesion than preserved river water that was higher in dissolved solids and specific conductance with a basic pH. Bacteria were also found growing in the matrix, which may enhance fme-size material aggregation through their adhesive properties. Differences between sediment-analysis methods were also investigated as pan of this study. Suspended-sediment concentration results obtained from one participating laboratory that used a total-suspended solids (TSS) method had greater variability and larger negative biases than results obtained when this laboratory used a suspended-sediment concentration method. When TSS methods were used to analyze the reference samples, the median suspended sediment concentration percent difference was -18.04 percent. When the laboratory used a suspended-sediment concentration method, the median suspended-sediment concentration percent difference was -2.74 percent. The percent difference was calculated as follows: Percent difference = (( reported mass - known mass)/known mass ) X 100.

Microbial ecology laboratory procedures manual NASA/MSFC

NASA Technical Reports Server (NTRS)

Huff, Timothy L.

1990-01-01

An essential part of the efficient operation of any microbiology laboratory involved in sample analysis is a standard procedures manual. The purpose of this manual is to provide concise and well defined instructions on routine technical procedures involving sample analysis and methods for monitoring and maintaining quality control within the laboratory. Of equal importance is the safe operation of the laboratory. This manual outlines detailed procedures to be followed in the microbial ecology laboratory to assure safety, analytical control, and validity of results.

Method of Analysis by the U.S. Geological Survey California District Sacramento Laboratory-- Determination of Dissolved Organic Carbon in Water by High Temperature Catalytic Oxidation, Method Validation, and Quality-Control Practices

USGS Publications Warehouse

Bird, Susan M.; Fram, Miranda S.; Crepeau, Kathryn L.

2003-01-01

An analytical method has been developed for the determination of dissolved organic carbon concentration in water samples. This method includes the results of the tests used to validate the method and the quality-control practices used for dissolved organic carbon analysis. Prior to analysis, water samples are filtered to remove suspended particulate matter. A Shimadzu TOC-5000A Total Organic Carbon Analyzer in the nonpurgeable organic carbon mode is used to analyze the samples by high temperature catalytic oxidation. The analysis usually is completed within 48 hours of sample collection. The laboratory reporting level is 0.22 milligrams per liter.

78 FR 300 - IDEXX Laboratories, Inc.; Analysis of Proposed Consent Order To Aid Public Comment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-01-03

... FEDERAL TRADE COMMISSION [File No. 101 0023] IDEXX Laboratories, Inc.; Analysis of Proposed... or deceptive acts or practices or unfair methods of competition. The attached Analysis to Aid Public.... The following Analysis to Aid Public Comment describes the terms of the consent agreement, and the...

Development, Implementation, and Analysis of a National Survey of Faculty Goals for Undergraduate Chemistry Laboratory

ERIC Educational Resources Information Center

Bruck, Aaron D.; Towns, Marcy

2013-01-01

This work reports the development of a survey for laboratory goals in undergraduate chemistry, the analysis of reliable and valid data collected from a national survey of college chemistry faculty, and a synthesis of the findings. The study used a sequential exploratory mixed-methods design. Faculty goals for laboratory emerged across seven…

Implementing EPA Method 537

EPA Science Inventory

This presentation describes EPA Method 537 for the analysis of 14 perfluorinated alkyl acids in drinking water as well as the challenges associated with preparing a laboratory for analysis using Method 537.

Development of Gold Standard Ion-Selective Electrode-Based Methods for Fluoride Analysis

PubMed Central

Martínez-Mier, E.A.; Cury, J.A.; Heilman, J.R.; Katz, B.P.; Levy, S.M.; Li, Y.; Maguire, A.; Margineda, J.; O’Mullane, D.; Phantumvanit, P.; Soto-Rojas, A.E.; Stookey, G.K.; Villa, A.; Wefel, J.S.; Whelton, H.; Whitford, G.M.; Zero, D.T.; Zhang, W.; Zohouri, V.

2011-01-01

Background/Aims: Currently available techniques for fluoride analysis are not standardized. Therefore, this study was designed to develop standardized methods for analyzing fluoride in biological and nonbiological samples used for dental research. Methods A group of nine laboratories analyzed a set of standardized samples for fluoride concentration using their own methods. The group then reviewed existing analytical techniques for fluoride analysis, identified inconsistencies in the use of these techniques and conducted testing to resolve differences. Based on the results of the testing undertaken to define the best approaches for the analysis, the group developed recommendations for direct and microdiffusion methods using the fluoride ion-selective electrode. Results Initial results demonstrated that there was no consensus regarding the choice of analytical techniques for different types of samples. Although for several types of samples, the results of the fluoride analyses were similar among some laboratories, greater differences were observed for saliva, food and beverage samples. In spite of these initial differences, precise and true values of fluoride concentration, as well as smaller differences between laboratories, were obtained once the standardized methodologies were used. Intraclass correlation coefficients ranged from 0.90 to 0.93, for the analysis of a certified reference material, using the standardized methodologies. Conclusion The results of this study demonstrate that the development and use of standardized protocols for F analysis significantly decreased differences among laboratories and resulted in more precise and true values. PMID:21160184

A method to evaluate performance reliability of individual subjects in laboratory research applied to work settings.

DOT National Transportation Integrated Search

1978-10-01

This report presents a method that may be used to evaluate the reliability of performance of individual subjects, particularly in applied laboratory research. The method is based on analysis of variance of a tasks-by-subjects data matrix, with all sc...

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)…

WHO Melting-Point Reference Substances

PubMed Central

Bervenmark, H.; Diding, N. Å.; Öhrner, B.

1963-01-01

Batches of 13 highly purified chemicals, intended for use as reference substances in the calibration of apparatus for melting-point determinations, have been subjected to a collaborative assay by 15 laboratories in 13 countries. All the laboratories performed melting-point determinations by the capillary methods described in the proposed text for the second edition of the Pharmacopoea Internationalis and some, in addition, carried out determinations by the microscope hot stage (Kofler) method, using both the “going-through” and the “equilibrium” technique. Statistical analysis of the data obtained by the capillary method showed that the within-laboratory variation was small and that the between-laboratory variation, though constituting the greatest part of the whole variance, was not such as to warrant the exclusion of any laboratory from the evaluation of the results. The average values of the melting-points obtained by the laboratories can therefore be used as constants for the substances in question, which have accordingly been established as WHO Melting-Point Reference Substances and included in the WHO collection of authentic chemical substances. As to the microscope hot stage method, analysis of the results indicated that the values obtained by the “going-through” technique did not differ significantly from those obtained by the capillary method, but the values obtained by the “equilibrium” technique were mostly significantly lower. PMID:20604137

A simple method for plasma total vitamin C analysis suitable for routine clinical laboratory use.

PubMed

Robitaille, Line; Hoffer, L John

2016-04-21

In-hospital hypovitaminosis C is highly prevalent but almost completely unrecognized. Medical awareness of this potentially important disorder is hindered by the inability of most hospital laboratories to determine plasma vitamin C concentrations. The availability of a simple, reliable method for analyzing plasma vitamin C could increase opportunities for routine plasma vitamin C analysis in clinical medicine. Plasma vitamin C can be analyzed by high performance liquid chromatography (HPLC) with electrochemical (EC) or ultraviolet (UV) light detection. We modified existing UV-HPLC methods for plasma total vitamin C analysis (the sum of ascorbic and dehydroascorbic acid) to develop a simple, constant-low-pH sample reduction procedure followed by isocratic reverse-phase HPLC separation using a purely aqueous low-pH non-buffered mobile phase. Although EC-HPLC is widely recommended over UV-HPLC for plasma total vitamin C analysis, the two methods have never been directly compared. We formally compared the simplified UV-HPLC method with EC-HPLC in 80 consecutive clinical samples. The simplified UV-HPLC method was less expensive, easier to set up, required fewer reagents and no pH adjustments, and demonstrated greater sample stability than many existing methods for plasma vitamin C analysis. When compared with the gold-standard EC-HPLC method in 80 consecutive clinical samples exhibiting a wide range of plasma vitamin C concentrations, it performed equivalently. The easy set up, simplicity and sensitivity of the plasma vitamin C analysis method described here could make it practical in a normally equipped hospital laboratory. Unlike any prior UV-HPLC method for plasma total vitamin C analysis, it was rigorously compared with the gold-standard EC-HPLC method and performed equivalently. Adoption of this method could increase the availability of plasma vitamin C analysis in clinical medicine.

Preanalytical errors in medical laboratories: a review of the available methodologies of data collection and analysis.

PubMed

West, Jamie; Atherton, Jennifer; Costelloe, Seán J; Pourmahram, Ghazaleh; Stretton, Adam; Cornes, Michael

2017-01-01

Preanalytical errors have previously been shown to contribute a significant proportion of errors in laboratory processes and contribute to a number of patient safety risks. Accreditation against ISO 15189:2012 requires that laboratory Quality Management Systems consider the impact of preanalytical processes in areas such as the identification and control of non-conformances, continual improvement, internal audit and quality indicators. Previous studies have shown that there is a wide variation in the definition, repertoire and collection methods for preanalytical quality indicators. The International Federation of Clinical Chemistry Working Group on Laboratory Errors and Patient Safety has defined a number of quality indicators for the preanalytical stage, and the adoption of harmonized definitions will support interlaboratory comparisons and continual improvement. There are a variety of data collection methods, including audit, manual recording processes, incident reporting mechanisms and laboratory information systems. Quality management processes such as benchmarking, statistical process control, Pareto analysis and failure mode and effect analysis can be used to review data and should be incorporated into clinical governance mechanisms. In this paper, The Association for Clinical Biochemistry and Laboratory Medicine PreAnalytical Specialist Interest Group review the various data collection methods available. Our recommendation is the use of the laboratory information management systems as a recording mechanism for preanalytical errors as this provides the easiest and most standardized mechanism of data capture.

7 CFR 58.812 - Methods of sample analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Methods of sample analysis. 58.812 Section 58.812... Procedures § 58.812 Methods of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL, as issued by the USDA, Agricultural...

7 CFR 58.245 - Method of sample analysis.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 7 Agriculture 3 2010-01-01 2010-01-01 false Method of sample analysis. 58.245 Section 58.245... Procedures § 58.245 Method of sample analysis. Samples shall be tested according to the applicable methods of laboratory analysis contained in either DA Instruction 918-RL as issued by the USDA, Agricultural Marketing...

Correlative and multivariate analysis of increased radon concentration in underground laboratory.

PubMed

Maletić, Dimitrije M; Udovičić, Vladimir I; Banjanac, Radomir M; Joković, Dejan R; Dragić, Aleksandar L; Veselinović, Nikola B; Filipović, Jelena

2014-11-01

The results of analysis using correlative and multivariate methods, as developed for data analysis in high-energy physics and implemented in the Toolkit for Multivariate Analysis software package, of the relations of the variation of increased radon concentration with climate variables in shallow underground laboratory is presented. Multivariate regression analysis identified a number of multivariate methods which can give a good evaluation of increased radon concentrations based on climate variables. The use of the multivariate regression methods will enable the investigation of the relations of specific climate variable with increased radon concentrations by analysis of regression methods resulting in 'mapped' underlying functional behaviour of radon concentrations depending on a wide spectrum of climate variables. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

MICROBIAL LABORATORY GUIDANCE MANUAL FOR THE ...

EPA Pesticide Factsheets

The Long-Term 2 Enhanced Surface Water Treatment Rule Laboratory Instruction Manual will be a compilation of all information needed by laboratories and field personnel to collect, analyze, and report the microbiological data required under the rule. The manual will provide laboratories with a single source of information that currently is available from various sources including the latest versions of Methods 1622 and 1623, including all approved, equivalent modifications; the procedures for E.coli methods approved for use under the LT2ESWTR; lists of vendor sources; data recording forms; data reporting requirements; information on the Laboratory Quality Assurance Evaluation Program for the Analysis of Cryptosporidium in Water; and sample collection procedures. Although most of this information is available elsewhere, a single, comprehensive compendium containing this information is needed to aid utilities and laboratories performing the sampling and analysis activities required under the LT2 rule. This manual will serve as an instruction manual for laboratories to use when collecting data for Crypto, E. coli and turbidity.

Integrated Data Collection Analysis (IDCA) Program - SSST Testing Methods

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the methods used for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis during the IDCA program. These methods changed throughout the Proficiency Test and the reasons for these changes are documented in this report. The most significant modifications in standard testing methods are: 1) including one specified sandpaper in impact testing among all the participants, 2) diversifying liquid test methods for selected participants, and 3) including sealed sample holders for thermal testingmore » by at least one participant. This effort, funded by the Department of Homeland Security (DHS), is putting the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study will suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. The testing performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent.« less

A laboratory demonstration of high-resolution hard X-ray and gamma-ray imaging using Fourier-transform techniques

NASA Technical Reports Server (NTRS)

Palmer, David; Prince, Thomas A.

1987-01-01

A laboratory imaging system has been developed to study the use of Fourier-transform techniques in high-resolution hard X-ray and gamma-ray imaging, with particular emphasis on possible applications to high-energy astronomy. Considerations for the design of a Fourier-transform imager and the instrumentation used in the laboratory studies is described. Several analysis methods for image reconstruction are discussed including the CLEAN algorithm and maximum entropy methods. Images obtained using these methods are presented.

The Kjeldahl method as a primary reference procedure for total protein in certified reference materials used in clinical chemistry. II. Selection of direct Kjeldahl analysis and its preliminary performance parameters.

PubMed

Vinklárková, Bára; Chromý, Vratislav; Šprongl, Luděk; Bittová, Miroslava; Rikanová, Milena; Ohnútková, Ivana; Žaludová, Lenka

2015-01-01

To select a Kjeldahl procedure suitable for the determination of total protein in reference materials used in laboratory medicine, we reviewed in our previous article Kjeldahl methods adopted by clinical chemistry and found an indirect two-step analysis by total Kjeldahl nitrogen corrected for its nonprotein nitrogen and a direct analysis made on isolated protein precipitates. In this article, we compare both procedures on various reference materials. An indirect Kjeldahl method gave falsely lower results than a direct analysis. Preliminary performance parameters qualify the direct Kjeldahl analysis as a suitable primary reference procedure for the certification of total protein in reference laboratories.

A Manual of Simplified Laboratory Methods for Operators of Wastewater Treatment Facilities.

ERIC Educational Resources Information Center

Westerhold, Arnold F., Ed.; Bennett, Ernest C., Ed.

This manual is designed to provide the small wastewater treatment plant operator, as well as the new or inexperienced operator, with simplified methods for laboratory analysis of water and wastewater. It is emphasized that this manual is not a replacement for standard methods but a guide for plants with insufficient equipment to perform analyses…

Data analysis considerations for pesticides determined by National Water Quality Laboratory schedule 2437

USGS Publications Warehouse

Shoda, Megan E.; Nowell, Lisa H.; Stone, Wesley W.; Sandstrom, Mark W.; Bexfield, Laura M.

2018-04-02

In 2013, the U.S. Geological Survey National Water Quality Laboratory (NWQL) made a new method available for the analysis of pesticides in filtered water samples: laboratory schedule 2437. Schedule 2437 is an improvement on previous analytical methods because it determines the concentrations of 225 fungicides, herbicides, insecticides, and associated degradates in one method at similar or lower concentrations than previously available methods. Additionally, the pesticides included in schedule 2437 were strategically identified in a prioritization analysis that assessed likelihood of occurrence, prevalence of use, and potential toxicity. When the NWQL reports pesticide concentrations for analytes in schedule 2437, the laboratory also provides supplemental information useful to data users for assessing method performance and understanding data quality. That supplemental information is discussed in this report, along with an initial analysis of analytical recovery of pesticides in water-quality samples analyzed by schedule 2437 during 2013–2015. A total of 523 field matrix spike samples and their paired environmental samples and 277 laboratory reagent spike samples were analyzed for this report (1,323 samples total). These samples were collected in the field as part of the U.S. Geological Survey National Water-Quality Assessment groundwater and surface-water studies and as part of the NWQL quality-control program. This report reviews how pesticide samples are processed by the NWQL, addresses how to obtain all the data necessary to interpret pesticide concentrations, explains the circumstances that result in a reporting level change or the occurrence of a raised reporting level, and describes the calculation and assessment of recovery. This report also discusses reasons why a data user might choose to exclude data in an interpretive analysis and outlines the approach used to identify the potential for decreased data quality in the assessment of method recovery. The information provided in this report is essential to understanding pesticide data determined by schedule 2437 and should be reviewed before interpretation of these data.

Calibration-free quantitative elemental analysis of meteor plasma using reference laser-induced breakdown spectroscopy of meteorite samples

NASA Astrophysics Data System (ADS)

Ferus, Martin; Koukal, Jakub; Lenža, Libor; Srba, Jiří; Kubelík, Petr; Laitl, Vojtěch; Zanozina, Ekaterina M.; Váňa, Pavel; Kaiserová, Tereza; Knížek, Antonín; Rimmer, Paul; Chatzitheodoridis, Elias; Civiš, Svatopluk

2018-03-01

Aims: We aim to analyse real-time Perseid and Leonid meteor spectra using a novel calibration-free (CF) method, which is usually applied in the laboratory for laser-induced breakdown spectroscopic (LIBS) chemical analysis. Methods: Reference laser ablation spectra of specimens of chondritic meteorites were measured in situ simultaneously with a high-resolution laboratory echelle spectrograph and a spectral camera for meteor observation. Laboratory data were subsequently evaluated via the CF method and compared with real meteor emission spectra. Additionally, spectral features related to airglow plasma were compared with the spectra of laser-induced breakdown and electric discharge in the air. Results: We show that this method can be applied in the evaluation of meteor spectral data observed in real time. Specifically, CF analysis can be used to determine the chemical composition of meteor plasma, which, in the case of the Perseid and Leonid meteors analysed in this study, corresponds to that of the C-group of chondrites.

Information Management Systems in the Undergraduate Instrumental Analysis Laboratory.

ERIC Educational Resources Information Center

Merrer, Robert J.

1985-01-01

Discusses two applications of Laboratory Information Management Systems (LIMS) in the undergraduate laboratory. They are the coulometric titration of thiosulfate with electrogenerated triiodide ion and the atomic absorption determination of calcium using both analytical calibration curve and standard addition methods. (JN)

A blinded international study on the reliability of genetic testing for GGGGCC-repeat expansions in C9orf72 reveals marked differences in results among 14 laboratories

PubMed Central

Akimoto, Chizuru; Volk, Alexander E; van Blitterswijk, Marka; Van den Broeck, Marleen; Leblond, Claire S; Lumbroso, Serge; Camu, William; Neitzel, Birgit; Onodera, Osamu; van Rheenen, Wouter; Pinto, Susana; Weber, Markus; Smith, Bradley; Proven, Melanie; Talbot, Kevin; Keagle, Pamela; Chesi, Alessandra; Ratti, Antonia; van der Zee, Julie; Alstermark, Helena; Birve, Anna; Calini, Daniela; Nordin, Angelica; Tradowsky, Daniela C; Just, Walter; Daoud, Hussein; Angerbauer, Sabrina; DeJesus-Hernandez, Mariely; Konno, Takuya; Lloyd-Jani, Anjali; de Carvalho, Mamede; Mouzat, Kevin; Landers, John E; Veldink, Jan H; Silani, Vincenzo; Gitler, Aaron D; Shaw, Christopher E; Rouleau, Guy A; van den Berg, Leonard H; Van Broeckhoven, Christine; Rademakers, Rosa; Andersen, Peter M; Kubisch, Christian

2014-01-01

Background The GGGGCC-repeat expansion in C9orf72 is the most frequent mutation found in patients with amyotrophic lateral sclerosis (ALS) and frontotemporal dementia (FTD). Most of the studies on C9orf72 have relied on repeat-primed PCR (RP-PCR) methods for detection of the expansions. To investigate the inherent limitations of this technique, we compared methods and results of 14 laboratories. Methods The 14 laboratories genotyped DNA from 78 individuals (diagnosed with ALS or FTD) in a blinded fashion. Eleven laboratories used a combination of amplicon-length analysis and RP-PCR, whereas three laboratories used RP-PCR alone; Southern blotting techniques were used as a reference. Results Using PCR-based techniques, 5 of the 14 laboratories got results in full accordance with the Southern blotting results. Only 50 of the 78 DNA samples got the same genotype result in all 14 laboratories. There was a high degree of false positive and false negative results, and at least one sample could not be genotyped at all in 9 of the 14 laboratories. The mean sensitivity of a combination of amplicon-length analysis and RP-PCR was 95.0% (73.9–100%), and the mean specificity was 98.0% (87.5–100%). Overall, a sensitivity and specificity of more than 95% was observed in only seven laboratories. Conclusions Because of the wide range seen in genotyping results, we recommend using a combination of amplicon-length analysis and RP-PCR as a minimum in a research setting. We propose that Southern blotting techniques should be the gold standard, and be made obligatory in a clinical diagnostic setting. PMID:24706941

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

Plemons, R.E.; Hopwood, W.H. Jr.; Hamilton, J.H.

For a number of years the Oak Ridge Y-12 Plant Laboratory has been analyzing coal predominately for the utilities department of the Y-12 Plant. All laboratory procedures, except a Leco sulfur method which used the Leco Instruction Manual as a reference, were written based on the ASTM coal analyses. Sulfur is analyzed at the present time by two methods, gravimetric and Leco. The laboratory has two major endeavors for monitoring the quality of its coal analyses. (1) A control program by the Plant Statistical Quality Control Department. Quality Control submits one sample for every nine samples submitted by the utilitiesmore » departments and the laboratory analyzes a control sample along with the utilities samples. (2) An exchange program with the DOE Coal Analysis Laboratory in Bruceton, Pennsylvania. The Y-12 Laboratory submits to the DOE Coal Laboratory, on even numbered months, a sample that Y-12 has analyzed. The DOE Coal Laboratory submits, on odd numbered months, one of their analyzed samples to the Y-12 Plant Laboratory to be analyzed. The results of these control and exchange programs are monitored not only by laboratory personnel, but also by Statistical Quality Control personnel who provide statistical evaluations. After analysis and reporting of results, all utilities samples are retained by the laboratory until the coal contracts have been settled. The utilities departments have responsibility for the initiation and preparation of the coal samples. The samples normally received by the laboratory have been ground to 4-mesh, reduced to 0.5-gallon quantities, and sealed in air-tight containers. Sample identification numbers and a Request for Analysis are generated by the utilities departments.« less

Evaluation of Methods for Analysis of Lead in Air Particulates: An Intra-Laboratory and Inter-Laboratory Comparison

EPA Science Inventory

In 2008, the United States Environmental Protection Agency (USEPA) set a new National Ambient Air Quality Standard (NAAQS) for lead (Pb) in total suspended particulate matter (Pb-TSP) which called for significant decreases in the allowable limits. The Federal Reference Method (FR...

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING LIGHT TRANSMISSION VISUALIZATION METHOD

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

Asphalt-Aggregate Interactions in Hot Recycling.

DTIC Science & Technology

1987-07-01

Mexico Powders and Granular Materials Laboratory for surface area/porosity measurements and discussion of results John Husler and Les Mcfadden at the...Alamos National Laboratory by X-Ray Fluorescence," LA-96630Ms, May, 1983. 29. Husler , J., "Standard Laboratory Methods for the Chemical Analysis of

40 CFR 98.176 - Data reporting requirements.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., you must report the following information for each process: (1) The carbon content of each process input and output used to determine CO2 emissions. (2) Whether the carbon content was determined from information from the supplier or by laboratory analysis, and if by laboratory analysis, the method used. (3...

The Use of ATR-FTIR in Conjunction with Thermal Analysis Methods for Efficient Identification of Polymer Samples: A Qualitative Multiinstrument Instrumental Analysis Laboratory Experiment

ERIC Educational Resources Information Center

Dickson-Karn, Nicole M.

2017-01-01

A multi-instrument approach has been applied to the efficient identification of polymers in an upper-division undergraduate instrumental analysis laboratory course. Attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR) is used in conjunction with differential scanning calorimetry (DSC) to identify 18 polymer samples and…

Clinical protein mass spectrometry.

PubMed

Scherl, Alexander

2015-06-15

Quantitative protein analysis is routinely performed in clinical chemistry laboratories for diagnosis, therapeutic monitoring, and prognosis. Today, protein assays are mostly performed either with non-specific detection methods or immunoassays. Mass spectrometry (MS) is a very specific analytical method potentially very well suited for clinical laboratories. Its unique advantage relies in the high specificity of the detection. Any protein sequence variant, the presence of a post-translational modification or degradation will differ in mass and structure, and these differences will appear in the mass spectrum of the protein. On the other hand, protein MS is a relatively young technique, demanding specialized personnel and expensive instrumentation. Many scientists and opinion leaders predict MS to replace immunoassays for routine protein analysis, but there are only few protein MS applications routinely used in clinical chemistry laboratories today. The present review consists of a didactical introduction summarizing the pros and cons of MS assays compared to immunoassays, the different instrumentations, and various MS protein assays that have been proposed and/or are used in clinical laboratories. An important distinction is made between full length protein analysis (top-down method) and peptide analysis after enzymatic digestion of the proteins (bottom-up method) and its implication for the protein assay. The document ends with an outlook on what type of analyses could be used in the future, and for what type of applications MS has a clear advantage compared to immunoassays. Copyright © 2015 Elsevier Inc. All rights reserved.

[Automation of chemical analysis in enology].

PubMed

Dubernet, M

1978-01-01

Automatic dosages took place a short time ago in oenology laboratories. First researchs about automation of usual manual analysis have been completed by I.N.R.A. Station of Dijon during 1969--1972 years. Then, other researchs were made and in 1974 the first automatic analyser appeared in application laboratories. In all cases continuous flow method was used. First dosages which has been carried out are volatic acidity, residual sugars, total SO2. The rate of work is 30 samples an hour. Then, an original way for free SO2 was suggested. At present, about a dozen of laboratories in France use these dosages. The ethanol dosage automation, very important in oenology, is very difficult to carry out. A new method using a thermometric analyzer is tested. Research about many dosages as tartaric, malic, lactic acids, glucose, fructose, glycérol, have been performed especially by I.N.R.A. Station in Narbonne. But these dosages are not current and at present no laboratory apply them. Now, equipments price and redemption, change of tradionnal dosages for automatical methods and the level of knowledge required for operators are well known. The reproducibility and the accuracy of the continuous flow automatic dosages allow, for enough important laboratories, to make an increasing number of analysis necessary for wine quality control.

Accuracy of p53 Codon 72 Polymorphism Status Determined by Multiple Laboratory Methods: A Latent Class Model Analysis

PubMed Central

Walter, Stephen D.; Riddell, Corinne A.; Rabachini, Tatiana; Villa, Luisa L.; Franco, Eduardo L.

2013-01-01

Introduction Studies on the association of a polymorphism in codon 72 of the p53 tumour suppressor gene (rs1042522) with cervical neoplasia have inconsistent results. While several methods for genotyping p53 exist, they vary in accuracy and are often discrepant. Methods We used latent class models (LCM) to examine the accuracy of six methods for p53 determination, all conducted by the same laboratory. We also examined the association of p53 with cytological cervical abnormalities, recognising potential test inaccuracy. Results Pairwise disagreement between laboratory methods occurred approximately 10% of the time. Given the estimated true p53 status of each woman, we found that each laboratory method is most likely to classify a woman to her correct status. Arg/Arg women had the highest risk of squamous intraepithelial lesions (SIL). Test accuracy was independent of cytology. There was no strong evidence for correlations of test errors. Discussion Empirical analyses ignore possible laboratory errors, and so are inherently biased, but test accuracy estimated by the LCM approach is unbiased when model assumptions are met. LCM analysis avoids ambiguities arising from empirical test discrepancies, obviating the need to regard any of the methods as a “gold” standard measurement. The methods we presented here to analyse the p53 data can be applied in many other situations where multiple tests exist, but where none of them is a gold standard. PMID:23441193

Steroid hormone analysis in diagnosis and treatment of DSD: position paper of EU COST Action BM 1303 'DSDnet'.

PubMed

Kulle, A; Krone, N; Holterhus, P M; Schuler, G; Greaves, R F; Juul, A; de Rijke, Y B; Hartmann, M F; Saba, A; Hiort, O; Wudy, S A

2017-05-01

Disorders or differences in sex development (DSD) comprise a heterogeneous group of conditions with an atypical sex development. For optimal diagnosis, highly specialised laboratory analyses are required across European countries. Working group 3 of EU COST (European Cooperation in Science and Technology) Action BM 1303 'DSDnet' 'Harmonisation of Laboratory Assessment' has developed recommendations on laboratory assessment for DSD regarding the use of technologies and analytes to be investigated. This position paper on steroid hormone analysis in diagnosis and treatment of DSD was compiled by a group of specialists in DSD and/or hormonal analysis, either from participating European countries or international partner countries. The topics discussed comprised analytical methods (immunoassay/mass spectrometry-based methods), matrices (urine/serum/saliva) and harmonisation of laboratory tests. The following positions were agreed upon: support of the appropriate use of immunoassay- and mass spectrometry-based methods for diagnosis and monitoring of DSD. Serum/plasma and urine are established matrices for analysis. Laboratories performing analyses for DSD need to operate within a quality framework and actively engage in harmonisation processes so that results and their interpretation are the same irrespective of the laboratory they are performed in. Participation in activities of peer comparison such as sample exchange or when available subscribing to a relevant external quality assurance program should be achieved. The ultimate aim of the guidelines is the implementation of clinical standards for diagnosis and appropriate treatment of DSD to achieve the best outcome for patients, no matter where patients are investigated or managed. © 2017 The authors.

Amie Sluiter | NREL

Science.gov Websites

biomass analysis methods and is primary author on 11 Laboratory Analytical Procedures, which are ) spectroscopic analysis methods. These methods allow analysts to predict the composition of feedstock and process . Patent No. 6,737,258 (2002) Featured Publications "Improved methods for the determination of drying

Inter-laboratory validation of an inexpensive streamlined method to measure inorganic arsenic in rice grain.

PubMed

Chaney, Rufus L; Green, Carrie E; Lehotay, Steven J

2018-05-04

With the establishment by CODEX of a 200 ng/g limit of inorganic arsenic (iAs) in polished rice grain, more analyses of iAs will be necessary to ensure compliance in regulatory and trade applications, to assess quality control in commercial rice production, and to conduct research involving iAs in rice crops. Although analytical methods using high-performance liquid chromatography-inductively coupled plasma-mass spectrometry (HPLC-ICP-MS) have been demonstrated for full speciation of As, this expensive and time-consuming approach is excessive when regulations are based only on iAs. We report a streamlined sample preparation and analysis of iAs in powdered rice based on heated extraction with 0.28 M HNO 3 followed by hydride generation (HG) under control of acidity and other simple conditions. Analysis of iAs is then conducted using flow-injection HG and inexpensive ICP-atomic emission spectroscopy (AES) or other detection means. A key innovation compared with previous methods was to increase the acidity of the reagent solution with 4 M HCl (prior to reduction of As 5+ to As 3+ ), which minimized interferences from dimethylarsinic acid. An inter-laboratory method validation was conducted among 12 laboratories worldwide in the analysis of six shared blind duplicates and a NIST Standard Reference Material involving different types of rice and iAs levels. Also, four laboratories used the standard HPLC-ICP-MS method to analyze the samples. The results between the methods were not significantly different, and the Horwitz ratio averaged 0.52 for the new method, which meets official method validation criteria. Thus, the simpler, more versatile, and less expensive method may be used by laboratories for several purposes to accurately determine iAs in rice grain. Graphical abstract Comparison of iAs results from new and FDA methods.

40 CFR 141.33 - Record maintenance.

Code of Federal Regulations, 2010 CFR

2010-07-01

... laboratory reports may be kept, or data may be transferred to tabular summaries, provided that the following...) Laboratory and person responsible for performing analysis; (5) The analytical technique/method used; and (6...

European external quality control study on the competence of laboratories to recognize rare sequence variants resulting in unusual genotyping results.

PubMed

Márki-Zay, János; Klein, Christoph L; Gancberg, David; Schimmel, Heinz G; Dux, László

2009-04-01

Depending on the method used, rare sequence variants adjacent to the single nucleotide polymorphism (SNP) of interest may cause unusual or erroneous genotyping results. Because such rare variants are known for many genes commonly tested in diagnostic laboratories, we organized a proficiency study to assess their influence on the accuracy of reported laboratory results. Four external quality control materials were processed and sent to 283 laboratories through 3 EQA organizers for analysis of the prothrombin 20210G>A mutation. Two of these quality control materials contained sequence variants introduced by site-directed mutagenesis. One hundred eighty-nine laboratories participated in the study. When samples gave a usual result with the method applied, the error rate was 5.1%. Detailed analysis showed that more than 70% of the failures were reported from only 9 laboratories. Allele-specific amplification-based PCR had a much higher error rate than other methods (18.3% vs 2.9%). The variants 20209C>T and [20175T>G; 20179_20180delAC] resulted in unusual genotyping results in 67 and 85 laboratories, respectively. Eighty-three (54.6%) of these unusual results were not recognized, 32 (21.1%) were attributed to technical issues, and only 37 (24.3%) were recognized as another sequence variant. Our findings revealed that some of the participating laboratories were not able to recognize and correctly interpret unusual genotyping results caused by rare SNPs. Our study indicates that the majority of the failures could be avoided by improved training and careful selection and validation of the methods applied.

An Investigative Graduate Laboratory Course for Teaching Modern DNA Techniques

ERIC Educational Resources Information Center

de Lencastre, Alexandre; Torello, A. Thomas; Keller, Lani C.

2017-01-01

This graduate-level DNA methods laboratory course is designed to model a discovery-based research project and engages students in both traditional DNA analysis methods and modern recombinant DNA cloning techniques. In the first part of the course, students clone the "Drosophila" ortholog of a human disease gene of their choosing using…

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 3

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 2

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

THE QUANTIFICATION OF AQUEOUS TRACERS IN LABORATORY AQUIFER MODELS USING A LIGHT TRANSMISSION VISUALIZATION METHOD - 1

EPA Science Inventory

The quantification of solute concentrations in laboratory aquifer models has been largely limited to the use of sampling ports, from which samples are collected for external analysis. One of the drawbacks to this method is that the act of sampling may disturb plume dynamics and ...

Forensic Analysis of Canine DNA Samples in the Undergraduate Biochemistry Laboratory

ERIC Educational Resources Information Center

Carson, Tobin M.; Bradley, Sharonda Q.; Fekete, Brenda L.; Millard, Julie T.; LaRiviere, Frederick J.

2009-01-01

Recent advances in canine genomics have allowed the development of highly distinguishing methods of analysis for both nuclear and mitochondrial DNA. We describe a laboratory exercise suitable for an undergraduate biochemistry course in which the polymerase chain reaction is used to amplify hypervariable regions of DNA from dog hair and saliva…

Multi-laboratory evaluations of the performance of Catellicoccus marimammalium PCR assays developed to target gull fecal sources

USGS Publications Warehouse

Sinigalliano, Christopher D.; Ervin, Jared S.; Van De Werfhorst, Laurie C.; Badgley, Brian D.; Ballestée, Elisenda; Bartkowiaka, Jakob; Boehm, Alexandria B.; Byappanahalli, Muruleedhara N.; Goodwin, Kelly D.; Gourmelon, Michèle; Griffith, John; Holden, Patricia A.; Jay, Jenny; Layton, Blythe; Lee, Cheonghoon; Lee, Jiyoung; Meijer, Wim G.; Noble, Rachel; Raith, Meredith; Ryu, Hodon; Sadowsky, Michael J.; Schriewer, Alexander; Wang, Dan; Wanless, David; Whitman, Richard; Wuertz, Stefan; Santo Domingo, Jorge W.

2013-01-01

Here we report results from a multi-laboratory (n = 11) evaluation of four different PCR methods targeting the 16S rRNA gene of Catellicoccus marimammalium originally developed to detect gull fecal contamination in coastal environments. The methods included a conventional end-point PCR method, a SYBR® Green qPCR method, and two TaqMan® qPCR methods. Different techniques for data normalization and analysis were tested. Data analysis methods had a pronounced impact on assay sensitivity and specificity calculations. Across-laboratory standardization of metrics including the lower limit of quantification (LLOQ), target detected but not quantifiable (DNQ), and target not detected (ND) significantly improved results compared to results submitted by individual laboratories prior to definition standardization. The unit of measure used for data normalization also had a pronounced effect on measured assay performance. Data normalization to DNA mass improved quantitative method performance as compared to enterococcus normalization. The MST methods tested here were originally designed for gulls but were found in this study to also detect feces from other birds, particularly feces composited from pigeons. Sequencing efforts showed that some pigeon feces from California contained sequences similar to C. marimammalium found in gull feces. These data suggest that the prevalence, geographic scope, and ecology of C. marimammalium in host birds other than gulls require further investigation. This study represents an important first step in the multi-laboratory assessment of these methods and highlights the need to broaden and standardize additional evaluations, including environmentally relevant target concentrations in ambient waters from diverse geographic regions.

Laboratory analytical methods for the determination of the hydrocarbon status of soils (a review)

NASA Astrophysics Data System (ADS)

Pikovskii, Yu. I.; Korotkov, L. A.; Smirnova, M. A.; Kovach, R. G.

2017-10-01

Laboratory analytical methods suitable for the determination of the hydrocarbon status of soils (a specific soil characteristic involving information on the total content and qualitative features of soluble (bitumoid) carbonaceous substances and individual hydrocarbons (polycyclic aromatic hydrocarbons, alkanes, etc.) in bitumoid, as well as the composition and content of hydrocarbon gases) have been considered. Among different physicochemical methods of study, attention is focused on the methods suitable for the wide use. Luminescence-bituminological analysis, low-temperature spectrofluorimetry (Shpolskii spectroscopy), infrared (IR) spectroscopy, gas chromatography, chromatography-mass spectrometry, and some other methods have been characterized, as well as sample preparation features. Advantages and limitations of each of these methods are described; their efficiency, instrumental complexity, analysis duration, and accuracy are assessed.

[How to Interpret and Use Routine Laboratory Data--Our Methods to Interpret Routine Laboratory Data--Chairmen's Introductory Remarks].

PubMed

Honda, Takayuki; Tozuka, Minoru

2015-09-01

In the reversed clinicopathological conference (R-CPC), three specialists in laboratory medicine interpreted routine laboratory data independently in order to understand the detailed state of a patient. R-CPC is an educational method to use laboratory data appropriately, and it is also important to select differential diagnoses in a process of clinical reasoning in addition to the present illness and physical examination. Routine laboratory tests can be performed repeatedly at a relatively low cost, and their time-series analysis can be performed. Interpretation of routine laboratory data is almost the same as taking physical findings. General findings are initially checked and then the state of each organ is examined. Although routine laboratory tests cost little, we can gain much more information from them about the patient than physical examinations.

The Optics and Alignment of the Divergent Beam Laboratory X-ray Powder Diffractometer and its Calibration Using NIST Standard Reference Materials.

PubMed

Cline, James P; Mendenhall, Marcus H; Black, David; Windover, Donald; Henins, Albert

2015-01-01

The laboratory X-ray powder diffractometer is one of the primary analytical tools in materials science. It is applicable to nearly any crystalline material, and with advanced data analysis methods, it can provide a wealth of information concerning sample character. Data from these machines, however, are beset by a complex aberration function that can be addressed through calibration with the use of NIST Standard Reference Materials (SRMs). Laboratory diffractometers can be set up in a range of optical geometries; considered herein are those of Bragg-Brentano divergent beam configuration using both incident and diffracted beam monochromators. We review the origin of the various aberrations affecting instruments of this geometry and the methods developed at NIST to align these machines in a first principles context. Data analysis methods are considered as being in two distinct categories: those that use empirical methods to parameterize the nature of the data for subsequent analysis, and those that use model functions to link the observation directly to a specific aspect of the experiment. We consider a multifaceted approach to instrument calibration using both the empirical and model based data analysis methods. The particular benefits of the fundamental parameters approach are reviewed.

The Kjeldahl method as a primary reference procedure for total protein in certified reference materials used in clinical chemistry. I. A review of Kjeldahl methods adopted by laboratory medicine.

PubMed

Chromý, Vratislav; Vinklárková, Bára; Šprongl, Luděk; Bittová, Miroslava

2015-01-01

We found previously that albumin-calibrated total protein in certified reference materials causes unacceptable positive bias in analysis of human sera. The simplest way to cure this defect is the use of human-based serum/plasma standards calibrated by the Kjeldahl method. Such standards, commutative with serum samples, will compensate for bias caused by lipids and bilirubin in most human sera. To find a suitable primary reference procedure for total protein in reference materials, we reviewed Kjeldahl methods adopted by laboratory medicine. We found two methods recommended for total protein in human samples: an indirect analysis based on total Kjeldahl nitrogen corrected for its nonprotein nitrogen and a direct analysis made on isolated protein precipitates. The methods found will be assessed in a subsequent article.

The Synthetic Experiment: E. B. Titchener's Cornell Psychological Laboratory and the Test of Introspective Analysis.

PubMed

Evans, Rand B

2017-01-01

Beginning in 1 9a0, a major thread of research was added to E. B. Titchener's Cornell laboratory: the synthetic experiment. Titchener and his graduate students used introspective analysis to reduce a perception, a complex experience, into its simple sensory constituents. To test the validity of that analysis, stimulus patterns were selected to reprodiuce the patterns of sensations found in the introspective analyses. If the original perception can be reconstructed in this way, then the analysis was considered validated. This article reviews development of the synthetic method in E. B. Titchener's laboratory at Cornell University and examines its impact on psychological research.

[Reversed clinicopathological conference (R-CPC)--interpreting laboratory data in the same way as physical findings].

PubMed

Sugano, Mitsutoshi; Shimada, Masashi; Moriyoshi, Miho; Kitagawa, Kiyoki; Nakashima, Hiromi; Wada, Hideo; Yanagihara, Katsunori; Fujisawa, Shinya; Yonekawa, Osamu; Honda, Takayuki

2012-05-01

Routine laboratory data are discussed by time series analysis in reversed clinicopathological conferences (R-CPC) at Shinshu University School of Medicine. We can identify fine changes in the laboratory data and the importance of negative data (without any changes) using time series analysis. Routine laboratory tests can be performed repeatedly and relatively cheaply, and time series analysis can be performed. The examination process of routine laboratory data in the R-CPC is almost the same as the process of taking physical findings. Firstly, general findings are checked and then the state of each organ is examined. Although routine laboratory data are cheap, we can obtain much more information about a patient's state than from physical examinations. In this R-CPC, several specialists in the various fields of laboratory medicine discussed the routine laboratory data of a patient, and we tried to understand the detailed state of the patient. R-CPC is an educational method to examine laboratory data and we, reconfirmed the usefulness of R-CPC to elucidate the clinical state of the patient.

Microalgae Compositional Analysis Laboratory Procedures | Bioenergy | NREL

Science.gov Websites

these methods build on years of research in algal biomass analysis. By combining the appropriate LAPs and Ash in Algal Biomass This procedure describes the methods used to determine the amount of moisture

Non-structural carbohydrates in woody plants compared among laboratories.

PubMed

Quentin, Audrey G; Pinkard, Elizabeth A; Ryan, Michael G; Tissue, David T; Baggett, L Scott; Adams, Henry D; Maillard, Pascale; Marchand, Jacqueline; Landhäusser, Simon M; Lacointe, André; Gibon, Yves; Anderegg, William R L; Asao, Shinichi; Atkin, Owen K; Bonhomme, Marc; Claye, Caroline; Chow, Pak S; Clément-Vidal, Anne; Davies, Noel W; Dickman, L Turin; Dumbur, Rita; Ellsworth, David S; Falk, Kristen; Galiano, Lucía; Grünzweig, José M; Hartmann, Henrik; Hoch, Günter; Hood, Sharon; Jones, Joanna E; Koike, Takayoshi; Kuhlmann, Iris; Lloret, Francisco; Maestro, Melchor; Mansfield, Shawn D; Martínez-Vilalta, Jordi; Maucourt, Mickael; McDowell, Nathan G; Moing, Annick; Muller, Bertrand; Nebauer, Sergio G; Niinemets, Ülo; Palacio, Sara; Piper, Frida; Raveh, Eran; Richter, Andreas; Rolland, Gaëlle; Rosas, Teresa; Saint Joanis, Brigitte; Sala, Anna; Smith, Renee A; Sterck, Frank; Stinziano, Joseph R; Tobias, Mari; Unda, Faride; Watanabe, Makoto; Way, Danielle A; Weerasinghe, Lasantha K; Wild, Birgit; Wiley, Erin; Woodruff, David R

2015-11-01

Non-structural carbohydrates (NSC) in plant tissue are frequently quantified to make inferences about plant responses to environmental conditions. Laboratories publishing estimates of NSC of woody plants use many different methods to evaluate NSC. We asked whether NSC estimates in the recent literature could be quantitatively compared among studies. We also asked whether any differences among laboratories were related to the extraction and quantification methods used to determine starch and sugar concentrations. These questions were addressed by sending sub-samples collected from five woody plant tissues, which varied in NSC content and chemical composition, to 29 laboratories. Each laboratory analyzed the samples with their laboratory-specific protocols, based on recent publications, to determine concentrations of soluble sugars, starch and their sum, total NSC. Laboratory estimates differed substantially for all samples. For example, estimates for Eucalyptus globulus leaves (EGL) varied from 23 to 116 (mean = 56) mg g(-1) for soluble sugars, 6-533 (mean = 94) mg g(-1) for starch and 53-649 (mean = 153) mg g(-1) for total NSC. Mixed model analysis of variance showed that much of the variability among laboratories was unrelated to the categories we used for extraction and quantification methods (method category R(2) = 0.05-0.12 for soluble sugars, 0.10-0.33 for starch and 0.01-0.09 for total NSC). For EGL, the difference between the highest and lowest least squares means for categories in the mixed model analysis was 33 mg g(-1) for total NSC, compared with the range of laboratory estimates of 596 mg g(-1). Laboratories were reasonably consistent in their ranks of estimates among tissues for starch (r = 0.41-0.91), but less so for total NSC (r = 0.45-0.84) and soluble sugars (r = 0.11-0.83). Our results show that NSC estimates for woody plant tissues cannot be compared among laboratories. The relative changes in NSC between treatments measured within a laboratory may be comparable within and between laboratories, especially for starch. To obtain comparable NSC estimates, we suggest that users can either adopt the reference method given in this publication, or report estimates for a portion of samples using the reference method, and report estimates for a standard reference material. Researchers interested in NSC estimates should work to identify and adopt standard methods. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Organic Analytical Service within the Superfund Contract Laboratory Program

EPA Pesticide Factsheets

This page contains information about the SOM02.4 statement of work for the analysis of organic compounds at hazardous waste sites. The SOW contains the analytical method and contractual requirements for laboratories.

Inorganic Analytical Service within the Superfund Contract Laboratory Program

EPA Pesticide Factsheets

This page contains information about the ISM02.4 statement of work for the analysis of metals and cyanide at hazardous waste sites. The SOW contains the analytical method and contractual requirements for laboratories.

Increasing Efficiency of Fecal Coliform Testing Through EPA-Approved Alternate Method Colilert*-18

NASA Technical Reports Server (NTRS)

Cornwell, Brian

2017-01-01

The 21 SM 9221 E multiple-tube fermentation method for fecal coliform analysis requires a large time and reagent investment for the performing laboratory. In late 2010, the EPA approved an alternative procedure for the determination of fecal coliforms designated as Colilert*-18. However, as of late 2016, only two VELAP-certified laboratories in the Commonwealth of Virginia have been certified in this method.

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.

A user-friendly approach to cost accounting in laboratory animal facilities.

PubMed

Baker, David G

2011-08-19

Cost accounting is an essential management activity for laboratory animal facility management. In this report, the author describes basic principles of cost accounting and outlines steps for carrying out cost accounting in laboratory animal facilities. Methods of post hoc cost accounting analysis for maximizing the efficiency of facility operations are also described.

A Laboratory Experiment for Rapid Determination of the Stability of Vitamin C

ERIC Educational Resources Information Center

Adem, Seid M.; Lueng, Sam H.; Elles, Lisa M. Sharpe; Shaver, Lee Alan

2016-01-01

Experiments in laboratory manuals intended for general, organic, and biological (GOB) chemistry laboratories include few opportunities for students to engage in instrumental methods of analysis. Many of these students seek careers in modern health-related fields where experience in spectroscopic techniques would be beneficial. A simple, rapid,…

New reporting procedures based on long-term method detection levels and some considerations for interpretations of water-quality data provided by the U.S. Geological Survey National Water Quality Laboratory

USGS Publications Warehouse

Childress, Carolyn J. Oblinger; Foreman, William T.; Connor, Brooke F.; Maloney, Thomas J.

1999-01-01

This report describes the U.S. Geological Survey National Water Quality Laboratory?s approach for determining long-term method detection levels and establishing reporting levels, details relevant new reporting conventions, and provides preliminary guidance on interpreting data reported with the new conventions. At the long-term method detection level concentration, the risk of a false positive detection (analyte reported present at the long-term method detection level when not in sample) is no more than 1 percent. However, at the long-term method detection level, the risk of a false negative occurrence (analyte reported not present when present at the long-term method detection level concentration) is up to 50 percent. Because this false negative rate is too high for use as a default 'less than' reporting level, a more reliable laboratory reporting level is set at twice the determined long-term method detection level. For all methods, concentrations measured between the laboratory reporting level and the long-term method detection level will be reported as estimated concentrations. Non-detections will be censored to the laboratory reporting level. Adoption of the new reporting conventions requires a full understanding of how low-concentration data can be used and interpreted and places responsibility for using and presenting final data with the user rather than with the laboratory. Users must consider that (1) new laboratory reporting levels may differ from previously established minimum reporting levels, (2) long-term method detection levels and laboratory reporting levels may change over time, and (3) estimated concentrations are less certain than concentrations reported above the laboratory reporting level. The availability of uncensored but qualified low-concentration data for interpretation and statistical analysis is a substantial benefit to the user. A decision to censor data after they are reported from the laboratory may still be made by the user, if merited, on the basis of the intended use of the data.

Development and Single-Laboratory Validation of a Liquid Chromatography Tandem Mass Spectrometry Method for Quantitation of Tetrodotoxin in Mussels and Oysters.

PubMed

Turner, Andrew D; Boundy, Michael J; Rapkova, Monika Dhanji

2017-09-01

In recent years, evidence has grown for the presence of tetrodotoxin (TTX) in bivalve mollusks, leading to the potential for consumers of contaminated products to be affected by Tetrodotoxin Shellfish Poisoning (TSP). A single-laboratory validation was conducted for the hydrophilic interaction LC (HILIC) tandem MS (MS/MS) analysis of TTX in common mussels and Pacific oysters-the bivalve species that have been found to contain TTXs in the United Kingdom in recent years. The method consists of a single-step dispersive extraction in 1% acetic acid, followed by a carbon SPE cleanup step before dilution and instrumental analysis. The full method was developed as a rapid tool for the quantitation of TTX, as well as for the associated analogs 4-epi-TTX; 5,6,11-trideoxy TTX; 11-nor TTX-6-ol; 5-deoxy TTX; and 4,9-anhydro TTX. The method can also be run as the acquisition of TTX together with paralytic shellfish toxins. Results demonstrated acceptable method performance characteristics for specificity, linearity, recovery, ruggedness, repeatability, matrix variability, and within-laboratory reproducibility for the analysis of TTX. The LOD and LOQ were fit-for-purpose in comparison to the current action limit for TTX enforced in The Netherlands. In addition, aspects of method performance (LOD, LOQ, and within-laboratory reproducibility) were found to be satisfactory for three other TTX analogs (11-nor TTX-6-ol, 5-deoxy TTX, and 4,9-anhydro TTX). The method was found to be practical and suitable for use in regulatory testing, providing rapid turnaround of sample analysis. Plans currently underway on a full collaborative study to validate a HILIC-MS/MS method for paralytic shellfish poisoning toxins will be extended to include TTX in order to generate international acceptance, ultimately for use as an alternative official control testing method should regulatory controls be adopted.

Evaluation of aircraft crash hazard at Los Alamos National Laboratory facilities

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

Selvage, R.D.

This report selects a method for use in calculating the frequency of an aircraft crash occurring at selected facilities at the Los Alamos National Laboratory (the Laboratory). The Solomon method was chosen to determine these probabilities. Each variable in the Solomon method is defined and a value for each variable is selected for fourteen facilities at the Laboratory. These values and calculated probabilities are to be used in all safety analysis reports and hazards analyses for the facilities addressed in this report. This report also gives detailed directions to perform aircraft-crash frequency calculations for other facilities. This will ensure thatmore » future aircraft-crash frequency calculations are consistent with calculations in this report.« less

A novel method to remotely measure food intake of free-living individuals in real time: the remote food photography method.

PubMed

Martin, Corby K; Han, Hongmei; Coulon, Sandra M; Allen, H Raymond; Champagne, Catherine M; Anton, Stephen D

2009-02-01

The aim of the present study was to report the first reliability and validity tests of the remote food photography method (RFPM), which consists of camera-enabled cell phones with data transfer capability. Participants take and transmit photographs of food selection and plate waste to researchers/clinicians for analysis. Following two pilot studies, adult participants (n 52; BMI 20-35 kg/m2 inclusive) were randomly assigned to the dine-in or take-out group. Energy intake (EI) was measured for 3 d. The dine-in group ate lunch and dinner in the laboratory. The take-out group ate lunch in the laboratory and dinner in free-living conditions (participants received a cooler with pre-weighed food that they returned the following morning). EI was measured with the RFPM and by directly weighing foods. The RFPM was tested in laboratory and free-living conditions. Reliability was tested over 3 d and validity was tested by comparing directly weighed EI to EI estimated with the RFPM using Bland-Altman analysis. The RFPM produced reliable EI estimates over 3 d in laboratory (r 0.62; P < 0.0001) and free-living (r 0.68; P < 0.0001) conditions. Weighed EI correlated highly with EI estimated with the RFPM in laboratory and free-living conditions (r>0.93; P < 0.0001). In two laboratory-based validity tests, the RFPM underestimated EI by - 4.7 % (P = 0.046) and - 5.5 % (P = 0.076). In free-living conditions, the RFPM underestimated EI by - 6.6 % (P = 0.017). Bias did not differ by body weight or age. The RFPM is a promising new method for accurately measuring the EI of free-living individuals. Error associated with the method is small compared with self-report methods.

Food adulteration analysis without laboratory prepared or determined reference food adulterant values.

PubMed

Kalivas, John H; Georgiou, Constantinos A; Moira, Marianna; Tsafaras, Ilias; Petrakis, Eleftherios A; Mousdis, George A

2014-04-01

Quantitative analysis of food adulterants is an important health and economic issue that needs to be fast and simple. Spectroscopy has significantly reduced analysis time. However, still needed are preparations of analyte calibration samples matrix matched to prediction samples which can be laborious and costly. Reported in this paper is the application of a newly developed pure component Tikhonov regularization (PCTR) process that does not require laboratory prepared or reference analysis methods, and hence, is a greener calibration method. The PCTR method requires an analyte pure component spectrum and non-analyte spectra. As a food analysis example, synchronous fluorescence spectra of extra virgin olive oil samples adulterated with sunflower oil is used. Results are shown to be better than those obtained using ridge regression with reference calibration samples. The flexibility of PCTR allows including reference samples and is generic for use with other instrumental methods and food products. Copyright © 2013 Elsevier Ltd. All rights reserved.

High variability in results of semen analysis in andrology laboratories in Tuscany (Italy): the experience of an external quality control (EQC) programme.

PubMed

Filimberti, E; Degl'Innocenti, S; Borsotti, M; Quercioli, M; Piomboni, P; Natali, I; Fino, M G; Caglieresi, C; Criscuoli, L; Gandini, L; Biggeri, A; Maggi, M; Baldi, E

2013-05-01

We report the results of the first three trials of an external quality control (EQC) programme performed in 71 laboratories executing semen analysis in Tuscany Region (Italy). At the end of the second trial, participants were invited to attend a teaching course illustrating and inviting to adhere to procedures recommended by WHO (V edition). Results of the first three trials of the EQC documented a huge variability in the procedures and the results. The highest variability was found for morphology (CV above 80% for all the trials), followed by count (CV of about 60% for all the trials) and motility (CV below 30% for all the trials). When results of sperm count and morphology were divided according to the used method, mean CV values did not show significant differences. CV for morphology dropped significantly at the third trial for most methods, indicating the usefulness of the teaching course for morphology assessment. Conversely, no differences were observed after the course for motility and for most methods to evaluate count, although CV values were lower at the second and third trial for the laboratories using the Burker cytometer. When results were divided according to tertiles of activity, the lowest mean bias values (difference between each laboratory result and the median value of the results) for count and morphology were observed for laboratories in the third tertile (performing over 200 semen analysis/year). Of interest, mean bias values for concentration dropped significantly at the third trial for low activity laboratories. In conclusion, lack of agreement of results of semen analysis in Tuscany is mainly because of the activity and the experience of the laboratory. Our study points out the importance of participating in EQC programmes and periodical teaching courses as well as the use of WHO recommended standardized procedures to increase precision and to allow the use of WHO reference values. © 2013 American Society of Andrology and European Academy of Andrology.

Application of portable X-ray fluorescence spectrometry in environmental investigation of heavy metal-contaminated sites and comparison with laboratory analysis

NASA Astrophysics Data System (ADS)

Ding, Liang; Wang, Shui; Cai, Bingjie; Zhang, Mancheng; Qu, Changsheng

2018-02-01

In this study, portable X-ray fluorescence spectrometry (pXRF) was used to measure the heavy metal contents of As, Cu, Cr, Ni, Pb and Zn in the soils of heavy metal-contaminated sites. The precision, accuracy and system errors of pXRF were evaluated and compared with traditional laboratory methods to examine the suitability of in situ pXRF. The results show that the pXRF analysis achieved satisfactory accuracy and precision in measuring As, Cr, Cu, Ni, Pb, and Zn in soils, and meets the requirements of the relevant detection technology specifications. For the certified reference soil samples, the pXRF results of As, Cr, Cu, Ni, Pb, and Zn show good linear relationships and coefficients of determination with the values measured using the reference analysis methods; with the exception of Ni, all the measured values were within the 95% confidence level. In the soil samples, the coefficients of determination between Cu, Zn, Pb, and Ni concentrations measured laboratory pXRF and the values measured with laboratory analysis all reach 0.9, showing a good linear relationship; however, there were large deviations between methods for Cr and As. This study provides reference data and scientific support for rapid detection of heavy metals in soils using pXRF in site investigation, which can better guide the practical application of pXRF.

Interlaboratory study of a liquid chromatography method for erythromycin: determination of uncertainty.

PubMed

Dehouck, P; Vander Heyden, Y; Smeyers-Verbeke, J; Massart, D L; Marini, R D; Chiap, P; Hubert, Ph; Crommen, J; Van de Wauw, W; De Beer, J; Cox, R; Mathieu, G; Reepmeyer, J C; Voigt, B; Estevenon, O; Nicolas, A; Van Schepdael, A; Adams, E; Hoogmartens, J

2003-08-22

Erythromycin is a mixture of macrolide antibiotics produced by Saccharopolyspora erythreas during fermentation. A new method for the analysis of erythromycin by liquid chromatography has previously been developed. It makes use of an Astec C18 polymeric column. After validation in one laboratory, the method was now validated in an interlaboratory study. Validation studies are commonly used to test the fitness of the analytical method prior to its use for routine quality testing. The data derived in the interlaboratory study can be used to make an uncertainty statement as well. The relationship between validation and uncertainty statement is not clear for many analysts and there is a need to show how the existing data, derived during validation, can be used in practice. Eight laboratories participated in this interlaboratory study. The set-up allowed the determination of the repeatability variance, s(2)r and the between-laboratory variance, s(2)L. Combination of s(2)r and s(2)L results in the reproducibility variance s(2)R. It has been shown how these data can be used in future by a single laboratory that wants to make an uncertainty statement concerning the same analysis.

Method development for the analysis of 1,4-dioxane in drinking water using solid-phase extraction and gas chromatography-mass spectrometry.

PubMed

Grimmett, Paul E; Munch, Jean W

2009-01-01

1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The United States Environmental Protection Agency's (U.S. EPA) National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of an activated carbon solid-phase extraction of 500-mL or 100-mL water samples using dichloromethane as the elution solvent. The extracts are analyzed by gas chromatography-mass spectrometry (GC-MS) in selected ion monitoring (SIM) mode. In the NERL laboratory, recovery of 1,4-dioxane ranged from 94-110% in fortified laboratory reagent water and recoveries of 96-102% were demonstrated for fortified drinking water samples. The relative standard deviations for replicate analyses were less than 6% at concentrations exceeding the minimum reporting level.

The Hazardous-Drums Project: A Multiweek Laboratory Exercise for General Chemistry Involving Environmental, Quality Control, and Cost Evaluation

ERIC Educational Resources Information Center

Hayes, David; Widanski, Bozena

2013-01-01

A laboratory experiment is described that introduces students to "real-world" hazardous waste management issues chemists face. The students are required to define an analytical problem, choose a laboratory analysis method, investigate cost factors, consider quality-control issues, interpret the meaning of results, and provide management…

Dioxins, Furans, PCBs, and Congeners Analytical Service within the Superfund Contract Laboratory Program

EPA Pesticide Factsheets

This page contains information about the DLM02.2 analytical service for the analysis of dioxins and furans at hazardous waste sites. The SOW contains the analytical method and contractual requirements for laboratories.

A 5-day method for determination of soluble silicon concentrations in nonliquid fertilizer materials using a sodium carbonate-ammonium nitrate extractant followed by visible spectroscopy with heteropoly blue analysis: single-laboratory validation.

PubMed

Sebastian, Dennis; Rodrigues, Hugh; Kinsey, Charles; Korndörfer, Gaspar; Pereira, Hamilton; Buck, Guilherme; Datnoff, Lawrence; Miranda, Stephen; Provance-Bowley, Mary

2013-01-01

A 5-day method for determining the soluble silicon (Si) concentrations in nonliquid fertilizer products was developed using a sodium carbonate (Na2CO3)-ammonium nitrate (NH4NO3) extractant followed by visible spectroscopy with heteropoly blue analysis at 660 nm. The 5-Day Na2CO3-NH4NO3 Soluble Si Extraction Method can be applied to quantify the plant-available Si in solid fertilizer products at levels ranging from 0.2 to 8.4% Si with an LOD of 0.06%, and LOQ of 0.20%. This Si extraction method for fertilizers correlates well with plant uptake of Si (r2 = 0.96 for a range of solid fertilizers) and is applicable to solid Si fertilizer products including blended products and beneficial substances. Fertilizer materials can be processed as received using commercially available laboratory chemicals and materials at ambient laboratory temperatures. The single-laboratory validation of the 5-Day Na2CO3-NH4NO3 Soluble Si Extraction Method has been approved by The Association of American Plant Food Control Officials for testing nonliquid Si fertilizer products.

Detection of rebar delamination using modal analysis

NASA Astrophysics Data System (ADS)

Blodgett, David W.

2003-08-01

A non-destructive method for early detection of reinforcement steel bars (re-bar) delamination in concrete structures has been developed. This method, termed modal analysis, has been shown effective in both laboratory and field experiments. In modal analysis, an audio speaker is used to generate flexural resonant modes in the re-bar in reinforced concrete structures. Vibrations associated with these modes are coupled to the surrounding concrete and propagate to the surface where they are detected using a laser vibrometer and/or accelerometer. Monitoring both the frequency and amplitude of these vibrations provides information on the bonding state of the embedded re-bar. Laboratory measurements were performed on several specially prepared concrete blocks with re-bar of varying degrees of simulated corrosion. Field measurements were performed on an old bridge about to be torn down in Howard County, Maryland and the results compared with those obtained using destructive analysis of the bridge after demolition. Both laboratory and field test results show this technique to be sensitive to re-bar delamination.

Methods for geochemical analysis

USGS Publications Warehouse

Baedecker, Philip A.

1987-01-01

The laboratories for analytical chemistry within the Geologic Division of the U.S. Geological Survey are administered by the Office of Mineral Resources. The laboratory analysts provide analytical support to those programs of the Geologic Division that require chemical information and conduct basic research in analytical and geochemical areas vital to the furtherance of Division program goals. Laboratories for research and geochemical analysis are maintained at the three major centers in Reston, Virginia, Denver, Colorado, and Menlo Park, California. The Division has an expertise in a broad spectrum of analytical techniques, and the analytical research is designed to advance the state of the art of existing techniques and to develop new methods of analysis in response to special problems in geochemical analysis. The geochemical research and analytical results are applied to the solution of fundamental geochemical problems relating to the origin of mineral deposits and fossil fuels, as well as to studies relating to the distribution of elements in varied geologic systems, the mechanisms by which they are transported, and their impact on the environment.

[Tasks and duties of veterinary reference laboratories for food borne zoonoses].

PubMed

Ellerbroek, Lüppo; Alter, T; Johne, R; Nöckler, K; Beutin, L; Helmuth, R

2009-02-01

Reference laboratories are of central importance for consumer protection. Field expertise and high scientific competence are basic requirements for the nomination of a national reference laboratory. To ensure a common approach in the analysis of zoonotic hazards, standards have been developed by the reference laboratories together with national official laboratories on the basis of Art. 33 of Directive (EG) No. 882/2004. Reference laboratories function as arbitrative boards in the case of ambivalent or debatable results. New methods for detection of zoonotic agents are developed and validated to provide tools for analysis, e. g., in legal cases, if results from different parties are disputed. Besides these tasks, national reference laboratories offer capacity building and advanced training courses and control the performance of ring trials to ensure consistency in the quality of analyses in official laboratories. All reference laboratories work according to the ISO standard 17025 which defines the grounds for strict laboratory quality rules and in cooperation with the respective Community Reference Laboratories (CRL). From the group of veterinary reference laboratories for food-borne zoonoses, the national reference laboratories are responsible for Listeria monocytogenes, for Campylobacter, for the surveillance and control of viral and bacterial contamination of bivalve molluscs, for E. coli, for the performance of analysis and tests on zoonoses (Salmonella), and from the group of parasitological zoonotic agents, the national reference laboratory for Trichinella.

Adaptation of the Conditions of US EPA Method 538 for the ...

EPA Pesticide Factsheets

Report The objective of this study was to evaluate U.S. EPA’s Method 538 for the assessment of drinking water exposure to the nerve agent degradation product, EA2192, the most toxic degradation product of nerve agent VX. As a result of the similarities in sample preparation and analysis that Method 538 uses for nonvolatile chemicals, this method is applicable to the nonvolatile Chemical Warfare Agent (CWA) degradation product, EA2192, in drinking water. The method may be applicable to other nonvolatile CWAs and their respective degradation products as well, but the method will need extensive testing to verify compatibility. Gaps associated with the need for analysis methods capable of analyzing such analytes were addressed by adapting the EPA 538 method for this CWA degradation product. Many laboratories have the experience and capability to run the already rigorous method for nonvolatile compounds in drinking water. Increasing the number of laboratories capable of carrying out these methods serves to significantly increase the surge laboratory capacity to address sample throughput during a large exposure event. The approach desired for this study was to start with a proven high performance liquid chromatography tandem mass spectrometry (HPLC/MS/MS) method for nonvolatile chemicals in drinking water and assess the inclusion of a similar nonvolatile chemical, EA2192.

INACCURATE REPORTING OF MINERAL COMPOSITION BY COMMERCIAL STONE ANALYSIS LABORATORIES: IMPLICATIONS FOR INFECTION AND METABOLIC STONES

PubMed Central

Krambeck, Amy E.; Khan, Naseem F.; Jackson, Molly E.; Lingeman, James E.; McAteer, James A; Williams, James C.

2011-01-01

INTRODUCTION The goal of this study was to determine the accuracy of stone composition analysis by commercial laboratories. METHODS 25 human renal stones with infrared spectroscopy (IR) determined compositions were fragmented into aliquots and studied with micro-computed tomography (CT) to ensure fragment similarity. Representative fragments of each stone were submitted to 5 commercial stone laboratories for blinded analysis. RESULTS All laboratories agreed on composition for 6 pure stones. Of 4 stones known to contain struvite, only 2(50%) were identified as struvite by all laboratories. Struvite was reported as a component by some laboratories for 4 stones previously determined not to contain struvite. Overall, there was disagreement regarding struvite in 6(24%) stones. For 9 calcium oxalate (CaOx) stones, all laboratories reported some mixture of CaOx, but the quantities of subtypes differed significantly among laboratories. In 6 apatite containing stones, apatite was missed by the laboratories in 20% of the samples. None of the laboratories identified atazanavir in a stone containing that antiviral drug. One laboratory reported protein in every sample, while all others reported it in only 1 sample. Nomenclature for apatite differed among laboratories, with one reporting apatite as carbonate apatite (CA) and never hydroxyapatite (HA), another never reporting CA and always reporting HA, and a third reporting CA as apatite with calcium carbonate. CONCLUSIONS Commercial laboratories reliably recognize pure calculi; however, variability in reporting of mixed calculi suggests a problem with accuracy of stone analysis results. Furthermore, there is a lack of standard nomenclature used by laboratories. PMID:20728108

The Significance of A Neglected Romanian Book - "The Methods of the Clinical Laboratory", by Ioan Manta and Alexandru Ciplea.

PubMed

Barsu, Cristian

2017-04-06

"The Methods of Clinical Laboratory" was the first comprehensive Romanian book in the medical laboratory field, having utility in clinical practice. It was written by Prof. Ioan Manta (1900-1979) and Alexandru Ciplea (1912-1988), both from the Cluj Faculty of Medicine. The volume was published for the first time in 1944, during the refuge of this Faculty in Sibiu, and for the second time in 1947, in Cluj. Our aim is to make a brief analysis of its structure and to put into evidence the importance of this book for the Romanian laboratory medicine, some techniques (e.g. microscopic techniques) keeping their validity until today. The authors made over 800 detailed presentations about: laboratory sampling and preservation techniques, different types of tests and methods for qualitative and quantitative determinations, techniques to prepare various solutions, microbiological culture media, laboratory stains and reagents, as well as maneuvering of some laboratory equipments. For each method, Manta and Ciplea presented: the principle of working method, reagents required, the working technique, mode of calculation, the result and its interpretation. It also includes some laboratory apparatus descriptions, as well as their mode of working. With regard to the scientific value and to the practical utility of this book, it remains a very important milestone in the Romanian medical literature of the XX-th century.

Performance evaluation of elemental analysis/isotope ratio mass spectrometry methods for the determination of the D/H ratio in tetramethylurea and other compounds--results of a laboratory inter-comparison.

PubMed

Bréas, Olivier; Thomas, Freddy; Zeleny, Reinhard; Calderone, Giovanni; Jamin, Eric; Guillou, Claude

2007-01-01

Tetramethylurea (TMU) with a certified D/H ratio is the internal standard for Site-specific Natural Isotope Fractionation measured by Nuclear Magnetic Resonance (SNIF-NMR) analysis of wine ethanol for detection of possible adulterations (Commission Regulation 2676/90). A new batch of a TMU certified reference material (CRM) is currently being prepared. Whereas SNIF-NMR has been employed up to now, Elemental Analysis/Isotope Ratio Mass Spectrometry ((2)H-EA-IRMS) was envisaged as the method of choice for value assignment of the new CRM, as more precise (better repeatable) data might be obtained, resulting in lower uncertainty of the certified value. In order to evaluate the accuracy and intra- and inter-laboratory reproducibility of (2)H-EA-IRMS methods, a laboratory inter-comparison was carried out by analysing TMU and other organic compounds, as well as some waters. The results revealed that experienced laboratories are capable of generating robust and well comparable data, which highlights the emerging potential of IRMS in food authenticity testing. However, a systematic bias between IRMS and SNIF-NMR reference data was observed for TMU; this lack of data consistency rules out the (2)H-IRMS technique for the characterisation measurement of the new TMU CRM.

Laboratory and quality assurance protocols for the analysis of herbicides in ground water from the Management Systems Evaluation Area, Princeton, Minnesota

USGS Publications Warehouse

Larson, S.J.; Capel, P.D.; VanderLoop, A.G.

1996-01-01

Laboratory and quality assurance procedures for the analysis of ground-water samples for herbicides at the Management Systems Evaluation Area near Princeton, Minnesota are described. The target herbicides include atrazine, de-ethylatrazine, de-isopropylatrazine, metribuzin, alachlor, 2,6-diethylaniline, and metolachlor. The analytical techniques used are solid-phase extraction, and analysis by gas chromatography with mass-selective detection. Descriptions of cleaning procedures, preparation of standard solutions, isolation of analytes from water, sample transfer methods, instrumental analysis, and data analysis are included.

Inquiry-based Laboratory Activities on Drugs Analysis for High School Chemistry Learning

NASA Astrophysics Data System (ADS)

Rahmawati, I.; Sholichin, H.; Arifin, M.

2017-09-01

Laboratory activity is an important part of chemistry learning, but cookbook instructions is still commonly used. However, the activity with that way do not improve students thinking skill, especially students creativity. This study aims to improve high school students creativity through inquiry-based laboratory on drugs analysis activity. Acid-base titration is used to be method for drugs analysis involving a color changing indicator. The following tools were used to assess the activity achievement: creative thinking test on acid base titration, creative attitude and action observation sheets, questionnaire of inquiry-based lab activities, and interviews. The results showed that the inquiry-based laboratory activity improving students creative thinking, creative attitude and creative action. The students reacted positively to this teaching strategy as demonstrated by results from questionnaire responses and interviews. This result is expected to help teachers to overcome the shortcomings in other laboratory learning.

Method Analysis of Microbial-Resistant Gypsum Products

EPA Science Inventory

Method Analysis of Microbial-Resistant Gypsum ProductsD.A. Betancourt1, T.R.Dean1, A. Evans2, and G.Byfield2 1. US Environmental Protection Agency, Office of Research and Development, National Risk Management Research Laboratory; RTP, NC 277112. RTI International, RTP, NCSeveral...

Biomass Compositional Analysis Laboratory Procedures | Bioenergy | NREL

Science.gov Websites

Compositional Analysis This procedure describes methods for sample drying and size reduction, obtaining samples methods used to determine the amount of solids or moisture present in a solid or slurry biomass sample as values? We have found that neutral detergent fiber (NDF) and acid detergent fiber (ADF) methods report

Evaluation of a multiclass, multiresidue liquid chromatography-tandem mass spectrometry method for analysis of 120 veterinary drugs in bovine kidney

USDA-ARS?s Scientific Manuscript database

Traditionally, regulatory monitoring of veterinary drug residues in food animal tissues involves the use of several single-class methods to cover a wide analytical scope. Multiclass, multiresidue methods of analysis tend to provide greater overall laboratory efficiency than the use of multiple meth...

Validation of pharmaceutical potency determinations by quantitative nuclear magnetic resonance spectrometry.

PubMed

Webster, Gregory K; Marsden, Ian; Pommerening, Cynthia A; Tyrakowski, Christina M

2010-05-01

With the changing development paradigms in the pharmaceutical industry, laboratories are challenged to release materials for clinical studies with rapid turnaround times. To minimize cost demands, many businesses are looking to develop ways of using early Good Manufacturing Practice (GMP) materials of active pharmaceutical ingredients (API) for Good Laboratory Practice (GLP) toxicology studies. To make this happen, the analytical laboratory releases the material by one of three scenarios: (1) holding the GLP release until full GMP testing is ready, (2) issuing a separate lot number for a portion of the GMP material and releasing the material for GLP use, or (3) releasing the lot of material for GLP using alternate (equivalent) method(s) not specified for GMP release testing. Many companies are finding the third scenario to be advantageous in terms of cost and efficiency through the use of quantitative nuclear magnetic resonance (q-NMR). The use of q-NMR has proved to be a single-point replacement for routine early development testing that previously combined elements of identity testing, chromatographic assay, moisture analysis, residual solvent analysis, and elemental analysis. This study highlights that q-NMR can be validated to meet current regulatory analytical method guidelines for routine pharmaceutical analysis.

Matrix-assisted laser desorption ionization-time of flight mass spectrometry: a fundamental shift in the routine practice of clinical microbiology.

PubMed

Clark, Andrew E; Kaleta, Erin J; Arora, Amit; Wolk, Donna M

2013-07-01

Within the past decade, clinical microbiology laboratories experienced revolutionary changes in the way in which microorganisms are identified, moving away from slow, traditional microbial identification algorithms toward rapid molecular methods and mass spectrometry (MS). Historically, MS was clinically utilized as a high-complexity method adapted for protein-centered analysis of samples in chemistry and hematology laboratories. Today, matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) MS is adapted for use in microbiology laboratories, where it serves as a paradigm-shifting, rapid, and robust method for accurate microbial identification. Multiple instrument platforms, marketed by well-established manufacturers, are beginning to displace automated phenotypic identification instruments and in some cases genetic sequence-based identification practices. This review summarizes the current position of MALDI-TOF MS in clinical research and in diagnostic clinical microbiology laboratories and serves as a primer to examine the "nuts and bolts" of MALDI-TOF MS, highlighting research associated with sample preparation, spectral analysis, and accuracy. Currently available MALDI-TOF MS hardware and software platforms that support the use of MALDI-TOF with direct and precultured specimens and integration of the technology into the laboratory workflow are also discussed. Finally, this review closes with a prospective view of the future of MALDI-TOF MS in the clinical microbiology laboratory to accelerate diagnosis and microbial identification to improve patient care.

Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry: a Fundamental Shift in the Routine Practice of Clinical Microbiology

PubMed Central

Clark, Andrew E.; Kaleta, Erin J.; Arora, Amit

2013-01-01

SUMMARY Within the past decade, clinical microbiology laboratories experienced revolutionary changes in the way in which microorganisms are identified, moving away from slow, traditional microbial identification algorithms toward rapid molecular methods and mass spectrometry (MS). Historically, MS was clinically utilized as a high-complexity method adapted for protein-centered analysis of samples in chemistry and hematology laboratories. Today, matrix-assisted laser desorption ionization–time of flight (MALDI-TOF) MS is adapted for use in microbiology laboratories, where it serves as a paradigm-shifting, rapid, and robust method for accurate microbial identification. Multiple instrument platforms, marketed by well-established manufacturers, are beginning to displace automated phenotypic identification instruments and in some cases genetic sequence-based identification practices. This review summarizes the current position of MALDI-TOF MS in clinical research and in diagnostic clinical microbiology laboratories and serves as a primer to examine the “nuts and bolts” of MALDI-TOF MS, highlighting research associated with sample preparation, spectral analysis, and accuracy. Currently available MALDI-TOF MS hardware and software platforms that support the use of MALDI-TOF with direct and precultured specimens and integration of the technology into the laboratory workflow are also discussed. Finally, this review closes with a prospective view of the future of MALDI-TOF MS in the clinical microbiology laboratory to accelerate diagnosis and microbial identification to improve patient care. PMID:23824373

A Computer Program to Implement the Chen Method of Dimensional Analysis

DTIC Science & Technology

1990-01-01

Director: AXHE-S (m. B Corna)U.S. Army TRADOX Systems Analysis Activity ATTdN: AXrE-IS (Mr. B. Corona) ATM: ATOR-TSL Aberden Proving Ground , MD 21005-5001...Laboratory I Aberdeen Proving Ground , MD 21005-5066 ATTN: AMSMI-ROC Redstone Arsenal, AL 35898-5242 Direct or D U.S. Army Human Engineering Laboratory 1...Kokinakis) U.S. Army Missile Laboratory Aberdeen Proving Ground , MD 21005-5066 ReTN AMSMI-R C1edstone Arsenal, AL 35898-5242 Director Director 1 U.S. Army

Performance testing of NIOSH Method 5524/ASTM Method D-7049-04, for determination of metalworking fluids.

PubMed

Glaser, Robert; Kurimo, Robert; Shulman, Stanley

2007-08-01

A performance test of NIOSH Method 5524/ASTM Method D-7049-04 for analysis of metalworking fluids (MWF) was conducted. These methods involve determination of the total and extractable weights of MWF samples; extractions are performed using a ternary blend of toluene:dichloromethane:methanol and a binary blend of methanol:water. Six laboratories participated in this study. A preliminary analysis of 20 blank samples was made to familiarize the laboratories with the procedure(s) and to estimate the methods' limits of detection/quantitation (LODs/LOQs). Synthetically generated samples of a semisynthetic MWF aerosol were then collected on tared polytetrafluoroethylene (PTFE) filters and analyzed according to the methods by all participants. Sample masses deposited (approximately 400-500 micro g) corresponded to amounts expected in an 8-hr shift at the NIOSH recommended exposure levels (REL) of 0.4 mg/m(3) (thoracic) and 0.5 mg/m(3) (total particulate). The generator output was monitored with a calibrated laser particle counter. One laboratory significantly underreported the sampled masses relative to the other five labs. A follow-up study compared only gravimetric results of this laboratory with those of two other labs. In the preliminary analysis of blanks; the average LOQs were 0.094 mg for the total weight analysis and 0.136 mg for the extracted weight analyses. For the six-lab study, the average LOQs were 0.064 mg for the total weight analyses and 0.067 mg for the extracted weight analyses. Using ASTM conventions, h and k statistics were computed to determine the degree of consistency of each laboratory with the others. One laboratory experienced problems with precision but not bias. The precision estimates for the remaining five labs were not different statistically (alpha = 0.005) for either the total or extractable weights. For all six labs, the average fraction extracted was > or =0.94 (CV = 0.025). Pooled estimates of the total coefficients of variation of analysis were 0.13 for the total weight samples and 0.13 for the extracted weight samples. An overall method bias of -5% was determined by comparing the overall mean concentration reported by the participants to that determined by the particle counter. In the three-lab follow-up study, the nonconsistent lab reported results that were unbiased but statistically less precise than the others; the average LOQ was 0.133 mg for the total weight analyses. It is concluded that aerosolized MWF sampled at concentrations corresponding to either of the NIOSH RELs can generally be shipped unrefrigerated, stored refrigerated up to 7 days, and then analyzed quantitatively and precisely for MWF using the NIOSH/ASTM procedures.

Measuring the glycemic index of foods: interlaboratory study.

PubMed

Wolever, Thomas M S; Brand-Miller, Jennie C; Abernethy, John; Astrup, Arne; Atkinson, Fiona; Axelsen, Mette; Björck, Inger; Brighenti, Furio; Brown, Rachel; Brynes, Audrey; Casiraghi, M Cristina; Cazaubiel, Murielle; Dahlqvist, Linda; Delport, Elizabeth; Denyer, Gareth S; Erba, Daniela; Frost, Gary; Granfeldt, Yvonne; Hampton, Shelagh; Hart, Valerie A; Hätönen, Katja A; Henry, C Jeya; Hertzler, Steve; Hull, Sarah; Jerling, Johann; Johnston, Kelly L; Lightowler, Helen; Mann, Neil; Morgan, Linda; Panlasigui, Leonora N; Pelkman, Christine; Perry, Tracy; Pfeiffer, Andreas F H; Pieters, Marlien; Ramdath, D Dan; Ramsingh, Rayna T; Robert, S Daniel; Robinson, Carol; Sarkkinen, Essi; Scazzina, Francesca; Sison, Dave Clark D; Sloth, Birgitte; Staniforth, Jane; Tapola, Niina; Valsta, Liisa M; Verkooijen, Inge; Weickert, Martin O; Weseler, Antje R; Wilkie, Paul; Zhang, Jian

2008-01-01

Many laboratories offer glycemic index (GI) services. We assessed the performance of the method used to measure GI. The GI of cheese-puffs and fruit-leather (centrally provided) was measured in 28 laboratories (n=311 subjects) by using the FAO/WHO method. The laboratories reported the results of their calculations and sent the raw data for recalculation centrally. Values for the incremental area under the curve (AUC) reported by 54% of the laboratories differed from central calculations. Because of this and other differences in data analysis, 19% of reported food GI values differed by >5 units from those calculated centrally. GI values in individual subjects were unrelated to age, sex, ethnicity, body mass index, or AUC but were negatively related to within-individual variation (P=0.033) expressed as the CV of the AUC for repeated reference food tests (refCV). The between-laboratory GI values (mean+/-SD) for cheese-puffs and fruit-leather were 74.3+/-10.5 and 33.2+/-7.2, respectively. The mean laboratory GI was related to refCV (P=0.003) and the type of restrictions on alcohol consumption before the test (P=0.006, r2=0.509 for model). The within-laboratory SD of GI was related to refCV (P<0.001), the glucose analysis method (P=0.010), whether glucose measures were duplicated (P=0.008), and restrictions on dinner the night before (P=0.013, r2=0.810 for model). The between-laboratory SD of the GI values is approximately 9. Standardized data analysis and low within-subject variation (refCV<30%) are required for accuracy. The results suggest that common misconceptions exist about which factors do and do not need to be controlled to improve precision. Controlled studies and cost-benefit analyses are needed to optimize GI methodology. The trial was registered at clinicaltrials.gov as NCT00260858.

Defining, illustrating and reflecting on logic analysis with an example from a professional development program.

PubMed

Tremblay, Marie-Claude; Brousselle, Astrid; Richard, Lucie; Beaudet, Nicole

2013-10-01

Program designers and evaluators should make a point of testing the validity of a program's intervention theory before investing either in implementation or in any type of evaluation. In this context, logic analysis can be a particularly useful option, since it can be used to test the plausibility of a program's intervention theory using scientific knowledge. Professional development in public health is one field among several that would truly benefit from logic analysis, as it appears to be generally lacking in theorization and evaluation. This article presents the application of this analysis method to an innovative public health professional development program, the Health Promotion Laboratory. More specifically, this paper aims to (1) define the logic analysis approach and differentiate it from similar evaluative methods; (2) illustrate the application of this method by a concrete example (logic analysis of a professional development program); and (3) reflect on the requirements of each phase of logic analysis, as well as on the advantages and disadvantages of such an evaluation method. Using logic analysis to evaluate the Health Promotion Laboratory showed that, generally speaking, the program's intervention theory appeared to have been well designed. By testing and critically discussing logic analysis, this article also contributes to further improving and clarifying the method. Copyright © 2013 Elsevier Ltd. All rights reserved.

Different spectrophotometric methods applied for the analysis of simeprevir in the presence of its oxidative degradation product: Acomparative study

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; El-Abasawi, Nasr M.; El-Olemy, Ahmed; Serag, Ahmed

2018-02-01

Five simple spectrophotometric methods were developed for the determination of simeprevir in the presence of its oxidative degradation product namely, ratio difference, mean centering, derivative ratio using the Savitsky-Golay filters, second derivative and continuous wavelet transform. These methods are linear in the range of 2.5-40 μg/mL and validated according to the ICH guidelines. The obtained results of accuracy, repeatability and precision were found to be within the acceptable limits. The specificity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. Furthermore, these methods were statistically comparable to RP-HPLC method and good results were obtained. So, they can be used for the routine analysis of simeprevir in quality-control laboratories.

Analysis of munitions constituents in groundwater using a field-portable GC-MS.

PubMed

Bednar, A J; Russell, A L; Hayes, C A; Jones, W T; Tackett, P; Splichal, D E; Georgian, T; Parker, L V; Kirgan, R A; MacMillan, D K

2012-05-01

The use of munitions constituents (MCs) at military installations can produce soil and groundwater contamination that requires periodic monitoring even after training or manufacturing activities have ceased. Traditional groundwater monitoring methods require large volumes of aqueous samples (e.g., 2-4 L) to be shipped under chain of custody, to fixed laboratories for analysis. The samples must also be packed on ice and shielded from light to minimize degradation that may occur during transport and storage. The laboratory's turn-around time for sample analysis and reporting can be as long as 45 d. This process hinders the reporting of data to customers in a timely manner; yields data that are not necessarily representative of current site conditions owing to the lag time between sample collection and reporting; and incurs significant shipping costs for samples. The current work compares a field portable Gas Chromatograph-Mass Spectrometer (GC-MS) for analysis of MCs on-site with traditional laboratory-based analysis using High Performance Liquid Chromatography with UV absorption detection. The field method provides near real-time (within ~1 h of sampling) concentrations of MCs in groundwater samples. Mass spectrometry provides reliable confirmation of MCs and a means to identify unknown compounds that are potential false positives for methods with UV and other non-selective detectors. Published by Elsevier Ltd.

Inter-laboratory variation in the chemical analysis of acidic forest soil reference samples from eastern North America

Treesearch

D.S. Ross; S.W. Bailey; R.D. Briggs; J. Curry; I.J. Fernandez; G. Fredriksen; C.L. Goodale; P.W. Hazlett; P.R. Heine; C.E. Johnson; J.T. Larson; G.B. Lawrence; R.K. Kolka; R. Ouimet; D. Pare; D. deB Richter; C.D. Schirmer; R.A. Warby

2015-01-01

Long-term forest soil monitoring and research often requires a comparison of laboratory data generated at different times and in different laboratories. Quantifying the uncertainty associated with these analyses is necessary to assess temporal changes in soil properties. Forest soil chemical properties, and methods to measure these properties, often differ from...

Interlaboratory Comparison Test as an Evaluation of Applicability of an Alternative Edible Oil Analysis by 1H NMR Spectroscopy.

PubMed

Zailer, Elina; Holzgrabe, Ulrike; Diehl, Bernd W K

2017-11-01

A proton (1H) NMR spectroscopic method was established for the quality assessment of vegetable oils. To date, several research studies have been published demonstrating the high potential of the NMR technique in lipid analysis. An interlaboratory comparison was organized with the following main objectives: (1) to evaluate an alternative analysis of edible oils by using 1H NMR spectroscopy; and (2) to determine the robustness and reproducibility of the method. Five different edible oil samples were analyzed by evaluating 15 signals (free fatty acids, peroxides, aldehydes, double bonds, and linoleic and linolenic acids) in each spectrum. A total of 21 NMR data sets were obtained from 17 international participant laboratories. The performance of each laboratory was assessed by their z-scores. The test was successfully passed by 90.5% of the participants. Results showed that NMR spectroscopy is a robust alternative method for edible oil analysis.

A novel method to remotely measure food intake of free-living people in real-time

PubMed Central

Martin, Corby K.; Han, Hongmei; Coulon, Sandra M.; Allen, H. Raymond; Champagne, Catherine M.; Anton, Stephen D.

2008-01-01

The aim of this study was to report the first reliability and validity tests of the Remote Food Photography Method (RFPM), which consists of camera-enabled cell phones with data transfer capability. Participants take and transmit photographs of food selection and plate waste to researchers/clinicians for analysis. Following two pilot studies, adult participants (N=52, 20≤BMI≤35) were randomly assigned to the dine-in or take-out group. Energy intake (EI) was measured for three days. The dine-in group ate lunch and dinner in the laboratory. The take-out group ate lunch in the laboratory and dinner in free-living conditions (participants received a cooler with pre-weighed food that they returned the following morning). Energy intake was measured with the RFPM and by directly weighing foods. The RFPM was tested in laboratory and free-living conditions. Reliability was tested over three days and validity was tested by comparing directly weighed EI to EI estimated with the RFPM using Bland-Altman analysis. The RFPM produced reliable EI estimates over three days in laboratory (r=.62, p<.0001) and free-living (r=.68, p<.0001) conditions. Weighed EI correlated highly with EI estimated with the RFPM in laboratory and free-living conditions (r’s>.93, p<.0001). In two laboratory-based validity tests, the RFPM underestimated EI by -4.7% (p=.046) and -5.5% (p=.076). In free-living conditions, the RFPM underestimated EI by -6.6% (p=.017). Bias did not differ by body weight or age. The RFPM is a promising new method for accurately measuring the EI of free-living people. Error associated with the method is small compared to self-report methods. PMID:18616837

Compositional Analysis of Lignocellulosic Feedstocks. 1. Review and Description of Methods

PubMed Central

2010-01-01

As interest in lignocellulosic biomass feedstocks for conversion into transportation fuels grows, the summative compositional analysis of biomass, or plant-derived material, becomes ever more important. The sulfuric acid hydrolysis of biomass has been used to measure lignin and structural carbohydrate content for more than 100 years. Researchers have applied these methods to measure the lignin and structural carbohydrate contents of woody materials, estimate the nutritional value of animal feed, analyze the dietary fiber content of human food, compare potential biofuels feedstocks, and measure the efficiency of biomass-to-biofuels processes. The purpose of this paper is to review the history and lineage of biomass compositional analysis methods based on a sulfuric acid hydrolysis. These methods have become the de facto procedure for biomass compositional analysis. The paper traces changes to the biomass compositional analysis methods through time to the biomass methods currently used at the National Renewable Energy Laboratory (NREL). The current suite of laboratory analytical procedures (LAPs) offered by NREL is described, including an overview of the procedures and methodologies and some common pitfalls. Suggestions are made for continuing improvement to the suite of analyses. PMID:20669951

Methodological considerations for implementation of lymphocyte subset analysis in a clinical reference laboratory.

PubMed

Muirhead, K A; Wallace, P K; Schmitt, T C; Frescatore, R L; Franco, J A; Horan, P K

1986-01-01

As the diagnostic utility of lymphocyte subset analysis has been recognized in the clinical research laboratory, a wide variety of reagents and cell preparation, staining and analysis methods have also been described. Methods that are perfectly suitable for analysis of smaller sample numbers in the biological or clinical research setting are not always appropriate and/or applicable in the setting of a high volume clinical reference laboratory. We describe here some of the specific considerations involved in choosing a method for flow cytometric analysis which minimizes sample preparation and data analysis time while maximizing sample stability, viability, and reproducibility. Monoclonal T- and B-cell reagents from three manufacturers were found to give equivalent results for a reference population of healthy individuals. This was true whether direct or indirect immunofluorescence staining was used and whether cells were prepared by Ficoll-Hypaque fractionation (FH) or by lysis of whole blood. When B cells were enumerated using a polyclonal anti-immunoglobulin reagent, less cytophilic immunoglobulin staining was present after lysis than after FH preparation. However, both preparation methods required additional incubation at 37 degrees C to obtain results concordant with monoclonal B-cell reagents. Standard reagents were chosen on the basis of maximum positive/negative separation and the availability of appropriate negative controls. The effects of collection medium and storage conditions on sample stability and reproducibility of subset analysis were also assessed. Specimens collected in heparin and stored at room temperature in buffered medium gave reproducible results for 3 days after specimen collection, using either FH or lysis as the preparation method. General strategies for instrument optimization, quality control, and biohazard containment are also discussed.

Establishing Substantial Equivalence: Proteomics

NASA Astrophysics Data System (ADS)

Lovegrove, Alison; Salt, Louise; Shewry, Peter R.

Wheat is a major crop in world agriculture and is consumed after processing into a range of food products. It is therefore of great importance to determine the consequences (intended and unintended) of transgenesis in wheat and whether genetically modified lines are substantially equivalent to those produced by conventional plant breeding. Proteomic analysis is one of several approaches which can be used to address these questions. Two-dimensional PAGE (2D PAGE) remains the most widely available method for proteomic analysis, but is notoriously difficult to reproduce between laboratories. We therefore describe methods which have been developed as standard operating procedures in our laboratory to ensure the reproducibility of proteomic analyses of wheat using 2D PAGE analysis of grain proteins.

Initial interlaboratory validation of an analytical method for the determination of lead in canned tuna to be used for monitoring and regulatory purposes.

PubMed

Santiago, E C; Bello, F B B

2003-06-01

The Association of Official Analytical Chemists (AOAC) Standard Method 972.23 (dry ashing and flame atomic absorption spectrophotometry (FAAS)), applied to the analysis of lead in tuna, was validated in three selected local laboratories to determine the acceptability of the method to both the Codex Alimentarius Commission (Codex) and the European Union (EU) Commission for monitoring lead in canned tuna. Initial validation showed that the standard AOAC method as performed in the three participating laboratories cannot satisfy the Codex/EU proposed criteria for the method detection limit for monitoring lead in fish at the present regulation level of 0.5 mg x kg(-1). Modification of the standard method by chelation/concentration of the digest solution before FAAS analysis showed that the modified method has the potential to meet Codex/EU criteria on sensitivity, accuracy and precision at the specified regulation level.

Comparative study on the selectivity of various spectrophotometric techniques for the determination of binary mixture of fenbendazole and rafoxanide.

PubMed

Saad, Ahmed S; Attia, Ali K; Alaraki, Manal S; Elzanfaly, Eman S

2015-11-05

Five different spectrophotometric methods were applied for simultaneous determination of fenbendazole and rafoxanide in their binary mixture; namely first derivative, derivative ratio, ratio difference, dual wavelength and H-point standard addition spectrophotometric methods. Different factors affecting each of the applied spectrophotometric methods were studied and the selectivity of the applied methods was compared. The applied methods were validated as per the ICH guidelines and good accuracy; specificity and precision were proven within the concentration range of 5-50 μg/mL for both drugs. Statistical analysis using one-way ANOVA proved no significant differences among the proposed methods for the determination of the two drugs. The proposed methods successfully determined both drugs in laboratory prepared and commercially available binary mixtures, and were found applicable for the routine analysis in quality control laboratories. Copyright © 2015 Elsevier B.V. All rights reserved.

Results of a collaborative study on DNA identification of aged bone samples

PubMed Central

Vanek, Daniel; Budowle, Bruce; Dubska-Votrubova, Jitka; Ambers, Angie; Frolik, Jan; Pospisek, Martin; Al Afeefi, Ahmed Anwar; Al Hosani, Khalid Ismaeil; Allen, Marie; Al Naimi, Khudooma Saeed; Al Salafi, Dina; Al Tayyari, Wafa Ali Rashid; Arguetaa, Wendy; Bottinelli, Michel; Bus, Magdalena M.; Cemper-Kiesslich, Jan; Cepil, Olivier; De Cock, Greet; Desmyter, Stijn; El Amri, Hamid; El Ossmani, Hicham; Galdies, Ruth; Grün, Sebastian; Guidet, Francois; Hoefges, Anna; Iancu, Cristian Bogdan; Lotz, Petra; Maresca, Alessandro; Nagy, Marion; Novotny, Jindrich; Rachid, Hajar; Rothe, Jessica; Stenersen, Marguerethe; Stephenson, Mishel; Stevanovitch, Alain; Strien, Juliane; Sumita, Denilce R.; Vella, Joanna; Zander, Judith

2017-01-01

Aim A collaborative exercise with several institutes was organized by the Forensic DNA Service (FDNAS) and the Institute of the Legal Medicine, 2nd Faculty of Medicine, Charles University in Prague, Czech Republic, with the aim to test performance of different laboratories carrying out DNA analysis of relatively old bone samples. Methods Eighteen laboratories participating in the collaborative exercise were asked to perform DNA typing of two samples of bone powder. Two bone samples provided by the National Museum and the Institute of Archaelogy in Prague, Czech Republic, came from archeological excavations and were estimated to be approximately 150 and 400 years old. The methods of genetic characterization including autosomal, gonosomal, and mitochondrial markers was selected solely at the discretion of the participating laboratory. Results Although the participating laboratories used different extraction and amplification strategies, concordant results were obtained from the relatively intact 150 years old bone sample. Typing was more problematic with the analysis of the 400 years old bone sample due to poorer quality. Conclusion The laboratories performing identification DNA analysis of bone and teeth samples should regularly test their ability to correctly perform DNA-based identification on bone samples containing degraded DNA and potential inhibitors and demonstrate that risk of contamination is minimized. PMID:28613037

Analysis of negative historical control group data from the in vitro micronucleus assay using TK6 cells.

PubMed

Lovell, David P; Fellows, Mick; Marchetti, Francesco; Christiansen, Joan; Elhajouji, Azeddine; Hashimoto, Kiyohiro; Kasamoto, Sawako; Li, Yan; Masayasu, Ozaki; Moore, Martha M; Schuler, Maik; Smith, Robert; Stankowski, Leon F; Tanaka, Jin; Tanir, Jennifer Y; Thybaud, Veronique; Van Goethem, Freddy; Whitwell, James

2018-01-01

The recent revisions of the Organisation for Economic Co-operation and Development (OECD) genetic toxicology test guidelines emphasize the importance of historical negative controls both for data quality and interpretation. The goal of a HESI Genetic Toxicology Technical Committee (GTTC) workgroup was to collect data from participating laboratories and to conduct a statistical analysis to understand and publish the range of values that are normally seen in experienced laboratories using TK6 cells to conduct the in vitro micronucleus assay. Data from negative control samples from in vitro micronucleus assays using TK6 cells from 13 laboratories were collected using a standard collection form. Although in some cases statistically significant differences can be seen within laboratories for different test conditions, they were very small. The mean incidence of micronucleated cells/1000 cells ranged from 3.2/1000 to 13.8/1000. These almost four-fold differences in micronucleus levels cannot be explained by differences in scoring method, presence or absence of exogenous metabolic activation (S9), length of treatment, presence or absence of cytochalasin B or different solvents used as vehicles. The range of means from the four laboratories using flow cytometry methods (3.7-fold: 3.5-12.9 micronucleated cells/1000 cells) was similar to that from the nine laboratories using other scoring methods (4.3-fold: 3.2-13.8 micronucleated cells/1000 cells). No laboratory could be identified as an outlier or as showing unacceptably high variability. Quality Control (QC) methods applied to analyse the intra-laboratory variability showed that there was evidence of inter-experimental variability greater than would be expected by chance (i.e. over-dispersion). However, in general, this was low. This study demonstrates the value of QC methods in helping to analyse the reproducibility of results, building up a 'normal' range of values, and as an aid to identify variability within a laboratory in order to implement processes to maintain and improve uniformity. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

Oil mist and vapour concentrations from drilling fluids: inter- and intra-laboratory comparison of chemical analyses.

PubMed

Galea, Karen S; Searl, Alison; Sánchez-Jiménez, Araceli; Woldbæk, Torill; Halgard, Kristin; Thorud, Syvert; Steinsvåg, Kjersti; Krüger, Kirsti; Maccalman, Laura; Cherrie, John W; van Tongeren, Martie

2012-01-01

There are no recognized analytical methods for measuring oil mist and vapours arising from drilling fluids used in offshore petroleum drilling industry. To inform the future development of improved methods of analysis for oil mist and vapours this study assessed the inter- and intra-laboratory variability in oil mist and vapour analysis. In addition, sample losses during transportation and storage were assessed. Replicate samples for oil mist and vapour were collected using the 37-mm Millipore closed cassette and charcoal tube assembly. Sampling was conducted in a simulated shale shaker room, similar to that found offshore for processing drilling fluids. Samples were analysed at two different laboratories, one in Norway and one in the UK. Oil mist samples were analysed using Fourier transform infrared spectroscopy (FTIR), while oil vapour samples were analysed by gas chromatography (GC). The comparison of replicate samples showed substantial within- and between-laboratory variability in reported oil mist concentrations. The variability in oil vapour results was considerably reduced compared to oil mist, provided that a common method of calibration and quantification was adopted. The study also showed that losses can occur during transportation and storage of samples. There is a need to develop a harmonized method for the quantification of oil mist on filter and oil vapour on charcoal supported by a suitable proficiency testing scheme for laboratories involved in the analysis of occupational hygiene samples for the petroleum industry. The uncertainties in oil mist and vapour measurement have substantial implications in relation to compliance with occupational exposure limits and also in the reliability of any exposure-response information reported in epidemiological studies.

Multicomponent blood lipid analysis by means of near infrared spectroscopy, in geese.

PubMed

Bazar, George; Eles, Viktoria; Kovacs, Zoltan; Romvari, Robert; Szabo, Andras

2016-08-01

This study provides accurate near infrared (NIR) spectroscopic models on some laboratory determined clinicochemical parameters (i.e. total lipid (5.57±1.95 g/l), triglyceride (2.59±1.36 mmol/l), total cholesterol (3.81±0.68 mmol/l), high density lipoprotein (HDL) cholesterol (2.45±0.58 mmol/l)) of blood serum samples of fattened geese. To increase the performance of multivariate chemometrics, samples significantly deviating from the regression models implying laboratory error were excluded from the final calibration datasets. Reference data of excluded samples having outlier spectra in principal component analysis were not marked as false. Samples deviating from the regression models but having non outlier spectra in PCA were identified as having false reference constituent values. Based on the NIR selection methods, 5% of the reference measurement data were rated as doubtful. The achieved models reached R(2) of 0.864, 0.966, 0.850, 0.793, and RMSE of 0.639 g/l, 0.232 mmol/l, 0.210 mmol/l, 0.241 mmol/l for total lipid, triglyceride, total cholesterol and HDL cholesterol, respectively, during independent validation. Classical analytical techniques focus on single constituents and often require chemicals, time-consuming measurements, and experienced technicians. NIR technique provides a quick, cost effective, non-hazardous alternative method for analysis of several constituents based on one single spectrum of each sample, and it also offers the possibility for looking at the laboratory reference data critically. Evaluation of reference data to identify and exclude falsely analyzed samples can provide warning feedback to the reference laboratory, especially in the case of analyses where laboratory methods are not perfectly suited to the subjected material and there is an increased chance of laboratory error. Copyright © 2016 Elsevier B.V. All rights reserved.

Materials and Methods for Streamlined Laboratory Analysis of Environmental Samples, FY 2016 Report

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

Addleman, Raymond S.; Naes, Benjamin E.; McNamara, Bruce K.

The International Atomic Energy Agency (IAEA) relies upon laboratory analysis of environmental samples (typically referred to as “swipes”) collected during on-site inspections of safeguarded facilities to support the detection and deterrence of undeclared activities. Unfortunately, chemical processing and assay of the samples is slow and expensive. A rapid, effective, and simple extraction process and analysis method is needed to provide certified results with improved timeliness at reduced costs (principally in the form of reduced labor), while maintaining or improving sensitivity and efficacy. To address these safeguard needs the Pacific Northwest National Laboratory (PNNL) explored and demonstrated improved methods for environmentalmore » sample (ES) analysis. Improvements for both bulk and particle analysis were explored. To facilitate continuity and adoption, the new sampling materials and processing methods will be compatible with existing IAEA protocols for ES analysis. PNNL collaborated with Oak Ridge National Laboratory (ORNL), which performed independent validation of the new bulk analysis methods and compared performance to traditional IAEA’s Network of Analytical Laboratories (NWAL) protocol. ORNL efforts are reported separately. This report describes PNNL’s FY 2016 progress, which was focused on analytical application supporting environmental monitoring of uranium enrichment plants and nuclear fuel processing. In the future the technology could be applied to other safeguard applications and analytes related to fuel manufacturing, reprocessing, etc. PNNL’s FY 2016 efforts were broken into two tasks and a summary of progress, accomplishments and highlights are provided below. Principal progress and accomplishments on Task 1, Optimize Materials and Methods for ICP-MS Environmental Sample Analysis, are listed below. • Completed initial procedure for rapid uranium extraction from ES swipes based upon carbonate-peroxide chemistry (delivered to ORNL for evaluation). • Explored improvements to carbonate-peroxide rapid uranium extraction chemistry. • Evaluated new sampling materials and methods (in collaboration with ORNL). • Demonstrated successful ES extractions from standard and novel swipes for a wide range uranium compounds of interest including UO 2F 2 and UO 2(NO 3) 2, U 3O 8 and uranium ore concentrate. • Completed initial discussions with commercial suppliers of PTFE swipe materials. • Submitted one manuscript for publication. Two additional drafts are being prepared. Principal progress and accomplishments on Task 2, Optimize Materials and Methods for Direct SIMS Environmental Sample Analysis, are listed below. • Designed a SIMS swipe sample holder that retrofits into existing equipment and provides simple, effective, and rapid mounting of ES samples for direct assay while enabling automation and laboratory integration. • Identified preferred conductive sampling materials with better performance characteristics. • Ran samples on the new PNNL NWAL equivalent Cameca 1280 SIMS system. • Obtained excellent agreement between isotopic ratios for certified materials and direct SIMS assay of very low levels of LEU and HEU UO 2F 2 particles on carbon fiber sampling material. Sample activities range from 1 to 500 CPM (uranium mass on sample is dependent upon specific isotope ratio but is frequently in the subnanogram range). • Found that the presence of the UF molecular ions, as measured by SIMS, provides chemical information about the particle that is separate from the uranium isotopics and strongly suggests that those particles originated from an UF6 enrichment activity. • Submitted one manuscript for publication. Another manuscript is in preparation.« less

40 CFR 408.61 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory...

40 CFR 408.71 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c...

40 CFR 408.81 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... components of a waste water amendable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory...

Reference method for detection of Pgp mediated multidrug resistance in human hematological malignancies: a method validated by the laboratories of the French Drug Resistance Network.

PubMed

Huet, S; Marie, J P; Gualde, N; Robert, J

1998-12-15

Multidrug resistance (MDR) associated with overexpression of the MDR1 gene and of its product, P-glycoprotein (Pgp), plays an important role in limiting cancer treatment efficacy. Many studies have investigated Pgp expression in clinical samples of hematological malignancies but failed to give definitive conclusion on its usefulness. One convenient method for fluorescent detection of Pgp in malignant cells is flow cytometry which however gives variable results from a laboratory to another one, partly due to the lack of a reference method rigorously tested. The purpose of this technical note is to describe each step of a reference flow cytometric method. The guidelines for sample handling, staining and analysis have been established both for Pgp detection with monoclonal antibodies directed against extracellular epitopes (MRK16, UIC2 and 4E3), and for Pgp functional activity measurement with Rhodamine 123 as a fluorescent probe. Both methods have been validated on cultured cell lines and clinical samples by 12 laboratories of the French Drug Resistance Network. This cross-validated multicentric study points out crucial steps for the accuracy and reproducibility of the results, like cell viability, data analysis and expression.

Topics on Test Methods for Space Systems and Operations Safety: Applicability of Experimental Data

NASA Technical Reports Server (NTRS)

Hirsch, David B.

2009-01-01

This viewgraph presentation reviews topics on test methods for space systems and operations safety through experimentation and analysis. The contents include: 1) Perception of reality through experimentation and analysis; 2) Measurements, methods, and correlations with real life; and 3) Correlating laboratory aerospace materials flammability data with data in spacecraft environments.

Method Development for the Analysis of 1,4-Dioxane in Drinking Water Using Solid Phase Extraction and Gas Chromatography/Mass Spectrometry

EPA Science Inventory

1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of...

Why Students Fail at Volumetric Analysis.

ERIC Educational Resources Information Center

Pickering, Miles

1979-01-01

Investigates the reasons for students' failure in an introductory volumetric analysis course by analyzing test papers and judging them against a hypothetical ideal method of grading laboratory techniques. (GA)

Quality-assurance plan for the analysis of fluvial sediment by laboratories of the U.S. Geological Survey

USGS Publications Warehouse

Matthes, Wilbur J.; Sholar, Clyde J.; George, John R.

1992-01-01

This report describes procedures used by the Iowa District sediment laboratory of the U.S. Geological Survey to assure the quality of sediment-laboratory data. These procedures can be used by other U.S. Geological Survey laboratories regardless of size and type of operation for quality assurance and quality control of specific sediment-laboratory processes. Also described are the equipment, specifications, calibration and maintenance, and the protocol for methods used in the analyses of fluvial sediment for concentration or particle size.

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

Quantitative analysis of unconjugated and total bisphenol A in human urine using solid-phase extraction and UPLC-MS/MS: method implementation, method qualification and troubleshooting.

PubMed

Buscher, Brigitte; van de Lagemaat, Dick; Gries, Wolfgang; Beyer, Dieter; Markham, Dan A; Budinsky, Robert A; Dimond, Stephen S; Nath, Rajesh V; Snyder, Stephanie A; Hentges, Steven G

2015-11-15

The aim of the presented investigation was to document challenges encountered during implementation and qualification of a method for bisphenol A (BPA) analysis and to develop and discuss precautions taken to avoid and to monitor contamination with BPA during sample handling and analysis. Previously developed and published HPLC-MS/MS methods for the determination of unconjugated BPA (Markham et al. Journal of Analytical Toxicology, 34 (2010) 293-303) [17] and total BPA (Markham et al. Journal of Analytical Toxicology, 38 (2014) 194-203) [20] in human urine were combined and transferred into another laboratory. The initial method for unconjugated BPA was developed and evaluated in two independent laboratories simultaneously. The second method for total BPA was developed and evaluated in one of these laboratories to conserve resources. Accurate analysis of BPA at sub-ppb levels is a challenging task as BPA is a widely used material and is ubiquitous in the environment at trace concentrations. Propensity for contamination of biological samples with BPA is reported in the literature during sample collection, storage, and/or analysis. Contamination by trace levels of BPA is so pervasive that even with extraordinary care, it is difficult to completely exclude the introduction of BPA into biological samples and, consequently, contamination might have an impact on BPA biomonitoring data. The applied UPLC-MS/MS method was calibrated from 0.05 to 25ng/ml. The limit of quantification was 0.1ng/ml for unconjugated BPA and 0.2ng/ml for total BPA, respectively, in human urine. Finally, the method was applied to urine samples derived from 20 volunteers. Overall, BPA can be analyzed in human urine with acceptable recovery and repeatability if sufficient measures are taken to avoid contamination throughout the procedure from sample collection until UPLC-MS/MS analysis. Copyright © 2015 The Authors. Published by Elsevier B.V. All rights reserved.

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.

Good Laboratory Practices of Materials Testing at NASA White Sands Test Facility

NASA Technical Reports Server (NTRS)

Hirsch, David; Williams, James H.

2005-01-01

An approach to good laboratory practices of materials testing at NASA White Sands Test Facility is presented. The contents include: 1) Current approach; 2) Data analysis; and 3) Improvements sought by WSTF to enhance the diagnostic capability of existing methods.

Puget Sound Dredged Disposal Analysis: Management Plan Assessment Report. Dredged Material Management Year 1990.

DTIC Science & Technology

1991-03-01

Sulfides BT Bioaccumulation Trigger L LP Ccn tract Laboratory Methods COC Chemical of Concern Corps U.S. Army Corps of Engineers cm centimeter cy cubic... Hydrocarbon (Compound) LOD Limit of Detection LPAH Low Molecular Weight Polynuclear Aromatic Hydrocarbon (Compound) MCLP Modified Contract Laboratory Method...Aromatic Hydrocarbons (HPAHs) (8 samples); * Benzofluoranthenes (7 samples); * Anthracene (6 samples); * Benzo(a)anthracene (6 samples); * Dibenzo(a,h

Quality Assessment of Urinary Stone Analysis: Results of a Multicenter Study of Laboratories in Europe

PubMed Central

Siener, Roswitha; Buchholz, Noor; Daudon, Michel; Hess, Bernhard; Knoll, Thomas; Osther, Palle J.; Reis-Santos, José; Sarica, Kemal; Traxer, Olivier; Trinchieri, Alberto

2016-01-01

After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis. PMID:27248840

Quality Assessment of Urinary Stone Analysis: Results of a Multicenter Study of Laboratories in Europe.

PubMed

Siener, Roswitha; Buchholz, Noor; Daudon, Michel; Hess, Bernhard; Knoll, Thomas; Osther, Palle J; Reis-Santos, José; Sarica, Kemal; Traxer, Olivier; Trinchieri, Alberto

2016-01-01

After stone removal, accurate analysis of urinary stone composition is the most crucial laboratory diagnostic procedure for the treatment and recurrence prevention in the stone-forming patient. The most common techniques for routine analysis of stones are infrared spectroscopy, X-ray diffraction and chemical analysis. The aim of the present study was to assess the quality of urinary stone analysis of laboratories in Europe. Nine laboratories from eight European countries participated in six quality control surveys for urinary calculi analyses of the Reference Institute for Bioanalytics, Bonn, Germany, between 2010 and 2014. Each participant received the same blinded test samples for stone analysis. A total of 24 samples, comprising pure substances and mixtures of two or three components, were analysed. The evaluation of the quality of the laboratory in the present study was based on the attainment of 75% of the maximum total points, i.e. 99 points. The methods of stone analysis used were infrared spectroscopy (n = 7), chemical analysis (n = 1) and X-ray diffraction (n = 1). In the present study only 56% of the laboratories, four using infrared spectroscopy and one using X-ray diffraction, fulfilled the quality requirements. According to the current standard, chemical analysis is considered to be insufficient for stone analysis, whereas infrared spectroscopy or X-ray diffraction is mandatory. However, the poor results of infrared spectroscopy highlight the importance of equipment, reference spectra and qualification of the staff for an accurate analysis of stone composition. Regular quality control is essential in carrying out routine stone analysis.

Laboratory Analytical Procedures | Bioenergy | NREL

Science.gov Websites

analytical procedures (LAPs) to provide validated methods for biofuels and pyrolysis bio-oils research . Biomass Compositional Analysis These lab procedures provide tested and accepted methods for performing

40 CFR 417.191 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... methylene blue active substances amenable to measurement by the method described in “Methods for Chemical Analysis of Water and Wastes,” 1971, Environmental Protection Agency, Analytical Quality Control Laboratory...

EURADOS intercomparison on emergency radiobioassay.

PubMed

Li, Chunsheng; Battisti, Paolo; Berard, Philippe; Cazoulat, Alain; Cuellar, Antonio; Cruz-Suarez, Rodolfo; Dai, Xiongxin; Giardina, Isabella; Hammond, Derek; Hernandez, Carolina; Kiser, Stephen; Ko, Raymond; Kramer-Tremblay, Sheila; Lecompte, Yannick; Navarro, Eva; Navas, Cristina; Sadi, Baki; Sierra, Inmaculada; Verrezen, Freddy; Lopez, Maria A

2015-12-01

Nine laboratories participated in an intercomparison exercise organised by the European Radiation Dosimetry Group (EURADOS) for emergency radiobioassay involving four high-risk radionuclides ((239)Pu, (241)Am, (90)Sr and (226)Ra). Diverse methods of analysis were used by the participating laboratories for the in vitro determination of each of the four radionuclides in urine samples. Almost all the methods used are sensitive enough to meet the requirements for emergency radiobioassay derived for this project in reference to the Clinical Decision Guide introduced by the NCRP. Results from most of the methods meet the requirements of ISO 28218 on accuracy in terms of relative bias and relative precision. However, some technical gaps have been identified. For example, some laboratories do not have the ability to assay samples containing (226)Ra, and sample turnaround time would be expected to be much shorter than that reported by many laboratories, as timely results for internal contamination and early decisions on medical intervention are highly desired. Participating laboratories are expected to learn from each other on the methods used to improve the interoperability among these laboratories. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Bridging theory and practice: Mixed methods approach to instruction of law and ethics within the pharmaceutical sciences.

PubMed

Wilby, Kyle John; Nasr, Ziad Ghantous

2016-11-01

Background: Professional responsibilities are guided by laws and ethics that must be introduced and mastered within pharmaceutical sciences training. Instructional design to teaching typically introduces concepts in a traditional didactic approach and requires student memorization prior to application within practice settings. Additionally, many centers rely on best practices from abroad, due to lack of locally published laws and guidance documents. Objectives: The aim of this paper was to summarize and critically evaluate a professional skills laboratory designed to enhance learning through diversity in instructional methods relating to pharmacy law and best practices regarding narcotics, controlled medications, and benzodiazepines. Setting: This study took place within the Professional Skills Laboratory at the College of Pharmacy at Qatar University. Method: A total of 25 students participated in a redesigned laboratory session administered by a faculty member, clinical lecturer, teaching assistant, and a professional skills laboratory technician. The laboratory consisted of eight independent stations that students rotated during the 3-h session. Stations were highly interactive in nature and were designed using non-traditional approaches such as charades, role-plays, and reflective drawings. All stations attempted to have students relate learned concepts to practice within Qatar. Main outcome measures: Student perceptions of the laboratory were measured on a post-questionnaire and were summarized descriptively. Using reflection and consensus techniques, two faculty members completed a SWOC (Strengths, Weaknesses, Opportunities, and Challenges) analysis in preparation for future cycles. Results: 100% (25/25) of students somewhat or strongly agreed that their knowledge regarding laws and best practices increased and that their learning experience was enhanced by a mixed-methods approach. A total of 96% (24/25) of students stated that the mixed-methods instructional approach should be continued in the future. The SWOC analysis identified the mixed methods approach and student feedback as strengths and opportunities, while resource shortages and lack of impact assessment were identified as weaknesses and challenges. Conclusion: Creative redesign of instructional methods pertaining to law and best practices was effective to achieve positive student perceptions regarding instructional methods and learning. Future cycles should include rigorous assessment methods to evaluate impact on student learning and practice.

Highlight on Bottlenecks in Food Allergen Analysis: Detection and Quantification by Mass Spectrometry.

PubMed

Planque, Mélanie; Arnould, Thierry; Renard, Patricia; Delahaut, Philippe; Dieu, Marc; Gillard, Nathlie

2017-07-01

Food laboratories have developed methods for testing allergens in foods. The efficiency of qualitative and quantitative methods is of prime importance in protecting allergic populations. Unfortunately, food laboratories encounter barriers to developing efficient methods. Bottlenecks include the lack of regulatory thresholds, delays in the emergence of reference materials and guidelines, and the need to detect processed allergens. In this study, ultra-HPLC coupled to tandem MS was used to illustrate difficulties encountered in determining method performances. We measured the major influences of both processing and matrix effects on the detection of egg, milk, soy, and peanut allergens in foodstuffs. The main goals of this work were to identify difficulties that food laboratories still encounter in detecting and quantifying allergens and to sensitize researchers to them.

Uncertainties in 63Ni and 55Fe determinations using liquid scintillation counting methods.

PubMed

Herranz, M; Idoeta, R; Abelairas, A; Legarda, F

2012-09-01

The implementation of (63)Ni and (55)Fe determination methods in an environmental laboratory implies their validation. In this process, the uncertainties related to these methods should be analysed. In this work, the expression of the uncertainty of the results obtained using separation methods followed by liquid scintillation counting is presented. This analysis includes the consideration of uncertainties coming from the different alternatives which these methods use as well as those which are specific to the individual laboratory and the competency of its operators in applying the standard ORISE (Oak Ridge Institute for Science and Education) methods. Copyright © 2012 Elsevier Ltd. All rights reserved.

Detection of martian amino acids by chemical derivatization coupled to gas chromatography: in situ and laboratory analysis.

PubMed

Rodier, C; Vandenabeele-Trambouze, O; Sternberg, R; Coscia, D; Coll, P; Szopa, C; Raulin, F; Vidal-Madjar, C; Cabane, M; Israel, G; Grenier-Loustalot, M F; Dobrijevic, M; Despois, D

2001-01-01

If there is, or ever was, life in our solar system beyond the Earth, Mars is the most likely place to search for. Future space missions will have then to take into account the detection of prebiotic molecules or molecules of biological significance such as amino acids. Techniques of analysis used for returned samples have to be very sensitive and avoid any chemical or biological contamination whereas in situ techniques have to be automated, fast and low energy consuming. Several possible methods could be used for in situ amino acid analyses on Mars, but gas chromatography would likely be the most suitable. Returned samples could be analyzed by any method in routine laboratory use such as gas chromatography, already successfully performed for analyses of organic matter including amino acids from martian meteorites. The derivatization step, which volatilizes amino acids to perform both in situ and laboratory analysis by gas chromatography, is discussed here. c2001 COSPAR. Published by Elsevier Science Ltd. All rights reserved.

An Analysis of Agricultural Mechanics Safety Practices in Agricultural Science Laboratories.

ERIC Educational Resources Information Center

Swan, Michael K.

North Dakota secondary agricultural mechanics instructors were surveyed regarding instructional methods and materials, safety practices, and equipment used in the agricultural mechanics laboratory. Usable responses were received from 69 of 89 instructors via self-administered mailed questionnaires. Findings were consistent with results of similar…

Concerns regarding a new culture method for Borrelia burgdorferi not approved for the diagnosis of Lyme disease.

PubMed

Nelson, Christina; Hojvat, Sally; Johnson, Barbara; Petersen, Jeannine; Schriefer, Marty; Beard, C Ben; Petersen, Lyle; Mead, Paul

2014-04-18

In 2005, CDC and the Food and Drug Administration (FDA) issued a warning regarding the use of Lyme disease tests whose accuracy and clinical usefulness have not been adequately established. Often these are laboratory-developed tests (also known as "home brew" tests) that are manufactured and used within a single laboratory and have not been cleared or approved by FDA. Recently, CDC has received inquiries regarding a laboratory-developed test that uses a novel culture method to identify Borrelia burgdorferi, the spirochete that causes Lyme disease. Patient specimens reportedly are incubated using a two-step pre-enrichment process, followed by immunostaining with or without polymerase chain reaction (PCR) analysis. Specimens that test positive by immunostaining or PCR are deemed "culture positive". Published methods and results for this laboratory-developed test have been reviewed by CDC. The review raised serious concerns about false-positive results caused by laboratory contamination and the potential for misdiagnosis.

Identification of the students' critical thinking skills through biochemistry laboratory work report

NASA Astrophysics Data System (ADS)

Anwar, Yunita Arian Sani; Senam, Laksono, Endang W.

2017-08-01

This work aims to (1) identify the critical thinking skills of student based on their ability to set up laboratory work reports, and (2) analyze the implementation of biochemistry laboratory work. The method of quantitative content analysis was employed. Quantitative data were in the form of critical thinking skills through the assessment of students' laboratory work reports and questionnaire data. Hoyo rubric was used to measure critical thinking skills with 10 indicators, namely clarity, accuracy, precision, consistency, relevance, evidence, reason, depth, breadth, and fairness. The research sample consisted of 105 students (35 male, 70 female) of Mataram University who took a Biochemistry course and 2 lecturers of Biochemistry course. The results showed students' critical thinking skills through laboratory work reports were still weak. Analysis of the questionnaire showed that three indicators become the biggest problems during the laboratory work implementation, namely, lecturers' involved in laboratory work implementation, the integration of laboratory work implementation of learning in the classroom has not been done optimally and laboratory work implementation as an effort to train critical thinking skills is not optimal yet.

HEATED PURGE AND TRAP METHOD DEVELOPMENT AND TESTING

EPA Science Inventory

The goal of the research was to develop a heated purge and trap method that could be used in conjunction with SW-846 method 8240 for the analysis of volatile, water soluble Appendix VIII analytes. The developed method was validated according to a partial single laboratory method ...

An Analysis of a Finite Element Method for Convection-Diffusion Problems. Part II. A Posteriori Error Estimates and Adaptivity.

DTIC Science & Technology

1983-03-01

AN ANALYSIS OF A FINITE ELEMENT METHOD FOR CONVECTION- DIFFUSION PROBLEMS PART II: A POSTERIORI ERROR ESTIMATES AND ADAPTIVITY by W. G. Szymczak Y 6a...PERIOD COVERED AN ANALYSIS OF A FINITE ELEMENT METHOD FOR final life of the contract CONVECTION- DIFFUSION PROBLEM S. Part II: A POSTERIORI ERROR ...Element Method for Convection- Diffusion Problems. Part II: A Posteriori Error Estimates and Adaptivity W. G. Szvmczak and I. Babu~ka# Laboratory for

The estimation of the measurement results with using statistical methods

NASA Astrophysics Data System (ADS)

Velychko, O.; Gordiyenko, T.

2015-02-01

The row of international standards and guides describe various statistical methods that apply for a management, control and improvement of processes with the purpose of realization of analysis of the technical measurement results. The analysis of international standards and guides on statistical methods estimation of the measurement results recommendations for those applications in laboratories is described. For realization of analysis of standards and guides the cause-and-effect Ishikawa diagrams concerting to application of statistical methods for estimation of the measurement results are constructed.

Combining Cloud Networks and Course Management Systems for Enhanced Analysis in Teaching Laboratories

ERIC Educational Resources Information Center

Abrams, Neal M.

2012-01-01

A cloud network system is combined with standard computing applications and a course management system to provide a robust method for sharing data among students. This system provides a unique method to improve data analysis by easily increasing the amount of sampled data available for analysis. The data can be shared within one course as well as…

Inverse Transient Analysis for Classification of Wall Thickness Variations in Pipelines

PubMed Central

Tuck, Jeffrey; Lee, Pedro

2013-01-01

Analysis of transient fluid pressure signals has been investigated as an alternative method of fault detection in pipeline systems and has shown promise in both laboratory and field trials. The advantage of the method is that it can potentially provide a fast and cost effective means of locating faults such as leaks, blockages and pipeline wall degradation within a pipeline while the system remains fully operational. The only requirement is that high speed pressure sensors are placed in contact with the fluid. Further development of the method requires detailed numerical models and enhanced understanding of transient flow within a pipeline where variations in pipeline condition and geometry occur. One such variation commonly encountered is the degradation or thinning of pipe walls, which can increase the susceptible of a pipeline to leak development. This paper aims to improve transient-based fault detection methods by investigating how changes in pipe wall thickness will affect the transient behaviour of a system; this is done through the analysis of laboratory experiments. The laboratory experiments are carried out on a stainless steel pipeline of constant outside diameter, into which a pipe section of variable wall thickness is inserted. In order to detect the location and severity of these changes in wall conditions within the laboratory system an inverse transient analysis procedure is employed which considers independent variations in wavespeed and diameter. Inverse transient analyses are carried out using a genetic algorithm optimisation routine to match the response from a one-dimensional method of characteristics transient model to the experimental time domain pressure responses. The accuracy of the detection technique is evaluated and benefits associated with various simplifying assumptions and simulation run times are investigated. It is found that for the case investigated, changes in the wavespeed and nominal diameter of the pipeline are both important to the accuracy of the inverse analysis procedure and can be used to differentiate the observed transient behaviour caused by changes in wall thickness from that caused by other known faults such as leaks. Further application of the method to real pipelines is discussed.

[Enzymatic analysis of the quality of foodstuffs].

PubMed

Kolesnov, A Iu

1997-01-01

Enzymatic analysis is an independent and separate branch of enzymology and analytical chemistry. It has become one of the most important methodologies used in food analysis. Enzymatic analysis allows the quick, reliable determination of many food ingredients. Often these contents cannot be determined by conventional methods, or if methods are available, they are determined only with limited accuracy. Today, methods of enzymatic analysis are being increasingly used in the investigation of foodstuffs. Enzymatic measurement techniques are used in industry, scientific and food inspection laboratories for quality analysis. This article describes the requirements of an optimal analytical method: specificity, sample preparation, assay performance, precision, sensitivity, time requirement, analysis cost, safety of reagents.

Cell-Free DNA Analysis in Maternal Blood: Differences in Estimates between Laboratories with Different Methodologies Using a Propensity Score Approach.

PubMed

Bevilacqua, Elisa; Jani, Jacques C; Letourneau, Alexandra; Duiella, Silvia F; Kleinfinger, Pascale; Lohmann, Laurence; Resta, Serena; Cos Sanchez, Teresa; Fils, Jean-François; Mirra, Marilyn; Benachi, Alexandra; Costa, Jean-Marc

2018-06-13

To evaluate the failure rate and performance of cell-free DNA (cfDNA) testing, mainly in terms of detection rates for trisomy 21, performed by 2 laboratories using different analytical methods. cfDNA testing was performed on 2,870 pregnancies with the HarmonyTM Prenatal Test using the targeted digital analysis of selected regions (DANSR) method, and on 2,635 pregnancies with the "Cerba test" using the genome-wide massively parallel sequencing (GW-MPS) method, with available outcomes. Propensity score analysis was used to match patients between the 2 groups. A comparison of the detection rates for trisomy 21 between the 2 laboratories was made. In all, 2,811 patients in the Harmony group and 2,530 patients in the Cerba group had no trisomy 21, 18, or 13. Postmatched comparisons of the patient characteristics indicated a higher no-result rate in the Harmony group (1.30%) than in the Cerba group (0.75%; p = 0.039). All 41 cases of trisomy 21 in the Harmony group and 93 cases in the Cerba group were detected. Both methods of cfDNA testing showed low no-result rates and a comparable performance in detecting trisomy 21; yet GW-MPS had a slightly lower no-result rate than the DANSR method. © 2018 S. Karger AG, Basel.

Analytical methods of the U.S. Geological Survey's New York District Water-Analysis Laboratory

USGS Publications Warehouse

Lawrence, Gregory B.; Lincoln, Tricia A.; Horan-Ross, Debra A.; Olson, Mark L.; Waldron, Laura A.

1995-01-01

The New York District of the U.S. Geological Survey (USGS) in Troy, N.Y., operates a water-analysis laboratory for USGS watershed-research projects in the Northeast that require analyses of precipitation and of dilute surface water and soil water for major ions; it also provides analyses of certain chemical constituents in soils and soil gas samples.This report presents the methods for chemical analyses of water samples, soil-water samples, and soil-gas samples collected in wateshed-research projects. The introduction describes the general materials and technicques for each method and explains the USGS quality-assurance program and data-management procedures; it also explains the use of cross reference to the three most commonly used methods manuals for analysis of dilute waters. The body of the report describes the analytical procedures for (1) solution analysis, (2) soil analysis, and (3) soil-gas analysis. The methods are presented in alphabetical order by constituent. The method for each constituent is preceded by (1) reference codes for pertinent sections of the three manuals mentioned above, (2) a list of the method's applications, and (3) a summary of the procedure. The methods section for each constitutent contains the following categories: instrumentation and equipment, sample preservation and storage, reagents and standards, analytical procedures, quality control, maintenance, interferences, safety considerations, and references. Sufficient information is presented for each method to allow the resulting data to be appropriately used in environmental investigations.

Lean management and medical laboratory: application in transfusionnal immuno-hematology.

PubMed

Thibert, Jean-Baptiste; Le Vacon, Françoise; Danic, Bruno

2017-10-01

Despite a common use in industrial applications, only a few studies describe the lean management methods in medical laboratory. These tools have been evaluated in analysis laboratory of blood donors, especially in immuno-hematology sector. The aim was to optimize the organization and maintain team cohesion and strong staff involvement in a restructuring context. The tools used and the results obtained are presented in this study.

Fault Tree Analysis: Investigation of Epidemic Hemorrhagic Fever Infection Acquired in Animal Laboratories in China.

PubMed

Liu, Xiao Yu; Xue, Kang Ning; Rong, Rong; Zhao, Chi Hong

2016-01-01

Epidemic hemorrhagic fever has been an ongoing threat to laboratory personnel involved in animal care and use. Laboratory transmissions and severe infections occurred over the past twenty years, even though the standards and regulations for laboratory biosafety have been issued, upgraded, and implemented in China. Therefore, there is an urgent need to identify risk factors and to seek effective preventive measures that can curb the incidences of epidemic hemorrhagic fever among laboratory personnel. In the present study, we reviewed literature that relevant to animals laboratory-acquired hemorrhagic fever infections reported from 1995 to 2015, and analyzed these incidences using fault tree analysis (FTA). The results of data analysis showed that purchasing of qualified animals and guarding against wild rats which could make sure the laboratory animals without hantaviruses, are the basic measures to prevent infections. During the process of daily management, the consciousness of personal protecting and the ability of personal protecting need to be further improved. Undoubtedly vaccination is the most direct and effective method, while it plays role after infection. So avoiding infections can't rely entirely on vaccination. Copyright © 2016 The Editorial Board of Biomedical and Environmental Sciences. Published by China CDC. All rights reserved.

Laboratory-based versus non-laboratory-based method for assessment of cardiovascular disease risk: the NHANES I Follow-up Study cohort

PubMed Central

Gaziano, Thomas A; Young, Cynthia R; Fitzmaurice, Garrett; Atwood, Sidney; Gaziano, J Michael

2008-01-01

Summary Background Around 80% of all cardiovascular deaths occur in developing countries. Assessment of those patients at high risk is an important strategy for prevention. Since developing countries have limited resources for prevention strategies that require laboratory testing, we assessed if a risk prediction method that did not require any laboratory tests could be as accurate as one requiring laboratory information. Methods The National Health and Nutrition Examination Survey (NHANES) was a prospective cohort study of 14 407 US participants aged between 25–74 years at the time they were first examined (between 1971 and 1975). Our follow-up study population included participants with complete information on these surveys who did not report a history of cardiovascular disease (myocardial infarction, heart failure, stroke, angina) or cancer, yielding an analysis dataset N=6186. We compared how well either method could predict first-time fatal and non-fatal cardiovascular disease events in this cohort. For the laboratory-based model, which required blood testing, we used standard risk factors to assess risk of cardiovascular disease: age, systolic blood pressure, smoking status, total cholesterol, reported diabetes status, and current treatment for hypertension. For the non-laboratory-based model, we substituted body-mass index for cholesterol. Findings In the cohort of 6186, there were 1529 first-time cardiovascular events and 578 (38%) deaths due to cardiovascular disease over 21 years. In women, the laboratory-based model was useful for predicting events, with a c statistic of 0·829. The c statistic of the non-laboratory-based model was 0·831. In men, the results were similar (0·784 for the laboratory-based model and 0·783 for the non-laboratory-based model). Results were similar between the laboratory-based and non-laboratory-based models in both men and women when restricted to fatal events only. Interpretation A method that uses non-laboratory-based risk factors predicted cardiovascular events as accurately as one that relied on laboratory-based values. This approach could simplify risk assessment in situations where laboratory testing is inconvenient or unavailable. PMID:18342687

Transcriptome analysis in non-model species: a new method for the analysis of heterologous hybridization on microarrays

PubMed Central

2010-01-01

Background Recent developments in high-throughput methods of analyzing transcriptomic profiles are promising for many areas of biology, including ecophysiology. However, although commercial microarrays are available for most common laboratory models, transcriptome analysis in non-traditional model species still remains a challenge. Indeed, the signal resulting from heterologous hybridization is low and difficult to interpret because of the weak complementarity between probe and target sequences, especially when no microarray dedicated to a genetically close species is available. Results We show here that transcriptome analysis in a species genetically distant from laboratory models is made possible by using MAXRS, a new method of analyzing heterologous hybridization on microarrays. This method takes advantage of the design of several commercial microarrays, with different probes targeting the same transcript. To illustrate and test this method, we analyzed the transcriptome of king penguin pectoralis muscle hybridized to Affymetrix chicken microarrays, two organisms separated by an evolutionary distance of approximately 100 million years. The differential gene expression observed between different physiological situations computed by MAXRS was confirmed by real-time PCR on 10 genes out of 11 tested. Conclusions MAXRS appears to be an appropriate method for gene expression analysis under heterologous hybridization conditions. PMID:20509979

Was the Driver Drunk? An Instrumental Methods Experiment for the Determination of Blood Alcohol Content.

ERIC Educational Resources Information Center

Zabzdyr, Jennifer L.; Lillard, Sheri J.

2001-01-01

Introduces a laboratory experiment for determining blood alcohol content using a combination of instrumental analysis and forensic science. Teaches the importance of careful laboratory technique and that experiments are conducted for a reason. Includes the procedure of the experiment. (Contains 17 references.) (YDS)

Using Quenching to Detect Corrosion on Sculptural Metalwork: A Real-World Application of Fluorescence Spectroscopy

ERIC Educational Resources Information Center

Hensen, Cory; Clare, Tami Lasseter; Barbera, Jack

2018-01-01

Fluorescence spectroscopy experiments are a frequently taught as part of upper-division teaching laboratories. To expose undergraduate students to an applied fluorescence technique, a corrosion detection method, using quenching, was adapted from authentic research for an instrumental analysis laboratory. In the experiment, students acquire…

How to Engage Medical Students in Chronobiology: An Example on Autorhythmometry

ERIC Educational Resources Information Center

Rol de Lama, M. A.; Lozano, J. P.; Ortiz, V.; Sanchez-Vazquez, F. J.; Madrid, J. A.

2005-01-01

This contribution describes a new laboratory experience that improves medical students' learning of chronobiology by introducing them to basic chronobiology concepts as well as to methods and statistical analysis tools specific for circadian rhythms. We designed an autorhythmometry laboratory session where students simultaneously played the role…

Iron Analysis by Redox Titration. A General Chemistry Experiment.

ERIC Educational Resources Information Center

Kaufman, Samuel; DeVoe, Howard

1988-01-01

Describes a simplified redox method for total iron analysis suitable for execution in a three-hour laboratory period by general chemistry students. Discusses materials, procedures, analyses, and student performance. (CW)

7 CFR 98.4 - Analytical methods.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 3 2014-01-01 2014-01-01 false Analytical methods. 98.4 Section 98.4 Agriculture... Analytical methods. (a) The majority of analytical methods used by the USDA laboratories to perform analyses of meat, meat food products and MREs are listed as follows: (1) Official Methods of Analysis of AOAC...

Metrological activity determination of 133Ba by sum-peak absolute method

NASA Astrophysics Data System (ADS)

da Silva, R. L.; de Almeida, M. C. M.; Delgado, J. U.; Poledna, R.; Santos, A.; de Veras, E. V.; Rangel, J.; Trindade, O. L.

2016-07-01

The National Laboratory for Metrology of Ionizing Radiation provides gamma sources of radionuclide and standardized in activity with reduced uncertainties. Relative methods require standards to determine the sample activity while the absolute methods, as sum-peak, not. The activity is obtained directly with good accuracy and low uncertainties. 133Ba is used in research laboratories and on calibration of detectors for analysis in different work areas. Classical absolute methods don't calibrate 133Ba due to its complex decay scheme. The sum-peak method using gamma spectrometry with germanium detector standardizes 133Ba samples. Uncertainties lower than 1% to activity results were obtained.

Supervised analysis of drug prescription sequences.

PubMed

Ficheur, Grégoire; Chazard, Emmanuel; Merlin, Béatrice; Ferret, Laurie; Luyckx, Michel; Beuscart, Régis

2013-01-01

Hospitals have at their disposal large databases that may be considered for reuse. The objective of this work is to evaluate the impact of a drug on a specific laboratory result by analyzing these data. This analysis first involves building a record of temporal patterns, including medical context, of drug prescriptions. Changes in outcome due to these patterns of drug prescription are assessed using short phases of the inpatient stay compared to monotonous changes in the laboratory result. To illustrate this technique, we investigated potassium chloride supplementation and its impact on kalemia. This method enables us to assess the impact of a drug (in its frequent context of prescription) on a laboratory result. This kind of analysis could play a role in post-marketing studies.

Fluorescence microplate readers as an alternative to flow injection analysis for determination of wort beta-glucan

USDA-ARS?s Scientific Manuscript database

Wort beta-glucan concentration is a critical malting quality parameter used to identify and avoid potential brewhouse filtration problems. ASBC method Wort-18 is widely used in malt analysis laboratories and brewhouses to measure wort beta-glucan levels. However, the chemistry underlying the method...

La pronunciacion espanola y los metodos de investigacion. (Spanish Pronunciation and Methods of Investigation.)

ERIC Educational Resources Information Center

Torreblanca, Maximo

1988-01-01

Discusses the validity of studies of Spanish pronunciation in terms of research methods employed. Topics include data collection in the laboratory vs. in a natural setting; recorded vs. non-recorded data; quality of the recording; aural analysis vs. spectrographic analysis; and transcriber reliability. Suggestions for improving data collection are…

Signal Detection Techniques for Diagnostic Monitoring of Space Shuttle Main Engine Turbomachinery

NASA Technical Reports Server (NTRS)

Coffin, Thomas; Jong, Jen-Yi

1986-01-01

An investigation to develop, implement, and evaluate signal analysis techniques for the detection and classification of incipient mechanical failures in turbomachinery is reviewed. A brief description of the Space Shuttle Main Engine (SSME) test/measurement program is presented. Signal analysis techniques available to describe dynamic measurement characteristics are reviewed. Time domain and spectral methods are described, and statistical classification in terms of moments is discussed. Several of these waveform analysis techniques have been implemented on a computer and applied to dynamc signals. A laboratory evaluation of the methods with respect to signal detection capability is described. A unique coherence function (the hyper-coherence) was developed through the course of this investigation, which appears promising as a diagnostic tool. This technique and several other non-linear methods of signal analysis are presented and illustrated by application. Software for application of these techniques has been installed on the signal processing system at the NASA/MSFC Systems Dynamics Laboratory.

Enzymatic Spectrophotometric Reaction Rate Determination of Glucose in Fruit Drinks and Carbonated Beverages. An Analytical Chemistry Laboratory Experiment for Food Science-Oriented Students

NASA Astrophysics Data System (ADS)

Vasilarou, Argyro-Maria G.; Georgiou, Constantinos A.

2000-10-01

The glucose oxidase-horseradish peroxidase coupled reaction using phenol and 4-aminoantipyrine is used for the kinetic determination of glucose in drinks and beverages. This laboratory experiment demonstrates the implementation of reaction rate kinetic methods of analysis, the use of enzymes as selective analytical reagents for the determination of substrates, the kinetic masking of ascorbic acid interference, and the analysis of glucose in drinks and beverages. The method is optimized for student use in the temperature range of 18-28 °C and can be used in low-budget laboratories equipped with an inexpensive visible photometer. The mixed enzyme-chromogen solution that is used is stable for two months. Precision ranged from 5.1 to 12% RSD for analyses conducted during a period of two months by 48 students.

Clinical Laboratories – Production Factories or Specialized Diagnostic Centers

PubMed Central

Tóth, Judit

2016-01-01

Since a large proportion of medical decisions are based on laboratory results, clinical laboratories should meet the increasing demand of clinicians and their patients. Huge central laboratories may process over 10 million tests annually; they act as production factories, measuring emergency and routine tests with sufficient speed and accuracy. At the same time, they also serve as specialized diagnostic centers where well-trained experts analyze and interpret special test results. It is essential to improve and constantly monitor this complex laboratory service, by several methods. Sample transport by pneumatic tube system, use of an advanced laboratory information system and point-of-care testing may result in decreased total turnaround time. The optimization of test ordering may result in a faster and more cost-effective laboratory service. Autovalidation can save time for laboratory specialists, when the analysis of more complex results requires their attention. Small teams of experts responsible for special diagnostic work, and their interpretative reporting according to predetermined principles, may help to minimize subjectivity of these special reports. Although laboratory investigations have become so diversely developed in the past decades, it is essential that the laboratory can provide accurate results relatively quickly, and that laboratory specialists can support the diagnosis and monitoring of patients by adequate interpretation of esoteric laboratory methods. PMID:27683528

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; in-bottle acid digestion of whole-water samples

USGS Publications Warehouse

Hoffman, G.L.; Fishman, M. J.; Garbarino, J.R.

1996-01-01

Water samples for trace-metal determinations routinely have been prepared in open laboratories. For example, the U.S. Geological Survey method I-3485-85 (Extraction Procedure, for Water- Suspended Sediment) is performed in a laboratory hood on a laboratory bench without any special precautions to control airborne contamination. This method tends to be contamination prone for several trace metals primarily because the samples are transferred, acidified, digested, and filtered in an open laboratory environment. To reduce trace-metal contamination of digested water samples, procedures were established that rely on minimizing sample-transfer steps and using a class-100 clean bench during sample filtration. This new procedure involves the following steps: 1. The sample is acidified with HCl directly in the original water-sample bottle. 2. The water-sample bottle with the cap secured is heated in a laboratory oven. 3. The digestate is filtered in a class-100 laminar-flow clean bench. The exact conditions used (that is, oven temperature, time of heating, and filtration methods) for this digestion procedure are described. Comparisons between the previous U.S Geological Survey open-beaker method I-3485-85 and the new in-bottle procedure for synthetic and field-collected water samples are given. When the new procedure is used, blank concentrations for most trace metals determined are reduced significantly.

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…

Failure analysis of electronic parts: Laboratory methods. [for destructive and nondestructive testing

NASA Technical Reports Server (NTRS)

Anstead, R. J. (Editor); Goldberg, E. (Editor)

1975-01-01

Failure analysis test methods are presented for use in analyzing candidate electronic parts and in improving future design reliability. Each test is classified as nondestructive, semidestructive, or destructive. The effects upon applicable part types (i.e. integrated circuit, transitor) are discussed. Methodology is given for performing the following: immersion tests, radio graphic tests, dewpoint tests, gas ambient analysis, cross sectioning, and ultraviolet examination.

Integrated Data Collection Analysis (IDCA) Program - RDX Type II Class 5 Standard, Data Set 1

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

This document describes the results of the first reference sample material—RDX Type II Class 5—examined in the proficiency study for small-scale safety and thermal (SSST) testing of explosive materials for the Integrated Data Collection Analysis (IDCA) Program. The IDCA program is conducting proficiency testing on homemade explosives (HMEs). The reference sample materials are being studied to establish the accuracy of traditional explosives safety testing for each performing laboratory. These results will be used for comparison to results from testing HMEs. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of thesemore » materials in perspective with standard military explosives. The results of the study will add SSST testing results for a broad suite of different HMEs to the literature, potentially suggest new guidelines and methods for HME testing, and possibly establish what are the needed accuracies in SSST testing to develop safe handling practices. Described here are the results for impact, friction, electrostatic discharge, and scanning calorimetry analysis of a reference sample of RDX Type II Class 5. The results from each participating testing laboratory are compared using identical test material and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. These results are then compared to historical data from various sources. The performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Air Force Research Laboratory/ RXQL (AFRL), Indian Head Division, Naval Surface Warfare Center, (IHD-NSWC), and Sandia National Laboratories (SNL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when test protocols are not identical.« less

Percent body fat estimations in college men using field and laboratory methods: A three-compartment model approach

PubMed Central

Moon, Jordan R; Tobkin, Sarah E; Smith, Abbie E; Roberts, Michael D; Ryan, Eric D; Dalbo, Vincent J; Lockwood, Chris M; Walter, Ashley A; Cramer, Joel T; Beck, Travis W; Stout, Jeffrey R

2008-01-01

Background Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. The purpose of this study was to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age men compared to the Siri three-compartment model (3C). Methods Thirty-one Caucasian men (22.5 ± 2.7 yrs; 175.6 ± 6.3 cm; 76.4 ± 10.3 kg) had their %fat estimated by bioelectrical impedance analysis (BIA) using the BodyGram™ computer program (BIA-AK) and population-specific equation (BIA-Lohman), near-infrared interactance (NIR) (Futrex® 6100/XL), four circumference-based military equations [Marine Corps (MC), Navy and Air Force (NAF), Army (A), and Friedl], air-displacement plethysmography (BP), and hydrostatic weighing (HW). Results All circumference-based military equations (MC = 4.7% fat, NAF = 5.2% fat, A = 4.7% fat, Friedl = 4.7% fat) along with NIR (NIR = 5.1% fat) produced an unacceptable total error (TE). Both laboratory methods produced acceptable TE values (HW = 2.5% fat; BP = 2.7% fat). The BIA-AK, and BIA-Lohman field methods produced acceptable TE values (2.1% fat). A significant difference was observed for the MC and NAF equations compared to both the 3C model and HW (p < 0.006). Conclusion Results indicate that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian men. When the use of a laboratory method is not feasible, BIA-AK, and BIA-Lohman are acceptable field methods to estimate %fat in this population. PMID:18426582

Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method

PubMed Central

Shen, Yueqian; Lindenbergh, Roderik; Wang, Jinhu

2016-01-01

A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis. PMID:28029121

Change Analysis in Structural Laser Scanning Point Clouds: The Baseline Method.

PubMed

Shen, Yueqian; Lindenbergh, Roderik; Wang, Jinhu

2016-12-24

A method is introduced for detecting changes from point clouds that avoids registration. For many applications, changes are detected between two scans of the same scene obtained at different times. Traditionally, these scans are aligned to a common coordinate system having the disadvantage that this registration step introduces additional errors. In addition, registration requires stable targets or features. To avoid these issues, we propose a change detection method based on so-called baselines. Baselines connect feature points within one scan. To analyze changes, baselines connecting corresponding points in two scans are compared. As feature points either targets or virtual points corresponding to some reconstructable feature in the scene are used. The new method is implemented on two scans sampling a masonry laboratory building before and after seismic testing, that resulted in damages in the order of several centimeters. The centres of the bricks of the laboratory building are automatically extracted to serve as virtual points. Baselines connecting virtual points and/or target points are extracted and compared with respect to a suitable structural coordinate system. Changes detected from the baseline analysis are compared to a traditional cloud to cloud change analysis demonstrating the potential of the new method for structural analysis.

Combined target factor analysis and Bayesian soft-classification of interference-contaminated samples: forensic fire debris analysis.

PubMed

Williams, Mary R; Sigman, Michael E; Lewis, Jennifer; Pitan, Kelly McHugh

2012-10-10

A bayesian soft classification method combined with target factor analysis (TFA) is described and tested for the analysis of fire debris data. The method relies on analysis of the average mass spectrum across the chromatographic profile (i.e., the total ion spectrum, TIS) from multiple samples taken from a single fire scene. A library of TIS from reference ignitable liquids with assigned ASTM classification is used as the target factors in TFA. The class-conditional distributions of correlations between the target and predicted factors for each ASTM class are represented by kernel functions and analyzed by bayesian decision theory. The soft classification approach assists in assessing the probability that ignitable liquid residue from a specific ASTM E1618 class, is present in a set of samples from a single fire scene, even in the presence of unspecified background contributions from pyrolysis products. The method is demonstrated with sample data sets and then tested on laboratory-scale burn data and large-scale field test burns. The overall performance achieved in laboratory and field test of the method is approximately 80% correct classification of fire debris samples. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

NASA Astrophysics Data System (ADS)

Yttri, K. E.; Schnelle-Kreiss, J.; Maenhaut, W.; Alves, C.; Bossi, R.; Bjerke, A.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Gülcin, A.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

2014-07-01

The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wild fire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for biomass burning particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied High-Performance Anion-Exchange Chromatography (HPAEC), four used High-Performance Liquid Chromatography (HPLC) or Ultra-Performance Liquid Chromatography (UPLC), and six resorted to Gas Chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 23%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e., for 33% of the laboratories the mean PE was within ±10%. For galactosan, the mean PE for the participating laboratories ranged from -84 to 593%, and as for mannosan 33% of the laboratories reported a mean PE within ±10%. The variability of the various analytical methods, as defined by their minimum and maximum PE value, was typically better for levoglucosan than for mannosan and galactosan, ranging from 3.2 to 41% for levoglucosan, from 10 to 67% for mannosan, and from 6 to 364% for galactosan. For the levoglucosan to mannosan ratio, which may be used to assess the relative importance of softwood vs. hardwood burning, the variability only ranged from 3.5 to 24%. To our knowledge, this is the first major intercomparison on analytical methods used to quantify monosaccharide anhydrides in ambient aerosol filter samples conducted and reported in the scientific literature. The results show that for levoglucosan the accuracy is only slightly lower than that reported for analysis of SO42- on filter samples, a constituent that has been analyzed by numerous laboratories for several decades, typically by ion chromatography, and which is considered a fairly easy constituent to measure. Hence, the results obtained for levoglucosan with respect to accuracy are encouraging and suggest that levels of levoglucosan, and to a lesser extent mannosan and galactosan, obtained by most of the analytical methods currently used to quantify monosaccharide anhydrides in ambient aerosol filter samples, are comparable. Finally, the various analytical methods used in the current study should be tested for other aerosol matrices and concentrations as well, the most obvious being summertime aerosol samples affected by wild fires and/or agricultural fires.

An intercomparison study of analytical methods used for quantification of levoglucosan in ambient aerosol filter samples

NASA Astrophysics Data System (ADS)

Yttri, K. E.; Schnelle-Kreis, J.; Maenhaut, W.; Abbaszade, G.; Alves, C.; Bjerke, A.; Bonnier, N.; Bossi, R.; Claeys, M.; Dye, C.; Evtyugina, M.; García-Gacio, D.; Hillamo, R.; Hoffer, A.; Hyder, M.; Iinuma, Y.; Jaffrezo, J.-L.; Kasper-Giebl, A.; Kiss, G.; López-Mahia, P. L.; Pio, C.; Piot, C.; Ramirez-Santa-Cruz, C.; Sciare, J.; Teinilä, K.; Vermeylen, R.; Vicente, A.; Zimmermann, R.

2015-01-01

The monosaccharide anhydrides (MAs) levoglucosan, galactosan and mannosan are products of incomplete combustion and pyrolysis of cellulose and hemicelluloses, and are found to be major constituents of biomass burning (BB) aerosol particles. Hence, ambient aerosol particle concentrations of levoglucosan are commonly used to study the influence of residential wood burning, agricultural waste burning and wildfire emissions on ambient air quality. A European-wide intercomparison on the analysis of the three monosaccharide anhydrides was conducted based on ambient aerosol quartz fiber filter samples collected at a Norwegian urban background site during winter. Thus, the samples' content of MAs is representative for BB particles originating from residential wood burning. The purpose of the intercomparison was to examine the comparability of the great diversity of analytical methods used for analysis of levoglucosan, mannosan and galactosan in ambient aerosol filter samples. Thirteen laboratories participated, of which three applied high-performance anion-exchange chromatography (HPAEC), four used high-performance liquid chromatography (HPLC) or ultra-performance liquid chromatography (UPLC) and six resorted to gas chromatography (GC). The analytical methods used were of such diversity that they should be considered as thirteen different analytical methods. All of the thirteen laboratories reported levels of levoglucosan, whereas nine reported data for mannosan and/or galactosan. Eight of the thirteen laboratories reported levels for all three isomers. The accuracy for levoglucosan, presented as the mean percentage error (PE) for each participating laboratory, varied from -63 to 20%; however, for 62% of the laboratories the mean PE was within ±10%, and for 85% the mean PE was within ±20%. For mannosan, the corresponding range was -60 to 69%, but as for levoglucosan, the range was substantially smaller for a subselection of the laboratories; i.e. for 33% of the laboratories the mean PE was within ±10%. For galactosan, the mean PE for the participating laboratories ranged from -84 to 593%, and as for mannosan 33% of the laboratories reported a mean PE within ±10%. The variability of the various analytical methods, as defined by their minimum and maximum PE value, was typically better for levoglucosan than for mannosan and galactosan, ranging from 3.2 to 41% for levoglucosan, from 10 to 67% for mannosan and from 6 to 364% for galactosan. For the levoglucosan to mannosan ratio, which may be used to assess the relative importance of softwood versus hardwood burning, the variability only ranged from 3.5 to 24 . To our knowledge, this is the first major intercomparison on analytical methods used to quantify monosaccharide anhydrides in ambient aerosol filter samples conducted and reported in the scientific literature. The results show that for levoglucosan the accuracy is only slightly lower than that reported for analysis of SO42- (sulfate) on filter samples, a constituent that has been analysed by numerous laboratories for several decades, typically by ion chromatography and which is considered a fairly easy constituent to measure. Hence, the results obtained for levoglucosan with respect to accuracy are encouraging and suggest that levels of levoglucosan, and to a lesser extent mannosan and galactosan, obtained by most of the analytical methods currently used to quantify monosaccharide anhydrides in ambient aerosol filter samples, are comparable. Finally, the various analytical methods used in the current study should be tested for other aerosol matrices and concentrations as well, the most obvious being summertime aerosol samples affected by wildfires and/or agricultural fires.

Quantitative Analysis by Isotopic Dilution Using Mass Spectroscopy: The Determination of Caffeine by GC-MS.

ERIC Educational Resources Information Center

Hill, Devon W.; And Others

1988-01-01

Describes a laboratory technique for quantitative analysis of caffeine by an isotopic dilution method for coupled gas chromatography-mass spectroscopy. Discusses caffeine analysis and experimental methodology. Lists sample caffeine concentrations found in common products. (MVL)

Inter-laboratory comparison of multi-locus variable-number tandem repeat analysis (MLVA) for verocytotoxin-producing Escherichia coli O157 to facilitate data sharing.

PubMed

Holmes, A; Perry, N; Willshaw, G; Hanson, M; Allison, L

2015-01-01

Multi-locus variable number tandem repeat analysis (MLVA) is used in clinical and reference laboratories for subtyping verocytotoxin-producing Escherichia coli O157 (VTEC O157). However, as yet there is no common allelic or profile nomenclature to enable laboratories to easily compare data. In this study, we carried out an inter-laboratory comparison of an eight-loci MLVA scheme using a set of 67 isolates of VTEC O157. We found all but two isolates were identical in profile in the two laboratories, and repeat units were homogeneous in size but some were incomplete. A subset of the isolates (n = 17) were sequenced to determine the actual copy number of representative alleles, thereby enabling alleles to be named according to international consensus guidelines. This work has enabled us to realize the potential of MLVA as a portable, highly discriminatory and convenient subtyping method.

40 CFR 136.6 - Method modifications and analytical requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS § 136.6 Method... person or laboratory using a test procedure (analytical method) in this part. (2) Chemistry of the method means the reagents and reactions used in a test procedure that allow determination of the analyte(s) of...

40 CFR 136.6 - Method modifications and analytical requirements.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS § 136.6 Method... person or laboratory using a test procedure (analytical method) in this Part. (2) Chemistry of the method means the reagents and reactions used in a test procedure that allow determination of the analyte(s) of...

40 CFR 136.6 - Method modifications and analytical requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS § 136.6 Method... person or laboratory using a test procedure (analytical method) in this part. (2) Chemistry of the method means the reagents and reactions used in a test procedure that allow determination of the analyte(s) of...

40 CFR 136.6 - Method modifications and analytical requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... PROGRAMS (CONTINUED) GUIDELINES ESTABLISHING TEST PROCEDURES FOR THE ANALYSIS OF POLLUTANTS § 136.6 Method... person or laboratory using a test procedure (analytical method) in this part. (2) Chemistry of the method means the reagents and reactions used in a test procedure that allow determination of the analyte(s) of...

Results of the International Energy Agency Round Robin on Fast Pyrolysis Bio-oil Production

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

Elliott, Douglas C.; Meier, Dietrich; Oasmaa, Anja

An international round robin study of the production of fast pyrolysis bio-oil was undertaken. Fifteen institutions in six countries contributed. Three biomass samples were distributed to the laboratories for processing in fast pyrolysis reactors. Samples of the bio-oil produced were transported to a central analytical laboratory for analysis. The round robin was focused on validating the pyrolysis community understanding of production of fast pyrolysis bio-oil by providing a common feedstock for bio-oil preparation. The round robin included: •distribution of 3 feedstock samples from a common source to each participating laboratory; •preparation of fast pyrolysis bio-oil in each laboratory with themore » 3 feedstocks provided; •return of the 3 bio-oil products (minimum 500 ml) with operational description to a central analytical laboratory for bio-oil property determination. The analyses of interest were: density, viscosity, dissolved water, filterable solids, CHN, S, trace element analysis, ash, total acid number, pyrolytic lignin, and accelerated aging of bio-oil. In addition, an effort was made to compare the bio-oil components to the products of analytical pyrolysis through GC/MS analysis. The results showed that clear differences can occur in fast pyrolysis bio-oil properties by applying different reactor technologies or configurations. The comparison to analytical pyrolysis method suggested that Py-GC/MS could serve as a rapid screening method for bio-oil composition when produced in fluid-bed reactors. Furthermore, hot vapor filtration generally resulted in the most favorable bio-oil product, with respect to water, solids, viscosity, and total acid number. These results can be helpful in understanding the variation in bio-oil production methods and their effects on bio-oil product composition.« less

A Network Steganography Lab on Detecting TCP/IP Covert Channels

ERIC Educational Resources Information Center

Zseby, Tanja; Vázquez, Félix Iglesias; Bernhardt, Valentin; Frkat, Davor; Annessi, Robert

2016-01-01

This paper presents a network security laboratory to teach data analysis for detecting TCP/IP covert channels. The laboratory is mainly designed for students of electrical engineering, but is open to students of other technical disciplines with similar background. Covert channels provide a method for leaking data from protected systems, which is a…

A Laboratory Exercise for Compatibility Testing of Hazardous Wastes in an Environmental Analysis Course.

ERIC Educational Resources Information Center

Chang, J. C.; And Others

1986-01-01

Discusses a new program at the University of Michigan in hazardous waste management. Describes a laboratory demonstration that deals with the reactivity and potential violence of several reactions that may be encountered on a hazardous waste site. Provides criteria for selecting particular compatibility testing methods. (TW)

A Laboratory Exercise to Determine Human ABO Blood Type by Noninvasive Methods

ERIC Educational Resources Information Center

Martin, Michael P.; Detzel, Stephen M.

2008-01-01

Analysis of single-nucleotide polymorphisms and their association with diseases and nondisease phenotypes is of growing importance in human biology studies. In this laboratory exercise, students determine the genetic basis for their ABO blood type; however, no blood is drawn. Students isolate genomic DNA from buccal mucosa cells that are present…

[Urinalysis in Italy in 2006].

PubMed

Gai, M; Lanfranco, G

2007-01-01

Urinalysis and proteinuria testing represent fundamental tests for the clinician, even though they too often lack standardization. Through the Italian Society of Nephrology Mailing List we sent a questionnaire to 282 centers, in order to assess the state of the art in Italy in the year 2006. 82% of the questionnaires were completed (nephrology laboratories: 64%, general laboratories: 36%). The questionnaire dealt with the main steps of preparation, analysis and report of urinalysis, and proteinuria / microalbuminuria measurement. 85% of the centers use first morning urine, and 7% second morning urine; only 57% of the centers supply with written instructions, 189 laboratories (82%) have only one bright field microscope, rate and time of centrifugation are very varied among centers, different units of measurement are used in reports. Few laboratories measure routinely the proteinuria / creatininuria ratio, there is no agreement on the urine sample type for microalbuminuria assay, total urinary proteins are measured through different methods. 92% of the centers is endowed with an internal quality control system, but only 47% participate in an external quality control program. These data confirm the lack of standardization for urine analysis methods and procedures.

An improved method for field extraction and laboratory analysis of large, intact soil cores

USGS Publications Warehouse

Tindall, J.A.; Hemmen, K.; Dowd, J.F.

1992-01-01

Various methods have been proposed for the extraction of large, undisturbed soil cores and for subsequent analysis of fluid movement within the cores. The major problems associated with these methods are expense, cumbersome field extraction, and inadequate simulation of unsaturated flow conditions. A field and laboratory procedure is presented that is economical, convenient, and simulates unsaturated and saturated flow without interface flow problems and can be used on a variety of soil types. In the field, a stainless steel core barrel is hydraulically pressed into the soil (30-cm diam. and 38 cm high), the barrel and core are extracted from the soil, and after the barrel is removed from the core, the core is then wrapped securely with flexible sheet metal and a stainless mesh screen is attached to the bottom of the core for support. In the laboratory the soil core is set atop a porous ceramic plate over which a soil-diatomaceous earth slurry has been poured to assure good contact between plate and core. A cardboard cylinder (mold) is fastened around the core and the empty space filled with paraffin wax. Soil cores were tested under saturated and unsaturated conditions using a hanging water column for potentials ???0. Breakthrough curves indicated that no interface flow occurred along the edge of the core. This procedure proved to be reliable for field extraction of large, intact soil cores and for laboratory analysis of solute transport.

Automated Classification and Analysis of Non-metallic Inclusion Data Sets

NASA Astrophysics Data System (ADS)

Abdulsalam, Mohammad; Zhang, Tongsheng; Tan, Jia; Webler, Bryan A.

2018-05-01

The aim of this study is to utilize principal component analysis (PCA), clustering methods, and correlation analysis to condense and examine large, multivariate data sets produced from automated analysis of non-metallic inclusions. Non-metallic inclusions play a major role in defining the properties of steel and their examination has been greatly aided by automated analysis in scanning electron microscopes equipped with energy dispersive X-ray spectroscopy. The methods were applied to analyze inclusions on two sets of samples: two laboratory-scale samples and four industrial samples from a near-finished 4140 alloy steel components with varying machinability. The laboratory samples had well-defined inclusions chemistries, composed of MgO-Al2O3-CaO, spinel (MgO-Al2O3), and calcium aluminate inclusions. The industrial samples contained MnS inclusions as well as (Ca,Mn)S + calcium aluminate oxide inclusions. PCA could be used to reduce inclusion chemistry variables to a 2D plot, which revealed inclusion chemistry groupings in the samples. Clustering methods were used to automatically classify inclusion chemistry measurements into groups, i.e., no user-defined rules were required.

The Master level optics laboratory at the Institute of Optics

NASA Astrophysics Data System (ADS)

Adamson, Per

2017-08-01

The master level optics laboratory is a biannual, intensive laboratory course in the fields of geometrical, physical and modern optics. This course is intended for the master level student though Ph.D. advisors which often recommend it to their advisees. The students are required to complete five standard laboratory experiments and an independent project during a semester. The goals of the laboratory experiments are for the students to get hands-on experience setting up optical laboratory equipment, collecting and analyzing data, as well as to communicate key results. The experimental methods, analysis, and results of the standard experiments are submitted in a journal style report, while an oral presentation is given for the independent project.

Percent body fat estimations in college men using field and laboratory methods: a three-compartment model approach.

PubMed

Moon, Jordan R; Tobkin, Sarah E; Smith, Abbie E; Roberts, Michael D; Ryan, Eric D; Dalbo, Vincent J; Lockwood, Chris M; Walter, Ashley A; Cramer, Joel T; Beck, Travis W; Stout, Jeffrey R

2008-04-21

Methods used to estimate percent body fat can be classified as a laboratory or field technique. However, the validity of these methods compared to multiple-compartment models has not been fully established. The purpose of this study was to determine the validity of field and laboratory methods for estimating percent fat (%fat) in healthy college-age men compared to the Siri three-compartment model (3C). Thirty-one Caucasian men (22.5 +/- 2.7 yrs; 175.6 +/- 6.3 cm; 76.4 +/- 10.3 kg) had their %fat estimated by bioelectrical impedance analysis (BIA) using the BodyGram computer program (BIA-AK) and population-specific equation (BIA-Lohman), near-infrared interactance (NIR) (Futrex(R) 6100/XL), four circumference-based military equations [Marine Corps (MC), Navy and Air Force (NAF), Army (A), and Friedl], air-displacement plethysmography (BP), and hydrostatic weighing (HW). All circumference-based military equations (MC = 4.7% fat, NAF = 5.2% fat, A = 4.7% fat, Friedl = 4.7% fat) along with NIR (NIR = 5.1% fat) produced an unacceptable total error (TE). Both laboratory methods produced acceptable TE values (HW = 2.5% fat; BP = 2.7% fat). The BIA-AK, and BIA-Lohman field methods produced acceptable TE values (2.1% fat). A significant difference was observed for the MC and NAF equations compared to both the 3C model and HW (p < 0.006). Results indicate that the BP and HW are valid laboratory methods when compared to the 3C model to estimate %fat in college-age Caucasian men. When the use of a laboratory method is not feasible, BIA-AK, and BIA-Lohman are acceptable field methods to estimate %fat in this population.

Applications of mid-infrared spectroscopy in the clinical laboratory setting.

PubMed

De Bruyne, Sander; Speeckaert, Marijn M; Delanghe, Joris R

2018-01-01

Fourier transform mid-infrared (MIR-FTIR) spectroscopy is a nondestructive, label-free, highly sensitive and specific technique that provides complete information on the chemical composition of biological samples. The technique both can offer fundamental structural information and serve as a quantitative analysis tool. Therefore, it has many potential applications in different fields of clinical laboratory science. Although considerable technological progress has been made to promote biomedical applications of this powerful analytical technique, most clinical laboratory analyses are based on spectroscopic measurements in the visible or ultraviolet (UV) spectrum and the potential role of FTIR spectroscopy still remains unexplored. In this review, we present some general principles of FTIR spectroscopy as a useful method to study molecules in specimens by MIR radiation together with a short overview of methods to interpret spectral data. We aim at illustrating the wide range of potential applications of the proposed technique in the clinical laboratory setting with a focus on its advantages and limitations and discussing the future directions. The reviewed applications of MIR spectroscopy include (1) quantification of clinical parameters in body fluids, (2) diagnosis and monitoring of cancer and other diseases by analysis of body fluids, cells, and tissues, (3) classification of clinically relevant microorganisms, and (4) analysis of kidney stones, nails, and faecal fat.

Large space antenna communications systems: Integrated Langley Research Center/Jet Propulsion Laboratory technology development activities. 1: Introduction

NASA Technical Reports Server (NTRS)

Campbell, T. G.

1983-01-01

The Jet Propulsion Laboratory and the Langley Research Center have been developing technology related to large space antennas (LSA) during the past several years. The need for a communication system research program became apparent during the recent studies for the Land Mobile Satellite System. This study indicated the need for additional research in (1) electromagnetic analysis methods, (2) design and development of multiple beam feed systems, and (3) the measurement methods for LSA reflectors.

Analysis of 85Kr: a comparison at the 10-14 level using micro-liter samples

PubMed Central

Yang, G. -M.; Cheng, C. -F.; Jiang, W.; Lu, Z. -T.; Purtschert, R.; Sun, Y. -R.; Tu, L. -Y.; Hu, S. -M.

2013-01-01

The isotopic abundance of 85Kr in the atmosphere, currently at the level of 10−11, has increased by orders of magnitude since the dawn of nuclear age. With a half-life of 10.76 years, 85Kr is of great interest as tracers for environmental samples such as air, groundwater and ice. Atom Trap Trace Analysis (ATTA) is an emerging method for the analysis of rare krypton isotopes at isotopic abundance levels as low as 10−14 using krypton gas samples of a few micro-liters. Both the reliability and reproducibility of the method are examined in the present study by an inter-comparison among different instruments. The 85Kr/Kr ratios of 12 samples, in the range of 10−13 to 10−10, are measured independently in three laboratories: a low-level counting laboratory in Bern, Switzerland, and two ATTA laboratories, one in Hefei, China, and another in Argonne, USA. The results are in agreement at the precision level of 5%. PMID:23549244

Interlaboratory comparability of serum cotinine measurements at smoker and nonsmoker concentration levels: A round-robin study

PubMed Central

Jacob, Peyton; Holiday, David B.; Benowitz, Neal L.; Sosnoff, Connie S.; Doig, Mira V.; Feyerabend, Colin; Aldous, Kenneth M.; Sharifi, Mehran; Kellogg, Mark D.; Langman, Loralie J.

2009-01-01

Introduction: Cotinine, the primary proximate metabolite of nicotine, is commonly measured as an index of exposure to tobacco in both active users of tobacco and nonsmokers with possible exposure to secondhand smoke (SHS). A number of laboratories have implemented analyses for measuring serum cotinine in recent years, but there have been few interlaboratory comparisons of the results. Among nonsmokers exposed to SHS, the concentration of cotinine in blood can be quite low, and extensive variability in these measurements has been reported in the past. Methods: In this study, a group of seven laboratories, all experienced in serum cotinine analysis, measured eight coded serum pools with concentrations ranging from background levels of about 0.05 ng/ml to relatively high concentrations in the active smokers range. All laboratories used either gas–liquid chromatography with nitrogen–phosphorus detection or liquid chromatography with mass spectrometric detection. Results: All seven laboratories reliably measured the cotinine concentrations in samples that were within the range of their methods. In each case, the results for the pools were correctly ranked in order, and no significant interlaboratory bias was observed at the 5% level of significance for results from any of the pools. Discussion: We conclude that present methods of chromatographic analysis of serum cotinine, as used by these experienced laboratories, are capable of providing accurate and precise results in both the smoker and the nonsmoker concentration range. PMID:19933777

Annual Report on the Activities and Publications of the DHS-DNDO-NTNFC Sponsored Post-doctoral Fellow at Los Alamos National Laboratory

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

Rim, Jung Ho; Tandon, Lav

This report is a summary of the projects Jung Rim is working on as a DHS postdoctoral fellow at Los Alamos National Laboratory. These research projects are designed to explore different radioanalytical methods to support nuclear forensics applications. The current projects discussed here include development of alpha spectroscopy method for 240/239Pu Isotopic ratio measurement, non-destructive uranium assay method using gamma spectroscopy, and 236U non-destructive uranium analysis using FRAM code. This report documents the work that has been performed since the start of the postdoctoral appointment.

Iodine in food- and dietary supplement–composition databases123

PubMed Central

Pehrsson, Pamela R; Patterson, Kristine Y; Spungen, Judith H; Wirtz, Mark S; Andrews, Karen W; Dwyer, Johanna T; Swanson, Christine A

2016-01-01

The US Food and Drug Administration (FDA) and the Nutrient Data Laboratory (NDL) of the USDA Agricultural Research Service have worked independently on determining the iodine content of foods and dietary supplements and are now harmonizing their efforts. The objective of the current article is to describe the harmonization plan and the results of initial iodine analyses accomplished under that plan. For many years, the FDA’s Total Diet Study (TDS) has measured iodine concentrations in selected foods collected in 4 regions of the country each year. For more than a decade, the NDL has collected and analyzed foods as part of the National Food and Nutrient Analysis Program; iodine analysis is now being added to the program. The NDL recently qualified a commercial laboratory to conduct iodine analysis of foods by an inductively coupled plasma mass spectrometry (ICP-MS) method. Co-analysis of a set of samples by the commercial laboratory using the ICP-MS method and by the FDA laboratory using its standard colorimetric method yielded comparable results. The FDA recently reviewed historical TDS data for trends in the iodine content of selected foods, and the NDL analyzed samples of a limited subset of those foods for iodine. The FDA and the NDL are working to combine their data on iodine in foods and to produce an online database that can be used for estimating iodine intake from foods in the US population. In addition, the NDL continues to analyze dietary supplements for iodine and, in collaboration with the NIH Office of Dietary Supplements, to publish the data online in the Dietary Supplement Ingredient Database. The goal is to provide, through these 2 harmonized databases and the continuing TDS focus on iodine, improved tools for estimating iodine intake in population studies. PMID:27534627

Analytical methods for characterization of explosives-contaminated sites on U.S. Army installations

NASA Astrophysics Data System (ADS)

Jenkins, Thomas F.; Walsh, Marianne E.; Thorne, Philip G.

1995-10-01

The U.S. Army manufactures munitions at facilities throughout the United States. Many of these facilities are contaminated with residues of explosives from production, disposal of off- specification, and out-of-data munitions. The first step in remediating these sites is careful characterization. Currently sites are being characterized using a combination of on-site field screening and off-site laboratory analysis. Most of the contamination is associated with TNT (2,4,6-trinitrotoluene) and RDX (hexahydro-1,3,5-tri-nitro-1,3,5-triazine) and their manufacturing impurities and environmental transformation products. Both colorimetric and enzyme immunoassay-based field screening methods have been used successfully for on-site characterization. These methods have similar detection capabilities but differ in their selectivity. Although field screening is very cost-effective, laboratory analysis is still required to fully characterize a site. Laboratory analysis for explosives residues in the United States is generally conducted using high-performance liquid chromatography equipped with a UV detector. Air-dried soils are extracted with acetonitrile in an ultrasonic bath. Water is analyzed directly if detection limits in the range of 10 - 20 (mu) g/L are acceptable, or preconcentrated using either salting-out solvent extraction with acetonitrile or solid phase extraction.

Prussian Blue Coated Electrode as a Sensor for Electroinactive Cations in Aqueous Solutions

ERIC Educational Resources Information Center

Byrd, Houston; Chapman, Blake E.; Talley, Christopher L.

2013-01-01

Prussian Blue (PB) is an excellent material as a sensor for electroinactive cations because of its electrochemical behavior and its zeolytic character. A simple 3-h laboratory designed for a quantitative analysis or an instrumental methods course is reported. This laboratory studies the transport of various cations into a PB-modified electrode…

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of inorganic and organic constituents in water and fluvial sediments

USGS Publications Warehouse

Fishman, M. J.

1993-01-01

Methods to be used to analyze samples of water, suspended sediment and bottom material for their content of inorganic and organic constituents are presented. Technology continually changes, and so this laboratory manual includes new and revised methods for determining the concentration of dissolved constituents in water, whole water recoverable constituents in water-suspended sediment samples, and recoverable concentration of constit- uents in bottom material. For each method, the general topics covered are the application, the principle of the method, interferences, the apparatus and reagents required, a detailed description of the analytical procedure, reporting results, units and significant figures, and analytical precision data. Included in this manual are 30 methods.

RAPID ON-SITE METHODS OF CHEMICAL ANALYSIS

EPA Science Inventory

The analysis of potentially hazardous air, water and soil samples collected and shipped to service laboratories off-site is time consuming and expensive. This Chapter addresses the practical alternative of performing the requisite analytical services on-site. The most significant...

Laboratory Detection and Analysis of Organic Compounds in Rocks Using HPLC and XRD Methods

NASA Technical Reports Server (NTRS)

Dragoi, D.; Kanik, I.; Bar-Cohen, Y.; Sherrit, S.; Tsapin, A.; Kulleck, J.

2004-01-01

In this work we describe an analytical method for determining the presence of organic compounds in rocks, limestone, and other composite materials. Our preliminary laboratory experiments on different rocks/limestone show that the organic component in mineralogical matrices is a minor phase on order of hundreds of ppm and can be better detected using high precision liquid chromatography (HPLC). The matrix, which is the major phase, plays an important role in embedding and protecting the organic molecules from the harsh Martian environment. Some rocks bear significant amounts of amino acids therefore, it is possible to identify these phases using powder x-ray diffraction (XRD) by crystallizing the organic. The method of detection/analysis of organics, in particular amino acids, that have been associated with life will be shown in the next section.

Evaluation of Brazilian Sugarcane Bagasse Characterization: An Interlaboratory Comparison Study

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

Sluiter, Justin B.; Chum, Helena; Gomes, Absai C.

2016-05-01

This paper describes a study of the variability of measured composition for a single bulk sugarcane bagasse conducted across eight laboratories using similar analytical methods, with the purpose of determining the expected variation for compositional analysis performed by different laboratories. The results show good agreement of measured composition within a single laboratory, but greater variability when results are compared among laboratories. These interlaboratory variabilities do not seem to be associated with a specific method or technique or any single piece of instrumentation. The summary censored statistics provide mean values and pooled standard deviations as follows: total extractives 6.7% (0.6%), wholemore » ash 1.5% (0.2%), glucan 42.3% (1.2%), xylan 22.3% (0.5%), total lignin 21.3% (0.4%), and total mass closure 99.4% (2.9%).« less

Utilization of Multimedia Laboratory: An Acceptance Analysis using TAM

NASA Astrophysics Data System (ADS)

Modeong, M.; Palilingan, V. R.

2018-02-01

Multimedia is often utilized by teachers to present a learning materials. Learning that delivered by multimedia enables people to understand the information of up to 60% of the learning in general. To applying the creative learning to the classroom, multimedia presentation needs a laboratory as a space that provides multimedia needs. This study aims to reveal the level of student acceptance on the multimedia laboratories, by explaining the direct and indirect effect of internal support and technology infrastructure. Technology Acceptance Model (TAM) is used as the basis of measurement on this research, through the perception of usefulness, ease of use, and the intention, it’s recognized capable of predicting user acceptance about technology. This study used the quantitative method. The data analysis using path analysis that focuses on trimming models, it’s performed to improve the model of path analysis structure by removing exogenous variables that have insignificant path coefficients. The result stated that Internal Support and Technology Infrastructure are well mediated by TAM variables to measure the level of technology acceptance. The implications suggest that TAM can measure the success of multimedia laboratory utilization in Faculty of Engineering UNIMA.

Chiral Analysis by Tandem Mass Spectrometry Using the Kinetic Method, by Polarimetry, and by [Superscript 1]H NMR Spectroscopy

ERIC Educational Resources Information Center

Fedick, Patrick W.; Bain, Ryan M.; Bain, Kinsey; Cooks, R. Graham

2017-01-01

The goal of this laboratory exercise was for students to understand the concept of chirality and how enantiomeric excess (ee) is experimentally determined using the analysis of ibuprofen as an example. Students determined the enantiomeric excess of the analyte by three different instrumental methods: mass spectrometry, nuclear magnetic resonance…

NHEXAS PHASE I ARIZONA STUDY--STANDARD OPERATING PROCEDURE--COMPENDIUM OF METHODS FOR ANALYSIS OF TRACE METALS AND PESTICIDES IN DIETARY SAMPLES USING TOTAL DIET STUDY PROCEDURES (FDA-COMPENDIUM)

EPA Science Inventory

This compendium contains seven SOPs developed by Food and Drug Administration (FDA) laboratories for methods of analyzing trace metals in dietary samples collected using Total Diet study procedures. The SOPs include the following: (1) Quality Control for Analysis of NHEXAS Food o...

Proficiency program for real-time PCR diagnosis of Bordetella pertussis infections in French hospital laboratories and at the French National Reference Center for Whooping Cough and other Bordetelloses.

PubMed

Caro, Valérie; Guiso, Nicole; Alberti, Corinne; Liguori, Sandrine; Burucoa, Christophe; Couetdic, Gérard; Doucet-Populaire, Florence; Ferroni, Agnès; Papin-Gibaud, Sophie; Grattard, Florence; Réglier-Poupet, Hélène; Raymond, Josette; Soler, Catherine; Bouchet, Sylvie; Charreau, Sandrine; Couzon, Brigitte; Leymarie, Isabelle; Tavares, Nicole; Choux, Mathilde; Bingen, Edouard; Bonacorsi, Stéphane

2009-10-01

With the support of a ministerial program for innovative and expensive technologies, dedicated to the economic evaluation of laboratory diagnosis of pertussis by real-time PCR, external quality assessment for real-time IS481 PCR was carried out. Coordinated by the National Centre of Reference of Pertussis and other Bordetelloses (NCR), this study aimed to harmonize and to assess the performances of eight participating microbiology hospital laboratories throughout the French territory. Between January 2006 and February 2007, 10 proficiency panels were sent by the NCR (ascending proficiency program), representing a total of 49 samples and including eight panels to analyze and evaluate the global sensitivity and specificity of real-time PCR, one to assess the limit of detection, and one to evaluate nucleic acid extraction methods. As part of the descending proficiency program, extracted DNA from clinical samples was sent by the eight participating laboratories in different panels and analyzed by the NCR. In the ascending proficiency analysis, the sensitivity and specificity of the real-time PCR methods were 92.2% and 94.3%, respectively. The limit of detection of the different methods ranged between 0.1 and 1 fg/microl (0.2 to 2 CFU/microl). The nucleic acid extraction methods showed similar performances. During the descending proficiency analysis, performed with 126 samples, the result of the NCR for 15 samples (11.9%) was discordant with the result obtained by the source laboratory. Despite several initial differences, harmonization was easy and performances were homogeneous. However, the risk of false-positive results remains quite high, and we strongly recommend establishment of uniform quality control procedures performed regularly.

[Development of molecular detection of food-borne pathogenic bacteria using miniaturized microfluidic devices].

PubMed

Iván, Kristóf; Maráz, Anna

2015-12-20

Detection and identification of food-borne pathogenic bacteria are key points for the assurance of microbiological food safety. Traditional culture-based methods are more and more replaced by or supplemented with nucleic acid based molecular techniques, targeting specific (preferably virulence) genes in the genomes. Internationally validated DNA amplification - most frequently real-time polymerase chain reaction - methods are applied by the food microbiological testing laboratories for routine analysis, which will result not only in shortening the time for results but they also improve the performance characteristics (e.g. sensitivity, specificity) of the methods. Beside numerous advantages of the polymerase chain reaction based techniques for routine microbiological analysis certain drawbacks have to be mentioned, such as the high cost of the equipment and reagents, as well as the risk of contamination of the laboratory environment by the polymerase chain reaction amplicons, which require construction of an isolated laboratory system. Lab-on-a-chip systems can integrate most of these laboratory processes within a miniaturized device that delivers the same specificity and reliability as the standard protocols. The benefits of miniaturized devices are: simple - often automated - use, small overall size, portability, sterility due to single use possibility. These miniaturized rapid diagnostic tests are being researched and developed at the best research centers around the globe implementing various sample preparation and molecular DNA amplification methods on-chip. In parallel, the aim of the authors' research is to develop microfluidic Lab-on-a-chip devices for the detection and identification of food-borne pathogenic bacteria.

Full-scale fatigue tests of CX-100 wind turbine blades. Part II: analysis

NASA Astrophysics Data System (ADS)

Taylor, Stuart G.; Jeong, Hyomi; Jang, Jae Kyeong; Park, Gyuhae; Farinholt, Kevin M.; Todd, Michael D.; Ammerman, Curtt M.

2012-04-01

This paper presents the initial analysis results of several structural health monitoring (SHM) methods applied to two 9- meter CX-100 wind turbine blades subjected to fatigue loading at the National Renewable Energy Laboratory's (NREL) National Wind Technology Center (NWTC). The first blade was a pristine blade, manufactured to standard CX-100 design specifications. The second blade was manufactured for the University of Massachusetts, Lowell (UMass), with intentional simulated defects within the fabric layup. Each blade was instrumented with a variety of sensors on its surface. The blades were subject to harmonic excitation at their first natural frequency with steadily increasing loading until ultimately reaching failure. Data from the sensors were collected between and during fatigue loading sessions. The data were measured at multi-scale frequency ranges using a variety of data acquisition equipment, including off-the-shelf systems and prototype data acquisition hardware. The data were analyzed to identify fatigue damage initiation and to assess damage progression. Modal response, diffuse wave-field transfer functions in time and frequency domains, and wave propagation methods were applied to assess the condition of the turbine blade. The analysis methods implemented were evaluated in conjunction with hardware-specific performance for their efficacy in enabling the assessment of damage progression in the blade. The results of this assessment will inform the selection of specific data to be collected and analysis methods to be implemented for a CX-100 flight test to be conducted in collaboration with Sandia National Laboratory at the U.S. Department of Agriculture's (USDA) Conservation and Production Research Laboratory (CPRL) in Bushland, Texas.

A multiclass multiresidue LC-MS/MS method for analysis of veterinary drugs in bovine kidney

USDA-ARS?s Scientific Manuscript database

The increased efficiency permitted by multiclass, multiresidue methods has made such approaches very attractive to laboratories involved in monitoring veterinary drug residues in animal tissues. In this current work, evaluation of a multiclass multiresidue LC-MS/MS method in bovine kidney is describ...

Time Domain Radar Laboratory Operating System Development and Transient EM Analysis.

DTIC Science & Technology

1981-09-01

polarization of the return, arg used. Other similar methods use amplitude and phase differences or special properties of Rayleigh region scattering. All these...3ptias Inverse Scattering ... 19 2. "!xact" Inverse Scattering !Nethod .. 20 3. Other Methods ................... 21 C. REVIEW OF TDRL PROGRESS AT SPS...explicit independant variable in.most methods . In the past, frequency domain analysis has been the primary means of analyzing aan-monochromatic EM

Lack of grading agreement among international hemostasis external quality assessment programs

PubMed Central

Olson, John D.; Jennings, Ian; Meijer, Piet; Bon, Chantal; Bonar, Roslyn; Favaloro, Emmanuel J.; Higgins, Russell A.; Keeney, Michael; Mammen, Joy; Marlar, Richard A.; Meley, Roland; Nair, Sukesh C.; Nichols, William L.; Raby, Anne; Reverter, Joan C.; Srivastava, Alok; Walker, Isobel

2018-01-01

Laboratory quality programs rely on internal quality control and external quality assessment (EQA). EQA programs provide unknown specimens for the laboratory to test. The laboratory's result is compared with other (peer) laboratories performing the same test. EQA programs assign target values using a variety of methods statistical tools and performance assessment of ‘pass’ or ‘fail’ is made. EQA provider members of the international organization, external quality assurance in thrombosis and hemostasis, took part in a study to compare outcome of performance analysis using the same data set of laboratory results. Eleven EQA organizations using eight different analytical approaches participated. Data for a normal and prolonged activated partial thromboplastin time (aPTT) and a normal and reduced factor VIII (FVIII) from 218 laboratories were sent to the EQA providers who analyzed the data set using their method of evaluation for aPTT and FVIII, determining the performance for each laboratory record in the data set. Providers also summarized their statistical approach to assignment of target values and laboratory performance. Each laboratory record in the data set was graded pass/fail by all EQA providers for each of the four analytes. There was a lack of agreement of pass/fail grading among EQA programs. Discordance in the grading was 17.9 and 11% of normal and prolonged aPTT results, respectively, and 20.2 and 17.4% of normal and reduced FVIII results, respectively. All EQA programs in this study employed statistical methods compliant with the International Standardization Organization (ISO), ISO 13528, yet the evaluation of laboratory results for all four analytes showed remarkable grading discordance. PMID:29232255

2017 GTO Project review Laboratory Evaluation of EGS Shear Stimulation.

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

Bauer, Stephen J.

The objectives and purpose of this research has been to produce laboratory-based experimental and numerical analyses to provide a physics-based understanding of shear stimulation phenomena (hydroshearing) and its evolution during stimulation. Water was flowed along fractures in hot and stressed fractured rock, to promote slip. The controlled laboratory experiments provide a high resolution/high quality data resource for evaluation of analysis methods developed by DOE to assess EGS “behavior” during this stimulation process. Segments of the experimental program will provide data sets for model input parameters, i.e., material properties, and other segments of the experimental program will represent small scale physicalmore » models of an EGS system, which may be modeled. The coupled lab/analysis project has been a study of the response of a fracture in hot, water-saturated fractured rock to shear stress experiencing fluid flow. Under this condition, the fracture experiences a combination of potential pore pressure changes and fracture surface cooling, resulting in slip along the fracture. The laboratory work provides a means to assess the role of “hydroshearing” on permeability enhancement in reservoir stimulation. Using the laboratory experiments and results to define boundary and input/output conditions of pore pressure, thermal stress, fracture shear deformation and fluid flow, and models were developed and simulations completed by the University of Oklahoma team. The analysis methods are ones used on field scale problems. The sophisticated numerical models developed contain parameters present in the field. The analysis results provide insight into the role of fracture slip on permeability enhancement-“hydroshear” is to be obtained. The work will provide valuable input data to evaluate stimulation models, thus helping design effective EGS.« less

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

PubMed Central

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

2012-01-01

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

Integrated Data Collection Analysis (IDCA) Program - KClO 4/Carbon Mixture

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO 4 and activated carbon—KClO 4/C mixture. This material was selected because of the challenge of performing SSST testing of a mixture of two solids. The mixture was found to be insensitive to impact, friction, and thermal stimulus, and somewhat sensitive to spark discharge. This effort, funded by the Department of Homeland Security (DHS), ultimately will putmore » the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO 4/carbon mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when these testing variables cannot be made consistent.« less

Evaluation of PLS, LS-SVM, and LWR for quantitative spectroscopic analysis of soils

USDA-ARS?s Scientific Manuscript database

Soil testing requires the analysis of large numbers of samples in laboratory that are often time consuming and expensive. Mid-infrared spectroscopy (mid-IR) and near-infrared spectroscopy (NIRS) are fast, non-destructive, and inexpensive analytical methods that have been used for soil analysis, in l...

Physico-Geometrical Kinetics of Solid-State Reactions in an Undergraduate Thermal Analysis Laboratory

ERIC Educational Resources Information Center

Koga, Nobuyoshi; Goshi, Yuri; Yoshikawa, Masahiro; Tatsuoka, Tomoyuki

2014-01-01

An undergraduate kinetic experiment of the thermal decomposition of solids by microscopic observation and thermal analysis was developed by investigating a suitable reaction, applicable techniques of thermal analysis and microscopic observation, and a reliable kinetic calculation method. The thermal decomposition of sodium hydrogen carbonate is…

Teaching General Principles and Applications of Dendrogeomorphology.

ERIC Educational Resources Information Center

Butler, David R.

1987-01-01

Tree-ring analysis in geomorphology can be incorporated into a number of undergraduate methods in order to reconstruct the history of a variety of geomorphic processes. Discusses dendrochronology, general principles of dendrogeomorphology, field sampling methods, laboratory techniques, and examples of applications. (TW)

External Standards or Standard Addition? Selecting and Validating a Method of Standardization

NASA Astrophysics Data System (ADS)

Harvey, David T.

2002-05-01

A common feature of many problem-based laboratories in analytical chemistry is a lengthy independent project involving the analysis of "real-world" samples. Students research the literature, adapting and developing a method suitable for their analyte, sample matrix, and problem scenario. Because these projects encompass the complete analytical process, students must consider issues such as obtaining a representative sample, selecting a method of analysis, developing a suitable standardization, validating results, and implementing appropriate quality assessment/quality control practices. Most textbooks and monographs suitable for an undergraduate course in analytical chemistry, however, provide only limited coverage of these important topics. The need for short laboratory experiments emphasizing important facets of method development, such as selecting a method of standardization, is evident. The experiment reported here, which is suitable for an introductory course in analytical chemistry, illustrates the importance of matrix effects when selecting a method of standardization. Students also learn how a spike recovery is used to validate an analytical method, and obtain a practical experience in the difference between performing an external standardization and a standard addition.

Phosphorus Concentrations in Stream-Water and Reference Samples - An Assessment of Laboratory Comparability

USGS Publications Warehouse

McHale, Michael R.; McChesney, Dennis

2007-01-01

In 2003, a study was conducted to evaluate the accuracy and precision of 10 laboratories that analyze water-quality samples for phosphorus concentrations in the Catskill Mountain region of New York State. Many environmental studies in this region rely on data from these different laboratories for water-quality analyses, and the data may be used in watershed modeling and management decisions. Therefore, it is important to determine whether the data reported by these laboratories are of comparable accuracy and precision. Each laboratory was sent 12 samples for triplicate analysis for total phosphorus, total dissolved phosphorus, and soluble reactive phosphorus. Eight of these laboratories reported results that met comparability criteria for all samples; the remaining two laboratories met comparability criteria for only about half of the analyses. Neither the analytical method used nor the sample concentration ranges appeared to affect the comparability of results. The laboratories whose results were comparable gave consistently comparable results throughout the concentration range analyzed, and the differences among methods did not diminish comparability. All laboratories had high data precision as indicated by sample triplicate results. In addition, the laboratories consistently reported total phosphorus values greater than total dissolved phosphorus values, and total dissolved phosphorus values greater than soluble reactive phosphorus values, as would be expected. The results of this study emphasize the importance of regular laboratory participation in sample-exchange programs.

Integrated Data Collection Analysis (IDCA) program--KClO 4/Dodecane Mixture

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of a mixture of KClO 4 and dodecane—KClO 4/dodecane mixture. This material was selected because of the challenge of performing SSST testing of a mixture of solid and liquid materials. The mixture was found to: 1) be less sensitive to impact than RDX, and PETN, 2) less sensitive to friction than RDX and PETN, and 3) less sensitive to spark thanmore » RDX and PETN. The thermal analysis showed little or no exothermic features suggesting that the dodecane volatilized at low temperatures. A prominent endothermic feature was observed and assigned to a phase transition of KClO 4. This effort, funded by the Department of Homeland Security (DHS), ultimately will put the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed to develop safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results are compared among the laboratories and then compared to historical data from various sources. The testing performers involved for the KClO 4/dodecane mixture are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to understand how to compare results when these testing variables cannot be made consistent.« less

A Reference Method for Measuring Emissions of SVOCs in ...

EPA Pesticide Factsheets

Semivolatile organic compounds (SVOCs) are indoor air pollutants that may may have significant adverse effects on human health, and emission of SVOCs from building materials and consumer products is of growing concern. Few chamber studies have been conducted due to the challenges associated with SVOC analysis and the lack of validation procedures. Thus there is an urgent need for a reliable and accurate chamber test method to verify the performance of these measurements. A reference method employing a specially-designed chamber and experimental protocol has been developed and is undergoing extensive evaluation. A pilot interlaboratory study (ILS) has been conducted with five laboratories performing chamber tests under identical conditions. Results showed inter-laboratory variations at 25% for SVOC emission rates, with greater agreement observed between intra-laboratory measurements for most of the participating laboratories. The measured concentration profiles also compared reasonably well to the mechanistic model, demonstrating the feasibility of the proposed reference method to independently assess laboratory performance and validate SVOC emission tests. There is an urgent need for improved understanding of the measurement uncertainties associated with SVOC emissions testing. The creation of specially-designed chambers and well-characterized materials serves as a critical prerequisite for improving the procedure used to measure SVOCs emitted from indoor

ERLN Technical Support for Labs

EPA Pesticide Factsheets

The Environmental Response Laboratory Network provides policies and guidance on lab and data requirements, Standardized Analytical Methods, and technical support for water and radiological sampling and analysis

Application of several methods for determining transfer functions and frequency response of aircraft from flight data

NASA Technical Reports Server (NTRS)

Eggleston, John M; Mathews, Charles W

1954-01-01

In the process of analyzing the longitudinal frequency-response characteristics of aircraft, information on some of the methods of analysis has been obtained by the Langley Aeronautical Laboratory of the National Advisory Committee for Aeronautics. In the investigation of these methods, the practical applications and limitations were stressed. In general, the methods considered may be classed as: (1) analysis of sinusoidal response, (2) analysis of transient response as to harmonic content through determination of the Fourier integral by manual or machine methods, and (3) analysis of the transient through the use of least-squares solutions of the coefficients of an assumed equation for either the transient time response or frequency response (sometimes referred to as curve-fitting methods). (author)

Quantifying inter-laboratory variability in stable isotope analysis of ancient skeletal remains.

PubMed

Pestle, William J; Crowley, Brooke E; Weirauch, Matthew T

2014-01-01

Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values. To address the issues arising from inter-laboratory comparisons, we devise a novel measure we term the Minimum Meaningful Difference (MMD), and demonstrate its application.

Quantifying Inter-Laboratory Variability in Stable Isotope Analysis of Ancient Skeletal Remains

PubMed Central

Pestle, William J.; Crowley, Brooke E.; Weirauch, Matthew T.

2014-01-01

Over the past forty years, stable isotope analysis of bone (and tooth) collagen and hydroxyapatite has become a mainstay of archaeological and paleoanthropological reconstructions of paleodiet and paleoenvironment. Despite this method's frequent use across anthropological subdisciplines (and beyond), the present work represents the first attempt at gauging the effects of inter-laboratory variability engendered by differences in a) sample preparation, and b) analysis (instrumentation, working standards, and data calibration). Replicate analyses of a 14C-dated ancient human bone by twenty-one archaeological and paleoecological stable isotope laboratories revealed significant inter-laboratory isotopic variation for both collagen and carbonate. For bone collagen, we found a sizeable range of 1.8‰ for δ13Ccol and 1.9‰ for δ15Ncol among laboratories, but an interpretatively insignificant average pairwise difference of 0.2‰ and 0.4‰ for δ13Ccol and δ15Ncol respectively. For bone hydroxyapatite the observed range increased to a troublingly large 3.5‰ for δ13Cap and 6.7‰ for δ18Oap, with average pairwise differences of 0.6‰ for δ13Cap and a disquieting 2.0‰ for δ18Oap. In order to assess the effects of preparation versus analysis on isotopic variability among laboratories, a subset of the samples prepared by the participating laboratories were analyzed a second time on the same instrument. Based on this duplicate analysis, it was determined that roughly half of the isotopic variability among laboratories could be attributed to differences in sample preparation, with the other half resulting from differences in analysis (instrumentation, working standards, and data calibration). These findings have serious implications for choices made in the preparation and extraction of target biomolecules, the comparison of results obtained from different laboratories, and the interpretation of small differences in bone collagen and hydroxyapatite isotope values. To address the issues arising from inter-laboratory comparisons, we devise a novel measure we term the Minimum Meaningful Difference (MMD), and demonstrate its application. PMID:25061843

Analysis of 161Tb by radiochemical separation and liquid scintillation counting

DOE PAGES

Jiang, J.; Davies, A.; Arrigo, L.; ...

2015-12-05

The determination of 161Tb activity is problematic due to its very low fission yield, short half-life, and the complication of its gamma spectrum. At AWE, radiochemically purified 161Tb solution was measured on a PerkinElmer 1220 Quantulus TM Liquid Scintillation Spectrometer. Since there was no 161Tb certified standard solution available commercially, the counting efficiency was determined by the CIEMAT/NIST Efficiency Tracing method. The method was validated during a recent inter-laboratory comparison exercise involving the analysis of a uranium sample irradiated with thermal neutrons. Lastly, the measured 161Tb result was in excellent agreement with the result using gamma spectrometry and the resultmore » obtained by Pacific Northwest National Laboratory.« less

Synthesis and Characterization of Potassium Tris(oxalato)ferrate(III) Trihydrate: A Spectrophotometric Method of Iron Analysis

NASA Astrophysics Data System (ADS)

Dallinger, Richard F.

1995-10-01

A previous Journal article [J. Chem. Educ. 1984, 61, 1098--1099] described a potassium tris(oxalato)ferrate(III) trihydrate empirical formula experiment that offered an excellent integrative experience in synthesis and characterization for general chemistry laboratory students. However, we have introduced a fast and accurate spectrophotometric method for the determination of iron in the product that takes the place of the photochemical-gravimetric procedure described in the article. Besides the pedagogic interest of bringing three different types of chemical analysis (titrimetric, gravimetric, and spectrophotometric) to bear on one compound, the new iron determination allows students to complete the experiment in 2, 3-hr laboratory periods rather than the 5 periods allotted in the original experiment.

Portable total reflection x-ray fluorescence analysis in the identification of unknown laboratory hazards

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

Liu, Ying, E-mail: liu.ying.48r@st.kyoto-u.ac.jp; Imashuku, Susumu; Sasaki, Nobuharu

In this study, a portable total reflection x-ray fluorescence (TXRF) spectrometer was used to analyze unknown laboratory hazards that precipitated on exterior surfaces of cooling pipes and fume hood pipes in chemical laboratories. With the aim to examine the accuracy of TXRF analysis for the determination of elemental composition, analytical results were compared with those of wavelength-dispersive x-ray fluorescence spectrometry, scanning electron microscope and energy-dispersive x-ray spectrometry, energy-dispersive x-ray fluorescence spectrometry, inductively coupled plasma atomic emission spectrometry, x-ray diffraction spectrometry (XRD), and x-ray photoelectron spectroscopy (XPS). Detailed comparison of data confirmed that the TXRF method itself was not sufficient tomore » determine all the elements (Z > 11) contained in the samples. In addition, results suggest that XRD should be combined with XPS in order to accurately determine compound composition. This study demonstrates that at least two analytical methods should be used in order to analyze the composition of unknown real samples.« less

Transferability and inter-laboratory variability assessment of the in vitro bovine oocyte fertilization test.

PubMed

Tessaro, Irene; Modina, Silvia C; Crotti, Gabriella; Franciosi, Federica; Colleoni, Silvia; Lodde, Valentina; Galli, Cesare; Lazzari, Giovanna; Luciano, Alberto M

2015-01-01

The dramatic increase in the number of animals required for reproductive toxicity testing imposes the validation of alternative methods to reduce the use of laboratory animals. As we previously demonstrated for in vitro maturation test of bovine oocytes, the present study describes the transferability assessment and the inter-laboratory variability of an in vitro test able to identify chemical effects during the process of bovine oocyte fertilization. Eight chemicals with well-known toxic properties (benzo[a]pyrene, busulfan, cadmium chloride, cycloheximide, diethylstilbestrol, ketoconazole, methylacetoacetate, mifepristone/RU-486) were tested in two well-trained laboratories. The statistical analysis demonstrated no differences in the EC50 values for each chemical in within (inter-runs) and in between-laboratory variability of the proposed test. We therefore conclude that the bovine in vitro fertilization test could advance toward the validation process as alternative in vitro method and become part of an integrated testing strategy in order to predict chemical hazards on mammalian fertility. Copyright © 2015 Elsevier Inc. All rights reserved.

Development, validation and comparison of NIR and Raman methods for the identification and assay of poor-quality oral quinine drops.

PubMed

Mbinze, J K; Sacré, P-Y; Yemoa, A; Mavar Tayey Mbay, J; Habyalimana, V; Kalenda, N; Hubert, Ph; Marini, R D; Ziemons, E

2015-01-01

Poor quality antimalarial drugs are one of the public's major health problems in Africa. The depth of this problem may be explained in part by the lack of effective enforcement and the lack of efficient local drug analysis laboratories. To tackle part of this issue, two spectroscopic methods with the ability to detect and to quantify quinine dihydrochloride in children's oral drops formulations were developed and validated. Raman and near infrared (NIR) spectroscopy were selected for the drug analysis due to their low cost, non-destructive and rapid characteristics. Both of the methods developed were successfully validated using the total error approach in the range of 50-150% of the target concentration (20%W/V) within the 10% acceptance limits. Samples collected on the Congolese pharmaceutical market were analyzed by both techniques to detect potentially substandard drugs. After a comparison of the analytical performance of both methods, it has been decided to implement the method based on NIR spectroscopy to perform the routine analysis of quinine oral drop samples in the Quality Control Laboratory of Drugs at the University of Kinshasa (DRC). Copyright © 2015 Elsevier B.V. All rights reserved.

Analysis of laboratory compaction methods of roller compacted concrete

NASA Astrophysics Data System (ADS)

Trtík, Tomáš; Chylík, Roman; Bílý, Petr; Fládr, Josef

2017-09-01

Roller-Compacted Concrete (RCC) is an ordinary concrete poured and compacted with machines typically used for laying of asphalt road layers. One of the problems connected with this technology is preparation of representative samples in the laboratory. The aim of this work was to analyse two methods of preparation of RCC laboratory samples with bulk density as the comparative parameter. The first method used dynamic compaction by pneumatic hammer. The second method of compaction had a static character. The specimens were loaded by precisely defined force in laboratory loading machine to create the same conditions as during static rolling (in the Czech Republic, only static rolling is commonly used). Bulk densities obtained by the two compaction methods were compared with core drills extracted from real RCC structure. The results have shown that the samples produced by pneumatic hammer tend to overestimate the bulk density of the material. For both compaction methods, immediate bearing index test was performed to verify the quality of compaction. A fundamental difference between static and dynamic compaction was identified. In static compaction, initial resistance to penetration of the mandrel was higher, after exceeding certain limit the resistance was constant. This means that the samples were well compacted just on the surface. Specimens made by pneumatic hammer actively resisted throughout the test, the whole volume was uniformly compacted.

Analysis of the Effect of Sequencing Lecture and Laboratory Instruction on Student Learning and Motivation Towards Learning Chemistry in an Organic Chemistry Lecture Course

ERIC Educational Resources Information Center

Pakhira, Deblina

2012-01-01

Exposure to organic chemistry concepts in the laboratory can positively affect student performance, learning new chemistry concepts and building motivation towards learning chemistry in the lecture. In this study, quantitative methods were employed to assess differences in student performance, learning, and motivation in an organic chemistry…

A Trend Analysis of Change in Interpersonal Skill Training Using Laboratory Training Methodology.

ERIC Educational Resources Information Center

Mulig, Joanne C.; Madden, J. M.

Past research on the effectiveness of laboratory training (the use of small group methods of experienced-based learning to produce personal change in attitudes and behaviors) has been deficient both in experimental design and in the concept of change. College students (N=128) participated in a study which used a series of 11 measurements to assess…

Clinical laboratory as an economic model for business performance analysis

PubMed Central

Buljanović, Vikica; Patajac, Hrvoje; Petrovečki, Mladen

2011-01-01

Aim To perform SWOT (strengths, weaknesses, opportunities, and threats) analysis of a clinical laboratory as an economic model that may be used to improve business performance of laboratories by removing weaknesses, minimizing threats, and using external opportunities and internal strengths. Methods Impact of possible threats to and weaknesses of the Clinical Laboratory at Našice General County Hospital business performance and use of strengths and opportunities to improve operating profit were simulated using models created on the basis of SWOT analysis results. The operating profit as a measure of profitability of the clinical laboratory was defined as total revenue minus total expenses and presented using a profit and loss account. Changes in the input parameters in the profit and loss account for 2008 were determined using opportunities and potential threats, and economic sensitivity analysis was made by using changes in the key parameters. The profit and loss account and economic sensitivity analysis were tools for quantifying the impact of changes in the revenues and expenses on the business operations of clinical laboratory. Results Results of simulation models showed that operational profit of €470 723 in 2008 could be reduced to only €21 542 if all possible threats became a reality and current weaknesses remained the same. Also, operational gain could be increased to €535 804 if laboratory strengths and opportunities were utilized. If both the opportunities and threats became a reality, the operational profit would decrease by €384 465. Conclusion The operational profit of the clinical laboratory could be significantly reduced if all threats became a reality and the current weaknesses remained the same. The operational profit could be increased by utilizing strengths and opportunities as much as possible. This type of modeling may be used to monitor business operations of any clinical laboratory and improve its financial situation by implementing changes in the next fiscal period. PMID:21853546

Testing high SPF sunscreens: a demonstration of the accuracy and reproducibility of the results of testing high SPF formulations by two methods and at different testing sites.

PubMed

Agin, Patricia Poh; Edmonds, Susan H

2002-08-01

The goals of this study were (i) to demonstrate that existing and widely used sun protection factor (SPF) test methodologies can produce accurate and reproducible results for high SPF formulations and (ii) to provide data on the number of test-subjects needed, the variability of the data, and the appropriate exposure increments needed for testing high SPF formulations. Three high SPF formulations were tested, according to the Food and Drug Administration's (FDA) 1993 tentative final monograph (TFM) 'very water resistant' test method and/or the 1978 proposed monograph 'waterproof' test method, within one laboratory. A fourth high SPF formulation was tested at four independent SPF testing laboratories, using the 1978 waterproof SPF test method. All laboratories utilized xenon arc solar simulators. The data illustrate that the testing conducted within one laboratory, following either the 1978 proposed or the 1993 TFM SPF test method, was able to reproducibly determine the SPFs of the formulations tested, using either the statistical analysis method in the proposed monograph or the statistical method described in the TFM. When one formulation was tested at four different laboratories, the anticipated variation in the data owing to the equipment and other operational differences was minimized through the use of the statistical method described in the 1993 monograph. The data illustrate that either the 1978 proposed monograph SPF test method or the 1993 TFM SPF test method can provide accurate and reproducible results for high SPF formulations. Further, these results can be achieved with panels of 20-25 subjects with an acceptable level of variability. Utilization of the statistical controls from the 1993 sunscreen monograph can help to minimize lab-to-lab variability for well-formulated products.

College of American Pathologists/American College of Medical Genetics proficiency testing for constitutional cytogenomic microarray analysis.

PubMed

Brothman, Arthur R; Dolan, Michelle M; Goodman, Barbara K; Park, Jonathan P; Persons, Diane L; Saxe, Debra F; Tepperberg, James H; Tsuchiya, Karen D; Van Dyke, Daniel L; Wilson, Kathleen S; Wolff, Daynna J; Theil, Karl S

2011-09-01

To evaluate the feasibility of administering a newly established proficiency test offered through the College of American Pathologists and the American College of Medical Genetics for genomic copy number assessment by microarray analysis, and to determine the reproducibility and concordance among laboratory results from this test. Surveys were designed through the Cytogenetic Resource Committee of the two colleges to assess the ability of testing laboratories to process DNA samples provided and interpret results. Supplemental questions were asked with each Survey to determine laboratory practice trends. Twelve DNA specimens, representing 2 pilot and 10 Survey challenges, were distributed to as many as 74 different laboratories, yielding 493 individual responses. The mean consensus for matching result interpretations was 95.7%. Responses to supplemental questions indicate that the number of laboratories offering this testing is increasing, methods for analysis and evaluation are becoming standardized, and array platforms used are increasing in probe density. The College of American Pathologists/American College of Medical Genetics proficiency testing program for copy number assessment by cytogenomic microarray is a successful and efficient mechanism for assessing interlaboratory reproducibility. This will provide laboratories the opportunity to evaluate their performance and assure overall accuracy of patient results. The high level of concordance in laboratory responses across all testing platforms by multiple facilities highlights the robustness of this technology.

40 CFR 408.121 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... those components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c) The term seafood shall mean the raw material, including freshwater and saltwater...

Soil Sampling Operating Procedure

EPA Pesticide Factsheets

EPA Region 4 Science and Ecosystem Support Division (SESD) document that describes general and specific procedures, methods, and considerations when collecting soil samples for field screening or laboratory analysis.

Sediment Sampling Operating Procedure

EPA Pesticide Factsheets

EPA Region 4 Science and Ecosystem Support Division (SESD) document that describes general and specific procedures, methods, and considerations when collecting sediment samples for field screening or laboratory analysis.

Determination of Reaction Stoichiometries by Flow Injection Analysis.

ERIC Educational Resources Information Center

Rios, Angel; And Others

1986-01-01

Describes a method of flow injection analysis intended for calculation of complex-formation and redox reaction stoichiometries based on a closed-loop configuration. The technique is suitable for use in undergraduate laboratories. Information is provided for equipment, materials, procedures, and sample results. (JM)

[Interlaboratory Study on Evaporation Residue Test for Food Contact Products (Report 1)].

PubMed

Ohno, Hiroyuki; Mutsuga, Motoh; Abe, Tomoyuki; Abe, Yutaka; Amano, Homare; Ishihara, Kinuyo; Ohsaka, Ikue; Ohno, Haruka; Ohno, Yuichiro; Ozaki, Asako; Kakihara, Yoshiteru; Kobayashi, Hisashi; Sakuragi, Hiroshi; Shibata, Hiroshi; Shirono, Katsuhiro; Sekido, Haruko; Takasaka, Noriko; Takenaka, Yu; Tajima, Yoshiyasu; Tanaka, Aoi; Tanaka, Hideyuki; Tonooka, Hiroyuki; Nakanishi, Toru; Nomura, Chie; Haneishi, Nahoko; Hayakawa, Masato; Miura, Toshihiko; Yamaguchi, Miku; Watanabe, Kazunari; Sato, Kyoko

2018-01-01

An interlaboratory study was performed to evaluate the equivalence between an official method and a modified method of evaporation residue test using three food-simulating solvents (water, 4% acetic acid and 20% ethanol), based on the Japanese Food Sanitation Law for food contact products. Twenty-three laboratories participated, and tested the evaporation residues of nine test solutions as blind duplicates. For evaporation, a water bath was used in the official method, and a hot plate in the modified method. In most laboratories, the test solutions were heated until just prior to evaporation to dryness, and then allowed to dry under residual heat. Statistical analysis revealed that there was no significant difference between the two methods, regardless of the heating equipment used. Accordingly, the modified method provides performance equal to the official method, and is available as an alternative method.

Universal immunogenicity validation and assessment during early biotherapeutic development to support a green laboratory.

PubMed

Bautista, Ami C; Zhou, Lei; Jawa, Vibha

2013-10-01

Immunogenicity support during nonclinical biotherapeutic development can be resource intensive if supported by conventional methodologies. A universal indirect species-specific immunoassay can eliminate the need for biotherapeutic-specific anti-drug antibody immunoassays without compromising quality. By implementing the R's of sustainability (reduce, reuse, rethink), conservation of resources and greener laboratory practices were achieved in this study. Statistical analysis across four biotherapeutics supported identification of consistent product performance standards (cut points, sensitivity and reference limits) and a streamlined universal anti-drug antibody immunoassay method implementation strategy. We propose an efficient, fit-for-purpose, scientifically and statistically supported nonclinical immunogenicity assessment strategy. Utilization of a universal method and streamlined validation, while retaining comparability to conventional immunoassays and meeting the industry recommended standards, provides environmental credits in the scientific laboratory. Collectively, individual reductions in critical material consumption, energy usage, waste and non-environment friendly consumables, such as plastic and paper, support a greener laboratory environment.

Manipulating Ratio Spectra for the Spectrophotometric Analysis of Diclofenac Sodium and Pantoprazole Sodium in Laboratory Mixtures and Tablet Formulation

PubMed Central

Bhatt, Nejal M.; Chavada, Vijay D.; Sanyal, Mallika; Shrivastav, Pranav S.

2014-01-01

Objective. Three sensitive, selective, and precise spectrophotometric methods based on manipulation of ratio spectra, have been developed and validated for the determination of diclofenac sodium and pantoprazole sodium. Materials and Methods. The first method is based on ratio spectra peak to peak measurement using the amplitudes at 251 and 318 nm; the second method involves the first derivative of the ratio spectra (Δλ = 4 nm) using the peak amplitudes at 326.0 nm for diclofenac sodium and 337.0 nm for pantoprazole sodium. The third is the method of mean centering of ratio spectra using the values at 318.0 nm for both the analytes. Results. All the three methods were linear over the concentration range of 2.0–24.0 μg/mL for diclofenac sodium and 2.0–20.0 μg/mL for pantoprazole sodium. The methods were validated according to the ICH guidelines and accuracy, precision, repeatability, and robustness are found to be within the acceptable limit. The results of single factor ANOVA analysis indicated that there is no significant difference among the developed methods. Conclusions. The developed methods provided simple resolution of this binary combination from laboratory mixtures and pharmaceutical preparations and can be conveniently adopted for routine quality control analysis. PMID:24701171

Automated Clean Chemistry for Bulk Analysis of Environmental Swipe Samples - FY17 Year End Report

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

Ticknor, Brian W.; Metzger, Shalina C.; McBay, Eddy H.

Sample preparation methods for mass spectrometry are being automated using commercial-off-the-shelf (COTS) equipment to shorten lengthy and costly manual chemical purification procedures. This development addresses a serious need in the International Atomic Energy Agency’s Network of Analytical Laboratories (IAEA NWAL) to increase efficiency in the Bulk Analysis of Environmental Samples for Safeguards program with a method that allows unattended, overnight operation. In collaboration with Elemental Scientific Inc., the prepFAST-MC2 was designed based on COTS equipment. It was modified for uranium/plutonium separations using renewable columns packed with Eichrom TEVA and UTEVA resins, with a chemical separation method based on the Oakmore » Ridge National Laboratory (ORNL) NWAL chemical procedure. The newly designed prepFAST-SR has had several upgrades compared with the original prepFAST-MC2. Both systems are currently installed in the Ultra-Trace Forensics Science Center at ORNL.« less

Spectrophotometric determination of meclizine hydrochloride and pyridoxine hydrochloride in laboratory prepared mixtures and in their pharmaceutical preparation

NASA Astrophysics Data System (ADS)

Ibrahim, Maha M.; Elzanfaly, Eman S.; El-Zeiny, Mohamed B.; Ramadan, Nesreen K.; Kelani, Khadiga M.

2017-05-01

In this paper, three rapid, simple, accurate and precise spectrophotometric methods were developed for the determination of meclizine hydrochloride in the presence of pyridoxine hydrochloride without previous separation. The methods under study are dual wavelength (DWL), ratio difference (RD) and continuous wavelet transform (CWT). On the other hand, pyridoxine hydrochloride (PYH) was determined directly at 291 nm. The methods obey Beer's law in the range of (5-50 μg/mL) for both compounds. All the methods were validated according to the ICH guidelines where the accuracy was found to be 98.29, 99.59, 100.42 and 100.62% for DWL, RD, CWT and PYH; respectively. Moreover the precision of the methods were calculated in terms of %RSD and it was found to be 0.545, 0.372, 1.287 and 0.759 for DWL, RD,CWT and PYH; respectively. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of pyridoxine hydrochloride and meclizine hydrochloride in quality-control laboratories.

Short communication: Analytical method and amount of preservative added to milk samples may alter milk urea nitrogen measurements.

PubMed

Weeks, Holley L; Hristov, Alexander N

2017-02-01

Milk urea N (MUN) is used by dairy nutritionists and producers to monitor dietary protein intake and is indicative of N utilization in lactating dairy cows. Two experiments were conducted to explore discrepancies in MUN results provided by 3 milk processing laboratories using different methods. An additional experiment was conducted to evaluate the effect of 2-bromo-2-nitropropane-1, 3-diol (bronopol) on MUN analysis. In experiment 1, 10 replicates of bulk tank milk samples, collected from the Pennsylvania State University's Dairy Center over 5 consecutive days, were sent to 3 milk processing laboratories in Pennsylvania. Average MUN differed between laboratory A (14.9 ± 0.40 mg/dL; analyzed on MilkoScan 4000; Foss, Hillerød, Denmark), laboratory B (6.5 ± 0.17 mg/dL; MilkoScan FT + 6000), and laboratory C (7.4 ± 0.36 mg/dL; MilkoScan 6000). In experiment 2, milk samples were spiked with urea at 0 (7.3 to 15.0 mg/dL, depending on the laboratory analyzing the samples), 17.2, 34.2, and 51.5 mg/dL of milk. Two 35-mL samples from each urea level were sent to the 3 laboratories used in experiment 1. Average analyzed MUN was greater than predicted (calculated for each laboratory based on the control; 0 mg of added urea): for laboratory A (23.2 vs. 21.0 mg/dL), laboratory B (18.0 vs. 13.3 mg/dL), and laboratory C (20.6 vs. 15.2 mg/dL). In experiment 3, replicated milk samples were preserved with 0 to 1.35 mg of bronopol/mL of milk and submitted to one milk processing laboratory that analyzed MUN using 2 different methods. Milk samples with increasing amounts of bronopol ranged in MUN concentration from 7.7 to 11.9 mg/dL and from 9.0 to 9.3 mg/dL when analyzed on MilkoScan 4000 or CL 10 (EuroChem, Moscow, Russia), respectively. In conclusion, measured MUN concentrations varied due to analytical procedure used by milk processing laboratories and were affected by the amount of bronopol used to preserve milk sample, when milk was analyzed using a mid-infrared analyzer. Thus, it is important to maintain consistency in milk sample preservation and analysis to ensure precision of MUN results. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The work of the European Union Reference Laboratory for Food Additives (EURL) and its support for the authorisation process of feed additives in the European Union: a review

PubMed Central

von Holst, Christoph; Robouch, Piotr; Bellorini, Stefano; de la Huebra, María José González; Ezerskis, Zigmas

2016-01-01

ABSTRACT This paper describes the operation of the European Union Reference Laboratory for Feed Additives (EURL) and its role in the authorisation procedure of feed additives in the European Union. Feed additives are authorised according to Regulation (EC) No. 1831/2003, which introduced a completely revised authorisation procedure and also established the EURL. The regulations authorising feed additives contain conditions of use such as legal limits of the feed additives, which require the availability of a suitable method of analysis for official control purposes under real world conditions. It is the task of the EURL to evaluate the suitability of analytical methods as proposed by the industry for this purpose. Moreover, the paper shows that one of the major challenges is the huge variety of the methodology applied in feed additive analysis, thus requiring expertise in quite different analytical areas. In order to cope with this challenge, the EURL is supported by a network of national reference laboratories (NRLs) and only the merged knowledge of all NRLs allows for a scientifically sound assessment of the analytical methods. PMID:26540604

Porometric properties of siliciclastic marine sand: A comparison of traditional laboratory measurements with image analysis and effective medium modeling

USGS Publications Warehouse

Reed, A.H.; Briggs, K.B.; Lavoie, D.L.

2002-01-01

During the 1999 sediment acoustics experiment (SAX99), porometric properties were measured and predicted for a well sorted, medium sand using standard laboratory geotechnical methods and image analysis of resin-impregnated sediments. Sediment porosity measured by laboratory water-weight-loss methods (0.372 ?? 0.0073 for mean ??1 standard deviation) is 0.026 lower than determined by microscopic image analysis of resin-impregnated sediments (0.398 ?? 0.029). Values of intrinsic permeability (m2) determined from constant-head permeameter measurements (3.29 ?? 10-11 ?? 0.60 ?? 10-11) and by microscopic image analysis coupled with effective medium theory modeling (2.78 ?? 10-11 ?? 1.01 ?? 10-11) are nearly identical within measurement error. The mean value of tortuosity factor measured from images is 1.49 ?? 0.09, which is in agreement with tortuosity factor determined from electrical resistivity measurements. Slight heterogeneity and anisotropy are apparent in the top three centimeters of sediment as determined by image-based porometric property measurements. However, the overall similarity for both measured and predicted values of porosity and permeability among and within SAX99 sites indicates sediments are primarily homogeneous and isotropic and pore size distributions are fairly uniform. The results indicate that an effective medium theory technique and two-dimensional image analysis accurately predicts bulk permeability in resin-impregnated sands.

DNA decontamination methods for internal quality management in clinical PCR laboratories.

PubMed

Wu, Yingping; Wu, Jianyong; Zhang, Zhihui; Cheng, Chen

2018-03-01

The polymerase chain reaction (PCR) technique, one of the most commonly applied methods in diagnostic and molecular biology, has a frustrating downside: the occurrence of false-positive signals due to contamination. In previous research, various DNA decontamination methods have been developed to overcome this limitation. Unfortunately, the use of random or poorly focused sampling methods for monitoring air and/or object surfaces leads to the incomplete elimination during decontamination procedures. We herein attempted to develop a novel DNA decontamination method (environmental surveillance, including surface and air sampling) and quality management program for clinical molecular diagnostic laboratories (or clinical PCR laboratories). Here, we performed a step-by-step evaluation of current DNA decontamination methods and developed an effective procedure for assessing the presence of decontaminating DNA via PCR analysis. Performing targeted environmental surveillance by sampling, which reached optimal performance over 2 weeks, and the decontamination process had been verified as reliable. Additionally, the process was validated to not affect PCR amplification efficiency based on a comparative study. In this study, effective guidelines for DNA decontamination were developed. The method employed ensured that surface DNA contamination could be effectively identified and eliminated. Furthermore, our study highlighted the importance of overall quality assurance and good clinical laboratory practices for preventing contamination, which are key factors for compliance with regulatory or accreditation requirements. Taken together, we provided the evidence that the presented scheme ranged from troubleshooting to the elimination of surface contamination, could serve as critical foundation for developing regular environmental surveillance guidelines for PCR laboratories. © 2017 Wiley Periodicals, Inc.

Forensic analysis of explosives using isotope ratio mass spectrometry (IRMS)--part 2: forensic inter-laboratory trial: bulk carbon and nitrogen stable isotopes in a range of chemical compounds (Australia and New Zealand).

PubMed

Benson, Sarah J; Lennard, Christopher J; Maynard, Philip; Hill, David M; Andrew, Anita S; Neal, Ken; Stuart-Williams, Hilary; Hope, Janet; Walker, G Stewart; Roux, Claude

2010-01-01

Comparability of data over time and between laboratories is a key issue for consideration in the development of global databases, and more broadly for quality assurance in general. One mechanism that can be utilized for evaluating traceability is an inter-laboratory trial. This paper addresses an inter-laboratory trial conducted across a number of Australian and New Zealand isotope ratio mass spectrometry (IRMS) laboratories. The main objective of this trial was to determine whether IRMS laboratories in these countries would record comparable values for the distributed samples. Four carbon containing and four nitrogen containing compounds were distributed to seven laboratories in Australia and one in New Zealand. The laboratories were requested to analyze the samples using their standard procedures. The data from each laboratory was evaluated collectively using International Standard ISO 13528 (Statistical methods for use in proficiency testing by inter-laboratory comparisons). "Warning signals" were raised against one participant in this trial. "Action signals" requiring corrective action were raised against four participants. These participants reviewed the data and possible sources for the discrepancies. This inter-laboratory trial was successful in providing an initial snapshot of the potential for traceability between the participating laboratories. The statistical methods described in this article could be used as a model for others needing to evaluate stable isotope results derived from multiple laboratories, e.g., inter-laboratory trials/proficiency testing. Ongoing trials will be conducted to improve traceability across the Australian and New Zealand IRMS community.

An approach to quality and performance control in a computer-assisted clinical chemistry laboratory.

PubMed Central

Undrill, P E; Frazer, S C

1979-01-01

A locally developed, computer-based clinical chemistry laboratory system has been in operation since 1970. This utilises a Digital Equipment Co Ltd PDP 12 and an interconnected PDP 8/F computer. Details are presented of the performance and quality control techniques incorporated into the system. Laboratory performance is assessed through analysis of results from fixed-level control sera as well as from cumulative sum methods. At a simple level the presentation may be considered purely indicative, while at a more sophisticated level statistical concepts have been introduced to aid the laboratory controller in decision-making processes. PMID:438340

Ink dating using thermal desorption and gas chromatography/mass spectrometry: comparison of results obtained in two laboratories.

PubMed

Koenig, Agnès; Bügler, Jürgen; Kirsch, Dieter; Köhler, Fritz; Weyermann, Céline

2015-01-01

An ink dating method based on solvent analysis was recently developed using thermal desorption followed by gas chromatography/mass spectrometry (GC/MS) and is currently implemented in several forensic laboratories. The main aims of this work were to implement this method in a new laboratory to evaluate whether results were comparable at three levels: (i) validation criteria, (ii) aging curves, and (iii) results interpretation. While the results were indeed comparable in terms of validation, the method proved to be very sensitive to maintenances. Moreover, the aging curves were influenced by ink composition, as well as storage conditions (particularly when the samples were not stored in "normal" room conditions). Finally, as current interpretation models showed limitations, an alternative model based on slope calculation was proposed. However, in the future, a probabilistic approach may represent a better solution to deal with ink sample inhomogeneity. © 2014 American Academy of Forensic Science.

Laboratory test for ice adhesion strength using commercial instrumentation.

PubMed

Wang, Chenyu; Zhang, Wei; Siva, Adarsh; Tiea, Daniel; Wynne, Kenneth J

2014-01-21

A laboratory test method for evaluating ice adhesion has been developed employing a commercially available instrument normally used for dynamic mechanical analysis (TA RSA-III). This is the first laboratory ice adhesion test that does not require a custom-built apparatus. The upper grip range of ∼10 mm is an enabling feature that is essential for the test. The method involves removal of an ice cylinder from a polymer coating with a probe and the determination of peak removal force (Ps). To validate the test method, the strength of ice adhesion was determined for a prototypical glassy polymer, poly(methyl methacrylate). The distance of the probe from the PMMA surface has been identified as a critical variable for Ps. The new test provides a readily available platform for investigating fundamental surface characteristics affecting ice adhesion. In addition to the ice release test, PMMA coatings were characterized using DSC, DCA, and TM-AFM.

Real-Time PCR in Clinical Microbiology: Applications for Routine Laboratory Testing

PubMed Central

Espy, M. J.; Uhl, J. R.; Sloan, L. M.; Buckwalter, S. P.; Jones, M. F.; Vetter, E. A.; Yao, J. D. C.; Wengenack, N. L.; Rosenblatt, J. E.; Cockerill, F. R.; Smith, T. F.

2006-01-01

Real-time PCR has revolutionized the way clinical microbiology laboratories diagnose many human microbial infections. This testing method combines PCR chemistry with fluorescent probe detection of amplified product in the same reaction vessel. In general, both PCR and amplified product detection are completed in an hour or less, which is considerably faster than conventional PCR detection methods. Real-time PCR assays provide sensitivity and specificity equivalent to that of conventional PCR combined with Southern blot analysis, and since amplification and detection steps are performed in the same closed vessel, the risk of releasing amplified nucleic acids into the environment is negligible. The combination of excellent sensitivity and specificity, low contamination risk, and speed has made real-time PCR technology an appealing alternative to culture- or immunoassay-based testing methods for diagnosing many infectious diseases. This review focuses on the application of real-time PCR in the clinical microbiology laboratory. PMID:16418529

A simplified method for monomeric carbohydrate analysis of corn stover biomass

USDA-ARS?s Scientific Manuscript database

Constituent determination of biomass for theoretical ethanol yield (TEY) estimation requires the removal of non-structural carbohydrates prior to analysis to prevent interference with the analytical procedure. According to the accepted U.S. Dept. of Energy-National Renewable Energy Laboratory (NREL)...

Spatial analysis of volatile organic compounds in South Philadelphia using passive samplers

EPA Science Inventory

Select volatile organic compounds (VOCs) were measured in the vicinity of a petroleum refinery and related operations in South Philadelphia, Pennsylvania, USA, using passive air sampling and laboratory analysis methods. Two-week, time-integrated samplers were deployed at 17 sites...

Soil Gas Sampling Operating Procedure

EPA Pesticide Factsheets

EPA Region 4 Science and Ecosystem Support Division (SESD) document that describes general and specific procedures, methods, and considerations when collecting soil gas samples for field screening or laboratory analysis.

Differences in results of analyses of concurrent and split stream-water samples collected and analyzed by the US Geological Survey and the Illinois Environmental Protection Agency, 1985-91

USGS Publications Warehouse

Melching, C.S.; Coupe, R.H.

1995-01-01

During water years 1985-91, the U.S. Geological Survey (USGS) and the Illinois Environmental Protection Agency (IEPA) cooperated in the collection and analysis of concurrent and split stream-water samples from selected sites in Illinois. Concurrent samples were collected independently by field personnel from each agency at the same time and sent to the IEPA laboratory, whereas the split samples were collected by USGS field personnel and divided into aliquots that were sent to each agency's laboratory for analysis. The water-quality data from these programs were examined by means of the Wilcoxon signed ranks test to identify statistically significant differences between results of the USGS and IEPA analyses. The data sets for constituents and properties identified by the Wilcoxon test as having significant differences were further examined by use of the paired t-test, mean relative percentage difference, and scattergrams to determine if the differences were important. Of the 63 constituents and properties in the concurrent-sample analysis, differences in only 2 (pH and ammonia) were statistically significant and large enough to concern water-quality engineers and planners. Of the 27 constituents and properties in the split-sample analysis, differences in 9 (turbidity, dissolved potassium, ammonia, total phosphorus, dissolved aluminum, dissolved barium, dissolved iron, dissolved manganese, and dissolved nickel) were statistically significant and large enough to con- cern water-quality engineers and planners. The differences in concentration between pairs of the concurrent samples were compared to the precision of the laboratory or field method used. The differences in concentration between pairs of the concurrent samples were compared to the precision of the laboratory or field method used. The differences in concentration between paris of split samples were compared to the precision of the laboratory method used and the interlaboratory precision of measuring a given concentration or property. Consideration of method precision indicated that differences between concurrent samples were insignificant for all concentrations and properties except pH, and that differences between split samples were significant for all concentrations and properties. Consideration of interlaboratory precision indicated that the differences between the split samples were not unusually large. The results for the split samples illustrate the difficulty in obtaining comparable and accurate water-quality data.

Techniques of Water-Resources Investigations of the United States Geological Survey. Book 5, Laboratory Analysis. Chapter A5, Methods for Determination of Radioactive Substances in Water and Fluvial Sediments.

ERIC Educational Resources Information Center

Thatcher, L. L.; And Others

Analytical methods for determining important components of fission and natural radioactivity found in water are reported. The discussion of each method includes conditions for application of the method, a summary of the method, interferences, required apparatus, procedures, calculations and estimation of precision. Isotopes considered are…

Polynuclear aromatic hydrocarbon analysis using the synchronous scanning luminoscope

NASA Astrophysics Data System (ADS)

Hyfantis, George J., Jr.; Teglas, Matthew S.; Wilbourn, Robert G.

2001-02-01

12 The Synchronous Scanning Luminoscope (SSL) is a field- portable, synchronous luminescence spectrofluorometer that was developed for on-site analysis of contaminated soil and ground water. The SSL is capable of quantitative analysis of total polynuclear aromatic hydrocarbons (PAHs) using phosphorescence and fluorescence techniques with a high correlation to laboratory data as illustrated by this study. The SSL is also capable of generating benzo(a)pyrene equivalency results, based on seven carcinogenic PAHs and Navy risk numbers, with a high correlation to laboratory data as illustrated by this study. These techniques allow rapid field assessments of total PAHs and benzo(a)pyrene equivalent concentrations. The Luminoscope is capable of detecting total PAHs to the parts per billion range. This paper describes standard field methods for using the SSL and describes the results of field/laboratory testing of PAHs. SSL results from two different hazardous waste sites are discussed.

Application of selected methods of remote sensing for detecting carbonaceous water pollution

NASA Technical Reports Server (NTRS)

Davis, E. M.; Fosbury, W. J.

1973-01-01

A reach of the Houston Ship Channel was investigated during three separate overflights correlated with ground truth sampling on the Channel. Samples were analyzed for such conventional parameters as biochemical oxygen demand, chemical oxygen demand, total organic carbon, total inorganic carbon, turbidity, chlorophyll, pH, temperature, dissolved oxygen, and light penetration. Infrared analyses conducted on each sample included reflectance ATR analysis, carbon tetrachloride extraction of organics and subsequent scanning, and KBr evaporate analysis of CCl4 extract concentrate. Imagery which was correlated with field and laboratory data developed from ground truth sampling included that obtained from aerial KA62 hardware, RC-8 metric camera systems, and the RS-14 infrared scanner. The images were subjected to analysis by three film density gradient interpretation units. Data were then analyzed for correlations between imagery interpretation as derived from the three instruments and laboratory infrared signatures and other pertinent field and laboratory analyses.

Mother Earth Chemistry: A Laboratory Course for Nonmajors

NASA Astrophysics Data System (ADS)

Roberts, J. L.; Selco, J. I.; Wacks, D. B.

1996-08-01

Mother Earth Chemistry is a laboratory-based course designed to introduce nonscience majors to chemistry using familiar products such as beer, soap, yogurt, and cheese as well as products made from soybeans, including soymilk, tofu, and tempeh. Students make the products and learn some of the chemistry and biochemistry involved in their home manufacture as well as the rudiments of chemical analysis, stoichiometry, and the scientific method.

Role and Evaluation of Interlaboratory Comparison Results in Laboratory Accreditation

NASA Astrophysics Data System (ADS)

Bode, P.

2008-08-01

Participation in interlaboratory comparisons provides laboratories an opportunity for independent assessment of their analytical performance, both in absolute way and in comparison with those by other techniques. However, such comparisons are hindered by differences in the way laboratories participate, e.g. at best measurement capability or under routine conditions. Neutron activation analysis laboratories, determining total mass fractions, often see themselves classified as `outliers' since the majority of other participants employ techniques with incomplete digestion methods. These considerations are discussed in relation to the way results from interlaboratory comparisons are evaluated by accreditation bodies following the requirements of Clause 5.9.1 of the ISO/IEC 17025:2005. The discussion and conclusions come largely forth from experiences in the author's own laboratory.

Comparison of urine analysis using manual and sedimentation methods.

PubMed

Kurup, R; Leich, M

2012-06-01

Microscopic examination of urine sediment is an essential part in the evaluation of renal and urinary tract diseases. Traditionally, urine sediments are assessed by microscopic examination of centrifuged urine. However the current method used by the Georgetown Public Hospital Corporation Medical Laboratory involves uncentrifuged urine. To encourage high level of care, the results provided to the physician must be accurate and reliable for proper diagnosis. The aim of this study is to determine whether the centrifuge method is more clinically significant than the uncentrifuged method. In this study, a comparison between the results obtained from centrifuged and uncentrifuged methods were performed. A total of 167 urine samples were randomly collected and analysed during the period April-May 2010 at the Medical Laboratory, Georgetown Public Hospital Corporation. The urine samples were first analysed microscopically by the uncentrifuged, and then by the centrifuged method. The results obtained from both methods were recorded in a log book. These results were then entered into a database created in Microsoft Excel, and analysed for differences and similarities using this application. Analysis was further done in SPSS software to compare the results using Pearson ' correlation. When compared using Pearson's correlation coefficient analysis, both methods showed a good correlation between urinary sediments with the exception of white bloods cells. The centrifuged method had a slightly higher identification rate for all of the parameters. There is substantial agreement between the centrifuged and uncentrifuged methods. However the uncentrifuged method provides for a rapid turnaround time.

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

Reverse transcription loop-mediated isothermal amplification (RT-LAMP), a light for mammalian transcript analysis in low-input laboratories.

PubMed

Pandey, Mamta; Singh, Dheer; Onteru, Suneel K

2018-06-01

Transcript analysis is usually performed by costly, time-consuming, and expertise intensive methods, like real time-PCR, microarray, etc. However, they are not much feasible in low-input laboratories. Therefore, we implemented the reverse transcription loop-mediated isothermal amplification (RT-LAMP) as a means of mammalian transcript analysis. Particularly, RT-LAMP was developed for buffalo aromatase cytochrome P450 (CYP19) transcript, to study its expression in 3D-cultured buffalo granulosa cells, which were exposed to lipopolysaccharide (LPS). The CYP19-RT-LAMP assay rapidly identified the LPS-induced downregulation of the CYP19 gene within 30 min at 63°C in a water bath. The assay was visualized via unaided eye by observing the change in turbidity and fluorescence, which were decreased by increasing the LPS exposure time to granulosa cells. Overall, the developed CYP19-RT-LAMP assay provided a hope on the application of RT-LAMP for mammalian transcript analysis in low-input laboratories. © 2017 Wiley Periodicals, Inc.

Soil Gas Sampling

EPA Pesticide Factsheets

Field Branches Quality System and Technical Procedures: This document describes general and specific procedures, methods and considerations to be used and observed when collecting soil gas samples for field screening or laboratory analysis.

Chromatography

MedlinePlus

Pincus MR, Lifshitz MS, Bock JL. Analysis: principles of instrumentation. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods . 23rd ed. St Louis, MO: Elsevier; 2017:chap 4.

ERLN Biological Focus Area

EPA Pesticide Factsheets

The Environmental Response Laboratory Network supports the goal to increase national capacity for biological analysis of environmental samples. This includes methods development and verification, technology transfer, and collaboration with USDA, FERN, CDC.

Tracing footprints of environmental events in tree ring chemistry using neutron activation analysis

NASA Astrophysics Data System (ADS)

Sahin, Dagistan

The aim of this study is to identify environmental effects on tree-ring chemistry. It is known that industrial pollution, volcanic eruptions, dust storms, acid rain and similar events can cause substantial changes in soil chemistry. Establishing whether a particular group of trees is sensitive to these changes in soil environment and registers them in the elemental chemistry of contemporary growth rings is the over-riding goal of any Dendrochemistry research. In this study, elemental concentrations were measured in tree-ring samples of absolutely dated eleven modern forest trees, grown in the Mediterranean region, Turkey, collected and dated by the Malcolm and Carolyn Wiener Laboratory for Aegean and Near Eastern Dendrochronology laboratory at Cornell University. Correlations between measured elemental concentrations in the tree-ring samples were analyzed using statistical tests to answer two questions. Does the current concentration of a particular element depend on any other element within the tree? And, are there any elements showing correlated abnormal concentration changes across the majority of the trees? Based on the detailed analysis results, the low mobility of sodium and bromine, positive correlations between calcium, zinc and manganese, positive correlations between trace elements lanthanum, samarium, antimony, and gold within tree-rings were recognized. Moreover, zinc, lanthanum, samarium and bromine showed strong, positive correlations among the trees and were identified as possible environmental signature elements. New Dendrochemistry information found in this study would be also useful in explaining tree physiology and elemental chemistry in Pinus nigra species grown in Turkey. Elemental concentrations in tree-ring samples were measured using Neutron Activation Analysis (NAA) at the Pennsylvania State University Radiation Science and Engineering Center (RSEC). Through this study, advanced methodologies for methodological, computational and experimental NAA were developed to ensure an acceptable accuracy and certainty in the elemental concentration measurements in tree-ring samples. Two independent analysis methods of NAA were used; the well known k-zero method and a novel method developed in this study, called the Multi-isotope Iterative Westcott (MIW) method. The MIW method uses reaction rate probabilities for a group of isotopes, which can be calculated by a neutronic simulation or measured by experimentation, and determines the representative values for the neutron flux and neutron flux characterization parameters based on Westcott convention. Elemental concentration calculations for standard reference material and tree-ring samples were then performed using the MIW and k-zero analysis methods of the NAA and the results were cross verified. In the computational part of this study, a detailed burnup coupled neutronic simulation was developed to analyze real-time neutronic changes in a TRIGA Mark III reactor core, in this study, the Penn State Breazeale Reactor (PSBR) core. To the best of the author`s knowledge, this is the first burnup coupled neutronic simulation with realistic time steps and full fuel temperature profile for a TRIGA reactor using Monte Carlo Utility for Reactor Evolutions (MURE) code and Monte Carlo Neutral-Particle Code (MCNP) coupling. High fidelity and flexibility in the simulation was aimed to replicate the real core operation through the day. This approach resulted in an enhanced accuracy in neutronic representation of the PSBR core with respect to previous neutronic simulation models for the PSBR core. An important contribution was made in the NAA experimentation practices employed in Dendrochemistry studies at the RSEC. Automated laboratory control and analysis software for NAA measurements in the RSEC Radionuclide Applications Laboratory was developed. Detailed laboratory procedures were written in this study comprising preparation, handling and measurements of tree-ring samples in the Radionuclide Applications Laboratory.

Woodstove Emission Sampling Methods Comparability Analysis and In-situ Evaluation of New Technology Woodstoves.

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

Simons, Carl A.

1988-06-01

One major objective of this study was to compare several woodstove particulate emission sampling methods under laboratory and in-situ conditions. The laboratory work compared the EPA Method 5H, EPA Method 5G, and OMNI Automated Woodstove Emission Sampler (AWES)/Data LOG'r particulate emission sampling systems. A second major objective of the study was to evaluate the performance of two integral catalytic, two low emission non-catalytic, and two conventional technology woodstoves under in-situ conditions with AWES/Data LOG'r system. The AWES/Data LOG'r and EPA Method 5G sampling systems were also compared in an in-situ test on one of the integral catalytic woodstove models. 7more » figs., 12 tabs.« less

Results of the Round Robin on opening-load measurement conducted by ASTM Task Group E24.04.04 on Crack Closure Measurement and Analysis

NASA Technical Reports Server (NTRS)

Phillips, Edward P.

1989-01-01

An experimental Round Robin on the measurement of the opening load in fatigue crack growth tests was conducted on Crack Closure Measurement and Analysis. The Round Robin evaluated the current level of consistency of opening load measurements among laboratories and to identify causes for observed inconsistency. Eleven laboratories participated in the testing of compact and middle-crack specimens. Opening-load measurements were made for crack growth at two stress-intensity factor levels, three crack lengths, and following an overload. All opening-load measurements were based on the analysis of specimen compliance data. When all of the results reported (from all participants, all measurement methods, and all data analysis methods) for a given test condition were pooled, the range of opening loads was very large--typically spanning the lower half of the fatigue loading cycle. Part of the large scatter in the reported opening-load results was ascribed to consistent differences in results produced by the various methods used to measure specimen compliance and to evaluate the opening load from the compliance data. Another significant portion of the scatter was ascribed to lab-to-lab differences in producing the compliance data when using nominally the same method of measurement.

Laboratory and 3-D distinct element analysis of the failure mechanism of a slope under external surcharge

NASA Astrophysics Data System (ADS)

Li, N.; Cheng, Y. M.

2015-01-01

Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient detail. There is however increasing interest in the consequences after the initiation of failure that includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more detail and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and a laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanisms and the post-failure mechanisms of slopes will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure, which can give additional information not available from the classical methods of analysis.

Laboratory and 3-D-distinct element analysis of failure mechanism of slope under external surcharge

NASA Astrophysics Data System (ADS)

Li, N.; Cheng, Y. M.

2014-09-01

Landslide is a major disaster resulting in considerable loss of human lives and property damages in hilly terrain in Hong Kong, China and many other countries. The factor of safety and the critical slip surface for slope stabilization are the main considerations for slope stability analysis in the past, while the detailed post-failure conditions of the slopes have not been considered in sufficient details. There are however increasing interest on the consequences after the initiation of failure which includes the development and propagation of the failure surfaces, the amount of failed mass and runoff and the affected region. To assess the development of slope failure in more details and to consider the potential danger of slopes after failure has initiated, the slope stability problem under external surcharge is analyzed by the distinct element method (DEM) and laboratory model test in the present research. A more refined study about the development of failure, microcosmic failure mechanism and the post-failure mechanism of slope will be carried out. The numerical modeling method and the various findings from the present work can provide an alternate method of analysis of slope failure which can give additional information not available from the classical methods of analysis.

40 CFR 408.141 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to this subpart. (b) The term oil and grease shall mean those components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c) The term seafood shall...

40 CFR 408.11 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to this subpart. (b) The term oil and grease shall mean those components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c) The term seafood shall...

40 CFR 408.51 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... apply to this subpart. (b) The term oil and grease shall mean those components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c) The term seafood shall...

Measurement of Air Pollutants in the Troposphere

ERIC Educational Resources Information Center

Clemitshaw, Kevin C.

2011-01-01

This article describes the principles, applications and performances of methods to measure gas-phase air pollutants that either utilise passive or active sampling with subsequent laboratory analysis or involve automated "in situ" sampling and analysis. It focuses on air pollutants that have adverse impacts on human health (nitrogen…

Removing external DNA contamination from arthropod predators destined for molecular gut-content analysis

USDA-ARS?s Scientific Manuscript database

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed pred...

Removing external DNA decontamination from arthropod predators destined for molecular gut-content analysis

USDA-ARS?s Scientific Manuscript database

Molecular gut-content analysis enables detection of arthropod predation with minimal disruption of ecosystem processes. Field and laboratory experiments have demonstrated that mass-collection methods, such as sweep-netting, vacuum sampling, and foliage beating, can lead to contamination of fed pred...

Safety and health practice among laboratory staff in Malaysian education sector

NASA Astrophysics Data System (ADS)

Husna Che Hassan, Nurul; Rasdan Ismail, Ahmad; Kamilah Makhtar, Nor; Azwadi Sulaiman, Muhammad; Syuhadah Subki, Noor; Adilah Hamzah, Noor

2017-10-01

Safety is the most important issue in industrial sector such as construction and manufacturing. Recently, the increasing number of accident cases reported involving school environment shows the important of safety issues in education sector. Safety awareness among staff in this sector is crucial in order to find out the method to prevent the accident occurred in future. This study was conducted to analyze the knowledge of laboratory staff in term of safety and health practice in laboratory. Survey questionnaires were distributing among 255 of staff laboratory from ten District Education Offices in Kelantan. Descriptive analysis shows that the understanding of safety and health practice are low while doing some job activities in laboratory. Furthermore, some of the staff also did not implemented safety practice that may contribute to unplanned event occur in laboratory. Suggestion that the staff at laboratory need to undergo on Occupational Safety and Health training to maintain and create safe environment in workplaces.

Development and Multi-laboratory Verification of U.S. EPA Method 540 for the Analysis of Drinking Water Contaminants by Solid Phase Extraction-LC/MS/MS

EPA Science Inventory

A drinking water method for 12 chemicals, predominately pesticides, is presented that addresses the occurrence monitoring needs of the U.S. Environmental Protection Agency (EPA) for a future Unregulated Contaminant Monitoring Regulation (UCMR). The method employs solid phase ext...

Development and Multi-laboratory Verification of US EPA Method 543 for the Analysis of Drinking Water Contaminants by Online Solid Phase Extraction-LC–MS-MS

EPA Science Inventory

A drinking water method for seven pesticides and pesticide degradates is presented that addresses the occurrence monitoring needs of the US Environmental Protection Agency (EPA) for a future Unregulated Contaminant Monitoring Regulation (UCMR). The method employs online solid pha...

Integrated Data Collection Analysis (IDCA) Program - Final Review September 12, 2012 at DHS

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Warner, Kirstin F.

The Integrated Data Collection Analysis (IDCA) program conducted a final program review at the Department of Homeland Security on September 12, 2012. The review was focused on the results of the program over the complete performance period. A summary presentation delineating the accomplished tasks started the meeting, followed by technical presentations on various issues that arose during the performance period. The presentations were completed with a statistical evaluation of the testing results from all the participants in the IDCA Proficiency Test study. The meeting closed with a discussion of potential sources of funding for continuing work to resolve some ofmore » these technical issues. This effort, funded by the Department of Homeland Security (DHS), put the issues of safe handling of these materials in perspective with standard military explosives. The study added Small-Scale Safety and Thermal (SSST) testing results for a broad suite of different HMEs to the literature, and suggested new guidelines and methods to develop safe handling practices for HMEs. Each participating testing laboratory used identical test materials and preparation methods wherever possible. Note, however, the test procedures differ among the laboratories. The results were compared among the laboratories and then compared to historical data from various sources. The testing performers involved were Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Naval Surface Warfare Center, Indian Head Division (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory, Tyndall AFB (AFRL/RXQL). These tests were conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent.« less

Non-matrix Matched Glass Disk Calibration Standards Improve XRF Micronutrient Analysis of Wheat Grain across Five Laboratories in India

PubMed Central

Guild, Georgia E.; Stangoulis, James C. R.

2016-01-01

Within the HarvestPlus program there are many collaborators currently using X-Ray Fluorescence (XRF) spectroscopy to measure Fe and Zn in their target crops. In India, five HarvestPlus wheat collaborators have laboratories that conduct this analysis and their throughput has increased significantly. The benefits of using XRF are its ease of use, minimal sample preparation and high throughput analysis. The lack of commercially available calibration standards has led to a need for alternative calibration arrangements for many of the instruments. Consequently, the majority of instruments have either been installed with an electronic transfer of an original grain calibration set developed by a preferred lab, or a locally supplied calibration. Unfortunately, neither of these methods has been entirely successful. The electronic transfer is unable to account for small variations between the instruments, whereas the use of a locally provided calibration set is heavily reliant on the accuracy of the reference analysis method, which is particularly difficult to achieve when analyzing low levels of micronutrient. Consequently, we have developed a calibration method that uses non-matrix matched glass disks. Here we present the validation of this method and show this calibration approach can improve the reproducibility and accuracy of whole grain wheat analysis on 5 different XRF instruments across the HarvestPlus breeding program. PMID:27375644

Evaluation of a multiresidue method for measuring fourteen chemical groups of pesticides in water by use of LC-MS-MS.

PubMed

Carvalho, J J; Jerónimo, P C A; Gonçalves, C; Alpendurada, M F

2008-11-01

European Council Directive 98/83/EC on the quality of water intended for human consumption brought a new challenge for water-quality control routine laboratories, mainly on pesticides analysis. Under the guidelines of ISO/IEC 17025:2005, a multiresidue method was developed, validated, implemented in routine, and studied with real samples during a one-year period. The proposed method enables routine laboratories to handle a large number of samples, since 28 pesticides of 14 different chemical groups can be quantitated in a single procedure. The method comprises a solid-phase extraction step and subsequent analysis by liquid chromatography-mass spectrometry (LC-MS-MS). The accuracy was established on the basis of participation in interlaboratory proficiency tests, with encouraging results (majority |z-score| <2), and the precision was consistently analysed over one year. The limits of quantitation (below 0.050 microg L(-1)) are in agreement with the enforced threshold value for pesticides of 0.10 microg L(-1). Overall method performance is suitable for routine use according to accreditation rules, taking into account the data collected over one year.

High Throughput Analytical Techniques for the Determination and Confirmation of Residues of 653 Multiclass Pesticides and Chemical Pollutants in Tea by GC/MS, GC/MS/MS, and LC/MS/MS: Collaborative Study, First Action 2014.09.

PubMed

Pang, Guo-Fang; Fan, Chun-Lin; Cao, Yan-Zhong; Yan, Fang; Li, Yan; Kang, Jian; Chen, Hui; Chang, Qiao-Ying

2015-01-01

Thirty laboratories from fom North and South America, Europe, and Asia participated in this AOAC collaborative study (15 from China; five from Germany; two each from Italy and the United States; and one each from the Republic of Korea, Canada, Spain, Japan, Belgium, and India). Participants represented government regulatory, commercial testing, university, research institute, and private laboratories. The single-laboratory validated (SLV) tea method was evaluated in the collaborative study to determine the recovery and reproducibility of the method under multilaboratory conditions. Since there were no restrictions regarding the type of analytical instrumentation to use for the analyses, laboratories used a combination of equipment that included GC/MS, GC/MS/MS, and LC/MS/MS instruments from 22 different manufacturers, 21 brands of GC and LC columns, 13 different GC temperature programming profiles, 11 LC gradient elution programs, and six different vendor manufactured SPE cartridges. Even though all the analytical performance parameters for all the 653 compounds had been determined in the SLV study, guidance was obtained from an expert review panel of the AOAC Method-Centric Committee on Pesticide Residues to conduct the multilaboratory collaborative study based on 20 selected compounds that can be analyzed by GC/MS and 20 compounds that can be analyzed by LC/MS/MS. Altogether, 560 samples covering the 40 selected pesticides were analyzed in the study. These samples included green tea and oolong tea samples fortified typically at the European Union maximum residue limit for regulatory guidance and compliance, aged tea samples incurred with 20 pesticides, and green tea and oolong tea samples incurred with five pesticides. The analysis of the 560 samples generated a total of 82 459 test results by the 30 participating laboratories. One laboratory failed to meet the proficiency requirements in the precollaborative study. Therefore, its data submitted for the collaborative study were excluded from further analysis and interpretation. The results presented are therefore the 6638 analytical results obtained from the 29 remaining laboratories, which included 1977 results generated by GC/MS, 1704 results by GC/MS/MS, and 2957 results by LC/MS/MS. It was determined after application of the Grubbs and Dixon tests for outliers to the data sets that there were 65 outlier results from the 1977 GC/MS results (3.3%), 65 outlier results from the 1704 GC/MS/MS results (3.8%), and 57 outlier results out of 2957 LC/MS/MS results (1.9%), representing 0.98, 0.98, and 0.86%, respectively, of the 6638 results generated in the study. Analysis with the AOAC statistical software package also confirmed that the method is rugged, and average recovery, average concentration, RSDr, RSDR, and HorRat values all meet recovery and reproducibility criteria for use in multiple laboratories. The Study Director is recommending this method for adoption as an AOAC First Action Official MethodSM.

Research and development of a field-ready protocol for sampling of phosgene from stationary source emissions: Diethylamine reagent studies. Research report, 11 July 1995--30 September 1996

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

Steger, J.L.; Bursey, J.T.; Merrill, R.G.

1999-03-01

This report presents the results of laboratory studies to develop and evaluate a method for the sampling and analysis of phosgene from stationary sources of air emissions using diethylamine (DEA) in toluene as the collection media. The method extracts stack gas from emission sources and stabilizes the reactive gas for subsequent analysis. DEA was evaluated both in a benchtop study and in a laboratory train spiking study. This report includes results for both the benchtop study and the train spiking study. Benchtop studies to evaluate the suitability of DEA for collecting and analyzing phosgene investigated five variables: storage time, DEAmore » concentration, moisture/pH, phosgene concentration, and sample storage temperature. Prototype sampling train studies were performed to determine if the benchtop chemical studies were transferable to a Modified Method 5 sampling train collecting phosgene in the presence of clean air mixed with typical stack gas components. Four conditions, which varied the moisture and phosgene spike were evaluated in triplicate. In addition to research results, the report includes a detailed draft method for sampling and analysis of phosgene from stationary source emissions.« less

Analysis of food taints and off-flavours: a review.

PubMed

Ridgway, K; Lalljie, S P D; Smith, R M

2010-02-01

Taints and off-flavours in foods are a major concern to the food industry. Identification of the compound(s) causing a taint or off-flavour in food and accurate quantification are critical in assessing the potential safety risks of a product or ingredient. Even when the tainting compound(s) are not at a level that would cause a safety concern, taints and off-flavours can have a significant impact on the quality and consumers' acceptability of products. The analysis of taints and off-flavour compounds presents an analytical challenge especially in an industrial laboratory environment because of the low levels, often complex matrices and potential for contamination from external laboratory sources. This review gives an outline of the origins of chemical taints and off-flavours and looks at the methods used for analysis and the merits and drawbacks of each technique. Extraction methods and instrumentation are covered along with possible future developments. Generic screening methods currently lack the sensitivity required to detect the low levels required for some tainting compounds and a more targeted approach is often required. This review highlights the need for a rapid but sensitive universal method of extraction for the unequivocal determination of tainting compounds in food.

A Simplified Digestion Protocol for the Analysis of Hg in Fish by Cold Vapor Atomic Absorption Spectroscopy

ERIC Educational Resources Information Center

Kristian, Kathleen E.; Friedbauer, Scott; Kabashi, Donika; Ferencz, Kristen M.; Barajas, Jennifer C.; O'Brien, Kelly

2015-01-01

Analysis of mercury in fish is an interesting problem with the potential to motivate students in chemistry laboratory courses. The recommended method for mercury analysis in fish is cold vapor atomic absorption spectroscopy (CVAAS), which requires homogeneous analyte solutions, typically prepared by acid digestion. Previously published digestion…

Qualitative Organic Analysis: An Efficient, Safer, and Economical Approach to Preliminary Tests and Functional Group Analysis

ERIC Educational Resources Information Center

Dhingra, Sunita; Angrish, Chetna

2011-01-01

Qualitative organic analysis of an unknown compound is an integral part of the university chemistry laboratory curriculum. This type of training is essential as students learn to approach a problem systematically and to interpret the results logically. However, considerable quantities of waste are generated by using conventional methods of…

Homogeneity study of a corn flour laboratory reference material candidate for inorganic analysis.

PubMed

Dos Santos, Ana Maria Pinto; Dos Santos, Liz Oliveira; Brandao, Geovani Cardoso; Leao, Danilo Junqueira; Bernedo, Alfredo Victor Bellido; Lopes, Ricardo Tadeu; Lemos, Valfredo Azevedo

2015-07-01

In this work, a homogeneity study of a corn flour reference material candidate for inorganic analysis is presented. Seven kilograms of corn flour were used to prepare the material, which was distributed among 100 bottles. The elements Ca, K, Mg, P, Zn, Cu, Fe, Mn and Mo were quantified by inductively coupled plasma optical emission spectrometry (ICP OES) after acid digestion procedure. The method accuracy was confirmed by analyzing the rice flour certified reference material, NIST 1568a. All results were evaluated by analysis of variance (ANOVA) and principal component analysis (PCA). In the study, a sample mass of 400mg was established as the minimum mass required for analysis, according to the PCA. The between-bottle test was performed by analyzing 9 bottles of the material. Subsamples of a single bottle were analyzed for the within-bottle test. No significant differences were observed for the results obtained through the application of both statistical methods. This fact demonstrates that the material is homogeneous for use as a laboratory reference material. Copyright © 2015 Elsevier Ltd. All rights reserved.

An International Ki67 Reproducibility Study

PubMed Central

2013-01-01

Background In breast cancer, immunohistochemical assessment of proliferation using the marker Ki67 has potential use in both research and clinical management. However, lack of consistency across laboratories has limited Ki67’s value. A working group was assembled to devise a strategy to harmonize Ki67 analysis and increase scoring concordance. Toward that goal, we conducted a Ki67 reproducibility study. Methods Eight laboratories received 100 breast cancer cases arranged into 1-mm core tissue microarrays—one set stained by the participating laboratory and one set stained by the central laboratory, both using antibody MIB-1. Each laboratory scored Ki67 as percentage of positively stained invasive tumor cells using its own method. Six laboratories repeated scoring of 50 locally stained cases on 3 different days. Sources of variation were analyzed using random effects models with log2-transformed measurements. Reproducibility was quantified by intraclass correlation coefficient (ICC), and the approximate two-sided 95% confidence intervals (CIs) for the true intraclass correlation coefficients in these experiments were provided. Results Intralaboratory reproducibility was high (ICC = 0.94; 95% CI = 0.93 to 0.97). Interlaboratory reproducibility was only moderate (central staining: ICC = 0.71, 95% CI = 0.47 to 0.78; local staining: ICC = 0.59, 95% CI = 0.37 to 0.68). Geometric mean of Ki67 values for each laboratory across the 100 cases ranged 7.1% to 23.9% with central staining and 6.1% to 30.1% with local staining. Factors contributing to interlaboratory discordance included tumor region selection, counting method, and subjective assessment of staining positivity. Formal counting methods gave more consistent results than visual estimation. Conclusions Substantial variability in Ki67 scoring was observed among some of the world’s most experienced laboratories. Ki67 values and cutoffs for clinical decision-making cannot be transferred between laboratories without standardizing scoring methodology because analytical validity is limited. PMID:24203987

Analysis of cocoa flavanols and procyanidins (DP 1-10) in cocoa-containing ingredients and products by rapid resolution liquid chromatography: single-laboratory validation.

PubMed

Machonis, Philip R; Jones, Matthew A; Kwik-Uribe, Catherine

2014-01-01

Recently, a multilaboratory validation (MLV) of AOAC Official Method 2012.24 for the determination of cocoa flavanols and procyanidins (CF-CP) in cocoa-based ingredients and products determined that the method was robust, reliable, and transferrable. Due to the complexity of the CF-CP molecules, this method required a run time exceeding 1 h to achieve acceptable separations. To address this issue, a rapid resolution normal phase LC method was developed, and a single-laboratory validation (SLV) study conducted. Flavanols and procyanidins with a degree of polymerization (DP) up to 10 were eluted in 15 min using a binary gradient applied to a diol stationary phase, detected using fluorescence detection, and reported as a total sum of DP 1-10. Quantification was achieved using (-)-epicatechin-based relative response factors for DP 2-10. Spike recovery samples and seven different types of cocoa-based samples were analyzed to evaluate the accuracy, precision, LOD, LOQ, and linearity of the method. The within-day precision of the reported content for the samples was 1.15-5.08%, and overall precision was 3.97-13.61%. Spike-recovery experiments demonstrated recoveries of over 98%. The results of this SLV were compared to those previously obtained in the MLV and found to be consistent. The translation to rapid resolution LC allowed for an 80% reduction in analysis time and solvent usage, while retaining the accuracy and reliability of the original method. The savings in both cost and time of this rapid method make it well-suited for routine laboratory use.

The effect of ion-exchange purification on the determination of plutonium at the New Brunswick Laboratory

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

Mitchell, W.G.; Spaletto, M.I.; Lewis, K.

The method of plutonium (Pu) determination at the Brunswick Laboratory (NBL) consists of a combination of ion-exchange purification followed by controlled-potential coulometric analysis (IE/CPC). The present report's purpose is to quantify any detectable Pu loss occurring in the ion-exchange (IE) purification step which would cause a negative bias in the NBL method for Pu analysis. The magnitude of any such loss would be contained within the reproducibility (0.05%) of the IE/CPC method which utilizes a state-of-the-art autocoulometer developed at NBL. When the NBL IE/CPC method is used for Pu analysis, any loss in ion-exchange purification (<0.05%) is confounded with themore » repeatability of the ion-exchange and the precision of the CPC analysis technique (<0.05%). Consequently, to detect a bias in the IE/CPC method due to the IE alone using the IE/CPC method itself requires that many randomized analyses on a single material be performed over time and that statistical analysis of the data be performed. The initial approach described in this report to quantify any IE loss was an independent method, Isotope Dilution Mass Spectrometry; however, the number of analyses performed was insufficient to assign a statistically significant value to the IE loss (<0.02% of 10 mg samples of Pu). The second method used for quantifying any IE loss of Pu was multiple ion exchanges of the same Pu aliquant; the small number of analyses possible per individual IE together with the column-to-column variability over multiple ion exchanges prevented statistical detection of any loss of <0.05%. 12 refs.« less

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust.

PubMed

Barone, T L; Patts, J R; Janisko, S J; Colinet, J F; Patts, L D; Beck, T W; Mischler, S E

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine.

Sampling and analysis method for measuring airborne coal dust mass in mixtures with limestone (rock) dust

PubMed Central

Barone, T. L.; Patts, J. R.; Janisko, S. J.; Colinet, J. F.; Patts, L. D.; Beck, T. W.; Mischler, S. E.

2016-01-01

Airborne coal dust mass measurements in underground bituminous coal mines can be challenged by the presence of airborne limestone dust, which is an incombustible dust applied to prevent the propagation of dust explosions. To accurately measure the coal portion of this mixed airborne dust, the National Institute for Occupational Safety and Health (NIOSH) developed a sampling and analysis protocol that used a stainless steel cassette adapted with an isokinetic inlet and the low temperature ashing (LTA) analytical method. The Mine Safety and Health Administration (MSHA) routinely utilizes this LTA method to quantify the incombustible content of bulk dust samples collected from the roof, floor, and ribs of mining entries. The use of the stainless steel cassette with isokinetic inlet allowed NIOSH to adopt the LTA method for the analysis of airborne dust samples. Mixtures of known coal and limestone dust masses were prepared in the laboratory, loaded into the stainless steel cassettes, and analyzed to assess the accuracy of this method. Coal dust mass measurements differed from predicted values by an average of 0.5%, 0.2%, and 0.1% for samples containing 20%, 91%, and 95% limestone dust, respectively. The ability of this method to accurately quantify the laboratory samples confirmed the validity of this method and allowed NIOSH to successfully measure the coal fraction of airborne dust samples collected in an underground coal mine. PMID:26618374

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

The breaking load method - Results and statistical modification from the ASTM interlaboratory test program

NASA Technical Reports Server (NTRS)

Colvin, E. L.; Emptage, M. R.

1992-01-01

The breaking load test provides quantitative stress corrosion cracking data by determining the residual strength of tension specimens that have been exposed to corrosive environments. Eight laboratories have participated in a cooperative test program under the auspices of ASTM Committee G-1 to evaluate the new test method. All eight laboratories were able to distinguish between three tempers of aluminum alloy 7075. The statistical analysis procedures that were used in the test program do not work well in all situations. An alternative procedure using Box-Cox transformations shows a great deal of promise. An ASTM standard method has been drafted which incorporates the Box-Cox procedure.

Reporting standards for Bland-Altman agreement analysis in laboratory research: a cross-sectional survey of current practice.

PubMed

Chhapola, Viswas; Kanwal, Sandeep Kumar; Brar, Rekha

2015-05-01

To carry out a cross-sectional survey of the medical literature on laboratory research papers published later than 2012 and available in the common search engines (PubMed, Google Scholar) on the quality of statistical reporting of method comparison studies using Bland-Altman (B-A) analysis. Fifty clinical studies were identified which had undertaken method comparison of laboratory analytes using B-A. The reporting of B-A was evaluated using a predesigned checklist with following six items: (1) correct representation of x-axis on B-A plot, (2) representation and correct definition of limits of agreement (LOA), (3) reporting of confidence interval (CI) of LOA, (4) comparison of LOA with a priori defined clinical criteria, (5) evaluation of the pattern of the relationship between difference (y-axis) and average (x-axis) and (6) measures of repeatability. The x-axis and LOA were presented correctly in 94%, comparison with a priori clinical criteria in 74%, CI reporting in 6%, evaluation of pattern in 28% and repeatability assessment in 38% of studies. There is incomplete reporting of B-A in published clinical studies. Despite its simplicity, B-A appears not to be completely understood by researchers, reviewers and editors of journals. There appear to be differences in the reporting of B-A between laboratory medicine journals and other clinical journals. A uniform reporting of B-A method will enhance the generalizability of results. © The Author(s) 2014 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Pathology economic model tool: a novel approach to workflow and budget cost analysis in an anatomic pathology laboratory.

PubMed

Muirhead, David; Aoun, Patricia; Powell, Michael; Juncker, Flemming; Mollerup, Jens

2010-08-01

The need for higher efficiency, maximum quality, and faster turnaround time is a continuous focus for anatomic pathology laboratories and drives changes in work scheduling, instrumentation, and management control systems. To determine the costs of generating routine, special, and immunohistochemical microscopic slides in a large, academic anatomic pathology laboratory using a top-down approach. The Pathology Economic Model Tool was used to analyze workflow processes at The Nebraska Medical Center's anatomic pathology laboratory. Data from the analysis were used to generate complete cost estimates, which included not only materials, consumables, and instrumentation but also specific labor and overhead components for each of the laboratory's subareas. The cost data generated by the Pathology Economic Model Tool were compared with the cost estimates generated using relative value units. Despite the use of automated systems for different processes, the workflow in the laboratory was found to be relatively labor intensive. The effect of labor and overhead on per-slide costs was significantly underestimated by traditional relative-value unit calculations when compared with the Pathology Economic Model Tool. Specific workflow defects with significant contributions to the cost per slide were identified. The cost of providing routine, special, and immunohistochemical slides may be significantly underestimated by traditional methods that rely on relative value units. Furthermore, a comprehensive analysis may identify specific workflow processes requiring improvement.

SIMILARITY PROPERTIES AND SCALING LAWS OF RADIATION HYDRODYNAMIC FLOWS IN LABORATORY ASTROPHYSICS

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

Falize, E.; Bouquet, S.; Michaut, C., E-mail: emeric.falize@cea.fr

The spectacular recent development of modern high-energy density laboratory facilities which concentrate more and more energy in millimetric volumes allows the astrophysical community to reproduce and to explore, in millimeter-scale targets and during very short times, astrophysical phenomena where radiation and matter are strongly coupled. The astrophysical relevance of these experiments can be checked from the similarity properties and especially scaling law establishment, which constitutes the keystone of laboratory astrophysics. From the radiating optically thin regime to the so-called optically thick radiative pressure regime, we present in this paper, for the first time, a complete analysis of the main radiatingmore » regimes that we encountered in laboratory astrophysics with the same formalism based on Lie group theory. The use of the Lie group method appears to be a systematic method which allows us to construct easily and systematically the scaling laws of a given problem. This powerful tool permits us to unify the recent major advances on scaling laws and to identify new similarity concepts that we discuss in this paper, and suggests important applications for present and future laboratory astrophysics experiments. All these results enable us to demonstrate theoretically that astrophysical phenomena in such radiating regimes can be explored experimentally thanks to powerful facilities. Consequently, the results presented here are a fundamental tool for the high-energy density laboratory astrophysics community in order to quantify the astrophysics relevance and justify laser experiments. Moreover, relying on Lie group theory, this paper constitutes the starting point of any analysis of the self-similar dynamics of radiating fluids.« less

Determining the Population Size of Pond Phytoplankton.

ERIC Educational Resources Information Center

Hummer, Paul J.

1980-01-01

Discusses methods for determining the population size of pond phytoplankton, including water sampling techniques, laboratory analysis of samples, and additional studies worthy of investigation in class or as individual projects. (CS)

Dual-Laboratory Validation of a Method for the Determination of Fructans in Infant Formula and Adult Nutritionals: First Action 2016.14.

PubMed

Brunt, Kommer; Sanders, Peter; Spichtig, Véronique; Ernste-Nota, Veronica; Sawicka, Paulina; Iwanoff, Kimberley; Van Soest, Jeroen; Lin, Paul Kong Thoo; Austin, Sean

2017-05-01

Until recently, only two AOAC Official MethodsSM have been available for the analysis of fructans: Method 997.08 and Method 999.03. Both are based on the analysis of the fructan component monosaccharides (glucose and fructose) after hydrolysis. The two methods have some limitations due to the strategies used for removing background interferences (such as from sucrose, α-glucooligosaccharides, and free sugars). The method described in this paper has been developed to overcome those limitations. The method is largely based on Method 999.03 and uses combined enzymatic and SPE steps to remove the interfering components without impacting the final analytical result. The method has been validated in two laboratories on infant formula and adult nutritionals. Recoveries were in the range of 86-119%, with most being in the range of 91-104%. RSDr values were in the range of 0.7-2.6%, with one exception when the fructan concentration was close to the LOQ, resulting in an RSDr of 8.9%. The performance is generally within the requirements outlined in the AOAC Standard Method Performance Requirements (SMPR® 2014.002), which specifies recoveries in the range of 90-110% and RSDr values below 6%.

Data Acquisition Using Xbox Kinect Sensor

ERIC Educational Resources Information Center

Ballester, Jorge; Pheatt, Charles B.

2012-01-01

The study of motion is central in physics education and has taken many forms as technology has provided numerous methods to acquire data. For example, the analysis of still or moving images is particularly effective in discussions of two-dimensional motion. Introductory laboratory measurement methods have progressed through water clocks, spark…

The Location of Sources of Human Computer Processed Cerebral Potentials for the Automated Assessment of Visual Field Impairment

PubMed Central

Leisman, Gerald; Ashkenazi, Maureen

1979-01-01

Objective psychophysical techniques for investigating visual fields are described. The paper concerns methods for the collection and analysis of evoked potentials using a small laboratory computer and provides efficient methods for obtaining information about the conduction pathways of the visual system.

77 FR 14814 - Tobacco Product Analysis; Scientific Workshop; Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-13

... work to develop tobacco reference products that are not currently available for laboratory use. Discuss... methods used to analyze tobacco products. FDA will invite speakers to address scientific and technical matters relating to the testing of tobacco reference products and the analytical methods used to measure...

40 CFR 408.41 - Specialized definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... shall apply to this subpart. (b) The term oil and grease shall mean those components of a waste water amenable to measurement by the method described in Methods for Chemical Analysis of Water and Wastes, 1971, Environmental Protection Agency, Analytical Quality Control Laboratory, page 217. (c) The term seafood shall...

The Development of Analytical Method for the Determination of Azelaic Acid Content in Cosmetic Cream Products

NASA Astrophysics Data System (ADS)

Lusianti, E.; Wibowo, R.; Hudiyono, S.

2018-01-01

Azelaic acid is one of the substances that has anti-acne and skin lightening effects which is often added to cosmetics. In the acne treatment, the azelaic acid is generally used with a concentration of 20% in cream formulation and 15% in gel. The use at concentrations below 10% is not recommended because it does not work effectively. While the use of above 10% is categorized as a medical treatment. In Indonesia, the Head of the National Agency of Drug and Food Control (BPOM) has issued Regulation No. 18 of 2015 on the Technical Requirements of Cosmetics Ingredients Annex V stating that the azelaic acid is banned in cosmetics. However, until this research began the BPOM has not had a valid method to identify it in cosmetics. Consequently, surveillance of such ingredient in products is hard to do. In this research, the fatty acid standard analysis method of AOAC International was modified and validated to be used in the laboratory. The method of analysis involves heating the cream preparations dissolved with methanol and then added BF3-methanol catalyst, followed by extraction and analysis using GCMS. The validation of method shows that the calibration curve is linear with correlative value of 0.9997. The method is fairly sensitive with 0.02% detection limit, and fairly precision with relative standard deviation (RSD) of between 0.626-0.961% and fairly accurate which the recovery percentage is 99.85% at range 98.27-100.72%. In sum the results demonstrate that the method can be used as a routine analysis method for laboratory testing.

The instruments in the first psychological laboratory in Mexico: antecedents, influence, and methods.

PubMed

Escobar, Rogelio

2014-11-01

Enrique O. Aragón established the first psychological laboratory in Mexico in 1916. This laboratory was inspired by Wundt's laboratory and by those created afterward in Germany and the United States. It was equipped with state-of-the art instruments imported from Germany in 1902 from Ernst Zimmermann who supplied instruments for Wundt's laboratory. Although previous authors have described the social events leading to the creation of the laboratory, there are limited descriptions of the instruments, their use, and their influence. With the aid of archival resources, the initial location of the laboratory was determined. The analysis of instruments revealed a previously overlooked relation with a previous laboratory of experimental physiology. The influence of the laboratory was traced by describing the careers of 4 students, 3 of them women, who worked with the instruments during the first 2 decades of the 20th century, each becoming accomplished scholars. In addition, this article, by identifying and analyzing the instruments shown in photographs of the psychological laboratory and in 1 motion film, provides information of the class demonstrations and the experiments conducted in this laboratory.

Interlaboratory comparison of chemical analysis of uranium mononitride

NASA Technical Reports Server (NTRS)

Merkle, E. J.; Davis, W. F.; Halloran, J. T.; Graab, J. W.

1974-01-01

Analytical methods were established in which the critical variables were controlled, with the result that acceptable interlaboratory agreement was demonstrated for the chemical analysis of uranium mononitride. This was accomplished by using equipment readily available to laboratories performing metallurgical analyses. Agreement among three laboratories was shown to be very good for uranium and nitrogen. Interlaboratory precision of + or - 0.04 percent was achieved for both of these elements. Oxygen was determined to + or - 15 parts per million (ppm) at the 170-ppm level. The carbon determination gave an interlaboratory precision of + or - 46 ppm at the 320-ppm level.

Using the failure mode and effects analysis model to improve parathyroid hormone and adrenocorticotropic hormone testing

PubMed Central

Magnezi, Racheli; Hemi, Asaf; Hemi, Rina

2016-01-01

Background Risk management in health care systems applies to all hospital employees and directors as they deal with human life and emergency routines. There is a constant need to decrease risk and increase patient safety in the hospital environment. The purpose of this article is to review the laboratory testing procedures for parathyroid hormone and adrenocorticotropic hormone (which are characterized by short half-lives) and to track failure modes and risks, and offer solutions to prevent them. During a routine quality improvement review at the Endocrine Laboratory in Tel Hashomer Hospital, we discovered these tests are frequently repeated unnecessarily due to multiple failures. The repetition of the tests inconveniences patients and leads to extra work for the laboratory and logistics personnel as well as the nurses and doctors who have to perform many tasks with limited resources. Methods A team of eight staff members accompanied by the Head of the Endocrine Laboratory formed the team for analysis. The failure mode and effects analysis model (FMEA) was used to analyze the laboratory testing procedure and was designed to simplify the process steps and indicate and rank possible failures. Results A total of 23 failure modes were found within the process, 19 of which were ranked by level of severity. The FMEA model prioritizes failures by their risk priority number (RPN). For example, the most serious failure was the delay after the samples were collected from the department (RPN =226.1). Conclusion This model helped us to visualize the process in a simple way. After analyzing the information, solutions were proposed to prevent failures, and a method to completely avoid the top four problems was also developed. PMID:27980440

Validation of a near infrared microscopy method for the detection of animal products in feedingstuffs: results of a collaborative study.

PubMed

Boix, A; Fernández Pierna, J A; von Holst, C; Baeten, V

2012-01-01

The performance characteristics of a near infrared microscopy (NIRM) method, when applied to the detection of animal products in feedingstuffs, were determined via a collaborative study. The method delivers qualitative results in terms of the presence or absence of animal particles in feed and differentiates animal from vegetable feed ingredients on the basis of the evaluation of near infrared spectra obtained from individual particles present in the sample. The specificity ranged from 86% to 100%. The limit of detection obtained on the analysis of the sediment fraction, prepared as for the European official method, was 0.1% processed animal proteins (PAPs) in feed, since all laboratories correctly identified the positive samples. This limit has to be increased up to 2% for the analysis of samples which are not sedimented. The required sensitivity for the official control is therefore achieved in the analysis of the sediment fraction of the samples where the method can be applied for the detection of the presence of animal meal. Criteria for the classification of samples, when fewer than five spectra are found, as being of animal origin needs to be set up in order to harmonise the approach taken by the laboratories when applying NIRM for the detection of the presence of animal meal in feed.

Integration of ANFIS, NN and GA to determine core porosity and permeability from conventional well log data

NASA Astrophysics Data System (ADS)

Ja'fari, Ahmad; Hamidzadeh Moghadam, Rasoul

2012-10-01

Routine core analysis provides useful information for petrophysical study of the hydrocarbon reservoirs. Effective porosity and fluid conductivity (permeability) could be obtained from core analysis in laboratory. Coring hydrocarbon bearing intervals and analysis of obtained cores in laboratory is expensive and time consuming. In this study an improved method to make a quantitative correlation between porosity and permeability obtained from core and conventional well log data by integration of different artificial intelligent systems is proposed. The proposed method combines the results of adaptive neuro-fuzzy inference system (ANFIS) and neural network (NN) algorithms for overall estimation of core data from conventional well log data. These methods multiply the output of each algorithm with a weight factor. Simple averaging and weighted averaging were used for determining the weight factors. In the weighted averaging method the genetic algorithm (GA) is used to determine the weight factors. The overall algorithm was applied in one of SW Iran’s oil fields with two cored wells. One-third of all data were used as the test dataset and the rest of them were used for training the networks. Results show that the output of the GA averaging method provided the best mean square error and also the best correlation coefficient with real core data.

Introducing Education for Sustainable Development in the Undergraduate Laboratory: Quantitative Analysis of Bioethanol Fuel and Its Blends with Gasoline by Using Solvatochromic Dyes

ERIC Educational Resources Information Center

Galgano, Paula D.; Loffredo, Carina; Sato, Bruno M.; Reichardt, Christian; El Seoud, Omar A.

2012-01-01

The concept of "Education for Sustainable Development", ESD, has been introduced in a period where chemistry education is undergoing a major change, both in emphasis and methods of teaching. Studying an everyday problem, with an important socio-economic impact in the laboratory is a part of this approach. Presently, the students in many…

Educational Software for Interference and Optical Diffraction Analysis in Fresnel and Fraunhofer Regions Based on MATLAB GUIs and the FDTD Method

ERIC Educational Resources Information Center

Frances, J.; Perez-Molina, M.; Bleda, S.; Fernandez, E.; Neipp, C.; Belendez, A.

2012-01-01

Interference and diffraction of light are elementary topics in optics. The aim of the work presented here is to develop an accurate and cheap optical-system simulation software that provides a virtual laboratory for studying the effects of propagation in both time and space for the near- and far-field regions. In laboratory sessions, this software…

Pressure-Assisted Chelating Extraction as a Teaching Tool in Instrumental Analysis

ERIC Educational Resources Information Center

Sadik, Omowunmi A.; Wanekaya, Adam K.; Yevgeny, Gelfand

2004-01-01

A novel instrumental-digestion technique using pressure-assisted chelating extraction (PACE), for undergraduate laboratory is reported. This procedure is used for exposing students to safe sample-preparation techniques, for correlating wet-chemical methods with modern instrumental analysis and comparing the performance of PACE with conventional…

A query for effective mean particle size of dry and high moisture corns

USDA-ARS?s Scientific Manuscript database

Eighteen dry and high moisture corns submitted to the University of Wisconsin Soil and Forage Analysis Laboratory (Marshfield, WI) for routine analysis were retained for mean particle size (MPS) and chemistry determinations. Mean particle size of corns was determined by the methods of the American S...

A Discussion of Water Pollution in the United States and Mexico; with High School Laboratory Activities for Analysis of Lead, Atrazine, and Nitrate.

ERIC Educational Resources Information Center

Kelter, Paul B.; Grundman, Julie; Hage, David S.; Carr, James D.; Castro-Acuna, Carlos Mauricio

1997-01-01

Presents discussions on sources, health impacts, methods of analysis as well as lengthy discussions of lead, nitrates, and atrazine as related to water pollution and the interdisciplinary nature of the modern chemistry curriculum. (DKM)

Analysis of a Suspected Drug Sample

ERIC Educational Resources Information Center

Schurter, Eric J.; Zook-Gerdau, Lois Anne; Szalay, Paul

2011-01-01

This general chemistry laboratory uses differences in solubility to separate a mixture of caffeine and aspirin while introducing the instrumental analysis methods of GCMS and FTIR. The drug mixture is separated by partitioning aspirin and caffeine between dichloromethane and aqueous base. TLC and reference standards are used to identify aspirin…

Multi-laboratory validation study of multilocus variable-number tandem repeat analysis (MLVA) for Salmonella enterica serovar Enteritidis, 2015

PubMed Central

Peters, Tansy; Bertrand, Sophie; Björkman, Jonas T; Brandal, Lin T; Brown, Derek J; Erdõsi, Tímea; Heck, Max; Ibrahem, Salha; Johansson, Karin; Kornschober, Christian; Kotila, Saara M; Le Hello, Simon; Lienemann, Taru; Mattheus, Wesley; Nielsen, Eva Møller; Ragimbeau, Catherine; Rumore, Jillian; Sabol, Ashley; Torpdahl, Mia; Trees, Eija; Tuohy, Alma; de Pinna, Elizabeth

2017-01-01

Multilocus variable-number tandem repeat analysis (MLVA) is a rapid and reproducible typing method that is an important tool for investigation, as well as detection, of national and multinational outbreaks of a range of food-borne pathogens. Salmonella enterica serovar Enteritidis is the most common Salmonella serovar associated with human salmonellosis in the European Union/European Economic Area and North America. Fourteen laboratories from 13 countries in Europe and North America participated in a validation study for MLVA of S. Enteritidis targeting five loci. Following normalisation of fragment sizes using a set of reference strains, a blinded set of 24 strains with known allele sizes was analysed by each participant. The S. Enteritidis 5-loci MLVA protocol was shown to produce internationally comparable results as more than 90% of the participants reported less than 5% discrepant MLVA profiles. All 14 participating laboratories performed well, even those where experience with this typing method was limited. The raw fragment length data were consistent throughout, and the inter-laboratory validation helped to standardise the conversion of raw data to repeat numbers with at least two countries updating their internal procedures. However, differences in assigned MLVA profiles remain between well-established protocols and should be taken into account when exchanging data. PMID:28277220

Inter-laboratory analysis of selected genetically modified plant reference materials with digital PCR.

PubMed

Dobnik, David; Demšar, Tina; Huber, Ingrid; Gerdes, Lars; Broeders, Sylvia; Roosens, Nancy; Debode, Frederic; Berben, Gilbert; Žel, Jana

2018-01-01

Digital PCR (dPCR), as a new technology in the field of genetically modified (GM) organism (GMO) testing, enables determination of absolute target copy numbers. The purpose of our study was to test the transferability of methods designed for quantitative PCR (qPCR) to dPCR and to carry out an inter-laboratory comparison of the performance of two different dPCR platforms when determining the absolute GM copy numbers and GM copy number ratio in reference materials certified for GM content in mass fraction. Overall results in terms of measured GM% were within acceptable variation limits for both tested dPCR systems. However, the determined absolute copy numbers for individual genes or events showed higher variability between laboratories in one third of the cases, most possibly due to variability in the technical work, droplet size variability, and analysis of the raw data. GMO quantification with dPCR and qPCR was comparable. As methods originally designed for qPCR performed well in dPCR systems, already validated qPCR assays can most generally be used for dPCR technology with the purpose of GMO detection. Graphical abstract The output of three different PCR-based platforms was assessed in an inter-laboratory comparison.

Determining the optimal forensic DNA analysis procedure following investigation of sample quality.

PubMed

Hedell, Ronny; Hedman, Johannes; Mostad, Petter

2018-07-01

Crime scene traces of various types are routinely sent to forensic laboratories for analysis, generally with the aim of addressing questions about the source of the trace. The laboratory may choose to analyse the samples in different ways depending on the type and quality of the sample, the importance of the case and the cost and performance of the available analysis methods. Theoretically well-founded guidelines for the choice of analysis method are, however, lacking in most situations. In this paper, it is shown how such guidelines can be created using Bayesian decision theory. The theory is applied to forensic DNA analysis, showing how the information from the initial qPCR analysis can be utilized. It is assumed the alternatives for analysis are using a standard short tandem repeat (STR) DNA analysis assay, using the standard assay and a complementary assay, or the analysis may be cancelled following quantification. The decision is based on information about the DNA amount and level of DNA degradation of the forensic sample, as well as case circumstances and the cost for analysis. Semi-continuous electropherogram models are used for simulation of DNA profiles and for computation of likelihood ratios. It is shown how tables and graphs, prepared beforehand, can be used to quickly find the optimal decision in forensic casework.

Livers provide a reliable matrix for real-time PCR confirmation of avian botulism.

PubMed

Le Maréchal, Caroline; Ballan, Valentine; Rouxel, Sandra; Bayon-Auboyer, Marie-Hélène; Baudouard, Marie-Agnès; Morvan, Hervé; Houard, Emmanuelle; Poëzevara, Typhaine; Souillard, Rozenn; Woudstra, Cédric; Le Bouquin, Sophie; Fach, Patrick; Chemaly, Marianne

2016-04-01

Diagnosis of avian botulism is based on clinical symptoms, which are indicative but not specific. Laboratory investigations are therefore required to confirm clinical suspicions and establish a definitive diagnosis. Real-time PCR methods have recently been developed for the detection of Clostridium botulinum group III producing type C, D, C/D or D/C toxins. However, no study has been conducted to determine which types of matrices should be analyzed for laboratory confirmation using this approach. This study reports on the comparison of different matrices (pooled intestinal contents, livers, spleens and cloacal swabs) for PCR detection of C. botulinum. Between 2013 and 2015, 63 avian botulism suspicions were tested and 37 were confirmed as botulism. Analysis of livers using real-time PCR after enrichment led to the confirmation of 97% of the botulism outbreaks. Using the same method, spleens led to the confirmation of 90% of botulism outbreaks, cloacal swabs of 93% and pooled intestinal contents of 46%. Liver appears to be the most reliable type of matrix for laboratory confirmation using real-time PCR analysis. Copyright © 2015 Elsevier Ltd. All rights reserved.

Comparative Study in Laboratory Rats to Validate Sperm Quality Methods and Endpoints

NASA Technical Reports Server (NTRS)

Price, W. A.; Briggs, G. B.; Alexander, W. K.; Still, K. R.; Grasman, K. A.

2000-01-01

Abstract The Naval Health Research Center, Detachment (Toxicology) performs toxicity studies in laboratory animals to characterize the risk of exposure to chemicals of Navy interest. Research was conducted at the Toxicology Detachment at WPAFB, OH in collaboration with Wright State University, Department of Biological Sciences for the validation of new bioassay methods for evaluating reproductive toxicity. The Hamilton Thorne sperm analyzer was used to evaluate sperm damage produced by exposure to a known testicular toxic agent, methoxyacetic acid and by inhalation exposure to JP-8 and JP-5 in laboratory rats. Sperm quality parameters were evaluated (sperm concentration, motility, and morphology) to provide evidence of sperm damage. The Hamilton Thorne sperm analyzer utilizes a DNA specific fluorescent stain (similar to flow cytometry) and digitized optical computer analysis to detect sperm cell damage. The computer assisted sperm analysis (CASA) is a more rapid, robust, predictive and sensitive method for characterizing reproductive toxicity. The results presented in this poster report validation information showing exposure to methoxyacetic acid causes reproductive toxicity and inhalation exposure to JP-8 and JP-5 had no significant effects. The CASA method detects early changes that result in reproductive deficits and these data will be used in a continuing program to characterize the toxicity of chemicals, and combinations of chemicals, of military interest to formulate permissible exposure limits.

H. W. Laboratory manual: 100 Area section

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

Not Available

1950-07-01

The purpose of this manual is to present a Hazard Breakdown of all jobs normally encountered in the laboratory work of the three sections comprising the Analytic Section, Metallurgy and Control Division of the Technical Department. A Hazard Breakdown is a careful analysis of any job in which the source of possible dangers is clearly indicated for each particular step. The analysis is prepared by individuals who are thoroughly familiar with the specific job or procedure. It is felt that if the hazards herein outlined are recognized by the Laboratory personnel and the suggested safety cautions followed, the chance formore » injury will be minimized and the worker will become generally more safety conscious. The manual, which is prefaced by the general safety rules applying to all the laboratories, is divided into three main sections, one for each of the three sections into which the Laboratories Division is divided. These sections are as follows: Section 1 -- 200 Area Control; Section 2 -- 100 Area Control; Section 3 -- 300 Area Control, Essential Materials, and Methods Improvement.« less

Methods for collection and analysis of water samples

USGS Publications Warehouse

Rainwater, Frank Hays; Thatcher, Leland Lincoln

1960-01-01

This manual contains methods used by the U.S. Geological Survey to collect, preserve, and analyze water samples. Throughout, the emphasis is on obtaining analytical results that accurately describe the chemical composition of the water in situ. Among the topics discussed are selection of sampling sites, frequency of sampling, field equipment, preservatives and fixatives, analytical techniques of water analysis, and instruments. Seventy-seven laboratory and field procedures are given for determining fifty-three water properties.

Coagulation dynamics of a blood sample by multiple scattering analysis

NASA Astrophysics Data System (ADS)

Faivre, Magalie; Peltié, Philippe; Planat-Chrétien, Anne; Cosnier, Marie-Line; Cubizolles, Myriam; Nougier, Christophe; Négrier, Claude; Pouteau, Patrick

2011-05-01

We report a new technique to measure coagulation dynamics on whole-blood samples. The method relies on the analysis of the speckle figure resulting from a whole-blood sample mixed with coagulation reagent and introduced in a thin chamber illuminated with a coherent light. A dynamic study of the speckle reveals a typical behavior due to coagulation. We compare our measured coagulation times to a reference method obtained in a medical laboratory.

A survey of current practices for genomic sequencing test interpretation and reporting processes in US laboratories.

PubMed

O'Daniel, Julianne M; McLaughlin, Heather M; Amendola, Laura M; Bale, Sherri J; Berg, Jonathan S; Bick, David; Bowling, Kevin M; Chao, Elizabeth C; Chung, Wendy K; Conlin, Laura K; Cooper, Gregory M; Das, Soma; Deignan, Joshua L; Dorschner, Michael O; Evans, James P; Ghazani, Arezou A; Goddard, Katrina A; Gornick, Michele; Farwell Hagman, Kelly D; Hambuch, Tina; Hegde, Madhuri; Hindorff, Lucia A; Holm, Ingrid A; Jarvik, Gail P; Knight Johnson, Amy; Mighion, Lindsey; Morra, Massimo; Plon, Sharon E; Punj, Sumit; Richards, C Sue; Santani, Avni; Shirts, Brian H; Spinner, Nancy B; Tang, Sha; Weck, Karen E; Wolf, Susan M; Yang, Yaping; Rehm, Heidi L

2017-05-01

While the diagnostic success of genomic sequencing expands, the complexity of this testing should not be overlooked. Numerous laboratory processes are required to support the identification, interpretation, and reporting of clinically significant variants. This study aimed to examine the workflow and reporting procedures among US laboratories to highlight shared practices and identify areas in need of standardization. Surveys and follow-up interviews were conducted with laboratories offering exome and/or genome sequencing to support a research program or for routine clinical services. The 73-item survey elicited multiple choice and free-text responses that were later clarified with phone interviews. Twenty-one laboratories participated. Practices highly concordant across all groups included consent documentation, multiperson case review, and enabling patient opt-out of incidental or secondary findings analysis. Noted divergence included use of phenotypic data to inform case analysis and interpretation and reporting of case-specific quality metrics and methods. Few laboratory policies detailed procedures for data reanalysis, data sharing, or patient access to data. This study provides an overview of practices and policies of experienced exome and genome sequencing laboratories. The results enable broader consideration of which practices are becoming standard approaches, where divergence remains, and areas of development in best practice guidelines that may be helpful.Genet Med advance online publication 03 Novemeber 2016.

A comparison of two laboratories for the measurement of wood dust using button sampler and diffuse reflection infrared Fourier-transform spectroscopy (DRIFTS).

PubMed

Chirila, Madalina M; Sarkisian, Khachatur; Andrew, Michael E; Kwon, Cheol-Woong; Rando, Roy J; Harper, Martin

2015-04-01

The current measurement method for occupational exposure to wood dust is by gravimetric analysis and is thus non-specific. In this work, diffuse reflection infrared Fourier transform spectroscopy (DRIFTS) for the analysis of only the wood component of dust was further evaluated by analysis of the same samples between two laboratories. Field samples were collected from six wood product factories using 25-mm glass fiber filters with the Button aerosol sampler. Gravimetric mass was determined in one laboratory by weighing the filters before and after aerosol collection. Diffuse reflection mid-infrared spectra were obtained from the wood dust on the filter which is placed on a motorized stage inside the spectrometer. The metric used for the DRIFTS analysis was the intensity of the carbonyl band in cellulose and hemicellulose at ~1735 cm(-1). Calibration curves were constructed separately in both laboratories using the same sets of prepared filters from the inhalable sampling fraction of red oak, southern yellow pine, and western red cedar in the range of 0.125-4 mg of wood dust. Using the same procedure in both laboratories to build the calibration curve and analyze the field samples, 62.3% of the samples measured within 25% of the average result with a mean difference between the laboratories of 18.5%. Some observations are included as to how the calibration and analysis can be improved. In particular, determining the wood type on each sample to allow matching to the most appropriate calibration increases the apparent proportion of wood dust in the sample and this likely provides more realistic DRIFTS results. Published by Oxford University Press on behalf of the British Occupational Hygiene Society 2014.

Mechanistic flexible pavement overlay design program.

DOT National Transportation Integrated Search

2009-07-01

The current Louisiana Department of Transportation and Development (LADOTD) overlay thickness design method follows the Component : Analysis procedure provided in the 1993 AASHTO pavement design guide. Since neither field nor laboratory tests a...

24 CFR 35.1315 - Collection and laboratory analysis of samples.

Code of Federal Regulations, 2013 CFR

2013-04-01

... of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1315...

24 CFR 35.1315 - Collection and laboratory analysis of samples.

Code of Federal Regulations, 2014 CFR

2014-04-01

... of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1315...

24 CFR 35.1315 - Collection and laboratory analysis of samples.

Code of Federal Regulations, 2012 CFR

2012-04-01

... of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1315...

24 CFR 35.1315 - Collection and laboratory analysis of samples.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1315...

24 CFR 35.1315 - Collection and laboratory analysis of samples.

Code of Federal Regulations, 2011 CFR

2011-04-01

... of Housing and Urban Development LEAD-BASED PAINT POISONING PREVENTION IN CERTAIN RESIDENTIAL STRUCTURES Methods and Standards for Lead-Paint Hazard Evaluation and Hazard Reduction Activities § 35.1315...

Mathematics for the Student Scientist.

ERIC Educational Resources Information Center

Lauten, A. Darien; Lauten, Gary N.

1998-01-01

Describes the Earth Day-Forest Watch Program which introduces kindergarten through high school level students to field laboratory and satellite-data analysis methods for assessing the health of Eastern White Pine forest stands. (DDR)

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

An investigative graduate laboratory course for teaching modern DNA techniques.

PubMed

de Lencastre, Alexandre; Thomas Torello, A; Keller, Lani C

2017-07-08

This graduate-level DNA methods laboratory course is designed to model a discovery-based research project and engages students in both traditional DNA analysis methods and modern recombinant DNA cloning techniques. In the first part of the course, students clone the Drosophila ortholog of a human disease gene of their choosing using Gateway ® cloning. In the second part of the course, students examine the expression of their gene of interest in human cell lines by reverse transcription PCR and learn how to analyze data from quantitative reverse transcription PCR (qRT-PCR) experiments. The adaptability of the Gateway ® cloning system is ideally suited for students to design and create different types of expression constructs to achieve a particular experimental goal (e.g., protein purification, expression in cell culture, and/or subcellular localization), and the genes chosen can be aligned to the research interests of the instructor and/or ongoing research in a department. Student evaluations indicate that the course fostered a genuine excitement for research and in depth knowledge of both the techniques performed and the theory behind them. Our long-term goal is to incorporate this DNA methods laboratory as the foundation for an integrated laboratory sequence for the Master of Science degree program in Molecular and Cellular Biology at Quinnipiac University, where students use the reagents and concepts they developed in this course in subsequent laboratory courses, including a protein methods and cell culture laboratory. © 2017 by The International Union of Biochemistry and Molecular Biology, 45(4):351-359, 2017. © 2017 The International Union of Biochemistry and Molecular Biology.

Direct PCR amplification of forensic touch and other challenging DNA samples: A review.

PubMed

Cavanaugh, Sarah E; Bathrick, Abigail S

2018-01-01

DNA evidence sample processing typically involves DNA extraction, quantification, and STR amplification; however, DNA loss can occur at both the DNA extraction and quantification steps, which is not ideal for forensic evidence containing low levels of DNA. Direct PCR amplification of forensic unknown samples has been suggested as a means to circumvent extraction and quantification, thereby retaining the DNA typically lost during those procedures. Direct PCR amplification is a method in which a sample is added directly to an amplification reaction without being subjected to prior DNA extraction, purification, or quantification. It allows for maximum quantities of DNA to be targeted, minimizes opportunities for error and contamination, and reduces the time and monetary resources required to process samples, although data analysis may take longer as the increased DNA detection sensitivity of direct PCR may lead to more instances of complex mixtures. ISO 17025 accredited laboratories have successfully implemented direct PCR for limited purposes (e.g., high-throughput databanking analysis), and recent studies indicate that direct PCR can be an effective method for processing low-yield evidence samples. Despite its benefits, direct PCR has yet to be widely implemented across laboratories for the processing of evidentiary items. While forensic DNA laboratories are always interested in new methods that will maximize the quantity and quality of genetic information obtained from evidentiary items, there is often a lag between the advent of useful methodologies and their integration into laboratories. Delayed implementation of direct PCR of evidentiary items can be attributed to a variety of factors, including regulatory guidelines that prevent laboratories from omitting the quantification step when processing forensic unknown samples, as is the case in the United States, and, more broadly, a reluctance to validate a technique that is not widely used for evidence samples. The advantages of direct PCR of forensic evidentiary samples justify a re-examination of the factors that have delayed widespread implementation of this method and of the evidence supporting its use. In this review, the current and potential future uses of direct PCR in forensic DNA laboratories are summarized. Copyright © 2017 Elsevier B.V. All rights reserved.

Lessons learned from implementing a wet laboratory molecular training workshop for beach water quality monitoring.

PubMed

Verhougstraete, Marc Paul; Brothers, Sydney; Litaker, Wayne; Blackwood, A Denene; Noble, Rachel

2015-01-01

Rapid molecular testing methods are poised to replace many of the conventional, culture-based tests currently used in fields such as water quality and food science. Rapid qPCR methods have the benefit of being faster than conventional methods and provide a means to more accurately protect public health. However, many scientists and technicians in water and food quality microbiology laboratories have limited experience using these molecular tests. To ensure that practitioners can use and implement qPCR techniques successfully, we developed a week long workshop to provide hands-on training and exposure to rapid molecular methods for water quality management. This workshop trained academic professors, government employees, private industry representatives, and graduate students in rapid qPCR methods for monitoring recreational water quality. Attendees were immersed in these new methods with hands-on laboratory sessions, lectures, and one-on-one training. Upon completion, the attendees gained sufficient knowledge and practice to teach and share these new molecular techniques with colleagues at their respective laboratories. Key findings from this workshop demonstrated: 1) participants with no prior experience could be effectively trained to conduct highly repeatable qPCR analysis in one week; 2) participants with different desirable outcomes required exposure to a range of different platforms and sample processing approaches; and 3) the collaborative interaction amongst newly trained practitioners, workshop leaders, and members of the water quality community helped foster a cohesive cohort of individuals which can advocate powerful cohort for proper implementation of molecular methods.

Lessons Learned from Implementing a Wet Laboratory Molecular Training Workshop for Beach Water Quality Monitoring

PubMed Central

Verhougstraete, Marc Paul; Brothers, Sydney; Litaker, Wayne; Blackwood, A. Denene; Noble, Rachel

2015-01-01

Rapid molecular testing methods are poised to replace many of the conventional, culture-based tests currently used in fields such as water quality and food science. Rapid qPCR methods have the benefit of being faster than conventional methods and provide a means to more accurately protect public health. However, many scientists and technicians in water and food quality microbiology laboratories have limited experience using these molecular tests. To ensure that practitioners can use and implement qPCR techniques successfully, we developed a week long workshop to provide hands-on training and exposure to rapid molecular methods for water quality management. This workshop trained academic professors, government employees, private industry representatives, and graduate students in rapid qPCR methods for monitoring recreational water quality. Attendees were immersed in these new methods with hands-on laboratory sessions, lectures, and one-on-one training. Upon completion, the attendees gained sufficient knowledge and practice to teach and share these new molecular techniques with colleagues at their respective laboratories. Key findings from this workshop demonstrated: 1) participants with no prior experience could be effectively trained to conduct highly repeatable qPCR analysis in one week; 2) participants with different desirable outcomes required exposure to a range of different platforms and sample processing approaches; and 3) the collaborative interaction amongst newly trained practitioners, workshop leaders, and members of the water quality community helped foster a cohesive cohort of individuals which can advocate powerful cohort for proper implementation of molecular methods. PMID:25822486

Integrated Data Collection Analysis (IDCA) Program - AN and Bullseye Smokeless Powder

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

Sandstrom, Mary M.; Brown, Geoffrey W.; Preston, Daniel N.

The Integrated Data Collection Analysis (IDCA) program is conducting a proficiency study for Small- Scale Safety and Thermal (SSST) testing of homemade explosives (HMEs). Described here are the results for impact, friction, electrostatic discharge, and differential scanning calorimetry analysis of ammonium nitrate (AN) mixed with Bullseye® smokeless powder (Gunpowder). The participants found the AN/Gunpowder to: 1) have a range of sensitivity to impact, comparable to or less than RDX, 2) be fairly insensitive to friction as measured by BAM and ABL, 3) have a range for ESD, from insensitive to more sensitive than PETN, and 4) have thermal sensitivity aboutmore » the same as PETN and Gunpowder. This effort, funded by the Department of Homeland Security (DHS), is putting the issues of safe handling of these materials in perspective with standard military explosives. The study is adding SSST testing results for a broad suite of different HMEs to the literature. Ultimately the study has the potential to suggest new guidelines and methods and possibly establish the SSST testing accuracies needed when developing safe handling practices for HMEs. Each participating testing laboratory uses identical test materials and preparation methods. Note, however, the test procedures differ among the laboratories. The testing performers involved are Lawrence Livermore National Laboratory (LLNL), Los Alamos National Laboratory (LANL), Indian Head Division, Naval Surface Warfare Center, (NSWC IHD), Sandia National Laboratories (SNL), and Air Force Research Laboratory (AFRL/RXQL). These tests are conducted as a proficiency study in order to establish some consistency in test protocols, procedures, and experiments and to compare results when these testing variables cannot be made consistent. Keywords: Small-scale safety testing, proficiency test, impact-, friction-, spark discharge-, thermal testing, round-robin test, safety testing protocols, HME, RDX, potassium perchlorate, potassium chlorate, sodium chlorate, sugar, dodecane, PETN, carbon, ammonium nitrate, Gunpowder, Bullseye® smokeless powder.« less

Service quality framework for clinical laboratories.

PubMed

Ramessur, Vinaysing; Hurreeram, Dinesh Kumar; Maistry, Kaylasson

2015-01-01

The purpose of this paper is to illustrate a service quality framework that enhances service delivery in clinical laboratories by gauging medical practitioner satisfaction and by providing avenues for continuous improvement. The case study method has been used for conducting the exploratory study, with focus on the Mauritian public clinical laboratory. A structured questionnaire based on the SERVQUAL service quality model was used for data collection, analysis and for the development of the service quality framework. The study confirms the pertinence of the following service quality dimensions within the context of clinical laboratories: tangibility, reliability, responsiveness, turnaround time, technology, test reports, communication and laboratory staff attitude and behaviour. The service quality framework developed, termed LabSERV, is vital for clinical laboratories in the search for improving service delivery to medical practitioners. This is a pioneering work carried out in the clinical laboratory sector in Mauritius. Medical practitioner expectations and perceptions have been simultaneously considered to generate a novel service quality framework for clinical laboratories.

Development, optimization, validation and application of faster gas chromatography - flame ionization detector method for the analysis of total petroleum hydrocarbons in contaminated soils.

PubMed

Zubair, Abdulrazaq; Pappoe, Michael; James, Lesley A; Hawboldt, Kelly

2015-12-18

This paper presents an important new approach to improving the timeliness of Total Petroleum Hydrocarbon (TPH) analysis in the soil by Gas Chromatography - Flame Ionization Detector (GC-FID) using the CCME Canada-Wide Standard reference method. The Canada-Wide Standard (CWS) method is used for the analysis of petroleum hydrocarbon compounds across Canada. However, inter-laboratory application of this method for the analysis of TPH in the soil has often shown considerable variability in the results. This could be due, in part, to the different gas chromatography (GC) conditions, other steps involved in the method, as well as the soil properties. In addition, there are differences in the interpretation of the GC results, which impacts the determination of the effectiveness of remediation at hydrocarbon-contaminated sites. In this work, multivariate experimental design approach was used to develop and validate the analytical method for a faster quantitative analysis of TPH in (contaminated) soil. A fractional factorial design (fFD) was used to screen six factors to identify the most significant factors impacting the analysis. These factors included: injection volume (μL), injection temperature (°C), oven program (°C/min), detector temperature (°C), carrier gas flow rate (mL/min) and solvent ratio (v/v hexane/dichloromethane). The most important factors (carrier gas flow rate and oven program) were then optimized using a central composite response surface design. Robustness testing and validation of model compares favourably with the experimental results with percentage difference of 2.78% for the analysis time. This research successfully reduced the method's standard analytical time from 20 to 8min with all the carbon fractions eluting. The method was successfully applied for fast TPH analysis of Bunker C oil contaminated soil. A reduced analytical time would offer many benefits including an improved laboratory reporting times, and overall improved clean up efficiency. The method was successfully applied for the analysis of TPH of Bunker C oil in contaminated soil. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Quality in the molecular microbiology laboratory.

PubMed

Wallace, Paul S; MacKay, William G

2013-01-01

In the clinical microbiology laboratory advances in nucleic acid detection, quantification, and sequence analysis have led to considerable improvements in the diagnosis, management, and monitoring of infectious diseases. Molecular diagnostic methods are routinely used to make clinical decisions based on when and how to treat a patient as well as monitor the effectiveness of a therapeutic regime and identify any potential drug resistant strains that may impact on the long term patient treatment program. Therefore, confidence in the reliability of the result provided by the laboratory service to the clinician is essential for patient treatment. Hence, suitable quality assurance and quality control measures are important to ensure that the laboratory methods and service meet the necessary regulatory requirements both at the national and international level. In essence, the modern clinical microbiology laboratory ensures the appropriateness of its services through a quality management system that monitors all aspects of the laboratory service pre- and post-analytical-from patient sample receipt to reporting of results, from checking and upholding staff competency within the laboratory to identifying areas for quality improvements within the service offered. For most European based clinical microbiology laboratories this means following the common International Standard Organization (ISO9001) framework and ISO15189 which sets out the quality management requirements for the medical laboratory (BS EN ISO 15189 (2003) Medical laboratories-particular requirements for quality and competence. British Standards Institute, Bristol, UK). In the United States clinical laboratories performing human diagnostic tests are regulated by the Centers for Medicare and Medicaid Services (CMS) following the requirements within the Clinical Laboratory Improvement Amendments document 1988 (CLIA-88). This chapter focuses on the key quality assurance and quality control requirements within the modern microbiology laboratory providing molecular diagnostics.

Rapid Radiochemical Methods for Asphalt Paving Material ...

EPA Pesticide Factsheets

Technical Brief Validated rapid radiochemical methods for alpha and beta emitters in solid matrices that are commonly encountered in urban environments were previously unavailable for public use by responding laboratories. A lack of tested rapid methods would delay the quick determination of contamination levels and the assessment of acceptable site-specific exposure levels. Of special concern are matrices with rough and porous surfaces, which allow the movement of radioactive material deep into the building material making it difficult to detect. This research focuses on methods that address preparation, radiochemical separation, and analysis of asphalt paving materials and asphalt roofing shingles. These matrices, common to outdoor environments, challenge the capability and capacity of very experienced radiochemistry laboratories. Generally, routine sample preparation and dissolution techniques produce liquid samples (representative of the original sample material) that can be processed using available radiochemical methods. The asphalt materials are especially difficult because they do not readily lend themselves to these routine sample preparation and dissolution techniques. The HSRP and ORIA coordinate radiological reference laboratory priorities and activities in conjunction with HSRP’s Partner Process. As part of the collaboration, the HSRP worked with ORIA to publish rapid radioanalytical methods for selected radionuclides in building material matrice

Comparative evaluation of matrix-assisted laser desorption ionisation-time of flight mass spectrometry and conventional phenotypic-based methods for identification of clinically important yeasts in a UK-based medical microbiology laboratory.

PubMed

Fatania, Nita; Fraser, Mark; Savage, Mike; Hart, Jason; Abdolrasouli, Alireza

2015-12-01

Performance of matrix-assisted laser desorption ionisation-time of flight mass spectrometry (MALDI-TOF MS) was compared in a side-by side-analysis with conventional phenotypic methods currently in use in our laboratory for identification of yeasts in a routine diagnostic setting. A diverse collection of 200 clinically important yeasts (19 species, five genera) were identified by both methods using standard protocols. Discordant or unreliable identifications were resolved by sequencing of the internal transcribed spacer region of the rRNA gene. MALDI-TOF and conventional methods were in agreement for 182 isolates (91%) with correct identification to species level. Eighteen discordant results (9%) were due to rarely encountered species, hence the difficulty in their identification using traditional phenotypic methods. MALDI-TOF MS enabled rapid, reliable and accurate identification of clinically important yeasts in a routine diagnostic microbiology laboratory. Isolates with rare, unusual or low probability identifications should be confirmed using robust molecular methods. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/

Rapid determination of fumonisins in corn-based products by liquid chromatography/tandem mass spectrometry.

PubMed

Li, Wei; Herrman, Timothy J; Dai, Susie Y

2010-01-01

A simple, fast, and robust method was developed for the determination of fumonisin B1 (FB1), fumonisin B2 (FB2), and fumonisin B3 (FB3) in corn-based human food and animal feed (cornmeal). The method involves a single extraction step followed by centrifugation and filtration before analysis by ultra-performance liquid chromatographylelectrospray ionization (UPLC/ESI)-MS/MS. The LC/MS/MS method developed here represents the fastest and simplest procedure (<30 min) among both conventional HPLC methods and other LC/MS methods using SPE cleanup. The potential for high throughput analysis makes the method particularly beneficial for regulatory agencies and analytical laboratories with a high sample volume. A single-laboratory validation was conducted by testing three different spiking levels (200, 500, and 1000 ng/g for FB1 and FB2; 100, 250, and 500 ng/g for FB3) for accuracy and precision. Recoveries of FB1 ranged from 93 to 98% with RSD values of 3-8%. Recoveries of FB2 ranged from 104 to 108%, with RSD values of 2-6%. Recoveries of FB3 ranged from 94 to 108%, with RSD values of 2-5%.

P300: Waves Identification with and without Subtraction of Traces

PubMed Central

Romero, Ana Carla Leite; Reis, Ana Cláudia Mirândola Barbosa; Oliveira, Anna Caroline Silva de; Oliveira Simões, Humberto de; Oliveira Junqueira, Cinthia Amorim de; Frizzo, Ana Cláudia Figueiredo

2017-01-01

Introduction  The P300 test requires well-defined and unique criteria, in addition to training for the examiners, for a uniform analysis of studies and to avoid variations and errors in the interpretation of measurement results. Objectives  The objective of this study is to verify whether there are differences in P300 with and without subtraction of traces of standard and nonstandard stimuli. Method  We conducted this study in collaboration with two research electrophysiology laboratories. From Laboratory 1, we selected 40 tests of subjects between 7–44 years, from Laboratory 2, we selected 83 tests of subjects between 18–44 years. We first performed the identification with the nonstandard stimuli; then, we subtracted the nonstandard stimuli from the standard stimuli. The examiners identified the waves, performing a descriptive and comparative analysis of traces with and without subtraction. Results  After a comparative analysis of the traces with and without subtraction, there was no significant difference when compared with analysis of traces in both laboratories, within the conditions, of right ears ( p  = 0.13 and 0.28 for differences between latency and amplitude measurements) and left ears ( p  = 0.15 and 0.09 for differences between latency and amplitude measurements) from Laboratory 1. As for Laboratory 2, when investigating both ears, results did not identify significant differences ( p  = 0.098 and 0.28 for differences between latency and amplitude measurements). Conclusion  There was no difference verified in traces with and without subtraction. We suggest the identification of this potential performed through nonstandard stimuli. PMID:29018497

Woodstove smoke and CO emissions: comparison of reference methods with the VIP sampler.

PubMed

Jaasma, D R; Champion, M C; Shelton, J W

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO2 concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six different woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.

Woodstove smoke and CO emissions: Comparison of reference methods with the VIP sampler

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

Jaasma, D.R.; Champion, M.C.; Shelton, J.W.

1990-06-01

A new field sampler has been developed for measuring the particulate matter (PM) and carbon monoxide emissions of woodburning stoves. Particulate matter is determined by carbon balance and the workup of a sample train which is similar to a room-temperature EPA Method 5G train. A steel tank, initially evacuated, serves as the motive force for sampling and also accumulates a gas sample for post-test analysis of time-averaged stack CO and CO{sub 2} concentrations. Workup procedures can be completed within 72 hours of sampler retrieval. The system has been compared to reference methods in two laboratory test series involving six differentmore » woodburning appliances and two independent laboratories. The correlation of field sampler emission rates and reference method rates is strong.« less

Results of interlaboratory comparison of fission track ages for 1992 fission track workshop

USGS Publications Warehouse

Miller, D.S.; Crowley, K.D.; Dokka, R.K.; Galbraith, R.F.; Kowallis, B.J.; Naeser, C.W.

1993-01-01

Two apatites and one sphene were made available to the fission track research community for analysis prior to the 1992 Fission Track Workshop held in Philadelphia, U.S.A., 13-17 July. Eighteen laboratories throughout the world received aliquots of apatite and sphene. To date, analyses by 33 different scientists have been representing 15 different laboratories. With respect to the previous two interlaboratory comparisons, there is a noticeable improvement in the accuracy of the age results (Naeser and Cebula, 1978; Naeser et al., 1981; Miller et al., 1985;Miller et al.1990). Ninety-four percent of the analysis used the external detector method (EDM) combined with the zeta technique while the remaining individuals used the population method (POP). Track length measurements (requested for the first time in the interlaboratory comparison studies) were in relatively good agreement. ?? 1993.

Determination of total carbohydrates in wine and wine-like beverages by HPLC with a refractive index detector: First Action 2013.12.

PubMed

Kupina, Steve; Roman, Mark

2014-01-01

An international collaborative study was conducted of an HPLC-refractive index (RI) detector method for the determination of the combined amounts of sugars, glycerol, organic acids, and phenolic compounds in wines and wine-like beverages. Nine collaborating laboratories representing major winery, contract laboratories, and government laboratories tested eight different materials as blind duplicates using the proposed method. Sample materials included red and white wines, port, wine cooler, and nonalcoholic wine. One material was a negative control, and one material was a reference material. Samples were either treated with an ion-exchange resin to remove interfering organic acids prior to analysis or left untreated to include organic acids and phenolics. Red wine samples were treated with polyvinylpolypyrrolidone to remove potential interferences from phenolics prior to analysis. The HPLC analyses were performed on a Bio-Rad Fast Acid Analysis Column using RI detection. Reproducibility (RSD(R)) for untreated samples (sugars + phenolics + organic acids) ranged from 6.6% for Titrivin AA4 reference material to 11.0% for dry red wine. RSD(R) for treated samples (sugars only) ranged from 6.8% for white zinfandel to 18.9% for dry white wine. RSD(R) for treated samples (sugars only) + glycerol ranged from 6.4% for white zinfandel to 19.8% for dry red wine. Based on these results, the method was adopted as Official First Action status for determination of total carbohydrates in wine and wine-like beverages.

Different spectrophotometric methods applied for the analysis of binary mixture of flucloxacillin and amoxicillin: A comparative study.

PubMed

Attia, Khalid A M; Nassar, Mohammed W I; El-Zeiny, Mohamed B; Serag, Ahmed

2016-05-15

Three different spectrophotometric methods were applied for the quantitative analysis of flucloxacillin and amoxicillin in their binary mixture, namely, ratio subtraction, absorbance subtraction and amplitude modulation. A comparative study was done listing the advantages and the disadvantages of each method. All the methods were validated according to the ICH guidelines and the obtained accuracy, precision and repeatability were found to be within the acceptable limits. The selectivity of the proposed methods was tested using laboratory prepared mixtures and assessed by applying the standard addition technique. So, they can be used for the routine analysis of flucloxacillin and amoxicillin in their binary mixtures. Copyright © 2016 Elsevier B.V. All rights reserved.

Solid-phase extraction and GC-MS analysis of THC-COOH method optimized for a high-throughput forensic drug-testing laboratory.

PubMed

Stout, P R; Horn, C K; Klette, K L

2001-10-01

In order to facilitate the confirmation analysis of large numbers of urine samples previously screened positive for delta9-tetrahydrocannabinol (THC), an extraction, derivitization, and GC-MS analysis method was developed. This method utilized a positive pressure manifold anion-exchange polymer-based solid-phase extraction followed by elution directly into the automated liquid sampling (ALS) vials. Rapid derivitization was accomplished using pentafluoropropionic anhydride/pentafluoropropanol (PFPA/PFPOH). Recoveries averaged 95% with a limit of detection of 0.875 ng/mL with a 3-mL sample volume. Performance of 11-nor-delta9-tetrahydrocannabinol-9-carboxylic acid (THC-COOH)-d3 and THC-COOH-d9 internal standards were evaluated. The method was linear to 900 ng/mL THC-COOH using THC-COOH-d9 with negligible contribution from the internal standard to very weak samples. Excellent agreement was seen with previous quantitations of human urine samples. More than 1000 human urine samples were analyzed using the method with 300 samples analyzed using an alternate qualifier ion (m/z 622) after some interference was observed with a qualifier ion (m/z 489). The 622 ion did not exhibit any interference even in samples with interfering peaks present in the 489 ion. The method resulted in dramatic reductions in processing time, waste production, and exposure hazards to laboratory personnel.

Validation of a PCR-based method for the detection of various rendered materials in feedstuffs using a forensic DNA extraction kit.

PubMed

Myers, Michael J; Yancy, Haile F; Araneta, Michael; Armour, Jennifer; Derr, Janice; Hoostelaere, Lawrence A D; Farmer, Doris; Jackson, Falana; Kiessling, William M; Koch, Henry; Lin, Huahua; Liu, Yan; Mowlds, Gabrielle; Pinero, David; Riter, Ken L; Sedwick, John; Shen, Yuelian; Wetherington, June; Younkins, Ronsha

2006-01-01

A method trial was initiated to validate the use of a commercial DNA forensic kit to extract DNA from animal feed as part of a PCR-based method. Four different PCR primer pairs (one bovine pair, one porcine pair, one ovine primer pair, and one multispecies pair) were also evaluated. Each laboratory was required to analyze a total of 120 dairy feed samples either not fortified (control, true negative) or fortified with bovine meat and bone meal, porcine meat and bone meal (PMBM), or lamb meal. Feeds were fortified with the animal meals at a concentration of 0.1% (wt/wt). Ten laboratories participated in this trial, and each laboratory was required to evaluate two different primer pairs, i.e., each PCR primer pair was evaluated by five different laboratories. The method was considered to be validated for a given animal source when three or more laboratories achieved at least 97% accuracy (29 correct of 30 samples for 96.7% accuracy, rounded up to 97%) in detecting the fortified samples for that source. Using this criterion, the method was validated for the bovine primer because three laboratories met the criterion, with an average accuracy of 98.9%. The average false-positive rate was 3.0% in these laboratories. A fourth laboratory was 80% accurate in identifying the samples fortified with bovine meat and bone meal. A fifth laboratory was not able to consistently extract the DNA from the feed samples and did not achieve the criterion for accuracy for either the bovine or multispecies PCR primers. For the porcine primers, the method was validated, with four laboratories meeting the criterion for accuracy with an average accuracy of 99.2%. The fifth laboratory had a 93.3% accuracy outcome for the porcine primer. Collectively, these five laboratories had a 1.3% false-positive rate for the porcine primer. No laboratory was able to meet the criterion for accuracy with the ovine primers, most likely because of problems with the synthesis of the primer pair; none of the positive control DNA samples could be detected with the ovine primers. The multispecies primer pair was validated in three laboratories for use with bovine meat and bone meal and lamb meal but not with PMBM. The three laboratories had an average accuracy of 98.9% for bovine meat and bone meal, 97.8% for lamb meal, and 63.3% for PMBM. When examined on an individual laboratory basis, one of these four laboratories could not identify a single feed sample containing PMBM by using the multispecies primer, whereas the other laboratory identified only one PMBM-fortified sample, suggesting that the limit of detection for PMBM with this primer pair is around 0.1% (wt/wt). The results of this study demonstrated that the DNA forensic kit can be used to extract DNA from animal feed, which can then be used for PCR analysis to detect animal-derived protein present in the feed sample.

Soils as an indicator of forest health: a guide to the collection, analysis, and interpretation of soil indicator data in the Forest Inventory and Analysis program

Treesearch

Katherine P O' Neill; Michael C. Amacher; Charles H. Perry

2005-01-01

Documents the types of data collected as part of the Forest Inventory and Analysis soil indicator, the field and laboratory methods used, and the rationale behind these data collection procedures. Guides analysts and researchers on incorporating soil indicator data into reports and research studies.

Bridging the gap between sample collection and laboratory analysis: using dried blood spots to identify human exposure to chemical agents

NASA Astrophysics Data System (ADS)

Hamelin, Elizabeth I.; Blake, Thomas A.; Perez, Jonas W.; Crow, Brian S.; Shaner, Rebecca L.; Coleman, Rebecca M.; Johnson, Rudolph C.

2016-05-01

Public health response to large scale chemical emergencies presents logistical challenges for sample collection, transport, and analysis. Diagnostic methods used to identify and determine exposure to chemical warfare agents, toxins, and poisons traditionally involve blood collection by phlebotomists, cold transport of biomedical samples, and costly sample preparation techniques. Use of dried blood spots, which consist of dried blood on an FDA-approved substrate, can increase analyte stability, decrease infection hazard for those handling samples, greatly reduce the cost of shipping/storing samples by removing the need for refrigeration and cold chain transportation, and be self-prepared by potentially exposed individuals using a simple finger prick and blood spot compatible paper. Our laboratory has developed clinical assays to detect human exposures to nerve agents through the analysis of specific protein adducts and metabolites, for which a simple extraction from a dried blood spot is sufficient for removing matrix interferents and attaining sensitivities on par with traditional sampling methods. The use of dried blood spots can bridge the gap between the laboratory and the field allowing for large scale sample collection with minimal impact on hospital resources while maintaining sensitivity, specificity, traceability, and quality requirements for both clinical and forensic applications.

A normalization method for combination of laboratory test results from different electronic healthcare databases in a distributed research network.

PubMed

Yoon, Dukyong; Schuemie, Martijn J; Kim, Ju Han; Kim, Dong Ki; Park, Man Young; Ahn, Eun Kyoung; Jung, Eun-Young; Park, Dong Kyun; Cho, Soo Yeon; Shin, Dahye; Hwang, Yeonsoo; Park, Rae Woong

2016-03-01

Distributed research networks (DRNs) afford statistical power by integrating observational data from multiple partners for retrospective studies. However, laboratory test results across care sites are derived using different assays from varying patient populations, making it difficult to simply combine data for analysis. Additionally, existing normalization methods are not suitable for retrospective studies. We normalized laboratory results from different data sources by adjusting for heterogeneous clinico-epidemiologic characteristics of the data and called this the subgroup-adjusted normalization (SAN) method. Subgroup-adjusted normalization renders the means and standard deviations of distributions identical under population structure-adjusted conditions. To evaluate its performance, we compared SAN with existing methods for simulated and real datasets consisting of blood urea nitrogen, serum creatinine, hematocrit, hemoglobin, serum potassium, and total bilirubin. Various clinico-epidemiologic characteristics can be applied together in SAN. For simplicity of comparison, age and gender were used to adjust population heterogeneity in this study. In simulations, SAN had the lowest standardized difference in means (SDM) and Kolmogorov-Smirnov values for all tests (p < 0.05). In a real dataset, SAN had the lowest SDM and Kolmogorov-Smirnov values for blood urea nitrogen, hematocrit, hemoglobin, and serum potassium, and the lowest SDM for serum creatinine (p < 0.05). Subgroup-adjusted normalization performed better than normalization using other methods. The SAN method is applicable in a DRN environment and should facilitate analysis of data integrated across DRN partners for retrospective observational studies. Copyright © 2015 John Wiley & Sons, Ltd.

Review of the probabilistic failure analysis methodology and other probabilistic approaches for application in aerospace structural design

NASA Technical Reports Server (NTRS)

Townsend, J.; Meyers, C.; Ortega, R.; Peck, J.; Rheinfurth, M.; Weinstock, B.

1993-01-01

Probabilistic structural analyses and design methods are steadily gaining acceptance within the aerospace industry. The safety factor approach to design has long been the industry standard, and it is believed by many to be overly conservative and thus, costly. A probabilistic approach to design may offer substantial cost savings. This report summarizes several probabilistic approaches: the probabilistic failure analysis (PFA) methodology developed by Jet Propulsion Laboratory, fast probability integration (FPI) methods, the NESSUS finite element code, and response surface methods. Example problems are provided to help identify the advantages and disadvantages of each method.

Methods for Human Dehydration Measurement

NASA Astrophysics Data System (ADS)

Trenz, Florian; Weigel, Robert; Hagelauer, Amelie

2018-03-01

The aim of this article is to give a broad overview of current methods for the identification and quantification of the human dehydration level. Starting off from most common clinical setups, including vital parameters and general patients' appearance, more quantifiable results from chemical laboratory and electromagnetic measurement methods will be reviewed. Different analysis methods throughout the electromagnetic spectrum, ranging from direct current (DC) conductivity measurements up to neutron activation analysis (NAA), are discussed on the base of published results. Finally, promising technologies, which allow for an integration of a dehydration assessment system in a compact and portable way, will be spotted.

Houston Methodist Variant Viewer: An Application to Support Clinical Laboratory Interpretation of Next-generation Sequencing Data for Cancer

PubMed Central

Christensen, Paul A.; Ni, Yunyun; Bao, Feifei; Hendrickson, Heather L.; Greenwood, Michael; Thomas, Jessica S.; Long, S. Wesley; Olsen, Randall J.

2017-01-01

Introduction: Next-generation-sequencing (NGS) is increasingly used in clinical and research protocols for patients with cancer. NGS assays are routinely used in clinical laboratories to detect mutations bearing on cancer diagnosis, prognosis and personalized therapy. A typical assay may interrogate 50 or more gene targets that encompass many thousands of possible gene variants. Analysis of NGS data in cancer is a labor-intensive process that can become overwhelming to the molecular pathologist or research scientist. Although commercial tools for NGS data analysis and interpretation are available, they are often costly, lack key functionality or cannot be customized by the end user. Methods: To facilitate NGS data analysis in our clinical molecular diagnostics laboratory, we created a custom bioinformatics tool termed Houston Methodist Variant Viewer (HMVV). HMVV is a Java-based solution that integrates sequencing instrument output, bioinformatics analysis, storage resources and end user interface. Results: Compared to the predicate method used in our clinical laboratory, HMVV markedly simplifies the bioinformatics workflow for the molecular technologist and facilitates the variant review by the molecular pathologist. Importantly, HMVV reduces time spent researching the biological significance of the variants detected, standardizes the online resources used to perform the variant investigation and assists generation of the annotated report for the electronic medical record. HMVV also maintains a searchable variant database, including the variant annotations generated by the pathologist, which is useful for downstream quality improvement and research projects. Conclusions: HMVV is a clinical grade, low-cost, feature-rich, highly customizable platform that we have made available for continued development by the pathology informatics community. PMID:29226007

Signal analysis techniques for incipient failure detection in turbomachinery

NASA Technical Reports Server (NTRS)

Coffin, T.

1985-01-01

Signal analysis techniques for the detection and classification of incipient mechanical failures in turbomachinery were developed, implemented and evaluated. Signal analysis techniques available to describe dynamic measurement characteristics are reviewed. Time domain and spectral methods are described, and statistical classification in terms of moments is discussed. Several of these waveform analysis techniques were implemented on a computer and applied to dynamic signals. A laboratory evaluation of the methods with respect to signal detection capability is described. Plans for further technique evaluation and data base development to characterize turbopump incipient failure modes from Space Shuttle main engine (SSME) hot firing measurements are outlined.

ANTERIOR CRUCIATE LIGAMENT RECONSTRUCTION USING THE DOUBLE-BUNDLE TECHNIQUE – EVALUATION IN THE BIOMECHANICS LABORATORY

PubMed Central

D'Elia, Caio Oliveira; Bitar, Alexandre Carneiro; Castropil, Wagner; Garofo, Antônio Guilherme Padovani; Cantuária, Anita Lopes; Orselli, Maria Isabel Veras; Luques, Isabela Ugo; Duarte, Marcos

2015-01-01

Objective: The objective of this study was to describe the methodology of knee rotation analysis using biomechanics laboratory instruments and to present the preliminary results from a comparative study on patients who underwent anterior cruciate ligament (ACL) reconstruction using the double-bundle technique. Methods: The protocol currently used in our laboratory was described. Three-dimensional kinematic analysis was performed and knee rotation amplitude was measured on eight normal patients (control group) and 12 patients who were operated using the double-bundle technique, by means of three tasks in the biomechanics laboratory. Results: No significant differences between operated and non-operated sides were shown in relation to the mean amplitudes of gait, gait with change in direction or gait with change in direction when going down stairs (p > 0.13). Conclusion: The preliminary results did not show any difference in the double-bundle ACL reconstruction technique in relation to the contralateral side and the control group. PMID:27027003

Inter-laboratory variation in the chemical analysis of acidic forest soil reference samples from eastern North America

USGS Publications Warehouse

Ross, Donald S.; Bailiey, Scott W; Briggs, Russell D; Curry, Johanna; Fernandez, Ivan J.; Fredriksen, Guinevere; Goodale, Christine L.; Hazlett, Paul W.; Heine, Paul R; Johnson, Chris E.; Larson, John T; Lawrence, Gregory B.; Kolka, Randy K; Ouimet, Rock; Pare, D; Richter, Daniel D.; Shirmer, Charles D; Warby, Richard A.F.

2015-01-01

Long-term forest soil monitoring and research often requires a comparison of laboratory data generated at different times and in different laboratories. Quantifying the uncertainty associated with these analyses is necessary to assess temporal changes in soil properties. Forest soil chemical properties, and methods to measure these properties, often differ from agronomic and horticultural soils. Soil proficiency programs do not generally include forest soil samples that are highly acidic, high in extractable Al, low in extractable Ca and often high in carbon. To determine the uncertainty associated with specific analytical methods for forest soils, we collected and distributed samples from two soil horizons (Oa and Bs) to 15 laboratories in the eastern United States and Canada. Soil properties measured included total organic carbon and nitrogen, pH and exchangeable cations. Overall, results were consistent despite some differences in methodology. We calculated the median absolute deviation (MAD) for each measurement and considered the acceptable range to be the median 6 2.5 3 MAD. Variability among laboratories was usually as low as the typical variability within a laboratory. A few areas of concern include a lack of consistency in the measurement and expression of results on a dry weight basis, relatively high variability in the C/N ratio in the Bs horizon, challenges associated with determining exchangeable cations at concentrations near the lower reporting range of some laboratories and the operationally defined nature of aluminum extractability. Recommendations include a continuation of reference forest soil exchange programs to quantify the uncertainty associated with these analyses in conjunction with ongoing efforts to review and standardize laboratory methods.

Academia Meets Industry.

PubMed

Schäfer, Christian; Paprotka, Tobias; Heitzer, Ellen; Eccleston, Mark; Noe, Johannes; Holdenrieder, Stefan; Diehl, Frank; Thierry, Alain

2016-01-01

Researchers working in industrial laboratories as well as in academic laboratories discussed topics related to the use of extracellular nucleic acids in different fields. These included areas like non-invasive prenatal diagnosis, the application of different methods for the analysis and characterization of patients with benign and malignant diseases and technical aspects associated with extracellular nucleic acids. In addition, the possibilities and chances for a cooperation of researchers working in different worlds, i.e. academia and industry, were discussed.

The Effects of Propellant Burn on the Surface Composition of Gun Steel

DTIC Science & Technology

1981-11-01

ion beam analysis method has been used to characterize the depths and compositions of the outer, sub-micron layers of gun steel surfaces that have...STEEL A. Niiler R. Birkmire S. E. Caldwell November 1981 US ARMY ARMAMENT RESEARCH AND DEVELOPMENT COMMAND BALLISTIC RESEARCH LABORATORY...1L162618AH80 11. CONTROLLING OFFICE NAME AND ADDRESS US Army Armament Research § Development Command Ballistic Research Laboratory ATTN: DRDAR-BL. APG

The paediatric change laboratory: optimising postgraduate learning in the outpatient clinic.

PubMed

Skipper, Mads; Musaeus, Peter; Nøhr, Susanne Backman

2016-02-02

This study aimed to analyse and redesign the outpatient clinic in a paediatric department. The study was a joint collaboration with the doctors of the department (paediatric residents and specialists) using the Change Laboratory intervention method as a means to model and implement change in the outpatient clinic. This study was motivated by a perceived failure to integrate the activities of the outpatient clinic, patient care and training of residents. The ultimate goal of the intervention was to create improved care for patients through resident learning and development. We combined the Change Laboratory intervention with an already established innovative process for residents, 3-h meetings. The Change Laboratory intervention method consists of a well-defined theory (Cultural-historical activity theory) and concrete actions where participants construct a new theoretical model of the activity, which in this case was paediatric doctors' workplace learning modelled in order to improve medical social practice. The notion of expansive learning was used during the intervention in conjunction with thematic analysis of data in order to fuel the process of analysis and intervention. The activity system of the outpatient clinic can meaningfully be analysed in terms of the objects of patient care and training residents. The Change Laboratory sessions resulted in a joint action plan for the outpatient clinic structured around three themes: (1) Before: Preparation, expectations, and introduction; (2) During: Structural context and resources; (3) After: Follow-up and feedback. The participants found the Change Laboratory method to be a successful way of sharing reflections on how to optimise the organisation of work and training with patient care in mind. The Change Laboratory approach outlined in this study succeeded to change practices and to help medical doctors redesigning their work. Participating doctors must be motivated to uncover inherent contradictions in their medical activity systems of which care and learning are both part. Facilitators must be willing to spend time analysing both historical paediatric practice, current data on practice, and steer clear of organisational issues that might hamper a transformative learning environment. To ensure long-term success, economical and organisational resources, participant buy-in and department leadership support play a major role.

Using experimental design modules for process characterization in manufacturing/materials processes laboratories

NASA Technical Reports Server (NTRS)

Ankenman, Bruce; Ermer, Donald; Clum, James A.

1994-01-01

Modules dealing with statistical experimental design (SED), process modeling and improvement, and response surface methods have been developed and tested in two laboratory courses. One course was a manufacturing processes course in Mechanical Engineering and the other course was a materials processing course in Materials Science and Engineering. Each module is used as an 'experiment' in the course with the intent that subsequent course experiments will use SED methods for analysis and interpretation of data. Evaluation of the modules' effectiveness has been done by both survey questionnaires and inclusion of the module methodology in course examination questions. Results of the evaluation have been very positive. Those evaluation results and details of the modules' content and implementation are presented. The modules represent an important component for updating laboratory instruction and to provide training in quality for improved engineering practice.

Methicillin-Resistant Staphylococcus aureus Control in the 21st Century: Laboratory Involvement Affecting Disease Impact and Economic Benefit from Large Population Studies

PubMed Central

Schora, Donna M.

2016-01-01

Methicillin-resistant Staphylococcus aureus (MRSA) infection is a global health care problem. Large studies (e.g., >25,000 patients) show that active surveillance testing (AST) followed by contact precautions for positive patients is an effective approach for MRSA disease control. With this approach, the clinical laboratory will be asked to select what AST method(s) to use and to provide data monitoring outcomes of the infection prevention interventions. This minireview summarizes evidence for MRSA disease control, reviews the involvement of the laboratory, and provides examples of how to undertake a program cost analysis. Health care organizations with total MRSA clinical infections of >0.3/1,000 patient days or bloodstream infections of >0.03/1,000 patient days should implement a MRSA control plan. PMID:27307459

Automated Analysis of Human Sperm Number and Concentration (Oligospermia) Using Otsu Threshold Method and Labelling

NASA Astrophysics Data System (ADS)

Susrama, I. G.; Purnama, K. E.; Purnomo, M. H.

2016-01-01

Oligospermia is a male fertility issue defined as a low sperm concentration in the ejaculate. Normally the sperm concentration is 20-120 million/ml, while Oligospermia patients has sperm concentration less than 20 million/ml. Sperm test done in the fertility laboratory to determine oligospermia by checking fresh sperm according to WHO standards in 2010 [9]. The sperm seen in a microscope using a Neubauer improved counting chamber and manually count the number of sperm. In order to be counted automatically, this research made an automation system to analyse and count the sperm concentration called Automated Analysis of Sperm Concentration Counters (A2SC2) using Otsu threshold segmentation process and morphology. Data sperm used is the fresh sperm directly in the analysis in the laboratory from 10 people. The test results using A2SC2 method obtained an accuracy of 91%. Thus in this study, A2SC2 can be used to calculate the amount and concentration of sperm automatically

Boric Acid in Kjeldahl Analysis

ERIC Educational Resources Information Center

Cruz, Gregorio

2013-01-01

The use of boric acid in the Kjeldahl determination of nitrogen is a variant of the original method widely applied in many laboratories all over the world. Its use is recommended by control organizations such as ISO, IDF, and EPA because it yields reliable and accurate results. However, the chemical principles the method is based on are not…

Quantitative laser-induced breakdown spectroscopy data using peak area step-wise regression analysis: an alternative method for interpretation of Mars science laboratory results

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

Clegg, Samuel M; Barefield, James E; Wiens, Roger C

2008-01-01

The ChemCam instrument on the Mars Science Laboratory (MSL) will include a laser-induced breakdown spectrometer (LIBS) to quantify major and minor elemental compositions. The traditional analytical chemistry approach to calibration curves for these data regresses a single diagnostic peak area against concentration for each element. This approach contrasts with a new multivariate method in which elemental concentrations are predicted by step-wise multiple regression analysis based on areas of a specific set of diagnostic peaks for each element. The method is tested on LIBS data from igneous and metamorphosed rocks. Between 4 and 13 partial regression coefficients are needed to describemore » each elemental abundance accurately (i.e., with a regression line of R{sup 2} > 0.9995 for the relationship between predicted and measured elemental concentration) for all major and minor elements studied. Validation plots suggest that the method is limited at present by the small data set, and will work best for prediction of concentration when a wide variety of compositions and rock types has been analyzed.« less

Testing of the Defense Waste Processing Facility Cold Chemical Dissolution Method in Sludge Batch 9 Qualification

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

Edwards, T.; Pareizs, J.; Coleman, C.

For each sludge batch that is processed in the Defense Waste Processing Facility (DWPF), the Savannah River National Laboratory (SRNL) tests the applicability of the digestion methods used by the DWPF Laboratory for elemental analysis of Sludge Receipt and Adjustment Tank (SRAT) Receipt samples and SRAT Product process control samples. DWPF SRAT samples are typically dissolved using a method referred to as the DWPF Cold Chemical or Cold Chem Method (CC), (see DWPF Procedure SW4- 15.201). Testing indicates that the CC method produced mixed results. The CC method did not result in complete dissolution of either the SRAT Receipt ormore » SRAT Product with some fine, dark solids remaining. However, elemental analyses did not reveal extreme biases for the major elements in the sludge when compared with analyses obtained following dissolution by hot aqua regia (AR) or sodium peroxide fusion (PF) methods. The CC elemental analyses agreed with the AR and PF methods well enough that it should be adequate for routine process control analyses in the DWPF after much more extensive side-by-side tests of the CC method and the PF method are performed on the first 10 SRAT cycles of the Sludge Batch 9 (SB9) campaign. The DWPF Laboratory should continue with their plans for further tests of the CC method during these 10 SRAT cycles.« less

Environmental regulation of plant gene expression: an RT-qPCR laboratory project for an upper-level undergraduate biochemistry or molecular biology course.

PubMed

Eickelberg, Garrett J; Fisher, Alison J

2013-01-01

We present a novel laboratory project employing "real-time" RT-qPCR to measure the effect of environment on the expression of the FLOWERING LOCUS C gene, a key regulator of floral timing in Arabidopsis thaliana plants. The project requires four 3-hr laboratory sessions and is aimed at upper-level undergraduate students in biochemistry or molecular biology courses. The project provides students with hands-on experience with RT-qPCR, the current "gold standard" for gene expression analysis, including detailed data analysis using the common 2-ΔΔCT method. Moreover, it provides a convenient starting point for many inquiry-driven projects addressing diverse questions concerning ecological biochemistry, naturally occurring genetic variation, developmental biology, and the regulation of gene expression in nature. Copyright © 2013 Wiley Periodicals, Inc.

Using Latent Class Analysis to Model Temperament Types

ERIC Educational Resources Information Center

Loken, Eric

2004-01-01

Mixture models are appropriate for data that arise from a set of qualitatively different subpopulations. In this study, latent class analysis was applied to observational data from a laboratory assessment of infant temperament at four months of age. The EM algorithm was used to fit the models, and the Bayesian method of posterior predictive checks…

Mass Spectrometry in Organic Synthesis: Claisen-Schmidt Base-Catalyzed Condensation and Hammett Correlation of Substituent Effects

ERIC Educational Resources Information Center

Bain, Ryan M.; Pulliam, Christopher J.; Yan, Xin; Moore, Kassandra F.; Mu¨ller, Thomas; Cooks, R. Graham

2014-01-01

Undergraduate laboratories generally teach an understanding of chemical reactivity using bulk or semimicroscale experiments with product isolation and subsequent chemical and spectroscopic analysis. In this study students were exposed to mass spectrometry as a means of chemical synthesis as well as analysis. The ionization method used, paper…

9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2010 CFR

2010-01-01

...) Analysis of samples. Laboratories may use any quantitative method for analysis of E. coli that is approved... FSIS in its nationwide microbiological baseline data collection programs and surveys. (Copies of... Surveys used in determining the prevalence of Salmonella on raw products are available in the FSIS Docket...

9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2011 CFR

2011-01-01

...) Analysis of samples. Laboratories may use any quantitative method for analysis of E. coli that is approved... FSIS in its nationwide microbiological baseline data collection programs and surveys. (Copies of... Surveys used in determining the prevalence of Salmonella on raw products are available in the FSIS Docket...

9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2014 CFR

2014-01-01

...) Analysis of samples. Laboratories may use any quantitative method for analysis of E. coli that is approved... FSIS in its nationwide microbiological baseline data collection programs and surveys. (Copies of... Surveys used in determining the prevalence of Salmonella on raw products are available in the FSIS Docket...

9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2012 CFR

2012-01-01

...) Analysis of samples. Laboratories may use any quantitative method for analysis of E. coli that is approved... FSIS in its nationwide microbiological baseline data collection programs and surveys. (Copies of... Surveys used in determining the prevalence of Salmonella on raw products are available in the FSIS Docket...

9 CFR 381.94 - Contamination with Microorganisms; process control verification criteria and testing; pathogen...

Code of Federal Regulations, 2013 CFR

2013-01-01

...) Analysis of samples. Laboratories may use any quantitative method for analysis of E. coli that is approved... FSIS in its nationwide microbiological baseline data collection programs and surveys. (Copies of... Surveys used in determining the prevalence of Salmonella on raw products are available in the FSIS Docket...

Combining PCR with Microscopy to Reduce Costs of Laboratory Diagnosis of Buruli Ulcer

PubMed Central

Yeboah-Manu, Dorothy; Asante-Poku, Adwoa; Asan-Ampah, Kobina; Ampadu, Emelia Danso Edwin; Pluschke, Gerd

2011-01-01

The introduction of antibiotic therapy as first-line treatment of Buruli ulcer underlines the importance of laboratory confirmation of clinical diagnosis. Because smear microscopy has very limited sensitivity, the technically demanding and more expensive IS2404 diagnostic polymerase chain reaction (PCR) has become the main method for confirmation. By optimization of the release of mycobacteria from swab specimen and concentration of bacterial suspensions before smearing, we were able to improve the detection rate of acid-fast bacilli by microscopy after Ziehl–Neelsen staining. Compared with IS2404 PCR, which is the gold standard diagnostic method, the sensitivity and specificity of microscopy with 100 concentrated specimens were 58.4% and 95.7%, respectively. We subsequently evaluated a stepwise laboratory confirmation algorithm with detection of AFB as first-line method and IS2404 PCR performed only with those samples that were negative in microscopic analysis. This stepwise approach reduced unit cost by more than 50% to $5.41, and the total costs were reduced from $917 to $433. PMID:22049046

Challenges in the size analysis of a silica nanoparticle mixture as candidate certified reference material

NASA Astrophysics Data System (ADS)

Kestens, Vikram; Roebben, Gert; Herrmann, Jan; Jämting, Åsa; Coleman, Victoria; Minelli, Caterina; Clifford, Charles; De Temmerman, Pieter-Jan; Mast, Jan; Junjie, Liu; Babick, Frank; Cölfen, Helmut; Emons, Hendrik

2016-06-01

A new certified reference material for quality control of nanoparticle size analysis methods has been developed and produced by the Institute for Reference Materials and Measurements of the European Commission's Joint Research Centre. The material, ERM-FD102, consists of an aqueous suspension of a mixture of silica nanoparticle populations of distinct particle size and origin. The characterisation relied on an interlaboratory comparison study in which 30 laboratories of demonstrated competence participated with a variety of techniques for particle size analysis. After scrutinising the received datasets, certified and indicative values for different method-defined equivalent diameters that are specific for dynamic light scattering (DLS), centrifugal liquid sedimentation (CLS), scanning and transmission electron microscopy (SEM and TEM), atomic force microscopy (AFM), particle tracking analysis (PTA) and asymmetrical-flow field-flow fractionation (AF4) were assigned. The value assignment was a particular challenge because metrological concepts were not always interpreted uniformly across all participating laboratories. This paper presents the main elements and results of the ERM-FD102 characterisation study and discusses in particular the key issues of measurand definition and the estimation of measurement uncertainty.

Laboratory testing of extravascular body fluids in Croatia: a survey of the Working group for extravascular body fluids of the Croatian Society of Medical Biochemistry and Laboratory Medicine

PubMed Central

Kopcinovic, Lara Milevoj; Vogrinc, Zeljka; Kocijan, Irena; Culej, Jelena; Aralica, Merica; Jokic, Anja; Antoncic, Dragana; Bozovic, Marija

2016-01-01

Introduction We hypothesized that extravascular body fluid (EBF) analysis in Croatia is not harmonized and aimed to investigate preanalytical, analytical and postanalytical procedures used in EBF analysis in order to identify key aspects that should be addressed in future harmonization attempts. Materials and methods An anonymous online survey created to explore laboratory testing of EBF was sent to secondary, tertiary and private health care Medical Biochemistry Laboratories (MBLs) in Croatia. Statements were designed to address preanalytical, analytical and postanalytical procedures of cerebrospinal, pleural, peritoneal (ascites), pericardial, seminal, synovial, amniotic fluid and sweat. Participants were asked to declare the strength of agreement with proposed statements using a Likert scale. Mean scores for corresponding separate statements divided according to health care setting were calculated and compared. Results The survey response rate was 0.64 (58 / 90). None of the participating private MBLs declared to analyse EBF. We report a mean score of 3.45 obtained for all statements evaluated. Deviations from desirable procedures were demonstrated in all EBF testing phases. Minor differences in procedures used for EBF analysis comparing secondary and tertiary health care MBLs were found. The lowest scores were obtained for statements regarding quality control procedures in EBF analysis, participation in proficiency testing programmes and provision of interpretative comments on EBF’s test reports. Conclusions Although good laboratory EBF practice is present in Croatia, procedures for EBF analysis should be further harmonized to improve the quality of EBF testing and patient safety. PMID:27812307

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; a method supplement for the determination of Fipronil and degradates in water by gas chromatography/mass spectrometry

USGS Publications Warehouse

Madsen, James F.; Sandstrom, Mark W.; Zaugg, Steven D.

2002-01-01

A method for the isolation and detemrination of fipronil and four of its degradates has been developed. This method adapts an analytical method created by the U.S. Geological Survey National Water Quality Laboratory in 1995 for the determination of a broad range of high-use pesticides typically found in filtered natural-water samples. In 2000, fipronil and four of its degradates were extracted, analyzed, and validated using this method. The recoveries for these five compounds in reagent-water samples fortified at 1 microgram per liter (ug/L) avereraged 98 percent. Initial method detection limits averaged 0.0029 ug/L. The performance of these five new compounds is consistent with the performance of the compounds in the initial method, making it possible to include them in addition to the other 41 pesticides and pesticide degradates in the original method.

Applicability of contact angle techniques used in the analysis of contact lenses, part 1: comparative methodologies.

PubMed

Campbell, Darren; Carnell, Sarah Maria; Eden, Russell John

2013-05-01

Contact angle, as a representative measure of surface wettability, is often employed to interpret contact lens surface properties. The literature is often contradictory and can lead to confusion. This literature review is part of a series regarding the analysis of hydrogel contact lenses using contact angle techniques. Here we present an overview of contact angle terminology, methodology, and analysis. Having discussed this background material, subsequent parts of the series will discuss the analysis of contact lens contact angles and evaluate differences in published laboratory results. The concepts of contact angle, wettability and wetting are presented as an introduction. Contact angle hysteresis is outlined and highlights the advantages in using dynamic analytical techniques over static methods. The surface free energy of a material illustrates how contact angle analysis is capable of providing supplementary surface characterization. Although single values are able to distinguish individual material differences, surface free energy and dynamic methods provide an improved understanding of material behavior. The frequently used sessile drop, captive bubble, and Wilhelmy plate techniques are discussed. Their use as both dynamic and static methods, along with the advantages and disadvantages of each technique, is explained. No single contact angle technique fully characterizes the wettability of a material surface, and the application of complimenting methods allows increased characterization. At present, there is not an ISO standard method designed for soft materials. It is important that each contact angle technique has a standard protocol, as small protocol differences between laboratories often contribute to a variety of published data that are not easily comparable.

The Pollution Detectives: Part II. Lead and Zinc Mining.

ERIC Educational Resources Information Center

Sanderson, P. L.

1988-01-01

Describes a field trip taken to an old mining area to study water pollution. Discussed are methods for silt analysis, reagent preparation, color charts, techniques, fieldwork, field results, and a laboratory study. (CW)

An interlaboratory comparison study on the measurement of elements in PM10

NASA Astrophysics Data System (ADS)

Yatkin, Sinan; Belis, Claudio A.; Gerboles, Michel; Calzolai, Giulia; Lucarelli, Franco; Cavalli, Fabrizia; Trzepla, Krystyna

2016-01-01

An inter-laboratory comparison study was conducted to measure elemental loadings on PM10 samples, collected in Ispra, a regional background/rural site in Italy, using three different XRF (X-ray Fluorescence) methods, namely Epsilon 5 by linear calibration, Quant'X by the standardless analysis, and PIXE (Particle Induced X-ray Emission) with linear calibration. A subset of samples was also analyzed by ICP-MS (Inductively Coupled Plasma-Mass Spectrometry). Several metrics including method detection limits (MDLs), precision, bias from a NIST standard reference material (SRM 2783) quoted values, relative absolute difference, orthogonal regression and the ratio of the absolute difference between the methods to claimed uncertainty were used to compare the laboratories. The MDLs were found to be comparable for many elements. Precision estimates were less than 10% for the majority of the elements. Absolute biases from SRM 2783 remained less than 20% for the majority of certified elements. The regression results of PM10 samples showed that the three XRF laboratories measured very similar mass loadings for S, K, Ti, Mn, Fe, Cu, Br, Sr and Pb with slopes within 20% of unity. The ICP-MS results confirmed the agreement and discrepancies between XRF laboratories for Al, K, Ca, Ti, V, Cu, Sr and Pb. The ICP-MS results are inconsistent with the XRF laboratories for Fe and Zn. The absolute differences between the XRF laboratories generally remained within their claimed uncertainties, showing a pattern generally consistent with the orthogonal regression results.

Piltdown Man: Combining the Instruction of Scientific Ethics and Qualitative Analysis

NASA Astrophysics Data System (ADS)

Vincent, John B.

1999-11-01

In combination with lectures on scientific method and the problems of scientific misconduct in a freshman chemistry course at The University of Alabama, a laboratory experiment was developed to allow students to feel some of the sense of scientific discovery associated with the exposure of the Piltdown Man fraud. This is accomplished by modifying a commonly performed freshman chemistry laboratory experiment, qualitative analysis of group III metal ions. Pieces of chalk are treated with chromium, manganese, and iron to simulate the treatment used to forge the Piltdown "fossils"; students can use techniques in qualitative analysis schemes for the group III ions to determine whether the samples are "forgeries" and if so which metal ion(s) were used.

Laboratory plant study on the melting process of asbestos waste

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

Sakai, Shinichi; Terazono, Atsushi; Takatsuki, Hiroshi

The melting process was studied as a method of changing asbestos into non-hazardous waste and recovering it as a reusable resource. In an initial effort, the thermal behaviors of asbestos waste in terms of physical and chemical structure have been studied. Then, 10 kg/h-scale laboratory plant experiments were carried out. By X-ray diffraction analysis, the thermal behaviors of sprayed-on asbestos waste revealed that chrysotile asbestos waste change in crystal structure at around 800 C, and becomes melted slag, mainly composed of magnesium silicate, at around 1,500 C. Laboratory plant experiments on the melting process of sprayed-on asbestos have shown thatmore » melted slag can be obtained. X-ray diffraction analysis of the melted slag revealed crystal structure change, and SEM analysis showed the slag to have a non-fibrous form. And more, TEM analysis proved the very high treatment efficiency of the process, that is, reduction of the asbestos content to 1/10{sup 6} as a weight basis. These analytical results indicate the effectiveness of the melting process for asbestos waste treatment.« less

The concept and science process skills analysis in bomb calorimeter experiment as a foundation for the development of virtual laboratory of bomb calorimeter

NASA Astrophysics Data System (ADS)

Kurniati, D. R.; Rohman, I.

2018-05-01

This study aims to analyze the concepts and science process skills in bomb calorimeter experiment as a basis for developing the virtual laboratory of bomb calorimeter. This study employed research and development method (R&D) to gain the answer to the proposed problems. This paper discussed the concepts and process skills analysis. The essential concepts and process skills associated with bomb calorimeter are analyze by optimizing the bomb calorimeter experiment. The concepts analysis found seven fundamental concepts to be concerned in developing the virtual laboratory that are internal energy, burning heat, perfect combustion, incomplete combustion, calorimeter constant, bomb calorimeter, and Black principle. Since the concept of bomb calorimeter, perfect and incomplete combustion created to figure out the real situation and contain controllable variables, in virtual the concepts displayed in the form of simulation. Meanwhile, the last four concepts presented in the form of animation because no variable found to be controlled. The process skills analysis detect four notable skills to be developed that are ability to observe, design experiment, interpretation, and communication skills.

Evaluation of nutrient quality-assurance data for Alexanders and Mount Rock Spring basins, Cumberland County, Pennsylvania

USGS Publications Warehouse

Witt, E. C.; Hippe, D.J.; Giovannitti, R.M.

1992-01-01

A total of 304 nutrient samples were collected from May 1990 through September 1991 to determine concentrations and loads of nutrients in water discharged from two spring basins in Cumberland County, Pa. Fifty-four percent of these nutrient samples were for the evaluation of (1) laboratory consistency, (2) container and preservative cleanliness, (3) maintenance of analyte representativeness as affected by three different preservation methods, and (4) comparison of analyte results with the "Most Probable Value" for Standard Reference Water Samples. Results of 37 duplicate analyses indicate that the Pennsylvania Department of Environmental Resources, Bureau of Laboratories (principal laboratory) remained within its ±10 percent goal for all but one analyte. Results of the blank analysis show that the sampling containers did not compromise the water quality. However, mercuric-chloride-preservation blanks apparently contained measurable ammonium in four of five samples and ammonium plus organic nitrogen in two of five samples. Interlaboratory results indicate substantial differences in the determination of nitrate and ammonium plus organic nitrogen between the principal laboratory and the U.S. Geological Survey National Water-Quality Laboratory. In comparison with the U.S. Environmental Protection Agency Quality-Control Samples, the principal laboratory was sufficiently accurate in its determination of nutrient anafytes. Analysis of replicate samples indicated that sulfuric-acid preservative best maintained the representativeness of the anafytes nitrate and ammonium plus organic nitrogen, whereas, mercuric chloride best maintained the representativeness of orthophosphate. Comparison of nutrient analyte determinations with the Most Probable Value for each preservation method shows that two of five analytes with no chemical preservative compare well, three of five with mercuric-chloride preservative compare well, and three of five with sulfuricacid preservative compare well.

[The actual possibilities of robotic microscopy in analysis automation and laboratory telemedicine].

PubMed

Medovyĭ, V S; Piatnitskiĭ, A M; Sokolinskiĭ, B Z; Balugian, R Sh

2012-10-01

The article discusses the possibilities of automation microscopy complexes manufactured by Cellavision and MEKOS to perform the medical analyses of blood films and other biomaterials. The joint work of the complex and physician in the regimen of automatic load stages, screening, sampling and sorting on types with simple morphology, visual sorting of sub-sample with complex morphology provides significant increase of method sensitivity, load decrease and enhancement of physician work conditions. The information technologies, the virtual slides and laboratory telemedicine included permit to develop the representative samples of rare types and pathologies to promote automation methods and medical research targets.

Review: Properties of sperm and seminal fluid, informed by research on reproduction and contraception.

PubMed

Cotton, Robin W; Fisher, Matthew B

2015-09-01

Forensic DNA testing is grounded in molecular biology and population genetics. The technologies that were the basis of restriction length polymorphism testing (RFLP) have given way to PCR based technologies. While PCR has been the pillar of short tandem repeat (STR) methods and will continue to be used as DNA sequencing and analysis of single nucleotide polymorphisms (SNPs) are introduced into human identification, the molecular biology techniques in use today represent significant advances since the introduction of STR testing. Large forensic laboratories with dedicated research teams and forensic laboratories which are part of academic institutions have the resources to keep track of advances which can then be considered for further research or incorporated into current testing methods. However, many laboratories have limited ability to keep up with research advances outside of the immediate area of forensic science and may not have access to a large university library systems. This review focuses on filling this gap with respect to areas of research that intersect with selected methods used in forensic biology. The review summarizes information collected from several areas of the scientific literature where advances in molecular biology have produced information relevant to DNA analysis of sexual assault evidence and methods used in presumptive and confirmatory identification of semen. Older information from the literature is also included where this information may not be commonly known and is relevant to current methods. The topics selected highlight (1) information from applications of proteomics to sperm biology and human reproduction, (2) seminal fluid proteins and prostate cancer diagnostics, (3) developmental biology of sperm from the fertility literature and (4) areas where methods are common to forensic analysis and research in contraceptive use and monitoring. Information and progress made in these areas coincide with the research interests of forensic biology and cross-talk between these disciplines may benefit both. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

A method for addressing differences in concentrations of fipronil and three degradates obtained by two different laboratory methods

USGS Publications Warehouse

Crawford, Charles G.; Martin, Jeffrey D.

2017-07-21

In October 2012, the U.S. Geological Survey (USGS) began measuring the concentration of the pesticide fipronil and three of its degradates (desulfinylfipronil, fipronil sulfide, and fipronil sulfone) by a new laboratory method using direct aqueous-injection liquid chromatography tandem mass spectrometry (DAI LC–MS/MS). This method replaced the previous method—in use since 2002—that used gas chromatography/mass spectrometry (GC/MS). The performance of the two methods is not comparable for fipronil and the three degradates. Concentrations of these four chemical compounds determined by the DAI LC–MS/MS method are substantially lower than the GC/MS method. A method was developed to correct for the difference in concentrations obtained by the two laboratory methods based on a methods comparison field study done in 2012. Environmental and field matrix spike samples to be analyzed by both methods from 48 stream sites from across the United States were sampled approximately three times each for this study. These data were used to develop a relation between the two laboratory methods for each compound using regression analysis. The relations were used to calibrate data obtained by the older method to the new method in order to remove any biases attributable to differences in the methods. The coefficients of the equations obtained from the regressions were used to calibrate over 16,600 observations of fipronil, as well as the three degradates determined by the GC/MS method retrieved from the USGS National Water Information System. The calibrated values were then compared to over 7,800 observations of fipronil and to the three degradates determined by the DAI LC–MS/MS method also retrieved from the National Water Information System. The original and calibrated values from the GC/MS method, along with measures of uncertainty in the calibrated values and the original values from the DAI LC–MS/MS method, are provided in an accompanying data release.

Detection, Characterization, and Typing of Shiga Toxin-Producing Escherichia coli.

PubMed

Parsons, Brendon D; Zelyas, Nathan; Berenger, Byron M; Chui, Linda

2016-01-01

Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab). Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA) and quantitative real time polymerase chain reaction (qPCR). Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS) have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance.

Detection, Characterization, and Typing of Shiga Toxin-Producing Escherichia coli

PubMed Central

Parsons, Brendon D.; Zelyas, Nathan; Berenger, Byron M.; Chui, Linda

2016-01-01

Shiga toxin-producing Escherichia coli (STEC) are responsible for gastrointestinal diseases reported in numerous outbreaks around the world. Given the public health importance of STEC, effective detection, characterization and typing is critical to any medical laboratory system. While non-O157 serotypes account for the majority of STEC infections, frontline microbiology laboratories may only screen for STEC using O157-specific agar-based methods. As a result, non-O157 STEC infections are significantly under-reported. This review discusses recent advances on the detection, characterization and typing of STEC with emphasis on work performed at the Alberta Provincial Laboratory for Public Health (ProvLab). Candidates for the detection of all STEC serotypes include chromogenic agars, enzyme immunoassays (EIA) and quantitative real time polymerase chain reaction (qPCR). Culture methods allow further characterization of isolates, whereas qPCR provides the greatest sensitivity and specificity, followed by EIA. The virulence gene profiles using PCR arrays and stx gene subtypes can subsequently be determined. Different non-O157 serotypes exhibit markedly different virulence gene profiles and a greater prevalence of stx1 than stx2 subtypes compared to O157:H7 isolates. Finally, recent innovations in whole genome sequencing (WGS) have allowed it to emerge as a candidate for the characterization and typing of STEC in diagnostic surveillance isolates. Methods of whole genome analysis such as single nucleotide polymorphisms and k-mer analysis are concordant with epidemiological data and standard typing methods, such as pulsed-field gel electrophoresis and multiple-locus variable number tandem repeat analysis while offering additional strain differentiation. Together these findings highlight improved strategies for STEC detection using currently available systems and the development of novel approaches for future surveillance. PMID:27148176

Advanced techniques for determining long term compatibility of materials with propellants

NASA Technical Reports Server (NTRS)

Green, R. L.; Stebbins, J. P.; Smith, A. W.; Pullen, K. E.

1973-01-01

A method for the prediction of propellant-material compatibility for periods of time up to ten years is presented. Advanced sensitive measurement techniques used in the prediction method are described. These include: neutron activation analysis, radioactive tracer technique, and atomic absorption spectroscopy with a graphite tube furnace sampler. The results of laboratory tests performed to verify the prediction method are presented.

Method 522 - Determination of 1,4-Dioxane in Drinking Water by Solid Phase Extraction (SPE) and Gas Chromatography Mass Spectrometry (GC/MS) with Selected Ion Monitoring (SIM)

EPA Science Inventory

1,4-Dioxane has been identified as a probable human carcinogen and an emerging contaminant in drinking water. The National Exposure Research Laboratory (NERL) has developed a method for the analysis of 1,4-dioxane in drinking water at ng/L concentrations. The method consists of...

Using Machine Learning and Data Analysis to Improve Customer Acquisition and Marketing in Residential Solar

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

Sigrin, Benjamin O

High customer acquisition costs remain a persistent challenge in the U.S. residential solar industry. Effective customer acquisition in the residential solar market is increasingly achieved with the help of data analysis and machine learning, whether that means more targeted advertising, understanding customer motivations, or responding to competitors. New research by the National Renewable Energy Laboratory, Sandia National Laboratories, Vanderbilt University, University of Pennsylvania, and the California Center for Sustainable Energy and funded through the U.S. Department of Energy's Solar Energy Evolution and Diffusion (SEEDS) program demonstrates novel computational methods that can help drive down costs in the residential solar industry.

Rapid identification of Bacillus anthracis spores in suspicious powder samples by using matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS).

PubMed

Dybwad, Marius; van der Laaken, Anton L; Blatny, Janet Martha; Paauw, Armand

2013-09-01

Rapid and reliable identification of Bacillus anthracis spores in suspicious powders is important to mitigate the safety risks and economic burdens associated with such incidents. The aim of this study was to develop and validate a rapid and reliable laboratory-based matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) analysis method for identifying B. anthracis spores in suspicious powder samples. A reference library containing 22 different Bacillus sp. strains or hoax materials was constructed and coupled with a novel classification algorithm and standardized processing protocol for various powder samples. The method's limit of B. anthracis detection was determined to be 2.5 × 10(6) spores, equivalent to a 55-μg sample size of the crudest B. anthracis-containing powder discovered during the 2001 Amerithrax incidents. The end-to-end analysis method was able to successfully discriminate among samples containing B. anthracis spores, closely related Bacillus sp. spores, and commonly encountered hoax materials. No false-positive or -negative classifications of B. anthracis spores were observed, even when the analysis method was challenged with a wide range of other bacterial agents. The robustness of the method was demonstrated by analyzing samples (i) at an external facility using a different MALDI-TOF MS instrument, (ii) using an untrained operator, and (iii) using mixtures of Bacillus sp. spores and hoax materials. Taken together, the observed performance of the analysis method developed demonstrates its potential applicability as a rapid, specific, sensitive, robust, and cost-effective laboratory-based analysis tool for resolving incidents involving suspicious powders in less than 30 min.

Rapid Identification of Bacillus anthracis Spores in Suspicious Powder Samples by Using Matrix-Assisted Laser Desorption Ionization–Time of Flight Mass Spectrometry (MALDI-TOF MS)

PubMed Central

van der Laaken, Anton L.; Blatny, Janet Martha; Paauw, Armand

2013-01-01

Rapid and reliable identification of Bacillus anthracis spores in suspicious powders is important to mitigate the safety risks and economic burdens associated with such incidents. The aim of this study was to develop and validate a rapid and reliable laboratory-based matrix-assisted laser desorption ionization–time of flight mass spectrometry (MALDI-TOF MS) analysis method for identifying B. anthracis spores in suspicious powder samples. A reference library containing 22 different Bacillus sp. strains or hoax materials was constructed and coupled with a novel classification algorithm and standardized processing protocol for various powder samples. The method's limit of B. anthracis detection was determined to be 2.5 × 106 spores, equivalent to a 55-μg sample size of the crudest B. anthracis-containing powder discovered during the 2001 Amerithrax incidents. The end-to-end analysis method was able to successfully discriminate among samples containing B. anthracis spores, closely related Bacillus sp. spores, and commonly encountered hoax materials. No false-positive or -negative classifications of B. anthracis spores were observed, even when the analysis method was challenged with a wide range of other bacterial agents. The robustness of the method was demonstrated by analyzing samples (i) at an external facility using a different MALDI-TOF MS instrument, (ii) using an untrained operator, and (iii) using mixtures of Bacillus sp. spores and hoax materials. Taken together, the observed performance of the analysis method developed demonstrates its potential applicability as a rapid, specific, sensitive, robust, and cost-effective laboratory-based analysis tool for resolving incidents involving suspicious powders in less than 30 min. PMID:23811517

Preparation, certification and interlaboratory analysis of workplace air filters spiked with high-fired beryllium oxide.

PubMed

Oatts, Thomas J; Hicks, Cheryl E; Adams, Amy R; Brisson, Michael J; Youmans-McDonald, Linda D; Hoover, Mark D; Ashley, Kevin

2012-02-01

Occupational sampling and analysis for multiple elements is generally approached using various approved methods from authoritative government sources such as the National Institute for Occupational Safety and Health (NIOSH), the Occupational Safety and Health Administration (OSHA) and the Environmental Protection Agency (EPA), as well as consensus standards bodies such as ASTM International. The constituents of a sample can exist as unidentified compounds requiring sample preparation to be chosen appropriately, as in the case of beryllium in the form of beryllium oxide (BeO). An interlaboratory study was performed to collect analytical data from volunteer laboratories to examine the effectiveness of methods currently in use for preparation and analysis of samples containing calcined BeO powder. NIST SRM(®) 1877 high-fired BeO powder (1100 to 1200 °C calcining temperature; count median primary particle diameter 0.12 μm) was used to spike air filter media as a representative form of beryllium particulate matter present in workplace sampling that is known to be resistant to dissolution. The BeO powder standard reference material was gravimetrically prepared in a suspension and deposited onto 37 mm mixed cellulose ester air filters at five different levels between 0.5 μg and 25 μg of Be (as BeO). Sample sets consisting of five BeO-spiked filters (in duplicate) and two blank filters, for a total of twelve unique air filter samples per set, were submitted as blind samples to each of 27 participating laboratories. Participants were instructed to follow their current process for sample preparation and utilize their normal analytical methods for processing samples containing substances of this nature. Laboratories using more than one sample preparation and analysis method were provided with more than one sample set. Results from 34 data sets ultimately received from the 27 volunteer laboratories were subjected to applicable statistical analyses. The observed performance data show that sample preparations using nitric acid alone, or combinations of nitric and hydrochloric acids, are not effective for complete extraction of Be from the SRM 1877 refractory BeO particulate matter spiked on air filters; but that effective recovery can be achieved by using sample preparation procedures utilizing either sulfuric or hydrofluoric acid, or by using methodologies involving ammonium bifluoride with heating. Laboratories responsible for quantitative determination of Be in workplace samples that may contain high-fired BeO should use quality assurance schemes that include BeO-spiked sampling media, rather than solely media spiked with soluble Be compounds, and should ensure that methods capable of quantitative digestion of Be from the actual material present are used.

Practical aspects of genetic identification of hallucinogenic and other poisonous mushrooms for clinical and forensic purposes

PubMed Central

Kowalczyk, Marek; Sekuła, Andrzej; Mleczko, Piotr; Olszowy, Zofia; Kujawa, Anna; Zubek, Szymon; Kupiec, Tomasz

2015-01-01

Aim To assess the usefulness of a DNA-based method for identifying mushroom species for application in forensic laboratory practice. Methods Two hundred twenty-one samples of clinical forensic material (dried mushrooms, food remains, stomach contents, feces, etc) were analyzed. ITS2 region of nuclear ribosomal DNA (nrDNA) was sequenced and the sequences were compared with reference sequences collected from the National Center for Biotechnology Information gene bank (GenBank). Sporological identification of mushrooms was also performed for 57 samples of clinical material. Results Of 221 samples, positive sequencing results were obtained for 152 (69%). The highest percentage of positive results was obtained for samples of dried mushrooms (96%) and food remains (91%). Comparison with GenBank sequences enabled identification of all samples at least at the genus level. Most samples (90%) were identified at the level of species or a group of closely related species. Sporological and molecular identification were consistent at the level of species or genus for 30% of analyzed samples. Conclusion Molecular analysis identified a larger number of species than sporological method. It proved to be suitable for analysis of evidential material (dried hallucinogenic mushrooms) in forensic genetic laboratories as well as to complement classical methods in the analysis of clinical material. PMID:25727040

Validation of the sperm class analyser CASA system for sperm counting in a busy diagnostic semen analysis laboratory.

PubMed

Dearing, Chey G; Kilburn, Sally; Lindsay, Kevin S

2014-03-01

Sperm counts have been linked to several fertility outcomes making them an essential parameter of semen analysis. It has become increasingly recognised that Computer-Assisted Semen Analysis (CASA) provides improved precision over manual methods but that systems are seldom validated robustly for use. The objective of this study was to gather the evidence to validate or reject the Sperm Class Analyser (SCA) as a tool for routine sperm counting in a busy laboratory setting. The criteria examined were comparison with the Improved Neubauer and Leja 20-μm chambers, within and between field precision, sperm concentration linearity from a stock diluted in semen and media, accuracy against internal and external quality material, assessment of uneven flow effects and a receiver operating characteristic (ROC) analysis to predict fertility in comparison with the Neubauer method. This work demonstrates that SCA CASA technology is not a standalone 'black box', but rather a tool for well-trained staff that allows rapid, high-number sperm counting providing errors are identified and corrected. The system will produce accurate, linear, precise results, with less analytical variance than manual methods that correlate well against the Improved Neubauer chamber. The system provides superior predictive potential for diagnosing fertility problems.

Development and single-laboratory validation of an HPLC method for the determination of cyclamate sweetener in foodstuffs.

PubMed

Scotter, M J; Castle, L; Roberts, D P T; Macarthur, R; Brereton, P A; Hasnip, S K; Katz, N

2009-05-01

A method for the determination of cyclamate has been developed and single-laboratory validated for a range of foodstuffs including carbonated and fruit-juice drinks, fruit preserves, spreads, and dairy desserts. The method uses the peroxide oxidation of cyclamate to cyclohexylamine followed by derivatization with trinitrobenzenesulfonic acid and analysis by a modified reversed-phase high-performance liquid chromatography-ultraviolet light (HPLC-UV). Cycloheptylamine is used as an internal standard. The limits of detection were in the range 1-20 mg kg(-1) and the analysis was linear up to 1300 mg kg(-1) cyclamic acid in foods and up to 67 mg l(-1) in beverages. Analytical recovery was between 82% and 123%, and results were recovery corrected. Precision was within experimentally predicted levels for all of the matrices tested and Horrat values for the combined standard uncertainty associated with the measurement of cyclamate between 0.4 (water-based drinks) and 1.7 (spreads). The method was used successfully to test three soft drink samples for homogeneity before analytical performance assessment. The method is recommended for use in monitoring compliance and for formal testing by collaborative trial.

Secure Embedded System Design Methodologies for Military Cryptographic Systems

DTIC Science & Technology

2016-03-31

Fault- Tree Analysis (FTA); Built-In Self-Test (BIST) Introduction Secure access-control systems restrict operations to authorized users via methods...failures in the individual software/processor elements, the question of exactly how unlikely is difficult to answer. Fault- Tree Analysis (FTA) has a...Collins of Sandia National Laboratories for years of sharing his extensive knowledge of Fail-Safe Design Assurance and Fault- Tree Analysis

Evaluation of chemical data from selected sites in the Surface-Water Ambient Monitoring Program (SWAMP) in Florida

USGS Publications Warehouse

Katz, B.G.; Collins, J.J.

1998-01-01

A cooperative study between the Florida Department of Environmental Protection (FDEP) and the U.S. Geological Survey was conducted to assess the integrity of selected water-quality data collected at 150 sites in the FDEP Surface-Water Ambient Monitoring Program (SWAMP) in Florida. The assessment included determining the consistency of the water-quality data collected statewide, including commonality of monitoring procedures and analytes, screening of the gross validity of a chemical analysis, and quality assurance and quality control (QA/QC) procedures. Four tests were used to screen data at selected SWAMP sites to estimate the gross validity of selected chemical data: (1) the ratio of dissolved solids (in milligrams per liter) to specific conductance (in microsiemens per centimeter); (2) the ratio of total cations (in milliequivalents per liter) multiplied by 100 to specific conductance (in microsiemens per centimeter); (3) the ratio of total anions (in milliequivalents per liter) multiplied by 100 to specific conductance (in microsiemens per centimeter); and (4) the ionic charge-balance error. Although the results of the four screening tests indicate that the chemical data generally are quite reliable, the extremely small number of samples (less than 5 percent of the total number of samples) with sufficient chemical information to run the tests may not provide a representative indication of the analytical accuracy of all laboratories in the program. In addition to the four screening tests, unusually low or high values were flagged for field and laboratory pH (less than 4.0 and greater than 9.0) and specific conductance (less than 10 and greater than 10,000 microsiemens per centimeter). The numbers of flagged data were less than 1 percent of the 19,937 water samples with pH values and less than 0.6 percent of the 16,553 water samples with specific conductance values. Thirty-four agencies responded to a detailed questionnaire that was sent to more than 60 agencies involved in the collection and analysis of surface-water-quality data for SWAMP. The purpose of the survey was to evaluate quality assurance methods and consistency of methods statewide. Information was compiled and summarized on monitoring network design, data review and upload procedures, laboratory and field sampling methods, and data practices. Currently, most agencies that responded to the survey follow FDEP-approved QA/QC protocol for sampling and have quality assurance practices for recording and reporting data. Also, most agencies responded that calibration procedures were followed in the laboratory for analysis of data, but no responses were given about the specific procedures. Approximately 50 percent of the respondents indicated that laboratory analysis methods have changed over time. With so many laboratories involved in analyzing samples for SWAMP, it is difficult to compare water quality from one site to another due to different reporting conventions for chemical constituents and different analytical methods over time. Most agencies responded that calibration methods are followed in the field, but no specific details were provided. Grab samples are the most common method of collection. Other data screening procedures are necessary to further evaluate the validity of chemical data collected at SWAMP sites. High variability in the concentration of targeted constituents may signal analytical problems, but more likely changes in concentration are related to hydrologic conditions. This underscores the need for accurate measurements of discharge, lake stage, tidal stage at the time of sampling so that changes in constituent concentrations can be properly evaluated and fluxes (loads) of nutrients or metals, for example, can be calculated and compared over time.

Developing Learning Tool of Control System Engineering Using Matrix Laboratory Software Oriented on Industrial Needs

NASA Astrophysics Data System (ADS)

Isnur Haryudo, Subuh; Imam Agung, Achmad; Firmansyah, Rifqi

2018-04-01

The purpose of this research is to develop learning media of control technique using Matrix Laboratory software with industry requirement approach. Learning media serves as a tool for creating a better and effective teaching and learning situation because it can accelerate the learning process in order to enhance the quality of learning. Control Techniques using Matrix Laboratory software can enlarge the interest and attention of students, with real experience and can grow independent attitude. This research design refers to the use of research and development (R & D) methods that have been modified by multi-disciplinary team-based researchers. This research used Computer based learning method consisting of computer and Matrix Laboratory software which was integrated with props. Matrix Laboratory has the ability to visualize the theory and analysis of the Control System which is an integration of computing, visualization and programming which is easy to use. The result of this instructional media development is to use mathematical equations using Matrix Laboratory software on control system application with DC motor plant and PID (Proportional-Integral-Derivative). Considering that manufacturing in the field of Distributed Control systems (DCSs), Programmable Controllers (PLCs), and Microcontrollers (MCUs) use PID systems in production processes are widely used in industry.

Residue analysis of tetracyclines in poultry muscle: shortcomings revealed by a proficiency test.

PubMed

Berendsen, B J A; Van Rhijn, J A

2006-11-01

A proficiency test for tetracycline drug residues in poultry muscle was organized according to the guidelines of International Laboratory Accreditation Cooperation (ILAC) ILAC-G13:2000 (2000). For the proficiency test, three test materials were prepared. The homogeneity and stability of the materials during the study were demonstrated. Sixteen laboratories accepted the invitation to participate in the proficiency test; 11 laboratories reported results within the time frame of the study. Most notably, only four of the participating laboratories complied with the definition of the maximum residue limit (MRL) concerning the inclusion of 4-epimers as stated in European Commission Regulation 281/96 (1996). Most participants reported values for the decision limit (CCalpha) and detection capability (CCbeta) and hence were already in compliance with European Commission 2002/657/EC (2002) for this aspect of method validation. However, some CCalpha and CCbeta values were not in agreement with the actual within-laboratory reproducibility calculated from the results reported in this proficiency test. Although most laboratories obtained satisfactory results, it is clear that an effort is needed to include 4-epiOTC, 4-epiTC and 4-epiCTC in the analytical methods. Moreover, reconsideration of values determined for CCalpha and CCbeta with respect to their accuracy may be necessary in some cases.

Accounting for differing exposure patterns between laboratory tests and the field in the assessment of long-term risks of pesticides to terrestrial vertebrates.

PubMed

Fischer, David L

2005-11-01

Long-term risks of pesticides to birds and mammals are currently assessed by comparing effects thresholds determined in chronic laboratory studies to exposure levels expected to occur in the field. However, there is often a mismatch between exposure patterns tested in the laboratory tests (exposure levels held constant) and those experienced by animals in the field (exposure levels varying over time). Three methods for addressing this problem are presented and discussed. Time-weighted averaging (TWA) converts a variable field exposure regime to a single value that can be compared directly to the laboratory test results. Body-burden modeling (BBM) is applied to both laboratory and field exposure regimes allowing a straightforward comparison of body residue levels expected for each situation. Temporal analysis (TA) uses expert judgment to decide if the length of time exposure exceeds a toxicity threshold is long enough to cause biologically significant effects. To reduce uncertainty in long-term assessments, the conduct of specialized laboratory tests in which test subjects are administered a time-varying exposure that mimics what occurs in the field should be considered. Such tests may also be useful testing the validity of each of these assessment methods.

First proficiency testing to evaluate the ability of European Union National Reference Laboratories to detect staphylococcal enterotoxins in milk products.

PubMed

Hennekinne, Jacques-Antoine; Gohier, Martine; Maire, Tiphaine; Lapeyre, Christiane; Lombard, Bertrand; Dragacci, Sylviane

2003-01-01

The European Commission has designed a network of European Union-National Reference Laboratories (EU-NRLs), coordinated by a Community Reference Laboratory (CRL), for control of hygiene of milk and milk products (Council Directive 92/46/ECC). As a common contaminant of milk and milk products such as cheese, staphylococcal enterotoxins are often involved in human outbreaks and should be monitored regularly. The main tasks of the EU-CRLs were to select and transfer to the EU-NRLs a reference method for detection of enterotoxins, and to set up proficiency testing to evaluate the competency of the European laboratory network. The first interlaboratory exercise was performed on samples of freeze-dried cheese inoculated with 2 levels of staphylococcal enterotoxins (0.1 and 0.25 ng/g) and on an uninoculated control. These levels were chosen considering the EU regulation for staphylococcal enterotoxins in milk and milk products and the limit of detection of the enzyme-linked immunosorbent assay test recommended in the reference method. The trial was conducted according to the recommendations of ISO Guide 43. Results produced by laboratories were compiled and compared through statistical analysis. Except for data from 2 laboratories for the uninoculated control and cheese inoculated at 0.1 ng/g, all laboratories produced satisfactory results, showing the ability of the EU-NRL network to monitor the enterotoxin contaminant.

Determination of Free and Total Choline and Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (LC/MS/MS): Single-Laboratory Validation, First Action 2015.10.

PubMed

Ellingson, David J; Shippar, Jeffrey J; Gilmore, Justin M

2016-01-01

Analytical methods for the analysis of both L-carnitine and choline are needed for reliable and accurate determination in infant formula and adult/pediatric nutritional formula. These compounds are different in how they are utilized by the human body, but are structurally similar. L-carnitine and choline are quaternary ammonium compounds, enabling both to be retained under acidic conditions with strong cation exchange (SCX) chromatography. This method analyzes both compounds simultaneously as either the free forms or as a total amount that includes bound sources such as phosphatidylcholine or acetylcarnitine. The free analysis consists of water extraction and analysis by LC/MS/MS, while the total analysis consists of extraction by acid assisted microwave hydrolysis and analysis by LC/MS/MS. Calibration standards used for calculations are extracted with all samples in the batch. A single laboratory validation (SLV) was performed following the guidelines of the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) utilizing the kit of materials provided. The results achieved meet the requirements of SMPR 2012.010 and 2012.013 for L-carnitine and total choline, respectively.

Convenient and Efficient Method for Quality Control Analysis of 18F-Fluorocholine: For a Small Scale GMP-based Radiopharmaceuticals Laboratory Set-up.

PubMed

Hassan, Hishar; Abu Bakar, Suharzelim; Halim, Khairul Najah Che A; Idris, Jaleezah; Nordin, Abdul Jalil

2016-01-01

Prostate cancer continues to be the most prevalent cancer in men in Malaysia. As time progresses, the prospect of PET imaging modality in diagnosis of prostate cancer is promising, with on-going improvement on novel tracers. Among all tracers, 18F-Fluorocholine is reported to be a reputable tracer and reliable diagnostic technique for prostate imaging. Nonetheless, only 18F-Fluorodeoxyglucose (18F-FDG) is available and used in most oncology cases in Malaysia. With a small scale GMP-based radiopharmaceuticals laboratory set-up, initial efforts have been taken to put Malaysia on 18F-Fluorocholine map. This article presents a convenient, efficient and reliable method for quality control analysis of 18F-Fluorocholine. Besides, the aim of this research work is to assist local GMP radiopharmaceuticals laboratories and local authority in Malaysia for quality control analysis of 18F-Fluorocholine guideline. In this study, prior to synthesis, quality control analysis method for 18F-Fluorocholine was developed and validated, by adapting the equipment set-up used in 18F-Fluorodeoxyglucose (18FFDG) routine production. Quality control on the 18F-Fluorocholine was performed by means of pH, radionuclidic identity, radio-high performance liquid chromatography equipped with ultraviolet, radio- thin layer chromatography, gas chromatography and filter integrity test. Post-synthesis; the pH of 18F-Fluorocholine was 6.42 ± 0.04, with half-life of 109.5 minutes (n = 12). The radiochemical purity was consistently higher than 99%, both in radio-high performance liquid chromatography equipped with ultraviolet (r-HPLC; SCX column, 0.25 M NaH2PO4: acetonitrile) and radio-thin layer chromatography method (r-TLC). The calculated relative retention time (RRT) in r-HPLC was 1.02, whereas the retention factor (Rf) in r-TLC was 0.64. Potential impurities from 18F-Fluorocholine synthesis such as ethanol, acetonitrile, dimethylethanolamine and dibromomethane were determined in gas chromatography. Using our parameters, (capillary column: DB-200, 30 m x 0.53 mm x 1 um) and oven temperature of 35°C (isothermal), all compounds were well resolved and eluted within 3 minutes. Level of ethanol and acetonitrile in 18F-Fluorocholine were detected below threshold limit; less than 5 mg/ml and 0.41 mg/ml respectively. Meanwhile, dimethylethanolamine and dibromomethane were undetectable. A convenient, efficient and reliable quality control analysis work-up procedure for 18FFluorocholine has been established and validated to comply all the release criteria. The convenient method of quality control analysis may provide a guideline to local GMP radiopharmaceutical laboratories to start producing 18F-Fluorocholine as a tracer for prostate cancer imaging.

Development of a Thermal Desorption Gas Chromatography-Mass Spectrometry Analysis Method for Airborne Dichlorodiphenyltrichloroethane

DTIC Science & Technology

2013-05-28

span of 1-250 ng DDT. Furthermore, laboratory and field experiments utilizing this method confirmed that significant DDT concentration differences ... different between the two sample introduction methods when comparing the same DDT mass which may be due to differences in the precision of split...degradation of DDT was significantly different between the liquid and TD methods (t-test; p < 0.001). For TD analyses the relative percent

An improved method of chemical analysis for low levels of nitrogen in forest streams or in rainwater.

Treesearch

Elly E. Holcombe; Duane G. Moore; Richard L. Fredriksen

1986-01-01

A modification of the macro-Kjeldahl method that provides increased sensitivity was developed for determining very low levels of nitrogen in forest streams and in rain-water. The method is suitable as a routine laboratory procedure. Analytical range of the method is 0.02 to 1.5 mg/L with high recovery and excellent precision and ac-curacy. The range can be increased to...

Quantitative trace analysis of polyfluorinated alkyl substances (PFAS) in ambient air samples from Mace Head (Ireland): A method intercomparison

NASA Astrophysics Data System (ADS)

Jahnke, Annika; Barber, Jonathan L.; Jones, Kevin C.; Temme, Christian

A method intercomparison study of analytical methods for the determination of neutral, volatile polyfluorinated alkyl substances (PFAS) was carried out in March, 2006. Environmental air samples were collected in triplicate at the European background site Mace Head on the west coast of Ireland, a site dominated by 'clean' westerly winds coming across the Atlantic. Extraction and analysis were performed at two laboratories active in PFAS research using their in-house methods. Airborne polyfluorinated telomer alcohols (FTOHs), fluorooctane sulfonamides and sulfonamidoethanols (FOSAs/FOSEs) as well as additional polyfluorinated compounds were investigated. Different native and isotope-labelled internal standards (IS) were applied at various steps in the analytical procedure to evaluate the different quantification strategies. Field blanks revealed no major blank problems. European background concentrations observed at Mace Head were found to be in a similar range to Arctic data reported in the literature. Due to trace-levels at the remote site, only FTOH data sets were complete and could therefore be compared between the laboratories. Additionally, FOSEs could partly be included. Data comparison revealed that despite the challenges inherent in analysis of airborne PFAS and the low concentrations, all methods applied in this study obtained similar results. However, application of isotope-labelled IS early in the analytical procedure leads to more precise results and is therefore recommended.

Development of guided inquiry-based laboratory worksheet on topic of heat of combustion

NASA Astrophysics Data System (ADS)

Sofiani, D.; Nurhayati; Sunarya, Y.; Suryatna, A.

2018-03-01

Chemistry curriculum reform shows an explicit shift from traditional approach to scientific inquiry. This study aims to develop a guided inquiry-based laboratory worksheet on topic of heat of combustion. Implementation of this topic in high school laboratory is new because previously some teachers only focused the experiment on determining the heat of neutralization. The method used in this study was development research consisted of three stages: define, design, and develop. In the define stage, curriculum analysis and material analysis were performed. In the design stage, laboratory optimization and product preparation were conducted. In the development stage, the product was evaluated by the experts and tested to a total of 20 eleventh-grade students. The instruments used in this study were assessment sheet and students’ response questionnaire. The assessment results showed that the guided inquiry-based laboratory worksheet has very good quality based on the aspects of content, linguistic, and graphics. The students reacted positively to the use of this guided inquiry-based worksheet as demonstrated by the results from questionnaire. The implications of this study is the laboratory activity should be directed to development of scientific inquiry skills in order to enhance students’ competences as well as the quality of science education.

A simple and fast method for extraction and quantification of cryptophyte phycoerythrin.

PubMed

Thoisen, Christina; Hansen, Benni Winding; Nielsen, Søren Laurentius

2017-01-01

The microalgal pigment phycoerythrin (PE) is of commercial interest as natural colorant in food and cosmetics, as well as fluoroprobes for laboratory analysis. Several methods for extraction and quantification of PE are available but they comprise typically various extraction buffers, repetitive freeze-thaw cycles and liquid nitrogen, making extraction procedures more complicated. A simple method for extraction of PE from cryptophytes is described using standard laboratory materials and equipment. The cryptophyte cells on the filters were disrupted at -80 °C and added phosphate buffer for extraction at 4 °C followed by absorbance measurement. The cryptophyte Rhodomonas salina was used as a model organism. •Simple method for extraction and quantification of phycoerythrin from cryptophytes.•Minimal usage of equipment and chemicals, and low labor costs.•Applicable for industrial and biological purposes.

New ORNL Method Could Unleash Solar Power Potential

ScienceCinema

Simpson, Mary Jane

2018-01-16

Measurement and data analysis techniques developed at the Department of Energy’s Oak Ridge National Laboratory could provide new insight into performance-robbing flaws in crystalline structures, ultimately improving the performance of solar cells.

Contacts in the Office of Pesticide Programs, Biological and Economic Analysis Division

EPA Pesticide Factsheets

BEAD provides pesticide use-related information and economic analyses in support of pesticide regulatory activities. BEAD's laboratories validate analytical methods and test public health antimicrobials to ensure that they work as intended.

Multi-laboratory validation study of multilocus variable-number tandem repeat analysis (MLVA) for Salmonella enterica serovar Enteritidis, 2015.

PubMed

Peters, Tansy; Bertrand, Sophie; Björkman, Jonas T; Brandal, Lin T; Brown, Derek J; Erdõsi, Tímea; Heck, Max; Ibrahem, Salha; Johansson, Karin; Kornschober, Christian; Kotila, Saara M; Le Hello, Simon; Lienemann, Taru; Mattheus, Wesley; Nielsen, Eva Møller; Ragimbeau, Catherine; Rumore, Jillian; Sabol, Ashley; Torpdahl, Mia; Trees, Eija; Tuohy, Alma; de Pinna, Elizabeth

2017-03-02

Multilocus variable-number tandem repeat analysis (MLVA) is a rapid and reproducible typing method that is an important tool for investigation, as well as detection, of national and multinational outbreaks of a range of food-borne pathogens. Salmonella enterica serovar Enteritidis is the most common Salmonella serovar associated with human salmonellosis in the European Union/European Economic Area and North America. Fourteen laboratories from 13 countries in Europe and North America participated in a validation study for MLVA of S. Enteritidis targeting five loci. Following normalisation of fragment sizes using a set of reference strains, a blinded set of 24 strains with known allele sizes was analysed by each participant. The S. Enteritidis 5-loci MLVA protocol was shown to produce internationally comparable results as more than 90% of the participants reported less than 5% discrepant MLVA profiles. All 14 participating laboratories performed well, even those where experience with this typing method was limited. The raw fragment length data were consistent throughout, and the inter-laboratory validation helped to standardise the conversion of raw data to repeat numbers with at least two countries updating their internal procedures. However, differences in assigned MLVA profiles remain between well-established protocols and should be taken into account when exchanging data. This article is copyright of The Authors, 2017.

Analysis of chemical concepts as the basic of virtual laboratory development and process science skills in solubility and solubility product subject

NASA Astrophysics Data System (ADS)

Syafrina, R.; Rohman, I.; Yuliani, G.

2018-05-01

This study aims to analyze the concept characteristics of solubility and solubility products that will serve as the basis for the development of virtual laboratory and students' science process skills. Characteristics of the analyzed concepts include concept definitions, concept attributes, and types of concepts. The concept analysis method uses concept analysis according to Herron. The results of the concept analysis show that there are twelve chemical concepts that become the prerequisite concept before studying the solubility and solubility and five core concepts that students must understand in the solubility and Solubility product. As many as 58.3% of the definitions of the concepts contained in high school textbooks support students' science process skills, the rest of the definition of the concept is memorized. Concept attributes that meet three levels of chemical representation and can be poured into a virtual laboratory have a percentage of 66.6%. Type of concept, 83.3% is a concept based on principle; and 16.6% concepts that state the process. Meanwhile, the science process skills that can be developed based on concept analysis are the ability to observe, calculate, measure, predict, interpret, hypothesize, apply, classify, and inference.

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; arsenic speciation in natural-water samples using laboratory and field methods

USGS Publications Warehouse

Garbarino, John R.; Bednar, Anthony J.; Burkhardt, Mark R.

2002-01-01

Analytical methods for the determination of arsenite [As(III)], arsenate [As(V)], dimethylarsinate (DMA), monomethylarsonate (MMA), and roxarsone in filtered natural-water samples are described. Various analytical methods can be used for the determination, depending on the arsenic species being determined. Arsenic concentration is determined by using inductively coupled plasma-mass spectrometry (ICP-MS) as an arsenic-specific detector for all methods. Laboratory-speciation methods are described that use an ion chromatographic column to separate the arsenic species; the column length, column packing, and mobile phase are dependent on the species of interest. Regardless of the separation technique, the arsenic species are introduced into plasma by eithe rpneumatic nebulization or arsine generation. Analysis times range from 2 to 8 minutes and method detection limits range from 0.1 to 0.6 microgram-arsenic per liter (ug-As/L), 10 to 60 picograms absolute (for a 100-microliter injection), depending on the arsenic species determined and the analytical method used. A field-generation specciation method also is described that uses a strong anion exchange cartridge to separate As(III) from As(V) in the field. As(III) in the eluate and the As(V) in the cartridge extract are determined by direct nebulization ICP-MS. Methylated arsenic species that also are retained on the cartridge will positively bias As(V) results without further laboratory separations. The method detection limit for field speciation is 0.3 ug-As/L. The distribution of arsenic species must be preserved in the field to eliminate changes caused by photochemical oxidation or metal oxyhydroxide precipitation. Preservation techniques, such as refrigeration, the addition of acides, or the additoin of ethylene-diaminetetraacetic acid (EDTA) and the effects of ambient light were tested. Of the preservatives evaluated, EDTA was found to work best with the laboratory- and field-speciation methods for all sample matrices tested. Storing the samples in opaque polytethylene bottles eliminated the effects of photochemical oxidation. The percentage change in As(III):As(V) ratios for an EDTA-preserved acid mine drainage (AMD) sample and ground-water sample during a 3-month period was -5 percent and +3 percent, respectively. The bias and variability of the methods were evaluated by comparing results for total arsenic and As(III), As(V), DMA, and MMA concentrations in ground water, AMD, and surface water. Seventy-one ground-water, 10 AMD, and 24 surface-water samples were analyzed. Concentrations in ground-water samples reached 720 ug-As/L for As(III) and 1080 ug-As/L for As(V); AMD samples reached 12800 ug-As/L for As(III) and 7050 ug-As/L for As(V); and surface-water samples reached 5 ug-As/L for As(III) and As(V). Inorganic arsenic species distribution in the samples ranged from 0 to 90 percent As(III). DMA and MMA were present only in surface-water samples from agricultural areas where the herbicide monosodium methylarsonate was applied; concentrations never exceeded 6 ug-As/L. Statistical analyses indicated that the difference between As(III) and As(V) concentrations for samples preserved with EDTA in opaque bottles and field-speciation results were analytically insignificant at the 95-percent confidence interval. There was no significant difference among the methods tested for total arsenic concentration. Percentage recovery for field samples spiked at 50 ug-As/L and analyzed by the laboratory-speciation method (n=2) ranged from 82 to 100 percent for As(III), 97 to 102 percent for As(V), 90 to 104 percent for DMA, and 81 to 96 percent for MMA; recoveries for samples spiked at 100 ug-As/L and analyzed by the field-speciation method ranged from 102 to 107 percent for As(III) and 105 to 106 percent for As(V). Laboratory-speciation results for Environment Canada reference material SLRS-2 closely matched reported concentrations. Laboratory-speciation metho

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.

ENFIN--A European network for integrative systems biology.

PubMed

Kahlem, Pascal; Clegg, Andrew; Reisinger, Florian; Xenarios, Ioannis; Hermjakob, Henning; Orengo, Christine; Birney, Ewan

2009-11-01

Integration of biological data of various types and the development of adapted bioinformatics tools represent critical objectives to enable research at the systems level. The European Network of Excellence ENFIN is engaged in developing an adapted infrastructure to connect databases, and platforms to enable both the generation of new bioinformatics tools and the experimental validation of computational predictions. With the aim of bridging the gap existing between standard wet laboratories and bioinformatics, the ENFIN Network runs integrative research projects to bring the latest computational techniques to bear directly on questions dedicated to systems biology in the wet laboratory environment. The Network maintains internally close collaboration between experimental and computational research, enabling a permanent cycling of experimental validation and improvement of computational prediction methods. The computational work includes the development of a database infrastructure (EnCORE), bioinformatics analysis methods and a novel platform for protein function analysis FuncNet.

TRACE ELEMENT ANALYSES OF URANIUM MATERIALS

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

Beals, D; Charles Shick, C

The Savannah River National Laboratory (SRNL) has developed an analytical method to measure many trace elements in a variety of uranium materials at the high part-per-billion (ppb) to low part-per-million (ppm) levels using matrix removal and analysis by quadrapole ICP-MS. Over 35 elements were measured in uranium oxides, acetate, ore and metal. Replicate analyses of samples did provide precise results however none of the materials was certified for trace element content thus no measure of the accuracy could be made. The DOE New Brunswick Laboratory (NBL) does provide a Certified Reference Material (CRM) that has provisional values for a seriesmore » of trace elements. The NBL CRM were purchased and analyzed to determine the accuracy of the method for the analysis of trace elements in uranium oxide. These results are presented and discussed in the following paper.« less

Application of LIBS and TMA for the determination of combustion predictive indices of coals and coal blends

NASA Astrophysics Data System (ADS)

Ctvrtnickova, T.; Mateo, M. P.; Yañez, A.; Nicolas, G.

2011-04-01

Presented work brings results of Laser-Induced Breakdown Spectroscopy (LIBS) and Thermo-Mechanical Analysis (TMA) of coals and coal blends used in coal fired power plants all over Spain. Several coal specimens, its blends and corresponding laboratory ash were analyzed by mentioned techniques and results were compared to standard laboratory methods. The indices of slagging, which predict the tendency of coal ash deposition on the boiler walls, were determined by means of standard chemical analysis, LIBS and TMA. The optimal coal suitable to be blended with the problematic national lignite coal was suggested in order to diminish the slagging problems. Used techniques were evaluated based on the precision, acquisition time, extension and quality of information they could provide. Finally, the applicability of LIBS and TMA to the successful calculation of slagging indices is discussed and their substitution of time-consuming and instrumentally difficult standard methods is considered.

Quantitative analysis of phosphoinositide 3-kinase (PI3K) signaling using live-cell total internal reflection fluorescence (TIRF) microscopy.

PubMed

Johnson, Heath E; Haugh, Jason M

2013-12-02

This unit focuses on the use of total internal reflection fluorescence (TIRF) microscopy and image analysis methods to study the dynamics of signal transduction mediated by class I phosphoinositide 3-kinases (PI3Ks) in mammalian cells. The first four protocols cover live-cell imaging experiments, image acquisition parameters, and basic image processing and segmentation. These methods are generally applicable to live-cell TIRF experiments. The remaining protocols outline more advanced image analysis methods, which were developed in our laboratory for the purpose of characterizing the spatiotemporal dynamics of PI3K signaling. These methods may be extended to analyze other cellular processes monitored using fluorescent biosensors. Copyright © 2013 John Wiley & Sons, Inc.

Effect of genetic algorithm as a variable selection method on different chemometric models applied for the analysis of binary mixture of amoxicillin and flucloxacillin: A comparative study

NASA Astrophysics Data System (ADS)

Attia, Khalid A. M.; Nassar, Mohammed W. I.; El-Zeiny, Mohamed B.; Serag, Ahmed

2016-03-01

Different chemometric models were applied for the quantitative analysis of amoxicillin (AMX), and flucloxacillin (FLX) in their binary mixtures, namely, partial least squares (PLS), spectral residual augmented classical least squares (SRACLS), concentration residual augmented classical least squares (CRACLS) and artificial neural networks (ANNs). All methods were applied with and without variable selection procedure (genetic algorithm GA). The methods were used for the quantitative analysis of the drugs in laboratory prepared mixtures and real market sample via handling the UV spectral data. Robust and simpler models were obtained by applying GA. The proposed methods were found to be rapid, simple and required no preliminary separation steps.

First derivative ratio spectrophotometric, HPTLC-densitometric, and HPLC determination of nicergoline in presence of its hydrolysis-induced degradation product.

PubMed

Ahmad, Abdel Kader S; Kawy, M Abdel; Nebsen, M

2002-10-15

Three methods are presented for the determination of Nicergoline in presence of its hydrolysis-induced degradation product. The first method was based on measurement of the first derivative of ratio spectra amplitude of Nicergoline at 291 nm. The second method was based on separation of Nicergoline from its degradation product followed by densitometric measurement of the spots at 287 nm. The separation was carried out on HPTLC silica gel F(254) plates, using methanol-ethyl acetate-glacial acetic acid (5:7:3, v/v/v) as mobile phase. The third method was based on high performance liquid chromatographic (HPLC) separation and determination of Nicergoline from its degradation product on a reversed phase, nucloesil C(18) column using a mobile phase of methanol-water-glacial acetic acid (80:20:0.1, v/v/v) with UV detection at 280 nm. Chlorpromazine hydrochloride was used as internal standard. Laboratory prepared mixtures containing different percentages of the degradation product were analysed by the proposed methods and satisfactory results were obtained. These methods have been successfully applied to the analysis of Nicergoline in Sermion tablets. The validities of these methods were ascertained by applying standard addition technique, the mean percentage recovery +/- R.S.D.% was found to be 99.47 +/- 0.752, 100.01 +/- 0.940, 99.75 +/- 0.740 for the first derivative of ratio spectra method, the HPTLC method and the HPLC method, respectively. The proposed methods were statistically compared with the manufacturer's HPLC method of analysis of Nicergoline and no significant difference was found with respect to both precision and accuracy. They have the advantage of being stability indicating. Therefore, they can be used for routine analysis of the drug in quality control laboratories. Copyright 2002 Elsevier Science B.V.

Development and Multi-laboratory Verification of US EPA ...

EPA Pesticide Factsheets

A drinking water method for seven pesticides and pesticide degradates is presented that addresses the occurrence monitoring needs of the US Environmental Protection Agency (EPA) for a future Unregulated Contaminant Monitoring Regulation (UCMR). The method employs online solid phase extraction-liquid chromatography–tandem mass spectrometry (SPE-LC–MS-MS). Online SPE-LC–MS-MS has the potential to offer cost-effective, faster, more sensitive and more rugged methods than the traditional offline SPE approach due to complete automation of the SPE process, as well as seamless integration with the LC–MS-MS system. The method uses 2-chloroacetamide, ascorbic acid and Trizma to preserve the drinking water samples for up to 28 days. The mean recoveries in drinking water (from a surface water source) fortified with method analytes are 87.1–112% with relative standard deviations of <14%. Single laboratory lowest concentration minimum reporting levels of 0.27–1.7 ng/L are demonstrated with this methodology. Multi-laboratory data are presented that demonstrate method ruggedness and transferability. The final method meets all of the EPA's UCMR survey requirements for sample collection and storage, precision, accuracy, and sensitivity. The journal article describes the development of drinking water Method 543 for analysis of selected CCL 3 chemicals. It is anticipated this method may be used in a future Unregulated Contaminant Monitoring Regulation to gather nationw

Reinventing the ames test as a quantitative lab that connects classical and molecular genetics.

PubMed

Goodson-Gregg, Nathan; De Stasio, Elizabeth A

2009-01-01

While many institutions use a version of the Ames test in the undergraduate genetics laboratory, students typically are not exposed to techniques or procedures beyond qualitative analysis of phenotypic reversion, thereby seriously limiting the scope of learning. We have extended the Ames test to include both quantitative analysis of reversion frequency and molecular analysis of revertant gene sequences. By giving students a role in designing their quantitative methods and analyses, students practice and apply quantitative skills. To help students connect classical and molecular genetic concepts and techniques, we report here procedures for characterizing the molecular lesions that confer a revertant phenotype. We suggest undertaking reversion of both missense and frameshift mutants to allow a more sophisticated molecular genetic analysis. These modifications and additions broaden the educational content of the traditional Ames test teaching laboratory, while simultaneously enhancing students' skills in experimental design, quantitative analysis, and data interpretation.

Apparatus and method for fluid analysis

DOEpatents

Wilson, Bary W.; Peters, Timothy J.; Shepard, Chester L.; Reeves, James H.

2004-11-02

The present invention is an apparatus and method for analyzing a fluid used in a machine or in an industrial process line. The apparatus has at least one meter placed proximate the machine or process line and in contact with the machine or process fluid for measuring at least one parameter related to the fluid. The at least one parameter is a standard laboratory analysis parameter. The at least one meter includes but is not limited to viscometer, element meter, optical meter, particulate meter, and combinations thereof.

The Structural Insulated Panel SIP Hut: Preliminary Evaluation of Energy Efficiency and Indoor Air Quality

DTIC Science & Technology

2015-08-19

laboratory analysis using EPA TO-15, and collection of gas samples in sorbent tubes for later analysis of aldehydes using NIOSH Method 2016. Total VOCs...measurement can be a general qualitative indicator of IAQ problems; formaldehyde and other aldehydes are common organic gases emitted from OSB; and...table in the middle of the hut. 5.1.2.3 Formaldehyde and other aldehydes Aldehydes were measured using both Dräger-tubes and by NIOSH Method 2016. The

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

Wiedenman, B. J.; White, T. L.; Mahannah, R. N.

Ion Chromatography (IC) is the principal analytical method used to support studies of Sludge Reciept and Adjustment Tank (SRAT) chemistry at DWPF. A series of prior analytical ''Round Robin'' (RR) studies included both supernate and sludge samples from SRAT simulant, previously reported as memos, are tabulated in this report.2,3 From these studies it was determined to standardize IC column size to 4 mm diameter, eliminating the capillary column from use. As a follow on test, the DWPF laboratory, the PSAL laboratory, and the AD laboratory participated in the current analytical RR to determine a suite of anions in SRAT simulantmore » by IC, results also are tabulated in this report. The particular goal was to confirm the laboratories ability to measure and quantitate glycolate ion. The target was + or - 20% inter-lab agreement of the analyte averages for the RR. Each of the three laboratories analyzed a batch of 12 samples. For each laboratory, the percent relative standard deviation (%RSD) of the averages on nitrate, glycolate, and oxalate, was 10% or less. The three laboratories all met the goal of 20% relative agreement for nitrate and glycolate. For oxalate, the PSAL laboratory reported an average value that was 20% higher than the average values reported by the DWPF laboratory and the AD laboratory. Because of this wider window of agreement, it was concluded to continue the practice of an additional acid digestion for total oxalate measurement. It should also be noted that large amounts of glycolate in the SRAT samples will have an impact on detection limits of near eluting peaks, namely Fluoride and Formate. A suite of scoping experiments are presented in the report to identify and isolate other potential interlaboratory disceprancies. Specific ion chromatography inter-laboratory method conditions and differences are tabulated. Most differences were minor but there are some temperature control equipment differences that are significant leading to a recommendation of a heated jacket for analytical columns that are remoted for use in radiohoods. A suggested method improvement would be to implement column temperture control at a temperature slightly above ambient to avoid peak shifting due to temperature fluctuations. Temperature control in this manner would improve short and longer term peak retention time stability. An unknown peak was observed during the analysis of glycolic acid and SRAT simulant. The unknown peak was determined to best match diglycolic acid. The development of a method for acetate is summaraized, and no significant amount of acetate was observed in the SRAT products tested. In addition, an alternative Gas Chromatograph (GC) method for glycolate is summarized.« less

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

Anheier, Norman C.; Cannon, Bret D.; Martinez, Alonzo

The International Atomic Energy Agency’s (IAEA’s) long-term research and development plan calls for more cost-effective and efficient safeguard methods to detect and deter misuse of gaseous centrifuge enrichment plants (GCEPs). The IAEA’s current safeguards approaches at GCEPs are based on a combination of routine and random inspections that include environmental sampling and destructive assay (DA) sample collection from UF6 in-process material and selected cylinders. Samples are then shipped offsite for subsequent laboratory analysis. In this paper, a new DA sample collection and onsite analysis approach that could help to meet challenges in transportation and chain of custody for UF6 DAmore » samples is introduced. This approach uses a handheld sampler concept and a Laser Ablation, Laser Absorbance Spectrometry (LAARS) analysis instrument, both currently under development at the Pacific Northwest National Laboratory. A LAARS analysis instrument could be temporarily or permanently deployed in the IAEA control room of the facility, in the IAEA data acquisition cabinet, for example. The handheld PNNL DA sampler design collects and stabilizes a much smaller DA sample mass compared to current sampling methods. The significantly lower uranium mass reduces the sample radioactivity and the stabilization approach diminishes the risk of uranium and hydrogen fluoride release. These attributes enable safe sample handling needed during onsite LAARS assay and may help ease shipping challenges for samples to be processed at the IAEA’s offsite laboratory. The LAARS and DA sampler implementation concepts will be described and preliminary technical viability results presented.« less

Droplet Microfluidic and Magnetic Particles Platform for Cancer Typing.

PubMed

Ferraro, Davide; Champ, Jérôme; Teste, Bruno; Serra, M; Malaquin, Laurent; Descroix, Stéphanie; de Cremoux, Patricia; Viovy, Jean-Louis

2017-01-01

Analyses of nucleic acids are routinely performed in hospital laboratories to detect gene alterations for cancer diagnosis and treatment decision. Among the different possible investigations, mRNA analysis provides information on abnormal levels of genes expression. Standard laboratory methods are still not adapted to the isolation and quantitation of low mRNA amounts and new techniques needs to be developed in particular for rare subsets analysis. By reducing the volume involved, time process, and the contamination risks, droplet microfluidics provide numerous advantages to perform analysis down to the single cell level.We report on a droplet microfluidic platform based on the manipulation of magnetic particles that allows the clinical analysis of tumor tissues. In particular, it allows the extraction of mRNA from the total-RNA sample, Reverse Transcription, and cDNA amplification, all in droplets.

A RAPID METHOD FOR THE EXTRACTION OF FUNGAL DNA FROM ENVIRONMENTAL SAMPLES: EVALUATION IN THE QUANTITATIVE ANALYSIS OF MEMNONIELLA ECHINATA CONIDIA USING REAL TIME DETECTION OF PCR PRODUCTS

EPA Science Inventory

New technologies are creating the potential for using nucleic acid sequence detection to perform routine microbiological analyses of environmental samples. Our laboratory has recently reported on the development of a method for the quantitative detection of Stachybotrys chartarum...

Single and combination diagnostic test efficiency and cost analysis for detection and isolation of avian influenza virus from wild bird cloacal swabs

USDA-ARS?s Scientific Manuscript database

Effective laboratory methods for identifying avian influenza virus (AIV) in wild bird populations are crucial to understanding the ecology of this pathogen. The gold standard method has been AIV isolation in chorioallantoic sac (CAS) of specific-pathogen-free (SPF) embryonating chicken eggs (ECE), ...

The First SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1)

NASA Technical Reports Server (NTRS)

Hooker, Stanford B. (Editor); Firestone, Elaine R. (Editor); Claustre, Herve; Ras, Josephine; VanHeukelem, Laurie; Berthon, Jean-Francois; Targa, Cristina; vanderLinde, Dirk; Barlow, Ray; Sessions, Heather

2001-01-01

Four laboratories, which had contributed to various aspects of SeaWiFS calibration and validation activities, participated in the first SeaWiFS HPLC Analysis Round-Robin Experiment (SeaHARRE-1): Horn Point Laboratory (USA), the Joint Research Centre (Italy), the Laboratoire de Physique et Chimie Marines (France), and the Marine and Coastal Management group (South Africa). The analyses of the data are presented in Chapter 1 and the individual methods of the four groups are presented in Chapters 2-5. The average (or overall) conclusions of the round-robin are derived from 12 in situ stations occupied during a cruise in the Mediterranean Sea, although, only 11 stations are used in the analyses. The data set is composed of 12 replicates taken during each sampling opportunity with 3 replicates going to each of the 4 laboratories. The average (or overall) results from the intercomparison of 15 pigments or pigment associations are as follows (in some cases, data subsets that exclude pigments which were not analyzed by all the laboratories, or that had unusually large variances, are used to exclude a variety of problematic pigments): a) the accuracy of the four methods in determining the concentration of total chlorophyll a is 7.9%, (one method did not separate mono- and divinyl chlorophyll a, and if the samples containing significant divinyl chlorophyll a concentrations are ignored, the four methods have an accuracy of 6.7%); b) the accuracy in determining the full set of pigments is 19.1%; c) there is a reduction in accuracy of approximately - 12.2% for every decade (factor of 10) decrease in concentration (based on a data subset); d) the precision of the four methods using a subset data is 8.617( 6.2% for an edited subset); e) the repeatability of the four methods using the subset data is 9.2% (7.2%; for an edited subset, and f) the reproducibility of the four methods using the subset data is 21.31% (15.0% for an edited subset).

Comprehensive Urine Drug Screen by Gas Chromatography/Mass Spectrometry (GC/MS).

PubMed

Ramoo, Bheemraj; Funke, Melissa; Frazee, Clint; Garg, Uttam

2016-01-01

Drug screening is an essential component of clinical toxicology laboratory service. Some laboratories use only automated chemistry analyzers for limited screening of drugs of abuse and few other drugs. Other laboratories use a combination of various techniques such as immunoassays, colorimetric tests, and mass spectrometry to provide more detailed comprehensive drug screening. Mass spectrometry, gas or liquid, can screen for hundreds of drugs and is often considered the gold standard for comprehensive drug screening. We describe an efficient and rapid gas chromatography/mass spectrometry (GC/MS) method for comprehensive drug screening in urine which utilizes a liquid-liquid extraction, sample concentration, and analysis by GC/MS.

The use of digital PCR to improve the application of quantitative molecular diagnostic methods for tuberculosis.

PubMed

Devonshire, Alison S; O'Sullivan, Denise M; Honeyborne, Isobella; Jones, Gerwyn; Karczmarczyk, Maria; Pavšič, Jernej; Gutteridge, Alice; Milavec, Mojca; Mendoza, Pablo; Schimmel, Heinz; Van Heuverswyn, Fran; Gorton, Rebecca; Cirillo, Daniela Maria; Borroni, Emanuele; Harris, Kathryn; Barnard, Marinus; Heydenrych, Anthenette; Ndusilo, Norah; Wallis, Carole L; Pillay, Keshree; Barry, Thomas; Reddington, Kate; Richter, Elvira; Mozioğlu, Erkan; Akyürek, Sema; Yalçınkaya, Burhanettin; Akgoz, Muslum; Žel, Jana; Foy, Carole A; McHugh, Timothy D; Huggett, Jim F

2016-08-03

Real-time PCR (qPCR) based methods, such as the Xpert MTB/RIF, are increasingly being used to diagnose tuberculosis (TB). While qualitative methods are adequate for diagnosis, the therapeutic monitoring of TB patients requires quantitative methods currently performed using smear microscopy. The potential use of quantitative molecular measurements for therapeutic monitoring has been investigated but findings have been variable and inconclusive. The lack of an adequate reference method and reference materials is a barrier to understanding the source of such disagreement. Digital PCR (dPCR) offers the potential for an accurate method for quantification of specific DNA sequences in reference materials which can be used to evaluate quantitative molecular methods for TB treatment monitoring. To assess a novel approach for the development of quality assurance materials we used dPCR to quantify specific DNA sequences in a range of prototype reference materials and evaluated accuracy between different laboratories and instruments. The materials were then also used to evaluate the quantitative performance of qPCR and Xpert MTB/RIF in eight clinical testing laboratories. dPCR was found to provide results in good agreement with the other methods tested and to be highly reproducible between laboratories without calibration even when using different instruments. When the reference materials were analysed with qPCR and Xpert MTB/RIF by clinical laboratories, all laboratories were able to correctly rank the reference materials according to concentration, however there was a marked difference in the measured magnitude. TB is a disease where the quantification of the pathogen could lead to better patient management and qPCR methods offer the potential to rapidly perform such analysis. However, our findings suggest that when precisely characterised materials are used to evaluate qPCR methods, the measurement result variation is too high to determine whether molecular quantification of Mycobacterium tuberculosis would provide a clinically useful readout. The methods described in this study provide a means by which the technical performance of quantitative molecular methods can be evaluated independently of clinical variability to improve accuracy of measurement results. These will assist in ultimately increasing the likelihood that such approaches could be used to improve patient management of TB.

Validation on milk and sprouts of EN ISO 16654:2001 - Microbiology of food and animal feeding stuffs - Horizontal method for the detection of Escherichia coli O157.

PubMed

Tozzoli, Rosangela; Maugliani, Antonella; Michelacci, Valeria; Minelli, Fabio; Caprioli, Alfredo; Morabito, Stefano

2018-05-08

In 2006, the European Committee for standardisation (CEN)/Technical Committee 275 - Food analysis - Horizontal methods/Working Group 6 - Microbiology of the food chain (TC275/WG6), launched the project of validating the method ISO 16654:2001 for the detection of Escherichia coli O157 in foodstuff by the evaluation of its performance, in terms of sensitivity and specificity, through collaborative studies. Previously, a validation study had been conducted to assess the performance of the Method No 164 developed by the Nordic Committee for Food Analysis (NMKL), which aims at detecting E. coli O157 in food as well, and is based on a procedure equivalent to that of the ISO 16654:2001 standard. Therefore, CEN established that the validation data obtained for the NMKL Method 164 could be exploited for the ISO 16654:2001 validation project, integrated with new data obtained through two additional interlaboratory studies on milk and sprouts, run in the framework of the CEN mandate No. M381. The ISO 16654:2001 validation project was led by the European Union Reference Laboratory for Escherichia coli including VTEC (EURL-VTEC), which organized the collaborative validation study on milk in 2012 with 15 participating laboratories and that on sprouts in 2014, with 14 participating laboratories. In both studies, a total of 24 samples were tested by each laboratory. Test materials were spiked with different concentration of E. coli O157 and the 24 samples corresponded to eight replicates of three levels of contamination: zero, low and high spiking level. The results submitted by the participating laboratories were analyzed to evaluate the sensitivity and specificity of the ISO 16654:2001 method when applied to milk and sprouts. The performance characteristics calculated on the data of the collaborative validation studies run under the CEN mandate No. M381 returned sensitivity and specificity of 100% and 94.4%, respectively for the milk study. As for sprouts matrix, the sensitivity resulted in 75.9% in the low level of contamination samples and 96.4% in samples spiked with high level of E. coli O157 and specificity was calculated as 99.1%. Copyright © 2018 Elsevier B.V. All rights reserved.

Pre-Nursing Students Perceptions of Traditional and Inquiry Based Chemistry Laboratories

NASA Astrophysics Data System (ADS)

Rogers, Jessica

This paper describes a process that attempted to meet the needs of undergraduate students in a pre-nursing chemistry class. The laboratory was taught in traditional verification style and students were surveyed to assess their perceptions of the educational goals of the laboratory. A literature review resulted in an inquiry based method and analysis of the needs of nurses resulted in more application based activities. This new inquiry format was implemented the next semester, the students were surveyed at the end of the semester and results were compared to the previous method. Student and instructor response to the change in format was positive. Students in the traditional format placed goals concerning technique above critical thinking and felt the lab was easy to understand and carry out. Students in the inquiry based lab felt they learned more critical thinking skills and enjoyed the independence of designing experiments and answering their own questions.

The impact of change in albumin assay on reference intervals, prevalence of 'hypoalbuminaemia' and albumin prescriptions.

PubMed

Coley-Grant, Deon; Herbert, Mike; Cornes, Michael P; Barlow, Ian M; Ford, Clare; Gama, Rousseau

2016-01-01

We studied the impact on reference intervals, classification of patients with hypoalbuminaemia and albumin infusion prescriptions on changing from a bromocresol green (BCG) to a bromocresol purple (BCP) serum albumin assay. Passing-Bablok regression analysis and Bland-Altman plot were used to compare Abbott BCP and Roche BCG methods. Linear regression analysis was used to compare in-house and an external laboratory Abbott BCP serum albumin results. Reference intervals for Abbott BCP serum albumin were derived in two different laboratories using pathology data from adult patients in primary care. Prescriptions for 20% albumin infusions were compared one year before and one year after changing the albumin method. Abbott BCP assay had a negative bias of approximately 6 g/L compared with Roche BCG method.There was good agreement (y = 1.04 x - 1.03; R(2 )= 0.9933) between in-house and external laboratory Abbott BCP results. Reference intervals for the serum albumin Abbott BCP assay were 31-45 g/L, different to those recommended by Pathology Harmony and the manufacturers (35-50 g/L). Following the change in method there was a large increase in the number of patients classified as hypoalbuminaemic using Pathology Harmony references intervals (32%) but not when retrospectively compared to locally derived reference intervals (16%) compared with the previous year (12%). The method change was associated with a 44.6% increase in albumin prescriptions. This equated to an annual increase in expenditure of £35,234. We suggest that serum albumin reference intervals be method specific to prevent misclassification of albumin status in patients. Change in albumin methodology may have significant impact on hospital resources. © The Author(s) 2015.

Capillary microextraction: A new method for sampling methamphetamine vapour.

PubMed

Nair, M V; Miskelly, G M

2016-11-01

Clandestine laboratories pose a serious health risk to first responders, investigators, decontamination companies, and the public who may be inadvertently exposed to methamphetamine and other chemicals used in its manufacture. Therefore there is an urgent need for reliable methods to detect and measure methamphetamine at such sites. The most common method for determining methamphetamine contamination at former clandestine laboratory sites is selected surface wipe sampling, followed by analysis with gas chromatography-mass spectrometry (GC-MS). We are investigating the use of sampling for methamphetamine vapour to complement such wipe sampling. In this study, we report the use of capillary microextraction (CME) devices for sampling airborne methamphetamine, and compare their sampling efficiency with a previously reported dynamic SPME method. The CME devices consisted of PDMS-coated glass filter strips inside a glass tube. The devices were used to dynamically sample methamphetamine vapour in the range of 0.42-4.2μgm -3 , generated by a custom-built vapour dosing system, for 1-15min, and methamphetamine was analysed using a GC-MS fitted with a ChromatoProbe thermal desorption unit. The devices showed good reproducibility (RSD<15%), and a curvilinear pre-equilibrium relationship between sampling times and peak area, which can be utilised for calibration. Under identical sampling conditions, the CME devices were approximately 30 times more sensitive than the dynamic SPME method. The CME devices could be stored for up to 3days after sampling prior to analysis. Consecutive sampling of methamphetamine and its isotopic substitute, d-9 methamphetamine showed no competitive displacement. This suggests that CME devices, pre-loaded with an internal standard, could be a feasible method for sampling airborne methamphetamine at former clandestine laboratories. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Downtime procedures for the 21st century: using a fully integrated health record for uninterrupted electronic reporting of laboratory results during laboratory information system downtimes.

PubMed

Oral, Bulent; Cullen, Regina M; Diaz, Danny L; Hod, Eldad A; Kratz, Alexander

2015-01-01

Downtimes of the laboratory information system (LIS) or its interface to the electronic medical record (EMR) disrupt the reporting of laboratory results. Traditionally, laboratories have relied on paper-based or phone-based reporting methods during these events. We developed a novel downtime procedure that combines advance placement of orders by clinicians for planned downtimes, the printing of laboratory results from instruments, and scanning of the instrument printouts into our EMR. The new procedure allows the analysis of samples from planned phlebotomies with no delays, even during LIS downtimes. It also enables the electronic reporting of all clinically urgent results during downtimes, including intensive care and emergency department samples, thereby largely avoiding paper- and phone-based communication of laboratory results. With the capabilities of EMRs and LISs rapidly evolving, information technology (IT) teams, laboratories, and clinicians need to collaborate closely, review their systems' capabilities, and design innovative ways to apply all available IT functions to optimize patient care during downtimes. Copyright© by the American Society for Clinical Pathology.

Validate or falsify: Lessons learned from a microscopy method claimed to be useful for detecting Borrelia and Babesia organisms in human blood.

PubMed

Aase, Audun; Hajdusek, Ondrej; Øines, Øivind; Quarsten, Hanne; Wilhelmsson, Peter; Herstad, Tove K; Kjelland, Vivian; Sima, Radek; Jalovecka, Marie; Lindgren, Per-Eric; Aaberge, Ingeborg S

2016-01-01

A modified microscopy protocol (the LM-method) was used to demonstrate what was interpreted as Borrelia spirochetes and later also Babesia sp., in peripheral blood from patients. The method gained much publicity, but was not validated prior to publication, which became the purpose of this study using appropriate scientific methodology, including a control group. Blood from 21 patients previously interpreted as positive for Borrelia and/or Babesia infection by the LM-method and 41 healthy controls without known history of tick bite were collected, blinded and analysed for these pathogens by microscopy in two laboratories by the LM-method and conventional method, respectively, by PCR methods in five laboratories and by serology in one laboratory. Microscopy by the LM-method identified structures claimed to be Borrelia- and/or Babesia in 66% of the blood samples of the patient group and in 85% in the healthy control group. Microscopy by the conventional method for Babesia only did not identify Babesia in any samples. PCR analysis detected Borrelia DNA in one sample of the patient group and in eight samples of the control group; whereas Babesia DNA was not detected in any of the blood samples using molecular methods. The structures interpreted as Borrelia and Babesia by the LM-method could not be verified by PCR. The method was, thus, falsified. This study underlines the importance of doing proper test validation before new or modified assays are introduced.

Inter-laboratory exercise on antibiotic drugs analysis in aqueous samples.

PubMed

Roig, B; Brogat, M; Mompelat, S; Leveque, J; Cadiere, A; Thomas, O

2012-08-30

An inter-laboratory exercise was organized under the PHARMAS EU project, by the Advanced School of Public Health (EHESP), in order to evaluate the performances of analytical methods for the measurement of antibiotics in waters (surface and tap). This is the first time such an exercise on antibiotics has been organized in Europe, using different kinds of analytical methods and devices. In this exercise thirteen laboratories from five countries (Canada, France, Italy, the Netherlands and Portugal) participated, and a total number of 78 samples were distributed. During the exercise, 2 testing samples (3 bottles of each) prepared from tap water and river water, respectively, spiked with antibiotics, were sent to participants and analyzed over a period of one month. A final number of 77 (98.7%) testing samples were considered. Depending on substances studied by each participant, 305 values in duplicate were collected, with the results for each sample being expressed as the target concentration. A statistical study was initiated using 611 results. The mean value, standard deviation, coefficient of variation, standard uncertainty of the mean, median, the minimum and maximum values of each series as well as the 95% confidence interval were obtained from each participant laboratory. In this exercise, 36 results (6% of accounted values) were outliers according to the distribution over the median (box plot). The outlier results were excluded. In order to establish the stability of testing samples in the course of the exercise, differences between variances obtained for every type of sample at different intervals were evaluated. The results showed no representative variations and it can be considered that all samples were stable during the exercise. The goals of this inter-laboratory study were to assess results variability when analysis is conducted by different laboratories, to evaluate the influence of different matrix samples, and to determine the rate at which participating laboratories successfully completed the tests initiated. Copyright © 2012 Elsevier B.V. All rights reserved.

Sulfuric acid/hydrogen peroxide digestion and colorimetric a collaborative study.

PubMed

Christians, D K; Aspelund, T G; Brayton, S V; Roberts, L L

1991-01-01

Seven laboratories participated in a collaborative study of a method for determination of phosphorus in meat and meat products. Samples are digested in sulfuric acid and hydrogen peroxide; digestion is complete in approximately 10 min. Phosphorus is determined by colorimetric analysis of a dilute aliquot of the sample digest. The collaborators analyzed 3 sets of blind duplicate samples from each of 6 classes of meat (U.S. Department of Agriculture classifications): smoked ham, water-added ham, canned ham, pork sausage, cooked sausage, and hamburger. The calibration curve was linear over the range of standard solutions prepared (phosphorus levels from 0.05 to 1.00%); levels in the collaborative study samples ranged from 0.10 to 0.30%. Standard deviations for repeatability (sr) and reproducibility (SR) ranged from 0.004 to 0.012 and 0.007 to 0.014, respectively. Corresponding relative standard deviations (RSDr and RSDR, respectively) ranged from 1.70 to 7.28% and 3.50 to 9.87%. Six laboratories analyzed samples by both the proposed method and AOAC method 24.016 (14th Ed.). One laboratory reported results by the proposed method only. Statistical evaluations indicated no significant difference between the 2 methods. The method has been adopted official first action by AOAC.

Laser based water equilibration method for d18O determination of water samples

NASA Astrophysics Data System (ADS)

Mandic, Magda; Smajgl, Danijela; Stoebener, Nils

2017-04-01

Determination of d18O with water equilibration method using mass spectrometers equipped with equilibration unit or Gas Bench is known already for many years. Now, with development of laser spectrometers this extends methods and possibilities to apply different technologies in laboratory but also in the field. The Thermo Scientific™ Delta Ray™ Isotope Ratio Infrared Spectrometer (IRIS) analyzer with the Universal Reference Interface (URI) Connect and Teledyne Cetac ASX-7100 offers high precision and throughput of samples. It employs optical spectroscopy for continuous measurement of isotope ratio values and concentration of carbon dioxide in ambient air, and also for analysis of discrete samples from vials, syringes, bags, or other user-provided sample containers. Test measurements and conformation of precision and accuracy of method determination d18O in water samples were done in Thermo Fisher application laboratory with three lab standards, namely ANST, Ocean II and HBW. All laboratory standards were previously calibrated with international reference material VSMOW2 and SLAP2 to assure accuracy of the isotopic values of the water. With method that we present in this work achieved repeatability and accuracy are 0.16‰ and 0.71‰, respectively, which fulfill requirements of regulatory method for wine and must after equilibration with CO2.

New method for stock-tank oil compositional analysis.

PubMed

McAndrews, Kristine; Nighswander, John; Kotzakoulakis, Konstantin; Ross, Paul; Schroeder, Helmut

2009-01-01

A new method for accurately determining stock-tank oil composition to normal pentatriacontane using gas chromatography is developed and validated. The new method addresses the potential errors associated with the traditional equipment and technique employed for extended hydrocarbon gas chromatography outside a controlled laboratory environment, such as on an offshore oil platform. In particular, the experimental measurement of stock-tank oil molecular weight with the freezing point depression technique and the use of an internal standard to find the unrecovered sample fraction are replaced with correlations for estimating these properties. The use of correlations reduces the number of necessary experimental steps in completing the required sample preparation and analysis, resulting in reduced uncertainty in the analysis.

Wind turbine acoustics

NASA Technical Reports Server (NTRS)

Hubbard, Harvey H.; Shepherd, Kevin P.

1990-01-01

Available information on the physical characteristics of the noise generated by wind turbines is summarized, with example sound pressure time histories, narrow- and broadband frequency spectra, and noise radiation patterns. Reviewed are noise measurement standards, analysis technology, and a method of characterizing wind turbine noise. Prediction methods are given for both low-frequency rotational harmonics and broadband noise components. Also included are atmospheric propagation data showing the effects of distance and refraction by wind shear. Human perception thresholds, based on laboratory and field tests, are given. Building vibration analysis methods are summarized. The bibliography of this report lists technical publications on all aspects of wind turbine acoustics.

Mobile laboratories: An innovative and efficient solution for radiological characterization of sites under or after decommissioning.

PubMed

Goudeau, V; Daniel, B; Dubot, D

2017-04-21

During the operation and the decommissioning of a nuclear site the operator must assure the protection of the workers and the environment. It must furthermore identify and classify the various wastes, while optimizing the associated costs. At all stages of the decommissioning radiological measurements are performed to determine the initial situation, to monitor the demolition and clean-up, and to verify the final situation. Radiochemical analysis is crucial for the radiological evaluation process to optimize the clean-up operations and to the respect limits defined with the authorities. Even though these types of analysis are omnipresent in activities such as the exploitation, the monitoring, and the cleaning up of nuclear plants, some nuclear sites do not have their own radiochemical analysis laboratory. Mobile facilities can overcome this lack when nuclear facilities are dismantled, when contaminated sites are cleaned-up, or in a post-accident situation. The current operations for the characterization of radiological soils of CEA nuclear facilities, lead to a large increase of radiochemical analysis. To manage this high throughput of samples in a timely manner, the CEA has developed a new mobile laboratory for the clean-up of its soils, called SMaRT (Shelter for Monitoring and nucleAR chemisTry). This laboratory is dedicated to the preparation and the radiochemical analysis (alpha, beta, and gamma) of potentially contaminated samples. In this framework, CEA and Eichrom laboratories has signed a partnership agreement to extend the analytical capacities and bring on site optimized and validated methods for different problematic. Gamma-emitting radionuclides can usually be measured in situ as little or no sample preparation is required. Alpha and beta-emitting radionuclides are a different matter. Analytical chemistry laboratory facilities are required. Mobile and transportable laboratories equipped with the necessary tools can provide all that is needed. The main advantage of a mobile laboratory is its portability; the shelter can be placed in the vicinity of nuclear facilities under decommissioning, or of contaminated sites with infrastructures unsuitable for the reception and treatment of radioactive samples. Radiological analysis can then be performed without the disadvantages of radioactive material transport. This paper describes how this solution allows a fast response and control of costs, with a high analytical capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

Communication methods and production techniques in fixed prosthesis fabrication: a UK based survey. Part 2: Production techniques

PubMed Central

Berry, J.; Nesbit, M.; Saberi, S.; Petridis, H.

2014-01-01

Aim The aim of this study was to identify the communication methods and production techniques used by dentists and dental technicians for the fabrication of fixed prostheses within the UK from the dental technicians' perspective. This second paper reports on the production techniques utilised. Materials and methods Seven hundred and eighty-two online questionnaires were distributed to the Dental Laboratories Association membership and included a broad range of topics, such as demographics, impression disinfection and suitability, and various production techniques. Settings were managed in order to ensure anonymity of respondents. Statistical analysis was undertaken to test the influence of various demographic variables such as the source of information, the location, and the size of the dental laboratory. Results The number of completed responses totalled 248 (32% response rate). Ninety percent of the respondents were based in England and the majority of dental laboratories were categorised as small sized (working with up to 25 dentists). Concerns were raised regarding inadequate disinfection protocols between dentists and dental laboratories and the poor quality of master impressions. Full arch plastic trays were the most popular impression tray used by dentists in the fabrication of crowns (61%) and bridgework (68%). The majority (89%) of jaw registration records were considered inaccurate. Forty-four percent of dental laboratories preferred using semi-adjustable articulators. Axial and occlusal under-preparation of abutment teeth was reported as an issue in about 25% of cases. Base metal alloy was the most (52%) commonly used alloy material. Metal-ceramic crowns were the most popular choice for anterior (69%) and posterior (70%) cases. The various factors considered did not have any statistically significant effect on the answers provided. The only notable exception was the fact that more methods of communicating the size and shape of crowns were utilised for large laboratories. Conclusion This study suggests that there are continuing issues in the production techniques utilised between dentists and dental laboratories. PMID:25257017

Gas Analysis and Control Methods for Thermal Batteries

DTIC Science & Technology

2013-09-01

THERMAL BATTERIES (PDFS) INC DOUG BRISCOE JEFFREY REINIG 3 ENERSYS ADVANCED SYSTEMS (PDFS) PAUL SCHISSELBAUER ANDREW SEIDEL TIM...MGMT ATTN RDRL CIO LL TECHL LIB 3 SANDIA NATIONAL LABORATORIES (PDFS) DANIEL WESOLOWSKI EDWARD PIEKOS ANNE GRILLET 2 ADVANCED

Urine Odor

MedlinePlus

... doctor. Brunzel NA. Physical examination of urine. In: Fundamentals of Urine and Body Fluid Analysis. 3rd ed. St. Louis, Mo.: Saunders Elsevier; 2013:97. McPherson RA, et al., eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St. Louis, Mo.: ...

Grepping Life: A New Paradigm for Analyzing Metagenomic Data

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

Berendzen, Joel

2010-06-04

Joel Berendzen of Los Alamos National Laboratory discusses a phylogenetic method based on answering the question "What Would Google Do?" on June 4, 2010 at the "Sequencing, Finishing, Analysis in the Future" meeting in Santa Fe, NM.

Using Optically Stimulated Electron Emission as an Inspection Method to Monitor Surface Contamination

NASA Technical Reports Server (NTRS)

Lingbloom, Mike S.

2008-01-01

During redesign of the Space Shuttle reusable solid rocket motor (RSRM), NASA amended the contract with ATK Launch Systems (then Morton Thiokol Inc.) with Change Order 966 to implement a contamination control and cleanliness verification method. The change order required: (1) A quantitative inspection method (2) A written record of actual contamination levels versus a known reject level (3) A method that is more sensitive than existing methods of visual and black light inspection. Black light inspection is only useful for inspection of contaminants that fluoresce near the 365 nm spectral line and is not useful for inspection of most silicones that will not produce strong fluorescence. Black light inspection conducted by a qualified inspector under controlled light is capable of detecting Conoco HD-2 grease in gross amounts and is very subjective due to operator sensitivity. Optically stimulated electron emission (OSEE), developed at the Materials and Process Laboratory at Marshall Space Flight Center (MSFC), was selected to satisfy Change Order 966. OSEE offers several important advantages over existing laboratory methods with similar sensitivity, e.g., spectroscopy and nonvolatile residue sampling, which provide turn around time, real time capability, and full coverage inspection capability. Laboratory methods require sample gathering and in-lab analysis, which sometimes takes several days to get results. This is not practical in a production environment. In addition, these methods do not offer full coverage inspection of the large components

Laboratory investigations of earthquake dynamics

NASA Astrophysics Data System (ADS)

Xia, Kaiwen

In this thesis this will be attempted through controlled laboratory experiments that are designed to mimic natural earthquake scenarios. The earthquake dynamic rupturing process itself is a complicated phenomenon, involving dynamic friction, wave propagation, and heat production. Because controlled experiments can produce results without assumptions needed in theoretical and numerical analysis, the experimental method is thus advantageous over theoretical and numerical methods. Our laboratory fault is composed of carefully cut photoelastic polymer plates (Homahte-100, Polycarbonate) held together by uniaxial compression. As a unique unit of the experimental design, a controlled exploding wire technique provides the triggering mechanism of laboratory earthquakes. Three important components of real earthquakes (i.e., pre-existing fault, tectonic loading, and triggering mechanism) correspond to and are simulated by frictional contact, uniaxial compression, and the exploding wire technique. Dynamic rupturing processes are visualized using the photoelastic method and are recorded via a high-speed camera. Our experimental methodology, which is full-field, in situ, and non-intrusive, has better control and diagnostic capacity compared to other existing experimental methods. Using this experimental approach, we have investigated several problems: dynamics of earthquake faulting occurring along homogeneous faults separating identical materials, earthquake faulting along inhomogeneous faults separating materials with different wave speeds, and earthquake faulting along faults with a finite low wave speed fault core. We have observed supershear ruptures, subRayleigh to supershear rupture transition, crack-like to pulse-like rupture transition, self-healing (Heaton) pulse, and rupture directionality.

GC-C-IRMS in routine doping control practice: 3 years of drug testing data, quality control and evolution of the method.

PubMed

Polet, Michael; Van Eenoo, Peter

2015-06-01

In order to detect the misuse of endogenous anabolic steroids, doping control laboratories require methods that allow differentiation between endogenous steroids and their synthetic copies. Gas chromatography combustion isotope ratio mass spectrometry (GC-C-IRMS) is capable of measuring the carbon isotope ratio of urinary steroids and this allows differentiation between both. GC-C-IRMS and its application to doping control has evolved a lot during the last decade and so have the World Anti-Doping Agency (WADA) technical documents that describe how GC-C-IRMS should be applied. Especially the WADA technical document of 2014 introduced a number of obligatory quality controls and a fixed methodology that should be used by all the doping control laboratories. This document imposed more uniform methods between the laboratories in order to decrease the interlaboratory standard deviation and acquire similar results for the analysis of the same urine samples. In this paper, 3 years of drug testing data of our GC-C-IRMS method in routine doping control practice is described, with an emphasis on the new WADA technical document and its implementation. Useful data for other doping control laboratories is presented focussing on general method setup, quality control and data collected from routine samples. The paper concentrates on how IRMS results shift or remain similar by switching to the 2014 WADA technical document and gives insight in a straightforward approach to calculate the measurement uncertainty.

Performance of human fecal anaerobe-associated PCR-based assays in a multi-laboratory method evaluation study

USGS Publications Warehouse

Layton, Blythe A.; Cao, Yiping; Ebentier, Darcy L.; Hanley, Kaitlyn; Ballesté, Elisenda; Brandão, João; Byappanahalli, Muruleedhara N.; Converse, Reagan; Farnleitner, Andreas H.; Gentry-Shields, Jennifer; Gourmelon, Michèle; Lee, Chang Soo; Lee, Jiyoung; Lozach, Solen; Madi, Tania; Meijer, Wim G.; Noble, Rachel; Peed, Lindsay; Reischer, Georg H.; Rodrigues, Raquel; Rose, Joan B.; Schriewer, Alexander; Sinigalliano, Chris; Srinivasan, Sangeetha; Stewart, Jill; ,; Laurie, C.; Wang, Dan; Whitman, Richard; Wuertz, Stefan; Jay, Jenny; Holden, Patricia A.; Boehm, Alexandria B.; Shanks, Orin; Griffith, John F.

2013-01-01

A number of PCR-based methods for detecting human fecal material in environmental waters have been developed over the past decade, but these methods have rarely received independent comparative testing in large multi-laboratory studies. Here, we evaluated ten of these methods (BacH, BacHum-UCD, Bacteroides thetaiotaomicron (BtH), BsteriF1, gyrB, HF183 endpoint, HF183 SYBR, HF183 Taqman®, HumM2, and Methanobrevibacter smithii nifH (Mnif)) using 64 blind samples prepared in one laboratory. The blind samples contained either one or two fecal sources from human, wastewater or non-human sources. The assay results were assessed for presence/absence of the human markers and also quantitatively while varying the following: 1) classification of samples that were detected but not quantifiable (DNQ) as positive or negative; 2) reference fecal sample concentration unit of measure (such as culturable indicator bacteria, wet mass, total DNA, etc); and 3) human fecal source type (stool, sewage or septage). Assay performance using presence/absence metrics was found to depend on the classification of DNQ samples. The assays that performed best quantitatively varied based on the fecal concentration unit of measure and laboratory protocol. All methods were consistently more sensitive to human stools compared to sewage or septage in both the presence/absence and quantitative analysis. Overall, HF183 Taqman® was found to be the most effective marker of human fecal contamination in this California-based study.

[Fundamentals of quality control systems in medical-biochemical laboratories--the role of marketing].

PubMed

Topić, E; Turek, S

2000-01-01

The basic criterion for the overall quality system in medical biochemistry laboratories concerning equipment, premises and laboratory staff in primary health care (PHC) (Regulations on quality systems and good laboratory practice of the Croatian Medical Biochemists Chamber, 1995, Regulations on categorization of medical biochemistry laboratories of the Croatian Medical Biochemists Chamber, 1996, EC4: Essential criteria for quality systems in medical laboratories. Eur J Clin Chem Clin Biochem 1997 in medical biochemical laboratories included in the First Croatia health project, Primary health care subproject, has been met by the marketing approach to the project. The equipment ensuring implementation of the complete laboratory program (NN/96), more accurate and precise analytical procedures, and higher reliability of laboratory test results compared with previous equipment, has been purchased by an international tender. Uniform technology and methods of analysis have ensured high standards of good laboratory services, yielding test results than can be transferred from primary to secondary health care level. The new equipment has improved organization between central and detached medical biochemistry laboratory units, while the high quality requirement has led to improvement in the staff structure, e.g., medical biochemists have been employed in laboratories that had previously worked without such a professional. Equipment renewal has been accompanied by proper education for all levels of PHC professionals.

Angiographic Validation of the American College of Cardiology Foundation–The Society of Thoracic Surgeons Collaboration on the Comparative Effectiveness of Revascularization Strategies Study

PubMed Central

Chakrabarti, Anjan K.; Grau-Sepulveda, Maria V.; O’Brien, Sean; Abueg, Cassandra; Ponirakis, Angelo; Delong, Elizabeth; Peterson, Eric; Klein, Lloyd W.; Garratt, Kirk N.; Weintraub, William S.; Gibson, C. Michael

2017-01-01

Background The goal of this study was to compare angiographic interpretation of coronary arteriograms by sites in community practice versus those made by a centralized angiographic core laboratory. Methods and Results The study population consisted of 2013 American College of Cardiology–National Cardiovascular Data Registry (ACC–NCDR) records with 2- and 3- vessel coronary disease from 54 sites in 2004 to 2007. The primary analysis compared Registry (NCDR)-defined 2- and 3-vessel disease versus those from an angiographic core laboratory analysis. Vessel-level kappa coefficients suggested moderate agreement between NCDR and core laboratory analysis, ranging from kappa=0.39 (95% confidence intervals, 0.32–0.45) for the left anterior descending artery to kappa=0.59 (95% confidence intervals, 0.55–0.64) for the right coronary artery. Overall, 6.3% (n=127 out of 2013) of those patients identified with multivessel disease at NCDR sites had had 0- or 1-vessel disease by core laboratory reading. There was no directional bias with regard to overcall, that is, 12.3% of cases read as 3-vessel disease by the sites were read as <3-vessel disease by the core laboratory, and 13.9% of core laboratory 3-vessel cases were read as <3-vessel by the sites. For a subset of patients with left main coronary disease, registry overcall was not linked to increased rates of mortality or myocardial infarction. Conclusions There was only modest agreement between angiographic readings in clinical practice and those from an independent core laboratory. Further study will be needed because the implications for patient management are uncertain. PMID:24496239

An audit of immunofixation requesting practices at a South African referral laboratory

PubMed Central

Rampursat, Yashna

2014-01-01

Background It is common practice in most chemical pathology laboratories for reflective immunofixation electrophoresis (IFE) to occur following the detection or suspicion of a paraprotein on serum protein electrophoresis (SPEP). The chemical pathology laboratory at Inkosi Albert Luthuli Central Hospital (IALCH) in Durban, South Africa, is currently the only non-private laboratory in the KwaZulu Natal province that performs SPEP analysis, with current practice requiring that the clinician request IFE following suggestion by the laboratory after a suspicious SPEP result. Objectives To review the current process for IFE at IALCH in the context of reflective testing and to examine the use of the alpha-2-globulin/alpha-1-globulin ratio as a predictor of a positive IFE result. Methods Data for 1260 consecutive SPEP tests performed at the IALCH National Health Laboratory Service were collected between February and July 2011. SPEP and IFE were performed with a Sebia Hydrasys automated electrophoresis system. The alpha-2-globulin/alpha-1-globulin ratio was calculated using density of corresponding fractions on SPEP. Results Analysis revealed that of the 1260 SPEPs performed during the analysis period, 304 IFEs were suggested by the reviewing pathologist. A total of 45 (15%) of the suggested IFEs were subsequently requested by the attending clinicians. Almost half (46.5%) (n = 20) of the suggested IFEs that were performed revealed the presence of a paraprotein. There was no statistically-significant difference between the alpha-2-globulin/alpha-1-globulin ratio for patients with positive or negative IFEs (p-value = 0.2). Conclusions This study reveals the need for reflective addition of IFE testing by the laboratory following suspicious findings on SPEP. PMID:29043173

Water-soluble vitamins.

PubMed

Konings, Erik J M

2006-01-01

Simultaneous Determination of Vitamins.--Klejdus et al. described a simultaneous determination of 10 water- and 10 fat-soluble vitamins in pharmaceutical preparations by liquid chromatography-diode-array detection (LC-DAD). A combined isocratic and linear gradient allowed separation of vitamins in 3 distinct groups: polar, low-polar, and nonpolar. The method was applied to pharmaceutical preparations, fortified powdered drinks, and food samples, for which results were in good agreement with values claimed. Heudi et al. described a separation of 9 water-soluble vitamins by LC-UV. The method was applied for the quantification of vitamins in polyvitaminated premixes used for the fortification of infant nutrition products. The repeatability of the method was evaluated at different concentration levels and coefficients of variation were <6.5%. The concentrations of vitamins found in premixes with the method were comparable to the values declared. A disadvantage of the methods mentioned above is that sample composition has to be known in advance. According to European legislation, for example, foods might be fortified with riboflavin phosphate or thiamin phosphate, vitamers which are not included in the simultaneous separations described. Vitamin B2.--Viñas et al. elaborated an LC analysis of riboflavin vitamers in foods. Vitamin B2 can be found in nature as the free riboflavin, but in most biological materials it occurs predominantly in the form of 2 coenzymes, flavin mononucleotide (FMN) and flavin-adenine dinucleotide (FAD). Several methods usually involve the conversion of these coenzymes into free riboflavin before quantification of total riboflavin. According to the authors, there is growing interest to know flavin composition of foods. The described method separates the individual vitamers isocratically. Accuracy of the method is tested with 2 certified reference materials (CRMs). Vitamin B5.-Methods for the determination of vitamin B5 in foods are limited because of their low sensitivity and poor selectivity. Pakin et al. proposed a post-column derivatization of pantothenic acid as a fluorescent compound and used this principle in a specific and sensitive method for the determination of free and bound pantothenic acid in a large variety of foods. A French laboratory invited European laboratories to participate in a series of collaborative studies for this method, which will be carried out in 2005/2006. A more sophisticated method was described by Mittermayer et al. They developed an LC-mass spectrometry (LC/MS) method for the determination of vitamin B5 in a wide range of fortified food products. Application of the method to various samples showed consistent results with those obtained by microbiology. Vitamin B6.-Method 2004.07, an LC method for the analysis of vitamin B6 in reconstituted infant formula, was published by Mann et al. In contrast with this method, which quantifies vitamin B6 after converting the phosphorylated and free vitamers into pyridoxine, Viñas et al. published an LC method which determines 6 vitamin B6 related compounds, the 3 B6 vitamers, their corresponding phosphorylated esters, and a metabolite. Accuracy was determined using 2 CRMs. Results were within the certified ranges. Vitamin C.-Franke et al. described an extensive study to vitamin C and flavonoid levels of fruits and vegetables consumed in Hawaii. Vitamin C was determined by measuring ascorbic acid in its reduced state by LC and coulometric detection along with UV absorbance detection at 245 nm. No attempts were made to assess levels of dehydroascorbic acid. Most recent research revealed that cell uptake of dehydroascorbic acid is unlikely to play a major role, which may explain the very low vitamin C activity of orally administered L-dehydroascorbic acid in rats. The food levels found by Franke et al. are variably lower, higher, or equal in comparison to other studies. Iwase described a method for the determination of ascorbic acid in foods using L-methionine for the pre-analysis sample stabilization. Electrochemical detection was used for the quantification. Traditionally, metaphosphoric acid was proven to be a useful dissolving agent for the determination of ascorbic acid. However, it dissolves in water very slowly, it is hygroscopic, and accurate weighing is not easy. Adjustment at pH 2-3 takes a long time. It appeared to be possible to replace metaphosphoric acid by 0.2% phosphoric acid. Methionine played an important role on the stability of ascorbic acid. The method seemed to be applicable to the routine analysis of ascorbic acid in foods. Folic Acid.-Microbiological analysis of total folate in foods is often considered as the golden standard compared to other methods based on, for example, LC. Koontz et al. showed results of total folate concentrations measured by microbiological assay in a variety of foods. Samples were submitted in a routine manner to experienced laboratories that regularly perform folate analysis fee-for-service basis in the United States. Each laboratory reported the use of a microbiological method similar to the AOAC Official Method for the determination of folic acid. Striking was, the use of 3 different pH extraction conditions by 4 laboratories. Only one laboratory reported using a tri-enzyme extraction. Results were evaluated. Results for folic acid fortified foods had considerably lower between-laboratory variation, 9-11%, versus >45% for other foods. Mean total folate ranged from 14 to 279 microg/100 g for a mixed vegetable reference material, from 5 to 70 microg/100 g for strawberries, and from 28 to 81 microg/100 g for wholemeal flour. One should realize a large variation in results, which might be caused by slight modifications in the microbiological analysis of total folate in foods or the analysis in various (unfortified) food matrixes. Furthermore, optimal combination of enzymes and reaction conditions may vary depending on the composition of the food. Padrangi and Laborde showed recently that treatment with alpha-amylase had no significant effect on measured folate in spinach, although addition of protease significantly increased the release of folate. LC/MS applications gain increasing attention because of their specificity. Rychlik used stable isotope dilution assays for the determination of the folate content of broccoli and bread. Compared to data in the literature and food data bases, amounts were significantly lower. Pawlosky et al., however, found comparable values for 5-methyltetrahydrofolic acid and folic acid by HPLC analysis with fluorescent detection and HPLC/MS. Among samples analyzed were CRMs and broccoli. Besides folic acid, other water-soluble vitamins were also determined by LC/MS/MS by Leporati et al. The method was applied to the quantitative analysis of the natural content of vitamins in typical Italian pasta samples, as well as in fortified pasta samples produced for the U.S. market. Biotin.-A paper from Staggs et al. included the assertion that existing biotin data in food composition tables are inaccurate because the majority are based on bioassays with all relevant disadvantages. Data in most cases are overestimated with consequences for recommendations for dietary biotin intake. An HPLC/avidin-binding assay was used to analyze 87 foods to support the hypothesis mentioned.

Application of wavelet and Fuorier transforms as powerful alternatives for derivative spectrophotometry in analysis of binary mixtures: A comparative study

NASA Astrophysics Data System (ADS)

Hassan, Said A.; Abdel-Gawad, Sherif A.

2018-02-01

Two signal processing methods, namely, Continuous Wavelet Transform (CWT) and the second was Discrete Fourier Transform (DFT) were introduced as alternatives to the classical Derivative Spectrophotometry (DS) in analysis of binary mixtures. To show the advantages of these methods, a comparative study was performed on a binary mixture of Naltrexone (NTX) and Bupropion (BUP). The methods were compared by analyzing laboratory prepared mixtures of the two drugs. By comparing performance of the three methods, it was proved that CWT and DFT methods are more efficient and advantageous in analysis of mixtures with overlapped spectra than DS. The three signal processing methods were adopted for the quantification of NTX and BUP in pure and tablet forms. The adopted methods were validated according to the ICH guideline where accuracy, precision and specificity were found to be within appropriate limits.

Comparision of ICP-OES and MP-AES in determing soil nutrients by Mechlich3 method

NASA Astrophysics Data System (ADS)

Tonutare, Tonu; Penu, Priit; Krebstein, Kadri; Rodima, Ako; Kolli, Raimo; Shanskiy, Merrit

2014-05-01

Accurate, routine testing of nutrients in soil samples is critical to understanding soil potential fertility. There are different factors which must be taken into account selecting the best analytical technique for soil laboratory analysis. Several techniques can provide adequate detection range for same analytical subject. In similar cases the choise of technique will depend on factors such as sample throughput, required infrastructure, ease of use, used chemicals and need for gas supply and operating costs. Mehlich 3 extraction method is widely used for the determination of the plant available nutrient elements contents in agricultural soils. For determination of Ca, K, and Mg from soil extract depending of laboratory ICP and AAS techniques are used, also flame photometry for K in some laboratories. For the determination of extracted P is used ICP or Vis spectrometry. The excellent sensitivity and wide working range for all extracted elements make ICP a nearly ideal method, so long as the sample throughput is big enough to justify the initial capital outlay. Other advantage of ICP techniques is the multiplex character (simultaneous acquisition of all wavelengths). Depending on element the detection limits are in range 0.1 - 1000 μg/L. For smaller laboratories with low sample throughput requirements the use of AAS is more common. Flame AAS is a fast, relatively cheap and easy technique for analysis of elements. The disadvantages of the method is single element analysis and use of flammable gas, like C2H2 and oxidation gas N2O for some elements. Detection limits of elements for AAS lays from 1 to 1000 μg/L. MP-AES offers a unique alternative to both, AAS and ICP-OES techniques with its detection power, speed of analysis. MP-AES is quite new, simple and relatively inexpensive multielemental technique, which is use self-sustained atmospheric pressure microwave plasma (MP) using nitrogen gas generated by nitrogen generator. Therefore not needs for argon and flammable (C2H2) gases, cylinder handling and the running costs of equipment are low. Detection limits of elements for MP-AES lays between the AAS and ICP ones. The objective of this study was to compare the results of soil analysis using two multielemental analytical methods - ICP-OES and MP-AES. In the experiment, different soil types with various texture, content of organic matter and pH were used. For the study soil samples of Albeluvisols, Leptosols, Cambisols, Regosols and Histosols were used . The plant available nutrients were estimated by Mehlich 3 extraction. The ICP-OES analysis were provided in the Estonian Agricultural Research Centre and MP-AES analysis in department of Soil Science and Agrochemistry at Estonian University of Life Sciences. The detection limits and limits of quantification of Ca, K, Mg and P in extracts are calculated and reported.

Field and laboratory data describing physical and chemical characteristics of metal-contaminated flood-plain deposits downstream from Lead, west-central South Dakota

USGS Publications Warehouse

Marron, D.C.

1988-01-01

Samples from metal-contaminated flood-plain sediments at 9 sites downstream from Lead, in west-central South Dakota, were collected during the summers of 1985-87 to characterize aspects of the sedimentology, chemistry, and geometry of a deposit that resulted from the discharge of a large volume of mining wastes into a river system. Field and laboratory data include stratigraphic descriptions, chemical contents and grain-size distributions of samples, and surveyed flood-plain positions of samples. This report describes sampling-site locations, and methods of sample collection and preservation, and subsequent laboratory analysis. Field and laboratory data are presented in 4 figures and 11 tables in the ' Supplemental Data ' section at the back of the report. (USGS)

Methods for determination of inorganic substances in water and fluvial sediments

USGS Publications Warehouse

Fishman, Marvin J.; Friedman, Linda C.

1989-01-01

Chapter Al of the laboratory manual contains methods used by the U.S. Geological Survey to analyze samples of water, suspended sediments, and bottom material for their content of inorganic constituents. Included are methods for determining the concentration of dissolved constituents in water, the total recoverable and total of constituents in water-suspended sediment samples, and the recoverable and total concentrations of constituents in samples of bottom material. The introduction to the manual includes essential definitions and a brief discussion of the use of significant figures in calculating and reporting analytical results. Quality control in the water-analysis laboratory is discussed, including the accuracy and precision of analyses, the use of standard-reference water samples, and the operation of an effective quality-assurance program. Methods for sample preparation and pretreatment are given also. A brief discussion of the principles of the analytical techniques involved and their particular application to water and sediment analysis is presented. The analytical methods of these techniques are arranged alphabetically by constituent. For each method, the general topics covered are the application, the principle of the method, the interferences, the apparatus and reagents required, a detailed description of the analytical procedure, reporting results, units and significant figures, and analytical precision data, when available. More than 126 methods are given for the determination of 70 inorganic constituents and physical properties of water, suspended sediment, and bottom material.

Methods for determination of inorganic substances in water and fluvial sediments

USGS Publications Warehouse

Fishman, Marvin J.; Friedman, Linda C.

1985-01-01

Chapter Al of the laboratory manual contains methods used by the Geological Survey to analyze samples of water, suspended sediments, and bottom material for their content of inorganic constituents. Included are methods for determining the concentration of dissolved constituents in water, total recoverable and total of constituents in water-suspended sediment samples, and recoverable and total concentrations of constituents in samples of bottom material. Essential definitions are included in the introduction to the manual, along with a brief discussion of the use of significant figures in calculating and reporting analytical results. Quality control in the water-analysis laboratory is discussed, including accuracy and precision of analyses, the use of standard reference water samples, and the operation of an effective quality assurance program. Methods for sample preparation and pretreatment are given also.A brief discussion of the principles of the analytical techniques involved and their particular application to water and sediment analysis is presented. The analytical methods involving these techniques are arranged alphabetically according to constituent. For each method given, the general topics covered are application, principle of the method, interferences, apparatus and reagents required, a detailed description of the analytical procedure, reporting results, units and significant figures, and analytical precision data, when available. More than 125 methods are given for the determination of 70 different inorganic constituents and physical properties of water, suspended sediment, and bottom material.

Program and Abstracts of the 40th Annual Meeting of the American Society of Tropical Medicine and Hygiene Held in Boston, Massachusetts on 1-5 December 1991

DTIC Science & Technology

1991-09-01

as well as with field samples collected in Chiapas , Mexico . A comparison of this method with standard microscopy and direct DNA probe analysis on 300... Mexico City, Mexico Dr. Claudio Ribeiro Rio de Janeiro, Brazil Dr. Lucia Braga Charlottesville, Virginia Dr. Hassan El Bushra Los Angeles, California...Public Health Laboratory, Leicester, England; and Regional Virus Laboratory, East Birmingham Hospital, Birmingham, England. SCIENTIFIC SESSION D

Software and hardware infrastructure for research in electrophysiology

PubMed Central

Mouček, Roman; Ježek, Petr; Vařeka, Lukáš; Řondík, Tomáš; Brůha, Petr; Papež, Václav; Mautner, Pavel; Novotný, Jiří; Prokop, Tomáš; Štěbeták, Jan

2014-01-01

As in other areas of experimental science, operation of electrophysiological laboratory, design and performance of electrophysiological experiments, collection, storage and sharing of experimental data and metadata, analysis and interpretation of these data, and publication of results are time consuming activities. If these activities are well organized and supported by a suitable infrastructure, work efficiency of researchers increases significantly. This article deals with the main concepts, design, and development of software and hardware infrastructure for research in electrophysiology. The described infrastructure has been primarily developed for the needs of neuroinformatics laboratory at the University of West Bohemia, the Czech Republic. However, from the beginning it has been also designed and developed to be open and applicable in laboratories that do similar research. After introducing the laboratory and the whole architectural concept the individual parts of the infrastructure are described. The central element of the software infrastructure is a web-based portal that enables community researchers to store, share, download and search data and metadata from electrophysiological experiments. The data model, domain ontology and usage of semantic web languages and technologies are described. Current data publication policy used in the portal is briefly introduced. The registration of the portal within Neuroscience Information Framework is described. Then the methods used for processing of electrophysiological signals are presented. The specific modifications of these methods introduced by laboratory researches are summarized; the methods are organized into a laboratory workflow. Other parts of the software infrastructure include mobile and offline solutions for data/metadata storing and a hardware stimulator communicating with an EEG amplifier and recording software. PMID:24639646

Software and hardware infrastructure for research in electrophysiology.

PubMed

Mouček, Roman; Ježek, Petr; Vařeka, Lukáš; Rondík, Tomáš; Brůha, Petr; Papež, Václav; Mautner, Pavel; Novotný, Jiří; Prokop, Tomáš; Stěbeták, Jan

2014-01-01

As in other areas of experimental science, operation of electrophysiological laboratory, design and performance of electrophysiological experiments, collection, storage and sharing of experimental data and metadata, analysis and interpretation of these data, and publication of results are time consuming activities. If these activities are well organized and supported by a suitable infrastructure, work efficiency of researchers increases significantly. This article deals with the main concepts, design, and development of software and hardware infrastructure for research in electrophysiology. The described infrastructure has been primarily developed for the needs of neuroinformatics laboratory at the University of West Bohemia, the Czech Republic. However, from the beginning it has been also designed and developed to be open and applicable in laboratories that do similar research. After introducing the laboratory and the whole architectural concept the individual parts of the infrastructure are described. The central element of the software infrastructure is a web-based portal that enables community researchers to store, share, download and search data and metadata from electrophysiological experiments. The data model, domain ontology and usage of semantic web languages and technologies are described. Current data publication policy used in the portal is briefly introduced. The registration of the portal within Neuroscience Information Framework is described. Then the methods used for processing of electrophysiological signals are presented. The specific modifications of these methods introduced by laboratory researches are summarized; the methods are organized into a laboratory workflow. Other parts of the software infrastructure include mobile and offline solutions for data/metadata storing and a hardware stimulator communicating with an EEG amplifier and recording software.

Mycotoxin contamination in laboratory rat feeds and their implications in animal research.

PubMed

Escrivá, Laura; Font, Guillermina; Berrada, Houda; Manyes, Lara

2016-09-01

Compound feed is particularly vulnerable to multi-mycotoxin contamination. A method for the determination of 12 mycotoxins; enniatins A, A1, B, B1; aflatoxins B1, B2, G1, G2; OTA; ZEA; T-2 and HT-2 by liquid chromatography-tandem mass spectrometry has been developed and applied for the analysis of laboratory rat commercial feeds. The method trueness was checked by recovery assays at three different spiked levels (n = 9). Recoveries ranged from 73% to 112%, and the intra-day and inter-day precision were lower than 9% and 13%, respectively. Limits of quantitation were lower than 15 μg/kg. Twenty-seven laboratory rats feed samples showed multi-contamination by at least three up to six different mycotoxins. ENNs B and B1, followed by ZEA were the most prevalent mycotoxins. T-2, HT-2, and OTA were not detected. ZEA showed the highest concentration levels reaching 492 μg/kg. The results underline the importance of implementing mycotoxin regular surveillance programs for laboratory animal feeds.

Conditions of High Resolution Melting Analysis on the Cobas z480 Instrument for the Genotyping of VKORC1 in the Clinical Routine Laboratory.

PubMed

Paar, Christian; Hammerl, Verena; Blessberger, Hermann; Stekel, Herbert; Steinwender, Clemens; Berg, Jörg

2016-12-01

High resolution melting (HRM) of amplicons is a simple method for genotyping of single nucleotide polymorphisms (SNPs). Albeit many applications reported, HRM seems to be rarely used in clinical laboratories. The suitability of HRM-PCR for the clinical laboratory was investigated for genotyping of SNPs of the vitamin K epoxide reductase complex unit 1 gene. About 100 DNA samples were analyzed by two different HRM-PCRs on the Cobas z480 instrument and compared with a PCR with fluorescently labeled probes (HybProbe-PCR) on the LightCycler 2.0 instrument as reference. Reliable genotyping with 100% matching results was obtained, when the amplicon size was small (63 bp) and DNA input was limited by e.g., sample dilution with salt-free water. DNA extracted by differing methods may be used for genotyping by HRM-PCR. Compared with HybProbe-PCR, HRM-PCR on the Cobas z480 instrument allows for higher through-put, however, at the cost of a higher degree of laboratory standardization and a slower turnaround.

[Analysis of the results of the SEIMC External Quality Control Program for HIV-1 and HCV viral loads. Year 2008].

PubMed

Mira, Nieves Orta; Serrano, María del Remedio Guna; Martínez, José Carlos Latorre; Ovies, María Rosario; Pérez, José L; Cardona, Concepción Gimeno

2010-01-01

Human immunodeficiency virus type 1 (HIV-1) and hepatitis C virus (HCV) viral load determinations are among the most relevant markers for the follow up of patients infected with these viruses. External quality control tools are crucial to ensure the accuracy of results obtained by microbiology laboratories. This article summarized the results obtained from the 2008 SEIMC External Quality Control Program for HIV-1 and HCV viral loads. In the HIV-1 program, a total of five standards were sent. One standard consisted in seronegative human plasma, while the remaining four contained plasma from 3 different viremic patients, in the range of 2-5 log(10) copies/mL; two of these standards were identical aiming to determine repeatability. The specificity was complete for all commercial methods, and no false positive results were reported by the participants. A significant proportion of the laboratories (24% on average) obtained values out of the accepted range (mean +/- 0.2 log(10) copies/mL), depending on the standard and on the method used for quantification. Repeatability was very good, with up to 95% of laboratories reporting results within the limits (D < 0.5 log(10) copias/mL). The HCV program consisted of two standards with different viral load contents. Most of the participants (88,7%) obtained results within the accepted range (mean +/- 1.96 SD log(10) UI/mL). Post-analytical errors due to mistranscription of the results were detected for HCV, but not for the HIV-1 program. Data from this analysis reinforce the utility of proficiency programmes to ensure the quality of the results obtained by a particular laboratory, as well as the importance of the post-analytical phase on the overall quality. Due to the remarkable interlaboratory variability, it is advisable to use the same method and the same laboratory for patient follow up. 2010 Elsevier España S.L. All rights reserved.

Method of Analysis by the U.S. Geological Survey California District Sacramento Laboratory?Determination of Trihalomethane Formation Potential, Method Validation, and Quality-Control Practices

USGS Publications Warehouse

Crepeau, Kathryn L.; Fram, Miranda S.; Bush, Noel

2004-01-01

An analytical method for the determination of the trihalomethane formation potential of water samples has been developed. The trihalomethane formation potential is measured by dosing samples with chlorine under specified conditions of pH, temperature, incubation time, darkness, and residual-free chlorine, and then analyzing the resulting trihalomethanes by purge and trap/gas chromatography equipped with an electron capture detector. Detailed explanations of the method and quality-control practices are provided. Method validation experiments showed that the trihalomethane formation potential varies as a function of time between sample collection and analysis, residual-free chlorine concentration, method of sample dilution, and the concentration of bromide in the sample.