WorldWideScience

Sample records for volume sample preparation

  1. Analytical Chemistry Laboratory (ACL) procedure compendium. Volume 2, Sample preparation methods

    Energy Technology Data Exchange (ETDEWEB)

    1993-08-01

    This volume contains the interim change notice for sample preparation methods. Covered are: acid digestion for metals analysis, fusion of Hanford tank waste solids, water leach of sludges/soils/other solids, extraction procedure toxicity (simulate leach in landfill), sample preparation for gamma spectroscopy, acid digestion for radiochemical analysis, leach preparation of solids for free cyanide analysis, aqueous leach of solids for anion analysis, microwave digestion of glasses and slurries for ICP/MS, toxicity characteristic leaching extraction for inorganics, leach/dissolution of activated metal for radiochemical analysis, extraction of single-shell tank (SST) samples for semi-VOC analysis, preparation and cleanup of hydrocarbon- containing samples for VOC and semi-VOC analysis, receiving of waste tank samples in onsite transfer cask, receipt and inspection of SST samples, receipt and extrusion of core samples at 325A shielded facility, cleaning and shipping of waste tank samplers, homogenization of solutions/slurries/sludges, and test sample preparation for bioassay quality control program.

  2. Sample Preparation and Extraction in Small Sample Volumes Suitable for Pediatric Clinical Studies: Challenges, Advances, and Experiences of a Bioanalytical HPLC-MS/MS Method Validation Using Enalapril and Enalaprilat

    Directory of Open Access Journals (Sweden)

    Bjoern B. Burckhardt

    2015-01-01

    Full Text Available In USA and Europe, medicines agencies force the development of child-appropriate medications and intend to increase the availability of information on the pediatric use. This asks for bioanalytical methods which are able to deal with small sample volumes as the trial-related blood lost is very restricted in children. Broadly used HPLC-MS/MS, being able to cope with small volumes, is susceptible to matrix effects. The latter restrains the precise drug quantification through, for example, causing signal suppression. Sophisticated sample preparation and purification utilizing solid-phase extraction was applied to reduce and control matrix effects. A scale-up from vacuum manifold to positive pressure manifold was conducted to meet the demands of high-throughput within a clinical setting. Faced challenges, advances, and experiences in solid-phase extraction are exemplarily presented on the basis of the bioanalytical method development and validation of low-volume samples (50 μL serum. Enalapril, enalaprilat, and benazepril served as sample drugs. The applied sample preparation and extraction successfully reduced the absolute and relative matrix effect to comply with international guidelines. Recoveries ranged from 77 to 104% for enalapril and from 93 to 118% for enalaprilat. The bioanalytical method comprising sample extraction by solid-phase extraction was fully validated according to FDA and EMA bioanalytical guidelines and was used in a Phase I study in 24 volunteers.

  3. Sample preparation and biopharmaceutical analysis

    OpenAIRE

    Farrelly, Gillian

    1998-01-01

    In chapter 1, an overview is given of sample preparation methods and analytical techniques in use today. Each one is discussed, and relevant examples are given. In chapter 2, the development of a method for the HPLC analysis of taurine in human plasma using acetonitrile precipitation and pre-column derivatisation with fluorescamine is presented. This procedure was found to be faster and easier to use than previous taurine assays. In chapter 3, the evaluation of novel aspirin derivativ...

  4. Microfluidic Sample Preparation for Immunoassays

    Energy Technology Data Exchange (ETDEWEB)

    Visuri, S; Benett, W; Bettencourt, K; Chang, J; Fisher, K; Hamilton, J; Krulevitch, P; Park, C; Stockton, C; Tarte, L; Wang, A; Wilson, T

    2001-08-09

    Researchers at Lawrence Livermore National Laboratory are developing means to collect and identify fluid-based biological pathogens in the forms of proteins, viruses, and bacteria. to support detection instruments, they are developing a flexible fluidic sample preparation unit. The overall goal of this Microfluidic Module is to input a fluid sample, containing background particulates and potentially target compounds, and deliver a processed sample for detection. They are developing techniques for sample purification, mixing, and filtration that would be useful to many applications including immunologic and nucleic acid assays. Many of these fluidic functions are accomplished with acoustic radiation pressure or dielectrophoresis. They are integrating these technologies into packaged systems with pumps and valves to control fluid flow through the fluidic circuit.

  5. Sample Preparation for Bioanalytical and Pharmaceutical Analysis.

    Science.gov (United States)

    Clark, Kevin D; Zhang, Cheng; Anderson, Jared L

    2016-12-06

    Biological and pharmaceutical samples represent formidable challenges in sample preparation that hold important consequences for bioanalysis and genotoxic impurity quantification. This Feature will emphasize significant advances toward the development of rapid, sensitive, and selective sample preparation methods.

  6. METALLOGRAPHIC SAMPLE PREPARATION STATION-CONSTRUCTIVE CONCEPT

    Directory of Open Access Journals (Sweden)

    AVRAM Florin Timotei

    2016-11-01

    Full Text Available In this paper we propose to present the issues involved in the case of the constructive conception of a station for metallographic sample preparation. This station is destined for laboratory work. The metallographic station is composed of a robot ABB IRB1600, a metallographic microscope, a gripping device, a manipulator, a laboratory grinding and polishing machine. The robot will be used for manipulation of the sample preparation and the manipulator take the sample preparation for processing.

  7. Alternative sample preparation methods for MALDI-MS

    Energy Technology Data Exchange (ETDEWEB)

    Hurst, G.B.; Buchanan, M.V. [Oak Ridge National Lab., TN (United States); Czartoski, T.J. [Kenyon College, Gambier, OH (United States)

    1994-12-31

    Since the introduction of matrix-assisted laser desorption and ionization (MALDI), sample preparation has been a limiting step in the applicability of this important technique for mass spectrometric analysis of biomolecules. A number of variations on the original sample preparation method for have been described. The {open_quotes}standard{close_quotes} method of MALDI sample preparation requires mixing a solution containing the analyte and a large excess of matrix, and allowing a small volume of this solution to dry on a probe tip before insertion into the mass spectrometer. The resulting sample can fairly inhomogeneous. As a result, the process of aiming the desorption laser at a favorable spot on the dried sample can be tedious and time-consuming. The authors are evaluating several approaches to MALDI sample preparation, with the goal of developing a faster and more reproducible method.

  8. Final Report BW Sample Collection& Preparation Device

    Energy Technology Data Exchange (ETDEWEB)

    Koopman, R P; Belgrader, P; Meyer, G; Benett, W J; Richards, J B; Hadley, D R; Stratton, P L; Milanovich, F P

    2002-01-31

    The objective of this project was to develop the technique needed to prepare a field collected sample for laboratory analysis and build a portable integrated biological detection instrument with new miniaturized and automated sample purification capabilities. The device will prepare bacterial spores, bacterial vegetative cells, and viral particles for PCR amplification.

  9. Modular microfluidic system for biological sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Rose, Klint A.; Mariella, Jr., Raymond P.; Bailey, Christopher G.; Ness, Kevin Dean

    2015-09-29

    A reconfigurable modular microfluidic system for preparation of a biological sample including a series of reconfigurable modules for automated sample preparation adapted to selectively include a) a microfluidic acoustic focusing filter module, b) a dielectrophoresis bacteria filter module, c) a dielectrophoresis virus filter module, d) an isotachophoresis nucleic acid filter module, e) a lyses module, and f) an isotachophoresis-based nucleic acid filter.

  10. Automated sample preparation for CE-SDS.

    Science.gov (United States)

    Le, M Eleanor; Vizel, Alona; Hutterer, Katariina M

    2013-05-01

    Traditionally, CE with SDS (CE-SDS) places many restrictions on sample composition. Requirements include low salt content, known initial sample concentration, and a narrow window of final sample concentration. As these restrictions require buffer exchange for many sample types, sample preparation is often tedious and yields poor sample recoveries. To improve capacity and streamline sample preparation, an automated robotic platform was developed using the PhyNexus Micro-Extractor Automated Instrument (MEA) for both the reduced and nonreduced CE-SDS assays. This automated sample preparation normalizes sample concentration, removes salts and other contaminants, and adds the required CE-SDS reagents, essentially eliminating manual steps during sample preparation. Fc-fusion proteins and monoclonal antibodies were used in this work to demonstrate benefits of this approach when compared to the manual method. With optimized conditions, this application has demonstrated decreased analyst "hands on" time and reduced total assay time. Sample recovery greater than 90% can be achieved, regardless of initial composition and concentration of analyte.

  11. Sample preparation in biological mass spectrometry

    CERN Document Server

    Ivanov, Alexander R

    2011-01-01

    The aim of this book is to provide the researcher with important sample preparation strategies in a wide variety of analyte molecules, specimens, methods, and biological applications requiring mass spectrometric analysis as a detection end-point.

  12. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR.

    OpenAIRE

    Goessens, Wil; Kluytmans, Jan; Toom, N.; van Rijsoort-Vos, T H; Stolz, Ernst; Verbrugh, Henri; Quint, Wim; Niesters, Bert

    1995-01-01

    textabstractIn the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of the clinical sample volume per PCR. By using this preparation procedure, 1,110 clinical samples were evaluated by PCR and by cell culture, and results were compared. After discordant ana...

  13. Molecularly imprinted polymers for bioanalytical sample preparation.

    Science.gov (United States)

    Gama, Mariana Roberto; Bottoli, Carla Beatriz Grespan

    2017-02-01

    Molecularly imprinted polymers (MIP) are stable polymers with molecular recognition abilities, provided by the presence of a template during their synthesis, and are excellent materials with high selectivity for sample preparation in bioanalytical methods. This short review discusses aspects of MIP preparation and its applications as a sorbent material in pharmaceutical and biomedical analysis. MIP in different extraction configurations, including classical solid-phase extraction, solid-phase microextraction, magnetic molecularly imprinted solid-phase extraction, microextraction by packed sorbent and solid-phase extraction in pipette tips, are used to illustrate the good performance of this type of sorbent for sample preparation procedures of complex matrices, especially prior to bioanalytical approaches.

  14. Sample preparation for SEM of plant surfaces

    OpenAIRE

    A.K. Pathan; Bond, J.; R.E. Gaskin

    2010-01-01

    Plant tissues must be dehydrated for observation in most electron microscopes. Although a number of sample processing techniques have been developed for preserving plant tissues in their original form and structure, none of them are guaranteed artefact-free. The current paper reviews common scanning electron microscopy techniques and the sample preparation methods employed for visualisation of leaves under specific types of electron microscopes. Common artefacts introduced by specific techniq...

  15. Sample preparation method for scanning force microscopy

    CERN Document Server

    Jankov, I R; Szente, R N; Carreno, M N P; Swart, J W; Landers, R

    2001-01-01

    We present a method of sample preparation for studies of ion implantation on metal surfaces. The method, employing a mechanical mask, is specially adapted for samples analysed by Scanning Force Microscopy. It was successfully tested on polycrystalline copper substrates implanted with phosphorus ions at an acceleration voltage of 39 keV. The changes of the electrical properties of the surface were measured by Kelvin Probe Force Microscopy and the surface composition was analysed by Auger Electron Spectroscopy.

  16. Scanning Electron Microscopy Sample Preparation and Imaging.

    Science.gov (United States)

    Nguyen, Jenny Ngoc Tran; Harbison, Amanda M

    2017-01-01

    Scanning electron microscopes allow us to reach magnifications of 20-130,000× and resolve compositional and topographical images with intense detail. These images are created by bombarding a sample with electrons in a focused manner to generate a black and white image from the electrons that bounce off of the sample. The electrons are detected using positively charged detectors. Scanning electron microscopy permits three-dimensional imaging of desiccated specimens or wet cells and tissues by using variable pressure chambers. SEM ultrastructural analysis and intracellular imaging supplement light microscopy for molecular profiling of prokaryotes, plants, and mammals. This chapter demonstrates how to prepare and image samples that are (a) desiccated and conductive, (b) desiccated and nonconductive but coated with an electron conductive film using a gold sputter coater, and (c) wet and maintained in a hydrated state using a Deben Coolstage.

  17. HASE - The Helsinki adaptive sample preparation line

    Energy Technology Data Exchange (ETDEWEB)

    Palonen, V., E-mail: vesa.palonen@helsinki.fi [Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 (Finland); Pesonen, A. [Laboratory of Chronology, Finnish Museum of Natural History, P.O. Box 64, FI-00014 (Finland); Herranen, T.; Tikkanen, P. [Department of Physics, University of Helsinki, P.O. Box 43, FI-00014 (Finland); Oinonen, M. [Laboratory of Chronology, Finnish Museum of Natural History, P.O. Box 64, FI-00014 (Finland)

    2013-01-15

    We have designed and built an adaptive sample preparation line with separate modules for combustion, molecular sieve handling, CO{sub 2} gas cleaning, CO{sub 2} storage, and graphitization. The line is also connected to an elemental analyzer. Operation of the vacuum equipment, a flow controller, pressure sensors, ovens, and graphitization reactors are automated with a reliable NI-cRIO real-time system. Stepped combustion can be performed in two ovens at temperatures up to 900 Degree-Sign C. Depending on the application, CuO or O{sub 2}-flow combustion can be used. A flow controller is used to adjust the O{sub 2} flow and pressure during combustion. For environmental samples, a module for molecular sieve regeneration and sample desorption is attached to the line replacing the combustion module. In the storage module, CO{sub 2} samples can be stored behind a gas-tight diaphragm valve and either stored for later graphitization or taken for measurements with separate equipment (AMS gas ion source or a separate mass spectrometer). The graphitization module consists of four automated reactors, capable of graphitizing samples with masses from 3 mg down to 50 {mu}g.

  18. Sample preparation for SEM of plant surfaces

    Directory of Open Access Journals (Sweden)

    A.K. Pathan

    2010-01-01

    Full Text Available Plant tissues must be dehydrated for observation in most electron microscopes. Although a number of sample processing techniques have been developed for preserving plant tissues in their original form and structure, none of them are guaranteed artefact-free. The current paper reviews common scanning electron microscopy techniques and the sample preparation methods employed for visualisation of leaves under specific types of electron microscopes. Common artefacts introduced by specific techniques on different leaf types are discussed. Comparative examples are depicted from our lab using similar techniques; the pros and cons for specific techniques are discussed. New promising techniques and microscopes, which can alleviate some of the problems encountered in conventional methods of leaf sample processing and visualisation, are also discussed. It is concluded that the choice of technique for a specific leaf sample is dictated by the surface features that need to be preserved (such as trichomes, epidermal cells or wax microstructure, the resolution to be achieved, availability of the appropriate processing equipment and the technical capabilities of the available electron microscope.

  19. FISHprep: A Novel Integrated Device for Metaphase FISH Sample Preparation

    DEFF Research Database (Denmark)

    Shah, Pranjul Jaykumar; Vedarethinam, Indumathi; Kwasny, Dorota;

    2011-01-01

    We present a novel integrated device for preparing metaphase chromosomes spread slides (FISHprep). The quality of cytogenetic analysis from patient samples greatly relies on the efficiency of sample pre-treatment and/or slide preparation. In cytogenetic slide preparation, cell cultures are routin...... with minimal handling for metaphase FISH slide preparation....

  20. Congener Production in Blood Samples During Preparation and Storage

    DEFF Research Database (Denmark)

    Felby, Søren; Nielsen, Erik

    1995-01-01

    Retsmedicin, congener production, preparation, head space GC, acetone, isobutanol, storage, blood samples, n-propanol, methanol, methylethylketone......Retsmedicin, congener production, preparation, head space GC, acetone, isobutanol, storage, blood samples, n-propanol, methanol, methylethylketone...

  1. Method of 14C Sample Preparation for AMS Measurement

    Directory of Open Access Journals (Sweden)

    YANG Xu-ran

    2015-02-01

    Full Text Available In order to carry out the application research of 14C by accelerator mass spectrometry (AMS, the principle of sample preparation were systematically studied and more attention was paid to improve the preparation process efficiently. The set of integrated system of sample preparation was built up on the research. The experimental results showed that the sample preparation scheme was able to meet the demand of AMS measurement.

  2. Preparation of High Surface Area, Large Pore Volume Alumina by Using β-Cyclodextrin as a Non-surfactant Template

    Institute of Scientific and Technical Information of China (English)

    Lai Jun WANG; Ming Fen WEN; Yu Shan LI; Dong YANG; Jing CHEN; Chong Li SONG

    2006-01-01

    A series of alumina samples were prepared using β-cyclodextrin as the non-surfactant template. These samples were characterized by XRD, BET and TEM. The results showed that the alumina samples prepared using β-cyclodextrin template had the higher surface areas (124-484 m2/g), larger pore volumes (0.7-1.27 mL/g) and more thermal stability than samples prepared without using β-cyclodextrin.

  3. Pressurized fluidized-bed hydroretorting of eastern oil shales. Volume 4, Task 5, Operation of PFH on beneficiated shale, Task 6, Environmental data and mitigation analyses and Task 7, Sample procurement, preparation, and characterization: Final report, September 1987--May 1991

    Energy Technology Data Exchange (ETDEWEB)

    1992-03-01

    The objective of Task 5 (Operation of Pressurized Fluidized-Bed Hydro-Retorting (PFH) on Beneficiated Shale) was to modify the PFH process to facilitate its use for fine-sized, beneficiated Eastern shales. This task was divided into 3 subtasks: Non-Reactive Testing, Reactive Testing, and Data Analysis and Correlations. The potential environment impacts of PFH processing of oil shale must be assessed throughout the development program to ensure that the appropriate technologies are in place to mitigate any adverse effects. The overall objectives of Task 6 (Environmental Data and Mitigation Analyses) were to obtain environmental data relating to PFH and shale beneficiation and to analyze the potential environmental impacts of the integrated PFH process. The task was divided into the following four subtasks. Characterization of Processed Shales (IGT), 6.2. Water Availability and Treatment Studies, 6.3. Heavy Metals Removal and 6.4. PFH Systems Analysis. The objective of Task 7 (Sample Procurement, Preparation, and Characterization) was to procure, prepare, and characterize raw and beneficiated bulk samples of Eastern oil shale for all of the experimental tasks in the program. Accomplishments for these tasks are presented.

  4. PREPARATION OF ULTRA-LOW VOLUME WEIGHT AUTOCLAVED AERATED CONCRETE

    Directory of Open Access Journals (Sweden)

    Ondrej Koutny

    2016-12-01

    Full Text Available Autoclaved aerated concrete is a modern construction material that gains its popularity especially due to its thermal insulation performance resulting from low volume weight and porous structure with sufficient mechanical strength. Nowadays, there are attempts to use this material for thermal insulation purposes and to replace current systems, which have many disadvantages, mainly concerning durability. The key for improvement of thermal insulation properties is therefore obtaining a material based on autoclaved aerated concrete with extremely low volume weight (below 200 kg/m ³ ensuring good thermal isolation properties, but with sufficient mechanical properties to allow easy manipulation. This material can be prepared by foaming very fine powder materials such as silica fume or very finely ground sand. This paper deals with the possibilities of preparation and summarizes the basic requirements for successful preparation of such a material.

  5. Homogeneous sample preparation of raw shrimp using dry ice.

    Science.gov (United States)

    Bunch, E A; Altwein, D M; Johnson, L E; Farley, J R; Hammersmith, A A

    1995-01-01

    Sample homogeneity is critical to accurate and reproducible analysis of trace residues in foods. A method of uniform sample preparation using dry ice is described for shrimp. Other sample preparation techniques for raw shrimp produce nonhomogeneous samples. Sample homogeneity was determined through analysis of chloramphenicol added to intact tiger or white shrimp prior to sample preparation. Simulated chloramphenicol residue levels were 50, 15, 10, and 5 ppb. No significant differences were noted when analyses of shrimp inoculated with chlor-amphenicol prior to sample preparation with dry ice were compared with analyses of shrimp spiked after grinding with dry ice. Grinding shrimp with dry ice produced samples with homogeneous chloramphenicol residues. This technique should be applicable to other tissues and vegetable products.

  6. Universal Sample Preparation Module for Molecular Analysis in Space Project

    Data.gov (United States)

    National Aeronautics and Space Administration — Lynntech proposes to develop and demonstrate the ability of a compact, light-weight, and automated universal sample preparation module (USPM) to process samples from...

  7. Preparation of protein samples for gel electrophoresis by sequential extraction

    Institute of Scientific and Technical Information of China (English)

    钟伯雄; 翁宏飚; 等

    2002-01-01

    Since preparation and solubilization of protein samples are crucial factors in proteome research,the authors established a sequential extraction technique to prepare protein samples from the body wall of the 5th instar larvae of silkworm.Bombyx mori.Two kinds of protein samples were obtained from the body wall using the method.Between the two types of samples only about 15% proteins were identical;the majority were different,indicating that more species of proteins could be obtained with the sequential extraction method;which will be useful for preparation of protein samples for proteome study.

  8. Preparation of protein samples for gel electrophoresis by sequential extraction

    Institute of Scientific and Technical Information of China (English)

    钟伯雄; 翁宏飚; 方维焕

    2002-01-01

    Since preparation and solubilization of protein samples are crucial factors in proteome research, the authors established a sequential extraction technique to prepare protein samples from the body wall of the 5th instar larvae of silkworm, Bombyx mori. Two kinds of protein samples were obtained from the body wall using the method. Between the two types of samples only about 15% proteins were identical; the majority were different, indicating that more species of proteins could be obtained with the sequential extraction method; which will be useful for preparation of protein samples for proteome study.

  9. Status report of AMS sample preparation laboratory at GADAM Centre, Gliwice, Poland

    Energy Technology Data Exchange (ETDEWEB)

    Piotrowska, N., E-mail: natalia.piotrowska@polsl.pl [GADAM Centre of Excellence, Department of Radioisotopes, Institute of Physics, Silesian University of Technology, Gliwice (Poland)

    2013-01-15

    The laboratory for {sup 14}C AMS sample preparation in the Gliwice Radiocarbon Laboratory has gradually evolved since its start in 1999 to cater for an increase in volume and variety of radiocarbon dating samples. To date, nearly 2000 graphite targets have been produced from materials such as plant macrofossils, charcoal, peat, bones, shells and wood. The equipment comprises a station for chemical preparation and high vacuum lines for production, purification and graphitization of sample carbon dioxide. The present capacity allows preparation of up to 400 targets annually for the needs of scientific projects and external orders for radiocarbon dating continuously received by the GADAM Centre of Excellence. The laboratory's sample preparation protocols and recent improvements are described and its performance during the 10 years of activity is discussed in terms of parameters obtained from reference materials prepared in this laboratory and demonstrated with a few science applications.

  10. TRU Waste Sampling Program: Volume I. Waste characterization

    Energy Technology Data Exchange (ETDEWEB)

    Clements, T.L. Jr.; Kudera, D.E.

    1985-09-01

    Volume I of the TRU Waste Sampling Program report presents the waste characterization information obtained from sampling and characterizing various aged transuranic waste retrieved from storage at the Idaho National Engineering Laboratory and the Los Alamos National Laboratory. The data contained in this report include the results of gas sampling and gas generation, radiographic examinations, waste visual examination results, and waste compliance with the Waste Isolation Pilot Plant-Waste Acceptance Criteria (WIPP-WAC). A separate report, Volume II, contains data from the gas generation studies.

  11. Snow White Trench Prepared for Sample Collection

    Science.gov (United States)

    2008-01-01

    The informally named 'Snow White' trench is the source for the next sample to be acquired by NASA's Phoenix Mars Lander for analysis by the wet chemistry lab. The Surface Stereo Imager on Phoenix took this shadow-enhanced image of the trench, on the eastern end of Phoenix's work area, on Sol 103, or the 103rd day of the mission, Sept. 8, 2008. The trench is about 23 centimeters (9 inches) wide. The wet chemistry lab is part of Phoenix's Microscopy, Electrochemistry and Conductivity suite of instruments. The Phoenix Mission is led by the University of Arizona, Tucson, on behalf of NASA. Project management of the mission is by NASA's Jet Propulsion Laboratory, Pasadena, Calif. Spacecraft development is by Lockheed Martin Space Systems, Denver.

  12. New reduced volume preparation regimen in colon capsule endoscopy

    Institute of Scientific and Technical Information of China (English)

    Yasuo Kakugawa; Kazuhide Higuchi; Shinji Tanaka; Hideki Ishikawa; Hisao Tajiri; Yutaka Saito; Shoichi Saito; Kenji Watanabe; Naoki Ohmiya; Mitsuyuki Murano; Shiro Oka; Tetsuo Arakawa; Hidemi Goto

    2012-01-01

    AIM:To evaluate the effectiveness of our proposed bowel preparation method for colon capsule endoscopy.METHODS:A pilot,multicenter,randomized controlled trial compared our proposed "reduced volume method" (group A) with the "conventional volume method" (group B) preparation regimens.Group A did not drink polyethylene glycol electrolyte lavage solution (PEGELS) the day before the capsule procedure,while group B drank 2 L.During the procedure day,groups A and B drank 2 L and 1 L of PEG-ELS,respectively,and swallowed the colon capsule (PillCam COLON(R) capsule).Two hours later the first booster of 100 g magnesium citrate mixed with 900 mL water was administered to both groups,and the second booster was administered six hours post capsule ingestion as long as the capsule had not been excreted by that time.Capsule videos were reviewed for grading of cleansing level.RESULTS:Sixty-four subjects were enrolled,with results from 60 analyzed.Groups A and B included 31 and 29 subjects,respectively.Twenty-nine (94%) subjects in group A and 25 (86%) subjects in group B had adequate bowel preparation (ns).Twenty-two (71%) of the 31 subjects in group A excreted the capsule within its battery life compared to 16 (55%) of the 29 subjects in group B (ns).Of the remaining 22 subjects whose capsules were not excreted within the battery life,all of the capsules reached the left side colon before they stopped functioning.A single adverse event was reported in one subject who had mild symptoms of nausea and vomiting one hour after starting to drink PEG-ELS,due to ingesting the PEG-ELS faster than recommended.CONCLUSION:Our proposed reduced volume bowel preparation method for colon capsule without PEG-ELS during the days before the procedure was as effective as the conventional volume method.

  13. Sample Preparation (SS): SE55_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available 80℃ until analysis. The frozen tissues were homogenized in five volumes of 80% aqueous methanol containing 0...SE55_SS01 Metabolic profiling Collected sample tissues were weighed and stored at -

  14. Sample preparation for atomic spectroscopy: evolution and future trends

    Directory of Open Access Journals (Sweden)

    Oliveira Elisabeth de

    2003-01-01

    Full Text Available Sample preparation is the critical step of any analytical protocol, and involves steps from simple dilution to partial or total dissolution. The methods include dry or wet decomposition of the samples in open or closed systems, using thermal, ultrasonic or radiant (infrared, ultraviolet and microwaves energy. This review emphasizes sample preparation for atomic spectroscopy. The present and future tendencies for sample preparation also involve on-line dissolution, extraction of the analytes, speciation, solid sample and slurry analysis, in situ and in vivo procedures, etc. Nowadays the goals are the best result, in the shortest time, with minimum contamination, using the smallest quantities of reagents and samples, and having low residue and waste generation, as well as maintaining the integrity of the sample and the traceability of the results, to have quality and confidence in the measurements as the primordial attributes required by the community and by the users.

  15. γ-ray spectrometry results versus sample preparation methods

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    According to recommended conditions two bio-samples, tea leave and flour, are prepared with different methods: grounding into powder and reducing to ash, then they were analyzed by γ ray spectrometry. Remarkable difference was shown between the measured values of tea samples prepared with these different methods. One of the reasons may be that the method of reducing to ash makes some nuclides lost. Compared with the "non-destructive"method of grounding into powder, the method of reducing to ash can be much more sensible to the loss of some nuclides. The probable reasons are discussed for the varied influences of different preparation methods of tea leave and flour samples.

  16. Microscale sample preparation for PCR of C. difficile infected stool

    Science.gov (United States)

    Gillers, Sara; Atkinson, Christopher D.; Bartoo, Aaron C.; Mahalanabis, Madhumita; Boylan, Michael O.; Schwartz, John H.; Klapperich, Catherine; Singh, Satish K.

    2015-01-01

    In this paper, we describe the design of a microfluidic sample preparation chip for human stool samples infected with Clostridium difficile. We established a polymerase chain reaction able to distinguish C. difficile in the presence of several other organisms found in the normal intestinal flora. A protocol for on-chip extraction of nucleic acids from clinical samples is described that can detect target DNA down to 5.0×10−3 ng of template. The assay and sample preparation chip were then validated using known positive and known negative clinical samples. The work presented has potential applications in both the developed and developing world. PMID:19505511

  17. Precise small volume sample handling for capillary electrophoresis.

    Science.gov (United States)

    Mozafari, Mona; Nachbar, Markus; Deeb, Sami El

    2015-09-03

    Capillary electrophoresis is one of the most important analytical techniques. Although the injected sample volume in capillary electrophoresis is only in the nanoliter range, most commercial CE-instruments need approximately 50 μL of the sample in the injection vial to perform the analysis. Hence, in order to fully profit from the low injection volumes, smaller vial volumes are required. Thus experiments were performed using silicone oil which has higher density than water (1.09 g/mL) to replace sample dead volume in the vial. The results were compared to those performed without using the silicone oil in the sample vial. As an example five standard proteins namely beta-lactoglobulin, BSA, HSA, Myoglobin and Ovalbumin, and one of the coagulation cascade involved proteins called vitonectin were investigated using capillary electrophoresis. Mobility ratios and peak areas were compared. However no significant changes were observed (RSDs% for mobility ratios and peak areas were better than 0.9% and 5.8% respectively). Afterwards an affinity capillary electrophoresis method was used to investigate the interactions of two proteins, namely HSA and vitronectin, with three ligands namely enoxaparin sodium, unfractionated heparin and pentosan polysulfate sodium (PPS). Mobility shift precision results showed that the employment of the filling has no noticeable effect on any of the protein-ligand interactions. Using a commercial PrinCE instrument and an autosampler the required sample volume is reduced down to 10 μL, and almost this complete volume can be subsequently injected during repeated experiments. This article is protected by copyright. All rights reserved.

  18. The effect of sample preparation and testing procedure on the ...

    African Journals Online (AJOL)

    The effect of sample preparation and testing procedure on the geotechnical ... of conventional laboratory testing, classification and evaluation systems, which were ... It should not be used to classify them based on conventional methods ...

  19. Preparation of Cytology Samples: Tricks of the Trade.

    Science.gov (United States)

    Moore, A Russell

    2017-01-01

    General principles and techniques for collection, preparation, and staining of cytologic samples in the general practice setting are reviewed. Tips for collection of digital images are also discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

  20. Modern methods of sample preparation for GC analysis

    OpenAIRE

    de Koning; Janssen, H.-G.; Brinkman, U.A.T.

    2009-01-01

    Today, a wide variety of techniques is available for the preparation of (semi-) solid, liquid and gaseous samples, prior to their instrumental analysis by means of capillary gas chromatography (GC) or, increasingly, comprehensive two-dimensional GC (GC × GC). In the past two decades, a large number of ‘modern’ sample-preparation techniques has been introduced, which have partly superseded their ‘classical’ counterparts. These novel techniques include off-line and on-line (sometimes semi- or f...

  1. Curatorial Works for the Hayabusa-Returned Sample and Preparation for Hayabusa2 Sample Curation

    Science.gov (United States)

    Yada, T.; Abe, M.; Okada, T.; Yurimoto, H.; Uesugi, M.; Karouji, Y.; Nakato, A.; Hashiguchi, M.; Nishimura, M.; Kumagai, K.; Matsui, S.; Yoshitake, M.; Sakamoto, K.; Nakano, Y.; Kawasaki, N.; Fujimoto, M.

    2016-08-01

    We continue describing Hayabusa-returned samples after its return in 2010. The number of described particles reaches around 650 and >540 of them are identified as Itokawa origin. We also start preparation for Hayabusa2 sample curation.

  2. Calcium isolation from large-volume human urine samples for 41Ca analysis by accelerator mass spectrometry.

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-08-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for (41)Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after (41)Ca administration during which human samples, collected over a lifetime, provide (41)Ca:Ca ratios that are significantly above background.

  3. Calcium Isolation from Large-Volume Human Urine Samples for 41Ca Analysis by Accelerator Mass Spectrometry

    Science.gov (United States)

    Miller, James J; Hui, Susanta K; Jackson, George S; Clark, Sara P; Einstein, Jane; Weaver, Connie M; Bhattacharyya, Maryka H

    2013-01-01

    Calcium oxalate precipitation is the first step in preparation of biological samples for 41Ca analysis by accelerator mass spectrometry. A simplified protocol for large-volume human urine samples was characterized, with statistically significant increases in ion current and decreases in interference. This large-volume assay minimizes cost and effort and maximizes time after 41Ca administration during which human samples, collected over a lifetime, provide 41Ca:Ca ratios that are significantly above background. PMID:23672965

  4. Volume Ray Casting with Peak Finding and Differential Sampling

    KAUST Repository

    Knoll, A.

    2009-11-01

    Direct volume rendering and isosurfacing are ubiquitous rendering techniques in scientific visualization, commonly employed in imaging 3D data from simulation and scan sources. Conventionally, these methods have been treated as separate modalities, necessitating different sampling strategies and rendering algorithms. In reality, an isosurface is a special case of a transfer function, namely a Dirac impulse at a given isovalue. However, artifact-free rendering of discrete isosurfaces in a volume rendering framework is an elusive goal, requiring either infinite sampling or smoothing of the transfer function. While preintegration approaches solve the most obvious deficiencies in handling sharp transfer functions, artifacts can still result, limiting classification. In this paper, we introduce a method for rendering such features by explicitly solving for isovalues within the volume rendering integral. In addition, we present a sampling strategy inspired by ray differentials that automatically matches the frequency of the image plane, resulting in fewer artifacts near the eye and better overall performance. These techniques exhibit clear advantages over standard uniform ray casting with and without preintegration, and allow for high-quality interactive volume rendering with sharp C0 transfer functions. © 2009 IEEE.

  5. Sample Preparation (SS): SE51_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available e Master NEO, BMS, Tokyo, Japan), and the seed powder was extracted with 1 mL of extraction buffer (0.1% HCO...trifugation (4 ℃, 10,000 rpm, 5 min), the sample tubes were subjected to sample preparation (buffer transfer

  6. New materials for sample preparation techniques in bioanalysis.

    Science.gov (United States)

    Nazario, Carlos Eduardo Domingues; Fumes, Bruno Henrique; da Silva, Meire Ribeiro; Lanças, Fernando Mauro

    2017-02-01

    The analysis of biological samples is a complex and difficult task owing to two basic and complementary issues: the high complexity of most biological matrices and the need to determine minute quantities of active substances and contaminants in such complex sample. To succeed in this endeavor samples are usually subject to three steps of a comprehensive analytical methodological approach: sample preparation, analytes isolation (usually utilizing a chromatographic technique) and qualitative/quantitative analysis (usually with the aid of mass spectrometric tools). Owing to the complex nature of bio-samples, and the very low concentration of the target analytes to be determined, selective sample preparation techniques is mandatory in order to overcome the difficulties imposed by these two constraints. During the last decade new chemical synthesis approaches has been developed and optimized, such as sol-gel and molecularly imprinting technologies, allowing the preparation of novel materials for sample preparation including graphene and derivatives, magnetic materials, ionic liquids, molecularly imprinted polymers, and much more. In this contribution we will review these novel techniques and materials, as well as their application to the bioanalysis niche. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Microfluidic Sample Preparation Methods for the Analysis of Milk Contaminants

    Directory of Open Access Journals (Sweden)

    Andrea Adami

    2016-01-01

    Full Text Available In systems for food analysis, one of the major challenges is related to the quantification of specific species into the complex chemical and physical composition of foods, that is, the effect of “matrix”; the sample preparation is often the key to a successful application of biosensors to real measurements but little attention is traditionally paid to such aspects in sensor research. In this critical review, we discuss several microfluidic concepts that can play a significant role in sample preparation, highlighting the importance of sample preparation for efficient detection of food contamination. As a case study, we focus on the challenges related to the detection of aflatoxin M1 in milk and we evaluate possible approaches based on inertial microfluidics, electrophoresis, and acoustic separation, compared with traditional laboratory and industrial methods for phase separation as a baseline of thrust and well-established techniques.

  8. MALDI MS sample preparation by using paraffin wax film: systematic study and application for peptide analysis.

    Science.gov (United States)

    Wang, Junhua; Chen, Ruibing; Ma, Mingming; Li, Lingjun

    2008-01-15

    Recently developed sample preparation techniques employing hydrophobic sample support have improved the detection sensitivity and mass spectral quality of matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). These methods concentrate the samples on target by minimizing the sample area via the solvent repellent effect of the target surface. In the current study, we employed the use of paraffin wax film (Parafilm M) for improved MALDI MS analysis of low-abundance peptide mixtures, including neuronal tissue releasate and protein tryptic digests. This thin film was found to strongly repel polar solvents including water, methanol, and acetonitrile, which enabled the application of a wide range of sample preparation protocols that involved the use of various organic solvents. A "nanoliter-volume deposition" technique employing a capillary column has been used to produce tiny ( approximately 400 microm) matrix spots of 2,5-dihydroxybenzoic acid on the film. By systematically optimizing the sample volume, solvent composition, and film treatment, the Parafilm M substrate in combination with the nanoliter-volume matrix deposition method allowed dilute sample to be concentrated on the film for MALDI MS analysis. Peptide mixtures with nanomolar concentrations have been detected by MALDI time-of-flight and MALDI Fourier transform ion cyclotron resonance mass spectrometers. Overall, the use of Parafilm M enabled improved sensitivity and spectral quality for the analysis of complex peptide mixtures.

  9. Fluidics platform and method for sample preparation and analysis

    Energy Technology Data Exchange (ETDEWEB)

    Benner, W. Henry; Dzenitis, John M.; Bennet, William J.; Baker, Brian R.

    2014-08-19

    Herein provided are fluidics platform and method for sample preparation and analysis. The fluidics platform is capable of analyzing DNA from blood samples using amplification assays such as polymerase-chain-reaction assays and loop-mediated-isothermal-amplification assays. The fluidics platform can also be used for other types of assays and analyzes. In some embodiments, a sample in a sealed tube can be inserted directly. The following isolation, detection, and analyzes can be performed without a user's intervention. The disclosed platform may also comprises a sample preparation system with a magnetic actuator, a heater, and an air-drying mechanism, and fluid manipulation processes for extraction, washing, elution, assay assembly, assay detection, and cleaning after reactions and between samples.

  10. Pulsed Direct Current Electrospray: Enabling Systematic Analysis of Small Volume Sample by Boosting Sample Economy.

    Science.gov (United States)

    Wei, Zhenwei; Xiong, Xingchuang; Guo, Chengan; Si, Xingyu; Zhao, Yaoyao; He, Muyi; Yang, Chengdui; Xu, Wei; Tang, Fei; Fang, Xiang; Zhang, Sichun; Zhang, Xinrong

    2015-11-17

    We had developed pulsed direct current electrospray ionization mass spectrometry (pulsed-dc-ESI-MS) for systematically profiling and determining components in small volume sample. Pulsed-dc-ESI utilized constant high voltage to induce the generation of single polarity pulsed electrospray remotely. This method had significantly boosted the sample economy, so as to obtain several minutes MS signal duration from merely picoliter volume sample. The elongated MS signal duration enable us to collect abundant MS(2) information on interested components in a small volume sample for systematical analysis. This method had been successfully applied for single cell metabolomics analysis. We had obtained 2-D profile of metabolites (including exact mass and MS(2) data) from single plant and mammalian cell, concerning 1034 components and 656 components for Allium cepa and HeLa cells, respectively. Further identification had found 162 compounds and 28 different modification groups of 141 saccharides in a single Allium cepa cell, indicating pulsed-dc-ESI a powerful tool for small volume sample systematical analysis.

  11. Sample preparation for quantitation of tritium by accelerator mass spectrometry.

    Science.gov (United States)

    Chiarappa-Zucca, Marina L; Dingley, Karen H; Roberts, Mark L; Velsko, Carol A; Love, Adam H

    2002-12-15

    The capability to prepare samples accurately and reproducibly for analysis of tritium (3H) content by accelerator mass spectrometry (AMS) greatly facilitates isotopic tracer studies in which attomole levels of 3H can be measured in milligram-sized samples. A method has been developed to convert the hydrogen of organic samples to a solid, titanium hydride, which can be analyzed by AMS. Using a two-step process, the sample is first oxidized to carbon dioxide and water. In the second step, the water is transferred within a heated manifold into a quartz tube, reduced to hydrogen gas using zinc, and reacted with titanium powder. The 3H/1H ratio of the titanium hydride is measured by AMS and normalized to standards whose ratios were determined by decay counting to calculate the amount of 3H in the original sample. Water, organic compounds, and biological samples with 3H activities measured by liquid scintillation counting were utilized to develop and validate the method. The 3H/1H ratios were quantified in samples that spanned 5 orders of magnitude, from 10(-10) to 10(-15), with a detection limit of 3.0 x 10(-15), which is equivalent to 0.02 dpm tritium/mg of material. Samples smaller than 2 mg were analyzed following addition of 2 mg of a tritium-free-hydrogen carrier. Preparation of organic standards containing both 14C and 3H in 2-mg organic samples demonstrated that this sample preparation methodology can also be applied to quantify both of these isotopes from a single sample.

  12. Basic tree-ring sample preparation techniques for aging aspen

    Science.gov (United States)

    Lance A. Asherin; Stephen A. Mata

    2001-01-01

    Aspen is notoriously difficult to age because of its light-colored wood and faint annual growth rings. Careful preparation and processing of aspen ring samples can overcome these problems, yield accurate age and growth estimates, and concisely date disturbance events present in the tree-ring record. Proper collection of aspen wood is essential in obtaining usable ring...

  13. Comprehensive workflow for wireline fluid sampling in an unconsolidated formations utilizing new large volume sampling equipment

    Energy Technology Data Exchange (ETDEWEB)

    Kvinnsland, S.; Brun, M. [TOTAL EandP Norge (Norway); Achourov, V.; Gisolf, A. [Schlumberger (Canada)

    2011-07-01

    Precise and accurate knowledge of fluid properties is essential in unconsolidated formations to the design of production facilities. Wireline formation testers (WFT) have a wide range of applications and the latest WFT can be used to define fluid properties in the wells drilled with oil based mud (OBM) by acquiring PVT and large volume samples. To use these technologies, a comprehensive workflow has to be implemented and the aim of this paper is to present such a workflow. A sampling was conducted in highly unconsolidated sand saturated with biodegradable fluid in the Hild filed in the North Sea. Results showed the use of comprehensive workflow to be successful in obtaining large volume samples with the contamination level below 1%. Oil was precisely characterized thanks to these samples and design updates to the project were made possible. This paper highlighted that the use of the latest WFT technologies can help better characterize fluids in unconsolidated formations and thus optimize production facilities design.

  14. Low-volume plus ascorbic acid vs high-volume plus simethicone bowel preparation before colonoscopy

    Institute of Scientific and Technical Information of China (English)

    Stefano Pontone; Rita Angelini; Monica Standoli; Gregorio Patrizi; Franco Culasso; Paolo Pontone; Adriano Redler

    2011-01-01

    AIM: To investigate the effectiveness of low-volume plus ascorbic acid [polyethylene glycol plus ascorbic acid (PEG + Asc)] and high-volume plus simethicone [polyethylene glycol plus simethicone (PEG + Sim)] bowel preparations.METHODS: A total of one hundred and forty-four outpatients (76 males), aged from 20 to 84 years (me dian age 59.5 years), who attended our Department, were divided into two groups, age and sex matched, and underwent colonoscopy. Two questionnaires, one for patients reporting acceptability and the other for endoscopists evaluating bowel cleansing effectiveness according to validated scales, were completed. Indica tions, timing of examination and endoscopical findings were recorded. Biopsy forceps were used as a measur ing tool in order to determine polyp endoscopic sizeestimation. Difficulty in completing the preparation was rated in a 5-point Likert scale (1 = easy to 5 = un able). Adverse experiences (fullness, cramps, nausea, vomiting, abdominal pain, headache and insomnia), number of evacuations and types of activities per formed during preparation (walking or resting in bed) were also investigated.RESULTS: Seventy-two patients were selected for each group. The two groups were age and sex matched as well as being comparable in terms of medical history and drug therapies taken. Fourteen patients dropped out from the trial because they did not complete the preparation procedure. Ratings of global bowel cleans ing examinations were considered to be adequate in 91% of PEG + Asc and 88% of PEG + Sim patients. Residual Stool Score indicated similar levels of amount and consistency of residual stool; there was a signifi cant difference in the percentage of bowel wall visuali zation in favour of PEG + Sim patients. In the PEG + Sim group, 12 adenomas < 10 mm diameter (5/left co lon + 7/right colon) vs 9 (8/left colon + 1/right colon) in the PEG + Asc group were diagnosed. Visualization of small lesions seems to be one of the primary advan tages of

  15. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    Goessens, W H; Kluytmans, J A; den Toom, N; van Rijsoort-Vos, T H; Niesters, B G; Stolz, E; Verbrugh, H A; Quint, W G

    In the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of

  16. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    Goessens, W H; Kluytmans, J A; den Toom, N; van Rijsoort-Vos, T H; Niesters, B G; Stolz, E; Verbrugh, H A; Quint, W G

    1995-01-01

    In the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least 4%, i.e., 80 microliters, of t

  17. Influence of volume of sample processed on detection of Chlamydia trachomatis in urogenital samples by PCR

    NARCIS (Netherlands)

    W.H.F. Goessens (Wil); J.A.J.W. Kluytmans (Jan); N. den Toom; T.H. van Rijsoort-Vos; E. Stolz (Ernst); H.A. Verbrugh (Henri); W.G.V. Quint (Wim); H.G.M. Niesters (Bert)

    1995-01-01

    textabstractIn the present study, it was demonstrated that the sensitivity of the PCR for the detection of Chlamydia trachomatis is influenced by the volume of the clinical sample which is processed in the PCR. An adequate sensitivity for PCR was established by processing at least

  18. Metabolic profiling of ultrasmall sample volumes with GC/MS: From microliter to nanoliter samples

    NARCIS (Netherlands)

    Koek, M.M.; Bakels, F.; Engel, W.; Maagdenberg, A. van den; Ferrari, M.D.; Coulier, L.; Hankemeier, T.

    2010-01-01

    Profiling of metabolites is increasingly used to study the functioning of biological systems. For some studies the volume of available samples is limited to only a few microliters or even less, for fluids such as cerebrospinal fluid (CSF) of small animals like mice or the analysis of individual oocy

  19. Applications of Liquid-Phase Microextraction in the Sample Preparation of Environmental Solid Samples

    Directory of Open Access Journals (Sweden)

    Helena Prosen

    2014-05-01

    Full Text Available Solvent extraction remains one of the fundamental sample preparation techniques in the analysis of environmental solid samples, but organic solvents are toxic and environmentally harmful, therefore one of the possible greening directions is its miniaturization. The present review covers the relevant research from the field of application of microextraction to the sample preparation of environmental solid samples (soil, sediments, sewage sludge, dust etc. published in the last decade. Several innovative liquid-phase microextraction (LPME techniques that have emerged recently have also been applied as an aid in sample preparation of these samples: single-drop microextraction (SDME, hollow fiber-liquid phase microextraction (HF-LPME, dispersive liquid-liquid microextraction (DLLME. Besides the common organic solvents, surfactants and ionic liquids are also used. However, these techniques have to be combined with another technique to release the analytes from the solid sample into an aqueous solution. In the present review, the published methods were categorized into three groups: LPME in combination with a conventional solvent extraction; LPME in combination with an environmentally friendly extraction; LPME without previous extraction. The applicability of these approaches to the sample preparation for the determination of pollutants in solid environmental samples is discussed, with emphasis on their strengths, weak points and environmental impact.

  20. Applications of reversible covalent chemistry in analytical sample preparation.

    Science.gov (United States)

    Siegel, David

    2012-12-07

    Reversible covalent chemistry (RCC) adds another dimension to commonly used sample preparation techniques like solid-phase extraction (SPE), solid-phase microextraction (SPME), molecular imprinted polymers (MIPs) or immuno-affinity cleanup (IAC): chemical selectivity. By selecting analytes according to their covalent reactivity, sample complexity can be reduced significantly, resulting in enhanced analytical performance for low-abundance target analytes. This review gives a comprehensive overview of the applications of RCC in analytical sample preparation. The major reactions covered include reversible boronic ester formation, thiol-disulfide exchange and reversible hydrazone formation, targeting analyte groups like diols (sugars, glycoproteins and glycopeptides, catechols), thiols (cysteinyl-proteins and cysteinyl-peptides) and carbonyls (carbonylated proteins, mycotoxins). Their applications range from low abundance proteomics to reversible protein/peptide labelling to antibody chromatography to quantitative and qualitative food analysis. In discussing the potential of RCC, a special focus is on the conditions and restrictions of the utilized reaction chemistry.

  1. [Optimized sample preparation for metabolome studies on Streptomyces coelicolor].

    Science.gov (United States)

    Li, Yihong; Li, Shanshan; Ai, Guomin; Wang, Weishan; Zhang, Buchang; Yang, Keqian

    2014-04-01

    Streptomycetes produce many antibiotics and are important model microorgansims for scientific research and antibiotic production. Metabolomics is an emerging technological platform to analyze low molecular weight metabolites in a given organism qualitatively and quantitatively. Compared to other Omics platform, metabolomics has greater advantage in monitoring metabolic flux distribution and thus identifying key metabolites related to target metabolic pathway. The present work aims at establishing a rapid, accurate sample preparation protocol for metabolomics analysis in streptomycetes. In the present work, several sample preparation steps, including cell quenching time, cell separation method, conditions for metabolite extraction and metabolite derivatization were optimized. Then, the metabolic profiles of Streptomyces coelicolor during different growth stages were analyzed by GC-MS. The optimal sample preparation conditions were as follows: time of low-temperature quenching 4 min, cell separation by fast filtration, time of freeze-thaw 45 s/3 min and the conditions of metabolite derivatization at 40 degrees C for 90 min. By using this optimized protocol, 103 metabolites were finally identified from a sample of S. coelicolor, which distribute in central metabolic pathways (glycolysis, pentose phosphate pathway and citrate cycle), amino acid, fatty acid, nucleotide metabolic pathways, etc. By comparing the temporal profiles of these metabolites, the amino acid and fatty acid metabolic pathways were found to stay at a high level during stationary phase, therefore, these pathways may play an important role during the transition between the primary and secondary metabolism. An optimized protocol of sample preparation was established and applied for metabolomics analysis of S. coelicolor, 103 metabolites were identified. The temporal profiles of metabolites reveal amino acid and fatty acid metabolic pathways may play an important role in the transition from primary to

  2. Preparation of SELEX Samples for Next-Generation Sequencing.

    Science.gov (United States)

    Tolle, Fabian; Mayer, Günter

    2016-01-01

    Fuelled by massive whole genome sequencing projects such as the human genome project, enormous technological advancements and therefore tremendous price drops could be achieved, rendering next-generation sequencing very attractive for deep sequencing of SELEX libraries. Herein we describe the preparation of SELEX samples for Illumina sequencing, based on the already established whole genome sequencing workflow. We describe the addition of barcode sequences for multiplexing and the adapter ligation, avoiding associated pitfalls.

  3. Recent advances in sample preparation techniques for effective bioanalytical methods.

    Science.gov (United States)

    Kole, Prashant Laxman; Venkatesh, Gantala; Kotecha, Jignesh; Sheshala, Ravi

    2011-01-01

    This paper reviews the recent developments in bioanalysis sample preparation techniques and gives an update on basic principles, theory, applications and possibilities for automation, and a comparative discussion on the advantages and limitation of each technique. Conventional liquid-liquid extraction (LLE), protein precipitation (PP) and solid-phase extraction (SPE) techniques are now been considered as methods of the past. The last decade has witnessed a rapid development of novel sample preparation techniques in bioanalysis. Developments in SPE techniques such as selective sorbents and in the overall approach to SPE, such as hybrid SPE and molecularly imprinted polymer SPE, have been addressed. Considerable literature has been published in the area of solid-phase micro-extraction and its different versions, e.g. stir bar sorptive extraction, and their application in the development of selective and sensitive bioanalytical methods. Techniques such as dispersive solid-phase extraction, disposable pipette extraction and micro-extraction by packed sorbent offer a variety of extraction phases and provide unique advantages to bioanalytical methods. On-line SPE utilizing column-switching techniques is rapidly gaining acceptance in bioanalytical applications. PP sample preparation techniques such as PP filter plates/tubes offer many advantages like removal of phospholipids and proteins in plasma/serum. Newer approaches to conventional LLE techniques (salting-out LLE) are also covered in this review article.

  4. Automated force volume image processing for biological samples.

    Directory of Open Access Journals (Sweden)

    Pavel Polyakov

    Full Text Available Atomic force microscopy (AFM has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image.

  5. Automated Force Volume Image Processing for Biological Samples

    Science.gov (United States)

    Duan, Junbo; Duval, Jérôme F. L.; Brie, David; Francius, Grégory

    2011-01-01

    Atomic force microscopy (AFM) has now become a powerful technique for investigating on a molecular level, surface forces, nanomechanical properties of deformable particles, biomolecular interactions, kinetics, and dynamic processes. This paper specifically focuses on the analysis of AFM force curves collected on biological systems, in particular, bacteria. The goal is to provide fully automated tools to achieve theoretical interpretation of force curves on the basis of adequate, available physical models. In this respect, we propose two algorithms, one for the processing of approach force curves and another for the quantitative analysis of retraction force curves. In the former, electrostatic interactions prior to contact between AFM probe and bacterium are accounted for and mechanical interactions operating after contact are described in terms of Hertz-Hooke formalism. Retraction force curves are analyzed on the basis of the Freely Jointed Chain model. For both algorithms, the quantitative reconstruction of force curves is based on the robust detection of critical points (jumps, changes of slope or changes of curvature) which mark the transitions between the various relevant interactions taking place between the AFM tip and the studied sample during approach and retraction. Once the key regions of separation distance and indentation are detected, the physical parameters describing the relevant interactions operating in these regions are extracted making use of regression procedure for fitting experiments to theory. The flexibility, accuracy and strength of the algorithms are illustrated with the processing of two force-volume images, which collect a large set of approach and retraction curves measured on a single biological surface. For each force-volume image, several maps are generated, representing the spatial distribution of the searched physical parameters as estimated for each pixel of the force-volume image. PMID:21559483

  6. Optimization for Peptide Sample Preparation for Urine Peptidomics

    Energy Technology Data Exchange (ETDEWEB)

    Sigdel, Tara K.; Nicora, Carrie D.; Hsieh, Szu-Chuan; Dai, Hong; Qian, Weijun; Camp, David G.; Sarwal, Minnie M.

    2014-02-25

    Analysis of native or endogenous peptides in biofluids can provide valuable insights into disease mechanisms. Furthermore, the detected peptides may also have utility as potential biomarkers for non-invasive monitoring of human diseases. The non-invasive nature of urine collection and the abundance of peptides in the urine makes analysis by high-throughput ‘peptidomics’ methods , an attractive approach for investigating the pathogenesis of renal disease. However, urine peptidomics methodologies can be problematic with regards to difficulties associated with sample preparation. The urine matrix can provide significant background interference in making the analytical measurements that it hampers both the identification of peptides and the depth of the peptidomics read when utilizing LC-MS based peptidome analysis. We report on a novel adaptation of the standard solid phase extraction (SPE) method to a modified SPE (mSPE) approach for improved peptide yield and analysis sensitivity with LC-MS based peptidomics in terms of time, cost, clogging of the LC-MS column, peptide yield, peptide quality, and number of peptides identified by each method. Expense and time requirements were comparable for both SPE and mSPE, but more interfering contaminants from the urine matrix were evident in the SPE preparations (e.g., clogging of the LC-MS columns, yellowish background coloration of prepared samples due to retained urobilin, lower peptide yields) when compared to the mSPE method. When we compared data from technical replicates of 4 runs, the mSPE method provided significantly improved efficiencies for the preparation of samples from urine (e.g., mSPE peptide identification 82% versus 18% with SPE; p = 8.92E-05). Additionally, peptide identifications, when applying the mSPE method, highlighted the biology of differential activation of urine peptidases during acute renal transplant rejection with distinct laddering of specific peptides, which was obscured for most proteins

  7. Radiocarbon accelerator mass spectrometry (AMS) sample preparation laboratory in Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Macario, Kita D.; Gomes, Paulo R. S.; Anjos, Roberto M. dos; Linares, Roberto; Queiroz, Eduardo; Oliveira, Fabiana M. de; Cardozo, Laio [Universidade Federal Fluminense (UFF), Niteroi, RJ (Brazil); Carvalho, Carla R.A. [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil)

    2011-07-01

    Full text: For decades Accelerator Mass Spectrometry has been widely used for radiocarbon measurements all over the world with application in several fields of science from archaeology to geosciences. This technique provides ultrasensitive analysis of reduced size samples or even specific compounds since sample atoms are accelerated to high energies and measured using nuclear particle detectors. Sample preparation is extremely important for accurate radiocarbon measurement and includes chemical pre-treatment to remove all possible contaminants. For beam extraction in the accelerator ion source, samples are usually converted to graphite. In this work we report a new radiocarbon sample preparation facility installed at the Physics Institute of Universidade Federal Fluminense (UFF), in Brazil. At the Nuclear Chronology Laboratory (LACRON) samples are chemically treated and converted to carbon dioxide by hydrolysis or combustion. A stainless steel based vacuum line was constructed for carbon dioxide separation and graphitization is performed in sealed quartz tubes in a muffle oven. Successful graphite production is important to provide stable beam currents and to minimize isotopic fractionation. Performance tests for graphite production are currently under way and isotopic analysis will soon be possible with the acquisition of a Single Stage AMS System by our group. The Single Stage Accelerator produced by National Electrostatic Corporation is a 250 kV air insulated accelerator especially constructed to measure the amount of {sup 14}C in small modern graphite samples to a precision of 0.3 % or better. With the installation of such equipment in the first half of 2012, UFF will be ready to perform the 14C -AMS technique. (author)

  8. Amorphous semiconductor sample preparation for transmission EXAFS measurements

    Energy Technology Data Exchange (ETDEWEB)

    Ridgway, M.C.; Glover, C.J.; Tan, H.H. [Australian National Univ., Canberra (Australia). Dept. of Electronic Materials Engineering] [and others

    1998-12-31

    A novel methodology has been developed for the preparation of amorphous semiconductor samples for use in transmission extended x-ray absorption fine structure (EXAFS) measurements. Epitaxial heterostructures were fabricated by metal organic chemical vapor deposition (group III-Vs) or molecular beam epitaxy (group IVs). An epitaxial layer of {approximately} 2 {micro}m thickness was separated from the underlying substrate by selective chemical etching of an intermediate sacrificial layer. Ion implantation was utilized to amorphize the epitaxial layer either before or after selective chemical etching. The resulting samples were both stoichiometric and homogeneous in contrast to those produced by conventional techniques. The fabrication of amorphous GaAs, InP, In{sub 0.53}Ga{sub 0.47}As and Si{sub x}Ge{sub 1{minus}x} samples is described. Furthermore, EXAFS measurements comparing both fluorescence and transmission detection, and crystalline and amorphized GaAs, are shown.

  9. Hands-free sample preparation platform for nucleic acid analysis.

    Science.gov (United States)

    Baier, T; Hansen-Hagge, T E; Gransee, R; Crombé, A; Schmahl, S; Paulus, C; Drese, K S; Keegan, H; Martin, C; O'Leary, J J; Furuberg, L; Solli, L; Grønn, P; Falang, I M; Karlgård, A; Gulliksen, A; Karlsen, F

    2009-12-07

    A Lab-On-Chip system with an instrument is presented which is capable of performing total sample preparation and automated extraction of nucleic acid from human cell samples fixed in a methanol based solution. The target application is extraction of mRNA from cervical liquid based cytology specimens for detection of transformed HPV-infections. The device accepts 3 ml of sample and performs the extraction in a disposable polymer chip of credit card size. All necessary reagents for cell lysis, washing, and elution are stored on-chip and the extraction is performed in two filter stages; one for cell pre-concentration and the other for nucleic acid capture. Tests performed using cancer cell lines and cervical liquid based cytology specimens confirm the extraction of HPV-mRNA by the system.

  10. A fast method to prepare water samples for 15N analysis

    Institute of Scientific and Technical Information of China (English)

    肖化云; 刘丛强

    2001-01-01

    Automatic element analyser is often used to prepare organic matters tor 15N analysis. It is seldom used to prepare water samples. Water samples are conventionally dealt with by Kjeldahl-Rittenberg technique. But it requires tedious and labor-intensive sample preparation. A fast and reliable method is proposed in this paper to prepare water samples for 15N analysis.

  11. Sample Preparation (SS) - Metabolonote | LSDB Archive [Life Science Database Archive metadata

    Lifescience Database Archive (English)

    Full Text Available 908/lsdba.nbdc01324-008 Description of data contents Detailed information regarding sample preparations comm...ed to by S (Sample information). Data file File name: metabolonote_sample_preparation..._details.zip File URL: ftp://ftp.biosciencedbc.jp/archive/metabolonote/LATEST/metabolonote_sample_preparation..._details.zip File size: 13 KB Simple search URL http://togodb.biosciencedbc.jp/togodb/view/metabolonote_sample_preparation... Preparation ID are merged into ID in the Simple search.) Sample Preparation ID The sample preparation detai

  12. Microsystem strategies for sample preparation in biological detection.

    Energy Technology Data Exchange (ETDEWEB)

    James, Conrad D.; Galambos, Paul C.; Bennett, Dawn Jonita (University of Maryland Baltimore County, Baltimore, MD); Manginell, Monica; Okandan, Murat; Acrivos, Andreas (The City College of New York, NY); Brozik, Susan Marie; Khusid, Boris (New Jersey Institute of Technology, Newark, NJ)

    2005-03-01

    The objective of this LDRD was to develop microdevice strategies for dealing with samples to be examined in biological detection systems. This includes three sub-components: namely, microdevice fabrication, sample delivery to the microdevice, and sample processing within the microdevice. The first component of this work focused on utilizing Sandia's surface micromachining technology to fabricate small volume (nanoliter) fluidic systems for processing small quantities of biological samples. The next component was to develop interfaces for the surface-micromachined silicon devices. We partnered with Micronics, a commercial company, to produce fluidic manifolds for sample delivery to our silicon devices. Pressure testing was completed to examine the strength of the bond between the pressure-sensitive adhesive layer and the silicon chip. We are also pursuing several other methods, both in house and external, to develop polymer-based fluidic manifolds for packaging silicon-based microfluidic devices. The second component, sample processing, is divided into two sub-tasks: cell collection and cell lysis. Cell collection was achieved using dielectrophoresis, which employs AC fields to collect cells at energized microelectrodes, while rejecting non-cellular particles. Both live and dead Staph. aureus bacteria have been collected using RF frequency dielectrophoresis. Bacteria have been separated from polystyrene microspheres using frequency-shifting dielectrophoresis. Computational modeling was performed to optimize device separation performance, and to predict particle response to the dielectrophoretic traps. Cell lysis is continuing to be pursued using microactuators to mechanically disrupt cell membranes. Novel thermal actuators, which can generate larger forces than previously tested electrostatic actuators, have been incorporated with and tested with cell lysis devices. Significant cell membrane distortion has been observed, but more experiments need to be

  13. On sample preparation and dielectric breakdown in nanostructured epoxy resins

    Energy Technology Data Exchange (ETDEWEB)

    Reading, M; Xu, Z; Lewin, P L; Vaughan, A S, E-mail: asv@ecs.soton.ac.uk [Tony Davies High Voltage Laboratory, University of Southampton (United Kingdom)

    2011-08-12

    There are many methods available to achieve a good dispersion of fillers within a polymeric matrix. This investigation considered several methods of dispersing three chosen fillers within an epoxy resin; the same processes were also performed on unfilled materials to investigate any effects they may have on the host material. For this investigation, the epoxy system (EP) was combined with sodium montmorillonite (MMT), micrometric silicon dioxide (SD) or nanometric silicon dioxide (NSD) as fillers. The effect of the different sample preparation routes on breakdown behaviour was then evaluated. While more thorough mixing protocols were found to lead to improved breakdown behaviour in the case of the various filled systems, surprisingly, an entirely equivalent form of behaviour was also seen in the unfilled epoxy. The influence of changes in sample geometry on the breakdown strength was established.

  14. Preparation of tissue samples for X-ray fluorescence microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Chwiej, Joanna [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland)]. E-mail: jchwiej@novell.ftj.agh.edu.pl; Szczerbowska-Boruchowska, Magdalena [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Lankosz, Marek [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Wojcik, Slawomir [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Falkenberg, Gerald [Hamburger Synchrotronstrahlungslabor at Deutsches Elektronen-Synchrotron, Notkestr. 85, Hamburg (Germany); Stegowski, Zdzislaw [Faculty of Physics and Applied Computer Science, AGH-University of Science and Technology, Al. Mickiewicza 30, 30-059 Cracow (Poland); Setkowicz, Zuzanna [Department of Neuroanatomy, Institute of Zoology, Jagiellonian University, Ingardena 6, 30-060 Cracow (Poland)

    2005-12-15

    As is well-known, trace elements, especially metals, play an important role in the pathogenesis of many disorders. The topographic and quantitative elemental analysis of pathologically changed tissues may shed some new light on processes leading to the degeneration of cells in the case of selected diseases. An ideal and powerful tool for such purpose is the Synchrotron Microbeam X-ray Fluorescence technique. It enables the carrying out of investigations of the elemental composition of tissues even at the single cell level. The tissue samples for histopathological investigations are routinely fixed and embedded in paraffin. The authors try to verify the usefulness of such prepared tissue sections for elemental analysis with the use of X-ray fluorescence microscopy. Studies were performed on rat brain samples. Changes in elemental composition caused by fixation in formalin or paraformaldehyde and embedding in paraffin were examined. Measurements were carried out at the bending magnet beamline L of the Hamburger Synchrotronstrahlungslabor HASYLAB in Hamburg. The decrease in mass per unit area of K, Br and the increase in P, S, Fe, Cu and Zn in the tissue were observed as a result of the fixation. For the samples embedded in paraffin, a lower level of most elements was observed. Additionally, for these samples, changes in the composition of some elements were not uniform for different analyzed areas of rat brain.

  15. Sampling-based motion planning with reachable volumes: Theoretical foundations

    KAUST Repository

    McMahon, Troy

    2014-05-01

    © 2014 IEEE. We introduce a new concept, reachable volumes, that denotes the set of points that the end effector of a chain or linkage can reach. We show that the reachable volume of a chain is equivalent to the Minkowski sum of the reachable volumes of its links, and give an efficient method for computing reachable volumes. We present a method for generating configurations using reachable volumes that is applicable to various types of robots including open and closed chain robots, tree-like robots, and complex robots including both loops and branches. We also describe how to apply constraints (both on end effectors and internal joints) using reachable volumes. Unlike previous methods, reachable volumes work for spherical and prismatic joints as well as planar joints. Visualizations of reachable volumes can allow an operator to see what positions the robot can reach and can guide robot design. We present visualizations of reachable volumes for representative robots including closed chains and graspers as well as for examples with joint and end effector constraints.

  16. Sample preparation strategies for food and biological samples prior to nanoparticle detection and imaging

    DEFF Research Database (Denmark)

    Larsen, Erik Huusfeldt; Löschner, Katrin

    2014-01-01

    fractionation (AFFF, or AF4) coupled on-line to various detectors including static and dynamic light scattering (LS), UV or fluorescence (FL) spectroscopies and ICP-MS have proven useful and powerful [1, 2, 3]. Furthermore, additional information obtained by an imaging method such as transmission electron...... microscopy (TEM) proved to be necessary for trouble shooting of results obtained from AFFF-LS-ICP-MS. Aqueous and enzymatic extraction strategies were tested for thorough sample preparation aiming at degrading the sample matrix and to liberate the AgNPs from chicken meat into liquid suspension. The resulting...

  17. Determination of cell electroporation in small-volume samples.

    Science.gov (United States)

    Saulis, Gintautas; Praneviciŭte, Rita

    2007-01-01

    Expose of cells to electric field pulses increases the cell membrane permeability. Intracellular potassium ions leak out of the cells through aqueous pores created in the membrane. This release is used here for the determination of the fraction of electroporated cells. To determine cell membrane electroporation in small-volume samples (40-50 miacrol), mini both potassium ion-selective and reference electrodes, with tip diameters of 1-1.5 mm and minimum immersion depths of 1 mm, were utilized. The obtained calibration graph was linear within the concentration range 0.2-100 mM. The slope was 50-51 and 53-56 mV per concentration order at 10-11 and 19-21 degrees C, respectively. Detection limit of the electrode was determined to be 0.05-0.08 mM, however, it was possible to work down to concentrations in the range of 0.01 mM. Experiments have been carried out on human erythrocytes exposed to a square-wave electric pulse with the duration of 0.1-2 ms. The extracellular potassium concentrations were in the range between 0.04-0.08 mM (intact cells) and 3-5 mM (100% electroporation). The obtained dependences of the fraction of electroporated cells on the pulse intensity were of a sigmoid shape. The dependence of the pulse amplitude required to electroporate 50% of cells on the pulse duration, obtained from the release of intracellular potassium ions, coincided with the one determined from the extent of hemolysis after 24 h-incubation at low temperature.

  18. Preparation and examination of monolithic in-needle extraction (MINE) device for the direct analysis of liquid samples

    Energy Technology Data Exchange (ETDEWEB)

    Pietrzyńska, Monika, E-mail: monikapietrzynska@gmail.com; Voelkel, Adam; Bielicka-Daszkiewicz, Katarzyna

    2013-05-07

    Graphical abstract: -- Highlights: •MINE device for isolation of analytes from water samples. •Nine polymer poly(styrene-divinylbenzene) monoliths prepared in stainless steel needles. •High efficiency of in-needle extraction systems based on monolithic materials. •New possibilities in sample preparation area. -- Abstract: Combination of extraction and chromatographic techniques opens NEW possibilities in sample preparation area. Macroporous poly(styrene-divinylbenzene) (PS-DVB) monoliths were prepared by in situ polymerization in stainless steel needles. The surface of stainless steel needle was modified earlier by the silane coupling agent. Monolithic materials located inside needles were used as the in-needle extraction device. Scanning electron microscope (SEM) images were obtained for nine monoliths. Spectra of prepared materials were also performed with the use of two techniques: Attenuated Total Reflectance (ATR) and Fourier Transform Infrared Spectroscopy (FTIR). The new monolithic in-needle extraction (MINE) devices were used in the preparation of a series of test water samples for chromatographic analysis. The extraction of phenolic compounds from water samples was carried out by pumping liquid samples through the MINE device. Obtained results indicate a high efficiency of in-needle extraction systems based on monolithic materials. Breakthrough volume and the sorption efficiency of prepared monolithic in-needle extraction devices were determined experimentally. The achieved recovery was close to 90%, and determined LOQ values varied between 0.4 and 6 μg.

  19. On-chip sample preparation for complete blood count from raw blood.

    Science.gov (United States)

    Nguyen, John; Wei, Yuan; Zheng, Yi; Wang, Chen; Sun, Yu

    2015-03-21

    This paper describes a monolithic microfluidic device capable of on-chip sample preparation for both RBC and WBC measurements from whole blood. For the first time, on-chip sample processing (e.g. dilution, lysis, and filtration) and downstream single cell measurement were fully integrated to enable sample preparation and single cell analysis from whole blood on a single device. The device consists of two parallel sub-systems that perform sample processing and electrical measurements for measuring RBC and WBC parameters. The system provides a modular environment capable of handling solutions of various viscosities by adjusting the length of channels and precisely controlling mixing ratios, and features a new 'offset' filter configuration for increased duration of device operation. RBC concentration, mean corpuscular volume (MCV), cell distribution width, WBC concentration and differential are determined by electrical impedance measurement. Experimental characterization of over 100,000 cells from 10 patient blood samples validated the system's capability for performing on-chip raw blood processing and measurement.

  20. Effect of sample preparation on charged impurities in graphene substrates

    Science.gov (United States)

    Burson, K. M.; Dean, C. R.; Watanabe, K.; Taniguchi, T.; Hone, J.; Kim, P.; Cullen, W. G.; Fuhrer, M. S.

    2013-03-01

    The mobility of graphene as fabricated on SiO2 has been found to vary widely depending on sample preparation conditions. Additionally, graphene mobility on SiO2 appears to be limited to ~20,000 cm2/Vs, likely due to charged impurities in the substrate. Here we present a study of the effect of fabrication procedures on substrate charged impurity density (nimp) utilizing ultrahigh-vacuum Kelvin probe force microscopy. We conclude that even minimal SEM exposure, as from e-beam lithography, induces an increased impurity density, while heating reduces the number of charges for sample substrates which already exhibit a higher impurity density. We measure both SiO2 and h-BN and find that all nimp values observed for SiO2 are higher than those observed for h-BN; this is consistent with the observed improvement in mobility for graphene devices fabricated on h-BN over those fabricated on SiO2 substrates. This work was supported by the US ONR MURI program, and the University of Maryland NSF-MRSEC under Grant No. DMR 05-20471.

  1. Miniaturized sample preparation method for determination of amphetamines in urine.

    Science.gov (United States)

    Nishida, Manami; Namera, Akira; Yashiki, Mikio; Kimura, Kojiro

    2004-07-16

    A simple and miniaturized sample preparation method for determination of amphetamines in urine was developed using on-column derivatization and gas chromatography-mass spectrometry (GC-MS). Urine was directly applied to the extraction column that was pre-packed with Extrelut and sodium carbonate. Amphetamine (AP) and methamphetamine (MA) in urine were adsorbed on the surface of Extrelut. AP and MA were then converted to a free base and derivatized to N-propoxycarbonyl derivatives using propylchloroformate on the column. Pentadeuterated MA was used as an internal standard. The recoveries of AP and MA from urine were 100 and 102%, respectively. The calibration curves showed linearity in the range of 0.50-50 microg/mL for AP and MA in urine. When urine samples containing two different concentrations (0.50 and 5.0 microg/mL) of AP and MA were determined, the intra-day and inter-day coefficients of variation were 1.4-7.7%. This method was applied to 14 medico-legal cases of MA intoxication. The results were compared and a good agreement was obtained with a HPLC method.

  2. Ultrasound: a subexploited tool for sample preparation in metabolomics.

    Science.gov (United States)

    Luque de Castro, M D; Delgado-Povedano, M M

    2014-01-02

    Metabolomics, one of the most recently emerged "omics", has taken advantage of ultrasound (US) to improve sample preparation (SP) steps. The metabolomics-US assisted SP step binomial has experienced a dissimilar development that has depended on the area (vegetal or animal) and the SP step. Thus, vegetal metabolomics and US assisted leaching has received the greater attention (encompassing subdisciplines such as metallomics, xenometabolomics and, mainly, lipidomics), but also liquid-liquid extraction and (bio)chemical reactions in metabolomics have taken advantage of US energy. Also clinical and animal samples have benefited from US assisted SP in metabolomics studies but in a lesser extension. The main effects of US have been shortening of the time required for the given step, and/or increase of its efficiency or availability for automation; nevertheless, attention paid to potential degradation caused by US has been scant or nil. Achievements and weak points of the metabolomics-US assisted SP step binomial are discussed and possible solutions to the present shortcomings are exposed. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. Automated acoustic matrix deposition for MALDI sample preparation.

    Science.gov (United States)

    Aerni, Hans-Rudolf; Cornett, Dale S; Caprioli, Richard M

    2006-02-01

    Novel high-throughput sample preparation strategies for MALDI imaging mass spectrometry (IMS) and profiling are presented. An acoustic reagent multispotter was developed to provide improved reproducibility for depositing matrix onto a sample surface, for example, such as a tissue section. The unique design of the acoustic droplet ejector and its optimization for depositing matrix solution are discussed. Since it does not contain a capillary or nozzle for fluid ejection, issues with clogging of these orifices are avoided. Automated matrix deposition provides better control of conditions affecting protein extraction and matrix crystallization with the ability to deposit matrix accurately onto small surface features. For tissue sections, matrix spots of 180-200 microm in diameter were obtained and a procedure is described for generating coordinate files readable by a mass spectrometer to permit automated profile acquisition. Mass spectral quality and reproducibility was found to be better than that obtained with manual pipet spotting. The instrument can also deposit matrix spots in a dense array pattern so that, after analysis in a mass spectrometer, two-dimensional ion images may be constructed. Example ion images from a mouse brain are presented.

  4. DIELECTRIC PROPERTIES OF STRAINED ICE. II : EFFECT OF SAMPLE PREPARATION METHOD

    OpenAIRE

    Itagaki, K.; Lemieux, G.

    1987-01-01

    Since most commonly used sample preparation methods for ice dielectric studies involve rather heavy mechanical straining, the effects of straining were studied and compared with more strain-free sample preparation methods.

  5. EVALUATION OF VAPOR EQUILIBRATION AND IMPACT OF PURGE VOLUME ON SOIL-GAS SAMPLING RESULTS

    Science.gov (United States)

    Sequential sampling was utilized at the Raymark Superfund site to evaluate attainment of vapor equilibration and the impact of purge volume on soil-gas sample results. A simple mass-balance equation indicates that removal of three to five internal volumes of a sample system shou...

  6. Measuring tree height and preparation volume table using an innovative method.

    Science.gov (United States)

    Lotfalian, Majid; Nouri, Zahra; Kooch, Yahya; Zobeiri, Mahmoud

    2007-10-15

    Zarbin (Cupressus sempervirence var. horizontalis) with its unique characteristics is one of the worthiest species which can be found in the central area of Alborz in the North of Iran. Especially in the Roodbar-manjil area, Chaloos-Hassanabad valley as well as it extends from Zarringol area to Gorgan. Although the distribution areas of this species have been protected, these forests have been invaded by the villagers who use this useful wood. For this reason in the Roodbar area, trees with DBH>30 cm are extremely rare. To recognize and to be aware of the stand quantity, the current research tries to calculate the species volume table in Roodbar area, to be the basis for any calculation of the volume of stand in the region. For this purpose, trees have been sampled using the line sampling method. After estimating the form factor, Tarif table have been prepared. In this study, a new method for measuring tree height is presented, in which, instead of measuring slope distance from observer to tree (which is difficult in young conifers because of existence branches in lower height) distance between the eye level of observer to tree butt is measured. Which doing of it is easier, time of field work is decreased and accuracy of measurement and calculation is increased.

  7. Sample preparation issues in NMR-based plant metabolomics: optimisation for Vitis wood samples.

    Science.gov (United States)

    Halabalaki, Maria; Bertrand, Samuel; Stefanou, Anna; Gindro, Katia; Kostidis, Sarantos; Mikros, Emmanuel; Skaltsounis, Leandros A; Wolfender, Jean-Luc

    2014-01-01

    Nuclear magnetic resonance (NMR) is one of the most commonly used analytical techniques in plant metabolomics. Although this technique is very reproducible and simple to implement, sample preparation procedures have a great impact on the quality of the metabolomics data. Investigation of different sample preparation methods and establishment of an optimised protocol for untargeted NMR-based metabolomics of Vitis vinifera L. wood samples. Wood samples from two different cultivars of V. vinifera with well-defined phenotypes (Gamaret and 2091) were selected as reference materials. Different extraction solvents (successively, dichloromethane, methanol and water, as well as ethyl acetate and 7:3 methanol-water (v/v)) and deuterated solvents (methanol-d4, 7:3 chloroform-d-methanol-d4 (v/v), dimethylsulphoxide-d6 and 9:1 dimethylsulphoxide-d6-water-d2 (v/v)) were evaluated for NMR acquisition, and the spectral quality was compared. The optimal extract concentration, chemical shift stability and peak area repeatability were also investigated. Ethyl acetate was found to be the most satisfactory solvent for the extraction of all representative chemical classes of secondary metabolites in V. vinifera wood. The optimal concentration of dried extract was 10 mg/mL and 7:3 chloroform-d-methanol-d4 (v/v) was the most suitable solvent system for NMR analysis. Multivariate data analysis was used to estimate the biological variation and clustering between different cultivars. Close attention should be paid to all required procedures before NMR analysis, especially to the selection of an extraction solvent and a deuterated solvent system to perform an extensive metabolomic survey of the specific matrix. Copyright © 2014 John Wiley & Sons, Ltd.

  8. Sample Preparation Report of the Fourth OPCW Confidence Building Exercise on Biomedical Sample Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Udey, R. N. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Corzett, T. H. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States); Alcaraz, A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2014-07-03

    Following the successful completion of the 3rd biomedical confidence building exercise (February 2013 – March 2013), which included the analysis of plasma and urine samples spiked at low ppb levels as part of the exercise scenario, another confidence building exercise was targeted to be conducted in 2014. In this 4th exercise, it was desired to focus specifically on the analysis of plasma samples. The scenario was designed as an investigation of an alleged use of chemical weapons where plasma samples were collected, as plasma has been reported to contain CWA adducts which remain present in the human body for several weeks (Solano et al. 2008). In the 3rd exercise most participants used the fluoride regeneration method to analyze for the presence of nerve agents in plasma samples. For the 4th biomedical exercise it was decided to evaluate the analysis of human plasma samples for the presence/absence of the VX adducts and aged adducts to blood proteins (e.g., VX-butyrylcholinesterase (BuChE) and aged BuChE adducts using a pepsin digest technique to yield nonapeptides; or equivalent). As the aging of VX-BuChE adducts is relatively slow (t1/2 = 77 hr at 37 °C [Aurbek et al. 2009]), soman (GD), which ages much more quickly (t1/2 = 9 min at 37 °C [Masson et al. 2010]), was used to simulate an aged VX sample. Additional objectives of this exercise included having laboratories assess novel OP-adducted plasma sample preparation techniques and analytical instrumentation methodologies, as well as refining/designating the reporting formats for these new techniques.

  9. Saliva sampling in global clinical studies: the impact of low sampling volume on performance of DNA in downstream genotyping experiments

    Science.gov (United States)

    2013-01-01

    Background The collection of viable DNA samples is an essential element of any genetics research programme. Biological samples for DNA purification are now routinely collected in many studies with a variety of sampling methods available. Initial observation in this study suggested a reduced genotyping success rate of some saliva derived DNA samples when compared to blood derived DNA samples prompting further investigation. Methods Genotyping success rate was investigated to assess the suitability of using saliva samples in future safety and efficacy pharmacogenetics experiments. The Oragene® OG-300 DNA Self-Collection kit was used to collect and extract DNA from saliva from 1468 subjects enrolled in global clinical studies. Statistical analysis evaluated the impact of saliva sample volume of collection on the quality, yield, concentration and performance of saliva DNA in genotyping assays. Results Across 13 global clinical studies that utilized the Oragene® OG-300 DNA Self-Collection kit there was variability in the volume of saliva sample collection with ~31% of participants providing 0.5 mL of saliva, rather than the recommended 2 mL. While the majority of saliva DNA samples provided high quality genotype data, collection of 0.5 mL volumes of saliva contributed to DNA samples being significantly less likely to pass genotyping quality control standards. Assessment of DNA sample characteristics that may influence genotyping outcomes indicated that saliva sample volume, DNA purity and turbidity were independently associated with sample genotype pass rate, but that saliva collection volume had the greatest effect. Conclusion When employing saliva sampling to obtain DNA, it is important to encourage all study participants to provide sufficient sample to minimize potential loss of data in downstream genotyping experiments. PMID:23759220

  10. Optimization and validation of sample preparation for metagenomic sequencing of viruses in clinical samples.

    Science.gov (United States)

    Lewandowska, Dagmara W; Zagordi, Osvaldo; Geissberger, Fabienne-Desirée; Kufner, Verena; Schmutz, Stefan; Böni, Jürg; Metzner, Karin J; Trkola, Alexandra; Huber, Michael

    2017-08-08

    Sequence-specific PCR is the most common approach for virus identification in diagnostic laboratories. However, as specific PCR only detects pre-defined targets, novel virus strains or viruses not included in routine test panels will be missed. Recently, advances in high-throughput sequencing allow for virus-sequence-independent identification of entire virus populations in clinical samples, yet standardized protocols are needed to allow broad application in clinical diagnostics. Here, we describe a comprehensive sample preparation protocol for high-throughput metagenomic virus sequencing using random amplification of total nucleic acids from clinical samples. In order to optimize metagenomic sequencing for application in virus diagnostics, we tested different enrichment and amplification procedures on plasma samples spiked with RNA and DNA viruses. A protocol including filtration, nuclease digestion, and random amplification of RNA and DNA in separate reactions provided the best results, allowing reliable recovery of viral genomes and a good correlation of the relative number of sequencing reads with the virus input. We further validated our method by sequencing a multiplexed viral pathogen reagent containing a range of human viruses from different virus families. Our method proved successful in detecting the majority of the included viruses with high read numbers and compared well to other protocols in the field validated against the same reference reagent. Our sequencing protocol does work not only with plasma but also with other clinical samples such as urine and throat swabs. The workflow for virus metagenomic sequencing that we established proved successful in detecting a variety of viruses in different clinical samples. Our protocol supplements existing virus-specific detection strategies providing opportunities to identify atypical and novel viruses commonly not accounted for in routine diagnostic panels.

  11. Gulf of Mexico continental slope study annual report, year 2. Volume 2. Primary volume. Interim report 1985-1986. [Sampling for hydrocarbons

    Energy Technology Data Exchange (ETDEWEB)

    1986-09-01

    This report, which was prepared in three volumes (Executive Summary, Primary Volume, and Appendix), details the findings of two years of sampling on the continental slope of the northern Gulf of Mexico at depths of 300-3000 m. Preliminary results from a third year of sampling are also presented. Physical and chemical measurements included: CTD casts at 35 stations; sediment characteristics, including hydrocarbons and bulk sediment parameters from 60 stations; tissue hydrocarbon levels of representative benthic organisms; and delta carbon-13 values from sediments and organisms, including comparison of areas of natural petroleum seepage to prevailing slope conditions. The biological oceanography section provides detailed enumeration of megafaunal specimens collected by trawling and of macro- and meiofaunal specimens collected with a 600 sq cm box core. Major megafaunal groups treated are Arthropoda, Echinodermata, and demersal fishes.

  12. Application of a Dual-Arm Robot in Complex Sample Preparation and Measurement Processes.

    Science.gov (United States)

    Fleischer, Heidi; Drews, Robert Ralf; Janson, Jessica; Chinna Patlolla, Bharath Reddy; Chu, Xianghua; Klos, Michael; Thurow, Kerstin

    2016-10-01

    Automation systems with applied robotics have already been established in industrial applications for many years. In the field of life sciences, a comparable high level of automation can be found in the areas of bioscreening and high-throughput screening. Strong deficits still exist in the development of flexible and universal fully automated systems in the field of analytical measurement. Reasons are the heterogeneous processes with complex structures, which include sample preparation and transport, analytical measurements using complex sensor systems, and suitable data analysis and evaluation. Furthermore, the use of nonstandard sample vessels with various shapes and volumes results in an increased complexity. The direct use of existing automation solutions from bioscreening applications is not possible. A flexible automation system for sample preparation, analysis, and data evaluation is presented in this article. It is applied for the determination of cholesterol in biliary endoprosthesis using gas chromatography-mass spectrometry (GC-MS). A dual-arm robot performs both transport and active manipulation tasks to ensure human-like operation. This general robotic concept also enables the use of manual laboratory devices and equipment and is thus suitable in areas with a high standardization grade.

  13. Federal Radiological Monitoring and Assessment Center Monitoring Manual Volume 2, Radiation Monitoring and Sampling

    Energy Technology Data Exchange (ETDEWEB)

    NSTec Aerial Measurement Systems

    2012-07-31

    The FRMAC Monitoring and Sampling Manual, Volume 2 provides standard operating procedures (SOPs) for field radiation monitoring and sample collection activities that are performed by the Monitoring group during a FRMAC response to a radiological emergency.

  14. Liquid chromatography-mass spectrometric determination of rufinamide in low volume plasma samples.

    Science.gov (United States)

    Gáll, Zsolt; Vancea, Szende; Dogaru, Maria T; Szilágyi, Tibor

    2013-12-01

    Quantification of rufinamide in plasma was achieved using a selective and sensitive liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) method. The chromatographic separation was achieved on a reversed phase column (Zorbax SB-C18 100mm×3mm, 3.5μm) under isocratic conditions. The mobile phase consisted of a mixture of water containing 0.1% formic acid and methanol (50:50, v/v). The mass spectrometric detection of the analyte was in multiple reaction monitoring mode (MRM) using an electrospray positive ionization (ESI positive). The monitored ions were 127m/z derived from 239m/z rufinamide and 108m/z derived from 251m/z the internal standard (lacosamide). Protein precipitation with methanol was applied for sample preparation using only 50μl aliquots. The concentration range was 40-2000ng/ml for rufinamide in plasma. The limit of detection was 1.25ng/ml and the lower limit of quantification was established at 5ng/ml rufinamide concentration. Selectivity and matrix effect was verified using individual human, rat and rabbit plasma samples. Short-term, post-preparative and freeze-thaw stability was also investigated. The proposed method provides accuracy, precision and high-throughput (short runtime 4.5min) for quantitative determination of rufinamide in plasma. This is the first reported liquid chromatography-tandem mass spectrometric (LC-MS/MS) method for analysis of rufinamide from low volume plasma samples. The LC-MS/MS method was validated according to the current official guidelines and can be applied to accurately measure rufinamide level of large number of plasma samples from clinical studies or therapeutic drug monitoring.

  15. Critical length sampling: a method to estimate the volume of downed coarse woody debris

    Science.gov (United States)

    G& #246; ran St& #229; hl; Jeffrey H. Gove; Michael S. Williams; Mark J. Ducey

    2010-01-01

    In this paper, critical length sampling for estimating the volume of downed coarse woody debris is presented. Using this method, the volume of downed wood in a stand can be estimated by summing the critical lengths of down logs included in a sample obtained using a relascope or wedge prism; typically, the instrument should be tilted 90° from its usual...

  16. DIAGNOdent measurements and correlation with the depth and volume of minimally invasive cavity preparations.

    Science.gov (United States)

    Hamilton, James C; Gregory, William A; Valentine, John B

    2006-01-01

    In this clinical study, DIAGNOdent (KaVo) was used to assess previously diagnosed carious lesions in the pits and fissures of first and second molars. The measurements from this device were correlated with the depth and volume of the cavity preparations that resulted from minimal intervention to remove occlusal carious lesions. Twenty-five patients, 18 years of age and older, who were previously scheduled for an occlusal restoration due to caries, were recruited and enrolled in this clinical study. These patients had 48 qualifying teeth without previous restorations, sealants or other carious lesions. The occlusal surface of each study tooth was cleaned utilizing ProphyFlex2 (KaVo). Two dentists separately traced the pit and fissure system of each tooth using DIAGNOdent for two 15-second periods each. The peak reading of each of the four measurements was recorded. An impression of the occlusal surface of each tooth was recorded with a polyvinyl siloxane bite registration material. The carious lesions were removed with an air abrasion unit employing a 0.015-inch nozzle opening utilizing minimal operative intervention. A low viscosity polyvinyl siloxane was used to take an impression of the cavity preparation impression, using the bite registration impression to form the occlusal surface of the preparation impression. The preparation impression volume was calculated from its weight, using the known density of the impression material. The greatest depth of the preparation was measured. The Pearson correlation coefficient was used to investigate any relationship between depth or volume of the preparation impression and the DIAGNOdent measurements. The correlation for preparation volume and maximum DIAGNOdent measurement was 0.191 (p = 0.189). Other logical subsets of cases also did not result in any statistically significant correlations between the DIAGNOdent readings and the depth or volume of the final cavity preparations.

  17. Amphiphilic mediated sample preparation for micro-flow cytometry

    Energy Technology Data Exchange (ETDEWEB)

    Clague, David S. (Livermore, CA); Wheeler, Elizabeth K. (Livermore, CA); Lee, Abraham P. (Irvine, CA)

    2009-03-17

    A flow cytometer includes a flow cell for detecting the sample, an oil phase in the flow cell, a water phase in the flow cell, an oil-water interface between the oil phase and the water phase, a detector for detecting the sample at the oil-water interface, and a hydrophobic unit operatively connected to the sample. The hydrophobic unit is attached to the sample. The sample and the hydrophobic unit are placed in an oil and water combination. The sample is detected at the interface between the oil phase and the water phase.

  18. Semiautomated Sample Preparation for Protein Stability and Formulation Screening via Buffer Exchange.

    Science.gov (United States)

    Ying, William; Levons, Jaquan K; Carney, Andrea; Gandhi, Rajesh; Vydra, Vicky; Rubin, A Erik

    2016-06-01

    A novel semiautomated buffer exchange process workflow was developed to enable efficient early protein formulation screening. An antibody fragment protein, BMSdab, was used to demonstrate the workflow. The process afforded 60% to 80% cycle time and scientist time savings and significant material efficiencies. These efficiencies ultimately facilitated execution of this stability work earlier in the drug development process, allowing this tool to inform the developability of potential candidates for development from a formulation perspective. To overcome the key technical challenges, the protein solution was buffer-exchanged by centrifuge filtration into formulations for stability screening in a 96-well plate with an ultrafiltration membrane, leveraging automated liquid handling and acoustic volume measurements to allow several cycles of exchanges. The formulations were transferred into a vacuum manifold and sterile filtered into a rack holding 96 glass vials. The vials were sealed with a capmat of individual caps and placed in stability stations. Stability of the samples prepared by this process and by the standard process was demonstrated to be comparable. This process enabled screening a number of formulations of a protein at an early pharmaceutical development stage with a short sample preparation time.

  19. Final LDRD report : development of sample preparation methods for ChIPMA-based imaging mass spectrometry of tissue samples.

    Energy Technology Data Exchange (ETDEWEB)

    Maharrey, Sean P.; Highley, Aaron M.; Behrens, Richard, Jr.; Wiese-Smith, Deneille

    2007-12-01

    The objective of this short-term LDRD project was to acquire the tools needed to use our chemical imaging precision mass analyzer (ChIPMA) instrument to analyze tissue samples. This effort was an outgrowth of discussions with oncologists on the need to find the cellular origin of signals in mass spectra of serum samples, which provide biomarkers for ovarian cancer. The ultimate goal would be to collect chemical images of biopsy samples allowing the chemical images of diseased and nondiseased sections of a sample to be compared. The equipment needed to prepare tissue samples have been acquired and built. This equipment includes an cyro-ultramicrotome for preparing thin sections of samples and a coating unit. The coating unit uses an electrospray system to deposit small droplets of a UV-photo absorbing compound on the surface of the tissue samples. Both units are operational. The tissue sample must be coated with the organic compound to enable matrix assisted laser desorption/ionization (MALDI) and matrix enhanced secondary ion mass spectrometry (ME-SIMS) measurements with the ChIPMA instrument Initial plans to test the sample preparation using human tissue samples required development of administrative procedures beyond the scope of this LDRD. Hence, it was decided to make two types of measurements: (1) Testing the spatial resolution of ME-SIMS by preparing a substrate coated with a mixture of an organic matrix and a bio standard and etching a defined pattern in the coating using a liquid metal ion beam, and (2) preparing and imaging C. elegans worms. Difficulties arose in sectioning the C. elegans for analysis and funds and time to overcome these difficulties were not available in this project. The facilities are now available for preparing biological samples for analysis with the ChIPMA instrument. Some further investment of time and resources in sample preparation should make this a useful tool for chemical imaging applications.

  20. Selecting Sample Preparation Workflows for Mass Spectrometry-Based Proteomic and Phosphoproteomic Analysis of Patient Samples with Acute Myeloid Leukemia

    Directory of Open Access Journals (Sweden)

    Maria Hernandez-Valladares

    2016-08-01

    Full Text Available Global mass spectrometry (MS-based proteomic and phosphoproteomic studies of acute myeloid leukemia (AML biomarkers represent a powerful strategy to identify and confirm proteins and their phosphorylated modifications that could be applied in diagnosis and prognosis, as a support for individual treatment regimens and selection of patients for bone marrow transplant. MS-based studies require optimal and reproducible workflows that allow a satisfactory coverage of the proteome and its modifications. Preparation of samples for global MS analysis is a crucial step and it usually requires method testing, tuning and optimization. Different proteomic workflows that have been used to prepare AML patient samples for global MS analysis usually include a standard protein in-solution digestion procedure with a urea-based lysis buffer. The enrichment of phosphopeptides from AML patient samples has previously been carried out either with immobilized metal affinity chromatography (IMAC or metal oxide affinity chromatography (MOAC. We have recently tested several methods of sample preparation for MS analysis of the AML proteome and phosphoproteome and introduced filter-aided sample preparation (FASP as a superior methodology for the sensitive and reproducible generation of peptides from patient samples. FASP-prepared peptides can be further fractionated or IMAC-enriched for proteome or phosphoproteome analyses. Herein, we will review both in-solution and FASP-based sample preparation workflows and encourage the use of the latter for the highest protein and phosphorylation coverage and reproducibility.

  1. Sampling based motion planning with reachable volumes: Application to manipulators and closed chain systems

    KAUST Repository

    McMahon, Troy

    2014-09-01

    © 2014 IEEE. Reachable volumes are a geometric representation of the regions the joints of a robot can reach. They can be used to generate constraint satisfying samples for problems including complicated linkage robots (e.g. closed chains and graspers). They can also be used to assist robot operators and to help in robot design.We show that reachable volumes have an O(1) complexity in unconstrained problems as well as in many constrained problems. We also show that reachable volumes can be computed in linear time and that reachable volume samples can be generated in linear time in problems without constraints. We experimentally validate reachable volume sampling, both with and without constraints on end effectors and/or internal joints. We show that reachable volume samples are less likely to be invalid due to self-collisions, making reachable volume sampling significantly more efficient for higher dimensional problems. We also show that these samples are easier to connect than others, resulting in better connected roadmaps. We demonstrate that our method can be applied to 262-dof, multi-loop, and tree-like linkages including combinations of planar, prismatic and spherical joints. In contrast, existing methods either cannot be used for these problems or do not produce good quality solutions.

  2. Comparison of uncertainties related to standardization of urine samples with volume and creatinine concentration

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Hansen, Ase Marie; Kristiansen, Jesper;

    2004-01-01

    When measuring biomarkers in urine, volume (and time) or concentration of creatinine are both accepted methods of standardization for diuresis. Both types of standardization contribute uncertainty to the final result. The aim of the present paper was to compare the uncertainty introduced when using...... that the uncertainty associated with creatinine standardization (19-35%) was higher than the uncertainty related to volume standardization (up to 10%, when not correcting for deviations from 24 h) for 24 h urine samples. However, volume standardization introduced an average bias of 4% due to missed volumes...... in population studies. When studying a single 24 h sample from one individual, there was a 15-20% risk that the sample was incomplete. In this case a bias of approximately 25% was introduced when using volume standardization, whereas the uncertainty related to creatinine standardization was independent...

  3. A technique for sampling low shrub vegetation, by crown volume classes

    Science.gov (United States)

    Jay R. Bentley; Donald W. Seegrist; David A. Blakeman

    1970-01-01

    The effects of herbicides or other cultural treatments of low shrubs can be sampled by a new technique using crown volume as the key variable. Low shrubs were grouped in 12 crown volume classes with index values based on height times surface area of crown. The number of plants, by species, in each class is counted on quadrats. Many quadrats are needed for highly...

  4. Microwave processing for sample preparation to evaluate mitochondrial ultrastructural damage in hemorrhagic shock.

    Science.gov (United States)

    Josephsen, Gary D; Josephsen, Kelly A; Beilman, Greg J; Taylor, Jodie H; Muiler, Kristine E

    2005-12-01

    This is a report of the adaptation of microwave processing in the preparation of liver biopsies for transmission electron microscopy (TEM) to examine ultrastructural damage of mitochondria in the setting of metabolic stress. Hemorrhagic shock was induced in pigs via 35% total blood volume bleed and a 90-min period of shock followed by resuscitation. Hepatic biopsies were collected before shock and after resuscitation. Following collection, biopsies were processed for TEM by a rapid method involving microwave irradiation (Giberson, 2001). Samples pre- and postshock of each of two animals were viewed and scored using the mitochondrial ultrastructure scoring system (Crouser et al., 2002), a system used to quantify the severity of ultrastructural damage during shock. Results showed evidence of increased ultrastructural damage in the postshock samples, which scored 4.00 and 3.42, versus their preshock controls, which scored 1.18 and 1.27. The results of this analysis were similar to those obtained in another model of shock (Crouser et al., 2002). However, the amount of time used to process the samples was significantly shortened with methods involving microwave irradiation.

  5. Preview of the NASA NNWG NDE Sample Preparation Handbook

    Science.gov (United States)

    2010-01-01

    This viewgraph presents a step-by-step how-to fabrication documentation of every kind of sample that is fabricated for MSFC by UA Huntsville, including photos and illustrations. The tabulation of what kind of samples are being fabricated for what NDE method, detailed instructions/documentation of the inclusion/creation of defects, detailed specifications for materials, processes, and equipment, case histories and/or experiences with the different fabrication methods and defect inclusion techniques, discussion of pitfalls and difficulties associated with sample fabrication and defect inclusion techniques, and a discussion of why certain fabrication techniques are needed as related to the specific NDE methods are included in this presentation.

  6. Sample Preparation (SS): SE45_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available tration of 15 ng µl-1 for each 1-µl injection. After 5-min centrifugation at 15,1...0 mg/ml in pyridine) was added to the sample. After 24 h of derivatization at room temperature, the sample w...µl of methoxyamine hydrochloride (20 mg ml-1 in pyridine) were added to the sample. After 24 h of derivatiza...f MSTFA at 37°C with shaking. After silylation 30 µl of n-heptane were added. All derivatization steps were

  7. The effects of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin

    Science.gov (United States)

    Küme, Tuncay; Şişman, Ali Rıza; Solak, Ahmet; Tuğlu, Birsen; Çinkooğlu, Burcu; Çoker, Canan

    2012-01-01

    Introductıon: We evaluated the effect of different syringe volume, needle size and sample volume on blood gas analysis in syringes washed with heparin. Materials and methods: In this multi-step experimental study, percent dilution ratios (PDRs) and final heparin concentrations (FHCs) were calculated by gravimetric method for determining the effect of syringe volume (1, 2, 5 and 10 mL), needle size (20, 21, 22, 25 and 26 G) and sample volume (0.5, 1, 2, 5 and 10 mL). The effect of different PDRs and FHCs on blood gas and electrolyte parameters were determined. The erroneous results from nonstandardized sampling were evaluated according to RiliBAK’s TEa. Results: The increase of PDRs and FHCs was associated with the decrease of syringe volume, the increase of needle size and the decrease of sample volume: from 2.0% and 100 IU/mL in 10 mL-syringe to 7.0% and 351 IU/mL in 1 mL-syringe; from 4.9% and 245 IU/mL in 26G to 7.6% and 380 IU/mL in 20 G with combined 1 mL syringe; from 2.0% and 100 IU/mL in full-filled sample to 34% and 1675 IU/mL in 0.5 mL suctioned sample into 10 mL-syringe. There was no statistical difference in pH; but the percent decreasing in pCO2, K+, iCa2+, iMg2+; the percent increasing in pO2 and Na+ were statistical significance compared to samples full-filled in syringes. The all changes in pH and pO2 were acceptable; but the changes in pCO2, Na+, K+ and iCa2+ were unacceptable according to TEa limits except fullfilled-syringes. Conclusions: The changes in PDRs and FHCs due nonstandardized sampling in syringe washed with liquid heparin give rise to erroneous test results for pCO2 and electrolytes. PMID:22838185

  8. Preparing and measuring ultra-small radiocarbon samples with the ARTEMIS AMS facility in Saclay, France

    Energy Technology Data Exchange (ETDEWEB)

    Delque-Kolic, E., E-mail: emmanuelle.delque-kolic@cea.fr [LMC14, CEA Saclay, Batiment 450 Porte 4E, 91191 Gif sur Yvette (France); Comby-Zerbino, C.; Ferkane, S.; Moreau, C.; Dumoulin, J.P.; Caffy, I.; Souprayen, C.; Quiles, A.; Bavay, D.; Hain, S.; Setti, V. [LMC14, CEA Saclay, Batiment 450 Porte 4E, 91191 Gif sur Yvette (France)

    2013-01-15

    The ARTEMIS facility in Saclay France measures, on average, 4500 samples a year for French organizations working in an array of fields, including environmental sciences, archeology and hydrology. In response to an increasing demand for the isolation of specific soil compounds and organic water fractions, we were motivated to evaluate our ability to reduce microgram samples using our standard graphitization lines and to measure the graphite thus obtained with our 3MV NEC Pelletron AMS. Our reduction facility consists of two fully automated graphitization lines. Each line has 12 reduction reactors with a reduction volume of 18 ml for the first line and 12 ml for the second. Under routine conditions, we determined that we could reduce the samples down to 10 {mu}g of carbon, even if the graphitization yield is consequently affected by the lower sample mass. Our results when testing different Fe/C ratios suggest that an amount of 1.5 mg of Fe powder was ideal (instead of lower amounts of catalyst) to prevent the sample from deteriorating too quickly under the Cs+ beam, and to facilitate pressing procedures. Several sets of microsamples produced from HOxI standard, international references and backgrounds were measured. When measuring {sup 14}C-free wood charcoal and HOxI samples we determined that our modern and dead blanks, due to the various preparation steps, were of 1.1 {+-} 0.8 and 0.2 {+-} 0.1 {mu}g, respectively. The results presented here were obtained for IAEA-C1, {sup 14}C-free wood, IAEA-C6, IAEA-C2 and FIRI C.

  9. Sample Preparation for Monolithic Refractories Part 1: Refractory Castables

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2010-01-01

    @@ 1 Scope This standard specifies the definition and test methods of flowability of dense and insulating refractory castables,and moulding equipment,moulding methods,curing and drying conditions of castables samples.

  10. Sample Preparation (SS): SE52_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available Tokyo, Japan) using a mixer mill (MM 300, Retsch) with a zirconia bead for 6 min... at 20 Hz. Next, the samples were centrifuged at 15,000 g for 10 min and filtered (Ultrafree-MC filter, 0.2 μm; Mil...lipore, Bedford, MA, USA). The sample extracts were then applied to an HLB μElution plate (Waters, Mil

  11. Tenth annual coal preparation, utilization, and environmental control contractors conference: Proceedings. Volume 1

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    Volume I contains papers presented at the following sessions: high efficiency preparation; advanced physical coal cleaning; superclean emission systems; air toxics and mercury measurement and control workshop; and mercury measurement and control workshop. Selected papers have been processed for inclusion in the Energy Science and Technology Database.

  12. Effect of sample volume size and sampling method on feline longitudinal myocardial velocity profiles from color tissue Doppler imaging.

    Science.gov (United States)

    Granström, Sara; Pipper, Christian Bressen; Møgelvang, Rasmus; Sogaard, Peter; Willesen, Jakob Lundgren; Koch, Jørgen

    2012-12-01

    The aims of this study were to compare the effect of sample volume (SV) size settings and sampling method on measurement variability and peak systolic (s'), and early (e') and late (a') diastolic longitudinal myocardial velocities using color tissue Doppler imaging (cTDI) in cats. Twenty cats with normal echocardiograms and 20 cats with hypertrophic cardiomyopathy. We quantified and compared empirical variance and average absolute values of s', e' and a' for three cardiac cycles using eight different SV settings (length 1,2,3 and 5 mm; width 1 and 2 mm) and three methods of sampling (end-diastolic sampling with manual tracking of the SV, end-systolic sampling without tracking, and random-frame sampling without tracking). No significant difference in empirical variance could be demonstrated between most of the tested SVs. However, the two settings with a length of 1 mm resulted in a significantly higher variance compared with all settings where the SV length exceeded 2 mm (p sampling method on the variability of measurements (p = 0.003) and manual tracking obtained the lowest variance. No difference in average values of s', e' or a' could be found between any of the SV settings or sampling methods. Within the tested range of SV settings, an SV length of 1 mm resulted in higher measurement variability compared with an SV length of 3 and 5 mm, and should therefore be avoided. Manual tracking of the sample volume is recommended. Copyright © 2012 Elsevier B.V. All rights reserved.

  13. COMPARISON OF SAMPLE PREPARATION METHODS FOR CHIP-CHIP ASSAYS

    OpenAIRE

    O'Geen, Henriette; Nicolet, Charles M.; Blahnik, Kim; Green, Roland; Farnham, Peggy J.

    2006-01-01

    A single ChIP sample does not provide enough DNA for hybridization to a genomic tiling array. A commonly used technique for amplifying the DNA obtained from ChIP assays is linker-mediated PCR (LMPCR). However, using this amplification method, we could not identify Oct4 binding sites on genomic tiling arrays representing 1% of the human genome (ENCODE arrays). In contrast, hybridization of a pool of 10 ChIP samples to the arrays produced reproducible binding patterns and low background signals...

  14. Quantitating morphological changes in biological samples during scanning electron microscopy sample preparation with correlative super-resolution microscopy.

    Science.gov (United States)

    Zhang, Ying; Huang, Tao; Jorgens, Danielle M; Nickerson, Andrew; Lin, Li-Jung; Pelz, Joshua; Gray, Joe W; López, Claudia S; Nan, Xiaolin

    2017-01-01

    Sample preparation is critical to biological electron microscopy (EM), and there have been continuous efforts on optimizing the procedures to best preserve structures of interest in the sample. However, a quantitative characterization of the morphological changes associated with each step in EM sample preparation is currently lacking. Using correlative EM and superresolution microscopy (SRM), we have examined the effects of different drying methods as well as osmium tetroxide (OsO4) post-fixation on cell morphology during scanning electron microscopy (SEM) sample preparation. Here, SRM images of the sample acquired under hydrated conditions were used as a baseline for evaluating morphological changes as the sample went through SEM sample processing. We found that both chemical drying and critical point drying lead to a mild cellular boundary retraction of ~60 nm. Post-fixation by OsO4 causes at least 40 nm additional boundary retraction. We also found that coating coverslips with adhesion molecules such as fibronectin prior to cell plating helps reduce cell distortion from OsO4 post-fixation. These quantitative measurements offer useful information for identifying causes of cell distortions in SEM sample preparation and improving current procedures.

  15. Optical biosensor system with integrated microfluidic sample preparation and TIRF based detection

    Science.gov (United States)

    Gilli, Eduard; Scheicher, Sylvia R.; Suppan, Michael; Pichler, Heinz; Rumpler, Markus; Satzinger, Valentin; Palfinger, Christian; Reil, Frank; Hajnsek, Martin; Köstler, Stefan

    2013-05-01

    There is a steadily growing demand for miniaturized bioanalytical devices allowing for on-site or point-of-care detection of biomolecules or pathogens in applications like diagnostics, food testing, or environmental monitoring. These, so called labs-on-a-chip or micro-total analysis systems (μ-TAS) should ideally enable convenient sample-in - result-out type operation. Therefore, the entire process from sample preparation, metering, reagent incubation, etc. to detection should be performed on a single disposable device (on-chip). In the early days such devices were mainly fabricated using glass or silicon substrates and adapting established fabrication technologies from the electronics and semiconductor industry. More recently, the development focuses on the use of thermoplastic polymers as they allow for low-cost high volume fabrication of disposables. One of the most promising materials for the development of plastic based lab-on-achip systems are cyclic olefin polymers and copolymers (COP/COC) due to their excellent optical properties (high transparency and low autofluorescence) and ease of processing. We present a bioanalytical system for whole blood samples comprising a disposable plastic chip based on TIRF (total internal reflection fluorescence) optical detection. The chips were fabricated by compression moulding of COP and microfluidic channels were structured by hot embossing. These microfluidic structures integrate several sample pretreatment steps. These are the separation of erythrocytes, metering of sample volume using passive valves, and reagent incubation for competitive bioassays. The surface of the following optical detection zone is functionalized with specific capture probes in an array format. The plastic chips comprise dedicated structures for simple and effective coupling of excitation light from low-cost laser diodes. This enables TIRF excitation of fluorescently labeled probes selectively bound to detection spots at the microchannel surface

  16. Microfluidic desalination. Capacitive deionization on chip for microfluidic sample preparation

    NARCIS (Netherlands)

    Roelofs, Susan Helena

    2015-01-01

    The main aim of the work described in this thesis is to implement the desalination technique capacitive deionization (CDI) on a microfluidic chip to improve the reproducibility in the analysis of biological samples for drug development. Secondly, microfluidic CDI allows for the in situ study of ion

  17. Influence of concentration and volume of precursor on the electrochemical properties of vanadium oxide thin films prepared by spray pyrolysis

    Energy Technology Data Exchange (ETDEWEB)

    Ingole, R. S.; Fugare, B. Y.; Lokhande, B. J., E-mail: bjlokhande@yahoo.com [School of Physical Sciences, Solapur University, Solapur 413 255, M.S. (India)

    2016-04-13

    Vanadium oxide (V{sub 2}O{sub 5}) thin films have been prepared by spray pyrolysis using different concentrations and volumes of precursor solution via aqueous route at 673K deposition temperature. The influences of concentration and volume on the structural, morphological and electrochemical properties of the deposited samples are studied well. X - ray diffraction study shows orthorhombic crystal structure with V{sub 2}O{sub 5} phase, confirmed by FTIR spectroscopy. Scanning electron microscopy shows granular, homogeneous and dense surface morphology. Cyclic voltammetery of all samples carried at all scan rates. Samples prepared using 0.05M, 40 ml of precursor solution shows highest specific capacitance 428.25 F/gm at 5 mV/s, Charge discharge behavior exhibits specific energy 18.73 Wh/kg, specific power 36.00 kW/kg, columbic efficiency 87.50 %. Impedance spectroscopy study was carried in the frequency range 1mHz – 1MHz, reveals pseudocapacitive behavior of the electrode exhibiting internal resistance 1.34 ohm.

  18. Effects of Sample Preparation on the Infrared Reflectance Spectra of Powders

    Energy Technology Data Exchange (ETDEWEB)

    Brauer, Carolyn S.; Johnson, Timothy J.; Myers, Tanya L.; Su, Yin-Fong; Blake, Thomas A.; Forland, Brenda M.

    2015-05-22

    While reflectance spectroscopy is a useful tool in identifying molecular compounds, laboratory measurement of solid (particularly powder) samples often is confounded by sample preparation methods. For example, both the packing density and surface roughness can have an effect on the quantitative reflectance spectra of powdered samples. Recent efforts in our group have focused on developing standard methods for measuring reflectance spectra that accounts for sample preparation, as well as other factors such as particle size and provenance. In this work, the effect of preparation method on sample reflectivity was investigated by measuring the directional-hemispherical spectra of samples that were hand-packed as well as pressed into pellets using an integrating sphere attached to a Fourier transform infrared spectrometer. The results show that the methods used to prepare the sample have a substantial effect on the measured reflectance spectra, as do other factors such as particle size.

  19. Repetitive Cyclic Potentiodynamic Polarization Scan Results for Reduced Sample Volume Testing

    Energy Technology Data Exchange (ETDEWEB)

    LaMothe, Margaret E. [Washington River Protection Solutions, Richland, WA (United States)

    2016-03-15

    This report is the compilation of data gathered after repetitively testing simulated tank waste and a radioactive tank waste sample using a cyclic potentiodynamic polarization (CPP) test method to determine corrosion resistance of metal samples. Electrochemistry testing of radioactive tank samples is often used to assess the corrosion susceptibility and material integrity of waste tank steel. Repetitive testing of radiological tank waste is occasionally requested at 222-S Laboratory due to the limited volume of radiological tank sample received for testing.

  20. Sample preparation and assay refinements for pathogen detection platforms

    Science.gov (United States)

    Lim, Daniel V.; Kearns, Elizabeth A.; Leskinen, Stephaney D.; Magaña, Sonia; Stroot, Joyce M.; Hunter, Dawn M.; Schlemmer, Sarah M.

    2009-02-01

    Food-borne and waterborne microbial pathogens are a potential problem in biowarfare and public health. Such pathogens can affect the health, combat readiness, and effectiveness of the warfighter in a battlefield environment and present potential threats to the civilian population through intentional or natural contamination of food and water. Conventional procedures to detect and identify microbial pathogens in food, water, and other materials can take days to perform and may provide inconclusive information. Research at the University of South Florida's Advanced Biosensors Laboratory (ABL) focuses on development of sample processing procedures and biosensor-based assays for rapid detection of biothreat agents. Rapid processing methods, including use of an automated concentrator of microorganisms in water, have been developed for complex matrix samples including ground beef, apple juice, produce, potable water and recreational water, enabling such samples to be directly tested by biosensor assays for target analytes. Bacillus atrophaeus spores and other bacteria can be concentrated from potable and recreational water at low levels with a dead-end hollow-fiber ultrafiltration concentration system. Target bacteria recovered by these processing procedures can be identified by evanescent wave, fiber optic biosensors or other detection platforms. Fiber optic biosensor assays have been improved to include subsequent PCR analysis and viability determination of captured target bacteria using broth enrichment and/or ATP luminescence.

  1. Quantitative analysis of intermediately and infinitely thick samples with thin sample approach without sample preparation using confocal X-ray fluorescence

    CERN Document Server

    Sun, Xue-Peng; Sun, Tian-Xi; Peng, Song; Sun, Wei-Yuan; Li, Fang-Zuo; Jiang, Bo-Wen; Ma, Yong-Zhong; Ding, Xun-Liang

    2015-01-01

    In order to validate that the confocal X-ray fluorescence had potential applications in analyzing the intermediately and infinitely thick samples with thin sample approach without sample preparations, as an example, the confocal X-ray fluorescence based on polycapillary X-ray optics was used to analyze multi elements solutions.

  2. Global metabolite analysis of yeast: evaluation of sample preparation methods

    DEFF Research Database (Denmark)

    Villas-Bôas, Silas Granato; Højer-Pedersen, Jesper; Åkesson, Mats Fredrik;

    2005-01-01

    , which is the analysis of a large number of metabolites with very diverse chemical and physical properties. This work reports the leakage of intracellular metabolites observed during quenching yeast cells with cold methanol solution, the efficacy of six different methods for the extraction...... of intracellular metabolites, and the losses noticed during sample concentration by lyophilization and solvent evaporation. A more reliable procedure is suggested for quenching yeast cells with cold methanol solution, followed by extraction of intracellular metabolites by pure methanol. The method can be combined...

  3. Sample preparation of metal alloys by electric discharge machining

    Science.gov (United States)

    Chapman, G. B., II; Gordon, W. A.

    1976-01-01

    Electric discharge machining was investigated as a noncontaminating method of comminuting alloys for subsequent chemical analysis. Particulate dispersions in water were produced from bulk alloys at a rate of about 5 mg/min by using a commercially available machining instrument. The utility of this approach was demonstrated by results obtained when acidified dispersions were substituted for true acid solutions in an established spectrochemical method. The analysis results were not significantly different for the two sample forms. Particle size measurements and preliminary results from other spectrochemical methods which require direct aspiration of liquid into flame or plasma sources are reported.

  4. Second generation laser-heated microfurnace for the preparation of microgram-sized graphite samples

    Science.gov (United States)

    Yang, Bin; Smith, A. M.; Long, S.

    2015-10-01

    We present construction details and test results for two second-generation laser-heated microfurnaces (LHF-II) used to prepare graphite samples for Accelerator Mass Spectrometry (AMS) at ANSTO. Based on systematic studies aimed at optimising the performance of our prototype laser-heated microfurnace (LHF-I) (Smith et al., 2007 [1]; Smith et al., 2010 [2,3]; Yang et al., 2014 [4]), we have designed the LHF-II to have the following features: (i) it has a small reactor volume of 0.25 mL allowing us to completely graphitise carbon dioxide samples containing as little as 2 μg of C, (ii) it can operate over a large pressure range (0-3 bar) and so has the capacity to graphitise CO2 samples containing up to 100 μg of C; (iii) it is compact, with three valves integrated into the microfurnace body, (iv) it is compatible with our new miniaturised conventional graphitisation furnaces (MCF), also designed for small samples, and shares a common vacuum system. Early tests have shown that the extraneous carbon added during graphitisation in each LHF-II is of the order of 0.05 μg, assuming 100 pMC activity, similar to that of the prototype unit. We use a 'budget' fibre packaged array for the diode laser with custom built focusing optics. The use of a new infrared (IR) thermometer with a short focal length has allowed us to decrease the height of the light-proof safety enclosure. These innovations have produced a cheaper and more compact device. As with the LHF-I, feedback control of the catalyst temperature and logging of the reaction parameters is managed by a LabVIEW interface.

  5. Second generation laser-heated microfurnace for the preparation of microgram-sized graphite samples

    Energy Technology Data Exchange (ETDEWEB)

    Yang, Bin; Smith, A.M.; Long, S.

    2015-10-15

    We present construction details and test results for two second-generation laser-heated microfurnaces (LHF-II) used to prepare graphite samples for Accelerator Mass Spectrometry (AMS) at ANSTO. Based on systematic studies aimed at optimising the performance of our prototype laser-heated microfurnace (LHF-I) (Smith et al., 2007 [1]; Smith et al., 2010 [2,3]; Yang et al., 2014 [4]), we have designed the LHF-II to have the following features: (i) it has a small reactor volume of 0.25 mL allowing us to completely graphitise carbon dioxide samples containing as little as 2 μg of C, (ii) it can operate over a large pressure range (0–3 bar) and so has the capacity to graphitise CO{sub 2} samples containing up to 100 μg of C; (iii) it is compact, with three valves integrated into the microfurnace body, (iv) it is compatible with our new miniaturised conventional graphitisation furnaces (MCF), also designed for small samples, and shares a common vacuum system. Early tests have shown that the extraneous carbon added during graphitisation in each LHF-II is of the order of 0.05 μg, assuming 100 pMC activity, similar to that of the prototype unit. We use a ‘budget’ fibre packaged array for the diode laser with custom built focusing optics. The use of a new infrared (IR) thermometer with a short focal length has allowed us to decrease the height of the light-proof safety enclosure. These innovations have produced a cheaper and more compact device. As with the LHF-I, feedback control of the catalyst temperature and logging of the reaction parameters is managed by a LabVIEW interface.

  6. Current advances and strategies towards fully automated sample preparation for regulated LC-MS/MS bioanalysis.

    Science.gov (United States)

    Zheng, Naiyu; Jiang, Hao; Zeng, Jianing

    2014-09-01

    Robotic liquid handlers (RLHs) have been widely used in automated sample preparation for liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalysis. Automated sample preparation for regulated bioanalysis offers significantly higher assay efficiency, better data quality and potential bioanalytical cost-savings. For RLHs that are used for regulated bioanalysis, there are additional requirements, including 21 CFR Part 11 compliance, software validation, system qualification, calibration verification and proper maintenance. This article reviews recent advances in automated sample preparation for regulated bioanalysis in the last 5 years. Specifically, it covers the following aspects: regulated bioanalysis requirements, recent advances in automation hardware and software development, sample extraction workflow simplification, strategies towards fully automated sample extraction, and best practices in automated sample preparation for regulated bioanalysis.

  7. Intelligent front-end sample preparation tool using acoustic streaming.

    Energy Technology Data Exchange (ETDEWEB)

    Cooley, Erika J.; McClain, Jaime L.; Murton, Jaclyn K.; Edwards, Thayne L.; Achyuthan, Komandoor E.; Branch, Darren W.; Clem, Paul Gilbert; Anderson, John Mueller; James, Conrad D.; Smith, Gennifer; Kotulski, Joseph Daniel

    2009-09-01

    time was 5-10 minutes for a volume of 50 {micro}L. Moreover, a unique feature of this technology is the ability to replace the cartridges for subsequent nucleic acid extractions.

  8. New Approach to Purging Monitoring Wells: Lower Flow Rates Reduce Required Purging Volumes and Sample Turbidity

    Science.gov (United States)

    It is generally accepted that monitoring wells must be purged to access formation water to obtain “representative” ground water quality samples. Historically anywhere from 3 to 5 well casing volumes have been removed prior to sample collection to evacuate the standing well water...

  9. An immunomagnetic separator for concentration of pathogenic micro-organisms from large volume samples

    Energy Technology Data Exchange (ETDEWEB)

    Rotariu, Ovidiu [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen (United Kingdom) and National Institute of R-D for Technical Physics I.F.T. Iasi, Mangeron 47 Blvd., Iasi (Romania)]. E-mail: o.rotariu@abdn.ac.uk; Ogden, Iain D. [Department of Medical Microbiology, University of Aberdeen, Aberdeen (United Kingdom); MacRae, Marion [Department of Medical Microbiology, University of Aberdeen, Aberdeen (United Kingdom); Badescu, Vasile [National Institute of R-D for Technical Physics I.F.T. Iasi, Mangeron 47 Blvd., Iasi (Romania); Strachan, Norval J.C. [School of Biological Sciences, University of Aberdeen, Cruickshank Building, St. Machar Drive, Aberdeen (United Kingdom)

    2005-05-15

    The standard method of immunomagnetic separation of pathogenic bacteria from food and environmental matrices processes 1 ml volumes. Pathogens present at low levels (<1 pathogenic bacteria per ml) will not be consistently detected by this method. Here a flow through immunomagnetic separator (FTIMS) has been designed and tested to process large volume samples (>50 ml). Preliminary results show that between 70 and 113 times more Escherchia coli O157 are recovered compared with the standard 1 ml method.

  10. Sample preparation for atomic-resolution STEM at low voltages by FIB

    Energy Technology Data Exchange (ETDEWEB)

    Schaffer, Miroslava, E-mail: mschaffer@SuperSTEM.org [SuperSTEM, STFC Daresbury Laboratories, Keckwick Lane, Warrington WA4 4AD (United Kingdom); Department of Engineering, George Holt Building, Ashton Street, Liverpool L69 3BX (United Kingdom); Schaffer, Bernhard [SuperSTEM, STFC Daresbury Laboratories, Keckwick Lane, Warrington WA4 4AD (United Kingdom); Kelvin Nanocharacterisation Centre, SUPA School of Physics and Astronomy, University of Glasgow, Glasgow G12 8QQ, Scotland (United Kingdom); Ramasse, Quentin [SuperSTEM, STFC Daresbury Laboratories, Keckwick Lane, Warrington WA4 4AD (United Kingdom); Department of Engineering, George Holt Building, Ashton Street, Liverpool L69 3BX (United Kingdom)

    2012-03-15

    While FIB sample preparation for transmission electron microscopy is a well established technique, few examples exist of samples of sufficient quality for atomic resolution imaging by aberration corrected (scanning) transmission electron microscopy (STEM). In this work we demonstrate the successful preparation of such samples from five different materials and present the refined lift-out preparation technique, which was applied here. Samples with parallel surfaces and a general thickness between 20 and 40 nm over a range of several {mu}m were repeatedly prepared and analyzed by Cs-corrected STEM at 60 and 100 kV. Here, a novel 'wedge pre-milling' step helps to keep the protective surface layers intact during the whole milling process, allowing features close to or at the sample surface to be analyzed without preparation damage. Another example shows the cross-sectional preparation of a working thin film solar cell device to a final thickness of 10 to 20 nm over {mu}m sized areas in the region of interest, enabling atomic resolution imaging and elemental mapping across general grain boundaries without projection artefacts. All sample preparation has been carried out in modern Dual-Beam FIB microscopes capable of low-kV Ga{sup +} ion milling, but without additional preparation steps after the FIB lift-out procedure. -- Highlights: Black-Right-Pointing-Pointer Suitability of stand-alone FIB preparation for atomic resolution STEM is shown. Black-Right-Pointing-Pointer Reproducible preparation of 10-40 nm thick samples from 5 different materials. Black-Right-Pointing-Pointer Low-kV milling and adjusted procedure for crystalline, homogeneously thin specimen. Black-Right-Pointing-Pointer Wedge pre-milling to protect surface-near features.

  11. Socioeconomic status and the cerebellar grey matter volume. Data from a well-characterised population sample.

    Science.gov (United States)

    Cavanagh, Jonathan; Krishnadas, Rajeev; Batty, G David; Burns, Harry; Deans, Kevin A; Ford, Ian; McConnachie, Alex; McGinty, Agnes; McLean, Jennifer S; Millar, Keith; Sattar, Naveed; Shiels, Paul G; Tannahill, Carol; Velupillai, Yoga N; Packard, Chris J; McLean, John

    2013-12-01

    The cerebellum is highly sensitive to adverse environmental factors throughout the life span. Socioeconomic deprivation has been associated with greater inflammatory and cardiometabolic risk, and poor neurocognitive function. Given the increasing awareness of the association between early-life adversities on cerebellar structure, we aimed to explore the relationship between early life (ESES) and current socioeconomic status (CSES) and cerebellar volume. T1-weighted MRI was used to create models of cerebellar grey matter volumes in 42 adult neurologically healthy males selected from the Psychological, Social and Biological Determinants of Ill Health study. The relationship between potential risk factors, including ESES, CSES and cerebellar grey matter volumes were examined using multiple regression techniques. We also examined if greater multisystem physiological risk index-derived from inflammatory and cardiometabolic risk markers-mediated the relationship between socioeconomic status (SES) and cerebellar grey matter volume. Both ESES and CSES explained the greatest variance in cerebellar grey matter volume, with age and alcohol use as a covariate in the model. Low CSES explained additional significant variance to low ESES on grey matter decrease. The multisystem physiological risk index mediated the relationship between both early life and current SES and grey matter volume in cerebellum. In a randomly selected sample of neurologically healthy males, poorer socioeconomic status was associated with a smaller cerebellar volume. Early and current socioeconomic status and the multisystem physiological risk index also apparently influence cerebellar volume. These findings provide data on the relationship between socioeconomic deprivation and a brain region highly sensitive to environmental factors.

  12. SAMPLING INTENSITY WITH FIXED PRECISION WHEN ESTIMATING VOLUME OF HUMAN BRAIN COMPARTMENTS

    Directory of Open Access Journals (Sweden)

    Rhiannon Maudsley

    2011-05-01

    Full Text Available Cavalieri sampling and point counting are frequently applied in combination with magnetic resonance (MR imaging to estimate the volume of human brain compartments. Current practice involves arbitrarily choosing the number of sections and sampling intensity within each section, and subsequently applying error prediction formulae to estimate the precision. The aim of this study is to derive a reference table for researchers who are interested in estimating the volume of brain regions, namely grey matter, white matter, and their union, to a given precision. In particular, this table, which is based on subsampling of a large brain data set obtained from coronal MR images, offers a recommendation for the minimum number of sections and mean number of points per section that are required to achieve a pre-defined coefficient of error of the volume estimator. Further analysis onMR brain data from a second human brain shows that the sampling intensity recommended is appropriate.

  13. pH adjustment of human blood plasma prior to bioanalytical sample preparation

    NARCIS (Netherlands)

    Hendriks, G.; Uges, D. R. A.; Franke, J. P.

    2008-01-01

    pH adjustment in bioanalytical sample preparation concerning ionisable compounds is one of the most common sample treatments. This is often done by mixing an aliquot of the sample with a proper buffer adjusted to the proposed pH. The pH of the resulting mixture however, does not necessarily have to

  14. Study of sample preparation for quantitative analysis of amino acids in human sweat by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Delgado-Povedano, M M; Calderón-Santiago, M; Priego-Capote, F; Luque de Castro, M D

    2016-01-01

    The determination of physiological levels of amino acids is important to aid in the diagnosis and treatment of several diseases and nutritional status of individuals. Amino acids are frequently determined in biofluids such as blood (serum or plasma) and urine; however, there are less common biofluids with different concentration profiles of amino acids that could be of interest. One of these biofluids is sweat that can be obtained in a non-invasive manner and is characterized by low complex composition. The analysis of amino acids in human sweat requires the development of sample preparation strategies according to the sample matrix and small collected volume. The influence of sample preparation on the quantitative analysis of amino acids in sweat by LC-MS/MS has been assessed through a comparison between two strategies: dilution of sweat and centrifugal microsolid-phase extraction (c-μSPE). In both cases, several dilution factors were assayed for in-depth knowledge of the matrix effects, and the use of c-μSPE provided the best results in terms of accuracy. The behavior of the target analytes was a function of the dilution factor, thus providing a pattern for sample preparation that depended on the amino acid to be determined. The concentration of amino acids in sweat ranges between 6.20 ng mL(-1) (for homocysteine) and 259.77 µg mL(-1) (for serine) with precision, expressed as relative standard deviation, within 1.1-21.4%.

  15. Sample Preparation of Corn Seed Tissue to Prevent Analyte Relocations for Mass Spectrometry Imaging

    Science.gov (United States)

    Kim, Shin Hye; Kim, Jeongkwon; Lee, Young Jin; Lee, Tae Geol; Yoon, Sohee

    2017-08-01

    Corn seed tissue sections were prepared by the tape support method using an adhesive tape, and mass spectrometry imaging (MSI) was performed. The effect of heat generated during sample preparation was investigated by time-of-flight secondary mass spectrometry (TOF-SIMS) imaging of corn seed tissue prepared by the tape support and the thaw-mounted methods. Unlike thaw-mounted sample preparation, the tape support method does not cause imaging distortion because of the absence of heat, which can cause migration of the analytes on the sample. By applying the tape-support method, the corn seed tissue was prepared without structural damage and MSI with accurate spatial information of analytes was successfully performed.

  16. Effect of sample preparation methods on photometric determination of the tellurium and cobalt content in the samples of copper concentrates

    Directory of Open Access Journals (Sweden)

    Viktoriya Butenko

    2016-03-01

    Full Text Available Methods of determination of cobalt and nickel in copper concentrates currently used in factory laboratories are very labor intensive and time consuming. The limiting stage of the analysis is preliminary chemical sample preparation. Carrying out the decomposition process of industrial samples with concentrated mineral acids in open systems does not allow to improve the metrological characteristics of the methods, for this reason improvement the methods of sample preparation is quite relevant and has a practical interest. The work was dedicated to the determination of the optimal conditions of preliminary chemical preparation of copper concentrate samples for the subsequent determination of cobalt and tellurium in the obtained solution using tellurium-spectrophotometric method. Decomposition of the samples was carried out by acid dissolving in individual mineral acids and their mixtures by heating in an open system as well as by using ultrasonification and microwave radiation in a closed system. In order to select the optimal conditions for the decomposition of the samples in a closed system the phase contact time and ultrasonic generator’s power were varied. Intensification of the processes of decomposition of copper concentrates with nitric acid (1:1, ultrasound and microwave radiation allowed to transfer quantitatively cobalt and tellurium into solution spending 20 and 30 min respectively. This reduced the amount of reactants used and improved the accuracy of determination by running the process in strictly identical conditions.

  17. Preparative separation of sesamin and sesamolin from defatted sesame meal via centrifugal partition chromatography with consecutive sample injection.

    Science.gov (United States)

    Jeon, Je-Seung; Park, Chae Lee; Syed, Ahmed Shah; Kim, Young-Mi; Cho, Il Je; Kim, Chul Young

    2016-02-01

    A preparative separation method using consecutive sample injection centrifugal partition chromatography (CPC) was developed to obtain sesamin and sesamolin from defatted sesame meal extracts. A two-phase solvent system consisting of n-hexane-ethyl acetate-methanol-water (8:2:8:2, v/v) was applied in reversed-phase mode (descending mode). Preliminary experiments with an SCPC-100 (column volume: 100mL) were performed to select the appropriate two-phase solvent system and sample injection times; these parameters were then used with an SCPC-1000 (column volume: 1000mL) in a 10-fold scale-up preparative run. A sample containing 3g of crude extract was consecutively injected four times onto the SCPC-1000, which yielded 328mg of sesamin and 168mg of sesamolin. These compounds were analyzed by high-performance liquid chromatography and determined to have purities of 95.6% and 93.9%, respectively. Sesamin and sesamolin (30μM) increased antioxidant response element (ARE) luciferase activity 2.6-fold and 1.9-fold, respectively.

  18. Preparation and investigation of bulk and thin film samples of strontium ferrite

    Directory of Open Access Journals (Sweden)

    A Poorbafrani

    2008-07-01

    Full Text Available   In this article, bulk and thin film samples of strontium ferrite have been studied. Due to the high electrical resistivity in strontium ferrite, energy loss due to eddy currents reduces and because of this, it can be used in high frequency magnetic circuits. On the other hand, strontium ferrite has attracted much attention as a permanent magnet. At first, we study the preparation process of bulk samples of strontium ferrite by a solid state reaction technique. In preparation of samples, to optimize the magnetic properties, we have used the stoichiometry factor (n = Fe2O3 / SrO of 5.25. In addition, we have used additives such as CaO and SiO2 to control grain growth. The samples have been prepared in two series: Isotropic and Anisotropic. For preparation of anisotropic samples, the magnetic field of 1T has been used for orientation of the grains during the press. Then, X-ray diffraction, Scanning Electron Microscopy (SEM, EDAX analysis and Magnetometer, was used for analyzing and comparing of structural and magnetic properties of isotropic and anisotropic samples. The results indicate that, due to the applied magnetic field, the structural and Magnetic properties of anisotropic samples improved efficiently because of the orientation of the grains during the press. In the next stage, we used bulk samples to prepare strontium ferrite thin films by Pulsed Laser Deposition technique (PLD. The Si (111 substrate has been used to prepare the thin films. Then we have studied the microstructure of thin films by X-ray diffraction, SEM and EDAX analysis. These studies on different samples show that for the preparation of crystalline phase of strontium ferrite thin films, the substrate temperature must be higher than 800˚C. The optimum conditions for preparation of strontium, ferrite thin films have been achieved on the substrate temperature of 840˚C and oxygen pressure of 75 mtorr.

  19. Comparison of uncertainties related to standardization of urine samples with volume and creatinine concentration

    DEFF Research Database (Denmark)

    Garde, Anne Helene; Hansen, Ase Marie; Kristiansen, Jesper

    2004-01-01

    When measuring biomarkers in urine, volume (and time) or concentration of creatinine are both accepted methods of standardization for diuresis. Both types of standardization contribute uncertainty to the final result. The aim of the present paper was to compare the uncertainty introduced when using...... the two types of standardization on 24 h samples from healthy individuals. Estimates of uncertainties were based on results from the literature supplemented with data from our own studies. Only the difference in uncertainty related to the two standardization methods was evaluated. It was found...... increase in convenience for the participants, when collecting small volumes rather than complete 24 h samples....

  20. Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared Detector Samples

    Science.gov (United States)

    2015-11-13

    Approved for Public Release; Distribution Unlimited Final Report: Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared...Final Report: Equipment for Topographical Preparation and Analysis of Various Semiconductor Infrared Detector Samples Report Title A used calibrated...camera will reinitialize and the video settings have to be reset. 6 Figure 4. This will open the both video overlay and the Dektak

  1. Advanced Curation Activities at NASA: Preparing for the Next Waves of Astromaterials Sample Return

    Science.gov (United States)

    Zeigler, R. A.; Allton, J. H.; Evans, C. A.; Fries, M. D.; McCubbin, F. M.; Nakamura-Messenger, K.; Righter, K.; Zolensky, M.; Stansbery, E. K.

    2017-02-01

    We discuss the current curatorial efforts for NASA's astromaterials collections, as well as efforts that are underway (or need to be undertaken) to prepare for the challenging curation conditions required by future sample return missions.

  2. Simple and Reproducible Sample Preparation for Single-Shot Phosphoproteomics with High Sensitivity

    DEFF Research Database (Denmark)

    Jersie-Christensen, Rosa R.; Sultan, Abida; Olsen, Jesper V

    2016-01-01

    The traditional sample preparation workflow for mass spectrometry (MS)-based phosphoproteomics is time consuming and usually requires multiple steps, e.g., lysis, protein precipitation, reduction, alkylation, digestion, fractionation, and phosphopeptide enrichment. Each step can introduce chemica...

  3. Robotic, MEMS-based Multi Utility Sample Preparation Instrument for ISS Biological Workstation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project will develop a multi-functional, automated sample preparation instrument for biological wet-lab workstations on the ISS. The instrument is based on a...

  4. Preparation of testate amoebae samples affects water table depth reconstructions in peatland palaeoecological studies

    Directory of Open Access Journals (Sweden)

    Eve Avel

    2013-05-01

    Full Text Available In peatland palaeoecological studies, the preparation of peat samples for testate amoebae (TA analysis involves boiling of samples and microsieving them through a 15-μm sieve. We studied the effect of these preparation stages on the estimation of TA assemblages and on the reconstruction of water table depths (WTD. Our results indicate that the TA assemblages of boiled and unboiled samples are not significantly different, while microsieving reduces the concentration of small TA taxa and results in significantly different TA assemblages. The differences between microsieved and unsieved TA assemblages were reflected also in predicted values of WTD, which indicated drier conditions in case of unsieved samples than in microsieved samples. We conclude that the boiling of samples might be omitted if TA are extracted from the fresh peat samples. Microsieving may lead to erroneous palaeoecological WTD reconstructions and should be avoided if small TA taxa are present in samples.

  5. On radiation damage in FIB-prepared softwood samples measured by scanning X-ray diffraction.

    Science.gov (United States)

    Storm, Selina; Ogurreck, Malte; Laipple, Daniel; Krywka, Christina; Burghammer, Manfred; Di Cola, Emanuela; Müller, Martin

    2015-03-01

    The high flux density encountered in scanning X-ray nanodiffraction experiments can lead to severe radiation damage to biological samples. However, this technique is a suitable tool for investigating samples to high spatial resolution. The layered cell wall structure of softwood tracheids is an interesting system which has been extensively studied using this method. The tracheid cell has a complex geometry, which requires the sample to be prepared by cutting it perpendicularly to the cell wall axis. Focused ion beam (FIB) milling in combination with scanning electron microscopy allows precise alignment and cutting without splintering. Here, results of a scanning X-ray diffraction experiment performed on a biological sample prepared with a focused ion beam of gallium atoms are reported for the first time. It is shown that samples prepared and measured in this way suffer from the incorporation of gallium atoms up to a surprisingly large depth of 1 µm.

  6. Demonstration of a frozen sample aliquotter to prepare plasma and serum aliquots without thawing frozen parent samples.

    Science.gov (United States)

    Ellis, Helena Judge; Venturini, Deborah S

    2013-06-01

    Human biospecimens represent invaluable resources to advance molecular medicine, epidemiology, and biomarker discovery/validation, among other biomedical research. Biobanks typically cryopreserve biospecimens to safeguard their biochemical composition. However, exposing specimens repeatedly to freeze/thaw cycles can degrade their integrity in unforeseen ways. Those biobanks storing liquid samples, thus, regularly make a fundamental compromise at collection time between freezing samples in many small volumes (e.g., 0.5 mL or smaller) or in fewer, larger volumes (e.g., 1.8 mL). The former eliminates the need to expose samples to repeated freeze/thaw cycling, although increasing up-front labor costs, consumables used, and cold storage space requirements. The latter decreases up-front labor costs, consumables, and cold storage requirements, yet exposes samples repeatedly to damaging freeze/thaw cycles when smaller aliquots are needed for analysis. The Rhode Island BioBank at Brown University (RIBB) thoroughly evaluated the performance of an original technology that minimizes a sample's exposure to freeze/thaw cycling by enabling the automated extraction of frozen aliquots from one single frozen parent sample without thawing it. A technology that eliminates unnecessary sample exposures to freeze/thaw cycles could help protect sample integrity, extend its useful life, and effectively rectify and eliminate the aforementioned need to compromise. This report presents the results of the evaluation, and conclusively demonstrates the technology's ability to extract multiple uniform frozen aliquots from a single cryotube of never-thawed frozen human plasma, which faithfully represent the parent sample when analyzed for typical biochemical analytes, showing a coefficient of variability lower than 5.5%.

  7. The electrical breakdown strength of pre-stretched elastomers, with and without sample volume conservation

    DEFF Research Database (Denmark)

    Zakaria, Shamsul Bin; Morshuis, Peter H. F.; Yahia, Benslimane Mohamed;

    2015-01-01

    strength of polydimethylsiloxane (PDMS) elastomers. Breakdown strength was determined for samples with and without volume conservation and was found to depend strongly on the stretch ratio and the thickness of thesamples. PDMS elastomers are shown to increase breakdown strength by a factor of ∼3 when...

  8. Independent assessment of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) sample preparation quality: A novel statistical approach for quality scoring.

    Science.gov (United States)

    Kooijman, Pieter C; Kok, Sander J; Weusten, Jos J A M; Honing, Maarten

    2016-05-05

    Preparation of samples according to an optimized method is crucial for accurate determination of polymer sample characteristics by Matrix-Assisted Laser Desorption Ionization (MALDI) analysis. Sample preparation conditions such as matrix choice, cationization agent, deposition technique or even the deposition volume should be chosen to suit the sample of interest. Many sample preparation protocols have been developed and employed, yet finding the optimal sample preparation protocol remains a challenge. Because an objective comparison between the results of diverse protocols is not possible, "gut-feeling" or "good enough" is often decisive in the search for an optimum. This implies that sub-optimal protocols are used, leading to a loss of mass spectral information quality. To address this problem a novel analytical strategy based on MALDI imaging and statistical data processing was developed in which eight parameters were formulated to objectively quantify the quality of sample deposition and optimal MALDI matrix composition and finally sum up to an overall quality score of the sample deposition. These parameters can be established in a fully automated way using commercially available mass spectrometry imaging instruments without any hardware adjustments. With the newly developed analytical strategy the highest quality MALDI spots were selected, resulting in more reproducible and more valuable spectra for PEG in a variety of matrices. Moreover, our method enables an objective comparison of sample preparation protocols for any analyte and opens up new fields of investigation by presenting MALDI performance data in a clear and concise way.

  9. Sample preparation for thermo-gravimetric determination and thermo-gravimetric characterization of refuse derived fuel.

    Science.gov (United States)

    Robinson, T; Bronson, B; Gogolek, P; Mehrani, P

    2016-02-01

    Thermo-gravimetric analysis (TGA) is a useful method for characterizing fuels. In the past it has been applied to the study of refuse derived fuel (RDF) and related materials. However, the heterogeneity of RDF makes the preparation of small representative samples very difficult and this difficulty has limited the effectiveness of TGA for characterization of RDF. A TGA method was applied to a variety of materials prepared from a commercially available RDF using a variety of procedures. Applicability of TGA method to the determination of the renewable content of RDF was considered. Cryogenic ball milling was found to be an effective means of preparing RDF samples for TGA. When combined with an effective sample preparation, TGA could be used as an alternative method for assessing the renewable content of RDF.

  10. Expanding the application of the tablet processing workstation to support the sample preparation of oral suspensions.

    Science.gov (United States)

    Opio, Alex Manuel; Nickerson, Beverly; Xue, Gang; Warzeka, John; Norris, Ken

    2011-06-01

    Sample preparation is the most time-consuming part of the analytical method for powder for oral suspension (POS) assay, purity, and preservative analysis, as this involves multiple dilution and filtration steps. The Tablet Processing Workstation (TPW) was used to automate the sample preparation of a POS formulation. Although the TPW is typically used to automate the preparation of solid oral dosage forms and powders, it contains all of the necessary components to perform POS sample preparation. The TPW exhibited acceptable repeatability in testing 3 lots using 10 replicate preparations per lot. Acceptable linearity of the drug and preservative in the presence of excipients was demonstrated over the range corresponding to 50-150% of intent. Accuracy showed suitable recoveries for all points evaluated. TPW results were shown to correlate to results obtained with the manual method. The TPW method was used to prepare samples in support of manufacturing scale-up efforts. With the efficiencies gained using the TPW, it was possible to analyze a large number of samples generated during process development activities for the POS formulation with minimal human intervention. The extensive data enabled trending of the manufacturing development runs and helped to identify optimization strategies for the process.

  11. Cytotoxicity of Light-Cured Dental Materials according to Different Sample Preparation Methods

    Science.gov (United States)

    Lee, Myung-Jin; Kim, Mi-Joo; Kwon, Jae-Sung; Lee, Sang-Bae; Kim, Kwang-Mahn

    2017-01-01

    Dental light-cured resins can undergo different degrees of polymerization when applied in vivo. When polymerization is incomplete, toxic monomers may be released into the oral cavity. The present study assessed the cytotoxicity of different materials, using sample preparation methods that mirror clinical conditions. Composite and bonding resins were used and divided into four groups according to sample preparation method: uncured; directly cured samples, which were cured after being placed on solidified agar; post-cured samples were polymerized before being placed on agar; and “removed unreacted layer” samples had their oxygen-inhibition layer removed after polymerization. Cytotoxicity was evaluated using an agar diffusion test, MTT assay, and confocal microscopy. Uncured samples were the most cytotoxic, while removed unreacted layer samples were the least cytotoxic (p cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility. PMID:28772647

  12. Preparation and characterization of microporous fibers for sample preparation and LC-MS determination of drugs.

    Science.gov (United States)

    Buszewski, Boguslaw; Nowaczyk, Jacek; Ligor, Tomasz; Olszowy, Pawel; Ligor, Magdalena; Wasiniak, Bartlomiej; Miekisch, Wolfram; Schubert, Jochen K; Amann, Anton

    2009-07-01

    The aim of this study was the preparation of polypyrrole (PPy) fibers for solid phase microextraction (SPME). PPy coatings were obtained during the electrochemical polymerization process. The utility of various metal wires (Fe, Cu, Ag, Cu/Ag, kanthal and medical stainless steel) as a support for polymers was compared. Various experimental conditions of the synthesis process such as scan rate, voltage limits and number of scans and deposition time were applied. The average polymer thickness was in the range of 7-125 microm and its weight was in the scope of 0.65-5.6 mg. Different techniques, mainly elemental analysis, Fourier transform infrared spectroscopy, microscopy, and chromatography were performed for the characterization of obtained fibers with microporous structure. The extraction efficiency of cardiovascular drugs (metoprolol, propranolol, oxprenolol, propafenone and mexiletine) by means of fibers was tested. The concentration of mentioned compounds in standard solution was in the span of 10-150 ng/mL. LC-MS was employed for determination of drugs in desorption solution. LODs varied from 0.013 to 1.51 ng/mL for metoprolol and mexiletine respectively. The repeatability of extraction was obtained with the RSD values lower than 10%.

  13. Determination of air-loop volume and radon partition coefficient for measuring radon in water sample.

    Science.gov (United States)

    Lee, Kil Yong; Burnett, William C

    A simple method for the direct determination of the air-loop volume in a RAD7 system as well as the radon partition coefficient was developed allowing for an accurate measurement of the radon activity in any type of water. The air-loop volume may be measured directly using an external radon source and an empty bottle with a precisely measured volume. The partition coefficient and activity of radon in the water sample may then be determined via the RAD7 using the determined air-loop volume. Activity ratios instead of absolute activities were used to measure the air-loop volume and the radon partition coefficient. In order to verify this approach, we measured the radon partition coefficient in deionized water in the temperature range of 10-30 °C and compared the values to those calculated from the well-known Weigel equation. The results were within 5 % variance throughout the temperature range. We also applied the approach for measurement of the radon partition coefficient in synthetic saline water (0-75 ppt salinity) as well as tap water. The radon activity of the tap water sample was determined by this method as well as the standard RAD-H2O and BigBottle RAD-H2O. The results have shown good agreement between this method and the standard methods.

  14. Reducing Spatial Heterogeneity of MALDI Samples with Marangoni Flows During Sample Preparation

    Science.gov (United States)

    Lai, Yin-Hung; Cai, Yi-Hong; Lee, Hsun; Ou, Yu-Meng; Hsiao, Chih-Hao; Tsao, Chien-Wei; Chang, Huan-Tsung; Wang, Yi-Sheng

    2016-08-01

    This work demonstrates a method to prepare homogeneous distributions of analytes to improve data reproducibility in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). Natural-air drying processes normally result in unwanted heterogeneous spatial distributions of analytes in MALDI crystals and make quantitative analysis difficult. This study demonstrates that inducing Marangoni flows within drying droplets can significantly reduce the heterogeneity problem. The Marangoni flows are accelerated by changing substrate temperatures to create temperature gradients across droplets. Such hydrodynamic flows are analyzed semi-empirically. Using imaging mass spectrometry, changes of heterogeneity of molecules with the change of substrate temperature during drying processes are demonstrated. The observed heterogeneities of the biomolecules reduce as predicted Marangoni velocities increase. In comparison to conventional methods, drying droplets on a 5 °C substrate while keeping the surroundings at ambient conditions typically reduces the heterogeneity of biomolecular ions by 65%-80%. The observation suggests that decreasing substrate temperature during droplet drying processes is a simple and effective means to reduce analyte heterogeneity for quantitative applications.

  15. Study of special performance and volume training loadings at swimmers in the year preparation

    Directory of Open Access Journals (Sweden)

    Balamutova N.M.

    2014-01-01

    Full Text Available Purpose : to study the dynamics of the special performance and volume of training load during annual training swimmers. Material / Methods : The study involved 14 teams of students of Kharkiv universities. All swimmers are of high qualification. Motor tests of special performance swimmers, functional tests were used to confirm the effectiveness of the training process. Results : The dynamics of special performance indicators and volume of training load of highly qualified swimmers in the annual cycle of training. Determined part of aerobic (58.3 %, aerobic- anaerobic special (34.5%, anaerobic- glycolytic (5.5%, anaerobic- alactate (1.7% loadings in the direction of total training load for the academic year. Conclusions : In preparing swimmers stayer is the most appropriate single-cycle construction of the annual cycle, and for swimmers, sprinters should be based on two-cycle version of the load distribution.

  16. Low-cost preparation of mesoporous silica with high pore volume

    Institute of Scientific and Technical Information of China (English)

    Shuling Shen; Wei Wu; Kai Guo; Jianfeng Chen

    2007-01-01

    Mesoporous silica materials with high pore volume were successfully prepared by the chemical precipitation method, with water glass and a biodegradable nonionic surfactant polyethylene glycol (PEG). The obtained materials were characterized by transmission electron microscopy (TEM), scanning electron microscopy (SEM), thermo gravimetric analyzer and differential scanning calorimetry (TG-DSC), nitrogen adsorption-desorption measurements, and X-ray diffraction (XRD). The results showed that the changes of the pore parameters depended on both the surfactant content and heat treatment temperature. When the content of PEG was 10wt% and the obtained PEG/SiO2 composite was heated at 600℃, the mesoporous silica with a pore volume of 2.2 cm3/g, a BET specific surface area of 361.55 m2/g, and a diameter of 2-4 μm could be obtained. The obtained mesoporous silica materials have potential applications in the fields of paint and plastic, as thickening, reinforcing, and flatting agents.

  17. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    Science.gov (United States)

    van der Sterre, Boy-Santhos; Hut, Rolf; van de Giesen, Nick

    2013-04-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the 150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  18. Repeating cytological preparations on liquid-based cytology samples: A methodological advantage?

    Science.gov (United States)

    Pinto, Alvaro P; Maia, Henrique Felde; di Loretto, Celso; Krunn, Patrícia; Túlio, Siumara; Collaço, Luis Martins

    2007-10-01

    This study investigates the rule that repeating cytological preparations on liquid-based cytology improves sample adequacy, diagnosis, microbiological, and hormonal evaluations. We reviewed 156 cases of pap-stained preparations of exfoliated cervical cells in two slides processed by DNA-Cytoliq System. After sample repeat/dilution, limiting factors affecting sample adequacy were removed in nine cases and three unsatisfactory cases were reclassified as satisfactory. Diagnosis was altered in 24 cases. Of these, the original diagnosis in 15 was atypical squamous cells of undetermined significance; after the second slide examination, diagnosis in 5 of the 15 cases changed to low-grade squamous intraepithelial lesion, 3 to high-grade squamous intraepithelial lesion, and 7 to absence of lesion. Microbiological evaluation was altered, with Candida sp. detected in two repeated slides. Repeat slide preparation or dilution of residual samples enhances cytological diagnosis and decreases effects of limiting factors in manually processed DIGENE DCS LBC.

  19. Gamut Volume Index: a color preference metric based on meta-analysis and optimized colour samples.

    Science.gov (United States)

    Liu, Qiang; Huang, Zheng; Xiao, Kaida; Pointer, Michael R; Westland, Stephen; Luo, M Ronnier

    2017-07-10

    A novel metric named Gamut Volume Index (GVI) is proposed for evaluating the colour preference of lighting. This metric is based on the absolute gamut volume of optimized colour samples. The optimal colour set of the proposed metric was obtained by optimizing the weighted average correlation between the metric predictions and the subjective ratings for 8 psychophysical studies. The performance of 20 typical colour metrics was also investigated, which included colour difference based metrics, gamut based metrics, memory based metrics as well as combined metrics. It was found that the proposed GVI outperformed the existing counterparts, especially for the conditions where correlated colour temperatures differed.

  20. Development of a high vacuum sample preparation system for helium mass spectrometer

    Science.gov (United States)

    Kumar, P.; Das, N. K.; Mallik, C.; Bhandari, R. K.

    2012-11-01

    A high vacuum sample preparation system for the 3He/4He ratio mass spectrometer (Helix SFT) has been developed to remove all the gaseous constituents excluding helium from the field gases. The sample preparation system comprises of turbo molecular pump, ion pump, zirconium getter, pipettes and vacuum gauges with controller. All these are fitted with cylindrical SS chamber using all metal valves. The field samples are initially treated with activated charcoal trap immersed in liquid nitrogen to cutoff major impurities and moisture present in the sample gas. A sample of 5 ml is collected out of this stage at a pressure of 10-2 mbar. This sample is subsequently purified at a reduced pressure of 10-7 mbar before it is injected into the ion source of the mass spectrometer. The sample pressure was maintained below 10-7 mbar with turbo molecular vacuum pumps and ion pumps. The sample gas passes through several getter elements and a cold finger with the help of manual high vacuum valves before it is fed to the mass spectrometer. Thus the high vacuum sample preparation system introduces completely clean, dry and refined helium sample to the mass spectrometer for best possible analysis of isotopic ratio of helium.

  1. Electromembrane extraction as a rapid and selective miniaturized sample preparation technique for biological fluids

    DEFF Research Database (Denmark)

    Gjelstad, Astrid; Pedersen-Bjergaard, Stig; Seip, Knut Fredrik

    2015-01-01

    This special report discusses the sample preparation method electromembrane extraction, which was introduced in 2006 as a rapid and selective miniaturized extraction method. The extraction principle is based on isolation of charged analytes extracted from an aqueous sample, across a thin film....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  2. TruSeq Stranded mRNA and Total RNA Sample Preparation Kits

    Science.gov (United States)

    Total RNA-Seq enabled by ribosomal RNA (rRNA) reduction is compatible with formalin-fixed paraffin embedded (FFPE) samples, which contain potentially critical biological information. The family of TruSeq Stranded Total RNA sample preparation kits provides a unique combination of unmatched data quality for both mRNA and whole-transcriptome analyses, robust interrogation of both standard and low-quality samples and workflows compatible with a wide range of study designs.

  3. Recovery of Salmonella from internally and externally contaminated whole tomatoes using several different sample preparation procedures.

    Science.gov (United States)

    Wang, Hua; Gill, Vikas S; Irvin, Kari A; Byrd, Mindi; Bolger, Cathryn M; Zheng, Jie; Dickey, Erin E; Duvall, Robert E; Jacobson, Andrew P; Hammack, Thomas S

    2012-01-01

    Studies were conducted to determine the relative effectiveness of whole soak [current Bacteriological Analytical Manual-(BAM) Salmonella method], quarter, stomach, and blend methods for the recovery of Salmonella organisms from internally and externally contaminated tomatoes. Tomatoes were subjected to three inoculation methods: surface inoculation, internal inoculation by injection, and immersion with single Salmonella serovars. The inoculation levels ranged from 1 to 100 CFU/tomato for surface and injection inoculation or 1 to 100 CFU/mL for immersion inoculation. Tomatoes were held for 3 days after inoculation at 2-6 degrees C prior to initiation of analysis. Contaminated tomatoes were soaked, quartered, stomached, and blended in appropriate portions of Universal Pre-enrichment broth, and incubated for 24 h at 35 +/- 2 degrees C. The BAM Salmonella culture method was followed thereafter, and tomatoes were treated as a low-microbial-load food. The stomaching procedure was significantly (P < 0.05) more effective than the whole soak procedure for recovery of internalized Salmonella from tomatoes (by injection). The blending procedure was arithmetically superior to the stomaching procedure for detection of internalized Salmonella from tomatoes (by immersion). The blending procedure showed the same effectiveness as the whole soak procedure for the detection of Salmonella on tomato surfaces. Comparisons between test portion-to-broth ratios (weight to volume) showed that a 1:3 test portion-to-broth ratio had a better buffering capacity for blended tomatoes than a 1:1 test portion-to-broth ratio. It is recommended that the current whole soak BAM tomato sample preparation procedure be replaced with a blending procedure and a 1:3 test portion-to-broth ratio.

  4. [Preparation technique of S2OF10 gas standard sample and determination method of the trace S2OF10 in SF6].

    Science.gov (United States)

    Wang, L; Wang, J

    1999-09-01

    In this paper a series of methods and techniques for the S2OF10 standard sample preparation and quantitative determination are presented. They are, the preparation of S2OF10 by preparative chromatography with adsorption/thermal desorption, the standard sample of S2OF10 gas prepared by exponential dilution and the gas chromatography/flame photometric detector(GC/FPD) determination of trace S2OF10 from an SF6 sample with quantitative calibration factor. Especially, the S2OF10 gas from a used SF6 sample was directly separated and concentrated through a U-adsorbent-tube packed with 300 mg of Porasil A in a cold trap (-63 degrees C) with liquid-nitrogen and chloroform. Then it was purified by preparative-GC and to be injected into a preparative system of standard gas sample. In the meantime, the S2OF10 gas obtained was confirmed by the methods of GC/FPD, infrared spectrophotometer(IR) and gas chromatography/mass spectrometer(GC/MS) separately. The sub-ppm(by volume) level of the S2OF10 and SF6 mixture samples were prepared by use of the exponential dilution system. The GC/FPD experimental results showed that the detection linear range of S2OF10 gas concentration was 0.80 x 10(-6)-2.60 x 10(-4) (volume fraction) and the quantitative calibration factor of the S2OF10 was 0.197 based on SF6. The determination errors of quantitative calibration factor were 1.8%-20% and S2OF10 recovery of the adsorption/thermal desorption was 98.2% (n = 9) and its relative standard deviation was 6.2%. In addition, the results also showed that it is a simple and rapid method with good linearity and reproducibility.

  5. High-throughput automated microfluidic sample preparation for accurate microbial genomics

    Science.gov (United States)

    Kim, Soohong; De Jonghe, Joachim; Kulesa, Anthony B.; Feldman, David; Vatanen, Tommi; Bhattacharyya, Roby P.; Berdy, Brittany; Gomez, James; Nolan, Jill; Epstein, Slava; Blainey, Paul C.

    2017-01-01

    Low-cost shotgun DNA sequencing is transforming the microbial sciences. Sequencing instruments are so effective that sample preparation is now the key limiting factor. Here, we introduce a microfluidic sample preparation platform that integrates the key steps in cells to sequence library sample preparation for up to 96 samples and reduces DNA input requirements 100-fold while maintaining or improving data quality. The general-purpose microarchitecture we demonstrate supports workflows with arbitrary numbers of reaction and clean-up or capture steps. By reducing the sample quantity requirements, we enabled low-input (∼10,000 cells) whole-genome shotgun (WGS) sequencing of Mycobacterium tuberculosis and soil micro-colonies with superior results. We also leveraged the enhanced throughput to sequence ∼400 clinical Pseudomonas aeruginosa libraries and demonstrate excellent single-nucleotide polymorphism detection performance that explained phenotypically observed antibiotic resistance. Fully-integrated lab-on-chip sample preparation overcomes technical barriers to enable broader deployment of genomics across many basic research and translational applications. PMID:28128213

  6. Reliable measurements for an image-derived sample volume in an open-configuration MR system

    Science.gov (United States)

    Han, Bong Soo; Lee, Man Woo; Hong, Cheolpyo

    2016-11-01

    Open-configuration magnetic resonance (MR) systems are becoming desirable for volume measurements of off-center samples due to their non-claustrophobic system configuration, excellent soft-tissue contrast, high efficiency, and low-cost. However, geometric distortion is produced by the unwanted background magnetic field and hinders volume measurements. The present study describes the characteristics of geometric distortion in off-center samples such as the thigh muscle and adipose tissue measurements using an open-type MR system. The American Association of Physicists in Medicine uniformity and linearity phantom was used for the detection and the evaluation of the geometric distortion. The geometric distortion decreased near the isocenter and increased toward the off-center. A cylindrical phantom image was acquired at the isocenter and was used as the distortion-free, reference image. Two cylindrical phantoms were scanned off-center at a position analogous to that of the human thigh. The differences between the two cylindrical phantom volumes and the reference volume were 1.62 % ± 0.16 and 5.18 % ± 0.14. Off-center-related MR imaging requires careful consideration for image interpretation and volumetric assessment of tissue.

  7. A proteomics sample preparation method for mature, recalcitrant leaves of perennial plants.

    Directory of Open Access Journals (Sweden)

    Deng Gang

    Full Text Available Sample preparation is key to the success of proteomics studies. In the present study, two sample preparation methods were tested for their suitability on the mature, recalcitrant leaves of six representative perennial plants (grape, plum, pear, peach, orange, and ramie. An improved sample preparation method was obtained: Tris and Triton X-100 were added together instead of CHAPS to the lysis buffer, and a 20% TCA-water solution and 100% precooled acetone were added after the protein extraction for the further purification of protein. This method effectively eliminates nonprotein impurities and obtains a clear two-dimensional gel electrophoresis array. The method facilitates the separation of high-molecular-weight proteins and increases the resolution of low-abundance proteins. This method provides a widely applicable and economically feasible technology for the proteomic study of the mature, recalcitrant leaves of perennial plants.

  8. LC-MS analysis of the plasma metabolome–a novel sample preparation strategy

    DEFF Research Database (Denmark)

    Skov, Kasper; Hadrup, Niels; Smedsgaard, Jørn

    2015-01-01

    of plasma samples: The first is protein precipitation; the second is protein precipitation followed by solid phase extraction with sub-fractionation into three sub-samples; a phospholipid, a lipid and a polar sub-fraction. Molecular feature extraction of the data files from LC-qTOF analysis of the samples......Blood plasma is a well-known body fluid often analyzed in studies on the effects of toxic compounds as physiological or chemical induced changes in the mammalian body are reflected in the plasma metabolome. Sample preparation prior to LC-MS based analysis of the plasma metabolome is a challenge...... as plasma contains compounds with very different properties. Besides, proteins, which usually are precipitated with organic solvent, phospholipids, are known to cause ion suppression in electrospray mass spectrometry. We have compared two different sample preparation techniques prior to LC-qTOF analysis...

  9. Automatic coal sample preparation system%煤炭自动制样系统

    Institute of Scientific and Technical Information of China (English)

    王兴无

    2015-01-01

    To solve the problems occurred during manual coal sample preparation,such as low work efficien-cy,high labor intensity,poor working environment,harmful to human beings and poor representativeness of the sample due to large error,the auto coal sample preparation system was designed.Performance tests like residue sample mass,fuel size,residue sample precision and sample preparation bias verified this system has met the requirements of GB/T 1 9494.3-2004 and GB 474-2008 on precision and bias.Its application not only improves the automation degree of sample preparation,but also reduces human disturbance factors in the sample preparation process.%为了解决电厂燃煤人工制样存在的工作效率低,劳动强度大,工作环境差,有害人体健康,误差大影响样品的代表性等问题,设计了煤炭自动制样系统.通过留样质量、出料粒径、留样精密度及制样偏倚等性能试验,证明该系统精密度和偏倚达到了 GB 474—2008和 GB/T 19494.3—2004规定的要求,其应用提高了样品制备的自动化程度,减少了制样过程人为因素的干扰.

  10. Electric transport measurements on bulk, polycrystalline MgB2 samples prepared at various reaction temperatures

    Science.gov (United States)

    Wiederhold, A.; Koblischka, M. R.; Inoue, K.; Muralidhar, M.; Murakami, M.; Hartmann, U.

    2016-03-01

    A series of disk-shaped, bulk MgB2 superconductors (sample diameter up to 4 cm) was prepared in order to improve the performance for superconducting super-magnets. Several samples were fabricated using a solid state reaction in pure Ar atmosphere from 750 to 950oC in order to determine the optimum processing parameters to obtain the highest critical current density as well as large trapped field values. Additional samples were prepared with added silver (up to 10 wt.-%) to the Mg and B powder. Magneto-resistance data and I/V-characteristics were recorded using an Oxford Instruments Teslatron system. From Arrhenius plots, we determine the TAFF pinning potential, U 0. The I/V-characteristics yield detailed information on the current flow through the polycrystalline samples. The current flow is influenced by the presence of pores in the samples. Our analysis of the achieved critical currents together with a thorough microstructure investigation reveals that the samples prepared at temperatures between 775°C and 805°C exhibit the smallest grains and the best connectivity between them, while the samples fabricated at higher reaction temperatures show a reduced connectivity and lower pinning potential. Doping the samples with silver leads to a considerable increase of the pinning potential and hence, the critical current densities.

  11. [Sample preparation methods for chromatographic analysis of organic components in atmospheric particulate matter].

    Science.gov (United States)

    Hao, Liang; Wu, Dapeng; Guan, Yafeng

    2014-09-01

    The determination of organic composition in atmospheric particulate matter (PM) is of great importance in understanding how PM affects human health, environment, climate, and ecosystem. Organic components are also the scientific basis for emission source tracking, PM regulation and risk management. Therefore, the molecular characterization of the organic fraction of PM has become one of the priority research issues in the field of environmental analysis. Due to the extreme complexity of PM samples, chromatographic methods have been the chief selection. The common procedure for the analysis of organic components in PM includes several steps: sample collection on the fiber filters, sample preparation (transform the sample into a form suitable for chromatographic analysis), analysis by chromatographic methods. Among these steps, the sample preparation methods will largely determine the throughput and the data quality. Solvent extraction methods followed by sample pretreatment (e. g. pre-separation, derivatization, pre-concentration) have long been used for PM sample analysis, and thermal desorption methods have also mainly focused on the non-polar organic component analysis in PM. In this paper, the sample preparation methods prior to chromatographic analysis of organic components in PM are reviewed comprehensively, and the corresponding merits and limitations of each method are also briefly discussed.

  12. Automated sample preparation for radiogenic and non-traditional metal isotope analysis by MC-ICP-MS

    Science.gov (United States)

    Field, M. P.; Romaniello, S. J.; Gordon, G. W.; Anbar, A. D.

    2012-12-01

    High throughput analysis is becoming increasingly important for many applications of radiogenic and non-traditional metal isotopes. While MC-ICP-MS instruments offer the potential for very high sample throughout, the requirement for labor-intensive sample preparation and purification procedures remains a substantial bottleneck. Current purification protocols require manually feeding gravity-driven separation columns, a process that is both costly and time consuming. This bottleneck is eliminated with the prepFAST-MC™, an automated, low-pressure ion exchange chromatography system that can process from 1 to 60 samples in unattended operation. The syringe-driven system allows sample loading, multiple acid washes, column conditioning and elution cycles necessary to isolate elements of interest and automatically collect up to 3 discrete eluent fractions at user-defined intervals (time, volume and flow rate). Newly developed protocols for automated purification of uranium illustrates high throughput (>30 per run), multiple samples processed per column (>30), complete (>99%) matrix removal, high recovery (> 98%, n=25), and excellent precision (2 sigma =0.03 permil, n=10). The prepFAST-MC™ maximizes sample throughput and minimizes costs associated with personnel and consumables providing an opportunity to greatly expand research horizons in fields where large isotopic data sets are required, including archeology, geochemistry, and climate/environmental science

  13. Local Environmental Dependence of Galaxy Properties in a Volume-Limited Sample of Main Galaxies

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Using a volume-limited sample of Main Galaxies from SDSS Data Release 5, we investigate the dependence of galaxy properties on local environment. For each galaxy, a local three-dimensional density is calculated. We find that the galaxy morphological type depends strongly on the local environment: galaxies in dense environments have predominantly early type morphologies. Galaxy colors have only a weak dependence on the environment. This puts an important constraint on the process of galaxy formation.

  14. Molecularly imprinted polymers for sample preparation and biosensing in food analysis: Progress and perspectives

    DEFF Research Database (Denmark)

    Ashley, Jon; Shahbazi, Mohammad-Ali; Kant, Krishna

    2017-01-01

    Molecularly imprinted polymers (MIPs) are biomimetics which can selectively bind to analytes of interest. One of the most interesting areas where MIPs have shown the biggest potential is food analysis. MIPs have found use as sorbents in sample preparation attributed to the high selectivity and high...... the imprinting methods which are applicable for imprinting food templates, summarize the recent progress in using MIPs for preparing and analysing food samples, and discuss the current limitations in the commercialisation of MIPs technology. Finally, future perspectives will be given....

  15. Analysis of aroma compounds of Roselle by Dynamic Headspace Sampling using different preparation methods

    DEFF Research Database (Denmark)

    Juhari, Nurul Hanisah Binti; Varming, Camilla; Petersen, Mikael Agerlin

    2015-01-01

    The influence of different methods of sample preparation on the aroma profiles of dried Roselle (Hibiscus sabdariffa) was studied. Least amounts of aroma compounds were recovered by analysis of whole dry calyxes (WD) followed by ground dry (GD), blended together with water (BTW), and ground...... and then mixed with water (GMW). The highest number of aroma compounds was found in Roselle treated in water bath (2hr/40°C) (GMWKB). GMW was chosen as the preparation method because it was shown to be an efficient extraction method without the possibility of excessive chemical changes of the sample....

  16. HPLC analysis of oxindole alkaloids in Uncaria tomentosa: sample preparation and analysis optimisation by factorial design.

    Science.gov (United States)

    Bertol, Gustavo; Franco, Luzia; Oliveira, Brás Heleno de

    2012-01-01

    Uncaria tomentosa ("cat's claw") is widely used for the treatment of some infectious and inflammatory diseases. Oxindole alkaloids are regarded as the most important components responsible for the biological activities attributed to the plant. Their analysis require efficient sample preparation and suitable reference standards but few are commercially available. To develop and validate a HPLC analytical method for oxindole alkaloids in Uncaria tomentosa with emphasis on sample preparation. Factorial experimental designs were used for the optimisation of both sample preparation and chromatographic separation. The optimised sample preparation involved extraction with aqueous ethanol, and the granulometry of the powdered plant material significantly influenced extraction yields. Mitraphylline was used as a calibration reference for the determination of total alkaloids. The method was fully validated and showed good selectivity, linearity (r²  ≥ 0.9996), accuracy (≥ 96%) and precision (RSD < 2.4%). Detection and quantification limits for mitraphylline were 0.8 and 2.4 ppm, respectively. The optimised chromatographic method, using organic buffer in the mobile phase, provided baseline separation of tetracyclic and pentacyclic alkaloids in the samples. Calibration using mitraphylline provided more accurate estimates of total alkaloid content when compared to other available reference alkaloids. Copyright © 2011 John Wiley & Sons, Ltd.

  17. Automated Sample Preparation for Radiogenic and Non-Traditional Metal Isotopes: Removing an Analytical Barrier for High Sample Throughput

    Science.gov (United States)

    Field, M. Paul; Romaniello, Stephen; Gordon, Gwyneth W.; Anbar, Ariel D.; Herrmann, Achim; Martinez-Boti, Miguel A.; Anagnostou, Eleni; Foster, Gavin L.

    2014-05-01

    MC-ICP-MS has dramatically improved the analytical throughput for high-precision radiogenic and non-traditional isotope ratio measurements, compared to TIMS. The generation of large data sets, however, remains hampered by tedious manual drip chromatography required for sample purification. A new, automated chromatography system reduces the laboratory bottle neck and expands the utility of high-precision isotope analyses in applications where large data sets are required: geochemistry, forensic anthropology, nuclear forensics, medical research and food authentication. We have developed protocols to automate ion exchange purification for several isotopic systems (B, Ca, Fe, Cu, Zn, Sr, Cd, Pb and U) using the new prepFAST-MC™ (ESI, Nebraska, Omaha). The system is not only inert (all-flouropolymer flow paths), but is also very flexible and can easily facilitate different resins, samples, and reagent types. When programmed, precise and accurate user defined volumes and flow rates are implemented to automatically load samples, wash the column, condition the column and elute fractions. Unattended, the automated, low-pressure ion exchange chromatography system can process up to 60 samples overnight. Excellent reproducibility, reliability, recovery, with low blank and carry over for samples in a variety of different matrices, have been demonstrated to give accurate and precise isotopic ratios within analytical error for several isotopic systems (B, Ca, Fe, Cu, Zn, Sr, Cd, Pb and U). This illustrates the potential of the new prepFAST-MC™ (ESI, Nebraska, Omaha) as a powerful tool in radiogenic and non-traditional isotope research.

  18. Ultimate detectability of volatile organic compounds: how much further can we reduce their ambient air sample volumes for analysis?

    Science.gov (United States)

    Kim, Yong-Hyun; Kim, Ki-Hyun

    2012-10-02

    To understand the ultimately lowest detection range of volatile organic compounds (VOCs) in air, application of a high sensitivity analytical system was investigated by coupling thermal desorption (TD) technique with gas chromatography (GC) and time-of-flight (TOF) mass spectrometry (MS). The performance of the TD-GC/TOF MS system was evaluated using liquid standards of 19 target VOCs prepared in the range of 35 pg to 2.79 ng per μL. Studies were carried out using both total ion chromatogram (TIC) and extracted ion chromatogram (EIC) mode. EIC mode was used for calibration to reduce background and to improve signal-to-noise. The detectability of 19 target VOCs, if assessed in terms of method detection limit (MDL, per US EPA definition) and limit of detection (LOD), averaged 5.90 pg and 0.122 pg, respectively, with the mean coefficient of correlation (R(2)) of 0.9975. The minimum quantifiable mass of target analytes, when determined using real air samples by the TD-GC/TOF MS, is highly comparable to the detection limits determined experimentally by standard. In fact, volumes for the actual detection of the major aromatic VOCs like benzene, toluene, and xylene (BTX) in ambient air samples were as low as 1.0 mL in the 0.11-2.25 ppb range. It was thus possible to demonstrate that most target compounds including those in low abundance could be reliably quantified at concentrations down to 0.1 ppb at sample volumes of less than 10 mL. The unique sensitivity of this advanced analytical system can ultimately lead to a shift in field sampling strategy with smaller air sample volumes facilitating faster, simpler air sampling (e.g., use of gas syringes rather than the relative complexity of pumps or bags/canisters), with greatly reduced risk of analyte breakthrough and minimal interference, e.g., from atmospheric humidity. The improved detection limits offered by this system can also enhance accuracy and measurement precision.

  19. Rotation-translation device for condensed-phase spectroscopy with small sample volumes

    Science.gov (United States)

    Nuernberger, Patrick; Krampert, Gerhard; Brixner, Tobias; Vogt, Gerhard

    2006-08-01

    We present and characterize an experimental device for optical spectroscopy with small sample volumes contained in a thin film. Employing rotational and translational motion, the sample transport speeds are high enough to offer a new sample volume for each interaction in time-resolved spectroscopy experiments working with a 1kHz repetition rate. This is especially suited for ultrafast femtosecond spectroscopy such as transient absorption spectroscopy or fluorescence upconversion. To reduce photodegradation and effects from local thermal heating, a large sample area is scanned in contrast to conventional devices with either only rotation or translation movements. For characterization of the setup, transient absorption experiments are carried out using the rotation-translation device and a conventional flow-cell setup, which exhibit similar signal-to-noise ratio in the two cases. The effects of photodegradation and diffusion are also investigated, demonstrating the suitability of the device for time-resolved spectroscopic experiments. The transient absorption data show that the setup is well suited for biomolecular samples, which are often only available in small amounts and are very sensitive to thermal heating.

  20. Instrument and method for X-ray diffraction, fluorescence, and crystal texture analysis without sample preparation

    Science.gov (United States)

    Gendreau, Keith (Inventor); Martins, Jose Vanderlei (Inventor); Arzoumanian, Zaven (Inventor)

    2010-01-01

    An X-ray diffraction and X-ray fluorescence instrument for analyzing samples having no sample preparation includes a X-ray source configured to output a collimated X-ray beam comprising a continuum spectrum of X-rays to a predetermined coordinate and a photon-counting X-ray imaging spectrometer disposed to receive X-rays output from an unprepared sample disposed at the predetermined coordinate upon exposure of the unprepared sample to the collimated X-ray beam. The X-ray source and the photon-counting X-ray imaging spectrometer are arranged in a reflection geometry relative to the predetermined coordinate.

  1. Validation of a fully automated robotic setup for preparation of whole blood samples for LC-MS toxicology analysis

    DEFF Research Database (Denmark)

    Andersen, David Wederkinck; Rasmussen, Brian; Linnet, Kristian

    2012-01-01

    A fully automated setup was developed for preparing whole blood samples using a Tecan Evo workstation. By integrating several add-ons to the robotic platform, the flexible setup was able to prepare samples from sample tubes to a 96-well sample plate ready for injection on liquid chromatography...

  2. Recent advances in sample preparation techniques and methods of sulfonamides detection - A review.

    Science.gov (United States)

    Dmitrienko, Stanislava G; Kochuk, Elena V; Apyari, Vladimir V; Tolmacheva, Veronika V; Zolotov, Yury A

    2014-11-19

    Sulfonamides (SAs) have been the most widely used antimicrobial drugs for more than 70 years, and their residues in foodstuffs and environmental samples pose serious health hazards. For this reason, sensitive and specific methods for the quantification of these compounds in numerous matrices have been developed. This review intends to provide an updated overview of the recent trends over the past five years in sample preparation techniques and methods for detecting SAs. Examples of the sample preparation techniques, including liquid-liquid and solid-phase extraction, dispersive liquid-liquid microextraction and QuEChERS, are given. Different methods of detecting the SAs present in food and feed and in environmental, pharmaceutical and biological samples are discussed.

  3. Influence of Sample Volume and Solvent Evaporation on Absorbance Spectroscopy in a Microfluidic "Pillar-Cuvette".

    Science.gov (United States)

    Kriel, Frederik H; Priest, Craig

    2016-01-01

    Spectroscopic analysis of solutions containing samples at high concentrations or molar absorptivity can present practical challenges. In absorbance spectroscopy, short optical path lengths or multiple dilution is required to bring the measured absorbance into the range of the Beer's Law calibration. We have previously reported an open "pillar-cuvette" with a micropillar array that is spontaneously filled with a precise (nL or μL) volume to create the well-defined optical path of, for example, 10 to 20 μm. Evaporation should not be ignored for open cuvettes and, herein, the volume of loaded sample and the rate of evaporation from the cuvette are studied. It was found that the volume of loaded sample (between 1 and 10 μL) had no effect on the Beer's Law calibration for methyl orange solutions (molar absorptivity of (2.42 ± 0.02)× 10(4) L mol(-1) cm(-1)) for cuvettes with a 14.2 ± 0.2 μm path length. Evaporation rates of water from methyl orange solutions were between 2 and 5 nL s(-1) (30 - 40% relative humidity; 23°C), depending on the sample concentration and ambient conditions. Evaporation could be reduced by placing a cover slip several millimeters above the cuvette. Importantly, the results show that a "drop-and-measure" method (measurement within ∼3 s of cuvette loading) eliminates the need for extrapolation of the absorbance-time data for accurate analysis of samples.

  4. Author Contribution to the Pu Handbook II: Chapter 37 LLNL Integrated Sample Preparation Glovebox (TEM) Section

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Mark A. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2016-10-25

    The development of our Integrated Actinide Sample Preparation Laboratory (IASPL) commenced in 1998 driven by the need to perform transmission electron microscopy studies on naturally aged plutonium and it’s alloys looking for the microstructural effects of the radiological decay process (1). Remodeling and construction of a laboratory within the Chemistry and Materials Science Directorate facilities at LLNL was required to turn a standard radiological laboratory into a Radiological Materials Area (RMA) and Radiological Buffer Area (RBA) containing type I, II and III workplaces. Two inert atmosphere dry-train glove boxes with antechambers and entry/exit fumehoods (Figure 1), having a baseline atmosphere of 1 ppm oxygen and 1 ppm water vapor, a utility fumehood and a portable, and a third double-walled enclosure have been installed and commissioned. These capabilities, along with highly trained technical staff, facilitate the safe operation of sample preparation processes and instrumentation, and sample handling while minimizing oxidation or corrosion of the plutonium. In addition, we are currently developing the capability to safely transfer small metallographically prepared samples to a mini-SEM for microstructural imaging and chemical analysis. The gloveboxes continue to be the most crucial element of the laboratory allowing nearly oxide-free sample preparation for a wide variety of LLNL-based characterization experiments, which includes transmission electron microscopy, electron energy loss spectroscopy, optical microscopy, electrical resistivity, ion implantation, X-ray diffraction and absorption, magnetometry, metrological surface measurements, highpressure diamond anvil cell equation-of-state, phonon dispersion measurements, X-ray absorption and emission spectroscopy, and differential scanning calorimetry. The sample preparation and materials processing capabilities in the IASPL have also facilitated experimentation at world-class facilities such as the

  5. Preparing to Receive and Handle Martian Samples When They Arrive on Earth

    Science.gov (United States)

    McCubbin, Francis M.

    2017-01-01

    The Astromaterials Acquisition and Curation Office at NASA Johnson Space Center (JSC) is responsible for curating all of NASA's extraterrestrial samples. Under the governing document, NASA Policy Directive (NPD) 7100.10F+ derivative NPR 'Curation of Extraterrestrial Materials', JSC is charged with 'The curation of all extraterrestrial material under NASA control, including future NASA missions. 'The Directive goes on to define Curation as including'...documentation, preservation, preparation, and distribution of samples for research, education, and public outreach."

  6. Comparison of estimates of hardwood bole volume using importance sampling, the centroid method, and some taper equations

    Science.gov (United States)

    Harry V., Jr. Wiant; Michael L. Spangler; John E. Baumgras

    2002-01-01

    Various taper systems and the centroid method were compared to unbiased volume estimates made by importance sampling for 720 hardwood trees selected throughout the state of West Virginia. Only the centroid method consistently gave volumes estimates that did not differ significantly from those made by importance sampling, although some taper equations did well for most...

  7. Optimization of sample preparation for accurate results in quantitative NMR spectroscopy

    Science.gov (United States)

    Yamazaki, Taichi; Nakamura, Satoe; Saito, Takeshi

    2017-04-01

    Quantitative nuclear magnetic resonance (qNMR) spectroscopy has received high marks as an excellent measurement tool that does not require the same reference standard as the analyte. Measurement parameters have been discussed in detail and high-resolution balances have been used for sample preparation. However, the high-resolution balances, such as an ultra-microbalance, are not general-purpose analytical tools and many analysts may find those balances difficult to use, thereby hindering accurate sample preparation for qNMR measurement. In this study, we examined the relationship between the resolution of the balance and the amount of sample weighed during sample preparation. We were able to confirm the accuracy of the assay results for samples weighed on a high-resolution balance, such as the ultra-microbalance. Furthermore, when an appropriate tare and amount of sample was weighed on a given balance, accurate assay results were obtained with another high-resolution balance. Although this is a fundamental result, it offers important evidence that would enhance the versatility of the qNMR method.

  8. Soil and Water – What is Detectable through Microbiological Sample Preparation Techniques

    Science.gov (United States)

    The concerns of a potential terrorist’s use of biological agents in soil and ground water are articulated by comparisons to major illnesses in this Country involving contaminated drinking water sources. Objectives are focused on the importance of sample preparation in the rapid, ...

  9. Analysis of biopharmaceutical proteins in biological matrices by LC-MS/MS I. Sample preparation

    NARCIS (Netherlands)

    Bischoff, Rainer; Bronsema, Kees J.; van de Merbel, Nico C.

    2013-01-01

    Part I of this review discusses sample-preparation aspects of quantifying biopharmaceutical proteins in complex biological matrices by LC-MS/MS with a focus on blood-derived body fluids. We conclude Part I with a short overview over options for automating the entire analytical procedure, which is

  10. Analysis of biopharmaceutical proteins in biological matrices by LC-MS/MS I. Sample preparation

    NARCIS (Netherlands)

    Bischoff, Rainer; Bronsema, Kees J.; van de Merbel, Nico C.

    2013-01-01

    Part I of this review discusses sample-preparation aspects of quantifying biopharmaceutical proteins in complex biological matrices by LC-MS/MS with a focus on blood-derived body fluids. We conclude Part I with a short overview over options for automating the entire analytical procedure, which is in

  11. Challenges of sample preparation for cross sectional EBSD analysis of electrodeposited nickel films

    DEFF Research Database (Denmark)

    Alimadadi, Hossein; Pantleon, Karen

    2009-01-01

    . Different procedures for sample preparation including mechanical grinding and polishing, electropolishing and focused ion beam milling have been applied to a nickel film electrodeposited on top of an amorphous Ni-P layer on a Cu-substrate. Reliable EBSD analysis of the whole cross section can be obtained...

  12. Standardized Sample Preparation Using a Drop-on-Demand Printing Platform

    Directory of Open Access Journals (Sweden)

    Paul M. Pellegrino

    2013-05-01

    Full Text Available Hazard detection systems must be evaluated with appropriate test material concentrations under controlled conditions in order to accurately identify and quantify unknown residues commonly utilized in theater. The existing assortment of hazard reference sample preparation methods/techniques presents a range of variability and reproducibility concerns, making it increasingly difficult to accurately assess optically- based detection technologies. To overcome these challenges, we examined the optimization, characterization, and calibration of microdroplets from a drop-on-demand microdispenser that has a proven capability for the preparation of energetic reference materials. Research presented herein focuses on the development of a simplistic instrument calibration technique and sample preparation protocol for explosive materials testing based on drop-on-demand technology. Droplet mass and reproducibility were measured using ultraviolet-visible (UV-Vis absorption spectroscopy. The results presented here demonstrate the operational factors that influence droplet dispensing for specific materials (e.g., energetic and interferents. Understanding these parameters permits the determination of droplet and sample uniformity and reproducibility (typical R2 values of 0.991, relative standard deviation or RSD ≤ 5%, and thus the demonstrated maturation of a successful and robust methodology for energetic sample preparation.

  13. Sample preparation composite and replicate strategy case studies for assay of solid oral drug products.

    Science.gov (United States)

    Nickerson, Beverly; Harrington, Brent; Li, Fasheng; Guo, Michele Xuemei

    2017-08-16

    Drug product assay is one of several tests required for new drug products to ensure the quality of the product at release and throughout the life cycle of the product. Drug product assay testing is typically performed by preparing a composite sample of multiple dosage units to obtain an assay value representative of the batch. In some cases replicate composite samples may be prepared and the reportable assay value is the average value of all the replicates. In previously published work by Harrington et al. (2014) [5], a sample preparation composite and replicate strategy for assay was developed to provide a systematic approach which accounts for variability due to the analytical method and dosage form with a standard error of the potency assay criteria based on compendia and regulatory requirements. In this work, this sample preparation composite and replicate strategy for assay is applied to several case studies to demonstrate the utility of this approach and its application at various stages of pharmaceutical drug product development. Copyright © 2017. Published by Elsevier B.V.

  14. A novel sample preparation method to avoid influence of embedding medium during nano-indentation

    Science.gov (United States)

    Yujie Meng; Siqun Wang; Zhiyong Cai; Timothy M. Young; Guanben Du; Yanjun Li

    2012-01-01

    The effect of the embedding medium on the nano-indentation measurements of lignocellulosic materials was investigated experimentally using nano-indentation. Both the reduced elastic modulus and the hardness of nonembedded cell walls were found to be lower than those of the embedded samples, proving that the embedding medium used for specimen preparation on cellulosic...

  15. Sample preparation for combined chemical analysis and bioassay application in water quality assessment

    NARCIS (Netherlands)

    Kolkman, A.; Schriks, M.; Brand, W; Bäuerlein, P.S.; van der Kooi, M.M.E.; van Doorn, R.H.; Emke, E.; Reus, A.; van der Linden, S.; de Voogt, P.; Heringa, M.B.

    2013-01-01

    The combination of in vitro bioassays and chemical screening can provide a powerful toolbox to determine biologically relevant compounds in water extracts. In this study, a sample preparation method is evaluated for the suitability for both chemical analysis and in vitro bioassays. A set of 39 chemi

  16. The role of sample preparation in interpretation of trace element concentration variability in moss bioindication studies

    Science.gov (United States)

    Migaszewski, Z.M.; Lamothe, P.J.; Crock, J.G.; Galuszka, A.; Dolegowska, S.

    2011-01-01

    Trace element concentrations in plant bioindicators are often determined to assess the quality of the environment. Instrumental methods used for trace element determination require digestion of samples. There are different methods of sample preparation for trace element analysis, and the selection of the best method should be fitted for the purpose of a study. Our hypothesis is that the method of sample preparation is important for interpretation of the results. Here we compare the results of 36 element determinations performed by ICP-MS on ashed and on acid-digested (HNO3, H2O2) samples of two moss species (Hylocomium splendens and Pleurozium schreberi) collected in Alaska and in south-central Poland. We found that dry ashing of the moss samples prior to analysis resulted in considerably lower detection limits of all the elements examined. We also show that this sample preparation technique facilitated the determination of interregional and interspecies differences in the chemistry of trace elements. Compared to the Polish mosses, the Alaskan mosses displayed more positive correlations of the major rock-forming elements with ash content, reflecting those elements' geogenic origin. Of the two moss species, P. schreberi from both Alaska and Poland was also highlighted by a larger number of positive element pair correlations. The cluster analysis suggests that the more uniform element distribution pattern of the Polish mosses primarily reflects regional air pollution sources. Our study has shown that the method of sample preparation is an important factor in statistical interpretation of the results of trace element determinations. ?? 2010 Springer-Verlag.

  17. Preparation and characterisation of magnetic nanostructured samples for inelastic neutron scattering experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzpaintner, Wolfgang

    2010-06-22

    Recent advances in thin-film structuring techniques have generated significant interest in the dynamics of spin waves in magnetic nanostructures and the possible use of inelastic neutron scattering (INS) for their investigation. This thesis describes the design and implementation, at GKSS Research Centre, of equipment for preparation of large and laterally submicron and nanometre structured magnetic samples for such future INS experiments. After a brief resume on spin waves in nanostructures, the development work on new purpose-designed equipment, including high vacuum (HV) argon ion beam milling and ultra high vacuum (UHV) e-beam evaporation setups, is described. Ni nanodot as well as Ni and novel Gd nanowire samples were prepared using combinations of sputter deposition, laser interference lithography, argon ion beam milling, e-beam evaporation and self organisation techniques. With reference to sample preparation, epitaxial growth studies for Ni on Si(100) substrate were performed, resulting in the development of a new deposition process, which by thermal tuning allows for the direct epitaxial growth of Ni on Si with unprecedented crystalline quality. The results of various characterisation experiments on the prepared nanostructured samples, including Scanning Electron Microscopy (SEM), microprobe analysis, Atomic and Magnetic Force Microscopy (AFM/MFM), Vibrating Sample Magnetometry (VSM), X-ray Diffraction (XRD) and Reflectivity (XRR), unpolarised and Polarised Neutron Scattering (PNR) and off-specular scattering by X-rays and neutrons using rocking scans and Time-Of-Flight Grazing Incidence Small Angle Neutron Scattering (TOF-GISANS), together with various analysis procedures such as Distorted-Wave Born Approximation (DWBA), are reported. The analysis of a Gd nanowire sample by TOF-GISANS led to a novel evaluation technique which in comparison with single wavelength methods allows portions of reciprocal space to be scanned without changing the angle of

  18. Challenges of biological sample preparation for SIMS imaging of elements and molecules at subcellular resolution

    Energy Technology Data Exchange (ETDEWEB)

    Chandra, Subhash [Cornell SIMS Laboratory, Department of Earth and Atmospheric Sciences, Snee Hall, Cornell University, Ithaca, NY 14853 (United States)], E-mail: sc40@cornell.edu

    2008-12-15

    Secondary ion mass spectrometry (SIMS) based imaging techniques capable of subcellular resolution characterization of elements and molecules are becoming valuable tools in many areas of biology and medicine. Due to high vacuum requirements of SIMS, the live cells cannot be analyzed directly in the instrument. The sample preparation, therefore, plays a critical role in preserving the native chemical composition for SIMS analysis. This work focuses on the evaluation of frozen-hydrated and frozen freeze-dried sample preparations for SIMS studies of cultured cells with a CAMECA IMS-3f dynamic SIMS ion microscope instrument capable of producing SIMS images with a spatial resolution of 500 nm. The sandwich freeze-fracture method was used for fracturing the cells. The complimentary fracture planes in the plasma membrane were characterized by field-emission secondary electron microscopy (FESEM) in the frozen-hydrated state. The cells fractured at the dorsal surface were used for SIMS analysis. The frozen-hydrated SIMS analysis of individual cells under dynamic primary ion beam (O{sub 2}{sup +}) revealed local secondary ion signal enhancements correlated with the water image signals of {sup 19}(H{sub 3}O){sup +}. A preferential removal of water from the frozen cell matrix in the Z-axis was also observed. These complications render the frozen-hydrated sample type less desirable for subcellular dynamic SIMS studies. The freeze-drying of frozen-hydrated cells, either inside the instrument or externally in a freeze-drier, allowed SIMS imaging of subcellular chemical composition. Morphological evaluations of fractured freeze-dried cells with SEM and confocal laser scanning microscopy (CLSM) revealed well-preserved mitochondria, Golgi apparatus, and stress fibers. SIMS analysis of fractured freeze-dried cells revealed well-preserved chemical composition of even the most highly diffusible ions like K{sup +} and Na{sup +} in physiologically relevant concentrations. The high K

  19. Transfer function design based on user selected samples for intuitive multivariate volume exploration

    KAUST Repository

    Zhou, Liang

    2013-02-01

    Multivariate volumetric datasets are important to both science and medicine. We propose a transfer function (TF) design approach based on user selected samples in the spatial domain to make multivariate volumetric data visualization more accessible for domain users. Specifically, the user starts the visualization by probing features of interest on slices and the data values are instantly queried by user selection. The queried sample values are then used to automatically and robustly generate high dimensional transfer functions (HDTFs) via kernel density estimation (KDE). Alternatively, 2D Gaussian TFs can be automatically generated in the dimensionality reduced space using these samples. With the extracted features rendered in the volume rendering view, the user can further refine these features using segmentation brushes. Interactivity is achieved in our system and different views are tightly linked. Use cases show that our system has been successfully applied for simulation and complicated seismic data sets. © 2013 IEEE.

  20. Enrichment of diluted cell populations from large sample volumes using 3D carbon-electrode dielectrophoresis.

    Science.gov (United States)

    Islam, Monsur; Natu, Rucha; Larraga-Martinez, Maria Fernanda; Martinez-Duarte, Rodrigo

    2016-05-01

    Here, we report on an enrichment protocol using carbon electrode dielectrophoresis to isolate and purify a targeted cell population from sample volumes up to 4 ml. We aim at trapping, washing, and recovering an enriched cell fraction that will facilitate downstream analysis. We used an increasingly diluted sample of yeast, 10(6)-10(2) cells/ml, to demonstrate the isolation and enrichment of few cells at increasing flow rates. A maximum average enrichment of 154.2 ± 23.7 times was achieved when the sample flow rate was 10 μl/min and yeast cells were suspended in low electrically conductive media that maximizes dielectrophoresis trapping. A COMSOL Multiphysics model allowed for the comparison between experimental and simulation results. Discussion is conducted on the discrepancies between such results and how the model can be further improved.

  1. A simple sample preparation method for measuring amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration.

    Science.gov (United States)

    Dong, Wei-Chong; Hou, Zi-Li; Jiang, Xin-Hui; Jiang, Ye

    2013-02-01

    A simple sample preparation method has been developed for the determination of amoxicillin in human plasma by hollow fiber centrifugal ultrafiltration (HF-CF-UF). A 400-μL plasma sample was placed directly into the HF-CF-UF device, which consisited of a slim glass tube and a U-shaped hollow fiber. After centrifugation at 1.25 × 10(3) g for 10 min, the filtrate was withdrawn from the hollow fiber and 20 µL was directly injected into the high-performance liquid chromatography (HPLC) for analysis. The calibration curve was linear over the range of 0.1-20 µg/mL (r = 0.9996) and the limit of detection was as low as 0.025 µg/mL. The average recovery and absolute recovery were 99.9% and 84.5%, respectively. Both the intra-day and inter-day precisions (relative standard deviation) were less than 3.1% for three concentrations (0.25, 2.5 and 10 µg/mL). The sample preparation process was simplified. Only after a single centrifugal ultrafiltration can the filtrate be injected directly into HPLC. The present method is simple, sensitive and accurate. It could be effective for the analysis of biological samples with high protein contents, especially for the biopharmaceutical analysis of drugs that use traditional isolation techniques for sample preparation such as the protein precipitation method.

  2. Community-Level Physiological Profiling of Microbial Communities in Constructed Wetlands: Effects of Sample Preparation.

    Science.gov (United States)

    Button, Mark; Weber, Kela; Nivala, Jaime; Aubron, Thomas; Müller, Roland Arno

    2016-03-01

    Community-level physiological profiling (CLPP) using BIOLOG® EcoPlates™ has become a popular method for characterizing and comparing the functional diversity, functional potential, and metabolic activity of heterotrophic microbial communities. The method was originally developed for profiling soil communities; however, its usage has expanded into the fields of ecotoxicology, agronomy, and the monitoring and profiling of microbial communities in various wastewater treatment systems, including constructed wetlands for water pollution control. When performing CLPP on aqueous samples from constructed wetlands, a wide variety of sample characteristics can be encountered and challenges may arise due to excessive solids, color, or turbidity. The aim of this study was to investigate the impacts of different sample preparation methods on CLPP performed on a variety of aqueous samples covering a broad range of physical and chemical characteristics. The results show that using filter paper, centrifugation, or settling helped clarify samples for subsequent CLPP analysis, however did not do so as effectively as dilution for the darkest samples. Dilution was able to provide suitable clarity for the darkest samples; however, 100-fold dilution significantly affected the carbon source utilization patterns (CSUPs), particularly with samples that were already partially or fully clear. Ten-fold dilution also had some effect on the CSUPs of samples which were originally clear; however, the effect was minimal. Based on these findings, for this specific set of samples, a 10-fold dilution provided a good balance between ease of use, sufficient clarity (for dark samples), and limited effect on CSUPs. The process and findings outlined here can hopefully serve future studies looking to utilize CLPP for functional analysis of microbial communities and also assist in comparing data from studies where different sample preparation methods were utilized.

  3. Isolation and purification of heroin from heroin street samples by preparative high performance liquid chromatography.

    Science.gov (United States)

    Guo, Zhen; Zheng, Hui; Lu, Yanzhen; Wei, Yun

    2012-09-10

    The present study established a novel method using preparative high performance liquid chromatography to isolate and purify heroin·HCl from heroin street samples to be used as a reference standard. Different kinds of mobile phases and columns were used, ultimately the mobile phase consisting of hexane-isopropanol-methanol (65:28:7, v/v) and the SIL preparative column prepared in laboratory were selected as the final condition. Heroin was further purified by the drowning-out crystallization method using isopropanol-methanol (50:1, v/v) and hexane as drowning-out anti-solvents and salting-out agents, respectively. The purity was assessed by analytical high performance liquid chromatography and the confirmation of the chemical structure was performed by IR and NMR. About 110.7mg of heroin·HCl at a purity of over 99.52% was obtained from 180mg of heroin street samples which contained 156.15mg of heroin·HCl component by preparative high performance liquid chromatography. This method is suitable for preparing heroin standards in forensic science area.

  4. Membrane biofouling characterization: effects of sample preparation procedures on biofilm structure and the microbial community

    KAUST Repository

    Xue, Zheng

    2014-07-15

    Ensuring the quality and reproducibility of results from biofilm structure and microbial community analysis is essential to membrane biofouling studies. This study evaluated the impacts of three sample preparation factors (ie number of buffer rinses, storage time at 4°C, and DNA extraction method) on the downstream analysis of nitrifying biofilms grown on ultrafiltration membranes. Both rinse and storage affected biofilm structure, as suggested by their strong correlation with total biovolume, biofilm thickness, roughness and the spatial distribution of EPS. Significant variations in DNA yields and microbial community diversity were also observed among samples treated by different rinses, storage and DNA extraction methods. For the tested biofilms, two rinses, no storage and DNA extraction with both mechanical and chemical cell lysis from attached biofilm were the optimal sample preparation procedures for obtaining accurate information about biofilm structure, EPS distribution and the microbial community. © 2014 © 2014 Taylor & Francis.

  5. Membrane biofouling characterization: effects of sample preparation procedures on biofilm structure and the microbial community.

    Science.gov (United States)

    Xue, Zheng; Lu, Huijie; Liu, Wen-Tso

    2014-01-01

    Ensuring the quality and reproducibility of results from biofilm structure and microbial community analysis is essential to membrane biofouling studies. This study evaluated the impacts of three sample preparation factors (ie number of buffer rinses, storage time at 4°C, and DNA extraction method) on the downstream analysis of nitrifying biofilms grown on ultrafiltration membranes. Both rinse and storage affected biofilm structure, as suggested by their strong correlation with total biovolume, biofilm thickness, roughness and the spatial distribution of EPS. Significant variations in DNA yields and microbial community diversity were also observed among samples treated by different rinses, storage and DNA extraction methods. For the tested biofilms, two rinses, no storage and DNA extraction with both mechanical and chemical cell lysis from attached biofilm were the optimal sample preparation procedures for obtaining accurate information about biofilm structure, EPS distribution and the microbial community.

  6. An enzyme-based DNA preparation method for application to forensic biological samples and degraded stains.

    Science.gov (United States)

    Lounsbury, Jenny A; Coult, Natalie; Miranian, Daniel C; Cronk, Stephen M; Haverstick, Doris M; Kinnon, Paul; Saul, David J; Landers, James P

    2012-09-01

    Extraction of DNA from forensic samples typically uses either an organic extraction protocol or solid phase extraction (SPE) and these methods generally involve numerous sample transfer, wash and centrifugation steps. Although SPE has been successfully adapted to the microdevice, it can be problematic because of lengthy load times and uneven packing of the solid phase. A closed-tube enzyme-based DNA preparation method has recently been developed which uses a neutral proteinase to lyse cells and degrade proteins and nucleases [14]. Following a 20 min incubation of the buccal or whole blood sample with this proteinase, DNA is polymerase chain reaction (PCR)-ready. This paper describes the optimization and quantitation of DNA yield using this method, and application to forensic biological samples, including UV- and heat-degraded whole blood samples on cotton or blue denim substrates. Results demonstrate that DNA yield can be increased from 1.42 (±0.21)ng/μL to 7.78 (±1.40)ng/μL by increasing the quantity of enzyme per reaction by 3-fold. Additionally, there is a linear relationship between the amount of starting cellular material added and the concentration of DNA in the solution, thereby allowing DNA yield estimations to be made. In addition, short tandem repeat (STR) profile results obtained using DNA prepared with the enzyme method were comparable to those obtained with a conventional SPE method, resulting in full STR profiles (16 of 16 loci) from liquid samples (buccal swab eluate and whole blood), dried buccal swabs and bloodstains and partial profiles from UV or heat-degraded bloodstains on cotton or blue denim substrates. Finally, the DNA preparation method is shown to be adaptable to glass or poly(methyl methacrylate) (PMMA) microdevices with little impact on STR peak height but providing a 20-fold reduction in incubation time (as little as 60 s), leading to a ≥1 h reduction in DNA preparation time.

  7. Characterization of solid heterogeneous waste fuel - the effect of sampling and preparation method; Karaktaerisering av fasta inhomogena avfallsbraenslen - inverkan av metoder foer provtagning och provberedning

    Energy Technology Data Exchange (ETDEWEB)

    Wikstroem-Blomqvist, Evalena; Franke, Jolanta; Johansson, Ingvar

    2007-12-15

    The aim of the project is to evaluate the possibilities to simplify the methods used during sampling and laboratory preparation of heterogeneous waste materials. Existing methods for solid fuel material is summarized and evaluated in the project. As a result of the project two new simplified methods, one for field sampling and one for laboratory preparation work has been suggested. One large challenge regarding waste sampling is to achieve a representative sample due to the considerable heterogeneity of the material. How do you perform a sampling campaign that will give rise to representative results without too large costs? The single largest important source of error is the sampling procedure, equivalent to about 80% of the total error. Meanwhile the sample reduction and laboratory work only represents 15 % and 5 % respectively. Thus, to minimize the total error it is very important that the sampling is well planned in a testing program. In the end a very small analytical sample (1 gram) should reflected a large heterogeneous sample population of 1000 of tons. In this project two sampling campaigns, the fall of 2006 and early winter 2007, were conducted at the waste power plant Renova in Gothenburg, Sweden. The first campaign consisted of three different sample sizes with different number of sub-samples. One reference sample (50 tons and 48 sub-samples), two samples consisting of 16 tons and 8 sub-samples and finally two 4 tons consisting of 2 sub-samples each. During the second sampling campaign, four additional 4 ton samples were taken to repeat and thus evaluate the simplified sampling method. This project concludes that the simplified sampling methods only consisting of two sub-samples and a total sample volume of 4 tons give rise to results with as good quality and precision is the more complicated methods tested. Moreover the results from the two sampling campaigns generated equivalent results. The preparation methods used in the laboratory can as well be

  8. Rapid sample preparation method for LC-MS/MS or GC-MS analysis of acrylamide in various food matrices.

    Science.gov (United States)

    Mastovska, Katerina; Lehotay, Steven J

    2006-09-20

    A fast and easy sample preparation procedure for analysis of acrylamide in various food matrices was developed and optimized. In its first step, deuterated acrylamide internal standard is added to 1 g of homogenized sample together with 5 mL of hexane, 10 mL of water, 10 mL of acetonitrile, 4 g of MgSO4, and 0.5 g of NaCl. Water facilitates the extraction of acrylamide; hexane serves for sample defatting; and the salt combination induces separation of water and acetonitrile layers and forces the majority of acrylamide into the acetonitrile layer. After vigorous shaking of the extraction mixture for 1 min and centrifugation, the upper hexane layer is discarded and a 1 mL aliquot of the acetonitrile extract is cleaned up by dispersive solid-phase extraction using 50 mg of primary secondary amine sorbent and 150 mg of anhydrous MgSO4. The final extract is analyzed either by liquid chromatography-tandem mass spectrometry or by gas chromatography-mass spectrometry (in positive chemical ionization mode) using the direct sample introduction technique for rugged large-volume injection.

  9. Automated high-volume aerosol sampling station for environmental radiation monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Toivonen, H.; Honkamaa, T.; Ilander, T.; Leppaenen, A.; Nikkinen, M.; Poellaenen, R.; Ylaetalo, S

    1998-07-01

    An automated high-volume aerosol sampling station, known as CINDERELLA.STUK, for environmental radiation monitoring has been developed by the Radiation and Nuclear Safety Authority (STUK), Finland. The sample is collected on a glass fibre filter (attached into a cassette), the airflow through the filter is 800 m{sup 3}/h at maximum. During the sampling, the filter is continuously monitored with Na(I) scintillation detectors. After the sampling, the large filter is automatically cut into 15 pieces that form a small sample and after ageing, the pile of filter pieces is moved onto an HPGe detector. These actions are performed automatically by a robot. The system is operated at a duty cycle of 1 d sampling, 1 d decay and 1 d counting. Minimum detectable concentrations of radionuclides in air are typically 1Ae10 x 10{sup -6} Bq/m{sup 3}. The station is equipped with various sensors to reveal unauthorized admittance. These sensors can be monitored remotely in real time via Internet or telephone lines. The processes and operation of the station are monitored and partly controlled by computer. The present approach fulfils the requirements of CTBTO for aerosol monitoring. The concept suits well for nuclear material safeguards, too 10 refs.

  10. Technical Note: New methodology for measuring viscosities in small volumes characteristic of environmental chamber particle samples

    Directory of Open Access Journals (Sweden)

    L. Renbaum-Wolff

    2012-10-01

    Full Text Available Herein, a method for the determination of viscosities of small sample volumes is introduced, with important implications for the viscosity determination of particle samples from environmental chambers (used to simulate atmospheric conditions. The amount of sample needed is < 1 μl, and the technique is capable of determining viscosities (η ranging between 10−3 and 103 Pascal seconds (Pa s in samples that cover a range of chemical properties and with real-time relative humidity and temperature control; hence, the technique should be well-suited for determining the viscosities, under atmospherically relevant conditions, of particles collected from environmental chambers. In this technique, supermicron particles are first deposited on an inert hydrophobic substrate. Then, insoluble beads (~1 μm in diameter are embedded in the particles. Next, a flow of gas is introduced over the particles, which generates a shear stress on the particle surfaces. The sample responds to this shear stress by generating internal circulations, which are quantified with an optical microscope by monitoring the movement of the beads. The rate of internal circulation is shown to be a function of particle viscosity but independent of the particle material for a wide range of organic and organic-water samples. A calibration curve is constructed from the experimental data that relates the rate of internal circulation to particle viscosity, and this calibration curve is successfully used to predict viscosities in multicomponent organic mixtures.

  11. Specimen Preparation for Metal Matrix Composites with a High Volume Fraction of Reinforcing Particles for EBSD Analysis

    Science.gov (United States)

    Smirnov, A. S.; Belozerov, G. A.; Smirnova, E. O.; Konovalov, A. V.; Shveikin, V. P.; Muizemnek, O. Yu.

    2016-07-01

    The paper deals with a procedure of preparing a specimen surface for the EBSD analysis of a metal matrix composite (MMC) with a high volume fraction of reinforcing particles. Unlike standard procedures of preparing a specimen surface for the EBSD analysis, the proposed procedure is iterative with consecutive application of mechanical and electrochemical polishing. This procedure significantly improves the results of an indexed MMC matrix in comparison with the standard procedure of specimen preparation. The procedure was verified on a MMC with pure aluminum (99.8% Al) as the matrix, SiC particles being used as reinforcing elements. The average size of the SiC particles is 14 μm, and their volume fraction amounts to 50% of the total volume of the composite. It has been experimentally found that, for making the EBSD analysis of a material matrix near reinforcing particles, the difference in height between the particles and the matrix should not exceed 2 µm.

  12. An efficient sample preparation method for high-throughput analysis of 15(S)-8-iso-PGF2α in plasma and urine by enzyme immunoassay.

    Science.gov (United States)

    Bielecki, A; Saravanabhavan, G; Blais, E; Vincent, R; Kumarathasan, P

    2012-01-01

    Although several methods have been reported on the analysis of the oxidative stress marker 15(S)-8-iso-prostaglandin-F2alpha (8-iso-PGF2α) in biological fluids, they either involve extensive sample preparation and costly technology or require high sample volume. This study presents a sample preparation method that utilizes low sample volume for 8-iso-PGF2α analysis in plasma and urine by an enzyme immunoassay (EIA). In brief, 8-iso-PGF2α in deproteinized plasma or native urine sample is complexed with an antibody and then captured by molecular weight cut-off filtration. This method was compared with two other sample preparation methods that are typically used in the analysis of 8-iso-PGF2α by EIA: Cayman's affinity column purification method and solid-phase extraction on C-18. The immunoaffinity purification method described here was superior to the other two sample preparation methods and yielded recovery values of 99.8 and 54.1% for 8-iso-PGF2α in plasma and urine, respectively. Analytical precision (relative standard deviation) was ±5% for plasma and ±15% for urine. The analysis of healthy human plasma and urine resulted in basal 8-iso-PGF2α levels of 31.8 ± 5.5 pg/mL and 2.9 ± 2.0 ng/mg creatinine, respectively. The robustness and analytical performance of this method makes it a promising tool for high-throughput screening of biological samples for 8-iso-PGF2α.

  13. Relationship between LIBS Ablation and Pit Volume for Geologic Samples: Applications for in situ Absolute Geochronology

    Science.gov (United States)

    Devismes, D.; Cohen, Barbara A.

    2014-01-01

    In planetary sciences, in situ absolute geochronology is a scientific and engineering challenge. Currently, the age of the Martian surface can only be determined by crater density counting. However this method has significant uncertainties and needs to be calibrated with absolute ages. We are developing an instrument to acquire in situ absolute geochronology based on the K-Ar method. The protocol is based on the laser ablation of a rock by hundreds of laser pulses. Laser Induced Breakdown Spectroscopy (LIBS) gives the potassium content of the ablated material and a mass spectrometer (quadrupole or ion trap) measures the quantity of 40Ar released. In order to accurately measure the quantity of released 40Ar in cases where Ar is an atmospheric constituent (e.g., Mars), the sample is first put into a chamber under high vacuum. The 40Arquantity, the concentration of K and the estimation of the ablated mass are the parameters needed to give the age of the rocks. The main uncertainties with this method are directly linked to the measures of the mass (typically some µg) and of the concentration of K by LIBS (up to 10%). Because the ablated mass is small compared to the mass of the sample, and because material is redeposited onto the sample after ablation, it is not possible to directly measure the ablated mass. Our current protocol measures the ablated volume and estimates the sample density to calculate ablated mass. The precision and accuracy of this method may be improved by using knowledge of the sample's geologic properties to predict its response to laser ablation, i.e., understanding whether natural samples have a predictable relationship between laser energy deposited and resultant ablation volume. In contrast to most previous studies of laser ablation, theoretical equations are not highly applicable. The reasons are numerous, but the most important are: a) geologic rocks are complex, polymineralic materials; b) the conditions of ablation are unusual (for example

  14. An integrated hybrid system for genetic analysis combining EWOD sample preparation and magnetic detection

    Energy Technology Data Exchange (ETDEWEB)

    Brennan, Des; Dinca, Mihai; Aherne, Margaret; Galvin, Paul [Tyndall National Institute, University College, Cork, Lee Maltings, Prospect Row, Cork (Ireland); Jary, Dorothee; Peponnet, Christine [CEA-LETI, Department of Technology for Biology and Health, 17 Avenue Des Martyrs, 38054 Grenoble (France); Cardosa, Filipe; Freitas, Paolo, E-mail: des.brennan@tyndall.ie [INESC-MN, Rua Alves Redol, 9, 1000-029 Lisbon (Portugal)

    2011-08-17

    Over the last decade microelectronic technologies have delivered significant advances in devices for point of care diagnostics. Complex microfluidic systems integrate components such as valves, pumps etc. to manipulate liquids. In recent years, the drive is to combine biochemical protocols in a single system, delivering 'sample in answer out'. An Electrowetting on Dielectric (EWOD) device offers the possibility to move and manipulate 64nl volumes implementing biochemical processes, while the magnetic sensor facilitates hybridisation detection. We outline an injection molding approach where EWOD and magnetic devices are integrated into a hybrid microfluidic system with the potential to implement 'sample in answer out' biological protocols.

  15. An integrated hybrid system for genetic analysis combining EWOD sample preparation and magnetic detection

    Science.gov (United States)

    Brennan, Des; Jary, Dorothee; Peponnet, Christine; Cardosa, Filipe; Freitas, Paolo; Dinca, Mihai; Aherne, Margaret; Galvin, Paul

    2011-08-01

    Over the last decade microelectronic technologies have delivered significant advances in devices for point of care diagnostics. Complex microfluidic systems integrate components such as valves, pumps etc. to manipulate liquids. In recent years, the drive is to combine biochemical protocols in a single system, delivering "sample in answer out". An Electrowetting on Dielectric (EWOD) device offers the possibility to move and manipulate 64nl volumes implementing biochemical processes, while the magnetic sensor facilitates hybridisation detection. We outline an injection molding approach where EWOD and magnetic devices are integrated into a hybrid microfluidic system with the potential to implement "sample in answer out" biological protocols.

  16. Compact low temperature scanning tunneling microscope with in-situ sample preparation capability

    Science.gov (United States)

    Kim, Jungdae; Nam, Hyoungdo; Qin, Shengyong; Kim, Sang-ui; Schroeder, Allan; Eom, Daejin; Shih, Chih-Kang

    2015-09-01

    We report on the design of a compact low temperature scanning tunneling microscope (STM) having in-situ sample preparation capability. The in-situ sample preparation chamber was designed to be compact allowing quick transfer of samples to the STM stage, which is ideal for preparing temperature sensitive samples such as ultra-thin metal films on semiconductor substrates. Conventional spring suspensions on the STM head often cause mechanical issues. To address this problem, we developed a simple vibration damper consisting of welded metal bellows and rubber pads. In addition, we developed a novel technique to ensure an ultra-high-vacuum (UHV) seal between the copper and stainless steel, which provides excellent reliability for cryostats operating in UHV. The performance of the STM was tested from 2 K to 77 K by using epitaxial thin Pb films on Si. Very high mechanical stability was achieved with clear atomic resolution even when using cryostats operating at 77 K. At 2 K, a clean superconducting gap was observed, and the spectrum was easily fit using the BCS density of states with negligible broadening.

  17. Experimental improvements in sample preparation for the track registration technique from dry and solution media

    Energy Technology Data Exchange (ETDEWEB)

    Suarez-Navarro, M.J. [Universidad Politecnica de Madrid (UPM), E.T.S.I de Caminos, Canales y Puertos, Profesor Aranguren s/n, 28040 Madrid (Spain)]. E-mail: he04@caminos.upm.es; Pujol, Ll. [Centro de Estudios y Experimentacion de Obras Publicas (CEDEX), Alfonso XII, 3, 28014 Madrid (Spain); Gonzalez-Gonzalez, J.A. [Universidad Politecnica de Madrid (UPM), E.T.S.I de Caminos, Canales y Puertos, Profesor Aranguren s/n, 28040 Madrid (Spain)

    2006-04-15

    This paper describes the sample preparation studies carried out to determine gross alpha activities in waste materials by means of alpha-particle track counting using CR-39 detector. Sample preparation for the track registration technique using evaporation or electroplating methods (also known as conventional 'dry methods') has a number of drawbacks. The distribution of tracks in different areas of the detector surface is non-uniform, so accurate quantitative determinations depend on tedious and time-consuming counting of tracks under an optical microscope. In this paper, we propose the use of tensioactives in sample preparation to achieve uniform track distribution over the entire detector surface, which enables track density to be evaluated by scanning a small representative area. Under our counting conditions, uniform distribution was achieved with 0.2 ml of Teg from a planchetted source. Furthermore, track registration techniques using solution media (also known as the 'wet methods') and conventional 'dry methods' were analysed and compared with the proposed method. The reproducibility of the procedure described in the study was tested by analysing gross alpha activity in two low-level nuclear waste samples at two different laboratories.

  18. Molecularly imprinted polymers for sample preparation and biosensing in food analysis: Progress and perspectives.

    Science.gov (United States)

    Ashley, Jon; Shahbazi, Mohammad-Ali; Kant, Krishna; Chidambara, Vinayaka Aaydha; Wolff, Anders; Bang, Dang Duong; Sun, Yi

    2017-05-15

    Molecularly imprinted polymers (MIPs) are biomimetics which can selectively bind to analytes of interest. One of the most interesting areas where MIPs have shown the biggest potential is food analysis. MIPs have found use as sorbents in sample preparation attributed to the high selectivity and high loading capacity. MIPs have been intensively employed in classical solid-phase extraction and solid-phase microextraction. More recently, MIPs have been combined with magnetic bead extraction, which greatly simplifies sample handling procedures. Studies have consistently shown that MIPs can effectively minimize complex food matrix effects, and improve recoveries and detection limits. In addition to sample preparation, MIPs have also been viewed as promising alternatives to bio-receptors due to the inherent molecular recognition abilities and the high stability in harsh chemical and physical conditions. MIPs have been utilized as receptors in biosensing platforms such as electrochemical, optical and mass biosensors to detect various analytes in food. In this review, we will discuss the current state-of-the-art of MIP synthesis and applications in the context of food analysis. We will highlight the imprinting methods which are applicable for imprinting food templates, summarize the recent progress in using MIPs for preparing and analysing food samples, and discuss the current limitations in the commercialisation of MIPs technology. Finally, future perspectives will be given.

  19. Comparison of sample preparation methods for the recovery of foodborne pathogens from fresh produce.

    Science.gov (United States)

    Kim, Se-Ri; Yoon, Yohan; Kim, Won-Il; Park, Kyeong-Hun; Yun, Hye-Jeong; Chung, Duck Hwa; Yun, Jong Chul; Ryu, Kyoung Yul

    2012-07-01

    Sample preparation methods (pummeling, pulsifying, sonication, and shaking by hand) were compared for achieving maximum recovery of foodborne pathogens from iceberg lettuce, perilla leaves, cucumber, green pepper, and cherry tomato. Antimicrobial and dehydration effects also were examined to investigate causes of poor recovery of pathogens. Each produce type was inoculated with Escherichia coli O157:H7, Salmonella Typhimurium, Listeria monocytogenes, Staphylococcus aureus, and Bacillus cereus at 6.0 log CFU/cm(2), and samples were prepared using the four methods. Bacterial populations recovered from the five types of produce were significantly different (P cucumber, and green pepper had no antimicrobial activity, the populations of E. coli O157:H7, Salmonella Typhimurium, B. cereus, and L. monocytogenes in cherry tomato extract were slightly reduced after these treatments (P 2 log CFU/cm(2) after exposure to 40% relative humidity for 1 h. No reduction was observed when the five pathogens were exposed to 90% relative humidity. These data suggest that pummeling and pulsifying are optimal sample preparation methods for detection of microorganisms. Acidic produce such as cherry tomato should be treated with a method that does not cause sample breakdown so that acid stress on the bacteria can be minimized. Dehydration stress also affects recovery of pathogens from produce.

  20. Tracer techniques for urine volume determination and urine collection and sampling back-up system

    Science.gov (United States)

    Ramirez, R. V.

    1971-01-01

    The feasibility, functionality, and overall accuracy of the use of lithium were investigated as a chemical tracer in urine for providing a means of indirect determination of total urine volume by the atomic absorption spectrophotometry method. Experiments were conducted to investigate the parameters of instrumentation, tracer concentration, mixing times, and methods for incorporating the tracer material in the urine collection bag, and to refine and optimize the urine tracer technique to comply with the Skylab scheme and operational parameters of + or - 2% of volume error and + or - 1% accuracy of amount of tracer added to each container. In addition, a back-up method for urine collection and sampling system was developed and evaluated. This back-up method incorporates the tracer technique for volume determination in event of failure of the primary urine collection and preservation system. One chemical preservative was selected and evaluated as a contingency chemical preservative for the storage of urine in event of failure of the urine cooling system.

  1. Should the mass of a nanoferrite sample prepared by autocombustion method be considered as a realistic preparation parameter?

    Science.gov (United States)

    Wahba, Adel Maher; Mohamed, Mohamed Bakr

    2017-02-01

    Detectable variations in structural, elastic and magnetic properties have been reported depending on the mass of the cobalt nanoferrite sample prepared by citrate autocombustion method. Heat released during the autocombustion process and its duration are directly proportional to the mass to be prepared, and is thus expected to affect both the crystallite size and the cation distribution giving rise to the reported variations in microstrain, magnetization, and coercivity. Formation of a pure spinel phase has been validated using X-ray diffraction patterns (XRD) and Fourier-transform infrared (FTIR) spectra. Crystallite sizes obtained from Williamson-Hall (W-H) method range from 28-87 nm, being further supported by images of high-resolution transmission electron microscope (HRTEM). Saturation magnetization and coercivity deduced from M-H hysteresis loops show a clear correlation with the cation distribution, which was proposed on the basis of experimentally obtained data of XRD, VSM, and IR. Elastic parameters have been estimated using the cation distribution and FTIR data, with a resulting trend quite opposite to that of the lattice parameter.

  2. HPLC/DAD determination of rosmarinic acid in Salvia officinalis: sample preparation optimization by factorial design

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Karina B. de [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Farmacia; Oliveira, Bras H. de, E-mail: bho@ufpr.br [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil). Dept. de Quimica

    2013-01-15

    Sage (Salvia officinalis) contains high amounts of the biologically active rosmarinic acid (RA) and other polyphenolic compounds. RA is easily oxidized, and may undergo degradation during sample preparation for analysis. The objective of this work was to develop and validate an analytical procedure for determination of RA in sage, using factorial design of experiments for optimizing sample preparation. The statistically significant variables for improving RA extraction yield were determined initially and then used in the optimization step, using central composite design (CCD). The analytical method was then fully validated, and used for the analysis of commercial samples of sage. The optimized procedure involved extraction with aqueous methanol (40%) containing an antioxidant mixture (ascorbic acid and ethylenediaminetetraacetic acid (EDTA)), with sonication at 45 deg C for 20 min. The samples were then injected in a system containing a C{sub 18} column, using methanol (A) and 0.1% phosphoric acid in water (B) in step gradient mode (45A:55B, 0-5 min; 80A:20B, 5-10 min) with flow rate of 1.0 mL min-1 and detection at 330 nm. Using this conditions, RA concentrations were 50% higher when compared to extractions without antioxidants (98.94 {+-} 1.07% recovery). Auto-oxidation of RA during sample extraction was prevented by the use of antioxidants resulting in more reliable analytical results. The method was then used for the analysis of commercial samples of sage. (author)

  3. Determination of Atto- to Femtogram Levels of Americium and Curium Isotopes in Large-Volume Urine Samples by Compact Accelerator Mass Spectrometry.

    Science.gov (United States)

    Dai, Xiongxin; Christl, Marcus; Kramer-Tremblay, Sheila; Synal, Hans-Arno

    2016-03-01

    Ultralow level analysis of actinides in urine samples may be required for dose assessment in the event of internal exposures to these radionuclides at nuclear facilities and nuclear power plants. A new bioassay method for analysis of sub-femtogram levels of Am and Cm in large-volume urine samples was developed. Americium and curium were co-precipitated with hydrous titanium oxide from the urine matrix and purified by column chromatography separation. After target preparation using mixed titanium/iron oxides, the final sample was measured by compact accelerator mass spectrometry. Urine samples spiked with known quantities of Am and Cm isotopes in the range of attogram to femtogram levels were measured for method evaluation. The results are in good agreement with the expected values, demonstrating the feasibility of compact accelerator mass spectrometry (AMS) for the determination of minor actinides at the levels of attogram/liter in urine samples to meet stringent sensitivity requirements for internal dosimetry assessment.

  4. Bio-sample preparation and gas chromatographic determination of benzodiazepines--a review.

    Science.gov (United States)

    Uddin, Mohammad Nasir; Samanidou, Victoria F; Papadoyannis, Ioannis N

    2013-08-01

    Benzodiazepines have become commonly prescribed medicines worldwide in the therapy of anxiety, sleep disorders and convulsive attacks because they are relatively safe, with mild side effects. The availability of rapid, sensitive and selective analytical methods is essential for the determination of these drugs in clinical and forensic cases. Benzodiazepines are usually present at trace levels (μg/mL or ng/mL) in a complex biological matrix, and the potentially interfering compounds need to be removed before analysis. Therefore, a sample preparation technique is often mandatory, both to extract the drugs of interest from the matrices and to increase their concentration. An extended and comprehensive review is presented herein, focusing on bio-sample preparation (pretreatment, extraction and derivatization) and gas chromatographic methods applied for the quantification of 1,4-benzodiazepines.

  5. On the use of ultracentrifugal devices for routine sample preparation in biomolecular magic-angle-spinning NMR.

    Science.gov (United States)

    Mandal, Abhishek; Boatz, Jennifer C; Wheeler, Travis B; van der Wel, Patrick C A

    2017-02-22

    A number of recent advances in the field of magic-angle-spinning (MAS) solid-state NMR have enabled its application to a range of biological systems of ever increasing complexity. To retain biological relevance, these samples are increasingly studied in a hydrated state. At the same time, experimental feasibility requires the sample preparation process to attain a high sample concentration within the final MAS rotor. We discuss these considerations, and how they have led to a number of different approaches to MAS NMR sample preparation. We describe our experience of how custom-made (or commercially available) ultracentrifugal devices can facilitate a simple, fast and reliable sample preparation process. A number of groups have since adopted such tools, in some cases to prepare samples for sedimentation-style MAS NMR experiments. Here we argue for a more widespread adoption of their use for routine MAS NMR sample preparation.

  6. Sample preparation for the analysis of flavors and off-flavors in foods.

    Science.gov (United States)

    Wilkes, J G; Conte, E D; Kim, Y; Holcomb, M; Sutherland, J B; Miller, D W

    2000-06-01

    Off-flavors in foods may originate from environmental pollutants, the growth of microorganisms, oxidation of lipids, or endogenous enzymatic decomposition in the foods. The chromatographic analysis of flavors and off-flavors in foods usually requires that the samples first be processed to remove as many interfering compounds as possible. For analysis of foods by gas chromatography (GC), sample preparation may include mincing, homogenation, centrifugation, distillation, simple solvent extraction, supercritical fluid extraction, pressurized-fluid extraction, microwave-assisted extraction, Soxhlet extraction, or methylation. For high-performance liquid chromatography of amines in fish, cheese, sausage and olive oil or aldehydes in fruit juice, sample preparation may include solvent extraction and derivatization. Headspace GC analysis of orange juice, fish, dehydrated potatoes, and milk requires almost no sample preparation. Purge-and-trap GC analysis of dairy products, seafoods, and garlic may require heating, microwave-mediated distillation, purging the sample with inert gases and trapping the analytes with Tenax or C18, thermal desorption, cryofocusing, or elution with ethyl acetate. Solid-phase microextraction GC analysis of spices, milk and fish can involve microwave-mediated distillation, and usually requires adsorption on poly(dimethyl)siloxane or electrodeposition on fibers followed by thermal desorption. For short-path thermal desorption GC analysis of spices, herbs, coffee, peanuts, candy, mushrooms, beverages, olive oil, honey, and milk, samples are placed in a glass-lined stainless steel thermal desorption tube, which is purged with helium and then heated gradually to desorb the volatiles for analysis. Few of the methods that are available for analysis of food flavors and off-flavors can be described simultaneously as cheap, easy and good.

  7. Fast detection of Noroviruses using a real-time PCR assay and automated sample preparation

    Directory of Open Access Journals (Sweden)

    Schmid Michael

    2004-06-01

    Full Text Available Abstract Background Noroviruses (NoV have become one of the most commonly reported causative agents of large outbreaks of non-bacterial acute gastroenteritis worldwide as well as sporadic gastroenteritis in the community. Currently, reverse transcriptase polymerase chain reaction (RT-PCR assays have been implemented in NoV diagnosis, but improvements that simplify and standardize sample preparation, amplification, and detection will be further needed. The combination of automated sample preparation and real-time PCR offers such refinements. Methods We have designed a new real-time RT-PCR assay on the LightCycler (LC with SYBR Green detection and melting curve analysis (Tm to detect NoV RNA in patient stool samples. The performance of the real-time PCR assay was compared with that obtained in parallel with a commercially available enzyme immunoassay (ELISA for antigen detection by testing a panel of 52 stool samples. Additionally, in a collaborative study with the Baden-Wuerttemberg State Health office, Stuttgart (Germany the real-time PCR results were blindly assessed using a previously well-established nested PCR (nPCR as the reference method, since PCR-based techniques are now considered as the "gold standard" for NoV detection in stool specimens. Results Analysis of 52 clinical stool samples by real-time PCR yielded results that were consistent with reference nPCR results, while marked differences between the two PCR-based methods and antigen ELISA were observed. Our results indicate that PCR-based procedures are more sensitive and specific than antigen ELISA for detecting NoV in stool specimens. Conclusions The combination of automated sample preparation and real-time PCR provided reliable diagnostic results in less time than conventional RT-PCR assays. These benefits make it a valuable tool for routine laboratory practice especially in terms of rapid and appropriate outbreak-control measures in health-care facilities and other settings.

  8. Development of an automated sample preparation module for environmental monitoring of biowarfare agents.

    Science.gov (United States)

    Hindson, Benjamin J; Brown, Steve B; Marshall, Graham D; McBride, Mary T; Makarewicz, Anthony J; Gutierrez, Dora M; Wolcott, Duane K; Metz, Thomas R; Madabhushi, Ramakrishna S; Dzenitis, John M; Colston, Billy W

    2004-07-01

    An automated sample preparation module, based upon sequential injection analysis (SIA), has been developed for use within an autonomous pathogen detection system. The SIA system interfaced aerosol sampling with multiplexed microsphere immunoassay-flow cytometric detection. Metering and sequestering of microspheres using SIA was found to be reproducible and reliable, over 24-h periods of autonomous operation. Four inbuilt immunoassay controls showed excellent immunoassay and system stability over five days of unattended continuous operation. Titration curves for two biological warfare agents, Bacillus anthracis and Yersinia pestis, obtained using the automated SIA procedure were shown to be similar to those generated using a manual microtiter plate procedure.

  9. Optimization of Proteomic Sample Preparation Procedures for Comprehensive Protein Characterization of Pathogenic Systems

    Science.gov (United States)

    Mottaz-Brewer, Heather M.; Norbeck, Angela D.; Adkins, Joshua N.; Manes, Nathan P.; Ansong, Charles; Shi, Liang; Rikihisa, Yasuko; Kikuchi, Takane; Wong, Scott W.; Estep, Ryan D.; Heffron, Fred; Pasa-Tolic, Ljiljana; Smith, Richard D.

    2008-01-01

    Mass spectrometry-based proteomics is a powerful analytical tool for investigating pathogens and their interactions within a host. The sensitivity of such analyses provides broad proteome characterization, but the sample-handling procedures must first be optimized to ensure compatibility with the technique and to maximize the dynamic range of detection. The decision-making process for determining optimal growth conditions, preparation methods, sample analysis methods, and data analysis techniques in our laboratory is discussed herein with consideration of the balance in sensitivity, specificity, and biomass losses during analysis of host-pathogen systems. PMID:19183792

  10. Preparation of Plant 41Ca Tracer Samples for Accelerator Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    ZHAO Qing-zhang1;JANG Ping-ping3;LIN De-yu4;YANG Xian-lin1;DOU Liang1;PANG Yi-jun1;WANG Xiao-ming1;ZHANG Hui1,5;YANG Xu-ran1;WU Shao-yong1;GAO Dong-sheng2;LI Ling2;WANG Lei2;SUN Ke-peng2;ZHOU Jun2;DONG Ke-jun1;HE Ming1

    2016-11-01

    Full Text Available Calcium plays an important role in the metabolism of plants and animals. In this paper, the preparation method of plant 41Ca for accelerator mass spectrometry (AMS measurement was developed for the first time in China. AMS, with its advantages of high sensitivity, small dose of radioactivity, high accuracy, large measuring range, and long tracer cycle, can be used to measure cosmogenic nuclide 41Ca , which has long half-life. The intensity of the beam in ion source is an important parameter for the sensitivity of AMS measurement. The high beam current can improve the sensitivity of AMS. The preparation methods of plant samples of 41Ca tracer were systematically studied to obtain high beam current using wet, dry and a combining method with wet and dry re-fluoride. A reliable preparation procedure of plant samples for 41Ca tracer and its optimization parameters were determined by testing beam currents of various samples and lay a foundation for the 41Ca-AMS technology at plant tracer applications.

  11. Sample preparation: a critical step in the analysis of cholesterol oxidation products.

    Science.gov (United States)

    Georgiou, Christiana A; Constantinou, Michalis S; Kapnissi-Christodoulou, Constantina P

    2014-02-15

    In recent years, cholesterol oxidation products (COPs) have drawn scientific interest, particularly due to their implications on human health. A big number of these compounds have been demonstrated to be cytotoxic, mutagenic, and carcinogenic. The main source of COPs is through diet, and particularly from the consumption of cholesterol-rich foods. This raises questions about the safety of consumers, and it suggests the necessity for the development of a sensitive and a reliable analytical method in order to identify and quantify these components in food samples. Sample preparation is a necessary step in the analysis of COPs in order to eliminate interferences and increase sensitivity. Numerous publications have, over the years, reported the use of different methods for the extraction and purification of COPs. However, no method has, so far, been established as a routine method for the analysis of COPs in foods. Therefore, it was considered important to overview different sample preparation procedures and evaluate the different preparative parameters, such as time of saponification, the type of organic solvents for fat extraction, the stationary phase in solid phase extraction, etc., according to recovery, precision and simplicity.

  12. DNA isolation and sample preparation for quantification of adduct levels by accelerator mass spectrometry.

    Science.gov (United States)

    Dingley, Karen H; Ubick, Esther A; Vogel, John S; Ognibene, Ted J; Malfatti, Michael A; Kulp, Kristen; Haack, Kurt W

    2014-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels.

  13. Improved sample preparation and counting techniques for enhanced tritium measurement sensitivity

    Science.gov (United States)

    Moran, J.; Aalseth, C.; Bailey, V. L.; Mace, E. K.; Overman, C.; Seifert, A.; Wilcox Freeburg, E. D.

    2015-12-01

    Tritium (T) measurements offer insight to a wealth of environmental applications including hydrologic tracking, discerning ocean circulation patterns, and aging ice formations. However, the relatively short half-life of T (12.3 years) limits its effective age dating range. Compounding this limitation is the decrease in atmospheric T content by over two orders of magnitude (from 1000-2000 TU in 1962 to low background proportional counters which, when combined, offer improved T measurement sensitivity (~4.5 mmoles of H2 equivalent) and will help expand the application of T age dating to smaller sample sizes linked to persistent environmental questions despite the limitations above. For instance, this approach can be used to T date ~ 2.2 mmoles of CH4 collected from sample-limited systems including microbial communities, soils, or subsurface aquifers and can be combined with radiocarbon dating to distinguish the methane's formation age from C age in a system. This approach can also expand investigations into soil organic C where the improved sensitivity will permit resolution of soil C into more descriptive fractions and provide direct assessments of the stability of specific classes of organic matter in soils environments. We are employing a multiple step sample preparation system whereby organic samples are first combusted with resulting CO2 and H2O being used as a feedstock to synthesize CH4. This CH4 is mixed with Ar and loaded directly into an ultra-low background proportional counter for measurement of T β decay in a shallow underground laboratory. Analysis of water samples requires only the addition of geologic CO2 feedstock with the sample for methane synthesis. The chemical nature of the preparation techniques enable high sample throughput with only the final measurement requiring T decay with total sample analysis time ranging from 2 -5 weeks depending on T content.

  14. Clinical Trial of 1000 Subjects Randomized to 5 Low-Volume Bowel Preparations for Colonoscopy and Their Acceptance of Split-Dose Bowel Preparations.

    Science.gov (United States)

    Gerard, David P; Foster, Diane B; Holden, John L; Kang, Jieun; Raiser, Manfred W

    2017-07-01

    We assessed the efficacy and tolerability of 5 low-volume bowel preparations for colonoscopy. We performed an investigator-blinded, randomized trial of 5 bowel preparations: 64 ounces of Gatorade and 306 or 357 g of PEG, both given the day prior; Gatorade and 306 g PEG, 2 L PEG-electrolyte solution with ascorbic acid, and sulfate solution, all 3 given as a split dose. One thousand outpatients consumed their preparation before a morning colonoscopy. The primary endpoint was colon cleanliness assessed by the Chicago Bowel Preparation Scale (BPS). Tolerability was assessed using a subject questionnaire. Another primary endpoint was patient acceptance of a split-dose bowel preparation assessed using a subject questionnaire. No statistically significant differences in the modified Chicago BPS were found among Gatorade and 357 g of PEG given as a day-prior dose and the 3 split-dose arms with 98.5% of colons cleansed adequately. The Gatorade and 357 g of PEG had significantly lower Chicago BPS fluid scores and Chicago BPS total scores (indicating dryer colons that required more irrigation) than the 3 split-dose arms. The Gatorade and PEG preparations were better tolerated. Many subjects are unwilling to consume a split-dose preparation and the majority of subjects would prefer a day-prior preparation with this preference highly dependent on the type of preparation they just consumed. The cleanliness of the colons was not significantly different among the 3 split-dose preparations. Day-prior dosing of Gatorade and 357 g of PEG allowed the mucosa to be visualized as well as did the split-dose preparations.

  15. Determination of the efficiency of a detector in gamma spectrometry of large-volume samples

    CERN Document Server

    Tertyshnik, E G

    2012-01-01

    The experimental - calculated method is proposed to determine the full energy peak efficiency (FEPE) of detectors {\\epsilon}(E) in case a measurement of the large-volume samples. Water is used as standard absorber in which the linear attenuation coefficients for photons {\\mu}0 (E) is well known. The value {\\mu} (E) in sample material (matrix of the sample) is determined experimentally by means of spectrometer. The formulas are given for calculation of the ratio {\\epsilon}(E)/ {\\epsilon}0(E), where {\\epsilon}0(E) is FEPE of the detector for photons those are arising in the container filled with water (it is found by adding in the container of the Reference radioactive solutions). To prove the validity of the method ethanol (density 0,8 g/cm3) and water solutions of salts (density 1,2 and 1,5 g/cm3) were used for simulation of the samples with different attenuation coefficients. Standard deviation between experimental and calculated efficiencies has been about 5 %.

  16. Reducing time and increasing sensitivity in sample preparation for adherent mammalian cell metabolomics.

    Science.gov (United States)

    Lorenz, Matthew A; Burant, Charles F; Kennedy, Robert T

    2011-05-01

    A simple, fast, and reproducible sample preparation procedure was developed for relative quantification of metabolites in adherent mammalian cells using the clonal β-cell line INS-1 as a model sample. The method was developed by evaluating the effect of different sample preparation procedures on high performance liquid chromatography- mass spectrometry quantification of 27 metabolites involved in glycolysis and the tricarboxylic acid cycle on a directed basis as well as for all detectable chromatographic features on an undirected basis. We demonstrate that a rapid water rinse step prior to quenching of metabolism reduces components that suppress electrospray ionization thereby increasing signal for 26 of 27 targeted metabolites and increasing total number of detected features from 237 to 452 with no detectable change of metabolite content. A novel quenching technique is employed which involves addition of liquid nitrogen directly to the culture dish and allows for samples to be stored at -80 °C for at least 7 d before extraction. Separation of quenching and extraction steps provides the benefit of increased experimental convenience and sample stability while maintaining metabolite content similar to techniques that employ simultaneous quenching and extraction with cold organic solvent. The extraction solvent 9:1 methanol: chloroform was found to provide superior performance over acetonitrile, ethanol, and methanol with respect to metabolite recovery and extract stability. Maximal recovery was achieved using a single rapid (∼1 min) extraction step. The utility of this rapid preparation method (∼5 min) was demonstrated through precise metabolite measurements (11% average relative standard deviation without internal standards) associated with step changes in glucose concentration that evoke insulin secretion in the clonal β-cell line INS-1.

  17. Evaluation of selected-ion flow-tube mass spectrometry for the measurement of ethanol, methanol and isopropanol in physiological fluids: effect of osmolality and sample volume.

    Science.gov (United States)

    Rowbottom, Lynn; Workman, Clive; Roberts, Norman B

    2009-09-01

    Selected-ion flow-tube mass spectrometry (SIFT-MS) is particularly suited for the analysis of volatile low molecular weight compounds. We have evaluated this technique for the assay of different alcohols in aqueous solutions, including blood plasma, and in particular whether the osmolality or sample volume affected vapourisation. Solutions of three different alcohols (methanol, ethanol and isopropanol) ranging from 0.005 to 50 mmol/L were prepared in deionised water (0 milliosmol), phosphate-buffered saline (690 mOsm), isotonic saline (294 mOsm) and plasma (296 mOsm). The vapour above the sample (50 to 1000 microL) contained in air-tight tubes at 37 degrees C was aspirated into the instrument. The outputs for ethanol, methanol and isopropanol were linear over the concentration range and independent of the sample volume and relatively independent of the osmolar concentration. SIFT-MS can reliably and accurately measure common alcohols in the headspace above aqueous solutions, including serum/plasma. This novel application of SIFT-MS is easy to follow, requires no sample preparation and the wide dynamic range will facilitate measurement of alcohols present from normal metabolism as well as when taken in excess or in accidental poisoning.

  18. A meta-analysis of randomized controlled trials of low-volume polyethylene glycol plus ascorbic acid versus standard-volume polyethylene glycol solution as bowel preparations for colonoscopy.

    Directory of Open Access Journals (Sweden)

    Qingsong Xie

    Full Text Available BACKGROUND: Standard-volume polyethylene glycol (PEG gut lavage solutions are safe and effective, but they require the consumption of large volumes of fluid. A new lower-volume solution of PEG plus ascorbic acid has been used recently as a preparation for colonoscopy. AIM: A meta-analysis was performed to compare the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy. STUDY: Electronic and manual searches were performed to identify randomized controlled trials (RCTs that compared the performance of low-volume PEG plus ascorbic acid with standard-volume PEG as bowel preparation for colonoscopy. After a methodological quality assessment and data extraction, the pooled estimates of bowel preparation efficacy during bowel cleansing, compliance with preparation, willingness to repeat the same preparation, and the side effects were calculated. We calculated pooled estimates of odds ratios (OR by fixed- and/or random-effects models. We also assessed heterogeneity among studies and the publication bias. RESULTS: Eleven RCTs were identified for analysis. The pooled OR for preparation efficacy during bowel cleansing and for compliance with preparation for low-volume PEG plus ascorbic acid were 1.08 (95% CI = 0.98-1.28, P = 0.34 and 2.23 (95% CI = 1.67-2.98, P<0.00001, respectively, compared with those for standard-volume PEG. The side effects of vomiting and nausea for low-volume PEG plus ascorbic acid were reduced relative to standard-volume PEG. There was no significant publication bias, according to a funnel plot. CONCLUSIONS: Low-volume PEG plus ascorbic acid gut lavage achieved non-inferior efficacy for bowel cleansing, is more acceptable to patients, and has fewer side effects than standard-volume PEG as a bowel preparation method for colonoscopy.

  19. Soybean and lactose in meat products and preparations sampled at retail

    Directory of Open Access Journals (Sweden)

    Filomena Piccolo

    2016-06-01

    Full Text Available Food allergies and intolerances have increased during the last decades and regulatory authorities have taken different measures to prevent and manage consumers’ adverse reactions, including correct labelling of foods. Aim of this work was to search for soybean and lactose in meat products and meat preparations taken from retail in some provinces of Campania Region (Southern Italy and to evaluate the food labels compliance with Regulation (EU n.1169/2011. Soybean and lactose were searched using commercial kits in n. 58 samples of meat products produced in or distributed by 19 establishments, and in n. 55 samples of meat products and n. 8 of meat preparations produced in 21 plants. All samples were selected on the basis of the absence of any information on the labels about the presence of the two searched allergens, with the exception of n. 5 samples tested for lactose. Traces of soybean were detected in 50 out of the 58 examined samples, at concentrations up to 0.93 mg kg–1. Only two samples contained levels above the detection limit of 0.31 mg kg–1. Lactose levels ranging from 0.11 to 2.95 g/100 g, i.e. above the detection limit, were found in all the tested samples (n. 63. The results of the present research underline the need for careful controls and planning by operators as part of the self-control plans, and deserve attention from the competent authorities considering not only the consumers’ health but also the great attention media pay to regulations providing consumers with information on food.

  20. Development of a sample preparation procedure of sewage sludge samples for the determination of polycyclic aromatic hydrocarbons based on selective pressurized liquid extraction.

    Science.gov (United States)

    Pena, Maria Teresa; Casais, Maria Carmen; Mejuto, Maria Carmen; Cela, Rafael

    2010-01-22

    An automated, simple and sensitive method based on selective pressurized liquid extraction (SPLE) was developed for the analysis of polycyclic aromatic hydrocarbons in sewage sludge samples. The new sample preparation procedure consists of on-line clean-up by inclusion of sorbents in the extraction cell, and combines elevated temperatures and pressures with liquid solvents to achieve fast and efficient removal of target analytes from complex sewage sludge matrices. The effects of various operational parameters (e.g. sample pretreatment, extraction solvent, temperature, pressure, static time, etc.) on the performance of SPLE procedure were carefully investigated, obtaining the best results when SPLE conditions were fixed at 140 degrees C, 1500 psi, static time of 5 min and n-hexane as extraction solvent. A new programmed temperature vaporization-gas chromatography-tandem mass spectrometry method based on large volume injection (PTV-LVI-GC-MS/MS) was also developed and analytical determinations were performed by high performance liquid chromatography coupled with fluorescence detection and GC-MS/MS. The extraction yields for the different compounds obtained by SPLE ranged from 84.8% to 106.6%. Quantification limits obtained for all of these studied compounds (between 0.0001 and 0.005 microg g(-1), dry mass) were well below the regulatory limits for all compounds considered. To test the accuracy of the SPLE technique, the optimized methodology was applied to the analysis of a certified reference material (sewage sludge (BCR088)) and a reference material (sewage sludge (RTC-CNS312-04)), with excellent results.

  1. Rapid Measurement of Food Adulteration with Minimal Sample Preparation and No Chromatography Using Ambient Ionization Mass Spectrometry.

    Science.gov (United States)

    Dalmia, Avinash

    2017-03-01

    A rapid method, with minimal sample preparation and no chromatography, was developed for analyzing food samples such as olive oil and pomegranate juice to measure adulteration with cheaper ingredients using the novel Direct Sample Analysis™ (DSA) ion source in conjunction with a time-of-flight (TOF)-MS. In less than 30 s, with minimal sample preparation and method development, adulteration of olive oil and pomegranate juice with cheaper seed oils and fruit juices, respectively, was measured with DSA/TOF-MS.

  2. Membrane-based sample preparation for ion chromatography-Techniques, instrumental configurations and applications.

    Science.gov (United States)

    Frenzel, Wolfgang; Markeviciute, Inga

    2017-01-06

    Sample preparation is the bottleneck of many analytical methods, including ion chromatography (IC). Procedures based on the application of membranes are important, yet not well appreciated means for clean-up and analyte preconcentration of liquid samples. Filtration, ultrafiltration, the variety of dialysis techniques, i.e. passive dialysis, Donnan dialysis and electrodialysis, as well as gas-diffusion are being reviewed here with respect to their application in combination with IC. Instrumental aspects including hardware requirements, configuration of membrane separation units and membrane characteristics are presented. Operation in batch and flow-through mode is described with emphasis on the latter to in-line coupling with IC, permitting fully automated operation. Attention is also drawn to dialysis probes and microdialysis both providing options for in-situ measurements with inherent selective sampling of analytes and sample preparation. The respective features of the various techniques are outlined with respect to the possibilities of matrix removal and selectivity enhancement. In this article, we provide examples of application of the diverse membrane separation techniques and discuss the benefits and limitations thereof.

  3. Comparison of two sample preparation procedures for HPLC determination of ochratoxin A

    Directory of Open Access Journals (Sweden)

    Vuković Gorica L.

    2009-01-01

    Full Text Available In preparation of samples for chromatographic determination of ochratoxin A, two types of columns were used for sample cleanup (SPE and immunoaffinity columns. The first method consisted of liquid-liquid extraction with a mixture of chloroform and phosphoric acid, followed by ion-exchange cleanup on Waters Oasis MAX columns. The sec­ond method consisted of extraction with a mixture of water and methanol, followed by LCTech OtaCLEAN immunoaf­finity column cleanup. Recoveries of the methods were determined at three levels in three repetitions for maize flour, and they were 84% (%RSD = 19.2 for the first method of sample preparation and 101% (%RSD = 2.2 for the second method. Values of LOQ for OTA were 0.25 and 1.00 μg/kg for the IAC and SPE clean-up procedures, respectively. Both methods comply with present regulations, but the MAX sample clean-up procedure should be used as an alternative, since the immunoaffinity column clean-up procedure is characterized by better reproducibility, accuracy, and efficiency.

  4. Removal of interfering substances in samples prepared for two-dimensional (2-D) electrophoresis.

    Science.gov (United States)

    Berkelman, Tom

    2008-01-01

    Biological samples may contain contaminants that interfere with analysis by two-dimensional (2-D) electrophoresis. Lysates or biological fluids are complex mixtures that contain a wide variety of nonprotein substances in addition to the proteins to be analyzed. These substances often interfere with the resolution of the electrophoretic separation or the visualization of the result. Macromolecules (e.g., polysaccharides and DNA) can interfere with electrophoretic separation by clogging gel pores. Small ionic molecules can impair isoelectric focusing (IEF) separation by rendering the sample too conductive. Other substances (e.g., phenolics and lipids) can bind to proteins, influencing their electrophoretic properties or solubility. In many cases, measures to remove interfering substances can result in significantly clearer 2-D patterns with more visible spots and better resolution. It should be borne in mind, however, that analysis of samples by 2-D electrophoresis is usually most successful and informative when performed with minimally processed samples, so it is important that any steps taken to remove interfering substance be appropriate to the sample and only performed when necessary. Procedures for the removal of interfering substances therefore represent a compromise between removing nonprotein contaminants, and minimizing interference with the integrity and relative abundances of the sample proteins. This chapter presents a number of illustrative examples of optimized sample preparation methods in which specific interfering substances are removed by a variety of different strategies.

  5. Precise quantification of dialysis using continuous sampling of spent dialysate and total dialysate volume measurement.

    Science.gov (United States)

    Argilés, A; Ficheux, A; Thomas, M; Bosc, J Y; Kerr, P G; Lorho, R; Flavier, J L; Stec, F; Adelé, C; Leblanc, M; Garred, L J; Canaud, B; Mion, H; Mion, C M

    1997-08-01

    The "gold standard" method to evaluate the mass balances achieved during dialysis for a given solute remains total dialysate collection (TDC). However, since handling over 100 liter volumes is unfeasible in our current dialysis units, alternative methods have been proposed, including urea kinetic modeling, partial dialysate collection (PDC) and more recently, monitoring of dialysate urea by on-line devices. Concerned by the complexity and costs generated by these devices, we aimed to adapt the simple "gold standard" TDC method to clinical practice by diminishing the total volumes to be handled. We describe a new system based on partial dialysate collection, the continuous spent sampling of dialysate (CSSD), and present its technical validation. Further, and for the first time, we report a long-term assessment of dialysis dosage in a dialysis clinic using both the classical PDC and the new CSSD system in a group of six stable dialysis patients who were followed for a period of three years. For the CSSD technique, spent dialysate was continuously sampled by a reversed automatic infusion pump at a rate of 10 ml/hr. The piston was automatically driven by the dialysis machine: switched on when dialysis started, off when dialysis terminated and held during the by pass periods. At the same time the number of production cycles of dialysate was monitored and the total volume of dialysate was calculated by multiplying the volume of the production chamber by the number of cycles. Urea and creatinine concentrations were measured in the syringe and the masses were obtained by multiplying this concentration by the total volume. CSSD and TDC were simultaneously performed in 20 dialysis sessions. The total mass of urea removed was calculated as 58038 and 60442 mmol/session (CSSD and TDC respectively; 3.1 +/- 1.2% variation; r = 0.99; y = 0.92x -28.9; P urea removal: 510 +/- 59 during the first year with PDC and 516 +/- 46 mmol/dialysis session during the third year, using CSSD

  6. Investigation of resins suitable for the preparation of biological sample for 3-D electron microscopy.

    Science.gov (United States)

    Kizilyaprak, Caroline; Longo, Giovanni; Daraspe, Jean; Humbel, Bruno M

    2015-02-01

    In the last two decades, the third-dimension has become a focus of attention in electron microscopy to better understand the interactions within subcellular compartments. Initially, transmission electron tomography (TEM tomography) was introduced to image the cell volume in semi-thin sections (∼ 500 nm). With the introduction of the focused ion beam scanning electron microscope, a new tool, FIB-SEM tomography, became available to image much larger volumes. During TEM tomography and FIB-SEM tomography, the resin section is exposed to a high electron/ion dose such that the stability of the resin embedded biological sample becomes an important issue. The shrinkage of a resin section in each dimension, especially in depth, is a well-known phenomenon. To ensure the dimensional integrity of the final volume of the cell, it is important to assess the properties of the different resins and determine the formulation which has the best stability in the electron/ion beam. Here, eight different resin formulations were examined. The effects of radiation damage were evaluated after different times of TEM irradiation. To get additional information on mass-loss and the physical properties of the resins (stiffness and adhesion), the topography of the irradiated areas was analysed with atomic force microscopy (AFM). Further, the behaviour of the resins was analysed after ion milling of the surface of the sample with different ion currents. In conclusion, two resin formulations, Hard Plus and the mixture of Durcupan/Epon, emerged that were considerably less affected and reasonably stable in the electron/ion beam and thus suitable for the 3-D investigation of biological samples.

  7. Automated radioanalytical system incorporating microwave-assisted sample preparation, chemical separation, and online radiometric detection for the monitoring of total 99Tc in nuclear waste processing streams.

    Science.gov (United States)

    Egorov, Oleg B; O'Hara, Matthew J; Grate, Jay W

    2012-04-03

    An automated fluidic instrument is described that rapidly determines the total (99)Tc content of aged nuclear waste samples, where the matrix is chemically and radiologically complex and the existing speciation of the (99)Tc is variable. The monitor links microwave-assisted sample preparation with an automated anion exchange column separation and detection using a flow-through solid scintillator detector. The sample preparation steps acidify the sample, decompose organics, and convert all Tc species to the pertechnetate anion. The column-based anion exchange procedure separates the pertechnetate from the complex sample matrix, so that radiometric detection can provide accurate measurement of (99)Tc. We developed a preprogrammed spike addition procedure to automatically determine matrix-matched calibration. The overall measurement efficiency that is determined simultaneously provides a self-diagnostic parameter for the radiochemical separation and overall instrument function. Continuous, automated operation was demonstrated over the course of 54 h, which resulted in the analysis of 215 samples plus 54 hly spike-addition samples, with consistent overall measurement efficiency for the operation of the monitor. A sample can be processed and measured automatically in just 12.5 min with a detection limit of 23.5 Bq/mL of (99)Tc in low activity waste (0.495 mL sample volume), with better than 10% RSD precision at concentrations above the quantification limit. This rapid automated analysis method was developed to support nuclear waste processing operations planned for the Hanford nuclear site.

  8. A developed wedge fixtures assisted high precision TEM samples pre-thinning method: Towards the batch lamella preparation

    Directory of Open Access Journals (Sweden)

    Dandan Wang

    2017-04-01

    Full Text Available Ion milling, wedge cutting or polishing, and focused ion beam (FIB milling are widely-used techniques for the transmission electron microscope (TEM sample preparation. Especially, the FIB milling provides a site-specific analysis, deposition, and ablation of materials in the micrometer and nanometer scale. However, the cost of FIB tools has been always a significant concern. Since it is inevitable to use the FIB technique, the improvement of efficiency is a key point. Traditional TEM sample preparation with FIB was routinely implemented on a single sample each time. Aiming at cost efficiency, a new pre-thinning technique for batch sample preparation was developed in this paper. The present proposal combines the sample preparation techniques with multi-samples thinning, cross-section scanning electron microscopy (SEM, wedge cutting, FIB and other sample pre-thinning techniques. The new pre-thinning technique is to prepare an edge TEM sample on a grinding and polishing fixture with a slant surface. The thickness of the wedges sample can be measured to 1∼2 μm under optical microscope. Therefore, this fixture is superior to the traditional optical method of estimating the membrane thickness. Moreover, by utilizing a multi-sample holding fixture, more samples can be pre-thinned simultaneously, which significantly improved the productivity of TEM sample preparation.

  9. Evaluation of neon focused ion beam milling for TEM sample preparation.

    Science.gov (United States)

    Pekin, T C; Allen, F I; Minor, A M

    2016-10-01

    Gallium-based focused ion beams generated from liquid-metal sources are widely used in micromachining and sample preparation for transmission electron microscopy, with well-known drawbacks such as sample damage and contamination. In this work, an alternative (neon) focused ion beam generated by a gas field-ionization source is evaluated for the preparation of electron-transparent specimens. To do so, electron-transparent sections of Si and an Al alloy are prepared with both Ga and Ne ion beams for direct comparison. Diffraction-contrast imaging and energy dispersive x-ray spectroscopy are used to evaluate the relative damage induced by the two beams, and cross-sections of milled trenches are examined to compare the implantation depth with theoretical predictions from Monte Carlo simulations. Our results show that for the beam voltages and materials systems investigated, Ne ion beam milling does not significantly reduce the focused ion beam induced artefacts. However, the Ne ion beam does enable more precise milling and may be of interest in cases where Ga contamination cannot be tolerated.

  10. A Novel Sample Preparation for Shotgun Proteomics Characterization of HCPs in Antibodies.

    Science.gov (United States)

    Huang, Lihua; Wang, Ning; Mitchell, Charles E; Brownlee, Tammy; Maple, Steven R; De Felippis, Michael R

    2017-05-16

    Residual host cell proteins (HCPs) in biopharmaceuticals derived from recombinant DNA technology can present potential safety risks to patients or compromise product stability. Thus, the downstream purification process is designed to demonstrate robust removal of these impurities. ELISA using polyclonal anti-HCP antibodies as reagents for capture, detection, and quantitation purposes is most commonly used to monitor HCP removal during process development, but this technique has limitations. More recently, LC-MS for residual HCP characterization has emerged as a powerful tool to support purification process development. However, mass spectrometry needs to overcome the enormous dynamic range to detect low ppm levels of residual HCPs in biopharmaceutical samples. We describe a simple and powerful methodology to characterize residual HCPs in (monoclonal) antibodies by combining a novel sample preparation procedure using trypsin digestion and a shotgun proteomics approach. Differing from the traditional methodology, the sample preparation approach maintains nearly intact antibody while HCPs are digested. Thus, the dynamic range for HCP detection by MS is 1 to 2 orders of magnitude less than the traditional trypsin digestion sample preparation procedure. HCP spiking experiments demonstrated that our method could detect 0.5 ppm of HCP with molecular weight >60 kDa, such as rPLBL2. Application of our method to analyze a high-purity NIST monoclonal antibody standard RM 8670 derived from a murine cell line expression system resulted in detection of 60 mouse HCPs; twice as many as previously reported with 2D-UPLC/IM/MS(E) method. A control monoclonal antibody used for 70 analyses over 450 days demonstrated that our method is robust.

  11. Novel sample preparation method for surfactant containing suppositories: effect of micelle formation on drug recovery.

    Science.gov (United States)

    Kalmár, Éva; Ueno, Konomi; Forgó, Péter; Szakonyi, Gerda; Dombi, György

    2013-09-01

    Rectal drug delivery is currently at the focus of attention. Surfactants promote drug release from the suppository bases and enhance the formulation properties. The aim of our work was to develop a sample preparation method for HPLC analysis for a suppository base containing 95% hard fat, 2.5% Tween 20 and 2.5% Tween 60. A conventional sample preparation method did not provide successful results as the recovery of the drug failed to fulfil the validation criterion 95-105%. This was caused by the non-ionic surfactants in the suppository base incorporating some of the drug, preventing its release. As guidance for the formulation from an analytical aspect, we suggest a well defined surfactant content based on the turbidimetric determination of the CMC (critical micelle formation concentration) in the applied methanol-water solvent. Our CMC data correlate well with the results of previous studies. As regards the sample preparation procedure, a study was performed of the effects of ionic strength and pH on the drug recovery with the avoidance of degradation of the drug during the procedure. Aminophenazone and paracetamol were used as model drugs. The optimum conditions for drug release from the molten suppository base were found to be 100 mM NaCl, 20-40 mM NaOH and a 30 min ultrasonic treatment of the final sample solution. As these conditions could cause the degradation of the drugs in the solution, this was followed by NMR spectroscopy, and the results indicated that degradation did not take place. The determined CMCs were 0.08 mM for Tween 20, 0.06 mM for Tween 60 and 0.04 mM for a combined Tween 20, Tween 60 system. Copyright © 2013 Elsevier B.V. All rights reserved.

  12. INFLUENCE OF SAMPLE THICKNESS ON ISOTHERMAL CRYSTALLIZATION KINETICS OF POLYMERS IN A CONFINED VOLUME

    Institute of Scientific and Technical Information of China (English)

    Hui Sun; Zhi-ying Zhang; Shi-zhen Wu; Bin Yu; Chang-fa Xiao

    2005-01-01

    Isothermal crystallization process of polymers in a confined volume was simulated in the case of instantaneous nucleation by use of the Monte Carlo method. The influence of sample thickness on some kinetic parameters of crystallization was quantitatively evaluated. It was found that there was a critical thickness value. Influence of thickness on the crystallization behavior was only found for samples of thickness near and less than the critical value. For thick samples the Avrami plot showed straight lines with a turning point at the late stage of crystallization due to the secondary crystallization. When the thickness was near or less than the critical value a primary turning point appeared in the Avrami plot at the very beginning of the crystallization process. A model was proposed to explain the mechanism of this phenomenon. According to this model the critical thickness value is related to the nucleation density or the average distance between adjacent nuclei, and the primary turning point is an indication of a transformation of crystal growth geometry from a three-dimensional mode to a two-dimensional one. Analysis of experimental results of PEO isothermally crystallized at 53.5℃ was consistent with the proposed model.

  13. Sample preparation methods for beeswax characterization by gas chromatography with flame ionization detection.

    Science.gov (United States)

    Jiménez, J J; Bernal, J L; del Nozal, M A J; Martín, M A T; Bernal, J

    2006-10-06

    New and simpler methods of sample preparation to determine several families of compounds in beeswax by conventional and high temperature gas chromatography are proposed. To analyze hydrocarbons and palmitates, a dilution of sample is enough whereas for the total acid content, a hydrolysis and simultaneous methylation with BF3-methanol results more effective than the usual methods; for the total content of alcohols, a further acetylation with acetic anhydride is necessary. Free alcohols are directly acetylated in a sample dissolution but for free acids and monoesterified 1,2,3-propanetriols analysis, a previous extraction with acetonitrile is required. The concentrations of all the compounds studied are expressed in weight percentage referred only to one standard: octadecyl octadecanoate. The precision of the analytical methods has been evaluated showing its importance in the analysis of beeswaxes used in apiculture.

  14. SAMPLING ARTIFACTS IN MEASUREMENT OF ELEMENTAL AND ORGANIC CARBON: LOW VOLUME SAMPLING IN INDOOR AND OUTDOOR ENVIRONMENTS

    Science.gov (United States)

    Experiments were completed to determine the extent of artifacts from sampling elemental carbon (EC) and organic carbon (OC) under sample conditions consistent with personal sampling. Two different types of experiments were completed; the first examined possible artifacts from oil...

  15. Practical Guide to Using Cryoprotectants in Biological Sample Preparation at Cryogenic temperature for Electron Microscopic Studies

    Directory of Open Access Journals (Sweden)

    A-Reum Je

    2011-10-01

    Full Text Available Cryo-fixation enables the preservation of the fine structures of intracellular organelles in a condition that is as close to their native state as possible compared with chemical fixation and room temperature processing. Fixation is the initial step for biological sample preparation in electron microscopy. This step is critically important because the goals of electron microscopic observation are fundamentally dependent on well-preserved specimens resulting from this fixation. In the present work, key components of cryo-fixation, cryoprotectants, are tested with various cell types of interest. The results show that dextran can be easily adapted for use with animal cells and cyanobacteria, whereas 1-hexadecene is applicable to plant and yeast cells. The current report provides useful information on the preparation of cryo-fixed biological specimens using high pressure freezing and freeze-substitution aimed at electron microscopic observation.

  16. Laboratory Investigation of Rivers State Clay Samples for Drilling Mud Preparation

    Directory of Open Access Journals (Sweden)

    Nmegbu, Chukwuma Godwin Jacob

    2014-06-01

    Full Text Available Drilling fluids are an integral part of any oil and gas industry, providing the ease to which wells are drilled to access subsurface reservoir fluids. Certain rheology and mineralogical properties of the clay material used for drilling mud preparation must be critically investigated since clay deposits in different location exhibits different characteristics. Clay samples were collected from three different geographical locations namely; Egbamini (Emolga, Afam Street (Port Harcourt and Oboboru (onelga local government areas in Rivers state. Their rheological and wall building properties were measured in the laboratory to determine their suitability for drilling mud formulation. Results showed that in their respective native states, they proved unsuitable for drilling mud preparation when compared to standard Bentonite because they were observed to show responses far below the required API standards for mud formulation.

  17. Preparation of carbon-nitride bulk samples in the presence of seed carbon-nitride films

    Energy Technology Data Exchange (ETDEWEB)

    Kim, J. I. [Korea University of Technology and Education, Chonan (Korea, Republic of); Zorov, N. B. [Moscow State University, Moscow (Russian Federation)

    2004-05-15

    A procedure was developed for preparing bulk carbon-nitride crystals from polymeric alpha-C{sub 3}N{sub 4.2} at high pressure and high temperature in the presence of seeds of crystalline carbon-nitride films prepared by using a high-voltage discharge plasma combined with pulsed laser ablation of a graphite target. The samples were evaluated by using X-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy, Auger electron spectroscopy (AES), secondary-ion mass spectrometry (SIMS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Notably, XPS studies of the film composition before and after thermobaric treatments demonstrated that the nitrogen composition in the alpha-C{sub 3}N{sub 4.2} material, which initially contained more than 58 % nitrogen, decreased during the annealing process and reached a common, stable composition of approx 45 %. The thermobaric experiments were performed at 10 - 77 kbar and 350 - 1200 .deg. C.

  18. Improved sample preparation for CE-LIF analysis of plant N-glycans.

    Science.gov (United States)

    Nagels, Bieke; Santens, Francis; Weterings, Koen; Van Damme, Els J M; Callewaert, Nico

    2011-12-01

    In view of glycomics studies in plants, it is important to have sensitive tools that allow one to analyze and characterize the N-glycans present on plant proteins in different species. Earlier methods combined plant-based sample preparations with CE-LIF N-glycan analysis but suffered from background contaminations, often resulting in non-reproducible results. This publication describes a reproducible and sensitive protocol for the preparation and analysis of plant N-glycans, based on a combination of the 'in-gel release method' and N-glycan analysis on a multicapillary DNA sequencer. Our protocol makes it possible to analyze plant N-glycans starting from low amounts of plant material with highly reproducible results. The developed protocol was validated for different plant species and plant cells.

  19. A generic sample preparation approach for LC–MS/MS bioanalysis of therapeutic monoclonal antibodies in serum applied to Infliximab

    Directory of Open Access Journals (Sweden)

    Anne J. Kleinnijenhuis

    2015-01-01

    Full Text Available In this study, we developed a generic bioanalytical workflow providing sensitive, specific, and accurate absolute quantification of therapeutic monoclonal antibodies in serum. The workflow involves magnetic beads coated with protein A to pull-down therapeutic monoclonal antibodies with affinity for protein A from the biological matrix, followed by tryptic digestion and LC-MS/MS quantification of a unique signature peptide, considering of course the matrix of interest and other present mAbs, if applicable. The feasibility of this approach was demonstrated for Infliximab (trade name Remicade in rat serum. The assigned signature peptide was monitored in the selected reaction monitoring (SRM mode. Assay variability was determined to be below 20%, except at the QC low level, which was provided through optimization of the sample preparation and monitoring of the LC-MS/MS using a stable isotope labeled signature peptide as internal standard. The 100 ng/ml lower limit of quantification using only 25 μl sample volume, is generally considered as sufficient for pharmaceutical development purposes for monoclonal antibodies.

  20. Human genomic DNA analysis using a semi-automated sample preparation, amplification, and electrophoresis separation platform.

    Science.gov (United States)

    Raisi, Fariba; Blizard, Benjamin A; Raissi Shabari, Akbar; Ching, Jesus; Kintz, Gregory J; Mitchell, Jim; Lemoff, Asuncion; Taylor, Mike T; Weir, Fred; Western, Linda; Wong, Wendy; Joshi, Rekha; Howland, Pamela; Chauhan, Avinash; Nguyen, Peter; Petersen, Kurt E

    2004-03-01

    The growing importance of analyzing the human genome to detect hereditary and infectious diseases associated with specific DNA sequences has motivated us to develop automated devices to integrate sample preparation, real-time PCR, and microchannel electrophoresis (MCE). In this report, we present results from an optimized compact system capable of processing a raw sample of blood, extracting the DNA, and performing a multiplexed PCR reaction. Finally, an innovative electrophoretic separation was performed on the post-PCR products using a unique MCE system. The sample preparation system extracted and lysed white blood cells (WBC) from whole blood, producing DNA of sufficient quantity and quality for a polymerase chain reaction (PCR). Separation of multiple amplicons was achieved in a microfabricated channel 30 microm x 100 microm in cross section and 85 mm in length filled with a replaceable methyl cellulose matrix operated under denaturing conditions at 50 degrees C. By incorporating fluorescent-labeled primers in the PCR, the amplicons were identified by a two-color (multiplexed) fluorescence detection system. Two base-pair resolution of single-stranded DNA (PCR products) was achieved. We believe that this integrated system provides a unique solution for DNA analysis.

  1. Sample preparation for laser-microdissection of soybean shoot apical meristem

    Directory of Open Access Journals (Sweden)

    Chui E. Wong

    2012-10-01

    Full Text Available The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissection. Here, we optimized the sample preparation for a major legume crop, soybean. We used Farmer’s solution as a fixative and paraffin as the embedding medium for soybean shoot apical meristem tissue without the use of any specialized equipment. Shorter time for tissue fixation (two days was found to be critical for the preservation of RNA in soybean shoot apical meristem. We further demonstrated the utility of this method for different tissues derived from soybean and rice. The method outlined here shall facilitate studies on crop plants involving laser-microdissection.

  2. Gel-aided sample preparation (GASP)--a simplified method for gel-assisted proteomic sample generation from protein extracts and intact cells.

    Science.gov (United States)

    Fischer, Roman; Kessler, Benedikt M

    2015-04-01

    We describe a "gel-assisted" proteomic sample preparation method for MS analysis. Solubilized protein extracts or intact cells are copolymerized with acrylamide, facilitating denaturation, reduction, quantitative cysteine alkylation, and matrix formation. Gel-aided sample preparation has been optimized to be highly flexible, scalable, and to allow reproducible sample generation from 50 cells to milligrams of protein extracts. This methodology is fast, sensitive, easy-to-use on a wide range of sample types, and accessible to nonspecialists. © 2014 The Authors. PROTEOMICS published by Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Error baseline rates of five sample preparation methods used to characterize RNA virus populations

    Science.gov (United States)

    Kugelman, Jeffrey R.; Wiley, Michael R.; Nagle, Elyse R.; Reyes, Daniel; Pfeffer, Brad P.; Kuhn, Jens H.; Sanchez-Lockhart, Mariano; Palacios, Gustavo F.

    2017-01-01

    Individual RNA viruses typically occur as populations of genomes that differ slightly from each other due to mutations introduced by the error-prone viral polymerase. Understanding the variability of RNA virus genome populations is critical for understanding virus evolution because individual mutant genomes may gain evolutionary selective advantages and give rise to dominant subpopulations, possibly even leading to the emergence of viruses resistant to medical countermeasures. Reverse transcription of virus genome populations followed by next-generation sequencing is the only available method to characterize variation for RNA viruses. However, both steps may lead to the introduction of artificial mutations, thereby skewing the data. To better understand how such errors are introduced during sample preparation, we determined and compared error baseline rates of five different sample preparation methods by analyzing in vitro transcribed Ebola virus RNA from an artificial plasmid-based system. These methods included: shotgun sequencing from plasmid DNA or in vitro transcribed RNA as a basic “no amplification” method, amplicon sequencing from the plasmid DNA or in vitro transcribed RNA as a “targeted” amplification method, sequence-independent single-primer amplification (SISPA) as a “random” amplification method, rolling circle reverse transcription sequencing (CirSeq) as an advanced “no amplification” method, and Illumina TruSeq RNA Access as a “targeted” enrichment method. The measured error frequencies indicate that RNA Access offers the best tradeoff between sensitivity and sample preparation error (1.4−5) of all compared methods. PMID:28182717

  4. Simple, Expendable, 3D-Printed Microfluidic Systems for Sample Preparation of Petroleum.

    Science.gov (United States)

    Kataoka, Érica M; Murer, Rui C; Santos, Jandyson M; Carvalho, Rogério M; Eberlin, Marcos N; Augusto, Fabio; Poppi, Ronei J; Gobbi, Angelo L; Hantao, Leandro W

    2017-03-21

    In this study, we introduce a simple protocol to manufacture disposable, 3D-printed microfluidic systems for sample preparation of petroleum. This platform is produced with a consumer-grade 3D-printer, using fused deposition modeling. Successful incorporation of solid-phase extraction (SPE) to microchip was ensured by facile 3D element integration using proposed approach. This 3D-printed μSPE device was applied to challenging matrices in oil and gas industry, such as crude oil and oil-brine emulsions. Case studies investigated important limitations of nonsilicon and nonglass microchips, namely, resistance to nonpolar solvents and conservation of sample integrity. Microfluidic features remained fully functional even after prolonged exposure to nonpolar solvents (20 min). Also, 3D-printed μSPE devices enabled fast emulsion breaking and solvent deasphalting of petroleum, yielding high recovery values (98%) without compromising maltene integrity. Such finding was ascertained by high-resolution molecular analyses using comprehensive two-dimensional gas chromatography and gas chromatography/mass spectrometry by monitoring important biomarker classes, such as C10 demethylated terpanes, ααα-steranes, and monoaromatic steroids. 3D-Printed chips enabled faster and reliable preparation of maltenes by exhibiting a 10-fold reduction in sample processing time, compared to the reference method. Furthermore, polar (oxygen-, nitrogen-, and sulfur-containing) analytes found in low-concentrations were analyzed by Fourier transform ion cyclotron resonance mass spectrometry. Analysis results demonstrated that accurate characterization may be accomplished for most classes of polar compounds, except for asphaltenes, which exhibited lower recoveries (82%) due to irreversible adsorption to sorbent phase. Therefore, 3D-printing is a compelling alternative to existing microfabrication solutions, as robust devices were easy to prepare and operate.

  5. Review of sample preparation strategies for MS-based metabolomic studies in industrial biotechnology.

    Science.gov (United States)

    Causon, Tim J; Hann, Stephan

    2016-09-28

    Fermentation and cell culture biotechnology in the form of so-called "cell factories" now play an increasingly significant role in production of both large (e.g. proteins, biopharmaceuticals) and small organic molecules for a wide variety of applications. However, associated metabolic engineering optimisation processes relying on genetic modification of organisms used in cell factories, or alteration of production conditions remain a challenging undertaking for improving the final yield and quality of cell factory products. In addition to genomic, transcriptomic and proteomic workflows, analytical metabolomics continues to play a critical role in studying detailed aspects of critical pathways (e.g. via targeted quantification of metabolites), identification of biosynthetic intermediates, and also for phenotype differentiation and the elucidation of previously unknown pathways (e.g. via non-targeted strategies). However, the diversity of primary and secondary metabolites and the broad concentration ranges encompassed during typical biotechnological processes means that simultaneous extraction and robust analytical determination of all parts of interest of the metabolome is effectively impossible. As the integration of metabolome data with transcriptome and proteome data is an essential goal of both targeted and non-targeted methods addressing production optimisation goals, additional sample preparation steps beyond necessary sampling, quenching and extraction protocols including clean-up, analyte enrichment, and derivatisation are important considerations for some classes of metabolites, especially those present in low concentrations or exhibiting poor stability. This contribution critically assesses the potential of current sample preparation strategies applied in metabolomic studies of industrially-relevant cell factory organisms using mass spectrometry-based platforms primarily coupled to liquid-phase sample introduction (i.e. flow injection, liquid

  6. Effects of sample preparation conditions on biomolecular solid-state NMR lineshapes

    Energy Technology Data Exchange (ETDEWEB)

    Jakeman, David L.; Mitchell, Dan J.; Shuttleworth, Wendy A.; Evans, Jeremy N.S. [Washington State University, Department of Biochemistry and Biophysics (United States)

    1998-10-15

    Sample preparation conditions with the 46 kDa enzyme complex of 5-enolpyruvyl-shikimate-3-phosphate (EPSP) synthase, shikimate-3-phosphate (S3P) and glyphosate (GLP) have been examined in an attempt to reduce linewidths in solid-state NMR spectra. The linewidths of {sup 13}P resonances associated with enzyme bound S3P and GLP in the lyophilized ternary complex have been reduced to 150 {+-} 12 Hz and 125 {+-} 7 Hz respectively, by a variety of methods involving additives and freezing techniques.

  7. Petrophysical studies of north American carbonate rock samples and evaluation of pore-volume compressibility models

    Science.gov (United States)

    da Silva, Gilberto Peixoto; Franco, Daniel R.; Stael, Giovanni C.; da Costa de Oliveira Lima, Maira; Sant'Anna Martins, Ricardo; de Moraes França, Olívia; Azeredo, Rodrigo B. V.

    2015-12-01

    In this work, we evaluate two pore volume compressibility models that are currently discussed in the literature (Horne, 1990; Jalalh, 2006b). Five groups of carbonate rock samples from the three following sedimentary basins in North America that are known for their association with hydrocarbon deposits were selected for this study: (i) the Guelph Formation of the Michigan Basin (Middle Silurian); (ii) the Edwards Formation of the Central Texas Platform (Middle Cretaceous); and (iii) the Burlington-Keokuk Formation of the Mississippian System (Lower Mississippian). In addition to the evaluation of the compressibility model, a petrophysical evaluation of these rock samples was conducted. Additional characterizations, such as grain density, the effective porosity, absolute grain permeability, thin section petrography, MICP and NMR, were performed to complement constant pore-pressure compressibility tests. Although both models presented an overall good representation of the compressibility behavior of the studied carbonate rocks, even when considering their broad porosity range (~ 2-38%), the model proposed by Jalalh (2006b) performed better with a confidence level of 95% and a prediction interval of 68%.

  8. Sample preparation and separation techniques for bioanalysis of morphine and related substances.

    Science.gov (United States)

    Hansen, Steen Honoré

    2009-03-01

    In present time the use or misuse of morphine and its derivatives are monitored by assaying the presence of the drug and its metabolites in biofluids. In the present review, focus is placed on the sample preparation and on the separation techniques used in the current best practices of bioanalysis of morphine and its major metabolites. However, as methods for testing the misuse of heroin, a morphine derivative, often involve bioanalytical methods that cover a number of other illicit drug substances, such methods are also included in the review. Furthermore, the review also includes bioanalysis in a broader perspective as analysis of plant materials, cell cultures and environmental samples. The review is not intended to cover all publications that include bioanalysis of morphine but is more to be considered a view into the current best practices of bioanalysis of morphine, its metabolites and other related substances.

  9. Capacitive deionization on-chip as a method for microfluidic sample preparation.

    Science.gov (United States)

    Roelofs, Susan H; Kim, Bumjoo; Eijkel, Jan C T; Han, Jongyoon; van den Berg, Albert; Odijk, Mathieu

    2015-03-21

    Desalination as a sample preparation step is essential for noise reduction and reproducibility of mass spectrometry measurements. A specific example is the analysis of proteins for medical research and clinical applications. Salts and buffers that are present in samples need to be removed before analysis to improve the signal-to-noise ratio. Capacitive deionization is an electrostatic desalination (CDI) technique which uses two porous electrodes facing each other to remove ions from a solution. Upon the application of a potential of 0.5 V ions migrate to the electrodes and are stored in the electrical double layer. In this article we demonstrate CDI on a chip, and desalinate a solution by the removal of 23% of Na(+) and Cl(-) ions, while the concentration of a larger molecule (FITC-dextran) remains unchanged. For the first time impedance spectroscopy is introduced to monitor the salt concentration in situ in real-time in between the two desalination electrodes.

  10. Desorption of Herbicides from Atmospheric Particulates During High-Volume Air Sampling

    Directory of Open Access Journals (Sweden)

    Dwight V. Quiring

    2011-11-01

    Full Text Available Pesticides can be present in the atmosphere either as vapours and/or in association with suspended particles. High-volume air sampling, in which air is aspirated first through a glass fibre filter to capture pesticides associated with atmospheric particulates and then polyurethane foam (PUF, often in combination with an adsorbent resin such as XAD-2, to capture pesticides present as vapours, is generally employed during atmospheric monitoring for pesticides. However, the particulate fraction may be underestimated because some pesticides may be stripped or desorbed from captured particulates due to the pressure drop created by the high flow of air through the filter. This possibility was investigated with ten herbicide active ingredients commonly used on the Canadian prairies (dimethylamine salts of 2,4-D, MCPA and dicamba, 2,4-D 2-ethylhexyl ester, bromoxynil octanoate, diclofop methyl ester, fenoxaprop ethyl ester, trifluralin, triallate and ethalfluralin and seven hydrolysis products (2,4-D, MCPA, dicamba, bromoxynil, diclofop, clopyralid and mecoprop. Finely ground heavy clay soil fortified with active ingredients/hydrolysis products was evenly distributed on the glass fibre filters of high-volume air samplers and air aspirated through the samplers at a flow rate of 12.5 m3/h for a 7-day period. The proportion desorbed as vapour from the fortified soil was determined by analysis of the PUF/XAD-2 resin composite cartridges. The extent of desorption from the fortified soil applied to the filters varied from 0% for each of the dimethylamine salts of 2,4-D, MCPA and dicamba to approximately 50% for trifluralin, triallate and ethalfluralin.

  11. Recent developments on field gas extraction and sample preparation methods for radiokrypton dating of groundwater

    Science.gov (United States)

    Yokochi, Reika

    2016-09-01

    Current and foreseen population growths will lead to an increased demand in freshwater, large quantities of which is stored as groundwater. The ventilation age is crucial to the assessment of groundwater resources, complementing the hydrological model approach based on hydrogeological parameters. Ultra-trace radioactive isotopes of Kr (81 Kr and 85 Kr) possess the ideal physical and chemical properties for groundwater dating. The recent advent of atom trap trace analyses (ATTA) has enabled determination of ultra-trace noble gas radioisotope abundances using 5-10 μ L of pure Kr. Anticipated developments will enable ATTA to analyze radiokrypton isotope abundances at high sample throughput, which necessitates simple and efficient sample preparation techniques that are adaptable to various sample chemistries. Recent developments of field gas extraction devices and simple and rapid Kr separation method at the University of Chicago are presented herein. Two field gas extraction devices optimized for different sampling conditions were recently designed and constructed, aiming at operational simplicity and portability. A newly developed Kr purification system enriches Kr by flowing a sample gas through a moderately cooled (138 K) activated charcoal column, followed by a gentle fractionating desorption. This simple process uses a single adsorbent and separates 99% of the bulk atmospheric gases from Kr without significant loss. The subsequent two stages of gas chromatographic separation and a hot Ti sponge getter further purify the Kr-enriched gas. Abundant CH4 necessitates multiple passages through one of the gas chromatographic separation columns. The presented Kr separation system has a demonstrated capability of extracting Kr with > 90% yield and 99% purity within 75 min from 1.2 to 26.8 L STP of atmospheric air with various concentrations of CH4. The apparatuses have successfully been deployed for sampling in the field and purification of groundwater samples.

  12. Matrix compatible solid phase microextraction coating, a greener approach to sample preparation in vegetable matrices.

    Science.gov (United States)

    Naccarato, Attilio; Pawliszyn, Janusz

    2016-09-01

    This work proposes the novel PDMS/DVB/PDMS fiber as a greener strategy for analysis by direct immersion solid phase microextraction (SPME) in vegetables. SPME is an established sample preparation approach that has not yet been adequately explored for food analysis in direct immersion mode due to the limitations of the available commercial coatings. The robustness and endurance of this new coating were investigated by direct immersion extractions in raw blended vegetables without any further sample preparation steps. The PDMS/DVB/PDMS coating exhibited superior features related to the capability of the external PDMS layer to protect the commercial coating, and showed improvements in terms of extraction capability and in the cleanability of the coating surface. In addition to having contributed to the recognition of the superior features of this new fiber concept before commercialization, the outcomes of this work serve to confirm advancements in the matrix compatibility of the PDMS-modified fiber, and open new prospects for the development of greener high-throughput analytical methods in food analysis using solid phase microextraction in the near future.

  13. Performance Evaluation of Fast Microfluidic Thermal Lysis of Bacteria for Diagnostic Sample Preparation

    Directory of Open Access Journals (Sweden)

    Evangelyn C. Alocilja

    2013-01-01

    Full Text Available Development of new diagnostic platforms that incorporate lab-on-a-chip technologies for portable assays is driving the need for rapid, simple, low cost methods to prepare samples for downstream processing or detection. An important component of the sample preparation process is cell lysis. In this work, a simple microfluidic thermal lysis device is used to quickly release intracellular nucleic acids and proteins without the need for additional reagents or beads used in traditional chemical or mechanical methods (e.g., chaotropic salts or bead beating. On-chip lysis is demonstrated in a multi-turn serpentine microchannel with external temperature control via an attached resistive heater. Lysis was confirmed for Escherichia coli by fluorescent viability assay, release of ATP measured with bioluminescent assay, release of DNA measured by fluorometry and qPCR, as well as bacterial culture. Results comparable to standard lysis techniques were achievable at temperatures greater than 65 °C and heating durations between 1 and 60 s.

  14. Technique for bone volume measurement from human femur head samples by classification of micro-CT image histograms

    Directory of Open Access Journals (Sweden)

    Franco Marinozzi

    2013-09-01

    Full Text Available INTRODUCTION: Micro-CT analysis is a powerful technique for a non-invasive evaluation of the morphometric parameters of trabecular bone samples. This elaboration requires a previous binarization of the images. A problem which arises from the binarization process is the partial volume artifact. Voxels at the external surface of the sample can contain both bone and air so thresholding operates an incorrect estimation of volume occupied by the two materials. AIM: The aim of this study is the extraction of bone volumetric information directly from the image histograms, by fitting them with a suitable set of functions. METHODS: Nineteen trabecular bone samples were extracted from femoral heads of eight patients subject to a hip arthroplasty surgery. Trabecular bone samples were acquired using micro-CT Scanner. Hystograms of the acquired images were computed and fitted by Gaussian-like functions accounting for: a gray levels produced by the bone x-ray absorption, b the portions of the image occupied by air and c voxels that contain a mixture of bone and air. This latter contribution can be considered such as an estimation of the partial volume effect. RESULTS: The comparison of the proposed technique to the bone volumes measured by a reference instrument such as by a helium pycnometer show the method as a good way for an accurate bone volume calculation of trabecular bone samples.

  15. Preparation of solid-state samples of a transition metal coordination compound for synchrotron radiation photoemission studies

    CERN Document Server

    Crotti, C; Celestino, T; Fontana, S

    2003-01-01

    The aim of this research was to identify a sample preparation method suitable for the study of transition metal complexes by photoemission spectroscopy with synchrotron radiation as the X-ray source, even in the case where the compound is not evaporable. Solid-phase samples of W(CO) sub 4 (dppe) [dppe=1,2-bis(diphenylphosphino)ethane] were prepared according to different methods and their synchrotron radiation XPS spectra measured. The spectra acquired from samples prepared by spin coating show core level peaks only slightly broader than the spectrum recorded from UHV evaporated samples. Moreover, for these samples the reproducibility of the binding energy values is excellent. The dependence of the spin coating technique on parameters such as solvent and solution concentration, spinning speed and support material was studied. The same preparation method also allowed the acquisition of valence band spectra, the main peaks of which were clearly resolved. The results suggest that use of the spin coating techniqu...

  16. Evaluation of sample preparation methods and optimization of nickel determination in vegetable tissues

    Directory of Open Access Journals (Sweden)

    Rodrigo Fernando dos Santos Salazar

    2011-02-01

    Full Text Available Nickel, although essential to plants, may be toxic to plants and animals. It is mainly assimilated by food ingestion. However, information about the average levels of elements (including Ni in edible vegetables from different regions is still scarce in Brazil. The objectives of this study were to: (a evaluate and optimize a method for preparation of vegetable tissue samples for Ni determination; (b optimize the analytical procedures for determination by Flame Atomic Absorption Spectrometry (FAAS and by Electrothermal Atomic Absorption (ETAAS in vegetable samples and (c determine the Ni concentration in vegetables consumed in the cities of Lorena and Taubaté in the Vale do Paraíba, State of São Paulo, Brazil. By means of the analytical technique for determination by ETAAS or FAAS, the results were validated by the test of analyte addition and recovery. The most viable method tested for quantification of this element was HClO4-HNO3 wet digestion. All samples but carrot tissue collected in Lorena contained Ni levels above the permitted by the Brazilian Ministry of Health. The most disturbing results, requiring more detailed studies, were the Ni concentrations measured in carrot samples from Taubaté, where levels were five times higher than permitted by Brazilian regulations.

  17. Preparation of Magnetic Hollow Molecularly Imprinted Polymers for Detection of Triazines in Food Samples.

    Science.gov (United States)

    Wang, Aixiang; Lu, Hongzhi; Xu, Shoufang

    2016-06-22

    Novel magnetic hollow molecularly imprinted polymers (M-H-MIPs) were proposed for highly selective recognition and fast enrichment of triazines in food samples. M-H-MIPs were prepared on the basis of multi-step swelling polymerization, followed by in situ growth of magnetic Fe3O4 nanoparticles on the surface of hollow molecularly imprinted polymers (H-MIPs). Transmission electron microscopy and scanning electron microscopy confirmed the successful immobilization of Fe3O4 nanoparticles on the surface of H-MIPs. M-H-MIPs could be separated simply using an external magnet. The binding adsorption results indicated that M-H-MIPs displayed high binding capacity and fast mass transfer property and class selective property for triazines. Langmuir isotherm and pseudo-second-order kinetic models fitted the best adsorption models for M-H-MIPs. M-H-MIPs were used to analyze atrazine, simazine, propazine, and terbuthylazine in corn, wheat, and soybean samples. Satisfactory recoveries were in the range of 80.62-101.69%, and relative standard deviation was lower than 5.2%. Limits of detection from 0.16 to 0.39 μg L(-1) were obtained. When the method was applied to test positive samples that were contaminated with triazines, the results agree well with those obtained from an accredited method. Thus, the M-H-MIP-based dispersive solid-phase extraction method proved to be a convenient and practical platform for detection of triazines in food samples.

  18. Optimized sample preparation of endoscopic collected pancreatic fluid for SDS-PAGE analysis.

    Science.gov (United States)

    Paulo, Joao A; Lee, Linda S; Wu, Bechien; Repas, Kathryn; Banks, Peter A; Conwell, Darwin L; Steen, Hanno

    2010-07-01

    The standardization of methods for human body fluid protein isolation is a critical initial step for proteomic analyses aimed to discover clinically relevant biomarkers. Several caveats have hindered pancreatic fluid proteomics, including the heterogeneity of samples and protein degradation. We aim to optimize sample handling of pancreatic fluid that has been collected using a safe and effective endoscopic collection method (endoscopic pancreatic function test). Using SDS-PAGE protein profiling, we investigate (i) precipitation techniques to maximize protein extraction, (ii) auto-digestion of pancreatic fluid following prolonged exposure to a range of temperatures, (iii) effects of multiple freeze-thaw cycles on protein stability, and (iv) the utility of protease inhibitors. Our experiments revealed that TCA precipitation resulted in the most efficient extraction of protein from pancreatic fluid of the eight methods we investigated. In addition, our data reveal that although auto-digestion of proteins is prevalent at 23 and 37 degrees C, incubation on ice significantly slows such degradation. Similarly, when the sample is maintained on ice, proteolysis is minimal during multiple freeze-thaw cycles. We have also determined the addition of protease inhibitors to be assay-dependent. Our optimized sample preparation strategy can be applied to future proteomic analyses of pancreatic fluid.

  19. Preparation of Biological Samples Containing Metoprolol and Bisoprolol for Applying Methods for Quantitative Analysis

    Directory of Open Access Journals (Sweden)

    Corina Mahu Ştefania

    2015-12-01

    Full Text Available Arterial hypertension is a complex disease with many serious complications, representing a leading cause of mortality. Selective beta-blockers such as metoprolol and bisoprolol are frequently used in the management of hypertension. Numerous analytical methods have been developed for the determination of these substances in biological fluids, such as liquid chromatography coupled with mass spectrometry, gas chromatography coupled with mass spectrometry, high performance liquid chromatography. Due to the complex composition of biological fluids a biological sample pre-treatment before the use of the method for quantitative determination is required in order to remove proteins and potential interferences. The most commonly used methods for processing biological samples containing metoprolol and bisoprolol were identified through a thorough literature search using PubMed, ScienceDirect, and Willey Journals databases. Articles published between years 2005-2015 were reviewed. Protein precipitation, liquid-liquid extraction and solid phase extraction are the main techniques for the extraction of these drugs from plasma, serum, whole blood and urine samples. In addition, numerous other techniques have been developed for the preparation of biological samples, such as dispersive liquid-liquid microextraction, carrier-mediated liquid phase microextraction, hollow fiber-protected liquid phase microextraction, on-line molecularly imprinted solid phase extraction. The analysis of metoprolol and bisoprolol in human plasma, urine and other biological fluids provides important information in clinical and toxicological trials, thus requiring the application of appropriate extraction techniques for the detection of these antihypertensive substances at nanogram and picogram levels.

  20. Determination of bromine, fluorine and iodine in mineral supplements using pyrohydrolysis for sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Taflik, Ticiane; Antes, Fabiane G.; Paniz, Jose N.G.; Flores, Erico M.M.; Dressler, Valderi L., E-mail: valdres@quimica.ufsm.br [Departamento de Quimica, Universidade Federal de Santa Maria, RS (Brazil); Duarte, Fabio A. [Escola de Quimica e Alimentos, Universidade Federal do Rio Grande, Rio Grande, RS (Brazil); Flores, Eder L.M. [Coordenacao de Engenharia de Alimentos, Universidade Tecnologica Federal do Parana, Medianeira, PR (Brazil)

    2012-03-15

    Pyrohydrolysis was employed for mineral supplements decomposition prior to F, Br and I determination. Fluoride determination was carried out by potentiometry using a fluoride-ion selective electrode, whereas Br and I were determined by inductively coupled plasma mass spectrometry. The main parameters that influence on pyrohydrolysis were investigated. After evaluation, the following conditions were established: reactor temperature of 1000 deg C during 10 min; sample plus accelerator mass ratio of 1 + 5 and carrier gas (air) flow rate of 200 mL min{sup -1} . The accuracy of the proposed method was evaluated by analyte recovery tests and analysis of certified reference materials of phosphate rock and soil. Commercial mineral supplement samples were analyzed. The limits of quantification were 16, 0.3 and 0.07 {mu}g g{sup -1} for F, Br and I, respectively. By using a relatively simple and low cost pyrohydrolysis system up to 5 samples can be processed per hour. The developed sample preparation procedure can be routinely employed for F, Br and I determination in mineral supplements. (author)

  1. Preparative divergent flow IEF without carrier ampholytes for separation of complex biological samples.

    Science.gov (United States)

    Stastna, Miroslava; Slais, Karel

    2010-01-01

    Efficient separation method is a crucial part of the process in which components of highly complex biological sample are identified and characterized. Based on the principles of recently newly established electrophoretic method called divergent flow IEF (DF IEF), we have tested the DF IEF instrument which is able to operate without the use of background carrier ampholytes. We have verified that during separation and focusing of sample consisting of high numbers of proteins (yeast lysate and wheat flour extract), the pH gradient of preparative DF IEF can be created by autofocusing of the sample components themselves without any addition of carrier ampholytes. In DF IEF, the proteins are separated, desalted and concentrated in one step. The fractions of yeast lysate sample, collected at the DF IEF output and subjected to gel IEF, contained the zones of proteins gradually covering the pI values from 3.7 to 8.5. In our experimental arrangement, the highest number of proteins has been found in fractions with pI values around 5.3 as detected by polyacrylamide gel IEF with CBB staining. During DF IEF, the selected protein bands have been concentrated up to 16.8-fold.

  2. Sample preparation for scanning electron microscopy of plant surfaces--horses for courses.

    Science.gov (United States)

    Pathan, A K; Bond, J; Gaskin, R E

    2008-12-01

    Plant tissues must be dehydrated for observation in most electron microscopes. Although a number of sample processing techniques have been developed for preserving plant tissues in their original form and structure, none of them are guaranteed artefact-free. The current paper reviews common scanning electron microscopy techniques and the sample preparation methods employed for visualisation of leaves under specific types of electron microscopes. Common artefacts introduced by specific techniques on different leaf types are discussed. Comparative examples are depicted from our lab using similar techniques; the pros and cons for specific techniques are discussed. New promising techniques and microscopes, which can alleviate some of the problems encountered in conventional methods of leaf sample processing and visualisation, are also discussed. It is concluded that the choice of technique for a specific leaf sample is dictated by the surface features that need to be preserved (such as trichomes, epidermal cells or wax microstructure), the resolution to be achieved, availability of the appropriate processing equipment and the technical capabilities of the available electron microscope.

  3. RNA SAMPLE PREPARATION APPLIED TO GENE EXPRESSION PROFILING FOR THE HORSE BIOLOGICAL PASSPORT.

    Science.gov (United States)

    Bailly-Chouriberry, Ludovic; Baudoin, Florent; Cormant, Florence; Glavieux, Yohan; Loup, Benoit; Garcia, Patrice; Popot, Marie-Agnès; Bonnaire, Yves

    2017-04-05

    The improvement of doping control is an on-going race. Techniques to fight against doping are usually based on the direct detection of drugs or their metabolites by analytical methods such as chromatography hyphenated to mass spectrometry after ad hoc sample preparation. Nowadays, omic methods constitute an attractive development and advances have been achieved particularly by application of molecular biology tools for detection of anabolic androgenic steroids (AAS), erythropoiesis-stimulating agent (ESA) or to control human growth hormone misuses. These interesting results across different animal species have suggested that modification of gene expression offers promising new methods of improving the window of detection of banned substances by targeting their effects on blood cell gene expression. In this context, the present study describes the possibility of using a modified version of the dedicated Human IVD (in vitro Diagnostics) PAXgene® Blood RNA Kit for horse gene expression analysis in blood collected on PAXgene® tubes applied to the Horse Biological Passport. The commercial kit was only approved for human blood samples and has required an optimization of specific technical requirements for equine blood samples. Improvements and recommendations were achieved for sample collection, storage and RNA extraction procedure. Following these developments, RNA yield and quality were demonstrated to be suitable for downstream gene expression analysis by qPCR techniques.

  4. Preparation and analysis of dust samples for medical examinations; Praeparation und Analytik der Staubproben fuer medizinische Untersuchungen

    Energy Technology Data Exchange (ETDEWEB)

    Armbruster, L. [Deutsche Montan Technologie GmbH, Essen (Germany). Gas and Fire Div.

    2004-07-01

    For medical research within this project three respirable dust samples have been prepared and analysed. The original bulk material came from three different stratigraphic horizons, for the preparation a multiplex classifier was used. The respirable samples showed the same size distribution as the samples used in former projects. The quartz content was rather low, but within the normal variability. Pure quartz particles without surface contamination are not present in the three samples. Nickel, lead, cobalt, and arsenic are the most significant trace elements in the samples. (orig.)

  5. Integration of monolithic porous polymer with droplet-based microfluidics on a chip for nano/picoliter volume sample analysis

    OpenAIRE

    Kim, Jin-Young; Chang, Soo-Ik; Andrew J deMello; O’Hare, Danny

    2014-01-01

    In this paper, a porous polymer nanostructure has been integrated with droplet-based microfluidics in a single planar format. Monolithic porous polymer (MPP) was formed selectively within a microfluidic channel. The resulting analyte bands were sequentially comartmentalised into droplets. This device reduces band broadening and the effects of post-column dead volume by the combination of the two techniques. Moreover it offers the precise control of nano/picoliter volume samples.

  6. Automation of sample preparation for mass cytometry barcoding in support of clinical research: protocol optimization.

    Science.gov (United States)

    Nassar, Ala F; Wisnewski, Adam V; Raddassi, Khadir

    2017-03-01

    Analysis of multiplexed assays is highly important for clinical diagnostics and other analytical applications. Mass cytometry enables multi-dimensional, single-cell analysis of cell type and state. In mass cytometry, the rare earth metals used as reporters on antibodies allow determination of marker expression in individual cells. Barcode-based bioassays for CyTOF are able to encode and decode for different experimental conditions or samples within the same experiment, facilitating progress in producing straightforward and consistent results. Herein, an integrated protocol for automated sample preparation for barcoding used in conjunction with mass cytometry for clinical bioanalysis samples is described; we offer results of our work with barcoding protocol optimization. In addition, we present some points to be considered in order to minimize the variability of quantitative mass cytometry measurements. For example, we discuss the importance of having multiple populations during titration of the antibodies and effect of storage and shipping of labelled samples on the stability of staining for purposes of CyTOF analysis. Data quality is not affected when labelled samples are stored either frozen or at 4 °C and used within 10 days; we observed that cell loss is greater if cells are washed with deionized water prior to shipment or are shipped in lower concentration. Once the labelled samples for CyTOF are suspended in deionized water, the analysis should be performed expeditiously, preferably within the first hour. Damage can be minimized if the cells are resuspended in phosphate-buffered saline (PBS) rather than deionized water while waiting for data acquisition.

  7. Optimum parity of volumes of training loadings in the one-cyclic experimental period of preparation taekwondo athletes high qualification

    Directory of Open Access Journals (Sweden)

    Saienko V.G.

    2010-09-01

    Full Text Available Efficiency of application of correlation of volumes of the trainings loadings is tested in preparation of sportsmen. 12 sportsmen took part in an experiment (age of 18-22, experience of employments from 8 to 15 years. On the extent of three months the program of preparation was used. All sportsmen conducted the identical amount of trainings employments - 105. The most effective construction of training process of sportsmen is certain in one-cyclic three months period. It has such correlation of volumes of trainings facilities: base technique - 10%, formal complexes of battle exercises - 9%, specially-preparatory exercises - 24%, exercises on shells - 17%, exercises with a partner - 17%, sparrings - 23%.

  8. Relationship Between LIBS Ablation and Pit Volume for Geologic Samples: Applications for the In Situ Absolute Geochronology

    Science.gov (United States)

    Devismes, Damien; Cohen, Barbara; Miller, J.-S.; Gillot, P.-Y.; Lefevre, J.-C.; Boukari, C.

    2014-01-01

    These first results demonstrate that LIBS spectra can be an interesting tool to estimate the ablated volume. When the ablated volume is bigger than 9.10(exp 6) cubic micrometers, this method has less than 10% of uncertainties. Far enough to be directly implemented in the KArLE experiment protocol. Nevertheless, depending on the samples and their mean grain size, the difficulty to have homogeneous spectra will increase with the ablated volume. Several K-Ar dating studies based on this approach will be implemented. After that, the results will be shown and discussed.

  9. Relationship between sample volumes and modulus of human vertebral trabecular bone in micro-finite element analysis.

    Science.gov (United States)

    Wen, Xin-Xin; Xu, Chao; Zong, Chun-Lin; Feng, Ya-Fei; Ma, Xiang-Yu; Wang, Fa-Qi; Yan, Ya-Bo; Lei, Wei

    2016-07-01

    Micro-finite element (μFE) models have been widely used to assess the biomechanical properties of trabecular bone. How to choose a proper sample volume of trabecular bone, which could predict the real bone biomechanical properties and reduce the calculation time, was an interesting problem. Therefore, the purpose of this study was to investigate the relationship between different sample volumes and apparent elastic modulus (E) calculated from μFE model. 5 Human lumbar vertebral bodies (L1-L5) were scanned by micro-CT. Cubic concentric samples of different lengths were constructed as the experimental groups and the largest possible volumes of interest (VOI) were constructed as the control group. A direct voxel-to-element approach was used to generate μFE models and steel layers were added to the superior and inferior surface to mimic axial compression tests. A 1% axial strain was prescribed to the top surface of the model to obtain the E values. ANOVA tests were performed to compare the E values from the different VOIs against that of the control group. Nonlinear function curve fitting was performed to study the relationship between volumes and E values. The larger cubic VOI included more nodes and elements, and more CPU times were needed for calculations. E values showed a descending tendency as the length of cubic VOI decreased. When the volume of VOI was smaller than (7.34mm(3)), E values were significantly different from the control group. The fit function showed that E values approached an asymptotic values with increasing length of VOI. Our study demonstrated that apparent elastic modulus calculated from μFE models were affected by the sample volumes. There was a descending tendency of E values as the length of cubic VOI decreased. Sample volume which was not smaller than (7.34mm(3)) was efficient enough and timesaving for the calculation of E.

  10. Sampling small volumes of ambient ammonia using a miniaturized gas sampler.

    Science.gov (United States)

    Timmer, Björn; Olthuis, Wouter; van den Berg, Albert

    2004-06-01

    The development of a gas sampler for a miniaturized ambient ammonia detector is described. A micromachined channel system is realized in glass and silicon using powder blasting and anodic bonding. The analyte gas is directly mixed with purified water, dissolving the ammonia that will dissociate into ammonium ions. Carrier gas bubbles are subsequently removed from the liquid stream through a venting hole sealed with a microporous water repellent PTFE membrane. A flow restrictor is placed at the outlet of the sampler to create a small overpressure underneath the membrane, enabling the gas to leave through the membrane. Experiments with a gas flow of 1 ml min(-1), containing ammonia concentrations ranging from 9.4 ppm to 0.6 ppm in a nitrogen carrier flow have been carried out, at a water flow of 20 microl min(-1). The ammonium concentration in the sample solution is measured with an electrolyte conductivity detector. The measured values correspond with the concentration calculated from the initial ammonia concentration in the analyte gas, the fifty times concentration enhancement due to the gas-liquid volume difference and the theoretical dissociation equilibrium as a function of the resulting pH.

  11. Preparation of Modified Magnetic Nanocomposites Dithiooxamide/Fe3O4 for Preconcentration and Determination of Trace Amounts of Cobalt Ions in Food and Natural Water Samples

    Directory of Open Access Journals (Sweden)

    Ali Mirabi

    2016-09-01

    Full Text Available The first study on the high efficiency of nanometer-sized magnetic nanoparticles (Fe3O4 coated with sodium dodecyl sulfate (SDS and dithiooxamide as a new sorbent solid phase extraction has been reported. Modified magnetic nanicomposites was used to preconcentrate and separate Co (II ions in food and environmental water samples. Magnetic nanoparticles were prepared by chemical precipitation of Fe (II and Fe (III salts from aqueous solution by ammonia solution. These magnetic nanoparticles and nanocomposites were characterized by scanning electron microscopy (SEM, transmission electron microscopy (TEM, thermo gravimetric analysis (TGA and elemental analysis CHNS. A micro sample introduction system was employed for the nebulization micro-volume of diluted solution into flame atomic absorption spectrometry (FAAS. The extraction conditions were optimized by selecting the appropriate extraction parameters including the amount of nanosorbent, pH value, volume of dithiooxamide and condition of eluting solution. The detection limit of this method for Co (II ions was 1.21 ng ml-1 and the R.S.D. was 0.9% (n=6. The advantages of this new method include rapidity, easy preparation of nanosorbents and a high preconcentration factor. The proposed method has been applied to the determination of Co (II ions at trace levels in real samples such as, kiwi, orange, cucumber, apple, green pepper, honey, potato, tap water, river water and sea water with satisfactory results.

  12. A 96-well screen filter plate for high-throughput biological sample preparation and LC-MS/MS analysis.

    Science.gov (United States)

    Peng, Sean X; Cousineau, Martin; Juzwin, Stephen J; Ritchie, David M

    2006-01-01

    A novel 96-well screen filter plate (patent pending) has been invented to eliminate a time-consuming and labor-intensive step in preparation of in vivo study samples--to remove blood or plasma clots. These clots plug the pipet tips during a manual or automated sample-transfer step causing inaccurate pipetting or total pipetting failure. Traditionally, these blood and plasma clots are removed by picking them out manually one by one from each sample tube before any sample transfer can be made. This has significantly slowed the sample preparation process and has become a bottleneck for automated high-throughput sample preparation using robotic liquid handlers. Our novel screen filter plate was developed to solve this problem. The 96-well screen filter plate consists of 96 stainless steel wire-mesh screen tubes connected to the 96 openings of a top plate so that the screen filter plate can be readily inserted into a 96-well sample storage plate. Upon insertion, the blood and plasma clots are excluded from entering the screen tube while clear sample solutions flow freely into it. In this way, sample transfer can be easily completed by either manual or automated pipetting methods. In this report, three structurally diverse compounds were selected to evaluate and validate the use of the screen filter plate. The plasma samples of these compounds were transferred and processed in the presence and absence of the screen filter plate and then analyzed by LC-MS/MS methods. Our results showed a good agreement between the samples prepared with and without the screen filter plate, demonstrating the utility and efficiency of this novel device for preparation of blood and plasma samples. The device is simple, easy to use, and reusable. It can be employed for sample preparation of other biological fluids that contain floating particulates or aggregates.

  13. A rapid HPLC column switching method for sample preparation and determination of β-carotene in food supplements.

    Science.gov (United States)

    Brabcová, Ivana; Hlaváčková, Markéta; Satínský, Dalibor; Solich, Petr

    2013-11-15

    A simple and automated HPLC column-switching method with rapid sample pretreatment has been developed for quantitative determination of β-carotene in food supplements. Commercially samples of food supplements were dissolved in chloroform with help of saponification with 1M solution of sodium hydroxide in ultrasound bath. A 20-min sample dissolution/extraction step was necessary before chromatography analysis to transfer β-carotene from solid state of food supplements preparations (capsules,tablets) to chloroform solution. Sample volume - 3μL of chloroform phase was directly injected into the HPLC system. Next on-line sample clean-up was achieved on the pretreatment precolumn Chromolith Guard Cartridge RP-18e (Merck), 10×4.6mm, with a washing mobile phase (methanol:water, 92:8, (v/v)) at a flow rate of 1.5mL/min. Valve switch to analytical column was set at 2.5min in a back-flush mode. After column switching to the analytical column Ascentis Express C-18, 30×4.6mm, particle size 2.7μm (Sigma Aldrich), the separation and determination of β-carotene in food supplements was performed using a mobile phase consisting of 100% methanol, column temperature at 60°C and flow rate 1.5mL/min. The detector was set at 450nm. Under the optimum chromatographic conditions standard calibration curve was measured with good linearity - correlation coefficient for β-carotene (r(2)=0.999014; n=6) between the peak areas and concentration of β-carotene 20-200μg/mL. Accuracy of the method defined as a mean recovery was in the range 96.66-102.40%. The intraday method precision was satisfactory at three concentration levels 20, 125 and 200μg/mL and relative standard deviations were in the range 0.90-1.02%. The chromatography method has shown high sample throughput during column-switching pretreatment process and analysis in one step in short time (6min) of the whole chromatographic analysis.

  14. Using Exclusion-Based Sample Preparation (ESP to Reduce Viral Load Assay Cost.

    Directory of Open Access Journals (Sweden)

    Scott M Berry

    Full Text Available Viral load (VL measurements are critical to the proper management of HIV in developing countries. However, access to VL assays is limited by the high cost and complexity of existing assays. While there is a need for low cost VL assays, performance must not be compromised. Thus, new assays must be validated on metrics of limit of detection (LOD, accuracy, and dynamic range. Patient plasma samples from the Joint Clinical Research Centre in Uganda were de-identified and measured using both an existing VL assay (Abbott RealTime HIV-1 and our assay, which combines low cost reagents with a simplified method of RNA isolation termed Exclusion-Based Sample Preparation (ESP.71 patient samples with VLs ranging from 3,000,000 copies/mL were used to compare the two methods. We demonstrated equivalent LOD (~50 copies/mL and high accuracy (average difference between methods of 0.08 log, R2 = 0.97. Using expenditures from this trial, we estimate that the cost of the reagents and consumables for this assay to be approximately $5 USD. As cost is a significant barrier to implementation of VL testing, we anticipate that our assay will enhance access to this critical monitoring test in developing countries.

  15. Using Exclusion-Based Sample Preparation (ESP) to Reduce Viral Load Assay Cost.

    Science.gov (United States)

    Berry, Scott M; Pezzi, Hannah M; Williams, Eram D; Loeb, Jennifer M; Guckenberger, David J; Lavanway, Alex J; Puchalski, Alice A; Kityo, Cissy M; Mugyenyi, Peter N; Graziano, Franklin M; Beebe, David J

    2015-01-01

    Viral load (VL) measurements are critical to the proper management of HIV in developing countries. However, access to VL assays is limited by the high cost and complexity of existing assays. While there is a need for low cost VL assays, performance must not be compromised. Thus, new assays must be validated on metrics of limit of detection (LOD), accuracy, and dynamic range. Patient plasma samples from the Joint Clinical Research Centre in Uganda were de-identified and measured using both an existing VL assay (Abbott RealTime HIV-1) and our assay, which combines low cost reagents with a simplified method of RNA isolation termed Exclusion-Based Sample Preparation (ESP).71 patient samples with VLs ranging from 3,000,000 copies/mL were used to compare the two methods. We demonstrated equivalent LOD (~50 copies/mL) and high accuracy (average difference between methods of 0.08 log, R2 = 0.97). Using expenditures from this trial, we estimate that the cost of the reagents and consumables for this assay to be approximately $5 USD. As cost is a significant barrier to implementation of VL testing, we anticipate that our assay will enhance access to this critical monitoring test in developing countries.

  16. Modular approach to customise sample preparation procedures for viral metagenomics: a reproducible protocol for virome analysis.

    Science.gov (United States)

    Conceição-Neto, Nádia; Zeller, Mark; Lefrère, Hanne; De Bruyn, Pieter; Beller, Leen; Deboutte, Ward; Yinda, Claude Kwe; Lavigne, Rob; Maes, Piet; Van Ranst, Marc; Heylen, Elisabeth; Matthijnssens, Jelle

    2015-11-12

    A major limitation for better understanding the role of the human gut virome in health and disease is the lack of validated methods that allow high throughput virome analysis. To overcome this, we evaluated the quantitative effect of homogenisation, centrifugation, filtration, chloroform treatment and random amplification on a mock-virome (containing nine highly diverse viruses) and a bacterial mock-community (containing four faecal bacterial species) using quantitative PCR and next-generation sequencing. This resulted in an optimised protocol that was able to recover all viruses present in the mock-virome and strongly alters the ratio of viral versus bacterial and 16S rRNA genetic material in favour of viruses (from 43.2% to 96.7% viral reads and from 47.6% to 0.19% bacterial reads). Furthermore, our study indicated that most of the currently used virome protocols, using small filter pores and/or stringent centrifugation conditions may have largely overlooked large viruses present in viromes. We propose NetoVIR (Novel enrichment technique of VIRomes), which allows for a fast, reproducible and high throughput sample preparation for viral metagenomics studies, introducing minimal bias. This procedure is optimised mainly for faecal samples, but with appropriate concentration steps can also be used for other sample types with lower initial viral loads.

  17. Effects of sample preparation on the optical properties of breast tissue

    Science.gov (United States)

    Marks, Fay A.

    1996-04-01

    The optical properties of biological tissue should be determined in vivo whenever possible. However, for those instances when in vivo studies are impractical, too expensive or inappropriate, and when blood flow is not an issue, the ability to perform in vitro studies then becomes invaluable. Optical absorption spectroscopy shows that it may be possible to obtain meaningful information about the optical properties of human breast tissue from in vitro samples if strict preparation and measuring protocols are used. That a strict protocol for storing and handling tissue is critical can be seen from our observations of changes in the optical absorption spectra that occur in response to formalin fixation, the passage of time, application of stains and dyes, and storage in growth medium of the excised tissue. In vivo optical absorption spectroscopy measurements have been made on human breast cancer xenografts and compared with in vitro measurements on breast biopsies prepared according to precise collection and treatment protocols. There is a 'window of opportunity' before time dependent changes in the UV optical absorption spectra of the excised tissue specimens occur. This time window of opportunity widens at longer wavelengths with the least changes occurring in the optical spectra in the NIR.

  18. Lights Will Guide You : Sample Preparation and Applications for Integrated Laser and Electron Microscopy

    Science.gov (United States)

    Karreman, M. A.

    2013-03-01

    Correlative microscopy is the combined use of two different forms of microscopy in the study of a specimen, allowing for the exploitation of the advantages of both imaging tools. The integrated Laser and Electron Microscope (iLEM), developed at Utrecht University, combines a fluorescence microscope (FM) and a transmission electron microscope (TEM) in a single set-up. The region of interest in the specimen is labeled or tagged with a fluorescent probe and can easily be identified within a large field of view with the FM. Next, this same area is retraced in the TEM and can be studied at high resolution. The iLEM demands samples that can be imaged with both FM and TEM. Biological specimen, typically composed of light elements, generate low image contrast in the TEM. Therefore, these samples are often ‘contrasted’ with heavy metal stains. FM, on the other hand, images fluorescent samples. Sample preparation for correlative microscopy, and iLEM in particular, is complicated by the fact that the heavy metals stains employed for TEM quench the fluorescent signal of the probe that is imaged with FM. The first part of this thesis outlines preparation procedures for biological material yielding specimen that can be imaged with the iLEM. Here, approaches for the contrasting of thin sections of cells and tissue are introduced that do not affect the fluorescence signal of the probe that marks the region of interest. Furthermore, two novel procedures, VIS2FIXH and VIS2FIX­FS are described that allow for the chemical fixation of thin sections of cryo-immobilized material. These procedures greatly expedite the sample preparation process, and open up novel possibilities for the immuno-labeling of difficult antigens, eg. proteins and lipids that are challenging to preserve. The second part of this thesis describes applications of iLEM in research in the field of life and material science. The iLEM was employed in the study of UVC induced apoptosis (programmed cell death) of

  19. Sample Preparation for Headspace GC Analysis of Residual Solvents in Hyaluronic Acid Derivative Fiber

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Hoon Joo; Kim, Dong Min; Yang, Jeong Soo [LG life Sciences, Ltd./R and D Park, Daejeon (Korea, Republic of); Kim, Chan Wha [Korea University, Seoul (Korea, Republic of)

    2006-02-15

    The aim of this study is to develop efficient sample preparation method for HS-GC analysis of residual solvents in HA derivative fiber. Compared to direct extraction of residual solvents from HA derivative fiber, the extraction through the hydrolysis of HA derivative fiber by HAse gave more complete and higher reproducible quantification of residual solvent. To validate HS-GC analysis method of residual solvents, specificity, limits of detection and quantification, linearity, accuracy and precision are investigated in the study. HA derivative fiber was hydrolyzed using HAse for headspace gas chromatographic analysis of residual solvents of ethanol, acetone and isopropanol in HA derivative fiber. This study showed that the developed method had specificity, linearity, accuracy and precision. In addition, it demonstrated that HS-GC coupled with matrix-breaking method such as hydrolysis was available for the determination of residual solvents in a matrix like HA derivative fiber.

  20. Applied Study on Magnetic Nanometer Beads in Preparation of Genechip Samples

    Institute of Scientific and Technical Information of China (English)

    陈慧; 高华方; 谢欣; 马雪梅; 杨渝珍

    2004-01-01

    Summary: A protocol for enrichment and adsorption of karyocyte from whole blood by using magnetic nanometer beads as solid-phase absorbents was presented. The PCR amplification could be accomplished by using the nanobeads with karyocyte as template directly and the PCR products were applied on an oligonucleotide array to do gene typing. The HLA-A PCR amplification system and a small HLA-A oligonucleotide microarray were applied as the platform and an experiment protocol of separating karyocyte from whole blood using the magnetic nanometer beads (Fe2O3) were set up.The experimental conditions were also discussed. It showed that pH level of PBS eluent, Taq enzyme quantity and fragment length of products could influent the amplification results, and the magnetic nano-beads could succeed in sample preparation in microarray to provide a promising way in automatic detection and lab-on-a-chip.

  1. NGSI FY15 Final Report. Innovative Sample Preparation for in-Field Uranium Isotopic Determinations

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Thomas M. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Meyers, Lisa [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-11-10

    Our FY14 Final Report included an introduction to the project, background, literature search of uranium dissolution methods, assessment of commercial off the shelf (COTS) automated sample preparation systems, as well as data and results for dissolution of bulk quantities of uranium oxides, and dissolution of uranium oxides from swipe filter materials using ammonium bifluoride (ABF). Also, discussed were reaction studies of solid ABF with uranium oxide that provided a basis for determining the ABF/uranium oxide dissolution mechanism. This report details the final experiments for optimizing dissolution of U3O8 and UO2 using ABF and steps leading to development of a Standard Operating Procedure (SOP) for dissolution of uranium oxides on swipe filters.

  2. Agarose- and alginate-based biopolymers for sample preparation: Excellent green extraction tools for this century.

    Science.gov (United States)

    Sanagi, Mohd Marsin; Loh, Saw Hong; Wan Ibrahim, Wan Nazihah; Pourmand, Neda; Salisu, Ahmed; Wan Ibrahim, Wan Aini; Ali, Imran

    2016-03-01

    Recently, there has been considerable interest in the use of miniaturized sample preparation techniques before the chromatographic monitoring of the analytes in unknown complex compositions. The use of biopolymer-based sorbents in solid-phase microextraction techniques has achieved a good reputation. A great variety of polysaccharides can be extracted from marine plants or microorganisms. Seaweeds are the major sources of polysaccharides such as alginate, agar, agarose, as well as carrageenans. Agarose and alginate (green biopolymers) have been manipulated for different microextraction approaches. The present review is focused on the classification of biopolymer and their applications in multidisciplinary research. Besides, efforts have been made to discuss the state-of-the-art of the new microextraction techniques that utilize commercial biopolymer interfaces such as agarose in liquid-phase microextraction and solid-phase microextraction.

  3. RESULTS FROM EPA FUNDED RESEARCH PROGRAMS ON THE IMPORTANCE OF PURGE VOLUME, SAMPLE VOLUME, SAMPLE FLOW RATE AND TEMPORAL VARIATIONS ON SOIL GAS CONCENTRATIONS

    Science.gov (United States)

    Two research studies funded and overseen by EPA have been conducted since October 2006 on soil gas sampling methods and variations in shallow soil gas concentrations with the purpose of improving our understanding of soil gas methods and data for vapor intrusion applications. Al...

  4. METHODOLOGICAL ASPECTS OF MOLASSES SAMPLE PREPARATION IN SULFUR DIOXIDE CONTENT DETERMINING

    Directory of Open Access Journals (Sweden)

    M. I. Egorova

    2015-01-01

    Full Text Available Summary. Molasses is characterized as sugar production by-product from primary or secondary sacchariferous raw materials. The features of the appearance, the chemical composition, molasses and exit directions of its use, depending on the type of production, in which it is formed. The value of molasses is demonstrated according to its total composition as well as its use directions. Statistics on beet molasses amounts in Russia is presented. Described consumer market molasses in Russia and abroad with its exports. Shown regulations contain requirements for the quality and safety of molasses, including sulfur dioxide. The data on sulfur allergenic properties are presented. Showing source of the sulfur dioxide in the residual molasses number of processing aids and the impact of its level in the value of raw molasses for use in biotechnological processes and fodder production. The necessity to develop methodology for determining the sulfur dioxide content in the molasses to control its security. The iodometric method, which is used in practice for determination of sulphur dioxide in foods are characterized. Differences molasses and sugar as objects of iodometric determination of sulfur dioxide, which leads to the inability to ascertain the equivalence point. The variants eliminate interfering background of dark-colored foods common in analytical chemistry. Advantages and disadvantages of the background masking and stripping the determination of sulfur dioxide in the darkcolored products. It was characterized by clarifying sugar solutions in optical control methods. The hypothesis about preferability of its use in sample molasses preparation for equivalence point fixation in iodometric titration is suggested. The tasks of experimental research for the development of sample preparation algorithm molasses in determining the content of sulphurous acid.

  5. ALGORITHM OF PREPARATION OF THE TRAINING SAMPLE USING 3D-FACE MODELING

    Directory of Open Access Journals (Sweden)

    D. I. Samal

    2016-01-01

    Full Text Available The algorithm of preparation and sampling for training of the multiclass qualifier of support vector machines (SVM is provided. The described approach based on the modeling of possible changes of the face features of recognized person. Additional features like perspectives of shooting, conditions of lighting, tilt angles were introduced to get improved identification results. These synthetic generated changes have some impact on the classifier learning expanding the range of possible variations of the initial image. The classifier learned with such extended example is ready to recognize unknown objects better. The age, emotional looks, turns of the head, various conditions of lighting, noise, and also some combinations of the listed parameters are chosen as the key considered parameters for modeling. The third-party software ‘FaceGen’ allowing to model up to 150 parameters and available in a demoversion for free downloading is used for 3D-modeling.The SVM classifier was chosen to test the impact of the introduced modifications of training sample. The preparation and preliminary processing of images contains the following constituents like detection and localization of area of the person on the image, assessment of an angle of rotation and an inclination, extension of the range of brightness of pixels and an equalization of the histogram to smooth the brightness and contrast characteristics of the processed images, scaling of the localized and processed area of the person, creation of a vector of features of the scaled and processed image of the person by a Principal component analysis (algorithm NIPALS, training of the multiclass SVM-classifier.The provided algorithm of expansion of the training selection is oriented to be used in practice and allows to expand using 3D-models the processed range of 2D – photographs of persons that positively affects results of identification in system of face recognition. This approach allows to compensate

  6. Three-dimensional sensitivity distribution and sample volume of low-induction-number electromagnetic-induction instruments

    Science.gov (United States)

    Callegary, J.B.; Ferre, T. P. A.; Groom, R.W.

    2012-01-01

    There is an ongoing effort to improve the understanding of the correlation of soil properties with apparent soil electrical conductivity as measured by low-induction-number electromagnetic-induction (LIN FEM) instruments. At a minimum, the dimensions of LIN FEM instruments' sample volume, the spatial distribution of sensitivity within that volume, and implications for surveying and analyses must be clearly defined and discussed. Therefore, a series of numerical simulations was done in which a conductive perturbation was moved systematically through homogeneous soil to elucidate the three-dimensional sample volume of LIN FEM instruments. For a small perturbation with electrical conductivity similar to that of the soil, instrument response is a measure of local sensitivity (LS). Our results indicate that LS depends strongly on the orientation of the instrument's transmitter and receiver coils and includes regions of both positive and negative LS. Integration of the absolute value of LS from highest to lowest was used to contour cumulative sensitivity (CS). The 90% CS contour was used to define the sample volume. For both horizontal and vertical coplanar coil orientations, the longest dimension of the sample volume was at the surface along the main instrument axis with a length of about four times the intercoil spacing (s) with maximum thicknesses of about 1 and 0.3 s, respectively. The imaged distribution of spatial sensitivity within the sample volume is highly complex and should be considered in conjunction with the expected scale of heterogeneity before the use and interpretation of LIN FEM for mapping and profiling. ?? Soil Science Society of America.

  7. Advanced sample preparation for the molecular quantification of Staphylococcus aureus in artificially and naturally contaminated milk.

    Science.gov (United States)

    Aprodu, Iuliana; Walcher, Georg; Schelin, Jenny; Hein, Ingeborg; Norling, Börje; Rådström, Peter; Nicolau, Anca; Wagner, Martin

    2011-03-01

    Sample treatment is an essential element when using real-time PCR for quantification of pathogens directly on food samples. This study comparatively evaluated three different principles of sample treatment, i.e. immunomagnetic separation based on phage-derived cell wall binding molecules, matrix solubilization and flotation, in order to establish their suitability for quantifying low numbers of Staphylococcus aureus in milk. All three procedures succeeded to remove S. aureus from the milk matrix, either raw or pasteurized, and, as a result of the concentration of the target cells, minimized the effect of milk associated PCR inhibitors. Sample preparation based on immunomagnetic separation albeit of being user friendly, specific and rapid, failed to allow quantification of low and medium numbers (<10(4)CFU) of S. aureus. In a mastitic milk model cell wall binding domain (CBD)-based target cell extraction revealed results most closely matching those derived from culture-based quantification. Both matrix lysis and flotation allowed quantification of S. aureus at a level of 1-10 cells per ml. Both methods resulted in higher numbers of bacterial cell equivalents (bce) than plating could reveal. Since both methods harvest cells that have been subjected to either mechanical and chemical stresses before quantification, we concluded that the higher bce numbers resulted from a disaggregation of S. aureus clusters initially present in the inoculum. Conclusively, since likely each S. aureus cell of a toxigenic strain contributes to enterotoxin production, molecular quantification could provide an even more realistic impact assessment in outbreak investigations than plating does.

  8. Main Trend Extraction Based on Irregular Sampling Estimation and Its Application in Storage Volume of Internet Data Center

    Science.gov (United States)

    Dou, Chao

    2016-01-01

    The storage volume of internet data center is one of the classical time series. It is very valuable to predict the storage volume of a data center for the business value. However, the storage volume series from a data center is always “dirty,” which contains the noise, missing data, and outliers, so it is necessary to extract the main trend of storage volume series for the future prediction processing. In this paper, we propose an irregular sampling estimation method to extract the main trend of the time series, in which the Kalman filter is used to remove the “dirty” data; then the cubic spline interpolation and average method are used to reconstruct the main trend. The developed method is applied in the storage volume series of internet data center. The experiment results show that the developed method can estimate the main trend of storage volume series accurately and make great contribution to predict the future volume value. 
 PMID:28090205

  9. Main Trend Extraction Based on Irregular Sampling Estimation and Its Application in Storage Volume of Internet Data Center

    Directory of Open Access Journals (Sweden)

    Beibei Miao

    2016-01-01

    Full Text Available The storage volume of internet data center is one of the classical time series. It is very valuable to predict the storage volume of a data center for the business value. However, the storage volume series from a data center is always “dirty,” which contains the noise, missing data, and outliers, so it is necessary to extract the main trend of storage volume series for the future prediction processing. In this paper, we propose an irregular sampling estimation method to extract the main trend of the time series, in which the Kalman filter is used to remove the “dirty” data; then the cubic spline interpolation and average method are used to reconstruct the main trend. The developed method is applied in the storage volume series of internet data center. The experiment results show that the developed method can estimate the main trend of storage volume series accurately and make great contribution to predict the future volume value.

  10. Phosphite determination in fertilizers after online sequential sample preparation in a flow injection system.

    Science.gov (United States)

    Dametto, Patrícia Roberta; Franzini, Vanessa Pezza; Gomes Neto, José Anchieta

    2007-07-25

    A flow injection spectrophotometric system is proposed for phosphite determination in fertilizers by the molybdenum blue method after the processing of each sample two times on-line without and with an oxidizing step. The flow system was designed to add sulfuric acid or permanganate solutions alternately into the system by simply displacing the injector-commutator from one resting position to another, allowing the determination of phosphate and total phosphate, respectively. The concentration of phosphite is obtained then by difference between the two measurents. The influence of flow rates, sample volume, and dimension of flow line connecting the injector-commutator to the main analytical channel was evaluated. The proposed method was applied to phosphite determination in commercial liquid fertilizers. Results obtained with the proposed FIA system were not statistically different from those obtained by titrimetry at the 95% confidence level. In addition, recoveries within 94 and 100% of spiked fertilizers were found. The relative standard deviation (n = 12) related to the phosphite-converted-phosphate peak alone was sampling rate was calculated as 15 determinations per hour, and the reagent consumption was about 6.3 mg of KMnO4, 200 mg of (NH4)6Mo7O24.4H2O, and 40 mg of ascorbic acid per measurement.

  11. Rapid specimen preparation to improve the throughput of electron microscopic volume imaging for three-dimensional analyses of subcellular ultrastructures with serial block-face scanning electron microscopy.

    Science.gov (United States)

    Thai, Truc Quynh; Nguyen, Huy Bang; Saitoh, Sei; Wu, Bao; Saitoh, Yurika; Shimo, Satoshi; Elewa, Yaser Hosny Ali; Ichii, Osamu; Kon, Yasuhiro; Takaki, Takashi; Joh, Kensuke; Ohno, Nobuhiko

    2016-09-01

    Serial block-face imaging using scanning electron microscopy enables rapid observations of three-dimensional ultrastructures in a large volume of biological specimens. However, such imaging usually requires days for sample preparation to reduce charging and increase image contrast. In this study, we report a rapid procedure to acquire serial electron microscopic images within 1 day for three-dimensional analyses of subcellular ultrastructures. This procedure is based on serial block-face with two major modifications, including a new sample treatment device and direct polymerization on the rivets, to reduce the time and workload needed. The modified procedure without uranyl acetate can produce tens of embedded samples observable under serial block-face scanning electron microscopy within 1 day. The serial images obtained are similar to the block-face images acquired by common procedures, and are applicable to three-dimensional reconstructions at a subcellular resolution. Using this approach, regional immune deposits and the double contour or heterogeneous thinning of basement membranes were observed in the glomerular capillary loops of an autoimmune nephropathy model. These modifications provide options to improve the throughput of three-dimensional electron microscopic examinations, and will ultimately be beneficial for the wider application of volume imaging in life science and clinical medicine.

  12. Detection of triazole deicing additives in soil samples from airports with low, mid, and large volume aircraft deicing activities.

    Science.gov (United States)

    McNeill, K S; Cancilla, D A

    2009-03-01

    Soil samples from three USA airports representing low, mid, and large volume users of aircraft deicing fluids (ADAFs) were analyzed by LC/MS/MS for the presence of triazoles, a class of corrosion inhibitors historically used in ADAFs. Triazoles, specifically the 4-methyl-1H-benzotriazole and the 5-methyl-1H-benzotriazole, were detected in a majority of samples and ranged from 2.35 to 424.19 microg/kg. Previous studies have focused primarily on ground and surface water impacts of larger volume ADAF users. The detection of triazoles in soils at low volume ADAF use airports suggests that deicing activities may have a broader environmental impact than previously considered.

  13. Sample preparation for metalloprotein analysis: A case study using horse chestnuts.

    Science.gov (United States)

    de Magalhães, Cristiana Schmidt; Arruda, Marco Aurélio Zezzi

    2007-03-30

    In the present work, 11 different procedures for protein and metalloprotein extraction from horse chestnuts (Aescullus hippocastanum L.) in natura were tested. After each extraction, total protein was determined and, after protein separation through sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE), those metals belonging to the protein structure were mapped by synchrotron radiation X-ray fluorescence (SRXRF). After mapping the elements (Cr, Fe and Mn) in the protein bands (ca. 33 and 23.7kDa), their concentrations were determined using atomic absorption spectrometry (ET AAS). Good results were obtained for protein extraction using a combination of grinding and sonication. However, this strategy was not suitable to preserve metal ions in the protein structure. In fact, there was 42% decrease on Mn concentration using this procedure, compared to that performed with sample agitation in water (taken as reference). On the other hand, when grinding and agitation with an extracting buffer was used, there was a 530% increase of Mn concentration, when compared to the reference procedure. These results indicate agreement between metal identification and determination in proteins as well as the great influence of the extraction procedure (i.e., the sample preparation step) for preserving metals in the protein structures.

  14. Sample preparation and in situ hybridization techniques for automated molecular cytogenetic analysis of white blood cells

    Energy Technology Data Exchange (ETDEWEB)

    Rijke, F.M. van de; Vrolijk, H.; Sloos, W. [Leiden Univ. (Netherlands)] [and others

    1996-06-01

    With the advent in situ hybridization techniques for the analysis of chromosome copy number or structure in interphase cells, the diagnostic and prognostic potential of cytogenetics has been augmented considerably. In theory, the strategies for detection of cytogenetically aberrant cells by in situ hybridization are simple and straightforward. In practice, however, they are fallible, because false classification of hybridization spot number or patterns occurs. When a decision has to be made on molecular cytogenetic normalcy or abnormalcy of a cell sample, the problem of false classification becomes particularly prominent if the fraction of aberrant cells is relatively small. In such mosaic situations, often > 200 cells have to be evaluated to reach a statistical sound figure. The manual enumeration of in situ hybridization spots in many cells in many patient samples is tedious. Assistance in the evaluation process by automation of microscope functions and image analysis techniques is, therefore, strongly indicated. Next to research and development of microscope hardware, camera technology, and image analysis, the optimization of the specimen for the (semi)automated microscopic analysis is essential, since factors such as cell density, thickness, and overlap have dramatic influences on the speed and complexity of the analysis process. Here we describe experiments that have led to a protocol for blood cell specimen that results in microscope preparations that are well suited for automated molecular cytogenetic analysis. 13 refs., 4 figs., 1 tab.

  15. Suspension trapping (STrap) sample preparation method for bottom-up proteomics analysis.

    Science.gov (United States)

    Zougman, Alexandre; Selby, Peter J; Banks, Rosamonde E

    2014-05-01

    Despite recent developments in bottom-up proteomics, the need still exists in a fast, uncomplicated, and robust method for comprehensive sample processing especially when applied to low protein amounts. The suspension trapping method combines the advantage of efficient SDS-based protein extraction with rapid detergent removal, reactor-type protein digestion, and peptide cleanup. Proteins are solubilized in SDS. The sample is acidified and introduced into the suspension trapping tip incorporating the depth filter and hydrophobic compartments, filled with the neutral pH methanolic solution. The instantly formed fine protein suspension is trapped in the depth filter stack-this crucial step is aimed at separating the particulate matter in space. SDS and other contaminants are removed in the flow-through, and a protease is introduced. Following the digestion, the peptides are cleaned up using the tip's hydrophobic part. The methodology allows processing of protein loads down to the low microgram/submicrogram levels. The detergent removal takes about 5 min, whereas the tryptic proteolysis of a cellular lysate is complete in as little as 30 min. We have successfully utilized the method for analysis of cellular lysates, enriched membrane preparations, and immunoprecipitates. We expect that due to its robustness and simplicity, the method will become an essential proteomics tool.

  16. Investigation into Alternative Sample Preparation Techniques for the Determination of Heavy Metals in Stationary Source Emission Samples Collected on Quartz Filters

    Directory of Open Access Journals (Sweden)

    Sharon L. Goddard

    2014-11-01

    Full Text Available Monitoring stationary source emissions for heavy metals generally requires the use of quartz filters to collect samples because of the high temperature and high moisture sampling environment. The documentary standard method sample preparation technique in Europe, EN 14385, uses digestion in hydrofluoric acid and nitric acid (HF/HNO3 followed by complexing with boric acid (H3BO3 prior to analysis. However, the use of this method presents a number of problems, including significant instrumental drift during analysis caused by the matrix components, often leading to instrument breakdown and downtime for repairs, as well as posing significant health and safety risks. The aim of this work was to develop an alternative sample preparation technique for emissions samples on quartz filters. The alternative techniques considered were: (i acid digestion in a fluoroboric acid (HBF4 and HNO3 mixture and (ii acid extraction in an aqua regia (AR mixture (HCl and HNO3. Assessment of the effectiveness of these options included determination of interferences and signal drift, as well as validating the different methods by measurement of matrix certified reference materials (CRMs, and comparing the results obtained from real test samples and sample blanks to determine limits of detection. The results showed that the HBF4/HNO3 mixture provides the most viable alternative to the documentary standard preparation technique.

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

    Science.gov (United States)

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

    2016-01-28

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

  18. Development of a novel high volume band compression injector for the analysis of complex samples like toxaphene pesticide.

    Science.gov (United States)

    Gagné, Jean-Pierre; Gouteux, Bruno; Bertrand, Michel J

    2009-01-16

    A new type of injector has been developed for gas chromatographic analysis. The injector has high volume and band compression (HVBC) capabilities useful for the analysis of complex samples. The injector consists essentially of a packed liner operated at room temperature while a narrow heated zone is used to axially scan the liner selectively desorbing the compounds of interest. The scanning speed, distance and temperature of the zone are precisely controlled. The liner is connected to an interface which can vent the solvent or any undesirable compounds, and transfer the analytes to an analytical column for separation and quantification. The injector is designed to be compatible with injection volumes from 1 to more than 250microL. At a low sample volume of 1microL, the injector has competitive performances compared to those of the "on-column" and "split/splitless" injectors for the fatty acid methyl esters and toxaphene compounds tested. For higher volumes, the system produces a linear response according to the injected volume. In this explorative study, the maximum volume injected seems to be limited by the saturation of the chromatographic system instead of being defined by the design of the injector. The HVBC injector can also be used to conduct "in situ" pretreatment of the sample before its transfer to the analytical column. For instance, a toxaphene sample was successively fractionated, using the HVBC injector, in six sub-fractions characterized by simpler chromatograms than the chromatogram of the original mixture. Finally, the ability of the HVBC injector to "freeze" the separation in time allowing the analyst to complete the analysis at a later time is also discussed.

  19. Improved method for collection of sputum for tuberculosis testing to ensure adequate sample volumes for molecular diagnostic testing.

    Science.gov (United States)

    Fisher, Mark; Dolby, Tania; Surtie, Shireen; Omar, Gaironesa; Hapeela, Nchimunya; Basu, Debby; DeWalt, Abby; Kelso, David; Nicol, Mark; McFall, Sally

    2017-04-01

    The quality and quantity of sputum collected has an important impact on the laboratory diagnosis of pulmonary TB. We conducted a pilot study to assess a new collection cups for the collection of sputum for the diagnosis of pulmonary tuberculosis. The pilot study utilized the standard collection cup in South Africa demonstrating a mean collection volume of 2.86±2.36SDml for 198 samples; 19% of the specimens contained 5ml. We designed and tested two novel sputum cups with a narrow bottom section and clear minimum and maximum markings to allow patients and clinicians to know whether sufficient sputum volume has been produced. The cups differed in their shape and manufacturing approach. The two options also support different mixing approaches being considered for a highly sensitive companion TB-screening assay being developed at Northwestern University (XtracTB assay). Sputum was collected from 102 patients at Nolungile Youth Centre, Khayelitsha, Cape Town, South Africa for a total of 204 samples. The mean volumes collected from the two cups were 2.70±0.88SDml and 2.88±0.89SDml. While the mean volumes of current and novel cups are similar, the volume ranges collected with the novel cups were narrower, and 98% of the specimen volumes were within the target range. Only 4 samples contained >5ml, but none were >6ml, and none of the specimens contained <1ml. The number of coughs that produced the samples, patient HIV and TB status plus qualitative descriptions of the sputum specimens were also evaluated.

  20. SAMPL5: 3D-RISM partition coefficient calculations with partial molar volume corrections and solute conformational sampling

    Science.gov (United States)

    Luchko, Tyler; Blinov, Nikolay; Limon, Garrett C.; Joyce, Kevin P.; Kovalenko, Andriy

    2016-11-01

    Implicit solvent methods for classical molecular modeling are frequently used to provide fast, physics-based hydration free energies of macromolecules. Less commonly considered is the transferability of these methods to other solvents. The Statistical Assessment of Modeling of Proteins and Ligands 5 (SAMPL5) distribution coefficient dataset and the accompanying explicit solvent partition coefficient reference calculations provide a direct test of solvent model transferability. Here we use the 3D reference interaction site model (3D-RISM) statistical-mechanical solvation theory, with a well tested water model and a new united atom cyclohexane model, to calculate partition coefficients for the SAMPL5 dataset. The cyclohexane model performed well in training and testing (R=0.98 for amino acid neutral side chain analogues) but only if a parameterized solvation free energy correction was used. In contrast, the same protocol, using single solute conformations, performed poorly on the SAMPL5 dataset, obtaining R=0.73 compared to the reference partition coefficients, likely due to the much larger solute sizes. Including solute conformational sampling through molecular dynamics coupled with 3D-RISM (MD/3D-RISM) improved agreement with the reference calculation to R=0.93. Since our initial calculations only considered partition coefficients and not distribution coefficients, solute sampling provided little benefit comparing against experiment, where ionized and tautomer states are more important. Applying a simple pK_{ {a}} correction improved agreement with experiment from R=0.54 to R=0.66, despite a small number of outliers. Better agreement is possible by accounting for tautomers and improving the ionization correction.

  1. Toward a Fieldable Atomic Mass Spectrometer for Safeguards Applications: Sample Preparation and Ionization

    Energy Technology Data Exchange (ETDEWEB)

    Barinaga, Charles J.; Hager, George J.; Hart, Garret L.; Koppenaal, David W.; Marcus, R. Kenneth; Jones, Sarah MH; Manard, Benjamin T.

    2014-10-31

    The International Atomic Energy Agency’s (IAEA’s) long-term research and development plan calls for the development of new methods to detect misuse at nuclear fuel cycle facilities such as reprocessing and enrichment plants. At enrichment plants, for example, the IAEA’s contemporary safeguards approaches are based on a combination of routine and random inspections that include collection of UF6 samples from in-process material and selected cylinders for subsequent analyses. These analyses include destructive analysis (DA) in a laboratory (typically by mass spectrometry [MS]) for isotopic characterization, and environmental sampling (ES) for subsequent laboratory elemental and isotopic analysis (also both typically by MS). One area of new method development includes moving this kind of isotope ratio analytical capability for DA and ES activities into the field. Some of the reasons for these developments include timeliness of results, avoidance of hazardous material shipments, and guidance for additional sample collecting. However, this capability does not already exist for several reasons, such as that most lab-based chemical and instrumental methods rely on laboratory infrastructure (highly trained staff, power, space, hazardous material handling, etc.) and require significant amounts of consumables (power, compressed gases, etc.). In addition, there are no currently available, fieldable instruments for atomic or isotope ratio analysis. To address these issues, Pacific Northwest National Laboratory (PNNL) and collaborator, Clemson University, are studying key areas that limit the fieldability of isotope ratio mass spectrometry for atomic ions: sample preparation and ionization, and reducing the physical size of a fieldable mass spectrometer. PNNL is seeking simple and robust techniques that could be effectively used by inspectors who may have no expertise in analytical MS. In this report, we present and describe the preliminary findings for three candidate

  2. A comparison of sample preparation strategies for biological tissues and subsequent trace element analysis using LA-ICP-MS.

    Science.gov (United States)

    Bonta, Maximilian; Török, Szilvia; Hegedus, Balazs; Döme, Balazs; Limbeck, Andreas

    2017-03-01

    Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) is one of the most commonly applied methods for lateral trace element distribution analysis in medical studies. Many improvements of the technique regarding quantification and achievable lateral resolution have been achieved in the last years. Nevertheless, sample preparation is also of major importance and the optimal sample preparation strategy still has not been defined. While conventional histology knows a number of sample pre-treatment strategies, little is known about the effect of these approaches on the lateral distributions of elements and/or their quantities in tissues. The technique of formalin fixation and paraffin embedding (FFPE) has emerged as the gold standard in tissue preparation. However, the potential use for elemental distribution studies is questionable due to a large number of sample preparation steps. In this work, LA-ICP-MS was used to examine the applicability of the FFPE sample preparation approach for elemental distribution studies. Qualitative elemental distributions as well as quantitative concentrations in cryo-cut tissues as well as FFPE samples were compared. Results showed that some metals (especially Na and K) are severely affected by the FFPE process, whereas others (e.g., Mn, Ni) are less influenced. Based on these results, a general recommendation can be given: FFPE samples are completely unsuitable for the analysis of alkaline metals. When analyzing transition metals, FFPE samples can give comparable results to snap-frozen tissues. Graphical abstract Sample preparation strategies for biological tissues are compared with regard to the elemental distributions and average trace element concentrations.

  3. Preparation of edible wild fruit and plant samples for analysis and some difficulties encountered in such analyses

    CSIR Research Space (South Africa)

    Strydom, ESP

    1969-12-01

    Full Text Available Freeze-dried samples are used for analysis and the methods of preparation of samples for freeze-drying are discussed. Freeze-drying has obvious advantages but has also a few minor disadvantages. Difficulties encountered in the determination of some...

  4. Selectivity in the sample preparation for the analysis of drug residues in products of animal origin using LC-MS

    NARCIS (Netherlands)

    Berendsen, B.J.A.; Stolker, A.A.M.; Nielen, M.W.F.

    2013-01-01

    Sample preparation is critical in relation to analysis time, sample throughput and therefore analysis costs. Due to recent advances in liquid chromatography-mass spectrometry (LC-MS) instrumentation, the detection of many compounds within one run became possible, and methods for the simultaneous ana

  5. New Sample Preparation Method for Quantification of Phenolic Compounds of Tea (Camellia sinensis L. Kuntze: A Polyphenol Rich Plant

    Directory of Open Access Journals (Sweden)

    P. A. Nimal Punyasiri

    2015-01-01

    Full Text Available Chemical analysis of the Sri Lankan tea (Camellia sinensis, L. germplasm would immensely contribute to the success of the tea breeding programme. However, the polyphenols, particularly catechins (flavan-3-ols, are readily prone to oxidation in the conventional method of sample preparation. Therefore, optimization of the present sample preparation methodology for the profiling of metabolites is much important. Two sample preparation methodologies were compared, fresh leaves (as in the conventional procedures and freeze-dried leaves (a new procedure, for quantification of major metabolites by employing two cultivars, one is known to be high quality black tea and the other low quality black tea. The amounts of major metabolites such as catechins, caffeine, gallic acid, and theobromine, recorded in the new sampling procedure via freeze-dried leaves, were significantly higher than those recorded in the conventional sample preparation procedure. Additionally new method required less amount of leaf sample for analysis of major metabolites and facilitates storage of samples until analysis. The freeze-dried method would be useful for high throughput analysis of large number of samples in shorter period without chemical deterioration starting from the point of harvest until usage. Hence, this method is more suitable for metabolite profiling of tea as well as other phenol rich plants.

  6. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    Science.gov (United States)

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  7. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING AIR SAMPLES FOR ANALYSIS OF POLAR PERSISTENT ORGANIC POLLUTANTS (SOP-5.13)

    Science.gov (United States)

    The method for extracting and preparing indoor and outdoor air samples for analysis of polar persistent organic pollutants is summarized in this SOP. It covers the preparation of samples that are to be analyzed by gas chromatography/mass spectrometry.

  8. Near-infrared diffuse reflectance spectroscopy with sample spots and chemometrics for fast determination of bovine serum albumin in micro-volume samples

    Institute of Scientific and Technical Information of China (English)

    Cai-Jing Cui; Wen-Sheng Cai; Xue-Guang Shao

    2013-01-01

    Near-infrared diffuse reflectance spectroscopy (NIRDRS) has attracted more and more attention in analyzing the components in samples with complex matrices.However,to apply this technique to micro-analysis,there are still some obstacles to overcome such as the low sensitivity and spectral overlapping associated with this approach.A method for fast determination of bovine serum albumin (BSA) in micro-volume samples was studied using NIRDRS with sample spots and chemometric techniques.10 μL of sample spotted on a filter paper substrate was used for the spectral measurements.Quantitative analysis was obtained by partial least squares (PLS) regression with signal processing and variable selection.The results show that the correlation coefficient (R) between the predicted and the reference concentration is 0.9897 and the recoveries are in the range of 87.4%-114.4% for the validation samples in the concentration range of 0.61-8.10 mg/mL.These results suggest that the method has the potential to quickly measure proteins in micro-volume solutions.

  9. A lab-on-a-chip system with integrated sample preparation and loop-mediated isothermal amplification for rapid and quantitative detection of Salmonella spp. in food samples

    DEFF Research Database (Denmark)

    Sun, Yi; Than Linh, Quyen; Hung, Tran Quang

    2015-01-01

    and usually take a few hours to days to complete. In response to the demand for rapid on line or at site detection of pathogens, in this study, we describe for the first time an eight-chamber lab-on-a-chip (LOC) system with integrated magnetic beads-based sample preparation and loop-mediated isothermal...

  10. Development of microwave-assisted drying methods for sample preparation for dried spot micro-X-ray fluorescence analysis.

    Science.gov (United States)

    Link, Dirk D; Kingston, H M; Havrilla, George J; Colletti, Lisa P

    2002-03-01

    Although dried spot micro X-ray fluorescence (MXRF) is an effective analytical technique for trace elemental analysis, the sample preparation procedures currently used suffer from a number of drawbacks. These drawbacks include relatively long preparation times, lack of control of the sample preparation environment, and possibility of loss of volatile analytes during the drying process. Microwave-assisted drying offers several advantages for dried spot preparation, including control of the environment and minimized volatility because of the differences between microwave heating and conventional heating. A microwave-assisted drying technique has been evaluated for use in preparing dried spots for trace analysis. Two apparatus designs for microwave drying were constructed and tested using multielement standard solutions, a standard reference material, and a "real-world" semiconductor cleaning solution. Following microwave-assisted drying of these aqueous samples, the residues were redissolved and analyzed by ICPMS. Effective recovery was obtained using the microwave drying methods, demonstrating that the microwave drying apparatus and methods described here may be more efficient alternatives for dried spot sample preparation.

  11. Remedial investigation sampling and analysis plan for J-Field, Aberdeen Proving Ground, Maryland. Volume 1: Field Sampling Plan

    Energy Technology Data Exchange (ETDEWEB)

    Benioff, P.; Biang, R.; Dolak, D.; Dunn, C.; Martino, L.; Patton, T.; Wang, Y.; Yuen, C.

    1995-03-01

    The Environmental Management Division (EMD) of Aberdeen Proving Ground (APG), Maryland, is conducting a remedial investigation and feasibility study (RI/FS) of the J-Field area at APG pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), as amended. J-Field is within the Edgewood Area of APG in Harford County, Maryland (Figure 1. 1). Since World War II activities in the Edgewood Area have included the development, manufacture, testing, and destruction of chemical agents and munitions. These materials were destroyed at J-Field by open burning and open detonation (OB/OD). Considerable archival information about J-Field exists as a result of efforts by APG staff to characterize the hazards associated with the site. Contamination of J-Field was first detected during an environmental survey of the Edgewood Area conducted in 1977 and 1978 by the US Army Toxic and Hazardous Materials Agency (USATHAMA) (predecessor to the US Army Environmental Center [AEC]). As part of a subsequent USATHAMA -environmental survey, 11 wells were installed and sampled at J-Field. Contamination at J-Field was also detected during a munitions disposal survey conducted by Princeton Aqua Science in 1983. The Princeton Aqua Science investigation involved the installation and sampling of nine wells and the collection and analysis of surficial and deep composite soil samples. In 1986, a Resource Conservation and Recovery Act (RCRA) permit (MD3-21-002-1355) requiring a basewide RCRA Facility Assessment (RFA) and a hydrogeologic assessment of J-Field was issued by the US Environmental Protection Agency (EPA). In 1987, the US Geological Survey (USGS) began a two-phased hydrogeologic assessment in data were collected to model, groundwater flow at J-Field. Soil gas investigations were conducted, several well clusters were installed, a groundwater flow model was developed, and groundwater and surface water monitoring programs were established that continue today.

  12. Rapid determination of benzene derivatives in water samples by trace volume solvent DLLME prior to GC-FID

    Energy Technology Data Exchange (ETDEWEB)

    Diao, Chun Peng; Wei, Chao Hai; Feng, Chun Hua [South China Univ. of Technology, Guangzhou Higher Education Mega Center (China). College of Environmental Science and Engineering; Guangdong Regular Higher Education Institutions, Guangzhou (China). Key Lab. of Environmental Protection and Eco-Remediation

    2012-05-15

    An inexpensive, simple and environmentally friendly method based on dispersive liquid liquid microextraction (DLLME) for rapid determination of benzene derivatives in water samples was proposed. A significant improvement of DLLME procedure was achieved. Trace volume ethyl acetate (60 {mu}L) was exploited as dispersion solvent instead of common ones such as methanol and acetone, the volume of which was more than 0.5 mL, and the organic solvent required in DLLME was reduced to a great extent. Only 83-{mu}L organic solvent was consumed in the whole analytic process and the preconcentration procedure was less than 10 min. The advantageous approach coupled with gas chromatograph-flame ionization detector was proposed for the rapid determination of benzene, toluene, ethylbenzene and xylene isomers in water samples. Results showed that the proposed approach was an efficient method for rapid determination of benzene derivatives in aqueous samples. (orig.)

  13. Fused silica capillaries with two segments of different internal diameters and inner surface roughnesses prepared by etching with supercritical water and used for volume coupling electrophoresis.

    Science.gov (United States)

    Horká, Marie; Karásek, Pavel; Roth, Michal; Šlais, Karel

    2017-02-22

    In this work, single-piece fused silica capillaries with two different internal diameter segments featuring different inner surface roughness were prepared by new etching technology with supercritical water and used for volume coupling electrophoresis. The concept of separation and online pre-concentration of analytes in high conductivity matrix is based on the online large-volume sample pre-concentration by the combination of transient isotachophoretic stacking and sweeping of charged proteins in micellar electrokinetic chromatography using non-ionogenic surfactant. The modified surface roughness step helped to the significant narrowing of the zones of examined analytes. The sweeping and separating steps were accomplished simultaneously by the use of phosphate buffer (pH 7) containing ethanol, non-ionogenic surfactant Brij 35, and polyethylene glycol (PEG 10000) after sample injection. Sample solution of a large volume (maximum 3.7 μL) dissolved in physiological saline solution was injected into the wider end of capillary with inlet inner diameter from 150, 185 or 218 μm. The calibration plots were linear (R(2) ∼ 0.9993) over a 0.060-1 μg/mL range for the proteins used, albumin and cytochrome c. The peak area RSDs from at least 20 independent measuremens were below 3.2%. This online pre-concentration technique produced a more than 196-fold increase in sensitivity, and it can be applied for detection of, e.g. the presence of albumin in urine (0.060 μg/mL).

  14. Humidity-controlled preparation of frozen-hydrated biological samples for cryogenic coherent x-ray diffraction microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Takayama, Yuki; Nakasako, Masayoshi [Department of Physics, Faculty of Science and Technology, Keio University, 3-14-1 Hiyoshi, Kohoku-ku, Kanagawa 223-8522 (Japan); RIKEN Harima Institute/SPring-8, 1-1-1 Kouto, Mikaduki, Sayo, Hyogo 679-5148 (Japan)

    2012-05-15

    Coherent x-ray diffraction microscopy (CXDM) has the potential to visualize the structures of micro- to sub-micrometer-sized biological particles, such as cells and organelles, at high resolution. Toward advancing structural studies on the functional states of such particles, here, we developed a system for the preparation of frozen-hydrated biological samples for cryogenic CXDM experiments. The system, which comprised a moist air generator, microscope, micro-injector mounted on a micromanipulator, custom-made sample preparation chamber, and flash-cooling device, allowed for the manipulation of sample particles in the relative humidity range of 20%-94%rh at 293 K to maintain their hydrated and functional states. Here, we report the details of the system and the operation procedure, including its application to the preparation of a frozen-hydrated chloroplast sample. Sample quality was evaluated through a cryogenic CXDM experiment conducted at BL29XUL of SPring-8. Taking the performance of the system and the quality of the sample, the system was suitable to prepare frozen-hydrated biological samples for cryogenic CXDM experiments.

  15. Rapid Preparation Methods of Biological Samples for Ionic Compounds Using Ion Exchange Type Monolithic Silica Spin Column

    OpenAIRE

    宮崎, 将太; 山田, 智子; 太田, 茂徳; 斉藤, 剛; 奈女良, 昭; 大平, 真義

    2010-01-01

    We developed a device comprising a spin column packed with ion exchange type (SCX and SAX) monolithic silica for extracting ionic compounds from biological samples. The methods involving the use of these spin column are not useful for the extraction of ionic analytes, but are highly reproducible for the analysis in serum and urine. This spin column enabled sample preparation in less than 10 min. Handling such as sample loading, washing, and elution of analytes, was exhibited by the centrifuga...

  16. Quality analysis of salmon calcitonin in a polymeric bioadhesive pharmaceutical formulation: sample preparation optimization by DOE.

    Science.gov (United States)

    D'Hondt, Matthias; Van Dorpe, Sylvia; Mehuys, Els; Deforce, Dieter; DeSpiegeleer, Bart

    2010-12-01

    A sensitive and selective HPLC method for the assay and degradation of salmon calcitonin, a 32-amino acid peptide drug, formulated at low concentrations (400 ppm m/m) in a bioadhesive nasal powder containing polymers, was developed and validated. The sample preparation step was optimized using Plackett-Burman and Onion experimental designs. The response functions evaluated were calcitonin recovery and analytical stability. The best results were obtained by treating the sample with 0.45% (v/v) trifluoroacetic acid at 60 degrees C for 40 min. These extraction conditions did not yield any observable degradation, while a maximum recovery for salmon calcitonin of 99.6% was obtained. The HPLC-UV/MS methods used a reversed-phase C(18) Vydac Everest column, with a gradient system based on aqueous acid and acetonitrile. UV detection, using trifluoroacetic acid in the mobile phase, was used for the assay of calcitonin and related degradants. Electrospray ionization (ESI) ion trap mass spectrometry, using formic acid in the mobile phase, was implemented for the confirmatory identification of degradation products. Validation results showed that the methodology was fit for the intended use, with accuracy of 97.4+/-4.3% for the assay and detection limits for degradants ranging between 0.5 and 2.4%. Pilot stability tests of the bioadhesive powder under different storage conditions showed a temperature-dependent decrease in salmon calcitonin assay value, with no equivalent increase in degradation products, explained by the chemical interaction between salmon calcitonin and the carbomer polymer.

  17. Tenth annual coal preparation, utilization, and environmental control contractors conference: Proceedings. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1994-08-01

    Volume II contains papers presented at the following sessions: combustion 2000 session; advanced research and technology development session; commercial/industrial combustion systems session; alternative fuels utilization session; environmental control poster session; and advanced combustion technology poster session. Selected papers have been processed separately for inclusion in the Energy Science and Technology Database.

  18. Adjustable virtual pore-size filter for automated sample preparation using acoustic radiation force

    Energy Technology Data Exchange (ETDEWEB)

    Jung, B; Fisher, K; Ness, K; Rose, K; Mariella, R

    2008-05-22

    We present a rapid and robust size-based separation method for high throughput microfluidic devices using acoustic radiation force. We developed a finite element modeling tool to predict the two-dimensional acoustic radiation force field perpendicular to the flow direction in microfluidic devices. Here we compare the results from this model with experimental parametric studies including variations of the PZT driving frequencies and voltages as well as various particle sizes and compressidensities. These experimental parametric studies also provide insight into the development of an adjustable 'virtual' pore-size filter as well as optimal operating conditions for various microparticle sizes. We demonstrated the separation of Saccharomyces cerevisiae and MS2 bacteriophage using acoustic focusing. The acoustic radiation force did not affect the MS2 viruses, and their concentration profile remained unchanged. With optimized design of our microfluidic flow system we were able to achieve yields of > 90% for the MS2 with > 80% of the S. cerevisiae being removed in this continuous-flow sample preparation device.

  19. Dynamic simulation tools for the analysis and optimization of novel collection, filtration and sample preparation systems

    Energy Technology Data Exchange (ETDEWEB)

    Clague, D; Weisgraber, T; Rockway, J; McBride, K

    2006-02-12

    The focus of research effort described here is to develop novel simulation tools to address design and optimization needs in the general class of problems that involve species and fluid (liquid and gas phases) transport through sieving media. This was primarily motivated by the heightened attention on Chem/Bio early detection systems, which among other needs, have a need for high efficiency filtration, collection and sample preparation systems. Hence, the said goal was to develop the computational analysis tools necessary to optimize these critical operations. This new capability is designed to characterize system efficiencies based on the details of the microstructure and environmental effects. To accomplish this, new lattice Boltzmann simulation capabilities where developed to include detailed microstructure descriptions, the relevant surface forces that mediate species capture and release, and temperature effects for both liquid and gas phase systems. While developing the capability, actual demonstration and model systems (and subsystems) of national and programmatic interest were targeted to demonstrate the capability. As a result, where possible, experimental verification of the computational capability was performed either directly using Digital Particle Image Velocimetry or published results.

  20. Methodologies and perspectives of proteomics applied to filamentous fungi: from sample preparation to secretome analysis.

    Science.gov (United States)

    Bianco, Linda; Perrotta, Gaetano

    2015-03-12

    Filamentous fungi possess the extraordinary ability to digest complex biomasses and mineralize numerous xenobiotics, as consequence of their aptitude to sensing the environment and regulating their intra and extra cellular proteins, producing drastic changes in proteome and secretome composition. Recent advancement in proteomic technologies offers an exciting opportunity to reveal the fluctuations of fungal proteins and enzymes, responsible for their metabolic adaptation to a large variety of environmental conditions. Here, an overview of the most commonly used proteomic strategies will be provided; this paper will range from sample preparation to gel-free and gel-based proteomics, discussing pros and cons of each mentioned state-of-the-art technique. The main focus will be kept on filamentous fungi. Due to the biotechnological relevance of lignocellulose degrading fungi, special attention will be finally given to their extracellular proteome, or secretome. Secreted proteins and enzymes will be discussed in relation to their involvement in bio-based processes, such as biomass deconstruction and mycoremediation.

  1. Atmospheric pressure microwave sample preparation procedure for the combined analysis of total phosphorus and kjeldahl nitrogen.

    Science.gov (United States)

    Collins, L W; Chalk, S J; Kingston, H M

    1996-08-01

    An atmospheric pressure microwave digestion method has been developed for the combined analysis of total phosphorus and Kjeldahl nitrogen in complex matrices. In comparison to the digestion steps in EPA Methods 365.4 (total phosphorus) and 351.x (Kjeldahl nitrogen), this method requires less time, eliminates the need for a catalyst, and reduces the toxicity of the waste significantly. It employs a microwave-assisted digestion step, using refluxing borosilicate glass vessels at atmospheric pressure. Traditionally, this method has a time-consuming sample preparation step and generates toxic waste through the use of heavy metal catalysts. These advantages are gained by the combination of a high boiling point acid (sulfuric acid) and the application of focused microwave irradiation, which enhances the digestion process by direct energy coupling. NIST standard reference materials 1572 (citrus leaves), 1577a (bovine liver), and 1566 (oyster tissue) and tryptophan were analyzed to validate the method. Phosphorus concentrations were determined by the colorimetric ascorbic acid method outlined in EPA Method 365.3. Kjeldahl nitrogen concentrations were determined using EPA Method 351.1. The results of the analyses showed good precision and are in excellent agreement with the NIST published values for both elements.

  2. Optimizing human semen cryopreservation by reducing test vial volume and repetitive test vial sampling

    DEFF Research Database (Denmark)

    Jensen, Christian F S; Ohl, Dana A; Parker, Walter R

    2015-01-01

    OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN: Prospec......OBJECTIVE: To investigate optimal test vial (TV) volume, utility and reliability of TVs, intermediate temperature exposure (-88°C to -93°C) before cryostorage, cryostorage in nitrogen vapor (VN2) and liquid nitrogen (LN2), and long-term stability of VN2 cryostorage of human semen. DESIGN...

  3. [Preparation of molecularly imprinted polymers using dummy template and the applications in selective solid-phase extraction of seven bisphenols from human urine, bovine serum and beer samples].

    Science.gov (United States)

    Yang, Jiajia; Li, Yun; Wang Jinchengt; Sun, Xiaoli; Chen, Jiping

    2015-05-01

    A molecularly imprinted polymer (MIP) for selective recognition of seven bisphenols (BPs) was prepared using dummy template phenolphthalein (PP) by bulk polymerization. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the prepared PP-MIP possessed narrow particle diameter distribution (40-60 µm), a specific surface area (S(BET)) of 359.77 m2/g and a total pore volume (Vt) of 0.730 cm3/g. The adsorption capacity for bisphenol A (BPA) of PP-MIP was evaluated by static adsorption experiment. And the Scatchard analysis revealed that the maximum specific adsorption capacity of PP-MIP was 4.661 µmol/g. Good class selectivity for BPA and its six structural analogues of bisphenol B (BPB) , bisphenol E (BPE), bisphenol AF (BPAF), bisphenol S (BPS), bisphenol AP (BPAP) and bisphenol Z (BPZ) was demonstrated by the chromatographic evaluation experiment. The prepared PP-MIP was successfully used as solid-phase extraction (SPE) sorbent for the separation and purification of the seven BPs in human urine, bovine serum and beer samples. Meanwhile, an accurate and sensitive MIP-SPE-HPLC method was established for the determination of the seven BPs in human urine, bovine serum and beer samples. The limits of detection (LODs) for the three samples were in the range of 1.2-2.0 µg/L. The results showed that good linearities were obtained in the range of 0.02-2 mg/L for the seven BPs and the correlation coefficients (r) were higher than 0.999 8. The recoveries of the BPs spiked in blank samples at two spiked levels (100 and 500 µg/L for each BP) were in the range of 90.1%-107.1% with the RSDs ≤ 8.1%. The proposed method is simple and reliable for the rapid detection of the seven BPs in human urine, bovine serum and beer samples.

  4. Development of a sample preparation procedure for the simultaneous determination of Np and Pu in clay samples

    Energy Technology Data Exchange (ETDEWEB)

    Renz, Tobias; Quinto, Francesca; Lagos, Markus; Plaschke, Markus; Bauer, Andreas; Geckeis, Horst [INE, KIT, Eggenstein-Leopoldshafen (Germany); Taubald, Heinrich [Eberhard Karls Universitaet, Tuebingen (Germany)

    2015-07-01

    Neptunium (Np) and plutonium (Pu) are two key radionuclides for the long-term disposal of nuclear waste. Within this context Opalinus Clay formations are considered as a potential location for disposal of high-level radioactive waste. In the framework of experiments studying the diffusion behavior and retention of actinides under repository conditions, the present work focuses on the development of an analytical-chemical procedure for the determination of Np and Pu in clay (or clay-rich soil) samples. The procedure aims at the simultaneous determination of Np and Pu at femto- to attogram levels with AMS. Fields of application are the investigation of global fallout actinides in environmental clay-rich samples or the diffusion behavior of actinides in compacted clay liners used as technical barriers in nuclear waste repositories. Clay samples are spiked with certified standards of Pu-242 and Np-237. The analytical method, including a) leaching of the spiked clay samples, b) redox adjustments of Np and Pu, c) chromatographic separation of Np and Pu from the sample matrix and d) measurement of the actinides with Sector Field (SF)-ICP-MS will be presented. The suitability of a Pu isotope as non-isotopic tracer for determination of Np-237 is evaluated by determining the chemical yield using SF-ICP-MS.

  5. Reproducibility of NMR Analysis of Urine Samples: Impact of Sample Preparation, Storage Conditions, and Animal Health Status

    Directory of Open Access Journals (Sweden)

    Christina Schreier

    2013-01-01

    Full Text Available Introduction. Spectroscopic analysis of urine samples from laboratory animals can be used to predict the efficacy and side effects of drugs. This employs methods combining 1H NMR spectroscopy with quantification of biomarkers or with multivariate data analysis. The most critical steps in data evaluation are analytical reproducibility of NMR data (collection, storage, and processing and the health status of the animals, which may influence urine pH and osmolarity. Methods. We treated rats with a solvent, a diuretic, or a nephrotoxicant and collected urine samples. Samples were titrated to pH 3 to 9, or salt concentrations increased up to 20-fold. The effects of storage conditions and freeze-thaw cycles were monitored. Selected metabolites and multivariate data analysis were evaluated after 1H NMR spectroscopy. Results. We showed that variation of pH from 3 to 9 and increases in osmolarity up to 6-fold had no effect on the quantification of the metabolites or on multivariate data analysis. Storage led to changes after 14 days at 4°C or after 12 months at −20°C, independent of sample composition. Multiple freeze-thaw cycles did not affect data analysis. Conclusion. Reproducibility of NMR measurements is not dependent on sample composition under physiological or pathological conditions.

  6. Reproducibility of NMR analysis of urine samples: impact of sample preparation, storage conditions, and animal health status.

    Science.gov (United States)

    Schreier, Christina; Kremer, Werner; Huber, Fritz; Neumann, Sindy; Pagel, Philipp; Lienemann, Kai; Pestel, Sabine

    2013-01-01

    Spectroscopic analysis of urine samples from laboratory animals can be used to predict the efficacy and side effects of drugs. This employs methods combining (1)H NMR spectroscopy with quantification of biomarkers or with multivariate data analysis. The most critical steps in data evaluation are analytical reproducibility of NMR data (collection, storage, and processing) and the health status of the animals, which may influence urine pH and osmolarity. We treated rats with a solvent, a diuretic, or a nephrotoxicant and collected urine samples. Samples were titrated to pH 3 to 9, or salt concentrations increased up to 20-fold. The effects of storage conditions and freeze-thaw cycles were monitored. Selected metabolites and multivariate data analysis were evaluated after (1)H NMR spectroscopy. We showed that variation of pH from 3 to 9 and increases in osmolarity up to 6-fold had no effect on the quantification of the metabolites or on multivariate data analysis. Storage led to changes after 14 days at 4°C or after 12 months at -20°C, independent of sample composition. Multiple freeze-thaw cycles did not affect data analysis. Reproducibility of NMR measurements is not dependent on sample composition under physiological or pathological conditions.

  7. Inverse supercritical fluid extraction as a sample preparation method for the analysis of the nanoparticle content in sunscreen agents.

    Science.gov (United States)

    Müller, David; Cattaneo, Stefano; Meier, Florian; Welz, Roland; de Vries, Tjerk; Portugal-Cohen, Meital; Antonio, Diana C; Cascio, Claudia; Calzolai, Luigi; Gilliland, Douglas; de Mello, Andrew

    2016-04-01

    We demonstrate the use of inverse supercritical carbon dioxide (scCO2) extraction as a novel method of sample preparation for the analysis of complex nanoparticle-containing samples, in our case a model sunscreen agent with titanium dioxide nanoparticles. The sample was prepared for analysis in a simplified process using a lab scale supercritical fluid extraction system. The residual material was easily dispersed in an aqueous solution and analyzed by Asymmetrical Flow Field-Flow Fractionation (AF4) hyphenated with UV- and Multi-Angle Light Scattering detection. The obtained results allowed an unambiguous determination of the presence of nanoparticles within the sample, with almost no background from the matrix itself, and showed that the size distribution of the nanoparticles is essentially maintained. These results are especially relevant in view of recently introduced regulatory requirements concerning the labeling of nanoparticle-containing products. The novel sample preparation method is potentially applicable to commercial sunscreens or other emulsion-based cosmetic products and has important ecological advantages over currently used sample preparation techniques involving organic solvents.

  8. Automated Gel Size Selection to Improve the Quality of Next-generation Sequencing Libraries Prepared from Environmental Water Samples.

    Science.gov (United States)

    Uyaguari-Diaz, Miguel I; Slobodan, Jared R; Nesbitt, Matthew J; Croxen, Matthew A; Isaac-Renton, Judith; Prystajecky, Natalie A; Tang, Patrick

    2015-04-17

    Next-generation sequencing of environmental samples can be challenging because of the variable DNA quantity and quality in these samples. High quality DNA libraries are needed for optimal results from next-generation sequencing. Environmental samples such as water may have low quality and quantities of DNA as well as contaminants that co-precipitate with DNA. The mechanical and enzymatic processes involved in extraction and library preparation may further damage the DNA. Gel size selection enables purification and recovery of DNA fragments of a defined size for sequencing applications. Nevertheless, this task is one of the most time-consuming steps in the DNA library preparation workflow. The protocol described here enables complete automation of agarose gel loading, electrophoretic analysis, and recovery of targeted DNA fragments. In this study, we describe a high-throughput approach to prepare high quality DNA libraries from freshwater samples that can be applied also to other environmental samples. We used an indirect approach to concentrate bacterial cells from environmental freshwater samples; DNA was extracted using a commercially available DNA extraction kit, and DNA libraries were prepared using a commercial transposon-based protocol. DNA fragments of 500 to 800 bp were gel size selected using Ranger Technology, an automated electrophoresis workstation. Sequencing of the size-selected DNA libraries demonstrated significant improvements to read length and quality of the sequencing reads.

  9. Development of a Solid Phase Extraction Method for Agricultural Pesticides in Large-Volume Water Samples

    Science.gov (United States)

    An analytical method using solid phase extraction (SPE) and analysis by gas chromatography/mass spectrometry (GC/MS) was developed for the trace determination of a variety of agricultural pesticides and selected transformation products in large-volume high-elevation lake water sa...

  10. Integrating Girl Child Issues into Population Education: Strategies and Sample Curriculum and Instructional Materials. Volume 2.

    Science.gov (United States)

    United Nations Educational, Scientific, and Cultural Organization, Bangkok (Thailand).

    One of the most important vehicles for promoting the concerns of the "girl child" and the elimination of gender bias is through education, and since programs in population education are being funded all over the world, population education is a suitable and effective medium for integrating messages on the girl child. This two-volume publication…

  11. Recent advances in metal-organic frameworks and covalent organic frameworks for sample preparation and chromatographic analysis.

    Science.gov (United States)

    Wang, Xuan; Ye, Nengsheng

    2017-09-04

    In the field of analytical chemistry, sample preparation and chromatographic separation are two core procedures. The means by which to improve the sensitivity, selectivity and detection limit of a method have become a topic of great interest. Recently, porous organic frameworks, such as metal-organic frameworks (MOFs) and covalent organic frameworks (COFs), have been widely used in this research area because of their special features, and different methods have been developed. This review summarizes the applications of MOFs and COFs in sample preparation and chromatographic stationary phases. The MOF- or COF-based solid-phase extraction (SPE), solid-phase microextraction (SPME), gas chromatography (GC), high-performance liquid chromatography (HPLC) and capillary electrochromatography (CEC) methods are described. The excellent properties of MOFs and COFs have resulted in intense interest in exploring their performance and mechanisms for sample preparation and chromatographic separation. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

  12. An On-Target Desalting and Concentration Sample Preparation Protocol for MALDI-MS and MS/MS Analysis

    DEFF Research Database (Denmark)

    Zhang, Xumin; Wang, Quanhui; Lou, Xiaomin;

    2012-01-01

    2DE coupled with MALDI-MS is one of the most widely used and powerful analytic technologies in proteomics study. The MALDI sample preparation method has been developed and optimized towards the combination of simplicity, sample-cleaning, and sample concentration since its introduction. Here we...... present a protocol of the so-called Sample loading, Matrix loading, and on-target Wash (SMW) method which fulfills the three criteria by taking advantage of the AnchorChip™ targets. Our method is extremely simple and no pre-desalting or concentration is needed when dealing with samples prepared from 2DE....... The protocol is amendable for automation and would pave the road for high-throughput MALDI-MS or MS/MS-based proteomics studies with guaranteed sensitivity and high identification rate. The method has been successfully applied to mouse liver proteome study and so far has been employed in other proteome studies...

  13. Preparation

    Directory of Open Access Journals (Sweden)

    M.M. Dardir

    2014-03-01

    Full Text Available Some hexanamide-mono and di-linoleniate esters were prepared by the reaction of linolenic acid and hexanamide (derived from the reaction of hexanoic acid and diethanolamine. The chemical structure for the newly prepared hexanamide-mono and di-linoleniate esters were elucidated using elemental analysis, (FTIR, H 1NMR and chemical ionization mass spectra (CI/Ms spectroscopic techniques. The results of the spectroscopic analysis indicated that they were prepared through the right method and they have high purity. The new prepared esters have high biodegradability and lower toxicity (environmentally friendly so they were evaluated as a synthetic-based mud (ester-based mud for oil-well drilling fluids. The evaluation included study of the rheological properties, filtration and thermal properties of the ester based-muds formulated with the newly prepared esters compared to the reference commercial synthetic-based mud.

  14. Preparation and characterization of magnetic carboxylated nanodiamonds for vortex-assisted magnetic solid-phase extraction of ziram in food and water samples.

    Science.gov (United States)

    Yılmaz, Erkan; Soylak, Mustafa

    2016-09-01

    A simple and rapid vortex-assisted magnetic solid phase extraction (VA-MSPE) method for the separation and preconcentration of ziram (zinc dimethyldithiocarbamate), subsequent detection of the zinc in complex structure of ziram by flame atomic absorption spectrometry (AAS) has been developed. The ziram content was calculated by using stoichiometric relationship between the zinc and ziram. Magnetic carboxylated nanodiamonds (MCNDs) as solid-phase extraction adsorbent was prepared and characterized by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) spectrometry and scanning electron microscopy (SEM). These magnetic carboxylated nanodiamonds carrying the ziram could be easily separated from the aqueous solution by applying an external magnetic field; no filtration or centrifugation was necessary. Some important factors influencing the extraction efficiency of ziram such as pH of sample solution, amount of adsorbent, type and volume of eluent, extraction and desorption time and sample volume were studied and optimized. The total extraction and detection time was lower than 10min The preconcentration factor (PF), the precision (RSD, n=7), the limit of detection (LOD) and limit of quantification (LOQ) were 160, 7.0%, 5.3µgL(-1) and 17.5µgL(-1), respectively. The interference of various ions has been examined and the method has been applied for the determination of ziram in various waters, foodstuffs samples and synthetic mixtures.

  15. Reference Equations for Static Lung Volumes and TLCO from a Population Sample in Northern Greece.

    Science.gov (United States)

    Michailopoulos, Pavlos; Kontakiotis, Theodoros; Spyratos, Dionisios; Argyropoulou-Pataka, Paraskevi; Sichletidis, Lazaros

    2015-02-14

    Background: The most commonly used reference equations for the measurement of static lung volumes/capacities and transfer factor of the lung for CO (TLCO) are based on studies around 30-40 years old with significant limitations. Objectives: Our aim was to (1) develop reference equations for static lung volumes and TLCO using the current American Thoracic Society/European Respiratory Society guidelines, and (2) compare the equations derived with those most commonly used. Methods: Healthy Caucasian subjects (234 males and 233 females) aged 18-91 years were recruited. All of them were healthy never smokers with a normal chest X-ray. Static lung volumes and TLCO were measured with a single-breath technique according to the latest guidelines. Results: Curvilinear regression prediction equations derived from the present study were compared with those that are most commonly used. Our reference equations in accordance with the latest studies show lower values for all static lung volume parameters and TLCO as well as a different way of deviation of those parameters (i.e. declining with age total lung capacity, TLCO age decline in both sex and functional residual capacity age rise in males). Conclusions: We suggest that old reference values of static lung volumes and TLCO should be updated, and our perception of deviation of some spirometric parameters should be revised. Our new reference curvilinear equations derived according to the latest guidelines could contribute to the updating by respiratory societies of old existing reference values and result in a better estimation of the lung function of contemporary populations with similar Caucasian characteristics. © 2015 S. Karger AG, Basel.

  16. Preparation of small volume, leuko and erythrocyte very poor platelet concentrates.

    Science.gov (United States)

    Valbonesi, M; Angelini, G; Malfanti, L; Lercari, G; Fella, M; Calderisi, S; Anselmo, A; Balistreri, M

    1986-05-01

    Recently developed automated discontinuous flow centrifuge (DFC) separators can produce leuko- and erythrocyte-poor platelet concentrates (PC). According to general experience with these machines it is difficult to obtain more than 4 X 10(11) platelets, though a second program set up by Coffe et al. appears to produce PC containing approximately 5 X 10(11) platelets suspended in a plasma volume of 390 ml. At our center we employed a new Dideco cell separator equipped with the surge pump and a technique developed for the production of small volume, RBC and WBC-very poor PC. In 60 routine procedures we obtained the following results: mean processing time 87 +/- 11 minutes; final volume of PC 136 +/- 19 ml, with a mean platelet yield of 5.21 X 10(11) platelets. WBC contamination was 1.8 X 10(8) (93% lymphocytes) and RBC were 3.1 X 10(8). Plasma volume as well as WBC and RBC contamination were reduced by recirculating PC after the 6th pass. The demand for single donor platelet concentrates (PC) is increasing progressively. Recently developed automated cell separators can produce leukocyte (WBC) and erythrocyte (RBC) poor PC. With these machines it may be difficult to obtain PC containing at least 4 X 10(11) platelets and less than 1 X 10(9) leukocytes (1, 2, 3) since donor variables such as hematocrit, precounts, buffy coat formation and initial plasma light transmission are of paramount importance for the efficiency of the program. At our center a prototype discontinuous flow centrifuge (DFC) cell separator equipped with the surge pump was studied.(ABSTRACT TRUNCATED AT 250 WORDS)

  17. Transmission Electron Microscopy (TEM) Sample Preparation of Si(1-x)Gex in c-Plane Sapphire Substrate

    Science.gov (United States)

    Kim, Hyun Jung; Choi, Sang H.; Bae, Hyung-Bin; Lee, Tae Woo

    2012-01-01

    The National Aeronautics and Space Administration-invented X-ray diffraction (XRD) methods, including the total defect density measurement method and the spatial wafer mapping method, have confirmed super hetero epitaxy growth for rhombohedral single crystalline silicon germanium (Si1-xGex) on a c-plane sapphire substrate. However, the XRD method cannot observe the surface morphology or roughness because of the method s limited resolution. Therefore the authors used transmission electron microscopy (TEM) with samples prepared in two ways, the focused ion beam (FIB) method and the tripod method to study the structure between Si1-xGex and sapphire substrate and Si1?xGex itself. The sample preparation for TEM should be as fast as possible so that the sample should contain few or no artifacts induced by the preparation. The standard sample preparation method of mechanical polishing often requires a relatively long ion milling time (several hours), which increases the probability of inducing defects into the sample. The TEM sampling of the Si1-xGex on sapphire is also difficult because of the sapphire s high hardness and mechanical instability. The FIB method and the tripod method eliminate both problems when performing a cross-section TEM sampling of Si1-xGex on c-plane sapphire, which shows the surface morphology, the interface between film and substrate, and the crystal structure of the film. This paper explains the FIB sampling method and the tripod sampling method, and why sampling Si1-xGex, on a sapphire substrate with TEM, is necessary.

  18. Bovine liver sample preparation and micro-homogeneity study for Cu and Zn determination by solid sampling electrothermal atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Nomura, Cassiana S. [Instituto de Quimica, Universidade de Sao Paulo, CP 26077, Sao Paulo, SP 05513-970 (Brazil); Silva, Cintia S. [Instituto de Quimica, Universidade de Sao Paulo, CP 26077, Sao Paulo, SP 05513-970 (Brazil); Nogueira, Ana R.A. [Embrapa Pecuaria Sudeste, CP 339, Sao Carlos, SP 13560-970 (Brazil); Oliveira, Pedro V. [Instituto de Quimica, Universidade de Sao Paulo, CP 26077, Sao Paulo, SP 05513-970 (Brazil)]. E-mail: pvolivei@iq.usp.br

    2005-06-30

    This work describes a systematic study for the bovine liver sample preparation for Cu and Zn determination by solid sampling electrothermal atomic absorption spectrometry. The main parameters investigated were sample drying, grinding process, particle size, sample size, microsample homogeneity, and their relationship with the precision and accuracy of the method. A bovine liver sample was prepared using different drying procedures: (1) freeze drying, and (2) drying in a household microwave oven followed by drying in a stove at 60 deg. C until constant mass. Ball and cryogenic mills were used for grinding. Less sensitive wavelengths for Cu (216.5 nm) and Zn (307.6 nm), and Zeeman-based three-field background correction for Cu were used to diminish the sensitivities. The pyrolysis and atomization temperatures adopted were 1000 deg. C and 2300 deg. C for Cu, and 700 deg. C and 1700 deg. C for Zn, respectively. For both elements, it was possible to calibrate the spectrometer with aqueous solutions. The use of 250 {mu}g of W + 200 {mu}g of Rh as permanent chemical modifier was imperative for Zn. Under these conditions, the characteristic mass and detection limit were 1.4 ng and 1.6 ng for Cu, and 2.8 ng and 1.3 ng for Zn, respectively. The results showed good agreement (95% confidence level) for homogeneity of the entire material (> 200 mg) when the sample was dried in microwave/stove and ground in a cryogenic mill. The microsample homogeneity study showed that Zn is more dependent on the sample pretreatment than Cu. The bovine liver sample prepared in microwave/stove and ground in a cryogenic mill presented results with the lowest relative standard deviation for Cu than Zn. Good accuracy and precision were observed for bovine liver masses higher than 40 {mu}g for Cu and 30 {mu}g for Zn. The concentrations of Cu and Zn in the prepared bovine liver sample were 223 mg kg{sup -} {sup 1} and 128 mg kg{sup -} {sup 1}, respectively. The relative standard deviations were lower

  19. Evaluation of Electrospray as a Sample Preparation Tool for Electron Microscopic Investigations: Toward Quantitative Evaluation of Nanoparticles.

    Science.gov (United States)

    Mielke, Johannes; Dohányosová, Pavla; Müller, Philipp; López-Vidal, Silvia; Hodoroaba, Vasile-Dan

    2017-02-01

    The potential of electrospray deposition, for the controlled preparation of particles for imaging in electron microscopes, is evaluated on various materials: from mono-modal suspensions of spherical particles to multimodal suspensions and to real-world industrial materials. It is shown that agglomeration is reduced substantially on the sample carrier, compared with conventional sample preparation techniques. For the first time, it is possible to assess the number concentration of a tri-modal polystyrene suspension by electron microscopy, due to the high deposition efficiency of the electrospray. We discovered that some suspension stabilizing surfactants form artifact particles during electrospraying. These can be avoided by optimizing the sprayed suspension.

  20. Development of a high throughput 96-well plate sample preparation method for the determination of trileptal (oxcarbazepine) and its metabolites in human plasma.

    Science.gov (United States)

    Souppart, C; Decherf, M; Humbert, H; Maurer, G

    2001-10-05

    A high throughput preparation method for the determination of trileptal (oxcarbazepine, OXC) and its mono (MHD) and dihydroxy (DHD) metabolites in human plasma, using 96-well plate technology, has been developed and validated according to international regulatory requirements. Preparation of plasma samples (50 microl) containing the compounds to be analysed involved solid-phase extraction (SPE) on Empore C18 96-well SPE plates. Eluates from the plate were injected onto a reversed-phase column (Hypersil C18,3 microm) with UV detection at 210 nm. Detector response was linear over the ranges 0.2-10, 0.1-200 and 0.1-20 micromol/l, for OXC, MHD and DHD, respectively, with relative standard deviations from 1 to 10% and mean accuracies within 4% of the nominal values (number of standard curves=3 in duplicate). The limits of quantitation were 0.2, 0.1 and 0.1 micromol/l, respectively. The overall mean accuracies ranged from 96 to 106% and precision was in the range 4 to 11%. Cross validation indicated no significant difference between plasma concentrations obtained using the 96-well method and the previous method using a traditional SPE method with a 50 mg C18 cartridge. About a threefold increase in sample throughput and a twofold decrease of plasma volume required for the assays, were the main advantages obtained from the previous method. The method was applied for the determination of 3000 plasma samples from clinical studies.

  1. Preparative chromatography for specific δ13C isotopic analysis of individual carbohydrates in environmental samples

    Science.gov (United States)

    Nouara, Amel; Panagiotopoulos, Christos; Balesdent, Jérôme; Sempéré, Richard

    2017-04-01

    Carbohydrates are among the most abundant organic molecules on the Earth and are present in all geochemical systems. Despite their high abundance in the environment, very few studies assessed their origin using molecular carbohydrate isotopic analyses. In contrast with bulk stable isotope analysis (BSIA), which gives the isotopic signature of the entire sample without any specification about its chemical composition, compound specific 13C isotopic analysis of individual sugars (CSIA) offers valuable information about the origin of single molecules. Previous investigations used gas or liquid chromatography coupled with isotope ratio mass spectroscopy (GC-IRMS; HPLC-IRMS) for CSIA of sugars however the former requires δ13C corrections due to the carbon added to the sugar (derivatization) while the later does not provide always adequate separations among monosaccharides. Here we used cation preparative chromatography (Ca2+, Pb2+ and Na+) with refractive index detection in order to produce pure monosaccharide targets for subsequent EA-IRMS analyses. Milli-Q water was used as eluant at a flow rate 0.6 ml min-1. In general, three successive purifications (Ca2+, Pb2+, Ca2+) were sufficient to produce pure compounds. Pure monosaccharides were compared with authentic monosaccharide standards using 1H NMR and/or mass spectroscopy. The detection limit of our technique was about 1µM/sugar with a precision of 10% (n=6). Blanks run with Milli-Q water after three successive purifications resulted in carbon content of 0.13 to 2.77 µgC per collected sugar. These values are much lower than the minimum required amount (5 µgC) of the EA-IRSMS system with a precision of ± 0.35 ‰. Application of our method to environmental samples resulted in δ13C values of glucose, fructose, and levoglucosan in the range of -24 to -26 ‰ (PM10 atmospheric particles), and -15‰ to -22 ‰ for arabinose, glucose, and xylose (marine high molecular dissolved organic matter). These results fall in

  2. Closer to the native state. Critical evaluation of cryo-techniques for Transmission Electron Microscopy: preparation of biological samples.

    Science.gov (United States)

    Mielanczyk, Lukasz; Matysiak, Natalia; Michalski, Marek; Buldak, Rafal; Wojnicz, Romuald

    2014-01-01

    Over the years Transmission Electron Microscopy (TEM) has evolved into a powerful technique for the structural analysis of cells and tissues at various levels of resolution. However, optimal sample preservation is required to achieve results consistent with reality. During the last few decades, conventional preparation methods have provided most of the knowledge about the ultrastructure of organelles, cells and tissues. Nevertheless, some artefacts can be introduced at all stagesofstandard electron microscopy preparation technique. Instead, rapid freezing techniques preserve biological specimens as close as possible to the native state. Our review focuses on different cryo-preparation approaches, starting from vitrification methods dependent on sample size. Afterwards, we discuss Cryo-Electron Microscopy Of VItreous Sections (CEMOVIS) and the main difficulties associated with this technique. Cryo-Focused Ion Beam (cryo-FIB) is described as a potential alternative for CEMOVIS. Another post-processing route for vitrified samples is freeze substitution and embedding in resin for structural analysis or immunolocalization analysis. Cryo-sectioning according to Tokuyasu is a technique dedicated to high efficiency immunogold labelling. Finally, we introduce hybrid techniques, which combine advantages of primary techniques originally dedicated to different approaches. Hybrid approaches permit to perform the study of difficult-to-fix samples and antigens or help optimize the sample preparation protocol for the integrated Laser and Electron Microscopy (iLEM) technique.

  3. Probabilistic Requirements (Partial) Verification Methods Best Practices Improvement. Variables Acceptance Sampling Calculators: Empirical Testing. Volume 2

    Science.gov (United States)

    Johnson, Kenneth L.; White, K. Preston, Jr.

    2012-01-01

    The NASA Engineering and Safety Center was requested to improve on the Best Practices document produced for the NESC assessment, Verification of Probabilistic Requirements for the Constellation Program, by giving a recommended procedure for using acceptance sampling by variables techniques as an alternative to the potentially resource-intensive acceptance sampling by attributes method given in the document. In this paper, the results of empirical tests intended to assess the accuracy of acceptance sampling plan calculators implemented for six variable distributions are presented.

  4. Quantitative in-situ TEM nanotensile testing of single crystal Ni facilitated by a new sample preparation approach.

    Science.gov (United States)

    Samaeeaghmiyoni, Vahid; Idrissi, Hosni; Groten, Jonas; Schwaiger, Ruth; Schryvers, Dominique

    2017-03-01

    Twin-jet electro-polishing and Focused Ion Beam (FIB) were combined to produce small size Nickel single crystal specimens for quantitative in-situ nanotensile experiments in the transmission electron microscope. The combination of these techniques allows producing samples with nearly defect-free zones in the centre in contrast to conventional FIB-prepared samples. Since TEM investigations can be performed on the electro-polished samples prior to in-situ TEM straining, specimens with desired crystallographic orientation and initial microstructure can be prepared. The present results reveal a dislocation nucleation-controlled plasticity, in which small loops induced by FIB near the edges of the samples play a central role. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Improved mass spectrometric analysis of membrane proteins based on rapid and versatile sample preparation on nanodiamond particles.

    Science.gov (United States)

    Pham, Minh D; Yu, Steve S-F; Han, Chau-Chung; Chan, Sunney I

    2013-07-16

    We have developed a novel streamlined sample preparation procedure for mass spectrometric (MS) analysis of membrane proteins using surface-oxidized nanodiamond particles. The platform consists of solid-phase extraction and elution of the membrane proteins on nanodiamonds, concentrating the membrane proteins on the nanodiamonds and separating out detergents, chaotropic agents, and salts, and other impurities that are often present at high concentrations in solubilized membrane preparations. In this manner, membrane-protein extracts are transformed into MS-ready samples in minutes. The protocol is not only fast, but also widely adaptable and highly effective for preparing generic membrane protein samples for both MALDI-MS studies of membrane-protein complexes and shotgun membrane proteomics studies. As proof of concept, we have demonstrated substantial improvements in the MALDI-MS analysis of the particulate methane monooxygenase (pMMO) complex, a three-subunit transmembrane protein solubilized in various detergent buffers. Enzymatic digestions of membrane proteins are also greatly facilitated since the proteins extracted on to the nanodiamonds are exposed on the surface of the nanoparticles rather than in SDS gels or in detergent solutions. We illustrate the effectiveness of nanodiamonds for SDS removal in the preparation of membrane proteins for MS analysis on the proteome level by examining the quality of the tryptic peptides prepared by on-surface nanodiamond digestion of an E. coli membrane fraction for shotgun proteomics.

  6. Sample preparation and direct electrospray ionization on a tip column for rapid mass spectrometry analysis of complex samples.

    Science.gov (United States)

    Huang, Yun-Qing; You, Jin-Qing; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-10-07

    A handheld pipette tip column electrospray ionization source (PTC-ESI source) was developed for rapid mass spectrometry analysis at ambient pressure. The PTC-ESI source was made up of three main component parts including a micro DC high voltage (HV) power supply, a micropipette and a disposable micropipette tip filled with a plug of adsorbent. A DC high voltage was applied to the sharp point of the micropipette tip column to induce electrospray ionization. The PTC-ESI source was successfully used for direct analysis of basic organic compounds, organic acids and peptides in a simple matrix. In the case of complex samples, micro-extraction based on the adsorbent phase filled in the pipette tip was used to remove impurities and concentrate target analytes prior to ionization. The eluting solution was not pipetted out, but directly dispersed in the form of electrospray from the pipette tip for ionization. The effectiveness of the PTC-ESI source has been further demonstrated by fast analysis of therapeutic compounds and endogenous bioactive chemicals in complex biological samples.

  7. Quantitative pH assessment of small-volume samples using a universal pH indicator.

    Science.gov (United States)

    Brown, Jeffrey D; Bell, Nathaniel; Li, Victoria; Cantrell, Kevin

    2014-10-01

    We developed a hue-based pH determination method to analyze digital images of samples in a 384-well plate after the addition of a universal pH indicator. The standard error of calibration for 69 pH standards was 0.078 pH units, and no sample gave an error greater than 0.23 units. We then used in-solution isoelectric focusing to determine the isoelectric point of Wnt3A protein in conditioned medium and after purification and applied the described method to assess the pH of these small-volume samples. End users may access our standard to assay the pH of their own samples with no additional calibration. Copyright © 2014 Elsevier Inc. All rights reserved.

  8. Recovery of Cryptosporidium oocysts from small and large volume water samples using a compressed foam filter system.

    Science.gov (United States)

    Sartory, D P; Parton, A; Parton, A C; Roberts, J; Bergmann, K

    1998-12-01

    A novel filter system comprising open cell reticulated foam rings compressed between retaining plates and fitted into a filtration housing was evaluated for the recovery of oocysts of Cryptosporidium from water. Mean recoveries of 90.2% from seeded small and large volume (100-2000 l) tap water samples, and 88.8% from 10-20 l river water samples, were achieved. Following a simple potassium citrate flotation concentrate clean-up procedure, mean recoveries were 56.7% for the tap water samples and 60.9% for river water samples. This represents a marked improvement in capture and recovery of Cryptosporidium oocysts from water compared with conventional polypropylene wound cartridge filters and membrane filters.

  9. Testing of high-volume sampler inlets for the sampling of atmospheric radionuclides.

    Science.gov (United States)

    Irshad, Hammad; Su, Wei-Chung; Cheng, Yung S; Medici, Fausto

    2006-09-01

    Sampling of air for radioactive particles is one of the most important techniques used to determine the nuclear debris from a nuclear weapon test in the Earth's atmosphere or those particles vented from underground or underwater tests. Massive-flow air samplers are used to sample air for any indication of radionuclides that are a signature of nuclear tests. The International Monitoring System of the Comprehensive Nuclear Test Ban Treaty Organization includes seismic, hydroacoustic, infrasound, and gaseous xenon isotopes sampling technologies, in addition to radionuclide sampling, to monitor for any violation of the treaty. Lovelace Respiratory Research Institute has developed a large wind tunnel to test the outdoor radionuclide samplers for the International Monitoring System. The inlets for these samplers are tested for their collection efficiencies for different particle sizes at various wind speeds. This paper describes the results from the testing of two radionuclide sampling units used in the International Monitoring System. The possible areas of depositional wall losses are identified and the losses in these areas are determined. Sampling inlet type 1 was tested at 2.2 m s wind speed for 5, 10, and 20-microm aerodynamic diameter particles. The global collection efficiency was about 87.6% for 10-microm particles for sampling inlet type 1. Sampling inlet type 2 was tested for three wind speeds at 0.56, 2.2, and 6.6 m s for 5, 10, and 20-microm aerodynamic diameter particles in two different configurations (sampling head lowered and raised). The global collection efficiencies for these configurations for 10-microm particles at 2.2 m s wind speed were 77.4% and 82.5%, respectively. The sampling flow rate was 600 m h for both sampling inlets.

  10. Preparation and development of land use energy consumption data sets. Volume 1, phase 1. Final report

    Energy Technology Data Exchange (ETDEWEB)

    1978-12-20

    An analysis was made of the potential usefulness of land-use-related data, the availability of relevant information in the literature, and potential approaches for data collection. This volume describes the results of the analysis, while Volume II contains technical backup materials. Chapter 2 discusses the issue of community classification: questions of classification and aggregation have been the most significant technical issues faced on the project, since they strongly affect the accuracy and usefulness of any data that are developed. Chapter 3 is concerned with consistency of accounting, primarily in the measurement of energy use. Transportation patterns, energy-transmission losses, and energy embodied in materials and structure can all be assigned to various land uses in a number of ways, and it is important to perform the assignment in a way that is valuable for the policies being evaluated. Thus, Chapter 3 forms the structure for the dependent variables of the system: the various types and patterns of energy use, while Chapter 2 describes the structure of the independent variables, which are the land-use patterns described, plus other factors such as climate. Chapter 4 takes these two structures and presents computations of energy use for the various patterns of land uses, based on the literature, and Chapter 5 discusses the implications of these analyses for energy planning. This leads directly to Chapter 6, where recommendations are made regarding both data collection and use of existing data. (MCW)

  11. SyPRID sampler: A large-volume, high-resolution, autonomous, deep-ocean precision plankton sampling system

    Science.gov (United States)

    Billings, Andrew; Kaiser, Carl; Young, Craig M.; Hiebert, Laurel S.; Cole, Eli; Wagner, Jamie K. S.; Van Dover, Cindy Lee

    2017-03-01

    The current standard for large-volume (thousands of cubic meters) zooplankton sampling in the deep sea is the MOCNESS, a system of multiple opening-closing nets, typically lowered to within 50 m of the seabed and towed obliquely to the surface to obtain low-spatial-resolution samples that integrate across 10 s of meters of water depth. The SyPRID (Sentry Precision Robotic Impeller Driven) sampler is an innovative, deep-rated (6000 m) plankton sampler that partners with the Sentry Autonomous Underwater Vehicle (AUV) to obtain paired, large-volume plankton samples at specified depths and survey lines to within 1.5 m of the seabed and with simultaneous collection of sensor data. SyPRID uses a perforated Ultra-High-Molecular-Weight (UHMW) plastic tube to support a fine mesh net within an outer carbon composite tube (tube-within-a-tube design), with an axial flow pump located aft of the capture filter. The pump facilitates flow through the system and reduces or possibly eliminates the bow wave at the mouth opening. The cod end, a hollow truncated cone, is also made of UHMW plastic and includes a collection volume designed to provide an area where zooplankton can collect, out of the high flow region. SyPRID attaches as a saddle-pack to the Sentry vehicle. Sentry itself is configured with a flight control system that enables autonomous survey paths to low altitudes. In its verification deployment at the Blake Ridge Seep (2160 m) on the US Atlantic Margin, SyPRID was operated for 6 h at an altitude of 5 m. It recovered plankton samples, including delicate living larvae, from the near-bottom stratum that is seldom sampled by a typical MOCNESS tow. The prototype SyPRID and its next generations will enable studies of plankton or other particulate distributions associated with localized physico-chemical strata in the water column or above patchy habitats on the seafloor.

  12. Development of a Novel Self-Enclosed Sample Preparation Device for DNA/RNA Isolation in Space

    Science.gov (United States)

    Zhang, Ye; Mehta, Satish K.; Pensinger, Stuart J.; Pickering, Karen D.

    2011-01-01

    Modern biology techniques present potentials for a wide range of molecular, cellular, and biochemistry applications in space, including detection of infectious pathogens and environmental contaminations, monitoring of drug-resistant microbial and dangerous mutations, identification of new phenotypes of microbial and new life species. However, one of the major technological blockades in enabling these technologies in space is a lack of devices for sample preparation in the space environment. To overcome such an obstacle, we constructed a prototype of a DNA/RNA isolation device based on our novel designs documented in the NASA New Technology Reporting System (MSC-24811-1/3-1). This device is self-enclosed and pipette free, purposely designed for use in the absence of gravity. Our design can also be modified easily for preparing samples in space for other applications, such as flowcytometry, immunostaining, cell separation, sample purification and separation according to its size and charges, sample chemical labeling, and sample purification. The prototype of our DNA/RNA isolation device was tested for efficiencies of DNA and RNA isolation from various cell types for PCR analysis. The purity and integrity of purified DNA and RNA were determined as well. Results showed that our developed DNA/RNA isolation device offers similar efficiency and quality in comparison to the samples prepared using the standard protocol in the laboratory.

  13. An automated on-line multidimensional HPLC system for protein and peptide mapping with integrated sample preparation

    NARCIS (Netherlands)

    Wagner, K.; Miliotis, T.; Marko-Varga, G; Bischoff, Rainer; Unger, K.K.

    2002-01-01

    A comprehensive on-line two-dimensional 2D-HPLC system with integrated sample preparation was developed for the analysis of proteins and peptides with a molecular weight below 20 kDa. The system setup provided fast separations and high resolving power and is considered to be a complementary techniqu

  14. A novel sample preparation method of matrix-assisted laser desorption/ionization time of flight mass spectrometry for polystyrene

    Institute of Scientific and Technical Information of China (English)

    Shu Zhang; Zhen Wen Zhao; Lei Xiong; Bin Xin; Wei Hua Hu; Shao Xiang Xiong

    2007-01-01

    A novel sample preparation method of matrix-assisted laser desorption/ionization mass spectrometry for polystyrene was reported.Compared to the conventional dried-droplet method, the efficiency of ionization and signal intensity of mass spectra were improved.The mechanism was also analyzed.

  15. Sludge batch 9 (SB9) acceptance evaluation. Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. J. [Savannah River Site (SRS), Aiken, SC (United States); Diprete, D. P. [Savannah River Site (SRS), Aiken, SC (United States); Pareizs, J. M. [Savannah River Site (SRS), Aiken, SC (United States)

    2016-02-10

    Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tank 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a composition expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.

  16. Sludge batch 9 (SB9) accepance evaluation: Radionuclide concentrations in tank 51 SB9 qualification sample prepared at SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Diprete, D. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL); Pareizs, J. [Savannah River Site (SRS), Aiken, SC (United States). Savannah River National Lab. (SRNL)

    2016-03-01

    Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch 9 (SB9) for processing in the Defense Waste Processing Facility (DWPF). The SB9 material is currently in Tank 51 and has been washed and prepared for transfer to Tank 40. The acceptance evaluation needs to be completed prior to the transfer of the material in Tank 51 to Tank 40. The sludge slurry in Tank 40 has already been qualified for DWPF processing and is currently being processed as Sludge Batch 8 (SB8). The radionuclide concentrations were measured or estimated in the Tank 51 SB9 Washed Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from a three liter sample of Tank 51 sludge slurry (HTF-51-15-81) taken on July 23, 2015. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of Savannah River Remediation (SRR) it was then adjusted per the Tank Farm washing strategy as of October 20, 2015. This final slurry now has a compositioniv expected to be similar to that of the slurry in Tank 51 after final preparations have been made for transfer of that slurry to Tank 40.

  17. Phase analysis of aluminium modified GeSbTe bulk prepared from XRD of samples

    Science.gov (United States)

    Sandhu, Sharanjit; Singh, D.; Kumar, S.; Thangaraj, R.

    2016-05-01

    Various compositions of Aluminium modified GST as Alx(Ge2Sb2Te5)1-x x= 0, 0.15, 0.20, 0.25, 0.30 are prepared to study as a phase change material. Bulk prepared is studied with XRD scans for various phases formed. Phases other than Ge2Sb2Te5 do come in but dominated one is Ge2Sb2Te5 hexagonal phase.

  18. Nuclear waste calorimeter for very large drums with 385 litres sample volume

    Energy Technology Data Exchange (ETDEWEB)

    Jossens, G.; Mathonat, C. [SETARAM Instrumentation, Caluire (France); Bachelet, F. [CEA Valduc, Is sur Tille (France)

    2015-03-15

    Calorimetry is a very precise and well adapted tool for the classification of drums containing nuclear waste material depending on their level of activities (low, medium, high). A new calorimeter has been developed by SETARAM Instrumentation and the CEA Valduc in France. This new calorimeter is designed for drums having a volume bigger than 100 liters. It guarantees high operator safety by optimizing drum handling and air circulation for cooling, and optimized software for direct measurement of the quantity of nuclear material. The LVC1380 calorimeter makes it possible to work over the range 10 to 3000 mW, which corresponds to approximately 0.03 to 10 g of tritium or 3 to 955 g of {sup 241}Pu in a volume up to 385 liters. This calorimeter is based on the heat flow measurement using Peltier elements which surround the drum in the 3 dimensions and therefore measure all the heat coming from the radioactive stuff whatever its position inside the drum. Calorimeter's insulating layers constitute a thermal barrier designed to filter disturbances until they represent less than 0.001 Celsius degrees and to eliminate long term disturbances associated, for example, with laboratory temperature variations between day and night. A calibration device based on Joule effect has also been designed. Measurement time has been optimized but remains long compared with other methods of measurement such as gamma spectrometry but its main asset is to have a good accuracy for low level activities.

  19. On-chip polarimetry for high-throughput screening of nanoliter and smaller sample volumes

    Science.gov (United States)

    Bornhop, Darryl J. (Inventor); Dotson, Stephen (Inventor); Bachmann, Brian O. (Inventor)

    2012-01-01

    A polarimetry technique for measuring optical activity that is particularly suited for high throughput screening employs a chip or substrate (22) having one or more microfluidic channels (26) formed therein. A polarized laser beam (14) is directed onto optically active samples that are disposed in the channels. The incident laser beam interacts with the optically active molecules in the sample, which slightly alter the polarization of the laser beam as it passes multiple times through the sample. Interference fringe patterns (28) are generated by the interaction of the laser beam with the sample and the channel walls. A photodetector (34) is positioned to receive the interference fringe patterns and generate an output signal that is input to a computer or other analyzer (38) for analyzing the signal and determining the rotation of plane polarized light by optically active material in the channel from polarization rotation calculations.

  20. Portable sample preparation and analysis system for micron and sub-micron particle characterization using light scattering and absorption spectroscopy

    Science.gov (United States)

    Stark, Peter C.; Zurek, Eduardo; Wheat, Jeffrey V.; Dunbar, John M.; Olivares, Jose A.; Garcia-Rubio, Luis H.; Ward, Michael D.

    2011-07-26

    There is provided a method and device for remote sampling, preparation and optical interrogation of a sample using light scattering and light absorption methods. The portable device is a filtration-based device that removes interfering background particle material from the sample matrix by segregating or filtering the chosen analyte from the sample solution or matrix while allowing the interfering background particles to be pumped out of the device. The segregated analyte is then suspended in a diluent for analysis. The device is capable of calculating an initial concentration of the analyte, as well as diluting the analyte such that reliable optical measurements can be made. Suitable analytes include cells, microorganisms, bioparticles, pathogens and diseases. Sample matrixes include biological fluids such as blood and urine, as well as environmental samples including waste water.

  1. Safety and quality assurance of chemotherapeutic preparations in a hospital production unit: acceptance sampling plan and economic impact.

    Science.gov (United States)

    Paci, A; Borget, I; Mercier, L; Azar, Y; Desmaris, R P; Bourget, P

    2012-06-01

    The opportunity to apply a sampling plan was evaluated. Costs were computed by a microcosting study. In 2003, a sampling plan was defined to reduce the number of chemotherapy quality controls while preserving the same level of quality. Recent qualitative and quantitative changes led us to define a second sampling plan supplemented by an economic evaluation to determine the cost and cost-savings of quality control. The study considers preparation produced during four semesters classified into three groups. The first one includes drugs produced below 200 batches a semester. Group 2, those for which the lot of preparation lots would have been rejected twice among these four semesters. Group 3, those would have been accepted (≥3 'acceptable lot'). A single sampling plan by attributes was applied to this group with an acceptance quality level of 1.65% and a lot tolerance percent defective below 5%. A micro-costing study was conducted on quality control, from the sampling to the validation of the results. Among 39 cytotoxic drugs, 11 were sampled which enabled to avoid a mean of 17,512 control assays per year. Each batch of the 28 non-sampled drugs was however analyzed. Costs were estimated at 2.98€ and 5.25€ for control assays depending of the analytical method. The savings from the application of the sampling plans was 153,207€ in 6 years. The sampling plan allowed maintaining constancy in number of controls and the level of quality with significant costsavings, despite a substantial increase in drugs to assay and in the number of preparations produced.

  2. Preparation of solid-phase microextraction fibers by in-mold coating strategy for derivatization analysis of 24-epibrassinolide in pollen samples.

    Science.gov (United States)

    Pan, Jialiang; Hu, Yuling; Liang, Tingan; Li, Gongke

    2012-11-02

    A novel and simple in-mold coating strategy was proposed for the preparation of uniform solid-phase microextraction (SPME) coatings. Such a strategy is based on the direct synthesis of the polymer coating on the surface of a solid fiber using a glass capillary as the mold. The capillary was removed and the polymer with well-controlled thickness could be coated on the silica fiber reproductively. Following the strategy, a new poly(acrylamide-co-ethylene glycol dimethacrylate) (poly(AM-co-EGDMA)) coating was prepared for the preconcentration of 24-epibrassinolide (24-epiBL) from plant matrix. The coating had the enrichment factor of 32 folds, and the extraction efficiency per unit thickness was 5 times higher than that of the commercial polydimethylsiloxane/divinylbenzene (PDMS/DVB) coating. A novel method based on SPME coupled with derivatization and large volume injection-high performance liquid chromatography (LVI-HPLC) was developed for the analysis of 24-epiBL. The linear range was 0.500-20.0 μg/L with the detection limit of 0.13 μg/L. The amounts of endogenous 24-epiBL in rape and sunflower breaking-wall pollens samples were determined with satisfactory recovery (77.8-104%) and reproducibility (3.9-7.9%). The SPME-DE/LVI-HPLC method is rapid, reliable, convenient and applicable for complicated plant samples.

  3. Combining Endometrium Sampling Device and SurePath Preparation to Screen for Endometrial Carcinoma: A Validation Study

    Directory of Open Access Journals (Sweden)

    Jia Wen

    2015-01-01

    Full Text Available Background: The aim of this study was to compare specimen adequacy of SAP-1 provided for cytology with that of dilation and curettage (D & C or hysteroscopy for histology, and evaluate the accuracy of combining endometrium sampling by SAP-1 and liquid-based cytology using SurePath preparation for screening endometrial carcinoma and its precursor. Methods: Endometrial specimens from women (n = 1514 with risk factors were obtained using an SAP-1 device for cytological analysis; histological samples were obtained from 375 of these women who underwent D & C or hysteroscopy. Cytological specimens were prepared to liquid-based smear using SurePath technology and stained by Papanicolaou. Histological samples were processed in routine pathology and stained by hematoxylin and eosin. Results: Adequate specimens for cytology were obtained from 1458/1541 patients (96.3%, while adequate samples for pathology were obtained from 285/375 patients (76%. However, for postmenopausal women, 1006 of 1045 cytology (86.3% were adequate, 153 of 238 histology (64.3% were adequate, it was easier to collect cytological specimens than histological specimens (P < 0.05. The accuracy of endometrial cytology for detecting endometrial carcinoma and its precursor was 92.4% (sensitivity, 73%; specificity, 95.8%; positive predictive value, 75%; and negative predictive value, 95.3%. Conclusions: Endometrial cytology using SAP-1 sampling and SurePath preparation may be a reliable approach for screening patients with endometrial carcinoma and its precursor.

  4. MCNP ESTIMATE OF THE SAMPLED VOLUME IN A NON-DESTRUCTIVE IN SITU SOIL CARBON ANALYSIS.

    Energy Technology Data Exchange (ETDEWEB)

    WIELOPOLSKI, L.; DIOSZEGI, I.; MITRA, S.

    2004-05-03

    Global warming, promoted by anthropogenic CO{sub 2} emission into the atmosphere, is partially mitigated by the photosynthesis processes of the terrestrial echo systems that act as atmospheric CO{sub 2} scrubbers and sequester carbon in soil. Switching from till to no till soils management practices in agriculture further augments this process. Carbon sequestration is also advanced by putting forward a carbon ''credit'' system whereby these can be traded between CO{sub 2} producers and sequesters. Implementation of carbon ''credit'' trade will be further promulgated by recent development of a non-destructive in situ carbon monitoring system based on inelastic neutron scattering (INS). Volumes and depth distributions defined by the 0.1, 1.0, 10, 50, and 90 percent neutron isofluxes, from a point source located at either 5 or 30 cm above the surface, were estimated using Monte Carlo calculations.

  5. Continuous-flow PCR using segmented flow and integrating sample preparation

    Science.gov (United States)

    Becker, Holger; Hlawatsch, Nadine; Carstens, Cornelia; Klemm, Richard; Gärtner, Claudia

    2009-02-01

    Continuous-flow PCR has proven to be a powerful method for the amplification of genetic material due to its high speed and the possibility to perform amplicon detection and separation on-chip. A unique possibility of this method is the simultaneous amplification of several samples within a single chip by sample stacking, either having identical samples in several sample plugs separated by e.g. a mineral oil or using different samples in each sample plug. We have demonstrated the viability of sample stacking with a commercially available continuous-flow PCR system with a variety of protocols and samples. Further integration steps like thermal lysis and on-chip lyophilisate storage have been performed, with subsequent successful PCR. Chip modules for DNA extraction either with magnetic beads or membrane filters have been developed.

  6. Powder Handling Device for X-ray Diffraction Analysis with Minimal Sample Preparation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project consists of developing a Vibrating Sample Holder (VSH) for planetary X-Ray Diffraction (XRD) instruments. The principle of this novel sample handling...

  7. Density-viscosity product of small-volume ionic liquid samples using quartz crystal impedance analysis.

    Science.gov (United States)

    McHale, Glen; Hardacre, Chris; Ge, Rile; Doy, Nicola; Allen, Ray W K; MacInnes, Jordan M; Bown, Mark R; Newton, Michael I

    2008-08-01

    Quartz crystal impedance analysis has been developed as a technique to assess whether room-temperature ionic liquids are Newtonian fluids and as a small-volume method for determining the values of their viscosity-density product, rho eta. Changes in the impedance spectrum of a 5-MHz fundamental frequency quartz crystal induced by a water-miscible room-temperature ionic liquid, 1-butyl-3-methylimiclazolium trifluoromethylsulfonate ([C4mim][OTf]), were measured. From coupled frequency shift and bandwidth changes as the concentration was varied from 0 to 100% ionic liquid, it was determined that this liquid provided a Newtonian response. A second water-immiscible ionic liquid, 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [C4mim][NTf2], with concentration varied using methanol, was tested and also found to provide a Newtonian response. In both cases, the values of the square root of the viscosity-density product deduced from the small-volume quartz crystal technique were consistent with those measured using a viscometer and density meter. The third harmonic of the crystal was found to provide the closest agreement between the two measurement methods; the pure ionic liquids had the largest difference of approximately 10%. In addition, 18 pure ionic liquids were tested, and for 11 of these, good-quality frequency shift and bandwidth data were obtained; these 12 all had a Newtonian response. The frequency shift of the third harmonic was found to vary linearly with square root of viscosity-density product of the pure ionic liquids up to a value of square root(rho eta) approximately 18 kg m(-2) s(-1/2), but with a slope 10% smaller than that predicted by the Kanazawa and Gordon equation. It is envisaged that the quartz crystal technique could be used in a high-throughput microfluidic system for characterizing ionic liquids.

  8. Benchmarking sample preparation/digestion protocols reveals tube-gel being a fast and repeatable method for quantitative proteomics.

    Science.gov (United States)

    Muller, Leslie; Fornecker, Luc; Van Dorsselaer, Alain; Cianférani, Sarah; Carapito, Christine

    2016-12-01

    Sample preparation, typically by in-solution or in-gel approaches, has a strong influence on the accuracy and robustness of quantitative proteomics workflows. The major benefit of in-gel procedures is their compatibility with detergents (such as SDS) for protein solubilization. However, SDS-PAGE is a time-consuming approach. Tube-gel (TG) preparation circumvents this drawback as it involves directly trapping the sample in a polyacrylamide gel matrix without electrophoresis. We report here the first global label-free quantitative comparison between TG, stacking gel (SG), and basic liquid digestion (LD). A series of UPS1 standard mixtures (at 0.5, 1, 2.5, 5, 10, and 25 fmol) were spiked in a complex yeast lysate background. TG preparation allowed more yeast proteins to be identified than did the SG and LD approaches, with mean numbers of 1979, 1788, and 1323 proteins identified, respectively. Furthermore, the TG method proved equivalent to SG and superior to LD in terms of the repeatability of the subsequent experiments, with mean CV for yeast protein label-free quantifications of 7, 9, and 10%. Finally, known variant UPS1 proteins were successfully detected in the TG-prepared sample within a complex background with high sensitivity. All the data from this study are accessible on ProteomeXchange (PXD003841).

  9. Comparison of detergent-based sample preparation workflows for LTQ-Orbitrap analysis of the Escherichia coli proteome.

    Science.gov (United States)

    Tanca, Alessandro; Biosa, Grazia; Pagnozzi, Daniela; Addis, Maria Filippa; Uzzau, Sergio

    2013-09-01

    This work presents a comparative evaluation of several detergent-based sample preparation workflows for the MS-based analysis of bacterial proteomes, performed using the model organism Escherichia coli. Initially, RapiGest- and SDS-based buffers were compared for their protein extraction efficiency and quality of the MS data generated. As a result, SDS performed best in terms of total protein yields and overall number of MS identifications, mainly due to a higher efficiency in extracting high molecular weight (MW) and membrane proteins, while RapiGest led to an enrichment in periplasmic and fimbrial proteins. Then, SDS extracts underwent five different MS sample preparation workflows, including: detergent removal by spin columns followed by in-solution digestion (SC), protein precipitation followed by in-solution digestion in ammonium bicarbonate or urea buffer, filter-aided sample preparation (FASP), and 1DE separation followed by in-gel digestion. On the whole, about 1000 proteins were identified upon LC-MS/MS analysis of all preparations (>1100 with the SC workflow), with FASP producing more identified peptides and a higher mean sequence coverage. Each protocol exhibited specific behaviors in terms of MW, hydrophobicity, and subcellular localization distribution of the identified proteins; a comparative assessment of the different outputs is presented.

  10. Quantitative Analysis of Heavy Metals in Water Based on LIBS with an Automatic Device for Sample Preparation

    Science.gov (United States)

    Hu, Li; Zhao, Nanjing; Liu, Wenqing; Meng, Deshuo; Fang, Li; Wang, Yin; Yu, Yang; Ma, Mingjun

    2015-08-01

    Heavy metals in water can be deposited on graphite flakes, which can be used as an enrichment method for laser-induced breakdown spectroscopy (LIBS) and is studied in this paper. The graphite samples were prepared with an automatic device, which was composed of a loading and unloading module, a quantitatively adding solution module, a rapid heating and drying module and a precise rotating module. The experimental results showed that the sample preparation methods had no significant effect on sample distribution and the LIBS signal accumulated in 20 pulses was stable and repeatable. With an increasing amount of the sample solution on the graphite flake, the peak intensity at Cu I 324.75 nm accorded with the exponential function with a correlation coefficient of 0.9963 and the background intensity remained unchanged. The limit of detection (LOD) was calculated through linear fitting of the peak intensity versus the concentration. The LOD decreased rapidly with an increasing amount of sample solution until the amount exceeded 20 mL and the correlation coefficient of exponential function fitting was 0.991. The LOD of Pb, Ni, Cd, Cr and Zn after evaporating different amounts of sample solution on the graphite flakes was measured and the variation tendency of their LOD with sample solution amounts was similar to the tendency for Cu. The experimental data and conclusions could provide a reference for automatic sample preparation and heavy metal in situ detection. supported by National Natural Science Foundation of China (No. 60908018), National High Technology Research and Development Program of China (No. 2013AA065502) and Anhui Province Outstanding Youth Science Fund of China (No. 1108085J19)

  11. Diagnostic PCR: validation and sample preparation are two sides of the same coin

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Wolffs, Petra; Radstrøm, Peter

    2004-01-01

    Increased use of powerful PCR technology for the routine detection of pathogens has focused attention on the need for international validation and preparation of official non-commercial guidelines. Bacteria of epidemiological importance should be the prime focus, although a "validation infrastruc......Increased use of powerful PCR technology for the routine detection of pathogens has focused attention on the need for international validation and preparation of official non-commercial guidelines. Bacteria of epidemiological importance should be the prime focus, although a "validation...

  12. In situ sampling of small volumes of soil solution using modified micro-suction cups

    NARCIS (Netherlands)

    Shen, Jianbo; Hoffland, E.

    2007-01-01

    Two modified designs of micro-pore-water samplers were tested for their capacity to collect unbiased soil solution samples containing zinc and citrate. The samplers had either ceramic or polyethersulfone (PES) suction cups. Laboratory tests of the micro-samplers were conducted using (a) standard sol

  13. Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 2: Mission payloads subsystem description

    Science.gov (United States)

    Dupnick, E.; Wiggins, D.

    1980-01-01

    The scheduling algorithm for mission planning and logistics evaluation (SAMPLE) is presented. Two major subsystems are included: The mission payloads program; and the set covering program. Formats and parameter definitions for the payload data set (payload model), feasible combination file, and traffic model are documented.

  14. Sampling of high amounts of bioaerosols using a high-volume electrostatic field sampler

    DEFF Research Database (Denmark)

    Madsen, A. M.; Sharma, Anoop Kumar

    2008-01-01

    by the electrostatic field sampler and 11.8 mg m(-3) when measured by the GSP inhalable dust sampler. The quantity (amount per mg dust) of total fungi, Aspergillus fumigatus, total bacteria, endotoxin and mesophilic actinomycetes sampled by the electrostatic field samplers and the Gravikon samplers varied within...

  15. The properties of a large volume-limited sample of face-on low surface brightness disk galaxies

    Institute of Scientific and Technical Information of China (English)

    Guo-Hu Zhong; Yan-Chun Liang; Feng-Shan Liu; Francois Hammer; Karen Disseau; Li-Cai Deng

    2012-01-01

    We select a large volume-limited sample of low surface brightness galaxies (LSBGs,2021) to investigate in detail their statistical properties and their differences from high surface brightness galaxies (HSBGs,3639).The distributions of stellar masses of LSBGs and HSBGs are nearly the same and they have the same median values.Thus this volume-limited sample has good completeness and is further removed from the effect of stellar masses on their other properties when we compare LSBGs to HSBGs.We found that LSBGs tend to have lower stellar metallicities and lower effective dust attenuations,indicating that they have lower dust than HSBGs.The LSBGs have relatively higher stellar mass-to-light ratios,higher gas fractions,lower star forming rates (SFRs),and lower specific SFRs than HSBGs.Moreover,with the decreasing surface brightness,gas fraction increases,but the SFRs and specific SFRs decrease rapidly for the sample galaxies.This could mean that the star formation histories between LSBGs and HSBGs are different,and HSBGs may have stronger star forming activities than LSBGs.

  16. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-01

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  17. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-30

    The purpose of this document is to provide guidelines to prepare specimens of uranium alloyed with 10 weight percent molybdenum (U-10Mo) for optical metallography and scanning electron microscopy. This document also provides instructions to set up an optical microscope and a scanning electron microscope to analyze U-10Mo specimens and to obtain the required information.

  18. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions.

    Science.gov (United States)

    Weber, Daniela; Davies, Michael J; Grune, Tilman

    2015-08-01

    Protein oxidation is involved in regulatory physiological events as well as in damage to tissues and is thought to play a key role in the pathophysiology of diseases and in the aging process. Protein-bound carbonyls represent a marker of global protein oxidation, as they are generated by multiple different reactive oxygen species in blood, tissues and cells. Sample preparation and stabilization are key steps in the accurate quantification of oxidation-related products and examination of physiological/pathological processes. This review therefore focuses on the sample preparation processes used in the most relevant methods to detect protein carbonyls after derivatization with 2,4-dinitrophenylhydrazine with an emphasis on measurement in plasma, cells, organ homogenates, isolated proteins and organelles. Sample preparation, derivatization conditions and protein handling are presented for the spectrophotometric and HPLC method as well as for immunoblotting and ELISA. An extensive overview covering these methods in previously published articles is given for researchers who plan to measure protein carbonyls in different samples.

  19. Optimization of crude enzyme preparation methods for analysis of glutamine synthetase activity in phytoplankton and field samples

    Institute of Scientific and Technical Information of China (English)

    WANG Yujue; WANG Dazhi; HONG Huasheng

    2009-01-01

    Glutamine synthetase (GS) is an important enzyme involved in nitrogen assimilation and metabolism in marine phytoplankton. However, little work has been done in situ due to the limitation of crude enzyme preparation methods. In this study, three enzyme preparation methods, high-speed centrifugation (HC, <10 000 g), ultracentrifugation (UC, 70 000 g), and ultrafiltration (UF) with 100 kμ, molecular weight cutoff, were compared using two diatom species (Asterionellopsis glacialis and Thalassiosira weissflogii), and two dinoflagellate species (Alexandrium catenella and Prorocentrum donghaiense) as experimental materials together with field samples collected from Xiamen Harbor, China. The results showed that HC is the best method to prepare crude enzymes for glutamine synthetase activity (GSA) in diatom species and diatom-dominant samples, while UF is the best method to extract GS from dinoflagellate species and dinoflagellate-dominant samples. For the HC method, the optimal centrifugal speed and time were 10 000 g and 35 min, respectively, and under these conditions, the highest GSA was obtained in all samples. This study indicates that both methods (HC and UF) overcome the limitation of centrifugal speed and could be applied to in situ GSA analysis, especially at sea.

  20. Clustering properties of a type-selected volume-limited sample of galaxies in the CFHTLS

    CERN Document Server

    McCracken, H J; Mellier, Y; Bertin, E; Guzzo, L; Arnouts, S; Le Fèvre, O; Zamorani, G

    2007-01-01

    (abridged) We present an investigation of the clustering of i'AB<24.5 galaxies in the redshift interval 0.2volume-limited galaxy catalogues. We study the dependence of the amplitude and slope of the galaxy correlation function on absolute B-band rest-frame luminosity, redshift and best-fitting spectral type. We find: 1. The comoving correlation length for all galaxies decreases steadily from z~0.3 to z~1. 2. At all redshifts and luminosities, galaxies with redder rest-frame colours have clustering amplitudes between two and three times higher than bluer ones. 3. For bright red and blue galaxies, the clustering amplitude is invariant with redshift. 4. At z~0.5, less luminous galaxies have higher clustering amplitudes of around 6 h-1 Mpc. 5. The relative bias between galaxies with red and blue rest-frame colours increases gradually towards fainter absolute magnitud...

  1. Optimizing Frozen Sample Preparation for Laser Microdissection: Assessment of CryoJane Tape-Transfer System®.

    Directory of Open Access Journals (Sweden)

    Yelena G Golubeva

    Full Text Available Laser microdissection is an invaluable tool in medical research that facilitates collecting specific cell populations for molecular analysis. Diversity of research targets (e.g., cancerous and precancerous lesions in clinical and animal research, cell pellets, rodent embryos, etc. and varied scientific objectives, however, present challenges toward establishing standard laser microdissection protocols. Sample preparation is crucial for quality RNA, DNA and protein retrieval, where it often determines the feasibility of a laser microdissection project. The majority of microdissection studies in clinical and animal model research are conducted on frozen tissues containing native nucleic acids, unmodified by fixation. However, the variable morphological quality of frozen sections from tissues containing fat, collagen or delicate cell structures can limit or prevent successful harvest of the desired cell population via laser dissection. The CryoJane Tape-Transfer System®, a commercial device that improves cryosectioning outcomes on glass slides has been reported superior for slide preparation and isolation of high quality osteocyte RNA (frozen bone during laser dissection. Considering the reported advantages of CryoJane for laser dissection on glass slides, we asked whether the system could also work with the plastic membrane slides used by UV laser based microdissection instruments, as these are better suited for collection of larger target areas. In an attempt to optimize laser microdissection slide preparation for tissues of different RNA stability and cryosectioning difficulty, we evaluated the CryoJane system for use with both glass (laser capture microdissection and membrane (laser cutting microdissection slides. We have established a sample preparation protocol for glass and membrane slides including manual coating of membrane slides with CryoJane solutions, cryosectioning, slide staining and dissection procedure, lysis and RNA extraction

  2. Sample preparation for an optimized extraction of localized metabolites in lichens: Application to Pseudevernia furfuracea.

    Science.gov (United States)

    Komaty, Sarah; Letertre, Marine; Dang, Huyen Duong; Jungnickel, Harald; Laux, Peter; Luch, Andreas; Carrié, Daniel; Merdrignac-Conanec, Odile; Bazureau, Jean-Pierre; Gauffre, Fabienne; Tomasi, Sophie; Paquin, Ludovic

    2016-04-01

    Lichens are symbiotic organisms known for producing unique secondary metabolites with attractive cosmetic and pharmacological properties. In this paper, we investigated three standard methods of preparation of Pseudevernia furfuracea (blender grinding, ball milling, pestle and mortar). The materials obtained were characterized by electronic microscopy, nitrogen adsorption and compared from the point of view of extraction. Their microscopic structure is related to extraction efficiency. In addition, it is shown using thalline reactions and mass spectrometry mapping (TOF-SIMS) that these metabolites are not evenly distributed throughout the organism. Particularly, atranorin (a secondary metabolite of interest) is mainly present in the cortex of P. furfuracea. Finally, using microwave assisted extraction (MAE) we obtained evidence that an appropriate preparation can increase the extraction efficiency of atranorin by a factor of five.

  3. Solid recovered fuels in the cement industry--semi-automated sample preparation unit as a means for facilitated practical application.

    Science.gov (United States)

    Aldrian, Alexia; Sarc, Renato; Pomberger, Roland; Lorber, Karl E; Sipple, Ernst-Michael

    2016-03-01

    One of the challenges for the cement industry is the quality assurance of alternative fuel (e.g., solid recovered fuel, SRF) in co-incineration plants--especially for inhomogeneous alternative fuels with large particle sizes (d95⩾100 mm), which will gain even more importance in the substitution of conventional fuels due to low production costs. Existing standards for sampling and sample preparation do not cover the challenges resulting from these kinds of materials. A possible approach to ensure quality monitoring is shown in the present contribution. For this, a specially manufactured, automated comminution and sample divider device was installed at a cement plant in Rohožnik. In order to prove its practical suitability with methods according to current standards, the sampling and sample preparation process were validated for alternative fuel with a grain size >30 mm (i.e., d95=approximately 100 mm), so-called 'Hotdisc SRF'. Therefore, series of samples were taken and analysed. A comparison of the analysis results with the yearly average values obtained through a reference investigation route showed good accordance. Further investigations during the validation process also showed that segregation or enrichment of material throughout the comminution plant does not occur. The results also demonstrate that compliance with legal standards regarding the minimum sample amount is not sufficient for inhomogeneous and coarse particle size alternative fuels. Instead, higher sample amounts after the first particle size reduction step are strongly recommended in order to gain a representative laboratory sample.

  4. Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE). Volume 3: The GREEDY algorithm

    Science.gov (United States)

    Dupnick, E.; Wiggins, D.

    1980-01-01

    The functional specifications, functional design and flow, and the program logic of the GREEDY computer program are described. The GREEDY program is a submodule of the Scheduling Algorithm for Mission Planning and Logistics Evaluation (SAMPLE) program and has been designed as a continuation of the shuttle Mission Payloads (MPLS) program. The MPLS uses input payload data to form a set of feasible payload combinations; from these, GREEDY selects a subset of combinations (a traffic model) so all payloads can be included without redundancy. The program also provides the user a tutorial option so that he can choose an alternate traffic model in case a particular traffic model is unacceptable.

  5. Brief communication: Endocranial volumes in an ontogenetic sample of chimpanzees from the Taï Forest National Park, Ivory Coast.

    Science.gov (United States)

    Neubauer, Simon; Gunz, Philipp; Schwarz, Uta; Hublin, Jean-Jacques; Boesch, Christophe

    2012-02-01

    Ontogenetic samples of endocranial volumes (EVs) from great apes and humans are critical for understanding the evolution of the brain growth pattern in the hominin lineage. However, high quality ontogenetic data are scarce, especially for nonhuman primates. Here, we provide original data derived from an osteological collection of a wild population of Pan troglodytes verus from the Taï Forest National Park, Ivory Coast. This sample is unique, because age, sex, and pedigree information are available for many specimens from behavioral observations in the wild. We scanned crania of all 30 immature specimens and 13 adult individuals using high-resolution computed tomography. We then created virtual casts of the bony braincase (endocasts) to measure EVs. We also measured cranial length, width, and height and attempted to relate cranial distances to EV via regression analysis. Our data are consistent with previous studies. The only neonate in the sample has an EV of 127 cm(3) or 34% of the adult mean. EV increases rapidly during early ontogeny. The average adult EV in this sample is 378.7 ± 30.1 cm(3) . We found sexual dimorphism in adults; males seem to be already larger than females before adult EV is attained. Regressions on cranial width and multiple regression provide better estimates for EV than regressions on cranial length or height. Increasing the sample size and compiling more high quality ontogenetic data of EV will help to reconcile ongoing discussions about the evolution of hominin brain growth. Copyright © 2011 Wiley Periodicals, Inc.

  6. Revisiting the Lick Observatory Supernova Search Volume-Limited Sample: Updated Classifications and Revised Stripped-envelope Supernova Fractions

    CERN Document Server

    Shivvers, Isaac; Zheng, Weikang; Filippenko, Alexei V; Silverman, Jeffrey M; Liu, Yuqian; Matheson, Thomas; Pastorello, Andrea; Graur, Or; Foley, Ryan J; Chornock, Ryan; Smith, Nathan; Leaman, Jesse; Benetti, Stefano

    2016-01-01

    We re-examine the classifications of supernovae (SNe) presented in the Lick Observatory Supernova Search (LOSS) volume-limited sample with a focus on the stripped-envelope SNe. The LOSS volumetric sample, presented by Leaman et al. (2011) and Li et al. (2011b), was calibrated to provide meaningful measurements of SN rates in the local universe; the results presented therein continue to be used for comparisons to theoretical and modeling efforts. Many of the objects from the LOSS sample were originally classified based upon only a small subset of the data now available, and recent studies have both updated some subtype distinctions and improved our ability to perform robust classifications, especially for stripped-envelope SNe. We re-examine the spectroscopic classifications of all events in the LOSS volumetric sample (180 SNe and SN impostors) and update them if necessary. We discuss the populations of rare objects in our sample including broad-lined Type Ic SNe, Ca-rich SNe, SN 1987A-like events (we identify...

  7. Detection of Helicobactor pylori by polymerase chain reaction: A comparison in sample preparation

    Directory of Open Access Journals (Sweden)

    Murugesan R

    2005-01-01

    Full Text Available Gastric biopsy samples obtained from 14 patients with upper abdominal pain, clinically diagnosed as acid peptic disease, were analysed for the presence of Helicobacter pylori (H. pylori by Polymerase Chain Reaction (PCR using partially (template A and completely purified DNA (template B. Antigen specific primer was used to analyse the sample by PCR method. The presence of H. pylori in the samples was confirmed by running a positive control. The presence of H. pylori was also detected by urease method using standard protocol. Among the 14 samples studied, 8 showed the presence of H. pylori with both templates A and B. Among these 8 samples only 3 showed positive for the presence of H. pylori with urease method. The present work discusses the results obtained in the detection of H. pylori in template A and B by PCR method.

  8. Nanoparticle-assisted laser desorption/ionization mass spectrometry: Novel sample preparation methods and nanoparticle screening for plant metabolite imaging

    Energy Technology Data Exchange (ETDEWEB)

    Yagnik, Gargey B. [Iowa State Univ., Ames, IA (United States)

    2016-02-19

    The main goal of the presented research is development of nanoparticle based matrix-assisted laser desorption ionization-mass spectrometry (MALDI-MS). This dissertation includes the application of previously developed data acquisition methods, development of novel sample preparation methods, application and comparison of novel nanoparticle matrices, and comparison of two nanoparticle matrix application methods for MALDI-MS and MALDI-MS imaging.

  9. High resolution triple resonance micro magic angle spinning NMR spectroscopy of nanoliter sample volumes.

    Science.gov (United States)

    Brauckmann, J Ole; Janssen, J W G Hans; Kentgens, Arno P M

    2016-02-14

    To be able to study mass-limited samples and small single crystals, a triple resonance micro-magic angle spinning (μMAS) probehead for the application of high-resolution solid-state NMR of nanoliter samples was developed. Due to its excellent rf performance this allows us to explore the limits of proton NMR resolution in strongly coupled solids. Using homonuclear decoupling we obtain unprecedented (1)H linewidths for a single crystal of glycine (Δν(CH2) = 0.14 ppm) at high field (20 T) in a directly detected spectrum. The triple channel design allowed the recording of high-resolution μMAS (13)C-(15)N correlations of [U-(13)C-(15)N] arginine HCl and shows that the superior (1)H resolution opens the way for high-sensitivity inverse detection of heteronuclei even at moderate spinning speeds and rf-fields. Efficient decoupling leads to long coherence times which can be exploited in many correlation experiments.

  10. Sample preparation for the analysis of complex carbohydrates by multicapillary gel electrophoresis with light-emitting diode induced fluorescence detection.

    Science.gov (United States)

    Olajos, Marcell; Hajós, Péter; Bonn, Guenther K; Guttman, András

    2008-06-01

    This paper evaluates various sample preparation methods for multicapillary gel electrophoresis based glycan analysis to support electrokinetic injection. First the removal of excess derivatization reagent is discussed. Although the Sephadex G10 filled multiscreen 96-well filter plate and Sephadex G10 filled pipet tips enabled increased analysis sensitivity, polyamide DPA-6S pipet tips worked particularly well. In this latter case an automated liquid handling system was used to increase purification throughput, necessary to feed the multicapillary electrophoresis unit. Problems associated with the high glucose content of such biological samples as normal human plasma were solved by applying ultrafiltration. Finally, a volatile buffer system was developed for exoglycosidase-based carbohydrate analysis.

  11. ARPA-E Impacts: A Sampling of Project Outcomes, Volume II

    Energy Technology Data Exchange (ETDEWEB)

    Rohlfing, Eric [Dept. of Energy (DOE), Washington DC (United States). Advanced Research Projects Agency-Energy (ARPA-E)

    2017-02-27

    The Advanced Research Projects Agency-Energy (ARPA-E) is demonstrating that a collaborative model has the power to deliver real value. The Agency’s first compilation booklet of impact sheets, published in 2016, began to tell the story of how ARPA-E has already made an impact in just seven years—funding a diverse and sophisticated research portfolio on advanced energy technologies that enable the United States to tackle our most pressing energy challenges. One year later our research investments continue to pay off, with a number of current and alumni project teams successfully commercializing their technologies and advancing the state of the art in transformative areas of energy science and engineering. There is no single measure that can fully illustrate ARPA-E’s success to date, but several statistics viewed collectively begin to reveal the Agency’s impact. Since 2009, ARPA-E has provided more than $1.5 billion in funding for 36 focused programs and three open funding solicitations, totaling over 580 projects. Of those, 263 are now alumni projects. Many teams have successfully leveraged ARPA-E’s investment: 56 have formed new companies, 68 have partnered with other government agencies to continue their technology development, and 74 teams have together raised more than $1.8 billion in reported funding from the private sector to bring their technologies to market. However, even when viewed together, those measures do not capture ARPA-E’s full impact. To best understand the Agency’s success, the specific scientific and engineering challenges that ARPA-E project teams have overcome must be understood. This booklet provides concrete examples of those successes, ranging from innovations that will bear fruit in the future to ones that are beginning to penetrate the market as products today. Importantly, half of the projects highlighted in this volume stem from OPEN solicitations, which the agency has run in 2009, 2012, and 2015. ARPA-E’s OPEN programs

  12. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  13. Natural air ventilation in underground galleries as a tool to increase radon sampling volumes for geologic monitoring

    Energy Technology Data Exchange (ETDEWEB)

    Eff-Darwich, Antonio [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Instituto de Astrofisica de Canarias, c/Via Lactea s/n, 38205 La Laguna, Tenerife (Spain)], E-mail: adarwich@ull.es; Vinas, Ronaldo [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Soler, Vicente [Estacion Volcanologica de Canarias, IPNA-CSIC, Av. Astrofisico Francisco Sanchez s/n, 38206 La Laguna, Tenerife (Spain); Nuez, Julio de la; Quesada, Maria L. [Departamento de Edafologia y Geologia, Universidad de La Laguna, Av. Astrofisico Francisco, Sanchez s/n, 38206 La Laguna, Tenerife (Spain)

    2008-09-15

    A simple numerical model was implemented to infer airflow (natural ventilation) in underground tunnels from the differences in the temporal patterns of radon, {sup 222}Rn, concentration time-series that were measured at two distant points in the interior of the tunnels. The main purpose of this work was to demonstrate that the installation of radon monitoring stations closer to the entrance of the tunnels was sufficient to remotely analyse the distribution of radon concentration in their interiors. This could ease the monitoring of radon, since the effective sampling volume of a single monitoring station located closer to the entrance of a tunnel is approximately 30,000 times larger than the sampling volume of a sub-soil radon sensor. This methodology was applied to an underground gallery located in the volcanic island of Tenerife, Canary Islands. This island constitutes an ideal laboratory to study the geo-dynamical behaviour of radon because of the existence of a vast network of galleries that conforms the main water supply of the island.

  14. Highly sensitive SERS detection of cancer proteins in low sample volume using hollow core photonic crystal fiber.

    Science.gov (United States)

    U S, Dinish; Fu, Chit Yaw; Soh, Kiat Seng; Ramaswamy, Bhuvaneswari; Kumar, Anil; Olivo, Malini

    2012-03-15

    Enzyme-linked immunosorbent assays (ELISA) are commonly used for detecting cancer proteins at concentration in the range of about ng-μg/mL. Hence it often fails to detect tumor markers at the early stages of cancer and other diseases where the amount of protein is extremely low. Herein, we report a novel photonic crystal fiber (PCF) based surface enhanced Raman scattering (SERS) sensing platform for the ultrasensitive detection of cancer proteins in an extremely low sample volume. As a proof of concept, epidermal growth factor receptors (EGFRs) in a lysate solution from human epithelial carcinoma cells were immobilized into the hollow core PCF. Highly sensitive detection of protein was achieved using anti-EGFR antibody conjugated SERS nanotag. This SERS nanotag probe was realized by anchoring highly active Raman molecules onto the gold nanoparticles followed by bioconjugation. The proposed sensing method can detect low amount of proteins at ∼100 pg in a sample volume of ∼10 nL. Our approach may lead to the highly sensitive protein sensing methodology for the early detection of diseases.

  15. Surface modified polypropylene pipette tips packed with a monolithic plug of adsorbent for high-throughput sample preparation.

    Science.gov (United States)

    Altun, Zeki; Hjelmström, Anette; Abdel-Rehim, Mohamed; Blomberg, Lars G

    2007-08-01

    UV-initiated poly(butyl methacrylate-ethylene glycol dimethacrylate) porous polymer monoliths were prepared in situ in polypropylene-based pipette tips for high-throughput sample preparation. Prior to the in situ polymerization, the surface of the PP tips was modified. In this work, two different surface modification approaches were tested for this purpose. First the photoinitiator benzophenone was used to generate radicals at the surface of PP by hydrogen abstraction. In the second modification approach, a thin layer of a polymer was directly grafted to the surface. The effect of surface modification was measured by contact angle measurements of a drop of water at the surface. As a result of the surface modification, scan electron microscopy images indicate a covalent attachment of the monolith to the wall of the pipette tip. Pipette tips modified with 5% BP in methanol and packed with a plug of monolith were further evaluated for high-throughput sample preparation. Using a liquid handling system, the extraction performance of packed pipette tips was tested for the analysis of ropivacaine in plasma samples. The recovery and reproducibility results were in accordance with internationally accepted criteria for qualitative and quantitative analysis of the test substance, ropivacaine.

  16. Preparation of magnetic graphene @polydopamine @Zr-MOF material for the extraction and analysis of bisphenols in water samples.

    Science.gov (United States)

    Wang, Xianying; Deng, Chunhui

    2015-11-01

    In this work, a simple method for the extraction and analysis of bisphenols in environmental samples was presented. And the prepared zirconium-based magnetic MOFs (magG@PDA@Zr-MOF) were used as the sorbents for the magnetic solid-phase extraction. With the simple solvothermal reaction and sol-gel method, the prepared material showed great characteristics of large surface area, homogeneous pore size, good magnetic responsivity and super-hydrophilicity. The large surface area provided abundant sites to extract target compounds; the magnetic property could simplify the whole extraction procedure; and the hydrophilicity improved the dispersibility of the material in matrix. Here, various extraction parameters were optimized, including amounts of sorbents, adsorption time, species of elution solvents and desorption time. The whole extraction procedure could be accomplished in 30 min. And under the optimized conditions, method validations were also studied, such as linearity, the limit of detection and recovery. Finally, the prepared material was used in real water samples. The results showed this material had good potential as the sorbent for the extraction of targets in environmental water samples.

  17. CePt2In7: Focused Ion Beam Sample Preparation for Quantum Oscillation Measurements under High Pressure

    Science.gov (United States)

    Kanter, Jakob; Moll, P.; Friedemann, S.; Alireza, P.; Sutherland, M.; Goh, S.; Ronning, F.; Bauer, E. D.; Batlogg, B.

    2013-03-01

    Electronic transport measurements under high pressures face several experimental challenges due to confined sample space and high forces acting on contacts and leads. As a result conventional preparation methods are often limited in the number of possible leads and usually do not allow for sample structuring. The Focused Ion Beam (FIB) enables sample contacting and structuring down to a sub-micrometre scale, making the measurement of several samples with complex shapes on a single anvil feasible. This talk will discuss Shubnikov-de Haas measurements of FIB prepared CePt2In7 samples under high pressures. CePt2In7 belongs to the CemMnIn3 m + 2 n heavy fermion family. Compared to the CeMIn5 members of this group, the structure of CePt2In7 has a more pronounced two dimensional character, but also exhibits an antiferromagnetically ordered as well as a superconducting phase. We have studied the changes of the quasiparticle masses for the various orbits as function of pressure approaching the quantum critical point.

  18. Molecularly imprinted polymer microspheres prepared by Pickering emulsion polymerization for selective solid-phase extraction of eight bisphenols from human urine samples.

    Science.gov (United States)

    Yang, Jiajia; Li, Yun; Wang, Jincheng; Sun, Xiaoli; Cao, Rong; Sun, Hao; Huang, Chaonan; Chen, Jiping

    2015-05-01

    The bisphenol A (BPA) imprinted polymer microspheres were prepared by simple Pickering emulsion polymerization. Compared to traditional bulk polymerization, both high yields of polymer and good control of particle sizes were achieved. The characterization results of scanning electron microscopy and nitrogen adsorption-desorption measurements showed that the obtained molecularly imprinted polymer microsphere (MIPMS) particles possessed regular spherical shape, narrow diameter distribution (30-60 μm), a specific surface area (S(BET)) of 281.26 m(2) g(-1) and a total pore volume (V(t)) of 0.459 cm(3) g(-1). Good specific adsorption capacity for BPA was obtained in the sorption experiment and good class selectivity for BPA and its seven structural analogs (bisphenol F, bisphenol B, bisphenol E, bisphenol AF, bisphenol S, bisphenol AP and bisphenol Z) was demonstrated by the chromatographic evaluation experiment. The MIPMS as solid-phase extraction (SPE) packing material was then evaluated for extraction and clean-up of these bisphenols (BPs) from human urine samples. An accurate and sensitive analytical method based on the MIPMS-SPE coupled with HPLC-DAD has been successfully established for simultaneous determination of eight BPs from human urine samples with detection limits of 1.2-2.2 ng mL(-1). The recoveries of BPs for urine samples at two spiking levels (100 and 500 ng mL(-1) for each BP) were in the range of 81.3-106.7% with RSD values below 8.3%.

  19. Development of the Dried Spot Sample Preparation Methodology and Applications to XRMF Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Colletti, Lisa P.; Havrilla, George J.

    1997-12-31

    The dried spot method has significant potential for trace elemental analysis using x-ray fluorescence. Small sample size coupled with spatially resolved excitation offers increased sensitivity for aqueous solutions. The primary limitation in applying this method to routine analyses is that much of the method development and fundamental aspects have not been investigated. We have studied the effects of a number of parameters on the quantitative capabilities of the dried spot method. These include thin-film substrates, drying methods, and solution composition. The small sample size offers opportunities for the analysis of a wide array of sample types including highly radioactive specimens.

  20. Powder Handling Device for X-ray Diffraction Analysis with Minimal Sample Preparation Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This project consists in developing a Vibrating Powder Handling System for planetary X-Ray Diffraction instruments. The principle of this novel sample handling...

  1. Preparation and characterization of single crystal samples for high-pressure experiments

    Energy Technology Data Exchange (ETDEWEB)

    Farber, D; Antonangeli, D; Aracne, C; Benterou, J

    2005-10-26

    To date, most research utilizing the diamond anvil cell (DAC) has been conducted with polycrystalline samples, thus the results are limited to addressing average bulk properties. However, experiments on single crystals can yield data on a range of orientation dependent properties such as thermal and electrical conductivity, magnetic susceptibility, elasticity and plasticity. Here we report new procedures to produce extremely high-quality metallic single crystal samples of size compatible with DAC experiments in the Mbar range. So far, we have produced samples of zinc, Al{sub 2}O{sub 3}, cobalt, molybdenum and cerium, and have evaluated the quality of the finished samples with white-light interferometry, synchrotron x-ray diffraction and inelastic x-ray scattering.

  2. Demonstration of the ExoMars sample preparation and distribution system jointly with an optical instrument head

    Science.gov (United States)

    Schulte, Wolfgang; Thiele, Hans; Hofmann, Peter; Baglioni, Pietro

    The ExoMars program will search for past and present life on Mars. ExoMars will address important scientific goals and demonstrate key in-situ enabling technologies. Among such technologies are the acquisition, preparation, distribution and analysis of samples from Mars surface rocks and from the subsurface. The 2018 mission will land an ESA rover on Mars which carries a sample preparation and distribution system (SPDS) and a suite of analytical instruments, the Pasteur Payload with its Analytical Laboratory Drawer (ALD). Kayser-Threde GmbH (Germany) will be responsible for the SPDS as a subcontractor under the mission prime Thales Alenia Space. The SPDS comprises a number of complex mechanisms and mechanical devices designed to transport drill core samples within the rover analytical laboratory, to crush them to powder with a fine grain size, to portion discrete amounts of powdered sample material, to distribute and fill the material into sample containers and to prepare flat sample surfaces for scientific analysis. Breadboards of the crushing mechanism, the dosing mechanism and a distribution carousel with sample containers and a powder sample surface flattening mechanism were built and tested. Kayser-Threde, as a member of the Spanish led ExoMars Raman Instrument team, is also responsible for development of the Raman optical head, which will be mounted inside ALD and will inspect the crushed samples, when they are presented to the instrument by the distribution carousel. Within this activity, which is performed under contract with the Institute of Physical Chemistry of the University of Jena (Germany) and funded by the German DLR, Kayser-Threde can demonstrate Raman measurements with the optical head and a COTS laser and spectrometer and thus simulate the full Raman instrument optical path. An autofocus system with actuator and feedback optics is also part of this activity, which allows focusing the 50 m Raman spot on the surface of the powdered sample

  3. Improved preparation of small biological samples for mercury analysis using cold vapor atomic absorption spectroscopy.

    Science.gov (United States)

    Adair, B M; Cobb, G P

    1999-05-01

    Concentrations of mercury in biological samples collected for environmental studies are often less than 0.1 microgram/g. Low mercury concentrations and small organ sizes in many wildlife species (approximately 0.1 g) increase the difficulty of mercury determination at environmentally relevant concentrations. We have developed a digestion technique to extract mercury from small (0.1 g), biological samples at these relevant concentrations. Mean recoveries (+/- standard error) from validation trials of mercury fortified tissue samples using cold vapor atomic absorption spectroscopy for analysis ranged from 102 +/- 4.3% (2.5 micrograms/L, n = 15) to 108 +/- 1.4% (25 micrograms/L, n = 15). Recoveries of inorganic mercury were 99 +/- 5 (n = 19) for quality assurance samples analyzed during environmental evaluations conducted during a 24 month period. This technique can be used to determine total mercury concentrations of 60 ng Hg/g sample. Samples can be analyzed in standard laboratories in a short time, at minimal cost. The technique is versatile and can be used to determine mercury concentrations in several different matrices, limiting the time and expense of method development and validation.

  4. Rapid screening and analysis of alpha- and gamma-emitting radionuclides in liquids using a single sample preparation procedure.

    Science.gov (United States)

    Parsa, Bahman; Henitz, James B; Carter, Jennifer A

    2011-02-01

    A multifaceted radiochemical testing procedure has been developed to analyze a large number of liquid samples and measure a wide range of radionuclides in a short period of time. This method involves a single, unique and fast sample preparation procedure and allows sequential/concurrent determination of analytes with accuracy and precision. The same prepared sample can be selectively analyzed by gross alpha counting, gamma-ray spectroscopy, and alpha spectroscopy. This method is especially attractive in radiological emergency events where analytical data will be needed urgently as a basis for protective action. Given the simplicity and rapidity of the method, it may be suitable for field portable laboratories, which could save time and the cost associated with the transit of samples to a fixed laboratory. A 100 mL aliquot of sample was spiked with ¹³³Ba and ⁵⁹Fe tracers and subjected to a chemical separation procedure using a combined BaSO4 and Fe(OH)3 co-precipitation scheme. Then, the gross alpha-particle activity of the prepared sample was measured with a low-background gas-proportional counter, followed by the analysis of its photon-emitters using a gamma-ray spectroscopy system with high-purity intrinsic Ge detectors. Gamma-ray determination of ¹³³Ba and ⁵⁹Fe tracers was used to assess the chemical recoveries of BaSO4 and Fe(OH)3 fractions, respectively. Selectivity of the radionuclides for co-precipitation with either BaSO4 or Fe(OH)3 components was also investigated. Alpha mass-efficiency curves were derived using ²³⁰Th and ²⁴¹Am standards as alpha-calibration sources. Various mixtures of radionuclides, including ⁵⁴Mn, ⁵⁷Co, ⁶⁰Co, ⁸⁵Sr, ⁸⁸Y, ¹⁰⁹Cd, ¹¹³Sn, ¹³⁷Cs, ¹³⁹Ce, ²⁰³Hg, ²⁰⁹Po, ²²⁶Ra, ²²⁸Ra, ²³⁰Th, ²⁴¹Am, and natural uranium were used in this study. Most were quantitatively assayed with high chemical recoveries. Alpha-isotope identification and assessment of the prepared

  5. Combining Endometrium Sampling Device and SurePath Preparation to Screen for Endometrial Carcinoma: A Validation Study

    Institute of Scientific and Technical Information of China (English)

    Jia Wen; Rui Chen; Jian Zhao; Yin Dong; Xi Yang; Qin-Ping Liao

    2015-01-01

    Background:The aim of this study was to compare specimen adequacy of SAP-I provided for cytology with that of dilation and curettage (D & C) or hysteroscopy for histology,and evaluate the accuracy of combining endometrium sampling by SAP-1 and liquid-based cytology using SurePath preparation for screening endometrial carcinoma and its precursor.Methods:Endometrial specimens from women (n =1514) with risk factors were obtained using an SAP-l device for cytological analysis; histological samples were obtained from 375 of these women who underwent D & C or hysteroscopy.Cytological specimens were prepared to liquid-based smear using SurePath technology and stained by Papanicolaou.Histological samples were processed in routine pathology and stained by hematoxylin and eosin.Results:Adequate specimens for cytology were obtained from 1458/1541 patients (96.3%),while adequate samples for pathology were obtained from 285/375 patients (76%).However,for postmenopausaI women,1006 of 1045 cytology (86.3%) were adequate,153 of 238 histology (64.3%) were adequate,it was easier to collect cytological specimens than histological specimens (P < 0.05).The accuracy of endometrial cytology for detecting endometrial carcinoma and its precursor was 92.4% (sensitivity,73%; specificity,95.8%; positive predictive value,75%; and negative predictive value,95.3%).Conclusions:Endometrial cytology using SAP-1 sampling and SurePath preparation may be a reliable approach for screening patients with endometrial carcinoma and its precursor.

  6. Time of flight secondary ion mass spectrometry of bone-Impact of sample preparation and measurement conditions.

    Science.gov (United States)

    Henss, Anja; Hild, Anne; Rohnke, Marcus; Wenisch, Sabine; Janek, Juergen

    2015-06-07

    Time of flight secondary ion mass spectrometry (ToF-SIMS) enables the simultaneous detection of organic and inorganic ions and fragments with high mass and spatial resolution. Due to recent technical developments, ToF-SIMS has been increasingly applied in the life sciences where sample preparation plays an eminent role for the quality of the analytical results. This paper focusses on sample preparation of bone tissue and its impact on ToF-SIMS analysis. The analysis of bone is important for the understanding of bone diseases and the development of replacement materials and new drugs for the cure of diseased bone. The main purpose of this paper is to find out which preparation process is best suited for ToF-SIMS analysis of bone tissue in order to obtain reliable and reproducible analytical results. The influence of the embedding process on the different components of bone is evaluated using principal component analysis. It is shown that epoxy resin as well as methacrylate based plastics (Epon and Technovit) as embedding materials do not infiltrate the mineralized tissue and that cut sections are better suited for the ToF-SIMS analysis than ground sections. In case of ground samples, a resin layer is smeared over the sample surface due to the polishing step and overlap of peaks is found. Beside some signals of fatty acids in the negative ion mode, the analysis of native, not embedded samples does not provide any advantage. The influence of bismuth bombardment and O2 flooding on the signal intensity of organic and inorganic fragments due to the variation of the ionization probability is additionally discussed. As C60 sputtering has to be applied to remove the smeared resin layer, its effect especially on the organic fragments of the bone is analyzed and described herein.

  7. Extended two-photon microscopy in live samples with Bessel beams: steadier focus, faster volume scans, and simpler stereoscopic imaging

    Science.gov (United States)

    Thériault, Gabrielle; Cottet, Martin; Castonguay, Annie; McCarthy, Nathalie; De Koninck, Yves

    2014-01-01

    Two-photon microscopy has revolutionized functional cellular imaging in tissue, but although the highly confined depth of field (DOF) of standard set-ups yields great optical sectioning, it also limits imaging speed in volume samples and ease of use. For this reason, we recently presented a simple and retrofittable modification to the two-photon laser-scanning microscope which extends the DOF through the use of an axicon (conical lens). Here we demonstrate three significant benefits of this technique using biological samples commonly employed in the field of neuroscience. First, we use a sample of neurons grown in culture and move it along the z-axis, showing that a more stable focus is achieved without compromise on transverse resolution. Second, we monitor 3D population dynamics in an acute slice of live mouse cortex, demonstrating that faster volumetric scans can be conducted. Third, we acquire a stereoscopic image of neurons and their dendrites in a fixed sample of mouse cortex, using only two scans instead of the complete stack and calculations required by standard systems. Taken together, these advantages, combined with the ease of integration into pre-existing systems, make the extended depth-of-field imaging based on Bessel beams a strong asset for the field of microscopy and life sciences in general. PMID:24904284

  8. A lab-on-a-chip system with integrated sample preparation and loop-mediated isothermal amplification for rapid and quantitative detection of Salmonella spp. in food samples.

    Science.gov (United States)

    Sun, Yi; Quyen, Than Linh; Hung, Tran Quang; Chin, Wai Hoe; Wolff, Anders; Bang, Dang Duong

    2015-04-21

    Foodborne disease is a major public health threat worldwide. Salmonellosis, an infectious disease caused by Salmonella spp., is one of the most common foodborne diseases. Isolation and identification of Salmonella by conventional bacterial culture or molecular-based methods are time consuming and usually take a few hours to days to complete. In response to the demand for rapid on line or on site detection of pathogens, in this study, we describe for the first time an eight-chamber lab-on-a-chip (LOC) system with integrated magnetic bead-based sample preparation and loop-mediated isothermal amplification (LAMP) for rapid and quantitative detection of Salmonella spp. in food samples. The whole diagnostic procedures including DNA isolation, isothermal amplification, and real-time detection were accomplished in a single chamber. Up to eight samples could be handled simultaneously and the system was capable to detect Salmonella at concentration of 50 cells per test within 40 min. The simple design, together with high level of integration, isothermal amplification, and quantitative analysis of multiple samples in short time, will greatly enhance the practical applicability of the LOC system for rapid on-site screening of Salmonella for applications in food safety control, environmental surveillance, and clinical diagnostics.

  9. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction.

    Science.gov (United States)

    Pena, M Teresa; Pensado, Luis; Casais, M Carmen; Mejuto, M Carmen; Cela, Rafael

    2007-04-01

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 microg kg(-1) dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials.

  10. Sample preparation of sewage sludge and soil samples for the determination of polycyclic aromatic hydrocarbons based on one-pot microwave-assisted saponification and extraction

    Energy Technology Data Exchange (ETDEWEB)

    Pena, M.T.; Pensado, Luis; Casais, M.C.; Mejuto, M.C.; Cela, Rafael [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia. Instituto de Investigacion y Analisis Alimentario, Santiago de Compostela (Spain)

    2007-04-15

    A microwave-assisted sample preparation (MASP) procedure was developed for the analysis of polycyclic aromatic hydrocarbons (PAHs) in sewage sludge and soil samples. The procedure involved the simultaneous microwave-assisted extraction of PAHs with n-hexane and the hydrolysis of samples with methanolic potassium hydroxide. Because of the complex nature of the samples, the extracts were submitted to further cleaning with silica and Florisil solid-phase extraction cartridges connected in series. Naphthalene, acenaphthene, fluorene, phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, chrysene, benzo[e]pyrene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[a]pyrene, dibenz[a,h]anthracene, benzo[g,h,i]perylene, and indeno[1,2,3-cd]pyrene, were considered in the study. Quantification limits obtained for all of these compounds (between 0.4 and 14.8 {mu}g kg{sup -1} dry mass) were well below of the limits recommended in the USA and EU. Overall recovery values ranged from 60 to 100%, with most losses being due to evaporation in the solvent exchange stages of the procedure, although excellent extraction recoveries were obtained. Validation of the accuracy was carried out with BCR-088 (sewage sludge) and BCR-524 (contaminated industrial soil) reference materials. (orig.)

  11. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  12. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DRINKING WATER SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP 5.23)

    Science.gov (United States)

    The method for extracting and preparing a drinking water sample for analysis of atrazine is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/ mass spectrometry.

  13. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DUST AND SOIL SAMPLES FOR ANALYSIS OF NEUTRAL PERSISTENT ORGANIC POLLUTANTS (SOP-5.14)

    Science.gov (United States)

    This SOP summarizes the method for extracting and preparing a dust or soil sample for analysis of neutral persistent organic pollutants. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/mass spectrometry.

  14. CTEPP STANDARD OPERATING PROCEDURE FOR EXTRACTING AND PREPARING DRINKING WATER SAMPLES FOR ANALYSIS OF PERSISTENT ORGANIC POLLUTANTS (SOP 5.23)

    Science.gov (United States)

    The method for extracting and preparing a drinking water sample for analysis of atrazine is summarized in this SOP. It covers the extraction and concentration of samples that are to be analyzed by gas chromatography/ mass spectrometry.

  15. Analysis of Three Compounds in Flos Farfarae by Capillary Electrophoresis with Large-Volume Sample Stacking

    Directory of Open Access Journals (Sweden)

    Hai-xia Yu

    2017-01-01

    Full Text Available The aim of this study was to develop a method combining an online concentration and high-efficiency capillary electrophoresis separation to analyze and detect three compounds (rutin, hyperoside, and chlorogenic acid in Flos Farfarae. In order to get good resolution and enrichment, several parameters such as the choice of running buffer, pH and concentration of the running buffer, organic modifier, temperature, and separation voltage were all investigated. The optimized conditions were obtained as follows: the buffer of 40 mM NaH2P04-40 mM Borax-30% v/v methanol (pH 9.0; the sample hydrodynamic injection of up to 4 s at 0.5 psi; 20 kV applied voltage. The diode-array detector was used, and the detection wavelength was 364 nm. Based on peak area, higher levels of selective and sensitive improvements in analysis were observed and about 14-, 26-, and 5-fold enrichment of rutin, hyperoside, and chlorogenic acid were achieved, respectively. This method was successfully applied to determine the three compounds in Flos Farfarae. The linear curve of peak response versus concentration was from 20 to 400 µg/ml, 16.5 to 330 µg/mL, and 25 to 500 µg/mL, respectively. The regression coefficients were 0.9998, 0.9999, and 0.9991, respectively.

  16. Overview of nongynecological samples prepared with liquid-based cytology medium.

    Science.gov (United States)

    Ren, Shuyue; Solomides, Charalambos; Draganova-Tacheva, Rossitza; Bibbo, Marluce

    2014-01-01

    Liquid-based cytology of nongynecological specimens is commonly used in cytology laboratories throughout the world and various processing methods, such as ThinPrep and SurePath, have been reported. The cytological features and performance of liquid-based cytology for various cytology specimens, including body cavity fluids, urine, brushing specimens and fine-needle aspiration of various lesions, were reviewed and compared with the experience of our laboratory and the literature published in PubMed. The parameters for the evaluation of liquid-based cytology and conventional smears were described in the various types of specimens. Criteria for the interpretation of nongynecological liquid-based cytology were highlighted to show differences in cell morphology, background and artifacts. The interpretation requires familiarity with the appearance of liquid-based cytology in the various types of preparations to avoid misdiagnosis. Cell blocks can be prepared with specimens preserved in a liquid-based cytology medium and immunocytochemical stains and molecular testing can be successfully performed. These are important adjuncts in order to reach a definitive diagnosis.

  17. Improvement of microtome cutting process of carbon nanotube composite sample preparation for TEM analysis

    Science.gov (United States)

    Trayner, Sarah

    As research progresses towards nanoscale materials, there has become a need for a more efficient and effective way to obtain ultra-thin samples for imaging under transmission electron microscope (TEM) for atomic resolution analysis. There are various methods used to obtain thin samples (epoxy composites, are of poor quality due to the sample cutting difficulties. Such poor quality samples are characterized by uneven sample thicknesses, objective overlapping, overall darkness due to large thickness, and defects such as cutting scratches. This research is a continuous effort to study and improve the ultra-microtome cutting technique to provide an effective and reliable approach of obtaining an ultra-thin (25-50 nm) cross section of a CNT/polymer composite for high resolution TEM analysis. Improvements were achieved by studying the relationships between the chosen cutting parameters, sample characteristics and TEM image quality. From this information, a cutting protocol was established so that ultra-thin sample slices can be achieved by different microtome operators for high resolution TEM analysis. In addition, a custom tool was created to aid in the sample collection process. In this research, three composite samples were studied for both microtome cutting and TEM analysis: 1) Unidirectional (UD) IM7/BMI composite; 2) Single-layer CNT buckypaper (BP)/epoxy nanocomposite; 3) 3-layer CNT BP/BMI nanocomposite. The resultant TEM images revealed a clear microstructure consisting of amorphous resin and graphite crystalline packing. UD IM7/BMI composite TEM results did not reveal an interfacial region resulting in a need for even thinner sliced cross sections. TEM results for the single-layer CNT BP/epoxy nanocomposite revealed the alignment direction of the nanotubes and numerous stacks of CNT bundles. In addition, there was visible flattening of CNT packing into dumbbell shapes similar to results obtain by Alan Windle. TEM results for the 3-layer CNT BP/BMI nanocomposite

  18. Development of a new sample preparation method based on liquid-liquid-liquid extraction combined with dispersive liquid-liquid microextraction and its application on unfiltered samples containing high content of solids.

    Science.gov (United States)

    Farajzadeh, Mir Ali; Abbaspour, Maryam

    2017-11-01

    A new sample preparation method based on liquid-liquid-liquid extraction combined with dispersive liquid-liquid microextraction followed by gas chromatography-flame ionization detection has been reported for the extraction/preconcentration and determination of trace levels of twelve pesticide residues from different samples with high content of solids without filtration. This method consists of a three-phase system including an aqueous phase (sample solution), acetonitrile, and hexane. The extraction mechanism is based on different affinities of the substances from the sample matrices towards each of the involved phase, which provides a high selectivity to the process. In other words, interfering hydrophobic compounds are transferred into hexane and will not be present in the final extract. Furthermore, ionic and polar compounds are retained in the aqueous phase. Therefore, only semi-polar compounds such as the studied pesticides are extracted into acetonitrile. In this method, a homogeneous solution of the aqueous phase and acetonitrile (a water-soluble extraction solvent) forms two clearly separated phases in the presence of sodium sulfate (as a phase separation agent) and simultaneously the analytes are extracted into the fine droplets of the acetonitrile collected on the surface of the aqueous phase. To achieve high enrichment factors, the acetonitrile phase is mixed with 1,2-dibromoethane (as a preconcentration solvent) at µL-level to perform the following dispersive liquid-liquid microextraction procedure. Several parameters that can affect extraction efficiency including kind and volume of extraction solvent, type and concentration of phase separation agent, hexane volume, kind of preconcentration solvent, and ionic strength were studied and optimized. Under the optimal conditions, extraction recoveries were obtained in the range of 53-93% and the calibration curves were linear in wide ranges with correlation coefficients ≥ 0.9983. Intra- (n = 6) and

  19. Secondary Ion Mass Spectrometry Imaging of Molecular Distributions in Cultured Neurons and Their Processes: Comparative Analysis of Sample Preparation

    Science.gov (United States)

    Tucker, Kevin R.; Li, Zhen; Rubakhin, Stanislav S.; Sweedler, Jonathan V.

    2012-11-01

    Neurons often exhibit a complex chemical distribution and topography; therefore, sample preparation protocols that preserve structures ranging from relatively large cell somata to small neurites and growth cones are important factors in secondary ion mass spectrometry (SIMS) imaging studies. Here, SIMS was used to investigate the subcellular localization of lipids and lipophilic species in neurons from Aplysia californica. Using individual neurons cultured on silicon wafers, we compared and optimized several SIMS sampling approaches. After an initial step to remove the high salt culturing media, formaldehyde, paraformaldehyde, and glycerol, and various combinations thereof, were tested for their ability to achieve cell stabilization during and after the removal of extracellular media. These treatments improved the preservation of cellular morphology as visualized with SIMS imaging. For analytes >250 Da, coating the cell surface with a 3.2 nm-thick gold layer increased the ion intensity; multiple analytes previously not observed or observed at low abundance were detected, including intact cholesterol and vitamin E molecular ions. However, once a sample was coated, many of the lower molecular mass (cell stabilization with glycerol and 4 % paraformaldehyde. The sample preparation methods described here enhance SIMS imaging of processes of individual cultured neurons over a broad mass range with enhanced image contrast.

  20. Practical aspects of the use of the X(2) holder for HRTEM-quality TEM sample preparation by FIB.

    Science.gov (United States)

    van Mierlo, Willem; Geiger, Dorin; Robins, Alan; Stumpf, Matthias; Ray, Mary Louise; Fischione, Paul; Kaiser, Ute

    2014-12-01

    The X(2) holder enables the effective production of thin, electron transparent samples for high-resolution transmission electron microscopy (HRTEM). Improvements to the X(2) holder for high-quality transmission electron microscopy (TEM) sample preparation are presented in this paper. We discuss the influence of backscattered electrons (BSE) from the sample holder in determining the lamella thickness in situ and demonstrate that a significant improvement in thickness determination can be achieved by comparatively simple means using the relative BSE intensity. We show (using Monte Carlo simulations) that by taking into account the finite collection angle of the electron backscatter detector, an approximately 20% underestimation of the lamella thickness in a silicon sample can be avoided. However, a correct thickness determination for light-element lamellas still remains a problem with the backscatter method; we introduce a more accurate method using the energy dispersive X-ray spectroscopy (EDX) signal for in situ thickness determination. Finally, we demonstrate how to produce a thin lamella with a nearly damage-free surface using the X(2) holder in combination with sub-kV polishing in the Fischione Instruments׳ NanoMill(®) TEM specimen preparation system.

  1. OPTIMAL METHOD FOR PREPARATION OF SILICATE ROCK SAMPLES FOR ANALYTICAL PURPOSES

    Directory of Open Access Journals (Sweden)

    Maja Vrkljan

    2004-12-01

    Full Text Available The purpose of this study was to determine an optimal dissolution method for silicate rock samples for further analytical purposes. Analytical FAAS method of determining cobalt, chromium, copper, nickel, lead and zinc content in gabbro sample and geochemical standard AGV-1 has been applied for verification. Dissolution in mixtures of various inorganic acids has been tested, as well as Na2CO3 fusion technique. The results obtained by different methods have been compared and dissolution in the mixture of HNO3 + HF has been recommended as optimal.

  2. Multiple double cross-section transmission electron microscope sample preparation of specific sub-10 nm diameter Si nanowire devices.

    Science.gov (United States)

    Gignac, Lynne M; Mittal, Surbhi; Bangsaruntip, Sarunya; Cohen, Guy M; Sleight, Jeffrey W

    2011-12-01

    The ability to prepare multiple cross-section transmission electron microscope (XTEM) samples from one XTEM sample of specific sub-10 nm features was demonstrated. Sub-10 nm diameter Si nanowire (NW) devices were initially cross-sectioned using a dual-beam focused ion beam system in a direction running parallel to the device channel. From this XTEM sample, both low- and high-resolution transmission electron microscope (TEM) images were obtained from six separate, specific site Si NW devices. The XTEM sample was then re-sectioned in four separate locations in a direction perpendicular to the device channel: 90° from the original XTEM sample direction. Three of the four XTEM samples were successfully sectioned in the gate region of the device. From these three samples, low- and high-resolution TEM images of the Si NW were taken and measurements of the NW diameters were obtained. This technique demonstrated the ability to obtain high-resolution TEM images in directions 90° from one another of multiple, specific sub-10 nm features that were spaced 1.1 μm apart.

  3. Urine sample preparation and fractionation for global proteome profiling by LC-MS.

    Science.gov (United States)

    Court, Magali; Garin, Jérôme; Masselon, Christophe D

    2015-01-01

    Urine has garnered tremendous interest over the past decade as a potential source of protein biomarkers for various pathologies. However, due to its low protein concentration and the presence of interfering compounds, urine constitutes a challenging analyte in proteomics. In the context of a project aimed at the discovery and evaluation of new candidate biomarkers of bladder cancer in urine, our laboratory has implemented and evaluated an array of preparation techniques for urinary proteome analysis. We present here the protocol that, in our hands, yielded the best overall proteome coverage with the lowest analytical effort. It begins with protein precipitation using trichloroacetic acid, in solution digestion and RP-C18 cartridge desalting of the resulting peptides mixture, and is followed by peptide fractionation by gel-free isoelectric focusing, and nano-LC-MS/MS for database compilation.

  4. Influence Of Sample Preparation Method On Isothermal Studies During Compatibility Screening Of Ofloxacin; Correlation With DSC Data

    Directory of Open Access Journals (Sweden)

    M. Misra, A. K. MISRA,, G. M. Panpalia

    2011-05-01

    Full Text Available Objectives: The compatibility of ofloxacin with somecommonly used diluents has been investigated usingisothermal stability studies (IST to allow relative ranking.Materials and Methods: The samples were prepared usingthree methods namely physical admixtures (with 5% addedmoisture, slugging and kneading in order to evaluate theeffect of mechanical treatment on the physicochemical stabilityof drug. To further verify the results of IST fresh binarymixtures were subjected to thermal analysis and an attemptwas made to correlate the results obtained from the twostudies.Results: The results from both DSC and IST revealed thatofloxacin was compatible with all the diluents used in thestudy. Among the three methods of sample preparation usedfor the study, the extent of degradation was more or less samein all the three methods indicating least influence of method ofsample preparation on the results of IST.Conclusions: From the study it was concluded that a betterco-correlation could have been obtained had ofloxacin beenmore unstable with few of the excipients than rest, used in thestudy. This way the extent of degradation would bedistinguishing enough to rank the excipients in decreasingorder of stability.

  5. Dried blood spots on carboxymethyl cellulose sheets: Rapid sample preparation based on dissolution and precipitation

    DEFF Research Database (Denmark)

    Skoglund Ask, Kristine; Pedersen-Bjergaard, Stig; Gjelstad, Astrid

    2016-01-01

    This short communication describes the use of carboxymethyl cellulose sheets as sampling material for dried blood spots. Whole blood, spiked with quetiapine, a hydrophobic and basic small molecule drug substance, was spotted on the sheet and subsequently dried. The dried spot was then almost...

  6. Lead biomonitoring in different organs of lead intoxicated rats employing GF AAS and different sample preparations.

    Science.gov (United States)

    de Sousa, Rafael Arromba; Sabarense, Céphora Maria; Prado, Gustavo L P; Metze, Konradin; Cadore, Solange

    2013-01-30

    An analytical procedure was developed for the determination of lead in different tissues from Wistar Hanover rats, previously intoxicated with lead acetate during a toxicological study. About 25 mg of dried sample (bone, liver, kidney, heart, lung and spleen) were mixed with 8.0 mL of 7.00 mol L(-1) nitric acid and digested using microwave radiation in closed vessel. Except for the bone samples, the other tissues could also be analyzed after alkaline solubilization with TMAH. All the digested or solubilized samples were analyzed by graphite furnace atomic absorption spectrometry. Good accuracy and precision were attained when analyzing reference standard materials (for bone, liver and kidney) and also from addition to recovery experiments (for heart, lung and spleen tissues). The method was applied to samples from nine animals and the results suggested that there is a profile for lead bioaccumulation in these animals, which seemed to adapt themselves to continuous lead exposure. Copyright © 2012 Elsevier B.V. All rights reserved.

  7. Sample Preparation and Identification of Biological, Chemical and Mid-Spectrum Agents

    Science.gov (United States)

    2005-10-01

    substrate molecule is called a hydrolase. Substrates commonly used are sodium hippurate, DNA, urea, esculin, starch , casein, lecithin and polysorbate-80...processed sample are first denatured and separated by gel electrophoresis [usually sodium dodecyl polyacrylamide gel electrophoresis (SDS-PAGE)] and

  8. Preparation and applicability of fresh fruit samples for the identification of radiation treatment by EPR

    Energy Technology Data Exchange (ETDEWEB)

    Yordanov, Nicola D. [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)], E-mail: ndyepr@bas.bg; Aleksieva, Katerina [Laboratory EPR, Institute of Catalysis, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2009-03-15

    The results of electron paramagnetic resonance (EPR) study on fresh fruits (whole pulp of pears, apples, peaches, apricots, avocado, kiwi and mango) before and after gamma-irradiation are reported using two drying procedures before EPR investigation. In order to remove water from non-irradiated and irradiated samples of the first batch, the pulp of fresh fruits is pressed, and the solid residue is washed with alcohol and dried at room temperature. The fruits of the second batch are pressed and dried in a standard laboratory oven at 40 deg. C. The results obtained with both drying procedures are compared. All samples under study show a singlet EPR line with g=2.0048{+-}0.0005 before irradiation. Irradiation gives rise to typical 'cellulose-like' EPR spectrum featuring one intensive line with g=2.0048{+-}0.0005 and two very weak satellite lines situated 3 mT at left and right of the central line. Only mango samples show a singlet line after irradiation. The fading kinetics of radiation-induced EPR signal is studied for a period of 50 days after irradiation. When the irradiated fruit samples are stored in their natural state and dried just before each EPR measurement, the satellite lines are measurable for less than 17 days of storage. Irradiated fruit samples, when stored dried, lose for 50 days ca. 40% of their radiation-induced radicals if treated with alcohol or ca. 70% if dried in an oven. The reported results unambiguously show that the presence of the satellite lines in the EPR spectra could be used for identification of radiation processing of fresh fruits, thus extending the validity of European Protocol EN 1787 (2000). Foodstuffs-Detection of Irradiated Food Containing Cellulose by EPR Spectroscopy. European Committee for Standardisation. Brussels for dry herbs.

  9. Preparation and applicability of fresh fruit samples for the identification of radiation treatment by EPR

    Science.gov (United States)

    Yordanov, Nicola D.; Aleksieva, Katerina

    2009-03-01

    The results of electron paramagnetic resonance (EPR) study on fresh fruits (whole pulp of pears, apples, peaches, apricots, avocado, kiwi and mango) before and after gamma-irradiation are reported using two drying procedures before EPR investigation. In order to remove water from non-irradiated and irradiated samples of the first batch, the pulp of fresh fruits is pressed, and the solid residue is washed with alcohol and dried at room temperature. The fruits of the second batch are pressed and dried in a standard laboratory oven at 40 °C. The results obtained with both drying procedures are compared. All samples under study show a singlet EPR line with g=2.0048±0.0005 before irradiation. Irradiation gives rise to typical "cellulose-like" EPR spectrum featuring one intensive line with g=2.0048±0.0005 and two very weak satellite lines situated 3 mT at left and right of the central line. Only mango samples show a singlet line after irradiation. The fading kinetics of radiation-induced EPR signal is studied for a period of 50 days after irradiation. When the irradiated fruit samples are stored in their natural state and dried just before each EPR measurement, the satellite lines are measurable for less than 17 days of storage. Irradiated fruit samples, when stored dried, lose for 50 days ca. 40% of their radiation-induced radicals if treated with alcohol or ca. 70% if dried in an oven. The reported results unambiguously show that the presence of the satellite lines in the EPR spectra could be used for identification of radiation processing of fresh fruits, thus extending the validity of European Protocol EN 1787 (2000). Foodstuffs—Detection of Irradiated Food Containing Cellulose by EPR Spectroscopy. European Committee for Standardisation. Brussels for dry herbs.

  10. Plasma, blood and liver tissue sample preparation methods for the separate quantification of liposomal-encapsulated prednisolone phosphate and non-encapsulated prednisolone

    NARCIS (Netherlands)

    Smits, Evelien A W; Soetekouw, José A; Bakker, Peter F A; Baijens, Bart J H; Vromans, Herman

    2015-01-01

    Besides the development of sample preparation methods for the determination of separate liposomal-encapsulated prednisolone phosphate and non-encapsulated prednisolone concentrations in murine plasma and blood, this article also presents the first description of an accurate sample preparation method

  11. Association between waist circumference and gray matter volume in 2344 individuals from two adult community-based samples.

    Science.gov (United States)

    Janowitz, Deborah; Wittfeld, Katharina; Terock, Jan; Freyberger, Harald Jürgen; Hegenscheid, Katrin; Völzke, Henry; Habes, Mohamad; Hosten, Norbert; Friedrich, Nele; Nauck, Matthias; Domanska, Grazyna; Grabe, Hans Jörgen

    2015-11-15

    We analyzed the putative association between abdominal obesity (measured in waist circumference) and gray matter volume (Study of Health in Pomerania: SHIP-2, N=758) adjusted for age and gender by applying volumetric analysis and voxel-based morphometry (VBM) with VBM8 to brain magnetic resonance (MR) imaging. We sought replication in a second, independent population sample (SHIP-TREND, N=1586). In a combined analysis (SHIP-2 and SHIP-TREND) we investigated the impact of hypertension, type II diabetes and blood lipids on the association between waist circumference and gray matter. Volumetric analysis revealed a significant inverse association between waist circumference and gray matter volume. VBM in SHIP-2 indicated distinct inverse associations in the following structures for both hemispheres: frontal lobe, temporal lobes, pre- and postcentral gyrus, supplementary motor area, supramarginal gyrus, insula, cingulate gyrus, caudate nucleus, olfactory sulcus, para-/hippocampus, gyrus rectus, amygdala, globus pallidus, putamen, cerebellum, fusiform and lingual gyrus, (pre-) cuneus and thalamus. These areas were replicated in SHIP-TREND. More than 76% of the voxels with significant gray matter volume reduction in SHIP-2 were also distinct in TREND. These brain areas are involved in cognition, attention to interoceptive signals as satiety or reward and control food intake. Due to our cross-sectional design we cannot clarify the causal direction of the association. However, previous studies described an association between subjects with higher waist circumference and future cognitive decline suggesting a progressive brain alteration in obese subjects. Pathomechanisms may involve chronic inflammation, increased oxidative stress or cellular autophagy associated with obesity.

  12. Considerations for the preparation of peat samples for palynology, and for the counting of pollen and non-pollen palynomorphs

    Directory of Open Access Journals (Sweden)

    F.M. Chambers

    2011-09-01

    Full Text Available Peat deposits are valuable archives for studying palaeoclimate, the history of local and regional vegetation, and human impact. The most widely applied laboratory analytical technique has been palynology (pollen analysis, which is often limited to the study of pollen and a few easily recognisable spores; however, a variety of other microfossils can be studied in peat deposits and can provide information on past environmental conditions. Among the so-called non-pollen palynomorphs (NPPs are fungal and algal spores that can be used as indicators for local hydrological changes and trophic conditions. This article provides an overview of aspects to consider and sample preparation methods for pollen, spores and other non-pollen palynomorph microfossils in peat deposits; advice on aids to pollen identification and counting; and a brief guide to the range of NPPs that can be counted from prepared subfossil-pollen microslides.

  13. Preparation of Samples for Leaf Architecture Studies, A Method for Mounting Cleared Leaves

    Directory of Open Access Journals (Sweden)

    Alejandra Vasco

    2014-09-01

    Full Text Available Premise of the study: Several recent waves of interest in leaf architecture have shown an expanding range of approaches and applications across a number of disciplines. Despite this increased interest, examination of existing archives of cleared and mounted leaves shows that current methods for mounting, in particular, yield unsatisfactory results and deterioration of samples over relatively short periods. Although techniques for clearing and staining leaves are numerous, published techniques for mounting leaves are scarce. Methods and Results: Here we present a complete protocol and recommendations for clearing, staining, and imaging leaves, and, most importantly, a method to permanently mount cleared leaves. Conclusions: The mounting protocol is faster than other methods, inexpensive, and straightforward; moreover, it yields clear and permanent samples that can easily be imaged, scanned, and stored. Specimens mounted with this method preserve well, with leaves that were mounted more than 35 years ago showing no signs of bubbling or discoloration.

  14. Comparison of sample preparation methods for reliable plutonium and neptunium urinalysis using automatic extraction chromatography.

    Science.gov (United States)

    Qiao, Jixin; Xu, Yihong; Hou, Xiaolin; Miró, Manuel

    2014-10-01

    This paper describes improvement and comparison of analytical methods for simultaneous determination of trace-level plutonium and neptunium in urine samples by inductively coupled plasma mass spectrometry (ICP-MS). Four sample pre-concentration techniques, including calcium phosphate, iron hydroxide and manganese dioxide co-precipitation and evaporation were compared and the applicability of different techniques was discussed in order to evaluate and establish the optimal method for in vivo radioassay program. The analytical results indicate that the various sample pre-concentration approaches afford dissimilar method performances and care should be taken for specific experimental parameters for improving chemical yields. The best analytical performances in terms of turnaround time (6h) and chemical yields for plutonium (88.7 ± 11.6%) and neptunium (94.2 ± 2.0%) were achieved by manganese dioxide co-precipitation. The need of drying ashing (≥ 7h) for calcium phosphate co-precipitation and long-term aging (5d) for iron hydroxide co-precipitation, respectively, rendered time-consuming analytical protocols. Despite the fact that evaporation is also somewhat time-consuming (1.5d), it endows urinalysis methods with better reliability and repeatability compared with co-precipitation techniques. In view of the applicability of different pre-concentration techniques proposed previously in the literature, the main challenge behind relevant method development is pointed to be the release of plutonium and neptunium associated with organic compounds in real urine assays. In this work, different protocols for decomposing organic matter in urine were investigated, of which potassium persulfate (K2S2O8) treatment provided the highest chemical yield of neptunium in the iron hydroxide co-precipitation step, yet, the occurrence of sulfur compounds in the processed sample deteriorated the analytical performance of the ensuing extraction chromatographic separation with chemical

  15. Preparation of polyethylene sacks for collection of precipitation samples for chemical analysis

    Science.gov (United States)

    Schroder, L.J.; Bricker, A.W.

    1985-01-01

    Polyethylene sacks are used to collect precipitation samples. Washing polyethylene with acetone, hexane, methanol, or nitric acid can change the adsorptive characteristics of the polyethylene. In this study, simulated precipitation at pH 4.5 was in contact with the polyethylene sacks for 21 days; subsamples were removed for chemical analysis at 7, 14, and 21 days after intitial contact. Sacks washed with acetone adsorbed iron and lithium; sacks washed with hexane adsorbed barium, iron , and lithium; sacks washed with methanol adsorbed calcium and iron; and sacks washed with 0.30 N nitric acid adsorbed iron. Leaching the plastic sacks with 0.15 N nitric acid did not result in 100-percent recovery of any of the adsorbed metals. Washing polyethylene sacks with dilute nitric acid caused the pH of the simulated precipitation to be decreased by 0.2 pH unit after 1 week of contact with the polyethylene. The specific conductance increased by 10 microsiemens per centimeter. Contamination of precipitation samples by lead was determined to be about 0.1 microgram per liter from contact with precleaned polyethylene sacks. No measurable contamination of precipitation samples by zinc occurred. (USGS)

  16. Preparation and characterization of magnetic molecularly imprinted polymers for the extraction of hexamethylenetetramine in milk samples.

    Science.gov (United States)

    Xu, Xing; Duhoranimana, Emmanuel; Zhang, Xiaoming

    2017-01-15

    Magnetic molecularly imprinted polymers (M-MIPs) were synthesized as the sorbents for extracting hexamethylenetetramine (HMT) from milk samples. Molecular simulations were used to calculate the interaction energies of the template monomers. The physical properties of M-MIPs were characterized. The adsorption isotherms and kinetics were investigated. Gas chromatography coupled with tandem mass spectrometry (GC-MS/MS) was applied to determine the amount of HMT residue in milk samples. In the optimized method, a linear calibration curve was obtained using a matrix-matched standard in the range of 1.0-50.0μgL(-1). The limit of detection (LOD) and limit of quantification (LOQ) was 0.3μgkg(-1) and 1.0μgkg(-1), respectively. The relative standard deviation (RSD) of the intra-day assay ranged from 2.6% to 5.2%, while that of the inter-day assay ranged from 3.6% to 11.5%. The recovery of HMT in milk samples ranged from 88.7% to 111.4%.

  17. High-Throughput Serum 25-Hydroxy Vitamin D Testing with Automated Sample Preparation.

    Science.gov (United States)

    Stone, Judy

    2016-01-01

    Serum from bar-coded tubes, and then internal standard, are pipetted to 96-well plates with an 8-channel automated liquid handler (ALH). The first precipitation reagent (methanol:ZnSO4) is added and mixed with the 8-channel ALH. A second protein precipitating agent, 1 % formic acid in acetonitrile, is added and mixed with a 96-channel ALH. After a 4-min delay for larger precipitates to settle to the bottom of the plate, the upper 36 % of the precipitate/supernatant mix is transferred with the 96-channel ALH to a Sigma Hybrid SPE(®) plate and vacuumed through for removal of phospholipids and precipitated proteins. The filtrate is collected in a second 96-well plate (collection plate) which is foil-sealed, placed in the autosampler (ALS), and injected into a multiplexed LC-MS/MS system running AB Sciex Cliquid(®) and MPX(®) software. Two Shimadzu LC stacks, with multiplex timing controlled by MPX(®) software, inject alternately to one AB Sciex API-5000 MS/MS using positive atmospheric pressure chemical ionization (APCI) and a 1.87 min water/acetonitrile LC gradient with a 2.1 × 20 mm, 2.7 μm, C18 fused core particle column (Sigma Ascentis Express). LC-MS/MS through put is ~44 samples/h/LC-MS/MS system with dual-LC channel multiplexing. Plate maps are transferred electronically from the ALH and reformatted into LC-MS/MS sample table format using the Data Innovations LLC (DI) Instrument Manager middleware application. Before collection plates are loaded into the ALS, the plate bar code is manually scanned to download the sample table from the DI middleware to the LC-MS/MS. After acquisition-LC-MS/MS data is analyzed with AB Sciex Multiquant(®) software using customized queries, and then results are transferred electronically via a DI interface to the LIS. 2500 samples/day can be extracted by two analysts using four ALHs in 4-6 h. LC-MS/MS analysis of those samples on three dual-channel LC multiplexed LC-MS/MS systems requires 19-21 h and data analysis can be

  18. Sample Preparation and Staining Methods for Two-Dimensional Polyacrylamide Gel Electrophoresis of Proteins from Animal Tissues

    Directory of Open Access Journals (Sweden)

    Levente Czegledi

    2010-05-01

    Full Text Available Proteomics in animal science as well as in other biological sciences is a significant tool in the post-genomic era. In proteomic studies the presence and relative abundance of expressed proteins of a cell, tissue or biological fluid is studied. Recently, the whole genome of more and more domestic animal species is known, but genes and the transcribed mRNA have no direct effect on biological systems as they are regulated by proteins, which explain the importance of proteomics. The most common tool in proteomic approach is the two-dimensional polyacrylamide gel electrophoresis (2D PAGE, when proteins are separated by their isoelectric point followed by their mass separation as a second dimension. In this study authors used different sample preparation and protein staining methods on meat,  liver and blood plasma and carried out 2D PAGE experiments. The most appropriate sample preparation methods are described in this paper. We concluded that depletion of major proteins in plasma is required but not necessary for meat and liver samples.

  19. Technical Note: An improved guideline for rapid and precise sample preparation of tree-ring stable isotope analysis

    Science.gov (United States)

    Schollaen, K.; Baschek, H.; Heinrich, I.; Helle, G.

    2015-07-01

    The procedure of wood sample preparation, including tree-ring dissection, cellulose extraction, homogenization and finally weighing and packing for stable isotope analysis is labour intensive and time consuming. We present an elaborated methodical guideline from pre-analyses considerations, wood sample preparation through semi-automated chemical extraction of cellulose directly from tree-ring cross-sections to tree-ring dissection for high-precision isotope ratio mass spectrometry. This guideline reduces time and maximizes the tree-ring stable isotope data throughput significantly. The method was applied to ten different tree species (coniferous and angiosperm wood) with different wood growth rates and differently shaped tree-ring boundaries. The tree-ring structures of the cellulose cross-sections largely remained well identifiable. FTIR (Fourier transform infrared) spectrometry and the comparison of stable isotope values with classical method confirm chemical purity of the resultant cellulose. Sample homogenization is no longer necessary. Cellulose extraction is now faster, cheaper and more user friendly allowing (i) the simultaneous treatment of wood cross-sections of a total length of 180 cm (equivalent to 6 increment cores of 30 cm length) and thickness of 0.5 to 2 mm, and (ii) precise tree-ring separation at annual to high-resolution scale utilizing manual devices or UV-laser microdissection microscopes.

  20. Technical Note: An improved guideline for rapid and precise sample preparation of tree-ring stable isotope analysis

    Directory of Open Access Journals (Sweden)

    K. Schollaen

    2015-07-01

    Full Text Available The procedure of wood sample preparation, including tree-ring dissection, cellulose extraction, homogenization and finally weighing and packing for stable isotope analysis is labour intensive and time consuming. We present an elaborated methodical guideline from pre-analyses considerations, wood sample preparation through semi-automated chemical extraction of cellulose directly from tree-ring cross-sections to tree-ring dissection for high-precision isotope ratio mass spectrometry. This guideline reduces time and maximizes the tree-ring stable isotope data throughput significantly. The method was applied to ten different tree species (coniferous and angiosperm wood with different wood growth rates and differently shaped tree-ring boundaries. The tree-ring structures of the cellulose cross-sections largely remained well identifiable. FTIR (Fourier transform infrared spectrometry and the comparison of stable isotope values with classical method confirm chemical purity of the resultant cellulose. Sample homogenization is no longer necessary. Cellulose extraction is now faster, cheaper and more user friendly allowing (i the simultaneous treatment of wood cross-sections of a total length of 180 cm (equivalent to 6 increment cores of 30 cm length and thickness of 0.5 to 2 mm, and (ii precise tree-ring separation at annual to high-resolution scale utilizing manual devices or UV-laser microdissection microscopes.

  1. Microscopic and mesoscopic structural features of an activated carbon sample, prepared from sorghum via activation by phosphoric acid

    Energy Technology Data Exchange (ETDEWEB)

    Temleitner, László [SPring-8, JASRI, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198 (Japan); Pusztai, László, E-mail: pusztai.laszlo@wigner.mta.hu [Institute for Solid State Physics and Optics, Wigner Research Centre for Physics, Hungarian Academy of Sciences, P.O. Box 49, H-1525 Budapest (Hungary); Rubio-Arroyo, Manuel F.; Aguilar-López, Sergio [Instituto de Quimica, UNAM, Circuito Exterior S/N, Ciudad Universitaria, Coyoacán, México D.F. 04510 (Mexico); Klimova, Tatiana [Facultad de Quimica, UNAM, Edif. E, Ciudad Universitaria, Coyoacán, México D.F. 04510 (Mexico); Pizio, Orest [Instituto de Quimica, UNAM, Circuito Exterior S/N, Ciudad Universitaria, Coyoacán, México D.F. 04510 (Mexico)

    2012-12-15

    Graphical abstract: Display Omitted Highlights: ► Preparation of a new activated carbon sample from sorghum. ► Characterization by adsorption/desorption methods. ► Determination of the structure by synchrotron X-ray diffraction. ► The sample is amorphous and contains distorted graphene fragments. ► A characteristic nanoscale distance is established from the radial distribution function. -- Abstract: An acidic chemical activation procedure has been used for preparing activated carbon with a surface area exceeding 1000 m{sup 2}/g from sorghum. In order to reveal structural features, synchrotron X-ray diffraction measurements have been performed. The structure of the material has been characterized by the total scattering structure factor and the radial distribution function describing short-range arrangement of atoms at distances of the order of a few atomic diameters as well as correlations at a longer scale, of the order of nanometers. The atomic arrangement has been found to be consistent with that of amorphous graphite-like carbon. As far as the mesoscopic structure is concerned, the presence of a characteristic distance is suggested on the basis of the clear nanometer scale oscillations of the radial distribution function, which distance may be assigned as the mesopore size in the material. It is suggested that the approach devized here may later be applied routinely for other activated carbon samples, too, for characterizing atomic and nanoscale order simultaneously.

  2. Solid-phase microextraction: a promising technique for sample preparation in environmental analysis.

    Science.gov (United States)

    Alpendurada, M F

    2000-08-11

    Solid-phase microextraction (SPME) is a simple and effective adsorption and desorption technique, which eliminates the need for solvents or complicated apparatus, for concentrating volatile or nonvolatile compounds in liquid samples or headspace. SPME is compatible with analyte separation and detection by gas chromatography and high-performance liquid chromatography, and provides linear results for wide concentrations of analytes. By controlling the polarity and thickness of the coating on the fibre, maintaining consistent sampling time, and adjusting other extraction parameters, an analyst can ensure highly consistent, quantifiable results for low concentration analytes. To date, about 400 articles on SPME have been published in different fields, including environment (water, soil, air), food, natural products, pharmaceuticals, biology, toxicology, forensics and theory. As the scope of SPME grew, new improvements were made with the appearance of new coatings that allowed an increase in the specificity of this extraction technique. The key part of the SPME fibre is of course the fibre coating. At the moment, 27 variations of fibre coating and size are available. Among the newest are a fibre assembly with a dual coating of divinylbenzene and Carboxen suspended in poly(dimethylsiloxane), and a series of 23 gauge fibres intended for specific septumless injection system. The growth of SPME is also reflected in the expanding number of the accessories that make the technology even easier to use Also available is a portable field sampler which is a self-contained unit that stores the SPME fibre after sampling and during the shipment to the laboratory. Several scientific publications show the results obtained in inter-laboratory validation studies in which SPME was applied to determine the presence of different organic compounds at ppt levels, which demonstrates the reliability of this extraction technique for quantitative analysis.

  3. Optimized sample preparation for two-dimensional gel electrophoresis of soluble proteins from chicken bursa of Fabricius

    Directory of Open Access Journals (Sweden)

    Zheng Xiaojuan

    2009-10-01

    Full Text Available Abstract Background Two-dimensional gel electrophoresis (2-DE is a powerful method to study protein expression and function in living organisms and diseases. This technique, however, has not been applied to avian bursa of Fabricius (BF, a central immune organ. Here, optimized 2-DE sample preparation methodologies were constructed for the chicken BF tissue. Using the optimized protocol, we performed further 2-DE analysis on a soluble protein extract from the BF of chickens infected with virulent avibirnavirus. To demonstrate the quality of the extracted proteins, several differentially expressed protein spots selected were cut from 2-DE gels and identified by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOF MS. Results An extraction buffer containing 7 M urea, 2 M thiourea, 2% (w/v 3-[(3-cholamidopropyl-dimethylammonio]-1-propanesulfonate (CHAPS, 50 mM dithiothreitol (DTT, 0.2% Bio-Lyte 3/10, 1 mM phenylmethylsulfonyl fluoride (PMSF, 20 U/ml Deoxyribonuclease I (DNase I, and 0.25 mg/ml Ribonuclease A (RNase A, combined with sonication and vortex, yielded the best 2-DE data. Relative to non-frozen immobilized pH gradient (IPG strips, frozen IPG strips did not result in significant changes in the 2-DE patterns after isoelectric focusing (IEF. When the optimized protocol was used to analyze the spleen and thymus, as well as avibirnavirus-infected bursa, high quality 2-DE protein expression profiles were obtained. 2-DE maps of BF of chickens infected with virulent avibirnavirus were visibly different and many differentially expressed proteins were found. Conclusion These results showed that method C, in concert extraction buffer IV, was the most favorable for preparing samples for IEF and subsequent protein separation and yielded the best quality 2-DE patterns. The optimized protocol is a useful sample preparation method for comparative proteomics analysis of chicken BF tissues.

  4. SAM Sample preparation and its impact on the detection of organic compounds on Mars

    Science.gov (United States)

    Buch, Arnaud; Szopa, Cyril; Coll, Patrice; Freissinet, Caroline; Glavin, Daniel; Belmahdi, Imene; François, Pascaline; Millan, Maeva; Eigenbrode, Jennifer; navarro, Rafael; Stern, Jennifer; Pinnick, Veronica; Coscia, David; Teinturier, Samuel; Miller, Kristen; Summons, Roger; Mahaffy, Paul

    2014-05-01

    The wet chemistry experiments on the Sample Analysis at Mars (SAM) [1] experiment in the Curiosity rover of the Mars Science Laboratory mission supports extraction of polar organic compounds from solid samples that improves their detection either by increasing the release of chemical species from solid sample matrices, or by changing their chemical structure to make compounds more amenable to gas chromatography mass spectrometry (GCMS). The wet chemistry approach provides an alternative to the nominal inert-thermal desorption/pyrolysis analytical protocol used by SAM [1] that is more aptly suited for polar components. SAM, includes two different wet chemistry experiments: MTBSTFA derivatization [2-3] and TMAH thermochemolysis [4]. Here we report on the nature of the MTBSTFA derivatization experiment on SAM, the detection of MTBSTFA products in the SAM evolved gas analysis and GCMS experiments, and the implications of this detection. Solid sample were heated up to approximately 840°C at a rate of 35°C/min under He flow. For GC analyses, the majority of the gas released was trapped on a hydrocarbon trap (Tenax®) over a specific temperature range. Adsorbed volatiles on the GC injection trap (IT) were then released into the GC column (CLP-MXT 30m x 0.25mm x 0.25µm) by rapidly heating the IT to 300°C. Then, in order better understand the part of compounds detected coming from internal reaction we have performed several lab experiments to mimic the SAM device. We have investigated the thermal degradation of Tenax®, and possible interaction with MTBSTFA and perchlorate in the SAM trap (Tenax®) to better constrain interpretations of SAM results on Mars. References: [1] Mahaffy, P. et al. (2012) Space Sci Rev, 170, 401-478. [2] Buch, A. et al. (2009) J chrom. A, 43, 143-151. [3] Stalport, F. et al. (2012) Planet. Space Sci. 67: 1-13 [4] Geffroy-Rodier, C. et al. (2009) JAAP, 85, 454-459. Acknowledgements: SAM-GC team acknowledges support from the French Space Agency

  5. Combination of direct swim-up technique and discontinuous Percoll gradient centrifugation for sperm preparation of oligoasthenozoospermic samples.

    Science.gov (United States)

    Chen, S U; Ho, H N; Chen, H F; Chao, K H; Wu, M Y; Chen, C D; Huang, S C; Lee, T Y; Yang, Y S

    1996-01-01

    Sperm recovery for assisted reproduction in oligoasthenozoospermic patients is not satisfying either by the swim-up technique or by Percoll gradient centrifugation, and no single technique is constantly preferred. The design of this study was to evaluate the effects of combining the two methods on improving the efficacy of sperm preparation in these poor samples. For each semen sample, 1 mL was treated with a combination method, which used direct swim-up technique to recover motile sperm swimming to the supernatant, and then the residual semen was subjected to two-layer discontinuous Percoll gradient procedure for further recovery of motile sperm. Another 1 mL was prepared with two-layer discontinuous Percoll gradient centrifugation alone for comparison. Parameters measured included sperm concentration, number of progressively motile sperm, percentage of progressive motility, percentage of motile sperm recovery, amount of debris, percentage of normal forms according to Kruger's strict criteria, and motion characteristics of sperm using computer-aided motility analysis. The results of 30 oligoasthenozoospermic samples demonstrated that the combination method achieved a significantly greater recovery of motile sperm than the two-layer discontinuous Percoll gradient centrifugation did (43.2 +/- 19.7% vs. 32.2 +/- 14.3%, p method than in those of Percoll gradient centrifugation alone, but the difference was not significant (63.7 +/- 21.8% vs. 58.7 +/- 20.1%). The debris of semen was removed equally well by both methods. The percentage of normal forms as well as motion characteristics, including curvilinear velocity, straight-line velocity, mean amplitude of lateral head displacement, and linearity, were similar in the samples treated by these two procedures. The combination of the direct swim-up technique and discontinuous Percoll gradient centrifugation combines the advantages of each procedure and results in greater recovery of motile sperm in oligoasthenozoospermic

  6. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yonghua [Iowa State Univ., Ames, IA (United States)

    2000-01-01

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an

  7. The effects of water sample treatment, preparation, and storage prior to cyanotoxin analysis for cylindrospermopsin, microcystin and saxitoxin.

    Science.gov (United States)

    Kamp, Lisa; Church, Jennifer L; Carpino, Justin; Faltin-Mara, Erin; Rubio, Fernando

    2016-02-25

    Cyanobacterial harmful algal blooms occur in freshwater lakes, ponds, rivers, and reservoirs, and in brackish waters throughout the world. The wide variety of cyanotoxins and their congeners can lead to frequent exposure of humans through consumption of meat, fish, seafood, blue-green algal products and water, accidental ingestion of contaminated water and cyanobacterial scum during recreational activities, and inhalation of cyanobacterial aerosols. Cyanotoxins can also occur in the drinking water supply. In order to monitor human exposure, sensitive analytical methods such as enzyme linked immunosorbent assay and liquid chromatography-mass spectrometry are often used. Regardless of the analytical method of choice, some problems regularly occur during sample collection, treatment, storage, and preparation which cause toxin loss and therefore underestimation of the true concentration. To evaluate the potential influence of sample treatment, storage and preparation materials on surface and drinking water samples, the effects of different types of materials on toxin recovery were compared. Collection and storage materials included glass and various types of plastics. It was found that microcystin congeners LA and LF adsorbed to polystyrene, polypropylene, high density polyethylene and polycarbonate storage containers, leading to low recoveries (microcystins, and saxitoxin. This study also demonstrated that after 15 min chlorine decreased the concentration of microcystin LR to microcystin LA and saxitoxin to <15%, therefore quenching of drinking water samples immediately upon sample collection is critical for accurate analysis. In addition, the effect of various drinking water treatment chemicals on toxin recovery and the behavior of those chemicals in the enzyme linked immunosorbent assays were also studied and are summarized.

  8. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    Energy Technology Data Exchange (ETDEWEB)

    Yonghua Zhang

    2002-05-27

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an

  9. Preparation of {sup 183,184}Re samples for modelling a rapid gas phase chemistry of Nielsbohrium (Ns), element 107

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, R.; Gaeggeler, H.W.; Eichler, B.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Chemical gas phase reactions of the heavier group 7 elements in the system O{sub 2}/H{sub 2}O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O{sub 3}/H{sub 2}O{sub 2}. For the experimental verification of this idea we prepared {sup 183}Re/{sup 184}Re samples for thermochromatography experiments with both gas systems. (author) 8 refs.

  10. Automation and integration of multiplexed on-line sample preparation with capillary electrophoresis for DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Tan, H.

    1999-03-31

    The purpose of this research is to develop a multiplexed sample processing system in conjunction with multiplexed capillary electrophoresis for high-throughput DNA sequencing. The concept from DNA template to called bases was first demonstrated with a manually operated single capillary system. Later, an automated microfluidic system with 8 channels based on the same principle was successfully constructed. The instrument automatically processes 8 templates through reaction, purification, denaturation, pre-concentration, injection, separation and detection in a parallel fashion. A multiplexed freeze/thaw switching principle and a distribution network were implemented to manage flow direction and sample transportation. Dye-labeled terminator cycle-sequencing reactions are performed in an 8-capillary array in a hot air thermal cycler. Subsequently, the sequencing ladders are directly loaded into a corresponding size-exclusion chromatographic column operated at {approximately} 60 C for purification. On-line denaturation and stacking injection for capillary electrophoresis is simultaneously accomplished at a cross assembly set at {approximately} 70 C. Not only the separation capillary array but also the reaction capillary array and purification columns can be regenerated after every run. DNA sequencing data from this system allow base calling up to 460 bases with accuracy of 98%.

  11. Comparison of three different sample preparation procedures for the determination of traffic-related elements in airborne particulate matter collected on glass fiber filters.

    Science.gov (United States)

    Castilho, Ivan N B; Welz, Bernhard; Vale, Maria Goreti R; de Andrade, Jailson B; Smichowski, Patricia; Shaltout, Abdallah A; Colares, Lígia; Carasek, Eduardo

    2012-01-15

    Three different procedures for sample preparation have been compared for the determination of Cu, Mo and Sb in airborne particulate matter (APM) collected on glass fiber filters using high-resolution continuum source graphite furnace atomic absorption spectrometry (HR-CS GF AAS). Direct solid sample analysis of the ground filters was compared with microwave-assisted acid leaching with aqua regia and ultrasound-assisted extraction also using aqua regia. The main absorption line at 324.754 nm or the secondary line at 216.509 nm was used for the determination of Cu, depending on the analyte content in the samples. The primary absorption line at 313.259 nm was used for Mo and the secondary line at 212.739 nm for Sb determination. The limits of detection (LOD, 3σ) found for the direct solid sampling method, based on ten atomizations of an unused filter were 15 μg g(-1) for all three analytes, corresponding to 40 ng m(-3) for a typical air volume of 1,440 m(3) collected over a period of 24h. The LOD for the other two methods were less than a factor of two inferior, but the total time required for an analysis was significantly longer. The repeatability of the measurements was between 3 and 9% (n=5), and the results obtained with the three methods did not show any significant difference. The ratio between the three analytes on the filters from areas of intense traffic was found to be around Cu:Mo:Sb≈4:1:1.4, which suggests that the source of all three elements is brake linings, i.e., related to automobile traffic. When the ratio deviated significantly from the above values, the source of contamination was assumed to be of different origin.

  12. Sample preparation for avian and porcine influenza virus cDNA amplification simplified: Boiling vs. conventional RNA extraction.

    Science.gov (United States)

    Fereidouni, Sasan R; Starick, Elke; Ziller, Mario; Harder, Timm C; Unger, Hermann; Hamilton, Keith; Globig, Anja

    2015-09-01

    RNA extraction and purification is a fundamental step that allows for highly sensitive amplification of specific RNA targets in PCR applications. However, commercial extraction kits that are broadly used because of their robustness and high yield of purified RNA are expensive and labor-intensive. In this study, boiling in distilled water or a commercial lysis buffer of different sample matrices containing avian or porcine influenza viruses was tested as an alternative. Real-time PCR (RTqPCR) for nucleoprotein gene fragment was used as read out. Results were compared with freshly extracted RNA by use of a commercial extraction kit. Different batches of virus containing materials, including diluted virus positive allantoic fluid or cell culture supernatant, and avian faecal, cloacal or oropharyngeal swab samples were used in this study. Simple boiling of samples without any additional purification steps can be used as an alternative RNA preparation method to detect influenza A virus nucleoprotein RNA in oropharyngeal swab samples, allantoic fluid or cell-culture supernatant. The boiling method is not applicable for sample matrices containing faecal material. Copyright © 2015 Elsevier B.V. All rights reserved.

  13. Filter-aided sample preparation with dimethyl labeling to identify and quantify milk fat globule membrane proteins.

    Science.gov (United States)

    Lu, Jing; Boeren, S; de Vries, S C; van Valenberg, H J F; Vervoort, J; Hettinga, K

    2011-12-10

    Bovine milk is a major nutrient source in many countries and it is produced at an industrial scale. Milk is a complex mixture of proteins, fats, carbohydrates, vitamins and minerals. The composition of the bovine milk samples can vary depending on the genetic makeup of the bovine species as well as environmental factors. It is therefore important to study the qualitative and quantitative differences of bovine milk samples. Proteins in milk can be present in casein micelles, in the serum (the water soluble fraction) or in fat globules. These fat globules have a double membrane layer with proteins being bound to or being incapsulated in the membrane layer. The identification and molecular composition of the milk proteins have gained increased interest in recent years. Proteomic techniques make it now possible to identify up to many thousands of proteins in one sample, however quantification of proteins is as yet not straightforward. We analyzed the proteins of the milk fat globule membrane using dimethyl labeling methods combined with a filter-aided sample preparation protocol. Using these methods, it is now possible to quantitatively study the detailed protein composition of many milk samples in a short period of time. Copyright © 2011 Elsevier B.V. All rights reserved.

  14. Effects of first-dose volume and exercise on the efficacy and tolerability of bowel preparations for colonoscopy in Chinese people

    Directory of Open Access Journals (Sweden)

    Qin Y

    2016-04-01

    Full Text Available Ying Qin, Wei Liu, Songbai Lin, Xiangfeng Li International Medical Services, Peking Union Medical College Hospital, Beijing, People’s Republic of China Aim: This study was designed to compare the efficacy and tolerability of bowel preparations with and without the higher first-dose volume of polyethylene glycol (PEG solution or exercise after drinking PEG solution in Chinese people. Methods: A total of 330 participants who had a colonoscopy done in Peking Union Medical College Hospital were randomly and evenly assigned to three groups. Participants in Group A ingested 1 L PEG solution and then ingested 2 L PEG solution at a rate of 250 mL every 15 minutes. Participants in Group B ingested 3 L PEG solution at a rate of 250 mL every 15 minutes and then exercised more than 10 minutes after ingesting each liter of PEG solution. Participants in Group C ingested 3 L PEG solution at a rate of 250 mL every 15 minutes. Experienced gastrointestinal endoscopists rated the efficacy of bowel preparations based on the Boston Bowel Preparation Scale score. A questionnaire regarding participants’ symptoms associated with bowel preparations was administered to evaluate participants’ tolerability. Results: The three groups had insignificant difference in the percentages of participants’ symptoms including dizziness, nausea, stomach ache, bloating, and asthenia. However, the percentages of participants having hunger sensation, sleep disturbance, and anal discomfort were significantly higher in groups with the higher first-dose volume of PEG solution or exercise after drinking PEG solution than without them. The three groups had insignificant difference in the Boston Bowel Preparation Scale score. Conclusion: Whether to add the higher first-dose volume of PEG solution and exercise after drinking PEG solution or not, all participants achieved a similar quality of bowel preparations. Bowel preparations without the additional first-dose volume of PEG

  15. NMR-based metabolomics: from sample preparation to applications in nutrition research.

    Science.gov (United States)

    Brennan, Lorraine

    2014-11-01

    Metabolomics is the study of metabolites present in biological samples such as biofluids, tissue/cellular extracts and culture media. Measurement of these metabolites is achieved through use of analytical techniques such as NMR and mass spectrometry coupled to liquid chromatography. Combining metabolomic data with multivariate data analysis tools allows the elucidation of alterations in metabolic pathways under different physiological conditions. Applications of NMR-based metabolomics have grown in recent years and it is now widely used across a number of disciplines. The present review gives an overview of the developments in the key steps involved in an NMR-based metabolomics study. Furthermore, there will be a particular emphasis on the use of NMR-based metabolomics in nutrition research. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Wang--Landau algorithm for entropic sampling of arch-based microstates in the volume ensemble of static granular packings

    Directory of Open Access Journals (Sweden)

    D. Slobinsky

    2015-03-01

    Full Text Available We implement the Wang-Landau algorithm to sample with equal probabilities the static configurations of a model granular system. The "non-interacting rigid arch model" used is based on the description of static configurations by means of splitting the assembly of grains into sets of stable arches. This technique allows us to build the entropy as a function of the volume of the packing for large systems. We make a special note of the details that have to be considered when defining the microstates and proposing the moves for the correct sampling in these unusual models. We compare our results with previous exact calculations of the model made at moderate system sizes. The technique opens a new opportunity to calculate the entropy of more complex granular models. Received: 19 January 2015, Accepted: 25 February 2015; Reviewed by: M. Pica Ciamarra, Nanyang Technological University, Singapore; Edited by: C. S. O'Hern; DOI: http://dx.doi.org/10.4279/PIP.070001 Cite as: D Slobinsky, L A Pugnaloni, Papers in Physics 7, 070001 (2015

  17. Preparation of a Ag-doped Bi-Sr-Ca-Cu-O bulk sample by the floating-zone method

    Science.gov (United States)

    Kubo, Yukio; Michishita, Kazuo; Shimizu, Noriyuki; Higashida, Yutaka; Yokoyama, Hisanori

    1989-11-01

    Bulk samples with nominal composition of Bi2Sr2CaCu2O(y) doped with 0, 10 and 20 wt pct Ag were prepared by the floating-zone method at growth rates of 2 mm/h and 5 mm/h. Ag-doping seems to slightly enhance J(c) while annealing is very effective for J(c) enhancement. From preliminary ac susceptibility measurements, the J(c) enhancement by annealing is considered to be due to improvement of the weak link between superconducting grains. The 10 percent Ag-doped sample grown at 2 mm/h possessed J(c) of 5360 A/sq cm at 77 K under zero magnetic field after annealing.

  18. Preparation of high J(c) Bi-Sr-Ca-Cu-O bulk sample by floating zone method

    Science.gov (United States)

    Kubo, Yukio; Michishita, Kazuo; Higashida, Yutaka; Mizuno, Masatoshi; Yokoyama, Hisanori

    1989-04-01

    Bi-Sr-Ca-Cu-O bulk samples with three different nominal compositions of Bi2Sr2CaCu2O(y) Bi2Sr2Ca2Cu3O(y) and Bi(0.7)Pb(0.3)SrCaCu(1.8)O(y) were prepared by the floating zone method at growth rates ranging from 2 mm/h to 70 mm/h. The sample grown at 2 mm/h with the nominal composition of Bi2Sr2CaCu2O(y) possessed high density, highly aligned morphology, and a transport critical current density higher than 1490 A/sq cm at 77 K under a zero magnetic field without any postannealing.

  19. Sample preparation followed by HPLC under harmless 100% aqueous conditions for determination of oxytetracycline in milk and eggs.

    Science.gov (United States)

    Furusawa, Naoto

    2004-05-01

    A simple and hazardous chemical-free method for the high-performance liquid chromatographic determination of oxytetracycline (OTC) residues in milk and eggs has been developed. Sample preparation consists in homogenization with an aqueous solution by means of a handheld ultrasonic homogenizer followed by centrifugal ultrafiltration. HPLC is performed with an isocratic aqueous mobile phase and a photodiode array detector. Average recoveries of OTC (0.05, 0.1, and 0.2 microg mL(-1) for milk; 0.1, 0.2, and 0.4 microg mL(-1) for eggs) were > or =84% with relative standard deviations of < or =2.3%. The total time required for the analysis of one sample and LOQs were <30 min and <0.1 microg mL(-1), respectively. In all the processes, no organic solvents or hazardous reagents were used.

  20. Dynamics of volume of competition practice and facilities of training of jumpers in length and triple in the process of long-term preparation

    Directory of Open Access Journals (Sweden)

    Sovenko S.P.

    2012-12-01

    Full Text Available Analysed and systematized information in relation to the volume of competition practice and facilities of different primary orientation of jumpers in length and triple in the process of long-term preparation. The expert questioning is conducted 16 trainers. The documents of planning of training process are analysed, the analysis of diaries of sportsmen is carried out (n=22. The volume of competition practice of sportsmen and facilities of training of different primary orientation is certain. The results of analysis in relation to the construction of training process are reflected by the leading trainers of Ukraine on track-and-field. An approach classification of facilities of training taking into account the specific of training process of sportsmen is presented. It is set that the volume of facilities of general preparation is most on the initial stages of long-term perfection, then stabilized on the stages specialized base and preparations to higher achievements and a few diminishes on maximal implementation of individual possibilities and maintainance of higher sporting trade phases. It is related to diminishing of duration of the general preparatory stages of annual preparation.

  1. Respiratory Allergy and Inflammation Due to Ambient Particles (RAIAP) Collection of Particulate Matter samples from 5 European sites with High Volume Cascade Impactors

    NARCIS (Netherlands)

    Cassee FR; Fokkens PHB; Leseman DLAC; Bloemen HJTh; Boere AJF; MGO

    2003-01-01

    The aim of this deliverable was to perform an European-wide collection of particulate samples. With the aid of two high-volume Cascade impactor (HVCI), coarse (2.5-10 mu m ) and fine (0.1-2.5 mu m) particulate samples were collected in Amsterdam, Lodz, Oslo, Rome and the Dutch sea-side (De Zilk) dur

  2. Respiratory Allergy and Inflammation Due to Ambient Particles (RAIAP) Collection of Particulate Matter samples from 5 European sites with High Volume Cascade Impactors

    NARCIS (Netherlands)

    Cassee FR; Fokkens PHB; Leseman DLAC; Bloemen HJTh; Boere AJF; MGO

    2003-01-01

    The aim of this deliverable was to perform an European-wide collection of particulate samples. With the aid of two high-volume Cascade impactor (HVCI), coarse (2.5-10 mu m ) and fine (0.1-2.5 mu m) particulate samples were collected in Amsterdam, Lodz, Oslo, Rome and the Dutch sea-side (De Zilk)

  3. EMPCA and Cluster Analysis of Quasar Spectra: Sample Preparation and Validation

    Science.gov (United States)

    Wagner, Cassidy; Leighly, Karen; Macinnis, Francis; Marrs, Adam; Richards, Gordon T.

    2017-01-01

    All quasars are fundamentally similar, powered by accretion of matter onto a super massive black hole. However, patterns of differences can be identified through the emission lines. Quasar broad absorption lines have been postulated to be responsible for feedback in galaxy evolution. Principal component analysis (PCA) quantifies trends in emission lines of quasars that can be used to predict and reconstruct the underlying continuum in broad absorption line quasars.Richards et al. 2011 hypothesized that emission-line variance across the rest-UV spectrum is correlated with C IV blueshift and equivalent width. We fit their composite spectra, constructed based on these properties, to identify trends for the purpose of creating simulated spectra to test the weighted Expectation Maximization PCA (EMPCA; Bailey 2012) and cluster analysis method discussed in adjacent poster by Marrs et al.More than 800 SDSS spectra from Allen et al. 2011, with a redshift range of z = 2.2 - 2.3, were selected for analysis, particularly spectra with high signal to noise ratios, without broad absorption lines, and without numerous narrow absorption lines. Interstellar and intergalactic absorption lines add variance that contaminates the principal components. To remove these lines, we smoothed the spectra using a Fourier transform and a low-pass filter. We then used a line-finding and -removal program to remove or flag narrow absorption lines. From the principal components that resulted from the PCA analysis we were able to reconstruct the continua of a small sample of BAL QSOs.

  4. Accelerating sample preparation through enzyme-assisted microfiltration of Salmonella in chicken extract.

    Science.gov (United States)

    Vibbert, Hunter B; Ku, Seockmo; Li, Xuan; Liu, Xingya; Ximenes, Eduardo; Kreke, Thomas; Ladisch, Michael R; Deering, Amanda J; Gehring, Andrew G

    2015-01-01

    Microfiltration of chicken extracts has the potential to significantly decrease the time required to detect Salmonella, as long as the extract can be efficiently filtered and the pathogenic microorganisms kept in a viable state during this process. We present conditions that enable microfiltration by adding endopeptidase from Bacillus amyloliquefaciens to chicken extracts or chicken rinse, prior to microfiltration with fluid flow on both retentate and permeate sides of 0.2 μm cutoff polysulfone and polyethersulfone hollow fiber membranes. After treatment with this protease, the distribution of micron, submicron, and nanometer particles in chicken extracts changes so that the size of the remaining particles corresponds to 0.4-1 μm. Together with alteration of dissolved proteins, this change helps to explain how membrane fouling might be minimized because the potential foulants are significantly smaller or larger than the membrane pore size. At the same time, we found that the presence of protein protects Salmonella from protease action, thus maintaining cell viability. Concentration and recovery of 1-10 CFU Salmonella/mL from 400 mL chicken rinse is possible in less than 4 h, with the microfiltration step requiring less than 25 min at fluxes of 0.028-0.32 mL/cm(2) min. The entire procedure-from sample processing to detection by polymerase chain reaction-is completed in 8 h.

  5. Evaluation of methods to prepare samples of leafy green vegetables for preenrichment with the Bacteriological Analytical Manual Salmonella culture method.

    Science.gov (United States)

    Jacobson, Andrew Patrick; Gill, Vikas Singh; Irvin, Kari Anne; Wang, Hua; Hammack, Thomas Seyliard

    2012-02-01

    Three sample preparation procedures, soak, stomach, and blend, were evaluated using the Bacteriological Analytical Manual Salmonella culture method with eight types of leafy green produce. In the soak method, test portions were added to lactose broth without homogenization; in the stomach method, test portions were stomached with lactose broth; and in the blend method, test portions were blended with lactose broth. Twenty artificially contaminated test portions were analyzed with each procedure in individual experimental trials. The number of test portions identified as positive were compared among the procedures. Statistically significant differences were identified with Fisher's exact two-tailed F test (P < 0.05). Where differences did occur (P < 0.05), the soak procedure was the most effective or was at least as effective as homogenization by either blending or stomaching. Statistically significant differences most frequently occurred with romaine lettuce and cabbage; for these items, blending was significantly less effective than the soak procedure. Overall, for all of the produce types examined, results showed that the soak procedure was more effective than either of the homogenization procedures in recovering Salmonella from leafy green produce. Of the 540 test portions examined by each sample preparation method, 344 were positive for the presence of Salmonella by soaking, 293 by stomaching, and 232 by blending. We recommend that the soak procedure replace homogenization for the analysis of leafy green produce because the soak procedure is more productive than homogenization by either blending or stomaching of the leafy green produce types as reported herein.

  6. The beauty of being (label)-free: sample preparation methods for SWATH-MS and next-generation targeted proteomics

    Science.gov (United States)

    Campbell, Kate; Deery, Michael J.; Lilley, Kathryn S.; Ralser, Markus

    2014-01-01

    The combination of qualitative analysis with label-free quantification has greatly facilitated the throughput and flexibility of novel proteomic techniques. However, such methods rely heavily on robust and reproducible sample preparation procedures. Here, we benchmark a selection of in gel, on filter, and in solution digestion workflows for their application in label-free proteomics. Each procedure was associated with differing advantages and disadvantages. The in gel methods interrogated were cost effective, but were limited in throughput and digest efficiency. Filter-aided sample preparations facilitated reasonable processing times and yielded a balanced representation of membrane proteins, but led to a high signal variation in quantification experiments. Two in solution digest protocols, however, gave optimal performance for label-free proteomics. A protocol based on the detergent RapiGest led to the highest number of detected proteins at second-best signal stability, while a protocol based on acetonitrile-digestion, RapidACN, scored best in throughput and signal stability but came second in protein identification. In addition, we compared label-free data dependent (DDA) and data independent (SWATH) acquisition on a TripleTOF 5600 instrument. While largely similar in protein detection, SWATH outperformed DDA in quantification, reducing signal variation and markedly increasing the number of precisely quantified peptides. PMID:24741437

  7. Investigation of the sample preparation and curing treatment effects on mechanical properties and bioactivity of silica rich metakaolin geopolymer.

    Science.gov (United States)

    Catauro, M; Bollino, F; Papale, F; Lamanna, G

    2014-03-01

    In many biomedical applications both the biological and mechanical behaviours of implants are of relevant interest; in the orthopaedic field, for example, favourable bioactivity and biocompatibility capabilities are necessary, but at the same time the mechanical characteristics of the implants must be such as to allow one to support the body weight. In the present work, the authors have examined the application of geopolymers with composition H24AlK7Si31O79 and ratio Si/Al=31 to be used in biomedical field, considering two different preparation methods: one of the activators (KOH) has been added as pellets in the potassium silicate solution, in the other as a water solution with 8M concentration. Moreover, a different water content was used and only some of the synthesized samples were heat treated. The chemical and microstructural characterizations of those materials have been carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Subsequently, the effects of the adopted preparation on the mechanical and biological properties have been studied: compressive strength tests have demonstrated that more fragile specimens were obtained when KOH was added as a solution. The bioactivity was successfully evaluated with the soaking of the samples in a simulated body fluid (SBF) for 3 weeks. The formation of a layer of hydroxyapatite on the surface of the materials has been shown both by SEM micrographs and EDS analyses.

  8. Matrix-assisted laser desorption/ionization sample preparation optimization for structural characterization of poly(styrene-co-pentafluorostyrene) copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Tisdale, Evgenia; Kennedy, Devin; Wilkins, Charles, E-mail: cwilkins@uark.edu

    2014-01-15

    Graphical abstract: -- Highlights: •We optimized sample preparation for MALDI TOF poly(styrene-copentafluorostyrene) co-polymers. •Influence of matrix choice was investigated. •Influence of matrix/analyte ratio was examined. •Influence of analyte/salt ratio (for Ag+ salt) was studied. -- Abstract: The influence of the sample preparation parameters (the choice of the matrix, matrix:analyte ratio, salt:analyte ratio) was investigated and optimal conditions were established for the MALDI time-of-flight mass spectrometry analysis of the poly(styrene-co-pentafluorostyrene) copolymers. These were synthesized by atom transfer radical polymerization. Use of 2,5-dihydroxybenzoic acid as matrix resulted in spectra with consistently high ion yields for all matrix:analyte:salt ratios tested. The optimized MALDI procedure was successfully applied to the characterization of three copolymers obtained by varying the conditions of polymerization reaction. It was possible to establish the nature of the end groups, calculate molecular weight distributions, and determine the individual length distributions for styrene and pentafluorostyrene monomers, contained in the resulting copolymers. Based on the data obtained, it was concluded that individual styrene chain length distributions are more sensitive to the change in the composition of the catalyst (the addition of small amount of CuBr{sub 2}) than is the pentafluorostyrene component distribution.

  9. Extraction chromatographic methods in the sample preparation sequence for thermal ionization mass spectrometric analysis of plutonium isotopes.

    Science.gov (United States)

    Grate, Jay W; O'Hara, Matthew J; Farawila, Anne F; Douglas, Matthew; Haney, Morgan M; Petersen, Steven L; Maiti, Tapas C; Aardahl, Christopher L

    2011-12-01

    A sample preparation sequence for actinide isotopic analysis by thermal ionization mass spectrometry (TIMS) is described that includes column-based extraction chromatography as the first separation step, followed by anion-exchange column separations. The sequence is designed to include a wet ashing step after the extraction chromatography to prevent any leached extractant or oxalic acid eluent reagents from interfering with subsequent separations, source preparation, or TIMS ionization. TEVA resin and DGA resin materials, containing extractants that consist only of C, N, O, and H atoms, were investigated for isolation of plutonium. Radiotracer level studies confirmed expected high yields from column-based separation procedures. Femtogram-level studies were carried out with TIMS detection, using multiple monoisotopic spikes applied sequentially throughout the separation sequence. Pu recoveries were 87% and 86% for TEVA and DGA resin separations, respectively. The Pu recoveries from 400 μL anion-exchange column separation sequences were 89% and 93% for trial sequences incorporating TEVA and DGA resin. Thus, a prior extraction chromatography step in the sequence did not interfere with the subsequent anion-exchange separation when a simple wet ash step was carried out in between these column separations. The average measurement efficiency for Pu, encompassing the chemical separation recoveries and the TIMS ionization efficiency, was 2.73% ± 0.77% (2σ) for the DGA resin trials and 2.67% ± 0.54% for the TEVA resin trials, compared to 3.41% and 2.37% (average 2.89%) for two control trials. These compare with an average measurement efficiency of 2.78% ± 1.70%, n = 33 from process benchmark analyses using Pu spikes processed through a sequence of oxalate precipitation, wet ash, iron hydroxide precipitation, and anion-exchange column separations. We conclude that extraction chromatography can be a viable separation procedure as part of a multistep sequence for TIMS

  10. The Evolution of P-wave Velocity in Fault Gouge: Initial Results for Samples from the SAFOD Volume.

    Science.gov (United States)

    Knuth, M. W.; Tobin, H. J.; Marone, C.

    2008-12-01

    We present initial results from a new technique for observing the evolution of elastic properties in sheared fault zone materials via acoustic wave velocity. The relationship between the mechanical strength of fault gouge and acoustic velocity during active deformation has important implications not only for a physical understanding of elasticity in deforming granular media, but also for the interpretation of the seismic velocity at the field scale. Experiments are conducted at atmospheric temperature and saturation state in a double-direct-shear testing apparatus, with normal stress stepped from 1 to 19 MPa to interrogate behavior during compaction, and sheared at a rate of 10 microns/second to observe changes in velocity with increasing strain. Tests are divided between those involving continuous shear to a displacement of 22.5 mm, and those with intervals of 3.75 mm shear separated by unloading and reloading sequences in normal stress. Velocity is measured by time-of-flight between two piezoelectric P-wave transducers set into the sample configuration on either side of the shearing layers. Samples tested include common laboratory standards for simulated fault gouge and field samples taken from representative localities in the 3D rock volume containing the San Andreas Fault Observatory at Depth experiment in Parkfield, California. The velocities of sand and clay end-member gouges are observed to behave differently under shear, and mixtures of quartz sand and montmorillonite behave differently from both end-member materials. Initial results suggest that particle sorting exerts a strong influence on both the absolute velocity and the evolution of velocity in response to increasing shear strain where the elastic properties of the grains are similar. We also observe a first-order relationship between the coefficient of friction and P-wave velocity that appears to be related to grain reorganization at the onset of shear following initial compaction.

  11. High-resolution liquid- and solid-state nuclear magnetic resonance of nanoliter sample volumes using microcoil detectors

    Science.gov (United States)

    Kentgens, A. P. M.; Bart, J.; van Bentum, P. J. M.; Brinkmann, A.; van Eck, E. R. H.; Gardeniers, J. G. E.; Janssen, J. W. G.; Knijn, P.; Vasa, S.; Verkuijlen, M. H. W.

    2008-02-01

    The predominant means to detect nuclear magnetic resonance (NMR) is to monitor the voltage induced in a radiofrequency coil by the precessing magnetization. To address the sensitivity of NMR for mass-limited samples it is worthwhile to miniaturize this detector coil. Although making smaller coils seems a trivial step, the challenges in the design of microcoil probeheads are to get the highest possible sensitivity while maintaining high resolution and keeping the versatility to apply all known NMR experiments. This means that the coils have to be optimized for a given sample geometry, circuit losses should be avoided, susceptibility broadening due to probe materials has to be minimized, and finally the B1-fields generated by the rf coils should be homogeneous over the sample volume. This contribution compares three designs that have been miniaturized for NMR detection: solenoid coils, flat helical coils, and the novel stripline and microslot designs. So far most emphasis in microcoil research was in liquid-state NMR. This contribution gives an overview of the state of the art of microcoil solid-state NMR by reviewing literature data and showing the latest results in the development of static and micro magic angle spinning (microMAS) solenoid-based probeheads. Besides their mass sensitivity, microcoils can also generate tremendously high rf fields which are very useful in v