WorldWideScience

Sample records for sample preparation procedures

  1. 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.

  2. Comparison of sample preparation procedures on metal(loid) fractionation patterns in lichens.

    Science.gov (United States)

    Kroukamp, E M; Godeto, T W; Forbes, P B C

    2017-08-13

    The effects of different sample preparation strategies and storage on metal(loid) fractionation trends in plant material is largely underresearched. In this study, a bulk sample of lichen Parmotrema austrosinense (Zahlbr.) Hale was analysed for its total extractable metal(loid) content by ICP-MS, and was determined to be adequately homogenous (82% for As, Cu, Mn, Pb, Sr and Zn but poor for other elements, where sample preparation strategies 'no sample preparation' and 'dried in a desiccator' had the best extraction recoveries. Cryogenic freezing procedures had a significantly (p lichens. Biotransformation over a period of a month is suspected for most elements, with the exception of Sr and Zn, where changes in the fractionation patterns were statistically significant (p < 0.05), indicating the need for minimal delay in sample cleaning and preservation when species fractionation patterns are of interest. This study also shows that the assumption that species stability can be ensured through cryopreservation and freeze drying techniques needs to be revisited.

  3. 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.

  4. Protocol: MYTHBUSTERS: a universal procedure for sample preparation for mass spectrometry.

    Science.gov (United States)

    Drabik, Anna; Ner-Kluza, Joanna; Bodzon-Kulakowska, Anna; Suder, Piotr

    Improvements in proteomic strategies from the development of new and robust separation and identification techniques have led to broad applications of proteomics to solve numerous biological questions. For all analyses, sample quality is unquestionably a critical factor; therefore protein extraction is of outmost importance. The ideal extraction method should provide reproducible spectra of the most comprehensive repertoire of proteins, while minimizing sample loss and degradation. It is already known that to capture the whole proteome is an unenforceable task. Many protein extraction protocols have been described, yet there is no "one perfect procedure" taking into account the vast diversity of biological and physical properties of proteins, including their charge, size, hydrophobicity, interactions and sub-cellular localization. The research presented here reflects the main obstacle occurring in proteomic experimental design; i.e. the lack of reproducibility as a result of alterations in protein extraction methods. We have performed a series of experiments, aimed towards identification of the aptamer-binding partners in cancerous cells. Aptamers are chemically synthesized, short, single-stranded nucleic acids with a strictly defined three-dimensional structure, which allows them to interact with a target molecule with high affinity. The low immunogenicity and cellular- targeting properties of aptamers might facilitate design of suitable drugs with low side-effects. Aptamers can be used for identification of molecules associated with a pathogenic state of a cell. Aptamers can be considered as a powerful tool, since they possess unique properties to benefit cancer diagnosis, prevention and treatment. We have used different types of protein extraction methods prior to analyses of complex biological samples by mass spectrometry, based on slight changes of homogenization buffers, and have observed the changes in the identified compounds. These results should prove to

  5. An investigation into the sample preparation procedure and analysis of cyanoacrylate adhesives using capillary electrophoresis

    OpenAIRE

    Whitaker, Gillian; Kincaid, Brendan J.; Van Hoof, Nicole; Regan, Fiona; Smyth, Malcolm R.; Leonard, Raymond G.

    2007-01-01

    In this study, the trace acid profile of cyanoacrylate adhesives was studied using capillary electrophoresis. Liquid–liquid extraction was employed as the sample preparation step before separation by capillary electrophoresis. The solubility of the adhesives was investigated using various organic solvents, e.g. hexane and dichloromethane, and chloroform was determined to be the optimum solvent as it enabled the full dissolution of the adhesive. A comprehensive stability study was performed ov...

  6. Investigation of propofol renal elimination by HPLC using supported liquid membrane procedure for sample preparation.

    Science.gov (United States)

    Dawidowicz, Andrzej L; Kalityński, Rafał; Trocewicz, Jerzy; Nestorowicz, Andrzej; Fijałkowska, Anna; Trela-Stachurska, Katarzyna

    2002-10-01

    One of the least explored subjects in the research on the metabolism of a widely used anaesthetic, propofol, is its excretion in an unchanged form. According to literature, the estimated percentage of applied propofol eliminated intact via kidneys is lower than 0.3%. The present study shows the amount of propofol excreted in an unchanged form with urine collected during the first 48 h after anaesthesia in five patients undergoing elective intracranial procedures. The drug was concentrated and selectively isolated from urine samples by supported liquid membrane technique and determined by HPLC with fluorescence detection. The amount of unchanged propofol eliminated with urine was approximately (0.004 +/- 0.002)% of the total applied dose. The obtained results may suggest that propofol in an unchanged form is not excreted by kidneys at all provided that all propofol determined in presented study originated from conjugates hydrolysis. Copyright 2002 John Wiley & Sons, Ltd.

  7. Toddler test or procedure preparation

    Science.gov (United States)

    Preparing toddler for test/procedure; Test/procedure preparation - toddler; Preparing for a medical test or procedure - toddler ... Before the test, know that your child will probably cry. Even if you prepare, your child may feel some discomfort or ...

  8. Preschooler test or procedure preparation

    Science.gov (United States)

    Preparing preschoolers for test/procedure; Test/procedure preparation - preschooler ... Preparing children for medical tests can reduce their anxiety. It can also make them less likely to cry and resist the procedure. Research shows that ...

  9. Optimized pre-thinning procedures of ion-beam thinning for TEM sample preparation by magnetorheological polishing.

    Science.gov (United States)

    Luo, Hu; Yin, Shaohui; Zhang, Guanhua; Liu, Chunhui; Tang, Qingchun; Guo, Meijian

    2017-10-01

    Ion-beam-thinning is a well-established sample preparation technique for transmission electron microscopy (TEM), but tedious procedures and labor consuming pre-thinning could seriously reduce its efficiency. In this work, we present a simple pre-thinning technique by using magnetorheological (MR) polishing to replace manual lapping and dimpling, and demonstrate the successful preparation of electron-transparent single crystal silicon samples after MR polishing and single-sided ion milling. Dimples pre-thinned to less than 30 microns and with little mechanical surface damage were repeatedly produced under optimized MR polishing conditions. Samples pre-thinned by both MR polishing and traditional technique were ion-beam thinned from the rear side until perforation, and then observed by optical microscopy and TEM. The results show that the specimen pre-thinned by MR technique was free from dimpling related defects, which were still residual in sample pre-thinned by conventional technique. Nice high-resolution TEM images could be acquired after MR polishing and one side ion-thinning. MR polishing promises to be an adaptable and efficient method for pre-thinning in preparation of TEM specimens, especially for brittle ceramics. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. A Loop-Mediated Isothermal Amplification Assay and Sample Preparation Procedure for Sensitive Detection of Xanthomonas fragariae in Strawberry

    Science.gov (United States)

    Wang, Hehe; Turechek, William W.

    2016-01-01

    Xanthomonas fragariae is a bacterium that causes angular leaf spot of strawberry. Asymptomatic infection is common and contributes to the difficulties in disease management. The aim of this study was to develop a loop-mediated isothermal amplification (LAMP) assay as an efficient method for detection of asymptomatic infections of X. fragariae. In addition, a new method of sample preparation was developed that allows sampling of a larger amount of plant tissue, hence increasing the detection rate in real-life samples. The sample preparation procedure includes an overnight incubation of strawberry tissues in phosphate-buffered saline (PBS), followed by a quick sample concentration and a boiling step to extract DNA for amplification. The detection limit of the LAMP assay was approximately 2×103 CFU/mL for pure bacteria culture and 300 CFU/mL for bacteria spiked strawberry leaf and petiole samples. LAMP provided a 2–3 fold lower detection limit than the standard qPCR assay but was faster, and more user-friendly. The LAMP assay should serve as a rapid, sensitive and cost-effective tool for detecting asymptomatic infections of X. fragariae in strawberry nursery stock and contribute to improved disease management. PMID:26766068

  11. 9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

    Science.gov (United States)

    2010-01-01

    ... samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... a representative sample of 30 eggs collected from a single day's production from the flock, must be... IgG antibodies set forth for testing serum in § 147.7 (for these tests the resultant supernatant...

  12. Avaliação de procedimentos de preparo de amostra de amendoim in natura para análise de aflatoxinas Evaluation of sample preparation procedures for aflatoxin analysis in raw peanut

    Directory of Open Access Journals (Sweden)

    Maria Antonia Calori-Domingues

    2010-01-01

    Full Text Available The variability in aflatoxin B1 concentration among peanut subsamples of 4 sample preparation procedures was evaluated. For each procedure, 18 samples were prepared involving dry comminuting/homogenization or dry roughly comminuting followed by the preparation of a aqueous slurry. Ten analytical samples were withdrawn from each sample/procedure and analyzed by thin layer chromatography. The coefficient of variation (CV% among each set of 10 analytical samples was assumed to be associated with the sample preparation procedure. The procedure that made use of a subsample mill and preparation of a subsample slurry, showed lower variability (CV% among the analytical subsamples.

  13. Sample preparation and data interpretation procedures for the examination of xenobiotic compounds in skin by indirect imaging MALDI-MS

    Science.gov (United States)

    Prideaux, Brendan; Atkinson, Sally J.; Carolan, Vikki A.; Morton, Jacqueline; Clench, Malcolm R.

    2007-02-01

    Aspects of the indirect examination of xenobiotic distribution on the surface of and within skin sections by imaging matrix assisted laser desorption ionisation mass spectrometry (MALDI-MS) have been examined. A solvent assisted blotting technique previously developed for the examination of the absorption of agrochemicals into leaves has been examined for the analysis of the distribution of hydrocortisone on the surface of skin. It was found that by careful control of the extraction and blotting procedure an 80-fold sensitivity improvement could by obtained over dry blotting with only 10% lateral diffusion of the image. However, in contrast it was found that the use of a hydrophobic blotting membrane was more suitable for the examination of the transdermal absorption of the pesticide chlorpyrifos. The potential of incorporating a derivatisation step into the solvent assisted blotting procedure was investigated by blotting isocyanate treated skin onto a methanol soaked blotting membrane. This served the dual purpose of derivatising the isocyanate to a stable substituted urea derivative and extracting it from the skin. Preliminary data indicate that this approach may have some merit for field sampling for such compound and clearly derivatisation also offers the potential for sensitivity enhancements. Finally, the use of principal components analysis with an ion species specific normalisation procedure is proposed to identify regions of drug treated skin where the ion abundance of the compound of interest is low.

  14. EFFECTIVE PROCEDURES FOR EXECUTIVE'S PREPARATION

    Directory of Open Access Journals (Sweden)

    Elisabet Martínez Mondéjar

    2014-05-01

    The aim of this article is to present methodological procedure that facilitates the executives  work with teachers that are preparing themselves to by promoting post from their  workplace from  a manual directed towards counseling executives  on how to develop the focalization, the selection and the evaluation and promotion of its teachers that are preparing themselves to by promoting post  from the work system itself  of the different levels of management from the University of Pedagogical Sciences " Felix Varela Morales " of Villa Clara.

  15. Frontally eluted components procedure with thin layer chromatography as a mode of sample preparation for high performance liquid chromatography quantitation of acetaminophen in biological matrix.

    Science.gov (United States)

    Klimek-Turek, A; Sikora, M; Rybicki, M; Dzido, T H

    2016-03-04

    A new concept of using thin-layer chromatography to sample preparation for the quantitative determination of solute/s followed by instrumental techniques is presented Thin-layer chromatography (TLC) is used to completely separate acetaminophen and its internal standard from other components (matrix) and to form a single spot/zone containing them at the solvent front position (after the final stage of the thin-layer chromatogram development). The location of the analytes and internal standard in the solvent front zone allows their easy extraction followed by quantitation by HPLC. The exctraction procedure of the solute/s and internal standard can proceed from whole solute frontal zone or its part without lowering in accuracy of quantitative analysis. Copyright © 2016 Elsevier B.V. All rights reserved.

  16. Sample Preparation of Nano-sized Inorganic Materials for Scanning Electron Microscopy or Transmission Electron Microscopy: Scientific Operating Procedure SOP-P-2

    Science.gov (United States)

    2015-07-01

    sample. Nano- sized particles have a tendency to agglomerate during sample preparation. ERDC/GSL SR-15-1 4 3 Scope This SOP is used to determine the...conductive vs. nonconductive samples. The preparation of nanomaterial samples for imaging can be challenging as these materials tend to agglomerate or...aggregated or agglomerated samples. Another way is to extract the material from the liquid. In selected cases, imaging of the nanoparticles is aided

  17. A solid phase extraction procedure for the simultaneous determination of total inorganic arsenic and trace metals in seawater: Sample preparation for total-reflection X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Staniszewski, B. [Department of Analytical Chemistry, Faculty of Chemistry, Adam Mickiewicz University, Grunwaldzka 6, 60-780 Poznan (Poland)], E-mail: bstanisz@amu.edu.pl; Freimann, P. [Bundesamt fuer Seeschifffahrt und Hydrographie, Wuestland 2, 22589 Hamburg (Germany)], E-mail: peter.freimann@bsh.de

    2008-11-15

    In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As{sup +3} with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L{sup -1}.

  18. A solid phase extraction procedure for the simultaneous determination of total inorganic arsenic and trace metals in seawater: Sample preparation for total-reflection X-ray fluorescence

    Science.gov (United States)

    Staniszewski, B.; Freimann, P.

    2008-11-01

    In this paper we present a procedure allowing total-reflection X-ray fluorescence spectrometry (TXRF) determinations of arsenic in water samples, especially in seawater samples. The procedure consists of an arsenate reduction step (performed by using a L-cysteine solution) followed by a complexation of As +3 with sodium dibenzyldithiocarbamate and solid phase extraction. The new procedure is a modification of a method developed by Prange and allows a simultaneous determination of As together with V, Fe, Ni, Cu, Zn, Pb, and U in seawater by TXRF. The procedure was tested using the Certified Reference Material CASS-4 and was later applied to regular seawater samples collected from the North Sea. The detection limit for arsenic is 10 ng L - 1 .

  19. Adolescent test or procedure preparation

    Science.gov (United States)

    ... for a medical test or procedure can reduce anxiety, encourage cooperation, and help your teen develop coping skills. ... to be there. Do not show your own anxiety. Looking anxious will make your adolescent more upset and worried. Research suggests that children ...

  20. 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.

  1. Microextraction by Packed Sorbent (MEPS) and Solid-Phase Microextraction (SPME) as Sample Preparation Procedures for the Metabolomic Profiling of Urine

    OpenAIRE

    Catarina Silva; Carina Cavaco; Rosa Perestrelo; Jorge Pereira; José S. Câmara

    2014-01-01

    For a long time, sample preparation was unrecognized as a critical issue in the analytical methodology, thus limiting the performance that could be achieved. However, the improvement of microextraction techniques, particularly microextraction by packed sorbent (MEPS) and solid-phase microextraction (SPME), completely modified this scenario by introducing unprecedented control over this process. Urine is a biological fluid that is very interesting for metabolomics studies, allowing human healt...

  2. Determination of novel brominated flame retardants and polybrominated diphenyl ethers in serum using gas chromatography-mass spectrometry with two simplified sample preparation procedures.

    Science.gov (United States)

    Gao, Le; Li, Jian; Wu, Yandan; Yu, Miaohao; Chen, Tian; Shi, Zhixiong; Zhou, Xianqing; Sun, Zhiwei

    2016-11-01

    Two simple and efficient pretreatment procedures have been developed for the simultaneous extraction and cleanup of six novel brominated flame retardants (NBFRs) and eight common polybrominated diphenyl ethers (PBDEs) in human serum. The first sample pretreatment procedure was a quick, easy, cheap, effective, rugged, and safe (QuEChERS)-based approach. An acetone/hexane mixture was employed to isolate the lipid and analytes from the serum with a combination of MgSO4 and NaCl, followed by a dispersive solid-phase extraction (d-SPE) step using C18 particles as a sorbent. The second sample pretreatment procedure was based on solid-phase extraction. The sample extraction and cleanup were conducted directly on an Oasis HLB SPE column using 5 % aqueous isopropanol, concentrated sulfuric acid, and 10 % aqueous methanol, followed by elution with dichloromethane. The NBFRs and PBDEs were then detected using gas chromatography-negative chemical ionization mass spectrometry (GC-NCI MS). The methods were assessed for repeatability, accuracy, selectivity, limits of detection (LODs), and linearity. The results of spike recovery experiments in fetal bovine serum showed that average recoveries ranged from 77.9 % to 128.8 % with relative standard deviations (RSDs) from 0.73 % to 12.37 % for most of the analytes. The LODs for the analytes in fetal bovine serum ranged from 0.3 to 50.8 pg/mL except for decabromodiphenyl ethane. The proposed method was successfully applied to the determination of the 14 brominated flame retardants in human serum. The two pretreatment procedures described here are simple, accurate, and precise, and are suitable for the routine analysis of human serum. Graphical Abstract Workflow of a QuEChERS-based approach (top) and an SPE-based approach (bottom) for the detection of PBDEs and NBFRs in serum.

  3. Microextraction by Packed Sorbent (MEPS) and Solid-Phase Microextraction (SPME) as Sample Preparation Procedures for the Metabolomic Profiling of Urine

    Science.gov (United States)

    Silva, Catarina; Cavaco, Carina; Perestrelo, Rosa; Pereira, Jorge; Câmara, José S.

    2014-01-01

    For a long time, sample preparation was unrecognized as a critical issue in the analytical methodology, thus limiting the performance that could be achieved. However, the improvement of microextraction techniques, particularly microextraction by packed sorbent (MEPS) and solid-phase microextraction (SPME), completely modified this scenario by introducing unprecedented control over this process. Urine is a biological fluid that is very interesting for metabolomics studies, allowing human health and disease characterization in a minimally invasive form. In this manuscript, we will critically review the most relevant and promising works in this field, highlighting how the metabolomic profiling of urine can be an extremely valuable tool for the early diagnosis of highly prevalent diseases, such as cardiovascular, oncologic and neurodegenerative ones. PMID:24958388

  4. A Guide for Preparing Procedure Training Aids.

    Science.gov (United States)

    1982-02-01

    Distribution/ Availability Codes Avail and/or Diot Special AGUIDE FOR PREPARING ~ PROCEDURE TRAINING AIDS cWilliam R. Terrell INSECTED Training Analysis... swiches o . o _______ postion 28 FT 9 With your finger, trace the steps ROAO MAP a Recall (1) how to perform, (2) systems response 0 Look up answers...copies) CO FLEASWTRACENPAC CO FLETRACEN SDIEGO Executive Director NAVINSTPRODEVDET VT-10 (Education Specialist) CO NAVSUBSCOL NLON ( Code 0110) CO

  5. 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.

  6. Comparison of transition-matrix sampling procedures

    DEFF Research Database (Denmark)

    Yevick, D.; Reimer, M.; Tromborg, Bjarne

    2009-01-01

    We compare the accuracy of the multicanonical procedure with that of transition-matrix models of static and dynamic communication system properties incorporating different acceptance rules. We find that for appropriate ranges of the underlying numerical parameters, algorithmically simple yet high...... accurate procedures can be employed in place of the standard multicanonical sampling algorithm....

  7. K-Median: Random Sampling Procedure

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. K-Median: Random Sampling Procedure. Sample a set of 1/ + 1 points from P. Let Q = first 1/ points, p = last point. Let T = Avg. 1-Median cost of P, c=1-Median. Let B1 = B(c,T/ 2), B2 = B(p, T). Let P' = points in B1.

  8. k-Means: Random Sampling Procedure

    Indian Academy of Sciences (India)

    First page Back Continue Last page Overview Graphics. k-Means: Random Sampling Procedure. Optimal 1-Mean is. Approximation of Centroid (Inaba et al). S = random sample of size O(1/ ); Centroid of S is a (1+ )-approx centroid of P with constant probability.

  9. 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.

  10. Optimising uncertainty in physical sample preparation.

    Science.gov (United States)

    Lyn, Jennifer A; Ramsey, Michael H; Damant, Andrew P; Wood, Roger

    2005-11-01

    Uncertainty associated with the result of a measurement can be dominated by the physical sample preparation stage of the measurement process. In view of this, the Optimised Uncertainty (OU) methodology has been further developed to allow the optimisation of the uncertainty from this source, in addition to that from the primary sampling and the subsequent chemical analysis. This new methodology for the optimisation of physical sample preparation uncertainty (u(prep), estimated as s(prep)) is applied for the first time, to a case study of myclobutanil in retail strawberries. An increase in expenditure (+7865%) on the preparatory process was advised in order to reduce the s(prep) by the 69% recommended. This reduction is desirable given the predicted overall saving, under optimised conditions, of 33,000 pounds Sterling per batch. This new methodology has been shown to provide guidance on the appropriate distribution of resources between the three principle stages of a measurement process, including physical sample preparation.

  11. 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

    Sample preparation is considered one of the limiting steps in microbial metabolome analysis. Eukaryotes and prokaryotes behave very differently during the several steps of classical sample preparation methods for analysis of metabolites. Even within the eukaryote kingdom there is a vast diversity...... of cell structures that make it imprudent to blindly adopt protocols that were designed for a specific group of microorganisms. We have therefore reviewed and evaluated the whole sample preparation procedures for analysis of yeast metabolites. Our focus has been on the current needs in metabolome analysis......, 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...

  12. School age test or procedure preparation

    Science.gov (United States)

    ... qualitative study of the pre-operative preparation of children, young people and their parents' for planned continence surgery: experiences and expectations. J Clin Nurs . 2012;21(13-14):1964- ...

  13. High throughput sample preparation in combination with gas chromatography coupled to triple quadrupole tandem mass spectrometry (GC-MS/MS): a smart procedure for (ultra)trace analysis of brominated flame retardants in fish.

    Science.gov (United States)

    Kalachova, Kamila; Cajka, Tomas; Sandy, Chris; Hajslova, Jana; Pulkrabova, Jana

    2013-02-15

    In this study, gas chromatography (GC) coupled to triple quadrupole tandem mass spectrometry (MS/MS) operated in electron ionisation mode (EI) has been shown to be an effective tool for the (ultra)trace analysis of several representative brominated flame retardants (BFRs) including polybrominated diphenyl ethers (PBDEs), pentabromotoluene (PBT), pentabromoethylbenzene (PBEB), etc. in complex food and environmental matrices. Using this type of instrumentation, improved selectivity and sensitivity of the instrumental analysis was achieved. In addition to GC-MS/MS (EI), a GC-MS method employing QqQ as a single quadrupole in negative chemical ionisation (NCI) mode was also developed, as this technique might be preferred for those compounds where EI did not provide suitable (intensive enough) mass transitions (e.g., decabromodiphenyl ethane). Following the development of the GC-MS/MS method, a substantial simplification of the sample preparation method was achieved by employing an ethyl acetate QuEChERS-based extraction followed by silica minicolumn clean-up. Using this novel approach, six samples may be prepared in approx. one hour, thus significant time savings were achieved compared to routinely used methods. In addition, the method employs the reduced amounts of organic solvent and other chemicals. Under the optimised conditions, recoveries of all target analytes using both GC-MS/MS (EI) and GC-MS (NCI) were within the range of 70-119% and repeatabilities of the analytical procedure were ≤ 16% at all three spiking levels (0.1, 1 and 5 μg kg(-1)). Regarding quantification limits (LOQs), as expected, a single quadruple operated in NCI provided significantly lower LOQs compared to EI. However, using the triple quadrupole mass analyser, comparable LOQs were achieved for both methods (0.005-1 μg kg(-1) and 0.005-0.1 μg kg(-1) for GC-MS/MS (EI) and GC-MS (NCI), respectively). Moreover, when highly selective mass transitions in GC-MS/MS (EI) were used for

  14. Relevance of sample preparation for flow cytometry.

    Science.gov (United States)

    Muccio, V E; Saraci, E; Gilestro, M; Oddolo, D; Ruggeri, M; Caltagirone, S; Bruno, B; Boccadoro, M; Omedè, P

    2017-10-06

    Flow cytometry is a useful tool for diagnosis and minimal residual disease (MRD) study of hematological diseases. Standard sample preparation protocols are characterized by stain-lyse-wash (SLW). To prevent nonspecific bindings and achieve high sensitivity in MRD studies, lyse-wash-stain-wash (LWSW) is required. To our knowledge, no comparison between the two methods has been performed. We compared mean fluorescence intensity (MFI), stain index, signal-to-noise ratio, and percentage of positive cells of 104 antibodies and of 13 selected antibodies tested in 10 samples simultaneously prepared with the two methods. MFI and percentages of positive cells obtained by the two methods did not show significant differences and showed a very high correlation. Stain index and signal-to-noise ratio presented higher values for kappa and lambda surface chains in LWSW samples and a trend of higher values for the other antibodies in SLW samples. We suggest to use LWSW method also at diagnosis to obtain more comparable antibody intensity expressions when samples from the same patient are processed for MRD evaluation after bulk lysis. Moreover, LWSW can prevent nonspecific bindings, shows no differences in the identification and quantitation of the populations of interest, and reduces acquisition of cell debris. © 2017 John Wiley & Sons Ltd.

  15. 7 CFR 42.121 - Sampling and inspection procedures.

    Science.gov (United States)

    2010-01-01

    ... recommence the above procedure. See § 42.123 for a flow diagram of the skip lot sampling plan. (b) Two... REGULATIONS STANDARDS FOR CONDITION OF FOOD CONTAINERS Skip Lot Sampling and Inspection Procedures § 42.121...

  16. Procedures for cryogenic X-ray ptychographic imaging of biological samples.

    Science.gov (United States)

    Yusuf, M; Zhang, F; Chen, B; Bhartiya, A; Cunnea, K; Wagner, U; Cacho-Nerin, F; Schwenke, J; Robinson, I K

    2017-03-01

    Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  17. Procedures for cryogenic X-ray ptychographic imaging of biological samples

    Directory of Open Access Journals (Sweden)

    M. Yusuf

    2017-03-01

    Full Text Available Biological sample-preparation procedures have been developed for imaging human chromosomes under cryogenic conditions. A new experimental setup, developed for imaging frozen samples using beamline I13 at Diamond Light Source, is described. This manuscript describes the equipment and experimental procedures as well as the authors' first ptychographic reconstructions using X-rays.

  18. 7 CFR 27.21 - Preparation of samples of cotton.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Preparation of samples of cotton. 27.21 Section 27.21... REGULATIONS COTTON CLASSIFICATION UNDER COTTON FUTURES LEGISLATION Regulations Inspection and Samples § 27.21 Preparation of samples of cotton. The samples from each bale shall be prepared as specified in this section...

  19. Microfluidic Vortex Enhancement for on-Chip Sample Preparation

    Directory of Open Access Journals (Sweden)

    Anna Haller

    2015-02-01

    Full Text Available In the past decade a large amount of analysis techniques have been scaled down to the microfluidic level. However, in many cases the necessary sample preparation, such as separation, mixing and concentration, remains to be performed off-chip. This represents a major hurdle for the introduction of miniaturized sample-in/answer-out systems, preventing the exploitation of microfluidic’s potential for small, rapid and accurate diagnostic products. New flow engineering methods are required to address this hitherto insufficiently studied aspect. One microfluidic tool that can be used to miniaturize and integrate sample preparation procedures are microvortices. They have been successfully applied as microcentrifuges, mixers, particle separators, to name but a few. In this work, we utilize a novel corner structure at a sudden channel expansion of a microfluidic chip to enhance the formation of a microvortex. For a maximum area of the microvortex, both chip geometry and corner structure were optimized with a computational fluid dynamic (CFD model. Fluorescent particle trace measurements with the optimized design prove that the corner structure increases the size of the vortex. Furthermore, vortices are induced by the corner structure at low flow rates while no recirculation is observed without a corner structure. Finally, successful separation of plasma from human blood was accomplished, demonstrating a potential application for clinical sample preparation. The extracted plasma was characterized by a flow cytometer and compared to plasma obtained from a standard benchtop centrifuge and from chips without a corner structure.

  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. Fluidics platform and method for sample preparation

    Science.gov (United States)

    Benner, Henry W.; Dzenitis, John M.

    2016-06-21

    Provided herein are fluidics platforms and related methods for performing integrated sample collection and solid-phase extraction of a target component of the sample all in one tube. The fluidics platform comprises a pump, particles for solid-phase extraction and a particle-holding means. The method comprises contacting the sample with one or more reagents in a pump, coupling a particle-holding means to the pump and expelling the waste out of the pump while the particle-holding means retains the particles inside the pump. The fluidics platform and methods herein described allow solid-phase extraction without pipetting and centrifugation.

  2. Finding even more anthropogenic indicators in mildly prepared sediment samples

    DEFF Research Database (Denmark)

    Enevold, Renée; Odgaard, Bent Vad

    2016-01-01

    NPPs in anthropogenic soils and archaeological samples are often numerous in types as well as in abundance. Preparing these soil samples with methods based on acid digestion holds the potential of severe bias leaving the NPP assemblages devoid of acid vulnerable NPPs. In many cases it might...... be worth the effort to prepare the NPP samples with as mild a preparation method as possible. We have mildly prepared NPP samples from a small forest hollow, Tårup Lund, Denmark. From the recovered NPP assemblages we attempt identifying anthropogenic indicators by comparing to the environmental information...

  3. Rapid Automated Sample Preparation for Biological Assays

    Energy Technology Data Exchange (ETDEWEB)

    Shusteff, M

    2011-03-04

    Our technology utilizes acoustic, thermal, and electric fields to separate out contaminants such as debris or pollen from environmental samples, lyse open cells, and extract the DNA from the lysate. The objective of the project is to optimize the system described for a forensic sample, and demonstrate its performance for integration with downstream assay platforms (e.g. MIT-LL's ANDE). We intend to increase the quantity of DNA recovered from the sample beyond the current {approx}80% achieved using solid phase extraction methods. Task 1: Develop and test an acoustic filter for cell extraction. Task 2: Develop and test lysis chip. Task 3: Develop and test DNA extraction chip. All chips have been fabricated based on the designs laid out in last month's report.

  4. Sampling procedure for the foliar analysis of deciduous trees

    NARCIS (Netherlands)

    Luyssaert, Sebastiaan; Raitio, Hannu; Vervaeke, Pieter; Mertens, Jan; Lust, Noël

    2002-01-01

    Sampling can be the source of the greatest errors in the overall results of foliar analysis. This paper reviews the variability in heavy metal concentrations in tree crowns, which is a feature that should be known and understood when designing a suitable leaf sampling procedure. The leaf sampling

  5. 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...

  6. A simplified procedure for preparation of undecalcified human bone sections

    DEFF Research Database (Denmark)

    Wallin, J A; Tkocz, I; Levinsen, J

    1985-01-01

    A new type of apparatus for sectioning samples of hard, undecalcified bone is described. Slices of fresh or archeological human bone 4-5 mm thick are dehydrated and then embedded in epoxy resin. The apparatus used to prepare sections from the resulting blocks consists of a low-speed rim...

  7. Preparation of Homogeneous MALDI Samples for Quantitative Applications.

    Science.gov (United States)

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

    2016-10-28

    This protocol demonstrates a simple sample preparation to reduce spatial heterogeneity in ion signals during matrix-assisted laser desorption/ionization (MALDI) mass spectrometry. The heterogeneity of ion signals is a severe problem in MALDI, which results in poor data reproducibility and makes MALDI unsuitable for quantitative analysis. By regulating sample plate temperature during sample preparation, thermal-induced hydrodynamic flows inside droplets of sample solution are able to reduce the heterogeneity problem. A room-temperature sample preparation chamber equipped with a temperature-regulated copper base block that holds MALDI sample plates facilitates precise control of the sample drying condition. After drying of sample droplets, the temperature of sample plates is returned to room temperature and removed from the chamber for subsequent mass spectrometric analysis. The areas of samples are examined with MALDI-imaging mass spectrometry to obtain the spatial distribution of all components in the sample. In comparison with the conventional dried-droplet method that prepares samples under ambient conditions without temperature control, the samples prepared with the method demonstrated herein show significantly better spatial distribution and signal intensity. According to observations using carbohydrate and peptide samples, decreasing substrate temperature while maintaining the surroundings at ambient temperature during the drying process can effectively reduce the heterogeneity of ion signals. This method is generally applicable to various combinations of samples and matrices.

  8. Final Report for X-ray Diffraction Sample Preparation Method Development

    Energy Technology Data Exchange (ETDEWEB)

    Ely, T. M.; Meznarich, H. K.; Valero, T.

    2018-01-30

    WRPS-1500790, “X-ray Diffraction Saltcake Sample Preparation Method Development Plan/Procedure,” was originally prepared with the intent of improving the specimen preparation methodology used to generate saltcake specimens suitable for XRD-based solid phase characterization. At the time that this test plan document was originally developed, packed powder in cavity supports with collodion binder was the established XRD specimen preparation method. An alternate specimen preparation method less vulnerable, if not completely invulnerable to preferred orientation effects, was desired as a replacement for the method.

  9. 7 CFR 61.34 - Drawing and preparation of sample.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 3 2010-01-01 2010-01-01 false Drawing and preparation of sample. 61.34 Section 61.34 Agriculture Regulations of the Department of Agriculture (Continued) AGRICULTURAL MARKETING SERVICE (Standards... Cottonseed Samplers § 61.34 Drawing and preparation of sample. Each licensed cottonseed sampler shall draw...

  10. NIF Anti-Reflective Coating Solutions: Preparation, Procedures and Specifications

    Energy Technology Data Exchange (ETDEWEB)

    Suratwala, T; Carman, L; Thomas, I

    2003-07-01

    The following document contains a detailed description of the preparation procedures for the antireflective coating solutions used for NIF optics. This memo includes preparation procedures for the coating solutions (sections 2.0-4.0), specifications and vendor information of the raw materials used and on all equipment used (section 5.0), and QA specifications (section 6.0) and procedures (section 7.0) to determine quality and repeatability of all the coating solutions. There are different five coating solutions that will be used to coat NIF optics. These solutions are listed below: (1) Colloidal silica (3%) in ethanol (2) Colloidal silica (2%) in sec-butanol (3) Colloidal silica (9%) in sec-butanol (deammoniated) (4) HMDS treated silica (10%) in decane (5) GR650 (3.3%) in ethanol/sec-butanol The names listed above are to be considered the official name for the solution. They will be referred to by these names in the remainder of this document. Table 1 gives a summary of all the optics to be coated including: (1) the surface to be coated; (2) the type of solution to be used; (3) the coating method (meniscus, dip, or spin coating) to be used; (4) the type of coating (broadband, 1?, 2?, 3?) to be made; (5) number of optics to be coated; and (6) the type of post processing required (if any). Table 2 gives a summary of the batch compositions and measured properties of all five of these solutions.

  11. 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.

  12. Preparation method matters: Aiming at higher NPP diversity and representativeness in sediment samples

    DEFF Research Database (Denmark)

    Enevold, Renée; Odgaard, Bent Vad

    2016-01-01

    of palynology in archaeological and forensic sciences. NPPs in anthropogenic soils and archaeological samples may be numerous in types as well as in abundance. However, preparing these soil samples with methods based on acid digestion potentially biases NPP assemblages because of differential damage or even...... dissolution of microfossils. In spite of this potential bias standard preparation procedures for pollen analysis have, in most cases without modification, generally been applied to palynological samples used for NPP analysis. We review briefly the advantages of high diversity NPP-analysis and preparation...

  13. 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.

  14. 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.

  15. Sampling of illicit drugs for quantitative analysis--part III: sampling plans and sample preparations.

    Science.gov (United States)

    Csesztregi, T; Bovens, M; Dujourdy, L; Franc, A; Nagy, J

    2014-08-01

    The findings in this paper are based on the results of our drug homogeneity studies and particle size investigations. Using that information, a general sampling plan (depicted in the form of a flow-chart) was devised that could be applied to the quantitative instrumental analysis of the most common illicit drugs: namely heroin, cocaine, amphetamine, cannabis resin, MDMA tablets and herbal cannabis in 'bud' form (type I). Other more heterogeneous forms of cannabis (type II) were found to require alternative, more traditional sampling methods. A table was constructed which shows the sampling uncertainty expected when a particular number of random increments are taken and combined to form a single primary sample. It also includes a recommended increment size; which is 1 g for powdered drugs and cannabis resin, 1 tablet for MDMA and 1 bud for herbal cannabis in bud form (type I). By referring to that table, individual laboratories can ensure that the sampling uncertainty for a particular drug seizure can be minimised, such that it lies in the same region as their analytical uncertainty for that drug. The table shows that assuming a laboratory wishes to quantitatively analyse a seizure of powdered drug or cannabis resin with a 'typical' heterogeneity, a primary sample of 15×1 g increments is generally appropriate. The appropriate primary sample for MDMA tablets is 20 tablets, while for herbal cannabis (in bud form) 50 buds were found to be appropriate. Our study also showed that, for a suitably homogenised primary sample of the most common powdered drugs, an analytical sample size of between 20 and 35 mg was appropriate and for herbal cannabis the appropriate amount was 200 mg. The need to ensure that the results from duplicate or multiple incremental sampling were compared, to demonstrate whether or not a particular seized material has a 'typical' heterogeneity and that the sampling procedure applied has resulted in a 'correct sample', was highlighted and the setting

  16. 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.

  17. 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 routinely used to process samples (for culture, arrest and fixation of cells) and/or to expand limited amount of samples (in case of prenatal diagnostics). Arguably, this expansion and other sample pretreatments form the longest part of the entire diagnostic protocols spanning over 3–4 days. We present here...... a novel device with an integrated expansion chamber to culture, arrest and fix metaphase cells followed by a subsequent splashing protocol leading to ample metaphase chromosome spreads on a glass slide for metaphase FISH analysis. The device provides an easy, disposable, low cost, integrated solution...

  18. Sample Preparation for Electron Probe Microanalysis-Pushing the Limits.

    Science.gov (United States)

    Geller, Joseph D; Engle, Paul D

    2002-01-01

    There are two fundamental considerations in preparing samples for electron probe microanalysis (EPMA). The first one may seem obvious, but we often find it is overlooked. That is, the sample analyzed should be representative of the population from which it comes. The second is a direct result of the assumptions in the calculations used to convert x-ray intensity ratios, between the sample and standard, to concentrations. Samples originate from a wide range of sources. During their journey to being excited under the electron beam for the production of x rays there are many possibilities for sample alteration. Handling can contaminate samples by adding extraneous matter. In preparation, the various abrasives used in sizing the sample by sawing, grinding and polishing can embed themselves. The most accurate composition of a contaminated sample is, at best, not representative of the original sample; it is misleading. Our laboratory performs EPMA analysis on customer submitted samples and prepares over 250 different calibration standards including pure elements, compounds, alloys, glasses and minerals. This large variety of samples does not lend itself to mass production techniques, including automatic polishing. Our manual preparation techniques are designed individually for each sample. The use of automated preparation equipment does not lend itself to this environment, and is not included in this manuscript. The final step in quantitative electron probe microanalysis is the conversion of x-ray intensities ratios, known as the "k-ratios," to composition (in mass fraction or atomic percent) and/or film thickness. Of the many assumptions made in the ZAF (where these letters stand for atomic number, absorption and fluorescence) corrections the localized geometry between the sample and electron beam, or takeoff angle, must be accurately known. Small angular errors can lead to significant errors in the final results. The sample preparation technique then becomes very

  19. Sample Preparation for Electron Probe Microanalysis—Pushing the Limits

    Science.gov (United States)

    Geller, Joseph D.; Engle, Paul D.

    2002-01-01

    There are two fundamental considerations in preparing samples for electron probe microanalysis (EPMA). The first one may seem obvious, but we often find it is overlooked. That is, the sample analyzed should be representative of the population from which it comes. The second is a direct result of the assumptions in the calculations used to convert x-ray intensity ratios, between the sample and standard, to concentrations. Samples originate from a wide range of sources. During their journey to being excited under the electron beam for the production of x rays there are many possibilities for sample alteration. Handling can contaminate samples by adding extraneous matter. In preparation, the various abrasives used in sizing the sample by sawing, grinding and polishing can embed themselves. The most accurate composition of a contaminated sample is, at best, not representative of the original sample; it is misleading. Our laboratory performs EPMA analysis on customer submitted samples and prepares over 250 different calibration standards including pure elements, compounds, alloys, glasses and minerals. This large variety of samples does not lend itself to mass production techniques, including automatic polishing. Our manual preparation techniques are designed individually for each sample. The use of automated preparation equipment does not lend itself to this environment, and is not included in this manuscript. The final step in quantitative electron probe microanalysis is the conversion of x-ray intensities ratios, known as the “k-ratios,” to composition (in mass fraction or atomic percent) and/or film thickness. Of the many assumptions made in the ZAF (where these letters stand for atomic number, absorption and fluorescence) corrections the localized geometry between the sample and electron beam, or takeoff angle, must be accurately known. Small angular errors can lead to significant errors in the final results. The sample preparation technique then becomes very

  20. A simplified procedure for preparation of undecalcified human bone sections.

    Science.gov (United States)

    Wallin, J A; Tkocz, I; Levinsen, J

    1985-11-01

    A new type of apparatus for sectioning samples of hard, undecalcified bone is described. Slices of fresh or archeological human bone 4-5 mm thick are dehydrated and then embedded in epoxy resin. The apparatus used to prepare sections from the resulting blocks consists of a low-speed rim-type diamond cut-off wheel and a slowly advancing table carrying the specimen held in a rotating mount. Sections may be cut at a thickness of 80 micron +/- 1%. After cleaning in an ultrasonic bath, these can be mounted on slides for quantitative microscopic examination with transmitted light. Grinding and polishing are not necessary. The results obtained are illustrated.

  1. Novel Sample-handling Approach for XRD Analysis with Minimal Sample Preparation

    Science.gov (United States)

    Sarrazin, P.; Chipera, S.; Bish, D.; Blake, D.; Feldman, S.; Vaniman, D.; Bryson, C.

    2004-01-01

    Sample preparation and sample handling are among the most critical operations associated with X-ray diffraction (XRD) analysis. These operations require attention in a laboratory environment, but they become a major constraint in the deployment of XRD instruments for robotic planetary exploration. We are developing a novel sample handling system that dramatically relaxes the constraints on sample preparation by allowing characterization of coarse-grained material that would normally be impossible to analyze with conventional powder-XRD techniques.

  2. Comparison of different sample preparation procedures for the detection and isolation of Escherichia coli O157:H7 and Non-O157 STECs from leafy greens and cilantro.

    Science.gov (United States)

    Kase, Julie A; Maounounen-Laasri, Anna; Son, Insook; Deer, Deanne M; Borenstein, Stacey; Prezioso, Samantha; Hammack, Thomas S

    2012-12-01

    The FDA Bacteriological Analytical Manual (BAM) method for the detection/isolation of Shiga toxin-producing Escherichia coli (STEC) involves enrichment of produce rinses, blended homogenates or stomached homogenates. However, the effectiveness of rinsing produce to remove attached bacteria is largely unknown. Moreover, PCR inhibitors can be released under physical treatment. The study objective was to determine the relative effectiveness of recovery methods for STEC contaminated produce. Spinach, lettuce, and cilantro were contaminated with E. coli O157:H7 or a non-O157 STEC, subjected to both the BAM method and a soak method, and tested by real-time PCR and cultural methods. For O157:H7 and non-O157:H7 STECs, the soak method was significantly more productive than leafy green rinses. Of 320 test portions, PCR of recovered colonies confirmed 148 were positive by rinsing and 271 were positive by soaking (an 83% increase in sensitivity). For recovery of O157:H7 from cilantro, of 60 test portions, positives were 38 by soaking, 41 by stomaching, and 28 by blending. Soaking and stomaching were significantly more productive than blending, although soaking was only arithmetically superior to stomaching. Based upon these results, it is recommended that a soak method replace the current BAM procedures. Published by Elsevier Ltd.

  3. 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

  4. Alpha-spectrometric analysis of uranium and thorium using solid-phase extraction for sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Weber, R.; Esterlund, R.A.; Patzelt, P

    1999-05-01

    A method is presented here for the preparation of thin uniform samples of naturally occurring uranium and thorium which are highly suitable for {alpha}-spectrometric analysis. The solid-phase extraction procedure simultaneously achieves a complete separation of the analytes from the sample matrix and a high enrichment factor for uranium and thorium, so that the ensuing eluate is ideally suited for either electrodeposition or ICP-MS, without the need for complicated and painstaking sample preparation. In contrast to conventional liquid-liquid phase-extraction methods, no organic waste solutions are produced, and the process can be easily automated.

  5. Magnetic separation techniques in sample preparation for biological analysis: a review.

    Science.gov (United States)

    He, Jincan; Huang, Meiying; Wang, Dongmei; Zhang, Zhuomin; Li, Gongke

    2014-12-01

    Sample preparation is a fundamental and essential step in almost all the analytical procedures, especially for the analysis of complex samples like biological and environmental samples. In past decades, with advantages of superparamagnetic property, good biocompatibility and high binding capacity, functionalized magnetic materials have been widely applied in various processes of sample preparation for biological analysis. In this paper, the recent advancements of magnetic separation techniques based on magnetic materials in the field of sample preparation for biological analysis were reviewed. The strategy of magnetic separation techniques was summarized. The synthesis, stabilization and bio-functionalization of magnetic nanoparticles were reviewed in detail. Characterization of magnetic materials was also summarized. Moreover, the applications of magnetic separation techniques for the enrichment of protein, nucleic acid, cell, bioactive compound and immobilization of enzyme were described. Finally, the existed problems and possible trends of magnetic separation techniques for biological analysis in the future were proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

  6. Advanced Curation Preparation for Mars Sample Return and Cold Curation

    Science.gov (United States)

    Fries, M. D.; Harrington, A. D.; McCubbin, F. M.; Mitchell, J.; Regberg, A. B.; Snead, C.

    2017-01-01

    NASA Curation is tasked with the care and distribution of NASA's sample collections, such as the Apollo lunar samples and cometary material collected by the Stardust spacecraft. Curation is also mandated to perform Advanced Curation research and development, which includes improving the curation of existing collections as well as preparing for future sample return missions. Advanced Curation has identified a suite of technologies and techniques that will require attention ahead of Mars sample return (MSR) and missions with cold curation (CCur) requirements, perhaps including comet sample return missions.

  7. 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. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

  8. Fluidics platform and method for sample preparation and analysis

    Science.gov (United States)

    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.

  9. Influence of manufacturing procedure on stability of Unguentum contra perniones preparations

    Directory of Open Access Journals (Sweden)

    Bošković Mirjana

    2005-01-01

    Full Text Available Background. Application of various technological procedures for the manufacture of officinal preparation ointment against chilblains (Unguentum contra perniones produce essential variations in the quality and stability of the final product. Changing the sequence of admixing active substances into the ointment base indicated the presence of incompatibility between the active substances, as well as between the active substances and the ointment base components. The aim was to examine the influence of various technological manufacturing procedures on quality and stability of the preparation. Methods. Changes in the samples of ointments and aqueous solutions of active substances were analyzed microscopically. Results. Microscopic analysis of hydrosoluble active substance solutions demonstrated destruction of ichthammol, induced by an acidic medium due to the dissolution of tannin and resorcinol, which is well known from the literature. It also demonstrated the destruction of tannin and resorcinol in aqueous solution, which had not been described in the literature. Application of the prescribed procedure for the manufacturing of ointment against chilblains, conceals the incompatibility reactions due to a slow dissolution of the tannin suspended in the officinal ointment base Unguentum cera lanae. Admixture of an ready-made aqueous solution of tannin caused an instant contact between ichthammol and the acidic medium, which caused the destruction or the complete absence of the formation of emulsion droplets. The problem of incompatibility reactions between lanolin alcohols in the ointment base and ichthammol and resorcinol, as well as the reaction between Peruvian balsam and sulfur from the ichthammol sulfate ion was observed. Numerous incompatibility reactions of ointment against chilblains, components indicated that it was necessary to introduce alterations in both the qualitative and quantitative composition of the preparation. Conclusion. Excipient

  10. The Effect of Sample Preparation and Testing Procedure

    African Journals Online (AJOL)

    School of Civil & Environmental Engineering, Addis Ababa Institute of Technology,. 3. Murray Rix Geotechnical, UK. Corresponding ... road, and the earth fill dam in Gilgel-Gibe for hydroelectric power generation are projects that ... and suitability of TWR laterite soils for roads, earthworks and other purposes. TWR laterite.

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

    African Journals Online (AJOL)

    It is concluded that the plasticity chart should be regarded as a guidance tool only for evaluating the likely properties of laterite soils. It should not be used to classify them based on conventional methods without due deference to their genesis. Unlike soils for which the Casagrande Plastcity Chart, as adopted in the United ...

  12. 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.

  13. Sample preparation with solid phase microextraction and exhaustive extraction approaches: Comparison for challenging cases.

    Science.gov (United States)

    Boyacı, Ezel; Rodríguez-Lafuente, Ángel; Gorynski, Krzysztof; Mirnaghi, Fatemeh; Souza-Silva, Érica A; Hein, Dietmar; Pawliszyn, Janusz

    2015-05-11

    In chemical analysis, sample preparation is frequently considered the bottleneck of the entire analytical method. The success of the final method strongly depends on understanding the entire process of analysis of a particular type of analyte in a sample, namely: the physicochemical properties of the analytes (solubility, volatility, polarity etc.), the environmental conditions, and the matrix components of the sample. Various sample preparation strategies have been developed based on exhaustive or non-exhaustive extraction of analytes from matrices. Undoubtedly, amongst all sample preparation approaches, liquid extraction, including liquid-liquid (LLE) and solid phase extraction (SPE), are the most well-known, widely used, and commonly accepted methods by many international organizations and accredited laboratories. Both methods are well documented and there are many well defined procedures, which make them, at first sight, the methods of choice. However, many challenging tasks, such as complex matrix applications, on-site and in vivo applications, and determination of matrix-bound and free concentrations of analytes, are not easily attainable with these classical approaches for sample preparation. In the last two decades, the introduction of solid phase microextraction (SPME) has brought significant progress in the sample preparation area by facilitating on-site and in vivo applications, time weighted average (TWA) and instantaneous concentration determinations. Recently introduced matrix compatible coatings for SPME facilitate direct extraction from complex matrices and fill the gap in direct sampling from challenging matrices. Following introduction of SPME, numerous other microextraction approaches evolved to address limitations of the above mentioned techniques. There is not a single method that can be considered as a universal solution for sample preparation. This review aims to show the main advantages and limitations of the above mentioned sample

  14. Effect of method of sample preparation on ruminal in situ ...

    African Journals Online (AJOL)

    The objective of this study was to investigate the effect of method of sample preparation on the degradation kinetics of herbage when applying the in situ technique. Ryegrass (Lolium multiflorum cv. Midmar) was harvested at three and four weeks after cutting and fertilizing with 200 kg nitrogen (N)/ha. Freshly cut herbage ...

  15. Modern methods of sample preparation for GC analysis

    NARCIS (Netherlands)

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

    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

  16. 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...... revealed 1792 molecular features from the protein precipitation procedure. The protein precipitation followed by solid phase extraction procedure with three sub-samples gave a total of 4234 molecular features. This suggests that sub-sampling into polar, lipid and phospholipid fractions enables extraction...

  17. Sample preparation of Medicago sativa L. hay for chemical analysis ...

    African Journals Online (AJOL)

    The objective of this study was to quantify the effect of the grinding procedure on the moisture and crude protein concentration of a ground Medicago sativa L. hay sample for quality grading. An additional aim was to investigate the accuracy of electronic moisture testers (EMT). Variance of analyses revealed significant ...

  18. An automation-assisted generic approach for biological sample preparation and LC-MS/MS method validation.

    Science.gov (United States)

    Zhang, Jie; Wei, Shimin; Ayres, David W; Smith, Harold T; Tse, Francis L S

    2011-09-01

    Although it is well known that automation can provide significant improvement in the efficiency of biological sample preparation in quantitative LC-MS/MS analysis, it has not been widely implemented in bioanalytical laboratories throughout the industry. This can be attributed to the lack of a sound strategy and practical procedures in working with robotic liquid-handling systems. Several comprehensive automation assisted procedures for biological sample preparation and method validation were developed and qualified using two types of Hamilton Microlab liquid-handling robots. The procedures developed were generic, user-friendly and covered the majority of steps involved in routine sample preparation and method validation. Generic automation procedures were established as a practical approach to widely implement automation into the routine bioanalysis of samples in support of drug-development programs.

  19. 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.

  20. Procedures for sampling and sample reduction within quality assurance systems for solid biofuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The objective of this experimental study on sampling was to determine the size and number of samples of biofuels required (taken at two sampling points in each case) and to compare two methods of sampling. The first objective of the sample-reduction exercise was to compare the reliability of various sampling methods, and the second objective was to measure the variations introduced as a result of reducing the sample size to form suitable test portions. The materials studied were sawdust, wood chips, wood pellets and bales of straw, and these were analysed for moisture, ash, particle size and chloride. The sampling procedures are described. The study was conducted in Scandinavia. The results of the study were presented in Leipzig in October 2004. The work was carried out as part of the UK's DTI Technology Programme: New and Renewable Energy.

  1. 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.

  2. Optimized preparation of urine samples for two-dimensional electrophoresis and initial application to patient samples

    DEFF Research Database (Denmark)

    Lafitte, Daniel; Dussol, Bertrand; Andersen, Søren

    2002-01-01

    OBJECTIVE: We optimized of the preparation of urinary samples to obtain a comprehensive map of urinary proteins of healthy subjects and then compared this map with the ones obtained with patient samples to show that the pattern was specific of their kidney disease. DESIGN AND METHODS: The urinary...

  3. Cr(VI) generation during sample preparation of solid samples – A ...

    African Journals Online (AJOL)

    Cr(VI) generation during sample preparation of solid samples – A chromite ore case study. R.I Glastonbury, W van der Merwe, J.P Beukes, P.G van Zyl, G Lachmann, C.J.H Steenkamp, N.F Dawson, M.H Stewart ...

  4. Secondary School Students' Reasoning about Conditional Probability, Samples, and Sampling Procedures

    Science.gov (United States)

    Prodromou, Theodosia

    2016-01-01

    In the Australian mathematics curriculum, Year 12 students (aged 16-17) are asked to solve conditional probability problems that involve the representation of the problem situation with two-way tables or three-dimensional diagrams and consider sampling procedures that result in different correct answers. In a small exploratory study, we…

  5. Sample preparation method for the combined extraction of ethyl glucuronide and drugs of abuse in hair.

    Science.gov (United States)

    Meier, Ulf; Briellmann, Thomas; Scheurer, Eva; Dussy, Franz

    2017-10-09

    Often in hair analysis, a small hair sample is available while the analysis of a multitude of structurally diverse substances with different concentration ranges is demanded. The analysis of the different substances often requires different sample preparation methods, increasing the amount of required hair sample. When segmental hair analysis is necessary, the amount of hair sample needed is further increased. Therefore, the required sample amount for a full analysis can quickly exceed what is available. To combat this problem, a method for the combined hair sample preparation using a single extraction procedure for analysis of ethyl glucuronide with liquid chromatography-multistage fragmentation mass spectrometry/multiple reaction monitoring (LC-MS3 /MRM) and common drugs of abuse with LC-MRM was developed. The combined sample preparation is achieved by separating ethyl glucuronide from the drugs of abuse into separate extracts by fractionation in the solid-phase extraction step during sample clean-up. A full validation for all substances for the parameters selectivity, linearity, limit of detection, limit of quantification, accuracy, precision, matrix effects, and recovery was successfully completed. The following drugs of abuse were included in the method: Amphetamine; methamphetamine; 3,4-methylenedioxy-N-methylamphetamine (MDMA); 3,4-methylenedioxyamphetamine (MDA); 3,4-methylenedioxy-N-ethylamphetamine (MDE); morphine; 6-monoacetylmorphine; codeine; acetylcodeine; cocaine; benzoylecgonine; norcocaine; cocaethylene; methadone; 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and methylphenidate. In conclusion, as only 1 sample preparation is needed with 1 aliquot of hair, the presented sample preparation allows an optimal analysis of both ethyl glucuronide and of the drugs of abuse, even when the sample amount is a limiting factor. Copyright © 2017 John Wiley & Sons, Ltd.

  6. Development of Radioanalytical and Microanalytical Procedures for the Determination of Actinides in Environmental Samples

    Energy Technology Data Exchange (ETDEWEB)

    Macsik, Zsuzsanna [Institute of Nuclear Techniques, Moegyetem rakpart 9, H-1111 Budapest (Hungary); Vajda, Nora [RadAnal Ltd., Bimbo ut 119/a, H-1026 Budapest (Hungary); Bene, Balazs [National Institute of Standards and Technology, Gaithersburg, MD 20899 (United States); Varga, Zsolt [Institute of Isotopes, Konkoly-Thege M. ut 29-33, H-1121 Budapest (Hungary)

    2008-07-01

    A radio-analytical procedure has been developed for the simultaneous determination of actinides in swipe samples by alpha-spectrometry after the separation of the actinides by extraction chromatography. The procedure is based on the complete decomposition of the sample by destruction with microwave digestion or ashing in furnace. Actinides are separated on an extraction chromatographic column filled with TRU resin (product of Eichrom Industries Inc.). Alpha sources prepared from the separated fractions of americium, plutonium, thorium and uranium are counted by alpha spectrometry. Micro-analytical procedure is being developed for the location and identification of individual particles containing fissile material using solid state nuclear track detectors. The parameters of alpha and fission track detection have been optimized and a procedure has been elaborated to locate the particles on the sample by defining the coordinates of the tracks created by the particles on the track detector. Development of a procedure is planned to separate the located particles using micromanipulator and these particles will be examined individually by different micro- and radio-analytical techniques. (authors)

  7. 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

  8. Fish Surgery: Presurgical Preparation and Common Surgical Procedures.

    Science.gov (United States)

    Sladky, Kurt K; Clarke, Elsburgh O

    2016-01-01

    Fish surgical procedures are commonplace in aquaria, zoos, laboratory facilities, and pet clinical practice. To incorporate fish surgery into a clinical setting, an understanding of anatomic differences between mammals and fish, bath anesthetics, and recirculating anesthesia techniques must be developed; a system or different size systems to accommodate anesthesia and surgery of particular species of concern at an institution or practice constructed; and familiar mammalian surgical principles applied with some adaptations. Common surgical procedures in fish include coeliotomy for intracoelomic mass removal, reproductive procedures, gastrointestinal foreign body removal, radiotransmitter placement, and integumentary mass excision. Copyright © 2016 Elsevier Inc. All rights reserved.

  9. Sampling procedure, receipt and conservation of water samples to determine environmental radioactivity; Procedimiento para el muestreo, recepcion y conservacion de muestras de agua para la determinacion de la radiactividad ambiental

    Energy Technology Data Exchange (ETDEWEB)

    Herranz, M.; Navarro, E.; Payeras, J. (and others)

    2009-07-01

    The present document informs about essential goals, processes and contents that the subgroups Samling and Samples Preparation and Conservation believe they should be part of the procedure to obtain a correct sampling, receipt, conservation and preparation of samples of continental, marine and waste water before qualifying its radioactive content.

  10. Combining Electrochemical Sensors with Miniaturized Sample Preparation for Rapid Detection in Clinical Samples

    Directory of Open Access Journals (Sweden)

    Natinan Bunyakul

    2014-12-01

    Full Text Available Clinical analyses benefit world-wide from rapid and reliable diagnostics tests. New tests are sought with greatest demand not only for new analytes, but also to reduce costs, complexity and lengthy analysis times of current techniques. Among the myriad of possibilities available today to develop new test systems, amperometric biosensors are prominent players—best represented by the ubiquitous amperometric-based glucose sensors. Electrochemical approaches in general require little and often enough only simple hardware components, are rugged and yet provide low limits of detection. They thus offer many of the desirable attributes for point-of-care/point-of-need tests. This review focuses on investigating the important integration of sample preparation with (primarily electrochemical biosensors. Sample clean up requirements, miniaturized sample preparation strategies, and their potential integration with sensors will be discussed, focusing on clinical sample analyses.

  11. 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.

  12. Yeast metabolomics: sample preparation for a GC/MS-based analysis.

    Science.gov (United States)

    Carneiro, Sónia; Pereira, Rui; Rocha, Isabel

    2014-01-01

    Metabolome sample preparation is one of the key factors in metabolomics analyses. The quality of the metabolome data will depend on the suitability of the experimental procedures to the cellular system (e.g., yeast cells) and the analytical performance. Here, we summarize a protocol for metabolome analysis of yeast cells using gas chromatography-mass spectrometry (GC-MS). First, the main phases of a metabolomics analysis are identified: sample preparation, metabolite extraction, and analysis. We also provide an overview on different methods used to quench samples and extract intracellular metabolites from yeast cells. This protocol provides a detailed description of a GC-MS-based analysis of yeast metabolome, in particular for metabolites containing amino and/or carboxyl groups, which represent most of the compounds participating in the central carbon metabolism.

  13. 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)

  14. Sample preparation and EFTEM of Meat Samples for Nanoparticle Analysis in Food

    Science.gov (United States)

    Lari, L.; Dudkiewicz, A.

    2014-06-01

    Nanoparticles are used in industry for personal care products and the preparation of food. In the latter application, their functions include the prevention of microbes' growth, increase of the foods nutritional value and sensory quality. EU regulations require a risk assessment of the nanoparticles used in foods and food contact materials before the products can reach the market. However, availability of validated analytical methodologies for detection and characterisation of the nanoparticles in food hampers appropriate risk assessment. As part of a research on the evaluation of the methods for screening and quantification of Ag nanoparticles in meat we have tested a new TEM sample preparation alternative to resin embedding and cryo-sectioning. Energy filtered TEM analysis was applied to evaluate thickness and the uniformity of thin meat layers acquired at increasing input of the sample demonstrating that the protocols used ensured good stability under the electron beam, reliable sample concentration and reproducibility.

  15. 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

    AFFF-ICP-MS fractograms, which corresponded to the enzymatic digests, showed a major nano-peak (about 80 % recovery of AgNPs spiked to the meat) plus new smaller peaks that eluted close to the void volume of the fractograms. Small, but significant shifts in retention time of AFFF peaks were observed......-ICP-MS analysis of their content of gold nanoparticles (AuNPs) was tested and compared with enzymatic sample preparation [3]. The results showed that the same results, with respect to the obtained number-based size distribution for AuNPs, were obtained for the two preparation methods. In contrast, the alkaline...

  16. Modern kinetic spectrophotometric procedure for estimation of furosemide drug as bulk form and in pharmaceuticals preparations

    Directory of Open Access Journals (Sweden)

    Al-Rufaie Mohauman Mohammad

    2016-12-01

    Full Text Available A simple, rapid, sensitive, inexpensive and easy to perform kinetic spectrophotometric procedure for the investigation of trace quantities of the drug, furosemide (FRO, as bulk and in the pharmaceutical preparations, has been improved upon. The enhanced method was depended on the fashioning of the Schiff ‘s base by the reaction of the aldehyde group present in the 5-sulfo salicylaldehyde reagent, and the primary amino group present in furosemide. The latter acts as a ligand for the formation of an intense colored complex with Co(II in an acidic medium, with maximum absorption at 608 nm. In the work, kinetic spectrophotometrics were established through the fixed time method. Moreover, Beer’s law was applied on the range of concentration between 5-100 ppm, while the molar absorptivity and the Sandell sensitivity were 3.9295×104 l.mol−1cm−1, 0.008 μg.cm−2, respectively. The detection limit (LOD was 2.133 µg/ml−1, and LOQ was 1.105 µg/ml−1. Ideal circumstances for all colour improvement were seen, and the suggested procedure has been effectively employed in investigating amounts of furosemide (FRO in bulk forms and in pharmaceutical preparations (tablets, injection sample. Additives and general excipient materials did not affect the studied method. A statistical comparison between the results that were obtained from the reference method gave good agreement.

  17. Influence of preparation procedure and ferric oxide nanoparticles ...

    Indian Academy of Sciences (India)

    2017-07-25

    plating industry, the table salt pro- duction, separation of inorganic ions from organic mixtures, desalination of saline water, recovery of acid and base from the spent ... The membrane samples were sputtered with gold and were ...

  18. A review of sample preparation and its influence on pH determination in concrete samples

    Directory of Open Access Journals (Sweden)

    S. Manso

    2017-01-01

    Full Text Available If we are to monitor the chemical processes in cementitious materials, then pH assays in the pore solutions of cement pastes, mortars, and concretes are of key importance. However, there is no standard method that regulates the sample-preparation method for pH determination. The state-of-the-art of different methods for pH determination in cementitious materials is presented in this paper and the influence of sample preparation in each case. Moreover, an experimental campaign compares three different techniques for pH determination. Its results contribute to establishing a basic criterion to help researchers select the most suitable method, depending on the purpose of the research. A simple tool is described for selecting the easiest and the most economic pH determination method, depending on the objective; especially for researchers and those with limited experience in this field.

  19. An evaluation procedure for flocculation of coal preparation plant tailings.

    Science.gov (United States)

    Sabah, E; Cengiz, I

    2004-03-01

    In solid-liquid separation of coal preparation plant tailings by flocculation, in addition to the type and amount of flocculants, the composition of waste materials including clay minerals must be determined in order to devise an effective and economic sedimentation system. In this study, the characterization of organic and inorganic impurities was made with the help of mineralogical data and instrumental analysis techniques. The effects of polymer type (medium and low anionic, cationic and nonionic), polymer dosage and suspension pH on flocculation mechanism of tailings particles (-0.18 mm) in the Tunçbilek Coal Preparation Plant tailings of Tunçbilek (Turkey) were investigated. Medium anionic polymer accelerated the settling rate of particles. An optimum settling rate (300 mm/min) was reached at a dosage rate of 34.19 g/ton-solids (2.0 mg/l), 51.28 g/ton-solids (3.0 mg/l), 102.56 g/ton-solids (6.0 mg/l) and 119.66 g/ton-solids (7.0mg/l) for medium anionic, low charged anionic, nonionic and cationic polymers, respectively. The lowest turbidity values at low polymer dosages were obtained by the cationic polymer at around 25.64 g/ton-solids (1.5 mg/l) polymer dosages; however, the low anionic and nonionic polymers produced lower turbidity values at higher dosages (>25.64 g/ton-solids). At optimum dosages of the polymer, the settling rate decreased at low and high pHs indicating that the natural pH (pH 8.3) of the suspension is the most appropriate pH for the settling rate. On the other hand, the water clarity values at natural pHs were high for all of the polymers.

  20. Guidelines for the preparation of emergency operating procedures. Resolution of comments on NUREG-0799

    Energy Technology Data Exchange (ETDEWEB)

    1982-08-01

    The purpose of this document is to identify the elements necessary for utilities to prepare and implement a program of Emergency Operating Procedures (EOPs) for use by control room personnel to assist in mitigating the consequences of a broad range of accidents and multiple equipment failures. This document applies only to the EOPs so designated; it does not address emergency preparedness or emergency planning. It also represents the resolution of comments on NUREG-0799, Draft Criteria for Preparation of Emergency Operating Procedures.

  1. 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

  2. Electrokinetics for sample preparation of biological molecules in biological samples using microfluidic systems.

    Science.gov (United States)

    Shallan, Aliaa I; Guijt, Rosanne M; Breadmore, Michael C

    2014-01-01

    Sample preparation is the first part of every analytical method, but is often considered only after the optimization of the method. It is traditionally performed using a range of techniques requiring extensive manual handling, with solid-phase extraction, liquid-liquid extraction, protein precipitation and ultracentrfiguation, among others, being used depending on the targets and the application. In this article, we will focus on alternatives based on electrokinetics for applications including sample clean-up, concentration and derivatization of large biological molecules (DNA, peptides and proteins) of diagnostic importance, as well as small molecules as a tool for therapeutic drug monitoring. This article describes these approaches in terms of mechanisms, applicability and potential to be integrated into a lab-on-a-chip device for directly processing biological samples. Examples dealing with treated or clean samples have been excluded except where they show exceptionally high value.

  3. 7 CFR 52.38 - Sampling plans and procedures for determining lot compliance.

    Science.gov (United States)

    2010-01-01

    ... 7 Agriculture 2 2010-01-01 2010-01-01 false Sampling plans and procedures for determining lot... Sampling § 52.38 Sampling plans and procedures for determining lot compliance. (a) Except as otherwise... Administrator, samples shall be selected from each lot in the exact number of sample units indicated for the lot...

  4. Comparison of sample preparation techniques for large-scale proteomics.

    Science.gov (United States)

    Kuljanin, Miljan; Dieters-Castator, Dylan Z; Hess, David A; Postovit, Lynne-Marie; Lajoie, Gilles A

    2017-01-01

    Numerous workflows exist for large-scale bottom-up proteomics, many of which achieve exceptional proteome depth. Herein, we evaluated the performance of several commonly used sample preparation techniques for proteomic characterization of HeLa lysates [unfractionated in-solution digests, SDS-PAGE coupled with in-gel digestion, gel-eluted liquid fraction entrapment electrophoresis (GELFrEE) technology, SCX StageTips and high-/low-pH reversed phase fractionation (HpH)]. HpH fractionation was found to be superior in terms of proteome depth (>8400 proteins detected) and fractionation efficiency compared to other techniques. SCX StageTip fractionation required minimal sample handling and was also a substantial improvement over SDS-PAGE separation and GELFrEE technology. Sequence coverage of the HeLa proteome increased to 38% when combining all workflows, however, total proteins detected improved only slightly to 8710. In summary, HpH fractionation and SCX StageTips are robust techniques and highly suited for complex proteome analysis. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Review of sample preparation techniques for the analysis of pesticide residues in soil.

    Science.gov (United States)

    Tadeo, José L; Pérez, Rosa Ana; Albero, Beatriz; García-Valcárcel, Ana I; Sánchez-Brunete, Consuelo

    2012-01-01

    This paper reviews the sample preparation techniques used for the analysis of pesticides in soil. The present status and recent advances made during the last 5 years in these methods are discussed. The analysis of pesticide residues in soil requires the extraction of analytes from this matrix, followed by a cleanup procedure, when necessary, prior to their instrumental determination. The optimization of sample preparation is a very important part of the method development that can reduce the analysis time, the amount of solvent, and the size of samples. This review considers all aspects of sample preparation, including extraction and cleanup. Classical extraction techniques, such as shaking, Soxhlet, and ultrasonic-assisted extraction, and modern techniques like pressurized liquid extraction, microwave-assisted extraction, solid-phase microextraction and QuEChERS (Quick, Easy, Cheap, Effective, Rugged, and Safe) are reviewed. The different cleanup strategies applied for the purification of soil extracts are also discussed. In addition, the application of these techniques to environmental studies is considered.

  6. 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.

  7. 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. Copyright © 2017 Elsevier B.V. All rights reserved.

  8. Optimal sampling and sample preparation for NIR-based prediction of field scale soil properties

    Science.gov (United States)

    Knadel, Maria; Peng, Yi; Schelde, Kirsten; Thomsen, Anton; Deng, Fan; Humlekrog Greve, Mogens

    2013-04-01

    The representation of local soil variability with acceptable accuracy and precision is dependent on the spatial sampling strategy and can vary with a soil property. Therefore, soil mapping can be expensive when conventional soil analyses are involved. Visible near infrared spectroscopy (vis-NIR) is considered a cost-effective method due to labour savings and relative accuracy. However, savings may be offset by the costs associated with number of samples and sample preparation. The objective of this study was to find the most optimal way to predict field scale total organic carbon (TOC) and texture. To optimize the vis-NIR calibrations the effects of sample preparation and number of samples on the predictive ability of models with regard to the spatial distribution of TOC and texture were investigated. Conditioned Latin hypercube sampling (cLHs) method was used to select 125 sampling locations from an agricultural field in Denmark, using electromagnetic induction (EMI) and digital elevation model (DEM) data. The soil samples were scanned in three states (field moist, air dried and sieved to 2 mm) with a vis-NIR spectrophotometer (LabSpec 5100, ASD Inc., USA). The Kennard-Stone algorithm was applied to select 50 representative soil spectra for the laboratory analysis of TOC and texture. In order to investigate how to minimize the costs of reference analysis, additional smaller subsets (15, 30 and 40) of samples were selected for calibration. The performance of field calibrations using spectra of soils at the three states as well as using different numbers of calibration samples was compared. Final models were then used to predict the remaining 75 samples. Maps of predicted soil properties where generated with Empirical Bayesian Kriging. The results demonstrated that regardless the state of the scanned soil, the regression models and the final prediction maps were similar for most of the soil properties. Nevertheless, as expected, models based on spectra from field

  9. An Automated Inpatient Split-dose Bowel Preparation System Improves Colonoscopy Quality and Reduces Repeat Procedures.

    Science.gov (United States)

    Yadlapati, Rena; Johnston, Elyse R; Gluskin, Adam B; Gregory, Dyanna L; Cyrus, Rachel; Werth, Lindsay; Ciolino, Jody D; Grande, David P; Keswani, Rajesh N

    2017-07-19

    Inpatient colonoscopy preparations are often inadequate, compromising patient safety and procedure quality, while resulting in greater hospital costs. The aims of this study were to: (1) design and implement an electronic inpatient split-dose bowel preparation order set; (2) assess the intervention's impact upon preparation adequacy, repeated colonoscopies, hospital days, and costs. We conducted a single center prospective pragmatic quasiexperimental study of hospitalized adults undergoing colonoscopy. The experimental intervention was designed using DMAIC (define, measure, analyze, improve, and control) methodology. Prospective data collected over 12 months were compared with data from a historical preintervention cohort. The primary outcome was bowel preparation quality and secondary outcomes included number of repeated procedures, hospital days, and costs. On the basis of a Delphi method and DMAIC process, we created an electronic inpatient bowel preparation order set inclusive of a split-dose bowel preparation algorithm, automated orders for rescue medications, and nursing bowel preparation checks. The analysis data set included 969 patients, 445 (46%) in the postintervention group. The adequacy of bowel preparation significantly increased following intervention (86% vs. 43%; P<0.01) and proportion of repeated procedures decreased (2.0% vs. 4.6%; P=0.03). Mean hospital days from bowel preparation initiation to discharge decreased from 8.0 to 6.9 days (P=0.02). The intervention resulted in an estimated 1-year cost-savings of $46,076 based on a reduction in excess hospital days associated with repeated and delayed procedures. Our interdisciplinary initiative targeting inpatient colonoscopy preparations significantly improved quality and reduced repeat procedures, and hospital days. Other institutions should consider utilizing this framework to improve inpatient colonoscopy value.

  10. The development of audio-visual materials to prepare patients for medical procedures: an oncology application.

    Science.gov (United States)

    Carey, M; Schofield, P; Jefford, M; Krishnasamy, M; Aranda, S

    2007-09-01

    This paper describes a systematic process for the development of educational audio-visual materials that are designed to prepare patients for potentially threatening procedures. Literature relating to the preparation of patients for potentially threatening medical procedures, psychological theory, theory of diffusion of innovations and patient information was examined. Four key principles were identified as being important: (1) stakeholder consultation, (2) provision of information to prepare patients for the medical procedure, (3) evidence-based content, and (4) promotion of patient confidence. These principles are described along with an example of the development of an audio-visual resource to prepare patients for chemotherapy treatment. Using this example, practical strategies for the application of each of the principles are described. The principles and strategies described may provide a practical, evidence-based guide to the development of other types of patient audio-visual materials.

  11. Implementation guide for turbidity threshold sampling: principles, procedures, and analysis

    Science.gov (United States)

    Jack Lewis; Rand Eads

    2009-01-01

    Turbidity Threshold Sampling uses real-time turbidity and river stage information to automatically collect water quality samples for estimating suspended sediment loads. The system uses a programmable data logger in conjunction with a stage measurement device, a turbidity sensor, and a pumping sampler. Specialized software enables the user to control the sampling...

  12. Automated fast procedure for the simultaneous extraction of hair sample performed with an automated workstation.

    Science.gov (United States)

    Angeli, I; Minoli, M; Ravelli, A; Gigli, F; Lodi, F

    2012-05-10

    Hair testing has a leading role in toxicology practice and even more in those aspects tightly linked to the assessment of psychoactive drug use and abuse in social life. The objective of the present study was to develop and validate an automated SPE sample-preparation step, suited for GC/MS confirmation analysis of basic drugs in hair drug control. The method was studied and optimized for quantitative determination and in a second time it was extended to real hair samples. The purpose of method validation was to ensure good reliability, reproducibility and quickness. Janus Automated Workstation (PerkinElmer) was employed to perform SPE hair extraction, using 96-well plate SPEC MP1 acquired from Varian (Agilent Technologies). After derivatization of dried extracts, screening confirmations were performed using gas chromatography (GC) followed by mass spectrometry (MS). GC/MS data were validated following standard guidelines, but our attention was focused on three headings: samples cross-contamination, "memory effect" and extraction recovery. Validation requests were fully accomplished and we always obtained best results with the automated procedure. For instance, analytes mean recovery was between 70 and 90% and data analysis proved that no contamination between samples occurred. The automated workstation has shown good reliability (cross contamination and "memory effect" were tested and excluded), effectiveness (no false negative was detected), solvent saving (500μL/sample vs traditionally LLE 4mL/sample) and quickness (50min for 96 tests cycle). Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

  13. High velocity air microabrasion for conservative tooth preparation: the principle and the clinical procedure.

    Science.gov (United States)

    Feinman, R A

    1995-10-01

    Various technologies within the dental armamentarium are applied to achieve the precise tooth preparations required for the different types of restorations. This article reintroduces the air microabrasion technique, which was first presented in 1945. The popular use of this technique had been postponed, pending the decrease in cost and development of compatible restorative materials to repair the tooth structure. With increased patient demand for less invasive preparation techniques and the decrease of the equipment cost, the use of air microbrasion for tooth preparation has been recognized. The history of the technology, its function, indications, advantages, and limitations are discussed, and a step-by-step clinical procedure is presented. The learning objective of this article is to familiarize the readers with this preparation procedure, enhancing the knowledge of preparation options.

  14. 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.

  15. 40 CFR 87.82 - Sampling and analytical procedures for measuring smoke exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Smoke Emissions (Aircraft Gas Turbine Engines) § 87.82 Sampling and analytical procedures for measuring smoke exhaust emissions. The system and procedures for sampling and...

  16. [Procedural guidelines. Good practice procedures for acquisition and preparation of cryopreserved human amniotic membranes from donor placentas].

    Science.gov (United States)

    Hahn, A; Thanos, M; Reinhard, T; Seitz, B; Steuhl, K-P; Meller, D

    2010-11-01

    A cornea/tissue bank must have an organizational structure in which responsibility and authority to issue directives are clearly defined. It must also use a documented quality management system on the basis of good practice procedures which is maintained to the current standards. The personnel of a cornea/tissue bank must be present in sufficient numbers and be suitably qualified. A cornea/tissue bank must be in possession of appropriate facilities which are suitable for the main purpose of preparation of cryopreserved human amniotic membranes from donor placentas. All equipment must be designed and maintained corresponding to the intended purpose. Deviations from the stipulated quality and safety standards must give rise to documented investigations which include decisions on options for correctional and preventive measures. Acquisition of donors and tissue sampling must be strictly controlled and documented. This also applies to entry of donor tissue in the cornea/tissue bank. Cryopreserved human amniotic membranes can only be preserved from donors undergoing caesarean section and who did not present any known infection of the abdominal cavity or any systemic blood borne infection. Contamination of media used for cryopreservation of donor placenta must be ruled out at least once. Measures must be taken to keep the risk of contamination as low as possible. Cryopreserved human amniotic membranes from donor placentas can only be released if defined criteria are fulfilled. Any suspicion of severe undesired reactions and events for the recipient of an amniotic membrane transplant must be registered with the authorities. The activities of a cornea/tissue bank must maintain and adapt to the state-of-the-art with respect to scientific progress.

  17. Sampling procedure for lake or stream surface water chemistry

    Science.gov (United States)

    Robert Musselman

    2012-01-01

    Surface waters collected in the field for chemical analyses are easily contaminated. This research note presents a step-by-step detailed description of how to avoid sample contamination when field collecting, processing, and transporting surface water samples for laboratory analysis.

  18. 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.

  19. 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.

  20. Monoaminergic uptake in synaptosomes prepared from frozen brain tissue samples of normal and narcoleptic canines.

    Science.gov (United States)

    Valtier, D; Dement, W C; Mignot, E

    1992-08-14

    Canine narcolepsy, a model of the human disorder, is associated with altered catecholamine but not serotonin (5-HT) metabolism in some brain areas, particularly the amygdala. A possible explanation for these global changes could be the existence of specific defects in monoamine uptake processes. We have studied the uptake of [3H]norepinephrine (NE), [3H]dopamine (DA) and [3H]5-HT in synaptosomes prepared from cortex and amygdala of narcoleptic and control Doberman pinscher brains. Since narcoleptic canines are relatively few in number, we have used a specific brain freezing procedure that has been reported to allow restoration of metabolically functional tissue upon thawing. Preliminary studies comparing monoamine uptake in fresh and frozen brain samples of both groups of dogs were carried out and demonstrated that this procedure significantly altered serotoninergic but not noradrenergic and dopaminergic uptake. All further investigations were then done on synaptosomes prepared from frozen samples. Our results demonstrate that synaptosomal uptake of [3H]NE, [3H]DA and [3H]5-HT in cortex and amygdala are not altered in narcolepsy.

  1. Sample preparation and orthogonal chromatography for broad polarity range plasma metabolomics: Application to human subjects with neurodegenerative dementia

    OpenAIRE

    Armirotti, Andrea; Basit, Abdul; Realini, Natalia; Caltagirone, Carlo; Bossù, Paola; Spalletta, Gianfranco; Piomelli, Daniele

    2014-01-01

    We describe a simple protocol for the preparation and orthogonal hydrophobic/hydrophilic LC-MS/MS analysis of mouse and human plasma samples, which enables the untargeted ("shotgun") or targeted profiling of hydrophilic, amphipathic, and hydrophobic constituents of plasma metabolome. The protocol is rapid, efficient, and reliable, and offers several advantages compared to current procedures. When applied to a training set of human plasma samples, the protocol allowed for the rapid acquisition...

  2. Chitosan-based hydrogel for dye removal from aqueous solutions: Optimization of the preparation procedure

    Science.gov (United States)

    Gioiella, Lucia; Altobelli, Rosaria; de Luna, Martina Salzano; Filippone, Giovanni

    2016-05-01

    The efficacy of chitosan-based hydrogels in the removal of dyes from aqueous solutions has been investigated as a function of different parameters. Hydrogels were obtained by gelation of chitosan with a non-toxic gelling agent based on an aqueous basic solution. The preparation procedure has been optimized in terms of chitosan concentration in the starting solution, gelling agent concentration and chitosan-to-gelling agent ratio. The goal is to properly select the material- and process-related parameters in order to optimize the performances of the chitosan-based dye adsorbent. First, the influence of such factors on the gelling process has been studied from a kinetic point of view. Then, the effects on the adsorption capacity and kinetics of the chitosan hydrogels obtained in different conditions have been investigated. A common food dye (Indigo Carmine) has been used for this purpose. Noticeably, although the disk-shaped hydrogels are in the bulk form, their adsorption capacity is comparable to that reported in the literature for films and beads. In addition, the bulk samples can be easily separated from the liquid phase after the adsorption process, which is highly attractive from a practical point of view. Compression tests reveal that the samples do not breakup even after relatively large compressive strains. The obtained results suggest that the fine tuning of the process parameters allows the production of mechanical resistant and highly adsorbing chitosan-based hydrogels.

  3. Preventing and Removing Contamination in a Natural Radiocarbon Sample Preparation Laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Zermeno, P; Kurdyla, D K; Buchholz, B A; Heller, S J; Frantz, B R; Brown, T A; Kashgarian, M

    2002-10-25

    The introduction of elevated {sup 14}C contamination into a natural radiocarbon sample preparation laboratory can occur through many different pathways. The most difficult to control is the introduction of contaminated samples from outside labs. Laboratories can remain {sup 14}C contaminated as a result of earlier tracer based research, even if ''hot'' work has not occurred in the laboratories in decades. Prior to accepting samples from outside collaborators, it is recommended that the collaborators test their labs for {sup 14}C contamination. Any surface in a lab that has high use by multiple people has the potential to be contaminated. The standard procedure for determining whether a collaborator's lab is contaminated consists of swiping lab surfaces with small glass fiber filters wetted with alcohol and measuring them for {sup 14}C content using AMS. Volatile {sup 14}C can be detected by using aerosol monitors consisting of fine soot that is depleted in {sup 14}C. These monitors can be set out in the laboratory in question to check for volatile {sup 14}C contamination. In the event that a hot sample is introduced in the natural radiocarbon sample prep laboratory, all sample submission should be stopped until the lab is declared clean. Samples already being processed should be completed along with {sup 14}C depleted material and measured by AMS. This will help determine if the contaminated samples have affected other samples in the laboratory. After a contamination event, the laboratory and associated equipment requires cleaning or disposal. All surfaces and equipment should be wiped down with acetone or ethanol. All chemicals in use should be disposed of in the appropriate waste containers and those waste containers removed from the lab. Once the natural radiocarbon laboratory has been thoroughly ''cleaned'', several background samples consisting of {sup 14}C depleted material should be processed through the lab and

  4. Influence of Sampling Procedure on Codeine Concentrations in Oral Fluid.

    Science.gov (United States)

    Coucke, Line D; De Smet, Lien; Verstraete, Alain G

    2016-03-01

    For many drugs, there is a poor correlation between the plasma and oral fluid (OF) concentrations, due to differences in OF pH, oral contamination, stimulation of OF flow and variability of the volume of sample taken. The aim of this study was to evaluate the OF/plasma ratio and variability in drug concentration in OF sampled by two commercially available collection systems: Saliva Collection System (SCS) and Quantisal. Blood and OF samples were collected from 12 volunteers after intake of 19.5 mg codeine phosphate. Six persons were sampled by SCS first, followed by Quantisal; six other participants used Quantisal before SCS. The OF content of SCS tubes was measured spectrophotometrically. The Quantisal devices were weighed to correct for the effectively obtained OF volume. Codeine was measured by gas chromatography-mass spectrometry. The mean codeine concentration at 1 h was 29.8 ± 18.8 μg/L in plasma, 72.8 ± 63.9 μg/L in SCS OF and 85.3 ± 72.6 μg/L in Quantisal OF. The mean OF/plasma ratio was 2.30 ± 0.77 (SCS) and 2.69 ± 1.94 (Quantisal). Pearson's correlation coefficient between OF and plasma codeine concentrations was statistically significantly (P = 0.005) higher for SCS (R(2) = 0.745) than for Quantisal (R(2) = 0.403). The variability in ratios with Quantisal was markedly reduced when used after SCS. Codeine concentrations measured in OF taken with SCS correlate better with plasma concentrations than in OF obtained with Quantisal, particularly when Quantisal was used first. © The Author 2015. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  5. A Highly Flexible, Automated System Providing Reliable Sample Preparation in Element- and Structure-Specific Measurements.

    Science.gov (United States)

    Vorberg, Ellen; Fleischer, Heidi; Junginger, Steffen; Liu, Hui; Stoll, Norbert; Thurow, Kerstin

    2016-10-01

    Life science areas require specific sample pretreatment to increase the concentration of the analytes and/or to convert the analytes into an appropriate form for the detection and separation systems. Various workstations are commercially available, allowing for automated biological sample pretreatment. Nevertheless, due to the required temperature, pressure, and volume conditions in typical element and structure-specific measurements, automated platforms are not suitable for analytical processes. Thus, the purpose of the presented investigation was the design, realization, and evaluation of an automated system ensuring high-precision sample preparation for a variety of analytical measurements. The developed system has to enable system adaption and high performance flexibility. Furthermore, the system has to be capable of dealing with the wide range of required vessels simultaneously, allowing for less cost and time-consuming process steps. However, the system's functionality has been confirmed in various validation sequences. Using element-specific measurements, the automated system was up to 25% more precise compared to the manual procedure and as precise as the manual procedure using structure-specific measurements. © 2015 Society for Laboratory Automation and Screening.

  6. An Efficient and Green Procedure for the Preparation of Acylals from ...

    African Journals Online (AJOL)

    NJD

    Alum [KAl(SO4)2.12H2O] is an inexpensive, efficient, non-toxic and mild catalyst for the preparation of acylals from aromatic and heteroaryl aldehydes ... green synthetic solution by avoiding toxic catalysts and hazardous solvents. KEYWORDS .... In order to demonstrate the high selectivity of the procedure, we investigated ...

  7. 45 CFR 640.4 - Responsibilities and procedures for preparation of an environmental assessment.

    Science.gov (United States)

    2010-10-01

    ... an environmental assessment. 640.4 Section 640.4 Public Welfare Regulations Relating to Public... § 640.4 Responsibilities and procedures for preparation of an environmental assessment. (a) Program... environmental impact that the applicant's proposed study may have. (c) Should an environmental assessment be...

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

    DEFF Research Database (Denmark)

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

    2011-01-01

    a novel device with an integrated expansion chamber to culture, arrest and fix metaphase cells followed by a subsequent splashing protocol leading to ample metaphase chromosome spreads on a glass slide for metaphase FISH analysis. The device provides an easy, disposable, low cost, integrated solution...... with minimal handling for metaphase FISH slide preparation....

  9. [Preparation of sedation-analgesia procedures in spanish paediatric emergency departments: A descriptive study].

    Science.gov (United States)

    Míguez Navarro, Concepción; Oikonomopoulou, Niki; Lorente Romero, Jorge; Vázquez López, Paula

    2017-07-24

    The objective of this study was to describe the current practice regarding the preparation of the sedation-analgesia (SA) procedures performed in the paediatric emergency centres in Spain. A multicentre, observational and prospective analytical study was carried out on the SA procedures that were performed on children under 18 years-old in 18 paediatric emergency departments between February 2015 and January 2016. A total of 658 SA procedures were registered in 18 hospitals of Spain, most of them to children older than 24 months. The type of the procedure was: simple analgesia in 57 (8.6%), sedation in 44 (6.7%), SA for a not very painful procedure in 275 (41.8%), and SA for a very painful procedure in 282 (42.9%). Informed consent was requested in 98.6% of the cases. The written form was more frequently preferred in the group of patients that received SA for a very painful procedure (76.6%) in comparison to a painful procedure or to simple analgesia (62.9% and 54.4%, respectively, P<.001). The staff that most frequently performed the SA procedures were the paediatricians of the emergency departments (64.3%), followed by Paediatrics Residents (30.7%). The most frequent reasons for the SA were traumatological (35.9%) and surgical (28.4%). Fasting was observed in 81% of the cases. More than two-thirds (67.3%, n=480) children were monitored, the majority (95.8%) of them using pulse oximetry. The pharmacological strategy used was the administration of one drug in 443 (67.3%) of the cases, mostly nitrous oxide, and a combination of drugs in 215 (32.7%), especially midazolam/ketamine (46.9%). The majority of the SA procedures analysed in this study have been carried out correctly and prepared in accordance with the current guidelines. Copyright © 2017. Publicado por Elsevier España, S.L.U.

  10. Influence of sample preparation on assay of phenolic acids from eggplant.

    Science.gov (United States)

    Luthria, Devanand L; Mukhopadhyay, Sudarsan

    2006-01-11

    Sample preparation is often overlooked and is frequently considered as "a means to an end". This systematic study with a phenolic-enriched substrate, eggplant (Solanum melongena L.), was undertaken to evaluate the substantial variations in the extraction techniques, solvents, and parameters as described in the published literature. Direct comparison of over 10 extraction procedures or conditions was performed to show the importance and influence of sample preparation on the assay of phenolic compounds. Chlorogenic acid (CA) was the most abundant phenolic acid accounting for >75% of the total phenolic acids content extracted from the eggplant sample. Optimum extraction of CA and total phenolics (TP) from Black Bell cultivar of eggplant were obtained when extractions were performed with a mixture of MeOH/H2O at a ratio of 80:20% v/v using a pressurized liquid extractor (PLE) at 100 degrees C. The amount of CA and TP extracted from eggplant by the previously reported procedures using a wrist shaker, rotary shaker, stirring, sonication, or reflux with different extraction solvents (acetone or varying composition of MeOH/H2O solvent mixtures) varied significantly between 5 and 95% as compared to PLE. The predominant phenolic acids in the free phenolic acid fraction of Black Beauty cultivar of eggplant were CA isomers. However, caffeic acid isomers were the major phenolic acids extracted from the base-hydrolyzed fraction. The total amount of caffeic acid extracted from the Italian Neon cultivar was more that twice that of four other eggplant cultivars (Orient Express, Calliope Zebra Stripe, Orient Charm Neon, and Black Beauty).

  11. The Recent Developments in Sample Preparation for Mass Spectrometry-Based Metabolomics.

    Science.gov (United States)

    Gong, Zhi-Gang; Hu, Jing; Wu, Xi; Xu, Yong-Jiang

    2017-07-04

    Metabolomics is a critical member in systems biology. Although great progress has been achieved in metabolomics, there are still some problems in sample preparation, data processing and data interpretation. In this review, we intend to explore the roles, challenges and trends in sample preparation for mass spectrometry- (MS-) based metabolomics. The newly emerged sample preparation methods were also critically examined, including laser microdissection, in vivo sampling, dried blood spot, microwave, ultrasound and enzyme-assisted extraction, as well as microextraction techniques. Finally, we provide some conclusions and perspectives for sample preparation in MS-based metabolomics.

  12. Recent advances in metal-organic frameworks and covalent organic frameworks for sample preparation and chromatographic analysis.

    Science.gov (United States)

    Wang, Xuan; Ye, Nengsheng

    2017-12-01

    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. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  13. Sample preparation for liquid chromatographic analysis of phytochemicals in biological fluids.

    Science.gov (United States)

    Oh, Ju-Hee; Lee, Young-Joo

    2014-01-01

    Natural products have been used traditionally for the treatment and prevention of diseases for thousands of years and are nowadays consumed as dietary supplements and herbal medicine. To ensure the safe and effective use of these herbal products, information about bioavailability of active compounds in plasma or target tissues should be provided via validated analytical methods combined with appropriate sampling methods. To provide comprehensive and abridged information about sample preparation methods for the quantification of phytochemicals in biological samples using liquid chromatography analysis. Sample pre-treatment procedures used in analytical methods for in vivo pharmacokinetic studies of natural compounds or herbal medicines were reviewed. These were categorised according to the biological matrices (plasma, bile, urine, faeces and tissues) and sample clean-up processes (protein precipitation, liquid-liquid extraction and solid-phase extraction). Although various kinds of sample pre-treatment methods have been developed, liquid-liquid extraction is still widely used and solid-phase extraction is becoming increasingly popular because of its efficiency for extensive clean up of complex matrix samples. However, protein precipitation is still favoured due to its simplicity. Sample treatment for phytochemical analysis in biological fluids is an indispensable and critical step to obtain high quality results. This step could dominate the overall analytical process because both the duration of the process as well as the reliability of the data depend in large part on its efficiency. Thus, special attention should be given to the choice of a proper sample treatment method that targets analytes and their biomatrix. Copyright © 2013 John Wiley & Sons, Ltd.

  14. Rapid sample preparation for detection and identification of avian influenza virus from chicken faecal samples using magnetic bead microsystem

    DEFF Research Database (Denmark)

    Dhumpa, Raghuram; Bu, Minqiang; Handberg, Kurt

    2010-01-01

    -PCR is a sensitive method for detection of AIV, it requires sample preparation including separation and purification of AIV and concentrate viral RNA. It is laborious and complex process especially for diagnosis using faecal sample. In this study, magnetic beads were used for immunoseparation of AIV in chicken...... faecal sample by a magnetic microsystem. Using this system, all the 16 hemagglutinin (H) and 9 neuraminidase (N) subtypes of AIV were separated and detected in spiked faecal samples using RT-PCR, without an RNA extraction step. This rapid sample preparation method can be integrated with a total analysis...

  15. Review of online coupling of sample preparation techniques with liquid chromatography.

    Science.gov (United States)

    Pan, Jialiang; Zhang, Chengjiang; Zhang, Zhuomin; Li, Gongke

    2014-03-07

    Sample preparation is still considered as the bottleneck of the whole analytical procedure, and efforts has been conducted towards the automation, improvement of sensitivity and accuracy, and low comsuption of organic solvents. Development of online sample preparation techniques (SP) coupled with liquid chromatography (LC) is a promising way to achieve these goals, which has attracted great attention. This article reviews the recent advances on the online SP-LC techniques. Various online SP techniques have been described and summarized, including solid-phase-based extraction, liquid-phase-based extraction assisted with membrane, microwave assisted extraction, ultrasonic assisted extraction, accelerated solvent extraction and supercritical fluids extraction. Specially, the coupling approaches of online SP-LC systems and the corresponding interfaces have been discussed and reviewed in detail, such as online injector, autosampler combined with transport unit, desorption chamber and column switching. Typical applications of the online SP-LC techniques have been summarized. Then the problems and expected trends in this field are attempted to be discussed and proposed in order to encourage the further development of online SP-LC techniques. Copyright © 2014 Elsevier B.V. All rights reserved.

  16. Desulfurization of Cysteine-Containing Peptides Resulting from Sample Preparation for Protein Characterization by MS

    Science.gov (United States)

    Wang, Zhouxi; Rejtar, Tomas; Zhou, Zhaohui Sunny; Karger, Barry L.

    2010-01-01

    In this paper, we have examined two cysteine modifications resulting from sample preparation for protein characterization by MS: (1) a previously observed conversion of cysteine to dehydroalanine, now found in the case of disulfide mapping and (2) a novel modification corresponding to conversion of cysteine to alanine. Using model peptides, the conversion of cysteine to dehydroalanine via β-elimination of a disulfide bond was seen to result from the conditions of typical tryptic digestion (37 °C, pH 7.0– 9.0) without disulfide reduction and alkylation.. Furthermore, the surprising conversion of cysteine to alanine was shown to occur by heating cysteine containing peptides in the presence of a phosphine (TCEP). The formation of alanine from cysteine, investigated by performing experiments in H2O or D2O, suggested a radical-based desulfurization mechanism unrelated to β-elimination. Importantly, an understanding of the mechanism and conditions favorable for cysteine desulfurization provides insight for the establishment of improved sample preparation procedures of protein analysis. PMID:20049891

  17. 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.

  18. A Method for Microalgae Proteomics Analysis Based on Modified Filter-Aided Sample Preparation.

    Science.gov (United States)

    Li, Song; Cao, Xupeng; Wang, Yan; Zhu, Zhen; Zhang, Haowei; Xue, Song; Tian, Jing

    2017-11-01

    With the fast development of microalgal biofuel researches, the proteomics studies of microalgae increased quickly. A filter-aided sample preparation (FASP) method is widely used proteomics sample preparation method since 2009. Here, a method of microalgae proteomics analysis based on modified filter-aided sample preparation (mFASP) was described to meet the characteristics of microalgae cells and eliminate the error caused by over-alkylation. Using Chlamydomonas reinhardtii as the model, the prepared sample was tested by standard LC-MS/MS and compared with the previous reports. The results showed mFASP is suitable for most of occasions of microalgae proteomics studies.

  19. 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.

  20. 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

    2017-09-01

    The improvement of doping control is an ongoing race. Techniques to fight 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. Copyright © 2017 John Wiley & Sons, Ltd. Copyright © 2017 John Wiley & Sons, Ltd.

  1. 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)

  2. 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

  3. Sample Preparation (SS): SE60_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available ch.com/) and a zirconia bead for 6 min at 20 Hz. Samples were centrifuged at 15 000 g for 10 min. ... ...emicals.com/), using a mixer mill (MM 300, Retsch, Haan, Germany, http://www.rets

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

    Lifescience Database Archive (English)

    Full Text Available ,000g for 10 min and filtration (Ultrafree-MC filter, 0.2 mm, Millipore), the sample extracts were applied t...o an HLB mElution plate (Waters) equilibrated with 80% aqueous methanol containing 0.1% acetic acid. ...

  5. 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

  6. 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

  7. Automated dried blood spots standard and QC sample preparation using a robotic liquid handler.

    Science.gov (United States)

    Yuan, Long; Zhang, Duxi; Aubry, Anne-Francoise; Arnold, Mark E

    2012-12-01

    A dried blood spot (DBS) bioanalysis assay involves many steps, such as the preparation of standard (STD) and QC samples in blood, the spotting onto DBS cards, and the cutting-out of the spots. These steps are labor intensive and time consuming if done manually, which, therefore, makes automation very desirable in DBS bioanalysis. A robotic liquid handler was successfully applied to the preparation of STD and QC samples in blood and to spot the blood samples onto DBS cards using buspirone as the model compound. This automated preparation was demonstrated to be accurate and consistent. However the accuracy and precision of automated preparation were similar to those from manual preparation. The effect of spotting volume on accuracy was evaluated and a trend of increasing concentrations of buspirone with increasing spotting volumes was observed. The automated STD and QC sample preparation process significantly improved the efficiency, robustness and safety of DBS bioanalysis.

  8. Influence of manufacturing procedure on stability of Unguentum contra perniones preparations

    OpenAIRE

    Bošković Mirjana; Toskić-Radojičić Marija

    2005-01-01

    Background. Application of various technological procedures for the manufacture of officinal preparation ointment against chilblains (Unguentum contra perniones) produce essential variations in the quality and stability of the final product. Changing the sequence of admixing active substances into the ointment base indicated the presence of incompatibility between the active substances, as well as between the active substances and the ointment base components. The aim was to examine the influ...

  9. Ultrasonic-based membrane aided sample preparation of urine proteomes.

    Science.gov (United States)

    Jesus, Jemmyson Romário; Santos, Hugo M; López-Fernández, H; Lodeiro, Carlos; Arruda, Marco Aurélio Zezzi; Capelo, J L

    2018-02-01

    A new ultrafast ultrasonic-based method for shotgun proteomics as well as label-free protein quantification in urine samples is developed. The method first separates the urine proteins using nitrocellulose-based membranes and then proteins are in-membrane digested using trypsin. The enzymatic digestion process is accelerated from overnight to four minutes using a sonoreactor ultrasonic device. Overall, the sample treatment pipeline comprising protein separation, digestion and identification is done in just 3h. The process is assessed using urine of healthy volunteers. The method shows that male can be differentiated from female using the protein content of urine in a fast, easy and straightforward way. 232 and 226 proteins are identified in urine of male and female, respectively. From this, 162 are common to both genders, whilst 70 are unique to male and 64 to female. From the 162 common proteins, 13 are present at levels statistically different (p minimalism concept as outlined by Halls, as each stage of this analysis is evaluated to minimize the time, cost, sample requirement, reagent consumption, energy requirements and production of waste products. Copyright © 2017 Elsevier B.V. All rights reserved.

  10. How to prepare cytological samples for molecular testing.

    Science.gov (United States)

    Bellevicine, Claudio; Malapelle, Umberto; Vigliar, Elena; Pisapia, Pasquale; Vita, Giulia; Troncone, Giancarlo

    2017-10-01

    This review is focused on the challenges in standardising and optimising molecular testing workflow in cytopathology. Although cytological samples yield optimal quality DNA, whose minimal amounts in most cases suffice even for multigene mutational profiling, the success of molecular testing is strongly dependent on standardised preanalytical protocols for maximising DNA yield and quality. Sample cytopreparation influences, even more, the quality of RNA and consequently the potential success of reverse transcription-PCR. Here, the educational and technical involvement of the cytopathologist as a relevant component of a multidisciplinary team, in the issues related to test request, specimen collection, fixation, processing, staining, tumour fraction enrichment, DNA quality/quantity assessment and storage conditions is discussed. In addition, the specific sample requirements related to more recent technological developments are examined, underlining the modern role of the cytopathologist, whose continuous education is crucial to meet the opportunities of molecular medicine. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2017. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

  11. Development of automated preparation system for isotopocule analysis of N2O in various air samples

    Science.gov (United States)

    Toyoda, Sakae; Yoshida, Naohiro

    2016-05-01

    Nitrous oxide (N2O), an increasingly abundant greenhouse gas in the atmosphere, is the most important stratospheric ozone-depleting gas of this century. Natural abundance ratios of isotopocules of N2O, NNO molecules substituted with stable isotopes of nitrogen and oxygen, are a promising index of various sources or production pathways of N2O and of its sink or decomposition pathways. Several automated methods have been reported to improve the analytical precision for the isotopocule ratio of atmospheric N2O and to reduce the labor necessary for complicated sample preparation procedures related to mass spectrometric analysis. However, no method accommodates flask samples with limited volume or pressure. Here we present an automated preconcentration system which offers flexibility with respect to the available gas volume, pressure, and N2O concentration. The shortest processing time for a single analysis of typical atmospheric sample is 40 min. Precision values of isotopocule ratio analysis are automated systems, but better than that of our previously reported manual measurement system.

  12. 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.

  13. Analytical procedures for determining Pb and Sr isotopic compositions in water samples by ID-TIMS

    Directory of Open Access Journals (Sweden)

    Veridiana Martins

    2008-01-01

    Full Text Available Few articles deal with lead and strontium isotopic analysis of water samples. The aim of this study was to define the chemical procedures for Pb and Sr isotopic analyses of groundwater samples from an urban sedimentary aquifer. Thirty lead and fourteen strontium isotopic analyses were performed to test different analytical procedures. Pb and Sr isotopic ratios as well as Sr concentration did not vary using different chemical procedures. However, the Pb concentrations were very dependent on the different procedures. Therefore, the choice of the best analytical procedure was based on the Pb results, which indicated a higher reproducibility from samples that had been filtered and acidified before the evaporation, had their residues totally dissolved, and were purified by ion chromatography using the Biorad® column. Our results showed no changes in Pb ratios with the storage time.

  14. On the assessment of extremely low breakdown probabilities by an inverse sampling procedure [gaseous insulation

    DEFF Research Database (Denmark)

    Thyregod, Poul; Vibholm, Svend

    1991-01-01

    the flashover probability function and the corresponding distribution of first breakdown voltages under the inverse sampling procedure, and show how this relation may be utilized to assess the single-shot flashover probability corresponding to the observed average first breakdown voltage. Since the procedure...

  15. 40 CFR 87.64 - Sampling and analytical procedures for measuring gaseous exhaust emissions.

    Science.gov (United States)

    2010-07-01

    ... AGENCY (CONTINUED) AIR PROGRAMS (CONTINUED) CONTROL OF AIR POLLUTION FROM AIRCRAFT AND AIRCRAFT ENGINES Test Procedures for Engine Exhaust Gaseous Emissions (Aircraft and Aircraft Gas Turbine Engines) § 87.64 Sampling and analytical procedures for measuring gaseous exhaust emissions. (a) The system and...

  16. Empirical aspects about Heckman Procedure Application: Is there sample selection bias in the Brazilian Industry

    OpenAIRE

    Flávio Kaue Fiuza-Moura; Katy Maia

    2015-01-01

    There are several labor market researches whose main goal is to analyze the probability of employment and the structure of wage determination and, for empirical purposes, most of these researches deploy Heckman sample selection bias hazard detection and correction procedure. However, few Brazilian studies are focused in this procedure applicability, especially concerning specific industries. This paper aims to approach these issues by testing the existence of sample selection bias in Brazilia...

  17. An improved stool concentration procedure for the detection of Cryptosporidium oocysts in Orang Asli stool samples.

    Science.gov (United States)

    Salleh, Fatmah Md; Moktar, Norhayati; Yasin, Azlin Mohd; Al-Mekhlafi, Hesham M; Anuar, Tengku Shahrul

    2014-11-01

    To improve the stool concentration procedure, we modified different steps of the standard formalin-ether concentration technique and evaluated these modifications by examining stool samples collected in the field. Seven samples were found positive by the modified formalin-ether concentration technique (M-FECT). Therefore, the M-FECT procedure provides enhanced detection of Cryptosporidium oocysts. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Mercury speciation in seafood samples by LC-ICP-MS with a rapid ultrasound-assisted extraction procedure: Application to the determination of mercury in Brazilian seafood samples.

    Science.gov (United States)

    Batista, Bruno Lemos; Rodrigues, Jairo L; de Souza, Samuel S; Oliveira Souza, Vanessa C; Barbosa, Fernando

    2011-06-15

    This paper describes a simple method for mercury speciation in seafood samples by LC-ICP-MS with a fast sample preparation procedure. Prior to analysis, mercury species were extracted from food samples with a solution containing mercaptoethanol, l-cysteine and HCl and sonication for 15min. Separation of mercury species was accomplished in less than 5min on a C8 reverse phase column with a mobile phase containing 0.05%-v/v mercaptoethanol, 0.4%m/v l-cysteine and 0.06molL(-1) ammonium acetate. The method detection limits were found to be 0.25, 0.20 and 0.1ngg(-1) for inorganic mercury, ethylmercury and methylmercury, respectively. Method accuracy is traceable to Certified Reference Materials (DOLT-3 and DORM-3) from the National Research Council Canada (NRCC). With the proposed method there is a considerable reduction of the time of sample preparation. Finally, the method was applied for the speciation of mercury in seafood samples purchased from the Brazilian market. Copyright © 2010 Elsevier Ltd. All rights reserved.

  19. Sample preparation for mass spectrometry imaging of plant tissues: a review

    Directory of Open Access Journals (Sweden)

    Yonghui eDong

    2016-02-01

    Full Text Available Mass spectrometry imaging (MSI is a mass spectrometry based molecular ion imaging technique. It provides the means for ascertaining the spatial distribution of a large variety of analytes directly on tissue sample surfaces without any labeling or staining steps. These advantages make it an attractive molecular histology tool in medical, pharmaceutical and biological research. Likewise, MSI has started gaining popularity in plant sciences; yet, information regarding sample preparation methods specific for plant tissues is still limited. Sample preparation is a crucial step that is directly associated with the quality and authenticity of the imaging results, it therefore demands in-depth studies based on the characteristics of plant samples. In this review, a sample preparation pipeline is discussed in detail and illustrated through selected practical examples. In particular, special concerns regarding sample preparation for plant imaging are critically evaluated. Finally, the applications of various MSI techniques in plants are reviewed according to different classes of plant metabolites.

  20. Bovine liver sample preparation and micro-homogeneity study for Cu and Zn determination by solid sampling electrothermal atomic absorption spectrometry

    Science.gov (United States)

    Nomura, Cassiana S.; Silva, Cíntia S.; Nogueira, Ana R. A.; Oliveira, Pedro V.

    2005-06-01

    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 °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 °C and 2300 °C for Cu, and 700 °C and 1700 °C for Zn, respectively. For both elements, it was possible to calibrate the spectrometer with aqueous solutions. The use of 250 μg of W + 200 μg 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 μg for Cu and 30 μg for Zn. The concentrations of Cu and Zn in the prepared bovine liver sample were 223 mg kg - 1 and 128 mg kg - 1, respectively. The relative standard deviations were lower than 6% ( n = 5). The accuracy of the entire

  1. Delineating sampling procedures: Pedagogical significance of analysing sampling descriptions and their justifications in TESL experimental research reports

    Directory of Open Access Journals (Sweden)

    Jason Miin-Hwa Lim

    2011-04-01

    Full Text Available Teaching second language learners how to write research reports constitutes a crucial component in programmes on English for Specific Purposes (ESP in institutions of higher learning. One of the rhetorical segments in research reports that merit attention has to do with the descriptions and justifications of sampling procedures. This genre-based study looks into sampling delineations in the Method-related sections of research articles on the teaching of English as a second language (TESL written by expert writers and published in eight reputed international refereed journals. Using Swales’s (1990 & 2004 framework, I conducted a quantitative analysis of the rhetorical steps and a qualitative investigation into the language resources employed in delineating sampling procedures. This investigation has considerable relevance to ESP students and instructors as it has yielded pertinent findings on how samples can be appropriately described to meet the expectations of dissertation examiners, reviewers, and supervisors. The findings of this study have furnished insights into how supervisors and instructors can possibly teach novice writers ways of using specific linguistic mechanisms to lucidly describe and convincingly justify the sampling procedures in the Method sections of experimental research reports.

  2. Preparation of clay mineral samples for high resolution x-ray imaging

    Science.gov (United States)

    Abbati, Gennaro; Seim, Christian; Legall, Herbert; Stiel, Holger; Thomas, Noel; Wilhein, Thomas

    2013-10-01

    In the development of optimum ceramic materials for plastic forming, it is of fundamental importance to gain insight into the compositions of the clay minerals. Whereas spectroscopic methods are adequate for determining the elemental composition of a given sample, a knowledge of the spatial composition, together with the shape and size of the particles leads to further, valuable insight. This requires an imaging technique such as high resolution X-ray microscopy. In addition, fluorescence spectroscopy provides a viable element mapping technique. Since the fine particle fraction of the materials has a major effect on physical properties like plasticity, the analysis is focused mainly on the smallest particles. To separate these from the bigger agglomerates, the raw material has to pass through several procedures like centrifugation and filtering. After that, one has to deposit a layer of appropriate thickness on to a suitable substrate. These preparative techniques are described here, starting from the clay mineral raw materials and proceeding through to samples that are ready to analyze. First results using high resolution x-ray imaging are shown.

  3. Site-Specific Cryo-focused Ion Beam Sample Preparation Guided by 3D Correlative Microscopy.

    Science.gov (United States)

    Arnold, Jan; Mahamid, Julia; Lucic, Vladan; de Marco, Alex; Fernandez, Jose-Jesus; Laugks, Tim; Mayer, Tobias; Hyman, Anthony A; Baumeister, Wolfgang; Plitzko, Jürgen M

    2016-02-23

    The development of cryo-focused ion beam (cryo-FIB) for the thinning of frozen-hydrated biological specimens enabled cryo-electron tomography (cryo-ET) analysis in unperturbed cells and tissues. However, the volume represented within a typical FIB lamella constitutes a small fraction of the biological specimen. Retaining low-abundance and dynamic subcellular structures or macromolecular assemblies within such limited volumes requires precise targeting of the FIB milling process. In this study, we present the development of a cryo-stage allowing for spinning-disk confocal light microscopy at cryogenic temperatures and describe the incorporation of the new hardware into existing workflows for cellular sample preparation by cryo-FIB. Introduction of fiducial markers and subsequent computation of three-dimensional coordinate transformations provide correlation between light microscopy and scanning electron microscopy/FIB. The correlative approach is employed to guide the FIB milling process of vitrified cellular samples and to capture specific structures, namely fluorescently labeled lipid droplets, in lamellas that are 300 nm thick. The correlation procedure is then applied to localize the fluorescently labeled structures in the transmission electron microscopy image of the lamella. This approach can be employed to navigate the acquisition of cryo-ET data within FIB-lamellas at specific locations, unambiguously identified by fluorescence microscopy. Copyright © 2016 Biophysical Society. Published by Elsevier Inc. All rights reserved.

  4. Rapid and efficient filtration-based procedure for separation and safe analysis of CBRN mixed samples.

    Directory of Open Access Journals (Sweden)

    Mostafa Bentahir

    Full Text Available Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV, Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA and pinacolyl methylphophonic acid (PMPA were used as VX and soman (GD nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm and three RNA extraction methods (Invisorb, EZ1 and Nuclisens were compared. RNA (MS2 and DNA (AcNPV quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR. Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  5. Rapid and Efficient Filtration-Based Procedure for Separation and Safe Analysis of CBRN Mixed Samples

    Science.gov (United States)

    Bentahir, Mostafa; Laduron, Frederic; Irenge, Leonid; Ambroise, Jérôme; Gala, Jean-Luc

    2014-01-01

    Separating CBRN mixed samples that contain both chemical and biological warfare agents (CB mixed sample) in liquid and solid matrices remains a very challenging issue. Parameters were set up to assess the performance of a simple filtration-based method first optimized on separate C- and B-agents, and then assessed on a model of CB mixed sample. In this model, MS2 bacteriophage, Autographa californica nuclear polyhedrosis baculovirus (AcNPV), Bacillus atrophaeus and Bacillus subtilis spores were used as biological agent simulants whereas ethyl methylphosphonic acid (EMPA) and pinacolyl methylphophonic acid (PMPA) were used as VX and soman (GD) nerve agent surrogates, respectively. Nanoseparation centrifugal devices with various pore size cut-off (30 kD up to 0.45 µm) and three RNA extraction methods (Invisorb, EZ1 and Nuclisens) were compared. RNA (MS2) and DNA (AcNPV) quantification was carried out by means of specific and sensitive quantitative real-time PCRs (qPCR). Liquid chromatography coupled to time-of-flight mass spectrometry (LC/TOFMS) methods was used for quantifying EMPA and PMPA. Culture methods and qPCR demonstrated that membranes with a 30 kD cut-off retain more than 99.99% of biological agents (MS2, AcNPV, Bacillus Atrophaeus and Bacillus subtilis spores) tested separately. A rapid and reliable separation of CB mixed sample models (MS2/PEG-400 and MS2/EMPA/PMPA) contained in simple liquid or complex matrices such as sand and soil was also successfully achieved on a 30 kD filter with more than 99.99% retention of MS2 on the filter membrane, and up to 99% of PEG-400, EMPA and PMPA recovery in the filtrate. The whole separation process turnaround-time (TAT) was less than 10 minutes. The filtration method appears to be rapid, versatile and extremely efficient. The separation method developed in this work constitutes therefore a useful model for further evaluating and comparing additional separation alternative procedures for a safe handling and

  6. 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. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. 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.)

  8. Sample preparation with an automated robotic workstation for organic acid analysis by gas chromatography-mass spectrometry.

    Science.gov (United States)

    Bengtsson, I M; Lehotay, D C

    1996-10-11

    We attempted to automate sample preparation for analysis of organic acids by gas chromatography-mass spectrometry using a computer-controlled, automated robotic workstation that is integrated and connected to the gas chromatography-mass spectrometry (HP-5890/5971) system. Of the two methods developed, one employed solvent extraction, while the other utilized a silica, solid-phase extraction cartridge. Both automated methods were compared to a manual, solvent extraction procedure used routinely in our laboratory. Normal, spiked urine, and urine from patients with a variety of metabolic abnormalities were analyzed. The robotic workstation did not meet all our requirements for a rapid, reliable, laboratory device. Recoveries with the automated procedures were less than with the manual method, and some organic acids important in the diagnosis of inborn errors of metabolism were not detected. Additionally, the robotic device had mechanical and design problems that made it slower and less reliable than the manual procedure.

  9. CTEPP STANDARD OPERATING PROCEDURE FOR SAMPLE SELECTION (SOP-1.10)

    Science.gov (United States)

    The procedures for selecting CTEPP study subjects are described in the SOP. The primary, county-level stratification is by region and urbanicity. Six sample counties in each of the two states (North Carolina and Ohio) are selected using stratified random sampling and reflect ...

  10. 77 FR 58804 - Testing of Product Samples for Listeria monocytogenes: Changes in Procedures

    Science.gov (United States)

    2012-09-24

    ... Food Safety and Inspection Service Testing of Product Samples for Listeria monocytogenes: Changes in... Inspection Service (FSIS) is announcing changes in procedures for Listeria (L.) monocytogenes product... products for laboratory analysis (21 U.S.C. 642(a) and 460(b)). RTE Sampling Programs for Listeria...

  11. 40 CFR 61.207 - Radium-226 sampling and measurement procedures.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 8 2010-07-01 2010-07-01 false Radium-226 sampling and measurement... for Radon Emissions From Phosphogypsum Stacks § 61.207 Radium-226 sampling and measurement procedures... § 61.206, the owner or operator of a phosphogypsum stack shall measure the average radium-226...

  12. 50 CFR 260.61 - Sampling plans and procedures for determining lot compliance.

    Science.gov (United States)

    2010-10-01

    ... determining lot compliance. 260.61 Section 260.61 Wildlife and Fisheries NATIONAL MARINE FISHERIES SERVICE... Sampling plans and procedures for determining lot compliance. (a) Except as otherwise provided for in this... shall be selected from each lot in the exact number of sample units indicated for the lot size in the...

  13. Spin column extraction as a new sample preparation method in bioanalysis.

    Science.gov (United States)

    Namera, Akira; Saito, Takashi

    2015-01-01

    Sample preparation is important in obtaining accurate data for qualification and quantification in bioanalysis. We have recently focused on monolithic silica for high-throughput analysis. These extraction processes - using monolithic silica packed in spin column - such as sample loading, washing and elution, are executed by centrifugation. There are several possibilities such as on-column derivatization for the determination of amines or carboxylic acids in the sample. The spin column extraction reduces the sample preparation time required for determination of drugs and other chemicals in biological materials and increases productivity in bioanalysis. We expect spin column extraction to become the mainstream method of sample processing in the future.

  14. 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.

  15. Simulated Waste for Leaching and Filtration Studies--Laboratory Preparation Procedure

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Harry D.; Russell, Renee L.; Peterson, Reid A.

    2009-10-27

    This report discusses the simulant preparation procedure for producing multi-component simulants for leaching and filtration studies, including development and comparison activities in accordance with the test plan( ) prepared and approved in response to the Test Specification 24590-WTP-TSP-RT-06-006, Rev 0 (Smith 2006). A fundamental premise is that this approach would allow blending of the different components to simulate a wide variety of feeds to be treated in the Hanford Tank Waste Treatment and Immobilization Plant (WTP). For example, a given feed from the planned feed vector could be selected, and the appropriate components would then be blended to achieve a representation of that particular feed. Using the blending of component simulants allows the representation of a much broader spectrum of potential feeds to the Pretreatment Engineering Platform (PEP).

  16. 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

  17. A recommended procedure for establishing the source level relationships between heroin case samples of unknown origins

    Directory of Open Access Journals (Sweden)

    Kar-Weng Chan

    2014-06-01

    Full Text Available A recent concern of how to reliably establish the source level relationships of heroin case samples is addressed in this paper. Twenty-two trafficking heroin case samples of unknown origins seized from two major regions (Kuala Lumpur and Penang in Malaysia were studied. A procedure containing six major steps was followed to analyze and classify these samples. Subsequently, with the aid of statistical control samples, reliability of the clustering result was assessed. The final outcome reveals that the samples seized from the two regions in 2013 had highly likely originated from two different sources. Hence, the six-step procedure is sufficient for any chemist who attempts to assess the relative source level relationships of heroin samples.

  18. Publishing nutrition research: a review of sampling, sample size, statistical analysis, and other key elements of manuscript preparation, Part 2.

    Science.gov (United States)

    Boushey, Carol J; Harris, Jeffrey; Bruemmer, Barbara; Archer, Sujata L

    2008-04-01

    Members of the Board of Editors recognize the importance of providing a resource for researchers to insure quality and accuracy of reporting in the Journal. This second monograph of a periodic series focuses on study sample selection, sample size, and common statistical procedures using parametric methods, and the presentation of statistical methods and results. Attention to sample selection and sample size is critical to avoid study bias. When outcome variables adhere to a normal distribution, then parametric procedures can be used for statistical inference. Documentation that clearly outlines the steps used in the research process will advance the science of evidence-based practice in nutrition and dietetics. Real examples from problem sets and published literature are provided, as well as reference to books and online resources.

  19. 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). © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  20. Sample treatment procedures for the determination of mineral constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry

    Directory of Open Access Journals (Sweden)

    Mendes Teresa M. F. F.

    2006-01-01

    Full Text Available Preparative methods for quantification of inorganic constituents in honey by Inductively Coupled Plasma Optical Emission Spectrometry (ICP OES using microwave assisted digestion and ultrasonication procedures were developed. Analytical aspects such as matrix complexity, instrumental optimization and the essentiality/toxicity of the species K, Ca, Mg, Na, Fe, Mn, Zn, Cu, Co, Ni, Pb, Cd were considered. Parameters such as plasma power, nebulizer flow rate, torch configuration and the convenience of the use of yttrium as internal standard were evaluated. Recoveries between 93 and 107% (microwave digestion and between 90 to 110% (ultrasonication procedure and relative standard deviations lower than 10% were obtained. Samples of Brazilian honeys, from different parts of the country, were analysed and the results obtained provide relevant information about their mineral content.

  1. 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...

  2. 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...

  3. In-Situ Sample Preparation Development for Extraterrestrial Life Detection and Characterization

    Science.gov (United States)

    Craft, K. L.; Bradburne, C.; Tiffany, J.; Hagedon, M.; Hibbitts, C.; Vandegriff, J.; Horst, S.

    2017-02-01

    In-situ life detection instrumentation require robust sample preparation techniques that need further development in the coming years to enable the exciting life discoveries we seek in both familiar and unfamiliar planetary environments.

  4. Optimised sample preparation of synovial fluid for detection of Chlamydia trachomatis DNA by polymerase chain reaction

    Science.gov (United States)

    Kuipers, J.; Nietfeld, L.; Dreses-Werringloe..., U.; Koehler, L.; Wollenhaupt, J.; Zeidler, H.; Hammer, M.

    1999-01-01

    OBJECTIVE—To optimise sample preparation of synovial fluid for Chlamydia trachomatis (CT) specific polymerase chain reaction (PCR).
METHODS—Serial dilutions of purified CT elementary bodies in synovial fluid were prepared. The synovial fluid pellet was processed by eight different methods of sample preparation. Then samples were analysed by CT specific PCR. The sensitivity of PCR was the basis of ranking of the eight different methods.
RESULTS—Highest sensitivity was achieved by methods including an additional step of DNA isolation. Additional extraction of protein and polysaccharides by cetyltrimethylammonium bromide (CTAB) increased sensitivity. Addition of hyaluronidase did not increase sensitivity of QIAEX-DNA extraction but was necessary, however, before phenol-chloroform-DNA extraction.
CONCLUSIONS—The method of synovial fluid sample preparation significantly influences the sensitivity of subsequent PCR. Additional DNA isolation and extraction of PCR inhibitors by CTAB led to higher sensitivity.

 Keywords: Chlamydia trachomatis; polymerase chain reaction; synovial fluid PMID:10343525

  5. Electrodeposition as an alternate method for preparation of environmental samples for iodide by AMS

    Energy Technology Data Exchange (ETDEWEB)

    Adamic, M.L., E-mail: Mary.Adamic@inl.gov [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Lister, T.E.; Dufek, E.J.; Jenson, D.D.; Olson, J.E. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States); Vockenhuber, C. [Laboratory of Ion Beam Physics, ETH Zurich, Otto-Stern-Weg 5, 8093 Zurich (Switzerland); Watrous, M.G. [Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83402 (United States)

    2015-10-15

    This paper presents an evaluation of an alternate method for preparing environmental samples for {sup 129}I analysis by accelerator mass spectrometry (AMS) at Idaho National Laboratory. The optimal sample preparation method is characterized by ease of preparation, capability of processing very small quantities of iodide, and ease of loading into a cathode. Electrodeposition of iodide on a silver wire was evaluated using these criteria. This study indicates that the electrochemically-formed silver iodide deposits produce ion currents similar to those from precipitated silver iodide for the same sample mass. Precipitated silver iodide samples are usually mixed with niobium or silver powder prior to loading in a cathode. Using electrodeposition, the silver is already mixed with the sample and can simply be picked up with tweezers, placed in the sample die, and pressed into a cathode. The major advantage of this method is that the silver wire/electrodeposited silver iodide is much easier to load into a cathode.

  6. 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.

  7. Sample preparation method for glass welding by ultrashort laser pulses yields higher seam strength.

    Science.gov (United States)

    Cvecek, K; Miyamoto, I; Strauss, J; Wolf, M; Frick, T; Schmidt, M

    2011-05-01

    Glass welding by ultrashort laser pulses allows joining without the need of an absorber or a preheating and postheating process. However, cracks generated during the welding process substantially impair the joining strength of the welding seams. In this paper a sample preparation method is described that prevents the formation of cracks. The measured joining strength of samples prepared by this method is substantially higher than previously reported values.

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

    Lifescience Database Archive (English)

    Full Text Available switchLanguage; BLAST Search Image Search Home About Archive Update History Data List Contact us Metabol...ed to by S (Sample information). Data file File name: metabolonote_sample_prepara...tion_details.zip File URL: ftp://ftp.biosciencedbc.jp/archive/metabolonote/LATEST/metabolonote_sample_prepar...ation_details.zip File size: 13 KB Simple search URL http://togodb.biosciencedbc.jp/togodb/view/metabolonote...ption Download License Update History of This Database Site Policy | Contact Us Sample Preparation (SS) - Metabolonote | LSDB Archive ...

  9. Evaluation of accuracy in implant site preparation performed in single- or multi-step drilling procedures.

    Science.gov (United States)

    Marheineke, Nadine; Scherer, Uta; Rücker, Martin; von See, Constantin; Rahlf, Björn; Gellrich, Nils-Claudius; Stoetzer, Marcus

    2017-12-17

    Dental implant failure and insufficient osseointegration are proven results of mechanical and thermal damage during the surgery process. We herein performed a comparative study of a less invasive single-step drilling preparation protocol and a conventional multiple drilling sequence. Accuracy of drilling holes was precisely analyzed and the influence of different levels of expertise of the handlers and additional use of drill template guidance was evaluated. Six experimental groups, deployed in an osseous study model, were representing template-guided and freehanded drilling actions in a stepwise drilling procedure in comparison to a single-drill protocol. Each experimental condition was studied by the drilling actions of respectively three persons without surgical knowledge as well as three highly experienced oral surgeons. Drilling actions were performed and diameters were recorded with a precision measuring instrument. Less experienced operators were able to significantly increase the drilling accuracy using a guiding template, especially when multi-step preparations are performed. Improved accuracy without template guidance was observed when experienced operators were executing single-step versus multi-step technique. Single-step drilling protocols have shown to produce more accurate results than multi-step procedures. The outcome of any protocol can be further improved by use of guiding templates. Operator experience can be a contributing factor. Single-step preparations are less invasive and are promoting osseointegration. Even highly experienced surgeons are achieving higher levels of accuracy by combining this technique with template guidance. Hereby template guidance enables a reduction of hands-on time and side effects during surgery and lead to a more predictable clinical diameter.

  10. Evaluation of Sampling and Sample Preparation Modifications for Soil Containing Metallic Residues

    Science.gov (United States)

    2012-01-01

    representation of the overall experimental design. Soil samples were transported to CRREL and air-dried on alumi - num trays. Once air-dried, each...60 s and then spread out onto an alumi - num cookie sheet. Digestion generally followed USEPA Method 3050B with the following exceptions. Two grams of

  11. 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. Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.

  12. Empirical aspects about Heckman Procedure Application: Is there sample selection bias in the Brazilian Industry

    Directory of Open Access Journals (Sweden)

    Flávio Kaue Fiuza-Moura

    2015-12-01

    Full Text Available There are several labor market researches whose main goal is to analyze the probability of employment and the structure of wage determination and, for empirical purposes, most of these researches deploy Heckman sample selection bias hazard detection and correction procedure. However, few Brazilian studies are focused in this procedure applicability, especially concerning specific industries. This paper aims to approach these issues by testing the existence of sample selection bias in Brazilian manufacturing industry, and to analyze the impact of the bias correction procedure over the estimated coefficients of OLS Mincer equations. We found sample selection bias hazard only in manufacturing segments which average wages are lower than market average and only in groups of workers which average wage level is below the market average (women, especially blacks. The analysis and comparison of Mincer equations with and without Heckman’s sample selection bias correction procedure brought up that the estimation’s coefficients related to wage differential for male over female workers and the wage differential for urban over non-urban workers tends to be overestimated in cases which the sample selection bias isn’t corrected.

  13. Clinical Evaluation of Different Pre-impression Preparation Procedures of Dental Arch.

    Science.gov (United States)

    Arora, Nitin; Arora, Monika; Gupta, Naveen; Agarwal, Manisha; Verma, Rohit; Rathod, Pankaj

    2015-07-01

    Bubbles and voids on the occlusal surface impede the actual intercuspation and pre-impression preparation aims to reduce the incidence of air bubbles and voids as well as influences the quality of occlusal reproduction and actual clinical intercuspation in the articulator. The study was undertaken to determine the influence of different pre-impression preparation procedures of antagonistic dental arch on the quality of the occlusal reproduction of the teeth in irreversible hydrocolloid impressions and to determine most reliable pre-impression preparation method to reduce the incidence of air bubbles. A total of 20 subjects were selected having full complement of mandibular teeth from second molar to second molar with well demarcated cusp height. 200 impressions were made with irreversible hydrocolloid material. The impressions were divided into five groups of 40 impressions each and each group had one specific type of pre-impression preparation. All the impressions were poured in die stone. A stereomicroscope with graduated eyepiece was used to count the number of bubbles on the occlusal surface of premolars and molars. The mean and standard deviations were calculated for each group. Mann-Whitney U-test was applied to find the significant difference between different groups. Least bubbles were found in the group in which oral cavity was dried by saliva ejector and fluid hydrocolloid was finger painted onto the occlusal surfaces immediately before the placement of impression tray in the mouth. It was found that finger painting the tooth surfaces with fluid hydrocolloid immediately before the placement of loaded impression tray in the mouth was the most reliable method. The oral cavity can be cleared more easily of excess saliva by vacuum suction rather than by use of an astringent solution.

  14. Comparison of ten different DNA extraction procedures with respect to their suitability for environmental samples.

    Science.gov (United States)

    Kuhn, Ramona; Böllmann, Jörg; Krahl, Kathrin; Bryant, Isaac Mbir; Martienssen, Marion

    2017-12-01

    DNA extraction for molecular biological applications usually requires target optimized extraction procedures depending on the origin of the samples. For environmental samples, a range of different procedures has been developed. We compared the applicability and efficiency of ten selected DNA extraction methods published in recent literature using four different environmental samples namely: activated sludge from a domestic wastewater treatment plant, river sediment, anaerobic digestion sludge and nitrifying enrichment culture. We assessed the suitability of the extraction procedures based on both DNA yield and quality. DNA quantification was performed by both ultra violet (UV) spectrophotometry and fluorescence spectrophotometry after staining with PicoGreen. In our study, DNA yields based on UV measurement were overestimated in most cases while DNA yields from fluorescence measurements correlated well with the sample load on agarose gels of crude DNA. The quality of the DNA extracts was determined by gel electrophoresis of crude DNA and PCR products from 16S rDNA with the universal primer set 27f/1525r. It was observed that gel electrophoresis of crude DNA was not always suitable to evaluate DNA integrity and purity since interfering background substances (e.g. humic substances) were not visible. Therefore, we strongly recommend examining the DNA quality of both crude DNA and 16S rDNA PCR products by gel electrophoresis when a new extraction method is established. Summarizing, we found four out of ten extraction procedures being applicable to all tested samples without noticeable restrictions. The procedure G (according to the standard method 432_10401 of the Lower Saxony State Office for Consumer Protection and Food Safety) had the broadest application range over procedure J (published by Wilson, 2001). These were followed by procedures F (Singka et al., 2012) and A (Bourrain et al., 1999). All four extraction procedures delivered reliable and reproducible crude

  15. In situ liquid-liquid extraction as a sample preparation method for matrix-assisted laser desorption/ionization MS analysis of polypeptide mixtures

    DEFF Research Database (Denmark)

    Kjellström, Sven; Jensen, Ole Nørregaard

    2003-01-01

    A novel liquid-liquid extraction (LLE) procedure was investigated for preparation of peptide and protein samples for matrix-assisted laser desorption/ionization mass spectrometry (MALDI MS). LLE using ethyl acetate as the water-immiscible organic solvent enabled segregation of hydrophobic...

  16. Influence of Freezing and Storage Procedure on Human Urine Samples in NMR-Based Metabolomics

    OpenAIRE

    Burkhard Luy; Bernhard Watzl; Stefan Heissler; Achim Bub; Rist, Manuela J.; Benjamin Görling; Claudia Muhle-Goll

    2013-01-01

    It is consensus in the metabolomics community that standardized protocols should be followed for sample handling, storage and analysis, as it is of utmost importance to maintain constant measurement conditions to identify subtle biological differences. The aim of this work, therefore, was to systematically investigate the influence of freezing procedures and storage temperatures and their effect on NMR spectra as a potentially disturbing aspect for NMR-based metabolomics studies. Urine sample...

  17. Influence of pre-analytical procedures on genomic DNA integrity in blood samples: the SPIDIA experience.

    Science.gov (United States)

    Malentacchi, F; Ciniselli, C M; Pazzagli, M; Verderio, P; Barraud, L; Hartmann, C C; Pizzamiglio, S; Weisbuch, S; Wyrich, R; Gelmini, S

    2015-02-02

    DNA integrity is a critical part of the definition of genomic DNA (gDNA) quality and can influence downstream molecular applications. Pre-analytical variables as sample storage and DNA extraction methods can influence the quality and quantity of isolated DNA and affect molecular test performances. The aim of this paper is to investigate the role of blood sample storage and DNA extraction procedures on gDNA integrity and gDNA fragmentation impact on a molecular test. 157 DNA samples deriving from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. 157 DNA samples derived from the Pan European 1st SPIDIA DNA External Quality Assessment (EQA), which aimed to investigate the influence of blood storage on gDNA quality and quantity, have been analyzed by Pulsed Field Gel Electrophoresis and ImageJ imaging software. Our results demonstrate that blood sample storage and DNA extraction procedures influence gDNA integrity and that the same blood sample which underwent a long range multiplex PCR based analytical test can provide different results if the adopted pre-analytical procedures are not standardized. Copyright © 2014 Elsevier B.V. All rights reserved.

  18. Application of the Mantel-Haenszel Procedure to Complex Samples of Items.

    Science.gov (United States)

    Allen, Nancy L.; Donoghue, John R.

    This Monte Carlo study examined the effect of complex sampling of items on the measurement of differential item functioning (DIF) using the Mantel-Haenszel procedure. Data were generated using a three-parameter logistic item response theory model according to the balanced incomplete block (BIB) design used in the National Assessment of Educational…

  19. Sampling procedure in a willow plantation for estimation of moisture content

    DEFF Research Database (Denmark)

    Nielsen, Henrik Kofoed; Lærke, Poul Erik; Liu, Na

    2015-01-01

    Heating value and fuel quality of wood is closely connected to moisture content. In this work the variation of moisture content (MC) of short rotation coppice (SRC) willow shoots is described for five clones during one harvesting season. Subsequently an appropriate sampling procedure minimising l...

  20. 40 CFR 91.413 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ...”) analysis, the analyzer response must be stable at greater than 99 percent of the final reading for the... only) by the grab (“bag”) technique outlined in paragraph (c) of this section. (e) Hydrocarbon hang-up... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Exhaust sample procedure-gaseous...

  1. Influence of Freezing and Storage Procedure on Human Urine Samples in NMR-Based Metabolomics

    Directory of Open Access Journals (Sweden)

    Burkhard Luy

    2013-04-01

    Full Text Available It is consensus in the metabolomics community that standardized protocols should be followed for sample handling, storage and analysis, as it is of utmost importance to maintain constant measurement conditions to identify subtle biological differences. The aim of this work, therefore, was to systematically investigate the influence of freezing procedures and storage temperatures and their effect on NMR spectra as a potentially disturbing aspect for NMR-based metabolomics studies. Urine samples were collected from two healthy volunteers, centrifuged and divided into aliquots. Urine aliquots were frozen either at −20 °C, on dry ice, at −80 °C or in liquid nitrogen and then stored at −20 °C, −80 °C or in liquid nitrogen vapor phase for 1–5 weeks before NMR analysis. Results show spectral changes depending on the freezing procedure, with samples frozen on dry ice showing the largest deviations. The effect was found to be based on pH differences, which were caused by variations in CO2 concentrations introduced by the freezing procedure. Thus, we recommend that urine samples should be frozen at −20 °C and transferred to lower storage temperatures within one week and that freezing procedures should be part of the publication protocol.

  2. Sample Design and Estimation Procedures for a National Health Examination Survey of Children.

    Science.gov (United States)

    Bryant, E. Earl; And Others

    This report presents considerations for sample design and estimation procedures for the Health Examination Survey, one of the major survey programs employed by the National Center for Health Statistics. The survey collects data which provide national estimates and distributions of various health characteristics related to the growth and…

  3. The preparation of patients taking anticoagulants for endoscopic procedures

    Directory of Open Access Journals (Sweden)

    Rafał Smoliński

    2016-12-01

    Full Text Available Drugs that inhibit platelet aggregation and  anticoagulants are widely used in  primary and  secondary prevention of thromboembolism and treatment of venous thrombosis. The use of these drugs is associated with an increased risk of bleeding during an endoscopic procedure, and their discontinuation leads to an increased risk of a thromboembolic event. The paper presents how to assess risk and how to prepare a patient treated with antiplatelet or anticoagulant drugs for endoscopic procedures. In each case, one should consider indications and planned duration of treatment as well as urgency of  the procedure. Diagnostic gastroscopy and  colonoscopy do  not usually require treatment modification, while the procedures with increased risk of bleeding require a change in therapy. In the case of antiplatelet drugs, it may be needed to stop it at a proper time before endoscopy. In the case of a dual antiplatelet therapy, when there are absolute indications for its use, one should consider postponing the procedure. Patients with increased risk of bleeding, treated with vitamin K antagonists, should have the treatment temporarily stopped and replaced with a bridging therapy with low molecular weight heparin; if the thromboembolic risk is assessed as low, a bridge therapy is not needed. The time to suspend the use of oral anticoagulants which are non-vitamin K antagonists depends on the risk of bleeding and renal function. Decisions concerning treatment may require consultation of a specialist ordering the anticoagulant or antiplatelet therapy as well as the opinion of an endoscopy centre in which the procedure is to be conducted. The doctor performing the examination should be informed about the treatment used by the patient and its modification.

  4. Sample preparation and orthogonal chromatography for broad polarity range plasma metabolomics: application to human subjects with neurodegenerative dementia.

    Science.gov (United States)

    Armirotti, Andrea; Basit, Abdul; Realini, Natalia; Caltagirone, Carlo; Bossù, Paola; Spalletta, Gianfranco; Piomelli, Daniele

    2014-06-15

    We describe a simple protocol for the preparation and orthogonal hydrophobic/hydrophilic LC-MS/MS analysis of mouse and human plasma samples, which enables the untargeted ("shotgun") or targeted profiling of hydrophilic, amphipathic, and hydrophobic constituents of plasma metabolome. The protocol is rapid, efficient, and reliable, and offers several advantages compared to current procedures. When applied to a training set of human plasma samples, the protocol allowed for the rapid acquisition of full LogP metabolic profiles in plasma samples obtained from cognitively healthy human subjects and age-matched subjects with mild cognitive impairment or Alzheimer's disease (n=15 each). Targeted analyses confirmed these findings, which are consistent with data previously published by other groups. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

  5. 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

  6. The new sample preparation line for radiocarbon measurements on atmospheric aerosol at LABEC

    Energy Technology Data Exchange (ETDEWEB)

    Calzolai, G., E-mail: calzolai@fi.infn.i [Department of Physics and Astronomy, Universita degli Studi di Firenze, Florence (Italy); INFN - Istituto Nazionale di Fisica Nucleare, Florence (Italy); Bernardoni, V. [Department of Physics, Universita degli Studi di Milano and INFN, Milan (Italy); Chiari, M.; Fedi, M.E. [INFN - Istituto Nazionale di Fisica Nucleare, Florence (Italy); Lucarelli, F. [Department of Physics and Astronomy, Universita degli Studi di Firenze, Florence (Italy); INFN - Istituto Nazionale di Fisica Nucleare, Florence (Italy); Nava, S. [INFN -Istituto Nazionale di Fisica Nucleare, Florence (Italy); Riccobono, F. [Department of Physics, Universita degli Studi di Milano and INFN, Milan (Italy); Taccetti, F. [INFN - Istituto Nazionale di Fisica Nucleare, Florence (Italy); Valli, G.; Vecchi, R. [Department of Physics, Universita degli Studi di Milano and INFN, Milan (Italy)

    2011-02-01

    Research highlights: {yields} A new sample preparation line for {sup 14}C analysis on aerosol samples was set up at LABEC. {yields} Effective combustion, selection and collection of the CO{sub 2} were achieved. {yields} The efficiency of the line is consistent with 100%. {yields} AMS tests of samples: reproducibility better than 3 per mille ; good background and accuracy.The line is designed to allow future {sup 14}C measurements on OC/EC. -- Abstract: Radiocarbon measurements on the carbonaceous aerosol fractions have been demonstrated as an effective tool for aerosol source apportionment. For these measurements, a new sample preparation facility was installed at the INFN-LABEC laboratory of Florence (Italy). The line was designed to allow the preparation of samples from different carbonaceous fractions: the combustion of the aerosol samples can be performed in helium or oxygen flows, according to thermal sequences. The evolved CO{sub 2} is cryogenically trapped and reduced to graphite, which is the target material for following Accelerator Mass Spectrometry (AMS) {sup 14}C measurements. This preparation line is described in detail in the paper. As a first step, the line was tested by means of AMS measurements performed on standards to check the reproducibility and the accuracy of the system; moreover, preliminary measurements on the total carbon fraction in aerosol samples were made. Results of these measurements are also reported.

  7. Optimized cryo-focused ion beam sample preparation aimed at in situ structural studies of membrane proteins.

    Science.gov (United States)

    Schaffer, Miroslava; Mahamid, Julia; Engel, Benjamin D; Laugks, Tim; Baumeister, Wolfgang; Plitzko, Jürgen M

    2017-02-01

    While cryo-electron tomography (cryo-ET) can reveal biological structures in their native state within the cellular environment, it requires the production of high-quality frozen-hydrated sections that are thinner than 300nm. Sample requirements are even more stringent for the visualization of membrane-bound protein complexes within dense cellular regions. Focused ion beam (FIB) sample preparation for transmission electron microscopy (TEM) is a well-established technique in material science, but there are only few examples of biological samples exhibiting sufficient quality for high-resolution in situ investigation by cryo-ET. In this work, we present a comprehensive description of a cryo-sample preparation workflow incorporating additional conductive-coating procedures. These coating steps eliminate the adverse effects of sample charging on imaging with the Volta phase plate, allowing data acquisition with improved contrast. We discuss optimized FIB milling strategies adapted from material science and each critical step required to produce homogeneously thin, non-charging FIB lamellas that make large areas of unperturbed HeLa and Chlamydomonas cells accessible for cryo-ET at molecular resolution. Copyright © 2016 Elsevier Inc. All rights reserved.

  8. Large sample neutron activation analysis avoids representative sub-sampling and sample preparation difficulties : An added value for forensic analysis

    NARCIS (Netherlands)

    Bode, P.; Romanò, Sabrina; Romolo, Francesco Saverio

    2017-01-01

    A crucial part of any chemical analysis is the degree of representativeness of the measurand(s) in the test portion for the same measurands in the object, originally collected for investigation. Such an object usually may have either to be homogenized and sub-sampled, or digested/dissolved. Any

  9. A Green Analytical Method Using Ultrasound in Sample Preparation for the Flow Injection Determination of Iron, Manganese, and Zinc in Soluble Solid Samples by Flame Atomic Absorption Spectrometry

    Directory of Open Access Journals (Sweden)

    M. Carmen Yebra

    2012-01-01

    Full Text Available A simple and rapid analytical method was developed for the determination of iron, manganese, and zinc in soluble solid samples. The method is based on continuous ultrasonic water dissolution of the sample (5–30 mg at room temperature followed by flow injection flame atomic absorption spectrometric determination. A good precision of the whole procedure (1.2–4.6% and a sample throughput of ca. 25 samples h–1 were obtained. The proposed green analytical method has been successfully applied for the determination of iron, manganese, and zinc in soluble solid food samples (soluble cocoa and soluble coffee and pharmaceutical preparations (multivitamin tablets. The ranges of concentrations found were 21.4–25.61 μg g-1 for iron, 5.74–18.30 μg g-1 for manganese, and 33.27–57.90 μg g-1 for zinc in soluble solid food samples and 3.75–9.90 μg g-1 for iron, 0.47–5.05 μg g-1 for manganese, and 1.55–15.12 μg g-1 for zinc in multivitamin tablets. The accuracy of the proposed method was established by a comparison with the conventional wet acid digestion method using a paired t-test, indicating the absence of systematic errors.

  10. A Green Analytical Method Using Ultrasound in Sample Preparation for the Flow Injection Determination of Iron, Manganese, and Zinc in Soluble Solid Samples by Flame Atomic Absorption Spectrometry

    Science.gov (United States)

    Yebra, M. Carmen

    2012-01-01

    A simple and rapid analytical method was developed for the determination of iron, manganese, and zinc in soluble solid samples. The method is based on continuous ultrasonic water dissolution of the sample (5–30 mg) at room temperature followed by flow injection flame atomic absorption spectrometric determination. A good precision of the whole procedure (1.2–4.6%) and a sample throughput of ca. 25 samples h–1 were obtained. The proposed green analytical method has been successfully applied for the determination of iron, manganese, and zinc in soluble solid food samples (soluble cocoa and soluble coffee) and pharmaceutical preparations (multivitamin tablets). The ranges of concentrations found were 21.4–25.61 μg g−1 for iron, 5.74–18.30 μg g−1 for manganese, and 33.27–57.90 μg g−1 for zinc in soluble solid food samples and 3.75–9.90 μg g−1 for iron, 0.47–5.05 μg g−1 for manganese, and 1.55–15.12 μg g−1 for zinc in multivitamin tablets. The accuracy of the proposed method was established by a comparison with the conventional wet acid digestion method using a paired t-test, indicating the absence of systematic errors. PMID:22567553

  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...... of quantitative reference DNA material and reagents, production of stringent protocols and tools for thermal cycler performance testing, uncomplicated sample preparation techniques, and extensive ring trials for assessment of the efficacy of selected matrix/pathogen detection protocols....

  12. Protocols for the analytical characterization of therapeutic monoclonal antibodies. II - Enzymatic and chemical sample preparation.

    Science.gov (United States)

    Bobaly, Balazs; D'Atri, Valentina; Goyon, Alexandre; Colas, Olivier; Beck, Alain; Fekete, Szabolcs; Guillarme, Davy

    2017-08-15

    The analytical characterization of therapeutic monoclonal antibodies and related proteins usually incorporates various sample preparation methodologies. Indeed, quantitative and qualitative information can be enhanced by simplifying the sample, thanks to the removal of sources of heterogeneity (e.g. N-glycans) and/or by decreasing the molecular size of the tested protein by enzymatic or chemical fragmentation. These approaches make the sample more suitable for chromatographic and mass spectrometric analysis. Structural elucidation and quality control (QC) analysis of biopharmaceutics are usually performed at intact, subunit and peptide levels. In this paper, general sample preparation approaches used to attain peptide, subunit and glycan level analysis are overviewed. Protocols are described to perform tryptic proteolysis, IdeS and papain digestion, reduction as well as deglycosylation by PNGase F and EndoS2 enzymes. Both historical and modern sample preparation methods were compared and evaluated using rituximab and trastuzumab, two reference therapeutic mAb products approved by Food and Drug Administration (FDA) and European Medicines Agency (EMA). The described protocols may help analysts to develop sample preparation methods in the field of therapeutic protein analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

  13. Automated digital microfluidic sample preparation for next-generation DNA sequencing.

    Science.gov (United States)

    Kim, Hanyoup; Bartsch, Michael S; Renzi, Ronald F; He, Jim; Van de Vreugde, James L; Claudnic, Mark R; Patel, Kamlesh D

    2011-12-01

    Next-generation sequencing (NGS) technology is a promising tool for identifying and characterizing unknown pathogens, but its usefulness in time-critical biodefense and public health applications is currently limited by the lack of fast, efficient, and reliable automated DNA sample preparation methods. To address this limitation, we are developing a digital microfluidic (DMF) platform to function as a fluid distribution hub, enabling the integration of multiple subsystem modules into an automated NGS library sample preparation system. A novel capillary interface enables highly repeatable transfer of liquid between the DMF device and the external fluidic modules, allowing both continuous-flow and droplet-based sample manipulations to be performed in one integrated system. Here, we highlight the utility of the DMF hub platform and capillary interface for automating two key operations in the NGS sample preparation workflow. Using an in-line contactless conductivity detector in conjunction with the capillary interface, we demonstrate closed-loop automated fraction collection of target analytes from a continuous-flow sample stream into droplets on the DMF device. Buffer exchange and sample cleanup, the most repeated steps in NGS library preparation, are also demonstrated on the DMF platform using a magnetic bead assay and achieving an average DNA recovery efficiency of 80%±4.8%. Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.

  14. A new way of solid dosage form samples preparation for SEM and FTIR using microtome.

    Science.gov (United States)

    Šimek, Michal; Grünwaldová, Veronika; Kratochvíl, Bohumil

    2014-06-01

    Rapid and correct production of generic solid dosage forms requires a large amount of analytical data and conclusions. Modern analytical techniques have a good resolution and accuracy and allow obtaining a lot of information about the original product. Scanning electron microscopy (SEM) is used for observation and assessing individual layers, core and surface of solid dosage forms. Fourier transform infrared (FTIR) spectroscopy mapping allows determining the distribution and characterization of individual components in a solid dosage form. However, the samples prepared by common way, using scalpel or tablet splitter, are not good enough. It was the reason for development of a new and better method of sample preparation, which uses microtome. Well-prepared samples analyzed by SEM and FTIR mapping allow to determine a solid dosage form formulation, excipient content and distribution of excipient and active pharmaceutical ingredient.

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

    Science.gov (United States)

    Gang, Deng; Xinyue, Zhong; Na, Zhang; Chengying, Lao; Bo, Wang; Dingxiang, Peng; Lijun, Liu

    2014-01-01

    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.

  16. 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.

  17. Destructive and nondestructive procedures to obtain chicken carcass samples for Escherichia coli and Salmonella spp. detection.

    Science.gov (United States)

    Cossi, Marcus Vinícius Coutinho; de Almeida, Michelle Vieira; Dias, Mariane Rezende; de Arruda Pinto, Paulo Sérgio; Nero, Luís Augusto

    2011-12-01

    Destructive and nondestructive sampling procedures were compared for Escherichia coli and Salmonella spp. detection in 60 fresh chicken carcasses, which were submitted to the following sampling procedures: rinsing, skin swabbing, tissue excision, and skin excision; the proximity or not to the cloacae region was also considered. The obtained results were compared to identify significant differences (pchicken carcasses were positive for E. coli, and five were positive for Salmonella spp. For E. coli, nonsignificant differences were observed between rinsing and tissue excision, rinsing and skin excision, and skin excision and tissue excision (p>0.05), thus indicating equivalencies between these techniques. Skin swabbing produced a statistically significant lower frequency of positive results (pE. coli, thus indicating its inadequacy for detection of this microorganism. For Salmonella spp., no significant differences were observed between the sampling techniques (p>0.05), possibly due to the low overall frequency of positive carcasses. No significant differences in the number of positive samples (E. coli or Salmonella spp.) were observed between samples collected near or far from the cloacae region (p>0.05), regardless of the sampling technique. The obtained results demonstrate that the tested sampling techniques were equivalent for Salmonella spp. detection in chicken carcasses, as observed for E. coli with the exception of skin swabbing.

  18. The beauty of being (label)-free: sample preparation methods for SWATH-MS and next-generation targeted proteomics.

    Science.gov (United States)

    Vowinckel, Jakob; Capuano, Floriana; Campbell, Kate; Deery, Michael J; Lilley, Kathryn S; Ralser, Markus

    2013-01-01

    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.

  19. 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....

  20. Investigating how fundamental parameters of XRF sample preparation and analysis affect the observed elemental concentration: an experiment using fluvial sediment from Sabah, Borneo.

    Science.gov (United States)

    Higton, Sam; Walsh, Rory

    2015-04-01

    X-Ray Fluorescence (XRF) is an important technique for measuring the concentrations of geochemical elements and inorganic contaminants adsorbed to sediments as an input to sediment tracing methods used to evaluate sediment transport dynamics in river catchments. In addition to traditional laboratory-based XRF instruments, the advent of increasingly advanced portable handheld XRF devices now mean that samples of fluvial sediment can be analysed in the field or in the laboratory following appropriate sample preparation procedures. There are limitations and sources of error associated with XRF sample preparation and analysis, however. It is therefore important to understand how fundamental parameters involved in sample preparation and analysis, such as sample compression and measurement exposure duration, affect observed variability in measurement results. Such considerations become important if the resulting measurement variability is high relative to the natural variability in element concentrations at a sample site. This paper deployed a simple experimental design to assess the impacts of varying a number of sample preparation and XRF analysis parameters on recorded measurements of elemental concentrations of the fine fraction (plastic sample cups were used for both the Rigaku laboratory machine and the Niton portable XRF machine. A computer-controlled desktop laboratory stand was used in conjunction with the Niton handheld XRF analyser to ensure consistent repeated measurements. Parameters investigated related to sample preparation included consistent mechanical compression of samples within the sample cup and film thickness. Parameters investigated related to XRF analysis included the XRF machine selected and measurement exposure duration. As XRF is a non-destructive technique, wherever possible the same sample material was used to test different parameters, so as to reduce variations due to the heterogeneous nature of sediment. Observed XRF measurements

  1. Sample preparation methods for the determination of plutonium and strontium in environmental samples by low level liquid scintillation counting and {alpha}-spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Solatie, D.; Carbol, P.; Hrnecek, E.; Betti, M. [European Commission, Joint Research Centre, Inst. for Transuranium Elements, Karlsruhe (Germany); Jaakkola, T. [Lab. of Radiochemistry, Univ. of Helsinki, Helsinki (Finland)

    2002-07-01

    Two different methods - leaching and microwave assisted total dissolution - have been exploited for the treatment of environmental samples for the determination of plutonium and strontium. Leaching applied to reference materials demonstrated the procedure to be applicable for the recovery of technogenic Pu and Sr from environmental samples. For the measurement of the alpha emitters of plutonium, co-precipitation with calcium oxalate and ferric hydroxide and separation with anion exchange has been used. For preparation of {alpha}-spectrometry sources, co-precipitation with NdF{sub 3} on a membrane filter or electro-deposition using the (NH{sub 4}){sub 2}C{sub 2}O{sub 4}/HCl method have been tested. The beta emitter {sup 241}Pu was measured by liquid scintillation counting. Pu isotope concentrations determined in the reference materials agreed well with the certified concentrations. {sup 90}Sr was measured in the leachate solutions from environmental samples collected close to a nuclear facility and from reference materials, after separation from the other leached elements, by liquid scintillation counting and Cherenkov counting. The {sup 90}Sr-concentrations determined in the reference materials agreed well with the certified concentrations. In the samples collected close a nuclear facility (soil, grass and sheep faeces), {sup 90}Sr was found at higher levels, which could also be correlated with the location of the sampling. (orig.)

  2. Labeling procedures for the preparation of {sup 188}Re- DMSA(V)

    Energy Technology Data Exchange (ETDEWEB)

    Brambilla, Tania P.; Osso Junior, Joao A., E-mail: taniabrambilla@yahoo.com.b, E-mail: jaosso@ipen.b [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2009-07-01

    {sup 188}Re has received a lot of attention in the past decade, due to its favorable nuclear characteristics [t{sub 1/2} 16.9 h, E{sub beta}{sub max} 2.12 MeV and E{sub gamma} 155 keV (15%) suitable for imaging], including the fact that it is carrier-free and can be obtained cost-effectively through the generator {sup 188}W-{sup 188}Re. Besides the therapeutic usefulness of {sup 188}Re, the emission of the 155 keV gamma photon is an added advantage since the biodistribution of {sup 188}Re-labeled agents can be evaluated in vivo with a gamma camera. Biodistribution studies of {sup 188}Re-DMSA(V) have shown that its general pharmacokinetic properties are similar to that of {sup 99}mTc-DMSA(V), so this agent could be used for targeted radiotherapy of the same tumors, i.e., medullary thyroid carcinoma, bone metastases, soft tissue, head and neck tumors. The aim of this work is to evaluate two labeling procedures for the preparation of {sup 188}Re- DMSA(V). {sup 188}Re-DMSA(V) was prepared by two methods. The first method was prepared using a commercial kit of DMSA(III) for labeling with {sup 99m}Tc, at high temperature (100 deg C). The second method was prepared in a vial containing 2.5 mg of DMSA, 1.00 mg of SnCl{sub 2}.2H2{sub O} and 30 mg of sodium oxalate, in a total volume of 1.1 mL. The pH was adjusted to 5 with 37% HCl. After labeling the solution was stirred and incubated for 15 min at room temperature. The radiochemical purity was determined using TLC-SG developed with two different solvent systems. Preliminary results for both methods of labeling {sup 188}Re-DMSA(V) showed that the labeling yield was >90%. (author)

  3. 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.

  4. Procedures Performed during Hospitalizations for Malignant Pleural Effusions: Data from the 2012 National Inpatient Sample.

    Science.gov (United States)

    Fortin, Marc; Taghizadeh, Niloofar; Tremblay, Alain

    2018-02-07

    Malignant pleural effusions (MPE) are a common clinical problem. Little is known about the burden of MPE and of the treatments used to alleviate its symptoms on the United States Health Care System. We aimed to obtain a better portrait of inpatient pleural procedures performed in the United States. We conducted a retrospective analysis of MPE-associated hospitalizations using the Healthcare Cost and Utilization Project-Nationwide Inpatient Sample, Agency for Healthcare Research and Quality (HCUP-NIS 2012). Descriptive statistics were used to analyze procedures performed and their complications. Univariate and multivariate logistic regression models were used to explore the relationship between procedures performed and inpatient mortality and length of stay. Among the 126,825 hospital admissions with a diagnosis of MPE, 72,240 included one or more pleural procedures. Thoracentesis (54,070) was the most frequently performed procedure followed by chest tube placement (23,035), chemical pleurodesis (10,240), and thoracoscopy (6,615). Hospitalization for lung and breast cancer was more likely to include pleural procedures compared to hospitalization for other types of cancer (59.2 and 65.6%, respectively, p < 0.0001). Chemical pleurodesis through a chest tube compared to thoracoscopic chemical pleurodesis was performed more frequently (57 vs. 43%, p < 0.001) and associated with a longer hospital stay (4.9 vs. 5.9 days, p < 0.001). Hospital admissions for MPE represent a large burden on the US Health Care System. Many hospitalizations are associated with procedures not expected to reduce the recurrence rate of this condition. © 2018 S. Karger AG, Basel.

  5. Assessing the safety and efficacy of drugs used in preparing the nose for diagnostic and therapeutic procedures: a systematic review.

    Science.gov (United States)

    Saif, A M; Farboud, A; Delfosse, E; Pope, L; Adke, M

    2016-10-01

    Local anaesthetics and vasoconstrictors are essential for pain control and to aid intra-operative haemostasis in nasal procedures. They also improve access, and reduce discomfort when performing nasal endoscopy. There are no clear guidelines on preparing the nose despite evermore diagnostic and therapeutic procedures utilising the nose as a point of access. This review aims to identify nasal preparations used in diagnostic and therapeutic nasal procedures and to examine their safety and efficacy. Systematic review. A search was carried out using PubMed, MEDLINE, Ovid EMBASE, the Cochrane library and references from the included articles. The inclusion criteria included: full-text English language articles with regard to nasal preparation for surgery. Case reports, systematic reviews, meta-analysis, double-blind placebo controlled randomised trials (RCTs) and case series were included. A total of 53 articles were retrieved: 13 articles on nasal preparation for operative procedures, six on functional endoscopic sinus surgery and 22 on nasendoscopy as well as six case reports. Cocaine was the most widely used topical preparation for operative procedures but was associated with more side-effects; thus, topical tetracaine and levobupivacaine infiltration are alternatives with equivalent efficacy but reduced adverse effects. All articles reviewed for functional endoscopic sinus surgery used a mixture containing lidocaine, adrenaline or both. Flexible nasendoscopy causes minimal patient discomfort and preparation is only recommended in selected patients, in contrast to rigid nasendoscopy which requires preparation. For operative procedures, such as septorhinoplasty, a single agent tetracaine or levobupivicaine provides an improved surgical field. In functional endoscopic sinus surgery, lidocaine-adrenaline preparations have resulted in significantly better surgical and patient outcomes. There is little evidence to support the routine use of pre-procedural nasal

  6. New procedure of selected biogenic amines determination in wine samples by HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Piasta, Anna M.; Jastrzębska, Aneta, E-mail: aj@chem.uni.torun.pl; Krzemiński, Marek P.; Muzioł, Tadeusz M.; Szłyk, Edward

    2014-06-27

    Highlights: • We proposed new procedure for derivatization of biogenic amines. • The NMR and XRD analysis confirmed the purity and uniqueness of derivatives. • Concentration of biogenic amines in wine samples were analyzed by RP-HPLC. • Sample contamination and derivatization reactions interferences were minimized. - Abstract: A new procedure for determination of biogenic amines (BA): histamine, phenethylamine, tyramine and tryptamine, based on the derivatization reaction with 2-chloro-1,3-dinitro-5-(trifluoromethyl)-benzene (CNBF), is proposed. The amines derivatives with CNBF were isolated and characterized by X-ray crystallography and {sup 1}H, {sup 13}C, {sup 19}F NMR spectroscopy in solution. The novelty of the procedure is based on the pure and well-characterized products of the amines derivatization reaction. The method was applied for the simultaneous analysis of the above mentioned biogenic amines in wine samples by the reversed phase-high performance liquid chromatography. The procedure revealed correlation coefficients (R{sup 2}) between 0.9997 and 0.9999, and linear range: 0.10–9.00 mg L{sup −1} (histamine); 0.10–9.36 mg L{sup -1} (tyramine); 0.09–8.64 mg L{sup −1} (tryptamine) and 0.10–8.64 mg L{sup −1} (phenethylamine), whereas accuracy was 97%–102% (recovery test). Detection limit of biogenic amines in wine samples was 0.02–0.03 mg L{sup −1}, whereas quantification limit ranged 0.05–0.10 mg L{sup −1}. The variation coefficients for the analyzed amines ranged between 0.49% and 3.92%. Obtained BA derivatives enhanced separation the analytes on chromatograms due to the inhibition of hydrolysis reaction and the reduction of by-products formation.

  7. Multivariate Optimization in Preconcentration Procedure for Manganese Determination in Seawater Samples by FAAS

    OpenAIRE

    Ferreira, Adriana C.; Korn, Maria das Graças Andrade; Ferreira, Sergio Luis Costa

    2004-01-01

    Texto completo: acesso restrito . p. 271-278 In the present paper, a preconcentration procedure for manganese determination in seawater samples by flame atomic absorption spectrometry (FAAS) is proposed. It is based on the solid phase extraction of manganese(II) ions as a 4-(2-pyridylazo-resorcinol) (PAR) chelate using activated carbon as sorbent. Optimization of the experimental parameters (pH, activated carbon mass, PAR mass and shaking time) was carried out using a two-level full factor...

  8. 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 its 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, high-pressure 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

  9. 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."

  10. GraFix: sample preparation for single-particle electron cryomicroscopy.

    Science.gov (United States)

    Kastner, Berthold; Fischer, Niels; Golas, Monika Mariola; Sander, Bjoern; Dube, Prakash; Boehringer, Daniel; Hartmuth, Klaus; Deckert, Jochen; Hauer, Florian; Wolf, Elmar; Uchtenhagen, Hannes; Urlaub, Henning; Herzog, Franz; Peters, Jan Michael; Poerschke, Dietmar; Lührmann, Reinhard; Stark, Holger

    2008-01-01

    We developed a method, named GraFix, that considerably improves sample quality for structure determination by single-particle electron cryomicroscopy (cryo-EM). GraFix uses a glycerol gradient centrifugation step in which the complexes are centrifuged into an increasing concentration of a chemical fixation reagent to prevent aggregation and to stabilize individual macromolecules. The method can be used to prepare samples for negative-stain, cryo-negative-stain and, particularly, unstained cryo-EM.

  11. Highly simplified lateral flow-based nucleic acid sample preparation and passive fluid flow control

    Science.gov (United States)

    Cary, Robert E.

    2015-12-08

    Highly simplified lateral flow chromatographic nucleic acid sample preparation methods, devices, and integrated systems are provided for the efficient concentration of trace samples and the removal of nucleic acid amplification inhibitors. Methods for capturing and reducing inhibitors of nucleic acid amplification reactions, such as humic acid, using polyvinylpyrrolidone treated elements of the lateral flow device are also provided. Further provided are passive fluid control methods and systems for use in lateral flow assays.

  12. [Sampling in qualitative research: a proposal for procedures to detect theoretical saturation].

    Science.gov (United States)

    Fontanella, Bruno Jose Barcellos; Luchesi, Bruna Moretti; Saidel, Maria Giovana Borges; Ricas, Janete; Turato, Egberto Ribeiro; Melo, Débora Gusmão

    2011-02-01

    A qualitative study's methodological transparency is considered a key factor for achieving its reliability and should be guaranteed by the researchers. Closing the sampling process by saturation is a common approach, but it is rarely made explicit in research reports. Qualitative researchers also commonly experience technical difficulties in objectively identifying saturation. This article proposes a method to organize sample closing by saturation, with a sequence of eight procedural steps for treating and analyzing data collected through open or semi-structured interviews or focus groups. The article aims to help researchers objectively explain how and when saturation occurred and to allow their readers to know how this process occurred.

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

    Directory of Open Access Journals (Sweden)

    Myung-Jin Lee

    2017-03-01

    Full Text Available 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 < 0.05. In the MTT assay, cell viability increased significantly in every group as the concentration of the extracts decreased (p < 0.05. Extracts from post-cured and removed unreacted layer samples of bonding resin were less toxic than post-cured and removed unreacted layer samples of composite resin. Removal of the oxygen-inhibition layer resulted in the lowest cytotoxicity. Clinicians should remove unreacted monomers on the resin surface immediately after restoring teeth with light-curing resin to improve the restoration biocompatibility.

  14. A New Stratified Sampling Procedure which Decreases Error Estimation of Varroa Mite Number on Sticky Boards.

    Science.gov (United States)

    Kretzschmar, A; Durand, E; Maisonnasse, A; Vallon, J; Le Conte, Y

    2015-06-01

    A new procedure of stratified sampling is proposed in order to establish an accurate estimation of Varroa destructor populations on sticky bottom boards of the hive. It is based on the spatial sampling theory that recommends using regular grid stratification in the case of spatially structured process. The distribution of varroa mites on sticky board being observed as spatially structured, we designed a sampling scheme based on a regular grid with circles centered on each grid element. This new procedure is then compared with a former method using partially random sampling. Relative error improvements are exposed on the basis of a large sample of simulated sticky boards (n=20,000) which provides a complete range of spatial structures, from a random structure to a highly frame driven structure. The improvement of varroa mite number estimation is then measured by the percentage of counts with an error greater than a given level. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  15. 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, ...

  16. A high-throughput sample preparation method for cellular proteomics using 96-well filter plates.

    Science.gov (United States)

    Switzar, Linda; van Angeren, Jordy; Pinkse, Martijn; Kool, Jeroen; Niessen, Wilfried M A

    2013-10-01

    A high-throughput sample preparation protocol based on the use of 96-well molecular weight cutoff (MWCO) filter plates was developed for shotgun proteomics of cell lysates. All sample preparation steps, including cell lysis, buffer exchange, protein denaturation, reduction, alkylation and proteolytic digestion are performed in a 96-well plate format, making the platform extremely well suited for processing large numbers of samples and directly compatible with functional assays for cellular proteomics. In addition, the usage of a single plate for all sample preparation steps following cell lysis reduces potential samples losses and allows for automation. The MWCO filter also enables sample concentration, thereby increasing the overall sensitivity, and implementation of washing steps involving organic solvents, for example, to remove cell membranes constituents. The optimized protocol allowed for higher throughput with improved sensitivity in terms of the number of identified cellular proteins when compared to an established protocol employing gel-filtration columns. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. Sample preparation and biomass determination of SRF model mixture using cryogenic milling and the adapted balance method

    Energy Technology Data Exchange (ETDEWEB)

    Schnöller, Johannes, E-mail: johannes.schnoeller@chello.at; Aschenbrenner, Philipp; Hahn, Manuel; Fellner, Johann; Rechberger, Helmut

    2014-11-15

    Highlights: • An alternative sample comminution procedure for SRF is tested. • Proof of principle is shown on a SRF model mixture. • The biogenic content of the SRF is analyzed with the adapted balance method. • The novel method combines combustion analysis and a data reconciliation algorithm. • Factors for the variance of the analysis results are statistically quantified. - Abstract: The biogenic fraction of a simple solid recovered fuel (SRF) mixture (80 wt% printer paper/20 wt% high density polyethylene) is analyzed with the in-house developed adapted balance method (aBM). This fairly new approach is a combination of combustion elemental analysis (CHNS) and a data reconciliation algorithm based on successive linearisation for evaluation of the analysis results. This method shows a great potential as an alternative way to determine the biomass content in SRF. However, the employed analytical technique (CHNS elemental analysis) restricts the probed sample mass to low amounts in the range of a few hundred milligrams. This requires sample comminution to small grain sizes (<200 μm) to generate representative SRF specimen. This is not easily accomplished for certain material mixtures (e.g. SRF with rubber content) by conventional means of sample size reduction. This paper presents a proof of principle investigation of the sample preparation and analysis of an SRF model mixture with the use of cryogenic impact milling (final sample comminution) and the adapted balance method (determination of biomass content). The so derived sample preparation methodology (cutting mills and cryogenic impact milling) shows a better performance in accuracy and precision for the determination of the biomass content than one solely based on cutting mills. The results for the determination of the biogenic fraction are within 1–5% of the data obtained by the reference methods, selective dissolution method (SDM) and {sup 14}C-method ({sup 14}C-M)

  18. A solid phase extraction-ion chromatography with conductivity detection procedure for determining cationic surfactants in surface water samples.

    Science.gov (United States)

    Olkowska, Ewa; Polkowska, Żaneta; Namieśnik, Jacek

    2013-11-15

    A new analytical procedure for the simultaneous determination of individual cationic surfactants (alkyl benzyl dimethyl ammonium chlorides) in surface water samples has been developed. We describe this methodology for the first time: it involves the application of solid phase extraction (SPE-for sample preparation) coupled with ion chromatography-conductivity detection (IC-CD-for the final determination). Mean recoveries of analytes between 79% and 93%, and overall method quantification limits in the range from 0.0018 to 0.038 μg/mL for surface water and CRM samples were achieved. The methodology was applied to the determination of individual alkyl benzyl quaternary ammonium compounds in environmental samples (reservoir water) and enables their presence in such types of waters to be confirmed. In addition, it is a simpler, less time-consuming, labour-intensive, avoiding use of toxic chloroform and significantly less expensive methodology than previously described approaches (liquid-liquid extraction coupled with liquid chromatography-mass spectrometry). Copyright © 2013 Elsevier B.V. All rights reserved.

  19. Comparison of three techniques in the preparation of samples for the crystallization of cervical flow in lactating dairy cattle

    Directory of Open Access Journals (Sweden)

    Reátegui J

    2017-08-01

    Full Text Available The objective was to compare three techniques of sample preparation for cervical flow crystallization (pressure imprint, touch imprint and smear, analyzing the tree forms (crystallization as a characterization of the cervical flow of dairy cattle, according to the day of collection and moment of the estrous cycle. Ten clinically healthy, multiparous Holstein Friesian dairy cows were sampled and 30 to 50 days postpartum. Each was collected from the vaginal cervix using a disposable pipette and a 50cc syringe. The two imprints and the smear were prepared on slides, with two-step protocol according to the methodology of Prado et al. (2012. The samples were then allowed to dry in the environment and the microscope was read with a higher magnification objective (40X to observe the formation of the crystals, these procedures were performed in 4 different moments of the estrous cycle (0, 7, 14, 21 days. To quantify the crystallization, a scale from 0 to 4 was used, which varies depending on the formation of typical crystals at least formation or absence. At day 0, 7, 14, 21, the crystallization level in the three techniques had significant difference (P <0.05. At day 0, 50% of the samples processed by the touch imprint and pressure imprint showed typical formation compared to 20% that were processed by the smear technique. On day 7, 80% of the samples processed by touch imprint, 90% of the smear technique and 70% of the pressure imprint, present atypical crystals. On day 14, 60% of the samples processed by the contact imprint and 30% and 40% of the samples processed by the smear technique and pressure imprint, respectively, showed atypical crystal formation. On day 21, 40% of the samples processed by the touch imprint and 10% of the samples processed by the smear technique and pressure imprint showed typical crystal formation. It is concluded that the techniques of preparation of samples influence the crystallization of cervical mucus, being the most

  20. Influence of the preparation procedure on the electrochemical properties of Pani(DMcT-Cu ion/carbon fiber composites

    Directory of Open Access Journals (Sweden)

    Canobre Sheila C.

    2003-01-01

    Full Text Available The electrochemical properties of Pani(DMcT-Cu ion/carbon fiber composites, obtained by electrochemical means, are analysed as a function of the preparation procedure and the different copper salts (CuCl2.2H2O or CuSO4 used as source of Cu2+ ions to be incorporated into the Pani(DMcT/carbon fiber composite. The composites were prepared according to two procedures: by adding the copper salt directly to the electrolyte during the polyaniline electrosynthesis (procedure A, or by allowing the copper ion to be physically adsorbed onto the carbon fiber prior to the polymer electroformation (procedure B. The electrochemical stability, electrical properties and morphology of the composites were analysed by cyclic voltammetry, electrochemical impedance spectroscopy and scanning electron microscopy, respectively.

  1. Gas-Assisted Annular Microsprayer for Sample Preparation for Time-Resolved Cryo-Electron Microscopy.

    Science.gov (United States)

    Lu, Zonghuan; Barnard, David; Shaikh, Tanvir R; Meng, Xing; Mannella, Carmen A; Yassin, Aymen; Agrawal, Rajendra; Wagenknecht, Terence; Lu, Toh-Ming

    2014-11-01

    Time-resolved cryo electron microscopy (TRCEM) has emerged as a powerful technique for transient structural characterization of isolated biomacromolecular complexes in their native state within the time scale of seconds to milliseconds. For TRCEM sample preparation, microfluidic device [9] has been demonstrated to be a promising approach to facilitate TRCEM biological sample preparation. It is capable of achieving rapidly aqueous sample mixing, controlled reaction incubation, and sample deposition on electron microscopy (EM) grids for rapid freezing. One of the critical challenges is to transfer samples to cryo-EM grids from the microfluidic device. By using microspraying method, the generated droplet size needs to be controlled to facilitate the thin ice film formation on the grid surface for efficient data collection, while not too thin to be dried out before freezing, i.e., optimized mean droplet size needs to be achieved. In this work, we developed a novel monolithic three dimensional (3D) annular gas-assisted microfluidic sprayer using 3D MEMS (MicroElectroMechanical System) fabrication techniques. The microsprayer demonstrated dense and consistent microsprays with average droplet size between 6-9 μm, which fulfilled the above droplet size requirement for TRCEM sample preparation. With droplet density of around 12-18 per grid window (window size is 58×58 μm), and the data collectible thin ice region of >50% total wetted area, we collected ~800-1000 high quality CCD micrographs in a 6-8 hour period of continuous effort. This level of output is comparable to what were routinely achieved using cryo-grids prepared by conventional blotting and manual data collection. In this case, weeks of data collection process with the previous device [9] has shortened to a day or two. And hundreds of microliter of valuable sample consumption can be reduced to only a small fraction.

  2. 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.

  3. 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.

  4. Procedural Skills of the Entrustable Professional Activities: Are Graduating US Medical Students Prepared to Perform Procedures in Residency?

    Science.gov (United States)

    Bruce, Adrienne N; Kumar, Anagha; Malekzadeh, Sonya

    Competency-based medical education has been successfully instituted in graduate medical education through the development of Milestones. Consequently, the Association of American Medical Colleges implemented the core entrustable professional activities initiative to complement this framework in undergraduate medical education. We sought to determine its efficacy by examining the experiences and confidence of recent medical school graduates with general procedural skills (entrustable professional activities 12). We administered an electronic survey to the MedStar Georgetown University Hospital intern class assessing their experiences with learning and evaluation as well as their confidence with procedural skills training during medical school. Simple linear regression was used to compare respondent confidence and the presence of formal evaluation in medical school. We received 28 complete responses, resulting in a 33% response rate, whereas most respondents indicated that basic cardiopulmonary resuscitation, bag/mask ventilation, and universal precautions were important to and evaluated by their medical school, this emphasis was not present for venipuncture, intravenous catheter placement, and arterial puncture. Mean summed scores of confidence for each skill indicated a statistically significant effect between confidence and evaluation of universal precaution skills. More advanced procedural skills are not considered as important for graduating medical students and are less likely to be taught and formally evaluated before graduation. Formal evaluation of some procedural skills is associated with increased confidence of the learner. Copyright © 2017 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

  5. 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.

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

    Science.gov (United States)

    Chandra, Subhash

    2008-12-01

    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 2+) revealed local secondary ion signal enhancements correlated with the water image signals of 19(H 3O) +. 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 + and Na + in physiologically relevant concentrations. The high K-low Na signature in individual cells

  7. 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

  8. Advancement of Solidification Processing Technology Through Real Time X-Ray Transmission Microscopy: Sample Preparation

    Science.gov (United States)

    Stefanescu, D. M.; Curreri, P. A.

    1996-01-01

    Two types of samples were prepared for the real time X-ray transmission microscopy (XTM) characterization. In the first series directional solidification experiments were carried out to evaluate the critical velocity of engulfment of zirconia particles in the Al and Al-Ni eutectic matrix under ground (l-g) conditions. The particle distribution in the samples was recorded on video before and after the samples were directionally solidified. In the second series samples of the above two type of composites were prepared for directional solidification runs to be carried out on the Advanced Gradient Heating Facility (AGHF) aboard the space shuttle during the LMS mission in June 1996. X-ray microscopy proved to be an invaluable tool for characterizing the particle distribution in the metal matrix samples. This kind of analysis helped in determining accurately the critical velocity of engulfment of ceramic particles by the melt interface in the opaque metal matrix composites. The quality of the cast samples with respect to porosity and instrumented thermocouple sheath breakage or shift could be easily viewed and thus helped in selecting samples for the space shuttle experiments. Summarizing the merits of this technique it can be stated that this technique enabled the use of cast metal matrix composite samples since the particle location was known prior to the experiment.

  9. On-line sample preparation for the determination of riboflavin and flavin mononucleotides in foodstuffs.

    Science.gov (United States)

    Greenway, G M; Kometa, N

    1994-05-01

    An on-line sample preparation method is described for the determination of riboflavin and flavin mononucleotide (FMN) in milk and cereal samples by high-performance liquid chromatography (HPLC) with fluorescence detection. The on-line system consists of microwave extraction followed by dialysis and trace enrichment with a C18 mini-column. Sample preparation was minimal, with milk samples being directly introduced into the system and cereal only needing to be ground prior to analysis. Results were obtained for a range of samples and these were found to be in agreement with the Association of Official Analytical Chemists (AOAC) method and a previously reported HPLC method. Recoveries were between 94 and 106% for a range of different samples and the relative standard deviation for ten samples was in the range 1.2-2.0%. During the microwave extraction all the flavin adenine dinucleotide (FAD) was converted into FMN and 15% of FMN was converted into riboflavin. The full analysis time on the ground samples was about 20 min.

  10. The Alaska Commercial Fisheries Water Quality Sampling Methods and Procedures Manual

    Energy Technology Data Exchange (ETDEWEB)

    Folley, G.; Pearson, L.; Crosby, C. [Alaska Dept. of Environmental Conservation, Soldotna, AK (United States); DeCola, E.; Robertson, T. [Nuka Research and Planning Group, Seldovia, AK (United States)

    2006-07-01

    A comprehensive water quality sampling program was conducted in response to the oil spill that occurred when the M/V Selendang Ayu ship ran aground near a major fishing port at Unalaska Island, Alaska in December 2004. In particular, the sampling program focused on the threat of spilled oil to the local commercial fisheries resources. Spill scientists were unable to confidently model the movement of oil away from the wreck because of limited oceanographic data. In order to determine which fish species were at risk of oil contamination, a real-time assessment of how and where the oil was moving was needed, because the wreck became a continual source of oil release for several weeks after the initial grounding. The newly developed methods and procedures used to detect whole oil during the sampling program will be presented in the Alaska Commercial Fisheries Water Quality Sampling Methods and Procedures Manual which is currently under development. The purpose of the manual is to provide instructions to spill managers while they try to determine where spilled oil has or has not been encountered. The manual will include a meaningful data set that can be analyzed in real time to assess oil movement and concentration. Sections on oil properties and processes will be included along with scientific water quality sampling methods for whole and dissolved phase oil to assess potential contamination of commercial fishery resources and gear in Alaska waters during an oil spill. The manual will present a general discussion of factors that should be considered when designing a sampling program after a spill. In order to implement Alaska's improved seafood safety measures, the spatial scope of spilled oil must be known. A water quality sampling program can provide state and federal fishery managers and food safety inspectors with important information as they identify at-risk fisheries. 11 refs., 7 figs.

  11. A METHOD FOR PREPARING A SUBSTRATE BY APPLYING A SAMPLE TO BE ANALYSED

    DEFF Research Database (Denmark)

    2017-01-01

    The invention relates to a method for preparing a substrate (105a) comprising a sample reception area (110) and a sensing area (111). The method comprises the steps of: 1) applying a sample on the sample reception area; 2) rotating the substrate around a predetermined axis; 3) during rotation......, at least part of the liquid travels from the sample reception area to the sensing area due to capillary forces acting between the liquid and the substrate; and 4) removing the wave of particles and liquid formed at one end of the substrate. The sensing area is closer to the predetermined axis than...... the sample reception area. The sample comprises a liquid part and particles suspended therein....

  12. Applied Focused Ion Beam Techniques for Sample Preparation of Astromaterials for Integrated Nano-Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Graham, G A; Teslich, N E; Kearsley, A T; Stadermann, F J; Stroud, R M; Dai, Z R; Ishii, H A; Hutcheon, I D; Bajt, S; Snead, C J; Weber, P K; Bradley, J P

    2007-02-20

    Sample preparation is always a critical step in study of micrometer sized astromaterials available for study in the laboratory, whether their subsequent analysis is by electron microscopy or secondary ion mass spectrometry. A focused beam of gallium ions has been used to prepare electron transparent sections from an interplanetary dust particle, as part of an integrated analysis protocol to maximize the mineralogical, elemental, isotopic and spectroscopic information extracted from one individual particle. In addition, focused ion beam techniques have been employed to extract cometary residue preserved on the rims and walls of micro-craters in 1100 series aluminum foils that were wrapped around the sample tray assembly on the Stardust cometary sample collector. Non-ideal surface geometries and inconveniently located regions of interest required creative solutions. These include support pillar construction and relocation of a significant portion of sample to access a region of interest. Serial sectioning, in a manner similar to ultramicrotomy, is a significant development and further demonstrates the unique capabilities of focused ion beam microscopy for sample preparation of astromaterials.

  13. 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.

  14. The impact of preparation and support procedures for children with sickle cell disease undergoing MRI

    Energy Technology Data Exchange (ETDEWEB)

    Cejda, Katherine R. [St. Jude Children' s Research Hospital, Child Life Program, Memphis, TN (United States); Smeltzer, Matthew P. [St. Jude Children' s Research Hospital, Department of Biostatistics, Memphis, TN (United States); Hansbury, Eileen N. [Baylor International Hematology Center of Excellence and the Texas Children' s Center for Global Health, Houston, TX (United States); McCarville, Mary Elizabeth; Helton, Kathleen J. [St. Jude Children' s Research Hospital, Department of Radiological Sciences, Memphis, TN (United States); Hankins, Jane S. [St. Jude Children' s Research Hospital, Department of Hematology, Memphis, TN (United States)

    2012-10-15

    Children with sickle cell disease (SCD) often undergo MRI studies to assess brain injury or to quantify hepatic iron. MRI requires the child to lie motionless for 30-60 min, thus sedation/anesthesia might be used to facilitate successful completion of exams, but this poses additional risks for SCD patients. To improve children's ability to cope with MRI examinations and avoid sedation, our institution established preparation and support procedures (PSP). To investigate the impact of PSP in reducing the need for sedation during MRI exams among children with SCD. Data on successful completion of MRI testing were compared among 5- to 12-year-olds who underwent brain MRI or liver R2*MRI with or without receiving PSP. Seventy-one children with SCD (median age 9.85 years, range 5.57-12.99 years) underwent a brain MRI (n = 60) or liver R2*MRI (n = 11). Children who received PSP were more likely to complete an interpretable MRI exam than those who did not 30 of 33; 91% vs. 27 of 38; 71%, unadjusted OR = 4.1 (P = 0.04) and OR = 8.5 (P < 0.01) when adjusting for age. PSP can help young children with SCD complete clinically interpretable, nonsedated MRI exams, avoiding the risks of sedation/anesthesia. (orig.)

  15. Automated sample preparation for ICP analysis of active pharmaceutical ingredients and intermediates.

    Science.gov (United States)

    Sims, Jonathan; Smith, Andrew; Patel, Dharmista; Batchelor, Richard; Carreira, Judith

    2011-10-01

    Routine testing of active pharmaceutical ingredients (APIs) for metal residues is an expectation of regulatory bodies such as the FDA (U.S. Food and Drug Administration). Sample preparation techniques are the rate-limiting step in the testing process and can be variable depending on the specific characteristics of the API under test. Simplification and standardization of the routine preparation of inductively coupled plasma spectroscopy sample solutions of organic compounds has been developed using a commercially available robotic workstation. Contamination from the metal components of the instrument and from sample tubes used in the methodology has been studied using a Design of Experiments approach. The optimized method described can be used for the measurement of trace metals in Pharmaceuticals at levels compliant with European and U.S. regulatory requirements. Copyright © 2011 Society for Laboratory Automation and Screening. Published by Elsevier Inc. All rights reserved.

  16. An overview of sample preparation and extraction of synthetic pyrethroids from water, sediment and soil.

    Science.gov (United States)

    Albaseer, Saeed S; Rao, R Nageswara; Swamy, Y V; Mukkanti, K

    2010-08-27

    The latest developments in sample preparation and extraction of synthetic pyrethroids from environmental matrices viz., water, sediment and soil were reviewed. Though the synthetic pyrethroids were launched in 1970s, to the best of authors' knowledge there was no review on this subject until date. The present status and recent advances made during the last 10 years in sample preparation including conservation and extraction techniques used in determination of synthetic pyrethroids in water, sediment and soil were discussed. Pre- and post-extraction treatments, sample stability during extraction and its influence upon the whole process of analytical determination were covered. Relative merits and demerits including the green aspects of extraction were evaluated. The current trends and future prospects were also addressed. 2010 Elsevier B.V. All rights reserved.

  17. Automated cellular sample preparation using a Centrifuge-on-a-Chip.

    Science.gov (United States)

    Mach, Albert J; Kim, Jae Hyun; Arshi, Armin; Hur, Soojung Claire; Di Carlo, Dino

    2011-09-07

    The standard centrifuge is a laboratory instrument widely used by biologists and medical technicians for preparing cell samples. Efforts to automate the operations of concentration, cell separation, and solution exchange that a centrifuge performs in a simpler and smaller platform have had limited success. Here, we present a microfluidic chip that replicates the functions of a centrifuge without moving parts or external forces. The device operates using a purely fluid dynamic phenomenon in which cells selectively enter and are maintained in microscale vortices. Continuous and sequential operation allows enrichment of cancer cells from spiked blood samples at the mL min(-1) scale, followed by fluorescent labeling of intra- and extra-cellular antigens on the cells without the need for manual pipetting and washing steps. A versatile centrifuge-analogue may open opportunities in automated, low-cost and high-throughput sample preparation as an alternative to the standard benchtop centrifuge in standardized clinical diagnostics or resource poor settings.

  18. Standardized Nanomechanical Atomic Force Microscopy Procedure (SNAP) for Measuring Soft and Biological Samples.

    Science.gov (United States)

    Schillers, Hermann; Rianna, Carmela; Schäpe, Jens; Luque, Tomas; Doschke, Holger; Wälte, Mike; Uriarte, Juan José; Campillo, Noelia; Michanetzis, Georgios P A; Bobrowska, Justyna; Dumitru, Andra; Herruzo, Elena T; Bovio, Simone; Parot, Pierre; Galluzzi, Massimiliano; Podestà, Alessandro; Puricelli, Luca; Scheuring, Simon; Missirlis, Yannis; Garcia, Ricardo; Odorico, Michael; Teulon, Jean-Marie; Lafont, Frank; Lekka, Malgorzata; Rico, Felix; Rigato, Annafrancesca; Pellequer, Jean-Luc; Oberleithner, Hans; Navajas, Daniel; Radmacher, Manfred

    2017-07-11

    We present a procedure that allows a reliable determination of the elastic (Young's) modulus of soft samples, including living cells, by atomic force microscopy (AFM). The standardized nanomechanical AFM procedure (SNAP) ensures the precise adjustment of the AFM optical lever system, a prerequisite for all kinds of force spectroscopy methods, to obtain reliable values independent of the instrument, laboratory and operator. Measurements of soft hydrogel samples with a well-defined elastic modulus using different AFMs revealed that the uncertainties in the determination of the deflection sensitivity and subsequently cantilever's spring constant were the main sources of error. SNAP eliminates those errors by calculating the correct deflection sensitivity based on spring constants determined with a vibrometer. The procedure was validated within a large network of European laboratories by measuring the elastic properties of gels and living cells, showing that its application reduces the variability in elastic moduli of hydrogels down to 1%, and increased the consistency of living cells elasticity measurements by a factor of two. The high reproducibility of elasticity measurements provided by SNAP could improve significantly the applicability of cell mechanics as a quantitative marker to discriminate between cell types and conditions.

  19. An efficient preparative procedure for main flavonoids from the peel of Trichosanthes kirilowii Maxim. using polyamide resin followed by semi-preparative high performance liquid chromatography.

    Science.gov (United States)

    Li, Aifeng; Sun, Ailing; Liu, Renmin; Zhang, Yongqing; Cui, Jichun

    2014-08-15

    In this study, a simple and efficient preparative procedure was developed for preparation of seven flavonoids from the peel of Trichosanthes kirilowii Maxim. using polyamide resin followed by semi-preparative high performance liquid chromatography (SPHPLC). First, the ethyl acetate fraction from the peel of T. kirilowii Maxim. obtained "prefractionation" using polyamide resin, which yielded two subfractions. And then the two subfractions were isolated by SPHPLC with an isocratic elution of methanol-water. Finally, seven known flavonoids were purified from 35 g of ethyl acetate extract including quercetin-3-O-[α-l-rhamnose (1→2)-β-d-glucopyranosyl]-5-O-β-d-glucopyranoside (19 mg), quercetin-3-O-rutinoside (24 mg), apigenin-7-O-β-d-glucopyranoside (10mg), diosmetin-7-O-β-d-glucopyranoside (45 mg), luteolin (21 mg), apigenin (15 mg), and diosmetin (56 mg). The purities of the compounds were determined by HPLC and the chemical structures were confirmed by UV and NMR analysis. In the present study, a simple, effective, and rapid procedure was established for preparative separation of multiple components from the peel of T. kirilowii Maxim. Furthermore, it was scalable and economical, so it was a promising basis for large-scale preparation of flavonoids from other plant extracts. Copyright © 2014. Published by Elsevier B.V.

  20. Minimizing technical variation during sample preparation prior to label-free quantitative mass spectrometry.

    Science.gov (United States)

    Scheerlinck, E; Dhaenens, M; Van Soom, A; Peelman, L; De Sutter, P; Van Steendam, K; Deforce, D

    2015-12-01

    Sample preparation is the crucial starting point to obtain high-quality mass spectrometry data and can be divided into two main steps in a bottom-up proteomics approach: cell/tissue lysis with or without detergents and a(n) (in-solution) digest comprising denaturation, reduction, alkylation, and digesting of the proteins. Here, some important considerations, among others, are that the reagents used for sample preparation can inhibit the digestion enzyme (e.g., 0.1% sodium dodecyl sulfate [SDS] and 0.5 M guanidine HCl), give rise to ion suppression (e.g., polyethylene glycol [PEG]), be incompatible with liquid chromatography-tandem mass spectrometry (LC-MS/MS) (e.g., SDS), and can induce additional modifications (e.g., urea). Taken together, all of these irreproducible effects are gradually becoming a problem when label-free quantitation of the samples is envisioned such as during the increasingly popular high-definition mass spectrometry (HDMS(E)) and sequential window acquisition of all theoretical fragment ion spectra (SWATH) data-independent acquisition strategies. Here, we describe the detailed validation of a reproducible method with sufficient protein yield for sample preparation without any known LC-MS/MS interfering substances by using 1% sodium deoxycholate (SDC) during both cell lysis and in-solution digest. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

  1. Cytology Preparations of Formalin Fixative Aid Detection of Giardia in Duodenal Biopsy Samples.

    Science.gov (United States)

    Panarelli, Nicole C; Gobara, Nariman; Hoda, Rana S; Chaump, Michael; Jessurun, Jose; Yantiss, Rhonda K

    2017-04-01

    Giardiasis is the most common intestinal parasitic infection in the United States. The organism elicits no, or minimal, inflammatory changes in duodenal biopsy samples, so it can be easily overlooked. We performed this study to determine whether Giardia could be isolated from the formalin fixative of biopsy samples, and to evaluate the value of fluid analysis in the assessment for potential infection. We prospectively evaluated duodenal biopsy samples from 92 patients with a clinical suspicion of giardiasis or symptoms compatible with that diagnosis (ie, diarrhea, bloating, or abdominal pain) Biopsy samples were routinely processed and stained with hematoxylin and eosin. Histologic diagnoses included giardiasis (5 cases, 4%), normal findings (64 cases, 70%), peptic injury/active duodenitis (12 cases, 13%), and intraepithelial lymphocytosis with villous blunting (10 cases, 12%). Fifteen cases (13%) showed detached degenerated epithelial cells or mucus droplets in the intervillous space that resembled Giardia. Cytology slides were prepared from formalin in the biopsy container using the standard Cytospin protocol and reviewed by a cytopathologist blinded to the biopsy findings. Cytologic evaluation revealed Giardia spp. in all 5 biopsy-proven cases, and identified an additional case that was not detected by biopsy analysis. Organisms were significantly more numerous (mean: 400 trophozoites; range, 120 to 810) and showed better morphologic features in cytology preparations compared with tissue sections (mean: 129 trophozoites; range, 37 to 253 organisms; P=0.05). Our findings suggest that cytology preparations from formalin fixative can resolve diagnostically challenging cases and even enhance Giardia detection in some cases.

  2. Preparation and Observation of Thick Biological Samples by Scanning Transmission Electron Tomography.

    Science.gov (United States)

    Trépout, Sylvain; Bastin, Philippe; Marco, Sergio

    2017-03-12

    This report describes a protocol for preparing thick biological specimens for further observation using a scanning transmission electron microscope. It also describes an imaging method for studying the 3D structure of thick biological specimens by scanning transmission electron tomography. The sample preparation protocol is based on conventional methods in which the sample is fixed using chemical agents, treated with a heavy atom salt contrasting agent, dehydrated in a series of ethanol baths, and embedded in resin. The specific imaging conditions for observing thick samples by scanning transmission electron microscopy are then described. Sections of the sample are observed using a through-focus method involving the collection of several images at various focal planes. This enables the recovery of in-focus information at various heights throughout the sample. This particular collection pattern is performed at each tilt angle during tomography data collection. A single image is then generated, merging the in-focus information from all the different focal planes. A classic tilt-series dataset is then generated. The advantage of the method is that the tilt-series alignment and reconstruction can be performed using standard tools. The collection of through-focal images allows the reconstruction of a 3D volume that contains all of the structural details of the sample in focus.

  3. Procedures for Handling and Chemical Analysis of Sediment and Water Samples,

    Science.gov (United States)

    1981-05-01

    Method 1: Potassium Chloride Extraction 3-154 Method 2: Distillation 3-155 Method 3: Distilled Water Extraction 3-157 Nitrogen (Nitrate) 3-159...185 Procedures for Water Samples 3-185 Method 1: Colorimotric, Semiautomated with Block Digestor 3-185 Method 2: Manual Colorimotrir, Titrimetrie 3-190...Phenfls 21.11 5.00 - 3(-.50 Total Phosphorus 9.00 6.00 - 12.50 Orthophosphorus 5.57 2.00 - 10.00 Potassium 8.77 2.00 - 20.00 (Continued) t Polychlorinated

  4. 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.

  5. 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.

  6. Polypyrrole solid phase microextraction: A new approach to rapid sample preparation for the monitoring of antibiotic drugs

    Energy Technology Data Exchange (ETDEWEB)

    Szultka, Malgorzata [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Kegler, Ricarda [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany); Fuchs, Patricia [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Olszowy, Pawel [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Miekisch, Wolfram; Schubert, Jochen K. [Department of Anaesthesia and Intensive Care, University of Rostock, Schillingallee 35, D-18057 Rostock (Germany); Buszewski, Boguslaw [Department of Environmental Chemistry and Bioanalytics, Faculty of Chemistry, Nicolaus, Copernicus University, Gagarin 7, 87-100 Torun (Poland); Mundkowski, Ralf G., E-mail: ralf.mundkowski@med.uni-rostock.de [Institute of Clinical Pharmacology, University of Rostock, Schillingallee 70, D-18057 Rostock (Germany)

    2010-05-14

    Simple or even rapid bioanalytical methods are rare, since they generally involve complicated, time-consuming sample preparation from the biological matrices like LLE or SPE. SPME provides a promising approach to overcome these limitations. The full potential of this innovative technique for medical diagnostics, pharmacotherapy or biochemistry has not been tapped yet. In-house manufactured SPME probes with polypyrrole (PPy) coating were evaluated using three antibiotics of high clinical relevance - linezolid, daptomycin, and moxifloxacin - from PBS, plasma, and whole blood. The PPy coating was characterised by scanning electron microscopy. Influences of pH, inorganic salt, and blood anticoagulants were studied for optimum performance. Extraction yields were determined from stagnant media as well as re-circulating human blood using the heart-and-lung machine model system. The PPy-SPME fibres showed high extraction yields, particularly regarding linezolid. The reproducibility of the method was optimised to achieve RSDs of 9% or 17% and 7% for SPME from stagnant or re-circulating blood using fresh and re-used fibres, respectively. The PPy-SPME approach was demonstrated to meet the requirements of therapeutic monitoring of the drugs tested, even from re-circulating blood at physiological flow rates. SPME represents a rapid and simple dual-step procedure with potency to significantly reduce the effort and expenditure of complicated sample preparations in biomedical analysis.

  7. Filter-Aided Sample Preparation (FASP) for Improved Proteome Analysis of Recombinant Chinese Hamster Ovary Cells.

    Science.gov (United States)

    Coleman, Orla; Henry, Michael; Clynes, Martin; Meleady, Paula

    2017-01-01

    Chinese hamster ovary (CHO) cells are the most commonly used mammalian host cell line for biopharmaceutical production because of their ability to correctly fold and posttranslationally modify recombinant proteins that are compatible with human use. Proteomics, along with other 'omic platforms, are being used to understand the biology of CHO cells with the ultimate aim of enhancing CHO cell factories for more efficient production of biopharmaceuticals. In this chapter, we will describe an efficient protocol called Filter Aided Sample Preparation (FASP) for the extraction of proteins from CHO cells for proteomic studies. FASP uses a common ultrafiltration device whereby the membrane pores are small enough to allow contaminating detergents to pass through, while proteins are too large and are retained and concentrated in the filter unit. This method of sample preparation and protein digestion is universally applicable and can be easily employed in any proteomics facilities as standard everyday laboratory reagents and equipment are used.

  8. 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....... 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....

  9. An introduction to sample preparation and imaging by cryo-electron microscopy for structural biology

    Science.gov (United States)

    Thompson, Rebecca F.; Walker, Matt; Siebert, C. Alistair; Muench, Stephen P.; Ranson, Neil A.

    2016-01-01

    Transmission electron microscopy (EM) is a versatile technique that can be used to image biological specimens ranging from intact eukaryotic cells to individual proteins >150 kDa. There are several strategies for preparing samples for imaging by EM, including negative staining and cryogenic freezing. In the last few years, cryo-EM has undergone a ‘resolution revolution’, owing to both advances in imaging hardware, image processing software, and improvements in sample preparation, leading to growing number of researchers using cryo-EM as a research tool. However, cryo-EM is still a rapidly growing field, with unique challenges. Here, we summarise considerations for imaging of a range of specimens from macromolecular complexes to cells using EM. PMID:26931652

  10. 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.

  11. Optimizing the preparation procedure of self-assembled monolayer of stearic acid for protection of cupronickel alloy.

    Science.gov (United States)

    Marušić, Katarina; Hajdari, Zana; Ćurković, Helena Otmačić

    2014-01-01

    The aim of this work is to examine the possibility of CuNi protection in chloride media by self-assembled monolayers (SAMs) of stearic acid (SA). In order to obtain a compact, well ordered monolayer, that will provide long term protection, different SAM preparation procedures are studied. The influence of CuNi pretreatment, SA solution temperature and temperature of the drying period followed after the SA treatment on the protective properties of stearic acid self-assembled layer are examined by electrochemical methods and surface analysis techniques. The obtained results show that for complete self-assembled film formation it is necessary to have a drying period after exposing the sample to the stearic acid solution. Heating of the SA solution and drying period at higher temperatures result in layers with better stability in chloride media. The most compact surface layer, that provides long lasting and efficient protection to the underlying alloy, is obtained when prior to SA solution exposure an oxide layer on CuNi surface was formed at elevated temperatures.

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

    Science.gov (United States)

    2013-05-07

    ring” effect , this effect is statistically negligible as compared to drop-and-dry methods. This is of particular concern with spatially sensitive ...Gillen, J.G. Fabrication of polymer microsphere particle standards containing trace explosives using an oil/water emulsion solvent extraction...technique and sample preparation protocol for explosive materials testing based on drop-on-demand technology. Droplet mass and reproducibility were measured

  13. [Preparation of sub-standard samples and XRF analytical method of powder non-metallic minerals].

    Science.gov (United States)

    Kong, Qin; Chen, Lei; Wang, Ling

    2012-05-01

    In order to solve the problem that standard samples of non-metallic minerals are not satisfactory in practical work by X-ray fluorescence spectrometer (XRF) analysis with pressed powder pellet, a method was studied how to make sub-standard samples according to standard samples of non-metallic minerals and to determine how they can adapt to analysis of mineral powder samples, taking the K-feldspar ore in Ebian-Wudu, Sichuan as an example. Based on the characteristic analysis of K-feldspar ore and the standard samples by X-ray diffraction (XRD) and chemical methods, combined with the principle of the same or similar between the sub-standard samples and unknown samples, the experiment developed the method of preparation of sub-standard samples: both of the two samples above mentioned should have the same kind of minerals and the similar chemical components, adapt mineral processing, and benefit making working curve. Under the optimum experimental conditions, a method for determination of SiO2, Al2O3, Fe2O3, TiO2, CaO, MgO, K2O and Na2O of K-feldspar ore by XRF was established. Thedetermination results are in good agreement with classical chemical methods, which indicates that this method was accurate.

  14. 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.

  15. 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

    of organic solvent, and into an aqueous receiver solution. The extraction is promoted by application of an electrical field, causing electrokinetic migration of the charged analytes. The method has shown to perform excellent clean-up and selectivity from complicated aqueous matrices like biological fluids......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...

  16. An Automated Sample Preparation System for Large-Scale DNA Sequencing

    Science.gov (United States)

    Marziali, Andre; Willis, Thomas D.; Federspiel, Nancy A.; Davis, Ronald W.

    1999-01-01

    Recent advances in DNA sequencing technologies, both in the form of high lane-density gels and automated capillary systems, will lead to an increased requirement for sample preparation systems that operate at low cost and high throughput. As part of the development of a fully automated sequencing system, we have developed an automated subsystem capable of producing 10,000 sequence-ready ssDNA templates per day from libraries of M13 plaques at a cost of $0.29 per sample. This Front End has been in high throughput operation since June, 1997 and has produced > 400,000 high-quality DNA templates. PMID:10330125

  17. Simulation of topography evolution and damage formation during TEM sample preparation using focused ion beams

    Energy Technology Data Exchange (ETDEWEB)

    Boxleitner, W. E-mail: wini@hobbit.fke.tuwien.ac.at; Hobler, G.; Klueppel, V.; Cerva, H

    2001-04-01

    Our recently developed simulation code FIBSIM is applied to topics related to transmission electron microscopy (TEM) sample preparation using focused ion beams (FIB). FIBSIM combines dynamic Monte Carlo simulation of collision cascades with two-dimensional, cell-based topography simulation. The influence of the scanning mode and of the beam current profile on the evolution of the surface contour is investigated. Furthermore, amorphous zones in silicon samples and damaged regions are predicted for different beam energies of 10, 30 and 50 keV. The thickness of the predicted amorphous regions is in good agreement with experimental TEM data.

  18. The effectiveness of drama therapy on preparation for diagnostic and therapeutic procedures in children suffering from cancer

    Directory of Open Access Journals (Sweden)

    Ľubica Ilievová

    2015-10-01

    Full Text Available Introduction: The integral part of the treatment of pediatric oncological patients is a range of diagnostic and therapeutic procedures. These procedures are often associated with the fear and anxiety of the suffering child. We investigated whether a psychological preparation through drama therapy and the therapeutic puppet may reduce the anxiety related to diagnostic and therapeutic procedures in the preschool or early school children suffering from cancer.Methods: Twenty consecutive pediatric patients of preschool and early school age, with the diagnosis of lymphoblastic leukemia, were included in the study. The patients were alternatingly assigned to experimental or control group, and subjected or not subjected to drama therapy, respectively. We measured the changes in heart rate, blood pressure and respiratory rate as indicators of anxiety and fear, before and after the diagnostic or therapeutic procedures.Results: Heart rate, blood pressure, and respiratory rate in pediatric oncological patients before and after the diagnostic or therapeutic procedure were significantly lower in the experimental group of patients.Conclusion: Our results show that psychological preparation using drama therapy and therapeutic puppet reduced the fear and anxiety related to diagnostic or therapeutic procedures in pediatric oncological patients.Key words: drama therapy; therapeutic puppet; children; oncology; psychology 

  19. Liquid-solid sample preparation followed by headspace solid-phase microextraction determination of multiclass pesticides in soil.

    Science.gov (United States)

    Durović, Rada D; Dordević, Tijana M; Santrić, Ljiljana R

    2012-01-01

    This paper describes development and validation of a multiresidue method for the determination of five pesticides (terbufos, prochloraz, chloridazon, pendimethalin, and fluorochloridone) belonging to different pesticide groups in soil samples by GC/MS, followed by its application in the analysis of some agricultural soil samples. The method is based on a headspace solid-phase microextraction method. Microextraction conditions, namely temperature, extraction time, and NaCI content, were tested and optimized using a 100 microm polydimethylsiloxane fiber. Three extraction solvents [methanol, methanol-acetone (1 + 1, v/v), and methanol-acetone-hexane (2 + 2 + 1, v/v/v)] and the optimum number of extraction steps within the sample preparation stage were optimized for the extraction procedure. LOD values for all the studied compounds were less than 12 microg/kg. Recovery values for multiple analyses of soil samples fortified at 30 microg/kg of each pesticide were higher than 64%. The method was proven to be repeatable, with RSD lower than 15%.

  20. Analytical procedures for the determination of fuel combustion products, anti-corrosive compounds, and de-icing compounds in airport runoff water samples.

    Science.gov (United States)

    Sulej, Anna Maria; Polkowska, Żaneta; Astel, Aleksander; Namieśnik, Jacek

    2013-12-15

    The purpose of this study is to propose and evaluate new procedures for determination of fuel combustion products, anti-corrosive and de-icing compounds in runoff water samples collected from the airports located in different regions and characterized by different levels of the activity expressed by the number of flights and the number of passengers (per year). The most difficult step in the analytical procedure used for the determination of PAHs, benzotriazoles and glycols is sample preparation stage, due to diverse matrix composition, the possibility of interference associated with the presence of components with similar physicochemical properties. In this study, five different versions of sample preparation using extraction techniques, such as: LLE and SPE, were tested. In all examined runoff water samples collected from the airports, the presence of PAH compounds and glycols was observed. In majority of the samples, BT compounds were determined. Runoff water samples collected from the areas of Polish and British international airports as well as local airports had similar qualitative composition, but quantitative composition of the analytes was very diverse. New and validated analytical methodologies ensure that the necessary information for assessing the negative impact of airport activities on the environment can be obtained. © 2013 Elsevier B.V. All rights reserved.

  1. A new selective enrichment procedure for isolating Pasteurella multocida from avian and environmental samples

    Science.gov (United States)

    Moore, M.K.; Cicnjak-Chubbs, L.; Gates, R.J.

    1994-01-01

    A selective enrichment procedure, using two new selective media, was developed to isolate Pasteurella multocida from wild birds and environmental samples. These media were developed by testing 15 selective agents with six isolates of P. multocida from wild avian origin and seven other bacteria representing genera frequently found in environmental and avian samples. The resulting media—Pasteurella multocida selective enrichment broth and Pasteurella multocida selective agar—consisted of a blood agar medium at pH 10 containing gentamicin, potassium tellurite, and amphotericin B. Media were tested to determine: 1) selectivity when attempting isolation from pond water and avian carcasses, 2) sensitivity for detection of low numbers of P. multocida from pure and mixed cultures, 3) host range specificity of the media, and 4) performance compared with standard blood agar. With the new selective enrichment procedure, P. multocida was isolated from inoculated (60 organisms/ml) pond water 84% of the time, whereas when standard blood agar was used, the recovery rate was 0%.

  2. High-resolution X-ray diffraction with no sample preparation.

    Science.gov (United States)

    Hansford, G M; Turner, S M R; Degryse, P; Shortland, A J

    2017-07-01

    It is shown that energy-dispersive X-ray diffraction (EDXRD) implemented in a back-reflection geometry is extremely insensitive to sample morphology and positioning even in a high-resolution configuration. This technique allows high-quality X-ray diffraction analysis of samples that have not been prepared and is therefore completely non-destructive. The experimental technique was implemented on beamline B18 at the Diamond Light Source synchrotron in Oxfordshire, UK. The majority of the experiments in this study were performed with pre-characterized geological materials in order to elucidate the characteristics of this novel technique and to develop the analysis methods. Results are presented that demonstrate phase identification, the derivation of precise unit-cell parameters and extraction of microstructural information on unprepared rock samples and other sample types. A particular highlight was the identification of a specific polytype of a muscovite in an unprepared mica schist sample, avoiding the time-consuming and difficult preparation steps normally required to make this type of identification. The technique was also demonstrated in application to a small number of fossil and archaeological samples. Back-reflection EDXRD implemented in a high-resolution configuration shows great potential in the crystallographic analysis of cultural heritage artefacts for the purposes of scientific research such as provenancing, as well as contributing to the formulation of conservation strategies. Possibilities for moving the technique from the synchrotron into museums are discussed. The avoidance of the need to extract samples from high-value and rare objects is a highly significant advantage, applicable also in other potential research areas such as palaeontology, and the study of meteorites and planetary materials brought to Earth by sample-return missions.

  3. 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.

  4. 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

  5. Pesticide-sampling equipment, sample-collection and processing procedures, and water-quality data at Chicod Creek, North Carolina, 1992

    Science.gov (United States)

    Manning, T.K.; Smith, K.E.; Wood, C.D.; Williams, J.B.

    1994-01-01

    Water-quality samples were collected from Chicod Creek in the Coastal Plain Province of North Carolina during the summer of 1992 as part of the U.S. Geological Survey's National Water-Quality Assessment Program. Chicod Creek is in the Albemarle-Pamlico drainage area, one of four study units designated to test equipment and procedures for collecting and processing samples for the solid-phase extraction of selected pesticides, The equipment and procedures were used to isolate 47 pesticides, including organonitrogen, carbamate, organochlorine, organophosphate, and other compounds, targeted to be analyzed by gas chromatography/mass spectrometry. Sample-collection and processing equipment equipment cleaning and set-up procedures, methods pertaining to collecting, splitting, and solid-phase extraction of samples, and water-quality data resulting from the field test are presented in this report Most problems encountered during this intensive sampling exercise were operational difficulties relating to equipment used to process samples.

  6. Sample preparation for arsenic speciation analysis in baby food by generation of substituted arsines with atomic absorption spectrometry detection.

    Science.gov (United States)

    Huber, Charles S; Vale, Maria Goreti R; Dessuy, Morgana B; Svoboda, Milan; Musil, Stanislav; Dědina, Jiři

    2017-12-01

    A slurry sampling procedure for arsenic speciation analysis in baby food by arsane generation, cryogenic trapping and detection with atomic absorption spectrometry is presented. Several procedures were tested for slurry preparation, including different reagents (HNO3, HCl and tetramethylammonium hydroxide - TMAH) and their concentrations, water bath heating and ultrasound-assisted agitation. The best results for inorganic arsenic (iAs) and dimethylarsinate (DMA) were reached when using 3molL-1 HCl under heating and ultrasound-assisted agitation. The developed method was applied for the analysis of five porridge powder and six baby meal samples. The trueness of the method was checked with a certified reference material (CRM) of total arsenic (tAs), iAs and DMA in rice (ERM-BC211). Arsenic recoveries (mass balance) for all samples and CRM were performed by the determination of the tAs by inductively coupled plasma mass spectrometry (ICP-MS) after microwave-assisted digestion and its comparison against the sum of the results from the speciation analysis. The relative limits of detection were 0.44, 0.24 and 0.16µgkg-1 for iAs, methylarsonate and DMA, respectively. The concentrations of the most toxic arsenic species (iAs) in the analyzed baby food samples ranged between 4.2 and 99µgkg-1 which were below the limits of 300, 200 and 100µgkg-1 set by the Brazilian, Chinese and European legislation, respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

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

    OpenAIRE

    Fischer, Roman; Benedikt M Kessler

    2015-01-01

    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...

  8. TEM sample preparation by femtosecond laser machining and ion milling for high-rate TEM straining experiments

    Energy Technology Data Exchange (ETDEWEB)

    Voisin, Thomas; Grapes, Michael D. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Zhang, Yong [Dept. of Mechanical Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States); Lorenzo, Nicholas; Ligda, Jonathan; Schuster, Brian [US Army Research Laboratory, Aberdeen Proving Ground, Aberdeen, MD 21005 (United States); Weihs, Timothy P. [Dept. of Materials Science and Engineering, Johns Hopkins University, Baltimore, MD 21218 (United States)

    2017-04-15

    To model mechanical properties of metals at high strain rates, it is important to visualize and understand their deformation at the nanoscale. Unlike post mortem Transmission Electron Microscopy (TEM), which allows one to analyze defects within samples before or after deformation, in situ TEM is a powerful tool that enables imaging and recording of deformation and the associated defect motion during mechanical loading. Unfortunately, all current in situ TEM mechanical testing techniques are limited to quasi-static strain rates. In this context, we are developing a new test technique that utilizes a rapid straining stage and the Dynamic TEM (DTEM) at the Lawrence Livermore National Laboratory (LLNL). The new straining stage can load samples in tension at strain rates as high as 4×10{sup 3}/s using two piezoelectric actuators operating in bending while the DTEM at LLNL can image in movie mode with a time resolution as short as 70 ns. Given the piezoelectric actuators are limited in force, speed, and displacement, we have developed a method for fabricating TEM samples with small cross-sectional areas to increase the applied stresses and short gage lengths to raise the applied strain rates and to limit the areas of deformation. In this paper, we present our effort to fabricate such samples from bulk materials. The new sample preparation procedure combines femtosecond laser machining and ion milling to obtain 300 µm wide samples with control of both the size and location of the electron transparent area, as well as the gage cross-section and length. - Highlights: • Tensile straining TEM specimens made by femtosecond laser machining and ion milling. • Accurate positioning of the electron transparent area within a controlled gauge region. • Optimization of femtosecond laser and ion milling parameters. • Fast production of numerous samples with a highly repeatable geometry.

  9. Enhanced procedural blank control for organic geochemical studies of critical sample material.

    Science.gov (United States)

    Leider, A; Schumacher, T C; Hallmann, C

    2016-09-01

    Organic contamination of sedimentary rocks can produce artefacts in studies of hydrocarbon composition, and this can have significant negative consequences for interpretations of the geobiological record. False positives - that is cases of non-syngenetic hydrocarbon biomarkers - are common in Precambrian studies, and significant challenges persist despite the intensive effort devoted to these studies. Efforts to standardize the 'burden of proof' for distinguishing between contamination and syngenetic material have to date failed to yield a simple or universal protocol, yet the need remains great, as both bitumen-lean rocks and bitumen-rich samples can be vulnerable to the accumulation of false-positive signals. In an effort to determine the best approach to quality control, we tested the capability of different blank materials to collect ambient contamination by assessing their capacity to adsorb hydrocarbons during storage in plastic bags and found that commonly used Quartz sand does not provide an adequate measure of storage- or laboratory-induced contamination. Brick blanks, having the advantage that they can parallel rock samples even during the sawing process, are characterized by similar poor adsorption properties. Primarily steered by mineralogy, organic carbon content and surface area, model-black shales can adsorb up to 20 times more contaminants than sand blanks and up to 200 times more contaminants than organic-free model-carbonates. This observation provides an explanation for reports and observations of seemingly systematic stratigraphic variation of contaminants, but mostly should raise awareness for the evaluation of procedural blanks, in particular of sample-to-blank ratios, when studying bitumen-lean rock samples of varying lithologies. Additionally, differences between the hydrocarbon profiles in plastic bags and the hydrocarbon signatures transferred to blank materials emphasize difficulties in the unequivocal detection of contamination sources

  10. 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.

  11. Sample preparation for precise and quantitative electron holographic analysis of semiconductor devices.

    Science.gov (United States)

    Han, Myung-Geun; Li, Jing; Xie, Qianghua; Fejes, Peter; Conner, James; Taylor, Bill; McCartney, Martha R

    2006-08-01

    Wedge polishing was used to prepare one-dimensional Si n-p junction and Si p-channel metal-oxide-silicon field effect transistor (pMOSFET) samples for precise and quantitative electrostatic potential analysis using off-axis electron holography. To avoid artifacts associated with ion milling, cloth polishing with 0.02-microm colloidal silica suspension was used for final thinning. Uniform thickness and no significant charging were observed by electron holography analysis for samples prepared entirely by this method. The effect of sample thickness was investigated and the minimum thickness for reliable results was found to be approximately 160 nm. Below this thickness, measured phase changes were smaller than expected. For the pMOSFET sample, quantitative analysis of two-dimensional electrostatic potential distribution showed that the metallurgical gate length (separation between two extension junctions) was approximately 54 nm, whereas the actual gate length was measured to be approximately 70 nm by conventional transmission electron microscopy. Thus, source and drain junction encroachment under the gate was 16 nm.

  12. Sample preparation for determining polychlorinated dibenzo-p-dioxins and dibenzofurans in environmental samples with the use of a modified carbon column

    Energy Technology Data Exchange (ETDEWEB)

    Soifer, V.S.; Soboleva, E.I.; Brodskii, E.S.; Klyuev, N.A. [Severtsov Institute of Developmental Morphology and Animal Ecology, Moscow (Russian Federation)

    1995-03-01

    Presently, the problem of environmental contamination with highly toxic compounds such as polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) is extremely urgent. These compounds, which accumulate in the fatty tissues of living organisms because of their lipophilicity and outstanding stability to external factors, can be concentrated in the highest links of trophic chains, affect reproduction processes and the immune system, and cause cancer. The necessity for careful monitoring of the PCDD and PCDF content in the environment is arising. In this work, based on the study of dioxin sorption and desorption on various carbon sorbents, the authors suggested a new modification of carbon columns with a minimum sorbent quantity that is sufficient for determining dioxins in actual samples. The elution of PCDDs and PCDFs from a carbon column on heating was first used; this procedure significantly increased the desorption efficiency and made it possible to employ direct-flow elution. The suggested model for the carbon microcolumn significantly simplified the scheme of sample preparation, markedly reduced its duration, and decreased the quantity of sorbent and the volume of solvent for elution and subsequent sorbent regeneration.

  13. Preparation of children for surgery and invasive procedures: milestones on the way to success.

    Science.gov (United States)

    Bar-Mor, G

    1997-08-01

    The cost of a preparation program is relatively low, but its value for the subject undergoing treatment is very high. Feelings of satisfaction and contentment usually accompany the preparation process, and are mutual. Therefore, it is highly recommended to make the necessary efforts to develop preparation programs and to implement them regularly and systematically. It is probable that a preparation program that allows for the special characteristics of each child and family, that is accompanied by diverse demonstration aids, and that stresses a love for children and counseling, as well as cooperation between all the agents involved ... should in most cases be a successful one.

  14. 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. Published 2016. This article is a U.S. Government work and is in the public domain in the USA.

  15. Comparison of noninvasive sample collection procedures for canine leishmaniasis diagnosis by PCR-hybridization

    Energy Technology Data Exchange (ETDEWEB)

    Ferreira, Sidney de Almeida; Andrade, Antero Silva Ribeiro de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mail: vidasnino@yahoo.com.br; antero@cdtn.br; Ituassu, Leonardo Trindade; Melo, Maria Norma de [Universidade Federal de Minas Gerais, Belo Horizonte, MG (Brazil)]. E-mail: melo@mono.icb.ufmg.br; ltituassu@yahoo.com.br

    2007-07-01

    The dogs are the main reservoir of the visceral leishmaniasis etiological agent Leishmania chagasi and these animals have to be systematically monitored. The aim of present work was to standardize a method for canine leishmaniasis diagnosis using DNA samples obtained by a noninvasive ways. Two kind of samples were compared: conjunctival swab and blood. The samples were analyzed by the Polymerase Chain Reaction (PCR) associated with the hybridization of {sup 32}P labeled DNA probes. An in vitro test was carried out using cotton swabs seeded with L. chagasi parasites at different cell numbers. After that, the PCR and hybridization sensitivity was evaluated in two groups of 23 seropositive dogs. Conjunctival swabs and 1,0 mL of blood were collected from each animal. 90 {mu}L of these blood were spotted onto filter paper and the remaining used to prepare the buffy coat. The DNA purification from cotton swabs was carried out through the phenol-chloroform (group 1) or boiling (group 2). The Wizard kit was used to DNA extraction from buffy coat. The filters were treated according to Dialab protocol. The analysis of the seeded samples showed that the PCR was able to identify until ten parasites while the following hybridization of the PCR products allows the detection of until one parasite. The PCR positivity for the conjunctival swabs were 73.9% and 52.2% respectively to the groups 1 and 2. For buffy coat the positivities were 43.5% and 56.5% respectively. The filters presented the lowest positivity. The hybridization step was not accomplished yet for these samples. (author)

  16. Effects of Analytical Procedures on the Repeatability of Malondialdehyde Determinations in Biological Samples

    Directory of Open Access Journals (Sweden)

    Sajad Azizi, Maryam Khoubnasabjafari, Aziz Shahrisa, Mehry Khoubnasabjafari, Jafar Soleymani, Abolghasem Jouyban

    2017-09-01

    Full Text Available Background: Malondialdehyde (MDA is a commonly used biomarker of oxidative stress in clinical studies and has been measured in many pathological conditions during last decades. Different analytical methods have been reported for determination of MDA in biological samples in which MDA was adducted with thiobarbituric acid (TBA to produce more sensitive chromophore and also convert it to a fluorescent compound. In spite of the routine applications of this derivatization and subsequent analysis of MDA in biomedical studies, its reliability, repeatability and reproducibility is questionable. The aim of this work is to investigate the effects of some factors on the repeatability of MDA determinations in standard solutions and also in plasma samples using spectroscopic method. Methods: MDA-TBA adduct is prepared in standard solutions and the effects of pH, temperature, reaction time, open, closed and reflux systems and the ratio of MDA and TBA is investigated by measuring the absorbance of the solution at 532 nm. These effects are also investigated in human plasma samples. Results: The best results are obtained at pH 2.5, temperature of 70 °C, reaction time of 150 minutes, reflux system and ratio of 2. Conclusion: Using the optimized conditions are resulted in better repeatability.

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

    Science.gov (United States)

    Hedell, Ronny; Hedman, Johannes; Mostad, Petter

    2017-07-17

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

  18. Rapid microbial sample preparation from blood using a novel concentration device.

    Directory of Open Access Journals (Sweden)

    Anna K Boardman

    Full Text Available Appropriate care for bacteremic patients is dictated by the amount of time needed for an accurate diagnosis. However, the concentration of microbes in the blood is extremely low in these patients (1-100 CFU/mL, traditionally requiring growth (blood culture or amplification (e.g., PCR for detection. Current culture-based methods can take a minimum of two days, while faster methods like PCR require a sample free of inhibitors (i.e., blood components. Though commercial kits exist for the removal of blood from these samples, they typically capture only DNA, thereby necessitating the use of blood culture for antimicrobial testing. Here, we report a novel, scaled-up sample preparation protocol carried out in a new microbial concentration device. The process can efficiently lyse 10 mL of bacteremic blood while maintaining the microorganisms' viability, giving a 30-μL final output volume. A suite of six microorganisms (Staphylococcus aureus, Streptococcus pneumoniae, Escherichia coli, Haemophilus influenzae, Pseudomonas aeruginosa, and Candida albicans at a range of clinically relevant concentrations was tested. All of the microorganisms had recoveries greater than 55% at the highest tested concentration of 100 CFU/mL, with three of them having over 70% recovery. At the lowest tested concentration of 3 CFU/mL, two microorganisms had recoveries of ca. 40-50% while the other four gave recoveries greater than 70%. Using a Taqman assay for methicillin-sensitive S. aureus (MSSAto prove the feasibility of downstream analysis, we show that our microbial pellets are clean enough for PCR amplification. PCR testing of 56 spiked-positive and negative samples gave a specificity of 0.97 and a sensitivity of 0.96, showing that our sample preparation protocol holds great promise for the rapid diagnosis of bacteremia directly from a primary sample.

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

    Science.gov (United States)

    Wang, Dandan; Huang, Yamin; Liu, Binghai; Zhu, Lei; Lam, Jeffrey; Mai, Zhihong

    2017-04-01

    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.

  20. 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.

  1. Critical evaluation of distillation procedure for the determination of methylmercury in soil samples.

    Science.gov (United States)

    Perez, Pablo A; Hintelman, Holger; Quiroz, Waldo; Bravo, Manuel A

    2017-11-01

    In the present work, the efficiency of distillation process for extracting monomethylmercury (MMHg) from soil samples was studied and optimized using an experimental design methodology. The influence of soil composition on MMHg extraction was evaluated by testing of four soil samples with different geochemical characteristics. Optimization suggested that the acid concentration and the duration of the distillation process were most significant and the most favorable conditions, established as a compromise for the studied soils, were determined to be a 70 min distillation using an 0.2 M acid. Corresponding limits of detection (LOD) and quantification (LOQ) were 0.21 and 0.7 pg absolute, respectively. The optimized methodology was applied with satisfactory results to soil samples and was compared to a reference methodology based on isotopic dilution analysis followed by gas chromatography-inductively coupled plasma mass spectrometry (IDA-GC-ICP-MS). Using the optimized conditions, recoveries ranged from 82 to 98%, which is an increase of 9-34% relative to the previously used standard operating procedure. Finally, the validated methodology was applied to quantify MMHg in soils collected from different sites impacted by coal fired power plants in the north-central zone of Chile, measuring MMHg concentrations ranging from 0.091 to 2.8 ng g-1. These data are to the best of our knowledge the first MMHg measurements reported for Chile. Copyright © 2017 Elsevier Ltd. All rights reserved.

  2. Rapid Microwave Digestion Procedures for the Elemental Analysis of Alloy and Slag Samples of Smelted Ocean Bed Polymetallic Nodules

    Directory of Open Access Journals (Sweden)

    Kumari Smita

    2013-01-01

    Full Text Available The use of microwave digester for digestion of alloy and slag samples of smelted ocean bed polymetallic nodules has permitted the complete digestion of samples, thereby replacing the tedious classical methods of digestion of samples. The digestion procedure includes two acid-closed digestions of samples in a microwave oven. Owing to the hazardous nature of perchloric acid, it was not used in developed digestion procedure. Digested sample solutions were analyzed for concentrations of various radicals and the effectiveness of the developed digestion methodology was tested using certified reference materials. It was found that the developed method is giving results comparable with that obtained from conventionally digested samples. In this digestion procedure, time required for digestion of samples was reduced to about 1 hour only from 8-9 hours of conventional digestion.

  3. Sample Preparation Strategies for the Effective Quantitation of Hydrophilic Metabolites in Serum by Multi-Targeted HILIC-MS/MS

    Directory of Open Access Journals (Sweden)

    Elisavet Tsakelidou

    2017-03-01

    Full Text Available The effect of endogenous interferences of serum in multi-targeted metabolite profiling HILIC-MS/MS analysis was investigated by studying different sample preparation procedures. A modified QuEChERS dispersive SPE protocol, a HybridSPE protocol, and a combination of liquid extraction with protein precipitation were compared to a simple protein precipitation. Evaluation of extraction efficiency and sample clean-up was performed for all methods. SPE sorbent materials tested were found to retain hydrophilic analytes together with endogenous interferences, thus additional elution steps were needed. Liquid extraction was not shown to minimise matrix effects. In general, it was observed that a balance should be reached in terms of recovery, efficient clean-up, and sample treatment time when a wide range of metabolites are analysed. A quick step for removing phospholipids prior to the determination of hydrophilic endogenous metabolites is required, however, based on the results from the applied methods, further studies are needed to achieve high recoveries for all metabolites.

  4. TEM sample preparation by femtosecond laser machining and ion milling for high-rate TEM straining experiments.

    Science.gov (United States)

    Voisin, Thomas; Grapes, Michael D; Zhang, Yong; Lorenzo, Nicholas; Ligda, Jonathan; Schuster, Brian; Weihs, Timothy P

    2017-04-01

    To model mechanical properties of metals at high strain rates, it is important to visualize and understand their deformation at the nanoscale. Unlike post mortem Transmission Electron Microscopy (TEM), which allows one to analyze defects within samples before or after deformation, in situ TEM is a powerful tool that enables imaging and recording of deformation and the associated defect motion during mechanical loading. Unfortunately, all current in situ TEM mechanical testing techniques are limited to quasi-static strain rates. In this context, we are developing a new test technique that utilizes a rapid straining stage and the Dynamic TEM (DTEM) at the Lawrence Livermore National Laboratory (LLNL). The new straining stage can load samples in tension at strain rates as high as 4×10 3 /s using two piezoelectric actuators operating in bending while the DTEM at LLNL can image in movie mode with a time resolution as short as 70ns. Given the piezoelectric actuators are limited in force, speed, and displacement, we have developed a method for fabricating TEM samples with small cross-sectional areas to increase the applied stresses and short gage lengths to raise the applied strain rates and to limit the areas of deformation. In this paper, we present our effort to fabricate such samples from bulk materials. The new sample preparation procedure combines femtosecond laser machining and ion milling to obtain 300µm wide samples with control of both the size and location of the electron transparent area, as well as the gage cross-section and length. Copyright © 2017 Elsevier B.V. All rights reserved.

  5. Efficacy of a children’s procedural preparation and distraction device on healing in acute burn wound care procedures: study protocol for a randomized controlled trial

    Directory of Open Access Journals (Sweden)

    Brown Nadia J

    2012-12-01

    Full Text Available Abstract Background The intense pain and anxiety triggered by burns and their associated wound care procedures are well established in the literature. Non-pharmacological intervention is a critical component of total pain management protocols and is used as an adjunct to pharmacological analgesia. An example is virtual reality, which has been used effectively to dampen pain intensity and unpleasantness. Possible links or causal relationships between pain/anxiety/stress and burn wound healing have previously not been investigated. The purpose of this study is to investigate these relationships, specifically by determining if a newly developed multi-modal procedural preparation and distraction device (Ditto™ used during acute burn wound care procedures will reduce the pain and anxiety of a child and increase the rate of re-epithelialization. Methods/design Children (4 to 12 years with acute burn injuries presenting for their first dressing change will be randomly assigned to either the (1 Control group (standard distraction or (2 Ditto™ intervention group (receiving Ditto™, procedural preparation and Ditto™ distraction. It is intended that a minimum of 29 participants will be recruited for each treatment group. Repeated measures of pain intensity, anxiety, stress and healing will be taken at every dressing change until complete wound re-epithelialization. Further data collection will aid in determining patient satisfaction and cost effectiveness of the Ditto™ intervention, as well as its effect on speed of wound re-epithelialization. Discussion Results of this study will provide data on whether the disease process can be altered by reducing stress, pain and anxiety in the context of acute burn wounds. Trial registration ACTRN12611000913976

  6. Changes of the elemental distributions in marine diatoms as a reporter of sample preparation artefacts. A nuclear microscopy application

    Energy Technology Data Exchange (ETDEWEB)

    Godinho, R.M. [Instituto de Bioengenharia e Biociências, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal); Instituto Português do Mar e da Atmosfera, Lisboa (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto (Portugal); Cabrita, M.T. [Instituto Português do Mar e da Atmosfera, Lisboa (Portugal); Centro Interdisciplinar de Investigação Marinha e Ambiental, Universidade do Porto, Porto (Portugal); Alves, L.C. [Centro de Ciências e Tecnologias Nucleares, Instituto Superior Técnico, Universidade de Lisboa, Sacavém (Portugal); Pinheiro, T., E-mail: murmur@ctn.ist.utl.pt [Instituto de Bioengenharia e Biociências, Instituto Superior Técnico, Universidade de Lisboa, Lisboa (Portugal)

    2015-04-01

    Studies of the elemental composition of whole marine diatoms cells have high interest as they constitute a direct measurement of environmental changes, and allow anticipating consequences of anthropogenic alterations to organisms, ecosystems and global marine geochemical cycles. Nuclear microscopy is a powerful tool allowing direct measurement of whole cells giving qualitative imaging of distribution, and quantitative determination of intracellular concentration. Major obstacles to the analysis of marine microalgae are high medium salinity and the recurrent presence of extracellular exudates produced by algae to maintain colonies in natural media and in vitro. The objective of this paper was to optimize the methodology of sample preparation of marine unicellular algae for elemental analysis with nuclear microscopy, allowing further studies on cellular response to metals. Primary cultures of Coscinodiscus wailesii maintained in vitro were used to optimize protocols for elemental analysis with nuclear microscopy techniques. Adequate cell preparation procedures to isolate the cells from media components and exudates were established. The use of chemical agents proved to be inappropriate for elemental determination and for intracellular morphological analysis. The assessment of morphology and elemental partitioning in cell compartments obtained with nuclear microscopy techniques enabled to infer their function in natural environment and imbalances in exposure condition. Exposure to metal affected C. wailesii morphology and internal elemental distribution.

  7. Impact of Sample Type and DNA Isolation Procedure on Genomic Inference of Microbiome Composition

    DEFF Research Database (Denmark)

    Knudsen, Berith Elkær; Bergmark, Lasse; Munk, Patrick

    2016-01-01

    was dependent on inherent specimen properties as well as DNA extraction method. We further show that bead beating or enzymatic treatment can increase the extraction of DNA from Gram-positive bacteria. Final DNA quantities could be increased by isolating DNA from a larger volume of cell lysate than...... resistance from different reservoirs. Here, we compare in a stepwise approach a total of eight commercially available DNA extraction kits and 16 procedures based on these for three specimentypes (human feces, pig feces, and hospital sewage). We assess DNA extraction using spike-in controls and different...... types of beads for bead beating, facilitating cell lysis. We evaluate DNA concentration, purity, and stability and microbial community composition using 16S rRNA gene sequencing and for selected samples using shotgun metagenomic sequencing. Our results suggest that inferred community composition...

  8. Improved extraction procedures for polychlorinated biphenyls in solid samples with aqueous sodium hydroxide under autoclave conditions.

    Science.gov (United States)

    Akimoto, Y; Inouye, Y

    2000-03-01

    The efficacy of the extraction of polychlorinated biphenyls (PCBs) from varnish-infiltrated insulating papers as a model of solid materials with an aqueous sodium hydroxide (NaOH) by autoclaving at 121 degrees C for 30 min was compared with those for the conventional procedures, i.e., saponification with 1 N ethanolic NaOH in a boiling water bath for 60 min and extraction with benzene in a Soxhlet apparatus. The newly invented autoclaving method was found to be superior to the conventional ones, yielding approximately 5- to 6-fold cumulative PCB congeners without being accompanied by extended decomposition. Therefore, the autoclave-based sample treatment is recommended for more accurate determination of PCBs in the case of PCB-impregnated solid materials such as hardened oils and resin-coated or -infiltrated papers instead of being treated conventionally.

  9. 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. © 2016 Society for Laboratory Automation and Screening.

  10. A sample preparation method for recovering suppressed analyte ions in MALDI TOF MS.

    Science.gov (United States)

    Lou, Xianwen; de Waal, Bas F M; Milroy, Lech-Gustav; van Dongen, Joost L J

    2015-05-01

    In matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI TOF MS), analyte signals can be substantially suppressed by other compounds in the sample. In this technical note, we describe a modified thin-layer sample preparation method that significantly reduces the analyte suppression effect (ASE). In our method, analytes are deposited on top of the surface of matrix preloaded on the MALDI plate. To prevent embedding of analyte into the matrix crystals, the sample solution were prepared without matrix and efforts were taken not to re-dissolve the preloaded matrix. The results with model mixtures of peptides, synthetic polymers and lipids show that detection of analyte ions, which were completely suppressed using the conventional dried-droplet method, could be effectively recovered by using our method. Our findings suggest that the incorporation of analytes in the matrix crystals has an important contributory effect on ASE. By reducing ASE, our method should be useful for the direct MALDI MS analysis of multicomponent mixtures. Copyright © 2015 John Wiley & Sons, Ltd.

  11. 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

  12. Standard Operating Procedure for In-house Preparation of 131I-rituximab for Radioimmunotherapy of Non-Hodgkin's Lymphoma

    OpenAIRE

    Pickford, Matthew D.; Turner, J. Harvey

    2012-01-01

    A Standard Operating Procedure (SOP) has been formulated for in-house preparation, quality control, dispensing and administration of 131I-rituximab appropriate for the safe, effective, radioimmunotherapy of non-Hodgkin lymphoma. A decade of experience of semi-automated radioiodination of rituximab in our hospital radiopharmaceutical laboratory was analysed. The methodology was then refined for safe, practical, affordable application to radioimmunotherapy of lymphoma in departments of nuclear ...

  13. Bowel preparation for pediatric colonoscopy: report of the NASPGHAN endoscopy and procedures committee.

    Science.gov (United States)

    Pall, Harpreet; Zacur, George M; Kramer, Robert E; Lirio, Richard A; Manfredi, Michael; Shah, Manoj; Stephen, Thomas C; Tucker, Neil; Gibbons, Troy E; Sahn, Benjamin; McOmber, Mark; Friedlander, Joel; Quiros, J A; Fishman, Douglas S; Mamula, Petar

    2014-09-01

    Pediatric bowel preparation protocols used before colonoscopy vary greatly, with no identified standard practice. The present clinical report reviews the evidence for several bowel preparations in children and reports on their use among North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition members. Publications in the pediatric literature for bowel preparation regimens are described, including mechanisms of action, efficacy and ease of use, and pediatric studies. A survey distributed to pediatric gastroenterology programs across the country reviews present national practice, and cleanout recommendations are provided. Finally, further areas for research are identified.

  14. Blotting-free and lossless cryo-electron microscopy grid preparation from nanoliter-sized protein samples and single-cell extracts.

    Science.gov (United States)

    Arnold, Stefan A; Albiez, Stefan; Bieri, Andrej; Syntychaki, Anastasia; Adaixo, Ricardo; McLeod, Robert A; Goldie, Kenneth N; Stahlberg, Henning; Braun, Thomas

    2017-03-01

    We present a sample preparation method for cryo-electron microscopy (cryo-EM) that requires only 3-20nL of sample to prepare a cryo-EM grid, depending on the protocol used. The sample is applied and spread on the grid by a microcapillary. The procedure does not involve any blotting steps, and real-time monitoring allows the water film thickness to be assessed and decreased to an optimum value prior to vitrification. We demonstrate that the method is suitable for high-resolution cryo-EM and will enable alternative electron microscopy approaches, such as single-cell visual proteomics. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

  15. 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.

  16. Comparison of claims data on hospitalization rates and repeat procedures in patients receiving a bowel preparation prior to colonoscopy.

    Science.gov (United States)

    Young, Lisa E; Sacks, Naomi C; Cyr, Philip L; Sharma, Abhishek; Dahdal, David N

    2017-01-01

    To evaluate outcomes of colorectal screening using sodium picosulfate and magnesium citrate compared with other prescription bowel-preparation agents. Primary endpoints were rates of procedure-associated hospitalizations, diagnosis at hospitalization, and rates of early repeat screenings. This retrospective cohort study identified patients using the Truven Health Analytics MarketScan databases, which contain fully adjudicated, de-identified, medical- and prescription-drug claims, as well as demographic and enrollment information for individuals with commercial, Medicaid, and Medicare supplemental insurance coverage. Patients who had a colonoscopy or sigmoidoscopy over a 3-year period were identified using International Classification of Diseases Clinical Modification procedure codes, recorded on claims from physicians and facilities. First, screening colonoscopy was identified for each patient, and the study was limited to those patients who could be observed for ≥6 months before and 3 months after the screening procedure. Total number of hospitalizations and rates of early repeat screenings were evaluated for all patients who received sodium picosulfate and magnesium citrate and compared with those who received other bowel-preparation agents. Individual prescription medications that could affect the outcome of the cleansing agent were identified; further evaluations were made to establish whether patients had comorbid conditions, such as chronic kidney disease, cardiovascular disease, or psychiatric illness. Statistical methods included descriptive statistics, two-tailed t-tests, and multivariate logistic regression. A total of 566,628 procedures were identified in the MarketScan databases and included in the study. Sodium picosulfate and magnesium citrate performed well in terms of safety outcomes, with no hospitalizations due to diagnosis of hyponatremia, dehydration, or other fluid disorders in the 10 days after procedure. Early repeat rates among

  17. Assessment of different sample preparation routes for mass spectrometric monitoring and imaging of lipids in bone cells via ToF-SIMS.

    Science.gov (United States)

    Schaepe, Kaija; Kokesch-Himmelreich, Julia; Rohnke, Marcus; Wagner, Alena-Svenja; Schaaf, Thimo; Wenisch, Sabine; Janek, Jürgen

    2015-03-19

    In ToF-SIMS analysis, the experimental outcome from cell experiments is to a great extent influenced by the sample preparation routine. In order to better judge this critical influence in the case of lipid analysis, a detailed comparison of different sample preparation routines is performed-aiming at an optimized preparation routine for systematic lipid imaging of cell cultures. For this purpose, human mesenchymal stem cells were analyzed: (a) as chemically fixed, (b) freeze-dried, and (c) frozen-hydrated. For chemical fixation, different fixatives, i.e., glutaraldehyde, paraformaldehyde, and a mixture of both, were tested with different postfixative handling procedures like storage in phosphate buffered saline, water or critical point drying. Furthermore, secondary lipid fixation via osmium tetroxide was taken into account and the effect of an ascending alcohol series with and without this secondary lipid fixation was evaluated. Concerning freeze-drying, three different postprocessing possibilities were examined. One can be considered as a pure cryofixation technique while the other two routes were based on chemical fixation. Cryofixation methods known from literature, i.e., freeze-fracturing and simple frozen-hydrated preparation, were also evaluated to complete the comparison of sample preparation techniques. Subsequent data evaluation of SIMS spectra in both, positive and negative, ion mode was performed via principal component analysis by use of peak sets representative for lipids. For freeze-fracturing, these experiments revealed poor reproducibility making this preparation route unsuitable for systematic investigations and statistic data evaluation. Freeze-drying after cryofixation showed improved reproducibility and well preserved lipid contents while the other freeze-drying procedures showed drawbacks in one of these criteria. In comparison, chemical fixation techniques via glutar- and/or paraformaldehyde proved most suitable in terms of reproducibility

  18. A user-friendly robotic sample preparation program for fully automated biological sample pipetting and dilution to benefit the regulated bioanalysis.

    Science.gov (United States)

    Jiang, Hao; Ouyang, Zheng; Zeng, Jianing; Yuan, Long; Zheng, Naiyu; Jemal, Mohammed; Arnold, Mark E

    2012-06-01

    Biological sample dilution is a rate-limiting step in bioanalytical sample preparation when the concentrations of samples are beyond standard curve ranges, especially when multiple dilution factors are needed in an analytical run. We have developed and validated a Microsoft Excel-based robotic sample preparation program (RSPP) that automatically transforms Watson worklist sample information (identification, sequence and dilution factor) to comma-separated value (CSV) files. The Freedom EVO liquid handler software imports and transforms the CSV files to executable worklists (.gwl files), allowing the robot to perform sample dilutions at variable dilution factors. The dynamic dilution range is 1- to 1000-fold and divided into three dilution steps: 1- to 10-, 11- to 100-, and 101- to 1000-fold. The whole process, including pipetting samples, diluting samples, and adding internal standard(s), is accomplished within 1 h for two racks of samples (96 samples/rack). This platform also supports online sample extraction (liquid-liquid extraction, solid-phase extraction, protein precipitation, etc.) using 96 multichannel arms. This fully automated and validated sample dilution and preparation process has been applied to several drug development programs. The results demonstrate that application of the RSPP for fully automated sample processing is efficient and rugged. The RSPP not only saved more than 50% of the time in sample pipetting and dilution but also reduced human errors. The generated bioanalytical data are accurate and precise; therefore, this application can be used in regulated bioanalysis.

  19. Comparison of sample preparation methods for detection of Chlamydia pneumoniae in bronchoalveolar lavage fluid by PCR.

    Science.gov (United States)

    Maass, M; Dalhoff, K

    1994-01-01

    Amplification inhibitors can lead to false-negative results for PCR. In order to evaluate the reliability of PCR for the detection of Chlamydia pneumoniae, the presence of PCR inhibitors in 75 bronchoalveolar lavage specimens was assessed after treatment by various sample preparation methods. Specimens were collected from patients with acute respiratory infections, including four cases of proven C. pneumoniae infection. Substances inhibitory to the amplification of chlamydial DNA continued to be present in 12% of the samples treated according to the commonly used single-step proteinase K digestion and in 31% of the samples processed by heat treatment. However, the complexing of DNA-contaminating proteins and polysaccharides from digested specimens to cetyltrimethylammonium bromide (CTAB) followed by DNA extraction efficiently removed inhibitors from all experimental samples and provided subsequent identification of all positive clinical samples by PCR. The CTAB method and proteinase K treatment had comparable detection limits of approximately 0.01 inclusion-forming units. CTAB-based DNA purification of respiratory specimens is recommended to increase the diagnostic sensitivity of PCR and confidence in negative results. Images PMID:7814512

  20. Filter-Aided Sample Preparation: The Versatile and Efficient Method for Proteomic Analysis.

    Science.gov (United States)

    Wiśniewski, J R

    2017-01-01

    Filter-aided sample preparation (FASP) is a versatile and efficient way of processing protein extracts for bottom-up proteomic analysis. The method repurposes centrifugal ultrafiltration concentrators for removal of detergents, protein cleavage, and isolation of pure peptide fractions. FASP can be used for protein cleavage with different proteinases either with single enzymes or in a mode of successive multienzyme digestion (MED)-FASP. The FASP methods are useful for processing of samples ranging in their sizes from submicrogram to several milligram amounts of total protein. They also allow peptide fractionation, and isolation and quantitation of total RNA and DNA acid contents. This chapter describes principles, limitations, and applications of FASP. Additionally detailed FASP and MED-FASP protocols are provided. © 2017 Elsevier Inc. All rights reserved.

  1. Evaluation of sample preparation methods for water activity determination in jerky and kippered beef: a research note.

    Science.gov (United States)

    Harper, N M; Getty, K J K; Boyle, E A E

    2010-10-01

    Commercially available packaged whole muscle beef jerky, chopped and formed beef jerky, and kippered beef steak were obtained from retail stores to determine the effect of two sample preparation methods on water activity (a(w)). Intact samples were prepared by cutting product into a hexagonal shape with a 3.2 cm diameter. Diced samples were prepared by cutting the product into 0.4 x 0.4 cm squares. Whole muscle jerky a(w) was higher (0.016 units; P0.05) in a(w) levels between the two preparation methods for chopped and formed jerky or kippered beef steak. An intact sample preparation method is recommended for a(w) determination of whole muscle jerky to obtain a more conservative value, especially if a(w) is near the margin of safety. Copyright (c) 2010 The American Meat Science Association. Published by Elsevier Ltd. All rights reserved.

  2. Simplified platelet sample preparation for SDS-PAGE-based proteomic studies.

    Science.gov (United States)

    Reicheltová, Zuzana; Májek, Pavel; Riedel, Tomáš; Suttnar, Jiří; Dyr, Jan E

    2012-08-01

    The goal of this study was to design an easy and simple protocol for platelet isolation and sample preparation for proteomic studies based on 2DE (IEF-SDS-PAGE) followed by Coomassie blue staining. Blood was collected by venipuncture into tubes coated with EDTA and platelet-rich plasma (PRP) was immediately obtained by centrifugation. PRP was stored refrigerated in closed Falcon tubes for 0, 1, 2, 3, 5, and 7 days and platelets were isolated by centrifugation. 2DE gels were stained with colloidal Coomassie blue stain and evaluated using the Progenesis SameSpots software. Spots that differed significantly in the gels of fresh and stored platelet samples were excised, digested with trypsin, and further analyzed using nanoLC-MS/MS. During the 7-day follow-up period, we found 20 spots that differed significantly (ANOVA p investigations, whenever it is not feasible to prepare washed platelets immediately after blood collection, the EDTA-anticoagulated PRP can be stored in test tubes at 4°C for up to 2 days for the platelet proteome investigation. © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. 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. Copyright © 2016 Elsevier Ltd. All rights reserved.

  4. Microfluidics cell sample preparation for analysis: Advances in efficient cell enrichment and precise single cell capture.

    Science.gov (United States)

    Huang, Liang; Bian, Shengtai; Cheng, Yinuo; Shi, Guanya; Liu, Peng; Ye, Xiongying; Wang, Wenhui

    2017-01-01

    Single cell analysis has received increasing attention recently in both academia and clinics, and there is an urgent need for effective upstream cell sample preparation. Two extremely challenging tasks in cell sample preparation-high-efficiency cell enrichment and precise single cell capture-have now entered into an era full of exciting technological advances, which are mostly enabled by microfluidics. In this review, we summarize the category of technologies that provide new solutions and creative insights into the two tasks of cell manipulation, with a focus on the latest development in the recent five years by highlighting the representative works. By doing so, we aim both to outline the framework and to showcase example applications of each task. In most cases for cell enrichment, we take circulating tumor cells (CTCs) as the target cells because of their research and clinical importance in cancer. For single cell capture, we review related technologies for many kinds of target cells because the technologies are supposed to be more universal to all cells rather than CTCs. Most of the mentioned technologies can be used for both cell enrichment and precise single cell capture. Each technology has its own advantages and specific challenges, which provide opportunities for researchers in their own area. Overall, these technologies have shown great promise and now evolve into real clinical applications.

  5. Effect of sample preparation on components and liver toxicity of Polygonum multiflorum.

    Science.gov (United States)

    Lv, G P; Meng, L Z; Han, D Q; Li, H Y; Zhao, J; Li, S P

    2015-05-10

    It was shown that different extracts had significant differences in the toxicity of Polygonum multiflorum. In this study, the effect of sample preparation on components and liver toxicity of different extracts from P. multiflorum were determined. Hepatoxic components were discovered based on biomembrane extraction. Comparative chemistry and toxicology between ethanol and water extracts were also performed. The results showed that ethanol extract had much stronger hepatotoxicity, the content of emodin-8-O-β-d-glucopyranoside, physcion-8-O-β-d-glucopyranoside, emodin and physcion was significantly higher in ethanol extract than in water extract, while the human hepatocytes extraction showed that 2,3,5,4'-tetrahydroxystilbene-2-O-β-d-glucopyranoside, emodin-8-O-β-d-glucopyranoside, physcion-8-O-β-d-glucopyranoside, emodin and physcion had interaction with human hepatocytes. The hepatotoxic effect of these components was investigated on human hepatocytes LO2 cells and emodin-8-O-β-d-glucopyranoside, physcion-8-O-β-d-glucopyranoside, emodin and physcion were finally confirmed to be, at least partial, hepatotoxic components. The results showed that sample preparation has significant effect on components in extracts of P. multiflorum especially the components related to hepatotoxicity. Water extract, the conventional administration form of Chinese herbs, is prefer for phytotherapy before well understanding their chemistry and biological activities. Copyright © 2015 Elsevier B.V. All rights reserved.

  6. Evaluation of cell wall preparations for proteomics: a new procedure for purifying cell walls from Arabidopsis hypocotyls

    Directory of Open Access Journals (Sweden)

    Canut Hervé

    2006-05-01

    Full Text Available Abstract Background The ultimate goal of proteomic analysis of a cell compartment should be the exhaustive identification of resident proteins; excluding proteins from other cell compartments. Reaching such a goal closely depends on the reliability of the isolation procedure for the cell compartment of interest. Plant cell walls possess specific difficulties: (i the lack of a surrounding membrane may result in the loss of cell wall proteins (CWP during the isolation procedure, (ii polysaccharide networks of cellulose, hemicelluloses and pectins form potential traps for contaminants such as intracellular proteins. Several reported procedures to isolate cell walls for proteomic analyses led to the isolation of a high proportion (more than 50% of predicted intracellular proteins. Since isolated cell walls should hold secreted proteins, one can imagine alternative procedures to prepare cell walls containing a lower proportion of contaminant proteins. Results The rationales of several published procedures to isolate cell walls for proteomics were analyzed, with regard to the bioinformatic-predicted subcellular localization of the identified proteins. Critical steps were revealed: (i homogenization in low ionic strength acid buffer to retain CWP, (ii purification through increasing density cushions, (iii extensive washes with a low ionic strength acid buffer to retain CWP while removing as many cytosolic proteins as possible, and (iv absence of detergents. A new procedure was developed to prepare cell walls from etiolated hypocotyls of Arabidopsis thaliana. After salt extraction, a high proportion of proteins predicted to be secreted was released (73%, belonging to the same functional classes as proteins identified using previously described protocols. Finally, removal of intracellular proteins was obtained using detergents, but their amount represented less than 3% in mass of the total protein extract, based on protein quantification. Conclusion The

  7. EVALUATION OF ARG-1 SAMPLES PREPARED BY CESIUM CARBONATE DISSOLUTION DURING THE ISOLOK SME ACCEPTABILITY TESTING

    Energy Technology Data Exchange (ETDEWEB)

    Edwards, T.; Hera, K.; Coleman, C.

    2011-12-05

    Evaluation of Defense Waste Processing Facility (DWPF) Chemical Process Cell (CPC) cycle time identified several opportunities to improve the CPC processing time. The Mechanical Systems & Custom Equipment Development (MS&CED) Section of the Savannah River National Laboratory (SRNL) recently completed the evaluation of one of these opportunities - the possibility of using an Isolok sampling valve as an alternative to the Hydragard valve for taking DWPF process samples at the Slurry Mix Evaporator (SME). The use of an Isolok for SME sampling has the potential to improve operability, reduce maintenance time, and decrease CPC cycle time. The SME acceptability testing for the Isolok was requested in Task Technical Request (TTR) HLW-DWPF-TTR-2010-0036 and was conducted as outlined in Task Technical and Quality Assurance Plan (TTQAP) SRNLRP-2011-00145. RW-0333P QA requirements applied to the task, and the results from the investigation were documented in SRNL-STI-2011-00693. Measurement of the chemical composition of study samples was a critical component of the SME acceptability testing of the Isolok. A sampling and analytical plan supported the investigation with the analytical plan directing that the study samples be prepared by a cesium carbonate (Cs{sub 2}CO{sub 3}) fusion dissolution method and analyzed by Inductively Coupled Plasma - Optical Emission Spectroscopy (ICP-OES). The use of the cesium carbonate preparation method for the Isolok testing provided an opportunity for an additional assessment of this dissolution method, which is being investigated as a potential replacement for the two methods (i.e., sodium peroxide fusion and mixed acid dissolution) that have been used at the DWPF for the analysis of SME samples. Earlier testing of the Cs{sub 2}CO{sub 3} method yielded promising results which led to a TTR from Savannah River Remediation, LLC (SRR) to SRNL for additional support and an associated TTQAP to direct the SRNL efforts. A technical report resulting

  8. Preparation of well-defined samples of AlPdMn quasicrystals for surface studies

    Science.gov (United States)

    Jenks, C. J.; Delaney, D. W.; Bloomer, T. E.; Chang, S.-L.; Lograsso, T. A.; Shen, Z.; Zhang, C.-M.; Thiel, P. A.

    1996-12-01

    We have developed a method for preparing single-grain, quasicrystalline AlPdMn samples for surface studies in ultrahigh vacuum. The main issues of concern are phase purity, the quality of the surface structure, and the surface, and the surface composition. Phase purity is enhanced by annealing the sample in ultra-pure Ar in a sealed quartz ampoule for several days before polishing. Polishing with colloidal silica allows secondary phases to be detected readily with an optical microscope. As a final precaution, phase purity can be checked sensitively with scanning Auger microscopy. After this stage, the sample can be cleaned in ultrahigh vacuum with ion bombardment. Annealing is required after bombardment to restore surface structure and to obtain a low-energy electron diffraction (LEED) pattern of an oriented sample. However, both ion bombardment and heating to temperatures above 870 K in vacuum, produce Pd-rich surfaces. As a final step, for the five-fold surface, we recommend heating briefly to 1050-1100 K and then annealing at 870 K for several hours. This produces both an excellent LEED pattern, and a surface composition close to that of the bulk.

  9. 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.

  10. 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.

  11. Ochratoxin A in raisins and currants: basic extraction procedure used in two small marketing surveys of the occurrence and control of the heterogeneity of the toxins in samples.

    Science.gov (United States)

    Möller, T E; Nyberg, M

    2003-11-01

    A basic extraction procedure for analysis of ochratoxin A (OTA) in currants and raisins is described, as well as the occurrence of OTA and a control of heterogeneity of the toxin in samples bought for two small marketing surveys 1999/2000 and 2001/02. Most samples in the surveys were divided into two subsamples that were individually prepared as slurries and analysed separately. The limit of quantification for the method was estimated as 0.1 microg kg(-1) and recoveries of 85, 90 and 115% were achieved in recovery experiments at 10, 5 and 0.1 microg kg(-1), respectively. Of all 118 subsamples analysed in the surveys, 96 (84%) contained ochratoxin A at levels above the quantification level and five samples (4%) contained more than the European Community legislation of 10 microg kg(-1). The OTA concentrations found in the first survey were in the range Big differences were often achieved between individual subsamples of the original sample, which indicate a wide heterogeneous distribution of the toxin. Data from the repeatability test as well as recovery experiments from the same slurries showed that preparation of slurries as described here seemed to give a homogeneous and representative sample. The extraction with the basic sodium bicarbonate-methanol mixture used in the surveys gave similar or somewhat higher OTA values on some samples tested in a comparison with a weak phosphoric acid water-methanol extraction mixture.

  12. Sample preparation and varistor physical properties measurement of ZnO+0.01Sb2O3

    Directory of Open Access Journals (Sweden)

    Juggaroen, N

    2003-01-01

    Full Text Available The disc-shape ZnO+0.01Sb2O3 samples were prepared by standard ceramic techniques. The sample indicates white colour and was characterized by XRD. The prepared sample is varistor which shows breakdown field strength of 87.18 V/mm and non-linearity exponent (α of 38.179. It is worth noting that the high electric field strength of 5128.2 V/mm causes sample resistance changing. Sample resistance before and after poling were 189.13 kΩ and 6.516 kΩ, respectively.

  13. 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.)

  14. Efficiency enhancement of perovskite solar cells by fabricating as-prepared film before sequential spin-coating procedure

    Energy Technology Data Exchange (ETDEWEB)

    Jiang, Jiajia [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Tao, Hai jun, E-mail: taohaijun@nuaa.edu.cn [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Jiangsu Collaborative Innovation Center of Photovolatic Science and Engineering, Changzhou University, Changzhou 213164, Jiangsu (China); Chen, Shanlong; Tan, Bin [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Zhou, Ning [Shanghai Electrochemical Energy Devices Research Center, School of Chemistry and Chemical Engineering, Shanghai Jiao Tong University, Shanghai 200240 (China); Zhu, Lumin; Zhao, Yuan [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China); Wang, Yuqiao [Jiangsu Optoelectronic Functional Materials and Engineering Laboratory, School of Chemistry and Chemical Engineering, Southeast University, Nanjing 211189 (China); Tao, Jie [Jiangsu Key Laboratory of Materials and Technology for Energy Conversion, College of material science and technology, Nanjing University of Aeronautics and Astronautics, Nanjing 211100 (China)

    2016-05-15

    Graphical abstract: Schematic illustration of modified two-step spin-coating procedure for MAPbI{sub 3} perovskite thin films. - Highlights: • An as-prepared CH{sub 3}NH{sub 3}PbI{sub 3} and PbI{sub 2} film was introduced before the traditional two-step process. • Smooth morphology and trace amount of remaining PbI{sub 2} benefit the performance of solar cell. • The optimal as-prepared film introduced improves the efficiency of CH{sub 3}NH{sub 3}PbI{sub 3} solar cells from 9.11% to 11.16%. - Abstract: Sequential spin-coating procedure is a widely adopted strategy to prepare CH{sub 3}NH{sub 3}PbI{sub 3} on mesostructured TiO{sub 2} electrode for organolead halide perovskite-based solar cells. However, this method suffers from the rough surface and excessively residual PbI{sub 2} in the resulting perovskite film, deteriorating the device performance seriously. Herein, a facial modified sequential solution deposition method, by introducing an as-prepared CH{sub 3}NH{sub 3}PbI{sub 3} and PbI{sub 2} film before the traditional two-step process, was proposed to fabricate the perovskite-based solar cell with smooth morphology and trace amount of remaining PbI{sub 2}. The optimal as-prepared film introduced improves the efficiency of CH{sub 3}NH{sub 3}PbI{sub 3} solar cells from 9.11% to 11.16%. The enhancement of device performance can be attributed to the increased light absorption ability and decreased recombination rate of carriers in CH{sub 3}NH{sub 3}PbI{sub 3} absorber.

  15. Improved determination of macroscopic parasite preparations using S10 modified plastination procedure

    Directory of Open Access Journals (Sweden)

    Elena Atanaskova

    2010-11-01

    Full Text Available Macroscopic preparations of parasites fixed in formaldehyde or alcohol don’t fulfill in complete the requests for education, as well as their determination, mainly because of the toxic fumes and not enough visible structure of fixed parasite. Using the modified С10 plastination method, parasites from three different phylum were prepared: Plathelminthes: Class Cestoda (Dipilidum caninum, Moniezia spp and larvae from T.Echinococcus granulosus - Echinococcus unilocularis, larvae from T. pisiformis - Cysticercus pisiformis, , larvae from T. hidatigena - Cysticercus tenuicollis, Phylum Nemathelminthes, Class Nematoda, (Ascaris suum, Macracanthorhynchus hirudinaceus, Diro filaria immitis, Phylum Arthropoda, Class Arachnida (tick from the Ixodidae family and Class Insecta (Gasterophilus intestinalis, Hypoderma bovis. The aim of this study was conserving the parasites in native condition with plastination method and improved determination according to their visible morphologic structure. Parasites were previously kept in 10% formaldehyde. Prepared parasites were dry, chemical free, not toxic and safe for the environment, flexible and with detained form and structure. There was a variation in the natural colors in some of the parasites, as a result from long-time formalin fixation. Preparations made with this method are permanent educative material which enables improved study of parasite’s structure.

  16. Concept formation based on value relations evaluated with a matching-to-sample procedure.

    Science.gov (United States)

    Pérez-González, Luis Antonio

    2008-01-01

    To study concept formation based on relations, adults were taught and tested on complex discriminations involving figures that varied in colors, forms, and orientations. In Experiment 1, participants learned to select figures with values A1 and B1 or values B1 and C1; thereafter, they consistently selected figures with values A1 and C1. Selections were based on the relations among the values, rather than on perceptual properties. Experiments 2 and 3 studied generalization with a matching-to-sample procedure: participants learned to select "yes" in the presence of the positive figures, such as A1B1, and "no" in the presence of the negative figures. Thereafter, all figures that resulted from combining three values of the three relevant dimensions were probed. Participants typically selected "yes" in the presence of the novel figures that had two or three values related to one another and selected "no" in the presence of the other figures. Finally, two participants learned a simple discrimination. They did not generalize responding to other figures with the same values; instead, their performance in the generalization test remained almost unaltered. Thus, the concept based on relations was not affected by the simple discrimination. These results showed some unique properties of the concept based on relations and challenge previous theories on concept formation.

  17. 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 pr...

  18. 76 FR 65953 - CBP Audit Procedures; Use of Sampling Methods and Offsetting of Overpayments and Over-Declarations

    Science.gov (United States)

    2011-10-25

    ... projection will not produce accurate audits unless an audit takes into account the specifics for each...-AD65 (Formerly RIN 1505-AC00) CBP Audit Procedures; Use of Sampling Methods and Offsetting of... Protection (CBP) regulations by adding provisions for the use of sampling methods in CBP audits and prior...

  19. Matrix removal in state of the art sample preparation methods for serum by charged aerosol detection and metabolomics-based LC-MS.

    Science.gov (United States)

    Schimek, Denise; Francesconi, Kevin A; Mautner, Anton; Libiseller, Gunnar; Raml, Reingard; Magnes, Christoph

    2016-04-07

    Investigations into sample preparation procedures usually focus on analyte recovery with no information provided about the fate of other components of the sample (matrix). For many analyses, however, and particularly those using liquid chromatography-mass spectrometry (LC-MS), quantitative measurements are greatly influenced by sample matrix. Using the example of the drug amitriptyline and three of its metabolites in serum, we performed a comprehensive investigation of nine commonly used sample clean-up procedures in terms of their suitability for preparing serum samples. We were monitoring the undesired matrix compounds using a combination of charged aerosol detection (CAD), LC-CAD, and a metabolomics-based LC-MS/MS approach. In this way, we compared analyte recovery of protein precipitation-, liquid-liquid-, solid-phase- and hybrid solid-phase extraction methods. Although all methods provided acceptable recoveries, the highest recovery was obtained by protein precipitation with acetonitrile/formic acid (amitriptyline 113%, nortriptyline 92%, 10-hydroxyamitriptyline 89%, and amitriptyline N-oxide 96%). The quantification of matrix removal by LC-CAD showed that the solid phase extraction method (SPE) provided the lowest remaining matrix load (48-123 μg mL(-1)), which is a 10-40 fold better matrix clean-up than the precipitation- or hybrid solid phase extraction methods. The metabolomics profiles of eleven compound classes, comprising 70 matrix compounds showed the trends of compound class removal for each sample preparation strategy. The collective data set of analyte recovery, matrix removal and matrix compound profile was used to assess the effectiveness of each sample preparation method. The best performance in matrix clean-up and practical handling of small sample volumes was showed by the SPE techniques, particularly HLB SPE. CAD proved to be an effective tool for revealing the considerable differences between the sample preparation methods. This detector can

  20. The use of heparin in preparing samples for blood-gas analysis.

    Science.gov (United States)

    Higgins, Chris

    2007-10-01

    Heparin is the only anticoagulant used to prepare samples for blood-gas analysis. There are two ways in which heparin can interfere with results. The first is high heparin concentration in blood, and the second is heparin dilution of blood if liquid rather than dried (lyophilized) heparin is used. Traditional blood-gas analytes (pH, pCO2, and pO2) are less affected than electrolytes (particularly ionized calcium), also measured on modern blood-gas analyzers. The sample requirements as far as heparin is concerned are thus less exacting if only pH, pCO2, and pO2 are to be measured. For these analytes, it is still essential that the heparin (either sodium or lithium) concentration is less than 200 IU/mL blood and that the blood is not diluted more than 5%. The inclusion of electrolytes in the test repertoire excludes the use of sodium heparin in favor of lithium heparin. The inclusion of ionized calcium in the test repertoire demands that the heparin should be lyophilized, and the concentration should not exceed 10 IU/mL blood, unless a specialized heparin that eliminates the effect of calcium binding by heparin is used. Whatever the heparin formulation, it is essential for accurate results that the correct volume of blood is sampled to achieve a correct heparin concentration (and dilution, if liquid heparin is used), and that blood and anticoagulant are well mixed immediately after sampling. One of the most common practical problems associated with blood-gas analysis is inadequate anticoagulation and the formation of small blood clots that can block the sample pathway of blood-gas analyzers and invalidate results. Inadequate mixing of specimen with heparin is usually the problem. Clearly, the lower the heparin concentration the greater is the risk that poor mixing technique will give rise to inadequate anticoagulation and the associated problems.

  1. Sample preparation vs quality of X-ray phase analysis results

    Directory of Open Access Journals (Sweden)

    R. Chylińska

    2007-12-01

    Full Text Available In this study, taking as an example the creep-resistant austenitic cast steel, the results of the investigations were presented whose aim was to show what effect the specimen surface condition, discussed in terms of its roughness obtained by grinding, polishing with diamond paste, electrolytic polishing and etching, may have on the quality of results obtained by X-ray phase analysis. The preset goal has been achieved comparing the quantity and intensity of reflections on X-ray diffraction patterns obtained from the prepared specimens. The test material was cast steel containing (in wt.%: 0.29%C, 1.02%Mn, 4.36%Si, 0.007%S, 0.015%P, 17.8%Cr, 29.3%Ni, 1.59%Nb and 1.19%Ti, subjected to the process of annealing at a temperature of 850oC for 100 hours. For identification of structural constituents by the technique of X-ray phase analysis, four solid specimens were prepared. Their surfaces were successively ground, polished, and subjected to electrolytic etching. The reference sample (isolate was obtained by the method of electrolytic extraction. In solid material the following phases were identified: Feγ, NbC and G; in the isolate additionally the presence of TiC, M23C6 and σ was reported. It has been proved that in the case of solid specimens partial identification of phase constituents may be carried out on surfaces subjected only to grinding with 600 grit abrasive paper without the need of any further preparation.

  2. Modified Sample Preparation Approach for the Determination of the Phenolic and Humic-Like Substances in Natural Organic Materials By the Folin Ciocalteu Method.

    Science.gov (United States)

    Pontoni, Ludovico; Panico, Antonio; Matanò, Alessia; van Hullebusch, Eric D; Fabbricino, Massimiliano; Esposito, Giovanni; Pirozzi, Francesco

    2017-12-06

    A novel modification of the sample preparation procedure for the Folin-Ciocalteu colorimetric assay for the determination of total phenolic compounds in natural solid and semisolid organic materials (e.g., foods, organic solid waste, soils, plant tissues, agricultural residues, manure) is proposed. In this method, the sample is prepared by adding sodium sulfate as a solid diluting agent before homogenization. The method allows for the determination of total phenols (TP) in samples with high solids contents, and it provides good accuracy and reproducibility. Additionally, this method permits analyses of significant amounts of sample, which reduces problems related to heterogeneity. We applied this method to phenols-rich lignocellulosic and humic-like solids and semisolid samples, including rice straw (RS), peat-rich soil (PS), and food waste (FW). The TP concentrations measured with the solid dilution (SD) preparation were substantially higher (increases of 41.4%, 15.5%, and 59.4% in RS, PS and FW, respectively) than those obtained with the traditional method (solids suspended in water). These results showed that the traditional method underestimates the phenolic contents in the studied solids.

  3. Urine sample preparation in 96-well filter plates for quantitative clinical proteomics.

    Science.gov (United States)

    Yu, Yanbao; Suh, Moo-Jin; Sikorski, Patricia; Kwon, Keehwan; Nelson, Karen E; Pieper, Rembert

    2014-06-03

    Urine is an important, noninvasively collected body fluid source for the diagnosis and prognosis of human diseases. Liquid chromatography mass spectrometry (LC-MS) based shotgun proteomics has evolved as a sensitive and informative technique to discover candidate disease biomarkers from urine specimens. Filter-aided sample preparation (FASP) generates peptide samples from protein mixtures of cell lysate or body fluid origin. Here, we describe a FASP method adapted to 96-well filter plates, named 96FASP. Soluble urine concentrates containing ~10 μg of total protein were processed by 96FASP and LC-MS resulting in 700-900 protein identifications at a 1% false discovery rate (FDR). The experimental repeatability, as assessed by label-free quantification and Pearson correlation analysis for shared proteins among replicates, was high (R ≥ 0.97). Application to urinary pellet lysates which is of particular interest in the context of urinary tract infection analysis was also demonstrated. On average, 1700 proteins (±398) were identified in five experiments. In a pilot study using 96FASP for analysis of eight soluble urine samples, we demonstrated that protein profiles of technical replicates invariably clustered; the protein profiles for distinct urine donors were very different from each other. Robust, highly parallel methods to generate peptide mixtures from urine and other body fluids are critical to increase cost-effectiveness in clinical proteomics projects. This 96FASP method has potential to become a gold standard for high-throughput quantitative clinical proteomics.

  4. 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.

  5. 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.

  6. Optimized sample preparation for MALDI mass spectrometry analysis of protected synthetic peptides.

    Science.gov (United States)

    Schaiberger, Audrey M; Moss, Jason A

    2008-04-01

    The recent development and commercialization of Fuzeon (enfuvirtide) demonstrated that a convergent strategy comprised of both solid- and solution-phase synthetic methodologies presents a viable route for peptide manufacturing on a multi-ton scale. In this strategy, the target sequence is prepared by stepwise solid-phase synthesis of protected peptide fragments, which are then coupled together in the solution-phase to give the full-length sequence. These synthetic methodologies pose a unique challenge for mass spectrometry (MS), as protected peptide intermediates are often marked by poor solubility, structural lability, and low ionization potential. Matrix-assisted laser desorption/ionization (MALDI) MS is uniquely suited to such analytes; however, generalized protocols for MALDI analysis of protected peptides have yet to be demonstrated. Herein, we report an operationally simple sample preparation method for MALDI analysis of protected peptides, which greatly facilitates the collection and interpretation of MS data. In this method, the difficulty in MS analysis of protected peptides has been greatly diminished by use of dithranol as a matrix and CsCl as an additive, giving rise to intentionally-formed Cs(+) adducts. With greatly reduced fragmentation, better crystalline morphology, and easier data interpretation, we anticipate that these findings will find utility in peptide process development and manufacturing settings for reaction monitoring, troubleshooting, and quality control.

  7. U.S. Geological Survey Noble Gas Laboratory’s standard operating procedures for the measurement of dissolved gas in water samples

    Science.gov (United States)

    Hunt, Andrew G.

    2015-08-12

    This report addresses the standard operating procedures used by the U.S. Geological Survey’s Noble Gas Laboratory in Denver, Colorado, U.S.A., for the measurement of dissolved gases (methane, nitrogen, oxygen, and carbon dioxide) and noble gas isotopes (helium-3, helium-4, neon-20, neon-21, neon-22, argon-36, argon-38, argon-40, kryton-84, krypton-86, xenon-103, and xenon-132) dissolved in water. A synopsis of the instrumentation used, procedures followed, calibration practices, standards used, and a quality assurance and quality control program is presented. The report outlines the day-to-day operation of the Residual Gas Analyzer Model 200, Mass Analyzer Products Model 215–50, and ultralow vacuum extraction line along with the sample handling procedures, noble gas extraction and purification, instrument measurement procedures, instrumental data acquisition, and calculations for the conversion of raw data from the mass spectrometer into noble gas concentrations per unit mass of water analyzed. Techniques for the preparation of artificial dissolved gas standards are detailed and coupled to a quality assurance and quality control program to present the accuracy of the procedures used in the laboratory.

  8. Sample processing and cDNA preparation for microbial metatranscriptomics in complex soil communities.

    Science.gov (United States)

    Carvalhais, Lilia C; Schenk, Peer M

    2013-01-01

    Soil presents one of the most complex environments for microbial communities as it provides many microhabitats that allow coexistence of thousands of species with important ecosystem functions. These include biomass and nutrient cycling, mineralization, and detoxification. Culture-independent DNA-based methods, such as metagenomics, have revealed operational taxonomic units that suggest a high diversity of microbial species and associated functions in soil. An emerging but technically challenging area to profile the functions of microorganisms and their activities is mRNA-based metatranscriptomics. Here, we describe issues and important considerations of soil sample processing and cDNA preparation for metatranscriptomics from bacteria and archaea and provide a set of methods that can be used in the required experimental steps. © 2013 Elsevier Inc. All rights reserved.

  9. Sample preparation and electrochemical data of Co3O4 working electrode for seawater splitting

    Directory of Open Access Journals (Sweden)

    Malkeshkumar Patel

    2017-10-01

    Full Text Available In this data article, we presented the electrochemical data of the working electrode made of Co3O4 semi-transparent film. Electrochemically stable, porous nature of Kirkendall-diffusion grown Co3O4 films were applied to generate hydrogen from the seawater splitting (Patel et al., 2017 [1]. The data presented in this article includes the photograph of prepared samples, polarization curves for water oxidation and Tafel plot, linear sweep voltammetry measurements under the pulsed light condition in 0.1 M Na2S2O3 electrolyte, and transient photoresponses with natural sea water. Moreover, seawater splitting using the Co3O4 working electrode is demonstrated.

  10. Isotachophoretic phenomena in electric field gradient focusing: perspectives for sample preparation and bioassays.

    Science.gov (United States)

    Quist, Jos; Vulto, Paul; Hankemeier, Thomas

    2014-05-06

    Isotachophoresis (ITP) and electric field gradient focusing (EFGF) are two powerful approaches for simultaneous focusing and separation of charged compounds. Remarkably, in many EFGF methods, isotachophoretic hallmarks have been found, including observations of plateau concentrations and contiguous analyte bands. We discuss the similarities between ITP and EFGF and describe promising possibilities to transfer the functionality and applications developed on one platform to other platforms. Of particular importance is the observation that single-electrolyte isotachophoretic separations with tunable ionic mobility window can be performed, as is illustrated with the example of depletion zone isotachophoresis (dzITP). By exploiting the rapid developments in micro- and nanofluidics, many interesting combinations of ITP and EFGF features can be achieved, yielding powerful analytical platforms for sample preparation, biomarker discovery, molecular interaction assays, drug screening, and clinical diagnostics.

  11. Metallurgical sample preparation at the Institute of Reference Materials and Measurements

    Science.gov (United States)

    Ingelbrecht, C.

    1995-05-01

    The Sample Preparation Group at IRMM provides targets for cross section measurements and fission fragment studies using the accelerators on site, and also supplies targets to collaborators and other users from universities and other nuclear centres. In addition, reactor dosimetry reference materials, flux monitor capsules and reactor temperature monitors are supplied to testing and power reactor facilities. The metallurgical activities in this field include a range of crucibleless and levitation melting techniques giving alloys of closely controlled composition and good homogeneity, facilities for foil and wire fabrication with inert atmosphere processing for reactive metals and high value isotopes and canning techniques including laser and electron beam welding. Many of these fabrication techniques are applied to actinide metals using equipment installed in glove boxes. Several techniques including spectrophotometry, mass spectrometry, atomic absorption and gamma spectrometry are available for alloy characterization.

  12. 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.

  13. 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. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. 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.

  15. 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

  16. 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.

  17. Preoperative vaginal preparation with baby shampoo compared with povidone-iodine before gynecologic procedures.

    Science.gov (United States)

    Lewis, Linda A; Lathi, Ruth B; Crochet, Patrice; Nezhat, Camran

    2007-01-01

    The objective of this study was to compare the postoperative infection rates between patients receiving either povidone-iodine (PI) or baby shampoo vaginal preparations before gynecologic surgery. Cohort study (Canadian Task Force classification II-2). University referral center for gynecologic endoscopy. All patients underwent minimally invasive gynecologic surgery including hysteroscopy or laparoscopy. The agents used for vaginal preparation were either baby shampoo in a 1:1 dilution with sterile normal saline solution or PI 7.5% scrub solution. Charts were reviewed for evidence of infection within 30 days of surgery (symptoms of urinary tract infection, abdominal or vaginal wound infections, temperature > 100.4 degrees F, and fungal or bacterial vaginitis). A total of 249 cases were collected; 96 subjects underwent surgery before the change to baby shampoo and 153 subjects after. Both groups were well matched for the types of surgery performed, age, risk factors for postoperative infections, and the postoperative diagnosis. The infection rates were 14/96 (14.6%) with PI preparation versus 18/153 (11.8%) with baby shampoo (p = .52). Baby shampoo should be studied as an alternative to PI because it is a nonirritating, inexpensive mild detergent. This preliminary study suggests that baby shampoo is as effective as PI in preventing postoperative infection.

  18. Determination of Cd and Pb in food slurries by GFAAS using cryogenic grinding for sample preparation.

    Science.gov (United States)

    Santos, D; Barbosa, F; Tomazelli, A C; Krug, F J; Nóbrega, J A; Arruda, M A Z

    2002-06-01

    A simple method combining slurry sampling after cryogenic grinding and the use of a permanent modification of the integrated platform inside the transversely heated graphite atomizer (THGA) was proposed for the determination of Cd and Pb in foods. Potentialities of the cryogenic grinding were evaluated for grinding different materials of difficult homogenization such as high fat and high fiber tissues. Animal and vegetal samples were cut into small pieces and ground in liquid nitrogen for 2 min. Slurries were prepared directly in the autosampler cup after cryogenic grinding by transferring an exact amount of homogeneous powdered material (5-20 mg) to the cup, followed by 1.00 mL of 0.2% (v/v) HNO3 containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 microg W and 200 microg Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH4H2PO4 conventional modifier improves tube lifetime and increases the pyrolysis temperature for Cd. Homogeneity tests, carried out by comparing the between- and within-batch precision for each kind of sample, showed no significant differences at the 95% confidence level, indicating good homogeneity for 5-20 mg masses. Detection limits were 3.3 ng g(-1) Cd and 75 ng g(-1) Pb for 1% m/v slurries. Results for determination of Cd and Pb in foods slurries were in agreement with those obtained with digested samples, since no statistical differences were found by the paired t-test at the 95% level.

  19. Standard Operating Procedure for In-house Preparation of (131)I-rituximab for Radioimmunotherapy of Non-Hodgkin's Lymphoma.

    Science.gov (United States)

    Pickford, Matthew D; Turner, J Harvey

    2012-09-01

    A Standard Operating Procedure (SOP) has been formulated for in-house preparation, quality control, dispensing and administration of (131)I-rituximab appropriate for the safe, effective, radioimmunotherapy of non-Hodgkin lymphoma. A decade of experience of semi-automated radioiodination of rituximab in our hospital radiopharmaceutical laboratory was analysed. The methodology was then refined for safe, practical, affordable application to radioimmunotherapy of lymphoma in departments of nuclear medicine in developing countries. This SOP has the potential to be incorporated into good laboratory practice conditions appropriate for local regulatory agency requirements.

  20. Radiochemical procedures for analysis of Pu, Am, Cs and Sr in water, soil, sediments and biota samples

    Energy Technology Data Exchange (ETDEWEB)

    Wong, K.M.; Jokela, T.A.; Noshkin, V.E.

    1994-02-01

    The Environmental Radioactivity Analysis Laboratory (ERAL) was established as an analytical facility. The primary function of ERAL is to provide fast and accurate radiological data of environmental samples. Over the years, many radiochemical procedures have been developed by the staffs of ERAL. As result, we have found that our procedures exist in many different formats and in many different notebooks, documents and files. Therefore, in order to provide for more complete and orderly documentation of the radiochemical procedures that are being used by ERAL, we have decided to standardize the format and compile them into a series of reports. This first report covers procedures we have developed and are using for the radiochemical analysis of Pu, Am, Cs, and Sr in various matrices. Additional analytical procedures and/or revisions for other elements will be reported as they become available through continuation of these compilation efforts.

  1. Effects of blood sample handling procedures on measurable inflammatory markers in plasma, serum and dried blood spot samples

    DEFF Research Database (Denmark)

    Skogstrand, K.; Thorsen, P.; Vogel, I.

    2008-01-01

    , and 30 days at the same temperatures. 27 inflammatory markers in serum and plasma and 25 markers in DBSS were measured by a previously validated multiplex sandwich immunoassay using Luminex xMAP technology. The measurable concentrations of several cytokines in serum and plasma were significantly......The interests in monitoring inflammation by immunoassay determination of blood inflammatory markers call for information on the stability of these markers in relation to the handling of blood samples. The increasing use of stored biobank samples for such ventures that may have been collected...... increased when blood samples were stored for a period of time before the centrifugation, for certain cytokines more than 1000 fold compared to serum and plasma isolated and frozen immediately after venepuncture. The concentrations in serum generally increased more than in plasma. The measurable...

  2. Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; preparation procedure for aquatic biological material determined for trace metals

    Science.gov (United States)

    Hoffman, Gerald L.

    1996-01-01

    A method for the chemical preparation of tissue samples that are subsequently analyzed for 22 trace metals is described. The tissue-preparation procedure was tested with three National Institute of Standards and Technology biological standard reference materials and two National Water Quality Laboratory homogenized biological materials. A low-temperature (85 degrees Celsius) nitric acid digestion followed by the careful addition of hydrogen peroxide (30-percent solution) is used to decompose the biological material. The solutions are evaporated to incipient dryness, reconstituted with 5 percent nitric acid, and filtered. After filtration the solutions were diluted to a known volume and analyzed by inductively coupled plasma-mass spectrometry (ICP-MS), inductively coupled plasma-atomic emission spectrometry (ICP-AES), and cold vapor-atomic absorption spectrophotometry (CV-AAS). Many of the metals were determined by both ICP-MS and ICP-AES. This report does not provide a detailed description of the instrumental procedures and conditions used with the three types of instrumentation for the quantitation of trace metals determined in this study. Statistical data regarding recovery, accuracy, and precision for individual trace metals determined in the biological material tested are summarized.

  3. Practical preparation procedures for docetaxel-loaded nanoparticles using polylactic acid-co-glycolic acid

    Science.gov (United States)

    Keum, Chang-Gu; Noh, Young-Wook; Baek, Jong-Suep; Lim, Ji-Ho; Hwang, Chan-Ju; Na, Young-Guk; Shin, Sang-Chul; Cho, Cheong-Weon

    2011-01-01

    Background Nanoparticles fabricated from the biodegradable and biocompatible polymer, polylactic-co-glycolic acid (PLGA), are the most intensively investigated polymers for drug delivery systems. The objective of this study was to explore fully the development of a PLGA nanoparticle drug delivery system for alternative preparation of a commercial formulation. In our nanoparticle fabrication, our purpose was to compare various preparation parameters. Methods Docetaxel-loaded PLGA nanoparticles were prepared by a single emulsion technique and solvent evaporation. The nanoparticles were characterized by various techniques, including scanning electron microscopy for surface morphology, dynamic light scattering for size and zeta potential, x-ray photoelectron spectroscopy for surface chemistry, and high-performance liquid chromatography for in vitro drug release kinetics. To obtain a smaller particle, 0.2% polyvinyl alcohol, 0.03% D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), 2% Poloxamer 188, a five-minute sonication time, 130 W sonication power, evaporation with magnetic stirring, and centrifugation at 8000 rpm were selected. To increase encapsulation efficiency in the nanoparticles, certain factors were varied, ie, 2–5 minutes of sonication time, 70–130 W sonication power, and 5–25 mg drug loading. Results A five-minute sonication time, 130 W sonication power, and a 10 mg drug loading amount were selected. Under these conditions, the nanoparticles reached over 90% encapsulation efficiency. Release kinetics showed that 20.83%, 40.07%, and 51.5% of the docetaxel was released in 28 days from nanoparticles containing Poloxamer 188, TPGS, or polyvinyl alcohol, respectively. TPGS and Poloxamer 188 had slower release kinetics than polyvinyl alcohol. It was predicted that there was residual drug remaining on the surface from x-ray photoelectron spectroscopy. Conclusion Our research shows that the choice of surfactant is important for controlled release of

  4. 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

  5. An efficient and sensitive method for preparing cDNA libraries from scarce biological samples.

    Science.gov (United States)

    Sterling, Catherine H; Veksler-Lublinsky, Isana; Ambros, Victor

    2015-01-01

    The preparation and high-throughput sequencing of cDNA libraries from samples of small RNA is a powerful tool to quantify known small RNAs (such as microRNAs) and to discover novel RNA species. Interest in identifying the small RNA repertoire present in tissues and in biofluids has grown substantially with the findings that small RNAs can serve as indicators of biological conditions and disease states. Here we describe a novel and straightforward method to clone cDNA libraries from small quantities of input RNA. This method permits the generation of cDNA libraries from sub-picogram quantities of RNA robustly, efficiently and reproducibly. We demonstrate that the method provides a significant improvement in sensitivity compared to previous cloning methods while maintaining reproducible identification of diverse small RNA species. This method should have widespread applications in a variety of contexts, including biomarker discovery from scarce samples of human tissue or body fluids. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

  6. Analysis of acute myelogenous leukemia: preparation of samples for genomic and proteomic analyses.

    Science.gov (United States)

    Gjertsen, Bjørn Tore; Øyan, Anne M; Marzolf, Bruz; Hovland, Randi; Gausdal, Gro; Døskeland, Stein-Ove; Dimitrov, Krassen; Golden, Allison; Kalland, Karl-Henning; Hood, Leroy; Bruserud, Øystein

    2002-06-01

    During the last decade, several large clinical studies have demonstrated that analysis of chromosomal abnormalities is an essential basis for therapeutic decisions in patients with acute myelogenous leukemia (AML), and cytogenetic studies should now be regarded as mandatory both for routine treatment and as a part of clinical investigations in AML. However, new techniques for detailed genetic characterization and analysis of gene expression as well as protein modulation will become important in the further classification of AML subsets and the development of risk-adapted therapeutic strategies. In this context, we emphasize the importance of population-based clinical studies as a basis for future therapeutic guidelines. Such studies will then require the inclusion of patients at small clinical centers without specialized hematological research laboratories. To document a high and uniform quality of the laboratory investigations, it will be necessary to collect material for later analysis in selected laboratories. In this article, we describe current methods for collection of biological samples that can be used for later preparation of DNA, RNA, and proteins. With the use of gradient-separated AML cells, it should be possible to establish the necessary techniques for collection and handling of biological samples even at smaller centers, and complete collections from all included patients should then be possible even in population-based clinical studies.

  7. Preparation of higher-actinide burnup and cross section samples. [LMFBR

    Energy Technology Data Exchange (ETDEWEB)

    Adair, H.L.; Kobisk, E.H.; Quinby, T.C.; Thomas, D.K.; Dailey, J.M.

    1981-01-01

    A joint research program involving the United States and the United Kingdom was instigated about four years ago for the purpose of studying burnup of higher actinides using in-core irradiation in the fast reactor at Dounreay, Scotland. Simultaneously, determination of cross sections of a wide variety of higher actinide isotopes was proposed. Coincidental neutron flux and energy spectral measurements were to be made using vanadium encapsulated dosimetry materials in the immediate region of the burnup and cross section samples. The higher actinide samples chosen for the burnup study were /sup 241/Am and /sup 244/Cm in the forms of Am/sub 2/O/sub 3/, Cm/sub 2/O/sub 3/, and Am/sub 6/ Cm(RE)/sub 7/O/sub 21/, where (RE) represents a mixture of lanthanide sesquioxides. It is the purpose of this paper to describe technology development and its application in the preparation of the fuel specimens and the cross section specimens that are being used in this cooperative program.

  8. 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. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Comparison of different methods for preparation and characterization of total RNA from cartilage samples to uncover osteoarthritis in vivo.

    Science.gov (United States)

    Ruettger, Anke; Neumann, Steffi; Wiederanders, Bernd; Huber, René

    2010-01-18

    The isolation of intact RNA can be very difficult when tissues are used that contain many RNAses or that are hard to homogenize, e.g. cartilage samples. Additionally, cartilaginous tissues are characterized by a low cellularity and an abundance of extracellular matrix (ECM) molecules. But given the growing interest in understanding pathogenesis of degenerative diseases, e.g. osteoarthritis (OA) and rheumatoid arthritis (RA), studies have to consider expression pattern of cells in its natural environment. We compared the current RNA isolation methods for the extraction of high-quality RNA of snap-frozen biopsies from limited amounts of hypocellular cartilaginous tissue. The focus of the study was to gather information about procedure-related differences in RNA quality and yield. Here, we describe two protocols, the phenol/chloroform-free filter-based method (RNAqueous kit) and the combined protocol (TRIzol(R)/RNeasy Mini kit), working in a reproducible and reliable manner. We conclude that preparation, storage, homogenization, and quality control are altogether critical steps for in-depth analysis of differential gene expression, especially in hypocellular tissues with highly crosslinked ECM like cartilage.

  10. Effect of sample preparation on the measurement of sugars, organic acids, and polyphenols in apple fruit by mid-infrared spectroscopy.

    Science.gov (United States)

    Bureau, Sylvie; Scibisz, Iwona; Le Bourvellec, Carine; Renard, Catherine M G C

    2012-04-11

    The objectives of this study were (i) to test different conditions of freezing, thawing, and grinding during sample preparation and (ii) to evaluate the possibility of using mid-infrared spectroscopy for analyzing the composition of sugars, organic acids, and polyphenols in apples. Seven commercial apple cultivars were chosen for their large variability in composition (total polyphenols from 406 to 1033 mg kg(-1) fresh weight). The different conditions of sample preparation affected only the phenolic compounds and not sugars or organic acids. The regression models of the mid-infrared spectra showed a good ability to estimate sugar and organic acid contents (R(2) ≥ 0.96), except for citric acid. Good predictions were obtained for total phenolic, flavan-3-ols, and procyanidins (R(2) ≥ 0.94) provided oxidation was avoided during sample preparation. A rapid and simple procedure was then proposed for phenolic compounds using sodium fluoride during sample homogenization at ambient temperature and freeze-drying before spectra acquisition.

  11. D10.8.1: Test and operation of the couplers preparation procedure

    CERN Document Server

    Napoly, O

    2013-01-01

    As far as the Task 10.8.1 is concerned the activity was to define the process of the automatic couplers cleaning, to have a full review of the different phases and to establish the necessary hardware components. After this the design of the machine and of its components has been realised. This has provided the faisability study and the costing of the automatic couplers cleaning machine. Hereafter we give a short summary of the main apects of the two phases: the definition of the automatic cleaning procedure and the study of the washing machine.

  12. Sample preparation and UHPLC-FD analysis of pteridines in human urine.

    Science.gov (United States)

    Tomšíková, H; Solich, P; Nováková, L

    2014-07-01

    Elevated levels of pteridines can indicate the activation of cellular immune system by certain diseases. No work dealing with the simultaneous determination of urinary neopterin, biopterin and their reduced forms has been published. Therefore, a new SPE-UHPLC-FD method for the analysis of these compounds has been developed. The main emphasis was put on the stability of dihydroforms during the sample processing and storage. As a stabilizing agent, dithiothreitol, at various concentrations, and various pH values (3.8-9.8) of working solutions were tested. Chromatographic separation was performed under HILIC isocratic conditions on BEH Amide column. The method was linear for the calibration standard solutions in the range of 10-10,000 ng/ml (dihydroforms) and 0.5-1000 ng/ml (oxidized forms), and for real samples in the range of 25-1000 ng/ml (dihydroforms) and 1-100 ng/ml (oxidized forms). The development of a new SPE sample preparation method was carried out on different types of sorbents (based on a mixed-mode cation exchange, porous graphitic carbon and a polymer comprising hydrophilic and hydrophobic components). Final validation was performed on a MCAX SPE column. Method accuracy ranged from 76.9 to 121.9%. The intra- and inter-day precision did not exceed 10.7%. The method provided high sensitivity for the use in routine clinical measurements of urine (LLOQ 1 ng/ml for oxidized forms and 25 ng/ml for dihydroforms). Average concentrations of biopterin, neopterin, and dihydrobiopterin found in urine of healthy persons were related to the mol of creatinine (66.8, 142.3, and 257.3 μmol/mol of creatinine, respectively) which corresponded to the literature data. The concentration of dihydroneopterin obtained using our method was 98.8 μmol/mol of creatinine. Copyright © 2014 Elsevier B.V. All rights reserved.

  13. Study of the first paramagnetic to ferromagnetic transition in as prepared samples of Mn–Fe–P–Si magnetocaloric compounds prepared by different synthesis routes

    Energy Technology Data Exchange (ETDEWEB)

    Bartok, A., E-mail: andras.bartok@satie.ens-cachan.fr [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France); Kustov, M.; Cohen, L.F. [Imperial College, London SW7 2AZ (United Kingdom); Pasko, A. [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France); Zehani, K.; Bessais, L. [CMTR, ICMPE, CNRS-UPEC, 2-8 rue Henri Dunant, F-94320 Thiais (France); Mazaleyrat, F.; LoBue, M. [SATIE, ENS Cachan, CNRS, Universite Paris-Saclay, 61 av President Wilson, F-94230 Cachan (France)

    2016-02-15

    Magnetocaloric materials with composition of Mn{sub 1.3}Fe{sub 0.65}P{sub 0.5} Si{sub 0.5} have been prepared by ball milling and solid-state reaction methods and consolidated using powder annealing, and conventional and spark plasma sintering. Magnetic and calorimetric measurements show remarkable differences upon first cooling, and slight differences on second and further coolings between the samples prepared by different synthesis routes. Further measurements using Hall probe imaging in high magnetic field have been also carried out. As-prepared samples have been cooled down just above the critical temperature, and the first phase transition has been induced by application of a magnetic field. Bulk samples show staircase isothermal magnetization curves whereas powders show smoother transition curves. - Highlights: • Mn–Fe–P–Si magnetocaloric materials have been prepared by different synthesis routes. • Magnetic measurements show remarkable differences upon first cooling. • First phase transition has been induced by application of a magnetic field. • Hall probe imaging in high magnetic field has also been carried out. • Bulk samples crack during the first PM–FM transition.

  14. High-Throughput Parallel Proteomic Sample Preparation Using 96-Well Polyvinylidene Fluoride (PVDF) Membranes and C18 Purification Plates.

    Science.gov (United States)

    Bennike, Tue Bjerg; Steen, Hanno

    2017-01-01

    Meaningful proteomic-based biomarker discovery projects using primary human-derived specimens require the analysis of hundreds of samples in order to address the issue of interpersonal variability. Thus, robust high-throughput methods for the digestion of plasma samples are a prerequisite for such large clinical proteomic studies with hundreds of samples. Commonly used sample preparation methods are often difficult to parallelize and/or automate. Herein we describe a method for parallel 96-well plate-based sample preparation. Protein digestion is performed in 96-well polyvinylidene fluoride (PVDF) membrane plates and the subsequent purification in 96-well reversed phase C18 purification plates, enabling the usage of multichannel pipettes in all steps. The protocol can be applied using neat or depleted plasma/serum samples, but has also proven effective with other sample types.

  15. First steps towards a generic sample preparation scheme for inorganic engineered nanoparticles in a complex matrix for detection, characterization, and quantification by asymmetric flow-field flow fractionation coupled to multi-angle light scattering and ICP-MS

    DEFF Research Database (Denmark)

    Wagner, Stephan; Legros, Samuel; Löschner, Katrin

    2015-01-01

    The applicability of a multi-step generic procedure to systematically develop sample preparation methods for the detection, characterization, and quantification of inorganic engineered nanoparticles (ENPs) in a complex matrix was successfully demonstrated. The research focused on the optimization...... content by asymmetric flow-field flow fractionation coupled to a multi-angle light scattering detector and an inductively coupled plasma mass spectrometer. Following the proposed generic procedure SiO2-ENPs were separated from a tomato soup. Two potential sample preparation methods were tested these being...... of the sample preparation, aiming to achieve a complete separation of ENPs from a complex matrix without altering the ENP size distribution and with minimal loss of ENPs. The separated ENPs were detected and further characterized in terms of particle size distribution and quantified in terms of elemental mass...

  16. RISK-ASSESSMENT PROCEDURES AND ESTABLISHING THE SIZE OF SAMPLES FOR AUDITING FINANCIAL STATEMENTS

    National Research Council Canada - National Science Library

    Daniel Botez

    2014-01-01

    In auditing financial statements, the procedures for the assessment of the risks and the calculation of the materiality differ from an auditor to another, by audit cabinet policy or advice professional bodies...

  17. Optimization of Procedures for Isolation of Mycobacteria from Soil and Water Samples Obtained in Northern India

    OpenAIRE

    Parashar, Deepti; D S Chauhan; Sharma, V.D; Chauhan, Aradhana; Chauhan, S.V.S.; Katoch, V.M.

    2004-01-01

    For isolation of environmental mycobacteria, a decontamination procedure has been standardized by which treatment with 3% sodium dodecyl sulfate plus 4% NaOH (15 and 30 min for rapid and slow growers, respectively) is followed by incubation with 2% cetrimide (5 and 15 min for fast- and slow-growing mycobacteria, respectively); this procedure was found to completely eliminate contamination with other organisms and resulted in the isolation of only mycobacteria.

  18. Improvement of a sample preparation method assisted by sodium deoxycholate for mass-spectrometry-based shotgun membrane proteomics.

    Science.gov (United States)

    Lin, Yong; Lin, Haiyan; Liu, Zhonghua; Wang, Kunbo; Yan, Yujun

    2014-11-01

    In current shotgun-proteomics-based biological discovery, the identification of membrane proteins is a challenge. This is especially true for integral membrane proteins due to their highly hydrophobic nature and low abundance. Thus, much effort has been directed at sample preparation strategies such as use of detergents, chaotropes, and organic solvents. We previously described a sample preparation method for shotgun membrane proteomics, the sodium deoxycholate assisted method, which cleverly circumvents many of the challenges associated with traditional sample preparation methods. However, the method is associated with significant sample loss due to the slightly weaker extraction/solubilization ability of sodium deoxycholate when it is used at relatively low concentrations such as 1%. Hence, we present an enhanced sodium deoxycholate sample preparation strategy that first uses a high concentration of sodium deoxycholate (5%) to lyse membranes and extract/solubilize hydrophobic membrane proteins, and then dilutes the detergent to 1% for a more efficient digestion. We then applied the improved method to shotgun analysis of proteins from rat liver membrane enriched fraction. Compared with other representative sample preparation strategies including our previous sodium deoxycholate assisted method, the enhanced sodium deoxycholate method exhibited superior sensitivity, coverage, and reliability for the identification of membrane proteins particularly those with high hydrophobicity and/or multiple transmembrane domains. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. Contemporary Sample Preparation Methods for the Detection of Ignitable Liquids in Suspect Arson Cases.

    Science.gov (United States)

    Bertsch, W; Ren, Q

    1999-12-01

    The isolation of ignitable liquid components, usually petroleum-based distillates from fire debris, is an important step in deciding whether a fire is of natural or incendiary origin. Steady progress has been made to develop sample preparation methods capable of enriching target analytes in high yield and within a short period of time. Heated headspace enrichment methods are currently most widely used. There are several variations of this basic technique. Carbon-based adsorbents are most popular. They come in different forms and shapes, including a flat sheet of polymer, impregnated with carbon particles. The analyst cuts a small strip from this sheet and suspends it in the heated headspace above the debris sample. The volatiles adsorb onto the carbon surface, eventually reaching an equilibrium condition. The process is usually carried out in an oven. This convenient method, called the static method, has largely replaced the dynamic method, which uses a granular charcoal adsorbent. In the latter, the heated headspace is drawn over a short trap packed with charcoal, using a source of vacuum such as a pump or pushed along using pressurized nitrogen. The headspace volatiles in both the static and dynamic method are recovered by elution with a solvent, usually carbon disulfide. Recently, a promising variation of the static headspace method has been introduced. It is based on the use of a tiny amount of a polysiloxane polymer which has been coated onto the tip of a thin silica fiber. The fiber can be retracted into a syringe-type needle and the adsorbed headspace vapor can be conveniently introduced into the heated injector port of a gas chromatograph. No solvent is required. This technique, abbreviated SPME (for solid-phase microextraction) has many attractive advantages but it is not without some problems. Low boiling range accelerants, including water-soluble polar substances such as ethanol, are poorly retained on methylsiloxane type polymers. The recent

  20. Development of a candidate reference measurement procedure for the analysis of cortisol in human serum samples by isotope dilution-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Kawaguchi, Migaku; Takatsu, Akiko

    2009-08-01

    A candidate reference measurement procedure involving isotope dilution coupled with gas chromatography-mass spectrometry (GC-MS) has been developed and critically evaluated. An isotopically labeled internal standard, cortisol-d(2), was added to a serum sample. After equilibration, solid-phase extractions (SPE) for sample preparation and derivatization with heptafluorobutyric anhydride (HFBA) were performed for GC-MS analysis. The limit of detection (LOD) and the limit of quantification (LOQ) were 5 and 20 ng g(-1), respectively. The recovery of the added cortisol ranged from 99.8 to 101.0%. Excellent precision was obtained with a within-day variation (RSD) of 0.7% for GC-MS analysis. The accuracy of the measurement was evaluated by comparing of results of this reference measurement procedure on lyophilized human serum reference materials for cortisol (European Reference Materials (ERM)-DA 192) as Certified Reference Materials (CRMs). The results of this method for total cortisol agreed with the certified values within some uncertainty. This method, which demonstrates simply, easy, good accuracy, high precision, and is free from interferences from structural analogues, qualifies as a reference measurement procedure.

  1. GC-MS identification of proteins in wall painting samples: a fast clean-up procedure to remove copper-based pigment interferences.

    Science.gov (United States)

    Gautier, Gwénaëlle; Colombini, Maria Perla

    2007-08-15

    A new approach was explored to purify proteins in a multi-step procedure for the characterisation of proteinaceous materials (casein, animal glue, and egg) in artwork samples by gas chromatography-mass spectrometry. High concentrations of inorganic salts, such as azurite, have been found to impair the determination of protein via amino acid analysis. The effect of varying concentrations of copper-based pigments on the quantification of amino acids was evaluated through the analysis of replica paintings prepared with the three types of proteinaceous materials. Glycine, aspartic and glutamic acids are the amino acids most affected by the presence of copper salts. In the case of high concentration of salts, this interference hampers the correct identification of the proteins. To eliminate the inorganic salts, a C18 pipette tip was used to clean-up the ammonia extracts before the acidic hydrolysis step. The clean-up procedure allows us to prevent the influence of the inorganic salts and thus allows correct protein identification, though the quantitative recovery of proteinaceous material is quite low. The effectiveness of the optimised procedure was evaluated by analysing samples from two Italian wall paintings from the 13th and the 14th centuries. Without the clean-up it would not have been possible to detect the presence of a mixture of egg and animal glue in one case, and that of egg in the other one.

  2. Enzymatic tissue digestion as an alternative sample preparation approach for quantitative analysis using liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yu, Chongwoo; Penn, Lara D; Hollembaek, John; Li, Wenlin; Cohen, Lucinda H

    2004-03-15

    Compound extraction from biological tissue often presents a challenge for the bioanalytical chemist. Labor-intensive homogenization or sonication of whole or powdered tissue is performed before compounds can be extracted and analyzed. Enzymatic digestion is commonly used for tissue dissociation and cell harvesting and offers the advantages of unattended sample preparation, potential automation, and low cost. The feasibility of enzymatic digestion as an alternate tissue preparation technique was evaluated for bioanalysis of drugs in conjunction with LC/MS/MS. Two different enzymes (collagenase and proteinase K) that are known to degrade connective tissues to allow tissue dissolution were chosen for evaluation, employing well-known antidepressants desipramine and fluoxetine as test compounds in dog and rat brain tissue. Comparison between enzymatic digestion and conventional homogenization tissue preparation was performed, including investigation of matrix ionization suppression of both methods using a postcolumn infusion system. Results showed that enzymatic digestion has extraction efficiency comparable to homogenization. Matrix ionization suppression was not observed for either the test compounds evaluated or the sample extraction method. Test compound levels of incurred tissue samples prepared by enzymatic digestion were in good agreement with the values obtained by the conventional homogenization tissue preparation, indicating that enzymatic digestion is an appropriate tissue sample preparation method.

  3. Picosecond laser micromachining prior to FIB milling for electronic microscopy sample preparation

    Science.gov (United States)

    Sikora, Aurélien; Fares, Lahouari; Adrian, Jérôme; Goubier, Vincent; Delobbe, Anne; Corbin, Antoine; Sentis, Marc; Sarnet, Thierry

    2017-10-01

    In order to check the manufacturing quality of electronic components using electron microscopy, the area of interest must be exposed. This requires the removal of a large quantity of matter without damaging the surrounding area. This step can be accomplished using ion milling but the processing can last a few hours. In order to accelerate the preparation of the samples, picosecond laser micromachining prior to Focused Ion Beam polishing is envisioned. Laser ablation allows the fast removal of matter but induces damages around the ablated area. Therefore the process has to be optimized in order to limit the size of both the heat affected zone and induced dislocation zone. For this purpose, cavities have been engraved in silicon and in electronic components, using a linearly polarized picosecond laser (∼50 ps) at three different wavelengths (343, 515 and 1030 nm). Results showed that the cross sectional shapes and the surface topologies can be tuned by the laser fluence and the number of pulses. Clear cross sections of bumps and cavity openings, exposing multilayer interfaces, are demonstrated. The silicon removal rates, tuned by the applied energy density, have been measured. Removal rates achieved at 200 kHz were typically hundred times higher than those achieved by ion milling and the best efficiency was obtained at 343 nm.

  4. 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.

  5. 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.

  6. A simple procedure for preparing chitin oligomers through acetone precipitation after hydrolysis in concentrated hydrochloric acid.

    Science.gov (United States)

    Kazami, Nao; Sakaguchi, Masayoshi; Mizutani, Daisuke; Masuda, Tatsuhiko; Wakita, Satoshi; Oyama, Fumitaka; Kawakita, Masao; Sugahara, Yasusato

    2015-11-05

    Chitin oligomers are of interest because of their numerous biologically relevant properties. To prepare chitin oligomers containing 4-6 GlcNAc units [(GlcNAc)4-6], α- and β-chitin were hydrolyzed with concentrated hydrochloric acid at 40 °C. The reactant was mixed with acetone to recover the acetone-insoluble material, and (GlcNAc)4-6 was efficiently recovered after subsequent water extraction. Composition analysis using gel permeation chromatography and MALDI-TOF mass spectrometry indicated that (GlcNAc)4-6 could be isolated from the acetone-insoluble material with recoveries of approximately 17% and 21% from the starting α-chitin and β-chitin, respectively. The acetone precipitation method is highly useful for recovering chitin oligomers from the acid hydrolysate of chitin. The changes in the molecular size and higher-order structure of chitin during the course of hydrolysis were also analyzed, and a model that explains the process of oligomer accumulation is proposed. Copyright © 2015 Elsevier Ltd. All rights reserved.

  7. 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...

  8. Quality Assessment of Platelet-Rich Fibrin-Like Matrix Prepared from Whole Blood Samples after Extended Storage.

    Science.gov (United States)

    Kawabata, Hideo; Isobe, Kazushige; Watanabe, Taisuke; Okudera, Toshimitsu; Nakamura, Masayuki; Suzuki, Masashi; Ryu, Jietsu; Kitamura, Yutaka; Okudera, Hajime; Okuda, Kazuhiro; Nakata, Koh; Kawase, Tomoyuki

    2017-09-18

    The platelet-rich fibrin-like matrix (PRFM) is usually prepared onsite and immediately used for regenerative therapy. Nonetheless, to meet the clinical necessity of preserving the PRFM without quality deterioration, we developed a method for preparation of PRFMs from short-term-stored whole blood (WB) samples. In this study, to evaluate the practical expiration date of storage, we extended the storage time of WB samples from 2 to 7 days and assessed the quality of the resulting PRFMs. WB samples collected with acid-citrate-dextrose were stored with gentle agitation at ambient temperature. To prepare PRFMs, the stored WB samples were mixed with CaCl₂ in glass tubes and centrifuged. Fibrin fiber networks, CD41 and CD62P expression, and Platelet Derived Growth Factor-BB (PDGF-BB) levels were examined by scanning electron microscopy (SEM), flow cytometry, and an Enzyme-Linked ImmunoSorbent Assay (ELISA), respectively. Long-term storage had no significant effect on either blood cell counts or platelet functions tested. The resulting PRFMs were visually identical to freshly prepared ones. PDGF-BB levels did not markedly decrease in a time-dependent manner. However, fibrin fibers gradually became thinner after storage. Although the coagulation activity may diminish, we propose that PRFMs can be prepared-without evident loss of quality-from WB samples stored for up to 7 days by our previously developed method.

  9. Establishing Reliable Cognitive Change in Children with Epilepsy: The Procedures and Results for a Sample with Epilepsy

    Science.gov (United States)

    van Iterson, Loretta; Augustijn, Paul B.; de Jong, Peter F.; van der Leij, Aryan

    2013-01-01

    The goal of this study was to investigate reliable cognitive change in epilepsy by developing computational procedures to determine reliable change index scores (RCIs) for the Dutch Wechsler Intelligence Scales for Children. First, RCIs were calculated based on stability coefficients from a reference sample. Then, these RCIs were applied to a…

  10. Solid Matrix Transformation and Tracer Addition using Molten Ammonium Bifluoride Salt as a Sample Preparation Method for Laser Ablation Inductively Coupled Plasma Mass Spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Grate, Jay W.; Gonzalez, Jhanis J.; O' Hara, Matthew J.; Kellogg, Cynthia M.; Morrison, Samuel S.; Koppenaal, David W.; Chan, George C.; Mao, Xianglei; Zorba, Vassilia; Russo, Richard

    2017-09-08

    Laser ablation (LA) is a means of sample introduction to inductively coupled plasma (ICP) mass spectrometry (MS) that avoids acid dissolution and chemical separation steps conventionally associated with solid sample analysis. At the same time, certain features of LA-ICP-MS are often mentioned in critical reviews including solid matrix variability and its influence on the ablation process, matrix dependent elemental fractionation, lack of matrix matched standards for external calibration, and limitations to internal calibration because it is challenging to add and distribute spikes into solid samples. In this paper we introduce the concept of a synergistic minimal sample preparation method that is used in combination with LA-ICP-MS as a means to overcome these limitations. The aim of this minimal sample preparation procedure is to reactively transform the original matrix to a more consistent matrix for LA-based analysis, thus reducing the effects of matrix variability, while enabling the addition of tracers. In conjunction with ICP-MS, we call this MTR-LA-ICP-MS, where MTR is derived from matrix transformation including the option to add tracers

  11. A new sample preparation technique for organochlorines in cod liver oil combining SPE and NP-HPLC with HRGC-ECD

    Energy Technology Data Exchange (ETDEWEB)

    Arend, M.W.; Ballschmiter, K. [Dept. of Analytical and Environmental Chemistry, Univ. of Ulm (Germany)

    2000-02-01

    The analysis of semivolatile organochlorines (polychlorinated biphenyls and chlorinated pesticides) in less polluted biomaterials requires specific strategies in controlling the blank in sample preparation. The procedure described here allows to decrease significantly the level of contamination during the clean-up step of fish oil. Solid-phase-extraction (SPE) on LiChrolut {sup trademark} EN and normal phase HPLC in the normal- and the backflush-mode were used to reduce the amount of solvents needed and the analysis time compared to established clean-up procedures. With a certified reference material (BCR-CRM 349; Cod Liver Oil) the precision and effectiveness of the new method were validated. Recovery rates of the Internal Standards (PCB 103 and TCN) lay between 75% and 90% at the {mu}g/kg lipid level. The quantitative analyses were carried out by high resolution gas chromatography with electron capture detector (HRGC-ECD). (orig.)

  12. Decomposition of methane over alumina supported Fe and Ni–Fe bimetallic catalyst: Effect of preparation procedure and calcination temperature

    Directory of Open Access Journals (Sweden)

    A.S. Al-Fatesh

    2018-02-01

    Full Text Available Catalytic decomposition of methane has been studied extensively as the production of hydrogen and formation of carbon nanotube is proven crucial from the scientific and technological point of view. In that context, variation of catalyst preparation procedure, calcination temperature and use of promoters could significantly alter the methane conversion, hydrogen yield and morphology of carbon nanotubes formed after the reaction. In this work, Ni promoted and unpromoted Fe/Al2O3 catalysts have been prepared by impregnation, sol–gel and co-precipitation method with calcination at two different temperatures. The catalysts were characterized by X-ray diffraction (XRD, N2 physisorption, temperature programmed reduction (TPR and thermogravimetric analysis (TGA techniques. The catalytic activity was tested for methane decomposition reaction. The catalytic activity was high when calcined at 500 °C temperature irrespective of the preparation method. However while calcined at high temperature the catalyst prepared by impregnation method showed a high activity. It is found from XRD and TPR characterization that disordered iron oxides supported on alumina play an important role for dissociative chemisorptions of methane generating molecular hydrogen. The transmission electron microscope technique results of the spent catalysts showed the formation of carbon nanotube which is having length of 32–34 nm. The Fe nanoparticles are present on the tip of the carbon nanotube and nanotube grows by contraction–elongation mechanism. Among three different methodologies impregnation method was more effective to generate adequate active sites in the catalyst surface. The Ni promotion enhances the reducibility of Fe/Al2O3 oxides showing a higher catalytic activity. The catalyst is stable up to six hours on stream as observed in the activity results.

  13. CTEPP STANDARD OPERATING PROCEDURE FOR HANDLING SAMPLE AND DATA CUSTODY (SOP-2.26)

    Science.gov (United States)

    This SOP describes the method for handling sample custody. A standardized Chain-of-Custody (CoC) Record is used to document the sample/data custody. Each participant is assigned one CoC Record for the samples/data collected at their home and/or day care center.

  14. 9 CFR 147.12 - Procedures for collection, isolation, and identification of Salmonella from environmental samples...

    Science.gov (United States)

    2010-01-01

    ... sanitizing soap prior to the sampling. Outer clothing, including gloves, should be changed between visits to... strength skim milk from USDA-APHIS “Recommended Sample Collection Methods for Environmental Samples.... Autoclave the assembled DS sampler bundle and transfer it with sterile forceps or other aseptic method to a...

  15. 40 CFR 90.413 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ... percent of the final reading for the dilute exhaust sample. The ADC must store a single value representing... dictates that exhaust emission sample bag analyzer readings below 15 percent of full scale should generally... dilute exhaust sampling only) by the grab (“bag”) technique outlined in paragraph (c) of this section. (e...

  16. Efficient sample preparation method based on solvent-assisted dispersive solid-phase extraction for the trace detection of butachlor in urine and waste water samples.

    Science.gov (United States)

    Aladaghlo, Zolfaghar; Fakhari, Alireza; Behbahani, Mohammad

    2016-10-01

    In this work, an efficient sample preparation method termed solvent-assisted dispersive solid-phase extraction was applied. The used sample preparation method was based on the dispersion of the sorbent (benzophenone) into the aqueous sample to maximize the interaction surface. In this approach, the dispersion of the sorbent at a very low milligram level was achieved by inserting a solution of the sorbent and disperser solvent into the aqueous sample. The cloudy solution created from the dispersion of the sorbent in the bulk aqueous sample. After pre-concentration of the butachlor, the cloudy solution was centrifuged and butachlor in the sediment phase dissolved in ethanol and determined by gas chromatography with flame ionization detection. Under the optimized conditions (solution pH = 7.0, sorbent: benzophenone, 2%, disperser solvent: ethanol, 500 μL, centrifuged at 4000 rpm for 3 min), the method detection limit for butachlor was 2, 3 and 3 μg/L for distilled water, waste water, and urine sample, respectively. Furthermore, the preconcentration factor was 198.8, 175.0, and 174.2 in distilled water, waste water, and urine sample, respectively. Solvent-assisted dispersive solid-phase extraction was successfully used for the trace monitoring of butachlor in urine and waste water samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. CTEPP STANDARD OPERATING PROCEDURE FOR DAY CARE CENTER SAMPLE SUBJECTS RECRUITMENT (SOP-1.11)

    Science.gov (United States)

    The CTEPP subject recruitment procedures for the daycare center component are described in the SOP. There are two stages in this phase of CTEPP subject recruitment. The objective of the first stage is to enroll daycare centers for the study. Six target counties in each state ar...

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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. Copyright © 2016 Elsevier B.V. All rights reserved.

  3. Automatic single-step quick, easy, cheap, effective, rugged and safe sample preparation devices for analysis of pesticide residues in foods.

    Science.gov (United States)

    Wang, Jishi; He, Zeying; Wang, Lu; Xu, Yaping; Peng, Yi; Liu, Xiaowei

    2017-10-27

    In this research, the manual two-step QuEChERS approach has been streamlined and automated into a one-step method using a cleanup tube fitted within an extraction tube. A novel automatic QuEChERS combination have been developed to simplify the QuEChERS procedures and improve sample preparation efficiency. This combination integrates QuEChERS procedures into a single run via the use of a vortex vibration-centrifuge device and a centrifuge filtration tube. To validate the efficiency of our automatic QuEChERS device, 270 pesticides were analyzed in plant origined foods including celery, tomatoes, leeks, eggplants, grapes, corn, green tea, and soybean oil using this automatic platform. The results were then compared with those obtained using the manual QuEChERS method. Different parameters were validated and compared including recovery, linearity, repeatability and limits of quantification (LOQ). Satisfactory results, comparable to results obtained using the manual QuEChERS method were obtained. The average recoveries ranged between 70% and 120% for most pesticides with associated relative standard deviations (RSDs) 0.990 within a linearity range of 2-500μg/kg. Compared to manual QuEChERS, this novel automatic QuEChERS device and combination could significantly improve the sample preparation efficiency for the multiresidue analysis of pesticides. Copyright © 2017. Published by Elsevier B.V.

  4. Pre-exposure to food temptation reduces subsequent consumption: A test of the procedure with a South-African sample.

    Science.gov (United States)

    Duh, Helen Inseng; Grubliauskiene, Aiste; Dewitte, Siegfried

    2016-01-01

    It has been suggested that the consumption of unhealthy Westernized diet in a context of poverty and resultant food insecurity may have contributed to South-Africa's status of the third fattest country in the World. Considering that a number of South-Africans are reported to have experienced, or are still experiencing food insecurity, procedures which have been shown to reduce the consumption of unhealthy food in higher income countries may be ineffective in South-Africa. We thus tested the robustness of the so called pre-exposure procedure in South-Africa. We also tested the moderating role of childhood poverty in the pre-exposure procedure. With the pre-exposure procedure, a respondent is exposed to a tempting unhealthy food (e.g. candy) in a context that is designed such that eating the food interferes with a task goal. The typical result is that this procedure spills over and reduces consumption of similar tempting food later on. An experimental study conducted in a South-African laboratory showed that the pre-exposure effect is robust even with a sample, where food insecurity prevails. Childhood poverty did not moderate the effect. This study proves that behavioral procedures aimed at reducing the consumption of unhealthy food would be valuable in less rich non-Western countries. Further testing of the robustness of the pre-exposure effect is however recommended in other poorer food insecure countries. Copyright © 2015 Elsevier Ltd. All rights reserved.

  5. Efficient DNP NMR of membrane proteins: sample preparation protocols, sensitivity, and radical location

    Energy Technology Data Exchange (ETDEWEB)

    Liao, Shu Y.; Lee, Myungwoon; Wang, Tuo [Massachusetts Institute of Technology, Department of Chemistry (United States); Sergeyev, Ivan V. [Bruker Biospin (United States); Hong, Mei, E-mail: meihong@mit.edu [Massachusetts Institute of Technology, Department of Chemistry (United States)

    2016-03-15

    Although dynamic nuclear polarization (DNP) has dramatically enhanced solid-state NMR spectral sensitivities of many synthetic materials and some biological macromolecules, recent studies of membrane-protein DNP using exogenously doped paramagnetic radicals as polarizing agents have reported varied and sometimes surprisingly limited enhancement factors. This motivated us to carry out a systematic evaluation of sample preparation protocols for optimizing the sensitivity of DNP NMR spectra of membrane-bound peptides and proteins at cryogenic temperatures of ~110 K. We show that mixing the radical with the membrane by direct titration instead of centrifugation gives a significant boost to DNP enhancement. We quantify the relative sensitivity enhancement between AMUPol and TOTAPOL, two commonly used radicals, and between deuterated and protonated lipid membranes. AMUPol shows ~fourfold higher sensitivity enhancement than TOTAPOL, while deuterated lipid membrane does not give net higher sensitivity for the membrane peptides than protonated membrane. Overall, a ~100 fold enhancement between the microwave-on and microwave-off spectra can be achieved on lipid-rich membranes containing conformationally disordered peptides, and absolute sensitivity gains of 105–160 can be obtained between low-temperature DNP spectra and high-temperature non-DNP spectra. We also measured the paramagnetic relaxation enhancement of lipid signals by TOTAPOL and AMUPol, to determine the depths of these two radicals in the lipid bilayer. Our data indicate a bimodal distribution of both radicals, a surface-bound fraction and a membrane-bound fraction where the nitroxides lie at ~10 Å from the membrane surface. TOTAPOL appears to have a higher membrane-embedded fraction than AMUPol. These results should be useful for membrane-protein solid-state NMR studies under DNP conditions and provide insights into how biradicals interact with phospholipid membranes.

  6. M3FT-17OR0301070211 - Preparation of Hot Isostatically Pressed AgZ Waste Form Samples

    Energy Technology Data Exchange (ETDEWEB)

    Jubin, Robert Thomas [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Bruffey, Stephanie H. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States); Jordan, Jacob A. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2017-10-01

    The production of radioactive iodine-bearing waste forms that exhibit long-term stability and are suitable for permanent geologic disposal has been the subject of substantial research interest. One potential method of iodine waste form production is hot isostatic pressing (HIP). Recent studies at Oak Ridge National Laboratory (ORNL) have investigated the conversion of iodine-loaded silver mordenite (I-AgZ) directly to a waste form by HIP. ORNL has performed HIP with a variety of sample compositions and pressing conditions. The base mineral has varied among AgZ (in pure and engineered forms), silver-exchanged faujasite, and silverexchanged zeolite A. Two iodine loading methods, occlusion and chemisorption, have been explored. Additionally, the effects of variations in temperature and pressure of the process have been examined, with temperature ranges of 525°C–1,100°C and pressure ranges of 100–300 MPa. All of these samples remain available to collaborators upon request. The sample preparation detailed in this document is an extension of that work. In addition to previously prepared samples, this report documents the preparation of additional samples to support stability testing. These samples include chemisorbed I-AgZ and pure AgI. Following sample preparation, each sample was processed by HIP by American Isostatic Presses Inc. and returned to ORNL for storage. ORNL will store the samples until they are requested by collaborators for durability testing. The sample set reported here will support waste form durability testing across the national laboratories and will provide insight into the effects of varied iodine content on iodine retention by the produced waste form and on potential improvements in waste form durability provided by the zeolite matrix.

  7. A lab-on-a-chip system integrating tissue sample preparation and multiplex RT-qPCR for gene expression analysis in point-of-care hepatotoxicity assessment.

    Science.gov (United States)

    Lim, Geok Soon; Chang, Joseph S; Lei, Zhang; Wu, Ruige; Wang, Zhiping; Cui, Kemi; Wong, Stephen

    2015-10-21

    A truly practical lab-on-a-chip (LOC) system for point-of-care testing (POCT) hepatotoxicity assessment necessitates the embodiment of full-automation, ease-of-use and "sample-in-answer-out" diagnostic capabilities. To date, the reported microfluidic devices for POCT hepatotoxicity assessment remain rudimentary as they largely embody only semi-quantitative or single sample/gene detection capabilities. In this paper, we describe, for the first time, an integrated LOC system that is somewhat close to a practical POCT hepatotoxicity assessment device - it embodies both tissue sample preparation and multiplex real-time RT-PCR. It features semi-automation, is relatively easy to use, and has "sample-in-answer-out" capabilities for multiplex gene expression analysis. Our tissue sample preparation module incorporating both a microhomogenizer and surface-treated paramagnetic microbeads yielded high purity mRNA extracts, considerably better than manual means of extraction. A primer preloading surface treatment procedure and the single-loading inlet on our multiplex real-time RT-PCR module simplify off-chip handling procedures for ease-of-use. To demonstrate the efficacy of our LOC system for POCT hepatotoxicity assessment, we perform a preclinical animal study with the administration of cyclophosphamide, followed by gene expression analysis of two critical protein biomarkers for liver function tests, aspartate transaminase (AST) and alanine transaminase (ALT). Our experimental results depict normalized fold changes of 1.62 and 1.31 for AST and ALT, respectively, illustrating up-regulations in their expression levels and hence validating their selection as critical genes of interest. In short, we illustrate the feasibility of multiplex gene expression analysis in an integrated LOC system as a viable POCT means for hepatotoxicity assessment.

  8. 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

  9. Analytical sample preparation strategies for the determination of antimalarial drugs in human whole blood, plasma and urine

    DEFF Research Database (Denmark)

    Casas, Monica Escolà; Hansen, Martin; Krogh, Kristine A

    2014-01-01

    Antimalarial drugs commonly referred to as antimalarials, include a variety of compounds with different physicochemical properties. There is a lack of information on antimalarial distribution in the body over time after administration, e.g. the drug concentrations in whole blood, plasma, and urine...... the available sample preparation strategies combined with liquid chromatographic (LC) analysis to determine antimalarials in whole blood, plasma and urine published over the last decade. Sample preparation can be done by protein precipitation, solid-phase extraction, liquid-liquid extraction or dilution. After...

  10. Comparison of green sample preparation techniques in the analysis of pyrethrins and pyrethroids in baby food by liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Petrarca, Mateus Henrique; Ccanccapa-Cartagena, Alexander; Masiá, Ana; Godoy, Helena Teixeira; Picó, Yolanda

    2017-05-12

    A new selective and sensitive liquid chromatography triple quadrupole mass spectrometry method was developed for simultaneous analysis of natural pyrethrins and synthetic pyrethroids residues in baby food. In this study, two sample preparation methods based on ultrasound-assisted dispersive liquid-liquid microextraction (UA-DLLME) and salting-out assisted liquid-liquid extraction (SALLE) were optimized, and then, compared regarding the performance criteria. Appropriate linearity in solvent and matrix-based calibrations, and suitable recoveries (75-120%) and precision (RSD values≤16%) were achieved for selected analytes by any of the sample preparation procedures. Both methods provided the analytical selectivity required for the monitoring of the insecticides in fruit-, cereal- and milk-based baby foods. SALLE, recognized by cost-effectiveness, and simple and fast execution, provided a lower enrichment factor, consequently, higher limits of quantification (LOQs) were obtained. Some of them too high to meet the strict legislation regarding baby food. Nonetheless, the combination of ultrasound and DLLME also resulted in a high sample throughput and environmental-friendly method, whose LOQs were lower than the default maximum residue limit (MRL) of 10μgkg(-1) set by European Community for baby foods. In the commercial baby foods analyzed, cyhalothrin and etofenprox were detected in different samples, demonstrating the suitability of proposed method for baby food control. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. Statistical considerations for plot design, sampling procedures, analysis, and quality assurance of ozone injury studies

    Science.gov (United States)

    Michael Arbaugh; Larry Bednar

    1996-01-01

    The sampling methods used to monitor ozone injury to ponderosa and Jeffrey pines depend on the objectives of the study, geographic and genetic composition of the forest, and the source and composition of air pollutant emissions. By using a standardized sampling methodology, it may be possible to compare conditions within local areas more accurately, and to apply the...

  12. Evidence-based concepts and procedures for bonded inlays and onlays. Part II. Guidelines for cavity preparation and restoration fabrication.

    Science.gov (United States)

    Rocca, Giovanni Tommaso; Rizcalla, Nicolas; Krejci, Ivo; Dietschi, Didier

    2015-01-01

    The second part of this article series presents an evidence-based update of clinical protocols and procedures for cavity preparation and restoration selection for bonded inlays and onlays. More than ever, tissue conservation dictates preparation concepts, even though some minimal dimensions still have to be considered for all restorative materials. In cases of severe bruxism or tooth fragilization, CAD/CAM composite resins or pressed CAD/CAM lithium disilicate glass ceramics are often recommended, although this choice relies mainly on scarce in vitro research as there is still a lack of medium- to long-term clinical evidence. The decision about whether or not to cover a cusp can only be made after a multifactorial analysis, which includes cavity dimensions and the resulting tooth biomechanical status, as well as occlusal and esthetic factors. The clinical impact of the modern treatment concepts that were outlined in the previous article - Dual Bonding (DB)/Immediate Dentin Sealing (IDS), Cavity Design Optimization (CDO), and Cervical Margins Relocation (CMR) - are described in detail in this article and discussed in light of existing clinical and scientific evidence for simpler, more predictable, and more durable results. Despite the wide choice of restorative materials (composite resin or ceramic) and techniques (classical or CAD/CAM), the cavity for an indirect restoration should meet five objective criteria before the impression.

  13. 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.

  14. A method for the measurement of shielding effectiveness of planar samples requiring no sample edge preparation or contact

    OpenAIRE

    Marvin, Andrew C.; Dawson, Linda; Flintoft, Ian Dand; Dawson, John F.

    2009-01-01

    A method is presented for the measurement of shielding effectiveness of planar materials with nonconducting surfaces such as carbon fiber composites. The method overcomes edge termination problems with such materials by absorbing edge-diffracted energy. A dynamic range of up to 100 dB has been demonstrated over a frequency range of 1-8.5 GHz, depending on the size of the sample under test. Comparison with ASTM D4935 and nested reverberation measurements of shielding effectiveness shows good a...

  15. A sample preparation process for LC-MS/MS analysis of total protein drug concentrations in monkey plasma samples with antibody.

    Science.gov (United States)

    Ji, Qin C; Rodila, Ramona; El-Shourbagy, Tawakol A

    2007-03-01

    The determination of protein concentrations in plasma samples often provides essential information in biomedical research, clinical diagnostics, and pharmaceutical discovery and development. Binding assays such as ELISA determine meaningful free analyte concentrations by using specific antigen or antibody reagents. Concurrently, mass spectrometric technology is becoming a promising complementary method to traditional binding assays. Mass spectrometric assays generally provide measurements of the total protein analyte concentration. However, it was found that antibodies may bind strongly with the protein analyte such that total concentrations cannot be determined. Thus, a sample preparation process was developed which included a novel "denaturing" step to dissociate binding between antibodies and the protein analyte prior to solid phase extraction of plasma samples and LC-MS/MS analysis. In so doing, the total protein analyte concentrations can be obtained. This sample preparation process was further studied by LC-MS analysis with a full mass range scan. It was found that the protein of interest and other plasma peptides were pre-concentrated, while plasma albumin was depleted in the extracts. This capability of the sample preparation process could provide additional advantages in proteomic research for biomarker discovery and validation. The performance of the assay with the novel denaturing step was further evaluated. The linear dynamic range was between 100.9ng/mL and 53920.0ng/mL with a coefficient of determination (r(2)) ranging from 0.9979 and 0.9997. For LLOQ and ULOQ samples, the inter-assay CV was 12.6% and 2.7% and inter-assay mean accuracies were 103.7% and 99.5% of theoretical concentrations, respectively. For QC samples, the inter-assay CV was between 2.1% and 4.9%, and inter-assay mean accuracies were between 104.1% and 110.0% of theoretical concentrations.

  16. 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.

  17. Standard operating procedures for collection of soil and sediment samples for the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study

    Science.gov (United States)

    Fisher, Shawn C.; Reilly, Timothy J.; Jones, Daniel K.; Benzel, William M.; Griffin, Dale W.; Loftin, Keith A.; Iwanowicz, Luke R.; Cohl, Jonathan A.

    2015-12-17

    An understanding of the effects on human and ecological health brought by major coastal storms or flooding events is typically limited because of a lack of regionally consistent baseline and trends data in locations proximal to potential contaminant sources and mitigation activities, sensitive ecosystems, and recreational facilities where exposures are probable. In an attempt to close this gap, the U.S. Geological Survey (USGS) has implemented the Sediment-bound Contaminant Resiliency and Response (SCoRR) strategy pilot study to collect regional sediment-quality data prior to and in response to future coastal storms. The standard operating procedure (SOP) detailed in this document serves as the sample-collection protocol for the SCoRR strategy by providing step-by-step instructions for site preparation, sample collection and processing, and shipping of soil and surficial sediment (for example, bed sediment, marsh sediment, or beach material). The objectives of the SCoRR strategy pilot study are (1) to create a baseline of soil-, sand-, marsh sediment-, and bed-sediment-quality data from sites located in the coastal counties from Maine to Virginia based on their potential risk of being contaminated in the event of a major coastal storm or flooding (defined as Resiliency mode); and (2) respond to major coastal storms and flooding by reoccupying select baseline sites and sampling within days of the event (defined as Response mode). For both modes, samples are collected in a consistent manner to minimize bias and maximize quality control by ensuring that all sampling personnel across the region collect, document, and process soil and sediment samples following the procedures outlined in this SOP. Samples are analyzed using four USGS-developed screening methods—inorganic geochemistry, organic geochemistry, pathogens, and biological assays—which are also outlined in this SOP. Because the SCoRR strategy employs a multi-metric approach for sample analyses, this

  18. Nonparametric relevance-shifted multiple testing procedures for the analysis of high-dimensional multivariate data with small sample sizes

    Directory of Open Access Journals (Sweden)

    Kropf Siegfried

    2008-01-01

    Full Text Available Abstract Background In many research areas it is necessary to find differences between treatment groups with several variables. For example, studies of microarray data seek to find a significant difference in location parameters from zero or one for ratios thereof for each variable. However, in some studies a significant deviation of the difference in locations from zero (or 1 in terms of the ratio is biologically meaningless. A relevant difference or ratio is sought in such cases. Results This article addresses the use of relevance-shifted tests on ratios for a multivariate parallel two-sample group design. Two empirical procedures are proposed which embed the relevance-shifted test on ratios. As both procedures test a hypothesis for each variable, the resulting multiple testing problem has to be considered. Hence, the procedures include a multiplicity correction. Both procedures are extensions of available procedures for point null hypotheses achieving exact control of the familywise error rate. Whereas the shift of the null hypothesis alone would give straight-forward solutions, the problems that are the reason for the empirical considerations discussed here arise by the fact that the shift is considered in both directions and the whole parameter space in between these two limits has to be accepted as null hypothesis. Conclusion The first algorithm to be discussed uses a permutation algorithm, and is appropriate for designs with a moderately large number of observations. However, many experiments have limited sample sizes. Then the second procedure might be more appropriate, where multiplicity is corrected according to a concept of data-driven order of hypotheses.

  19. Kinetic studies in solid state reactions by sample-controlled methods and advanced analysis procedures

    OpenAIRE

    Pérez-Maqueda, Luis A.; Criado, J. M.; Sánchez-Jiménez, P.E.; Perejón, Antonio

    2013-01-01

    A comparative study of both conventional rising temperature and sample-controlled methods, like constant rate thermal analysis (CRTA), is carried out after analyzing a set of solid state reactions using both methods. It is shown that CRTA avoids the influence of heat and mass transfer phenomena for a wide range of sample sizes leading to reliable kinetic parameters. On the other hand, conventional rising temperature methods yield α–T plots dependent on experimental conditions, even when using...

  20. Blood plasma sample preparation method to determine thyroid hormone-disrupting compounds in Effect-Directed Analysis

    NARCIS (Netherlands)

    Simon, E.; Bytingsvik, J.; Jonker, W.; Leonards, P.E.G.; de Boer, J.; Jenssen, B.M.; Lie, E.; Aars, J.; Hamers, T.H.M.; Lamoree, M.H.

    2011-01-01

    A sample preparation method combining solid-phase extraction (SPE) and liquid-liquid extraction (LLE) was developed to be used in Effect-Directed Analysis (EDA) of blood plasma. Until now such a method was not available. It can be used for extraction of a broad range of thyroid hormone

  1. 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.

  2. 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.

  3. Cyclization of the N-Terminal X-Asn-Gly Motif during Sample Preparation for Bottom-Up Proteomics

    DEFF Research Database (Denmark)

    Zhang, Xumin; Højrup, Peter

    2010-01-01

    We, herein, report a novel -17 Da peptide modification corresponding to an N-terminal cyclization of peptides possessing the N-terminal motif of X-Asn-Gly. The cyclization occurs spontaneously during sample preparation for bottom-up proteomics studies. Distinct from the two well-known N...

  4. 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.

  5. Development of a Modified Smart System for Robust Transcriptome Library Preparation from Limited Quantities of Compromised Samples

    Science.gov (United States)

    Chang, C.; Farmer, A.; Bostick, Magnolia

    2013-01-01

    Next Generation Sequencing has revolutionized biomedical research by providing sequence data on millions of short DNA fragments, in parallel. In particular, NGS has enabled RNA expression analysis over the entire transcriptome with high sensitivity and dynamic range. Currently, the field is seeking methods to utilize challenging samples that are either compromised or are only available in limited amounts. Overcoming these constraints will demand highly sensitive and robust sample preparation methods. One powerful method for cDNA preparation is SMART™ technology (Switching Mechanism At the 5′ end of the RNA Template), which utilizes the template switching activity of reverse transcriptase to enable the direct addition of a PCR adaptor to the 3′ end of the first-strand cDNA, thus avoiding inefficient ligation steps. One drawback of SMART technology is its current inability to work with compromised samples, owing to its dependence on an oligo dT primer for first strand synthesis. A modified SMART system has been developed including the use of random primers to work with samples containing compromised or degraded RNA. Data (including gene body coverage, reproducibility, and mappability metrics) will be presented for both chemically degraded RNA samples and FFPE RNA prepared using the modified SMART system. This modified SMART protocol will be especially useful for small samples of degraded RNA. It is capable of generating cDNA libraries for transcriptome profiling from as little as 1 ng of total RNA.

  6. Novel field sampling procedure for the determination of methiocarb residues in surface waters from rice fields.

    Science.gov (United States)

    Primus, T M; Kohler, D J; Avery, M; Bolich, P; Way, M O; Johnston, J J

    2001-12-01

    Methiocarb was extracted from surface water samples collected at experimental rice field sites in Louisiana and Texas. The sampling system consisted of a single-stage 90-mm Empore extraction disk unit equipped with a battery-powered vacuum pump. After extraction, the C-18 extraction disks were stored in an inert atmosphere at -10 degrees C and shipped overnight to the laboratory. The disks were extracted with methanol and the extracts analyzed by reversed-phase high-performance liquid chromatography with a methanol/water mobile phase. Methiocarb was detected by ultraviolet absorption at 223 nm and quantified with the use of calibration standards. Recoveries from control surface water samples fortified at 5.0, 10, 50, and 100 ng/mL methiocarb averaged 92 +/- 7%. A method limit of detection for methiocarb in rice field surface water was estimated to be 0.23 ng/mL at 223 nm.

  7. Multistate evaluation of an ultrafiltration-based procedure for simultaneous recovery of enteric microbes in 100-liter tap water samples.

    Science.gov (United States)

    Hill, Vincent R; Kahler, Amy M; Jothikumar, Narayanan; Johnson, Trisha B; Hahn, Donghyun; Cromeans, Theresa L

    2007-07-01

    Ultrafiltration (UF) is increasingly being recognized as a potentially effective procedure for concentrating and recovering microbes from large volumes of water and treated wastewater. Because of their very small pore sizes, UF membranes are capable of simultaneously concentrating viruses, bacteria, and parasites based on size exclusion. In this study, a UF-based water sampling procedure was used to simultaneously recover representatives of these three microbial classes seeded into 100-liter samples of tap water collected from eight cities covering six hydrologic areas of the United States. The UF-based procedure included hollow-fiber UF as the primary step for concentrating microbes and then used membrane filtration for bacterial culture assays, immunomagnetic separation for parasite recovery and quantification, and centrifugal UF for secondary concentration of viruses. Water samples were tested for nine water quality parameters to investigate whether water quality data correlated with measured recovery efficiencies and molecular detection levels. Average total method recovery efficiencies were 71, 97, 120, 110, and 91% for phiX174 bacteriophage, MS2 bacteriophage, Enterococcus faecalis, Clostridium perfringens spores, and Cryptosporidium parvum oocysts, respectively. Real-time PCR and reverse transcription-PCR (RT-PCR) for seeded microbes and controls indicated that tap water quality could affect the analytical performance of molecular amplification assays, although no specific water quality parameter was found to correlate with reduced PCR or RT-PCR performance.

  8. [Sampling procedure for a survey of an interventional study on acute respiratory infections].

    Science.gov (United States)

    Ramón Bravo, J; González Ochoa, E

    1993-01-01

    A description is made of the methodology used for obtaining a sample made up of 500 children under 5 years and 500 adults 65 year old and more, in order to carry out an intervention study on acute respiratory tract infections in an urban zone in Havana City and in a rural zone in Matanzas province, where different intervention stops will be taken with regards sanitary education about management of acute respiratory tract infections for the population and training for primary care medical personnel. We show the way the selected sample fits was planned with a very homogeneous distribution in the 8 areas under study, which allows for great reliability in the results.

  9. MEMS reagent and sample handling procedure: Feasibility of viral antibody detection by passive immune agglutination

    Science.gov (United States)

    Bailey, G. D.; Tenoso, H. J.

    1975-01-01

    An attempt was made to develop a test requiring no preadsorption steps for the assessment of antibodies to rubella and mumps viruses using the passive immune agglutination (PIA) method. Both rubella and mumps antigens and antibodies were prepared. Direct PIA tests, using rubella antigen-coated beads, and indirect PIA tests, using rubella antibody-coated beads, were investigated. Attempts, using either method, were unsuccessful. Serum interference along with nonspecific agglutination of beads by the rubella antigen resulted in no specific response under the test conditions investigated. A new, highly sensitive approach, the enzyme immunoassay (EIA) test system, is recommended to overcome the nonspecificity. This system is a logical outgrowth of some of the solid phase work done on MEMS and represents the next generation tests system that can be directly applied to early disease detection and monitoring.

  10. RISK-ASSESSMENT PROCEDURES AND ESTABLISHING THE SIZE OF SAMPLES FOR AUDITING FINANCIAL STATEMENTS

    Directory of Open Access Journals (Sweden)

    Daniel Botez

    2014-12-01

    Full Text Available In auditing financial statements, the procedures for the assessment of the risks and the calculation of the materiality differ from an auditor to another, by audit cabinet policy or advice professional bodies. All, however, have the reference International Audit Standards ISA 315 “Identifying and assessing the risks of material misstatement through understanding the entity and its environment” and ISA 320 “Materiality in planning and performing an audit”. On the basis of specific practices auditors in Romania, the article shows some laborious and examples of these aspects. Such considerations are presented evaluation of the general inherent risk, a specific inherent risk, the risk of control and the calculation of the materiality.

  11. Occurrence of Arcobacter in Iranian poultry and slaughterhouse samples implicates contamination by processing equipment and procedures.

    Science.gov (United States)

    Khoshbakht, R; Tabatabaei, M; Shirzad Aski, H; Seifi, S

    2014-01-01

    1. The occurrence of Arcobacter spp. and three pathogenic species of Arcobacter from Iranian poultry carcasses was investigated at different steps of broiler processing to determine critical control points for reducing carcass contamination. 2. Samples were collected from (a) cloaca immediately before processing, (b) different points during processing and (c) at different stations in a processing plant of a slaughterhouse in southern Iran. 3. After enrichment steps in Arcobacter selective broth, DNA of the samples was extracted and three significant pathogen species of Arcobacter were identified based on polymerase chain reaction (PCR) detection of 16S rRNA and specific species PCR. 4. Out of a total of 540 samples, 244 (45%) were positive for Arcobacter spp. Arcobacter butzleri was more frequently detected (73% ± 13.9%) than A. cryaeophilus (9% ± 13.9%) and A. skirrowii (4.1%). In addition, co-colonisation (A. butzleri and A. cryaerophilus) occurred in 13.9% of the positive samples. 5. The results indicate a high prevalence of Arcobacter in the investigated slaughterhouse and broiler carcasses and that Arcobacter is not a normal flora of the broilers. Evidence for the presence of Arcobacter in the environment and water of processing plants suggests that these are sources of contamination of poultry carcasses. In addition, contamination of the poultry carcasses can spread between poultry meats in different parts and processes of the slaughterhouse (pre-scalding to after evisceration).

  12. Comparison of two different procedures for quantification of drugs of abuse in postmortem brain samples

    DEFF Research Database (Denmark)

    Reiter, Birgit; Stimpfl, Thomas; Holm, Karen Marie Dollerup

    The aim of this study was to compare a routine method for qualitative and quantitative analysis of body-fluids and tissue samples developed in Vienna to a routine method developed for blood used in Copenhagen. No optimization was performed beforehand on the Copenhagen method to accommodate for the...... for the use of brain tissue....

  13. Continuous quality control of the blood sampling procedure using a structured observation scheme

    DEFF Research Database (Denmark)

    Seemann, Tine Lindberg; Nybo, Mads

    2016-01-01

    blood drawings by 39 phlebotomists were observed in the pilot study, while 84 blood drawings by 34 phlebotomists were observed in the follow-up study. In the pilot study, the three major error items were hand hygiene (42% error), mixing of samples (22%), and order of draw (21%). Minor significant...

  14. Sampling procedure in a willow plantation for chemical elements important for biomass combustion quality

    DEFF Research Database (Denmark)

    Liu, Na; Nielsen, Henrik Kofoed; Jørgensen, Uffe

    2015-01-01

    Willow (Salix spp.) is expected to contribute significantly to the woody bioenergy system in the future, so more information on how to sample the quality of the willow biomass is needed. The objectives of this study were to investigate the spatial variation of elements within shoots of a willow...

  15. 1979 Reserve Force Studies Surveys: Survey Design, Sample Design and Administrative Procedures,

    Science.gov (United States)

    1981-08-01

    Dental Service 17 Reception Cnt. 11Other 46 Total 2914 The heterogeneity of the units poses a problem for a unit sampling plan. Namely, if the...regular schoel or collae 04. What is tha ZIP Code ZIP Cods thats you think you will ama c0oMsil In tha futura? If af tha placa whare your highest grade

  16. Information Sampling and Group Decision Making: The Effects of an Advocacy Decision Procedure and Task Experience

    Science.gov (United States)

    Greitemeyer, Tobias; Schulz-Hardt, Stefan; Brodbeck, Felix C.; Frey, Dieter

    2006-01-01

    Group discussions tend to focus on information that was previously known by all members (shared information) rather than information known by only 1 member (unshared information). If the shared information implies a suboptimal alternative, this sampling bias is associated with inaccurate group decisions. The present study examines the impact of 2…

  17. Fish Farm Inspections and Sampling Procedures: The Mediterranean Point of View

    DEFF Research Database (Denmark)

    Vendramin, Niccolò

    2012-01-01

    Marine Mediterranean aquaculture meant as intesive rearing system for zootechnical production has known a recent development extremely fast. The development of efficacious breeding protocols, the availability of artificial feeding more and more efficient and some principles adopted in facing dise...... firstly. In this presentation, mainly based on pictures, different aspects of clinical inspection/sampling protocols are described....

  18. 40 CFR 89.411 - Exhaust sample procedure-gaseous components.

    Science.gov (United States)

    2010-07-01

    ... reading. (5) Zero and span each range to be used on each analyzer operated prior to the beginning of the... bag sample technique outlined in paragraph (c) of this section. (e) Hydrocarbon hangup. If HC hangup... the difference between the readings obtained greater than or equal to 2 percent of full scale...

  19. Ficolin-2 reveals different analytical and biological properties dependent on different sample handling procedures

    DEFF Research Database (Denmark)

    Hein, Estrid; Bay, Jakob T; Munthe-Fog, Lea

    2013-01-01

    mediated formation of the terminal complement complex was observed under the applied assay conditions. In conclusion, our results show that Ficolin-2 is a promiscuous molecule and that care should be taken during sampling, handling and matrix chosen for measurement of Ficolin-2 levels and activity....

  20. Study on different pre-treatment procedures for metal determination in Orujo spirit samples by ICP-AES

    Energy Technology Data Exchange (ETDEWEB)

    Barciela, Julia; Vilar, Manuela; Garcia-Martin, Sagrario [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain); Pena, Rosa M. [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)], E-mail: qarosa@lugo.usc.es; Herrero, Carlos [Departamento de Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Universidad de Santiago de Compostela, Campus de Lugo, 27002 Lugo (Spain)], E-mail: cherrero@lugo.usc.es

    2008-10-17

    In this work several pre-treatment methods were studied for metal (Na, K, Mg, Cu and Ca) determination in Orujo spirit samples using inductively coupled plasma atomic emission spectrometry (ICP-AES). Dilution, digestion, evaporation, and cryogenic desolvatation techniques were comparatively evaluated. Because of their analytical characteristics, digestion and evaporation with nitrogen current were found to be appropriate procedures for the determination of metals in alcoholic spirit samples. Yet, if simplicity and application time are to be considered, the latter-evaporation in a water bath with a nitrogen current-stands out as the optimum procedure for any further determinations in Orujo samples by ICP-AES. Low detection levels and wide linear ranges (sufficient to determine these metals in the samples studied) were achieved for each metal. The recoveries (in the 97.5-100.5% range) and the precision (R.S.D. lower than 5.6%) obtained were also satisfactory. The selected procedure was applied to determine the content of metals in 80 representative Galician Orujo spirit samples with and without a Certified Brand of Origin (CBO) which had been produced using different distillation systems. The metal concentrations ranged between 0.37 and 79.7 mg L{sup -1} for Na,

  1. 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...

  2. The development of metabolomic sampling procedures for Pichia pastoris, and baseline metabolome data.

    Directory of Open Access Journals (Sweden)

    Gregory D Tredwell

    Full Text Available Metabolic profiling is increasingly being used to investigate a diverse range of biological questions. Due to the rapid turnover of intracellular metabolites it is important to have reliable, reproducible techniques for sampling and sample treatment. Through the use of non-targeted analytical techniques such as NMR and GC-MS we have performed a comprehensive quantitative investigation of sampling techniques for Pichia pastoris. It was clear that quenching metabolism using solutions based on the standard cold methanol protocol caused some metabolite losses from P. pastoris cells. However, these were at a low level, with the NMR results indicating metabolite increases in the quenching solution below 5% of their intracellular level for 75% of metabolites identified; while the GC-MS results suggest a slightly higher level with increases below 15% of their intracellular values. There were subtle differences between the four quenching solutions investigated but broadly, they all gave similar results. Total culture extraction of cells + broth using high cell density cultures typical of P. pastoris fermentations, was an efficient sampling technique for NMR analysis and provided a gold standard of intracellular metabolite levels; however, salts in the media affected the GC-MS analysis. Furthermore, there was no benefit in including an additional washing step in the quenching process, as the results were essentially identical to those obtained just by a single centrifugation step. We have identified the major high-concentration metabolites found in both the extra- and intracellular locations of P. pastoris cultures by NMR spectroscopy and GC-MS. This has provided us with a baseline metabolome for P. pastoris for future studies. The P. pastoris metabolome is significantly different from that of Saccharomyces cerevisiae, with the most notable difference being the production of high concentrations of arabitol by P. pastoris.

  3. SAMPL4 & DOCK3.7: lessons for automated docking procedures

    Science.gov (United States)

    Coleman, Ryan G.; Sterling, Teague; Weiss, Dahlia R.

    2014-03-01

    The SAMPL4 challenges were used to test current automated methods for solvation energy, virtual screening, pose and affinity prediction of the molecular docking pipeline DOCK 3.7. Additionally, first-order models of binding affinity were proposed as milestones for any method predicting binding affinity. Several important discoveries about the molecular docking software were made during the challenge: (1) Solvation energies of ligands were five-fold worse than any other method used in SAMPL4, including methods that were similarly fast, (2) HIV Integrase is a challenging target, but automated docking on the correct allosteric site performed well in terms of virtual screening and pose prediction (compared to other methods) but affinity prediction, as expected, was very poor, (3) Molecular docking grid sizes can be very important, serious errors were discovered with default settings that have been adjusted for all future work. Overall, lessons from SAMPL4 suggest many changes to molecular docking tools, not just DOCK 3.7, that could improve the state of the art. Future difficulties and projects will be discussed.

  4. Evaluation of sample preparation methods for the detection of total metal content using inductively coupled plasma optical emission spectrometry (ICP-OES) in wastewater and sludge

    Science.gov (United States)

    Dimpe, K. M.; Ngila, J. C.; Mabuba, N.; Nomngongo, P. N.

    Heavy metal contamination exists in aqueous wastes and sludge of many industrial discharges and domestic wastewater, among other sources. Determination of metals in the wastewater and sludge requires sample pre-treatment prior to analysis because of certain challenges such as the complexity of the physical state of the sample, which may lead to wrong readings in the measurement. This is particularly the case with low analyte concentration to be detected by the instrument. The purpose of this work was to assess and validate the different sample preparation methods namely, hot plate and microwave-assisted digestion procedures for extraction of metal ions in wastewater and sludge samples prior to their inductively coupled plasma optical emission spectrometric (ICP-OES) determination. For the extraction of As, Al, Cd, Cr, Cu, Fe, Mn, Ni, Pb, Zn, three acid mixtures, that is, HNO3/H2O2, HNO3/HClO4/H2O2 and aqua regia + H2O2, were evaluated. Influent wastewater spiked with the SRM (CWW-TM-B) was used for the optimization of acid mixtures affecting the extraction procedure. After sample digestion, the filtration capabilities of cellulose-acetate filter paper and the acrodisc syringe filter with the pore size of 0.45 μm were compared. In terms of performance, acrodisc syringe filter in terms of the improved recoveries obtained, was found to be the best filtration method compared to the filter paper. Based on the analytical results obtained, microwave-assisted digestion (MAD) using aqua regia + H2O2 mixture was found to be the most suitable method for extraction of heavy metals and major elements in all the sample matrices. Therefore, MAD using aqua regia + H2O2 mixture was used for further investigations. The precision of the developed MAD method expressed in terms of relative standard deviations (% RSD) for different metals was found to be wastewater and sludge.

  5. Comparative study of methods for DNA preparation from olive oil samples to identify cultivar SSR alleles in commercial oil samples: possible forensic applications.

    Science.gov (United States)

    Breton, Catherine; Claux, Delphine; Metton, Isabelle; Skorski, Gilbert; Bervillé, André

    2004-02-11

    Virgin olive oil is made from diverse cultivars either mixed or single. Those ensure different tastes and typicity, and these may be also enhanced by the region of production of cultivars. The different olive oil labels correspond to their chemical composition and acidity. Labels also may correspond to a protected origin indication, and thus, such oils contain a given composition in cultivars. To verify the main cultivars used at the source of an olive oil sample, our method is based on DNA technology. DNA is present in all olive oil samples and even in refined oil, but the quantity may depend on the oil processing technology and oil conservation conditions. Thus, several supports were used to retain DNA checking different techniques (silica extraction, hydroxyapatite, magnetic beads, and spun column) to prepare DNA from variable amounts of oil. At this stage, it was usable for amplification through PCR technology and especially with the magnetic beads, and further purification processes were checked. Finally, the final method used magnetic beads. DNA is released from beads in a buffer. Once purified, we showed that it did not contain compounds inhibiting PCR amplification using SSR primers. Aliquot dilution fractions of this solution were successfully routinely used through PCR with different SSR primer sets. This enables confident detection of eventual alien alleles in oil samples. First applied to virgin oil samples of known composition, either single cultivars or mixtures of them, the method was verified working on commercial virgin oil samples using bottles bought in supermarkets. Last, we defined a protocol starting from 2 x 40 mL virgin olive oil, and DNA was prepared routinely in about 5 h. It was convenient to genotype together several loci per sample to check whether alleles were in accordance with those of expected cultivars. Thus, forensic applications of our method are expected. However, the method needs further improvement to work on all oil samples.

  6. 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.

  7. 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.

  8. Separation of four flavonoids from Rhodiola rosea by on-line combination of sample preparation and counter-current chromatography.

    Science.gov (United States)

    Ma, Chaoyang; Hu, Liming; Fu, Qianyun; Gu, Xiaohong; Tao, Guanjun; Wang, Hongxin

    2013-09-06

    Purification of four flavonoids from Rhodiola rosea was developed by on-line combination of sample preparation and counter-current chromatography (CCC). Flavonoid sample was prepared by dynamic ultrasonic-assisted and solid-phase extraction using ion liquids as extractant. The preparation conditions were optimized by D-optimal design as follows: 2mol/L of 1-ethyl-3-methylimidazolium bromide concentration, 360W of ultrasonic power, 1.5mL/min of flow rate, 35min of extraction time and 0.5mL (absorbent) per g (material) of absorbent amount. The prepared sample solution (20mL) was loaded and injected directly into CCC column for final separation. As a result, four flavonoids, herbacetin-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside 1 (40.1mg), kaempferol-3-O-β-d-glucopyranosyl-7-O-α-l-rhamn-opyranoside 2 (4.6mg), kaempferol 3-O-β-d-glucopyranoside-(2→1)-β-d-xylopyranoside 3 (20.2mg) and herbacetin-8-O-β-d-glucopyranoside 4 (22.5mg), were obtained from 20g of R. rosea material using ethyl acetate-n-butanol-H2O as solvent system at a ratio of 4:1:5 by CCC. Their structures were identified by ESI-MS/MS, NMR methods. Their purities determined by UPLC were 98.5%, 95.4%, 98.1% and 97.5%, respectively. Kaempferol-3-O-β-d-glucopyranosyl-7-O-α-l-rhamnopyranoside 2 and herbacetin-8-O-β-d-glucopyrano-side 4 were isolated for first time from R. rosea. The purification method was simple, efficient and evaded tedious sample preparation process. Copyright © 2013 Elsevier B.V. All rights reserved.

  9. A novel PFIB sample preparation protocol for correlative 3D X-ray CNT and FIB-TOF-SIMS tomography

    Energy Technology Data Exchange (ETDEWEB)

    Priebe, Agnieszka, E-mail: agnieszka.priebe@gmail.com [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France); Audoit, Guillaume; Barnes, Jean-Paul [Univ. Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, F-38054 Grenoble (France)

    2017-02-15

    We present a novel sample preparation method that allows correlative 3D X-ray Computed Nano-Tomography (CNT) and Focused Ion Beam Time-Of-Flight Secondary Ion Mass Spectrometry (FIB-TOF-SIMS) tomography to be performed on the same sample. In addition, our invention ensures that samples stay unmodified structurally and chemically between the subsequent experiments. The main principle is based on modifying the topography of the X-ray CNT experimental setup before FIB-TOF-SIMS measurements by incorporating a square washer around the sample. This affects the distribution of extraction field lines and therefore influences the trajectories of secondary ions that are now guided more efficiently towards the detector. As the result, secondary ion detection is significantly improved and higher, i.e. statistically better, signals are obtained. - Highlights: • Novel sample preparation for correlative 3D X-ray CNT and FIB-TOF-SIMS is presented. • Two experiments are conducted on exactly the same sample without any modifications. • Introduction of a square washer around the sample leads to increased ion detection.

  10. Applications of Experimental Design to the Optimization of Microextraction Sample Preparation Parameters for the Analysis of Pesticide Residues in Fruits and Vegetables.

    Science.gov (United States)

    Abdulra'uf, Lukman Bola; Sirhan, Ala Yahya; Tan, Guan Huat

    2015-01-01

    Sample preparation has been identified as the most important step in analytical chemistry and has been tagged as the bottleneck of analytical methodology. The current trend is aimed at developing cost-effective, miniaturized, simplified, and environmentally friendly sample preparation techniques. The fundamentals and applications of multivariate statistical techniques for the optimization of microextraction sample preparation and chromatographic analysis of pesticide residues are described in this review. The use of Placket-Burman, Doehlert matrix, and Box-Behnken designs are discussed. As observed in this review, a number of analytical chemists have combined chemometrics and microextraction techniques, which has helped to streamline sample preparation and improve sample throughput.

  11. Forensic analysis of Salvia divinorum using multivariate statistical procedures. Part II: association of adulterated samples to S. divinorum.

    Science.gov (United States)

    Willard, Melissa A Bodnar; McGuffin, Victoria L; Smith, Ruth Waddell

    2012-01-01

    Salvia divinorum is a plant material that is of forensic interest due to the hallucinogenic nature of the active ingredient, salvinorin A. In this study, S. divinorum was extracted and spiked onto four different plant materials (S. divinorum, Salvia officinalis, Cannabis sativa, and Nicotiana tabacum) to simulate an adulterated sample that might be encountered in a forensic laboratory. The adulterated samples were extracted and analyzed by gas chromatography-mass spectrometry, and the resulting total ion chromatograms were subjected to a series of pretreatment procedures that were used to minimize non-chemical sources of variance in the data set. The data were then analyzed using principal components analysis (PCA) to investigate association of the adulterated extracts to unadulterated S. divinorum. While association was possible based on visual assessment of the PCA scores plot, additional procedures including Euclidean distance measurement, hierarchical cluster analysis, Student's t tests, Wilcoxon rank-sum tests, and Pearson product moment correlation were also applied to the PCA scores to provide a statistical evaluation of the association observed. The advantages and limitations of each statistical procedure in a forensic context were compared and are presented herein.

  12. Comparative analysis of EV isolation procedures for miRNAs detection in serum samples

    Directory of Open Access Journals (Sweden)

    Zoraida Andreu

    2016-06-01

    Full Text Available Extracellular vesicles (EVs are emerging as potent non-invasive biomarkers. However, current methodologies are time consuming and difficult to translate to clinical practice. To analyse EV-encapsulated circulating miRNA, we searched for a quick, easy and economic method to enrich frozen human serum samples for EV. We compared the efficiency of several protocols and commercial kits to isolate EVs. Different methods based on precipitation, columns or filter systems were tested and compared with ultracentrifugation, which is the most classical protocol to isolate EVs. EV samples were assessed for purity and quantity by nanoparticle tracking analysis and western blot or cytometry against major EV protein markers. For biomarker validation, levels of a set of miRNAs were determined in EV fractions and compared with their levels in total serum. EVs isolated with precipitation-based methods were enriched for a subgroup of miRNAs that corresponded to miRNAs described to be encapsulated into EVs (miR-126, miR-30c and miR-143, while the detection of miR-21, miR-16-5p and miR-19a was very low compared with total serum. Our results point to precipitation using polyethylene glycol (PEG as a suitable method for an easy and cheap enrichment of serum EVs for miRNA analyses. The overall performance of PEG was very similar, or better than other commercial precipitating reagents, in both protein and miRNA yield, but in comparison to them PEG is much cheaper. Other methods presented poorer results, mostly when assessing miRNA by qPCR analyses. Using PEG precipitation in a longitudinal study with human samples, we demonstrated that miRNA could be assessed in frozen samples up to 8 years of storage. We report a method based on a cut-off value of mean of fold EV detection versus serum that provides an estimate of the degree of encapsulation of a given miRNA.

  13. Application of solid phase extraction procedures for rare earth elements determination in environmental samples.

    Science.gov (United States)

    Pyrzynska, Krystyna; Kubiak, Anna; Wysocka, Irena

    2016-07-01

    Determination of rare earth elements in environmental samples requires often pre-concentration and separation step due to a low metal content and high concentration of the interfering matrix components. A solid phase extraction technique with different kind of solid sorbents offers a high enrichment factor, rapid phase separation and the possibility of its combination with various detection techniques used either in on-line or off-line mode. The recent developments in this area published over the last five years are presented and discussed in this paper. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. A Discussion of Procedures and Equipment for the Comprehensive Test Ban Treaty On-Site Inspection Environmental Sampling and Analysis

    Energy Technology Data Exchange (ETDEWEB)

    Wogman, Ned A.; Milbrath, Brian D.; Payne, Rosara F.; Seifert, Carolyn E.; Friese, Judah I.; Miley, Harry S.; Bowyer, Ted W.; Hanlen, Richard C.; Onishi, Yasuo; Hayes, James C.; Wigmosta, Mark S.

    2011-02-01

    This paper is intended to serve as a scientific basis to start discussions of the available environmental sampling techniques and equipment that have been used in the past that could be considered for use within the context of the Comprehensive Nuclear-Test-Ban Treaty (CTBT) on-site inspections (OSI). This work contains information on the techniques, equipment, costs, and some operational procedures associated with environmental sampling that have actually been used in the past by the United States for the detection of nuclear explosions. This paper also includes a discussion of issues, recommendations, and questions needing further study within the context of the sampling and analysis of aquatic materials, atmospheric gases, atmospheric particulates, vegetation, sediments and soils, fauna, and drill-back materials.

  15. Determination of protein carbonyls in plasma, cell extracts, tissue homogenates, isolated proteins: Focus on sample preparation and derivatization conditions

    Directory of Open Access Journals (Sweden)

    Daniela Weber

    2015-08-01

    Full Text Available 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.

  16. How Confocal Is Confocal Raman Microspectroscopy on the Skin? Impact of Microscope Configuration and Sample Preparation on Penetration Depth Profiles.

    Science.gov (United States)

    Lunter, Dominique Jasmin

    2016-01-01

    The aim of the study was to elucidate the effect of sample preparation and microscope configuration on the results of confocal Raman microspectroscopic evaluation of the penetration of a pharmaceutical active into the skin (depth profiling). Pig ear skin and a hydrophilic formulation containing procaine HCl were used as a model system. The formulation was either left on the skin during the measurement, or was wiped off or washed off prior to the analysis. The microscope configuration was varied with respect to objectives and pinholes used. Sample preparation and microscope configuration had a tremendous effect on the results of depth profiling. Regarding sample preparation, the best results could be observed when the formulation was washed off the skin prior to the analysis. Concerning microscope configuration, the use of a 40 × 0.6 numerical aperture (NA) objective in combination with a 25-µm pinhole or a 100 × 1.25 NA objective in combination with a 50-µm pinhole was found to be advantageous. Complete removal of the sample from the skin before the analysis was found to be crucial. A thorough analysis of the suitability of the chosen microscope configuration should be performed before acquiring concentration depth profiles. © 2016 S. Karger AG, Basel.

  17. 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. © 2015 Published by Elsevier Ltd.

  18. Sample preparation and liquid chromatography-tandem mass spectrometry for multiple steroids in mammalian and avian circulation.

    Directory of Open Access Journals (Sweden)

    Lee Koren

    Full Text Available Blood samples from wild mammals and birds are often limited in volume, allowing researchers to quantify only one or two steroids from a single sample by immunoassays. In addition, wildlife serum or plasma samples are often lipemic, necessitating stringent sample preparation. Here, we validated sample preparation for simultaneous liquid chromatography--tandem mass spectrometry (LC-MS/MS quantitation of cortisol, corticosterone, 11-deoxycortisol, dehydroepiandrosterone (DHEA, 17β-estradiol, progesterone, 17α-hydroxyprogesterone and testosterone from diverse mammalian (7 species and avian (5 species samples. Using 100 µL of serum or plasma, we quantified (signal-to-noise (S/N ratio ≥ 10 4-7 steroids depending on the species and sample, without derivatization. Steroids were extracted from serum or plasma using automated solid-phase extraction where samples were loaded onto C18 columns, washed with water and hexane, and then eluted with ethyl acetate. Quantitation by LC-MS/MS was done in positive ion, multiple reaction-monitoring (MRM mode with an atmospheric pressure chemical ionization (APCI source and heated nebulizer (500°C. Deuterated steroids served as internal standards and run time was 15 minutes. Extraction recoveries were 87-101% for the 8 analytes, and all intra- and inter-run CVs were ≤ 8.25%. This quantitation method yields good recoveries with variable lipid-content samples, avoids antibody cross-reactivity issues, and delivers results for multiple steroids. Thus, this method can enrich datasets by providing simultaneous quantitation of multiple steroids, and allow researchers to reimagine the hypotheses that could be tested with their volume-limited, lipemic, wildlife samples.

  19. PROBLEMS ENCOUNTERED BY COUNSELING TEACHERS WHILE PREPARING SCIENTIFIC PROJECTS: SAMPLE OF TURKEY

    OpenAIRE

    Yasin Ünsal

    2016-01-01

    The aim of this study is to determine the basic problems encountered by counseling teachers in the fields of science and maths while preparing scientific projects. Screening model was used in the study. The data were collected by using survey method. Being developed for this purpose; the survey form was applied to 192 project counselors from various branches (like Physics, Chemistry, Biology, Maths, Science and Technology) at public schools in Turkey. As a result of the study, it was determin...

  20. Sample preparation and biomass determination of SRF model mixture using cryogenic milling and the adapted balance method.

    Science.gov (United States)

    Schnöller, Johannes; Aschenbrenner, Philipp; Hahn, Manuel; Fellner, Johann; Rechberger, Helmut

    2014-11-01

    The biogenic fraction of a simple solid recovered fuel (SRF) mixture (80 wt% printer paper/20 wt% high density polyethylene) is analyzed with the in-house developed adapted balance method (aBM). This fairly new approach is a combination of combustion elemental analysis (CHNS) and a data reconciliation algorithm based on successive linearisation for evaluation of the analysis results. This method shows a great potential as an alternative way to determine the biomass content in SRF. However, the employed analytical technique (CHNS elemental analysis) restricts the probed sample mass to low amounts in the range of a few hundred milligrams. This requires sample comminution to small grain sizes (sample size reduction. This paper presents a proof of principle investigation of the sample preparation and analysis of an SRF model mixture with the use of cryogenic impact milling (final sample comminution) and the adapted balance method (determination of biomass content). The so derived sample preparation methodology (cutting mills and cryogenic impact milling) shows a better performance in accuracy and precision for the determination of the biomass content than one solely based on cutting mills. The results for the determination of the biogenic fraction are within 1-5% of the data obtained by the reference methods, selective dissolution method (SDM) and (14)C-method ((14)C-M). Copyright © 2014 Elsevier Ltd. All rights reserved.

  1. New procedure for recovering extra- and intracellular DNA from marine sediment samples

    Science.gov (United States)

    Alawi, M.; Kallmeyer, J.

    2012-12-01

    Extracellular DNA (eDNA) is a ubiquitous biological compound in aquatic sediment and soil. Despite major methodological advances, analysis of DNA from sediment is still technically challenging, not just because of the co-elution of inhibitory substances, but also due to co-elution of extracellular DNA, which potentially leads to an overestimate of the actual diversity. Previous studies suggested that eDNA might play an important role in biogeochemical element cycling, horizontal gene transfer and stabilization of biofilm structures. Several protocols based on the precipitation of eDNA e.g. with CTAB and ethanol have already been published. However, using these methods we did not succeed in quantifying very low amounts of eDNA (e.g. applications like PCR can be performed. To evaluate the new extraction method two sediments with rather opposing composition were analyzed. Sediment from the South Pacific Gyre, the most oligotrophic oceanic region on earth and organic-rich Baltic Sea sediment (Northern Germany) were processed. Using this new procedure high purity genomic iDNA and eDNA with a molecular size range between 20 bp and 50k bp can be simultaneously recovered even from very oligotrophic sediment with very low cell abundances. The main fraction of recovered eDNA was suitable for downstream applications like PCR and had a molecular size that indicates minimal shearing. Despite about two decades of research many questions about deep subsurface life remain unanswered. The fact that microbes can be found even in deep oligotrophic marine sediment raises the fundamental questions of the types and availability of substrates and their biogeochemical cycling. This is the first study that provides evidence that eDNA is an important potential substrate for microorganisms in the deep biosphere. Also, our results show a link between cell counts and eDNA content, indicating that the eDNA pool in the investigated sediment consist mainly of microbial DNA. Comparative sequence

  2. Improved sample preparation for direct quantitative detection of Escherichia coli O157 in soil using qPCR without pre-enrichment.

    Science.gov (United States)

    Highmore, Callum J; Rothwell, Steve D; Keevil, Charles W

    2017-07-01

    The prominence of fresh produce as a vehicle for foodborne pathogens such as enterohaemorrhagic Escherichia coli (EHEC) O157 is rising, where disease cases can cause hospitalization and in some cases death. This rise emphasises the necessity for accurate and sensitive methods for detection of pathogens in soil, potential sources of contamination of fresh produce. The complexity of the soil matrix has previously proven prohibitive to pathogen detection via molecular methods without the use of a culture enrichment step, thereby excluding the detection of viable but non-culturable cells. Here, a sample preparation procedure to facilitate a direct qPCR assay is developed for the detection of E. coli O157 in soil, bypassing culture steps in favour of sample separation through pulsification release and filtration. In sand and peat-based compost, the method is sensitive to 10 CFU g-1 soil. When testing soils from agricultural sites, it was found that several were qPCR positive for E. coli O157 while being culture-negative, with peat-based compost possessing a concentration of 200 tir gene copies per gram. This procedure offers a rapid, quantitative assessment of the potential presence of E. coli O157 in soils which can act as a prescreen of their suitability to grow fresh produce safely. © 2017 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

  3. Advantages of automation in plasma sample preparation prior to HPLC/MS/MS quantification: application to the determination of cilazapril and cilazaprilat in a bioequivalence study.

    Science.gov (United States)

    Kolocouri, Filomila; Dotsikas, Yannis; Apostolou, Constantinos; Kousoulos, Constantinos; Soumelas, Georgios-Stefanos; Loukas, Yannis L

    2011-01-01

    An HPLC/MS/MS method characterized by complete automation and high throughput was developed for the determination of cilazapril and its active metabolite cilazaprilat in human plasma. All sample preparation and analysis steps were performed by using 2.2 mL 96 deep-well plates, while robotic liquid handling workstations were utilized for all liquid transfer steps, including liquid-liquid extraction. The whole procedure was very fast compared to a manual procedure with vials and no automation. The method also had a very short chromatographic run time of 1.5 min. Sample analysis was performed by RP-HPLC/MS/MS with positive electrospray ionization using multiple reaction monitoring. The calibration curve was linear in the range of 0.500-300 and 0.250-150 ng/mL for cilazapril and cilazaprilat, respectively. The proposed method was fully validated and proved to be selective, accurate, precise, reproducible, and suitable for the determination of cilazapril and cilazaprilat in human plasma. Therefore, it was applied to a bioequivalence study after per os administration of 2.5 mg tablet formulations of cilazapril.

  4. A Procedure to Determine the Optimal Sensor Positions for Locating AE Sources in Rock Samples

    Science.gov (United States)

    Duca, S.; Occhiena, C.; Sambuelli, L.

    2015-03-01

    Within a research work aimed to better understand frost weathering mechanisms of rocks, laboratory tests have been designed to specifically assess a theoretical model of crack propagation due to ice segregation process in water-saturated and thermally microcracked cubic samples of Arolla gneiss. As the formation and growth of microcracks during freezing tests on rock material is accompanied by a sudden release of stored elastic energy, the propagation of elastic waves can be detected, at the laboratory scale, by acoustic emission (AE) sensors. The AE receiver array geometry is a sensitive factor influencing source location errors, for it can greatly amplify the effect of small measurement errors. Despite the large literature on the AE source location, little attention, to our knowledge, has been paid to the description of the experimental design phase. As a consequence, the criteria for sensor positioning are often not declared and not related to location accuracy. In the present paper, a tool for the identification of the optimal sensor position on a cubic shape rock specimen is presented. The optimal receiver configuration is chosen by studying the condition numbers of each of the kernel matrices, used for inverting the arrival time and finding the source location, and obtained for properly selected combinations between sensors and sources positions.

  5. Determination of carbohydrate-deficient transferrin in human serum with capillary zone electrophoresis. Sample preparation strategies for the removal of interferences caused by increased levels of immunoglobulins.

    Science.gov (United States)

    Lanz, Christian; Falmagne, Jean-Bernard; de l'Escaille, François; Marti, Ulrich; Thormann, Wolfgang

    2008-10-03

    Capillary zone electrophoresis (CZE) in fused-silica capillaries is an effective analytical approach for the separation and determination of the transferrin (Tf) isoforms and thus carbohydrate-deficient transferrin (CDT) in human serum. Sera of patients with progressed liver cirrhosis are prone to interferences in the beta region which prevent the proper determination of CDT by CZE without additional sample preparation. Efforts to identify, reduce or even eliminate these interferences have been undertaken. Data obtained by ultrafiltration, affinity subtraction procedures using protein A, protein L and antibodies against immunoglobulins or Tf, and immunopurification of Tf suggest that the interferences in the patient sera are caused by increased levels of IgA and IgM and are best eliminated by immunopurification. Avian IgY antibody spin column immunocapture of serum Tf followed by CZE analysis of the stripped and concentrated fraction is shown to provide an attractive approach for CDT monitoring in sera with beta region interferences.

  6. 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.

  7. Ruthenium oxide/carbon composites with microporous or mesoporous carbon as support and prepared by two procedures. A comparative study as supercapacitor electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Pico, F. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain); Morales, E. [Instituto de Ciencia y Tecnologia de Polimeros (ICTP), CSIC, Juan de la Cierva 3, E-28006-Madrid (Spain); Fernandez, J.A.; Centeno, T.A. [Instituto Nacional del Carbon (INCAR), CSIC, Francisco Pintado Fe 26, E-33011-Oviedo (Spain); Ibanez, J. [Centro Nacional de Investigaciones Metalurgicas (CENIM), CSIC, Avda. Gregorio del Amo 8, E-28040-Madrid (Spain); Rojas, R.M.; Amarilla, J.M. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain); Rojo, J.M. [Instituto de Ciencia de Materiales de Madrid (ICMM), Consejo Superior de Investigaciones Cientificas (CSIC), Sor Juana Ines de la Cruz 3, Cantoblanco, E-28049-Madrid (Spain)], E-mail: jmrojo@icmm.csic.es

    2009-03-01

    Composites are prepared by deposition of nanoparticles of RuO{sub 2}.xH{sub 2}O (1-4 nm) on two carbons: microporous carbon (1.3 nm of average micropore size) and mesoporous carbon (11 nm of average mesopore size). Two-preparation procedures are used: (i) procedure A consisting of repetitive impregnations of the carbons with RuCl{sub 3}.0.5H{sub 2}O solutions, and (ii) procedure B based on impregnation of the carbons with Ru(acac){sub 3} vapour. The procedure B leads to supported RuO{sub 2}.xH{sub 2}O particles that appear more crystalline than those obtained by the procedure A. Specific capacitance and specific surface area of the composites are discussed as functions of the RuO{sub 2} content, and different dependences for the composites derived from the two carbons are found. Mesoporous carbon is better support than microporous carbon. Procedure A leads to supported RuO{sub 2}.xH{sub 2}O particles with higher specific capacitance than the particles deposited by procedure B.

  8. Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

    Science.gov (United States)

    Roque, Inês; Lourenço, Rui; Marques, Ana; Coelho, João Pedro; Coelho, Cláudia; Pereira, Eduarda; Rabaça, João E; Roulin, Alexandre

    2016-04-01

    Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios.

  9. Heterodyne non-demolition measurements on cold atomic samples: towards the preparation of non-classical states for atom interferometry

    Science.gov (United States)

    Bernon, S.; Vanderbruggen, T.; Kohlhaas, R.; Bertoldi, A.; Landragin, A.; Bouyer, P.

    2011-06-01

    We report on a novel experiment to generate non-classical atomic states via quantum non-demolition (QND) measurements on cold atomic samples prepared in a high-finesse ring cavity. The heterodyne technique developed for QND detection exhibits an optical shot-noise limited behavior for local oscillator optical power of a few hundred μW, and a detection bandwidth of several GHz. This detection tool is used in a single pass to follow non-destructively the internal state evolution of an atomic sample when subjected to Rabi oscillations or a spin-echo interferometric sequence.

  10. Heterodyne non-demolition measurements on cold atomic samples: towards the preparation of non-classical states for atom interferometry

    Energy Technology Data Exchange (ETDEWEB)

    Bernon, S; Vanderbruggen, T; Kohlhaas, R; Bertoldi, A; Bouyer, P [Laboratoire Charles Fabry de l' Institut d' Optique, CNRS and Universite Paris-Sud Campus Polytechnique, RD 128, F-91127 Palaiseau cedex (France); Landragin, A, E-mail: simon.bernon@institutoptique.fr [LNE-SYRTE, Observatoire de Paris, CNRS and UPMC 61 avenue de l' Observatoire, F-75014 Paris (France)

    2011-06-15

    We report on a novel experiment to generate non-classical atomic states via quantum non-demolition (QND) measurements on cold atomic samples prepared in a high-finesse ring cavity. The heterodyne technique developed for QND detection exhibits an optical shot-noise limited behavior for local oscillator optical power of a few hundred {mu}W, and a detection bandwidth of several GHz. This detection tool is used in a single pass to follow non-destructively the internal state evolution of an atomic sample when subjected to Rabi oscillations or a spin-echo interferometric sequence.

  11. 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...

  12. Universal nucleic acids sample preparation method for cells, spores and their mixture

    Science.gov (United States)

    Bavykin, Sergei [Darien, IL

    2011-01-18

    The present invention relates to a method for extracting nucleic acids from biological samples. More specifically the invention relates to a universal method for extracting nucleic acids from unidentified biological samples. An advantage of the presently invented method is its ability to effectively and efficiently extract nucleic acids from a variety of different cell types including but not limited to prokaryotic or eukaryotic cells and/or recalcitrant organisms (i.e. spores). Unlike prior art methods which are focused on extracting nucleic acids from vegetative cell or spores, the present invention effectively extracts nucleic acids from spores, multiple cell types or mixtures thereof using a single method. Important that the invented method has demonstrated an ability to extract nucleic acids from spores and vegetative bacterial cells with similar levels effectiveness. The invented method employs a multi-step protocol which erodes the cell structure of the biological sample, isolates, labels, fragments nucleic acids and purifies labeled samples from the excess of dye.

  13. Preparation and certification of two new bulk welding fume reference materials for use in laboratories undertaking analysis of occupational hygiene samples.

    Science.gov (United States)

    Butler, Owen; Musgrove, Darren; Stacey, Peter

    2014-01-01

    Workers can be exposed to fume, arising from welding activities, which contain toxic metals and metalloids. Occupational hygienists need to assess and ultimately minimize such exposure risks. The monitoring of the concentration of particles in workplace air is one assessment approach whereby fume, from representative welding activities, is sampled onto a filter and returned to a laboratory for analysis. Inductively coupled plasma-atomic emission spectrometry and inductively coupled plasma-mass spectrometry are generally employed as instrumental techniques of choice for the analysis of such filter samples. An inherent difficulty, however, with inductively coupled plasma-based analytical techniques is that they typically require a sample to be presented for analysis in the form of a solution. The efficiency of the required dissolution step relies heavily upon the skill and experience of the analyst involved. A useful tool in assessing the efficacy of this dissolution step would be the availability and subsequent analysis of welding fume reference materials with stated elemental concentrations and matrices that match as closely as possible the matrix composition of welding fume samples submitted to laboratories for analysis. This article describes work undertaken at the Health and Safety Laboratory to prepare and certify two new bulk welding fume reference materials that can be routinely used by analysts to assess the performance of the digestion procedures they employ in their laboratories.

  14. Influence of the preparation procedure on the catalytic activity of gold supported on diamond nanoparticles for phenol peroxidation.

    Science.gov (United States)

    Martin, Roberto; Navalon, Sergio; Delgado, Juan Jose; Calvino, Jose J; Alvaro, Mercedes; Garcia, Hermenegildo

    2011-08-16

    The catalytic activity of diamond-supported gold nanoparticle (Au/D) samples prepared by the deposition/precipitation method have been correlated as a function of the pH and the reduction treatment. It was found that the most active material is the one prepared at pH 5 followed by subsequent thermal treatment at 300 °C under hydrogen. TEM images show that Au/D prepared under optimal conditions contain very small gold nanoparticles with sizes below 2 nm that are proposed to be responsible for the catalytic activity. Tests of productivity using large phenol (50 g L(-1)) and H(2)O(2) excesses (100 g L(-1)) and reuse gives a minimum TON of 458,759 moles of phenol degraded per gold atom. Analysis of the organic compounds extracted from the deactivated solid catalyst indicates that the poisons are mostly hydroxylated dicarboxylic acids arising from the degradative oxidation of the phenyl ring. By determining the efficiency for phenol degradation and the amount of O(2) evolved two different reactions of H(2)O(2) decomposition (the Fenton reaction at acidic pH values and spurious O(2) evolution at basic pH values) are proposed for Au/D catalysis. The activation energy of the two processes is very similar (ranging between 30 and 35 kJ mol(-1)). By using dimethylsulfoxide as a radical scavenger and N-tert-butyl-α-phenylnitrone as a spin trap under aerated conditions, the EPR spectrum of the expected PBN-OCH(3) adduct was detected, supporting the generation of HO(.), characteristic of Fenton chemistry in the process. Phenol degradation, on the other hand, exhibits the same activation energy as H(2)O(2) decomposition at pH 4 (due to the barrierless attack of HO(.) to phenol), but increases the activation energy gradually up to about 90 kJ mol(-1) at pH 7 and then undergoes a subsequent reduction as the pH increases reaching another minimum at pH 8.5 (49 kJ mol(-1)). Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Determination of aglycones of ginsenosides in ginseng preparations sold in Sweden and in urine samples from Swedish athletes consuming ginseng.

    Science.gov (United States)

    Cui, J F; Garle, M; Björkhem, I; Eneroth, P

    1996-04-01

    Recently developed gas chromatographic and gas chromatographic-mass spectrometric methods were used to characterize 17 different commercial ginseng preparations sold in Sweden. The contents of total ginsenosides per capsule or per tablet varied from 2.1 to 13.3 mg. Unlike the other preparations, a red ginseng and three liquid ginseng preparations (after releasing the sugar moieties from ginsenosides) were shown also to contain significant amounts of 20-epimers of 20(S)-protopanaxadiol and 20(S)-protopanaxatriol as well as their corresponding 24,25-hydrated compounds. In addition to the genuine and artificial sapogenins mentioned above, two epimeric pairs of prosapogenines (ginsenoside Rg3 and 20(S)-Rg3, ginsenoside Rh1 and 20(R)-Rh1) were also found in the liquid formulations. These results suggest that hydrolysis, epimerization and hydration in the side-chain of the aglycone moiety of ginsenosides may occur in the liquid formulations under weak acidic conditions (pH 3.0-3.5 with 9-10% of alcohol at room temperature). The new method was also used to determine the aglycones of ginsenosides in urine samples from Swedish athletes stating that they had consumed ginseng preparations within 10 days before urine collection. Out of the 65 samples analysed, 60 were found to contain 20(S)-protopanaxatriol. The concentrations of 20(S)-protopanaxatriol ginsenosides varied from 2 to 35 ng ml-1 urine. This is the first demonstration of uptake of ginsenosides in humans after oral administration of ginseng preparations.

  16. Standard Operating Procedure for the Preparation of Lead-Containing Paint Films and Lead-in-Paint Diagnostic Test Materials

    Science.gov (United States)

    This SOP describes the preparation of stand-alone, lead paint films, prepared according to the old paint recipes. Further, this SOP describes the use of these paint films for the preparation of simulated old paints on a variety of substrates. Substrates used included wood, stee...

  17. Liquid-Based Medium Used to Prepare Cytological Breast Nipple Fluid Improves the Quality of Cellular Samples Automatic Collection

    Science.gov (United States)

    Zonta, Marco Antonio; Velame, Fernanda; Gema, Samara; Filassi, Jose Roberto; Longatto-Filho, Adhemar

    2014-01-01

    Background Breast cancer is the second cause of death in women worldwide. The spontaneous breast nipple discharge may contain cells that can be analyzed for malignancy. Halo® Mamo Cyto Test (HMCT) was recently developed as an automated system indicated to aspirate cells from the breast ducts. The objective of this study was to standardize the methodology of sampling and sample preparation of nipple discharge obtained by the automated method Halo breast test and perform cytological evaluation in samples preserved in liquid medium (SurePath™). Methods We analyzed 564 nipple fluid samples, from women between 20 and 85 years old, without history of breast disease and neoplasia, no pregnancy, and without gynecologic medical history, collected by HMCT method and preserved in two different vials with solutions for transport. Results From 306 nipple fluid samples from method 1, 199 (65%) were classified as unsatisfactory (class 0), 104 (34%) samples were classified as benign findings (class II), and three (1%) were classified as undetermined to neoplastic cells (class III). From 258 samples analyzed in method 2, 127 (49%) were classified as class 0, 124 (48%) were classified as class II, and seven (2%) were classified as class III. Conclusion Our study suggests an improvement in the quality and quantity of cellular samples when the association of the two methodologies is performed, Halo breast test and the method in liquid medium. PMID:29147397

  18. A comparison of sample preparation methods for extracting volatile organic compounds (VOCs) from equine faeces using HS-SPME.

    Science.gov (United States)

    Hough, Rachael; Archer, Debra; Probert, Christopher

    2018-01-01

    Disturbance to the hindgut microbiota can be detrimental to equine health. Metabolomics provides a robust approach to studying the functional aspect of hindgut microorganisms. Sample preparation is an important step towards achieving optimal results in the later stages of analysis. The preparation of samples is unique depending on the technique employed and the sample matrix to be analysed. Gas chromatography mass spectrometry (GCMS) is one of the most widely used platforms for the study of metabolomics and until now an optimised method has not been developed for equine faeces. To compare a sample preparation method for extracting volatile organic compounds (VOCs) from equine faeces. Volatile organic compounds were determined by headspace solid phase microextraction gas chromatography mass spectrometry (HS-SPME-GCMS). Factors investigated were the mass of equine faeces, type of SPME fibre coating, vial volume and storage conditions. The resultant method was unique to those developed for other species. Aliquots of 1000 or 2000 mg in 10 ml or 20 ml SPME headspace were optimal. From those tested, the extraction of VOCs should ideally be performed using a divinylbenzene-carboxen-polydimethysiloxane (DVB-CAR-PDMS) SPME fibre. Storage of faeces for up to 12 months at - 80 °C shared a greater percentage of VOCs with a fresh sample than the equivalent stored at - 20 °C. An optimised method for extracting VOCs from equine faeces using HS-SPME-GCMS has been developed and will act as a standard to enable comparisons between studies. This work has also highlighted storage conditions as an important factor to consider in experimental design for faecal metabolomics studies.

  19. Determination of Bovine Lactoferrin in Food by HPLC with a Heparin Affinity Column for Sample Preparation.

    Science.gov (United States)

    Zhang, Yin; Lou, Fei; Wu, Wei; Dong, Xin; Ren, Jia; Shen, Qiuguang

    2017-01-01

    An HPLC method was developed for the quantitative determination of bovine lactoferrin (bLF) in sterilized milk, modified milk, fermented milk, infant formula, adult formula, rice cereal, vitamin function drink, and protein powder products. bLF was first extracted with a phosphate buffer (pH 8), underwent cleanup in a heparin affinity column, and was detected by HPLC with a C4 column and diode-array detector at a wavelength of 280 nm. The proposed method provided a linear detection range of 10.0-1000 μg/mL with an LOD of 0.6 mg/100 g in liquid samples and 3 mg/100 g in solid samples and an LOQ of 2 mg/100 g in liquid samples and 10 mg/100 g in solid samples. In addition, the method showed good recovery for various samples, ranging from 76 to 96%. The method had several remarkable advantages, including ease of handling, high sensitivity and accuracy, good reproducibility, and low-cost detection. Based on the distinctive properties presented here, we believe the proposed HPLC assay holds great promise for the oversight and detection of bLF in testing organizations, dairy enterprises, and regulatory authorities.

  20. Mercury Determination in Fish Samples by Chronopotentiometric Stripping Analysis Using Gold Electrodes Prepared from Recordable CDs

    Directory of Open Access Journals (Sweden)

    Andrei Florin Danet

    2008-11-01

    Full Text Available A simple method for manufacturing gold working electrodes for chronopotentiometric stripping measurements from recordable CD-R’s is described. These gold electrodes are much cheaper than commercially available ones. The electrochemical behavior of such an electrode and the working parameters for mercury determination by chronopotentiometric stripping analysis were studied. Detection limit was 0.30 μg Hg/L and determination limit was 1.0 μg Hg/L for a deposition time of 600 s. Using the developed working electrodes it was possible to determine the total mercury in fish samples. A method for fish sample digestion was developed by using a mixture of fuming nitric acid and both concentrated sulfuric and hydrochloric acids. The recovery degree for a known amount of mercury introduced in the sample before digestion was 95.3% (n=4.

  1. 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.

  2. Applications of derivatization reactions to trace organic compounds during sample preparation based on pressurized liquid extraction.

    Science.gov (United States)

    Carro, Antonia M; González, Paula; Lorenzo, Rosa A

    2013-06-28

    Pressurized liquid extraction (PLE) is an exhaustive technique used for the extraction of analytes from solid samples. Temperature, pressure, solvent type and volume, and the addition of other reagents notably influence the efficiency of the extraction. The analytical applications of this technique can be improved by coupling with appropriate derivatization reactions. The aim of this review is to discuss the recent applications of the sequential combination of PLE with derivatization and the approaches that involve simultaneous extraction and in situ derivatization. The potential of the latest developments to the trace analysis of environmental, food and biological samples is also analyzed. Copyright © 2013 Elsevier B.V. All rights reserved.

  3. 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.

  4. Dengue virus purification and sample preparation for cryo-electron microscopy.

    Science.gov (United States)

    Tan, Joanne L; Lok, Shee Mei

    2014-01-01

    Cryo-electron microscopy (cryo-EM) is a valuable tool used to study the structures of icosahedral viruses without having to resort to crystallization. During the last few decades, significant progress has been made where virus structures previously resolved only to low resolution have now breached the sub-nanometer threshold. Critical to such excellent results are the acquisition of highly purified virus samples and well-frozen samples in vitreous ice. With the virus particles locked in their native conformations, cryo-EM together with single-particle analysis can then be deployed to study the structures of the viruses in their fully hydrated states.

  5. A review on sample preparation and chromatographic determination of acephate and methamidophos in

    Directory of Open Access Journals (Sweden)

    Vijay Kumar

    2015-09-01

    Full Text Available Acephate and its metabolite methamidophos are common organophosphorus insecticide used for crop protection. High uses of acephate and methamidophos have induced health issues and environmental pollution. Their undesired presence in the environment is creating ecotoxicology and may harm human health. It is therefore essential to detect the presence of acephate and methamidophos even in trace level. In this review, we have tried to accommodate successful methods of detection of acephate and methamidophos in the different biological media. Their recovery and residue analysis in different media such as vegetables, human and animal tissues have also included. The most common method for their determination is based on chromatographic separation and identification. Among different chromatographic methods, LC and GC coupled with different detectors have used. But, they both need extensive pretreatment and cleanup procedure, before undergoing chromatographic separation and identification. LC coupled with mass spectrometry (LCMS is sometime able to detect acephate and methamidophos in ppm level.

  6. SOURCES OF VARIABILITY IN COLLECTION AND PREPARATION OF PAINT AND LEAD-COATING SAMPLES

    Science.gov (United States)

    Chronic exposure of children to lead can result in permanent physiologic impairment. Since surfaces coated with lead-containing paints and varnishes are potential sources of exposure, it is extremely important that reliable methods for sampling and analysis be available. The so...

  7. 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...

  8. A novel sample preparation method using rapid nonheated saponification method for the determination of cholesterol in emulsified foods.

    Science.gov (United States)

    Jeong, In-Seek; Kwak, Byung-Man; Ahn, Jang-Hyuk; Leem, Donggil; Yoon, Taehyung; Yoon, Changyong; Jeong, Jayoung; Park, Jung-Min; Kim, Jin-Man

    2012-10-01

    In this study, nonheated saponification was employed as a novel, rapid, and easy sample preparation method for the determination of cholesterol in emulsified foods. Cholesterol content was analyzed using gas chromatography with a flame ionization detector (GC-FID). The cholesterol extraction method was optimized for maximum recovery from baby food and infant formula. Under these conditions, the optimum extraction solvent was 10 mL ethyl ether per 1 to 2 g sample, and the saponification solution was 0.2 mL KOH in methanol. The cholesterol content in the products was determined to be within the certified range of certified reference materials (CRMs), NIST SRM 1544 and SRM 1849. The results of the recovery test performed using spiked materials were in the range of 98.24% to 99.45% with an relative standard devitation (RSD) between 0.83% and 1.61%. This method could be used to reduce sample pretreatment time and is expected to provide an accurate determination of cholesterol in emulsified food matrices such as infant formula and baby food. A novel, rapid, and easy sample preparation method using nonheated saponification was developed for cholesterol detection in emulsified foods. Recovery tests of CRMs were satisfactory, and the recoveries of spiked materials were accurate and precise. This method was effective and decreased the time required for analysis by 5-fold compared to the official method. © 2012 Institute of Food Technologists®

  9. Determination of thiobencarb in water samples by gas chromatography using a homogeneous liquid-liquid microextraction via flotation assistance procedure

    Directory of Open Access Journals (Sweden)

    H.A. Mashayekhi

    2013-09-01

    Full Text Available Homogeneous liquid-liquid microextraction via flotation assistance (HLLME-FA coupled with gas chromatography-flame ionization detection (GC-FID was applied for the extraction and determination of thiobencarb in water samples. In this study, a special extraction cell was designed to facilitate collection of the low-density solvent extraction. No centrifugation was required in this procedure. The water sample solution was added into the extraction cell which contained an appropriate mixture of toluene (as an extraction solvent and acetone (as a homogeneous solvent. By using air flotation, the organic solvent was collected at the conical part of the designed cell. The effect of the different parameters on the efficiency of extraction such as type and volume of extraction and homogeneous solvents, ionic strength and extraction time were studied and optimized. Under the optimal conditions, linearity of the method was in the range of 1.0-200 µg L-1. The relative standard deviations in the real samples varied from 7.8-11.7 % (n = 3. The proposed method was successfully applied to analysis of thiobencarb in the water samples and satisfactory results were obtained.DOI: http://dx.doi.org/10.4314/bcse.v27i3.4

  10. Preparation of in-house reference soil sample containing high levels of naturally occurring radioactive materials from the oil industry.

    Science.gov (United States)

    Al-Masri, M S; Aba, A; Al-Hamwi, A; Shakhashiro, A

    2004-12-01

    An in-house reference soil sample containing high levels of naturally occurring radioactive materials collected from contaminated areas in the Syrian oilfields has been prepared as a part of the quality assurance program in AECS. Homogeneity of the sample has been examined using three methods, viz. particle size distribution of the sample matrix, total alpha/beta counting and gamma spectrometry. In conjunction with Dixon and Grubb tests as statistical tools, ten random samples from the original sample were used for this investigation. Reference values for the three radium isotopes (224Ra, 226Ra, 228Ra) were determined using gamma spectrometry equipped with HPGe detectors having high relative efficiencies of 80%, while the reference value of 210Pb in the sample was determined using radiochemical separation and counting of its daughter 210Po by alpha spectrometry. ANOVA analysis was used to estimate the uncertainties due to measurement and inhomogeneity of the sample; uncertainty due to inhomogeneity was found to be around 2.6 times the measurement uncertainty.

  11. 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%. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. The choice of preparation method for the determination of Alternaria toxins from wheat samples by LC-MS/MS

    Directory of Open Access Journals (Sweden)

    Hajnal-Janić Elizabet P.

    2014-01-01

    Full Text Available Cereals are the primary source of human diet, wheat being the third most produced grain worldwide, and in Serbia second most produced grain, just behind corn. As a result of climate change and global warming, frequent occurrences of mycobiota on steep grains can produce a negative impact on the safety of food products and their quality, which inevitably leads to large economic losses. Although Fusarium spp. remains a main source of mycotoxins contamination of wheat, in recent years, due to the evident climatic changes affecting agricultural production, other mycotoxigenic fungi have been pointed out as important wheat contaminants. Among them are the fungi of the genus Alternaria, especially A. alternata, which under favourable conditions, produces mycotoxins such as alternariol, alternariol monomethyl ether, tenuazonic acid, and other Alternaria toxins. Taking into account the toxicity of metabolites produced by certain species of fungi of the genus Alternaria in the system from farm to table, it is necessary to develop specific and sensitive analytical methods in order to implement systematic controls of occurrence of Alternaria toxins. Liquid chromatography coupled to (tandem mass spectrometry (LC-MS/MS has become the technique of choice for the detection and quantification of Alternaria toxins in food and feed. There are several limiting factors such as the efficiency of sample cleanup and the lack of reference materials for food and feed. The aim of this study was to choose the most suitable preparation method for the determination of Alternaria toxins from wheat samples by LC-MS/MS technique based on published sample preparation methods, with possible modifications, which are used in analysis of mycotoxins. Modified method of wheat samples preparation by extraction with ethyl acetate was selected as acceptable based on extraction efficiency of analytes of interest.

  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. Target preparation and characterization for multielemental analysis of liquid samples by use of accelerators

    CERN Document Server

    Liendo, J A; Fletcher, N R; Gómez, J; Caussyn, D D; Myers, S H; Castelli, C; Sajo-Bohus, L

    1999-01-01

    Elastic scattering at forward angles is tested as a useful alternative method to characterize liquid samples of scientific and/or technological interest. Solid residues of such samples deposited on light backings have been bombarded with 16 MeV sup 7 Li and 24 MeV sup 1 sup 6 O beams in order to determine the experimental configuration giving the best elemental mass separation. The elastically scattered ions were detected at 16 deg. , 20 deg. and 28 deg. with surface barrier detectors. The ratios between the mass separation and the line width obtained in the spectral region between carbon and oxygen varied between 2 and 13. This method is particularly useful for an accurate elemental characterization below sodium which is beyond the scope of standard techniques such as PIXE and TXRF provided the ion beam type, its kinetic energy and the target thickness are considered simultaneously.

  15. Sample Preparation and Mounting of Drosophila Embryos for Multiview Light Sheet Microscopy.

    Science.gov (United States)

    Schmied, Christopher; Tomancak, Pavel

    2016-01-01

    Light sheet fluorescent microscopy (LSFM), and in particular its most widespread flavor Selective Plane Illumination Microscopy (SPIM), promises to provide unprecedented insights into developmental dynamics of entire living systems. By combining minimal photo-damage with high imaging speed and sample mounting tailored toward the needs of the specimen, it enables in toto imaging of embryogenesis with high spatial and temporal resolution. Drosophila embryos are particularly well suited for SPIM imaging because the volume of the embryo does not change from the single cell embryo to the hatching larva. SPIM microscopes can therefore image Drosophila embryos embedded in rigid media, such as agarose, from multiple angles every few minutes from the blastoderm stage until hatching. Here, we describe sample mounting strategies to achieve such a recording. We also provide detailed protocols to realize multiview, long-term, time-lapse recording of Drosophila embryos expressing fluorescent markers on the commercially available Zeiss Lightsheet Z.1 microscope and the OpenSPIM.

  16. Influence of Fasting Status and Sample Preparation on Metabolic Biomarker Measurements in Postmenopausal Women.

    Science.gov (United States)

    Murphy, Neil; Falk, Roni T; Messinger, Diana B; Pollak, Michael; Xue, Xiaonan; Lin, Juan; Sgueglia, Robin; Strickler, Howard D; Gaudet, Mia M; Gunter, Marc J

    2016-01-01

    Epidemiologic data linking metabolic markers-such as insulin, insulin-like growth factors (IGFs)-and adipose tissue-derived factors with cancer are inconsistent. Between-study differences in blood collection protocols, in particular participant's fasting status, may influence measurements. We investigated the impact of fasting status and blood sample processing time on components of the insulin/IGF axis and in adipokines in a controlled feeding study of 45 healthy postmenopausal-women aged 50-75 years. Fasting blood samples were drawn (T0), after which subjects ate a standardized breakfast; subsequent blood draws were made at 1 hour (T1), 3 hours (T3), and 6 hours (T6) after breakfast. Serum samples were assayed for insulin, C-peptide, total- and free-IGF-I, IGF-binding protein [BP]-1 and -3, total and high molecular weight (HMW)-adiponectin, retinol binding protein-4, plasminogen activator inhibitor (PAI)-1, and resistin. Insulin and C-peptide levels followed similar postprandial trajectories; intra-class correlation coefficients [ICC] for insulin = 0.75, (95%CI:0.64-0.97) and C-peptide (ICC = 0.66, 95%CI:0.54-0.77) were similarly correlated in fasting (Spearman correlation, r = 0.78, 95%CI:0.64-0.88) and postprandial states (T1, r = 0.77 (95%CI: 0.62-0.87); T3,r = 0.78 (95%CI: 0.63-0.87); T6,r = 0.77 (95%CI: 0.61-0.87)). Free-IGF-I and IGFBP-1 levels were also affected by fasting status, whereas total-IGF-I and IGFBP-3 levels remained unchanged. Levels of adipokines were largely insensitive to fasting status and blood sample processing delays. Several components of the insulin/IGF axis were significantly impacted by fasting state and in particular, C-peptide levels were substantially altered postprandially and in a similar manner to insulin.

  17. Dielectrophoretic sample preparation for environmental monitoring of microorganisms: Soil particle removal.

    Science.gov (United States)

    Fatoyinbo, Henry O; McDonnell, Martin C; Hughes, Michael P

    2014-07-01

    Detection of pathogens from environmental samples is often hampered by sensors interacting with environmental particles such as soot, pollen, or environmental dust such as soil or clay. These particles may be of similar size to the target bacterium, preventing removal by filtration, but may non-specifically bind to sensor surfaces, fouling them and causing artefactual results. In this paper, we report the selective manipulation of soil particles using an AC electrokinetic microfluidic system. Four heterogeneous soil samples (smectic clay, kaolinitic clay, peaty loam, and sandy loam) were characterised using dielectrophoresis to identify the electrical difference to a target organism. A flow-cell device was then constructed to evaluate dielectrophoretic separation of bacteria and clay in a continous flow through mode. The average separation efficiency of the system across all soil types was found to be 68.7% with a maximal separation efficiency for kaolinitic clay at 87.6%. This represents the first attempt to separate soil particles from bacteria using dielectrophoresis and indicate that the technique shows significant promise; with appropriate system optimisation, we believe that this preliminary study represents an opportunity to develop a simple yet highly effective sample processing system.

  18. Lessons Learned from Preparing OSIRIS-REx Spectral Analog Samples for Bennu

    Science.gov (United States)

    Schrader, D. L.; McCoy, T. J.; Cody, G. D.; King, A. J.; Schofield, P. F.; Russell, S. S.; Connolly, H. C., Jr.; Keller, L. P.; Donaldson Hanna, K.; Bowles, N.; hide

    2017-01-01

    NASA's OSIRIS-REx sample return mission launched on September 8th, 2016 to rendezvous with B-type asteroid (101955) Bennu in 2018. Type C and B asteroids have been linked to carbonaceous chondrites because of their similar visible - to - near infrared (VIS-NIR) spectral properties [e.g., 1,2]. The OSIRIS-REx Visible and Infrared Spectrometer (OVIRS) and the Thermal Emission Spectrometer (OTES) will make spectroscopic observations of Bennu during the encounter. Constraining the presence or absence of hydrous minerals (e.g., Ca-carbonate, phyllosilicates) and organic molecules will be key to characterizing Bennu [3] prior to sample site selection. The goal of this study was to develop a suite of analog and meteorite samples and obtain their spectral properties over the wavelength ranges of OVIRS (0.4- 4.3 micrometer) and OTES (5.0-50 micrometer). These spectral data were used to validate the mission science-data processing system. We discuss the reasoning behind the study and share lessons learned.

  19. SLUDGE BATCH 6 ACCEPTANCE EVALUATION: RADIONUCLIDE CONCENTRATIONS IN TANK 51 SB6 QUALIFICATION SAMPLE PREPARED AT SRNL

    Energy Technology Data Exchange (ETDEWEB)

    Bannochie, C.; Bibler, N.; Diprete, D.

    2010-05-21

    Presented in this report are radionuclide concentrations required as part of the program of qualifying Sludge Batch Six (SB6) for processing in the Defense Waste Processing Facility (DWPF). The SB6 material is currently in Tank 51 being 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 and is currently being processed as SB5. The radionuclide concentrations were measured or estimated in the Tank 51 SB6 Qualification Sample prepared at Savannah River National Laboratory (SRNL). This sample was prepared from the three liter sample of Tank 51 sludge slurry (HTF-51-09-110) taken on October 8, 2009. The sample was delivered to SRNL where it was initially characterized in the Shielded Cells. Under the direction of the Liquid Waste Organization it was then modified by eight washes, nine decants, an addition of Pu from Canyon Tank 16.3, and an addition of NaNO{sub 2}. 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. Determining the radionuclide concentrations in this Tank 51 SB6 Qualification Sample is part of the work requested in Technical Task Request (TTR) No. HLW-DWPF-TTR-2009-0014. The work with this qualification sample is covered by a Task Technical and Quality Assurance Plan and an Analytical Study Plan. The radionuclides included in this report are needed for the DWPF Radiological Program Evaluation, the DWPF Waste Acceptance Criteria (TSR/WAC) Evaluation, and the DWPF Solid Waste Characterization Program (TTR Task I.2). Radionuclides required to meet the Waste Acceptance Product Specifications (TTR Task II.2.) will be measured at a later date after the slurry from Tank 51 has been transferred to Tank 40. Then a sample of the as-processed SB6 will be taken and transferred

  20. Thermal conductivity measurement of sintered Vibro-packed fuel. 1. Study on sample preparation method

    Energy Technology Data Exchange (ETDEWEB)

    Mizuno, Mineo; Kosaka, Yuji; Ogawa, Shinta [Nuclear Development Corp., Tokai, Ibaraki (Japan)

    2002-02-01

    An experimental study was carried out in order to grasp the sintering condition of the Vibro-packed fuel bed. A disc shaped bed of UO{sub 2} particles manufactured by the tumbling granulation method was sintered in constant load and temperature using a creep examination machine. The following results were obtained. 1) Sintering for about 2 hours and 30 minutes under the temperature of 1700degC and the compression load condition of 7 MPa generated 4.5 - 4.7% strain of the bed and about 40% neck ratio between particles. 2) Larger neck ratio was observed in larger sintering strain bed. This result implies the aimed neck ratio can be prepared by the adjustment of the sintering strain. 3) Sintering strain of the bed was depend on the particle size. In case of the large size particle, sintering strain became large. It was considered that it was based on the increase of local stress caused by the reduction of contact points according to particle diameter increase. 4) When the particle diameter becomes small, the particle neck ratio perpendicular to the load direction became small in comparison with the load direction, and the tendency that a particle becomes easy to separate was recognized. 5) >From the grain size measurement result of particle before and after a sintering experiment, no significant change of the crystal grain size was recognized. (author)