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Sample records for sample preparation

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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...

  8. 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.

  9. 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...

  10. 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.

  11. 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...

  12. 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.

  13. 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...

  14. 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.

  15. 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...

  16. 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

  17. 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

  18. 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.

  19. 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

  20. 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.

  1. 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...

  2. 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.

  3. 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.

  4. 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 ...

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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...

  10. 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 ...

  11. 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

  12. 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

  13. 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.

  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. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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.

  1. 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.

  2. 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....

  3. 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.

  4. 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.

  5. 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...

  6. 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.

  7. 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.

  8. 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

  9. 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

  10. 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. ...

  11. 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 ...

  12. Microsystem strategies for sample preparation in biological detection.

    Energy Technology Data Exchange (ETDEWEB)

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

    2005-03-01

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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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...

  19. 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.

  20. 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.

  1. 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

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

    DEFF Research Database (Denmark)

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

    2016-01-01

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

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

    Data.gov (United States)

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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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

  9. 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.

  10. 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 ...

  11. 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.

  12. 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

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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

  19. 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....

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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....

  6. 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.

  7. 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

  8. 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."

  9. 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.

  10. 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.

  11. 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.

  12. 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, ...

  13. 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.

  14. 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

  15. 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.

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

    Science.gov (United States)

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

    2011-01-01

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

  17. 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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-15

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

  19. 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.

  20. 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.

  1. 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....

  2. 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...

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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)

  18. 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.

  19. 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....

  20. 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

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. [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.

  6. 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.

  7. 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.

  8. 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...

  9. 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

  10. 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.

  11. 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.

  12. 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...

  13. 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.

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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

  14. 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.

  15. 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

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  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. 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.

  3. 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).

  4. 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.

  5. 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.)

  6. 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...

  7. 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

    be very useful for future proteomic studies and the design of studies in terms of sample preparation, especially sample homogenization and protein extraction.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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

  5. 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.

  6. 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

  7. 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.

  8. 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.

  9. 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

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  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. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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

  20. 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...

  1. 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.

  2. 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...

  3. 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

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. 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.

  10. 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...

  11. 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.

  12. 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.

  13. 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...

  14. 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.

  15. 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.

  16. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-03-30

    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.

  17. U-10Mo Sample Preparation and Examination using Optical and Scanning Electron Microscopy

    Energy Technology Data Exchange (ETDEWEB)

    Prabhakaran, Ramprashad [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Joshi, Vineet V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rhodes, Mark A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Schemer-Kohrn, Alan L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Guzman, Anthony D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lavender, Curt A. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2016-10-01

    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.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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...

  7. 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

  8. 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.

  9. 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

  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

    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.

  11. 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

  12. 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...

  13. 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

  14. 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.

  15. 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.

  16. 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.

  17. 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.

  18. 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.

  19. 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...

  20. 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.

  1. 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.

  2. 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.)

  3. 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

  4. 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.

  5. 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

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

  13. 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)

  14. 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...

  15. 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...

  16. 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®

  17. 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.

  18. 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.)

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. 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.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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.

  9. 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.

  10. 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

  11. 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)

  12. Collection, storage, and filtration of in vivo study samples using 96-well filter plates to facilitate automated sample preparation and LC/MS/MS analysis.

    Science.gov (United States)

    Berna, M; Murphy, A T; Wilken, B; Ackermann, B

    2002-03-01

    The benefits of high-throughput bioanalysis within the pharmaceutical industry are well established. One of the most significant bottlenecks in bioanalysis is transferring in vivo-generated study samples from their collection tubes during sample preparation and extraction. In most cases, the plasma samples must be stored frozen prior to analysis, and the freeze/thaw (F/T) process introduces thrombin clots that are capable of plugging pipets and automated liquid-transfer systems. A new approach to dealing with this problem involves the use of Ansys Captiva 96-well 20-microm polypropylene filter plates to collect, store frozen, and filter plasma samples prior to bioanalysis. The samples are collected from the test subjects, and the corresponding plasma samples are placed directly into the wells of the filter plate. Two Duoseal (patent pending) covers are used to seal the top and bottom of the plate, and the plate is stored at down to -70 degrees C. Prior to sample analysis, the seals are removed and the plate is placed in a 96-well SPE manifold. As the plasma thaws, it passes (by gravity or mild vacuum) through the polypropylene filter into a 96-well collection plate. A multichannel pipet or automated liquid-transfer system is used to transfer sample aliquots without fear of plugging. A significant advantage of this approach is that, unlike other methods, issues related to incomplete pipetting are virtually eliminated. The entire process is rapid since thawing and filtering take place simultaneously, and if a second F/T cycle is required for reanalysis, it is not necessary to refilter the samples (additional clotting was not observed after three F/T cycles). This technique was tested using monkey, rat, and dog plasma and sodium heparin and EDTA anticoagulants. To assess the possibility of nonspecific binding to the polypropylene filter, a variety of drug candidates from diverse drug classes were studied. Validation data generated for two Lilly compounds from distinct

  13. Nucleic acid sample preparation for in vitro molecular diagnosis: from conventional techniques to biotechnology.

    Science.gov (United States)

    Rahman, Md Mahbubor; Elaissari, Abdelhamid

    2012-11-01

    Nucleic acid (DNA and RNA)-based molecular diagnosis is a promising laboratory technique because of its ability to identify disease accurately. However, one of its disadvantages is the inevitable purification and detection of nucleic acids from other contaminated entities. Different nano- and microparticles have been developed for use in an advanced, efficient high-throughput autosystem for the purification and detection of nucleic acid samples for use in molecular diagnoses. In this review, we discuss recent advances in the development of particle-based nucleic acid purification and detection. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Influence of Fasting Status and Sample Preparation on Metabolic Biomarker Measurements in Postmenopausal Women.

    Directory of Open Access Journals (Sweden)

    Neil Murphy

    Full Text Available 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.

  15. 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.

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

    Science.gov (United States)

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

    2016-02-01

    A preparative separation method using consecutive sample injection centrifugal partition chromatography (CPC) was developed to obtain sesamin and sesamolin from defatted sesame meal extracts. A two-phase solvent system consisting of n-hexane-ethyl acetate-methanol-water (8:2:8:2, v/v) was applied in reversed-phase mode (descending mode). Preliminary experiments with an SCPC-100 (column volume: 100mL) were performed to select the appropriate two-phase solvent system and sample injection times; these parameters were then used with an SCPC-1000 (column volume: 1000mL) in a 10-fold scale-up preparative run. A sample containing 3g of crude extract was consecutively injected four times onto the SCPC-1000, which yielded 328mg of sesamin and 168mg of sesamolin. These compounds were analyzed by high-performance liquid chromatography and determined to have purities of 95.6% and 93.9%, respectively. Sesamin and sesamolin (30μM) increased antioxidant response element (ARE) luciferase activity 2.6-fold and 1.9-fold, respectively. Copyright © 2016 Elsevier B.V. All rights reserved.

  17. Sample Preparation and Staining Methods for Two-Dimensional Polyacrylamide Gel Electrophoresis of Proteins from Animal Tissues

    Directory of Open Access Journals (Sweden)

    Levente Czegledi

    2010-05-01

    Full Text Available Proteomics in animal science as well as in other biological sciences is a significant tool in the post-genomic era. In proteomic studies the presence and relative abundance of expressed proteins of a cell, tissue or biological fluid is studied. Recently, the whole genome of more and more domestic animal species is known, but genes and the transcribed mRNA have no direct effect on biological systems as they are regulated by proteins, which explain the importance of proteomics. The most common tool in proteomic approach is the two-dimensional polyacrylamide gel electrophoresis (2D PAGE, when proteins are separated by their isoelectric point followed by their mass separation as a second dimension. In this study authors used different sample preparation and protein staining methods on meat,  liver and blood plasma and carried out 2D PAGE experiments. The most appropriate sample preparation methods are described in this paper. We concluded that depletion of major proteins in plasma is required but not necessary for meat and liver samples.

  18. Improvement of microtome cutting process of carbon nanotube composite sample preparation for TEM analysis

    Science.gov (United States)

    Trayner, Sarah

    As research progresses towards nanoscale materials, there has become a need for a more efficient and effective way to obtain ultra-thin samples for imaging under transmission electron microscope (TEM) for atomic resolution analysis. There are various methods used to obtain thin samples (resin and graphite crystalline packing. UD IM7/BMI composite TEM results did not reveal an interfacial region resulting in a need for even thinner sliced cross sections. TEM results for the single-layer CNT BP/epoxy nanocomposite revealed the alignment direction of the nanotubes and numerous stacks of CNT bundles. In addition, there was visible flattening of CNT packing into dumbbell shapes similar to results obtain by Alan Windle. TEM results for the 3-layer CNT BP/BMI nanocomposite revealed uniformly cut resin. However, when the diamond knife reached graphite crystalline regions, the nanotube either became deformed into a cone-like structure, was cut at a thicker thickness than the resin, or folded over onto itself. This is most likely a result of the nanotubes high mechanical properties in response to the stress of cutting.

  19. Automation and integration of multiplexed on-line sample preparation with capillary electrophoresis for DNA sequencing

    Energy Technology Data Exchange (ETDEWEB)

    Tan, H.

    1999-03-31

    The purpose of this research is to develop a multiplexed sample processing system in conjunction with multiplexed capillary electrophoresis for high-throughput DNA sequencing. The concept from DNA template to called bases was first demonstrated with a manually operated single capillary system. Later, an automated microfluidic system with 8 channels based on the same principle was successfully constructed. The instrument automatically processes 8 templates through reaction, purification, denaturation, pre-concentration, injection, separation and detection in a parallel fashion. A multiplexed freeze/thaw switching principle and a distribution network were implemented to manage flow direction and sample transportation. Dye-labeled terminator cycle-sequencing reactions are performed in an 8-capillary array in a hot air thermal cycler. Subsequently, the sequencing ladders are directly loaded into a corresponding size-exclusion chromatographic column operated at {approximately} 60 C for purification. On-line denaturation and stacking injection for capillary electrophoresis is simultaneously accomplished at a cross assembly set at {approximately} 70 C. Not only the separation capillary array but also the reaction capillary array and purification columns can be regenerated after every run. DNA sequencing data from this system allow base calling up to 460 bases with accuracy of 98%.

  20. Toward the Development of a Glucose Dehydrogenase-Based Saliva Glucose Sensor Without the Need for Sample Preparation.

    Science.gov (United States)

    Lin, Chi; Pratt, Breanna; Honikel, Mackenzie; Jenish, Alaina; Ramesh, Bhavna; Alkhan, Amnah; La Belle, Jeffrey T

    2018-01-01

    Strict glycemic control is known to be a vital key in the management of diabetes mellitus (DM). However, traditional methods face limitations in their efficacy due to the pain and invasiveness of needle pricking which often discourages DM patients from performing the required number of tests per day. Saliva glucose (SG) sensing has long been considered a noninvasive alternative to blood glucose monitoring for diabetes management, however the sample preparation and sensor detection limit have been deemed as challenges to overcome. Herein, we describe a preliminary clinical validation of a disposable SG sensor without any requirement for sample preparation. The sensor utilizes glucose dehydrogenase flavine-adenine dinucleotide (GDH-FAD) in conjunction with disposable screen printed electrodes to measure glucose levels in saliva collected directly from 9 healthy subjects. Cyclic voltammetry and amperometric-time (Amp-it) assays were used to develop calibration curves and test subjects. Sensor calibration was performed using simulated saliva at 6.5 pH and 37ºC. The lower limit of detection was determined to be 0.11 mg/dL. A lag time of 15 minutes with a positive correlation between SG and BG levels was found, which agrees with literature results. The detected SG ranges from 2.38 to 3.40 mg/dL over a BG range of 90 to 143 mg/dL. This is the first reported use of measuring SG with GDH-FAD without prior sample preparation. Upon optimization, the sensor has the potential to serve as a supplement to blood glucose monitoring.

  1. High Throughput Sample Preparation and Analysis for DNA Sequencing, PCR and Combinatorial Screening of Catalysis Based on Capillary Array Technique

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, Yonghua [Iowa State Univ., Ames, IA (United States)

    2000-01-01

    Sample preparation has been one of the major bottlenecks for many high throughput analyses. The purpose of this research was to develop new sample preparation and integration approach for DNA sequencing, PCR based DNA analysis and combinatorial screening of homogeneous catalysis based on multiplexed capillary electrophoresis with laser induced fluorescence or imaging UV absorption detection. The author first introduced a method to integrate the front-end tasks to DNA capillary-array sequencers. protocols for directly sequencing the plasmids from a single bacterial colony in fused-silica capillaries were developed. After the colony was picked, lysis was accomplished in situ in the plastic sample tube using either a thermocycler or heating block. Upon heating, the plasmids were released while chromsomal DNA and membrane proteins were denatured and precipitated to the bottom of the tube. After adding enzyme and Sanger reagents, the resulting solution was aspirated into the reaction capillaries by a syringe pump, and cycle sequencing was initiated. No deleterious effect upon the reaction efficiency, the on-line purification system, or the capillary electrophoresis separation was observed, even though the crude lysate was used as the template. Multiplexed on-line DNA sequencing data from 8 parallel channels allowed base calling up to 620 bp with an accuracy of 98%. The entire system can be automatically regenerated for repeated operation. For PCR based DNA analysis, they demonstrated that capillary electrophoresis with UV detection can be used for DNA analysis starting from clinical sample without purification. After PCR reaction using cheek cell, blood or HIV-1 gag DNA, the reaction mixtures was injected into the capillary either on-line or off-line by base stacking. The protocol was also applied to capillary array electrophoresis. The use of cheaper detection, and the elimination of purification of DNA sample before or after PCR reaction, will make this approach an

  2. A validated HPLC-UV method and optimization of sample preparation technique for norepinephrine and serotonin in mouse brain.

    Science.gov (United States)

    Thomas, Jaya; Khanam, Razia; Vohora, Divya

    2015-01-01

    Norepinephrine and serotonin are two important neurotransmitters whose variations in brain are reported to be associated with many common neuropsychiatric disorders. Yet, relevant literature on estimation of monoamines in biological samples using HPLC-UV is limited. The present study involves the development of a simultaneous HPLC-UV method for estimation of norepinephrine and serotonin along with optimization of the sample preparation technique. Chromatographic separation was achieved by injecting 20 µL of the sample after extraction into Quaternary pump HPLC equipped with C18 column using 0.05% formic acid and acetonitrile (90:10, v/v) as the mobile phase with 1 mL min(-1) flow rate. The developed method was validated as per the ICH guidelines in terms of linearity, accuracy, repeatability, precision, and robustness. The method showed a wide range of linearity (50-4000 and 31.25-4000 ng mL(-1) for norepinephrine and serotonin, respectively). The recovery was found to be in the range of 86.04-89.01% and 86.43-89.61% for norepinephrine and serotonin, respectively. The results showed low value of %RSD for repeatability, intra and inter-day precision, and robustness studies. Four different methods were used for the extraction of these neurotransmitters and the best one with maximum recovery was ascertained. Here, we developed and validated a simple, accurate, and reliable method for the estimation of norepinephrine and serotonin in mice brain samples using HPLC-UV. The method was successfully applied to quantify these neurotransmitters in mice brain extracted by optimized sample preparation technique.

  3. On-target sample preparation of 4-sulfophenyl isothiocyanate-derivatized peptides using AnchorChip Targets

    DEFF Research Database (Denmark)

    Zhang, Xumin; Rogowska-Wrzesinska, Adelina; Roepstorff, Peter

    2008-01-01

    De novo sequencing of tryptic peptides by post source decay (PSD) or collision induced dissociation (CID) analysis using MALDI TOF-TOF instruments is due to the easy interpretation facilitated by the introduction of N-terminal sulfonated derivatives. Recently, a stable and cheap reagent, 4......-sulfophenyl isothiocyanate (SPITC), has been successfully used for N-terminal derivatization. Previously described methods have always used desalting and concentration by reverse-phase chromatography prior to mass spectrometric analysis. Here we present an on-target sample preparation method based on Anchor...

  4. Preparation of {sup 183,184}Re samples for modelling a rapid gas phase chemistry of Nielsbohrium (Ns), element 107

    Energy Technology Data Exchange (ETDEWEB)

    Eichler, R.; Gaeggeler, H.W.; Eichler, B.; Tuerler, A. [Paul Scherrer Inst. (PSI), Villigen (Switzerland)

    1997-09-01

    Chemical gas phase reactions of the heavier group 7 elements in the system O{sub 2}/H{sub 2}O are presumably best suited for a separation of Nielsbohrium from the lighter transactinides. We expect a higher reaction velocity using the more reactive gas system O{sub 3}/H{sub 2}O{sub 2}. For the experimental verification of this idea we prepared {sup 183}Re/{sup 184}Re samples for thermochromatography experiments with both gas systems. (author) 8 refs.

  5. A Microbiome DNA Enrichment Method for Next-Generation Sequencing Sample Preparation.

    Science.gov (United States)

    Yigit, Erbay; Feehery, George R; Langhorst, Bradley W; Stewart, Fiona J; Dimalanta, Eileen T; Pradhan, Sriharsa; Slatko, Barton; Gardner, Andrew F; McFarland, James; Sumner, Christine; Davis, Theodore B

    2016-07-01

    "Microbiome" is used to describe the communities of microorganisms and their genes in a particular environment, including communities in association with a eukaryotic host or part of a host. One challenge in microbiome analysis concerns the presence of host DNA in samples. Removal of host DNA before sequencing results in greater sequence depth of the intended microbiome target population. This unit describes a novel method of microbial DNA enrichment in which methylated host DNA such as human genomic DNA is selectively bound and separated from microbial DNA before next-generation sequencing (NGS) library construction. This microbiome enrichment technique yields a higher fraction of microbial sequencing reads and improved read quality resulting in a reduced cost of downstream data generation and analysis. © 2016 by John Wiley & Sons, Inc. Copyright © 2016 John Wiley & Sons, Inc.

  6. NMR-based metabolomics: from sample preparation to applications in nutrition research.

    Science.gov (United States)

    Brennan, Lorraine

    2014-11-01

    Metabolomics is the study of metabolites present in biological samples such as biofluids, tissue/cellular extracts and culture media. Measurement of these metabolites is achieved through use of analytical techniques such as NMR and mass spectrometry coupled to liquid chromatography. Combining metabolomic data with multivariate data analysis tools allows the elucidation of alterations in metabolic pathways under different physiological conditions. Applications of NMR-based metabolomics have grown in recent years and it is now widely used across a number of disciplines. The present review gives an overview of the developments in the key steps involved in an NMR-based metabolomics study. Furthermore, there will be a particular emphasis on the use of NMR-based metabolomics in nutrition research. Copyright © 2014 Elsevier B.V. All rights reserved.

  7. 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.

  8. Haemolysis during sample preparation alters microRNA content of plasma.

    Directory of Open Access Journals (Sweden)

    Michaela B Kirschner

    Full Text Available The presence of cell-free microRNAs (miRNAs has been detected in a range of body fluids. The miRNA content of plasma/serum in particular has been proposed as a potential source of novel biomarkers for a number of diseases. Nevertheless, the quantification of miRNAs from plasma or serum is made difficult due to inefficient isolation and lack of consensus regarding the optimal reference miRNA. The effect of haemolysis on the quantification and normalisation of miRNAs in plasma has not been investigated in great detail. We found that levels of miR-16, a commonly used reference gene, showed little variation when measured in plasma samples from healthy volunteers or patients with malignant mesothelioma or coronary artery disease. Including samples with evidence of haemolysis led to variation in miR-16 levels and consequently decreased its ability to serve as a reference. The levels of miR-16 and miR-451, both present in significant levels in red blood cells, were proportional to the degree of haemolysis. Measurements of the level of these miRNAs in whole blood, plasma, red blood cells and peripheral blood mononuclear cells revealed that the miRNA content of red blood cells represents the major source of variation in miR-16 and miR-451 levels measured in plasma. Adding lysed red blood cells to non-haemolysed plasma allowed a cut-off level of free haemoglobin to be determined, below which miR-16 and miR-451 levels displayed little variation between individuals. In conclusion, increases in plasma miR-16 and miR-451 are caused by haemolysis. In the absence of haemolysis the levels of both miR-16 and miR-451 are sufficiently constant to serve as normalisers.

  9. Defining a sample preparation workflow for advanced virus detection and understanding sensitivity by next-generation sequencing.

    Science.gov (United States)

    Wang, Christopher J; Feng, Szi Fei; Duncan, Paul

    2014-01-01

    The application of next-generation sequencing (also known as deep sequencing or massively parallel sequencing) for adventitious agent detection is an evolving field that is steadily gaining acceptance in the biopharmaceutical industry. In order for this technology to be successfully applied, a robust method that can isolate viral nucleic acids from a variety of biological samples (such as host cell substrates, cell-free culture fluids, viral vaccine harvests, and animal-derived raw materials) must be established by demonstrating recovery of model virus spikes. In this report, we implement the sample preparation workflow developed by Feng et. al. and assess the sensitivity of virus detection in a next-generation sequencing readout using the Illumina MiSeq platform. We describe a theoretical model to estimate the detection of a target virus in a cell lysate or viral vaccine harvest sample. We show that nuclease treatment can be used for samples that contain a high background of non-relevant nucleic acids (e.g., host cell DNA) in order to effectively increase the sensitivity of sequencing target viruses and reduce the complexity of data analysis. Finally, we demonstrate that at defined spike levels, nucleic acids from a panel of model viruses spiked into representative cell lysate and viral vaccine harvest samples can be confidently recovered by next-generation sequencing. © PDA, Inc. 2014.

  10. Preparation and characterization of pyrromethene-567 dye-doped polymer samples using Gamma Irradiation Polymerization Method (GIPM)

    Energy Technology Data Exchange (ETDEWEB)

    Al-Ghamdi, Attieh A., E-mail: aaaalghamdi4@kau.edu.sa [Center of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia); Mahrous, Eiman M. [Taibah University, Department of Physics, Madinah (Saudi Arabia); Al-Enizi, Abdullah M. [King Saud University, Department of Chemistry, Riyadh (Saudi Arabia); Azam, Ameer [Center of Nanotechnology, King Abdulaziz University, Jeddah (Saudi Arabia)

    2015-01-15

    Dye-doped polymer gain media laser samples of pyrromethene-567 in a mixture with methyl methacrylate and 2-hydroxyethyl methacrylate copolymer have been prepared and synthesized by the Conventional Thermal Polymerization Method (CTPM) using an oven, and by the Gamma Irradiation Polymerization Method (GIPM) using Cobalt-60 ({sup 60}Co). Physical properties comprising absorption molar coefficients, absorption cross sections, fluorescence quantum yields, fluorescence life times, and emission cross sections were determined and calculated from the measured absorption and emission spectra. The efficiency and photo-stability of samples fabricated by both methods were measured and compared. The time required for synthesis was reduced by 90% using the GIPM. Complete polymerization of the GIPM sample was found to be at 7 kGy. Further, the GIPM produces high laser damage resistance material, which might be attributed to the highly dense polymeric network structure formed as a result of the effect of gamma radiation on MMA and HEMA monomers. - Highlights: • Samples of PM-567 in a mixture with MMA/HEMA were synthesized by the GIPM. • The time required for synthesis was reduced by 90% using the GIPM. • Complete polymerization of the GIPM sample was at 7 kGy. • The laser media produced is fast and free of contamination that gives high purity material. • The GIPM produced a high laser damage resistance material.

  11. Differentiation and classification of beers with flame atomic spectrometry and molecular absorption spectrometry and sample preparation assisted by microwaves

    Science.gov (United States)

    Bellido-Milla, Dolores; Moreno-Perez, Juana M.; Hernández-Artiga, María. P.

    2000-07-01

    The characterization of beer samples has a lot of interest because their composition can affect the taste and stability of beer and consumer health. Flame atomic absorption spectrometry was used to determine Fe, Mn, Zn, Cu, Mg, Ca and Al. Sodium and K were determined by flame atomic emission spectrometry. A sample preparation method was developed, based on treatment with HNO 3 and H 2O 2 in a microwave oven. This has many advantages over the methods found in the literature. The combination of the results of atomic spectrometry and the spectrum obtained by molecular absorption spectrometry provides information on the inorganic and organic components of the samples. The application of chemometric techniques to chemical composition data could be extremely useful for food quality control. The metal concentrations, the molecular absorption spectrum, the pH and conductivity of each sample were subject to analysis of variance and linear discriminant analysis. Twenty-five different beer samples were used to differentiate and classify different types of beers.

  12. Sampling

    CERN Document Server

    Thompson, Steven K

    2012-01-01

    Praise for the Second Edition "This book has never had a competitor. It is the only book that takes a broad approach to sampling . . . any good personal statistics library should include a copy of this book." —Technometrics "Well-written . . . an excellent book on an important subject. Highly recommended." —Choice "An ideal reference for scientific researchers and other professionals who use sampling." —Zentralblatt Math Features new developments in the field combined with all aspects of obtaining, interpreting, and using sample data Sampling provides an up-to-date treat

  13. A Comprehensive Guide for Performing Sample Preparation and Top-Down Protein Analysis.

    Science.gov (United States)

    Padula, Matthew P; Berry, Iain J; O Rourke, Matthew B; Raymond, Benjamin B A; Santos, Jerran; Djordjevic, Steven P

    2017-04-07

    Methodologies for the global analysis of proteins in a sample, or proteome analysis, have been available since 1975 when Patrick O'Farrell published the first paper describing two-dimensional gel electrophoresis (2D-PAGE). This technique allowed the resolution of single protein isoforms, or proteoforms, into single 'spots' in a polyacrylamide gel, allowing the quantitation of changes in a proteoform's abundance to ascertain changes in an organism's phenotype when conditions change. In pursuit of the comprehensive profiling of the proteome, significant advances in technology have made the identification and quantitation of intact proteoforms from complex mixtures of proteins more routine, allowing analysis of the proteome from the 'Top-Down'. However, the number of proteoforms detected by Top-Down methodologies such as 2D-PAGE or mass spectrometry has not significantly increased since O'Farrell's paper when compared to Bottom-Up, peptide-centric techniques. This article explores and explains the numerous methodologies and technologies available to analyse the proteome from the Top-Down with a strong emphasis on the necessity to analyse intact proteoforms as a better indicator of changes in biology and phenotype. We arrive at the conclusion that the complete and comprehensive profiling of an organism's proteome is still, at present, beyond our reach but the continuing evolution of protein fractionation techniques and mass spectrometry brings comprehensive Top-Down proteome profiling closer.

  14. Challenges Associated with Sample Preparation for the Analysis of PBDEs in Human Serum.

    Science.gov (United States)

    Siddique, Shabana; Kosarac, Ivana; Kubwabo, Cariton; Harris, Shelley

    2016-01-01

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many applications; however, certain PBDE congeners are persistent, bioaccumulative, and toxic to both humans and the environment. PBDEs have been found in human specimens, and a variety of analytical techniques have been used for their determination in biological matrixes. Nevertheless, obtaining a relatively clean analytical blank sample during PBDE analysis is a big challenge because of the ubiquitous nature of these compounds. Thus, the present study was conducted to compare the PBDE background levels associated with the three most commonly used extraction techniques: liquid-liquid extraction (LLE), SPE, and accelerated solvent extraction (ASE). Conventionally used blank matrixes (HPLC grade water, Milli-Q water, and air) were spiked with internal standards and extracted using LLE, SPE, or ASE. The extracts were analyzed by GC/electron ionization-tandem MS. The ASE method achieved the lowest background levels for nearly all the PBDE congeners analyzed, which may be attributed to the stainless steel and closed-vessel nature of the ASE cells.

  15. Sample preparation method considerations for integrated transcriptomic and proteomic analysis of tumors.

    Science.gov (United States)

    Bhat, Anupama Rajan; Gupta, Manoj Kumar; Krithivasan, Priya; Dhas, Kunal; Nair, Jayalakshmi; Reddy, Ram Bhupal; Sudheendra, Holalugunda Vittalamurthy; Chavan, Sandip; Vardhan, Harsha; Darsi, Sujatha; Balakrishnan, Lavanya; Katragadda, Shanmukh; Kekatpure, Vikram; Suresh, Amritha; Tata, Pramila; Panda, Binay; Kuriakose, Moni A; Sirdeshmukh, Ravi

    2017-03-01

    Sample processing protocols that enable compatible recovery of differentially expressed transcripts and proteins are necessary for integration of the multiomics data applied in the analysis of tumors. In this pilot study, we compared two different isolation methods for extracting RNA and protein from laryngopharyngeal tumor tissues and the corresponding adjacent normal sections. In Method 1, RNA and protein were isolated from a single tissue section sequentially and in Method 2, the extraction was carried out using two different sections and two independent and parallel protocols for RNA and protein. RNA and protein from both methods were subjected to RNA-seq and iTRAQ-based LC-MS/MS analysis, respectively. Analysis of data revealed that a higher number of differentially expressed transcripts and proteins were concordant in their regulation trends in Method 1 as compared to Method 2. Cross-method comparison of concordant entities revealed that RNA and protein extraction from the same tissue section (Method 1) recovered more concordant entities that are missed in the other extraction method (Method 2) indicating heterogeneity in distribution of these entities in different tissue sections. Method 1 could thus be the method of choice for integrated analysis of transcriptome and proteome data. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. In situ aqueous derivatization as sample preparation technique for gas chromatographic determinations.

    Science.gov (United States)

    Ferreira, Ana María Casas; Laespada, María Esther Fernández; Pavón, José Luis Pérez; Cordero, Bernardo Moreno

    2013-06-28

    The use of derivatization reactions is a common practice in analytical laboratories. Although in many cases it is tedious and time-consuming, it does offer a good alternative for the determination of analytes not compatible to gas chromatography. Many of the reactions reported in the literature occur in organic medium. However, in situ aqueous derivatization reactions, which can be performed directly in aqueous medium, offer important advantages over those mentioned above, such as no need of a previous extraction step and easy automation. Here we review the most recent developments and applications of in situ aqueous derivatization. The discussion focuses on the derivatization reactions used for the determination of alcohols and phenols, carboxylic acids, aldehydes and ketones, nitrogen-containing compounds and thiols in different aqueous matrices, such as environmental, biological and food samples. Several reactions are described for each functional group (acylation, alkylation, esterification, among others) and, in some cases, the same reagents can be used for several functional groups, such that there is an unavoidable overlap between sections. Finally, attention is also focused on the techniques used for the introduction of the derivatives formed in the aqueous medium into the chromatographic system. The implementation of in situ aqueous derivatization coupled to preconcentration techniques has permitted the enhancement of recoveries and improvements in the separation, selectivity and sensitivity of the analytical methods. Copyright © 2013 Elsevier B.V. All rights reserved.

  17. A Comprehensive Guide for Performing Sample Preparation and Top-Down Protein Analysis

    Science.gov (United States)

    Padula, Matthew P.; Berry, Iain J.; O′Rourke, Matthew B.; Raymond, Benjamin B.A.; Santos, Jerran; Djordjevic, Steven P.

    2017-01-01

    Methodologies for the global analysis of proteins in a sample, or proteome analysis, have been available since 1975 when Patrick O′Farrell published the first paper describing two-dimensional gel electrophoresis (2D-PAGE). This technique allowed the resolution of single protein isoforms, or proteoforms, into single ‘spots’ in a polyacrylamide gel, allowing the quantitation of changes in a proteoform′s abundance to ascertain changes in an organism′s phenotype when conditions change. In pursuit of the comprehensive profiling of the proteome, significant advances in technology have made the identification and quantitation of intact proteoforms from complex mixtures of proteins more routine, allowing analysis of the proteome from the ‘Top-Down’. However, the number of proteoforms detected by Top-Down methodologies such as 2D-PAGE or mass spectrometry has not significantly increased since O’Farrell’s paper when compared to Bottom-Up, peptide-centric techniques. This article explores and explains the numerous methodologies and technologies available to analyse the proteome from the Top-Down with a strong emphasis on the necessity to analyse intact proteoforms as a better indicator of changes in biology and phenotype. We arrive at the conclusion that the complete and comprehensive profiling of an organism′s proteome is still, at present, beyond our reach but the continuing evolution of protein fractionation techniques and mass spectrometry brings comprehensive Top-Down proteome profiling closer. PMID:28387712

  18. Microbial profile of a kefir sample preparations: grains in natura and lyophilized and fermented suspension

    Directory of Open Access Journals (Sweden)

    Rafaela Strada de Oliveira Bergmann

    2010-12-01

    Full Text Available Probiotics are supplementary foods developed by microbial strains that improve animal health beyond basic nutrition. Probiotics are consumed orally, regardless of being considered as normal inhabitants of the intestines, able to survive in enzimatic and biliary secretions. Kefir is a probiotic originated from the old continent, fermented by several bacteria and yeasts, encapsulated in a polyssacharide matrix, and resembles jelly grains. Kefir is also presented as its sourish product both in sugary or milky suspensions containing vitamins, aminoacids, peptides, carbohydrates, ethanol, and volatile compounds. Kefir is known to have a diverse microbial content depending on the country and fermentative substrates, which cause distinct probiotic effects. In this sense, the purpose of this work was to isolate, identify, and quantify the microbial content of a native sugary kefir sample (fermented suspension and lyophilized natural grains. Serial dilutions were plated on Rogosa agar (AR and De Man, Rogosa and Sharpe (MRS, for Lactobacillus; Brain Heart Infusion (BHI, for total bacteria; Sabouraud-Dextrose-Agar (SDA, for yeasts and filamentous fungi; Thioglycolate Agar (TA, for Streptococcus, Acetobacteria and Leuconostoc; and Coconut Water Agar (CWA, and CWA supplemented with yeast extract (CWAY, for various genera. Genera and species for all strains were identified through biochemical reactions and specific API systems. The microbial profile of kefir was different from other sources of grains despite the presence of similar microorganisms and others which have not been reported yet. The data obtained with the CWA and CWAE media suggest that both substrates are alternative and salutary media for culture of kefir strains.

  19. 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.

  20. 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.

  1. 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.

  2. Investigation of the sample preparation and curing treatment effects on mechanical properties and bioactivity of silica rich metakaolin geopolymer.

    Science.gov (United States)

    Catauro, M; Bollino, F; Papale, F; Lamanna, G

    2014-03-01

    In many biomedical applications both the biological and mechanical behaviours of implants are of relevant interest; in the orthopaedic field, for example, favourable bioactivity and biocompatibility capabilities are necessary, but at the same time the mechanical characteristics of the implants must be such as to allow one to support the body weight. In the present work, the authors have examined the application of geopolymers with composition H24AlK7Si31O79 and ratio Si/Al=31 to be used in biomedical field, considering two different preparation methods: one of the activators (KOH) has been added as pellets in the potassium silicate solution, in the other as a water solution with 8M concentration. Moreover, a different water content was used and only some of the synthesized samples were heat treated. The chemical and microstructural characterizations of those materials have been carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Subsequently, the effects of the adopted preparation on the mechanical and biological properties have been studied: compressive strength tests have demonstrated that more fragile specimens were obtained when KOH was added as a solution. The bioactivity was successfully evaluated with the soaking of the samples in a simulated body fluid (SBF) for 3 weeks. The formation of a layer of hydroxyapatite on the surface of the materials has been shown both by SEM micrographs and EDS analyses. Copyright © 2013. Published by Elsevier B.V.

  3. 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.

  4. Sample preparation of biological macromolecular assemblies for the determination of high-resolution structures by cryo-electron microscopy.

    Science.gov (United States)

    Stark, Holger; Chari, Ashwin

    2016-02-01

    Single particle cryo-EM has recently developed into a powerful tool to determine the 3D structure of macromolecular complexes at near-atomic resolution, which allows structural biologists to build atomic models of proteins. All technical aspects of cryo-EM technology have been considerably improved over the last two decades, including electron microscopic hardware, image processing software and the ever growing speed of computers. This leads to a more widespread use of the technique, and it can be anticipated that further automation of electron microscopes and image processing tools will soon fully shift the focus away from the technological aspects, onto biological questions that can be answered. In single particle cryo-EM, no crystals of a macromolecule are required. In contrast to X-ray crystallography, this significantly facilitates structure determination by cryo-EM. Nevertheless, a relatively high level of biochemical control is still essential to obtain high-resolution structures by cryo-EM, and it can be anticipated that the success of the cryo-EM technology goes hand in hand with further developments of sample purification and preparation techniques. This will allow routine high-resolution structure determination of the many macromolecular complexes of the cell that until now represent evasive targets for X-ray crystallographers. Here we discuss the various biochemical tools that are currently available and the existing sample purification and preparation techniques for cryo-EM grid preparation that are needed to obtain high-resolution images for structure determination. © The Author 2015. Published by Oxford University Press on behalf of The Japanese Society of Microscopy. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  5. 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.

  6. 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%.

  7. 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.

  8. A "three-in-one" sample preparation method for simultaneous determination of B-group water-soluble vitamins in infant formula using VitaFast(®) kits.

    Science.gov (United States)

    Zhang, Heng; Lan, Fang; Shi, Yupeng; Wan, Zhi-Gang; Yue, Zhen-Feng; Fan, Fang; Lin, Yan-Kui; Tang, Mu-Jin; Lv, Jing-Zhang; Xiao, Tan; Yi, Changqing

    2014-06-15

    VitaFast(®) test kits designed for the microbiological assay in microtiter plate format can be applied to quantitative determination of B-group water-soluble vitamins such as vitamin B12, folic acid and biotin, et al. Compared to traditional microbiological methods, VitaFast(®) kits significantly reduce sample processing time and provide greater reliability, higher productivity and better accuracy. Recently, simultaneous determination of vitamin B12, folic acid and biotin in one sample is urgently required when evaluating the quality of infant formulae in our practical work. However, the present sample preparation protocols which are developed for individual test systems, are incompatible with simultaneous determination of several analytes. To solve this problem, a novel "three-in-one" sample preparation method is herein developed for simultaneous determination of B-group water-soluble vitamins using VitaFast(®) kits. The performance of this novel "three-in-one" sample preparation method was systematically evaluated through comparing with individual sample preparation protocols. The experimental results of the assays which employed "three-in-one" sample preparation method were in good agreement with those obtained from conventional VitaFast(®) extraction methods, indicating that the proposed "three-in-one" sample preparation method is applicable to the present three VitaFast(®) vitamin test systems, thus offering a promising alternative for the three independent sample preparation methods. The proposed new sample preparation method will significantly improve the efficiency of infant formulae inspection. Copyright © 2013 Elsevier Ltd. All rights reserved.

  9. Efficacy of screens in removing long fibers from an aerosol stream – sample preparation technique for toxicology studies

    Science.gov (United States)

    Ku, Bon Ki; Deye, Gregory J.; Turkevich, Leonid A.

    2015-01-01

    Fiber dimension (especially length) and biopersistence are thought to be important variables in determining the pathogenicity of asbestos and other elongate mineral particles. In order to prepare samples of fibers for toxicology studies, it is necessary to develop and evaluate methods for separating fibers by length in the micrometer size range. In this study, we have filtered an aerosol of fibers through nylon screens to investigate whether such screens can efficiently remove the long fibers (L >20 μm, a typical macrophage size) from the aerosol stream. Such a sample, deficient in long fibers, could then be used as the control in a toxicology study to investigate the role of length. A well-dispersed aerosol of glass fibers (a surrogate for asbestos) was generated by vortex shaking a Japan Fibrous Material Research Association (JFMRA) glass fiber powder. Fibers were collected on a mixed cellulose ester (MCE) filter, imaged with phase contrast microscopy (PCM) and lengths were measured. Length distributions of the fibers that penetrated through various screens (10, 20 and 60 μm mesh sizes) were analyzed; additional study was made of fibers that penetrated through double screen and centrally blocked screen configurations. Single screens were not particularly efficient in removing the long fibers; however, the alternative configurations, especially the centrally blocked screen configuration, yielded samples substantially free of the long fibers. PMID:24417374

  10. Efficacy of screens in removing long fibers from an aerosol stream--sample preparation technique for toxicology studies.

    Science.gov (United States)

    Ku, Bon Ki; Deye, Gregory J; Turkevich, Leonid A

    2014-02-01

    Fiber dimension (especially length) and biopersistence are thought to be important variables in determining the pathogenicity of asbestos and other elongate mineral particles. In order to prepare samples of fibers for toxicology studies, it is necessary to develop and evaluate methods for separating fibers by length in the micrometer size range. In this study, we have filtered an aerosol of fibers through nylon screens to investigate whether such screens can efficiently remove the long fibers (L >20 µm, a typical macrophage size) from the aerosol stream. Such a sample, deficient in long fibers, could then be used as the control in a toxicology study to investigate the role of length. A well-dispersed aerosol of glass fibers (a surrogate for asbestos) was generated by vortex shaking a Japan Fibrous Material Research Association (JFMRA) glass fiber powder. Fibers were collected on a mixed cellulose ester (MCE) filter, imaged with phase contrast microscopy (PCM) and lengths were measured. Length distributions of the fibers that penetrated through various screens (10, 20 and 60 µm mesh sizes) were analyzed; additional study was made of fibers that penetrated through double screen and centrally blocked screen configurations. Single screens were not particularly efficient in removing the long fibers; however, the alternative configurations, especially the centrally blocked screen configuration, yielded samples substantially free of the long fibers.

  11. 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.

  12. Desorption electrospray ionisation mass spectrometry: A rapid screening tool for veterinary drug preparations and forensic samples from hormone crime investigations

    Energy Technology Data Exchange (ETDEWEB)

    Nielen, M.W.F. [RIKILT Institute of Food Safety, P.O. Box 230, 6700 AE Wageningen (Netherlands); Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen (Netherlands)], E-mail: michel.nielen@wur.nl; Hooijerink, H. [RIKILT Institute of Food Safety, P.O. Box 230, 6700 AE Wageningen (Netherlands); Claassen, F.C. [Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen (Netherlands); Engelen, M.C. van [RIKILT Institute of Food Safety, P.O. Box 230, 6700 AE Wageningen (Netherlands); Beek, T.A. van [Wageningen University, Laboratory of Organic Chemistry, Dreijenplein 8, 6703 HB Wageningen (Netherlands)

    2009-04-01

    Hormone and veterinary drug screening and forensics can benefit from the recent developments in desorption electrospray ionisation (DESI) mass spectrometry (MS). In this work the feasibility of DESI application has been studied. Using a linear ion trap or quadrupole time-of-flight (TOF) MS instrument both full-scan and data-dependent collision-induced dissociation MS{sup n} spectra were acquired in seconds without sample preparation. Preliminary data are presented for the rapid screening of (pro)hormone supplement samples, an illegal steroid cocktail and forensic samples from veterinary drug investigations. The potential of this DESI approach is clearly demonstrated since compounds observed could be independently confirmed by liquid chromatography/TOFMS with accurate mass measurement, and/or proton nuclear magnetic resonance spectroscopy. Specific concerns related to false-positive and false-negative findings due to limitations in quantification and memory-effects are briefly discussed. It is envisaged that DESI will achieve a prominent role in hormone and veterinary drug analysis in the near future.

  13. 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.

  14. Preparation of Magnetic Sorbent with Surface Modified by C18for Removal of Selected Organic Pollutants from Aqueous Samples

    Science.gov (United States)

    Kuráň, Pavel; Pilnaj, Dominik; Ciencialová, Lucie; Pšenička, Martin

    2017-12-01

    Magnetic sorbents have great potential in environmental applications due to their simple synthesis and separation in magnetic field, usability in heterogeneous systems and low toxicity. Possible syntheses, surface modifications and characteristics were described by Li et al 2013. This type of solid-phase extraction is being successfully used in various fields as health care, microbiology, biotechnologies or sample preconcentration in analytical chemistry. In this preliminary study we report on the preparation and application of magnetically separable sorbent with surface modified by C18 alkyl chain for purification of water contaminated by environmentally hazardous organic compounds. Magnetic cores were co-precipitated from Fe2+ and Fe3+ chlorides in alkalic aqueous solution. Surface of synthetized Fe3O4 was modified with SiO2 by tetraethylorthosilicate to assure physico-chemical stability. Furthermore, Fe3O4/SiO2 complex has been treated by C18 functional group, which provides good affinity towards hydrophobic substances in water. Efficiency of sorption under various conditions has been examined on benzene, toluene, ethylbenzene and xylenes (BTEX), compounds found in petroleum products which contaminate air, soil and groundwater near of store tanks. Sorption kinetics was followed by gas chromatography with mass spectrometry. The preliminary sorption kinetics data and efficiency of BTEX removal point at the possible application of prepared magnetic sorbent for BTEX removal, especially for ethylbenzene and xylenes.

  15. 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.

  16. Graphene-Based Materials as Solid Phase Extraction Sorbent for Trace Metal Ions, Organic Compounds, and Biological Sample Preparation.

    Science.gov (United States)

    Ibrahim, Wan Aini Wan; Nodeh, Hamid Rashidi; Sanagi, Mohd Marsin

    2016-07-03

    Graphene is a new carbon-based material that is of interest in separation science. Graphene has extraordinary properties including nano size, high surface area, thermal and chemical stability, and excellent adsorption affinity to pollutants. Its adsorption mechanisms are through non-covalent interactions (π-π stacking, electrostatic interactions, and H-bonding) for organic compounds and covalent interactions for metal ions. These properties have led to graphene-based material becoming a desirable adsorbent in a popular sample preparation technique known as solid phase extraction (SPE). Numerous studies have been published on graphene applications in recent years, but few review papers have focused on its applications in analytical chemistry. This article focuses on recent preconcentration of trace elements, organic compounds, and biological species using SPE-based graphene, graphene oxide, and their modified forms. Solid phase microextraction and micro SPE (µSPE) methods based on graphene are discussed.

  17. Reduction of the nitro group during sample preparation may cause underestimation of the nitration level in 3-nitrotyrosine immunoblotting

    DEFF Research Database (Denmark)

    Söderling, Ann-Sofi; Hultman, Lena; Delbro, Dick

    2007-01-01

    We noted differences in the antibody response to 3-nitrotyrosine (NO(2)Tyr) in fixed and non-fixed tissues, and studied therefore potential problems associated with non-fixed tissues in Western blot analyses. Three different monoclonal anti-nitrotyrosine antibodies in Western blot analysis...... of inflammatory stimulated rat abdominal, liver and lung tissue homogenates caused no immunoreactivity, in contrast to a polyclonal nitrotyrosine antibody applied in fixed and non-fixed tissues. Western blot studies using both mono- and polyclonal antibodies showed a temperature- and heme group...... is not detected by anti-NO(2)Tyr antibodies. Western blot analysis may therefore underestimate the level of tissue nitration, and factors causing a reduction of NO(2)Tyr during sample preparation might conceal the actual nitration of proteins....

  18. MRT letter: localization of endogenous hydrogen peroxide by modified processes of sample preparation for transmission electron microscope in Escherichia coli.

    Science.gov (United States)

    Li, Xin; Hu, Rongliu; Zhu, Wenxue; Fan, Jinling; Pang, Xinyue; Wang, Na; Wang, Liping; Yang, Lipeng; Zhao, Chunyan; He, Chenyang

    2013-02-01

    The bacterial endogenous hydrogen peroxide (H(2)O(2)) was detected cytochemically by its reaction with cerium chloride (CeCl(3)) to produce electron-dense deposits of cerium perhydroxides. The sequence of fixation and CeCl(3) staining of H(2)O(2) in the processing of transmission electron microscope (TEM) sample preparation is crucial to the localization of endogenous H(2)O(2) in Escherichia coli. In this study, results confirmed that the process that fixation simultaneously with CeCl(3) staining provided optimum effects for H(2)O(2) localization in E. coli. The modified process of TEM provides very efficient protection for H(2)O(2) localization and more accurate quantization for the H(2)O(2) accumulation in bacterial cells. Copyright © 2012 Wiley Periodicals, Inc.

  19. Investigation of the sample preparation and curing treatment effects on mechanical properties and bioactivity of silica rich metakaolin geopolymer

    Energy Technology Data Exchange (ETDEWEB)

    Catauro, M., E-mail: michelina.catauro@unina2.it; Bollino, F.; Papale, F.; Lamanna, G.

    2014-03-01

    In many biomedical applications both the biological and mechanical behaviours of implants are of relevant interest; in the orthopaedic field, for example, favourable bioactivity and biocompatibility capabilities are necessary, but at the same time the mechanical characteristics of the implants must be such as to allow one to support the body weight. In the present work, the authors have examined the application of geopolymers with composition H{sub 24}AlK{sub 7}Si{sub 31}O{sub 79} and ratio Si/Al = 31 to be used in biomedical field, considering two different preparation methods: one of the activators (KOH) has been added as pellets in the potassium silicate solution, in the other as a water solution with 8 M concentration. Moreover, a different water content was used and only some of the synthesized samples were heat treated. The chemical and microstructural characterizations of those materials have been carried out by Fourier transform infrared spectroscopy (FT-IR) and scanning electron microscopy (SEM). Subsequently, the effects of the adopted preparation on the mechanical and biological properties have been studied: compressive strength tests have demonstrated that more fragile specimens were obtained when KOH was added as a solution. The bioactivity was successfully evaluated with the soaking of the samples in a simulated body fluid (SBF) for 3 weeks. The formation of a layer of hydroxyapatite on the surface of the materials has been shown both by SEM micrographs and EDS analyses. - Highlights: • Rich metakaolin geopolymer activated with KOH/K{sub 2}SiO{sub 3} and thermal treatment • Mechanical and bioactivity test to evaluate consolidation and bone bonding ability • Order of addition of reactants and thermal treatment influence mechanical properties.

  20. Investigation of CPD and HMDS Sample Preparation Techniques for Cervical Cells in Developing Computer-Aided Screening System Based on FE-SEM/EDX

    OpenAIRE

    Yessi Jusman; Siew Cheok Ng; Noor Azuan Abu Osman

    2014-01-01

    This paper investigated the effects of critical-point drying (CPD) and hexamethyldisilazane (HMDS) sample preparation techniques for cervical cells on field emission scanning electron microscopy and energy dispersive X-ray (FE-SEM/EDX). We investigated the visualization of cervical cell image and elemental distribution on the cervical cell for two techniques of sample preparation. Using FE-SEM/EDX, the cervical cell images are captured and the cell element compositions are extracted for both ...

  1. 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.

  2. Preparation of C₁₈-functionalized magnetic polydopamine microspheres for the enrichment and analysis of alkylphenols in water samples.

    Science.gov (United States)

    Wang, Xianying; Deng, Chunhui

    2016-02-01

    In this work, C18-functionalized magnetic polydopamine microspheres (Fe3O4@PDA@C18) were successfully synthesized and applied to the analysis of alkylphenols in water samples. The magnetic Fe3O4 particles coated with hydrophilic surface were synthesized via a solvothermal reaction and the self-polymerization of dopamine. And then the C18 groups were fabricated by a silylanization method. Benefit from the merits of Fe3O4 particles, polydopamine coating and C18 groups, the Fe3O4@PDA@C18 material possessed several properties of super magnetic responsiviness, good water dispersibility, π-electron system and hydrophobic C18 groups. Thus, the materials had great potential to be developed as the adsorbent for the magnetic solid-phase extraction (MSPE) technique. Here, we selected three kinds of alkylphenols (4-tert-octylphenol, 4-n-nonylphenol, 4-n-octylphenol) to be the target analyst for evaluating the performance of the prepared material. In this study, various extraction parameters were investigated and optimized, such as pH values of water sample solution, amount of adsorbents, adsorption and desorption time, the species of desorption solution. Meanwhile, the method validations were studied, including linearity, limit of detection and method precision. From the results, Fe3O4@PDA@C18 composites were successfully applied as the adsorbents for the extraction of alkylphenols in water samples. The proposed material provided an approach for a simple, rapid magnetic solid-phase extraction for hydrophobic compounds in environmental samples. Copyright © 2015 Elsevier B.V. All rights reserved.

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

    Science.gov (United States)

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

    2013-11-15

    A simple and automated HPLC column-switching method with rapid sample pretreatment has been developed for quantitative determination of β-carotene in food supplements. Commercially samples of food supplements were dissolved in chloroform with help of saponification with 1M solution of sodium hydroxide in ultrasound bath. A 20-min sample dissolution/extraction step was necessary before chromatography analysis to transfer β-carotene from solid state of food supplements preparations (capsules,tablets) to chloroform solution. Sample volume - 3μL of chloroform phase was directly injected into the HPLC system. Next on-line sample clean-up was achieved on the pretreatment precolumn Chromolith Guard Cartridge RP-18e (Merck), 10×4.6mm, with a washing mobile phase (methanol:water, 92:8, (v/v)) at a flow rate of 1.5mL/min. Valve switch to analytical column was set at 2.5min in a back-flush mode. After column switching to the analytical column Ascentis Express C-18, 30×4.6mm, particle size 2.7μm (Sigma Aldrich), the separation and determination of β-carotene in food supplements was performed using a mobile phase consisting of 100% methanol, column temperature at 60°C and flow rate 1.5mL/min. The detector was set at 450nm. Under the optimum chromatographic conditions standard calibration curve was measured with good linearity - correlation coefficient for β-carotene (r(2)=0.999014; n=6) between the peak areas and concentration of β-carotene 20-200μg/mL. Accuracy of the method defined as a mean recovery was in the range 96.66-102.40%. The intraday method precision was satisfactory at three concentration levels 20, 125 and 200μg/mL and relative standard deviations were in the range 0.90-1.02%. The chromatography method has shown high sample throughput during column-switching pretreatment process and analysis in one step in short time (6min) of the whole chromatographic analysis. Copyright © 2013 Elsevier Ltd. All rights reserved.

  4. A method for sampling and tissue preparation of the parathyroid glands in miniature pigs for toxicity studies.

    Science.gov (United States)

    Soshin, Tomomi; Takai, Hirotake; Kato, Chie; Fujii, Etsuko; Matsuo, Saori; Ito, Tsuneo; Suzuki, Masami

    2010-04-01

    Miniature swine (minipigs) are often used in non-rodent toxicity studies. However, unlike other animal species, the parathyroid glands of minipigs are often covered with thymic tissue and are similar in color, making macroscopical identification difficult. We investigated a method for sampling and tissue preparation of the parathyroid glands using 5- to 7-month-old minipigs. The glands were identified by finding the insertion site of a branch from the carotid artery into the cervical part of the thymus. Then the glands were marked and sampled. In a preliminary study, the glands were macroscopically and microscopically detected in 3/8 animals. The glands were not identified macroscopically in 5/8 animals but were detected in 3 of these animals. In total, we succeeded in detection of the glands in 6/8 animals (75%). The method was applied in the main toxicity study, and we succeeded in 100% detection through technical advancement. The method described herein enables high rate of detection and is useful in the pathological evaluation of the parathyroid glands of minipigs.

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

    Directory of Open Access Journals (Sweden)

    Anne J. Kleinnijenhuis

    2015-01-01

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

  6. Preparation of viral samples within biocontainment for ultrastructural analysis: Utilization of an innovative processing capsule for negative staining.

    Science.gov (United States)

    Monninger, Mitchell K; Nguessan, Chrystal A; Blancett, Candace D; Kuehl, Kathleen A; Rossi, Cynthia A; Olschner, Scott P; Williams, Priscilla L; Goodman, Steven L; Sun, Mei G

    2016-12-01

    Transmission electron microscopy can be used to observe the ultrastructure of viruses and other microbial pathogens with nanometer resolution. In a transmission electron microscope (TEM), the image is created by passing an electron beam through a specimen with contrast generated by electron scattering from dense elements in the specimen. Viruses do not normally contain dense elements, so a negative stain that places dense heavy metal salts around the sample is added to create a dark border. To prepare a virus sample for a negative stain transmission electron microscopy, a virus suspension is applied to a TEM grid specimen support, which is a 3mm diameter fragile specimen screen coated with a few nanometers of plastic film. Then, deionized (dI) water rinses and a negative stain solution are applied to the grid. All infectious viruses must be handled in a biosafety cabinet (BSC) and many require a biocontainment laboratory environment. Staining viruses in biosafety levels (BSL) 3 and 4 is especially challenging because the support grids are small, fragile, and easily moved by air currents. In this study we evaluated a new device for negative staining viruses called mPrep/g capsule. It is a capsule that holds up to two TEM grids during all processing steps and for storage after staining is complete. This study reports that the mPrep/g capsule method is valid and effective to negative stain virus specimens, especially in high containment laboratory environments. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

  7. Direct sample preparation methods for the detection of Plum pox virus by real-time RT-PCR.

    Science.gov (United States)

    Capote, Nieves; Bertolini, Edson; Olmos, Antonio; Vidal, Eduardo; Martínez, Maria Carmen; Cambra, Mariano

    2009-03-01

    Direct systems to process plant materials allowed high-throughput testing of Plum pox virus (PPV) by real-time reverse transcription (RT)-PCR without nucleic acids purification. Crude plant extracts were diluted in buffer or spotted on membranes to be used as templates. Alternatively, immobilized PPV targets were amplified from fresh sections of plant tissues printed or squashed onto the same supports, without extract preparation. Spot real-time RT-PCR was validated as a PPV diagnostic method in samples collected during the dormancy period and showed high sensitivity (93.6%), specificity (98.0%), and post-test probability (97.9%) towards sharka disease. In an analysis of 2919 Prunus samples by spot real-time RT-PCR and DASI-ELISA 90.8% of the results coincided, demonstrating high agreement (k = 0.77 +/- 0.01) between the two techniques. These results validate the use of immobilized PPV targets and spot real-time RT-PCR as screening method for largescale analyses.

  8. Determination of Mycotoxins in Brown Rice Using QuEChERS Sample Preparation and UHPLC–MS-MS

    Science.gov (United States)

    Jettanajit, Adisorn; Nhujak, Thumnoon

    2016-01-01

    QuEChERS sample preparation was optimized and validated using solvent extraction with 10% (v/v) acetic acid-containing acetonitrile in the presence of four salts (anh. MgSO4, NaCl, sodium citrate tribasic dihydrate and sodium citrate dibasic sesquihydrate) and dispersive solid-phase extraction with mixed sorbents (octadecylsilane, primary and secondary amine and silica sorbents) for an ultra high performance liquid chromatography–tandem mass spectrometric determination of nine mycotoxins in brown rice: aflatoxins (AFB1, AFB2, AFG1 and AFG2), fumonisins (FB1 and FB2), deoxynivalenol, ochratoxin A and zearalenone (ZON). Our developed method allows for the determination of trace levels of mycotoxins with method detection limits in the range of 1.4–25 µg/kg, below the maximum limits of EU regulations, and with an acceptable accuracy and precision, and recoveries in the range of 81–101% with relative standard deviations of 5–19% over a mycotoxin concentration range of 5.0–1,000 µg/kg. Six out of fourteen real samples of brown rice were found to be contaminated with at least one of these mycotoxins, ranging from 2.49–5.41 µg/kg of FB1, 4.33 ± 0.04 µg/kg of FB2 and 6.10–14.88 µg/kg of ZON. PMID:26796964

  9. [Ultra-Fine Pressed Powder Pellet Sample Preparation XRF Determination of Multi-Elements and Carbon Dioxide in Carbonate].

    Science.gov (United States)

    Li, Xiao-li; An, Shu-qing; Xu, Tie-min; Liu, Yi-bo; Zhang, Li-juan; Zeng, Jiang-ping; Wang, Na

    2015-06-01

    The main analysis error of pressed powder pellet of carbonate comes from particle-size effect and mineral effect. So in the article in order to eliminate the particle-size effect, the ultrafine pressed powder pellet sample preparation is used to the determination of multi-elements and carbon-dioxide in carbonate. To prepare the ultrafine powder the FRITSCH planetary Micro Mill machine and tungsten carbide media is utilized. To conquer the conglomeration during the process of grinding, the wet grinding is preferred. The surface morphology of the pellet is more smooth and neat, the Compton scatter effect is reduced with the decrease in particle size. The intensity of the spectral line is varied with the change of the particle size, generally the intensity of the spectral line is increased with the decrease in the particle size. But when the particle size of more than one component of the material is decreased, the intensity of the spectral line may increase for S, Si, Mg, or decrease for Ca, Al, Ti, K, which depend on the respective mass absorption coefficient . The change of the composition of the phase with milling is also researched. The incident depth of respective element is given from theoretical calculation. When the sample is grounded to the particle size of less than the penetration depth of all the analyte, the effect of the particle size on the intensity of the spectral line is much reduced. In the experiment, when grounded the sample to less than 8 μm(d95), the particle-size effect is much eliminated, with the correction method of theoretical α coefficient and the empirical coefficient, 14 major, minor and trace element in the carbonate can be determined accurately. And the precision of the method is much improved with RSD < 2%, except Na2O. Carbon is ultra-light element, the fluorescence yield is low and the interference is serious. With the manual multi-layer crystal PX4, coarse collimator, empirical correction, X-ray spectrometer can be used to

  10. Urine sample preparation in 96-well filter plates to characterize inflammatory and infectious diseases of the urinary tract.

    Science.gov (United States)

    Yu, Yanbao; Pieper, Rembert

    2015-01-01

    Urine has been an important body fluid source for diagnostic and prognostic biomarkers of diseases for a long time. Technological advances during the last two decades have enabled a fundamental shift from the discovery of candidate protein biomarkers using single-assay platforms to highly parallel liquid chromatography tandem mass spectrometry (LC-MS/MS)-based proteomic analysis platforms. MS/MS-based approaches such as multiple reaction monitoring (MRM) are also being used increasingly for targeted protein biomarker validation. In large part due to the fact that the majority of protein in voided urine is soluble, such studies have focused on the analysis of urine supernatants, whereas the pellets were discarded after centrifugal sedimentation. Urine sediments are of particular value in the analysis of urinary tract infections (UTI). The LC-MS/MS methods now have sufficient resolving power and sensitivity to survey metaproteomes--the entirety of proteins derived from multiple organisms that interact with each other in mutualistic or antagonistic fashion. Challenges of proteomic analysis of urine include the high dynamic range of protein abundance, high levels of protein post-translational modifications, and high quantities of natural protease inhibitors. Recently, a robust and scalable workflow that can parallelize the processing of multiple urinary supernatant and sediment samples was developed and validated in our lab. This method utilizes 96-well format filter-aided sample preparation (96FASP) strategy and was shown to successfully identify large numbers of proteins from urine samples. Processing 10-50 µg total protein in single experiment, LC-MS/MS with a Q-Exactive mass spectrometer resulted in more than 1,100 distinct human protein identifications from urine supernatants, and around 400 microbial and 1,400 human protein identifications from urine sediments. The surveys are a rich data resource not only for biomarker discovery but also to interrogate

  11. 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

  12. Complementary Sample Preparation Strategies for Analysis of Cereal β-Glucan Oxidation Products by UPLC-MS/MS

    Directory of Open Access Journals (Sweden)

    Samy Boulos

    2017-11-01

    Full Text Available The oxidation of cereal (1→3,1→4-β-D-glucan can influence the health promoting and technological properties of this linear, soluble homopolysaccharide by introduction of new functional groups or chain scission. Apart from deliberate oxidative modifications, oxidation of β-glucan can already occur during processing and storage, which is mediated by hydroxyl radicals (HO• formed by the Fenton reaction. We present four complementary sample preparation strategies to investigate oat and barley β-glucan oxidation products by hydrophilic interaction ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS, employing selective enzymatic digestion, graphitized carbon solid phase extraction (SPE, and functional group labeling techniques. The combination of these methods allows for detection of both lytic (C1, C3/4, C5 and non-lytic (C2, C4/3, C6 oxidation products resulting from HO•-attack at different glucose-carbons. By treating oxidized β-glucan with lichenase and β-glucosidase, only oxidized parts of the polymer remained in oligomeric form, which could be separated by SPE from the vast majority of non-oxidized glucose units. This allowed for the detection of oligomers with mid-chain glucuronic acids (C6 and carbonyls, as well as carbonyls at the non-reducing end from lytic C3/C4 oxidation. Neutral reducing ends were detected by reductive amination with anthranilic acid/amide as labeled glucose and cross-ring cleaved units (arabinose, erythrose after enzyme treatment and SPE. New acidic chain termini were observed by carbodiimide-mediated amidation of carboxylic acids as anilides of gluconic, arabinonic, and erythronic acids. Hence, a full characterization of all types of oxidation products was possible by combining complementary sample preparation strategies. Differences in fine structure depending on source (oat vs. barley translates to the ratio of observed oxidized oligomers, with in-depth analysis corroborating a

  13. Preparation and Characterization of Mg1-xB2 Bulk Samples and Cu/Nb Sheathed Wires with Low Grade Amorphous Boron Powder

    DEFF Research Database (Denmark)

    Grivel, Jean-Claude; Alexiou, Aikaterini; Rubesova, Katerina

    2014-01-01

    MgB2 bulk and wire samples were prepared using cheap, low grade amorphous boron powders. Based on chemical analysis performed on the starting reagents, three nominal stoichiometries were studied. It was found that the structural and superconducting properties of the bulk samples were not affected...

  14. Fluoride and chloride determination in fossil fuels after sample preparation by pyrohydrolysis; Preparo de amostras de combustiveis fosseis por piroidrolise para a determinacao de fluor e cloro

    Energy Technology Data Exchange (ETDEWEB)

    Antes, Fabiane G.; Duarte, Fabio A.; Flores, Eder L. M.; Paniz, Jose Neri G.; Flores, Erico M. M.; Dressler, Valderi L., E-mail: valdres@quimica.ufsm.b [Universidade Federal de Santa Maria (DQ/UFSM), RS (Brazil). Dept. de Quimica

    2010-07-01

    Pyrohydrolysis is proposed for fossil fuels sample preparation for further fluorine and chlorine determination. Samples were heated during 10 min at temperatures up to 1000 deg C. Water vapor was passed through the reactor and the volatile products were condensed and collected in NH{sub 4}OH solution. Fluoride was determined by potentiometry using an ion selective electrode (ISE) and Cl by ICP OES and DRC-ICP-MS. The results are in good agreement with certified values and the precision is better than 10% (n = 4). Sample preparation by means of pyrohydrolysis is relatively simple, whereas chlorine and fluorine can be determined at low concentrations (author)

  15. 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

  16. Investigation of CPD and HMDS sample preparation techniques for cervical cells in developing computer-aided screening system based on FE-SEM/EDX.

    Science.gov (United States)

    Jusman, Yessi; Ng, Siew Cheok; Abu Osman, Noor Azuan

    2014-01-01

    This paper investigated the effects of critical-point drying (CPD) and hexamethyldisilazane (HMDS) sample preparation techniques for cervical cells on field emission scanning electron microscopy and energy dispersive X-ray (FE-SEM/EDX). We investigated the visualization of cervical cell image and elemental distribution on the cervical cell for two techniques of sample preparation. Using FE-SEM/EDX, the cervical cell images are captured and the cell element compositions are extracted for both sample preparation techniques. Cervical cell image quality, elemental composition, and processing time are considered for comparison of performances. Qualitatively, FE-SEM image based on HMDS preparation technique has better image quality than CPD technique in terms of degree of spread cell on the specimen and morphologic signs of cell deteriorations (i.e., existence of plate and pellet drying artifacts and membrane blebs). Quantitatively, with mapping and line scanning EDX analysis, carbon and oxygen element compositions in HMDS technique were higher than the CPD technique in terms of weight percentages. The HMDS technique has shorter processing time than the CPD technique. The results indicate that FE-SEM imaging, elemental composition, and processing time for sample preparation with the HMDS technique were better than CPD technique for cervical cell preparation technique for developing computer-aided screening system.

  17. Development of an improved sample preparation platform for acidic endogenous hormones in plant tissues using electromembrane extraction.

    Science.gov (United States)

    Suh, Joon Hyuk; Han, Sang Beom; Wang, Yu

    2017-12-30

    Despite their importance in pivotal signaling pathways due to trace quantities and complex matrices, the analysis of plant hormones is a challenge. Here, to improve this issue, we present an electromembrane extraction technology combined with liquid chromatography-tandem mass spectrometry for determination of acidic plant hormones including jasmonic acid, abscisic acid, salicylic acid, benzoic acid, gibberellic acid and gibberellin A4 in plant tissues. Factors influencing extraction efficiency, such as voltage, extraction time and stirring rate were optimized using a design of experiments. Analytical performance was evaluated in terms of specificity, linearity, limit of quantification, precision, accuracy, recovery and repeatability. The results showed good linearity (r2 > 0.995), precision and acceptable accuracy. The limit of quantification ranged from 0.1 to 10 ng mL-1, and the recoveries were 34.6-50.3%. The developed method was applied in citrus leaf samples, showing better clean-up efficiency, as well as higher sensitivity compared to a previous method using liquid-liquid extraction. Organic solvent consumption was minimized during the process, making it an appealing method. More noteworthy, electromembrane extraction has been scarcely applied to plant tissues, and this is the first time that major plant hormones were extracted using this technology, with high sensitivity and selectivity. Taken together, this work gives not only a novel sample preparation platform using an electric field for plant hormones, but also a good example of extracting complex plant tissues in a simple and effective way. Copyright © 2017 Elsevier B.V. All rights reserved.

  18. Subgrain boundary analyses in deformed orthopyroxene by TEM/STEM with EBSD-FIB sample preparation technique

    Science.gov (United States)

    Kogure, Toshihiro; Raimbourg, Hugues; Kumamoto, Akihito; Fujii, Eiko; Ikuhara, Yuichi

    2014-12-01

    High-resolution structure analyses using electron beam techniques have been performed for the investigation of subgrain boundaries (SGBs) in deformed orthopyroxene (Opx) in mylonite from Hidaka Metamorphic Belt, Hokkaido, Japan, to understand ductile deformation mechanism of silicate minerals in shear zones. Scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD) analysis of Opx porphyroclasts in the mylonitic rock indicated that the crystal orientation inside the Opx crystals gradually changes by rotation about the b-axis by SGBs and crystal folding. In order to observe the SGBs along the b-axis by transmission electron microscopy (TEM) or scanning TEM (STEM), the following sample preparation protocol was adopted. First, petrographic thin sections were slightly etched with hydrofluoric acid to identify SGBs in SEM. The Opx crystals whose b-axes were oriented close to the normal of the surface were identified by EBSD, and the areas containing SGBs were picked and thinned for (S) TEM analysis with a focused ion beam instrument with micro-sampling system. High-resolution TEM imaging of the SGBs in Opx revealed various boundary structures from a periodic array of dissociated (100) [001] edge dislocations to partially or completely incoherent crystals, depending on the misorientation angle. Atomic-resolution STEM imaging clearly confirmed the formation of clinopyroxene (Cpx) structure between the dissociated partial dislocations. Moreover, X-ray microanalysis in STEM revealed that the Cpx contains a considerable amount of calcium replacing iron. Such chemical inhomogeneity may limit glide motion of the dislocation and eventually the plastic deformation of the Opx porphyroclasts at a low temperature. Chemical profiles across the high-angle incoherent SGB also showed an enrichment of the latter in calcium at the boundary, suggesting that SGBs are an efficient diffusion pathway of calcium out of host Opx grain during cooling.

  19. Low-Cost 3D Printers Enable High-Quality and Automated Sample Preparation and Molecular Detection.

    Directory of Open Access Journals (Sweden)

    Kamfai Chan

    Full Text Available Most molecular diagnostic assays require upfront sample preparation steps to isolate the target's nucleic acids, followed by its amplification and detection using various nucleic acid amplification techniques. Because molecular diagnostic methods are generally rather difficult to perform manually without highly trained users, automated and integrated systems are highly desirable but too costly for use at point-of-care or low-resource settings. Here, we showcase the development of a low-cost and rapid nucleic acid isolation and amplification platform by modifying entry-level 3D printers that cost between $400 and $750. Our modifications consisted of replacing the extruder with a tip-comb attachment that houses magnets to conduct magnetic particle-based nucleic acid extraction. We then programmed the 3D printer to conduct motions that can perform high-quality extraction protocols. Up to 12 samples can be processed simultaneously in under 13 minutes and the efficiency of nucleic acid isolation matches well against gold-standard spin-column-based extraction technology. Additionally, we used the 3D printer's heated bed to supply heat to perform water bath-based polymerase chain reactions (PCRs. Using another attachment to hold PCR tubes, the 3D printer was programmed to automate the process of shuttling PCR tubes between water baths. By eliminating the temperature ramping needed in most commercial thermal cyclers, the run time of a 35-cycle PCR protocol was shortened by 33%. This article demonstrates that for applications in resource-limited settings, expensive nucleic acid extraction devices and thermal cyclers that are used in many central laboratories can be potentially replaced by a device modified from inexpensive entry-level 3D printers.

  20. Low-Cost 3D Printers Enable High-Quality and Automated Sample Preparation and Molecular Detection

    Science.gov (United States)

    Chan, Kamfai; Coen, Mauricio; Hardick, Justin; Gaydos, Charlotte A.; Wong, Kah-Yat; Smith, Clayton; Wilson, Scott A.; Vayugundla, Siva Praneeth; Wong, Season

    2016-01-01

    Most molecular diagnostic assays require upfront sample preparation steps to isolate the target’s nucleic acids, followed by its amplification and detection using various nucleic acid amplification techniques. Because molecular diagnostic methods are generally rather difficult to perform manually without highly trained users, automated and integrated systems are highly desirable but too costly for use at point-of-care or low-resource settings. Here, we showcase the development of a low-cost and rapid nucleic acid isolation and amplification platform by modifying entry-level 3D printers that cost between $400 and $750. Our modifications consisted of replacing the extruder with a tip-comb attachment that houses magnets to conduct magnetic particle-based nucleic acid extraction. We then programmed the 3D printer to conduct motions that can perform high-quality extraction protocols. Up to 12 samples can be processed simultaneously in under 13 minutes and the efficiency of nucleic acid isolation matches well against gold-standard spin-column-based extraction technology. Additionally, we used the 3D printer’s heated bed to supply heat to perform water bath-based polymerase chain reactions (PCRs). Using another attachment to hold PCR tubes, the 3D printer was programmed to automate the process of shuttling PCR tubes between water baths. By eliminating the temperature ramping needed in most commercial thermal cyclers, the run time of a 35-cycle PCR protocol was shortened by 33%. This article demonstrates that for applications in resource-limited settings, expensive nucleic acid extraction devices and thermal cyclers that are used in many central laboratories can be potentially replaced by a device modified from inexpensive entry-level 3D printers. PMID:27362424

  1. Low-Cost 3D Printers Enable High-Quality and Automated Sample Preparation and Molecular Detection.

    Science.gov (United States)

    Chan, Kamfai; Coen, Mauricio; Hardick, Justin; Gaydos, Charlotte A; Wong, Kah-Yat; Smith, Clayton; Wilson, Scott A; Vayugundla, Siva Praneeth; Wong, Season

    2016-01-01

    Most molecular diagnostic assays require upfront sample preparation steps to isolate the target's nucleic acids, followed by its amplification and detection using various nucleic acid amplification techniques. Because molecular diagnostic methods are generally rather difficult to perform manually without highly trained users, automated and integrated systems are highly desirable but too costly for use at point-of-care or low-resource settings. Here, we showcase the development of a low-cost and rapid nucleic acid isolation and amplification platform by modifying entry-level 3D printers that cost between $400 and $750. Our modifications consisted of replacing the extruder with a tip-comb attachment that houses magnets to conduct magnetic particle-based nucleic acid extraction. We then programmed the 3D printer to conduct motions that can perform high-quality extraction protocols. Up to 12 samples can be processed simultaneously in under 13 minutes and the efficiency of nucleic acid isolation matches well against gold-standard spin-column-based extraction technology. Additionally, we used the 3D printer's heated bed to supply heat to perform water bath-based polymerase chain reactions (PCRs). Using another attachment to hold PCR tubes, the 3D printer was programmed to automate the process of shuttling PCR tubes between water baths. By eliminating the temperature ramping needed in most commercial thermal cyclers, the run time of a 35-cycle PCR protocol was shortened by 33%. This article demonstrates that for applications in resource-limited settings, expensive nucleic acid extraction devices and thermal cyclers that are used in many central laboratories can be potentially replaced by a device modified from inexpensive entry-level 3D printers.

  2. Sample-first preparation: a method for surface-assisted laser desorption/ionization time-of-flight mass spectrometry analysis of cyclic oligosaccharides.

    Science.gov (United States)

    Wu, Hsin-Pin; Su, Chih-Lin; Chang, Hui-Chiu; Tseng, Wei-Lung

    2007-08-15

    A new sample preparation method for the analysis of cyclic oligosaccharides in surface-assisted laser desorption/ionization mass spectrometry (SALDI-MS) is presented. We call this new technique "sample first method", in which a sample is deposited first and then bare gold nanoparticles (AuNPs), which serve as the SALDI matrixes, are added to the top of the sample layer. The use of the sample first method offers significant advantages for improving shot-to-shot reproducibility, enhancing the ionization efficiency of the analyte, and reducing sample preparation time as compared to the dried-droplet method, wherein samples and bare AuNPs are mixed and dried together. The relative standard deviation (RSD) values of the signal intensity as calculated from 65 sample spots was 25% when the sample first methods were applied to the analysis of beta-cyclodextrin. The results were more homogeneous as compared to the outcome using dried-droplet preparation of AuNPs (RSD=66%) and 2,5-dihydroxybenzoic acid (RSD=209%). We also found out that the optimal concentration of AuNP for ionization efficiency is 7.4 nM (4.52x10(12) particles/mL) while the lowest detectable concentration of cyclic oligosaccharides through this approach is 0.25 microM. Except for the cyclic oligosaccharide, the proposed method was also applied to the analyses of other biological samples, including neutral carbohydrate and steroid, aminothiols, and peptides as well as proteins.

  3. Rapid determination of rat plasma uridine levels by HPLC-ESI-MS utilizing the Captiva plates for sample preparation.

    Science.gov (United States)

    Williams, Marta G; Palandra, Joe; Shobe, Eric M

    2003-06-01

    A rapid, accurate and precise HPLC-ESI-MS method for the determination of rat plasma uridine concentrations was developed and is described here. Sample preparation involves methanol precipitation of plasma proteins in a 96-well Captiva protein precipitation filter plate. A clear extract is drawn through the filter plate with vacuum, followed by evaporation of the extract and subsequent reconstitution prior to chromatography on a reversed-phase column with an aqueous mobile phase [0.1% (v/v) glacial acetic acid]. Detection was accomplished by positive-ion electrospray ionization mass spectrometry. A calibration curve ranging in concentration from 0.78 to 25 microM was constructed by best-fit, 1/x weighting linear regression analysis of the calibration standard concentrations vs peak height ratios of analyte with internal standard. The correlation coefficient was >0.995. The overall assay accuracy as shown by the back-calculated concentrations of the calibration curve ranged from 96.6 to 103% with RSD ranging from 4.5 to 20%. While this assay method was developed for the determination of uridine in rat plasma, it could be readily adapted for determination of uridine in plasma from other species, such as human. Copyright 2003 John Wiley & Sons, Ltd.

  4. Preparation of porous n-type silicon sample plates for desorption/ionization on silicon mass spectrometry (DIOS-MS).

    Science.gov (United States)

    Tuomikoski, S; Huikko, K; Grigoras, K; Ostman, P; Kostiainen, R; Baumann, M; Abian, J; Kotiaho, T; Franssila, S

    2002-11-01

    This study focuses on porous silicon (pSi) fabrication methods and properties for desorption ionization on silicon mass spectrometry (DIOS-MS). PSi was prepared using electrochemical etching of n-type silicon in HF-ethanol solution. Porous areas were defined by a double-sided illumination arrangement: front-side porous areas were masked by a stencil mask, eliminating the need for standard photolithography, and backside illumination was used for the backside ohmic contact. Backside illumination improved the uniformity of the porosified areas. Porosification conditions, surface derivatizations and storage conditions were explored to optimize pSi area, pore size and pore depth. Chemical derivatization of the pSi surfaces improved the DIOS-MS performance providing better ionization efficiency and signal stability with lower laser energy. Droplet spreading and drying patterns on pSi were also examined. Pore sizes of 50-200 nm were found to be optimal for droplet evaporation and pore filling with the sample liquid, as measured by DIOS efficiency. With DIOS, significantly better detection sensitivity was obtained (e.g. 150 fmol for midazolam) than with desorption ionization from a standard MALDI steel plate without matrix addition (30 pmol for midazolam). Also the noise that disturbs the detection of low-molecular weight compounds at m/z MS spectra and good detection sensitivity at the 100-150 fmol level for pharmaceutical compounds were achieved with DIOS-MS.

  5. 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.

  6. Preparation of biocompatible molecularly imprinted shell on superparamagnetic iron oxide nanoparticles for selective depletion of bovine hemoglobin in biological sample.

    Science.gov (United States)

    Hao, Yi; Gao, Ruixia; Liu, Dechun; Zhang, Bianbian; Tang, Yuhai; Guo, Zengjun

    2016-05-15

    Bovine hemoglobin (BHb), as one of the high-abundance proteins, could seriously mask and hamper the analysis of low-abundance proteins in serum. To selectively deplete BHb, we design a simple and effective strategy for preparation of biocompatible molecularly imprinted shell on superparamagnetic iron oxide nanoparticles through surface imprinting technique combined with template immobilization strategy. Firstly, template proteins are immobilized on the directly aldehyde-functionalized magnetic nanoparticles through imine bonds. Then, with gelatin as functional monomer, a polymeric network molded around the immobilized template proteins is obtained. Finally, the specific cavities for BHb are fabricated after removing the template proteins. The effects of imprinting conditions were investigated and the optimal imprinting conditions are found to be 40mg of BHb, 150mg of gelatin, and 8h of polymerization time. The resultant materials exhibit good dispersion, high crystallinity, and satisfactory superparamagnetic property with a high saturation magnetization (33.43emug(-1)). The adsorption experiments show that the imprinted nanomaterials have high adsorption capacity of 93.1mgg(-1), fast equilibrium time of 35min, and satisfactory selectivity for target protein. Meanwhile, the obtained polymers could be used without obvious deterioration after six adsorption-desorption cycles. In addition, the resultant polymers are successfully applied in the selective isolation BHb from bovine blood sample, which could provide an alternative solution for the preparatory work of proteomics. Copyright © 2016 Elsevier Inc. All rights reserved.

  7. 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.

  8. Evaluating focused ion beam and ultramicrotome sample preparation for analytical microscopies of the cathode layer of a polymer electrolyte membrane fuel cell

    Science.gov (United States)

    de A. Melo, Lis G.; Hitchcock, Adam P.; Berejnov, Viatcheslav; Susac, Darija; Stumper, Juergen; Botton, Gianluigi A.

    2016-04-01

    Optimizing the structure of the porous electrodes of polymer electrolyte membrane fuel cells (PEM-FC) can improve device power and durability. Analytical microscopy techniques are important tools for measuring the electrode structure, thereby providing guidance for structural optimization. Transmission Electron Microscopy (TEM), with either Energy Dispersive X-Ray (EDX) or Electron Energy Loss Spectroscopy (EELS) analysis, and Scanning Transmission X-Ray Microscopy (STXM) are complementary methods which, together, provide a powerful approach for PEM-FC electrode analysis. Both TEM and STXM require thin (50-200 nm) samples, which can be prepared either by Focused Ion Beam (FIB) milling or by embedding and ultramicrotomy. Here we compare TEM and STXM spectromicroscopy analysis of FIB and ultramicrotomy sample preparations of the same PEM-FC sample, with focus on how sample preparation affects the derived chemical composition and spatial distributions of carbon support and ionomer. The FIB lamella method, while avoiding pore-filling by embedding media, had significant problems. In particular, in the FIB sample the carbon support was extensively amorphized and the ionomer component suffered mass loss and structural damage. Although each sample preparation technique has a role to play in PEM-FC optimization studies, it is important to be aware of the limitations of each method.

  9. Comparison of different sample preparation methods for platinum determination in cultured cells by graphite furnace atomic absorption spectrometry

    Directory of Open Access Journals (Sweden)

    Man Xiao

    2017-01-01

    Full Text Available Background Platinum-based agents are widely used in chemotherapy against solid tumors and insufficient intracellular drug accumulation is one of the leading causes of platinum resistance which is associated with poor survival of tumor patients. Thus, the detection of intracellular platinum is pivotal for studies aiming to overcome platinum resistance. In the present study, we aimed to establish a reliable graphite furnace atomic absorption spectrometry (GFAAS-based assay to quantify the intracellular platinum content for cultured cells. Methods Several most commonly applied cell preparation methods, including 0.2% HNO3, 0.2% Triton X-100, concentrated nitric acid, RIPA combined with concentrated nitric acid and hydroxide, followed by GFAAS for platinum detection were compared in ovarian, cervical and liver cancer cell lines to obtain the optimal one, and parameters regarding linearity, accuracy, precision and sensitivity were evaluated. Influence of other metals on platinum detection and the storage conditions of samples were also determined. Results The treatment of cells with 0.2% HNO3 was superior to other approaches with fewer platinum loss and better repeatability. The recovery rate and precision of this method were 97.3%–103.0% and 1.4%–3.8%, respectively. The average recoveries in the presence of other metals were 95.1%–103.1%. The detection limit was 13.23 ug/L. The recovery rate of platinum remained acceptable even in cell samples stored in −20 °C or −80 °C for two months. Discussion After comparison, we found that 0.2% HNO3 was optimal for intracellular platinum quantification based on GFAAS, which presented values compatible with that of inductively-coupled plasma mass-spectrometry (ICP-MS, and this is partially attributed to the simplicity of this method. Moreover, the assay was proved to be accurate, sensitive, cost-effective and suitable for the research of platinum-based antitumor therapy.

  10. Determination of exposure of dispensary drug preparers to cyclophosphamide by passive sampling and liquid chromatography with tandem mass spectrometry.

    Science.gov (United States)

    Wakui, Nobuyuki; Ookubo, Tetuo; Iwasaki, Yusuke; Ito, Rie; Mitui, Miyuki; Yano, Yuichi; Saito, Koichi; Nakazawa, Hiroyuki

    2013-03-01

    To determine cyclophosphamide exposure to preparers during tablet crushing and subsequent handling by analyzing indoor air collected using a high-performance volatile organic compounds-solvent desorption (VOC-SD) passive air sampler. The passive sampler was taped to the mask over the mouth of the preparer and indoor air was collected during crushing and preparation of cyclophosphamide tablets (Endoxan®). After collection, the carbon molecular sieve adsorbent of the passive sampler was placed in a centrifuge tube, and 1 mL of carbon disulfide was used to elute cyclophosphamide from the adsorbent. Liquid-liquid extraction with 1 mL of water was performed, and the aqueous phase was used as the test solution. Cyclophosphamide concentration was determined by liquid chromatography with ultraviolet and tandem mass spectrometry detection. Cyclophosphamide concentration was detected in the range of 7.6-157.7 ng/sampler. Our results showed that low-level exposure occurred near the mouth of the preparer, which could present risks for long-term exposure, especially if combined with multiple toxic drug exposures. The anticancer drug monitoring methodology described here is a simple exposure assessment that can be used to ensure the safety of hospital pharmacy tablet preparers. Furthermore, since the anticancer drug exposure risk is very high for preparers, preparation should be in hood or with face mask.

  11. Can an inadequate cervical cytology sample in ThinPrep be converted to a satisfactory sample by processing it with a SurePath preparation?

    Science.gov (United States)

    Sørbye, Sveinung Wergeland; Pedersen, Mette Kristin; Ekeberg, Bente; Williams, Merete E Johansen; Sauer, Torill; Chen, Ying

    2017-01-01

    The Norwegian Cervical Cancer Screening Program recommends screening every 3 years for women between 25 and 69 years of age. There is a large difference in the percentage of unsatisfactory samples between laboratories that use different brands of liquid-based cytology. We wished to examine if inadequate ThinPrep samples could be satisfactory by processing them with the SurePath protocol. A total of 187 inadequate ThinPrep specimens from the Department of Clinical Pathology at University Hospital of North Norway were sent to Akershus University Hospital for conversion to SurePath medium. Ninety-one (48.7%) were processed through the automated "gynecologic" application for cervix cytology samples, and 96 (51.3%) were processed with the "nongynecological" automatic program. Out of 187 samples that had been unsatisfactory by ThinPrep, 93 (49.7%) were satisfactory after being converted to SurePath. The rate of satisfactory cytology was 36.6% and 62.5% for samples run through the "gynecology" program and "nongynecology" program, respectively. Of the 93 samples that became satisfactory after conversion from ThinPrep to SurePath, 80 (86.0%) were screened as normal while 13 samples (14.0%) were given an abnormal diagnosis, which included 5 atypical squamous cells of undetermined significance, 5 low-grade squamous intraepithelial lesion, 2 atypical glandular cells not otherwise specified, and 1 atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion. A total of 2.1% (4/187) of the women got a diagnosis of cervical intraepithelial neoplasia 2 or higher at a later follow-up. Converting cytology samples from ThinPrep to SurePath processing can reduce the number of unsatisfactory samples. The samples should be run through the "nongynecology" program to ensure an adequate number of cells.

  12. Can an inadequate cervical cytology sample in ThinPrep be converted to a satisfactory sample by processing it with a SurePath preparation?

    Directory of Open Access Journals (Sweden)

    Sveinung Wergeland Sorbye

    2017-01-01

    Full Text Available Background: The Norwegian Cervical Cancer Screening Program recommends screening every 3 years for women between 25 and 69 years of age. There is a large difference in the percentage of unsatisfactory samples between laboratories that use different brands of liquid-based cytology. We wished to examine if inadequate ThinPrep samples could be satisfactory by processing them with the SurePath protocol. Materials and Methods: A total of 187 inadequate ThinPrep specimens from the Department of Clinical Pathology at University Hospital of North Norway were sent to Akershus University Hospital for conversion to SurePath medium. Ninety-one (48.7% were processed through the automated “gynecologic” application for cervix cytology samples, and 96 (51.3% were processed with the “nongynecological” automatic program. Results: Out of 187 samples that had been unsatisfactory by ThinPrep, 93 (49.7% were satisfactory after being converted to SurePath. The rate of satisfactory cytology was 36.6% and 62.5% for samples run through the “gynecology” program and “nongynecology” program, respectively. Of the 93 samples that became satisfactory after conversion from ThinPrep to SurePath, 80 (86.0% were screened as normal while 13 samples (14.0% were given an abnormal diagnosis, which included 5 atypical squamous cells of undetermined significance, 5 low-grade squamous intraepithelial lesion, 2 atypical glandular cells not otherwise specified, and 1 atypical squamous cells cannot exclude high-grade squamous intraepithelial lesion. A total of 2.1% (4/187 of the women got a diagnosis of cervical intraepithelial neoplasia 2 or higher at a later follow-up. Conclusions: Converting cytology samples from ThinPrep to SurePath processing can reduce the number of unsatisfactory samples. The samples should be run through the “nongynecology” program to ensure an adequate number of cells.

  13. Evaluation of a New Device for Simplifying and Standardizing Stool Sample Preparation for Viral Molecular Testing with Limited Hands-On Time

    OpenAIRE

    Feghoul, Linda; Salmona, Maud; Cherot, Janine; Fahd, Mony; Dalle, Jean-Hugues; Vachon, Carole; Perrod, Aurélie; Bourgeois, Philippe; Scieux, Catherine; Baruchel, André; Simon, François; Legoff, Jérôme

    2016-01-01

    Sensitive molecular assays have greatly improved the diagnosis of viral gastroenteritis. However, the proper preparation of stool samples for clinical testing remains an issue. bioMérieux has developed a stool preprocessing device (SPD) that includes a spoon for calibrated sampling and a vial containing buffer, glass beads, and two filters. The resulting stool filtrate is used for nucleic acid extraction. The purpose of this study was to evaluate the performance of the SPD for the quantificat...

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

    Science.gov (United States)

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

    2012-01-01

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

  15. 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.

  16. Evaluation of a fast and simple sample preparation method for PBDE flame retardants and DDT pesticides in fish for analysis by ELISA compared with GC-MS/MS

    Science.gov (United States)

    A simple, fast, and cost-effective sample preparation method, previously developed and validated for the analysis of organic contaminants in fish using low-pressure gas chromatography tandem mass spectrometry (LPGC-MS/MS), was evaluated for analysis of polybrominated diphenyl ethers (PBDEs) and dich...

  17. Automated column liquid chromatographic determination of amoxicillin and cefadroxil in bovine serum and muscle tissue using on-line dialysis for sample preparation

    NARCIS (Netherlands)

    Snippe, N; van de Merbel, N C; Ruiter, F P; Steijger, O M; Lingeman, H; Brinkman, U A

    1994-01-01

    A fully automated method is described for the determination of amoxicillin and cefadroxil in bovine serum and muscle tissue. The method is based on the on-line combination of dialysis and solid-phase extraction for sample preparation, and column liquid chromatography with ultraviolet detection. In

  18. 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...

  19. Determination of thromboxanes, leukotrienes and lipoxins using high-temperature capillary liquid chromatography-tandem mass spectrometry and on-line sample preparation

    DEFF Research Database (Denmark)

    Dahl, Sandra Rinne; Kleiveland, Charlotte Ramstad; Kassem, Moustapha

    2009-01-01

    culture supernatants was developed and validated. In the present method, a high temperature (70 degrees C) was used for the separation on the analytical column to obtain efficient chromatography of the thromboxanes. An on-line sample preparation was performed, where peptides/proteins contained...

  20. Trace element analysis of humus-rich natural water samples:method development for UV-LED assisted photocatalytic sample preparation and hydride generation ICP-MS analysis

    OpenAIRE

    Havia, J. (Johanna)

    2017-01-01

    Abstract Humus-rich natural water samples, containing high concentrations of dissolved organic carbon (DOC), are challenging for certain analytical methods used in trace element analysis, including hydride generation methods and electrochemical methods. In order to obtain reliable results, the samples must to be pretreated to release analytes from humic acid complexes prior to the determination. In this study, methods for both pretreatment and analysis steps were developed. Arsenic is ...

  1. Optimization of Sample Preparation for the Identification and Quantification of Saxitoxin in Proficiency Test Mussel Sample using Liquid Chromatography-Tandem Mass Spectrometry

    Directory of Open Access Journals (Sweden)

    Kirsi Harju

    2015-11-01

    Full Text Available Saxitoxin (STX and some selected paralytic shellfish poisoning (PSP analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS. Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk. Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of ±1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD.

  2. Optimization of Sample Preparation and Instrumental Parameters for the Rapid Analysis of Drugs of Abuse in Hair samples by MALDI-MS/MS Imaging

    Science.gov (United States)

    Flinders, Bryn; Beasley, Emma; Verlaan, Ricky M.; Cuypers, Eva; Francese, Simona; Bassindale, Tom; Clench, Malcolm R.; Heeren, Ron M. A.

    2017-08-01

    Matrix-assisted laser desorption/ionization-mass spectrometry imaging (MALDI-MSI) has been employed to rapidly screen longitudinally sectioned drug user hair samples for cocaine and its metabolites using continuous raster imaging. Optimization of the spatial resolution and raster speed were performed on intact cocaine contaminated hair samples. The optimized settings (100 × 150 μm at 0.24 mm/s) were subsequently used to examine longitudinally sectioned drug user hair samples. The MALDI-MS/MS images showed the distribution of the most abundant cocaine product ion at m/z 182. Using the optimized settings, multiple hair samples obtained from two users were analyzed in approximately 3 h: six times faster than the standard spot-to-spot acquisition method. Quantitation was achieved using longitudinally sectioned control hair samples sprayed with a cocaine dilution series. A multiple reaction monitoring (MRM) experiment was also performed using the `dynamic pixel' imaging method to screen for cocaine and a range of its metabolites, in order to differentiate between contaminated hairs and drug users. Cocaine, benzoylecgonine, and cocaethylene were detectable, in agreement with analyses carried out using the standard LC-MS/MS method. [Figure not available: see fulltext.

  3. Optimization of Sample Preparation for the Identification and Quantification of Saxitoxin in Proficiency Test Mussel Sample using Liquid Chromatography-Tandem Mass Spectrometry.

    Science.gov (United States)

    Harju, Kirsi; Rapinoja, Marja-Leena; Avondet, Marc-André; Arnold, Werner; Schär, Martin; Burrell, Stephen; Luginbühl, Werner; Vanninen, Paula

    2015-11-25

    Saxitoxin (STX) and some selected paralytic shellfish poisoning (PSP) analogues in mussel samples were identified and quantified with liquid chromatography-tandem mass spectrometry (LC-MS/MS). Sample extraction and purification methods of mussel sample were optimized for LC-MS/MS analysis. The developed method was applied to the analysis of the homogenized mussel samples in the proficiency test (PT) within the EQuATox project (Establishment of Quality Assurance for the Detection of Biological Toxins of Potential Bioterrorism Risk). Ten laboratories from eight countries participated in the STX PT. Identification of PSP toxins in naturally contaminated mussel samples was performed by comparison of product ion spectra and retention times with those of reference standards. The quantitative results were obtained with LC-MS/MS by spiking reference standards in toxic mussel extracts. The results were within the z-score of ±1 when compared to the results measured with the official AOAC (Association of Official Analytical Chemists) method 2005.06, pre-column oxidation high-performance liquid chromatography with fluorescence detection (HPLC-FLD).

  4. 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.

  5. 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.

  6. Simplified sample preparation method for protein identification by matrix-assisted laser desorption/ionization mass spectrometry: in-gel digestion on the probe surface

    DEFF Research Database (Denmark)

    Stensballe, A; Jensen, Ole Nørregaard

    2001-01-01

    for protein identification similar to that obtained by the traditional protocols for in-gel digestion and MALDI peptide mass mapping of human proteins, i.e. approximately 60%. The overall performance of the novel on-probe digestion method is comparable with that of the standard in-gel sample preparation...... protocol while being less labour intensive and more cost-effective due to minimal consumption of reagents, enzymes and consumables. Preliminary data obtained on a MALDI quadrupole-TOF tandem mass spectrometer demonstrated the utility of the on-probe digestion protocol for peptide mass mapping and peptide....../ionization-time of flight mass spectrometry (MALDI-TOF-MS) is used as the first protein screening method in many laboratories because of its inherent simplicity, mass accuracy, sensitivity and relatively high sample throughput. We present a simplified sample preparation method for MALDI-MS that enables in-gel digestion...

  7. 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

  8. Data on step-by-step atomic force microscopy monitoring of changes occurring in single melanoma cells undergoing ToF SIMS specialized sample preparation protocol.

    Science.gov (United States)

    Bobrowska, J; Pabijan, J; Wiltowska-Zuber, J; Jany, B R; Krok, F; Awsiuk, K; Rysz, J; Budkowski, A; Lekka, M

    2016-09-01

    Data included in this article are associated with the research article entitled 'Protocol of single cells preparation for time-of-flight secondary ion mass spectrometry' (Bobrowska et al., 2016 in press) [1]. This data file contains topography images of single melanoma cells recorded using atomic force microscopy (AFM). Single cells cultured on glass surface were subjected to the proposed sample preparation protocol applied to prepare biological samples for time-of-flight secondary ion mass spectrometry (ToF SIMS) measurements. AFM images were collected step-by-step for the single cell, after each step of the proposed preparation protocol. It consists of four main parts: (i) paraformaldehyde fixation, (ii) salt removal, (iii) dehydrating, and (iv) sample drying. In total 13 steps are required, starting from imaging of a living cell in a culture medium and ending up at images of a dried cell in the air. The protocol was applied to melanoma cells from two cell lines, namely, WM115 melanoma cells originated from primary melanoma site and WM266-4 ones being the metastasis of WM115 cells to skin.

  9. 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

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

    DEFF Research Database (Denmark)

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

    2012-01-01

    -mass spectrometry using several preparation techniques, including protein precipitation, solid-phase extraction and centrifugation, without any manual intervention. Pipetting of a known aliquot of whole blood was achieved by integrating a balance and performing gravimetric measurements. The system was able...

  11. Automated Sample Preparation (ASP): Development of a Rapid Method to Sequentially Isolate Nucleic Acids and Protein from Any Sample Type by a Cartridge-Based System

    Science.gov (United States)

    2013-11-27

    by the buffer solution. For instance, the DNAPro appears to perform better when the diluent was Joint Portal Shield Buffer. This relationship did...spores and comparison of DNA yields from spores and spiked environmental samples. Journal of Microbiological Methods, 2009. 76(1): p. 30-37. 3...time PCR. European Journal of Clinical Microbiology & Infectious Diseases, 2008. 27(2): p. 109-114. 4. Boom, R., et al., Rapid and simple method

  12. 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.

  13. Urea free and more efficient sample preparation method for mass spectrometry based protein identification via combining the formic acid-assisted chemical cleavage and trypsin digestion.

    Science.gov (United States)

    Wu, Shuaibin; Yang, Kaiguang; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2011-10-30

    A formic acid (FA)-assisted sample preparation method was presented for protein identification via mass spectrometry (MS). Detailedly, an aqueous solution containing 2% FA and dithiothreitol was selected to perform protein denaturation, aspartic acid (D) sites cleavage and disulfide linkages reduction simultaneously at 108°C for 2h. Subsequently, FA wiped off via vacuum concentration. Finally, iodoacetamide (IAA) alkylation and trypsin digestion could be performed ordinally. A series of model proteins (BSA, β-lactoglobulin and apo-Transferrin) were treated respectively using such method, followed by matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS) analysis. The identified peptide number was increased by ∼ 80% in comparison with the conventional urea-assisted sample preparation method. Moreover, BSA identification was achieved efficiently down to femtomole (25 ± 0 sequence coverage and 16 ± 1 peptides) via such method. In contrast, there were not peptides identified confidently via the urea-assisted method before desalination via the C18 zip tip. The absence of urea in this sample preparation method was an advantage for the more favorable digestion and MALDI-TOF MS analysis. The performances of two methods for the real sample (rat liver proteome) were also compared, followed by a nanoflow reversed-phase liquid chromatography with electrospray ionization tandem mass spectrometry system analysis. As a result, 1335 ± 43 peptides were identified confidently (false discovery rate method, corresponding to 295 ± 12 proteins (of top match=1 and requiring 2 unique peptides at least). In contrast, there were only 1107 ± 16 peptides (corresponding to 231 ± 10 proteins) obtained from the conventional urea-assisted method. It was serving as a more efficient protein sample preparation method for researching specific proteomes better, and providing assistance to develop other proteomics analysis methods, such as, peptide

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

    Directory of Open Access Journals (Sweden)

    Bjoern B. Burckhardt

    2015-01-01

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

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

    Science.gov (United States)

    Burckhardt, Bjoern B; Laeer, Stephanie

    2015-01-01

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

  16. Evaluation of micro-colorimetric lipid determination method with samples prepared using sonication and accelerated solvent extraction methods.

    Science.gov (United States)

    Billa, Nanditha; Hubin-Barrows, Dylan; Lahren, Tylor; Burkhard, Lawrence P

    2014-02-01

    Two common laboratory extraction techniques were evaluated for routine use with the micro-colorimetric lipid determination method developed by Van Handel (1985) [2] and recently validated for small samples by Inouye and Lotufo (2006) [1]. With the accelerated solvent extraction method using chloroform:methanol solvent and the colorimetric lipid determination method, 28 of 30 samples had significant proportional bias (α=1%, determined using standard additions) and 1 of 30 samples had significant constant bias (α=1%, determined using Youden Blank measurements). With sonic extraction, 0 of 6 samples had significant proportional bias (α=1%) and 1 of 6 samples had significant constant bias (α=1%). These demonstrate that the accelerated solvent extraction method with chloroform:methanol solvent system creates an interference with the colorimetric assay method, and without accounting for the bias in the analysis, inaccurate measurements would be obtained. Published by Elsevier B.V.

  17. Label-Free Quantitative Analysis of Mitochondrial Proteomes Using the Multienzyme Digestion-Filter Aided Sample Preparation (MED-FASP) and "Total Protein Approach".

    Science.gov (United States)

    Wiśniewski, Jacek R

    2017-01-01

    Determination of proteome composition and measuring of changes in protein titers provide important information with a substantial value for studying mitochondria.This chapter describes a workflow for the quantitative analysis of mitochondrial proteome with a focus on sample preparation and quantitative analysis of the data. The workflow involves the multienzyme digestion-filter aided sample preparation (MED-FASP) protocol enabling efficient extraction of proteins and high rate of protein-to-peptide conversion. Consecutive protein digestion with Lys C and trypsin enables generation of peptide fractions with minimal overlap, largely increases the number of identified proteins, and extends their sequence coverage. Abundances of proteins identified by multiple peptides can be assessed by the "Total Protein Approach."

  18. A new sample preparation method compatible with capillary electrophoresis and laser-induced fluorescence for improving detection of low levels of beta-lactoglobulin in infant foods.

    Science.gov (United States)

    Pelaez-Lorenzo, Cristina; Diez-Masa, Jose Carlos; Vasallo, Isabel; de Frutos, Mercedes

    2009-09-07

    Beta-lactoglobulin (betaLG) is the main allergenic protein in cow's milk and can cause allergy even when present at very low concentration. The aim of this work is to develop an innovative sample preparation method fully compatible with capillary electrophoresis and laser-induced fluorescence detection for improving the sensitivity when analyzing betaLG. Different types of baby food were on purpose contaminated with diverse dairy desserts and submitted to thermal treatment to simulate potential contamination at production. Sample preparation prior to CE analysis was performed by the classical extraction method and by the innovative one, and the results were compared. Analysis was performed by capillary electrophoresis with laser-induced fluorescence detection. The innovative method permitted to detect contaminations as low as 1 part of yoghurt in 10,000 parts of baby food.

  19. 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...

  20. An improved method of sample preparation on AnchorChip targets for MALDI-MS and MS/MS and its application in the liver proteome project

    DEFF Research Database (Denmark)

    Zhang, Xumin; Shi, Liang; Shu, Shaokung

    2007-01-01

    An improved method for sample preparation for MALDI-MS and MS/MS using AnchorChip targets is presented. The method, termed the SMW method (sample, matrix wash), results in better sensitivity for peptide mass fingerprinting as well as for sequencing by MS/MS than previously published methods. The ...... solution. The method was validated for protein identification from a 2-DE based liver proteome study. The SMW method resulted in identification of many more proteins and in most cases with a better score than the previously published methods....

  1. Advanced fluidic handling and use of two-phase flow for high throughput structural investigation of proteins on a microfluidic sample preparation platform

    DEFF Research Database (Denmark)

    Lafleur, Josiane P.; Snakenborg, Detlef; Møller, M.

    2010-01-01

    Research on the structure of proteins can bring forth a wealth of information about biological function and can be used to better understand the processes in living cells. This paper reports a new microfluidic sample preparation system for the structural investigation of proteins by Small Angle X......-ray Scattering (SAXS). The system includes hardware and software features for precise fluidic control, synchrotron beamline control, UV absorbance measurements and automated data analysis. The precise fluidic handling capabilities are used to transport and precisely position samples as small as 500 n...

  2. 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

  3. Decision preparation, satisfaction and regret in a multi-center sample of men with newly diagnosed localized prostate cancer.

    Science.gov (United States)

    Berry, Donna L; Wang, Qian; Halpenny, Barbara; Hong, Fangxin

    2012-08-01

    To describe relationships between use of the Personal Patient Profile-Prostate (P3P) decision support system and patient characteristics, and perceived preparation for decision making (PrepDM), satisfaction and decisional regret in the context of prostate cancer treatment choice. 494 men with localized prostate cancer (LPC) were randomized to receive the P3P intervention or usual care and completed pre-treatment, 1-month and 6-month outcome measures. Multivariable linear regression models were fit for each outcome. Physician consult visits prior to enrollment, race/ethnicity, and use of clinic-provided books were significant predictors of perceived PrepDM at 1 month. Prior Internet use and PrepDM significantly predicted 6-month decision satisfaction. Decisional regret was significantly predicted by demographics, anxiety, PrepDM score, and EPIC bowel domain score at 6 months. Use of P3P did not predict any outcome. While the P3P intervention did not significantly affect the outcomes, pre-enrollment information and preparation were strong predictors of the 1- and 6-month outcomes. Decision regret was significantly influenced by personal characteristics and post-treatment symptoms/side effects. Information received and used between biopsy and the treatment options consult visit is likely to make a difference in decision satisfaction. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

  4. Reversed-phase vortex-assisted liquid-liquid microextraction: a new sample preparation method for the determination of amygdalin in oil and kernel samples.

    Science.gov (United States)

    Hosseini, Mohammad; Heydari, Rouhollah; Alimoradi, Mohammad

    2015-02-01

    A novel, simple, and rapid reversed-phase vortex-assisted liquid-liquid microextraction coupled with high-performance liquid chromatography has been introduced for the extraction, clean-up, and preconcentration of amygdalin in oil and kernel samples. In this technique, deionized water was used as the extracting solvent. Unlike the reversed-phase dispersive liquid-liquid microextraction, dispersive solvent was eliminated in the proposed method. Various parameters that affected the extraction efficiency, such as extracting solvent volume and its pH, vortex, and centrifuging times were evaluated and optimized. The calibration curve shows good linearity (r(2) = 0.9955) and precision (RSD < 5.2%) in the range of 0.07-20 μg/mL. The limit of detection and limit of quantitation were 0.02 and 0.07 μg/mL, respectively. The recoveries were in the range of 96.0-102.0% with relative standard deviation values ranging from 4.0 to 5.1%. Unlike the conventional extraction methods for plant extracts, no evaporative and re-solubilizing operations were needed in the proposed technique. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  5. Subcritical water extraction combined with molecular imprinting technology for sample preparation in the detection of triazine herbicides.

    Science.gov (United States)

    Zhao, Fengnian; Wang, Shanshan; She, Yongxin; Zhang, Chao; Zheng, Lufei; Jin, Maojun; Shao, Hua; Jin, Fen; Du, Xinwei; Wang, Jing

    2017-09-15

    A selective, environmentally friendly, and cost-effective sample extraction method based on a combination of subcritical water extraction (SWE) and molecularly imprinted solid-phase extraction (MISPE) was developed for the determination of eight triazine herbicides in soil samples by liquid chromatography-tandem mass spectrometry (LC-MS/MS). In SWE, the highest extraction yields of triazine herbicides were obtained under 150°C for 15min using 20% ethanol as the organic modifier. Addition of MIP during SWE increased the extraction efficiency, and using MIP as a selective SPE sorbent improved the enrichment capability. Soil samples were treated with the optimized extraction MIP/SWE-MISPE method and analyzed by LC-MS/MS. The novel technique was then applied to soil samples for the determination of triazine herbicides, and better recoveries (78.9%-101%) were obtained compared with using SWE-MISPE (30%-67%). Moreover, this newly developed method displayed good linearity (R2>0.99) and precision (2.7-9.8%), and low enough detection limits (0.4-3.3μgkg-1). This combination of SWE and MIP technology is a simple, effective and promising method to selectively extract class-specific compounds in complex samples. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. The stability of TNT, RDX and PETN in simulated post-explosion soils: Implications of sample preparation for analysis.

    Science.gov (United States)

    Yu, H A; DeTata, D A; Lewis, S W; Nic Daeid, N

    2017-03-01

    Explosives residues in soils may be a useful source of evidence following the detonation of an improvised explosive device (IED), such as a vehicle-borne IED. Soil samples collected from the vicinity of an explosion scene will often be stored for some time prior to analysis, yet explosives residues in soil samples are susceptible to rapid degradation or transformation. Although some research has assessed the use of different storage temperatures with a view to reducing explosives' degradation over time, further research examining the degradation of explosives in soil when stored under a variety of storage conditions is crucial to determine the optimal sample collection and storage procedures for soil containing explosives residues. In this work, three different soils were spiked with solutions of TNT, RDX and PETN and stored either at room temperature, refrigerated or frozen. Samples were extracted over 6 weeks, with additional samples gamma-irradiated or nitrogen purged prior to storage. Experimental results indicate that TNT underwent very rapid degradation at room temperature, attributed to microbial action, whereas PETN and RDX proved to be more stable. Gamma irradiation and nitrogen purging proved of some benefit for mitigating TNT degradation, with lower storage temperatures ultimately proving the most effective method of mitigating degradation. Copyright © 2016 Elsevier B.V. All rights reserved.

  7. Degradation and interconversion of plant pteridines during sample preparation and ultra-high performance liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Van Daele, Jeroen; Blancquaert, Dieter; Kiekens, Filip; Van Der Straeten, Dominique; Lambert, Willy E; Stove, Christophe P

    2016-03-01

    The degradation and interconversion of a selected set of pterins (dihydroneopterin, hydroxymethyldihydropterin, dihydroxanthopterin, neopterin, hydroxymethylpterin, xanthopterin, 6-formylpterin, 6-carboxypterin and pterin), spiked to charcoal-treated potato and Arabidopsis thaliana matrix was investigated, together with their relative recovery in potato and A. thaliana. As a result, a matrix-specific procedure for the ultra-high performance liquid chromatography-tandem mass spectrometry based determination of 6 aromatic pterins (neopterin, hydroxymethylpterin, xanthopterin, 6-formylpterin, 6-carboxypterin and pterin) is proposed: 1.5ml of an N2-flushed, alkaline (pH=10) extraction solvent is added to 200mg of plant sample. After boiling and homogenization, the samples are incubated: Arabidopsis samples for 30min at room temperature, while shaking, and potato samples for 2h at 37°C (applying a dienzyme treatment with α-amylase and protease). After a final boiling step, the samples are ultrafiltrated and resulting extracts are analyzed by UHPLC-MS/MS. Copyright © 2015 Elsevier Ltd. All rights reserved.

  8. Analysis of {sup 129}I in lichens by accelerator mass spectrometry through a microwave-based sample preparation method

    Energy Technology Data Exchange (ETDEWEB)

    Gomez-Guzman, J.M. [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Lopez-Gutierrez, J.M., E-mail: lguti@us.e [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Dpto. de Fisica Aplicada I, Escuela Universitaria Politecnica, c/. Virgen de Africa 7, 41011 Seville (Spain); Pinto, A.R. [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Holm, E. [Department of Radiation Physics, Lund University Hospital, S-22185 Lund (Sweden); Garcia-Leon, M. [Centro Nacional de Aceleradores (CNA), Avda. Thomas Alva Edison 7, Isla de la Cartuja, 41092 Seville (Spain); Dpto. Fisica Atomica, Molecular y Nuclear, Avda. Reina Mercedes, s/n, 41012 Seville (Spain)

    2010-04-15

    The presence of {sup 129}I in the environment has been strongly influenced by the artificial nuclear emissions since the beginning of the nuclear era in the mid 20th century. In order to know more about the different sources and their relative impact in different zones, it is necessary to complete the amount of measurements of this radionuclide in environmental samples. In this work, {sup 129}I has been determined in lichen samples (Cladonia alpestris) from Rogen Lake in Central Sweden. A method based on microwave digestion was developed for these measurements in order to improve speed and reduce contamination. Based on this method, {sup 129}I concentrations in some lichen samples from Lake Rogen (Sweden) have been measured, showing the impact of the Chernobyl accident and nuclear fuel reprocessing plants.

  9. Analysis of 129I in lichens by accelerator mass spectrometry through a microwave-based sample preparation method

    Science.gov (United States)

    Gómez-Guzmán, J. M.; López-Gutiérrez, J. M.; Pinto, A. R.; Holm, E.; García-León, M.

    2010-04-01

    The presence of 129I in the environment has been strongly influenced by the artificial nuclear emissions since the beginning of the nuclear era in the mid 20th century. In order to know more about the different sources and their relative impact in different zones, it is necessary to complete the amount of measurements of this radionuclide in environmental samples. In this work, 129I has been determined in lichen samples ( Cladonia alpestris) from Rogen Lake in Central Sweden. A method based on microwave digestion was developed for these measurements in order to improve speed and reduce contamination. Based on this method, 129I concentrations in some lichen samples from Lake Rogen (Sweden) have been measured, showing the impact of the Chernobyl accident and nuclear fuel reprocessing plants.

  10. Modern sample preparation techniques for gas chromatography-mass spectrometry analysis of environmental markers of chemical warfare agents use

    NARCIS (Netherlands)

    Terzic, O.; de Voogt, P.; Banoub, J.

    2014-01-01

    The chapter introduces problematics of on-site chemical analysis in the investigations of past chemical warfare agents (CWA) events. An overview of primary environmental degradation pathways of CWA leading to formation of chemical markers of their use is given. Conventional and modern sample

  11. Filter-aided sample preparation with dimethyl labeling to identify and quantify milk fat globule membrane proteins.

    NARCIS (Netherlands)

    Lu, J.; Boeren, J.A.; Vries, de S.C.; Valenberg, van H.J.F.; Vervoort, J.J.M.; Hettinga, K.A.

    2011-01-01

    Bovine milk is a major nutrient source in many countries and it is produced at an industrial scale. Milk is a complex mixture of proteins, fats, carbohydrates, vitamins and minerals. The composition of the bovine milk samples can vary depending on the genetic makeup of the bovine species as well as

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

    Czech Academy of Sciences Publication Activity Database

    Huber, C. S.; Vale, M. G. R.; Dessuy, M. B.; Svoboda, Milan; Musil, Stanislav; Dědina, Jiří

    2017-01-01

    Roč. 175, DEC (2017), s. 406-412 ISSN 0039-9140 R&D Projects: GA MŠk(CZ) LH15174 Institutional support: RVO:68081715 Keywords : slurry sampling * methyl-substituted arsenic species * hydride generation-cryotrapping-atomic absorption spectrometry Subject RIV: CB - Analytical Chemistry, Separation OBOR OECD: Analytical chemistry Impact factor: 4.162, year: 2016

  13. 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.

  14. Preparation of magnetic poly(diethyl vinylphosphonate-co-ethylene glycol dimethacrylate) for the determination of chlorophenols in water samples.

    Science.gov (United States)

    Li, Xiao-Shui; Xu, Li-Dan; Shan, Ya-Bing; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-11-23

    In this work, a novel type of magnetic polymer particle, magnetic poly(diethyl vinylphosphonate-co-ethylene glycol dimethacrylate) [Fe(3)O(4)@p(DEVP-co-EDMA)], was successfully synthesized and applied for the extraction and determination of chlorophenols in water samples by coupling with high-performance liquid chromatography (HPLC). Fe(3)O(4)@p(DEVP-co-EDMA) was synthesized by a simple seeded radical polymerization method and exhibited well-defined core-shell structure and good magnetic response ability. In addition, the magnetic polymer had the advantages of abundant adsorption sites and high enrichment efficiency. Due to the presence of PO group in the skeleton of polymer, the magnetic polymer material displayed excellent extraction performance for chlorophenols, such as 2-chlorophenol (2-CP), 2,4-dichlorophenol (2,4-DCP) and 2,4,6-trichlorophenol (2,4,6-TCP). Hydrophobic skeleton of the magnetic polymer also provided strong interaction with the target analytes, especially pentachlorophenol (PCP) which is a kind of non-polar chlorophenol. Desorption solution, pH of water sample, extraction time and desorption time, the amount of adsorbent, and the volume of desorption solution were optimized. Under the optimized conditions, the linear ranges of four chlorophenols were 2-500 ng/mL with the limits of detection (S/N=3) ranging from 0.20 to 0.34 ng/mL. The repeatability was investigated by evaluating the intra- and inter-day precisions with relative standard deviations (RSDs) lower than 15.0%. The recoveries for real water samples were in the range of 92.7-108.0%. Collectively, the results indicated that the novel Fe(3)O(4)@p(DEVP-co-EDMA) was successfully applied in the extraction and detection of chlorophenols from water samples, and the magnetic polymer particle showed potential applications in the analysis of polar compounds. Copyright © 2012 Elsevier B.V. All rights reserved.

  15. Evaluation of Loring Air Force Base, Maine, in Preparation for a Public Health Assessment - Data Gap Sampling and Analysis Plan

    Science.gov (United States)

    1994-06-01

    landfill was monitored at the LF- 1 seep into Green Pond . The data gap is whether the metals are bioaccumulating in the stocked fish. The potential...receptors are currently on-base personnel who eat Green Pond stocked fish. Future biota pathway exposure receptors may be the off-base residents, since the...land use scenario indicates that the pond may become a recreational area. Recommendation: Sample Green Pond fish tissue to ensure metals are not

  16. Preparation of magnetic molecularly imprinted polymers by atom transfer radical polymerization for the rapid extraction of avermectin from fish samples.

    Science.gov (United States)

    You, Xiaoxiao; Gao, Lei; Qin, Dongli; Chen, Ligang

    2017-01-01

    A novel and highly efficient approach to obtain magnetic molecularly imprinted polymers is described to detect avermectin in fish samples. The magnetic molecularly imprinted polymers were synthesized by surface imprinting polymerization using magnetic multiwalled carbon nanotubes as the support materials, atom transfer radical polymerization as the polymerization method, avermectin as template, acrylamide as functional monomer, and ethylene glycol dimethacrylate as crosslinker. The characteristics of the magnetic molecularly imprinted polymers were assessed by using transmission electron microscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, vibrating sample magnetometry, X-ray diffraction, and thermogravimetric analysis. The binding characteristics of magnetic molecularly imprinted polymers were researched through isothermal adsorption experiment, kinetics adsorption experiment, and the selectivity experiment. Coupled with ultra high performance liquid chromatography and tandem mass spectrometry, the extraction conditions of the magnetic molecularly imprinted polymers as adsorbents for avermectin were investigated in detail. The recovery of avermectin was 84.2-97.0%, and the limit of detection was 0.075 μg/kg. Relative standard deviations of intra- and inter-day precisions were in the range of 1.7-2.9% and 3.4-5.6%, respectively. The results demonstrated that the extraction method not only has high selectivity and accuracy, but also is convenient for the determination of avermectin in fish samples. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  17. New sample preparation method based on task-specific ionic liquids for extraction and determination of copper in urine and wastewater.

    Science.gov (United States)

    Trtić-Petrović, Tatjana; Dimitrijević, Aleksandra; Zdolšek, Nikola; Đorđević, Jelena; Tot, Aleksandar; Vraneš, Milan; Gadžurić, Slobodan

    2017-11-02

    In this study, four hydrophilic ionic liquids (ILs) containing 1-alkyl-3-methylimidazolim cation and either salicylate or chloride anions were synthetized and studied as new task-specific ionic liquids (TSILs) suitable for aqueous biphasic system (ABS) formation and selective one-step extraction of copper(II). TSILs are designed so that the anion is responsible for forming the complex with metal(II) and preventing hydrolysis of metal cations at very strong alkaline pH, whereas the cation is responsible for selective extraction of metal(II)-salicylate complexes. It was found that 1-butyl-3-methylimidazolium salicylate could be used for selective extraction of Cu(II) in the presence of Zn(II), Cd(II), and Pb(II) at very alkaline solution without metal hydroxide formation. It was assumed that formation of metal(II)-salicylate complexes prevents the hydrolysis of the metal ions in alkaline solutions. The determined stability constants for Cu(II)-salicylate complexes, where salicylate was derived from different ionic liquids, indicated that there was no significant influence of the cation of the ionic liquid on the stability of the complexes. The ABS based on 1-butyl-3-methylimidazolium salicylate has been applied as the sample preparation step prior to voltammetric determination of Cu(II). The effect of volume of aqueous sample and IL and extraction time were investigated and optimum extraction conditions were determined. The obtained detection limits were 8 ng dm-3. The optimized method was applied for the determination of Cu(II) in tap water, wastewater, and urine. The study indicated that application of the ABS based on 1-butyl-3-methylimidazolium salicylate ionic liquid could be successfully applied as the sample preparation method for the determination of Cu(II) from various environmental samples. Graphical abstract Aqueous biphasic system based on task-specific ionic liquid as a sample pretreatment for selective determination of Cu(II) in biological and

  18. Preparation of bismuth stannate/silver@silver chloride film samples with enhanced photocatalytic performance and self-cleaning ability.

    Science.gov (United States)

    Zhao, Xiaojuan; Lv, Xiang; Cui, Hongda; Wang, Tianhe

    2017-12-01

    We report a novel technique to fabricate bismuth stannate/silver@silver chloride (Bi 2 Sn 2 O 7 /Ag@AgCl) films on conventional glass substrates. The film exhibited a remarkable self-cleaning capability against organic dyes under visible light. Porous Bi 2 Sn 2 O 7 (BSO) film was first sintered on a glass substrate, followed by implantation of AgCl in it and photo-induction to produce Ag@AgCl. The degradation of organic dyes and photoelectrochemical studies indicate that, compared with BSO film, Bi 2 Sn 2 O 7 /Ag@AgCl film had a much improved photocatalytic ability, probably due to the enhanced electron transfer efficiency and synergistic effect of visible light absorption of the two semiconductors. The possible mechanism of this marked improvement was investigated and interpreted in terms of electrons and holes separation efficiency and charge circulation routes at the interfaces within the Bi 2 Sn 2 O 7 /Ag@AgCl composite film. The film provided in this study may well have practical applications due to its simplicity of preparation, excellent photocatalytic ability and reasonable stability. Copyright © 2017. Published by Elsevier Inc.

  19. Development of a Method for a Sensitive Simultaneous Determination of Dopamine and Paracetamol in Biological Samples and Pharmaceutical Preparations

    Directory of Open Access Journals (Sweden)

    Ali Babaei

    2011-01-01

    Full Text Available A chemically modified electrode is constructed based on multiwalled carbon nanotube—modified glassy carbon electrode (MWCNTs/GCE. The measurements were carried out by application of differential pulse voltammetry (DPV, cyclic voltammetry (CV, and chronoamperometry (CA methods. Application of DPV method showed wide linear range of DA from 1 μM to 540 μM and a detection limit of 0.098 μM (S/N=3. The linear range of PAR of 3 μM to 300 μM and a detection limit of 0.15 μM, were obtained. The modified electrode showed electrochemical responses with high sensitivity, high selectivity, and excellent stability for DA and PAR determination at optimal conditions, which makes it a suitable sensor for simultaneous submicromolar detection of DA and PAR in solutions. The analytical performance of this sensor has been evaluated for detection of DA and PAR in human serum, human urine, and pharmaceutical preparation with satisfactory results.

  20. Green and efficient sample preparation method for the determination of catalyst residues in margarine by ICP-MS.

    Science.gov (United States)

    Hartwig, Carla Andrade; Pereira, Rodrigo Mendes; Novo, Diogo La Rosa; Oliveira, Dirce Taina Teixeira; Mesko, Marcia Foster

    2017-11-01

    Responding to the need for green and efficient methods to determine catalyst residues with suitable precision and accuracy in samples with high fat content, the present work evaluates a microwave-assisted ultraviolet digestion (MW-UV) system for margarines and subsequent determination of Ni, Pd and Pt using inductively coupled plasma mass spectrometry (ICP-MS). It was possible to digest up to 500mg of margarine using only 10mL of 4molL -1 HNO 3 with a digestion efficiency higher than 98%. This allowed the determination of catalyst residues using the ICP-MS and free of interferences. For this purpose, the following experimental parameters were evaluated: concentration of digestion solution, sample mass and microwave irradiation program. The residual carbon content was used as a parameter to evaluate the efficiency of digestion and to select the most suitable experimental conditions. The accuracy evaluation was performed by recovery tests using a standard solution and certified reference material, and recoveries ranging from 94% to 99% were obtained for all analytes. The limits of detection for Ni, Pd and Pt using the proposed method were 35.6, 0.264 and 0.302ngg -1 , respectively. When compared to microwave-assisted digestion (MW-AD) in closed vessels using concentrated HNO 3 (used as a reference method for sample digestion), the proposed MW-UV could be considered an excellent alternative for the digestion of margarine, as this method requires only a diluted nitric acid solution for efficient digestion. In addition, MW-UV provides appropriate solutions for further ICP-MS determination with suitable precision (relative standard deviation catalyst residues was in agreement with the current legislation or recommendations. Copyright © 2017 Elsevier B.V. All rights reserved.

  1. A low cost point-of-care viscous sample preparation device for molecular diagnosis in the developing world; an example of microfluidic origami.

    Science.gov (United States)

    Govindarajan, A V; Ramachandran, S; Vigil, G D; Yager, P; Böhringer, K F

    2012-01-07

    The lab-on-a-chip concept has led to several point-of-care (POC) diagnostic microfluidic platforms. However, few of these can process raw samples for molecular diagnosis and fewer yet are suited for use in a resource-limited setting without permanent electrical infrastructure. We present here a very low cost paper microfluidic device for POC extraction of bacterial DNA from raw viscous samples--a challenge for conventional microfluidic platforms. This is an example of "microfluidic origami" in that the system is activated by folding; demonstrated here is room temperature cell lysis and DNA extraction from pig mucin (simulating sputum) spiked with E. coli without the use of external power. The microfluidic origami device features dry reagent storage and rehydration of the lysis buffer. We demonstrate DNA extraction from samples with a bacterial load as low as 33 CFU ml(-1). Extraction times, starting from the raw sample, have been optimized to about 1.5 h without the use of external power, or to within 1 h using an oven or a heater block. The fabrication of this paper microfluidic device can be translated into high volume production in the developing world without the need for a semiconductor clean room or a microfabrication facility. The sample preparation can be performed with the addition of just the sample, water, ethanol and elute buffer to the device, thus reducing chemical hazards during transport and handling.

  2. Sample Preparation and Liquid Chromatography Mass Spectrometry Analysis of Alkylphenolic Compounds and Steroid Sex Hormones in Sediments

    Directory of Open Access Journals (Sweden)

    Mira Petrovia

    2002-01-01

    Full Text Available A new methodology, based on the use of accelerated solvent extraction (ASE and highly selective cleanup using restricted access material (RAM on-line coupled with liquid chromatography–mass spectrometry (LC–MS, is presented for the simultaneous and unequivocal determination of alkylphenol ethoxylates (APEOs, their degradation products and halogenated derivatives, and steroid sex hormones in sediment samples. Using the integrated RAM–LC–MS system, the simultaneous determination of alkylphenolic compounds and sex hormones was achieved, yielding recoveries higher than 60% and producing low MS background noise.

  3. ICP-MS-based characterization of inorganic nanoparticles--sample preparation and off-line fractionation strategies.

    Science.gov (United States)

    Fabricius, Anne-Lena; Duester, Lars; Meermann, Björn; Ternes, Thomas A

    2014-01-01

    Validated and easily applicable analytical tools are required to develop and implement regulatory frameworks and an appropriate risk assessment for engineered nanoparticles (ENPs). Concerning metal-based ENPs, two main aspects are the quantification of the absolute mass concentration and of the "dissolved" fraction in, e.g., (eco)toxicity and environmental studies. To provide information on preparative aspects and on potential uncertainties, preferably simple off-line methods were compared to determine (1) the total concentration of suspensions of five metal-based ENP materials (Ag, TiO2, CeO2, ZnO, and Au; two sizes), and (2) six methods to quantify the "dissolved" fraction of an Ag ENP suspension. Focusing on inductively coupled plasma-mass spectrometry, the total concentration of the ENP suspensions was determined by direct measurement, after acidification and after microwave-assisted digestion. Except for Au 10 nm, the total concentrations determined by direct measurements were clearly lower than those measured after digestion (between 61.1 % for Au 200 nm and 93.7 % for ZnO). In general, acidified suspensions delivered better recoveries from 89.3 % (ZnO) to 99.3 % (Ag). For the quantification of dissolved fractions two filtration methods (ultrafiltration and tangential flow filtration), centrifugation and ion selective electrode were mainly appropriate with certain limitations, while dialysis and cloud point extraction cannot be recommended. With respect to precision, time consumption, applicability, as well as to economic demands, ultrafiltration in combination with microwave digestion was identified as best practice.

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

    Directory of Open Access Journals (Sweden)

    Ali Mirabi

    2016-09-01

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

  5. Flow-injection chemiluminescence determination of cloxacillin in water samples and pharmaceutical preparation by using CuO nanosheets-enhanced luminol-hydrogen peroxide system

    Science.gov (United States)

    Khataee, Alireza; Iranifam, Mortaza; Fathinia, Mehrangiz; Nikravesh, Mina

    2015-01-01

    In this paper, a rapid and sensitive flow-injection chemiluminescence (flow-CL) system was developed for the determination of cloxacillin sodium in environmental water samples and pharmaceutical preparations. The method was based on the enhancement effect of cloxacillin sodium on the CL reaction of luminal-H2O2-CuO nanosheets (NSs) in alkaline medium. The CuO nanosheets were synthesized using a green sonochemical method. The physical properties of the synthesized CuO nanosheets were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses. The influences of various experimental factors such as H2O2, NaOH, luminol and CuO nanosheets concentrations were investigated. Under the optimum conditions, the enhanced CL intensity was linearly related to the concentration of cloxacillin sodium in the range of the 0.05-30.00 mg L-1 with a correlation coefficient of 0.995. The corresponding detection limit (3σ) was calculated to be 0.026 mg L-1. The relative standard deviation (RSD) of the developed method was 2.21% with 11 repeated measurements of 4.00 mg L-1 cloxacillin sodium. Also, a total analysis time per sample was 30 s which confirmed the rapidity of the proposed method. The analytical applicability of the proposed CL system was assessed by determining cloxacillin sodium in spiked environmental water samples and pharmaceutical preparation. Furthermore, the possible mechanism of CL reaction was discussed.

  6. Preparation and use of maize tassels' activated carbon for the adsorption of phenolic compounds in environmental waste water samples.

    Science.gov (United States)

    Olorundare, O F; Msagati, T A M; Krause, R W M; Okonkwo, J O; Mamba, B B

    2015-04-01

    The determination and remediation of three phenolic compounds bisphenol A (BPA), ortho-nitrophenol (o-NTP), parachlorophenol (PCP) in wastewater is reported. The analysis of these molecules in wastewater was done using gas chromatography (GC) × GC time-of-flight mass spectrometry while activated carbon derived from maize tassel was used as an adsorbent. During the experimental procedures, the effect of various parameters such as initial concentration, pH of sample solution, eluent volume, and sample volume on the removal efficiency with respect to the three phenolic compounds was studied. The results showed that maize tassel produced activated carbon (MTAC) cartridge packed solid-phase extraction (SPE) system was able to remove the phenolic compounds effectively (90.84-98.49%, 80.75-97.11%, and 78.27-97.08% for BPA, o-NTP, and PCP, respectively). The MTAC cartridge packed SPE sorbent performance was compared to commercially produced C18 SPE cartridges and found to be comparable. All the parameters investigated were found to have a notable influence on the adsorption efficiency of the phenolic compounds from wastewaters at different magnitudes.

  7. Chromatin immunoprecipitation (ChIP: revisiting the efficacy of sample preparation, sonication, quantification of sheared DNA, and analysis via PCR.

    Directory of Open Access Journals (Sweden)

    Pamela D Schoppee Bortz

    Full Text Available The "quantitative" ChIP, a tool commonly used to study protein-DNA interactions in cells and tissue, is a difficult assay often plagued with technical error. We present, herein, the process required to merge multiple protocols into a quick, reliable and easy method and an approach to accurately quantify ChIP DNA prior to performing PCR. We demonstrate that high intensity sonication for at least 30 min is required for full cellular disruption and maximum DNA recovery because ChIP lysis buffers fail to lyse formaldehyde-fixed cells. In addition, extracting ChIP DNA with chelex-100 yields samples that are too dilute for evaluation of shearing efficiency or quantification via nanospectrophotometry. However, DNA extracted from the Mock-ChIP supernatant via the phenol-chloroform-isoamyl alcohol (PCIA method can be used to evaluate DNA shearing efficiency and used as the standard in a fluorescence-based microplate assay. This enabled accurate quantification of DNA in chelex-extracted ChIP samples and normalization to total DNA concentration prior to performing real-time PCR (rtPCR. Thus, a quick ChIP assay that can be completed in nine bench hours over two days has been validated along with a rapid, accurate and repeatable way to quantify ChIP DNA. The resulting rtPCR data more accurately depicts treatment effects on protein-DNA interactions of interest.

  8. 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.

  9. Liquid-phase sample preparation method for real-time monitoring of airborne asbestos fibers by dual-mode high-throughput microscopy.

    Science.gov (United States)

    Cho, Myoung-Ock; Kim, Jung Kyung; Han, Hwataik; Lee, Jeonghoon

    2013-01-01

    Asbestos that had been used widely as a construction material is a first-level carcinogen recognized by the World Health Organization. It can be accumulated in body by inhalation causing virulent respiratory diseases including lung cancer. In our previous study, we developed a high-throughput microscopy (HTM) system that can minimize human intervention accompanied by the conventional phase contrast microscopy (PCM) through automated counting of fibrous materials and thus significantly reduce analysis time and labor. Also, we attempted selective detection of chrysotile using DksA protein extracted from Escherichia coli through a recombinant protein production technique, and developed a dual-mode HTM (DM-HTM) by upgrading the HTM device. We demonstrated that fluorescently-labeled chrysotile asbestos fibers can be identified and enumerated automatically among other types of asbestos fibers or non-asbestos particles in a high-throughput manner through a newly modified HTM system for both reflection and fluorescence imaging. However there is a limitation to apply DM-HTM to airborne sample with current air collecting method due to the difficulty of applying the protein to dried asbestos sample. Here, we developed a technique for preparing liquid-phase asbestos sample using an impinger normally used to collect odor molecules in the air. It would be possible to improve the feasibility of the dual-mode HTM by integrating a sample preparation unit for making collected asbestos sample dispersed in a solution. The new technique developed for highly sensitive and automated asbestos detection can be a potential alternative to the conventional manual counting method, and it may be applied on site as a fast and reliable environmental monitoring tool.

  10. A fast and sensitive LC-MS/MS method for the quantification of fosfomycin in human urine and plasma using one sample preparation method and HILIC chromatography.

    Science.gov (United States)

    Wijma, Rixt A; Bahmany, Soma; Wilms, E B; van Gelder, T; Mouton, Johan W; Koch, Birgit C P

    2017-09-01

    Fosfomycin is an old antibiotic that is increasingly prescribed because of emergence of the antibiotic resistance and the growing incidence of multi-drug resistant infections. Surprisingly, little is known about its pharmacokinetics (PK) and the pharmacodynamics (PD). Quantification of fosfomycin in both urine and plasma provides insight into the PK/PD characteristics of fosfomycin, which is crucial for the optimization of the therapy and the prevention of the emergence of resistance. An analytical method is therefore needed for the quantification of fosfomycin in both urine and plasma. A fast and sensitive tandem mass spectrometry method in combination with HILIC chromatography for the quantification of fosfomycin with a universal sample preparation method for urine and plasma was developed and validated according to FDA guidelines. The universal sample preparation method only requires 100μL of a sample, the addition of the internal standard fosfomycin-13C3 benzylamine and an ultrafiltration step. The method is applicable for the concentration range of 0.75-375mg/L (R2 of 0.9998 in both matrices) encompassing the clinically relevant concentration range based on the susceptibility of possible (uro)pathogens in the clinical setting. The validation results for urine and plasma for all QC levels, were samples were stable at 4°C and 15°C for at least 72h and stored samples at -80°C were stable for at least 6 months. Selectivity and sensitivity were confirmed and no carry-over was observed. The method was successfully applied in two pharmacokinetic studies in healthy volunteers and patients respectively. Copyright © 2017 Elsevier B.V. All rights reserved.

  11. MSPD sample preparation approach for reversed-phase liquid chromatographic analysis of pesticide residues in stem of coconut palm.

    Science.gov (United States)

    Ferreira, Jordana Alves; Santos, Luís Fabrício Santana; Souza, Nicaellen Roberta da Silva; Navickiene, Sandro; de Oliveira, Frederico Alberto; Talamini, Viviane

    2013-08-01

    A method was developed using matrix solid-phase dispersion, together with liquid chromatography with ultraviolet diode array detector for determination of carbofuran, difenoconazole, β-cyfluthrin, spirodiclofen and thiophanate-methyl in stem of coconut palm. The best results were obtained using 2.0 g of stem, 1.6 g of Florisil as sorbent and cyclohexane:acetone mixture (4:1). The method was validated using stem samples spiked with pesticides at four concentration levels (0.05-2.0 μg/g). Average recoveries ranged from 70 % to 114.3 %, with relative standard deviations between 1.2 % and 19.2 %. Detection and quantification limits were in the ranges 0.02-0.03 and 0.05-0.1 μg/g, respectively.

  12. Routine sample preparation and HPLC analysis for ascorbic acid (vitamin C) determination in wheat plants and Arabidopsis leaf tissues.

    Science.gov (United States)

    Szalai, Gabriella; Janda, T; Pál, Magda

    2014-06-01

    Plants have developed various mechanisms to protect themselves against oxidative stress. One of the most important non-enzymatic antioxidants is ascorbic acid. There is thus a need for a rapid, sensitive method for the analysis of the reduced and oxidised forms of ascorbic acid in crop plants. In this paper a simple, economic, selective, precise and stable HPLC method is presented for the detection of ascorbate in plant tissue. The sensitivity, the short retention time and the simple isocratic elution mean that the method is suitable for the routine quantification of ascorbate in a high daily sample number. The method has been found to be better than previously reported methods, because of the use of an economical, readily available mobile phase, UV detection and the lack of complicated extraction procedures. The method has been tested on Arabidopsis plants with different ascorbate levels and on wheat plants during Cd stress.

  13. Combination of dispersive liquid-liquid microextraction and solid-phase microextraction: An efficient hyphenated sample preparation method.

    Science.gov (United States)

    Jafari, Mohammad T; Saraji, Mohammad; Mossaddegh, Mehdi

    2016-09-30

    Two well-known microextraction methods, dispersive liquid-liquid microextraction (DLLME) and solid-phase microextraction (SPME), were combined, resulting in as an encouraging method. The method, named DLLME-SPME, was performed based on total vaporization technique. For the DLLME step, 1,1,2,2-tetrachloroethane and acetonitrile were used as extraction and disperser solvents, respectively. Halloysite nanotubes-titanium dioxide was used as the fiber coating in the SPME step. The method was applied for the extraction of diazinon and parathion (as the test compounds) in environmental water samples and fruit juices, and gas chromatography-corona discharge ion mobility spectrometry was used as the determination apparatus. Desorption temperature and time, extraction temperature and time, and the volume of the extracting solvent in the DLLME step were optimized as the effective parameters on the extraction efficiency. The relative standard deviations (RSDs) of intra-day were found to be 4-7% and 6-8% for diazinon and parathion, respectively. Also, the RSDs of inter-day were 7-9% and 8-10% for diazinon and parathion, respectively. The limits of quantification and detection were obtained to be 0.015 and 0.005μgL(-1) for diazinon, and 0.020 and 0.007μgL(-1) for parathion. A good linearity range (r(2)˃0.993) was obtained in the range of 0.015-3.000 and 0.020-3.000μgL(-1) for diazinon and parathion, respectively. The high enrichment factors were obtained as 3150 and 2965 for diazinon and parathion, respectively. This method showed high sensitivity with good recovery values (between 87 and 99%) for the extraction of target analytes in the real samples. Overall, the results revealed that the developed DLLME-SPME method had better extraction efficiency than DLLME and SPME alone. Copyright © 2016 Elsevier B.V. All rights reserved.

  14. Comparison of pre-analytical FFPE sample preparation methods and their impact on massively parallel sequencing in routine diagnostics.

    Directory of Open Access Journals (Sweden)

    Carina Heydt

    Full Text Available Over the last years, massively parallel sequencing has rapidly evolved and has now transitioned into molecular pathology routine laboratories. It is an attractive platform for analysing multiple genes at the same time with very little input material. Therefore, the need for high quality DNA obtained from automated DNA extraction systems has increased, especially to those laboratories which are dealing with formalin-fixed paraffin-embedded (FFPE material and high sample throughput. This study evaluated five automated FFPE DNA extraction systems as well as five DNA quantification systems using the three most common techniques, UV spectrophotometry, fluorescent dye-based quantification and quantitative PCR, on 26 FFPE tissue samples. Additionally, the effects on downstream applications were analysed to find the most suitable pre-analytical methods for massively parallel sequencing in routine diagnostics. The results revealed that the Maxwell 16 from Promega (Mannheim, Germany seems to be the superior system for DNA extraction from FFPE material. The extracts had a 1.3-24.6-fold higher DNA concentration in comparison to the other extraction systems, a higher quality and were most suitable for downstream applications. The comparison of the five quantification methods showed intermethod variations but all methods could be used to estimate the right amount for PCR amplification and for massively parallel sequencing. Interestingly, the best results in massively parallel sequencing were obtained with a DNA input of 15 ng determined by the NanoDrop 2000c spectrophotometer (Thermo Fisher Scientific, Waltham, MA, USA. No difference could be detected in mutation analysis based on the results of the quantification methods. These findings emphasise, that it is particularly important to choose the most reliable and constant DNA extraction system, especially when using small biopsies and low elution volumes, and that all common DNA quantification techniques can

  15. Preparation of NO2-Aged Silver-Functionalized Silica-Aerogel and Silver Mordenite Samples

    Energy Technology Data Exchange (ETDEWEB)

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

    2016-10-01

    Reprocessing used nuclear fuel can result in the volatilization of radioactive gaseous species, including 129I, into the various process off-gas streams. In order to comply with US regulatory requirements, plant off-gas streams must be treated to remove the iodine prior to discharging the off-gas into the environment. The performance of available gas removal methods depends not only on the concentration of the volatile radioisotope of interest, but also on other constituents that could be present in the reprocessing off-gas streams. Some of the constituents, such as NOx produced during fuel dissolution, are known to have deleterious effects on the capture performance of silver-based sorbents used for iodine removal. Commercially available reduced silver mordenite (AgZ) has an iodine saturation concentration of 7.0-9.0 wt%, and its iodine sorption capacity is reduced by 20-50% as a result of NO2 aging. Silverfunctionalized silica aerogel (AgAerogel), an alternative for iodine capture, has an initial iodine saturation of 29.0 wt% and its iodine capacity is only reduced by 15% from NO2 aging. Understanding the differences in aging behavior between AgZ and AgAerogel is critical to determining the behavior of these sorbents under realistic off-gas conditions. To assist in future technical studies on this topic, samples of both AgZ and AgAerogel were aged with NO2. In the experiment, 10.2190 g of AgZ and 10.1771 g of AgAerogel were exposed to a static 0.75% NO2/dry air blend for a period of 28 days. The samples were then removed and stored under argon until needed for future experiments.=

  16. Two-Dimensional Capillary Electrophoresis with On-Line Sample Preparation and Cyclodextrin Separation Environment for Direct Determination of Serotonin in Human Urine

    Directory of Open Access Journals (Sweden)

    Juraj Piešťanský

    2017-10-01

    Full Text Available An advanced two-dimensional capillary electrophoresis method, based on on-line combination of capillary isotachophoresis and capillary zone electrophoresis with cyclodextrin additive in background electrolyte, was developed for effective determination of serotonin in human urine. Hydrodynamically closed separation system and large bore capillaries (300–800 µm were chosen for the possibility to enhance the sample load capacity, and, by that, to decrease limit of detection. Isotachophoresis served for the sample preseparation, defined elimination of sample matrix constituents (sample clean up, and preconcentration of the analyte. Cyclodextrin separation environment enhanced separation selectivity of capillary zone electrophoresis. In this way, serotonin could be successfully separated from the rest of the sample matrix constituents migrating in capillary zone electrophoresis step so that human urine could be directly (i.e., without any external sample preparation injected into the analyzer. The proposed method was successfully validated, showing favorable parameters of sensitivity (limit of detection for serotonin was 2.32 ng·mL−1, linearity (regression coefficient higher than 0.99, precision (repeatability of the migration time and peak area were in the range of 0.02–1.17% and 5.25–7.88%, respectively, and recovery (ranging in the interval of 90.0–93.6%. The developed method was applied for the assay of the human urine samples obtained from healthy volunteers. The determined concentrations of serotonin in such samples were in the range of 12.4–491.2 ng·mL−1 that was in good agreement with literature data. This advanced method represents a highly effective, reliable, and low-cost alternative for the routine determination of serotonin as a biomarker in human urine.

  17. Comparative clinical sample preparation of DNA and RNA viral nucleic acids for a commercial deep sequencing system (Illumina MiSeq(®)).

    Science.gov (United States)

    Ullmann, Leila Sabrina; de Camargo Tozato, Claudia; Malossi, Camila Dantas; da Cruz, Tais Fukuta; Cavalcante, Raíssa Vasconcelos; Kurissio, Jacqueline Kazue; Cagnini, Didier Quevedo; Rodrigues, Marianna Vaz; Biondo, Alexander Welker; Araujo, João Pessoa

    2015-08-01

    Sequence-independent methods for viral discovery have been widely used for whole genome sequencing of viruses. Different protocols for viral enrichment, library preparation and sequencing have increasingly been more available and at lower costs. However, no study to date has focused on optimization of viral sample preparation for commercial deep sequencing. Accordingly, the aim of the present study was to evaluate an In-House enzymatic protocol for double-stranded DNA (dsDNA) synthesis and also compare the use of a commercially available kit protocol (Nextera XT, Illumina Inc, San Diego, CA, USA) and its combination with a library quantitation kit (Kapa, Kapa Biosystems, Wilmington, MA, USA) for deep sequencing (Illumina Miseq). Two RNA viruses (canine distemper virus and dengue virus) and one ssDNA virus (porcine circovirus type 2) were tested with the optimized protocols. The tested method for dsDNA synthesis has shown satisfactory results and may be used in laboratory setting, particularly when enzymes are already available. Library preparation combining commercial kits (Nextera XT and Kapa) has yielded more reads and genome coverage, probably due to a lack of small fragment recovering at the normalization step of Nextera XT. In addition, libraries may be diluted or concentrated to provide increase on genome coverage with Kapa quantitation. Copyright © 2015 Elsevier B.V. All rights reserved.

  18. Simultaneous stereoselective detection of chiral fungicides in soil by LC-MS/MS with fast sample preparation.

    Science.gov (United States)

    Chai, Tingting; Jia, Qi; Yang, Shuming; Qiu, Jing

    2014-03-01

    An enantioselective method was developed for the simultaneous detection of five chiral fungicides in soil, including fenbuconazole (1), tetraconazole (2), nuarimol (3), triticonazole (4), and simeconazole (5) by LC-MS/MS on a chiral stationary phase of cellulose tris-(3-chloro-4-methylphenylcarbamate) with a gradient elution. A new multifunctional filter was designed to simplify the QuEChERS (where QuEChERS is quick, easy, cheap, effective, rugged, and safe) method by simultaneous cleanup and filtration when the sample extracts were directly passed through it. Good linearities (R2 > 0.9980) were obtained in the range 0.005-2.5 mg/L, and the recovery rates were 77.4-103.6% with RSDs of 0.7-12.2% for intraday precision and 1.2-11.0% for interday precision. The LODs and LOQs for all enantiomers were in the range 0.1-0.2 and 0.25-0.5 μg/kg, respectively. The analysis of the incubated soil suggests that this method is reliable and practical for the stereoselective detection of chiral fungicides. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  19. 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.

  20. Rapid mass spectrometric analysis of 15N-Leu incorporation fidelity during preparation of specifically labeled NMR samples.

    Science.gov (United States)

    Truhlar, Stephanie M E; Cervantes, Carla F; Torpey, Justin W; Kjaergaard, Magnus; Komives, Elizabeth A

    2008-09-01

    Advances in NMR spectroscopy have enabled the study of larger proteins that typically have significant overlap in their spectra. Specific (15)N-amino acid incorporation is a powerful tool for reducing spectral overlap and attaining reliable sequential assignments. However, scrambling of the label during protein expression is a common problem. We describe a rapid method to evaluate the fidelity of specific (15)N-amino acid incorporation. The selectively labeled protein is proteolyzed, and the resulting peptides are analyzed using MALDI mass spectrometry. The (15)N incorporation is determined by analyzing the isotopic abundance of the peptides in the mass spectra using the program DEX. This analysis determined that expression with a 10-fold excess of unlabeled amino acids relative to the (15)N-amino acid prevents the scrambling of the (15)N label that is observed when equimolar amounts are used. MALDI TOF-TOF MS/MS data provide additional information that shows where the "extra" (15)N labels are incorporated, which can be useful in confirming ambiguous assignments. The described procedure provides a rapid technique to monitor the fidelity of selective labeling that does not require a lot of protein. These advantages make it an ideal way of determining optimal expression conditions for selectively labeled NMR samples.

  1. Determination of macro- and micronutrients in plant leaves by high-resolution continuum source flame atomic absorption spectrometry combining instrumental and sample preparation strategies

    Science.gov (United States)

    Oliveira, Silvana R.; Gomes Neto, José A.; Nóbrega, Joaquim A.; Jones, Bradley T.

    2010-04-01

    A method for determination of B, Ca, Cu, Fe, K, Mg, Mn, Mo, P, S and Zn in plant tissues by high-resolution continuum source flame atomic absorption spectrometry (HR-CS FAAS) is proposed. This method is based on special features of HR-CS-AAS, such as side pixel registration, wavelength integrated absorbance, and molecular absorption bands, for determining macro- and micronutrients in foliar analysis without requiring several different strategies for sample preparation and adjustment of the analytes concentration ranges. Plant samples were analyzed and results for certified materials were in agreement at a 95% confidence level (paired t-test) with reference values. Recoveries of analytes added to plant digests varied within the 82-112% interval. Relative standard deviations ( n = 12) were lower than or equal to 5.7% for all analytes in all concentration ranges.

  2. Preparation and evaluation of a novel molecularly imprinted polymer coating for selective extraction of indomethacin from biological samples by electrochemically controlled in-tube solid phase microextraction

    Energy Technology Data Exchange (ETDEWEB)

    Asiabi, Hamid [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Yamini, Yadollah, E-mail: yyamini@modares.ac.ir [Department of Chemistry, Tarbiat Modares University, P.O. Box 14115-175, Tehran (Iran, Islamic Republic of); Seidi, Shahram; Ghahramanifard, Fazel [Department of Analytical Chemistry, Faculty of Chemistry, K.N. Toosi University of Technology, Tehran (Iran, Islamic Republic of)

    2016-03-24

    In the present work, an automated on-line electrochemically controlled in-tube solid-phase microextraction (EC-in-tube SPME) coupled with HPLC-UV was developed for the selective extraction and preconcentration of indomethacin as a model analyte in biological samples. Applying an electrical potential can improve the extraction efficiency and provide more convenient manipulation of different properties of the extraction system including selectivity, clean-up, rate, and efficiency. For more enhancement of the selectivity and applicability of this method, a novel molecularly imprinted polymer coated tube was prepared and applied for extraction of indomethacin. For this purpose, nanostructured copolymer coating consisting of polypyrrole doped with ethylene glycol dimethacrylate was prepared on the inner surface of a stainless-steel tube by electrochemical synthesis. The characteristics and application of the tubes were investigated. Electron microscopy provided a cross linked porous surface and the average thickness of the MIP coating was 45 μm. Compared with the non-imprinted polymer coated tubes, the special selectivity for indomethacin was discovered with the molecularly imprinted coated tube. Moreover, stable and reproducible responses were obtained without being considerably influenced by interferences commonly existing in biological samples. Under the optimal conditions, the limits of detection were in the range of 0.07–2.0 μg L{sup −1} in different matrices. This method showed good linearity for indomethacin in the range of 0.1–200 μg L{sup −1}, with coefficients of determination better than 0.996. The inter- and intra-assay precisions (RSD%, n = 3) were respectively in the range of 3.5–8.4% and 2.3–7.6% at three concentration levels of 7, 70 and 150 μg L{sup −1}. The results showed that the proposed method can be successfully applied for selective analysis of indomethacin in biological samples. - Graphical abstract: An automated on

  3. Sample preparation-free, real-time detection of microRNA in human serum using piezoelectric cantilever biosensors at attomole level.

    Science.gov (United States)

    Johnson, Blake N; Mutharasan, Raj

    2012-12-04

    A sensitive, selective, sample preparation-free method for near real-time detection of microRNA in buffer and human serum is given using gold (Au)-coated dynamic piezoelectric cantilever sensors. Sensor response to thiolated DNA probe chemisorption, hsa-let-7a hybridization, labeled-DNA hybridization, and Au nanoparticle-functionalized DNA hybridization was monitored continuously in flowing liquid samples using custom flow-cells. The assay showed successful detection of target let-7a with a dynamic range spanning 6 orders of magnitude (10 fM-1 nM) with a limit of detection of less than 10 attomoles (∼4 fM). The serum background had negligible effect on sensitivity relative to the results obtained in the buffer due to reduction in nonspecific binding caused by continuous sensor vibration. Both hybridization and nonspecific binding reduction were confirmed using fluorescence-based assays to support sensor-based results. The sensor-based method demonstrated excellent selectivity for the microRNA target in comparison with similar microRNA differing by only a single nucleotide (hsa-let-7c) and random microRNA sequences. Au nanoparticle-based amplification of sensor response was investigated and led to an order of magnitude improvement in the detection limit and a 128% amplification of sensor response over the entire dynamic range. Au nanoparticle amplification was verified by scanning electron microscopy. The cantilever sensor-based microRNA assay provides competitive sensitivity with current microRNA detection methods and has the advantage of requiring no sample preparation, even when working with biological samples that contain a complex background.

  4. Multiresidue method for the determination of 77 pesticides in wine using QuEChERS sample preparation and gas chromatography with mass spectrometry.

    Science.gov (United States)

    Jiang, Y; Li, X; Xu, J; Pan, C; Zhang, J; Niu, W

    2009-06-01

    A method based on a QuEChERS (quick, easy, cheap, effective, rugged, safe) sample preparation method and gas chromatography with mass spectrometric detection by selected ion monitoring (GC/MS-SIM) was developed for simultaneous determination of 77 pesticide residues in wine. An extraction of 10 ml of sample with acetonitrile followed by liquid-liquid partition formed by the addition of 4 g MgSO(4) and 3 g NaCl was applied in the sample preparation. The clean-up was carried out by applying dispersive solid-phase with 150 mg MgSO(4) as well as 50 mg primary secondary amine (PSA). One quantitation ion and at least two identification ions were selected in the analytical method for each pesticide compound by GC/MS. The recovery data were obtained by spiking blank samples at two concentration levels (0.05 and 0.2 mg l(-1)). The recoveries of all pesticides were in the range 70-110%, with intra-day precision of less than 15%, and the inter-day precision of less than 22% and 15% for 0.05 and 0.2 mg l(-1) fortification levels, respectively. Linearity was between 0.02 and 2 mg l(-1) with determination coefficients (R(2)) greater than 0.98 for all compounds. The limits of quantification (LOQs) for the 77 pesticides ranged from 0.003 to 0.05 mg l(-1). This method was applied for routine analysis in market products.

  5. Optical properties of (162173) 1999 JU3: in preparation for the JAXA Hayabusa 2 sample return mission

    Energy Technology Data Exchange (ETDEWEB)

    Ishiguro, Masateru [Department of Physics and Astronomy, Seoul National University, Gwanak, Seoul 151-742 (Korea, Republic of); Kuroda, Daisuke [Okayama Astrophysical Observatory, National Astronomical Observatory of Japan, Asakuchi, Okayama 719-0232 (Japan); Hasegawa, Sunao; Abe, Masanao; Yoshikawa, Makoto [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, Sagamihara, Kanagawa 252-5210 (Japan); Kim, Myung-Jin [Department of Astronomy, Yonsei University, 50 Yonsei-ro, Seodaemun-gu, Seoul 120-749 (Korea, Republic of); Choi, Young-Jun [Korea Astronomy and Space Science Institute, 776 Daedeokdae-ro, Yuseong-gu, Daejeon 305-348 (Korea, Republic of); Moskovitz, Nicholas [Lowell Observatory, 1400 W. Mars Hill Road, Flagstaff, AZ 86001 (United States); Abe, Shinsuke [Department of Aerospace Engineering, Nihon University, 7-24-1 Narashinodai Funabashi, Chiba 274-8501 (Japan); Pan, Kang-Sian [Institute of Astronomy, National Central University, 300 Jhongda Road, Jhongli, Taoyuan 32001, Taiwan (China); Takahashi, Jun; Takagi, Yuhei; Arai, Akira [Nishi-Harima Astronomical Observatory, Center for Astronomy, University of Hyogo, Sayo, Hyogo 679-5313 (Japan); Tokimasa, Noritaka [Sayo Town Office, 2611-1 Sayo, Sayo-cho, Sayo, Hyogo 679-5380 (Japan); Hsieh, Henry H. [Academia Sinica Institute of Astronomy and Astrophysics, Roosevelt Road, Taipei 10617, Taiwan (China); Thomas-Osip, Joanna E.; Osip, David J. [The Observatories of the Carnegie Institute of Washington, Las Campanas Observatory, Colina El Pino, Casilla 601, La Serena (Chile); Urakawa, Seitaro [Bisei Spaceguard Center, Japan Spaceguard Association, 1716-3 Okura, Bisei-cho, Ibara, Okayama 714-1411 (Japan); Hanayama, Hidekazu [Ishigakijima Astronomical Observatory, National Astronomical Observatory of Japan, 1024-1 Arakawa, Ishigaki, Okinawa 907-0024 (Japan); Sekiguchi, Tomohiko [Department of Teacher Training, Hokkaido University of Education, 9 Hokumon, Asahikawa 070-8621 (Japan); and others

    2014-09-01

    We investigated the magnitude-phase relation of (162173) 1999 JU3, a target asteroid for the JAXA Hayabusa 2 sample return mission. We initially employed the International Astronomical Union's H-G formalism but found that it fits less well using a single set of parameters. To improve the inadequate fit, we employed two photometric functions: the Shevchenko and Hapke functions. With the Shevchenko function, we found that the magnitude-phase relation exhibits linear behavior in a wide phase angle range (α = 5°-75°) and shows weak nonlinear opposition brightening at α < 5°, providing a more reliable absolute magnitude of H {sub V} = 19.25 ± 0.03. The phase slope (0.039 ± 0.001 mag deg{sup –1}) and opposition effect amplitude (parameterized by the ratio of intensity at α = 0.°3 to that at α = 5°, I(0.°3)/I(5°) = 1.31 ± 0.05) are consistent with those of typical C-type asteroids. We also attempted to determine the parameters for the Hapke model, which are applicable for constructing the surface reflectance map with the Hayabusa 2 onboard cameras. Although we could not constrain the full set of Hapke parameters, we obtained possible values, w = 0.041, g = –0.38, B {sub 0} = 1.43, and h = 0.050, assuming a surface roughness parameter θ-bar = 20°. By combining our photometric study with a thermal model of the asteroid, we obtained a geometric albedo of p {sub v} = 0.047 ± 0.003, phase integral q = 0.32 ± 0.03, and Bond albedo A {sub B} = 0.014 ± 0.002, which are commensurate with the values for common C-type asteroids.

  6. Preparation of molecularly imprinted polymeric fibers using a single bifunctional monomer for the solid-phase microextraction of parabens from environmental solid samples.

    Science.gov (United States)

    Díaz-Álvarez, Myriam; Smith, Stephen P; Spivak, David A; Martín-Esteban, Antonio

    2016-02-01

    In this study, molecularly imprinted polymer fibers for solid-phase microextraction have been prepared with a single bifunctional monomer, N,O-bismethacryloyl ethanolamine using the so-called "one monomer molecularly imprinted polymers" method, replacing the conventional combination of functional monomer and cross-linker to form high fidelity binding sites. For comparison, imprinted fibers were prepared following the conventional approach based on ethylene glycol dimethacrylate as cross-linker and methacrylic acid as monomer. The recognition performance of the new fibers was evaluated in the solid-phase microextraction of parabens, and from this study it was concluded that they provided superior performance over conventionally formulated fibers. Ultimately, real-world environmental testing on spiked solid samples was successful by the molecularly imprinted solid-phase microextraction of samples, and the relative recoveries obtained at enrichment levels of 10 ng/g of parabens were within 78-109% for soil and 83-109% for sediments with a relative standard deviation <15% (n = 3). © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  7. A review of novel strategies of sample preparation for the determination of antibacterial residues in foodstuffs using liquid chromatography-based analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Marazuela, M.D., E-mail: marazuela@quim.ucm.es [Department of Analytical Chemistry, Faculty of Chemistry, Universidad Complutense de Madrid, E-28040 Madrid (Spain); Bogialli, S. [Department of Chemistry, University of Rome ' La Sapienza' , Piazza Aldo Moro, 5 00185 Rome (Italy)

    2009-07-10

    The determination of trace residues and contaminants in food has been of growing concern over the past few years. Residual antibacterials in food constitute a risk to human health, especially because they can contribute to the transmission of antibiotic-resistant pathogenic bacteria through the food chain. Therefore, to ensure food safety EU and USA regulatory agencies have established lists of forbidden or banned substances and tolerance levels for authorized veterinary drugs (e.g. antibacterials). In addition, the EU Commission Decision 2002/657/EC has set requirements about the performance of analytical methods for the determination of veterinary drug residues in food and feedstuffs. During the past years, the use of powerful mass spectrometric detectors in combination with innovative chromatographic technologies has solved many problems related to sensitivity and selectivity of this type of analysis. However sample preparation still remains as the bottleneck step, mainly in terms of analysis time and sources of error. This review covering research published between 2004 and 2008 intends to provide an update overview of the past five years, on recent trends in sample preparation for the determination of antibacterial residues in foods, making special emphasis in on-line, high-throughput, multi-class methods and including several applications in detail.

  8. abFASP-MS: affinity-based filter-aided sample preparation mass spectrometry for quantitative analysis of chemically labeled protein complexes.

    Science.gov (United States)

    Huber, Marie L; Sacco, Roberto; Parapatics, Katja; Skucha, Anna; Khamina, Kseniya; Müller, André C; Rudashevskaya, Elena L; Bennett, Keiryn L

    2014-02-07

    Affinity purification coupled to 1-D gel-free liquid chromatography mass spectrometry (LC-MS) is a well-established and widespread approach for the analyses of noncovalently interacting protein complexes. In this study, two proteins conjugated to a streptavidin-binding peptide and hemagglutinin double tag were expressed in the respective Flp-In HEK293 cell lines: green fluorescent protein (SH-GFP) and TANK binding kinase 1 (SH-TBK1_MOUSE). Fluorescent anti-HA immunoblots revealed that the expression level of SH-GFP was ∼50% lower than that of SH-TBK1_MOUSE. Subsequently, the input material was normalized to obtain a similar quantity of purified SH-tagged proteins. Optimization of the release of protein complexes from the anti-HA-agarose with different eluting agents was then assessed. With respect to the total number of protein groups identified in the purified complexes, elution with 2% SDS surpassed both 100 mM glycine and 100 mM formic acid. Relative quantitation of the purified protein complexes using TMT 6-plex reagents confirmed the higher efficiency of the 2% SDS elution followed by filter-aided sample preparation (FASP). The data presented in this study provide a new application of FASP to quantitative MS analysis of affinity-purified protein complexes. We have termed the approach abFASP-MS, or affinity-based filter-aided sample preparation mass spectrometry.

  9. 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.

  10. abFASP-MS: Affinity-Based Filter-Aided Sample Preparation Mass Spectrometry for Quantitative Analysis of Chemically Labeled Protein Complexes

    Science.gov (United States)

    2014-01-01

    Affinity purification coupled to 1-D gel-free liquid chromatography mass spectrometry (LC–MS) is a well-established and widespread approach for the analyses of noncovalently interacting protein complexes. In this study, two proteins conjugated to a streptavidin-binding peptide and hemagglutinin double tag were expressed in the respective Flp-In HEK293 cell lines: green fluorescent protein (SH-GFP) and TANK binding kinase 1 (SH-TBK1_MOUSE). Fluorescent anti-HA immunoblots revealed that the expression level of SH-GFP was ∼50% lower than that of SH-TBK1_MOUSE. Subsequently, the input material was normalized to obtain a similar quantity of purified SH-tagged proteins. Optimization of the release of protein complexes from the anti-HA-agarose with different eluting agents was then assessed. With respect to the total number of protein groups identified in the purified complexes, elution with 2% SDS surpassed both 100 mM glycine and 100 mM formic acid. Relative quantitation of the purified protein complexes using TMT 6-plex reagents confirmed the higher efficiency of the 2% SDS elution followed by filter-aided sample preparation (FASP). The data presented in this study provide a new application of FASP to quantitative MS analysis of affinity-purified protein complexes. We have termed the approach abFASP-MS, or affinity-based filter-aided sample preparation mass spectrometry. PMID:24400740

  11. 'Proteomic basics--sample preparation and separation': the 1st European Summer School in Kloster Neustift, 12-18 August, 2007 Brixen/Bressanone, South Tyrol, Italy.

    Science.gov (United States)

    Marcus, Katrin; Kühn-Hölsken, Eva; Schmidt, Carla; Schulenborg, Thomas; Urlaub, Henning

    2008-01-01

    Proteomics is rapidly developing into a routine approach for protein analysis in many laboratories. The series of European-wide Summer Schools 'Proteomics Basics' (http://www.proteomic-basics.eu/) aims at teaching of comprehensive knowledge in proteomics research and applied technologies for master and graduate students and postdocs currently moving into the field of proteomic research. In the next 3 years the series will cover the theoretical basis of the fundamental topics in the various areas of proteomic analysis, i.e. sample preparation and handling, mass spectrometry, post-translational modifications and quantitation given by leading experts in the field. This summer school series embodies a unique advantage in comparison with conventional scientific meetings and university curricula: internationally renowned experts will give a detailed perspective view of the fundamentals of their particular proteome research area, something which is usually not encountered at conferences and congresses. Here, we give a report on the first European Summer School 'Sample Preparation and Handling' within the series 'Proteomic Basics' that was held at the monastery in Neustift close to Bressanone/Brixen, Italy from August 12 to 18, 2007.

  12. Evaluation of a New Device for Simplifying and Standardizing Stool Sample Preparation for Viral Molecular Testing with Limited Hands-On Time.

    Science.gov (United States)

    Feghoul, Linda; Salmona, Maud; Cherot, Janine; Fahd, Mony; Dalle, Jean-Hugues; Vachon, Carole; Perrod, Aurélie; Bourgeois, Philippe; Scieux, Catherine; Baruchel, André; Simon, François; LeGoff, Jérôme

    2016-04-01

    Sensitive molecular assays have greatly improved the diagnosis of viral gastroenteritis. However, the proper preparation of stool samples for clinical testing remains an issue. bioMérieux has developed a stool preprocessing device (SPD) that includes a spoon for calibrated sampling and a vial containing buffer, glass beads, and two filters. The resulting stool filtrate is used for nucleic acid extraction. The purpose of this study was to evaluate the performance of the SPD for the quantification of human adenovirus (HAdV) DNA in stool samples collected from hematopoietic stem cell transplant (HSCT) recipients. HAdV DNA was quantified with the Adenovirus R-gene kit. The suitability of the device to reproducibly quantify HAdV DNA in stools using different extraction platforms (easyMAG and QIAsymphony) was determined using archived HAdV-positive stool samples. Coefficients of variation of HAdV DNA quantifications ranged from 1.79% to 1.83%, and no difference in quantification was observed between the two extraction systems. The HAdV DNA limit of quantification using the SPD was 3.75 log10copies/g of stool. HAdV DNA quantification using the SPD was then compared to that of the routine preprocessing technique on 75 fresh stool samples collected prospectively from pediatric HSCT recipients at risk for HAdV infections. Thirty-eight samples were HAdV DNA positive with both the SPD and routine preprocessing methods. HAdV DNA loads were on average 1.14-log10copies/g of stool higher with the SPD (Pstool samples in DNA. The use of the SPD for the detection of other gastrointestinal infections warrants further evaluation. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

  13. A dilute-and-shoot sample preparation strategy for new and used lubricating oils for Ca, P, S and Zn determination by total reflection X-ray fluorescence

    Science.gov (United States)

    Mota, Mariana F. B.; Gama, Ednilton M.; Rodrigues, Gabrielle de C.; Rodrigues, Guilherme D.; Nascentes, Clésia C.; Costa, Letícia M.

    2018-01-01

    In this work, a dilute-and-shoot method was developed for Ca, P, S and Zn determination in new and used lubricating oil samples by total reflection X-ray fluorescence (TXRF). The oil samples were diluted with organic solvents followed by addition of yttrium as internal standard and the TXRF measurements were performed after solvent evaporation. The method was optimized using an interlaboratorial reference material. The experimental parameters evaluated were sample volume (50 or 100 μL), measurement time (250 or 500 s) and volume deposited on the quartz glass sample carrier (5 or 10 μL). All of them were evaluated and optimized using xylene, kerosene and hexane. Analytical figures of merit (accuracy, precision, limit of detection and quantification) were used to evaluate the performance of the analytical method for all solvents. The recovery rates varied from 99 to 111% and the relative standard deviation remained between 1.7% and 10% (n = 8). For all elements, the results obtained by applying the new method were in agreement with the certified value. After the validation step, the method was applied for Ca, P, S and Zn quantification in eight new and four used lubricating oil samples, for all solvents. The concentration of the elements in the samples varied in the ranges of 1620-3711 mg L- 1 for Ca, 704-1277 mg L- 1 for P, 2027-9147 mg L- 1 for S, and 898-1593 mg L- 1 for Zn. The association of TXRF with a dilute-and-shoot sample preparation strategy was efficient for Ca, P, S and Zn determination in lubricating oils, presenting accurate results. Additionally, the time required for analysis is short, the reagent volumes are low minimizing waste generation, and the technique does not require calibration curves.

  14. High resolution, high precision, simultaneous measurements of δD and δ18O using a CRDS analyzer with an ultrasonic nebulizer sample preparation module.

    Science.gov (United States)

    Gkinis, Vasileios; Morrie, Valerie; Jones, Tyler; Vaughn, Bruce; White, James

    2013-04-01

    The recent advent of commercial Cavity Ring Down Spectroscopy (CRDS) has initiated the development of numerous new Continuous Flow Analysis (CFA) methods for high resolution, high precision measurements of greenhouse gas concentrations and isotopic ratios of water from ice cores. Depending on the sample preparation method and the calibration schemes applied, these new systems have proved to be precise, accurate and extremely versatile, allowing for high quality measurements performed in the field. However there are still challenges to be addressed. Measurements need to be accurately calibrated with respect to international standards (SMOW - SLAP in the case of water). A proper characterization of the precision and the accuracy of a system is another task that needs to be performed. Apparent sample diffusion affects the produced signals in ways that are unique not only to different systems but also to different implementations of the same system, reducing the resolution that can be obtained. Parameters such as melt rate, sample flow, cavity volume and the method of sample preparation can significantly alter the performance of the analytical method. These effects can be accurately characterized with a series of experiments and consequently corrected for using spectral filtering techniques. Last but not least, proper monitoring of the melting process is necessary in order to assign an ice core depth scale on the data produced. In this work we present an integrated system for high resolution, high precision water isotopic analysis from a continuously melted ice core sample, using a commercial CRDS analyzer (Picarro L2130 -i) . The system utilizes an ultrasonic concentric nebulizer in order to achieve complete fractionation free vaporization of the continuous flow water sample. An adjacent home made calibration module allows for the injection of local standards accurately characterized with respect to the SMOW - SLAP scale. The system has been used for the high

  15. Monitoring of cefepime in human serum and plasma by micellar electrokinetic capillary chromatography: Improvement of sample preparation and validation by liquid chromatography coupled to mass spectrometry.

    Science.gov (United States)

    Šestáková, Nela; Theurillat, Regula; Sendi, Parham; Thormann, Wolfgang

    2017-04-01

    Cefepime monitoring in deproteinized human serum and plasma by micellar electrokinetic capillary chromatography and liquid chromatography coupled to mass spectrometry in presence of other drugs is reported. For micellar electrokinetic capillary chromatography, sample preparation comprised dodecylsulfate protein precipitation at pH 4.5 using an increased buffer concentration compared to that of a previous assay and removal of hydrophobic compounds with dichloromethane. This provided robust conditions for cefepime analysis in the presence of sulfamethoxazole and thus enabled its determination in samples of patients that receive cotrimoxazole. The liquid chromatography assay is based upon use of a column with a pentafluorophenyl-propyl modified and multiendcapped stationary phase and the coupling to electrospray ionization with a single quadrupole detector. The performances of both assays with multilevel internal calibration were assessed with calibration and control samples and both assays were determined to be robust. Cefepime levels monitored by micellar electrokinetic capillary chromatography in samples from patients that were treated with cefepime only and with cefepime and cotrimoxazole were found to compare well with those obtained by liquid chromatography coupled to mass spectrometry. Cefepime drug levels determined by micellar electrokinetic capillary chromatography could thereby be validated. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Preparation of Fe3O4 nanoparticle enclosure hydroxylated multi-walled carbon nanotubes for the determination of aconitines in human serum samples.

    Science.gov (United States)

    Zhang, Hong-Fei; Shi, Yan-Ping

    2012-04-29

    A magnetic carbon nanomaterial for Fe(3)O(4) enclosure hydroxylated multi-walled carbon nanotubes (Fe(3)O(4)-EC-MWCNTs-OH) was prepared by the aggregating effect of Fe(3)O(4) nanoparticle on MWCNTs-OH, and combined with high-performance liquid chromatography (HPLC)/diode array detection (DAD) to determine the aconitines (aconitine, hypaconitine and mesaconitine) in human serum samples. Compared with other extraction modes investigated in experiment, Fe(3)O(4)-EC-MWCNTs-OH sorbents showed a good affinity to target analytes. Some important parameters that could influence extraction efficiency of aconitines, including the extraction mode, amounts of Fe(3)O(4)-EC-MWCNTs-OH, pH of sample solution, extraction time, desorption solvent and desorption time, were optimized. Under optimal conditions, the recoveries of spiked serum samples were between 98.0% and 103.0%; relative standard deviations (RSDs) ranged from 0.9% to 6.2%. The correlation coefficients varied from 0.9996 to 0.9998. The limits of detection ranged from 3.1 ng mL(-1) to 4.1 ng mL(-1) at a signal-to-noise ratio of 3. The experimental results showed that the proposed method was feasible for the analysis of aconitines in serum samples. Copyright © 2012 Elsevier B.V. All rights reserved.

  17. Diagnostic performance of a newly developed salivary cortisol and cortisone measurement using an LC-MS/MS method with simple and rapid sample preparation.

    Science.gov (United States)

    Mészáros, K; Karvaly, G; Márta, Z; Magda, B; Tőke, J; Szücs, N; Tóth, M; Rácz, K; Patócs, A

    2017-08-16

    Late-night salivary cortisol level is one of the first-line tests recommended by the Endocrine Society for the diagnosis of endogenous hypercortisolism. Most routine laboratories measure cortisol levels using immunoassay tests which fail to determine low cortisol levels accurately due to the numerous interfering substances. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) method with simple and rapid sample preparation was developed for the simultaneous measurement of cortisol and cortisone and its performance in the diagnosis of endogenous hypercortisolism was evaluated. 324 late-night saliva samples were analyzed from which 272 samples were derived from patients with a suspected diagnosis of endogenous hypercortisolism. Salivary cortisol levels were assayed using an electrochemiluminescent immunoassay (ECLIA, Cortisol II, Roche), and simultaneous measurement of cortisol and cortisone was performed using an LC-MS/MS method. A strong correlation between cortisol results measured using ECLIA and LC-MS/MS (r 2 = 0.892) was demonstrated. Receiver operating characteristics (ROC) analysis showed good diagnostic performance of cortisol and cortisone levels assayed using LC-MS/MS method and for cortisol measured using ECLIA. Late-night salivary cortisol and cortisone are useful parameters for the diagnosis of hypercortisolism. Using samples obtained from patients where the diagnosis of hypercortisolism is extremely challenging cut-off values for midnight salivary cortisol and cortisone measured by LC-MS/MS method were established.

  18. 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.

  19. 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.

  20. Shotgun analysis of membrane proteomes by an improved SDS-assisted sample preparation method coupled with liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Lin, Yong; Jiang, Huajun; Yan, Yujun; Peng, Bin; Chen, Jinhua; Lin, Haiyan; Liu, Zhonghua

    2012-12-12

    Analysis of the membrane proteins, particularly the integral membrane proteins, is limited by the inherent membrane hydrophobicity. Sodium dodecyl sulfate (SDS) is one of the most efficient reagents used for the extraction of membrane proteins, but its presence in samples interferes with LC-MS-based proteomic analyses because it affects RP-LC separations and electrospray ionization. In this paper, we present an improved sample preparation strategy based on SDS-assisted digestion and peptide-level SDS-removal using an optimized potassium dodecyl sulfate (KDS) precipitation method (SSDP method) for shotgun analysis of the membrane proteome. This method utilizes a high concentration of SDS (1.0%) to lyse the membranes and to solubilize the hydrophobic membrane proteins, resulting in a more complete protein digestion in the diluted SDS buffer (0.1% SDS), and a high efficiency of SDS removal and peptide recovery by the optimized KDS precipitation for protein identification. The SSDP method provides evidence that proteins can be efficiently digested, and the SDS can be decreased to 95% peptide recovery. Compared to other sample preparation methods commonly used in shotgun membrane proteomics, the newly developed method not only increased the identified number of the total proteins, membrane proteins and integral membrane proteins by an average of 33.1%, 37.2% and 40.5%, respectively, but also leading to the identification of highest number of matching peptides. All the results showed that the method yielded better recovery and reliability in the identification of the proteins especially the highly hydrophobic integral membrane proteins, and thus providing a promising tool for the shotgun analysis of membrane proteome. Copyright © 2012 Elsevier B.V. All rights reserved.

  1. Preparation of stir cake sorptive extraction based on polymeric ionic liquid for the enrichment of benzimidazole anthelmintics in water, honey and milk samples

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yulei [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China); Zhang, Jie [Key Lab of Urban Environment and Health, Institute of Urban Environment, Chinese Academy of Sciences (China); Huang, Xiaojia, E-mail: hxj@xmu.edu.cn [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China); Yuan, Dongxing [State Key Laboratory of Marine Environmental Science, Key Laboratory of the Ministry of Education for Coastal and Wetland Ecosystem, College of the Environment and Ecology, Xiamen University, Siming Road, P.O. Box 1009, Xiamen 361005 (China)

    2014-08-20

    Highlights: • A new polymeric ionic liquid-based monolith was prepared. • The monolith was used as the extractive medium of stir cake sorptive extraction. • The SCSE–AMIIDB can extract benzimidazole anthelmintics (BAs) effectively. • A combination of SCSE–AMIIDB–LD–HPLC/DAD was developed. • The combination was applied to monitor trace BAs in water, milk and honey samples. - Abstract: In this work, a new stir cake sorptive extraction (SCSE) using polymeric ionic liquid monolith as sorbent was prepared. The sorbent was obtained by in situ copolymerization of an ionic liquid, 1-allyl-3-methylimidazolium bis[(trifluoro methyl)sulfonyl]imide (AMII) and divinylbenzene (DB) in the presence of N,N-dimethylformamide. The influence of the content of ionic liquid and the porogen in the polymerization mixture on extraction performance was studied thoroughly. The physicochemical properties of the polymeric ionic liquid were characterized by infrared spectroscopy, elemental analysis, scanning electron microscopy and mercury intrusion porosimetry. The usefulness of SCSE–AMIIDB was demonstrated by the enrichment of trace benzimidazole anthelmintics. Several parameters affecting the extraction efficiency were investigated, and under the optimized conditions, a simple and effective method for the determination of trace benzimidazoles residues in water, milk and honey samples was established by coupling SCSE–AMIIDB with high performance liquid chromatography/diode array detection (SCSE–AMIIDB–HPLC/DAD). Results indicated that the limits of detection (S/N = 3) for target compounds were 0.020–0.072 μg L{sup −1}, 0.035–0.10 μg L{sup −1} and 0.026–0.076 μg L{sup −1} in water, milk and honey samples, respectively. In addition, an acceptable reproducibility was achieved by evaluating the repeatability and intermediate precision with relative standard deviations (RSD) of less than 9% and 11%, respectively. Finally, the established AMII

  2. Solid matrix transformation and tracer addition using molten ammonium bifluoride salt as a sample preparation method for laser ablation inductively coupled plasma mass spectrometry.

    Science.gov (United States)

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

    2017-09-08

    Solid sampling and analysis methods, such as laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS), are challenged by matrix effects and calibration difficulties. Matrix-matched standards for external calibration are seldom available and it is difficult to distribute spikes evenly into a solid matrix as internal standards. While isotopic ratios of the same element can be measured to high precision, matrix-dependent effects in the sampling and analysis process frustrate accurate quantification and elemental ratio determinations. Here we introduce a potentially general solid matrix transformation approach entailing chemical reactions in molten ammonium bifluoride (ABF) salt that enables the introduction of spikes as tracers or internal standards. Proof of principle experiments show that the decomposition of uranium ore in sealed PFA fluoropolymer vials at 230 °C yields, after cooling, new solids suitable for direct solid sampling by LA. When spikes are included in the molten salt reaction, subsequent LA-ICP-MS sampling at several spots indicate that the spikes are evenly distributed, and that U-235 tracer dramatically improves reproducibility in U-238 analysis. Precisions improved from 17% relative standard deviation for U-238 signals to 0.1% for the ratio of sample U-238 to spiked U-235, a factor of over two orders of magnitude. These results introduce the concept of solid matrix transformation (SMT) using ABF, and provide proof of principle for a new method of incorporating internal standards into a solid for LA-ICP-MS. This new approach, SMT-LA-ICP-MS, provides opportunities to improve calibration and quantification in solids based analysis. Looking forward, tracer addition to transformed solids opens up LA-based methods to analytical methodologies such as standard addition, isotope dilution, preparation of matrix-matched solid standards, external calibration, and monitoring instrument drift against external calibration standards.

  3. Facile preparation of a polydopamine-based monolith for multiple monolithic fiber solid-phase microextraction of triazine herbicides in environmental water samples.

    Science.gov (United States)

    Zhang, Zirui; Mei, Meng; Huang, Yanmei; Huang, Xiaojia; Huang, Hanyue; Ding, Yuxin

    2017-02-01

    A new multiple monolithic fiber solid-phase microextraction using a polydopamine-based monolith as the extraction medium is proposed. The monolith was synthesized by facile in situ copolymerization of N-methacryldopamine and dual cross-linkers (divinylbenzene/ethylenedimethacrylate) in the presence of N,N-dimethylformamide. The effect of the contents of N-methacryldopamine and porogen in the polymerization mixture on the extraction performance was investigated thoroughly. A series of characterization studies was performed to validate the structure and properties of the monolith. The prepared multiple monolithic fibers were used for the extraction of triazine herbicides in environmental water samples. After the optimization of the extraction parameters, a convenient, sensitive, cost-effective, and environmentally friendly method for the determination of trace triazine herbicides in water samples was developed by coupling multiple monolithic fibers solid-phase microextraction with high-performance liquid chromatography and diode array detection. The results indicated that the limits of detection and quantification for the target compounds were 0.031-0.14 and 0.10-0.45 μg/L, respectively. Good precision and reproducibility were obtained with the relative standard deviations below 10%. The developed method was applied to the analysis of the triazine herbicides in different water samples (lake, river, and farmland waters). The recoveries of the method were in the range between 79.6 and 117%. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. The risk of altering soil and sediment samples upon extract preparation for analytical and bio-analytical investigations--a review.

    Science.gov (United States)

    Seiler, Thomas-Benjamin; Schulze, Tobias; Hollert, Henner

    2008-04-01

    Organic total extracts play an important role in soil and sediment risk assessment. Beside a routine application in analytical chemistry, they are used in bio-analytical investigations as a "worst-case scenario" or, e.g., in order to simulate chronic intoxication, and as samples for effect-directed analysis. While theoretically providing highly reliable data and good reproducibility, the whole process of sample handling and extract preparation can lead to extracts that might fail to accurately represent a toxic potential of their corresponding sampling site. This review identifies and discusses the most important possible alterations that have the potential to lead to over and, more often, underestimation of the effectiveness of extracts. Since incorrect data will compromise soil and sediment risk assessment as a whole, results from analytical and bio-analytical investigations of extracts demand cautious interpretation. Reliability of extract testing grows with reproducibility; experiments should therefore be repeated with independent extraction replicates. New or optimized extraction procedures should circumvent the issues mentioned here while being suitable for routine application.

  5. Simplifying sample preparation using fabric phase sorptive extraction technique for the determination of benzodiazepines in blood serum by high-performance liquid chromatography.

    Science.gov (United States)

    Samanidou, Victoria; Kaltzi, Ioanna; Kabir, Abuzar; Furton, Kenneth G

    2016-06-01

    Fabric phase sorptive extraction (FPSE), a recently introduced novel sample preparation technology, has been evaluated for the extraction of benzodiazepines from human blood serum. FPSE utilizes a flexible fabric surface as the substrate platform for creating sol-gel hybrid organic-inorganic sorbent coatings. FPSE media can be introduced directly into the sample containing the target analyte(s), requiring no need for prior sample pretreatment or clean-up. Benzodiazepines were selected as model analytes because they represent one of the most widely used therapeutic drugs in psychiatry and are also amongst the most frequently encountered drugs in forensic toxicology. The chromatographic separation of target analytes was performed on a LiChroCART-LiChrospher®100 RP-18e (5 µm, 250 × 4 mm) analytical column, operated at room temperature. Ternary gradient elution was applied with a mobile phase that consisted of acetonitrile, methanol and ammonium acetate (0.05 M), which was delivered at a flow rate of 1.0 mL/min. Diode array detection was performed with monitoring at 240 nm. FPSE was performed using cellulose fabric extraction media coated with sol-gel poly(ethylene glycol) (sol-gel PEG). Absolute recovery values in the equilibrium state for the examined benzodiazepines were found to be 27% for bromazepam, 63% for lorazepam, 42 % for diazepam and 39% for alprazolam. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  6. Preparation and evaluation of amino modified graphene solid-phase microextraction fiber and its application to the determination of synthetic musks in water samples.

    Science.gov (United States)

    Li, Siyan; Zhu, Fang; Jiang, Ruifen; Ouyang, Gangfeng

    2016-01-15

    In the current study, amino modified (NH2-modified) graphene was developed as a solid-phase microextraction (SPME) coating for the first time. The structure of the NH2-modified graphene was characterized by X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy (TEM). The fiber was fabricated using xylene-diluted silicone sealant as an adhesion agent. The performance and feasibility of the NH2-modified graphene fiber was evaluated through autosampler-assisted direct immersion (DI) SPME followed by gas chromatography-mass spectrometry (GC/MS) for the analysis of five synthetic musks (muscone, galaxolide, musk-xylene, tonalide and musk-ketone) in aqueous samples. The results showed that the prepared fiber had good thermal stability, excellent solvent resistance and a long service lifetime (more than 200 replicate extraction cycles). The proposed autosampler-assisted DI-SPME-GC/MS method showed low limits of detection (0.46-5.96 ng L(-1)), wide linear ranges (5-500 ng L(-1)), and acceptable reproducibility (relative standard deviation, RSD<12%). Finally, the method was successfully applied to the analysis of synthetic musks in environmental water samples with good recoveries (82.3-112%) and satisfactory precisions (RSD<9.9%). These results indicated that the NH2-modified graphene provided a promising alternative in sample pretreatment. Copyright © 2015 Elsevier B.V. All rights reserved.

  7. RareCyte® CTC Analysis Step 1: AccuCyte® Sample Preparation for the Comprehensive Recovery of Nucleated Cells from Whole Blood.

    Science.gov (United States)

    Ramirez, Arturo B; U'Ren, Lance; Campton, Daniel E; Stewart, David; Nordberg, Joshua J; Stilwell, Jackie L; Kaldjian, Eric P

    2017-01-01

    The RareCyte platform addresses important technology limitations of current circulating tumor cell (CTC) collection methods, and expands CTC interrogation to include advanced phenotypic characterization and single-cell molecular analysis. In this respect, it represents the "next generation" of cell-based liquid biopsy technologies. In order to identify and analyze CTCs, RareCyte has developed an integrated sample preparation, imaging and individual cell retrieval process. The first step in the process, AccuCyte(®), allows the separation, collection, and transfer to a slide the nucleated cell fraction of the blood that contains CTCs. Separation and collection are based on cell density-rather than size or surface molecular expression-and are performed within a closed system, without wash or lysis steps, enabling high CTC recovery. Here, we describe our technique for nucleated cell collection from a blood sample, and the spreading of these nucleated cells onto glass slides permitting immunofluorescent staining, cell identification, and individual cell picking described in subsequent chapters. In addition to collection of rare cells such as CTCs, AccuCyte also collects cells of the circulating immune system onto archivable slides as well as plasma from the same sample.

  8. Bipolar Electrode Sample Preparation Devices

    Science.gov (United States)

    Wang, Yi (Inventor); Song, Hongjun (Inventor); Pant, Kapil (Inventor)

    2017-01-01

    An analyte selection device can include: a body defining a fluid channel having a channel inlet and channel outlet; a bipolar electrode (BPE) between the inlet and outlet; one of an anode or cathode electrically coupled with the BPE on a channel inlet side of the BPE and the other of the anode or cathode electrically coupled with the BPE on a channel outlet side of the BPE; and an electronic system operably coupled with the anode and cathode so as to polarize the BPE. The fluid channel can have any shape or dimension. The channel inlet and channel outlet can be longitudinal or lateral with respect to the longitudinal axis of the channel. The BPE can be any metallic member, such as a flat plate on a wall or mesh as a barrier BPE. The anode and cathode can be located at a position that polarizes the BPE.

  9. Preparation of highly stable fullerene C60 decorated graphene oxide nanocomposite and its sensitive electrochemical detection of dopamine in rat brain and pharmaceutical samples.

    Science.gov (United States)

    Thirumalraj, Balamurugan; Palanisamy, Selvakumar; Chen, Shen-Ming; Lou, Bih-Show

    2016-01-15

    The research community has continuously paid much attention on the preparation of hybrid of carbon nanomaterials owing to combine their unique properties. Herein, we report the preparation of highly stable fullerene C60 (C60) wrapped graphene oxide (GO) nanocomposite by using a simple sonication method. The fabricated GO-C60 nanocomposite modified glassy carbon electrode shows a good sensitivity and lower oxidation overpotential towards dopamine (DA) than that of pristine GO and C60. The fabricated sensor detects the DA in the linear response range of 0.02-73.5μM. The limit of detection is estimated to be 0.008μM based on 3σ with a sensitivity of 4.23μAμM(-1)cm(-2). The fabricated sensor also exhibits other features such as good selectivity, stability, reproducibility and repeatability. The proposed sensor exhibits good practicality towards the detection of DA in rat brain and commercial DA injection samples. Copyright © 2015 Elsevier Inc. All rights reserved.

  10. Sample preparation strategies for one- and two-dimensional gel electrophoretic separation of plant proteins and the influence on arsenic and zinc bindings.

    Science.gov (United States)

    Schmidt, Anne-Christine; Ahlswede, Julia; Störr, Bianca

    2009-10-01

    A sample preparation method including protein extraction by an aqueous buffer system, precipitation with trichloroacetic acid, washing with acetone, and desalting by dialysis was developed for 2D gel electrophoresis of mature leaves from Tropaeolum majus, a plant species with a high content of glucosinolates. By the optimized method, 1D- and 2D-gels could also be produced from Festuca rubra leaves and Helianthus annuus seeds. A strong influence of the varied protein preparation parameters on arsenic and zinc bindings was observed. Microwave-digestion with subsequent atomic spectroscopy analysis of protein fractions revealed the highest arsenic binding capacity of 76.2+/-1.7% for proteins from sunflower seeds spiked with arsenite. After spiking of T. majus extracts with different arsenic species and zinc salts to 100microg As or Zn in 10mL, 9.5+/-0.97%, 0.95+/-0.39%, 0.24+/-0.02%, 0.20+/-0.09%, 0.02%, 0.83+/-0.02%, 2.21+/-1.64%, and 1.45+/-0.69% were recovered in the final protein fraction for phenylarsine oxide, arsenite, arsenate, monomethylarsonate, dimethylarsinate, zinc chloride, zinc sulfate, and zinc acetate, respectively. The cultivation of T. majus under arsenic exposure resulted in a highly elevated arsenic-binding capacity of the proteins that was also dependent on the kind of arsenic species in the following order: arsenite (14.9%)>monomethylarsonate (12.4%)>arsenate (10.8%)>dimethylarsinate (0.32%).

  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. 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

  13. 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.

  14. 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.

  15. Proteomic study of a model causative agent of harmful red tide, Prorocentrum triestinum I: Optimization of sample preparation methodologies for analyzing with two-dimensional electrophoresis.

    Science.gov (United States)

    Chan, Leo Lai; Lo, Samuel Chun-Lap; Hodgkiss, Ivor John

    2002-09-01

    A comprehensive study to find the optimal sample preparation conditions for two-dimensional electrophoresis (2-DE) analysis of Prorocentrum triestinum, a model causative agent of harmful algal blooms (HABs) was carried out. The four major sample preparation steps for 2-DE: (a) cell disruption: i.e. sonication and homogenization with glass beads; (b) protein extraction : i.e. sequential and independent extraction procedures; (c) pre-electrophoretic treatment: these included (i) treatment with RNAase/DNAase or benzonase; (ii) ultracentrifugation to sediment large macromolecules such as DNA; (iii) desalting and concentration by ultrafiltration through a Microcon centrifugal filter device (MWCO: 3000 daltons); and (iv) desalting by a micro BioSpin chromatography column (MWCO: 6000 daltons); and (d) rehydration buffers, reducing agents and sample application in the first dimension isoelectric focussing were studied. Our results showed that sonication is easy to perform and resulted in a higher protein yield. Among the four extraction buffers, the urea containing buffers resulted in the extraction of the highest amount of protein while tris(hydroxymethyl)aminomethane buffers and trichloroacetic acid (TCA)/acetone precipitation allowed detection of a higher number of protein species (i.e. protein spots). Desalting by BioSpin and ultrafiltration have improved the 2-DE resolution of the water soluble fraction but have less effect on urea containing fractions. TCA/acetone precipitation was able to desalt all protein fractions independent of the extraction media, however extended exposure to this low pH medium has caused protein modification. Introduction of either DNase/RNase or benzonase treatment did not improve the discriminatory power of the 2-DE but this treatment did yield 2-DE with the clearest background. Proteolytic digestion was inhibited by addition of a protease inhibitor cocktail. Taken overall, a combination of sequential extraction and desalting by Bio

  16. Detection of Salmonella enterica in Meat in Less than 5 Hours by a Low-Cost and Noncomplex Sample Preparation Method.

    Science.gov (United States)

    Fachmann, M S R; Löfström, C; Hoorfar, J; Hansen, F; Christensen, J; Mansdal, S; Josefsen, M H

    2017-03-01

    Salmonella is recognized as one of the most important foodborne bacteria and has wide health and socioeconomic impacts worldwide. Fresh pork meat is one of the main sources of Salmonella , and efficient and fast methods for detection are therefore necessary. Current methods for Salmonella detection in fresh meat usually include >16 h of culture enrichment, in a few cases meat, consisting of a 3-h enrichment in standard buffered peptone water and a real-time PCR-compatible sample preparation method based on filtration, centrifugation, and enzymatic digestion, followed by fast-cycling real-time PCR detection. The method was validated in an unpaired comparative study against the Nordic Committee on Food Analysis (NMKL) reference culture method 187. Pork meat samples ( n = 140) were either artificially contaminated with Salmonella at 0, 1 to 10, or 10 to 100 CFU/25 g of meat or naturally contaminated. Cohen's kappa for the degree of agreement between the rapid method and the reference was 0.64, and the relative accuracy, sensitivity, and specificity for the rapid method were 81.4, 95.1, and 97.9%, respectively. The 50% limit of detections (LOD 50 s) were 8.8 CFU/25 g for the rapid method and 7.7 CFU/25 g for the reference method. Implementation of this method will enable faster release of Salmonella low-risk meat, providing savings for meat producers, and it will help contribute to improved food safety. IMPORTANCE While the cost of analysis and hands-on time of the presented rapid method were comparable to those of reference culture methods, the fast product release by this method can provide the meat industry with a competitive advantage. Not only will the abattoirs save costs for work hours and cold storage, but consumers and retailers will also benefit from fresher meat with a longer shelf life. Furthermore, the presented sample preparation might be adjusted for application in the detection of other pathogenic bacteria in different sample types. Copyright © 2017

  17. Improved sample preparation of glyphosate and methylphosphonic acid by EPA method 6800A and time-of-flight mass spectrometry using novel solid-phase extraction.

    Science.gov (United States)

    Wagner, Rebecca; Wetzel, Stephanie J; Kern, John; Kingston, H M Skip

    2012-02-01

    The employment of chemical weapons by rogue states and/or terrorist organizations is an ongoing concern in the United States. The quantitative analysis of nerve agents must be rapid and reliable for use in the private and public sectors. Current methods describe a tedious and time-consuming derivatization for gas chromatography-mass spectrometry and liquid chromatography in tandem with mass spectrometry. Two solid-phase extraction (SPE) techniques for the analysis of glyphosate and methylphosphonic acid are described with the utilization of isotopically enriched analytes for quantitation via atmospheric pressure chemical ionization-quadrupole time-of-flight mass spectrometry (APCI-Q-TOF-MS) that does not require derivatization. Solid-phase extraction-isotope dilution mass spectrometry (SPE-IDMS) involves pre-equilibration of a naturally occurring sample with an isotopically enriched standard. The second extraction method, i-Spike, involves loading an isotopically enriched standard onto the SPE column before the naturally occurring sample. The sample and the spike are then co-eluted from the column enabling precise and accurate quan