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Sample records for biological sample preparation

  1. Modular microfluidic system for biological sample preparation

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-09-29

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

  2. Preparation of biological samples for SIMS analyses

    International Nuclear Information System (INIS)

    Full text: For the first time at ANSTO, a program of SIMS analysis of biological samples was undertaken. This presentation will discuss how the wide variety of samples were prepared, and the methods used to gain useful information from SIMS analysis. Lack of matrix-matched standards made quantification difficult, but the strength of SIMS lies in the ability to detect a wide range of stable isotopes with good spatial resolution. This makes the technique suitable for studying organisms that archive signature elements in their structure. Samples such as bivalve shells and crocodile osteoderms were vacuum-impregnated in resin to a size suitable for the SIMS sample holder. Polishing was followed by a sputter coating with gold to alleviate charging of the sample during SIMS analysis. Some samples were introduced directly on the sample holder, either stuck to a glass slide or simply held in place with spring and backing plate. The only treatment in this case was gold coating and degassing in a vacuum pumping station. The porous nature of materials such as leaves and stromatolites requires a period of time under vacuum to remove gases which could interfere with the ultra high vacuum required for SIMS analysis. A calcite standard was used for comparison of oxygen isotopic ratios, but the only matrix-matched standard was available for metal analysis of coral skeletons. Otherwise, the calcium content of the material was assumed to be uniform and acted as an internal standard from which isotopic ratios of other elements could be determined. SIMS analysis of biological samples demonstrated that some matrices could reveal an archive of pollution histories. These samples require matrix-matched standards if the trends observed from analyses are to be quantified

  3. Efficient Sample Preparation from Complex Biological Samples Using a Sliding Lid for Immobilized Droplet Extractions

    OpenAIRE

    Casavant, Benjamin P.; Guckenberger, David J.; Beebe, David J.; Berry, Scott M

    2014-01-01

    Sample preparation is a major bottleneck in many biological processes. Paramagnetic particles (PMPs) are a ubiquitous method for isolating analytes of interest from biological samples and are used for their ability to thoroughly sample a solution and be easily collected with a magnet. There are three main methods by which PMPs are used for sample preparation: (1) removal of fluid from the analyte-bound PMPs, (2) removal of analyte-bound PMPs from the solution, and (3) removal of the substrate...

  4. Biological sample preparation and 41Ca AMS measurement at LLNL

    International Nuclear Information System (INIS)

    Calcium metabolism in biology may be better understood by the use of 41Ca tracer, although requiring detection by accelerator mass spectrometry (AMS). Methodologies for preparation of urine samples and subsequent AMS measurement were investigated. Novel attempts at preparing CaH2 were unsuccessful, but CaF2 of sufficient purity could be produced by precipitation of calcium from urine as oxalate, followed by separation of calcium by cation exchange chromatography and washing the CaF2 precipitate. The presence of some remaining impurities could be compensated for by selecting the appropriate accelerated ion charge state for AMS. The use of projectile X-rays for isobar discrimination was explored as an alternative to the co nventional dE/dx detector. (orig.)

  5. Sampling and sample preparation methods for the analysis of trace elements in biological material

    International Nuclear Information System (INIS)

    The authors attempt to give a most systamtic possible treatment of the sample taking and sample preparation of biological material (particularly in human medicine) for trace analysis (e.g. neutron activation analysis, atomic absorption spectrometry). Contamination and loss problems are discussed as well as the manifold problems of the different consistency of solid and liquid biological materials, as well as the stabilization of the sample material. The process of dry and wet ashing is particularly dealt with, where new methods are also described. (RB)

  6. Sample preparation techniques of biological material for isotope analysis

    International Nuclear Information System (INIS)

    Sample preparation is an essential step in all isotope-aided experiments but often it is not given enough attention. The methods of sample preparation are very important to obtain reliable and precise analytical data and for further interpretation of results. The size of a sample required for chemical analysis is usually very small (10mg-1500mg). On the other hand the amount of harvested plant material from plots in a field experiment is often bulky (several kilograms) and the entire sample is too large for processing. In addition, while approaching maturity many crops show not only differences in physical consistency but also a non-uniformity in 15N content among plant parts, requiring a plant fractionation or separation into parts (vegetative and reproductive) e.g. shoots and spikes, in case of small grain cereals, shoots and pods in case of grain legumes and tops and roots or beets (including crown) in case of sugar beet, etc. In any case the ultimate goal of these procedures is to obtain representative subsample harvested from greenhouse or field experiments for chemical analysis. Before harvesting an isotopic-aided experiment the method of sampling has to be selected. It should be based on the type of information required in relation to the objectives of the research and the availability of resources (staff, sample preparation equipment, analytical facilities, chemicals and supplies, etc.). 10 refs, 3 figs, 3 tabs

  7. 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

  8. Evaluation of biological sample preparation for immunosignature-based diagnostics.

    Science.gov (United States)

    Chase, Brian Andrew; Johnston, Stephen Albert; Legutki, Joseph Barten

    2012-03-01

    To address the need for a universal system to assess health status, we previously described a method termed "immunosignaturing" which splays the entire humoral antibody repertoire across a peptide microarray. Two important issues relative to the potential broad use of immunosignatures are sample preparation and stability. In the present study, we compared the immunosignatures developed from serum, plasma, saliva, and antibodies eluted from blood dried onto filter paper. We found that serum and plasma provide identical immunosignatures. Immunosignatures derived from dried blood also correlated well with those from nondried serum from the same individual. Immunosignatures derived from dried blood were capable of distinguishing naïve mice from those infected with influenza virus. Saliva was applied to the arrays, and the IgA immunosignature correlated strongly with that from dried blood. Finally, we demonstrate that dried blood retains immunosignature information even when exposed to high temperature. This work expands the potential diagnostic uses for immunosignatures. These features suggest that different forms of archival samples can be used for diagnosis development and that in prospective studies samples can be easily procured. PMID:22237890

  9. 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...

  10. Total Integrated Sample Preparation for Microfluidic Immunoassays in Complex Biological Matrices

    OpenAIRE

    Apori, Akwasi Asare

    2011-01-01

    A high-throughput protein analysis platform with integrated sample preparation is developed to address the identified technology gaps in biomarker validation, clinical and point-of-care diagnostics. The goals of the technology are to automate and integrate protein sample preparation with electrokinetic separations, implement immunoassays capable of processing raw biological fluids, and perform high-throughput protein assays targeted for disease diagnosis.Integration of multiple functions is ...

  11. 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.

  12. 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

    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 of....... Technical aspects of electromembrane extraction, important extraction parameters as well as a handful of examples of applications from different biological samples and bioanalytical areas are discussed in the paper....

  13. Methods of biological fluids sample preparation - biogenic amines, methylxanthines, water-soluble vitamins.

    Science.gov (United States)

    Płonka, Joanna

    2015-01-01

    In recent years demands on the amount of information that can be obtained from the analysis of a single sample have increased. For time and economic reasons it is necessary to examine at the same time larger number of compounds, and compounds from different groups. This can best be seen in such areas as clinical analysis. In many diseases, the best results for patients are obtained when treatment fits the individual characteristics of the patient. Dosage monitoring is important at the beginning of therapy and in the full process of treatment. In the treatment of many diseases biogenic amines (dopamine, serotonin) and methylxanthines (theophylline, theobromine, caffeine) play an important role. They are used as drugs separately or in combination with others to support and strengthen the action of other drugs - for example, the combination of caffeine and paracetamol. Vitamin supplementation may be also an integral part of the treatment process. Specification of complete sample preparation parameters for extraction of the above compounds from biological matrices has been reviewed. Particular attention was given to the preparation stage and extraction methods. This review provides universal guidance on establishing a common procedures across laboratories to facilitate the preparation and analysis of all discussed compounds. PMID:25381720

  14. 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

    Accurate and precise characterization of metrics such as size, mass, shape etc. of nanoparticles (NPs) remains a challenging task. In order to determine quantitative metrics that are relevant in food monitoring or in risk assessment, an instrumental separation method like asymmetric field flow...... 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...... for the meat sample extracts and the corresponding neat AgNP suspension, and rendered sizing by way of calibration with AgNPs as sizing standards inaccurate. In order to gain further insight into the sizes of the separated AgNPs, or their possible dissolved state, fractions of the AFFF eluate were...

  15. Preparation of chitosan grafted graphite composite for sensitive detection of dopamine in biological samples.

    Science.gov (United States)

    Palanisamy, Selvakumar; Thangavelu, Kokulnathan; Chen, Shen-Ming; Gnanaprakasam, P; Velusamy, Vijayalakshmi; Liu, Xiao-Heng

    2016-10-20

    The accurate detection of dopamine (DA) levels in biological samples such as human serum and urine are essential indicators in medical diagnostics. In this work, we describe the preparation of chitosan (CS) biopolymer grafted graphite (GR) composite for the sensitive and lower potential detection of DA in its sub micromolar levels. The composite modified electrode has been used for the detection of DA in biological samples such as human serum and urine. The GR-CS composite modified electrode shows an enhanced oxidation peak current response and low oxidation potential for the detection of DA than that of electrodes modified with bare, GR and CS discretely. Under optimum conditions, the fabricated GR-CS composite modified electrode shows the DPV response of DA in the linear response ranging from 0.03 to 20.06μM. The detection limit and sensitivity of the sensor were estimated as 0.0045μM and 6.06μA μM(-1)cm(-2), respectively. PMID:27474582

  16. A self-contained polymeric cartridge for automated biological sample preparation.

    Science.gov (United States)

    Xu, Guolin; Lee, Daniel Yoke San; Xie, Hong; Chiew, Deon; Hsieh, Tseng-Ming; Ali, Emril Mohamed; Lun Looi, Xing; Li, Mo-Huang; Ying, Jackie Y

    2011-09-01

    Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic cartridge contains all the necessary reagents for pathogen and cell lysis, DNA/RNA extraction, impurity washes, DNA/RNA elution and waste processing in a completely sealed cartridge. The entire sample preparation processes are automatically conducted within the cartridge on a desktop unit using a pneumatic fluid manipulation approach. Reagents transportation is achieved with a combination of push and pull forces (with compressed air and vacuum, respectively), which are connected to the pneumatic inlets at the bottom of the cartridge. These pneumatic forces are regulated by pinch valve manifold and two pneumatic syringe pumps within the desktop unit. The performance of this pneumatic reagent delivery method was examined. We have demonstrated the capability of the on-cartridge RNA extraction and cancer-specific gene amplification from 10 copies of MCF-7 breast cancer cells. The on-cartridge DNA recovery efficiency was 54-63%, which was comparable to or better than the conventional manual approach using silica spin column. The lab cartridge would be suitable for integration with lab-chip real-time polymerase chain reaction devices in providing a portable system for decentralized disease diagnosis. PMID:22662036

  17. 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. PMID:22357562

  18. Neutron beam preparation with Am-Be source for analysis of biological samples with PGNAA method

    International Nuclear Information System (INIS)

    Material analysis with prompt gamma neutron activation analysis (PGNAA) requires a proper geometrical arrangement for equipments in laboratory. Application of PGNAA in analysis of biological samples, due to small size of sample, needs attention to the dimension of neutron beam. In our work, neutron source has been made of 241Am-Be type. Activity of 241Am was 20 Ci which lead to neutron source strength of 4.4 x 107 neutrons per second. Water has been considered as the basic shielding material for the neutron source. The effect of various concentration of boric acid in the reduction of intensity of fast and thermal components of the neutron beam and gamma ray has been investigated. Gamma ray is produced by (α, n) reaction in Am-Be source (4.483 MeV), neutron capture by hydrogen (2.224 MeV), and neutron capture by boron (0.483 MeV). Various types of neutron and gamma ray dosimeters have been employed including BF3 and NE-213 detectors to detect fast and thermal neutrons. BGO scintillation detector has been used for gamma ray spectroscopy. It is shown that the gamma and neutron radiation dose due to direct beam is of the same magnitude as the dose due to radiation scattered in the laboratory ambient. It is concluded that 14 kg boric acid dissolved in 1,000 kg water is the optimum solution to surround the neutron source. The experimental results have been compared with Monte Carlo simulation. (author)

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

    Science.gov (United States)

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

    2016-01-28

    Green chemistry principles for developing methodologies have gained attention in analytical chemistry in recent decades. A growing number of analytical techniques have been proposed for determination of organic persistent pollutants in environmental and biological samples. In this light, the current review aims to present state-of-the-art sample preparation approaches based on green analytical principles proposed for the determination of polybrominated diphenyl ethers (PBDEs) and metabolites (OH-PBDEs and MeO-PBDEs) in environmental and biological samples. Approaches to lower the solvent consumption and accelerate the extraction, such as pressurized liquid extraction, microwave-assisted extraction, and ultrasound-assisted extraction, are discussed in this review. Special attention is paid to miniaturized sample preparation methodologies and strategies proposed to reduce organic solvent consumption. Additionally, extraction techniques based on alternative solvents (surfactants, supercritical fluids, or ionic liquids) are also commented in this work, even though these are scarcely used for determination of PBDEs. In addition to liquid-based extraction techniques, solid-based analytical techniques are also addressed. The development of greener, faster and simpler sample preparation approaches has increased in recent years (2003-2013). Among green extraction techniques, those based on the liquid phase predominate over those based on the solid phase (71% vs. 29%, respectively). For solid samples, solvent assisted extraction techniques are preferred for leaching of PBDEs, and liquid phase microextraction techniques are mostly used for liquid samples. Likewise, green characteristics of the instrumental analysis used after the extraction and clean-up steps are briefly discussed. PMID:26755134

  20. 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. PMID:26671943

  1. Pre-separation of biological samples using of preparative divergent flow isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Vykydalová, Marie; Moravcová, Dana; Kahle, Vladislav; Šlais, Karel

    Warsaw, 2009. s. 83. [International Congress of Young Chemists. 14.10.2009-18.10.2009, Warsaw] R&D Projects: GA AV ČR IAAX00310701; GA MŠk LC06023 Institutional research plan: CEZ:AV0Z40310501 Keywords : preparative divergent flow isoelectric focusing * extract * wheat flour Subject RIV: CB - Analytical Chemistry, Separation

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

    OpenAIRE

    Corina Mahu Ştefania; Monica Hăncianu; Luminiţa Agoroaei; Anda Cristina Coman Băbuşanu; Elena Butnaru

    2015-01-01

    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. ...

  3. Biological sample collector

    Science.gov (United States)

    Murphy, Gloria A.

    2010-09-07

    A biological sample collector is adapted to a collect several biological samples in a plurality of filter wells. A biological sample collector may comprise a manifold plate for mounting a filter plate thereon, the filter plate having a plurality of filter wells therein; a hollow slider for engaging and positioning a tube that slides therethrough; and a slide case within which the hollow slider travels to allow the tube to be aligned with a selected filter well of the plurality of filter wells, wherein when the tube is aligned with the selected filter well, the tube is pushed through the hollow slider and into the selected filter well to sealingly engage the selected filter well and to allow the tube to deposit a biological sample onto a filter in the bottom of the selected filter well. The biological sample collector may be portable.

  4. Preparation of biological samples for transmission X-ray microanalysis: a review of alternative procedures to the use of sectioned material

    International Nuclear Information System (INIS)

    Although transmission X-ray microanalysis of biological material has traditionally been carried out mainly on sectioned preparations, a number of alternative procedures exist. These are considered under three major headings - whole cell preparations, analysis of cell homogenates and biological fluids, and applications of the technique to microsamples of purified biochemicals. These three aspects provide a continuous range of investigative level - from the cellular to the molecular. The use of X-ray microanalysis with whole cell preparations is considered in reference to eukaryote (animal) cells and prokaryotes - where it has particular potential in environmental studies on bacteria. In the case of cell homogenates and biological fluids, the technique has been used mainly with microdroplets of animal material. The use of X-ray microanalysis with purified biochemicals is considered in relation to both particulate and non-particulate samples. In the latter category, the application of this technique for analysis of thin films of metalloprotein is particularly emphasised. It is concluded that wider use could be made of the range of preparative techniques available - both within a particular investigation, and in diverse fields of study. Transmission X-ray microanalysis has implications for environmental, physiological and molecular biology as well as cell biology

  5. 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.

  6. Final Report BW Sample Collection& Preparation Device

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-01-31

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

  7. Sample preparation for inductively coupled plasma mass spectrometric determination of the zinc-70 to zinc-68 isotope ratio in biological samples

    International Nuclear Information System (INIS)

    Sample preparation was optimized for the 70Zn:68Zn isotope ratio determinations performed with inductively coupled plasma mass spectrometry in blood, faeces and urine from human pre-term babies after oral or intravenous administration of enriched 70Zn. The preparation techniques achieved complete decomposition, matrix separation, maximum preconcentration and minimum contamination. After sample decomposition, Zn was extracted into CCl4 with ammonium pyrrolidin-1-yldithioformate and back extracted into 1.2 mol dm-3 HNO3 for analysis. Residual chloride resulting from dissolved CCl4 in the acid led to interference by 35Cl2+, and the procedure was modified to evaporate the CCl4. Extraction was unnecessary for faecal samples. Under optimized conditions the 70Zn:68Zn isotope ratio can be measured with acceptable precision (200 ng cm-3 in the analytical solution). (Author)

  8. 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. PMID:26939073

  9. Enhanced Biological Sampling Data

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — This is a database of a variety of biological, reproductive, and energetic data collected from fish on the continental shelf in the northwest Atlantic Ocean....

  10. Quantitative evaluation of freeze-substitution effects on preservation of nuclear antigens during preparation of biological samples for immunoelectron microscopy

    Czech Academy of Sciences Publication Activity Database

    Sobol, Margaryta; Philimonenko, Vlada; Philimonenko, Anatoly; Hozák, Pavel

    2012-01-01

    Roč. 138, č. 1 (2012), s. 167-177. ISSN 0948-6143 R&D Projects: GA AV ČR KAN200520704; GA MŠk 2B06063; GA MŠk LC545; GA ČR GAP305/11/2232 Institutional research plan: CEZ:AV0Z50520514 Keywords : immuno-gold labeling * automated freeze-substitution * LR White * immunohistochemistry * high-pressure freezing Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.613, year: 2012

  11. Biological Sample Monitoring Database (BSMDBS)

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The Biological Sample Monitoring Database System (BSMDBS) was developed for the Northeast Fisheries Regional Office and Science Center (NER/NEFSC) to record and...

  12. Effect of sample preparation techniques on the concentrations and distributions of elements in biological tissues using µSRXRF: a comparative study

    International Nuclear Information System (INIS)

    Routine tissue sample preparation using chemical fixatives is known to preserve the morphology of the tissue being studied. A competitive method, cryofixation followed by freeze drying, involves no chemical agents and maintains the biological function of the tissue. The possible effects of both sample preparation techniques in terms of the distribution of bio-metals (calcium (Ca), copper (Cu) zinc (Zn), and iron (Fe) specifically) in human skin tissue samples was investigated. Micro synchrotron radiation x-ray fluorescence (μSRXRF) was used to map bio-metal distribution in epidermal and dermal layers of human skin samples from various locations of the body that have been prepared using both techniques. For Ca, Cu and Zn, there were statistically significant differences between the epidermis and dermis using the freeze drying technique (p = 0.02, p < 0.01, and p < 0.01, respectively). Also using the formalin fixed, paraffin embedded technique the levels of Ca, Cu and Zn, were significantly different between the epidermis and dermis layers (p = 0.03, p < 0.01, and p < 0.01, respectively). However, the difference in levels of Fe between the epidermis and dermis was unclear and further analysis was required. The epidermis was further divided into two sub-layers, one mainly composed of the stratum corneum and the other deeper layer, the stratum basale. It was found that the difference between the distribution of Fe in the two epidermal layers using the freeze drying technique resulted in a statistically significant difference (p = 0.012). This same region also showed a difference in Fe using the formalin fixed, paraffin embedded technique (p < 0.01). The formalin fixed, paraffin embedded technique also showed a difference between the deeper epidermal layer and the dermis (p < 0.01). It can be concluded that studies involving Ca, Cu and Zn might show similar results using both sample preparation techniques, however studies involving Fe would need more

  13. OXI-FLO: an instrument concept for the combined sample preparation and measurement of low energy beta radio-labelled biological samples

    International Nuclear Information System (INIS)

    The purpose of the development of the OXI-FLO instrument was to provide an automated system which will produce accurate, reproducible results at a cost which is competitive with current techniques, but which also provides savings in labor. An oxidizer, coupled with a liquid scintillation counter (LSC) has many advantages. The techniques of vial-less LSC was pioneered in this company, during the development of the RSP-β400 Sample Processor, therefore, the technology of transferring and counting a liquid in a stop-flow mode was readily available. The OXI-ONE Sample Oxidizer, also marketed by Radiomatic Instruments, lends itself naturally to the OXI-FLO concept, since the LSC vial is not an integral part of the oxidizer and can be substituted with a different device. These two technologies combined are the basis of the OXI-FLO instrument

  14. Microholographic imaging of biological samples

    International Nuclear Information System (INIS)

    A camera system suitable for x-ray microholography has been constructed. Visible light Fourier transform microholograms of biological samples and other test targets have been recorded and reconstructed digitally using a glycerol microdrop as a reference wave source. Current results give a resolution of ∼4 - 10 λ with λ = 514.5 nm. 11 refs., 1 fig

  15. PIXE and its applications to biological samples

    International Nuclear Information System (INIS)

    Throughout this century, industrialized society has seriously affected the ecology by introducing huge amounts of pollutants into the atmosphere as well as marine and soil environments. On the other hand, it is known that these pollutants, in excess of certain levels of concentration, not only put at risk the life of living beings but may also cause the extinction of some species. It is therefore of basic importance to substantially increase quantitative determinations of trace element concentrations in biological specimens in order to assess the effects of pollutants. It is in this field that PIXE plays a key role in these studies, where its unique analytical properties are decisive. Moreover, since the importance of these research has been recognized in many countries, many scientists have been encouraged to continue or initiate new research programmes aimed to solve the worldwide pollution problem. This document presents an overview of those papers reporting the application of PIXE analysis to biological samples during this last decade of the 20th century and recounts the number of PIXE laboratories dedicating their efforts to find the clues of the biological effects of the presence of pollutants introduced in living beings. Sample preparation methods, different kinds of samples under study and the use of complementary analytical techniques are also illustrated. (author). 108 refs

  16. 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

    2016-03-01

    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. PMID:26839178

  17. The MEGAPIE PIE sample preparation

    International Nuclear Information System (INIS)

    On the way towards Accelerator-driven Systems (ADS), the MEGAPIE (Mega-Watt Pilot Experiment) project is one of the key milestones. The MEGAPIE project aimed to prove that a liquid Lead-Bismuth-Eutectic (LBE) spallation target can be licensed, planned, built, operated, dismantled, examined and disposed. The project has finished the phase of producing the samples for Post-irradiation Examination (PIE). Samples to study structural material property changes due to the harsh environment of high temperatures, contact with flowing liquid metal (LBE), proton and neutron irradiation will be investigated by all partner laboratories (CEA, CNRS, ENEA, KIT, PSI and SCK-CEN). (authors)

  18. Innovative methods for inorganic sample preparation

    International Nuclear Information System (INIS)

    Procedures and guidelines are given for the dissolution of a variety of selected materials using fusion, microwave, and Parr bomb techniques. These materials include germanium glass, corium-concrete mixtures, and zeolites. Emphasis is placed on sample-preparation approaches that produce a single master solution suitable for complete multielement characterization of the sample. In addition, data are presented on the soil microwave digestion method approved by the Environmental Protection Agency (EPA). Advantages and disadvantages of each sample-preparation technique are summarized

  19. Sample preparation for single molecule localization microscopy.

    Science.gov (United States)

    Allen, John R; Ross, Stephen T; Davidson, Michael W

    2013-11-21

    Single molecule localization-based optical nanoscopy was introduced in 2006, surpassing traditional diffraction-limited resolutions by an order of magnitude. Seven years later, this superresolution technique is continuing to follow a trend of increasing popularity and pervasiveness, with the proof-of-concept work long finished and commercial implementations now available. However one important aspect that tends to become lost in translation is the importance of proper sample preparation, with very few resources addressing the considerations that must be made when preparing samples for imaging with single molecule level sensitivity. Presented here is a an in-depth analysis of all aspects of sample preparation for single molecule superresolution, including both live and fixed cell preparation, choice of fluorophore, fixation and staining techniques, and imaging buffer considerations. PMID:24084850

  20. Preparation of honey sample for tritium monitoring

    International Nuclear Information System (INIS)

    The method of preparation of honey sample for tritium monitoring was described. The equipments consist of an air and honey supply system, a quartz combustor with CM-type monolithic combustion catalyst and a condensation system. In the equipments, honey sample was converted into cooling water by the distilling, cracking and carbonizing procedures for tritium counting. The recovery ratio is 99.0 ± 4.5 percent for tritiated water and 96.0 ± 2.0 for tritiated organic compounds. It is a feasible preparing method for the total tritium monitoring in honey sample

  1. Fluorine ion transmission through thin biological samples

    International Nuclear Information System (INIS)

    F2+ beam with 3 MeV is used to irradiate thin biological samples (onion inner surface membrane and kidney bean coat) in the transmission measurement, its current density is 400∼800 nA/cm2. Results show that the onion samples can be broken up quickly under ion irradiating; as to kidney bean samples, about 60% of the implanted ions penetrate the samples, most of them lose part of their energy, fewer ions are found to be able to transmit through the sample without energy loss. SEM experiments are carried out to study sample's damage induced by the ions irradiation

  2. Fluorine ion transmission through thin biological samples

    Institute of Scientific and Technical Information of China (English)

    XueJian-Ming; WangYu-Gang; 等

    1998-01-01

    F2+ beam with 3MeV is used to irradiate thin biological samples(onion inner suface membrane and kidney bean coat)in the transmission measurement ,its current density is 400-800nA/cm2,Results show that the onion samples can be broken up quickly under ion irradiating;as to kidney bean samples,about 60% of the implanted ions penetrate the samples,most of them lose part of their eneregy,fewer ions are found to be able to transmit through the sample without energy loss.SEM experiments are carried out to study sample's damage induced by the ions irradiation.

  3. Sample preparation for x-ray analysis

    International Nuclear Information System (INIS)

    Full text: In my experience over many years it is not uncommon for a geologist to present a suite of rocks or powders for analysis and demand results of high analytical precision which are not warranted for the following reasons: 1. Sample collection is unsatisfactory. 2. Little or no attention has been given to cleaning and splitting the sample. The ultimate aim of the preparation laboratory is to produce a homogeneous, uncontaminated aliquot of the total sample pulverised to a grain size of less than 10 microns. Clearly this is not possible as the grinding equipment will always impart some level of contamination to the sample and there is no grinder available which can produce powders of grain size less than 10 microns without imparting unacceptable levels of contamination to the sample. Modern x-ray spectrometers are extremely stable instruments. Most laboratories run a drift monitor at the start of each shift or when starting analyses requiring a different calibration. Depending on the method of sample preparation errors from this source can be up to two orders of magnitude greater than instrumental errors. For this reason it is imperative that sample preparation methods for a particular analysis are carefully set up and that these procedures are followed implicitly by the sample preparation laboratory. All too often sample preparation is relegated to a secondary role carried out in poorly designed work areas with inappropriate equipment by poorly trained unsupervised staff. Over the past few years staffing reductions and the requirement to crush an increasingly large volume of sample has given the impetus to develop improved jaw crushers. An example of this is the Boyd Crusher which has been designed to minimise these problems, ie this crusher has high throughput, can be easily cleaned and produces minimal contamination. Copyright (1999) Australian X-ray Analytical Association Inc

  4. Sample preparations for spark source mass spectrography

    International Nuclear Information System (INIS)

    Methods have been developed for the preparation of various materials for spark source mass spectrography. The essential features of these preparations (all which can provide adequate precision in a cost-effective manner) consist in obtaining spark-stable electrode sample pieces, a common matrix, a reduction of anomolous effects in the spark, the incorporation of a suitable internal standard for plate response normalization, and a reduction in time

  5. Recommendations for sampling for prevention of hazards in civil defense. On analytics of chemical, biological and radioactive contaminations. Brief instruction for the CBRN (chemical, biological, radioactive, nuclear) sampling

    International Nuclear Information System (INIS)

    The recommendation for sampling for prevention of hazards in civil defense is describing the analytics of chemical, biological and radioactive contaminations and includes detail information on the sampling, protocol preparation and documentation procedures. The volume includes a separate brief instruction for the CBRN (chemical, biological, radioactive, nuclear) sampling.

  6. Preparation and characterization of magnetic nanocomposite of Schiff base/silica/magnetite as a preconcentration phase for the trace determination of heavy metal ions in water, food and biological samples using atomic absorption spectrometry.

    Science.gov (United States)

    Bagheri, Hasan; Afkhami, Abbas; Saber-Tehrani, Mohammad; Khoshsafar, Hosein

    2012-08-15

    A versatile and robust solid phase with both magnetic property and a very high adsorption capacity is presented on the basis of modification of iron oxide-silica magnetic particles with a newly synthesized Schiff base (Fe(3)O(4)/SiO(2)/L). The structure of the resulting product was confirmed by Fourier transform infrared (FT-IR) spectra, X-ray diffraction (XRD) spectrometry and transmission electron microscopy (TEM). We developed an efficient and cost-effective method for the preconcentration of trace amounts of Pb(II), Cd(II) and Cu(II) in environmental and biological samples using this novel magnetic solid phase. Prepared magnetic solid phase is an ideal support because it has a large surface area, good selectivity and can be easily retrieved from large volumes of aqueous solutions. The possible parameters affecting the enrichment were optimized. Under the optimal conditions, the method detection limit was 0.14, 0.19 and 0.12 μg L(-1) for Pb(II), Cd(II) and Cu(II) ions, respectively. The established method has been successfully applied to analyze real samples, and satisfactory results were obtained. All these indicated that this magnetic phase had a great potential in environmental and biological fields. PMID:22841051

  7. Precise and automated microfluidic sample preparation.

    Energy Technology Data Exchange (ETDEWEB)

    Crocker, Robert W.; Patel, Kamlesh D.; Mosier, Bruce P.; Harnett, Cindy K.

    2004-07-01

    Autonomous bio-chemical agent detectors require sample preparation involving multiplex fluid control. We have developed a portable microfluidic pump array for metering sub-microliter volumes at flowrates of 1-100 {micro}L/min. Each pump is composed of an electrokinetic (EK) pump and high-voltage power supply with 15-Hz feedback from flow sensors. The combination of high pump fluid impedance and active control results in precise fluid metering with nanoliter accuracy. Automated sample preparation will be demonstrated by labeling proteins with fluorescamine and subsequent injection to a capillary gel electrophoresis (CGE) chip.

  8. Determination of halogens, with special reference to iodine, in geological and biological samples using pyrohydrolysis for preparation and inductively coupled plasma mass spectrometry and ion chromatography for measurement.

    Science.gov (United States)

    Schnetger, B; Muramatsu, Y

    1996-11-01

    A method for determining iodine, bromine, chlorine and fluorine in geological and biological materials is described. In a quartz tube, solid material was heated to 1100 degrees C under a wet oxygen flow (pyrohydrolysis). By this process the halogens (I, Br, Cl, F) were separated from the matrix and then collected in a receiver solution. The chemical yield of iodine was determined by a radioactive tracer. ICP-MS and ion chromatographic measurements were used for the determination of the halogens. The method was optimized by investigating different experimental conditions. All four halogens can be trapped in the receiver solution from one combustion procedure. Precision and accuracy were evaluated by the analysis of environmental standard reference materials (rock, soil, milk, leaves, marine tissue). The concentrations in the materials analysed were in the ranges 0.006-50 mg kg-1 for I, 0.06-1300 mg kg-1 for Br, 50-1100 mg kg-1 for F and 400-11000 mg kg-1 for Cl. The lower values represent the practical detection limit of this method. The results obtained by the proposed method and the certified values are in good agreement. PMID:8952450

  9. Discovering biological progression underlying microarray samples.

    Directory of Open Access Journals (Sweden)

    Peng Qiu

    2011-04-01

    Full Text Available In biological systems that undergo processes such as differentiation, a clear concept of progression exists. We present a novel computational approach, called Sample Progression Discovery (SPD, to discover patterns of biological progression underlying microarray gene expression data. SPD assumes that individual samples of a microarray dataset are related by an unknown biological process (i.e., differentiation, development, cell cycle, disease progression, and that each sample represents one unknown point along the progression of that process. SPD aims to organize the samples in a manner that reveals the underlying progression and to simultaneously identify subsets of genes that are responsible for that progression. We demonstrate the performance of SPD on a variety of microarray datasets that were generated by sampling a biological process at different points along its progression, without providing SPD any information of the underlying process. When applied to a cell cycle time series microarray dataset, SPD was not provided any prior knowledge of samples' time order or of which genes are cell-cycle regulated, yet SPD recovered the correct time order and identified many genes that have been associated with the cell cycle. When applied to B-cell differentiation data, SPD recovered the correct order of stages of normal B-cell differentiation and the linkage between preB-ALL tumor cells with their cell origin preB. When applied to mouse embryonic stem cell differentiation data, SPD uncovered a landscape of ESC differentiation into various lineages and genes that represent both generic and lineage specific processes. When applied to a prostate cancer microarray dataset, SPD identified gene modules that reflect a progression consistent with disease stages. SPD may be best viewed as a novel tool for synthesizing biological hypotheses because it provides a likely biological progression underlying a microarray dataset and, perhaps more importantly, the

  10. Sample preparation method for scanning force microscopy

    CERN Document Server

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

    2001-01-01

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

  11. A review of analytical methods for the determination of four new phosphodiesterase type 5 inhibitors in biological samples and pharmaceutical preparations

    Directory of Open Access Journals (Sweden)

    Cristiane Franco Codevilla

    2013-03-01

    Full Text Available The introduction of oral phosphodiesterase type 5 inhibitor therapy in 1998 revolutionized the treatment of erectile dysfunction. Erectile dysfunction is the most common sexual problem in men. It often has a profound effect on intimate relationships and quality of life. The analysis of pharmaceuticals is an important part of the drug development process as well as for routine analysis and quality control of commercial formulations. Whereas the determination of sildenafil citrate, vardenafil and tadalafil are well documented by a variety of methods, there are few publications about the determination of udenafil, lodenafil carbonate, mirodenafil and avanafil. The paper presents a brief review of the action mechanism, adverse effects, pharmacokinetics and the most recent analytical methods that can determine drug concentration in biological matrices and pharmaceutical formulations of these four drugs.A introdução da terapia oral com inibidores da fosfodiesterase tipo 5, em 1998, revolucionou o tratamento da disfunção erétil. A disfunção erétil é o problema sexual mais comum em homens. Muitas vezes tem um efeito profundo nas relações íntimas e na qualidade de vida. A análise de produtos farmacêuticos é uma parte importante do processo de desenvolvimento de fármacos, bem como para a análise de rotina e controle de qualidade das formulações comerciais. Enquanto a determinação do citrato de sildenafila, vardenafila e tadalafila está bem documentada por uma variedade de métodos, existem poucas publicações sobre a determinação de udenafila, carbonato de lodenafila, mirodenafila e avanafila. O artigo apresenta uma breve revisão do mecanismo de ação, efeitos adversos, farmacocinética e os mais recentes métodos analíticos, que podem determinar a concentração do fármaco em matrizes biológicas e formulações farmacêuticas destes quatro fármacos.

  12. Generic on-line solid phase extraction sample preparation strategies for the analysis of drugs in biological matrices by LC-MS/MS.

    Science.gov (United States)

    Bourgogne, Emmanuel; Grivet, Chantal; Varesio, Emmanuel; Hopfgartner, Gérard

    2015-01-01

    In the present work we investigate the integration of a single hardware platform (Prospekt-2) allowing on-line SPE with pre-/post-trapping dilution and direct injection of plasma extracts, and also compare the benefits and challenges of the different approaches for pharmaceutical drugs with heterogeneous physicochemical properties. In the first part, the generic use of on-line SPE with direct plasma injection or after protein precipitation was investigated for the quantitative analysis of talinolol. In the second part, pre-trapping and post-trapping dilution for on-line SPE is discussed for generic method development on an oxadiazole and its major metabolite. Finally, the difference of performance between direct plasma injection vs. off-line liquid-liquid extraction is also described for the quantification of buprenorphine and naltrexone down to 50 and 100 pg/ml using a 0.25 ml plasma aliquot. All assays were in human plasma and detection was performed by mass spectrometry detection either on simple or triple stage quadrupoles. Regardless of the tested strategy, assays were found linear, with precision and accuracy with <15% for all quality controls samples and <20% for lower limit of quantitation. PMID:25459926

  13. Fast x-ray fluorescence microtomography of hydrated biological samples.

    Directory of Open Access Journals (Sweden)

    Enzo Lombi

    Full Text Available Metals and metalloids play a key role in plant and other biological systems as some of them are essential to living organisms and all can be toxic at high concentrations. It is therefore important to understand how they are accumulated, complexed and transported within plants. In situ imaging of metal distribution at physiological relevant concentrations in highly hydrated biological systems is technically challenging. In the case of roots, this is mainly due to the possibility of artifacts arising during sample preparation such as cross sectioning. Synchrotron x-ray fluorescence microtomography has been used to obtain virtual cross sections of elemental distributions. However, traditionally this technique requires long data acquisition times. This has prohibited its application to highly hydrated biological samples which suffer both radiation damage and dehydration during extended analysis. However, recent advances in fast detectors coupled with powerful data acquisition approaches and suitable sample preparation methods can circumvent this problem. We demonstrate the heightened potential of this technique by imaging the distribution of nickel and zinc in hydrated plant roots. Although 3D tomography was still impeded by radiation damage, we successfully collected 2D tomograms of hydrated plant roots exposed to environmentally relevant metal concentrations for short periods of time. To our knowledge, this is the first published example of the possibilities offered by a new generation of fast fluorescence detectors to investigate metal and metalloid distribution in radiation-sensitive, biological samples.

  14. On-chip Ultrasonic Sample Preparation

    OpenAIRE

    Iranmanesh, Ida Sadat

    2015-01-01

    Acoustofluidics has become a well-established technology in the lab-on-a-chip scientific community. The technology involves primarily the manipulation of fluids and/or particles in microfluidic systems. It is used today for variety of applications such as handling, sorting, washing and separation of cells or micro-particles, and for mixing and pumping of fluids. When such manipulation functions are integrated in micro-devices, the technology has been used for clinical sample preparation as we...

  15. Atomic force microscopy of biological samples.

    Science.gov (United States)

    Allison, David P; Mortensen, Ninell P; Sullivan, Claretta J; Doktycz, Mitchel J

    2010-01-01

    The ability to evaluate structural-functional relationships in real time has allowed scanning probe microscopy (SPM) to assume a prominent role in post genomic biological research. In this mini-review, we highlight the development of imaging and ancillary techniques that have allowed SPM to permeate many key areas of contemporary research. We begin by examining the invention of the scanning tunneling microscope (STM) by Binnig and Rohrer in 1982 and discuss how it served to team biologists with physicists to integrate high-resolution microscopy into biological science. We point to the problems of imaging nonconductive biological samples with the STM and relate how this led to the evolution of the atomic force microscope (AFM) developed by Binnig, Quate, and Gerber, in 1986. Commercialization in the late 1980s established SPM as a powerful research tool in the biological research community. Contact mode AFM imaging was soon complemented by the development of non-contact imaging modes. These non-contact modes eventually became the primary focus for further new applications including the development of fast scanning methods. The extreme sensitivity of the AFM cantilever was recognized and has been developed into applications for measuring forces required for indenting biological surfaces and breaking bonds between biomolecules. Further functional augmentation to the cantilever tip allowed development of new and emerging techniques including scanning ion-conductance microscopy (SICM), scanning electrochemical microscope (SECM), Kelvin force microscopy (KFM) and scanning near field ultrasonic holography (SNFUH). PMID:20672388

  16. Atomic force microscopy of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Doktycz, Mitchel John [ORNL

    2010-01-01

    The ability to evaluate structural-functional relationships in real time has allowed scanning probe microscopy (SPM) to assume a prominent role in post genomic biological research. In this mini-review, we highlight the development of imaging and ancillary techniques that have allowed SPM to permeate many key areas of contemporary research. We begin by examining the invention of the scanning tunneling microscope (STM) by Binnig and Rohrer in 1982 and discuss how it served to team biologists with physicists to integrate high-resolution microscopy into biological science. We point to the problems of imaging nonconductive biological samples with the STM and relate how this led to the evolution of the atomic force microscope (AFM) developed by Binnig, Quate, and Gerber, in 1986. Commercialization in the late 1980s established SPM as a powerful research tool in the biological research community. Contact mode AFM imaging was soon complemented by the development of non-contact imaging modes. These non-contact modes eventually became the primary focus for further new applications including the development of fast scanning methods. The extreme sensitivity of the AFM cantilever was recognized and has been developed into applications for measuring forces required for indenting biological surfaces and breaking bonds between biomolecules. Further functional augmentation to the cantilever tip allowed development of new and emerging techniques including scanning ion-conductance microscopy (SICM), scanning electrochemical microscope (SECM), Kelvin force microscopy (KFM) and scanning near field ultrasonic holography (SNFUH).

  17. Sample preparation methods for determination of drugs of abuse in hair samples: A review.

    Science.gov (United States)

    Vogliardi, Susanna; Tucci, Marianna; Stocchero, Giulia; Ferrara, Santo Davide; Favretto, Donata

    2015-02-01

    Hair analysis has assumed increasing importance in the determination of substances of abuse, both in clinical and forensic toxicology investigations. Hair analysis offers particular advantages over other biological matrices (blood and urine), including a larger window of detection, ease of collection and sample stability. In the present work, an overview of sample preparation techniques for the determination of substances of abuse in hair is provided, specifically regarding the principal steps in hair sample treatment-decontamination, extraction and purification. For this purpose, a survey of publications found in the MEDLINE database from 2000 to date was conducted. The most widely consumed substances of abuse and psychotropic drugs were considered. Trends in simplification of hair sample preparation, washing procedures and cleanup methods are discussed. Alternative sample extraction techniques, such as head-space solid phase microextraction (HS-SPDE), supercritical fluid extraction (SFE) and molecularly imprinted polymers (MIP) are also reported. PMID:25604816

  18. EDUTAINMENT SOFTWARE EVALUATION PREPARED FOR BIOLOGY INSTRUCTION

    Directory of Open Access Journals (Sweden)

    Yılmaz KARA

    2009-05-01

    Full Text Available The aim of this study is to determine whether an edutainment software program, called “Biyoskop” prepared for computer assisted biology instruction, has educational quality according to the criteria which have to be taken into consideration during the evaluation process of an educational software program. The subjects of the study consist of a group of 48 biology teachers. In this research, “educational software evaluation scale”, which lists the criteria necessary for courseware programs used in computer assisted instruction, has been used in order to attain teachers’ evaluations regarding the appropriateness of content, ease-of-use, technical and educational adequacy of the software. As a result of the analysis of the gathered data, it has been evaluated that the software ranks “average” in terms of adequacy due to the lack of sufficient qualifications, such as the relation of the content to the target behavior, compatibility with the curriculum, providing opportunities of progress for the students asking for further information, providing additional activities and containing an achievement test.

  19. Ergonomic analysis of radiopharmaceuticals samples preparation process

    International Nuclear Information System (INIS)

    The doses of radioisotopes to be administrated in patients for diagnostic effect or therapy are prepared in the radiopharmacological sector. The preparation process adopts techniques that are aimed to reduce the exposition time of the professionals and the absorption of excessive doses for patients. The ergonomic analysis of this process contributes in the prevention of occupational illnesses and to prevent risks of accidents during the routines, providing welfare and security to the involved users and conferring to the process an adequate working standard. In this context it is perceived relevance of studies that deal with the analysis of factors that point with respect to the solution of problems and for establishing proposals that minimize risks in the exercise of the activities. Through a methodology that considers the application of the concepts of Ergonomics, it is searched the improvement of the effectiveness or the quality and reduction of the difficulties lived for the workers. The work prescribed, established through norms and procedures codified will be faced with the work effectively carried through, the real work, shaped to break the correct appreciation, with focus in the activities. This work has as objective to argue an ergonomic analysis of samples preparation process of radioisotopes in the Setor de Radiofarmacia do Hospital Universitario Clementino Fraga Filho da Universidade Federal do Rio de Janeiro (UFRJ). (author)

  20. Sample preparation for SEM of plant surfaces

    Directory of Open Access Journals (Sweden)

    A.K. Pathan

    2010-01-01

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

  1. Ethanol analysis from biological samples by dual rail robotic autosampler.

    Science.gov (United States)

    Morris-Kukoski, Cynthia L; Jagerdeo, Eshwar; Schaff, Jason E; LeBeau, Marc A

    2007-05-01

    Detection, identification, and quantitation of ethanol and other low molecular weight volatile compounds in liquid matrices by headspace gas chromatography-flame ionization detection (HS-GC-FID) and headspace gas chromatography-mass spectrometry (HS-GC-MS) are becoming commonly used practices in forensic laboratories. Although it is one of the most frequently utilized procedures, sample preparation is usually done manually. Implementing the use of a dual-rail, programmable autosampler can minimize many of the manual steps in sample preparation. The autosampler is configured so that one rail is used for sample preparation and the other rail is used as a traditional autosampler for sample introduction into the gas chromatograph inlet. The sample preparation rail draws up and sequentially adds a saturated sodium chloride solution and internal standard (0.08%, w/v acetonitrile) to a headspace vial containing a biological sample, a calibrator, or a control. Then, the analytical rail moves the sample to the agitator for incubation, followed by sampling of the headspace for analysis. Using DB-624 capillary columns, the method was validated on a GC-FID and confirmed with a GC-MS. The analytes (ethanol, acetonitrile) and possible interferences (acetaldehyde, methanol, pentane, diethyl ether, acetone, isopropanol, methylene chloride, n-propanol, and isovaleraldehyde) were baseline resolved for both the GC-FID and GC-MS methods. This method demonstrated acceptable linearity from 0 to 1500 mg/dL. The lower limit of quantitation (LOQ) was determined to be 17 mg/dL and the limit of detection was 5 mg/dL. PMID:17223393

  2. Sample preparation techniques in trace element analysis by X-ray emission spectroscopy

    International Nuclear Information System (INIS)

    The report, written under a research contract with the IAEA, contains a detailed presentation of the most difficult problem encountered in the trace element analysis by methods of the X-ray emission spectroscopy, namely the sample preparation techniques. The following items are covered. Sampling - with specific consideration of aerosols, water, soil, biological materials, petroleum and its products, storage of samples and their handling. Pretreatment of samples - preconcentration, ashing, solvent extraction, ion exchange and electrodeposition. Sample preparations for PIXE - analysis - backings, target uniformity and homogeneity, effects of irradiation, internal standards and specific examples of preparation (aqueous, biological, blood serum and solid samples). Sample preparations for radioactive sources or tube excitation - with specific examples (water, liquid and solid samples, soil, geological, plants and tissue samples). Finally, the problem of standards and reference materials, as well as that of interlaboratory comparisons, is discussed

  3. 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...

  4. Biological sampling for marine radioactivity monitoring

    International Nuclear Information System (INIS)

    Strategies and methodologies for using marine organisms to monitor radioactivity in marine waters are presented. When the criteria for monitoring radioactivity is to determine routes of radionuclide transfer to man, the ''critical pathway'' approach is often applied. Alternatively, where information on ambient radionuclide levels and distributions is sought, the approach of selecting marine organisms as ''bioindicators'' of radioactivity is generally used. Whichever approach is applied, a great deal of knowledge is required about the physiology and ecology of the specific organism chosen. In addition, several criteria for qualifying as a bioindicator species are discussed; e.g., it must be a sedentary species which reflects the ambient radionuclide concentration at a given site, sufficiently long-lived to allow long-term temporal sampling, widely distributed to allow spatial comparisons, able to bioconcentrate the radionuclide to a relatively high degree, while showing a simple correlation between radionuclide content in its tissues with that in the surrounding waters. Useful hints on the appropriate species to use and the best way to collect and prepare organisms for radioanalysis are also given. It is concluded that benthic algae and bivalve molluscs generally offer the greatest potential for use as a ''bioindicator'' species in radionuclide biomonitoring programmes. Where knowledge on contribution to radiological dose is required, specific edible marine species should be the organisms of choice; however, both purposes can be served when the edible species chosen through critical pathway analysis is also an excellent bioaccumulator of the radionuclide of interest. (author)

  5. 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

  6. Preparing Synthetic Biology for the World

    Directory of Open Access Journals (Sweden)

    Gerd H.G. Moe-Behrens

    2013-01-01

    Full Text Available Synthetic Biology promises low-cost, exponentially scalable products and global health solutions in the form of self-replicating organisms, or living devices. As these promises are realized, proof-of-concept systems will gradually migrate from tightly regulated laboratory or industrial environments into private spaces as, for instance, probiotic health products, food, and even do-it-yourself bioengineered systems. What additional steps, if any, should be taken before releasing engineered self-replicating organisms into a broader user space? In this review, we explain how studies of genetically modified organisms lay groundwork for the future landscape of biosafety. Early in the design process, biological engineers are anticipating potential hazards and developing innovative tools to mitigate risk. Here, we survey lessons learned, ongoing efforts to engineer intrinsic biocontainment, and how different stakeholders in synthetic biology can act to accomplish best practices for biosafety.

  7. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    International Nuclear Information System (INIS)

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation

  8. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Science.gov (United States)

    Vavpetič, P.; Vogel-Mikuš, K.; Jeromel, L.; Ogrinc Potočnik, N.; Pongrac, P.; Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M.; Pelicon, P.

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on-off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm2 and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  9. Elemental distribution and sample integrity comparison of freeze-dried and frozen-hydrated biological tissue samples with nuclear microprobe

    Energy Technology Data Exchange (ETDEWEB)

    Vavpetič, P., E-mail: primoz.vavpetic@ijs.si [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Vogel-Mikuš, K. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Jeromel, L. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); Ogrinc Potočnik, N. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia); FOM-Institute AMOLF, Science Park 104, 1098 XG Amsterdam (Netherlands); Pongrac, P. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Department of Plant Physiology, University of Bayreuth, Universitätstr. 30, 95447 Bayreuth (Germany); Drobne, D.; Pipan Tkalec, Ž.; Novak, S.; Kos, M.; Koren, Š.; Regvar, M. [Biotechnical Faculty, Department of Biology, University of Ljubljana, Jamnikarjeva 101, SI-1000 Ljubljana (Slovenia); Pelicon, P. [Jožef Stefan Institute, Jamova 39, SI-1000 Ljubljana (Slovenia)

    2015-04-01

    The analysis of biological samples in frozen-hydrated state with micro-PIXE technique at Jožef Stefan Institute (JSI) nuclear microprobe has matured to a point that enables us to measure and examine frozen tissue samples routinely as a standard research method. Cryotome-cut slice of frozen-hydrated biological sample is mounted between two thin foils and positioned on the sample holder. The temperature of the cold stage in the measuring chamber is kept below 130 K throughout the insertion of the samples and the proton beam exposure. Matrix composition of frozen-hydrated tissue is consisted mostly of ice. Sample deterioration during proton beam exposure is monitored during the experiment, as both Elastic Backscattering Spectrometry (EBS) and Scanning Transmission Ion Microscopy (STIM) in on–off axis geometry are recorded together with the events in two PIXE detectors and backscattered ions from the chopper in a single list-mode file. The aim of this experiment was to determine differences and similarities between two kinds of biological sample preparation techniques for micro-PIXE analysis, namely freeze-drying and frozen-hydrated sample preparation in order to evaluate the improvements in the elemental localisation of the latter technique if any. In the presented work, a standard micro-PIXE configuration for tissue mapping at JSI was used with five detection systems operating in parallel, with proton beam cross section of 1.0 × 1.0 μm{sup 2} and a beam current of 100 pA. The comparison of the resulting elemental distributions measured at the biological tissue prepared in the frozen-hydrated and in the freeze-dried state revealed differences in elemental distribution of particular elements at the cellular level due to the morphology alteration in particular tissue compartments induced either by water removal in the lyophilisation process or by unsatisfactory preparation of samples for cutting and mounting during the shock-freezing phase of sample preparation.

  10. Influences of sample preparations on dentine ESR signals

    International Nuclear Information System (INIS)

    The work is to study influences of sample preparations on dentine ESR (electron spin resonance) signals, in order to use dentine samples for dose reconstruction, which has been performed with enamel samples. The dentine and enamel samples were collected from non-irradiated adult teeth and prepared by mechanical or mechanical plus chemical methods. The samples were scanned by an ESR spectrometer before and after their irradiation by 60Co γ-rays. The sensitivities of ESR signals of dentine and enamel samples to irradiation dose differed significantly among different sample preparation methods. The results show that dentine samples mechanically and chemically prepared have good enough ESR response to low dose γ-ray irradiations, and it is possible to use the dentine samples for dose reconstruction, as a substitution to enamel samples when they are short of supply. (authors)

  11. Sampling and Analysis Instruction for the Demolition of the Masonry Block for the 108-F Biological Laboratory

    International Nuclear Information System (INIS)

    This sampling and analysis instruction (SAI) has been prepared to clearly define the sampling and analysis activities to be performed in support of the demolition and disposition (or disposal) of the 108-F Biological Laboratory masonry block walls

  12. Biological Sample Ambient Preservation (BioSAP) Device Project

    Data.gov (United States)

    National Aeronautics and Space Administration — To address NASA's need for alternative methods for ambient preservation of human biological samples collected during extended spaceflight and planetary operations,...

  13. Fluidics platform and method for sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    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.

  14. 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...

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

    Institute of Scientific and Technical Information of China (English)

    钟伯雄; 翁宏飚; 等

    2002-01-01

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

  16. Components for automated microfluidics sample preparation and analysis

    Science.gov (United States)

    Archer, M.; Erickson, J. S.; Hilliard, L. R.; Howell, P. B., Jr.; Stenger, D. A.; Ligler, F. S.; Lin, B.

    2008-02-01

    The increasing demand for portable devices to detect and identify pathogens represents an interdisciplinary effort between engineering, materials science, and molecular biology. Automation of both sample preparation and analysis is critical for performing multiplexed analyses on real world samples. This paper selects two possible components for such automated portable analyzers: modified silicon structures for use in the isolation of nucleic acids and a sheath flow system suitable for automated microflow cytometry. Any detection platform that relies on the genetic content (RNA and DNA) present in complex matrices requires careful extraction and isolation of the nucleic acids in order to ensure their integrity throughout the process. This sample pre-treatment step is commonly performed using commercially available solid phases along with various molecular biology techniques that require multiple manual steps and dedicated laboratory space. Regardless of the detection scheme, a major challenge in the integration of total analysis systems is the development of platforms compatible with current isolation techniques that will ensure the same quality of nucleic acids. Silicon is an ideal candidate for solid phase separations since it can be tailored structurally and chemically to mimic the conditions used in the laboratory. For analytical purposes, we have developed passive structures that can be used to fully ensheath one flow stream with another. As opposed to traditional flow focusing methods, our sheath flow profile is truly two dimensional, making it an ideal candidate for integration into a microfluidic flow cytometer. Such a microflow cytometer could be used to measure targets captured on either antibody- or DNA-coated beads.

  17. Uranium-233 analysis of biological samples

    International Nuclear Information System (INIS)

    Two liquid scintillation techniques were compared for 233U analysis: a two-phase extraction system (D2EHPA) developed by Keough and Powers, 1970, for Pu analysis; and a single-phase emulsion system (TT21) that holds the total sample in suspension with the scintillator. The first system (D2EHPA) was superior in reducing background (two- to threefold) and in accommodating a larger sample volume (fivefold). Samples containing > 50 mg/ml of slats were not extracted quantitatively by D2EHPA

  18. 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...

  19. Ultra-Fast Sample Preparation for High-Throughput Proteomics

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-Ferrer, Daniel; Hixson, Kim K.; Belov, Mikhail E.; Smith, Richard D.

    2011-06-21

    Sample preparation oftentimes can be the Achilles Heel of any analytical process and in the field of proteomics, preparing samples for mass spectrometric analysis is no exception. Current goals, concerning proteomic sample preparation on a large scale, include efforts toward improving reproducibility, reducing the time of processing and ultimately the automation of the entire workflow. This chapter reviews an array of recent approaches applied to bottom-up proteomics sample preparation to reduce the processing time down from hours to minutes. The current state-of-the-art in the field uses different energy inputs like microwave, ultrasound or pressure to perform the four basic steps in sample preparation: protein extraction, denaturation, reduction and alkylation, and digestion. No single energy input for enhancement of proteome sample preparation has become the universal gold standard. Instead, a combination of different energy inputs tend to produce the best results. This chapter further describes the future trends in the field such as the hyphenation of sample preparation with downstream detection and analysis systems. Finally, a detailed protocol describing the combined use of both pressure cycling technology and ultrasonic energy inputs to hasten proteomic sample preparation is presented.

  20. Integrated microfabricated biodevices. New advances in sample preparation (T2)

    International Nuclear Information System (INIS)

    Full text: Interdisciplinary science and technologies have converged in the past few years to create exciting challenges and opportunities, which involve novel, integrated microfabricated systems, facilitating large-scale analytical applications. These new devices are referred to as lab-on-a-chip or micro Total Analysis Systems (uTAS). Their development involves both established and evolving technologies, which include microlithography, micromachining, micro-electromechanical systems (MEMS) technology, microfluidics and nanotechnology. The advent of this extremely powerful and rapid analysis technique opens up new horizons in analytical chemistry and molecular biology, capable of revealing global changes in gene expression levels by enabling genome, proteome and metabolome analysis on microchips. This presentation will provide an overview of the key device subject areas and the basic interdisciplinary technologies. It will also give a better understanding of how to utilize these miniaturized technologies as well as to provide appropriate technical solutions to problems perceived as being more fundamental. Theoretical and practical aspects of integrating sample preparation/purification and analysis units with chemical and biochemical reactors in monolithic microdevices are going to be thoroughly discussed. Important applications for this novel 'synergized' technology in high throughput analysis of biologically important molecules will also be addressed. (author)

  1. 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.

  2. Miniaturized sample preparation based on carbon nanostructures

    OpenAIRE

    Cárdenas Soledad

    2014-01-01

    The evolution of analytical methodologies has been driven by the objective to reduce the complexity of sample treatment while increasing the efficiency of the overall analytical process. For this reason, the analytical chemist takes into consideration advances in other scientific areas and systematically evaluates the potential influence that such discoveries might have on its own discipline. This is the present situation with nanostructured materials, which have alrea...

  3. PIXE - Analysis for environmental and biological samples

    International Nuclear Information System (INIS)

    The usefulness and accuracy of PIXE as an analytical tool in the study of trace elements in environmental samples of the Brazilian Cerrado are discussed. The report lists actual and forthcoming publications resulting from the study. The mechanism of exchange of elements in solution in water to aerosols has been investigated. For details of the procedure the reader is referred to an earlier report

  4. Microradiagraphy of biological samples with Timepix

    Czech Academy of Sciences Publication Activity Database

    Dammer, J.; Weyda, František; Beneš, J.; Sopko, V.; Jakůbek, J.; Vondráček, V.

    2011-01-01

    Roč. 6, C11005 (2011), s. 1-6. ISSN 1748-0221. [International workshop on radiation imaging detectors /13./. Zurich, 03.07.2011-07.07.2011] R&D Projects: GA MŠk 2B06005 Grant ostatní: GA MŠk(CZ) LC06041; GA AV ČR(CZ) IAA600550614; GA MŠk(CZ) 2B06007; Research Program(CZ) 6840770029; Research Program(CZ) 6840770040; GA MŠk-spolupráce s CERN(CZ) 1P04LA211 Institutional research plan: CEZ:AV0Z50070508 Keywords : X-ray detectors * X-ray radiography and digital radiography (DR) * pixelated detectors and associated VLSI electronics Subject RIV: EA - Cell Biology Impact factor: 1.869, year: 2011 http://iopscience.iop.org/1748-0221/6/11/C11005/pdf/1748-0221_6_11_C11005.pdf

  5. Novel sample preparation method for molecular detection of Mollicutes in cell culture samples.

    Science.gov (United States)

    Lehmann, David; Jouette, Sébastien; Olivieri, Frédéric; Laborde, Sandra; Rofel, Céline; Simon, Emmanuelle; Metz, Didier; Felden, Luc; Ribault, Sébastien

    2010-02-01

    Research laboratories, raw materials and media suppliers as well as the biopharmaceutical industry face recurrent contamination with Mollicutes. Culture-based detection methods are very slow (28 days) and could ideally be replaced by nucleic acid testing (NAT) for rapid result. These methods are nonetheless hampered by their companion sample preparation methods. They are limited by the volume tested (0.1 to 5 mL), the protein/nucleic acid content they can accommodate and are generally performed in an open environment. The processing of low volumes of complex matrices is associated to several issues such as poor representativeness, low sensitivity, inhibition and false positives. The novel sample preparation method described in this study has been developed to overcome these limitations and to process 20-mL samples containing high loads of eukaryotic cells. A dual-membrane device is coupled to magnetic bead purification. In one single and closed device, eukaryotic cells and microorganisms are separated, contaminants are concentrated, lysed and corresponding nucleic acids are collected. This novel sample preparation method has been tested with 9 different Mollicutes. The ability to detect the contaminants down to 0.6 CFU/mL by real-time PCR among hundreds of millions of CHO-S cells (Chinese hamster ovary cells, adapted to serum-free suspension culture), without biological pre-enrichment, has been demonstrated. The novel device has been compared to manual silica spin columns, which remain the gold standard in most laboratories. These columns failed to yield the same limit of detection and reproducible results without separating mammalian cells from contaminants. Co-culture experiments have shown that the novel method allows detection of Mollicutes grown for days in presence of mammalian cells, despite the fact that these microorganisms can adhere to eukaryotic cells or invade them. The co-culture data also suggest that the novel sample preparation device might improve

  6. Insight into Biological Apatite: Physiochemical Properties and Preparation Approaches

    Directory of Open Access Journals (Sweden)

    Quan Liu

    2013-01-01

    Full Text Available Biological apatite is an inorganic calcium phosphate salt in apatite form and nano size with a biological derivation. It is also the main inorganic component of biological hard tissues such as bones and teeth of vertebrates. Consequently, biological apatite has a wide application in dentistry and orthopedics by using as dental fillers and bone substitutes for bone reconstruction and regeneration. Given this, it is of great significance to obtain a comprehensive understanding of its physiochemical and biological properties. However, upon the previous studies, inconsistent and inadequate data of such basic properties as the morphology, crystal size, chemical compositions, and solubility of biological apatite were reported. This may be ascribed to the differences in the source of raw materials that biological apatite are made from, as well as the effect of the preparation approaches. Hence, this paper is to provide some insights rather than a thorough review of the physiochemical properties as well as the advantages and drawbacks of various preparation methods of biological apatite.

  7. γ-ray spectrometry results versus sample preparation methods

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

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

  8. γ-ray spectrometry results versus sample preparation methods

    International Nuclear Information System (INIS)

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

  9. TruSeq Stranded mRNA and Total RNA Sample Preparation Kits

    Science.gov (United States)

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

  10. The preparation of biological reference materials for QUASIMEME

    OpenAIRE

    Kotterman, M.J.J.

    2011-01-01

    Biological materials, consisting of three different batches of mussels; from Den Helder harbour (POPs, TBT), Irish mussels (metals) and Wadden Sea mussels, fortified with highly contaminated mussels from Belgium (POPs), and of one batch of turbot liver (metals) have been prepared for use in QUASIMEME interlaboratory studies for metal and organic contaminant analyses. The homogeneity of the prepared material was tested for metals or POPs, depending on the intended use of the material, and indi...

  11. Preparation and biological efficacy of haddock bone calcium tablets

    Institute of Scientific and Technical Information of China (English)

    霍健聪; 邓尚贵; 谢超; 童国忠

    2010-01-01

    To investigate the possible use of waste products obtained after processing haddock, the present study prepared haddock bone calcium powder by NaOH and ethanol soaking (alkalinealcohol method) and prepared haddock bone calcium tablets using the powder in combination with appropriate excipients. The biological efficacy of the haddock bone calcium tablets was investigated using Wistar rats as an experiment model. Results show that the optimal parameters for the alkalinealcohol method are: NaOH concentration 1...

  12. Recent advances in particle-induced X-ray emission analysis applied to biological samples

    International Nuclear Information System (INIS)

    Papers reporting the application of particle induced X-ray emission (PIXE) analysis to biological samples continue to appear regularly in the literature. The majority of these papers deal with blood, hair, and other common body organs while a few deal with biological samples from the environnment. A variety of sample preparation methods have been demonstrated, a number of which are improvements, refinements and extensions of the thick- and thin-sample preparation methods reported in the early development of PIXE. While many papers describe the development of PIXE techniques some papers are now describing applications of the methods to serious biological problems. The following two factors may help to stimulate more consistant use of the PIXE method. First, each PIXE facility should be organized to give rapid sample processing and should have available several sample preparation and handling methods. Second, those with the skill to use PIXE methods need to become closely associated with researches knowledge able in medical and biological sciences and they also need to become more involved in project planning and sample handling. (orig.)

  13. Manipulation of biological samples using micro and nano techniques

    DEFF Research Database (Denmark)

    Castillo, Jaime; Dimaki, Maria; Svendsen, Winnie Edith

    2009-01-01

    The constant interest in handling, integrating and understanding biological systems of interest for the biomedical field, the pharmaceutical industry and the biomaterial researchers demand the use of techniques that allow the manipulation of biological samples causing minimal or no damage to thei...

  14. Micro and Nano Techniques for the Handling of Biological Samples

    DEFF Research Database (Denmark)

    Micro and Nano Techniques for the Handling of Biological Samples reviews the different techniques available to manipulate and integrate biological materials in a controlled manner, either by sliding them along a surface (2-D manipulation), or by gripping and moving them to a new position (3-D...

  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...... 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...

  16. Preparation of privatization samples for envelopes `A` and `C`

    Energy Technology Data Exchange (ETDEWEB)

    Winters, W.I., Westinghouse Hanford

    1996-07-17

    As part of the TWRS Privatization process, the DOE has committed to provide each of the two contractors who submitted successful bids with ten 125 mL samples of Hanford tank waste meeting chemical and radionuclide criteria specified as Waste Envelope A, B, and C. This test plan describes how the samples will be prepared before shipment.

  17. Development of sample preparation method for honey analysis using PIXE

    International Nuclear Information System (INIS)

    We developed an original preparation method for honey samples (samples in paste-like state) specifically designed for PIXE analysis. The results of PIXE analysis of thin targets prepared by adding a standard containing nine elements to honey samples demonstrated that the preparation method bestowed sufficient accuracy on quantitative values. PIXE analysis of 13 kinds of honey was performed, and eight mineral components (Si, P, S, K, Ca, Mn, Cu and Zn) were detected in all honey samples. The principal mineral components were K and Ca, and the quantitative value for K accounted for the majority of the total value for mineral components. K content in honey varies greatly depending on the plant source. Chestnuts had the highest K content. In fact, it was 2-3 times that of Manuka, which is known as a high quality honey. K content of false-acacia, which is produced in the greatest abundance, was 1/20 that of chestnuts. (author)

  18. Field Sample Preparation Method Development for Isotope Ratio Mass Spectrometry

    International Nuclear Information System (INIS)

    Non-proliferation and International Security (NA-241) established a working group of researchers from Los Alamos National Laboratory (LANL), Pacific Northwest National Laboratory (PNNL) and Savannah River National Laboratory (SRNL) to evaluate the utilization of in-field mass spectrometry for safeguards applications. The survey of commercial off-the-shelf (COTS) mass spectrometers (MS) revealed no instrumentation existed capable of meeting all the potential safeguards requirements for performance, portability, and ease of use. Additionally, fieldable instruments are unlikely to meet the International Target Values (ITVs) for accuracy and precision for isotope ratio measurements achieved with laboratory methods. The major gaps identified for in-field actinide isotope ratio analysis were in the areas of: 1. sample preparation and/or sample introduction, 2. size reduction of mass analyzers and ionization sources, 3. system automation, and 4. decreased system cost. Development work in 2 through 4, numerated above continues, in the private and public sector. LANL is focusing on developing sample preparation/sample introduction methods for use with the different sample types anticipated for safeguard applications. Addressing sample handling and sample preparation methods for MS analysis will enable use of new MS instrumentation as it becomes commercially available. As one example, we have developed a rapid, sample preparation method for dissolution of uranium and plutonium oxides using ammonium bifluoride (ABF). ABF is a significantly safer and faster alternative to digestion with boiling combinations of highly concentrated mineral acids. Actinides digested with ABF yield fluorides, which can then be analyzed directly or chemically converted and separated using established column chromatography techniques as needed prior to isotope analysis. The reagent volumes and the sample processing steps associated with ABF sample digestion lend themselves to automation and field

  19. Fluidics platform and method for sample preparation and analysis

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-08-19

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

  20. Preparation and application of various nanoparticles in biology and medicine

    Directory of Open Access Journals (Sweden)

    Vardan Gasparyan

    2013-02-01

    Full Text Available The present paper considers prospects for application of various nanoparticles in biology and medicine. Here are presented data on preparation of gold and silver nanoparticles, and effects of shape of these nanoparticles on their optical properties. Application of these nanoparticles in diagnostics, for drug delivery and therapy, and preparation of magnetic nanoparticles from iron and cobalt salts are also discussed. Application of these nanoparticles as magnetic resonance imaging (MRI contrast agents and as vehicles for drug delivery, and preparation of quantum dots and their application as prospective nanoparticles for multiplex analysis and for visualization of cellular processes will be tackled. Finally, prospects for new types of nanocomposites (metallic nano-shells will be not overlooked.

  1. Sample preparation for special PIE-techniques at ITU

    International Nuclear Information System (INIS)

    Several sample preparation techniques were developed and installed in hot cells. The techniques were conceived to evaluate the performance of highly burnt fuel rods and include: (a) a device for the removal of the fuel, (b) a method for the preparation of the specimen ends for the welding of new end caps and for the careful cleaning of samples for Transmission Electron Microscopy and Glow Discharge Mass Spectroscopy, (c) a sample pressurisation device for long term creep tests, and (d) a diameter measuring device for creep or burst samples. Examples of the determination of the mechanical properties, the behaviour under transient conditions and for the assessment of the corrosion behaviour of high burnup cladding materials are presented. (author)

  2. Preparation of archaeological samples for its dating by thermoluminescence

    International Nuclear Information System (INIS)

    The present work shows the results of the preparation of archaeological samples for their dating by thermoluminescence (Tl) using the Fine grain technique established by Zimmerman but with the varying of such preparation was realized in normal daylight conditions, only the taking of the Tl readings were realized in dark room and red light. In the chapter 1 basic concepts are described about: matter constitution, radioactivity, units and radiation magnitudes, and thermoluminescence. In the chapter 2 some theoretical aspects on dating are showed. It is described how realizing the samples collection, the fine grain method, the determination of the accumulated dose through the years or paleodoses (P=Q+I) by mean of the increasing to obtain the dose equivalent dose (Q) and the signal regeneration method to obtain the correction factor by supra linearity (1), the determination of the annual dose rate to apply the age equation and the evaluation of the age uncertainty with the error limits. The development of experimental part with samples from the archaeological site named Edzna in Campeche, Mexico is described in the chapter 3. The results are presented in the chapter 4. It was obtained an age for the sample named CH7 it was obtained an age of 389 ± years. In conclusion the preparation of the archaeological samples for their dating by Tl in the conditions before mentioned is reliable, but they must be realized more studies with samples of well known age, preparing them in normal daylight conditions and simultaneously in dark room with red light. In order to observe how respond the minerals present in the sample at different dose rapidity, the same samples must be radiated with radiation sources with different dose rate. (Author)

  3. An influence of sample preparation on microstructure of dental hydroxylapatite

    Czech Academy of Sciences Publication Activity Database

    Kallistová, Anna; Skála, Roman; Malíková, R.; Horáček, I.

    Brno: Masaryk University ; Czech Geological Society, 2014 - (Macek, I.). s. 59-60 ISBN N. [Central European Mineralogical Conference /4./. 23.04.2014-26.04.2014, Skalský Dvůr] Institutional support: RVO:67985831 Keywords : hydroxylapatite * crystallite size * crystallite microstrain * sample preparation Subject RIV: DB - Geology ; Mineralogy

  4. New Methods of Sample Preparation for Atom Probe Specimens

    Science.gov (United States)

    Kuhlman, Kimberly, R.; Kowalczyk, Robert S.; Ward, Jennifer R.; Wishard, James L.; Martens, Richard L.; Kelly, Thomas F.

    2003-01-01

    Magnetite is a common conductive mineral found on Earth and Mars. Disk-shaped precipitates approximately 40 nm in diameter have been shown to have manganese and aluminum concentrations. Atom-probe field-ion microscopy (APFIM) is the only technique that can potentially quantify the composition of these precipitates. APFIM will be used to characterize geological and planetary materials, analyze samples of interest for geomicrobiology; and, for the metrology of nanoscale instrumentation. Prior to APFIM sample preparation was conducted by electropolishing, the method of sharp shards (MSS), or Bosch process (deep reactive ion etching) with focused ion beam (FIB) milling as a final step. However, new methods are required for difficult samples. Many materials are not easily fabricated using electropolishing, MSS, or the Bosch process, FIB milling is slow and expensive, and wet chemistry and the reactive ion etching are typically limited to Si and other semiconductors. APFIM sample preparation using the dicing saw is commonly used to section semiconductor wafers into individual devices following manufacture. The dicing saw is a time-effective method for preparing high aspect ratio posts of poorly conducting materials. Femtosecond laser micromachining is also suitable for preparation of posts. FIB time required is reduced by about a factor of 10 and multi-tip specimens can easily be fabricated using the dicing saw.

  5. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    CERN Document Server

    Rhinow, Daniel; Weber, Nils-Eike; Beyer, André; Gölzhäuser, Armin; Kühlbrandt, Werner; Hampp, Norbert; Turchanin, Andrey; 10.1016/j.ultramic.2011.01.028

    2011-01-01

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ~ 1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, sus...

  6. Introduction of a cryosectioning-ToF-SIMS instrument for analysis of non-dehydrated biological samples

    Science.gov (United States)

    Möller, J.; Beumer, A.; Lipinsky, D.; Arlinghaus, H. F.

    2006-07-01

    Tof-SIMS and laser-SNMS are becoming increasingly important tools for analysing the elemental and molecular distribution in biological samples. We have developed the prototype of an in-vacuum cryosectioning instrument directly attached to a ToF-SIMS/laser-SNMS instrument, which allows preparing and analyzing frozen non-dehydrated biological samples. Due to unavoidable effects during the handling, storing, and preparation of frozen samples, even inside the vacuum, it must be ensured that the analyzed surface is from the sample and not a preparation artefact. To this effect, a model structure, similar to the biological samples and with a defined chemical composition, was analyzed under varying thermal treatment before and during analysis, respectively, in order to identify a balance between evaporating and subliming adsorbed materials and the effect of freeze-drying on the measured signal.

  7. [Critical aspects in determining total radioactivity of biological samples].

    Science.gov (United States)

    Del Vecchio, M P; Paolini, M; Corsi, C; Bauer, C

    1989-03-01

    During measurements of radioactivity in some milk samples with liquid scintillation counter (about one year after the nuclear accident of Chernobyl) we have observed an increase of the values of scintillation fluid with the passing of time. Although this enhancement is absolutely small (about 2 c.p.m. in 500 min), it is very important for an exact measurement of samples at low counting, as those tested. Our protocol of measure provides for insertion of alternate blanks and samples in the automatic sample-holders of liquid scintillation counter. The values of measurement of samples are taken during the increase phase subtracting the value of blank interpolated on the increasing straight line from c.p.m. of sample. Finally, we report the collected values of the whole radioactivity in some milk samples: at least 5-6 nCi/L contrary to about 1 nCi/L of 137Cs reported by USL. In our opinion it is important to consider the whole radioactivity as measure of the overall biological danger of radioactive samples. In fact, this measurement takes into account also biologically very dangerous radionuclides as 3H, 14C, 90Sr. PMID:2765252

  8. Sampling, storage and sample preparation procedures for X ray fluorescence analysis of environmental materials

    International Nuclear Information System (INIS)

    X ray fluorescence (XRF) method is one of the most commonly used nuclear analytical technique because of its multielement and non-destructive character, speed, economy and ease of operation. From the point of view of quality assurance practices, sampling and sample preparation procedures are the most crucial steps in all analytical techniques, (including X ray fluorescence) applied for the analysis of heterogeneous materials. This technical document covers recent modes of the X ray fluorescence method and recent developments in sample preparation techniques for the analysis of environmental materials. Refs, figs, tabs

  9. Chitooligosaccharide and Its Derivatives: Preparation and Biological Applications

    Directory of Open Access Journals (Sweden)

    Gaurav Lodhi

    2014-01-01

    Full Text Available Chitin is a natural polysaccharide of major importance. This biopolymer is synthesized by an enormous number of living organisms; considering the amount of chitin produced annually in the world, it is the most abundant polymer after cellulose. The most important derivative of chitin is chitosan, obtained by partial deacetylation of chitin under alkaline conditions or by enzymatic hydrolysis. Chitin and chitosan are known to have important functional activities but poor solubility makes them difficult to use in food and biomedicinal applications. Chitooligosaccharides (COS are the degraded products of chitosan or chitin prepared by enzymatic or chemical hydrolysis of chitosan. The greater solubility and low viscosity of COS have attracted the interest of many researchers to utilize COS and their derivatives for various biomedical applications. In light of the recent interest in the biomedical applications of chitin, chitosan, and their derivatives, this review focuses on the preparation and biological activities of chitin, chitosan, COS, and their derivatives.

  10. Sample Preparation for N-Glycosylation Analysis of Therapeutic Monoclonal Antibodies by Electrophoresis

    Czech Academy of Sciences Publication Activity Database

    Szekrényes, A.; Partyka, Jan; Varadi, C.; Křenková, Jana; Foret, František; Guttman, András

    vol. 1274. New York: Springer Science+Business Media, 2015, s. 183-195. (Methods in Molecular Biology). ISBN 978-1-4939-2352-6 R&D Projects: GA ČR(CZ) GAP301/11/2055 Institutional support: RVO:68081715 Keywords : capillary electrophoresis * monoclonal antibodies * sample preparation Subject RIV: CB - Analytical Chemistry, Separation https://link.springer.com/protocol/10.1007%2F978-1-4939-2353-3_16

  11. Sample preparation and electron microscopy of hydrocracking catalysts

    Science.gov (United States)

    Husain, S.; McComb, D. W.; Perkins, J. M.; Haswell, R.

    2008-08-01

    This work focuses on the preparation of zeolite and alumina hydrocracking catalysts for investigation by electron energy-loss spectroscopy (EELS). EELS can potentially give new insights into the location and structure of coke which can result in catalyst deactivation. Three sample preparation techniques have been used - microtoming, focussed ion beam milling (LIB) and conventional ion beam milling. Crushing and grinding the catalyst pellets has been discounted as a preparation technique as the spatial relationship between the coke and the catalyst is lost using this method. Microtomed sections show some mechanical damage while sections milled in a single beam LIB microscope show gallium decoration in pores and were too thick for EELS. Conventional ion beam milling has proved to be most successful as it results in extensive thin regions and maintains the spatial distribution of the zeolite and alumina phases.

  12. On multielement analysis of biological samples with the aid of neutron activation

    International Nuclear Information System (INIS)

    A main objective of this study was elucidation of problems of sampling and sample preparation methods for multielement analysis of environmental and biological specimens. Another was assessment of the potentials of multielement neutron activation analysis (NAA) in environmental and biological research. In an attempt to explain the great differences in the elemental concentration ranges between biopsy and autopsy samples as reported in the literature, it was shown that post mortem changes induce great variations in the apparent elemental composition of autopsy specimens resulting in serious systematic errors. Applications of NAA to analysis of tissues of experimental animals, human tissues in health and disease, and environmental samples are illustrated with several examples. The suitability of NAA for routine analysis of elements such as Cr, Mo and Se, which are difficult to determine by other methods has been specially discussed. (author)

  13. Use of compressed fluids for sample preparation: Food applications

    OpenAIRE

    Mendiola, J. A.; Herrero, Miguel; Cifuentes, Alejandro; Ibáñez, Elena

    2007-01-01

    This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in...

  14. Collection and preparation of marine samples for radionuclide analysis

    International Nuclear Information System (INIS)

    The ultimate goal of research in radioecology is to be able to predict the pathways of radioactive material in the environment and hence estimate possible doses to the population in various regions. Knowledge of levels of contamination are necessary to maintain control of operations of nuclear facilities. Correct methods of sample collection, handling and preparation are among the most important parts for a correct assessment. On basis of the final results of radionuclide concentrations, scientific, medical and political decisions are taken. (author)

  15. Sample preparation method for induced mutation on orchid

    International Nuclear Information System (INIS)

    Studies on the induction of mutation in Dendrobium orchid at MINT has produced a number of new orchid mutant cultivars. Tissue culture techniques on orchid seeds and meristem cloning are employed in preparing the samples for the mutation induction. Solid medium based on the Murashige and Skoog (1962) and liquid medium based on Vacin and Went (1949) were found to be suitable in producing protocorm like bodies (PLBs) that are required for the irradiation treatment. (Author)

  16. Activation Analysis of Biological Samples of Forensic Interest

    International Nuclear Information System (INIS)

    In forensic (crime investigation) studies, samples of a biological origin are frequently used as evidence. Often it is necessary to compare one sample (associated with a victim or the scene of a crime) with another sample of the same general type (associated with a suspect in some way). The purpose of such comparisons is to establish, if possible, that - to a high degree of probability - the two samples have a common origin. Typically, all available relevant methods of comparison are utilized in such cases by the criminalist: microscopic examination; X-ray diffraction; infra-red, visible, and ultra-violet spectrometry; and various methods of elemental analysis. The forensic applications of high-flux thermal-neutron activation analysis (NAA) have shown great promise and are attracting considerable attention. The authors' laboratory has been engaged in such forensic NAA research and development studies for the past five years. (It also operates a non-profit Forensic Activation Analysis Service, available to all law enforcement agencies, for the NAA comparison of evidence samples involved in actual criminal cases. Samples from many actual cases have been thus examined.) In the United States, NAA results have now been successfully presented in court in some 20 actual cases. Some of the evidence-type materials of interest are non-biological; others are biological. Only the latter will be discussed in this paper. The principal evidence-type materials of a biological nature that have been examined in this laboratory by high-flux thermal-NAA to date are the following: hair, blood, faeces, urine, fingernails, skin, wood, tobacco, whisky, green plants, and marijuana. (In addition, a number of these evidence-type materials have also been studied in this laboratory by high-flux photonuclear activation analysis (PNAA); attention in this paper will be largely devoted to the thermal-NAA forensic studies.) The main topics to be reported upon in this paper are: (1) limits of

  17. Preparation of TEM samples for hard ceramic powders.

    Science.gov (United States)

    Xu, Qiang; Kumar, Vikas; de Kruijff, Tom; Jansen, Jacob; Zandbergen, Henny W

    2008-12-01

    It is challenging to prepare a good sample for high-resolution electron microscopy of polycrystalline ceramic powders containing hard particles or particles with a strong preferential cleavage. Here we demonstrate that embedding the particles in a Cu matrix in a pressed pellet allows for straightforward conventional ion milling. The method is applied to powders of Mg10Ir19B16 and Na0.5CoO2 to show its feasibility, whereby transmission electron microscopy (TEM) samples with crystalline areas thinner than 10 nm can be obtained easily. PMID:18722061

  18. Preparation of TEM samples for hard ceramic powders

    International Nuclear Information System (INIS)

    It is challenging to prepare a good sample for high-resolution electron microscopy of polycrystalline ceramic powders containing hard particles or particles with a strong preferential cleavage. Here we demonstrate that embedding the particles in a Cu matrix in a pressed pellet allows for straightforward conventional ion milling. The method is applied to powders of Mg10Ir19B16 and Na0.5CoO2 to show its feasibility, whereby transmission electron microscopy (TEM) samples with crystalline areas thinner than 10 nm can be obtained easily.

  19. Preparation of TEM samples for hard ceramic powders

    Energy Technology Data Exchange (ETDEWEB)

    Xu Qiang [National Centre for HREM, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Lorentzweg 1, Delft (Netherlands)], E-mail: q.xu@tudelft.nl; Kumar, Vikas [National Centre for HREM, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Lorentzweg 1, Delft (Netherlands)], E-mail: V.Kumar@tudelft.nl; Kruijff, Tom de [National Centre for HREM, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Lorentzweg 1, Delft (Netherlands)], E-mail: t.r.dekruijff@tudelft.nl; Jansen, Jacob [National Centre for HREM, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Lorentzweg 1, Delft (Netherlands)], E-mail: joukj@hrem.nano.tudelft.nl; Zandbergen, Henny W. [National Centre for HREM, Kavli Institute of Nanoscience, Delft University of Technology, 2628 CJ Lorentzweg 1, Delft (Netherlands)], E-mail: h.w.zandbergen@tudelft.nl

    2008-12-15

    It is challenging to prepare a good sample for high-resolution electron microscopy of polycrystalline ceramic powders containing hard particles or particles with a strong preferential cleavage. Here we demonstrate that embedding the particles in a Cu matrix in a pressed pellet allows for straightforward conventional ion milling. The method is applied to powders of Mg{sub 10}Ir{sub 19}B{sub 16} and Na{sub 0.5}CoO{sub 2} to show its feasibility, whereby transmission electron microscopy (TEM) samples with crystalline areas thinner than 10 nm can be obtained easily.

  20. Apparatus for preparing a sample for mass spectrometry

    Science.gov (United States)

    Villa-Aleman, Eliel

    1994-01-01

    An apparatus for preparing a sample for analysis by a mass spectrometer system. The apparatus has an entry chamber and an ionization chamber separated by a skimmer. A capacitor having two space-apart electrodes followed by one or more ion-imaging lenses is disposed in the ionization chamber. The chamber is evacuated and the capacitor is charged. A valve injects a sample gas in the form of sample pulses into the entry chamber. The pulse is collimated by the skimmer and enters the ionization chamber. When the sample pulse passes through the gap between the electrodes, it discharges the capacitor and is thereby ionized. The ions are focused by the imaging lenses and enter the mass analyzer, where their mass and charge are analyzed.

  1. Novel sample preparation for operando TEM of catalysts

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Benjamin K.; Barker, Trevor M. [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287-6106 (United States); Crozier, Peter A., E-mail: crozier@asu.edu [School for Engineering of Matter, Transport and Energy, Arizona State University, Tempe, AZ 85287-6106 (United States)

    2015-09-15

    A new TEM sample preparation method is developed to facilitate operando TEM of gas phase catalysis. A porous Pyrex-fiber pellet TEM sample was produced, allowing a comparatively large amount of catalyst to be loaded into a standard Gatan furnace-type tantalum heating holder. The increased amount of catalyst present inside the environmental TEM allows quantitative determination of the gas phase products of a catalytic reaction performed in-situ at elevated temperatures. The product gas concentration was monitored using both electron energy loss spectroscopy (EELS) and residual gas analysis (RGA). Imaging of catalyst particles dispersed over the pellet at atomic resolution is challenging, due to charging of the insulating glass fibers. To overcome this limitation, a metal grid is placed into the holder in addition to the pellet, allowing catalyst particles dispersed over the grid to be imaged, while particles in the pellet, which are assumed to experience identical conditions, contribute to the overall catalytic conversion inside the environmental TEM cell. The gas within the cell is determined to be well-mixed, making this assumption reasonable. - Highlights: • High in-situ conversion of CO to CO{sub 2} achieved by a novel TEM sample preparation method. • A 3 mm fiber pellet increases the TEM sample surface area by 50×. • Operando atomic resolution is maintained by also including a 3 mm grid in the sample. • Evidence for a well-mixed gas composition inside the ETEM cell is given.

  2. Novel sample preparation for operando TEM of catalysts

    International Nuclear Information System (INIS)

    A new TEM sample preparation method is developed to facilitate operando TEM of gas phase catalysis. A porous Pyrex-fiber pellet TEM sample was produced, allowing a comparatively large amount of catalyst to be loaded into a standard Gatan furnace-type tantalum heating holder. The increased amount of catalyst present inside the environmental TEM allows quantitative determination of the gas phase products of a catalytic reaction performed in-situ at elevated temperatures. The product gas concentration was monitored using both electron energy loss spectroscopy (EELS) and residual gas analysis (RGA). Imaging of catalyst particles dispersed over the pellet at atomic resolution is challenging, due to charging of the insulating glass fibers. To overcome this limitation, a metal grid is placed into the holder in addition to the pellet, allowing catalyst particles dispersed over the grid to be imaged, while particles in the pellet, which are assumed to experience identical conditions, contribute to the overall catalytic conversion inside the environmental TEM cell. The gas within the cell is determined to be well-mixed, making this assumption reasonable. - Highlights: • High in-situ conversion of CO to CO2 achieved by a novel TEM sample preparation method. • A 3 mm fiber pellet increases the TEM sample surface area by 50×. • Operando atomic resolution is maintained by also including a 3 mm grid in the sample. • Evidence for a well-mixed gas composition inside the ETEM cell is given

  3. Nitrogen isotope ratio analysis of small samples: sample preparation and calibration

    International Nuclear Information System (INIS)

    A method for the preparation of samples in the range of 14-100 μg of organic and precipitated N for mass spectrometric isotope ratio analysis is described. In vacuo combustion and molecular sieve trapping of the sample gas into a 0.5 mL mass spectrometer inlet volume are employed. Samples can be processed at a rate of two to three per hour. The standard deviation of 12 analyses of a peptone preparation was 0.10%. The results of an interlaboratory calibration effort are presented. The materials tested were peptone, thiourea, histidine, kerogen, and two (NH4)2SO4 standards. The results of these comparisons were with the range +/-0.12 delta15N or less. Peptone was found to provide a more rigorous test of the combustion and preparation system than nitrogen salts and organic compounds of lower molecular weight. 20 references, 1 figure, 1 table

  4. Some pitfalls in chemical sample preparation for accelerator mass spectrometry

    International Nuclear Information System (INIS)

    Sophisticated sample preparation including the determination of stable nuclides are an essential prerequisite for high-accuracy accelerator mass spectrometry (AMS) data. Improvements in the low-level regime already paid back, however, some pitfalls still exist or are (re-) appearing due to recent developments: 1.) As most samples prepared for 10Be-AMS need the addition of 9Be in the form of a liquid solution of known 9Be-concentration and commercial solutions contain too much 10Be, solutions from minerals originating from deep mines have been established. Special attention has recently been paid to the preparation of such a 9Be-carrier by the determination of the 9Be-value by an interlaboratory comparison. It could be shown that deviations between different labs exist, thus, it is strongly advised to have such solutions analysed at more than a single lab to prevent incorrect 10Be-results. 2.) In our approach to analyse as many radionuclides as possible in a single meteorite sample, small changes in the established chemical separation have been tested. Though, the secondary formation of partially insoluble compounds of Mg and Al by the pressure digestion is strongly influenced, thus, yielding to too low 27Al-results in the taken aliquot and overall incorrect 26Al-results.

  5. Toxicological Analysis of Some Drugs of Abuse in Biological Samples

    Directory of Open Access Journals (Sweden)

    Anne Marie Ciobanu

    2015-10-01

    Full Text Available Consumption of drugs of abuse is a scourge of modern world. Abuse, drug addiction and their consequences are one of the major current problems of European society because of the significant repercussions in individual, family, social and economic level. In this context, toxicological analysis of the drugs of abuse in biological samples is a useful tool for: diagnosis of drug addiction, checking an auto-response, mandatory screening in some treatment programs, identification of a substance in the case of an overdose, determining compliance of the treatment. The present paper aims to address the needs of healthcare professionals involved in drugs addiction treatment through systematic presentation of information regarding their toxicological analysis. Basically, it is a tool that help you to select the suitable biological sample and the right collecting time, as well as the proper analysis technique, depending on the purpose of analysis, pharmacokinetic characteristics of the drugs of abuse, available equipment and staff expertise.

  6. Novel Sample Preparation Method for Safe and Rapid Detection of Bacillus anthracis Spores in Environmental Powders and Nasal Swabs

    OpenAIRE

    Luna, Vicki A.; King, Debra; Davis, Carisa; Rycerz, Tony; Ewert, Matthew; Cannons, Andrew; Amuso, Philip; Cattani, Jacqueline

    2003-01-01

    Bacillus anthracis spores have been used as a biological weapon in the United States. We wanted to develop a safe, rapid method of sample preparation that provided safe DNA for the detection of spores in environmental and clinical specimens. Our method reproducibly detects B. anthracis in samples containing

  7. Incubation Station for the Bacterial Growth Study in Biological Samples

    OpenAIRE

    Carlos Rafael Duharte Rodríguez; Ibrain Ceballo Acosta; Carmen B. Busoch Morlán; Ángel Regueiro Gómez

    2015-01-01

    This work shows the designing and characterization of a prototype of laboratory incubator as support of Microbiology research, in particular for the research of the bacterial growth in biological samples through optic methods (Turbidimetry) and electrometric measurements of bioimpedance. It shows the results of simulation and experimentation of the design proposed for the canals of measurement of the variables: temperature and humidity, with a high linearity from the adequate selection of the...

  8. Toxicological Analysis of Some Drugs of Abuse in Biological Samples

    OpenAIRE

    Anne Marie Ciobanu; Daniela Baconi; Cristian Bălălău; Carolina Negrei; Miriana Stan; Maria Bârcă

    2015-01-01

    Consumption of drugs of abuse is a scourge of modern world. Abuse, drug addiction and their consequences are one of the major current problems of European society because of the significant repercussions in individual, family, social and economic level. In this context, toxicological analysis of the drugs of abuse in biological samples is a useful tool for: diagnosis of drug addiction, checking an auto-response, mandatory screening in some treatment programs, identification of a substance ...

  9. Energy-filtered transmission electron microscopy of biological samples on highly transparent carbon nanomembranes

    International Nuclear Information System (INIS)

    Ultrathin carbon nanomembranes (CNM) comprising crosslinked biphenyl precursors have been tested as support films for energy-filtered transmission electron microscopy (EFTEM) of biological specimens. Due to their high transparency CNM are ideal substrates for electron energy loss spectroscopy (EELS) and electron spectroscopic imaging (ESI) of stained and unstained biological samples. Virtually background-free elemental maps of tobacco mosaic virus (TMV) and ferritin have been obtained from samples supported by ∼1 nm thin CNM. Furthermore, we have tested conductive carbon nanomembranes (cCNM) comprising nanocrystalline graphene, obtained by thermal treatment of CNM, as supports for cryoEM of ice-embedded biological samples. We imaged ice-embedded TMV on cCNM and compared the results with images of ice-embedded TMV on conventional carbon film (CC), thus analyzing the gain in contrast for TMV on cCNM in a quantitative manner. In addition we have developed a method for the preparation of vitrified specimens, suspended over the holes of a conventional holey carbon film, while backed by ultrathin cCNM. -- Research highlights: → We examine ultrathin carbon nanomembranes (CNM) as supports for biological TEM. → CNM comprise crosslinked biphenyl precursors. → CNM supports enable background-free elemental mapping of heavy and light elements. → We perform cryoEM of ice-embedded biological samples on graphene-like conductive CNM.

  10. Measurement of n-alkanals and hydroxyalkenals in biological samples.

    Science.gov (United States)

    Holley, A E; Walker, M K; Cheeseman, K H; Slater, T F

    1993-09-01

    A modified method was developed to measure nM levels of a range of n-alkanals and hydroxyalkenals in biological samples such as blood plasma and tissue homogenates and also in Folch lipid extracts of these samples. Butylated hydroxytoluene (BHT) and desferrioxamine (Desferal) were added to samples to prevent artifactual peroxidation. Aldehydes were reacted with 1,3-cyclohexanedione (CHD), cleaned up by solid-phase extraction on a Sep-Pak C18 cartridge and the fluorescent decahydroacridine derivatives resolved by reverse-phase high-performance liquid chromatography (HPLC) with gradient elution. A wider range of aldehydes was detected in lipid extracts of plasma and liver homogenate compared to whole (unextracted) samples. Human plasma contained nM levels of acetaldehyde, propanal, butanal, pentanal, hexanal, and heptanal. 4-Hydroxynonenal (0.93 nmol/g) and alkanals with two to six carbons (up to 7.36 nmol/g) were detected in rat liver. Recovery of aldehydes added to whole plasma or to lipid extracts of plasma was dependent on carbon chain length, varying from 95% for acetaldehyde to 8% for decanal. Recovery from biological samples was significantly less than that of standards taken through the Sep-Pak clean-up procedure, suggesting that aldehydes can bind to plasma protein and lipid components. PMID:8406128

  11. Chiral speciation of selenoamino acids in biological samples.

    Science.gov (United States)

    Chen, Beibei; He, Man; Zhong, Cheng; Hu, Bin

    2014-10-10

    In this paper, the "state of the art" of chiral speciation of selenoamino acids (SeAAs) in biological samples is critically reviewed. The significance and the features of such studies are highlighted. A special focus lies on chiral speciation of SeAAs by hyphenation techniques in which a chiral separation method (such as gas chromatography (GC), high performance liquid chromatography (HPLC) and capillary electrophoresis (CE)) is on-line coupled with an elemental specific detector, especially inductively coupled plasma mass spectrometry (ICP-MS). The advances in the development and application of hyphenation techniques in chiral speciation of SeAAs in biological samples are summarized and a perspective for future developments including sophisticated and innovative applications is discussed. Overall, HPLC-ICP-MS is more applicable than GC/CE-ICP-MS for chiral speciation of SeAAs. In the future, more novel chiral HPLC methods with high enantio-resolution, low cost and robustness, and their more applications in real biological samples analysis are expected. PMID:25130085

  12. Use of STM for analysis of surfaces of biological samples

    Science.gov (United States)

    Permjakov, N. K.; Ananyan, M. A.; Luskinovich, P. N.; Sorokovoi, V. I.; Saveliev, S. V.

    1999-04-01

    Scanning tunnelling microscopy (STM) was used to image the cell surfaces of the olfactory organ of the shark Carcharhinus longimanus and ectoderm of the frog Xenopus laevis blastulae of 1024 stages, as well as human low-density lipoproteins surface. The samples from two of these objects were prepared by using traditional techniques for scanning electron microscopy (SEM). The lipoprotein samples were prepared by drying in the air. A comparison of the STM images with the earlier obtained SEM images indicates that there are some earlier unknown details of the surface structures of receptor microvilli and support cell membranes of the olfactory organ of the shark. There was found a fold of membrane on the surface of the ectodermal frog embryo cells, which covered yolk granules. STM images of the lipoprotein surface were obtained without increasing conductivity treatment.

  13. Sample preparation of archaeological materials for PIXE analysis

    International Nuclear Information System (INIS)

    A method to prepare thin samples of archaeological materials such as potteries and bones for PIXE analysis is presented. In this method fine powder of the matter under analysis is suspended and deposited on polycarbonate filters. The process takes place in a chamber where clean air and the powder are mixed and forced to pass through the filter. Thin samples with typical mass density of about 50 μg cm-2 are obtained. The uniformity of the mass deposit has been optically tested with a He-Ne laser showing fluctuations of the order of one percent. Samples of clay standards from NIST were prepared with this method and analyzed by PIXE. The agreement between these results and NIST values is very good, with linear correlation factors close to unity. The method was applied to study the elemental composition of clay from different fragments of a Chilean pre-Hispanic pottery piece. These results are very consistent showing that the analysis of samples from a small fragment can represent the whole piece. (author) 8 refs.; 4 figs.; 1 tab

  14. Preparation of graphene thin films for radioactive samples.

    Science.gov (United States)

    Roteta, Miguel; Fernández-Martínez, Rodolfo; Mejuto, Marcos; Rucandio, Isabel

    2016-03-01

    A new method for the preparation of conductive thin films is presented. The metallization of VYNS films guarantees the electrical conductivity but it results in the breaking of a high proportion of them. Graphene, a two-dimensional nanostructure of monolayer or few layers graphite has attracted a great deal of attention because of its excellent properties such as a good chemical stability, mechanical resistance and extraordinary electronic transport properties. In this work, the possibilities of graphene have been explored as a way to produce electrical conductive thin films without an extra metallization process. The procedure starts with preparing homogenous suspensions of reduced graphene oxide (rGO) in conventional VYNS solutions. Ultra-sonication is used to ensure a good dispersibility of rGO. Graphene oxide (GO) is prepared via oxidation of graphite and subsequent exfoliation by sonication. Different chemically rGO were obtained by reaction with hydrazine sulfate, sodium borohydride, ascorbic acid and hydroiodic acid as reducing agents. The preparation of the thin graphene films is done in a similar way as the conventional VYNS foil preparation procedure. Drops of the solution are deposited onto water. The graphene films have been used to prepare sources containing some electron capture radionuclides ((109)Cd, (55)Fe, (139)Ce) with an activity in the order of 3kBq. The samples have been measured to test the attainable low energy electron efficiency and the energy resolution of Auger and conversion electrons by 4π (electron capture)-γ coincidence measurements. The 4π (electron capture)-γ coincidence setup includes a pressurized proportional counter and a NaI(Tl) detector. Tests with different pressures up to 1000kPa were carried out. All these tests show similar values in both parameters (efficiency and resolution) as those obtained by using the conventional metallized films without the drawback of the high percentage of broken films. PMID:26651168

  15. Combining electrochemical sensors with miniaturized sample preparation for rapid detection in clinical samples.

    Science.gov (United States)

    Bunyakul, Natinan; Baeumner, Antje J

    2015-01-01

    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. PMID:25558994

  16. Digital microfluidic hub for automated nucleic acid sample preparation.

    Energy Technology Data Exchange (ETDEWEB)

    He, Jim; Bartsch, Michael S.; Patel, Kamlesh D.; Kittlaus, Eric A.; Remillared, Erin M.; Pezzola, Genevieve L.; Renzi, Ronald F.; Kim, Hanyoup

    2010-07-01

    We have designed, fabricated, and characterized a digital microfluidic (DMF) platform to function as a central hub for interfacing multiple lab-on-a-chip sample processing modules towards automating the preparation of clinically-derived DNA samples for ultrahigh throughput sequencing (UHTS). The platform enables plug-and-play installation of a two-plate DMF device with consistent spacing, offers flexible connectivity for transferring samples between modules, and uses an intuitive programmable interface to control droplet/electrode actuations. Additionally, the hub platform uses transparent indium-tin oxide (ITO) electrodes to allow complete top and bottom optical access to the droplets on the DMF array, providing additional flexibility for various detection schemes.

  17. Microfluidic solutions enabling continuous processing and monitoring of biological samples: A review.

    Science.gov (United States)

    Karle, Marc; Vashist, Sandeep Kumar; Zengerle, Roland; von Stetten, Felix

    2016-07-27

    The last decade has witnessed tremendous advances in employing microfluidic solutions enabling Continuous Processing and Monitoring of Biological Samples (CPMBS), which is an essential requirement for the control of bio-processes. The microfluidic systems are superior to the traditional inline sensors due to their ability to implement complex analytical procedures, such as multi-step sample preparation, and enabling the online measurement of parameters. This manuscript provides a backgound review of microfluidic approaches employing laminar flow, hydrodynamic separation, acoustophoresis, electrophoresis, dielectrophoresis, magnetophoresis and segmented flow for the continuous processing and monitoring of biological samples. The principles, advantages and limitations of each microfluidic approach are described along with its potential applications. The challenges in the field and the future directions are also provided. PMID:27251944

  18. Toward greener analytical techniques for the absolute quantification of peptides in pharmaceutical and biological samples.

    Science.gov (United States)

    Van Eeckhaut, Ann; Mangelings, Debby

    2015-09-10

    Peptide-based biopharmaceuticals represent one of the fastest growing classes of new drug molecules. New reaction types included in the synthesis strategies to reduce the rapid metabolism of peptides, along with the availability of new formulation and delivery technologies, resulted in an increased marketing of peptide drug products. In this regard, the development of analytical methods for quantification of peptides in pharmaceutical and biological samples is of utmost importance. From the sample preparation step to their analysis by means of chromatographic or electrophoretic methods, many difficulties should be tackled to analyze them. Recent developments in analytical techniques emphasize more and more on the use of green analytical techniques. This review will discuss the progresses in and challenges observed during green analytical method development for the quantification of peptides in pharmaceutical and biological samples. PMID:25864956

  19. Focused-microwave-assisted sample preparation (M8)

    International Nuclear Information System (INIS)

    Full text: Focused-microwave-assisted sample preparation is a suitable strategy when dealing with high masses of organic samples. However, the final acid concentration of the digestate can difficult routine analytical measurements using spectroscopic techniques. Acids could be evaporated, but this step could be slow even when using microwave-assisted heating and requires a scrubber system for acid vapor collection and neutralization. We are investigating two procedures to decrease the acid concentration of digestates. The first one is based on acid vapor phase digestion of samples contained in PTFE devices' inserted into the microwave flask. The acid solution is heated by absorption of microwave radiation, then the acid vapor partially condenses in the upper part of the reaction flask and it is partially collected in each sample container. Calcium, Fe, Mg, Mn, and Zn were quantitatively recovered in samples of animal and vegetable tissues. Better recoveries were attained when adding a small volume of sodium hypochlorite to the sample. This effect is probably related to the generation of chlorine in the sample container after collecting condensed acid. The second procedure developed is based on the gradual addition of liquid samples to a previously heated acid digestion mixture. This procedure was successfully applied for digestion of milk, fruit juices, and red wine. The main advantage is the possibility of digesting up to four-fold more sample using up to ten-fold lower amounts of concentrated acids. Results obtained using both digestion procedures and measurements by ICP-OES with axial view will be presented. (author)

  20. Use of compressed fluids for sample preparation: food applications.

    Science.gov (United States)

    Mendiola, José A; Herrero, Miguel; Cifuentes, Alejandro; Ibañez, Elena

    2007-06-01

    This review attempts to provide an updated overview (including works published till June 2006) on the latest applications of compressed fluids as sample preparation techniques for food analysis. After a general review of the principles of supercritical fluid extraction (SFE) and pressurized liquid extraction (PLE; also called accelerated solvent extraction, ASE or subcritical water extraction, SWE, when water is employed as extraction solvent), the principal applications of such techniques in the mentioned fields of food and natural products are described, discussing their main advantages and drawbacks. PMID:17353022

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

    International Nuclear Information System (INIS)

    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

  2. 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.

  3. Optimization of dielectrophoretic separation and concentration of pathogens in complex biological samples

    Science.gov (United States)

    Bisceglia, E.; Cubizolles, M.; Mallard, F.; Pineda, F.; Francais, O.; Le Pioufle, B.

    2013-05-01

    Sample preparation is a key issue of modern analytical methods for in vitro diagnostics of diseases with microbiological origins: methods to separate bacteria from other elements of the complex biological samples are of great importance. In the present study, we investigated the DEP force as a way to perform such a de-complexification of the sample by extracting micro-organisms from a complex biological sample under a highly non-uniform electric field in a micro-system based on an interdigitated electrodes array. Different parameters were investigated to optimize the capture efficiency, such as the size of the gap between the electrodes and the height of the capture channel. These parameters are decisive for the distribution of the electric field inside the separation chamber. To optimize these relevant parameters, we performed numerical simulations using COMSOL Multiphysics and correlated them with experimental results. The optimization of the capture efficiency of the device has first been tested on micro-organisms solution but was also investigated on human blood samples spiked with micro-organisms, thereby mimicking real biological samples.

  4. Preparation and biological efficacy of haddock bone calcium tablets

    Science.gov (United States)

    Huo, Jiancong; Deng, Shanggui; Xie, Chao; Tong, Guozhong

    2010-03-01

    To investigate the possible use of waste products obtained after processing haddock, the present study prepared haddock bone calcium powder by NaOH and ethanol soaking (alkalinealcohol method) and prepared haddock bone calcium tablets using the powder in combination with appropriate excipients. The biological efficacy of the haddock bone calcium tablets was investigated using Wistar rats as an experiment model. Results show that the optimal parameters for the alkalinealcohol method are: NaOH concentration 1 mol/L, immersion time 30 h; ethanol concentration 60%, immersion time 15 h. A mixture of 2% polyvinylpyrrolidone in ethanol was used as an excipient at a ratio of 1:2 to full-cream milk powder, without the use of a disintegrating agent. This process provided satisfactory tablets in terms of rigidity and taste. Animal studies showed that the haddock bone calcium tablets at a dose of 2 g·kg-1·d-1 or 5g·kg-1·d-1 significantly increased blood calcium and phosphorus levels and bone calcium content in rats. Therefore, these tablets could be used for calcium supplementation and prevent osteoporosis. Although the reasons of high absorption in the rats fed with haddock bone calcium tablets are unclear, it is suggested that there are some factors, such as treatment with method of alkaline-alcohol or the added milk, may play positive roles in increasing absorption ratio.

  5. Three sample preparation protocols for polymerase chain reaction based detection of Cryptosporidium parvum in environmental samples.

    Science.gov (United States)

    Kostrzynska, M; Sankey, M; Haack, E; Power, C; Aldom, J E; Chagla, A H; Unger, S; Palmateer, G; Lee, H; Trevors, J T; De Grandis, S A

    1999-02-01

    Cryptosporidium parvum is a protozoan parasite responsible for an increasing number of outbreaks of gastrointestinal illness worldwide. In this report, we describe development of sample preparation protocols for polymerase chain reaction (PCR)-based detection of C. parvum in fecal material and environmental water samples. Two of these methods were found adequate for isolation of Cryptosporidium DNA from filtered water pellet suspensions. The first involved several filtration steps, immunomagnetic separation and freeze-thaw cycles. The second method involved filtration, addition of EnviroAmp lysis reagent, freeze-thaw cycles and precipitation of the DNA with isopropanol. Using nested PCR, we detected 100 oocysts/ml of filtered water pellet suspension, with either of the above sample preparation procedures. Nested PCR increased sensitivity of the assay by two to three orders of magnitude as compared to the primary PCR. The detection limit for seeded fecal samples was 10-fold higher than for filtered environmental water pellet suspension. Nested PCR results showed 62.4 and 91.1% correlation with immunofluorescence assay (IFA) for fecal samples and filtered environmental water pellet suspensions, respectively. This correlation decreased to 47.2% and 44.4%, respectively, when only IFA positive samples were analyzed. However, in fecal samples contaminated with a high number (> 10(5)/g) of C. parvum oocysts, this correlation was 100%. PMID:10076632

  6. Determinate the BPA in biological samples by spectrophotometry

    International Nuclear Information System (INIS)

    Boron neutron capture therapy (BNCT) is a new radiation therapy, of which clinical interest has focused primarily on the treatment of high-grade gliomas. At present, the most effective drug for BNCT is p-Boronophenylalanine (BPA), because it has little side effect and low toxicity, persisted longer in tumors compared with related molecules. The method of 3-Methoxy-Methylenimine H spectrophotometry was established to measure the concentration of 10B in biological samples. The biodistribution of the BPA was studied in normal mice. (authors)

  7. Incubation Station for the Bacterial Growth Study in Biological Samples

    Directory of Open Access Journals (Sweden)

    Carlos Rafael Duharte Rodríguez

    2015-12-01

    Full Text Available This work shows the designing and characterization of a prototype of laboratory incubator as support of Microbiology research, in particular for the research of the bacterial growth in biological samples through optic methods (Turbidimetry and electrometric measurements of bioimpedance. It shows the results of simulation and experimentation of the design proposed for the canals of measurement of the variables: temperature and humidity, with a high linearity from the adequate selection of the corresponding sensors and the analogue components of every canal, controlled with help of a microcontroller AT89C51 (ATMEL with adequate benefi ts for this type of application.

  8. S- to N-Palmitoyl Transfer During Proteomic Sample Preparation

    Science.gov (United States)

    Ji, Yuhuan; Bachschmid, Markus M.; Costello, Catherine E.; Lin, Cheng

    2016-04-01

    N-palmitoylation has been reported in a number of proteins and suggested to play an important role in protein localization and functions. However, it remains unclear whether N-palmitoylation is a direct enzyme-catalyzed process, or results from intramolecular S- to N-palmitoyl transfer. Here, using the S-palmitoyl peptide standard, GCpalmLGNAK, as the model system, we observed palmitoyl migration from the cysteine residue to either the peptide N-terminus or the lysine side chain during incubation in both neutral and slightly basic buffers commonly used in proteomic sample preparation. Palmitoyl transfer can take place either intra- or inter-molecularly, with the peptide N-terminus being the preferred migration site, presumably because of its lower basicity. The extent of intramolecular palmitoyl migration was low in the system studied, as it required the formation of an entropically unfavored macrocycle intermediate. Intermolecular palmitoyl transfer, however, remained a tangible problem, and may lead to erroneous reporting of in vivo N-palmitoylation. It was found that addition of the MS-compatible detergent RapiGest could significantly inhibit intermolecular palmitoyl transfer, as well as thioester hydrolysis and DTT-induced thioester cleavage. Finally, palmitoyl transfer from the cysteine residue to the peptide N-terminus can also occur in the gas phase, during collision-induced dissociation, and result in false identification of N-palmitoylation. Therefore, one must be careful with both sample preparation and interpretation of tandem mass spectra in the study of N-palmitoylation.

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

    Science.gov (United States)

    Chwiej, Joanna; Szczerbowska-Boruchowska, Magdalena; Lankosz, Marek; Wojcik, Slawomir; Falkenberg, Gerald; Stegowski, Zdzislaw; Setkowicz, Zuzanna

    2005-12-01

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

  10. Waste minimization in analytical chemistry through innovative sample preparation techniques

    International Nuclear Information System (INIS)

    Because toxic solvents and other hazardous materials are commonly used in analytical methods, characterization procedures result in significant and costly amount of waste. We are developing alternative analytical methods in the radiological and organic areas to reduce the volume or form of the hazardous waste produced during sample analysis. For the radiological area, we have examined high-pressure, closed-vessel microwave digestion as a way to minimize waste from sample preparation operations. Heated solutions of strong mineral acids can be avoided for sample digestion by using the microwave approach. Because reactivity increases with pressure, we examined the use of less hazardous solvents to leach selected contaminants from soil for subsequent analysis. We demonstrated the feasibility of this approach by extracting plutonium from a NET reference material using citric and tartaric acids with microwave digestion. Analytical results were comparable to traditional digestion methods, while hazardous waste was reduced by a factor often. We also evaluated the suitability of other natural acids, determined the extraction performance on a wider variety of soil types, and examined the extraction efficiency of other contaminants. For the organic area, we examined ways to minimize the wastes associated with the determination of polychlorinated biphenyls (PCBs) in environmental samples. Conventional methods for analyzing semivolatile organic compounds are labor intensive and require copious amounts of hazardous solvents. For soil and sediment samples, we have a method to analyze PCBs that is based on microscale extraction using benign solvents (e.g., water or hexane). The extraction is performed at elevated temperatures in stainless steel cells containing the sample and solvent. Gas chromatography-mass spectrometry (GC/MS) was used to quantitate the analytes in the isolated extract. More recently, we developed a method utilizing solid-phase microextraction (SPME) for natural

  11. The use of contrast agent for imaging biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J; Sopko, V; Jakubek, J [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ 12800 Prague 2 (Czech Republic); Weyda, F, E-mail: jiri.dammer@utef.cvut.cz [Biological center of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic)

    2011-01-15

    The technique of X-ray transmission imaging has been available for over a century and is still among the fastest and easiest approaches to the studies of internal structure of biological samples. Recent advances in semiconductor technology have led to the development of new types of X-ray detectors with direct conversion of interacting X-ray photon to an electric signal. Semiconductor pixel detectors seem to be specially promising; compared to the film technique, they provide single-quantum and real-time digital information about the objects being studied. We describe the recently developed radiographic apparatus, equipped with Medipix2 semiconductor pixel detector. The detector is used as an imager that counts individual photons of ionizing radiation, emitted by an X-ray tube (micro- or nano-focus FeinFocus). Thanks to the wide dynamic range of the Medipix2 detector and its high spatial resolution better than 1{mu}m, the setup is particularly suitable for radiographic imaging of small biological samples, including in-vivo observations with contrast agent (Optiray). Along with the description of the apparatus we provide examples of the use iodine contrast agent as a tracer in various insects as model organisms. The motivation of our work is to develop our imaging techniques as non-destructive and non-invasive. Microradiographic imaging helps detect organisms living in a not visible environment, visualize the internal biological processes and also to resolve the details of their body (morphology). Tiny live insects are an ideal object for our studies.

  12. Gas-assisted annular microsprayer for sample preparation for time-resolved cryo-electron microscopy

    International Nuclear Information System (INIS)

    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, a microfluidic device 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 a microspraying method, the generated droplet size needs to be controlled to facilitate thin ice film formation on the grid surface for efficient data collection, whilst not being so thin that it dries out before freezing, i.e. an 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 and 9 μm, which fulfilled the droplet size requirement for TRCEM sample preparation. With droplet density of around 12–18 per grid window (window size 58  ×  58 μm), and a data collectible thin ice region of >50% total wetted area, we collected ∼800–1000 high quality CCD micrographs in a 6–8 h period of continuous effort. This level of output is comparable to what were routinely achieving using cryo-grids prepared by conventional blotting and manual data collection. In this case, weeks of data collection with the previous device has been shortened to a day or two. And hundreds of microliters of valuable sample consumption can be reduced to only a small fraction. (paper)

  13. Supporting Sampling and Sample Preparation Tools for Isotope and Nuclear Analysis

    International Nuclear Information System (INIS)

    Nuclear and related techniques can help develop climate-smart agricultural practices by optimizing water and nutrient use efficiency, assessing organic carbon sequestration in soil, and assisting in the evaluation of soil erosion control measures. Knowledge on the behaviour of radioactive materials in soil, water and foodstuffs is also essential in enhancing nuclear emergency preparedness and response. Appropriate sampling and sample preparation are the first steps to ensure the quality and effective use of the measurements and this publication provides comprehensive detail on the necessary steps

  14. Iodine-129: Sample preparation, quality assurance and analysis of environmental samples

    International Nuclear Information System (INIS)

    The long-lived radionuclide 129I (half-live 15.7 Ma) occurs in the environment due to spontaneous fission of uranium in the earth-crust and in oceans, and due to cosmic-ray induced spallation of xenon in the stratosphere. Military and civilian use of induced nuclear fission by man increased natural abundances by two to seven orders of magnitude during the last sixty years. Among that, substantial emissions originate from reprocessing of spent nuclear fuel. Three main goals are pursued by examining 129I in environmental materials: The observation of dimensions and radiological relevances of anthropogenic emissions during the last decades, the use of 129I as a tracer of environmental processes, and the determination of natural, pre-nuclear 129I/127I ratios. For that, precipitation, surface, and ground waters from Lower Saxony, Germany, were systematically investigated from 1997 to 1999, extended by single seawater samples. In addition, a reconstruction of past 129I concentrations and 129I/127I ratios was attempted with archived soil and thyroid samples. Accelerator mass spectrometry (AMS) was used in this study. Besides the measurements of environmental samples, emphasis was laid upon the refinement of these analytical and chemical procedures: New sample preparation methods, quality assurance, the possibility of a carrier-free sample preparation and measurement with AMS, and a detailed statistical evaluation of raw data

  15. Inductively coupled plasma mass spectrometry in the analysis of biological samples and pharmaceutical drugs

    Science.gov (United States)

    Ossipov, K.; Seregina, I. F.; Bolshov, M. A.

    2016-04-01

    Inductively coupled plasma mass spectrometry (ICP-MS) is widely used in the analysis of biological samples (whole blood, serum, blood plasma, urine, tissues, etc.) and pharmaceutical drugs. The shortcomings of this method related to spectral and non-spectral interferences are manifested in full measure in determination of the target analytes in these complex samples strongly differing in composition. The spectral interferences are caused by similarity of masses of the target component and sample matrix components. Non-spectral interferences are related to the influence of sample matrix components on the physicochemical processes taking place during formation and transportation of liquid sample aerosols into the plasma, on the value and spatial distribution of plasma temperature and on the transmission of the ion beam from the interface to mass spectrometer detector. The review is devoted to analysis of different mechanisms of appearance of non-spectral interferences and to ways for their minimization or elimination. Special attention is paid to the techniques of biological sample preparation, which largely determine the mechanisms of the influence of sample composition on the results of element determination. The ways of lowering non-spectral interferences by instrumental parameter tuning and application of internal standards are considered. The bibliography includes 189 references.

  16. Nitrogen-Containing Apigenin Analogs: Preparation and Biological Activity

    Directory of Open Access Journals (Sweden)

    Jinyi Wang

    2012-12-01

    Full Text Available A series of nitrogen-containing apigenin analogs 4a–j was synthesized via Mannich reactions to develop anticancer, antibacterial, and antioxidant agents from plant-derived flavonoids. The chemical structures of these compounds were confirmed using 1H-NMR, 13C-NMR, and ESI-MS. The in vitro biological activities of the analogs were evaluated via assays of their antiproliferative, antibacterial, and antioxidant activities. The prepared apigenin analogs exhibited different antiproliferative activities against four human cancer cell lines, namely human cervical (HeLa, human hepatocellular liver (HepG2, human lung (A549, and human breast (MCF-7 cancer cells. Compound 4i showed the most favorable in vitro antiproliferative activity with IC50 values of 40, 40, 223, and 166 μg/mL against HeLa, HepG2, A549, and MCF-7, respectively. The 1,1-diphenyl-2-picrylhydrazyl (DPPH free radical scavenging activity assay also showed that 4i had the most potent antioxidant activity, with the smallest IC50 value (334.8 μg/mL. The antibacterial activities of the analogs were determined using a two-fold serial dilution technique against four pathogenic bacteria, namely Staphylococcus aureus, Bacillus subtilis, Escherichia coli, and Pseudomonas aeruginosa. All the prepared apigenin analogs exhibited more potent activities than the parent apigenin. Compounds 4h and 4j, in particular, exhibited the best inhibitory activities against the Gram-positive bacteria Staphylococcus aureus and Bacillus subtilis with MIC values of 3.91 and 1.95 μg/mL, respectively.

  17. Evaluation of a gas chromatography method for azelaic acid determination in selected biological samples

    Directory of Open Access Journals (Sweden)

    Mahdi Garelnabi

    2010-09-01

    Full Text Available Background: Azelaic acid (AzA is the best known dicarboxilic acid to have pharmaceutical benefits and clinical applications and also to be associated with some diseases pathophysiology. Materials and Methods: We extracted and methylesterified AzA and determined its concentration in human plasma obtained from healthy individuals and also in mice fed AzA containing diet for three months. Results: AzA was detected in Gas Chromatography (GC and confirmed by Liquid chromatography mass spectrometry (LCMS, and gas chromatography mass spectrometry (GCMC. Our results have shown that AzA can be determined efficiently in selected biological samples by GC method with 1nM limit of detection (LoD and the limit of quantification (LoQ; was established at 50nM. Analytical Sensitivity as assayed by hexane demonstrated an analytical sensitivity at 0.050nM. The method has demonstrated 8-10% CV batch repeatability across the sample types and 13-18.9% CV for the Within-Lab Precision analysis. The method has shown that AzA can efficiently be recovered from various sample preparation including liver tissue homogenate (95% and human plasma (97%. Conclusions: Because of its simplicity and lower limit of quantification, the present method provides a useful tool for determining AzA in various biological sample preparations.

  18. Analysis of biological slurry samples by total x-ray fluorescence after in situ microwave digestion

    International Nuclear Information System (INIS)

    Biological slurry samples were analyzed by total reflection x-ray fluorescence (TXRF) after an in situ microwave digestion procedure on the quartz reflector. This method lead to the removal of the matrix by the digestion and permits the enrichment of the analites by using sample amounts higher than those normally used in TXRF for the thin layer requirement since the organic matrix is removed. In consequence, the pre-concentration of sample is performed and the detection capability is increased by a quasi direct method. The samples analyzed were the international IAEA blood standard, the SRM bovine liver 1577-a standard and fresh onion tissues. Slurries were prepared in three ways: a.- weighing a sample amount on the reflector and adding suprapure nitric acid and internal standard followed by microwave digestion, b.-weighing a sample amount and water with an appropriate concentration of the internal standard in an Eppendorf vial, taking then an aliquot to the quartz reflector for microwave digestion with suprapure nitric acid, c.- weighing a sample amount of fresh tissue, homogenising with high speed homegenator to obtain a slurry sample which can be diluted in an ependorf vial with water an the internal standard. Then an aliquot is taken to the reflector for microwave digestion with suprapure nitric acid. Further details of sample preparation procedures will be discussed during presentation. The analysis was carried out in a Canberra spectrometer using the Kalpha lines of the Ag and Mo tubes. The elements Ca, K, Fe, Cu, Zn, Se, Mn, Rb, Br, Sr were determined. The effect of the preparation procedure was evaluated by the accuracy and precision of the results for each element and the percent of recovery. (author)

  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. 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)

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

    International Nuclear Information System (INIS)

    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 C18 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)

  2. Trends in sample preparation 2002. Development and application. Book of abstracts

    International Nuclear Information System (INIS)

    This conference comprised topics dealing with sample preparation such as: sample decomposition, solvent extraction, derivatization techniques and uncertainty in sample preparation. In particular microwave assisted sample preparation techniques and equipment were discussed. The papers were organized under the general topics: trace element analysis, trace analysis of organic compounds, high performance instrumentation in sample preparation, speciation analysis and posters session. Those papers of INIS interest are cited individually. (nevyjel)

  3. Use of robotic systems for radiochemical sample changing and for analytical sample preparation

    International Nuclear Information System (INIS)

    Two uses of the Perkin-Elmer (PE) robotic system will be presented. In the first, a PE robot functions as an automatic sample changer for up to five low energy photon spectrometry (LEPS) detectors operated with a Nuclear Data ND 6700 system. The entire system, including the robot, is controlled by an IBM PC-AT using software written in compiled BASIC. Problems associated with the development of the system and modifications to the robot will be presented. In the second, an evaluation study was performed to assess the abilities of the PE robotic system for performing complex analytical sample preparation procedures. For this study, a robotic system based upon the PE robot and auxiliary devices was constructed and programmed to perform the preparation of final product samples (UO3) for accountability and impurity specification analyses. These procedures require sample dissolution, dilution, and liquid-liquid extraction steps. The results of an in-depth evaluation of all system components will be presented

  4. Use of robotic systems for radiochemical sample changing and for analytical sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Delmastro, J.R.; Hartenstein, S.D.; Wade, M.A.

    1989-05-15

    Two uses of the Perkin-Elmer (PE) robotic system will be presented. In the first, a PE robot functions as an automatic sample changer for up to five low energy photon spectrometry (LEPS) detectors operated with a Nuclear Data ND 6700 system. The entire system, including the robot, is controlled by an IBM PC-AT using software written in compiled BASIC. Problems associated with the development of the system and modifications to the robot will be presented. In the second, an evaluation study was performed to assess the abilities of the PE robotic system for performing complex analytical sample preparation procedures. For this study, a robotic system based upon the PE robot and auxiliary devices was constructed and programmed to perform the preparation of final product samples (UO{sub 3}) for accountability and impurity specification analyses. These procedures require sample dissolution, dilution, and liquid-liquid extraction steps. The results of an in-depth evaluation of all system components will be presented.

  5. "Rinse and trickle": a protocol for TEM preparation and investigation of inorganic fibers from biological material.

    Science.gov (United States)

    Vigliaturo, Ruggero; Capella, Silvana; Rinaudo, Caterina; Belluso, Elena

    2016-07-01

    The purpose of this work is to define a sample preparation protocol that allows inorganic fibers and particulate matter extracted from different biological samples to be characterized morphologically, crystallographically and chemically by transmission electron microscopy-energy dispersive spectroscopy (TEM-EDS). The method does not damage or create artifacts through chemical attacks of the target material. A fairly rapid specimen preparation is applied with the aim of performing as few steps as possible to transfer the withdrawn inorganic matter onto the TEM grid. The biological sample is previously digested chemically by NaClO. The salt is then removed through a series of centrifugation and rinse cycles in deionized water, thus drastically reducing the digestive power of the NaClO and concentrating the fibers for TEM analysis. The concept of equivalent hydrodynamic diameter is introduced to calculate the settling velocity during the centrifugation cycles. This technique is applicable to lung tissues and can be extended to a wide range of organic materials. The procedure does not appear to cause morphological damage to the fibers or modify their chemistry or degree of crystallinity. The extrapolated data can be used in interdisciplinary studies to understand the pathological effects caused by inorganic materials. PMID:27151190

  6. Micro-radiography of biological samples with medical contrast agents

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J., E-mail: jiri.dammer@lf1.cuni.cz [Charles University in Prague, First Faculty of Medicine, Salmovská 1, 120 00 Prague 2 (Czech Republic); Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, 180 81 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Weyda, F. [Faculty of Science, University of South Bohemia, Branisovska 31, 370 05 Ceske Budejovice (Czech Republic); Benes, J. [Charles University in Prague, First Faculty of Medicine, Salmovská 1, 120 00 Prague 2 (Czech Republic); Sopko, V. [Hospital Na Bulovce, Department of Radiological Physics, Budinova 2, 180 81 Prague 8 (Czech Republic); Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, 128 00 Prague 2 (Czech Republic); Gelbic, I. [Biology Centre, AS CR, Institute of Entomology, Department of Biochemistry and Physiology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic)

    2013-12-01

    Micro-radiography is an imaging technique that uses X-rays to study the internal structures of objects. This fast and easy imaging tool is based on differential X-ray attenuation by various tissues and structures within biological samples. The experimental setup described is based on the semiconductor pixel X-ray detector Medipix2 and X-ray micro-focus tube. Our micro-radiographic system has been recently used not only for the examination of internal structures of various arthropods and other biological objects but also for tracing some processes in selected model species (we used living larvae of mosquito Culex quinquefasciatus). Low concentrations of iodine, lanthanum or gold particles were used as a tracer (contrast agent). Such contrast agents increase the absorption of X-rays and allow a better visibility of internal structures of model organisms (especially the various cavities, pores, etc.). In addition, the movement of tracers in selected timing experiments demonstrates some physiological functions of digestive and excretory system.

  7. Micro-radiography of biological samples with medical contrast agents

    International Nuclear Information System (INIS)

    Micro-radiography is an imaging technique that uses X-rays to study the internal structures of objects. This fast and easy imaging tool is based on differential X-ray attenuation by various tissues and structures within biological samples. The experimental setup described is based on the semiconductor pixel X-ray detector Medipix2 and X-ray micro-focus tube. Our micro-radiographic system has been recently used not only for the examination of internal structures of various arthropods and other biological objects but also for tracing some processes in selected model species (we used living larvae of mosquito Culex quinquefasciatus). Low concentrations of iodine, lanthanum or gold particles were used as a tracer (contrast agent). Such contrast agents increase the absorption of X-rays and allow a better visibility of internal structures of model organisms (especially the various cavities, pores, etc.). In addition, the movement of tracers in selected timing experiments demonstrates some physiological functions of digestive and excretory system

  8. Pressure pulse induced-damage in live biological samples

    Science.gov (United States)

    Bo, C.; Balzer, J.; Godfrey, S.; Francois, M.; Saffell, J. L.; Rankin, S. M.; Proud, W. G.; Brown, K. A.

    2012-08-01

    Developing a cellular and molecular understanding of the nature of traumatic and post-traumatic effects of blast on live biological samples is critical for improving clinical outcomes. To analyze the effects of blast waves upon the cellular structures and the underlying physiological and biochemical changes, we have constructed an experimental platform capable of delivering compression waves, of amplitudes relevant to blast, to cell suspensions in a contained environment. Initial characterization of the system shows that cell cultures can be subjected to high-intensity compression waves up to 15 MPa in pressure and duration of 80 ± 10μs. Studies of mouse mesenchymal stem cells subjected to two different pressure impulses were analysed by cell counting, cell viability assays and microscopic evaluation: the experiments present evidence suggestive of increased levels of damage and loss of cellular integrity compared to uncompressed cell cultures.

  9. Digital holography microscopy in 3D biologic samples analysis

    Energy Technology Data Exchange (ETDEWEB)

    Ricardo, J O; Palacios, F; Palacios, G F; Sanchez, A [Department of Physics, University of Oriente (Cuba); Muramatsu, M [Department of General Physics, University of Sao Paulo - Sao Paulo (Brazil); Gesualdi, M [Engineering center, Models and Applied Social Science, UFABC - Sao Paulo (Brazil); Font, O [Department of Bio-ingeniering, University of Oriente - Santiago de Cuba (Cuba); Valin, J L [Mechanics Department, ISPJAE, Habana (Cuba); Escobedo, M; Herold, S [Department of Computation, University of Oriente (Cuba); Palacios, D F, E-mail: frpalaciosf@gmail.com [Department of Nuclear physics, University of Simon BolIva (Venezuela, Bolivarian Republic of)

    2011-01-01

    In this work it is used a setup for Digital Holography Microscopy (MHD) for 3D biologic samples reconstruction. The phase contrast image reconstruction is done by using the Double propagation Method. The system was calibrated and tested by using a micrometric scale and pure phase object respectively. It was simulated the human red blood cell (erythrocyte) and beginning from the simulated hologram the digital 3D phase image for erythrocytes it was calculated. Also there was obtained experimental holograms of human erythrocytes and its corresponding 3D phase images, being evident the correspondence qualitative and quantitative between these characteristics in the simulated erythrocyte and in the experimentally calculated by DHM in both cases.

  10. Digital holography microscopy in 3D biologic samples analysis

    International Nuclear Information System (INIS)

    In this work it is used a setup for Digital Holography Microscopy (MHD) for 3D biologic samples reconstruction. The phase contrast image reconstruction is done by using the Double propagation Method. The system was calibrated and tested by using a micrometric scale and pure phase object respectively. It was simulated the human red blood cell (erythrocyte) and beginning from the simulated hologram the digital 3D phase image for erythrocytes it was calculated. Also there was obtained experimental holograms of human erythrocytes and its corresponding 3D phase images, being evident the correspondence qualitative and quantitative between these characteristics in the simulated erythrocyte and in the experimentally calculated by DHM in both cases.

  11. Measurement of copper in biological samples by flame or electrothermal atomic absorption spectrometry.

    Science.gov (United States)

    Evenson, M A

    1988-01-01

    Guidelines presented here allow for copper analysis of biological materials by methods that are very sensitive, that require little sample preparation, that have few chemical or spectral interferences, that are inexpensive, and that require only usual care in contamination control. The commercial instruments for FAAS and ETAAS from Perkin-Elmer, from Varian, and from Instrumentation Laboratories Inc. (Allied Analytical Systems) all work well in either the flame or the flameless mode. Background correction techniques are not essential for copper analysis if care is taken with the sample preparation to minimize the background signals. Different types of burners will work adequately if one makes certain that the viscosity of the sample and the control products are similar to the calibration standards. Further, dilution of samples is preferred over increasing the viscosity of the calibration standards by the addition of a protein containing solution or a substance such as glycerol. A 1:10 dilution of blood plasma or serum with dilute nitric acid or water is all that is necessary for copper analysis by the FFAS methods. Cation and anion effects should be tested by bracketing the concentrations of the ions found in the sample with known amounts of ions in the sample solutions. Increasing the concentrations of the ions thought to interfere while keeping the copper concentration constant is another way to test for ion interferences.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:3374386

  12. Novel sample preparation for operando TEM of catalysts.

    Science.gov (United States)

    Miller, Benjamin K; Barker, Trevor M; Crozier, Peter A

    2015-09-01

    A new TEM sample preparation method is developed to facilitate operando TEM of gas phase catalysis. A porous Pyrex-fiber pellet TEM sample was produced, allowing a comparatively large amount of catalyst to be loaded into a standard Gatan furnace-type tantalum heating holder. The increased amount of catalyst present inside the environmental TEM allows quantitative determination of the gas phase products of a catalytic reaction performed in-situ at elevated temperatures. The product gas concentration was monitored using both electron energy loss spectroscopy (EELS) and residual gas analysis (RGA). Imaging of catalyst particles dispersed over the pellet at atomic resolution is challenging, due to charging of the insulating glass fibers. To overcome this limitation, a metal grid is placed into the holder in addition to the pellet, allowing catalyst particles dispersed over the grid to be imaged, while particles in the pellet, which are assumed to experience identical conditions, contribute to the overall catalytic conversion inside the environmental TEM cell. The gas within the cell is determined to be well-mixed, making this assumption reasonable. PMID:25974880

  13. Microwave radiation as a factor intensifying sample preparation: analysis of samples with an organic matrix

    International Nuclear Information System (INIS)

    Specific features of SHF-(mirowave) decomposition of a sample to ascertain microcomponents in objects with an organic matrix have been considered. The amount of organic substances remaining in solution after decomposition has been evaluated. It has been shown that they do not affect the subsequent determination of metallic impurities by the ICP-AES and ET-AAS methods. Methods of macro- and microcomponents determination in phyto-objects, vegetable oils, biological liquids, perfumery and cosmetics at the level of contents 10-2-10-3% Sr, 10-5-10-6% Cd have been elaborated

  14. Microwave-assisted digestion procedures for biological samples with diluted nitric acid: identification of reaction products.

    Science.gov (United States)

    Gonzalez, Mário H; Souza, Gilberto B; Oliveira, Regina V; Forato, Lucimara A; Nóbrega, Joaquim A; Nogueira, Ana Rita A

    2009-07-15

    Microwave-assisted sample preparation using diluted nitric acid solutions is an alternative procedure for digesting organic samples. The efficiency of this procedure depends on the chemical properties of the samples and in this work it was evaluated by the determination of crude protein amount, fat and original carbon. Soybeans grains, bovine blood, bovine muscle and bovine viscera were digested in a cavity-microwave oven using oxidant mixtures in different acid concentrations. The digestion efficiency was evaluated based on the determination of residual carbon content and element recoveries using inductively coupled plasma optical emission spectrometry (ICP OES). In order to determine the main residual organic compounds, the digests were characterized by nuclear magnetic resonance ((1)H NMR). Subsequently, studies concerning separation of nitrobenzoic acid isomers were performed by ion pair reversed phase liquid chromatography using a C18 stationary phase, water:acetonitrile:methanol (75:20:5, v/v/v)+0.05% (v/v) TFA as mobile phase and ultraviolet detection at 254 nm. Sample preparation based on diluted acids proved to be feasible and a recommendable alternative for organic sample digestion, reducing both the reagent volumes and the variability of the residues as a result of the process of decomposition. It was shown that biological matrices containing amino acids, proteins and lipids in their composition produced nitrobenzoic acid isomers and other organic compounds after cleavage of chemical bonds. PMID:19559896

  15. Sample preparation for measuring cow's progesterone in radioimmunoassay technique application

    International Nuclear Information System (INIS)

    Sample preparation for measuring cow's progesterone in radioimmunoassay technique application has been done. Preparation includes the preparation of samples of cow's milk samples that has been carried out artificial insemination on day 0, 11 and 21. Then the standard making of progesterone in the form of fresh milk or skim milk (non fat) that has been removed its progesterone and through a series of chemical processes. The last is the preparation work on samples using the RIA kit I125. With this milk samples preparation, samples can be counted using RIA counter so that concentration of progesterone hormone can be determined accurately. (author)

  16. 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.

  17. Separation and enrichment of trace ractopamine in biological samples by uniformly-sized molecularly imprinted polymers

    Institute of Scientific and Technical Information of China (English)

    Ya Li; Qiang Fua; Meng Liu; Yuan-Yuan Jiao; Wei Du; Chong Yu; Jing Liu; Chun Chang; Jian Lu

    2012-01-01

    In order to prepare a high capacity packing material for solid-phase extraction with specific recognition ability of trace ractopamine in biological samples, uniformly-sized, molecularly imprinted polymers (MIPs) were prepared by a multi-step swelling and polymerization method using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, and toluene as a porogen respectively. Scanning electron microscope and specific surface area were employed to identify the characteristics of MIPs. Ultraviolet spectroscopy, Fourier transform infrared spectroscopy, Scatchard analysis and kinetic study were performed to interpret the specific recognition ability and the binding process of MIPs. The results showed that, compared with other reports, MIPs synthetized in this study showed high adsorption capacity besides specific recognition ability. The adsorption capacity of MIPs was 0.063 mmol/g at 1 mmol/L ractopamine concentra- tion with the distribution coefficient 1.70. The resulting MIPs could be used as solid-phase extraction materials for separation and enrichment of trace ractopamine in biological samples.

  18. Direct Observation of Wet Biological Samples by Graphene Liquid Cell Transmission Electron Microscopy.

    Science.gov (United States)

    Park, Jungwon; Park, Hyesung; Ercius, Peter; Pegoraro, Adrian F; Xu, Chen; Kim, Jin Woong; Han, Sang Hoon; Weitz, David A

    2015-07-01

    Recent development of liquid phase transmission electron microscopy (TEM) enables the study of specimens in wet ambient conditions within a liquid cell; however, direct structural observation of biological samples in their native solution using TEM is challenging since low-mass biomaterials embedded in a thick liquid layer of the host cell demonstrate low contrast. Furthermore, the integrity of delicate wet samples is easily compromised during typical sample preparation and TEM imaging. To overcome these limitations, we introduce a graphene liquid cell (GLC) using multilayer graphene sheets to reliably encapsulate and preserve biological samples in a liquid for TEM observation. We achieve nanometer scale spatial resolution with high contrast using low-dose TEM at room temperature, and we use the GLC to directly observe the structure of influenza viruses in their native buffer solution at room temperature. The GLC is further extended to investigate whole cells in wet conditions using TEM. We also demonstrate the potential of the GLC for correlative studies by TEM and fluorescence light microscopy imaging. PMID:26065925

  19. The preparation of albumin as a biological drug from human plasma by fiber filtration

    Directory of Open Access Journals (Sweden)

    Mousavi Hosseini K

    2011-08-01

    Full Text Available "nBackground: In recent years, consumption of whole-blood for the treatment of patients has decreased but use of biological plasma-derived medicines such as albumin, immunoglobulin and coagulation factors have increased instead. Paying attention to albumin molecular structure is important for its isolation from human plasma. Albumin is a single-chain protein consisting of about 585 amino acids and a molecular weight of 66500 Daltons. Albumin is a stable molecule and it is spherical in shape. There are different methods for human albumin preparation. Considering the large consumption of this biological drug in clinical settings, methods with fewer steps in production line are of big advantage in saving time and manufacturing more products."n "nMethods: In this project, we prepared human albumin using hollow fiber cartridges in order to omit the rework on fraction V+VI. Human albumin is usually produced by the application of cold ethanol method, where albumin is obtained from fraction V by doing a rework on fraction V+VI to separate fraction V."n "nResults: In the current work, human albumin was prepared from fraction V+VI by the help of hollow fiber cartridges. With a concentration of 20%, the obtained albumin had 96.5% of monomer and 3.5% of polymer and polymer aggregate."n "nConclusion: Comparing the obtained human albumin with a number of commercial human albumin samples by the use of SDS-page, the results were satisfactory regarding the 3.5 percent polymer and aggregate rate for the prepared albumin.

  20. Fully Automated Sample Preparation for Ultrafast N-Glycosylation Analysis of Antibody Therapeutics.

    Science.gov (United States)

    Szigeti, Marton; Lew, Clarence; Roby, Keith; Guttman, Andras

    2016-04-01

    There is a growing demand in the biopharmaceutical industry for high-throughput, large-scale N-glycosylation profiling of therapeutic antibodies in all phases of product development, but especially during clone selection when hundreds of samples should be analyzed in a short period of time to assure their glycosylation-based biological activity. Our group has recently developed a magnetic bead-based protocol for N-glycosylation analysis of glycoproteins to alleviate the hard-to-automate centrifugation and vacuum-centrifugation steps of the currently used protocols. Glycan release, fluorophore labeling, and cleanup were all optimized, resulting in a process with excellent yield and good repeatability. This article demonstrates the next level of this work by automating all steps of the optimized magnetic bead-based protocol from endoglycosidase digestion, through fluorophore labeling and cleanup with high-throughput sample processing in 96-well plate format, using an automated laboratory workstation. Capillary electrophoresis analysis of the fluorophore-labeled glycans was also optimized for rapid (processing of the automated sample preparation workflow. Ultrafast N-glycosylation analyses of several commercially relevant antibody therapeutics are also shown and compared to their biosimilar counterparts, addressing the biological significance of the differences. PMID:26429557

  1. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    Energy Technology Data Exchange (ETDEWEB)

    None

    2013-09-01

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological

  2. Amchitka Island, Alaska, Biological Monitoring Report 2011 Sampling Results

    International Nuclear Information System (INIS)

    The Long-Term Surveillance and Maintenance (LTS&M) Plan for the U.S. Department of Energy (DOE) Office of Legacy Management (LM) Amchitka Island sites describes how LM plans to conduct its mission to protect human health and the environment at the three nuclear test sites located on Amchitka Island, Alaska. Amchitka Island, near the western end of the Aleutian Islands, is approximately 1,340 miles west-southwest of Anchorage, Alaska. Amchitka is part of the Aleutian Island Unit of the Alaska Maritime National Wildlife Refuge, which is administered by the U.S. Fish and Wildlife Service (USFWS). Since World War II, Amchitka has been used by multiple U.S. government agencies for various military and research activities. From 1943 to 1950, it was used as a forward air base for the U.S. Armed Forces. During the middle 1960s and early 1970s, the U.S. Department of Defense (DOD) and the U.S. Atomic Energy Commission (AEC) used a portion of the island as a site for underground nuclear tests. During the late 1980s and early 1990s, the U.S. Navy constructed and operated a radar station on the island. Three underground nuclear tests were conducted on Amchitka Island. DOD, in conjunction with AEC, conducted the first nuclear test (named Long Shot) in 1965 to provide data that would improve the United States' capability of detecting underground nuclear explosions. The second nuclear test (Milrow) was a weapons-related test conducted by AEC in 1969 as a means to study the feasibility of detonating a much larger device. Cannikin, the third nuclear test on Amchitka, was a weapons-related test detonated on November 6, 1971. With the exception of small concentrations of tritium detected in surface water shortly after the Long Shot test, radioactive fission products from the tests remain in the subsurface at each test location As a continuation of the environmental monitoring that has taken place on Amchitka Island since before 1965, LM in the summer of 2011 collected biological and

  3. Total airborne mold particle sampling: evaluation of sample collection, preparation and counting procedures, and collection devices.

    Science.gov (United States)

    Godish, Diana; Godish, Thad

    2008-02-01

    This study was conducted to evaluate (i) procedures used to collect, prepare, and count total airborne mold spore/particle concentrations, and (ii) the relative field performance of three commercially available total airborne mold spore/particle sampling devices. Differences between factory and laboratory airflow calibration values of axial fan-driven sampling instruments (used in the study) indicated a need for laboratory calibration using a mass flow meter to ensure that sample results were accurately calculated. An aniline blue-amended Calberla's solution adjusted to a pH of 4.2-4.4 provided good sample mounting/counting results using Dow Corning high vacuum grease, Dow Corning 280A adhesive, and Dow Corning 316 silicone release spray for samples collected using mini-Burkard and Allergenco samplers. Count variability among analysts was most pronounced in 5% counts of relatively low mold particle deposition density samples and trended downward with increased count percentage and particle deposition density. No significant differences were observed among means of 5, 10, and 20% counts and among analysts; a significant interaction effect was observed between analysts' counts and particle deposition densities. Significantly higher mini-Burkard and Air-O-Cell total mold spore/particle counts for 600x vs. 400x (1.9 and 2.3 x higher, respectively), 1000x vs. 600x (1.9 and 2.2 x higher, respectively) and 1000x vs. 400x (3.6 and 4.6 x higher, respectively) comparisons indicated that 1000x magnification counts best quantified total airborne mold spore/particles using light microscopy, and that lower magnification counts may result in unacceptable underreporting of airborne mold spore/particle concentrations. Modest but significantly higher (1.2x) total mold spore concentrations were observed with Allergenco vs. mini-Burkard samples collected in co-located, concurrently operated sampler studies; moderate but significantly higher mini-Burkard count values (1.4x) were

  4. Thiosemicarbazones: preparation methods, synthetic applications and biological importance

    International Nuclear Information System (INIS)

    Thiosemicarbazones are a class of compounds known by their chemical and biological properties, such as antitumor, antibacterial, antiviral and antiprotozoal activity. Their ability to form chelates with metals has great importance in their biological activities. Their synthesis is very simple, versatile and clean, usually giving high yields. They are largely employed as intermediates, in the synthesis of others compounds. This article is a survey of some of these characteristics showing their great importance to organic and medicinal chemistry. (author)

  5. Analytical approaches for assaying metallodrugs in biological samples: recent methodological developments and future trends.

    Science.gov (United States)

    Timerbaev, Andrei; Sturup, Stefan

    2012-03-01

    Contemporary medicine increasingly relies on metal-based drugs and correspondingly growing in importance is the monitoring of the drugs and their metabolites in biological samples. Over the last decade, a range of analytical techniques have been developed in order to improve administration strategies for clinically approved compounds and understand pharmacokinetics, pharmacodynamics, and metabolism of new drugs so as ultimately to make their clinical development more effective. This paper gives an overview of various separation and detection methods, as well as common sample preparation strategies, currently in use to achieve the intended goals. The critical discussion of existing analytical technologies encompasses notably their detection capability, ability to handle biological matrices with minimum pretreatment, sample throughput, and cost efficiency. The main attention is devoted to those applications that are progressed to real-world biosamples and selected examples are given to illustrate the overall performance and applicability of advanced analytical systems. Also emphasized is the emerging role of inductively coupled plasma mass spectrometry (ICP-MS), both as a standalone instrument (for determination of metals originating from drug compounds) and as an element-specific detector in combinations with liquid chromatography or capillary electrophoresis (for drug metabolism studies). An increasing number of academic laboratories are using ICP-MS technology today, and this review will focus on the analytical possibilities of ICP-MS which would before long provide the method with the greatest impact on the clinical laboratory. PMID:21838702

  6. Preparation and characterization of silver particle encapsulated biopolymer nano-colloid substrate for surface enhanced raman scattering (SERS) for biological applications

    Science.gov (United States)

    To detect biological samples such as foodborne pathogens, Surface Enhanced Raman Scattering (SERS) substrate was prepared and its characteristics were analyzed in this work. Silver biopolymer nano colloidal substrate was prepared by adding silver nitrate to 2% polyvinyl alcohol (PVA) solution and ...

  7. A self-contained polymeric cartridge for automated biological sample preparationa

    OpenAIRE

    Xu, Guolin; Lee, Daniel Yoke San; Xie, Hong; Chiew, Deon; Hsieh, Tseng-Ming; Ali, Emril Mohamed; Lun Looi, Xing; Li, Mo-Huang; Ying, Jackie Y.

    2011-01-01

    Sample preparation is one of the most crucial processes for nucleic acids based disease diagnosis. Several steps are required for nucleic acids extraction, impurity washes, and DNA/RNA elution. Careful sample preparation is vital to the obtaining of reliable diagnosis, especially with low copies of pathogens and cells. This paper describes a low-cost, disposable lab cartridge for automatic sample preparation, which is capable of handling flexible sample volumes of 10 μl to 1 ml. This plastic ...

  8. 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. PMID:26769364

  9. 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.

  10. High resolution x-ray microtomography of biological samples: Requirements and strategies for satisfying them

    Energy Technology Data Exchange (ETDEWEB)

    Loo, B.W. Jr. [Univ. of California, San Francisco, CA (United States)]|[Univ. of California, Davis, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States); Rothman, S.S. [Univ. of California, San Francisco, CA (United States)]|[Lawrence Berkeley National Lab., CA (United States)

    1997-02-01

    High resolution x-ray microscopy has been made possible in recent years primarily by two new technologies: microfabricated diffractive lenses for soft x-rays with about 30-50 nm resolution, and high brightness synchrotron x-ray sources. X-ray microscopy occupies a special niche in the array of biological microscopic imaging methods. It extends the capabilities of existing techniques mainly in two areas: a previously unachievable combination of sub-visible resolution and multi-micrometer sample size, and new contrast mechanisms. Because of the soft x-ray wavelengths used in biological imaging (about 1-4 nm), XM is intermediate in resolution between visible light and electron microscopies. Similarly, the penetration depth of soft x-rays in biological materials is such that the ideal sample thickness for XM falls in the range of 0.25 - 10 {mu}m, between that of VLM and EM. XM is therefore valuable for imaging of intermediate level ultrastructure, requiring sub-visible resolutions, in intact cells and subcellular organelles, without artifacts produced by thin sectioning. Many of the contrast producing and sample preparation techniques developed for VLM and EM also work well with XM. These include, for example, molecule specific staining by antibodies with heavy metal or fluorescent labels attached, and sectioning of both frozen and plastic embedded tissue. However, there is also a contrast mechanism unique to XM that exists naturally because a number of elemental absorption edges lie in the wavelength range used. In particular, between the oxygen and carbon absorption edges (2.3 and 4.4 nm wavelength), organic molecules absorb photons much more strongly than does water, permitting element-specific imaging of cellular structure in aqueous media, with no artifically introduced contrast agents. For three-dimensional imaging applications requiring the capabilities of XM, an obvious extension of the technique would therefore be computerized x-ray microtomography (XMT).

  11. 9 CFR 113.3 - Sampling of biological products.

    Science.gov (United States)

    2010-01-01

    ... bacterial vaccines; (iii) Two samples of Coccidiosis Vaccine; (iv) Eighteen samples of Rabies Vaccine...) Twenty-two single-dose or 14 multiple-dose samples of Rabies Vaccine, Killed Virus; (viii) Sixteen single... be stated in the filed Outline of Production. (b) Unless otherwise prescribed by the...

  12. Improvements in high purity radioxenon sample preparation and analysis

    International Nuclear Information System (INIS)

    This paper describes the production and analysis of high purity radioxenon samples. The University of Texas' 1.1 MW TRIGA research reactor is used for radioactive sample production via neutron activation. The reactor's facilities include a pneumatic system for precise irradiation of samples. In order to use the pneumatic facilities, gaseous samples have been encapsulated in quartz to fit into the polyethylene vials designed for the system. Enriched, stable, isotopically pure xenon gas is irradiated with neutrons in order to activate it to radioxenon isotopes, which are then measured with a β-γ coincidence system. The system enhancement and procedures to produce the radioxenon samples are described and examples of first of their kind measurements are shown for 125Xe, 127Xe, 129m Xe, and 137Xe. (author)

  13. Using γ spectrometry to study the influence on determination results of samples prepared with different preparation methods

    International Nuclear Information System (INIS)

    According to condition recommended in references, two bio-samples, the tea leaves and the wheat flour, are prepared with two different methods of ground into powder and reduced to ash. The radionuclides in the samples are analysed by γ spectrometry. The results show that the measured values of tea samples prepared by different method have outstanding difference, and the preparation method of reduced to ash makes some nuclides of the the sample lost. Comparing with the nondestructive method of ground into powder samples, the method of reduced to ash could make the detection sensibility much higher, but its suitability for kinds of samples and nuclides has some limitation, so its application have to be careful. At the same time it is shown in the work that developing the study about influence on determination results of samples prepared with different methods still has very significance. The probable reasons are discussed for widely different influence with different preparation method of the tea leaves and wheat flour. (6 tabs.)

  14. Preview of the NASA NNWG NDE Sample Preparation Handbook

    Science.gov (United States)

    2010-01-01

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

  15. Influence of sample preparation on the assay of isoflavones

    Science.gov (United States)

    The complexity of sample matrices, coexistence of multiple forms of bioactive phytochemicals, and their interaction of with other cellular components pose a significant challenge for optimize extraction and accurate estimation of bioactive phytochemicals in foods and dietary supplements. This artic...

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

    Institute of Scientific and Technical Information of China (English)

    Zhang Xiaohui; Peng Xigao

    2010-01-01

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

  17. Simplified polymer characterization after microwave assisted sample preparation (T9)

    International Nuclear Information System (INIS)

    Full text: Beside the determination of fillers and heavy metals in polymers after decomposition more often stabilizers, fire inhibitors and antistatic additive agents are measured alter using fast microwave accelerated solvent extraction. Determination of heavy metal traces for example in food packaging materials needs high sample weight to detect small amounts of impurities. High sample weight is also needed for plastic waste providing the homogeneity for representative analysis. Due to the high concentration of' organic carbon and the fact that the materials swim on the acid surface, closed vessel digestion had limits concerning sample weight. A new vessel insert in combination with extremely fast reaction control allows now to double or triple usual sample weights. High performance vessels can also be used to decompose polymers filled with TiO2, talcum, fibers or similar within short one or two step procedures gaining solutions without precipitates. Additional filtration or sample treatment is not necessary. For the determination of organic components more and more classical, but time consuming methods are replaced by microwave assisted solvent extraction. Instead of hours or even half days using Soxhlet extraction samples can be extracted within minutes using vessels and rotors similar to those used for decomposition. The dual use of one basic microwave instrument for both, analysis of inorganic as well as organic parameters will help to increase efficiency by reduced costs. (author)

  18. Entropic Sampling and Natural Selection in Biological Evolution

    OpenAIRE

    Choi, M. Y.; Lee, H. Y.; Kim, D.; Park, S H

    1996-01-01

    With a view to connecting random mutation on the molecular level to punctuated equilibrium behavior on the phenotype level, we propose a new model for biological evolution, which incorporates random mutation and natural selection. In this scheme the system evolves continuously into new configurations, yielding non-stationary behavior of the total fitness. Further, both the waiting time distribution of species and the avalanche size distribution display power-law behaviors with exponents close...

  19. Application of scanning electrochemical microscopy to biological samples

    OpenAIRE

    Lee, C.(Institute of Physics, Academia Sinica, Taipei, Taiwan); Kwak, J.; Bard, A J

    1990-01-01

    The scanning electrochemical microscope can be used in the feedback mode in two-dimensional scans over biological substrates to obtain topographic information at the micrometer level. In this mode, the effect of distance between a substrate (either conductive or insulating) and a scanning ultramicroelectrode tip on the electrolytic current flowing at the tip is recorded as a function of the tip x-y position. Scans of the upper surface of a grass leaf and the lower surface of a Ligustrum sinen...

  20. Preparation and biological studies of 68Ga-DOTA-alendronate

    OpenAIRE

    Ashraf Fakhari; Amir Jalilian; Fariba Johari-daha; Mehdi Shafiee-Ardestani; Ali Khalaj

    2016-01-01

    Objective(s): In line with previous research on the development of conjugated bisphosphonate ligands as new bone-avid agents, in this study, DOTA conjugated alendronate (DOTA-ALN) was synthesized and evaluated after labeling with gallium-68 (68Ga).Methods: DOTA-ALN was synthesized and characterized, followed by 68Ga-DOTA-ALN preparation, using DOTA-ALN and 68GaCl3 (pH: 4-5) at 92-95°C for 10 min. Stability tests, hydroxyapatite assay, partition coefficient calculation,biodistribution studies,...

  1. [Biological properties of L-asparaginase preparations from E. coli in cell cultures].

    Science.gov (United States)

    Kondrat'eva, N A; Dobrynin, Ia V; Merkulov, M F

    1978-01-01

    Non-specific cytotoxicity and specific antitumor activity of 5 preparations of L-asparaginase from E. coli were studied. Two cell line, i.e. the asparagine-dependent (Berkitt lymphoma cells) and asparagin-independent (human ovary cancer cells) were used as the test-system. Incorporation of 3H-thimidine into DNA was the criterion of the preparation effect on the cells. Preparation I with the specific activity of 60-90 IU per 1 mg of protein obtained at the first stages of purification had high non-specific cytotoxicity. Preparation II obtained after further purification of preparation I, as well as preparation II without any stabilizer with the specific activity of 200 IU/mg were not inferior to the "Bayer" preparation by their biological properties. Addition of L-asparaginase to the preparation as a stabilizer of excessive glycine (preparation IV) increased its non-specific cytotoxicity and interfered with the study of its properties in the cell systems. Mannitol (preparation V) had no effect on the biological activity of L-asparaginase preparation. PMID:341799

  2. The measurement of radioactive microspheres in biological samples

    International Nuclear Information System (INIS)

    Measurements of the distribution of radioactive microspheres are used in investigations of regional coronary blood flow, but the size and shape of the heart varies for different test animals, and the organ is frequently divided into smaller pieces for studies of regional perfusion. Errors are introduced by variations in the distribution of the radioactive source and the amount of Compton scatter in different samples. A technique has therefore been developed to allow the counting of these tissue samples in their original form, and correction factors have been derived to inter-relate the various counting geometries thus encountered. Dogs were injected with microspheres labelled with 141Ce, 51Cr or 85Sr. The tissue samples did not require remodelling to fit a standard container, and allowance was made for the inhomogeneous distribution in the blood samples. The activities in the centrifuged blood samples were correlated with those from the tissue samples by a calibration procedure involving comparisons of the counts from samples of microspheres embedded in sachets of gelatine, and similar samples mixed with blood and then centrifuged. The calibration data have indicated that 51Cr behaves anomalously, and its use as a label for microspheres may introduce unwarranted errors. A plane cylindrical 10 x 20 cm NaI detector was used, and a 'worst case' correction of 20% was found to be necessary for geometry effects. The accuracy of this method of correlating different geometries was tested by remodelling the same tissue sample into different sizes and comparing the results, and the validity of the technique was supported by agreement of the final results with previously published data. (U.K.)

  3. Research on Catalytic Properties of Palladium Catalyst Prepared by Biological Reduction Method

    Institute of Scientific and Technical Information of China (English)

    Zhang Feng; Fu Jiquan

    2013-01-01

    This paper relates to highly dispersed supported Pd/MWCNTs and Pd/α-Al2O3 catalysts prepared by biological reduction method. The physico-chemical properties and the difference in catalytic activity of Pd catalysts prepared by bio-logical reduction method and chemical method, respectively, were investigated using XRD, TEM and speciifc surface char-acterization methods. The catalytic properties of catalysts were studied through activity evaluation means. The test results showed that the catalysts prepared by biological method were characteristic of small Pd nanoparticle size, good dispersion and low agglomeration, while possessing a high activity and stability in styrene hydrogenation reaction in comparison with catalysts prepared via the chemical method.

  4. Preparation and biological studies of 68Ga-DOTA-alendronate

    Directory of Open Access Journals (Sweden)

    Ashraf Fakhari

    2016-07-01

    Full Text Available Objective(s: In line with previous research on the development of conjugated bisphosphonate ligands as new bone-avid agents, in this study, DOTA conjugated alendronate (DOTA-ALN was synthesized and evaluated after labeling with gallium-68 (68Ga.Methods: DOTA-ALN was synthesized and characterized, followed by 68Ga-DOTA-ALN preparation, using DOTA-ALN and 68GaCl3 (pH: 4-5 at 92-95°C for 10 min. Stability tests, hydroxyapatite assay, partition coefficient calculation,biodistribution studies, and imaging were performed on the developed agent in normal rats.Results: The complex was prepared with high radiochemical purity (>99% as depicted by radio thin-layer chromatography; specific activity: 310-320GBq/mmol after solid phase purification and was stabilized for up to 90 min with a logP value of -2.91. Maximum ligand binding (65% was observed in the presence of 50 mg of hydroxyapatite; a major portion of the activity was excreted through the kidneys. With the exception of excretory organs, gastrointestinal tract organs, including the liver, intestine, and colon, showed significant uptake; however, the bone uptake was low (

  5. Preparation and Biological Study of 68Ga-DOTA-alendronate

    Science.gov (United States)

    Fakhari, Ashraf; Jalilian, Amir R.; Johari-Daha, Fariba; Shafiee-Ardestani, Mehdi; Khalaj, Ali

    2016-01-01

    Objective(s): In line with previous research on the development of conjugated bisphosphonate ligands as new bone-avid agents, in this study, DOTA-conjugated alendronate (DOTA-ALN) was synthesized and evaluated after labeling with gallium-68 (68Ga). Methods: DOTA-ALN was synthesized and characterized, followed by 68Ga-DOTA-ALN preparation, using DOTA-ALN and 68GaCl3 (pH: 4-5) at 92-95° C for 10 min. Stability tests, hydroxyapatite assay, partition coefficient calculation, biodistribution studies, and imaging were performed on the developed agent in normal rats. Results: The complex was prepared with high radiochemical purity (>99% as depicted by radio thin-layer chromatography; specific activity: 310-320 GBq/mmol) after solid phase purification and was stabilized for up to 90 min with a log P value of -2.91. Maximum ligand binding (65%) was observed in the presence of 50 mg of hydroxyapatite; a major portion of the activity was excreted through the kidneys. With the exception of excretory organs, gastrointestinal tract organs, including the liver, intestine, and colon, showed significant uptake; however, the bone uptake was low (<1%) at 30 min after the injection. The data were also confirmed by sequential imaging at 30-90 min following the intravenous injection. Conclusion: The high solubility and anionic properties of the complex led to major renal excretion and low hydroxyapatite uptake; therefore, the complex failed to demonstrate bone imaging behaviors. PMID:27408898

  6. 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

    of intracellular metabolites, and the losses noticed during sample concentration by lyophilization and solvent evaporation. A more reliable procedure is suggested for quenching yeast cells with cold methanol solution, followed by extraction of intracellular metabolites by pure methanol. The method can be combined...

  7. Sample Preparation (SS): SE58_SS01 [Metabolonote[Archive

    Lifescience Database Archive (English)

    Full Text Available 1 μL injection. After centrifugation, a 200 μL aliquot of the supernatant (∼0.5 mg of DW of each sample) wa... Each isotope compound was adjusted to a final concentration of 15 ng/μL for each

  8. 9 CFR 147.8 - Procedures for preparing egg yolk samples for diagnostic tests.

    Science.gov (United States)

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Procedures for preparing egg yolk samples for diagnostic tests. 147.8 Section 147.8 Animals and Animal Products ANIMAL AND PLANT HEALTH... IMPROVEMENT PLAN Blood Testing Procedures § 147.8 Procedures for preparing egg yolk samples for...

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-05-22

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

  10. Ultrastructure of Plant Leaf Cuticles in relation to Sample Preparation as Observed by Transmission Electron Microscopy

    Science.gov (United States)

    Guzmán, Paula; Fernández, Victoria; García, María Luisa; Fernández, Agustín; Gil, Luis

    2014-01-01

    The leaf cuticular ultrastructure of some plant species has been examined by transmission electron microscopy (TEM) in only few studies. Attending to the different cuticle layers and inner structure, plant cuticles have been grouped into six general morphological types. With the aim of critically examining the effect of cuticle isolation and preparation for TEM analysis on cuticular ultrastructure, adaxial leaf cuticles of blue-gum eucalypt, grey poplar, and European pear were assessed, following a membrane science approach. The embedding and staining protocols affected the ultrastructure of the cuticles analysed. The solubility parameter, surface tension, and contact angles with water of pure Spurr's and LR-White resins were within a similar range. Differences were however estimated for resin : solvent mixtures, since Spurr's resin is combined with acetone and LR-White resin is mixed with ethanol. Given the composite hydrophilic and lipophilic nature of plant cuticles, the particular TEM tissue embedding and staining procedures employed may affect sample ultrastructure and the interpretation of the results in physicochemical and biological terms. It is concluded that tissue preparation procedures may be optimised to facilitate the observation of the micro- and nanostructure of cuticular layers and components with different degrees of polarity and hydrophobicity. PMID:24895682

  11. Laboratory manual on sample preparation procedures for x-ray micro-analysis

    International Nuclear Information System (INIS)

    X-ray micro fluorescence is a non-destructive and sensitive method for studying the microscopic distribution of different elements in almost all kinds of samples. Since the beginning of this century, x-rays and electrons have been used for the analysis of many different kinds of material. Techniques which rely on electrons are mainly developed for microscopic studies, and are used in conventional Electron Microscopy (EM) or Scanning Electron Microscopy (SEM), while x-rays are widely used for chemical analysis at the microscopic level. The first chemical analysis by fluorescence spectroscopy using small x-ray beams was conducted in 1928 by Glockner and Schreiber. Since then much work has been devoted to developing different types of optical systems for focusing an x-ray beam, but the efficiency of these systems is still inferior to the conventional electron optical systems. However, even with a poor optical efficiency, the x-ray microbeam has many advantages compared with electron or proton induced x-ray emission methods. These include: The analyses are non-destructive, losses of mass are negligible, and due to the low thermal loading of x-rays, materials which may be thermally degraded can be analysed; Samples can be analysed in air, and no vacuum is required, therefore specimens with volatile components such as water in biological samples, can be imaged at normal pressure and temperature; No charging occurs during analysis and therefore coating of the sample with a conductive layer is not necessary; With these advantages, simpler sample preparation procedures including mounting and preservation can be used

  12. Elemental analysis of biological samples using deuteron induced X-rays and charged particles

    International Nuclear Information System (INIS)

    A method for elemental analysis in biological samples is presented. Samples were exposed to 4 MeV deuterons and both charged particle and X-ray spectra were recorded. The method was tested on a biopsi of mouseliver and a blood-serum-sample and was found promising for rapid analysis of samples associated with small amounts of material (μg). (Auth.)

  13. Identification of cadmium in biological samples using neutron activation analysis with radiochemistry separations

    International Nuclear Information System (INIS)

    Chile's 7500 km coastline of the Southern Pacific ocean, with about 4500 km of continental coastline that contains a variety of different geographical zones. This variety means that there is a great diversity of marine resources such as fish, shellfish and seaweeds. The utilization of these resources has been increasing in recent years making this sector an economically important one. The catch as of May 2002 came to 1.9 million tons and exports of the different species amounted to US$611.5 million as of April. But this important economic resource is being threatened by the technical demands imposed by importing countries, mainly the specific requirements for sanitary certification for fishery export products, depending on the markets of destination. The chemical element cadmium is one of the most strictly controlled elements due some shellfish accumulate a large amount of this element and to its high toxicity. The Chilean standard's analytical procedures for cadmium determination in hydro biological products, which must be met by laboratories that certify and control these products for export, are now being evaluated. Through its Chemical Metrology Unit, the Chilean Nuclear Energy Commission is strongly supporting this sector by preparing the secondary reference or control materials, and it has developed and implemented nuclear analytical methods for the certification of these materials, which will be used mostly in collaborative studies. This work describes the methodology developed for the determination of cadmium in biological samples, particularly in shellfish and fish (author)

  14. Application of scanning electrochemical microscopy to biological samples.

    Science.gov (United States)

    Lee, C; Kwak, J; Bard, A J

    1990-03-01

    The scanning electrochemical microscope can be used in the feedback mode in two-dimensional scans over biological substrates to obtain topographic information at the micrometer level. In this mode, the effect of distance between a substrate (either conductive or insulating) and a scanning ultramicroelectrode tip on the electrolytic current flowing at the tip is recorded as a function of the tip x-y position. Scans of the upper surface of a grass leaf and the lower surface of a Ligustrum sinensis leaf (which show open stomata structures) immersed in aqueous solution are shown. Scans of the upper surface of an elodea leaf in the dark and under irradiation, where the tip reaction is the reduction of oxygen produced by photosynthesis, demonstrate the possibility of obtaining information about the distribution of reaction sites on the substrate surface. PMID:2308933

  15. The use contrast agent for imaging biological samples

    Czech Academy of Sciences Publication Activity Database

    Dammer, J.; Weyda, František; Sopko, V.; Jakůbek, J.

    2011-01-01

    Roč. 6, C01096 (2011), s. 1-7. ISSN 1748-0221. [International Workshop on Radiation Imaging Detectors /12./. Cambridge, 11.07.2010-15.7.2010] R&D Projects: GA MŠk 2B06005 Grant ostatní: Research Program(CZ) 6840770029; Research Program(CZ) 6840770040; GA AV ČR(CZ) IAA600550614; GA MŠk(CZ) 2B06007; GA MŠk(CZ) 1PO4LA211; GA MŠk(CZ) LC06041 Institutional research plan: CEZ:AV0Z50070508 Keywords : x-ray radiography and digital radiography (DR) * x-ray detectors * inspections with x-rays Subject RIV: EA - Cell Biology Impact factor: 1.869, year: 2011

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

    Science.gov (United States)

    Zheng, Naiyu; Jiang, Hao; Zeng, Jianing

    2014-09-01

    Robotic liquid handlers (RLHs) have been widely used in automated sample preparation for liquid chromatography-tandem mass spectrometry (LC-MS/MS) bioanalysis. Automated sample preparation for regulated bioanalysis offers significantly higher assay efficiency, better data quality and potential bioanalytical cost-savings. For RLHs that are used for regulated bioanalysis, there are additional requirements, including 21 CFR Part 11 compliance, software validation, system qualification, calibration verification and proper maintenance. This article reviews recent advances in automated sample preparation for regulated bioanalysis in the last 5 years. Specifically, it covers the following aspects: regulated bioanalysis requirements, recent advances in automation hardware and software development, sample extraction workflow simplification, strategies towards fully automated sample extraction, and best practices in automated sample preparation for regulated bioanalysis. PMID:25384595

  17. Alpha spectrometry sample preparation using selectively adsorbing thin films

    International Nuclear Information System (INIS)

    Several years ago, Switzerland introduced limits for natural radionuclides in food, e.g. 1 Bq/l for 226Ra or 10 Bq/l for the sum of 238U and 234U in drinking water. To make enforcement by regional (cantonal) laboratories more attractive, simplified analytical methods had to be offered, at least for drinking water. A first step has been the development of radium adsorbing sheets. A 20 mm x 20 mm MnO2 film on a polyamide substrate adsorbs more than 80% of the radium present in a 100 ml water sample within 6 h. The film is thin enough to allow for high resolution alpha spectrometry. A second step now under way is to produce thin films, which selectively adsorb uranium. Actually, an ion exchange resin with diphosphonic and sulfonic acid groups is used for this purpose. Although not yet very thin, these films make possible energy resolutions far better than with any liquid scintillation alpha spectrometry method. Adsorption efficiencies are more than 80% after 20 h exposition to a 100 ml water sample (20 mm x 20 mm sheet). A third step is to have a system that measures radionuclide concentrations in water on-line. A prototype is presented where radionuclides are adsorbed on a film in contact with the water. A Si-detector placed on the other side of the film support counts the alphas passing through

  18. Critical tests for determination of microbiological quality and biological activity in commercial vermicompost samples of different origins.

    Science.gov (United States)

    Grantina-Ievina, Lelde; Andersone, Una; Berkolde-Pīre, Dace; Nikolajeva, Vizma; Ievinsh, Gederts

    2013-12-01

    The aim of the present paper was to show that differences in biological activity among commercially produced vermicompost samples can be found by using a relatively simple test system consisting of microorganism tests on six microbiological media and soilless seedling growth tests with four vegetable crop species. Significant differences in biological properties among analyzed samples were evident both at the level of microbial load as well as plant growth-affecting activity. These differences were mostly manufacturer- and feedstock-associated, but also resulted from storage conditions of vermicompost samples. A mature vermicompost sample that was produced from sewage sludge still contained considerable number of Escherichia coli. Samples from all producers contained several potentially pathogenic fungal species such as Aspergillus fumigatus, Pseudallescheria boidii, Pseudallescheria fimeti, Pseudallescheria minutispora, Scedosporium apiospermum, Scedosporium prolificans, Scopulariopsis brevicaulis, Stachybotrys chartarum, Geotrichum spp., Aphanoascus terreus, and Doratomyces columnaris. In addition, samples from all producers contained plant growth-promoting fungi from the genera Trichoderma and Mortierella. The described system can be useful both for functional studies aiming at understanding of factors affecting quality characteristics of vermicompost preparations and for routine testing of microbiological quality and biological activity of organic waste-derived composts and vermicomposts. PMID:23504062

  19. 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

    Avian influenza virus (AIV) is an infectious agent of birds and mammals. AIV is causing huge economic loss and can be a threat to human health. Reverse transcriptase polymerase chain reaction (RT-PCR) has been used as a method for the detection and identification of AIV virus. Although RT-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...

  20. Adaptive optics for deeper imaging of biological samples.

    Science.gov (United States)

    Girkin, John M; Poland, Simon; Wright, Amanda J

    2009-02-01

    Optical microscopy has been a cornerstone of life science investigations since its first practical application around 400 years ago with the goal being subcellular resolution, three-dimensional images, at depth, in living samples. Nonlinear microscopy brought this dream a step closer, but as one images more deeply the material through which you image can greatly distort the view. By using optical devices, originally developed for astronomy, whose optical properties can be changed in real time, active compensation for sample-induced aberrations is possible. Submicron resolution images are now routinely recorded from depths over 1mm into tissue. Such active optical elements can also be used to keep conventional microscopes, both confocal and widefield, in optimal alignment. PMID:19272766

  1. Soft Robotic Grippers for Biological Sampling on Deep Reefs

    Science.gov (United States)

    Galloway, Kevin C.; Becker, Kaitlyn P.; Phillips, Brennan; Kirby, Jordan; Licht, Stephen; Tchernov, Dan; Gruber, David F.

    2016-01-01

    Abstract This article presents the development of an underwater gripper that utilizes soft robotics technology to delicately manipulate and sample fragile species on the deep reef. Existing solutions for deep sea robotic manipulation have historically been driven by the oil industry, resulting in destructive interactions with undersea life. Soft material robotics relies on compliant materials that are inherently impedance matched to natural environments and to soft or fragile organisms. We demonstrate design principles for soft robot end effectors, bench-top characterization of their grasping performance, and conclude by describing in situ testing at mesophotic depths. The result is the first use of soft robotics in the deep sea for the nondestructive sampling of benthic fauna.

  2. Specific methods for theophylline assay in biological samples

    International Nuclear Information System (INIS)

    The objective of monitoring theophylline plasma levels in in therapeutic work is well established, and the consequences of using unspecific analytical methods are obvious. For the determination of pharmacokinetic parameters, concentrations far below the therapeutic range must often be measured. Interferences acceptable in therapeutic monitoring of theophylline could cause severe inaccuracy at these drug levels. The term specificity and its meaning are discussed in general and in relation to the different steps of the analytical procedure (e.g., sampling and sample work-up). Different analytical methods for theophylline are discussed in terms of specificity. Plasma concentrations of paraxanthine (1,7-dimethylxanthine) - a metabolite of caffeine - as high as 3 μg/ml have been observed, and the compound can interfere in various theophylline assay methods. An example is given of the pharmacokinetic consequences. (author)

  3. The models of experimental magnetic measurements of various biological samples

    International Nuclear Information System (INIS)

    Complete text of publication follows. At the Geomagnetic Institute, in the Laboratory for paleomagnetism and archeomagnetism research and at the Geomagnetic Observatory, Grocka (GCK) during the period from November 2004 to February 2008 the researchers carried out experimental magnetic measurements of the total-intensity gradient of the magnetic field vector (changes in the total magnetisation vector) of various biomaterials. Measurements of the gradient total intensity of the magnetic field vector were carried out by GSM-19 magnetometers of high accuracy and recording resolution (accuracy: ΔF=0.1 nT; sampling rate: 1-5 per second). During these experimental biomagnetic measurements samples of water, tissue, blood, cotton, wool, pitch and magnetite-powder were used. In this study, the part of the biomagnetic measurement results relate to the water, blood and tissue. The results of the measurements of gradient total-intensity of the magnetic field for the biomaterial samples showed physical processes which are connected with the diamagnetic and paramagnetic properties of such biomaterials.

  4. Transuranium analysis methodologies for biological and environmental samples

    International Nuclear Information System (INIS)

    Analytical procedures for the most abundant transuranium nuclides in the environment (i.e., plutonium and, to a lesser extent, americium) are available. There is a lack of procedures for doing sequential analysis for Np, Pu, Am, and Cm in environmental samples, primarily because of current emphasis on Pu and Am. Reprocessing requirements and waste disposal connected with the fuel cycle indicate that neptunium and curium must be considered in environmental radioactive assessments. Therefore it was necessary to develop procedures that determine all four of these radionuclides in the environment. The state of the art of transuranium analysis methodology as applied to environmental samples is discussed relative to different sample sources, such as soil, vegetation, air, water, and animals. Isotope-dilution analysis with 243Am (239Np) and 236Pu or 242Pu radionuclide tracers is used. Americium and curium are analyzed as a group, with 243Am as the tracer. Sequential extraction procedures employing bis(2-ethyl-hexyl)orthophosphoric acid (HDEHP) were found to result in lower yields and higher Am--Cm fractionation than ion-exchange methods

  5. Determination of Alkali Ions in Biological and Environmental Samples.

    Science.gov (United States)

    Hauser, Peter C

    2016-01-01

    An overview of the common methods for the determination of the alkali metals is given. These are drawn from all of the three principle branches of quantitative analysis and consist mainly of optical atomic spectrometric methods, ion-selective electrodes, and the separation methods of ion-chromatography and capillary electrophoresis. Their main characteristics and performance parameters are discussed. Important specific applications are also examined, namely clinical analysis, single cell analysis, the analysis of soil samples and hydroponic nutrient solutions, as well as the detection of the radioactive (137)Cs isotope. PMID:26860298

  6. Sample preparation by focused ion beam micromachining for transmission electron microscopy imaging in front-view.

    Science.gov (United States)

    Jublot, Michael; Texier, Michael

    2014-01-01

    This article deals with the development of an original sample preparation method for transmission electron microscopy (TEM) using focused ion beam (FIB) micromachining. The described method rests on the use of a removable protective shield to prevent the damaging of the sample surface during the FIB lamellae micromachining. It enables the production of thin TEM specimens that are suitable for plan view TEM imaging and analysis of the sample surface, without the deposition of a capping layer. This method is applied to an indented silicon carbide sample for which TEM analyses are presented to illustrate the potentiality of this sample preparation method. PMID:24200984

  7. The study of trace element distribution in biological samples with NAA for human health

    International Nuclear Information System (INIS)

    A one day representative mixed diet of an adult Korean was collected from the data based on the food intake of 108 healthy subjects between the ages 20 and 50. Sampling for the Korean total diet was carried out by the way of using a market basket study based on the Korean standard food consumption scheme reported by the Korean Nutrition Society. Average consumption frequency of different food items for a one day representative mixed diet of an adult Korean and the amount of each item to prepare a one day Korean representative total diet are surveyed. The analytical methods involve both instrumental and radiochemical neutron activation techniques developed for the determination of the elements Cs, I, Sr, Th and U in various kinds of food samples. Concentrations of trace elements including 5 important elements for radiological protection, U, Th, Cs, Sr and I in the Korean total diet and the 4 most frequently consumed Korean foodstuffs have been analyzed by neutron activation analysis. Detection limits for U, Th, Sr and I were improved to ppb levels by radiochemical separation after neutron irradiation. Five biological NIST reference materials were also analyzed for quality control of the analysis. Seventeen trace elements in the Korean total diet and four Korean representative foodstuffs were also analyzed quantitatively by instrumental neutron activation analysis. The elemental distributions in supplemental healthy food and Korean and Chinese origin oriental medicine were also identified. The amount of trace elements ingested with the hair analysis of oriental medicine takers were estimated. The amounts of trace elements inhaled with the analysis of foundry air, blood and hair of foundry workers were also estimated. The basic estimation method in view of health and environment with the neutron activation analysis of biological samples such as foods and hair was established with the result. Nationwide usage system of the NAA facility in Hanaro in many different and

  8. Potential artifacts associated with historical preparation of joint compound samples and reported airborne asbestos concentrations.

    Science.gov (United States)

    Brorby, G P; Sheehan, P J; Berman, D W; Bogen, K T; Holm, S E

    2011-05-01

    Airborne samples collected in the 1970s for drywall workers using asbestos-containing joint compounds were likely prepared and analyzed according to National Institute of Occupational Safety and Health Method P&CAM 239, the historical precursor to current Method 7400. Experimentation with a re-created, chrysotile-containing, carbonate-based joint compound suggested that analysis following sample preparation by the historical vs. current method produces different fiber counts, likely because of an interaction between the different clearing and mounting chemicals used and the carbonate-based joint compound matrix. Differences were also observed during analysis using Method 7402, depending on whether acetic acid/dimethylformamide or acetone was used during preparation to collapse the filter. Specifically, air samples of sanded chrysotile-containing joint compound prepared by the historical method yielded fiber counts significantly greater (average of 1.7-fold, 95% confidence interval: 1.5- to 2.0-fold) than those obtained by the current method. In addition, air samples prepared by Method 7402 using acetic acid/dimethylformamide yielded fiber counts that were greater (2.8-fold, 95% confidence interval: 2.5- to 3.2-fold) than those prepared by this method using acetone. These results indicated (1) there is an interaction between Method P&CAM 239 preparation chemicals and the carbonate-based joint compound matrix that reveals fibers that were previously bound in the matrix, and (2) the same appeared to be true for Method 7402 preparation chemicals acetic acid/dimethylformamide. This difference in fiber counts is the opposite of what has been reported historically for samples of relatively pure chrysotile dusts prepared using the same chemicals. This preparation artifact should be considered when interpreting historical air samples for drywall workers prepared by Method P&CAM 239. PMID:21462068

  9. Method for sample preparation for cryoelectron microscopy (CEM) microreactor and loading platform

    NARCIS (Netherlands)

    Zandbergen, H.W.; Ahn, C.W.

    2008-01-01

    A method for sample preparation for cryoelectron microscopy (CEM), wherein the sample is held in a microreactor, wherein the conditions in the microreactor are regulated relative to the environment, wherein the sample in the microreactor is frozen according to a quench freeze process, whereupon the

  10. Open focused microwave-assisted sample preparation for rapid total and mercury species determination in environmental solid samples

    OpenAIRE

    Tseng, C M; Garraud, H.; D. Amouroux; Donard, O. F. X.; Diego, A

    1998-01-01

    This paper describes rapid, simple microwave-assisted leaching/ digestion procedures for total and mercury species determination in sediment samples and biomaterials. An open focused microwave system allowed the sample preparation time to be dramatically reduced to only 24 min when a power of 40-80 W was applied. Quantitative leaching of methylmercury from sediments by HNO3 solution and complete dissolution of biomaterials by an alkaline solution, such as 25% TMAH solution, were obtained. Met...

  11. 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.

  12. Study on the determination of palladium in biological samples by the method of neutron activation analysis

    International Nuclear Information System (INIS)

    Palladium is one of platinum group elements present in the nature at very low concentrations. However with the use of this element in the automobile catalyzers Pd became a new pollutant. Besides, Pd has been studied in the preparation of new antitumour drugs. Consequently, there is a need to determine Pd concentrations in biological and environmental samples. This study presents palladium results obtained in the analysis of biological samples and reference materials using instrumental thermal and epithermal neutron activation analysis (INAA and ENAA). The solvent extraction and solid phase extraction separation methods were also applied before ENAA. The samples analyzed in this study were, reference material BCR 723 - Palladium, Platinum and Rhodium in road dust, CCQM-P63 automotive catalyst material of the Proficiency Test and bovine tissue samples containing palladium prepared in the laboratory. Samples and palladium synthetic standard were irradiated at the IEA-R1 nuclear research reactor under thermal neutron flux of about 4 x 10 12 n cm-2 s-1, during a period of 4 and 16 h for INAA and ENAA, respectively. The induced gamma activity of 109Pd to the sample and standard was measured using a hyper pure Ge detector coupled to a gamma ray spectrometer. The palladium concentration was calculated by comparative method. The gamma ray energy of 109Pd radioisotope measured was of 88.0 keV, located in a spectrum region of low energy where occurs the interference of X rays, 'Bremsstrahlung' radiations, as well as Compton effect of 24Na. The pre-separation of palladium from interfering elements by solvent extraction was performed using dimethylglyoxime complexant and chloroform as diluent. In the case of the pre separation procedure using solid reversed phase column, the palladium was retained using N,N-diethyl-N'-benzoyl thiourea complexant and eluted using ethanol. Aliquots of the resulting solutions from the pre-separations, free of interfering elements, were transferred

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

    Directory of Open Access Journals (Sweden)

    A Poorbafrani

    2008-07-01

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

  14. Cadmium determination in biological samples using neutron activation analysis with radiochemical separations

    International Nuclear Information System (INIS)

    Chile has 7500 km of coastline on the Southern Pacific ocean,with about 4500 km of continental coastline that contains a variety of different geographical zones.This variety means that there is a great diversity of marine resources such as fish, shellfish and seaweeds. The utilization of these resources has been increasing in recent years making this sector an economically important one. The catch as of May 2002 came to 1.9 million tons and exports of the different species amounted to US$611.5 million as of April.But this important economic resource is being threatened by the technical demands imposed by importing countries, mainly the specific requirements for sanitary certification for fishery export products, depending on the markets of destination. The chemical element cadmium is one of the most strictly controlled elements due some shellfish accumulate a large amount of this element and to its high toxicity. The Chilean standard's analytical procedures for cadmium determination in hydro biological products, which must be met by laboratories that certify and control these products for export, are now being evaluated. Through its Chemical Metrology Unit, the Chilean Nuclear Energy Commission is strongly supporting this sector by preparing the secondary reference or control materials, and it has developed and implemented nuclear analytical methods for the certification of these materials, which will be used mostly in collaborative studies. This work describes the methodology developed for the determination of cadmium in biological samples, particularly in shellfish and fish. The method is based on neutron activation analysis with radiochemical separations, using the radioisotopes 115Cd and 115mIn, generated in the samples by bombarding with neutrons in a nuclear reactor. The samples were digested at 110oC with H2SO4 and H2O2 and then the radioactive cadmium element was separated from the other elements present in the samples using a Bio Rad AG 2-X8 resin

  15. Diagnostic PCR: validation and sample preparation are two sides of the same coin

    DEFF Research Database (Denmark)

    Hoorfar, Jeffrey; Wolffs, Petra; Radstrøm, Peter

    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....

  16. Effects of preparation methods of biomedical samples on PIXE measurement sensitivity

    International Nuclear Information System (INIS)

    Instrumental sample preparation techniques for PIXE measurements of human blood serum and bovine muscle were investigated. The techniques studied were direct measurement of a drop, drying on a foil and on an Al cup, lyophilization on a foil, pellet pressing of dried material, microtome sectioning and biopsy preparation. The same serum and muscle were used in each procedure allowing the comparison of detection limits between different methods. The most beneficial technique for both samples was lyophilization and pellet pressing. (author)

  17. Detection of heavy metals in biological samples through anodic stripping voltammetry

    OpenAIRE

    Buzea, Vlad; Florescu, Monica; Badea, Mihaela

    2012-01-01

    The toxicological aspects due to the presence of heavy metals in biological samples impose to have accurate and rapid methods for their detection. This paper is aimed to review approaches to anodic stripping voltammetry (ASV) determination of several heavy metals (lead, cadmium, copper, mercury, zinc) in biological matrices (blood, urine, saliva, tissue sample). Analytical performances (LOD, data linearity range, sensitivity) of the reviewed methods were presented for several electrochemical ...

  18. Preparing Biology Teachers to Teach Evolution in a Project-Based Approach

    Science.gov (United States)

    Cook, Kristin; Buck, Gayle; Park Rogers, Meredith

    2012-01-01

    This study investigates a project-based learning (PBL) approach to teaching evolution to inform efforts in teacher preparation. Data analysis of a secondary biology educator teaching evolution through a PBL approach illuminated: (1) active student voice, which allowed students to reflect on their positioning on evolution and consider multiple…

  19. Method for sample preparation for cryoelectron microscopy (CEM) microreactor and loading platform

    OpenAIRE

    H.W. Zandbergen; Ahn, C. W.

    2008-01-01

    A method for sample preparation for cryoelectron microscopy (CEM), wherein the sample is held in a microreactor, wherein the conditions in the microreactor are regulated relative to the environment, wherein the sample in the microreactor is frozen according to a quench freeze process, whereupon the sample, in frozen condition, is placed in the electron microscope. A microreactor for use with cryoelectron microscopy (CEM), comprising a first and second membrane, which membranes, at least in a ...

  20. The study on human health and environment by neutron activation analysis of biological samples

    International Nuclear Information System (INIS)

    - Choice of samples for the research goal and survey of individual food habit and sampling for the meaningful statistical output - Development of the optimum analytical method for the analysis of trace elements in biological samples such as hair, blood, and foods. - Quantitative analysis of several samples to identify the source of trace elements into human body. - Evaluation in view of health and environment to the trace elements in various sources which can be introduced inside human body

  1. Preparation and validation of gross alpha/beta samples used in EML's quality assessment program

    International Nuclear Information System (INIS)

    A set of water and filter samples have been incorporated into the existing Environmental Measurements Laboratory's (EML) Quality Assessment Program (QAP) for gross alpha/beta determinations by participating DOE laboratories. The participating laboratories are evaluated by comparing their results with the EML value. The preferred EML method for measuring water and filter samples, described in this report, uses gas flow proportional counters with 2 in. detectors. Procedures for sample preparation, quality control and instrument calibration are presented. Liquid scintillation (LS) counting is an alternative technique that is suitable for quantifying both the alpha (241Am, 230Th and 238Pu) and beta (90Sr/90Y) activity concentrations in the solutions used to prepare the QAP water and air filter samples. Three LS counting techniques (Cerenkov, dual dpm and full spectrum analysis) are compared. These techniques may be used to validate the activity concentrations of each component in the alpha/beta solution before the QAP samples are actually prepared

  2. Fused glass sample preparation for quantitative laser-induced breakdown spectroscopy of geologic materials

    International Nuclear Information System (INIS)

    Laser-induced breakdown spectroscopy is a powerful analytical method, but LIBS is subject to a matrix effect which can limit its ability to produce quantitative results in complex materials such as geologic samples. Various methods of sample preparation, calibration, and data processing have been attempted to compensate for the matrix effect and improve LIBS precision. This study focuses on sample preparation by comparing fused glass as a preparation for powdered material to the more commonly used method of pressing powder into pellets for LIBS analysis of major elements in complex geologic materials. Pelletizing powdered material is a common and convenient method for preparing samples but problems with the physical matrix brought on by inconsistencies in the homogeneity, density, and laser absorption, coupled with the chemical matrix problem lead to spectral peak responses that are not always consistent with the absolute concentration of representative elements. Twenty-two mineral and rock samples were analyzed for eight major oxide elements. Samples were prepared under both glass and pellet methods and compared for internal precision and overall accuracy. Fused glass provided a more consistent physical matrix and yielded more reliable peak responses in the LIBS analysis than did the pressed pellet preparation. Statistical comparisons demonstrated that the glass samples expressed stronger separability between different mineral species based on the eight elements than for the pressed pellets and showed better spot-to-spot repeatability. Regression models showed substantially better correlations and predictive ability among the elements for the glass preparation than did those for the pressed pellets. - Highlights: • Glass improves analytical results in LIBS analysis compared to pressed pellets. • Glass yields higher precision and better calibration models than do pressed pellets. • Low concentrations and trace elements remained detectable in fused glass

  3. Sample validity in biological trace element and organic nutrient research studies

    International Nuclear Information System (INIS)

    The state of the art of the biological trace element investigations is overviewed. Questions of biological validity, such as the influence of the 'status of sampling' of human subjects on the concentrations of selected elements are studied. Analytical validity problems, e.g. stability of Cd, Hg and Pb concentration in selected specimens, stability of selected organic nutrients in NBS SRMs, etc. are also discussed. Finally, it is concluded that the development of new biological reference materials should take into account the multidisciplinary demands of biological trace element investigations. (author) 20 refs.; 6 tables

  4. Contribution to the sample preparation in the radionuclide X-ray fluorescence analysis of hair

    International Nuclear Information System (INIS)

    Methods of sample treatment in XRF analysis of hair are studied in view of the effect on analytical results. A new method is proposed based on the incomplete ashing of hair followed by pellet preparation. Its suitability is estimated on the XRF analysis of real hair samples collected from 4 healthy adults. (author) 12 refs.; 4 figs.; 1 tab

  5. A new method for preparing thin samples of pottery shards for PIXE analysis

    International Nuclear Information System (INIS)

    A novel method, based on the centrifugal precipitation technique, has been used for preparing thin (1 mg/cm2) uniform and homogeneous samples of pottery shards for PIXE analysis. The reproducibility of the results has been tested on standard Perlman-Asaro samples and ancient Greek pottery shards. The abundances of more than 12 elements can be reliably measured. (orig.)

  6. Before the injection--modern methods of sample preparation for separation techniques.

    Science.gov (United States)

    Smith, Roger M

    2003-06-01

    The importance of sample preparation methods as the first stage in an analytical procedure is emphasised and examined. Examples are given of the extraction and concentration of analytes from solid, liquid and gas phase matrices, including solvent phase extractions, such as supercritical fluids and superheated water extraction, solid-phase extraction and solid-phase microextraction, headspace analysis and vapour trapping. The potential role of selective extraction methods, including molecular imprinted phases and affinity columns, are considered. For problem samples alternative approaches, such as derivatisation are discussed, and potential new approaches minimising sample preparation are noted. PMID:12877164

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

    Science.gov (United States)

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

    2016-08-01

    This work demonstrates a method to prepare homogeneous distributions of analytes to improve data reproducibility in matrix-assisted laser desorption/ionization (MALDI) mass spectrometry (MS). Natural-air drying processes normally result in unwanted heterogeneous spatial distributions of analytes in MALDI crystals and make quantitative analysis difficult. This study demonstrates that inducing Marangoni flows within drying droplets can significantly reduce the heterogeneity problem. The Marangoni flows are accelerated by changing substrate temperatures to create temperature gradients across droplets. Such hydrodynamic flows are analyzed semi-empirically. Using imaging mass spectrometry, changes of heterogeneity of molecules with the change of substrate temperature during drying processes are demonstrated. The observed heterogeneities of the biomolecules reduce as predicted Marangoni velocities increase. In comparison to conventional methods, drying droplets on a 5 °C substrate while keeping the surroundings at ambient conditions typically reduces the heterogeneity of biomolecular ions by 65%-80%. The observation suggests that decreasing substrate temperature during droplet drying processes is a simple and effective means to reduce analyte heterogeneity for quantitative applications. Graphical Abstract ᅟ. PMID:27126469

  8. Application of radiochemical methods for development of new biological preparation designed for soil bioremediation

    International Nuclear Information System (INIS)

    Full text: Internationally the bioremediation of agricultural lands contaminated by persistent chloroorganic compounds by means of the microbial methods are used as the most low-cost and the most effective. One of the factors reducing efficacy of microbial degradation, is often the low quantity of microorganisms - destructors in the soil. Therefore, we have designed bioremediation technology of soils, contaminated by organochlorine compounds, with use of the alive microorganisms as active agent. We developed the biological preparation containing 5 aboriginal active strains of bacteria - destructors of persistent chloroorganic compounds and investigated the ability of biological preparation to increase the bioremediation potential of contaminated soils. To carry out the investigation we developed the complex of radiochemical methods with use of tritium labeled PCBs, including the following methods: 1.The method to define the accumulation and degradation of PCBs in soil bacteria in culture allows determination of quantitative characteristics of bacterial strains. 2. The method to define the PCBs degradation by soil bacteria strains in model conditions in the soil allows to estimate the PCB-destructive activity of strains after introducing in soil. 3. A method to define the PCB-destructive activity of own microbiota of contaminated soil. 4. A method to define the effect of stimulation of the PCB-destructive activity of biological preparation and own microbiota of soil with the help of biofertilizers. By using the developed radiochemical methods we have carried out investigation on creation of new biological preparation on the basis of strains of soil bacteria - destructors of PCBs. We also determined the quality and quantity characteristics of HCCH and PCBs-destructive activity of new biological preparation. It is shown that the new biological preparation is capable of accumulation and destruction of the PCBs in culture and in soil at model conditions. Thus, the

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

    International Nuclear Information System (INIS)

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

  10. Preparation of rock samples for measurement of the thermal neutron macroscopic absorption cross-section

    International Nuclear Information System (INIS)

    Preparation of rock samples for the measurement of the thermal neutron macroscopic absorption cross-section in small cylindrical two-region systems by a pulsed technique is presented. Requirements which should be fulfilled during the preparation of the samples due to physical assumptions of the method are given. A cylindrical vessel is filled with crushed rock and saturated with a medium strongly absorbing thermal neutrons. Water solutions of boric acid of well-known macroscopic absorption cross-section are used. Mass contributions of the components in the sample are specified. This is necessary for the calculation of the thermal neutron macroscopic absorption cross-section of the rock matrix. The conditions necessary for assuring the required accuracy of the measurement are given and the detailed procedure of preparation of the rock sample is described. (author)

  11. Determination of uranium in seawater, biological samples and sediments using laser induced fluorescence spectrometry

    International Nuclear Information System (INIS)

    Uranium has been determined in seawater, biological samples and sediments using laser induced fluorescence spectrometry (LIFS). The biological samples and sediments are digested with a mixture of HNO3, HClO4 and HF. The conductivity of the seawater should be below 5.0 mS and the pH of the sample should be in the range 6.5-9.0. The volume of the reagent used to enhance the fluorescence intensity was 0.5 ml. Comparison with other methods was favorable, LIFS being rapid, simple and sensitive, and well suited to environmental monitoring. (author)

  12. Determination of trace elements in biological samples by inductively coupled plasma mass spectrometry with tetramethylammonium hydroxide solubilization at room temperature.

    Science.gov (United States)

    Batista, Bruno Lemos; Grotto, Denise; Rodrigues, Jairo Lisboa; Souza, Vanessa Cristina de Oliveira; Barbosa, Fernando

    2009-07-30

    A simple method for sample preparation of biological samples for trace elements determination by inductively coupled plasma mass spectrometry (ICP-MS) is described. Prior to analysis, 75 mg of the biological samples were accurately weighed into (15 mL) conical tubes. Then, 1 mL of 50% (v/v) tetramethylammonium hydroxide (TMAH) solution was added to the samples, incubated at room temperature for 12 h and the volume made up to 10 mL with a solution containing 0.5% (v/v) HNO(3), 0.01% (v/v) Triton X-100 and 10 microg L(-1) of Rh. After preparation samples may be stored at -20 degrees C during 3 days until the analysis by ICP-MS. With these conditions, the use of the dynamic reaction cell was only mandatory for chromium determination. Method detection limits were 0.2145, 0.0020, 0.0051, 0.0017, 0.0027, 0.0189, 0.02, 0.5, 0.1, 0.0030, 0.0043, 0.0066, 0.0009, 0.020, 0.0043, 0.1794, 0.1 microg(-1) for Al, As, Ba, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Pb, Sb, Se, Sr, V and Zn, respectively. Validation data are provided based on the analysis of six certified reference materials (CRMs) purchased from the National Institute of Standards and Technology (NIST) and National Research Council Canada (NRCC). Additional validation was provided by the analysis of brain, kidney, liver and heart samples collected from rats and analyzed by the proposed method and by using microwave digestion. PMID:19523552

  13. Plan view TEM sample preparation using the focused ion beam lift-out technique

    International Nuclear Information System (INIS)

    Localized plan view TEM samples have been prepared from silicon semiconductor wafers using the focused ion beam lift-out technique. Two different methods of sample preparation before FIB machining were found to be successful: mounting cleaved samples sandwiched together or adding silver paint and cleaving through paint and samples. The plan view technique offers site specific TEM capability from a horizontal section rather than a vertical cross section. The sections can be taken from any layer and can be angled if desired. Results have been obtained from metal layers in a semiconductor device structure. TEM micrographs of tungsten plug arrays show non-uniform barrier layer coverage and tungsten grain size across the via. Hundreds of plugs have been cut through in one sample, thereby offering statistical as well as specific structural information. Metal and polysilicon lines have been examined for grain size and uniformity in a single micrograph. Plan view samples from continuous metal layers can also be made

  14. Collection and preparation of bottom sediment samples for analysis of radionuclides and trace elements

    International Nuclear Information System (INIS)

    The publication is the first in a series of TECDOCs on sampling and sample handling as part of the IAEA support to improve reliability of nuclear analytical techniques (NATs) in Member State laboratories. The purpose of the document is to provide information on the methods for collecting sediments, the equipment used, and the sample preparation techniques for radionuclide and elemental analysis. The most appropriate procedures for defining the strategies and criteria for selecting sampling locations, for sample storage and transportation are also given. Elements of QA/QC and documentation needs for sampling and sediment analysis are discussed. Collection and preparation of stream and river bottom sediments, lake bottom sediments, estuary bottom sediments, and marine (shallow) bottom sediments are covered. The document is intended to be a comprehensive manual for the collection and preparation of bottom sediments as a prerequisite to obtain representative and meaningful results using NATs. Quality assurance and quality control (QA/QC) is emphasized as an important aspect to ensure proper collection, transportation, preservation, and analysis since it forms the basis for interpretation and legislation. Although there are many approaches and methods available for sediment analyses, the scope of the report is limited to sample preparation for (1) analysis of radionuclides (including sediment dating using radionuclides such as Pb-210 and Cs-137) and (2) analysis of trace, minor and major elements using nuclear and related analytical techniques such as NAA, XRF and PIXE

  15. Improved Butanol-Methanol (BUME) Method by Replacing Acetic Acid for Lipid Extraction of Biological Samples.

    Science.gov (United States)

    Cruz, Mutya; Wang, Miao; Frisch-Daiello, Jessica; Han, Xianlin

    2016-07-01

    Extraction of lipids from biological samples is a critical step in lipidomics, especially for shotgun lipidomics where lipid extracts are directly infused into a mass spectrometer. The butanol-methanol (BUME) extraction method was originally developed to extract lipids from plasma samples with 1 % acetic acid. Considering some lipids are sensitive to acidic environments, we modified this protocol by replacing acetic acid with lithium chloride solution and extended the modified extraction to tissue samples. Although no significant reduction of plasmalogen levels in the acidic BUME extracts of rat heart samples was found, the modified method was established to extract various tissue samples, including rat liver, heart, and plasma. Essentially identical profiles of the majority of lipid classes were obtained from the extracts of the modified BUME and traditional Bligh-Dyer methods. However, it was found that neither the original, nor the modified BUME method was suitable for 4-hydroxyalkenal species measurement in biological samples. PMID:27245345

  16. Membrane materials for storing biological samples intended for comparative nanotoxicological testing

    Science.gov (United States)

    Metelkin, A.; Kuznetsov, D.; Kolesnikov, E.; Chuprunov, K.; Kondakov, S.; Osipov, A.; Samsonova, J.

    2015-11-01

    The study is aimed at identifying the samples of most promising membrane materials for storing dry specimens of biological fluids (Dried Blood Spots, DBS technology). Existing sampling systems using cellulose fiber filter paper have a number of drawbacks such as uneven distribution of the sample spot, dependence of the spot spreading area on the individual biosample properties, incomplete washing-off of the sample due to partially inconvertible sorption of blood components on cellulose fibers, etc. Samples of membrane materials based on cellulose, polymers and glass fiber with applied biosamples were studied using methods of scanning electron microscopy, FT-IR spectroscopy and surface-wetting measurement. It was discovered that cellulose-based membrane materials sorb components of biological fluids inside their structure, while membranes based on glass fiber display almost no interaction with the samples and biological fluid components dry to films in the membrane pores between the structural fibers. This characteristic, together with the fact that membrane materials based on glass fiber possess sufficient strength, high wetting properties and good storage capacity, attests them as promising material for dry samples of biological fluids storage systems.

  17. Chemometric and Statistical Analyses of ToF-SIMS Spectra of Increasingly Complex Biological Samples

    Energy Technology Data Exchange (ETDEWEB)

    Berman, E S; Wu, L; Fortson, S L; Nelson, D O; Kulp, K S; Wu, K J

    2007-10-24

    Characterizing and classifying molecular variation within biological samples is critical for determining fundamental mechanisms of biological processes that will lead to new insights including improved disease understanding. Towards these ends, time-of-flight secondary ion mass spectrometry (ToF-SIMS) was used to examine increasingly complex samples of biological relevance, including monosaccharide isomers, pure proteins, complex protein mixtures, and mouse embryo tissues. The complex mass spectral data sets produced were analyzed using five common statistical and chemometric multivariate analysis techniques: principal component analysis (PCA), linear discriminant analysis (LDA), partial least squares discriminant analysis (PLSDA), soft independent modeling of class analogy (SIMCA), and decision tree analysis by recursive partitioning. PCA was found to be a valuable first step in multivariate analysis, providing insight both into the relative groupings of samples and into the molecular basis for those groupings. For the monosaccharides, pure proteins and protein mixture samples, all of LDA, PLSDA, and SIMCA were found to produce excellent classification given a sufficient number of compound variables calculated. For the mouse embryo tissues, however, SIMCA did not produce as accurate a classification. The decision tree analysis was found to be the least successful for all the data sets, providing neither as accurate a classification nor chemical insight for any of the tested samples. Based on these results we conclude that as the complexity of the sample increases, so must the sophistication of the multivariate technique used to classify the samples. PCA is a preferred first step for understanding ToF-SIMS data that can be followed by either LDA or PLSDA for effective classification analysis. This study demonstrates the strength of ToF-SIMS combined with multivariate statistical and chemometric techniques to classify increasingly complex biological samples

  18. Sample preparation method for ICP-MS measurement of 99Tc in a large amount of environmental samples

    International Nuclear Information System (INIS)

    Sample preparation for measurement of 99Tc in a large amount of soil and water samples by ICP-MS has been developed using 95mTc as a yield tracer. This method is based on the conventional method for a small amount of soil samples using incineration, acid digestion, extraction chromatography (TEVA resin) and ICP-MS measurement. Preliminary concentration of Tc has been introduced by co-precipitation with ferric oxide. The matrix materials in a large amount of samples were more sufficiently removed with keeping the high recovery of Tc than previous method. The recovery of Tc was 70-80% for 100 g soil samples and 60-70% for 500 g of soil and 500 L of water samples. The detection limit of this method was evaluated as 0.054 mBq/kg in 500 g soil and 0.032 μBq/L in 500 L water. The determined value of 99Tc in the IAEA-375 (soil sample collected near the Chernobyl Nuclear Reactor) was 0.25 ± 0.02 Bq/kg. (author)

  19. Analytical characterization of high-level mixed wastes using multiple sample preparation treatments

    International Nuclear Information System (INIS)

    The Analytical Chemistry Laboratory at the Pacific Northwest Laboratory in Richland, Washington, is actively involved in performing analytical characterization of high-level mixed waste from Hanford's single shell and double shell tank characterization programs. A full suite of analyses is typically performed on homogenized tank core samples. These analytical techniques include inductively-coupled plasma-atomic emission spectroscopy, total organic carbon methods and radiochemistry methods, as well as many others, all requiring some type of remote sample-preparation treatment to solubilize the tank sludge material for analysis. Most of these analytical methods typically use a single sample-preparation treatment, inherently providing elemental information only. To better understand and interpret tank chemistry and assist in identifying chemical compounds, selected analytical methods are performed using multiple sample-preparation treatments. The sample preparation treatments used at Pacific Northwest Laboratory for this work with high-level mixed waste include caustic fusion, acid digestion, and water leach. The type of information available by comparing results from different sample-prep treatments includes evidence for the presence of refractory compounds, acid-soluble compounds, or water-soluble compounds. Problems unique to the analysis of Hanford tank wastes are discussed. Selected results from the Hanford single shell ferrocyanide tank, 241-C-109, are presented, and the resulting conclusions are discussed

  20. Preparation of ferric-activated sludge-based adsorbent from biological sludge for tetracycline removal.

    Science.gov (United States)

    Yang, Xin; Xu, Guoren; Yu, Huarong; Zhang, Zhao

    2016-07-01

    Ferric activation was novelly used to produce sludge-based adsorbent (SBA) from biological sludge through pyrolysis, and the adsorbents were applied to remove tetracycline from aqueous solution. The pyrolysis temperature and mass ratio (activator/dried sludge) greatly influenced the surface area and pore characteristics of SBA. Ferric activation could promote the porous structure development of adsorbents, and the optimum preparation conditions were pyrolysis temperature 750°C and mass ratio (activator/dried sludge) 0.5. In batch experiments, ferric-activated SBA showed a higher adsorption capacity for tetracycline than non-activated SBA, because the enhanced mesoporous structure favored the diffusion of tetracycline into the pores, the iron oxides and oxygen-containing functional groups in the adsorbents captured tetracycline by surface complexation. The results indicate that ferric activation is an effective approach for preparing adsorbents from biological sludge to remove tetracycline, providing a potential option for waste resource recovery. PMID:27038265

  1. 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.

  2. Preparing Federal Coordinating Officers (FCOs) to operate in Chemical, Biological, Radiological, and Nuclear (CBRN) environments

    OpenAIRE

    Russell, Tony.

    2008-01-01

    CHDS State/Local In this thesis the Federal Emergency Management Agency's (FEMA) Federal Coordinating Officer (FCO) function is examined as it relates to Chemical, Biological, Radiological and Nuclear (CBRN) operations. It is suggested that targeted changes can be made to ensure the FCOs are better prepared to manage the additional complexities of a CBRN environment. The changes include addressing the FCOs from the systems approach- internally to improve the FCO personal and professio...

  3. On the accuracy of protein determination in large biological samples by prompt gamma neutron activation analysis

    International Nuclear Information System (INIS)

    A prompt gamma neutron activation analysis (PGNAA) facility has been developed for the determination of nitrogen and thus total protein in large volume biological samples or the whole body of small animals. In the present work, the accuracy of nitrogen determination by PGNAA in phantoms of known composition as well as in four raw ground meat samples of about 1 kg mass was examined. Dumas combustion and Kjeldahl techniques were also used for the assessment of nitrogen concentration in the meat samples. No statistically significant differences were found between the concentrations assessed by the three techniques. The results of this work demonstrate the applicability of PGNAA for the assessment of total protein in biological samples of 0.25-1.5 kg mass, such as a meat sample or the body of small animal even in vivo with an equivalent radiation dose of about 40 mSv

  4. Presence of pesticide residues in water, sediment and biological samples taken from aquatic environments in Honduras

    International Nuclear Information System (INIS)

    The objective of this study was to detect the presence of persistent pesticides in water, sediment and biological samples taken from aquatic environments in Honduras during the period 1995-98. Additionally, the LC50 for 2 fungicides and 2 insecticides on post-larval Penaeus vannamei was determined in static water bioassays. A total of 80 water samples, 16 sediment samples and 7 biological samples (fish muscle tissue) were analyzed for detection of organochlorine and organophosphate pesticide residues. The results of sample analyses indicate a widespread contamination of Honduran continental and coastal waters with organochlorine pesticides. Most detections were of low (50 values and were therefore found to be much more toxic to the post-larval shrimp than the fungicides tridemorph and propiconazole. (author)

  5. Quantitation of vitamin B6 in biological samples by isotope dilution mass spectrometry

    International Nuclear Information System (INIS)

    Methods have been developed for the simultaneous quantitative analysis of vitamin B6 forms in biological samples by isotope dilution mass spectrometry using deuterated forms of pyridoxine, pyridoxal, pyridoxamine, and pyridoxic acid. The biological fluid or tissue sample was homogenized and then treated with a cocktail containing appropriate amounts of each deuterated vitamer, as well as the deuterated, phosphorylated vitamer forms. The individual vitamers were isolated from the homogenate by a complex high-performance liquid chromatographic procedure that provided separate fractions for each of the six vitamers found in biological samples. Aldehydic B6 vitamers were reduced to the alcohol form prior to acetylation and analysis by gas chromatography/mass spectrometry (GC/MS). The three resulting vitamers were analyzed by electron ionization GC/MS using a silicone capillary column. The methods have been applied to analysis of vitamin B6 in liver, milk, urine, and feces at levels as low as 0.02 nmol/ml

  6. A pre-treatment device designed for tritium analysis in biological samples

    International Nuclear Information System (INIS)

    Objective: To design a new pre-treatment device and to evaluate its efficiency in order to monitor the tritium levels in biological samples. Methods: The detection efficiency of tritium was determined with standard tritiated water. Recovery of tritiated water and organically bound tritium (OBT) were detected with high, medium and low activities of standard tritiated water and 3H-TdR (tritiated thymidine), respectively. Comparison of three kinds of biological samples using different pre-treatment devices was shown. Results: The standard curve can be used in environmental tritium measurement and the detection efficiency for tritium was 23.3%. When 40.0 g rice with standard HTO or 3H-TdR was pretreated with this device, the average recovery of HTO and OBT was about 95.4% , which showed good reproducibility.The comparison results were similar. Conclusions: The pre-treatment device can be used to survey the OBT in environmental biological samples. (authors)

  7. Quantitation of vitamin B6 in biological samples by isotope dilution mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Hachey, D.L.; Coburn, S.P.; Brown, L.T.; Erbelding, W.F.; DeMark, B.; Klein, P.D.

    1985-11-15

    Methods have been developed for the simultaneous quantitative analysis of vitamin B6 forms in biological samples by isotope dilution mass spectrometry using deuterated forms of pyridoxine, pyridoxal, pyridoxamine, and pyridoxic acid. The biological fluid or tissue sample was homogenized and then treated with a cocktail containing appropriate amounts of each deuterated vitamer, as well as the deuterated, phosphorylated vitamer forms. The individual vitamers were isolated from the homogenate by a complex high-performance liquid chromatographic procedure that provided separate fractions for each of the six vitamers found in biological samples. Aldehydic B6 vitamers were reduced to the alcohol form prior to acetylation and analysis by gas chromatography/mass spectrometry (GC/MS). The three resulting vitamers were analyzed by electron ionization GC/MS using a silicone capillary column. The methods have been applied to analysis of vitamin B6 in liver, milk, urine, and feces at levels as low as 0.02 nmol/ml.

  8. Supercritical fluid extraction and ultra performance liquid chromatography of respiratory quinones for microbial community analysis in environmental and biological samples.

    Science.gov (United States)

    Hanif, Muhammad; Atsuta, Yoichi; Fujie, Koichi; Daimon, Hiroyuki

    2012-01-01

    Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE) and ultra performance liquid chromatography (UPLC) method for the analysis of bacterial respiratory quinones (RQ) in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA) detector was successfully applied to the simultaneous determination of ubiquinones (UQ) and menaquinones (MK) without tedious pretreatment. Supercritical carbon dioxide (scCO(2)) extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost) and biological samples (swine and Japanese quail feces). PMID:22391598

  9. Supercritical Fluid Extraction and Ultra Performance Liquid Chromatography of Respiratory Quinones for Microbial Community Analysis in Environmental and Biological Samples

    Directory of Open Access Journals (Sweden)

    Koichi Fujie

    2012-03-01

    Full Text Available Microbial community structure plays a significant role in environmental assessment and animal health management. The development of a superior analytical strategy for the characterization of microbial community structure is an ongoing challenge. In this study, we developed an effective supercritical fluid extraction (SFE and ultra performance liquid chromatography (UPLC method for the analysis of bacterial respiratory quinones (RQ in environmental and biological samples. RQ profile analysis is one of the most widely used culture-independent tools for characterizing microbial community structure. A UPLC equipped with a photo diode array (PDA detector was successfully applied to the simultaneous determination of ubiquinones (UQ and menaquinones (MK without tedious pretreatment. Supercritical carbon dioxide (scCO2 extraction with the solid-phase cartridge trap proved to be a more effective and rapid method for extracting respiratory quinones, compared to a conventional organic solvent extraction method. This methodology leads to a successful analytical procedure that involves a significant reduction in the complexity and sample preparation time. Application of the optimized methodology to characterize microbial communities based on the RQ profile was demonstrated for a variety of environmental samples (activated sludge, digested sludge, and compost and biological samples (swine and Japanese quail feces.

  10. Sample preparation procedure for the determination of polycyclic aromatic hydrocarbons in petroleum vacuum residue and bitumen

    Energy Technology Data Exchange (ETDEWEB)

    Gilgenast, Ewelina; Boczkaj, Grzegorz; Kaminski, Marian [Gdansk University of Technology, Chemical Faculty, Department of Chemical and Process Engineering, Gdansk (Poland); Przyjazny, Andrzej [Kettering University, Chemistry and Biochemistry Department, Flint, MI (United States)

    2011-08-15

    This paper describes a novel method of sample preparation for the determination of trace concentrations of polycyclic aromatic hydrocarbons (PAHs) in high-boiling petroleum products. Limits of quantitation of the investigated PAHs in materials of this type range from tens of nanograms per kilogram to <20 {mu}g/kg. The studies revealed that in order to separate most of interferences from the analytes without a significant loss of PAHs, it is necessary to use size exclusion chromatography as the first step of sample preparation, followed by adsorption using normal-phase liquid chromatography. The use of orthogonal separation procedure described in the paper allows the isolation of only a group of unsubstituted and substituted aromatic hydrocarbons with a specific range of molar mass. The lower the required limit of quantitation of PAHs, the larger is the scale of preparative liquid chromatography in both steps of sample preparation needed. The use of internal standard allows quantitative results to be corrected for the degree of recovery of PAHs during the sample preparation step. Final determination can be carried out using HPLC-FLD, GC-MS, or HPLC-UV-VIS/DAD. The last technique provides a degree of identification through the acquired UV-VIS spectra. (orig.)

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

    Science.gov (United States)

    Liao, Shu Y; Lee, Myungwoon; Wang, Tuo; Sergeyev, Ivan V; Hong, Mei

    2016-03-01

    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. PMID:26873390

  12. FACE Analysis as a Fast and Reliable Methodology to Monitor the Sulfation and Total Amount of Chondroitin Sulfate in Biological Samples of Clinical Importance

    Directory of Open Access Journals (Sweden)

    Evgenia Karousou

    2014-06-01

    Full Text Available Glycosaminoglycans (GAGs due to their hydrophilic character and high anionic charge densities play important roles in various (pathophysiological processes. The identification and quantification of GAGs in biological samples and tissues could be useful prognostic and diagnostic tools in pathological conditions. Despite the noteworthy progress in the development of sensitive and accurate methodologies for the determination of GAGs, there is a significant lack in methodologies regarding sample preparation and reliable fast analysis methods enabling the simultaneous analysis of several biological samples. In this report, developed protocols for the isolation of GAGs in biological samples were applied to analyze various sulfated chondroitin sulfate- and hyaluronan-derived disaccharides using fluorophore-assisted carbohydrate electrophoresis (FACE. Applications to biologic samples of clinical importance include blood serum, lens capsule tissue and urine. The sample preparation protocol followed by FACE analysis allows quantification with an optimal linearity over the concentration range 1.0–220.0 µg/mL, affording a limit of quantitation of 50 ng of disaccharides. Validation of FACE results was performed by capillary electrophoresis and high performance liquid chromatography techniques.

  13. Classification and Cluster Analysis of Complex Time-of-Flight Secondary Ion Mass Spectrometry for Biological Samples

    OpenAIRE

    Reichenbach, Stephen E; Tian, Xue; Tao, Qingping; Henderson, Alex

    2009-01-01

    Identifying and separating subtly different biological samples is one of the most critical tasks in biological analysis. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) is becoming a popular and important technique in the analysis of biological samples, because it can detect molecular information and characterize chemical composition. ToF-SIMS spectra of biological samples are enormously complex with large mass ranges and many peaks. As a result the classification and cluster analys...

  14. 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.

  15. Spectroscopic analysis of bosentan in biological samples after a liquid-liquid microextraction

    Science.gov (United States)

    Sajedi-Amin, Sanaz; Assadpour-Zeynali, Karim; Panahi-Azar, Vahid; Kebriaeezadeh, Abbas; Khoubnasabjafari, Maryam; Ansarin, Khalil; Jouyban-Gharamaleki, Vahid; Jouyban, Abolghasem

    2015-01-01

    Introduction:Microextraction processes with UV-Vis measurement have been developed and validated for analysis of bosentan in biological samples. Methods:In this work, liquid–liquid microextraction procedures (DLLME & USAEME) were employed for cleanup, pre-concentration, and determination of bosentan in biological samples by UV-Vis spectroscopy at 270 nm. The method was validated and applied to the determination of bosentan in spiked serum, exhaled breath condensate and urine samples. Results:Various experimental factors including type of extraction and dispersive solvents and their volumes, pH, sonication time and centrifuging time were investigated. Under the optimum conditions, the method was linear in the range of 1.0–5.0 μg.mL-1, with coefficient of determination (R2) of > 0.998. The limit of detection (LOD) was 0.07 mg.L-1. Recovery of the target analyte in biological samples was 106.2%. The method could be easily applied for higher concentration of bosentan and needs more improvement for application in the pharmacokinetic investigations where more sensitive methods are required. Conclusion:A simple, low cost, precise and accurate spectrophotometric analysis of bosentan in biological samples after liquid-liquid microextraction were developed and validated for routine analyses. PMID:26929923

  16. An examination of the structural and biological properties of three intravenous immunoglobulin preparations.

    Science.gov (United States)

    Law, D T; Painter, R H

    1986-03-01

    Three commercial preparations of immunoglobulin G prepared for administration by the i.v. route were tested for their physical integrity and in vitro biological activity. Size exclusion chromatography by HPLC in native and denaturing buffers together with SDS-PAGE analysis were used to determine whether covalent-bond cleavage had occurred as a result of procedures used in their preparation. C1 complement binding assays and measurements of competitive binding to an Fc receptor-bearing promonocyte cell line U937 were used to assess whether such changes had altered the capacity of these preparations to engage biological effector functions. A purified IgG1 myeloma protein was used as a reference standard. WinRho, an unmodified IgG, consisted almost wholly of monomeric IgG by HPLC size exclusion and showed no evidence of proteolytic fragments in denaturing buffers or on SDS-PAGE. Sandoglobulin, a product treated at pH 4 with pepsin, contained about 10% dimeric protein and, as revealed under denaturing conditions, about 2% fragments. Relative affinity of binding to U937 cells was similar to WinRho. C1 binding by Sandoglobulin showed normal activity with 50% inhibition at 2.8 nM. Gamimune, modified by partial reduction and alkylation, contained about 15% dimers. Between 20 and 30% of the preparation retained covalent interchain disulfides. Binding to U937 cells was two-fold weaker than the other preparations and binding to C1 was also diminished and modified. This accords well with previous reports of the deleterious effect of reduction and alkylation on Fc function. PMID:3713708

  17. Combining desorption electrospray ionization mass spectrometry and nuclear magnetic resonance for differential metabolomics without sample preparation.

    Science.gov (United States)

    Chen, Huanwen; Pan, Zhengzheng; Talaty, Nari; Raftery, Daniel; Cooks, R Graham

    2006-01-01

    Desorption electrospray ionization mass spectrometry (DESI-MS) and nuclear magnetic resonance (NMR) spectroscopy are used to provide data on urine examined without sample preparation to allow differentiation between diseased (lung cancer) and healthy mice. Principal component analysis (PCA) is used to shortlist compounds with potential for biomarker screening which are responsible for significant differences between control urine samples and samples from diseased animals. Similar PCA score plots have been achieved by DESI-MS and NMR, using a subset of common detected metabolites. The common compounds detected by DESI and NMR have the same changes in sign of their concentrations thereby indicating the usefulness of corroborative analytical methods. The effects of different solvents and surfaces on the DESI mass spectra are also evaluated and optimized. Over 80 different metabolites were successfully identified by DESI-MS and tandem mass spectrometry experiments, with no prior sample preparation. PMID:16628593

  18. Optimization of Sample Preparation for the Analysis of Selenium Metabolites in Trout

    OpenAIRE

    Bouzas Ramos, Diego

    2014-01-01

    When speciation of ultratrace level compounds is performed, sample preparation often results to be a crucial step in the analysis. The use of high performance liquid chromatography (HPLC) also requires in most cases a sample whose matrix was purified in order to preserve the chromatographic support and thus ensure a proper separation. Analysis of selenium metabolites in blood is a challenge because of the very low concentrations found and the presence of proteins that deteriorate the chromato...

  19. 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 chemical...... artifacts, in vitro protein and peptide modifications, and contaminations. Those often result in sample loss and affect the sensitivity, dynamic range and accuracy of the mass spectrometric analysis. Here we describe a simple and reproducible phosphoproteomics protocol, where lysis, denaturation, reduction...

  20. 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.

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

    OpenAIRE

    Wong, Chui E; Mohan B. Singh; Bhalla, Prem L

    2012-01-01

    The shoot apical meristem houses stem cells responsible for the continuous formation of aerial plant organs including leaves and stems throughout the life of plants. Laser-microdissection in combination with high-throughput technology such as next generation sequencing permits an in-depth analysis of molecular events associated with specific cell type of interest. Sample preparation is the most critical step in ensuring good quality RNA to be extracted from samples following laser-microdissec...

  2. Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays

    International Nuclear Information System (INIS)

    We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface

  3. Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays

    Science.gov (United States)

    Ploykrachang, K.; Hasegawa, J.; Kondo, K.; Fukuda, H.; Oguri, Y.

    2014-07-01

    We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface.

  4. Development of a micro-XRF system for biological samples based on proton-induced quasimonochromatic X-rays

    Energy Technology Data Exchange (ETDEWEB)

    Ploykrachang, K., E-mail: ploykrachang.k.aa@m.titech.ac.jp [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Hasegawa, J. [Department of Energy Sciences, Interdisciplinary Graduate School of Science and Engineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8502 (Japan); Kondo, K.; Fukuda, H.; Oguri, Y. [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2014-07-15

    We have developed a micro-XRF system based on a proton-induced quasimonochromatic X-ray (QMXR) microbeam for in vivo measurement of biological samples. A 2.5-MeV proton beam impinged normally on a Cu foil target that was slightly thicker than the proton range. The emitted QMXR behind the Cu target was focused with a polycapillary X-ray half lens. For application to analysis of wet or aquatic samples, we prepared a QMXR beam with an incident angle of 45° with respect to the horizontal plane by using a dipole magnet in order to bend the primary proton beam downward by 45°. The focal spot size of the QMXR microbeam on a horizontal sample surface was evaluated to be 250 × 350 μm by a wire scanning method. A microscope camera with a long working distance was installed perpendicular to the sample surface to identify the analyzed position on the sample. The fluorescent radiation from the sample was collected by a Si-PIN photodiode X-ray detector. Using the setup above, we were able to successfully measure the accumulation and distribution of Co in the leaves of a free-floating aquatic plant on a dilute Co solution surface.

  5. The NOSAMS sample preparation laboratory in the next millenium: Progress after the WOCE program

    International Nuclear Information System (INIS)

    Since 1991, the primary charge of the National Ocean Sciences AMS (NOSAMS) facility at the Woods Hole Oceanographic Institution has been to supply high throughput, high precision AMS 14C analyses for seawater samples collected as part of the World Ocean Circulation Experiment (WOCE). Approximately 13,000 samples taken as part of WOCE should be fully analyzed by the end of Y2K. Additional sample sources and techniques must be identified and incorporated if NOSAMS is to continue in its present operation mode. A trend in AMS today is the ability to routinely process and analyze radiocarbon samples that contain tiny amounts (14C analysis has been recognized as a major facility goal. The installation of a new 134-position MC-SNICS ion source, which utilizes a smaller graphite target cartridge than presently used, is one step towards realizing this goal. New preparation systems constructed in the sample preparation laboratory (SPL) include an automated bank of 10 small-volume graphite reactors, an automated system to process organic carbon samples, and a multi-dimensional preparative capillary gas chromatograph (PCGC)

  6. Optimization and comparison of bottom-up proteomic sample preparation for early-stage Xenopus laevis embryos.

    Science.gov (United States)

    Peuchen, Elizabeth H; Sun, Liangliang; Dovichi, Norman J

    2016-07-01

    Xenopus laevis is an important model organism in developmental biology. While there is a large literature on changes in the organism's transcriptome during development, the study of its proteome is at an embryonic state. Several papers have been published recently that characterize the proteome of X. laevis eggs and early-stage embryos; however, proteomic sample preparation optimizations have not been reported. Sample preparation is challenging because a large fraction (~90 % by weight) of the egg or early-stage embryo is yolk. We compared three common protein extraction buffer systems, mammalian Cell-PE LB(TM) lysing buffer (NP40), sodium dodecyl sulfate (SDS), and 8 M urea, in terms of protein extraction efficiency and protein identifications. SDS extracts contained the highest concentration of proteins, but this extract was dominated by a high concentration of yolk proteins. In contrast, NP40 extracts contained ~30 % of the protein concentration as SDS extracts, but excelled in discriminating against yolk proteins, which resulted in more protein and peptide identifications. We then compared digestion methods using both SDS and NP40 extraction methods with one-dimensional reverse-phase liquid chromatography-tandem mass spectrometry (RPLC-MS/MS). NP40 coupled to a filter-aided sample preparation (FASP) procedure produced nearly twice the number of protein and peptide identifications compared to alternatives. When NP40-FASP samples were subjected to two-dimensional RPLC-ESI-MS/MS, a total of 5171 proteins and 38,885 peptides were identified from a single stage of embryos (stage 2), increasing the number of protein identifications by 23 % in comparison to other traditional protein extraction methods. PMID:27137514

  7. Molecularly Imprinted Solid-Phase Extraction and Liquid Chromatography for Biological Samples

    OpenAIRE

    Möller, Kristina

    2006-01-01

    This thesis focuses on the use of molecularly imprinted polymers as selective sorbents for solid-phase extraction (MISPE). The MISPE methods developed were mainly intended for use with biological samples, such as human urine and blood plasma. These body fluids are complex samples, which often need an effective clean-up step before analysis to reduce the levels of possible interfering substances from the matrix, especially if the analytes are present in trace amounts. Solid-phase extraction (S...

  8. Great Meteor East: an interim report on biological sampling and general relationship to physical oceanography

    International Nuclear Information System (INIS)

    The report deals with work carried out in June/July 1985 on RRS Discovery Cruise 156 to GME. The general physical oceanography of the area and the vertical distribution of chlorophyll a and nutrients are described. Primary production measurements and results are discussed in detail. Biological sampling of benthic and pelagic animals is described together with the subsequent laboratory treatment of the samples and some preliminary data on midwater biomass. (author)

  9. Determination of element concentrations in biological reference materials by solid sampling and other analytical methods

    Energy Technology Data Exchange (ETDEWEB)

    Schauenburg, H.; Weigert, P. (Bundesgesundheitsamt, Berlin (Germany). Centre for Surveillance and Health Evaluation of Environmental Chemicals (ZEBS))

    1992-04-01

    Using solid sampling with graphite furnace atomic absorption spectrometry (GFAAS), values for cadmium, copper, lead and zinc in six biological reference materials were obtained from up to four laboratories participating in three collaborative studies. These results are compared with those obtained with other methods used in routine analysis from laboratories of official food control. Under certain conditions solid sampling with GFAAS seems to be suitable for routine analysis as well as conventional methods. (orig.).

  10. QuEChERS sample preparation approach for mass spectrometric analysis of pesticide residues in foods

    Science.gov (United States)

    This chapter describes an easy, rapid, and low-cost sample preparation approach for the determination of pesticide residues in foods using gas and/or liquid chromatographic (GC and/or LC) analytical separation and mass spectrometric (MS) detection. The approach is known as QuEChERS, which stands fo...

  11. On-chip sample preparation by controlled release of antibodies for simple CD4 counting

    NARCIS (Netherlands)

    Beck, M.; Brockhuis, S.; Velde, van der N.; Breukers, C.; Greve, J.; Terstappen, L.W.M.M.

    2012-01-01

    We present a simple system for CD4 and CD8 counting for point-of-care HIV staging in low-resource settings. Automatic sample preparation is achieved through a dried reagent coating inside a thin (26 μm) counting chamber, allowing the delayed release of fluorochrome conjugated monoclonal antibodies a

  12. Influence of sample preparation on the microstructure of tooth enamel apatite

    Czech Academy of Sciences Publication Activity Database

    Kallistová, Anna; Skála, Roman; Horáček, I.; Miyajima, N.; Malíková, R.

    2015-01-01

    Roč. 48, č. 3 (2015), s. 763-768. ISSN 0021-8898 Institutional support: RVO:67985831 Keywords : X-ray powder diffraction * sample preparation * microstructure * dental hydroxyapatite Subject RIV: BM - Solid Matter Physics ; Magnetism Impact factor: 3.720, year: 2014

  13. 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 t...

  14. Method development for mass spectrometry based molecular characterization of fossil fuels and biological samples

    Science.gov (United States)

    Mahat, Rajendra K.

    In an analytical (chemical) method development process, the sample preparation step usually determines the throughput and overall success of the analysis. Both targeted and non-targeted methods were developed for the mass spectrometry (MS) based analyses of fossil fuels (coal) and lipidomic analyses of a unique micro-organism, Gemmata obscuriglobus. In the non-targeted coal analysis using GC-MS, a microwave-assisted pressurized sample extraction method was compared with the traditional extraction method, such as Soxhlet. On the other hand, methods were developed to establish a comprehensive lipidomic profile and to confirm the presence of endotoxins (a.k.a. lipopolysaccharides, LPS) in Gemmata.. The performance of pressurized heating techniques employing hot-air oven and microwave irradiation were compared with that of Soxhlet method in terms of percentage extraction efficiency and extracted analyte profiles (via GC-MS). Sub-bituminous (Powder River Range, Wyoming, USA) and bituminous (Fruitland formation, Colorado, USA) coal samples were tested. Overall 30-40% higher extraction efficiencies (by weight) were obtained with a 4 hour hot-air oven and a 20 min microwave-heating extraction in a pressurized container when compared to a 72 hour Soxhlet extraction. The pressurized methods are 25 times more economic in terms of solvent/sample amount used and are 216 times faster in term of time invested for the extraction process. Additionally, same sets of compounds were identified by GC-MS for all the extraction methods used: n-alkanes and diterpanes in the sub-bituminous sample, and n-alkanes and alkyl aromatic compounds in the bituminous coal sample. G. obscuriglobus, a nucleated bacterium, is a micro-organism of high significances from evolutionary, cell and environmental biology standpoints. Although lipidomics is an essential tool in microbiological systematics and chemotaxonomy, complete lipid profile of this bacterium is still lacking. In addition, the presence of

  15. Integrated quantification and identification of aldehydes and ketones in biological samples

    NARCIS (Netherlands)

    Siegel, David; Meinema, Anne C; Permentier, Hjalmar; Hopfgartner, Gérard; Bischoff, Rainer

    2014-01-01

    The identification of unknown compounds remains to be a bottleneck of mass spectrometry (MS)-based metabolomics screening experiments. Here, we present a novel approach which facilitates the identification and quantification of analytes containing aldehyde and ketone groups in biological samples by

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

    International Nuclear Information System (INIS)

    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

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

    Energy Technology Data Exchange (ETDEWEB)

    Kreuzpaintner, Wolfgang

    2010-06-22

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

  18. Protease inhibitors as possible pitfalls in proteomic analyses of complex biological samples

    OpenAIRE

    Clifton, James; Huang, Feilei; Rucevic, Marijana; Cao, Lulu; Hixson, Douglas; Josic, Djuro

    2011-01-01

    Sample preparation, especially protein and peptide fractionation prior to identification by mass spectrometry (MS) are typically applied to reduce sample complexity. The second key element in this process is proteolytic digestion that is performed mostly by trypsin. Optimization of this step is an important factor in order to achieve both speed and better performance of proteomic analysis, and tryptic digestion prior to the MS analysis is topic of many studies. To date, only few studies pay a...

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

    Science.gov (United States)

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

    2016-03-01

    Community-level physiological profiling (CLPP) using BIOLOG® EcoPlates™ has become a popular method for characterizing and comparing the functional diversity, functional potential, and metabolic activity of heterotrophic microbial communities. The method was originally developed for profiling soil communities; however, its usage has expanded into the fields of ecotoxicology, agronomy, and the monitoring and profiling of microbial communities in various wastewater treatment systems, including constructed wetlands for water pollution control. When performing CLPP on aqueous samples from constructed wetlands, a wide variety of sample characteristics can be encountered and challenges may arise due to excessive solids, color, or turbidity. The aim of this study was to investigate the impacts of different sample preparation methods on CLPP performed on a variety of aqueous samples covering a broad range of physical and chemical characteristics. The results show that using filter paper, centrifugation, or settling helped clarify samples for subsequent CLPP analysis, however did not do so as effectively as dilution for the darkest samples. Dilution was able to provide suitable clarity for the darkest samples; however, 100-fold dilution significantly affected the carbon source utilization patterns (CSUPs), particularly with samples that were already partially or fully clear. Ten-fold dilution also had some effect on the CSUPs of samples which were originally clear; however, the effect was minimal. Based on these findings, for this specific set of samples, a 10-fold dilution provided a good balance between ease of use, sufficient clarity (for dark samples), and limited effect on CSUPs. The process and findings outlined here can hopefully serve future studies looking to utilize CLPP for functional analysis of microbial communities and also assist in comparing data from studies where different sample preparation methods were utilized. PMID:26563413

  20. Fast quantitative retardance imaging of biological samples using quadri-wave interferometry (Conference Presentation)

    Science.gov (United States)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of polarized spatially coherent illumination to perform linear retardance imaging and measurements of semi-transparent biological samples using a quantitative phase imaging technique [1]. Quantitative phase imaging techniques [2-5] are used in microscopy for the imaging of semi-transparent samples and gives information about the optical path difference (OPD). The strength of those techniques is their non-invasive (the sample is not labelled) and fast approach. However, this high contrast is non-specific and cannot be linked to specific properties of the sample. To overcome this limitation, we propose to use polarized light in combination with QPI. Indeed, anisotropy has been used to reveal ordered fibrous structures in biological samples without any staining or labelling with polarized light microscopy [6-8]. Recent studies have shown polarimetry as a potential diagnostic tool for various dermatological diseases on thick tissue samples [9]. Particularly, specific collagen fibers spatial distribution has been demonstrated to be a signature for the optical diagnosis and prognosis of cancer in tissues [10]. In this paper, we describe a technical improvement of our technique based on high-resolution quadri-wave lateral shearing interferometry (QWLSI) and liquid crystal retarder to perform quantitative linear birefringence measurements on biological samples. The system combines a set of quantitative phase images with different excitation polarizations to create birefringence images. These give information about the local retardance and orientation of biological anisotropic components. We propose using a commercial QWLSI [11] (SID4Bio, Phasics SA, Saint Aubin, France) directly plugged onto a lateral video port of an inverted microscope (TE2000-U, Nikon, Japan). We are able to take retardance images in less than 1 second which allows us to record dynamic phenomena (living cells study) and make high speed acquisitions to reconstruct tissues virtual

  1. Preparation of samples taken from the Alshar mine for x-ray fluorescence spectrometry (Macedonia)

    International Nuclear Information System (INIS)

    Preparation of samples which contain a large amount of arsenic, antimony and thallium sulphides, by fusion with sodium or lithium tetraborate, for x-ray spectrochemical analysis, could not be applied directly, due to the volatility of the compounds which are of analytical interest and the destruction of Pt-crucibles. To prevent the evaporation of thallium, arsenic and antimony compounds during fusion, two different methods are described: fusion of the sample and the flux with the addition of oxidizing agents; and fusion of the dry residue which remains after dissolving the sample in nitric acid or in 'aqua regia' and evaporation of the excess of acids. (author). 3 refs., 7 tabs

  2. Sample Preparation for Fungal Community Analysis by High-Throughput Sequencing of Barcode Amplicons.

    Science.gov (United States)

    Clemmensen, Karina Engelbrecht; Ihrmark, Katarina; Durling, Mikael Brandström; Lindahl, Björn D

    2016-01-01

    Fungal species participate in vast numbers of processes in the landscape around us. However, their often cryptic growth, inside various substrates and in highly diverse species assemblages, has been a major obstacle to thorough analysis of fungal communities, hampering exhaustive description of the fungal kingdom. Recent technological developments allowing rapid, high-throughput sequencing of mixed communities from many samples at once are currently having a tremendous impact in fungal community ecology. Universal DNA extraction followed by amplification and sequencing of fungal species-level barcodes such as the nuclear internal transcribed spacer (ITS) region now enable identification and relative quantification of fungal community members across well-replicated experimental settings. Here, we present the sample preparation procedure presently used in our laboratory for fungal community analysis by high-throughput sequencing of amplified ITS2 markers. We focus on the procedure optimized for studies of total fungal communities in humus-rich soils, wood, and litter. However, this procedure can be applied to other sample types and markers. We focus on the laboratory-based part of sample preparation, that is, the procedure from the point where samples enter the laboratory until amplicons are submitted for sequencing. Our procedure comprises four main parts: (1) universal DNA extraction, (2) optimization of PCR conditions, (3) production of tagged ITS amplicons, and (4) preparation of the multiplexed amplicon mix to be sequenced. The presented procedure is independent of the specific high-throughput sequencing technology used, which makes it highly versatile. PMID:26791497

  3. 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.

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

    Science.gov (United States)

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

    2014-01-01

    Ensuring the quality and reproducibility of results from biofilm structure and microbial community analysis is essential to membrane biofouling studies. This study evaluated the impacts of three sample preparation factors (ie number of buffer rinses, storage time at 4°C, and DNA extraction method) on the downstream analysis of nitrifying biofilms grown on ultrafiltration membranes. Both rinse and storage affected biofilm structure, as suggested by their strong correlation with total biovolume, biofilm thickness, roughness and the spatial distribution of EPS. Significant variations in DNA yields and microbial community diversity were also observed among samples treated by different rinses, storage and DNA extraction methods. For the tested biofilms, two rinses, no storage and DNA extraction with both mechanical and chemical cell lysis from attached biofilm were the optimal sample preparation procedures for obtaining accurate information about biofilm structure, EPS distribution and the microbial community. PMID:25115516

  5. Comparison of in-house and commercial sample preparation and PCR amplification systems for detection of human immunodeficiency virus type 1 DNA in blood samples from Tanzanian adults.

    OpenAIRE

    Lyamuya, E; Bredberg-Rådén, U; Albert, J.; Grankvist, O; Msangi, V; Kagoma, C.; Mhalu, F; Biberfeld, G

    1997-01-01

    This study compared the performance of several in-house nested PCR systems and the Amplicor human immunodeficiency virus type 1 (HIV-1) PCR kit in the detection of HIV-1 DNA in Tanzanian samples prepared by two different methods. All six of the in-house primer sets evaluated had a higher sensitivity for HIV DNA detection in samples prepared by the Amplicor PCR sample preparation method than in those prepared by the Ficoll-Isopaque (FIP) density gradient centrifugation method. A sensitivity of...

  6. Quantitative and dynamic measurements of biological fresh samples with X-ray phase contrast tomography

    International Nuclear Information System (INIS)

    Quantitative measurements of biological fresh samples based on three-dimensional densitometry using X-ray phase contrast tomography are presented. X-ray phase contrast tomography using a Talbot grating interferometer was applied to biological fresh samples which were not fixed by any fixatives. To achieve a high-throughput measurement for the fresh samples the X-ray phase contrast tomography measurement procedure was improved. The three-dimensional structure of a fresh mouse fetus was clearly depicted as a mass density map using X-ray phase contrast tomography. The mouse fetus measured in the fresh state was then fixed by formalin and measured in the fixed state. The influence of the formalin fixation on soft tissue was quantitatively evaluated by comparing the fresh and fixed samples. X-ray phase contrast tomography was also applied to the dynamic measurement of a biological fresh sample. Morphological changes of a ring-shaped fresh pig aorta were measured tomographically under different degrees of stretching

  7. Quantitative and dynamic measurements of biological fresh samples with X-ray phase contrast tomography

    Energy Technology Data Exchange (ETDEWEB)

    Hoshino, Masato, E-mail: hoshino@spring8.or.jp; Uesugi, Kentaro [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan); Tsukube, Takuro [Japanese Red Cross Kobe Hospital, 1-3-1 Wakinohamakaigandori, Chuo-ku, Kobe, Hyogo 651-0073 (Japan); Yagi, Naoto [Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo, Hyogo 679-5198 (Japan)

    2014-10-08

    Quantitative measurements of biological fresh samples based on three-dimensional densitometry using X-ray phase contrast tomography are presented. X-ray phase contrast tomography using a Talbot grating interferometer was applied to biological fresh samples which were not fixed by any fixatives. To achieve a high-throughput measurement for the fresh samples the X-ray phase contrast tomography measurement procedure was improved. The three-dimensional structure of a fresh mouse fetus was clearly depicted as a mass density map using X-ray phase contrast tomography. The mouse fetus measured in the fresh state was then fixed by formalin and measured in the fixed state. The influence of the formalin fixation on soft tissue was quantitatively evaluated by comparing the fresh and fixed samples. X-ray phase contrast tomography was also applied to the dynamic measurement of a biological fresh sample. Morphological changes of a ring-shaped fresh pig aorta were measured tomographically under different degrees of stretching.

  8. Demonstration Exercise of a Validated Sample Collection Method for Powders Suspected of Being Biological Agents in Georgia 2006

    International Nuclear Information System (INIS)

    August 7, 2006 the state of Georgia conducted a collaborative sampling exercise between the Georgia National Guard 4th Civil Support Team Weapons of Mass Destruction (CST-WMD) and the Georgia Department of Human Resources Division of Public Health demonstrating a recently validated bulk powder sampling method. The exercise was hosted at the Federal Law Enforcement Training Center (FLETC) at Glynn County, Georgia and involved the participation of the Georgia Emergency Management Agency (GEMA), Georgia National Guard, Georgia Public Health Laboratories, the Federal Bureau of Investigation Atlanta Office, Georgia Coastal Health District, and the Glynn County Fire Department. The purpose of the exercise was to demonstrate a recently validated national sampling standard developed by the American Standards and Test Measures (ASTM) International; ASTM E2458 Standard Practice for Bulk Sample Collection and Swab Sample Collection of Visible Powders Suspected of Being Biological Agents from Nonporous Surfaces. The intent of the exercise was not to endorse the sampling method, but to develop a model for exercising new sampling methods in the context of existing standard operating procedures (SOPs) while strengthening operational relationships between response teams and analytical laboratories. The exercise required a sampling team to respond real-time to an incident cross state involving a clandestine bio-terrorism production lab found within a recreational vehicle (RV). Sample targets consisted of non-viable gamma irradiated B. anthracis Sterne spores prepared by Dugway Proving Ground. Various spore concentration levels were collected by the ASTM method, followed by on- and off-scene analysis utilizing the Center for Disease Control (CDC) Laboratory Response Network (LRN) and National Guard Bureau (NGB) CST mobile Analytical Laboratory Suite (ALS) protocols. Analytical results were compared and detailed surveys of participant evaluation comments were examined. I will present

  9. A comparison of techniques for the metallographic preparation of thermal sprayed samples

    Science.gov (United States)

    Smith, M. F.; McGuffin, D. T.; Henfling, J. A.; Lenling, W. J.

    1993-09-01

    Metallographic preparation of thermal spray coated samples is often difficult because hard and soft materials, which normally require different polishing techniques, are commonly present in a single spraycoated sample. In addition, the microstructures of many spray- deposited materials make them prone to pull-out damage during cutting, grinding, and polishing operations. This study compares alternative metallographic techniques to prepare three common types of thermal sprayed coatings: (1) a plasma sprayed alumina-titania wear coating, (2) a plasma sprayed zirconia thermal barrier coating, and (3) a high-velocity oxy-fuel (HVOF) sprayed tungsten- carbide/cobalt (WC/Co) hard coating. Each coating was deposited onto a steel substrate and was prepared with metallographic protocols based on silicon carbide (SiC) papers, bonded diamond platens, and diamond slurries. Polishing with SiC papers generally produced edge rounding and significant pull- out, which increased the apparent porosity of the coatings. Polishing with bonded diamond platens produced less edge rounding, but some pull- out was still observed. Preparation by diamond slurry lapping consistently produced the best overall results. Porosity artifacts produced by polishing with SiC papers and bonded diamond platens also resulted in spuriously low hardness values for the WC/Co samples; however, hardness results for the two ceramic coatings were not affected by the polishing method.

  10. Evaluation of oxidation techniques for preparing bioassay and environmental samples for liquid scintillation counting

    International Nuclear Information System (INIS)

    In environmental and biological monitoring for carbon-14 and tritium, the presence of color and chemical quenching agents in the samples can degrade the efficiency of liquid scintillation counting. A series of experiments was performed to evaluate the usefulness, under routine conditions, of first oxidizing the samples to improve the counting by removing the color and quenching agents. The scintillation counter was calibrated for the effects of quenching agents on its counting efficiency. Oxidizing apparatus was tested for its ability to accurately recover the 14C and 3H in the samples. Scintillation counting efficiences were compared for a variety of oxidized and unoxidized environmental and bioassay samples. The overall conclusion was that, for routine counting, oxidation of such samples is advantageous when they are highly quenched or in solid form

  11. Simultaneous determination of arsenic and selenium in biological samples by HG-AFS

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Hanwen; Liu, Zhanfeng; Shi, Hongmei [Hebei University, College of Chemistry and Environmental Science, Baoding (China); Wu, Wenjuan [Third Hospital of Hebei Medical University, Department of Radiology, Shijiazhuang 050051 (China); Li, Liqing [Hebei University, College of Chemistry and Environmental Science, Baoding (China); Taishan College, Department of Chemistry, Shan Dong Taian (China)

    2005-06-01

    A new method is proposed for simultaneous determination of traces of arsenic (As) and selenium (Se) in biological samples by hydride-generation double-channel non-dispersive atomic-fluorescence spectrometry (HG-AFS) from tartaric acid media. The effects of analytical conditions on fluorescence signal intensity were investigated and optimized. Interferences from coexisting ions were evaluated. Under optimum conditions linear response ranges above 20 {mu}g L{sup -1} for As and 32 {mu}g L{sup -1} for Se were obtained with detection limits of 0.13 and 0.12 {mu}g L{sup -1}, respectively. The precision for elevenfold determination of As at the 4 {mu}g L{sup -1} level and of Se at the 8 {mu}g L{sup -1} level were 2.7 and 1.9% (RSD), respectively. Recoveries of 92.5-95.5% for As and 101.2-108.4% for Se were obtained for four biological samples and two certified biological reference materials. The proposed method has the advantages of simple operation, high sensitivity, and high efficiency; it was successfully used for simultaneous determination of As and Se in biological samples. (orig.)

  12. Will Women Diagnosed with Breast Cancer Provide Biological Samples for Research Purposes?

    Directory of Open Access Journals (Sweden)

    Shelley A Harris

    Full Text Available Little is known about the response rates for biological sample donation and attitudes towards control recruitment, especially in younger women. The goals of this pilot study were to determine in women recently diagnosed with breast cancer, the proportion of cases willing to provide biological samples and for purposes of control recruitment, contact information for friends or colleagues.A population-based sample of breast cancer cases (n = 417, 25-74 years was recruited from the Ontario Cancer Registry in 2010 and self-administered questionnaires were completed to determine willingness to provide samples (spot or 24-hr urine, saliva, blood and contact information for friends/colleagues for control recruitment. Using Χ2 analyses of contingency tables we evaluated if these proportions varied by age group (<45 and 45+ and other factors such as ethnicity, education, income, body mass index (BMI, smoking status and alcohol consumption.Cases were willing to provide blood samples, by visiting a clinic (62% or by having a nurse visit the home (61%. Moreover, they would provide saliva (73%, and morning or 24-hr urine samples (66% and 52%. Younger cases (≤45 were 3 times (OR more likely more than older cases to agree to collect morning urine (95% CI: 1.15-8.35. Only 26% of cases indicated they would provide contact information of friends or work colleagues to act as controls. Educated cases were more likely to agree to provide samples, and cases who consumed alcohol were more willing to provide contact information. Ethnicity, income, BMI and smoking had little effect on response rates.Reasonable response rates for biological sample collection should be expected in future case controls studies in younger women, but other methods of control selection must be devised.

  13. Methods for collection and analysis of aquatic biological and microbiological samples

    Science.gov (United States)

    Britton, L.J.; Greeson, P.E.

    1988-01-01

    Chapter A4, methods for collection and analyses of aquatic biological and microbiological samples, contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. Part 1 consists of detailed descriptions of more than 45 individual methods, including those for bacteria, phytoplankton, zooplankton, seston, periphyton, macrophytes, benthic invertebrates, fish and other vertebrates, cellular contents, productivity and bioassay. Each method is summarized, and the applications, interferences, apparatus, reagents, analyses, calculations, reporting of results, precisions, and references are given. Part 2 consists of a glossary. Part 3 is a list of taxonomic references. (USGS)

  14. A supplement to "Methods for collection and analysis of aquatic biological and microbiological samples"

    Science.gov (United States)

    1979-01-01

    The report contains methods used by the U.S. Geological Survey to collect, preserve, and analyze waters to determine their biological and microbiological properties. It supplements, "Methods for Collection and Analysis of Aquatic Biological and Microbiological Samples" (TWRI, Book 5, Chapter A4, 1977, edited by P. E. Greeson, T. A. Ehlke, G. A. Irwin, B. W. Lium, and K. V. Slack). Included in the supplement are 5 new methods, a new section of selected taxonomic references for Ostracoda, and 6 revised methods.

  15. Effect of host plant on gypsy moth diet and biological efficacy of Btk preparations

    Directory of Open Access Journals (Sweden)

    Milanović Slobodan

    2006-01-01

    Full Text Available The effect of two host plants, Turkey oak (Quercus cerris L and black poplar (Populus nigra L on gypsy moth (Lymantria dispar L development was researched. The effect of host plant was determined based on the parameters which characterize the diet, growth and efficacy of conversion of ingested food of the third instar caterpillars. Along with the effect on development, the effect of host plant on the efficacy of biological preparation based on the bacterium Bacillus thuringiensis var. kurstaki in gypsy moth caterpillar suppression was also researched. The differences in parameters characterizing the diet, growth, and efficacy of ingested food between experimental groups of caterpillars grown on poplar and Turkey oak leaves are explained by the differences in the chemical composition of the leaves of these tree species. The efficacy of Btk preparation is conditioned by the mechanism and content of different groups of defense substances in the leaves of the applied tree species.

  16. Biological preparation of chitosan nanoparticles and its in vitro antifungal efficacy against some phytopathogenic fungi.

    Science.gov (United States)

    Sathiyabama, M; Parthasarathy, R

    2016-10-20

    The aim of the present study was to prepare Chitosan nanoparticles through biological method with high antifungal activities. Chitosan nanoparticles were prepared by the addition of anionic proteins isolated from Penicillium oxalicum culture to chitosan solutions. The formation of chitosan nanoparticles was preliminary confirmed by UV-vis spectrophotometric analysis. The physico-chemical properties of the chitosan nanoparticles were determined by size and zeta potential analysis, FTIR analysis, HRTEM and XRD pattern. The chitosan nanoparticles were evaluated for its potential to inhibit the growth of phytopathogens viz., Pyricularia grisea, Alternaria solani, Fusarium oxysporum. It is evident from our results that chitosan nanoparticles inhibit the growth of phytopathogens tested. Chitosan nanoparticle treated chickpea seeds showed positive morphological effects such as enhanced germination%, seed vigor index and vegetative biomass of seedlings. All these results indicate that chitosan nanoparticle can be used further under field condition to protect various crops from the devastating fungal pathogens as well as growth promoters. PMID:27474573

  17. 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.

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

    International Nuclear Information System (INIS)

    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.

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

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jungdae [Department of Physics, The University of Texas, Austin, Texas 78712 (United States); Department of Physics and EHSRC, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Nam, Hyoungdo; Schroeder, Allan; Shih, Chih-Kang, E-mail: shih@physics.utexas.edu [Department of Physics, The University of Texas, Austin, Texas 78712 (United States); Qin, Shengyong [Department of Physics, The University of Texas, Austin, Texas 78712 (United States); Department of Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); ICQD, Hefei National Laboratory for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei, Anhui 230026 (China); Kim, Sang-ui [Department of Physics and EHSRC, University of Ulsan, Ulsan 680-749 (Korea, Republic of); Eom, Daejin [Korea Research Institute of Standards and Science, Daejeon 305-340 (Korea, Republic of)

    2015-09-15

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

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

    Science.gov (United States)

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

    2015-09-01

    We report on the design of a compact low temperature scanning tunneling microscope (STM) having in-situ sample preparation capability. The in-situ sample preparation chamber was designed to be compact allowing quick transfer of samples to the STM stage, which is ideal for preparing temperature sensitive samples such as ultra-thin metal films on semiconductor substrates. Conventional spring suspensions on the STM head often cause mechanical issues. To address this problem, we developed a simple vibration damper consisting of welded metal bellows and rubber pads. In addition, we developed a novel technique to ensure an ultra-high-vacuum (UHV) seal between the copper and stainless steel, which provides excellent reliability for cryostats operating in UHV. The performance of the STM was tested from 2 K to 77 K by using epitaxial thin Pb films on Si. Very high mechanical stability was achieved with clear atomic resolution even when using cryostats operating at 77 K. At 2 K, a clean superconducting gap was observed, and the spectrum was easily fit using the BCS density of states with negligible broadening. PMID:26429448

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

    Science.gov (United States)

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

    2015-09-01

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

  2. Constructing Database for Drugs and its Application to Biological Sample by HPTLC and GC/MS

    Energy Technology Data Exchange (ETDEWEB)

    Yoo, Y.C.; Park, S.W.; Lim, M.A.; Baeck, S.K.; Park, S.Y.; Lee, J.S.; Lee, J.S. [National Institute of Scientific investigation, Seoul (Korea); Lho, D.S. [Korea Institute of Science and Technology, Seoul (Korea)

    2000-04-01

    For the identification of unknown drugs in biological samples, we attempted rapid high performance thin layer chromatographic method which is sensitive and selective chromatographic analysis of high performance thin layer chromatography (HPTLC) with automated TLC sampler and ultra-violet (UV) scanner. We constructed HPTLC database (DB) on two hundred five drugs by using the data of Rf values and UV spectra (scan 200-360 nm) as well as gas chromatography/mass spectrometry (GC/MS) DB on ninety six drugs by using the data of relative retention time (RRT) on lidocain and mass spectra. After extracting drugs in geological sample by solid phase extraction (Clean Screen ZSDAU020), we applied them to HPTLC and GC/MS DB. Drugs, especially extracted from biological samples, showed good matching ratio to HPTLC DB and these drugs were confirmed by GC/MS. In conclusion, this DB system is thought to be very useful method for the screening of unknown drugs in biological samples. (author). 9 refs., 2 tabs., 6 figs.

  3. Hyperspectral imaging of nanoparticles in biological samples: Simultaneous visualization and elemental identification.

    Science.gov (United States)

    Peña, María Del Pilar Sosa; Gottipati, Abhishek; Tahiliani, Sahil; Neu-Baker, Nicole M; Frame, Mary D; Friedman, Adam J; Brenner, Sara A

    2016-05-01

    While engineered nanomaterials (ENMs) are increasingly incorporated into industrial processes and consumer products, the potential biological effects and health outcomes of exposure remain unknown. Novel advanced direct visualization techniques that require less time, cost, and resource investment than electron microscopy (EM) are needed for identifying and locating ENMs in biological samples. Hyperspectral imaging (HSI) combines spectrophotometry and imaging, using advanced optics and algorithms to capture a spectrum from 400 to 1000 nm at each pixel in an enhanced dark-field microscopic (EDFM) image. HSI-EDFM can be used to confirm the identity of the materials of interest in a sample and generate an image "mapping" their presence and location in a sample. Hyperspectral mapping is particularly important for biological samples, where ENM morphology is visually indistinct from surrounding tissue structures. While use of HSI (without mapping) is increasing, no studies to date have compared results from hyperspectral mapping with conventional methods. Thus, the objective of this study was to utilize EDFM-HSI to locate, identify, and map metal oxide ENMs in ex vivo histological porcine skin tissues, a toxicological model of cutaneous exposure, and compare findings with those of Raman spectroscopy (RS), energy-dispersive X-ray spectroscopy (EDS), and scanning electron microscopy (SEM). Results demonstrate that EDFM-HSI mapping is capable of locating and identifying ENMs in tissue, as confirmed by conventional methods. This study serves as initial confirmation of EDFM-HSI mapping as a novel and higher throughput technique for ENM identification in biological samples, and serves as the basis for further protocol development utilizing EDFM-HSI for semiquantitation of ENMs. Microsc. Res. Tech. 79:349-358, 2016. © 2016 Wiley Periodicals, Inc. PMID:26864497

  4. 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.

  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. PMID:22827101

  6. Sample preparation methods for LC-MS-based global aqueous metabolite profiling.

    Science.gov (United States)

    Beltran, Antoni; Samino, Sara; Yanes, Oscar

    2014-01-01

    Metabolite extraction is a key step in metabolomic analyses, particularly for untargeted studies. The extraction determines the types of metabolites that will be detected and the analytical platform to be used. In this chapter we describe two protocols aimed at detecting polar metabolites from biological samples; the first is aimed at detecting reduced species by LC/MS, and the second satisfies the requirements for both NMR and LC/MS analysis simultaneously. PMID:25270923

  7. imFASP: An integrated approach combining in-situ filter-aided sample pretreatment with microwave-assisted protein digestion for fast and efficient proteome sample preparation.

    Science.gov (United States)

    Zhao, Qun; Fang, Fei; Wu, Ci; Wu, Qi; Liang, Yu; Liang, Zhen; Zhang, Lihua; Zhang, Yukui

    2016-03-17

    An integrated sample preparation method, termed "imFASP", which combined in-situ filter-aided sample pretreatment and microwave-assisted trypsin digestion, was developed for preparation of microgram and even nanogram amounts of complex protein samples with high efficiency in 1 h. For imFASP method, proteins dissolved in 8 M urea were loaded onto a filter device with molecular weight cut off (MWCO) as 10 kDa, followed by in-situ protein preconcentration, denaturation, reduction, alkylation, and microwave-assisted tryptic digestion. Compared with traditional in-solution sample preparation method, imFASP method generated more protein and peptide identifications (IDs) from preparation of 45 μg Escherichia coli protein sample due to the higher efficiency, and the sample preparation throughput was significantly improved by 14 times (1 h vs. 15 h). More importantly, when the starting amounts of E. coli cell lysate decreased to nanogram level (50-500 ng), the protein and peptide identified by imFASP method were improved at least 30% and 44%, compared with traditional in-solution preparation method, suggesting dramatically higher peptide recovery of imFASP method for trace amounts of complex proteome samples. All these results demonstrate that the imFASP method developed here is of high potential for high efficient and high throughput preparation of trace amounts of complex proteome samples. PMID:26920773

  8. Applications of Blue Light-curing Acrylic Resin to Forensic Sample Preparation and Microtomy.

    Science.gov (United States)

    Groves, Ethan; Palenik, Christopher S

    2016-03-01

    This study discusses the results of an evaluation of a one-part blue light-curing acrylic resin for embedding trace evidence prior to the preparation of thin sections with a microtome. Through a comparison to several epoxy resins, the physical properties relevant to both trace evidence examination and analytical microscopy in general, including as viscosity, clarity, color, hardness, and cure speed, were explored. Finally, thin sections from paint samples embedded in this acrylic resin were evaluated to determine if, through smearing or impregnation, the resin contributed to the infrared spectra. The results of this study show that blue light-curing acrylic resins provide the desired properties of an embedding medium, generate high-quality thin sections, and can significantly simplify the preparation of paint chips, fibers and a multitude of other types of microscopic samples in the forensic trace evidence laboratory. PMID:27404623

  9. Optimization of proteomic sample preparation procedures for comprehensive protein characterization of pathogenic systems

    Energy Technology Data Exchange (ETDEWEB)

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

    2008-12-19

    The elucidation of critical functional pathways employed by pathogens and hosts during an infectious cycle is both challenging and central to our understanding of infectious diseases. In recent years, mass spectrometry-based proteomics has been used as a powerful tool to identify key pathogenesis-related proteins and pathways. Despite the analytical power of mass spectrometry-based technologies, samples must be appropriately prepared to characterize the functions of interest (e.g. host-response to a pathogen or a pathogen-response to a host). The preparation of these protein samples requires multiple decisions about what aspect of infection is being studied, and it may require the isolation of either host and/or pathogen cellular material.

  10. 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.

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

    Science.gov (United States)

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

    2000-06-01

    Off-flavors in foods may originate from environmental pollutants, the growth of microorganisms, oxidation of lipids, or endogenous enzymatic decomposition in the foods. The chromatographic analysis of flavors and off-flavors in foods usually requires that the samples first be processed to remove as many interfering compounds as possible. For analysis of foods by gas chromatography (GC), sample preparation may include mincing, homogenation, centrifugation, distillation, simple solvent extraction, supercritical fluid extraction, pressurized-fluid extraction, microwave-assisted extraction, Soxhlet extraction, or methylation. For high-performance liquid chromatography of amines in fish, cheese, sausage and olive oil or aldehydes in fruit juice, sample preparation may include solvent extraction and derivatization. Headspace GC analysis of orange juice, fish, dehydrated potatoes, and milk requires almost no sample preparation. Purge-and-trap GC analysis of dairy products, seafoods, and garlic may require heating, microwave-mediated distillation, purging the sample with inert gases and trapping the analytes with Tenax or C18, thermal desorption, cryofocusing, or elution with ethyl acetate. Solid-phase microextraction GC analysis of spices, milk and fish can involve microwave-mediated distillation, and usually requires adsorption on poly(dimethyl)siloxane or electrodeposition on fibers followed by thermal desorption. For short-path thermal desorption GC analysis of spices, herbs, coffee, peanuts, candy, mushrooms, beverages, olive oil, honey, and milk, samples are placed in a glass-lined stainless steel thermal desorption tube, which is purged with helium and then heated gradually to desorb the volatiles for analysis. Few of the methods that are available for analysis of food flavors and off-flavors can be described simultaneously as cheap, easy and good. PMID:10890508

  12. Taking samples from the reactor components in preparation for dismantling the TRIGA reactor at the Medical University of Hannover

    International Nuclear Information System (INIS)

    After shutting down the facility at the end of 1996 the spent TRIGA fuel elements from the research reactor at the Medical University of Hanover (MHH) were returned to the United States in the summer of 1999 and thus disposed of for the MHH. Consequently one of the main prerequisites for dismantling the TRIGA reactor as planned has been fulfilled. In preparation for dismantling the facility a number of samples were taken from the various reactor components in 2000. The aim of the samples being taken was to establish the radiological condition of the facility in more detail, in particular the condition of the activated components in the reactor tank and the biological shield in the core area. Up to now the calculated estimates for these components had been based mainly on the details provided in the facility documentation when operation started at the beginning of the 1970s, showing that the evaluation of the activity and dose rates was too high. This was confirmed in 1998 in the course of measuring contamination and dose rates when samples were taken from some reactor components before the fuel elements were removed. For example, drill samples were taken from the bottom part of a graphite blind element and from the central radiation beam tube in the core area and then analyzed by the U.R.A. Laboratory of the University of Regensburg. As it is planned to dismantle the reactor facility completely by hand, it is necessary to have realistic radiological data in order to prepare for the dismantling procedure. Furthermore, both the release of radioactive materials into the environment and the costs for external disposal of the radioactive waste from the dismantling of the reactor are to be kept to a minimum. (orig.)

  13. A sample preparation method of individual aerosol particles in SPM analysis

    International Nuclear Information System (INIS)

    A new method for sample preparation of individual aerosol particle in SPM analysis was developed. Aerosol particles were collected directly on the polyvinyl butyral (PVB) foil by using air sampler. Microscopic observation indicates that the particles were separated completely and the interval of particles was reasonable. The SPM experiment proves that PVB foils have excellent stability under proton microbeam bombardment and are a suitable backing material for supporting the single particle for SPM analysis. (authors)

  14. Sample preparation for scanning Kelvin probe microscopy studies on cross sections of organic solar cells

    OpenAIRE

    Michael Scherer; Rebecca Saive; Dominik Daume; Michael Kröger; Wolfgang Kowalsky

    2013-01-01

    We prepared cross sections of P3HT:PCBM bulk heterojunction (BHJ) organic solar cells (OSCs) for the characterization of their potential distribution with scanning Kelvin probe microscopy. We compared results of samples obtained by microtome cutting of OSCs on plastic substrates, cleaving of OSCs on glass substrates, and milling with a focused ion beam. Their potential distributions were in good agreement with each other. Under short circuit conditions, potential gradients were detected in vi...

  15. Sample preparation for accelerator mass spectrometry at the University of Washington

    International Nuclear Information System (INIS)

    The adaptation of the University of Washington FN tandem Van de Graaff to accelerator mass spectrometry (AMS), as well as some of the results obtained, are described in another paper in this volume (Farwell et al., 1981). Here we discuss our experiences in preparing carbon and beryllium samples that give large and stable ion beams when used in our Extrion cesium sputter source with an inverted cesium beam geometry

  16. On the preparation of electron sensor using LiRbSO4 samples

    Science.gov (United States)

    El-Muraikhi, M.; Kassem, M. E.; Gaafar, M.; Abdel Gawad, M. M. H.; Ragab, I. M.

    2005-01-01

    The dielectric spectroscopy of metal-metal sulfate LiRbSO4 samples are described with particular emphasis on sensor performance to be used in the field of radiation. The obtained results as the effect of different electron energy beams at fixed dose, 0.5 Gy, showed abrupt change of the electrical properties (electrical conductivity, capacitance, and loss tangent). The results can be explained on the basis of radiation-induced defects followed by radiation quenching. The prepared samples can be used in the field of radiation dosimeter.

  17. Electroanalytical Determination of Danofloxacin in Biological Samples Using Square Wave Voltammetry

    Directory of Open Access Journals (Sweden)

    Chirley Vanessa Boone

    2014-10-01

    Full Text Available The voltammetric behavior of danofloxacin (DFX has been studied, in aqueous solution, on a glassy carbon electrode using square wave voltammetry (SWV as electroanalytical technique. After optimization of the experimental conditions, DFX was analyzed in spiked biologic samples using a Britton-Robinson buffer with pH = 5.0 as the supporting electrolyte. Oxidation occurs at 0.98 V vs. Ag/AgCl in a two-electron process controlled by adsorption of the electrogenerated products on the electrode surface. A acceptable recovery was obtained for assay of spiked biologic samples, with value of 98.7% for the swine urine and 95.3 % for the bovine urine.

  18. Estimate of beta and gamma contamination in vegetable and animal biologic samples using GM detectors

    International Nuclear Information System (INIS)

    The paper presents the use of a large area Geiger-Mueller Detector (GMD) with aluminium window of 50 mm thickness (3,4 mg/cm2) in a measuring chain in order to estimate the beta and gamma contamination of biologic samples. The technical data for GMD are: - window area for gamma radiation: 300 cm2; - grid transmission: 80%; - operating voltage: 1100 - 1300 V; - minimum detectable beta energy: 125 keV; - dead time: 250 ms; - background (shielded with 100 mm Pb + 1 mm Cu): 6 pulses/s; - service life: 5 x 108 counts. Using this GMD together with a set of large area beta standard sources and a set of point gamma sources we could estimate beta and gamma contamination in the energy range 125 keV - 2.5 MeV for biologic samples. (authors)

  19. Correction of radiation absorption on biological samples using Rayleigh to Compton scattering ratio

    Science.gov (United States)

    Pereira, Marcelo O.; Conti, Claudio de Carvalho; dos Anjos, Marcelino J.; Lopes, Ricardo T.

    2012-06-01

    The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E gamma-ray source of 241Am (59.54 keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples.

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

    Science.gov (United States)

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

    2014-01-01

    Accelerator mass spectrometry (AMS) is a highly sensitive technique used for the quantification of adducts following exposure to carbon-14- or tritium-labeled chemicals, with detection limits in the range of one adduct per 10(11)-10(12) nucleotides. The protocol described in this chapter provides an optimal method for isolating and preparing DNA samples to measure isotope-labeled DNA adducts by AMS. When preparing samples, special precautions must be taken to avoid cross-contamination of isotope among samples and produce a sample that is compatible with AMS. The DNA isolation method described is based upon digestion of tissue with proteinase K, followed by extraction of DNA using Qiagen isolation columns. The extracted DNA is precipitated with isopropanol, washed repeatedly with 70 % ethanol to remove salt, and then dissolved in water. DNA samples are then converted to graphite or titanium hydride and the isotope content measured by AMS to quantify adduct levels. This method has been used to reliably generate good yields of uncontaminated, pure DNA from animal and human tissues for analysis of adduct levels. PMID:24623226

  1. Preparation of resistance random access memory samples for in situ transmission electron microscopy experiments

    Energy Technology Data Exchange (ETDEWEB)

    Kudo, Masaki, E-mail: masakikudo@ist.hokudai.ac.jp; Arita, Masashi; Ohno, Yuuki; Fujii, Takashi; Hamada, Kouichi; Takahashi, Yasuo

    2013-04-30

    The ion-shadow method, an ion milling process using carbon particles as the mask material, is investigated as a means of preparing resistance random access memory (ReRAM) samples for in situ transmission electron microscopy (TEM). With a milling time of 1 hour (Ar{sup +}, 5 kV, 1 mA), multiple long needles (> 5 μm), on which there are miniaturized ReRAM devices comprising a ReRAM insulating layer sandwiched by two metallic electrodes, are formed on the substrate. Device sizes of up to several hundreds of nm are easily obtained with the method. The internal part of small devices (i.e., up to 100 nm) can be observed by TEM. Electrical measurements using an in situ TEM holder demonstrate that sufficient electric contact is obtained without any electric shortage between the electrodes due to re-deposition of milled material. The ion-shadow method is confirmed to be a quick and easy method suitable for in situ TEM experiments, especially for ReRAM devices which are highly susceptible to destruction during the switching operation. - Highlights: ► Preparation method of in situ transmission electron microscopy samples is shown. ► Long and sharp needle-shaped samples are formed with the ion-shadow method. ► Resistive switching samples are formed at the tips of needle-shaped samples. ► Current–voltage characteristics obtained in an electron microscope are shown.

  2. Sample Preparation for in vitro Analysis of Iodine in Thyroid Tissue using X-ray Fluorescence

    Directory of Open Access Journals (Sweden)

    Gertrud Berg

    2008-01-01

    Full Text Available Iodine is enriched and stored in the thyroid gland. Due to several factors, the size of the thyroid iodine pool varies both between individuals and within individuals over time. Excess iodine as well as iodine deficiency may promote thyroid cancer. Therefore, knowledge of iodine content and distribution within thyroid cancer tissue is of interest. X-ray fluorescence analysis (XRF and secondary ion mass spectrometry (SIMS are two methods that can be used to assess iodine content in thyroid tissue. With both techniques, choice of sample preparation affects the results. Aldehyde fixatives are required for SIMS analysis while a freezing method might be satisfactory for XRF analysis. The aims of the present study were primarily to evaluate a simple freezing technique for preserving samples for XRF analysis and also to use XRF to evaluate the efficacy of using aldehyde fixatives to prepare samples for SIMS analysis. Ten porcine thyroids were sectioned into four pieces that were either frozen or fixed in formaldehyde, glutaraldehyde, or a modified Karnovsky fixative. The frozen samples were assessed for iodine content with XRF after 1 and 2 months, and the fixed samples were analyzed for iodine content after 1 week. Freezing of untreated tissue yielded no significant iodine loss, whereas fixation with aldehydes yielded an iodine loss of 14–30%, with Karnovsky producing the least loss.

  3. Preparation of resistance random access memory samples for in situ transmission electron microscopy experiments

    International Nuclear Information System (INIS)

    The ion-shadow method, an ion milling process using carbon particles as the mask material, is investigated as a means of preparing resistance random access memory (ReRAM) samples for in situ transmission electron microscopy (TEM). With a milling time of 1 hour (Ar+, 5 kV, 1 mA), multiple long needles (> 5 μm), on which there are miniaturized ReRAM devices comprising a ReRAM insulating layer sandwiched by two metallic electrodes, are formed on the substrate. Device sizes of up to several hundreds of nm are easily obtained with the method. The internal part of small devices (i.e., up to 100 nm) can be observed by TEM. Electrical measurements using an in situ TEM holder demonstrate that sufficient electric contact is obtained without any electric shortage between the electrodes due to re-deposition of milled material. The ion-shadow method is confirmed to be a quick and easy method suitable for in situ TEM experiments, especially for ReRAM devices which are highly susceptible to destruction during the switching operation. - Highlights: ► Preparation method of in situ transmission electron microscopy samples is shown. ► Long and sharp needle-shaped samples are formed with the ion-shadow method. ► Resistive switching samples are formed at the tips of needle-shaped samples. ► Current–voltage characteristics obtained in an electron microscope are shown

  4. Radioisotope Sample Measurement Techniques in Medicine and Biology. Proceedings of the Symposium on Radioisotope Sample Measurement Techniques

    International Nuclear Information System (INIS)

    The medical and biological applications of radioisotopes depend on two basically different types of measurements, those on living subjects in vivo and those on samples in vitro. The International Atomic Energy Agency has in the past held several meetings on in vivo measurement techniques, notably whole-body counting and radioisotope scanning. The present volume contains the Proceedings of the first Symposium the Agency has organized to discuss the various aspects of techniques for sample measurement in vitro. The range of these sample measurement techniques is very wide. The sample may weigh a few milligrams or several hundred grams, and may be in the gaseous, liquid or solid state. Its radioactive content may consist of a single, known radioisotope or several unknown ones. The concentration of radioactivity may be low, medium or high. The measurements may be made manually or automatically and any one of the many radiation detectors now available may be used. The 53 papers presented at the Symposium illustrate the great variety of methods now in use for radioactive- sample measurements. The first topic discussed is gamma-ray spectrometry, which finds an increasing number of applications in sample measurements. Other sections of the Proceedings deal with: the use of computers in gamma-ray spectrometry and multiple tracer techniques; recent developments in activation analysis where both gamma-ray spectrometry and computing techniques are applied; thin-layer and paper radio chromatographic techniques for use with low energy beta-ray emitters; various aspects of liquid scintillation counting techniques in the measurement of alpha- and beta-ray emitters, including chemical and colour quenching; autoradiographic techniques; calibration of equipment; and standardization of radioisotopes. Finally, some applications of solid-state detectors are presented; this section may be regarded as a preview of important future developments. The meeting was attended by 203 participants

  5. Dopant mapping in thin FIB prepared silicon samples by Off-Axis Electron Holography

    International Nuclear Information System (INIS)

    Modern semiconductor devices function due to accurate dopant distribution. Off-Axis Electron Holography (OAEH) in the transmission electron microscope (TEM) can map quantitatively the electrostatic potential in semiconductors with high spatial resolution. For the microelectronics industry, ongoing reduction of device dimensions, 3D device geometry, and failure analysis of specific devices require preparation of thin TEM samples, under 70 nm thick, by focused ion beam (FIB). Such thicknesses, which are considerably thinner than the values reported to date in the literature, are challenging due to FIB induced damage and surface depletion effects. Here, we report on preparation of TEM samples of silicon PN junctions in the FIB completed by low-energy (5 keV) ion milling, which reduced amorphization of the silicon to 10 nm thick. Additional perpendicular FIB sectioning enabled a direct measurement of the TEM sample thickness in order to determine accurately the crystalline thickness of the sample. Consequently, we find that the low-energy milling also resulted in a negligible thickness of electrically inactive regions, approximately 4 nm thick. The influence of TEM sample thickness, FIB induced damage and doping concentrations on the accuracy of the OAEH measurements were examined by comparison to secondary ion mass spectrometry measurements as well as to 1D and 3D simulations of the electrostatic potentials. We conclude that for TEM samples down to 100 nm thick, OAEH measurements of Si-based PN junctions, for the doping levels examined here, resulted in quantitative mapping of potential variations, within ∼0.1 V. For thinner TEM samples, down to 20 nm thick, mapping of potential variations is qualitative, due to a reduced accuracy of ∼0.3 V. This article is dedicated to the memory of Zohar Eliyahou. - Highlights: • Quantitative potential mapping of Si PN junctions by Off-Axis Electron Holography in thin FIB prepared samples, down to 50 nm thick. • Reduction of

  6. Specific determination of clinical and toxicological important substances in biological samples by LC-MS

    International Nuclear Information System (INIS)

    This thesis of this dissertation is the specific determination of clinical and toxicological important substances in biological samples by LC-MS. Nicotine was determined in serum after application of nicotine plaster and nicotine nasal spray with HPLC-ESI-MS. Cotinine was determined direct in urine with HPLC-ESI-MS. Short time anesthetics were determined in blood and cytostatics were determined in liquor with HPLC-ESI-MS. (botek)

  7. Reflective interferometric chamber for quantitative phase imaging of biological sample dynamics

    OpenAIRE

    Shaked, Natan T.; Zhu, Yizheng; Badie, Nima; Bursac, Nenad; Wax, Adam

    2010-01-01

    We introduce a new interferometric setup for single-exposure wide-field holographic phase imaging of highly dynamic biological samples. In this setup, the interferometric signal originates from a specially designed reflective interferometric chamber (InCh), creating an off-axis interferogram on the output plane of the system. The setup only requires the InCh and a simple reflection-mode two lens imaging system, without the need for additional optical elements such as gratings in the beam path...

  8. Sample preparation and direct electrospray ionization on a tip column for rapid mass spectrometry analysis of complex samples.

    Science.gov (United States)

    Huang, Yun-Qing; You, Jin-Qing; Yuan, Bi-Feng; Feng, Yu-Qi

    2012-10-01

    A handheld pipette tip column electrospray ionization source (PTC-ESI source) was developed for rapid mass spectrometry analysis at ambient pressure. The PTC-ESI source was made up of three main component parts including a micro DC high voltage (HV) power supply, a micropipette and a disposable micropipette tip filled with a plug of adsorbent. A DC high voltage was applied to the sharp point of the micropipette tip column to induce electrospray ionization. The PTC-ESI source was successfully used for direct analysis of basic organic compounds, organic acids and peptides in a simple matrix. In the case of complex samples, micro-extraction based on the adsorbent phase filled in the pipette tip was used to remove impurities and concentrate target analytes prior to ionization. The eluting solution was not pipetted out, but directly dispersed in the form of electrospray from the pipette tip for ionization. The effectiveness of the PTC-ESI source has been further demonstrated by fast analysis of therapeutic compounds and endogenous bioactive chemicals in complex biological samples. PMID:22898704

  9. Assessment of the differential linear coherent scattering coefficient of biological samples

    International Nuclear Information System (INIS)

    New differential linear coherent scattering coefficient, μCS, data for four biological tissue types (fat pork, tendon chicken, adipose and fibroglandular human breast tissues) covering a large momentum transfer interval (0.07≤q≤70.5 nm-1), resulted from combining WAXS and SAXS data, are presented in order to emphasize the need to update the default data-base by including the molecular interference and the large-scale arrangements effect. The results showed that the differential linear coherent scattering coefficient demonstrates influence of the large-scale arrangement, mainly due to collagen fibrils for tendon chicken and fibroglandular breast samples, and triacylglycerides for fat pork and adipose breast samples at low momentum transfer region. While, at high momentum transfer, the μCS reflects effects of molecular interference related to water for tendon chicken and fibroglandular samples and, fatty acids for fat pork and adipose samples.

  10. Determination of the sampling factor in biological standards using INAA and PIXE analysis

    International Nuclear Information System (INIS)

    Variations in the distribution of elemental concentrations in most biological materials suggest that a subsample, taken from a specimen containing the elements of interest, may not be representative of the specimen due to lack of homogeneity. It is therefore important when using a trace-element analysis technique, to know the representative mass, defined by a sampling factor for a given relative subsampling error, for whichever material is analysed and for each element detected. We have used two complementary techniques, instrumental neutron activation analysis (INAA) using short-lived radionuclides and proton-induced X-ray emission (PIXE) analysis to determine the concentration of 17 elements and obtain their sampling factors in a number of biological standards. In the case of PIXE a 2 MeV, 0.5 mm diameter proton beam was used and the sampling factor was expressed in terms of the number of spots on the target material required for a representative sample mass to be analysed. Six elements, Cl, Ca, Cu, K, Mn and Br, were detected by both techniques and results show that the values of the sampling factors are technique-dependent. (orig.)

  11. Correction of radiation absorption on biological samples using Rayleigh to Compton scattering ratio

    Energy Technology Data Exchange (ETDEWEB)

    Pereira, Marcelo O., E-mail: marcelocefetrj@gmail.com [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, Rio de Janeiro (Brazil); Basic Disciplines Department, CEFET-RJ Uned Nova Iguacu, Rio de Janeiro (Brazil); Conti, Claudio de Carvalho [Radiation Protection and Dosimetry Institute, CNEN/IRD, Rio de Janeiro (Brazil); Anjos, Marcelino J. dos [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, Rio de Janeiro (Brazil); Physics Institute, State University of Rio de Janeiro, Rio de Janeiro (Brazil); Lopes, Ricardo T. [Nuclear Instrumentation Laboratory, PEN/COPPE/UFRJ, Rio de Janeiro (Brazil)

    2012-06-01

    The aim of this work was to develop a method to correct the absorbed radiation (the mass attenuation coefficient curve) in low energy (E < 30 keV) applied to a biological matrix based on the Rayleigh to Compton scattering ratio and the effective atomic number. For calibration, scattering measurements were performed on standard samples of radiation produced by a gamma-ray source of {sup 241}Am (59.54 keV) also applied to certified biological samples of milk powder, hay powder and bovine liver (NIST 1557B). In addition, six methods of effective atomic number determination were used as described in literature to determinate the Rayleigh to Compton scattering ratio (R/C), in order to calculate the mass attenuation coefficient. The results obtained by the proposed method were compared with those obtained using the transmission method. The experimental results were in good agreement with transmission values suggesting that the method to correct radiation absorption presented in this paper is adequate for biological samples.

  12. Biological samples positioning device for irradiations on a radial channel at the nuclear research reactor

    International Nuclear Information System (INIS)

    For the demand of an experimental device for biological samples positioning system for irradiations on a radial channel at the nuclear research reactor in operation was constructed and started up a device for the place and remove of the biological samples from the irradiation channels without interrupting the operation of the reactor. The economical valuations are effected comparing with another type of device with the same functions. This work formed part of an international project between Cuba and Brazil that undertook the study of the induced damages by various types of ionizing radiation in DNA molecules. Was experimentally tested the proposed solution, which demonstrates the practical validity of the device. As a result of the work, the experimental device for biological samples irradiations are installed and operating in the radial beam hole No3(BH3) for more than five years at the IEA-R1 Brazilian research reactor according to the solicited requirements the device. The designed device increases considerably the type of studies can be conducted in this reactor. Its practical application in research taking place in that facility, in the field of radiobiology and dosimetry, and so on is immediate

  13. Application of Compton suppression spectrometry in the improvement of nuclear analytical techniques for biological samples

    International Nuclear Information System (INIS)

    Compton Suppression Factors (SF) and Compton Reduction Factors (RF) of the UT Austin's Compton suppression spectrometer being parameters characterizing the system performance were measured using ''1''3''7Cs and ''6''0Co point sources. The system performance was evaluated as a function of energy and geometry. The (P/C), A(P/C), (P/T), Cp, and Ce were obtained for each of the parameters. The natural background reduction factor in the anticoincidence mode and that of normal mode was calculated and its effect on the detection limit of biological samples evaluated. Applicability of the spectrometer and the method for biological samples was tested in the measurement of twenty-four elements (Ba, Sr, I, Br, Cu, V, Mg, Na, Cl, Mn, Ca, Sn, In, K, Mo, Cd, Zn, As, Sb, Ni, Rb, Cs, Fe, and Co) commonly found in food, milk, tea and tobacco items. They were determined from seven National Institute for Standard and Technology (NIST) certified reference materials (rice flour, oyster tissue, non-fat powdered milk, peach leaves, tomato leaves, apple leaves, and citrus leaves). Our results shows good agreement with the NIST certified values, indicating that the method developed in the present study is suitable for the determination of aforementioned elements in biological samples without undue interference problems

  14. Sampling designs matching species biology produce accurate and affordable abundance indices

    Directory of Open Access Journals (Sweden)

    Grant Harris

    2013-12-01

    Full Text Available Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling, it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS data from 42 Alaskan brown bears (Ursus arctos. Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion, and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture

  15. Sampling designs matching species biology produce accurate and affordable abundance indices

    Science.gov (United States)

    Farley, Sean; Russell, Gareth J.; Butler, Matthew J.; Selinger, Jeff

    2013-01-01

    Wildlife biologists often use grid-based designs to sample animals and generate abundance estimates. Although sampling in grids is theoretically sound, in application, the method can be logistically difficult and expensive when sampling elusive species inhabiting extensive areas. These factors make it challenging to sample animals and meet the statistical assumption of all individuals having an equal probability of capture. Violating this assumption biases results. Does an alternative exist? Perhaps by sampling only where resources attract animals (i.e., targeted sampling), it would provide accurate abundance estimates more efficiently and affordably. However, biases from this approach would also arise if individuals have an unequal probability of capture, especially if some failed to visit the sampling area. Since most biological programs are resource limited, and acquiring abundance data drives many conservation and management applications, it becomes imperative to identify economical and informative sampling designs. Therefore, we evaluated abundance estimates generated from grid and targeted sampling designs using simulations based on geographic positioning system (GPS) data from 42 Alaskan brown bears (Ursus arctos). Migratory salmon drew brown bears from the wider landscape, concentrating them at anadromous streams. This provided a scenario for testing the targeted approach. Grid and targeted sampling varied by trap amount, location (traps placed randomly, systematically or by expert opinion), and traps stationary or moved between capture sessions. We began by identifying when to sample, and if bears had equal probability of capture. We compared abundance estimates against seven criteria: bias, precision, accuracy, effort, plus encounter rates, and probabilities of capture and recapture. One grid (49 km2 cells) and one targeted configuration provided the most accurate results. Both placed traps by expert opinion and moved traps between capture sessions, which

  16. Polymer monolithic capillary microextraction on-line coupled with inductively coupled plasma-mass spectrometry for the determination of trace Au and Pd in biological samples

    Science.gov (United States)

    Liu, Xiaolan; He, Man; Chen, Beibei; Hu, Bin

    2014-11-01

    A novel method based on on-line polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Au and Pd in biological samples. For this purpose, poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was prepared and functionalized with mercapto groups. The prepared monolith exhibited good selectivity to Au and Pd, and good resistance to strong acid with a long life span. Factors affecting the extraction efficiency of CME, such as sample acidity, sample flow rate, eluent conditions and coexisting ion interference were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) were 5.9 ng L- 1 for Au and 8.3 ng L- 1 for Pd, and the relative standard deviations (RSDs, c = 50 ng L -1, n = 7) were 6.5% for Au and 1.1% for Pd, respectively. The developed method was successfully applied to the determination of Au and Pd in human urine and serum samples with the recovery in the range of 84-118% for spiked samples. The developed on-line polymer monolithic CME-ICP-MS method has the advantages of rapidity, simplicity, low sample/reagent consumption, high sensitivity and is suitable for the determination of trace Au and Pd in biological samples with limited amount available and complex matrix.

  17. A fully automated plasma protein precipitation sample preparation method for LC-MS/MS bioanalysis.

    Science.gov (United States)

    Ma, Ji; Shi, Jianxia; Le, Hoa; Cho, Robert; Huang, Judy Chi-jou; Miao, Shichang; Wong, Bradley K

    2008-02-01

    This report describes the development and validation of a robust robotic system that fully integrates all peripheral devices needed for the automated preparation of plasma samples by protein precipitation. The liquid handling system consisted of a Tecan Freedom EVO 200 liquid handling platform equipped with an 8-channel liquid handling arm, two robotic plate-handling arms, and two plate shakers. Important additional components integrated into the platform were a robotic temperature-controlled centrifuge, a plate sealer, and a plate seal piercing station. These enabled unattended operation starting from a stock solution of the test compound, a set of test plasma samples and associated reagents. The stock solution of the test compound was used to prepare plasma calibration and quality control samples. Once calibration and quality control samples were prepared, precipitation of plasma proteins was achieved by addition of three volumes of acetonitrile. Integration of the peripheral devices allowed automated sequential completion of the centrifugation, plate sealing, piercing and supernatant transferral steps. The method produced a sealed, injection-ready 96-well plate of plasma extracts. Accuracy and precision of the automated system were satisfactory for the intended use: intra-day and the inter-day precision were excellent (C.V.<5%), while the intra-day and inter-day accuracies were acceptable (relative error<8%). The flexibility of the platform was sufficient to accommodate pharmacokinetic studies of different numbers of animals and time points. To the best of our knowledge, this represents the first complete automation of the protein precipitation method for plasma sample analysis. PMID:18226589

  18. Preparing nano-calcium phosphate particles via a biologically friendly pathway

    Energy Technology Data Exchange (ETDEWEB)

    Hu Qinghong; Xu Xurong; Tang Ruikang [Department of Chemistry and Centre of Biopathways and Biomaterials, Zhejiang University, Hangzhou, Zhejang 310027 (China); Ji Huijiao; Liu Yukan; Zhang Ming, E-mail: rtang@zju.edu.c [Department of Biology, Zhejiang University, Hangzhou, Zhejiang 310058 (China)

    2010-08-01

    It is widely agreed that nano-calcium phosphates (CaP) play an important role in tissue engineering and medical application due to their unique biological characteristics. However, the properties of nano-CaP, including bioactivity, biocompatibility and mechanical properties, are tailored over wide ranges by controlling the size and morphology of particles. Therefore, it is important to develop synthesis methods which can control the particle size distribution and shape uniformly. In this study, we report that polyacrylic acid (PAA) can act as an efficient agent to modulate nano-CaP formation. The dimension of the resultant sphere-like nanoparticles (5-60 nm) can readily be regulated by changing PAA concentrations (75-200 {mu}g ml{sup -1}). In contrast to other additives, PAA is a water-soluble polymer that has already been used as an excellent biocompatible implant material in vivo. Our in vitro proliferation experiments of bone marrow mesenchymal stem cells (BMSCs) demonstrate that the involvement of PAA does not change the bioactivity of the resultant nano-CaP. In contrast, the nano-CaP fabricated by using another typical control agent, hexadecyl (cetyl) trimethyl ammonium bromide, suppressed the cell proliferation of BMSCs. Thus, we suggest that the biopolymer, PAA, can provide a more biologically friendly pathway to prepare biological nano-CaP for biomedical application. (communication)

  19. Preparing nano-calcium phosphate particles via a biologically friendly pathway

    International Nuclear Information System (INIS)

    It is widely agreed that nano-calcium phosphates (CaP) play an important role in tissue engineering and medical application due to their unique biological characteristics. However, the properties of nano-CaP, including bioactivity, biocompatibility and mechanical properties, are tailored over wide ranges by controlling the size and morphology of particles. Therefore, it is important to develop synthesis methods which can control the particle size distribution and shape uniformly. In this study, we report that polyacrylic acid (PAA) can act as an efficient agent to modulate nano-CaP formation. The dimension of the resultant sphere-like nanoparticles (5-60 nm) can readily be regulated by changing PAA concentrations (75-200 μg ml-1). In contrast to other additives, PAA is a water-soluble polymer that has already been used as an excellent biocompatible implant material in vivo. Our in vitro proliferation experiments of bone marrow mesenchymal stem cells (BMSCs) demonstrate that the involvement of PAA does not change the bioactivity of the resultant nano-CaP. In contrast, the nano-CaP fabricated by using another typical control agent, hexadecyl (cetyl) trimethyl ammonium bromide, suppressed the cell proliferation of BMSCs. Thus, we suggest that the biopolymer, PAA, can provide a more biologically friendly pathway to prepare biological nano-CaP for biomedical application. (communication)

  20. Sample preparation of drinking, ground and waste water as well as of sewage sludge, residual materials and wastes

    International Nuclear Information System (INIS)

    The primary objective of the preparation of water and sewage sludge samples consists in reducing the volume of the sample aimed at increasing their activity concentration or specific activity, that means the radionuclide(s) to be determined are to be enriched in the sample in order to reduce the detection limit. As a rule, a simplified preparation procedure may be used, such as evaporation of water samples, drying of sludge samples, because the determination of nuclides by means of gamma spectroscopy is performed parallely and undisturbedly. It is also usual to combine different preparation procedures, e.g. to evaporate a water sample converting it into a measuring preparation in filter geometry for gamma spectroscopy, and further converting it into an yttrium-90 measuring preparation in order to determine strontium-90 via the daughter nuclide. (orig./DG)

  1. Preconcentration and determination of heavy metals in water, sediment and biological samples

    Directory of Open Access Journals (Sweden)

    Shirkhanloo Hamid

    2011-01-01

    Full Text Available In this study, a simple, sensitive and accurate column preconcentration method was developed for the determination of Cd, Cu and Pb ions in river water, urine and sediment samples by flame atomic absorption spectrometry. The procedure is based on the retention of the analytes on a mixed cellulose ester membrane (MCEM column from buffered sample solutions and then their elution from the column with nitric acid. Several parameters, such as pH of the sample solution, volume of the sample and eluent and flow rates of the sample were evaluated. The effects of diverse ions on the preconcentration were also investigated. The recoveries were >95 %. The developed method was applied to the determination of trace metal ions in river water, urine and sediment samples, with satisfactory results. The 3δ detection limits for Cu, Pb and Cd were found to be 2, 3 and 0.2 μg dm−3, respectively. The presented procedure was successfully applied for determination of the copper, lead and cadmium contents in real samples, i.e., river water and biological samples.

  2. Preparation Of Deposited Sediment Sample By Casting Method For Environmental Study

    International Nuclear Information System (INIS)

    The preparation of deposited sediment sample by castingmethod for environmental study has been carried out. This method comprises separation of size fraction and casting process. The deposited sediment samples were wet sieved to separate the size fraction of >500 mum, (250-500) mum, (125-250) mum and (63-125) mum and settling procedures were followed for the separation of (40-63) mum, (20-40) mum, (10-20) mum and oC, ashed at 450oC, respectively. In the casting process of sample, it was used polyester rapid cure resin and methyl ethyl ketone peroxide (MEKP) hardener. The moulded sediment sample was poured onto caster, allow for 60 hours long. The aim of this method is to get the casted sample which can be used effectively, efficiently and to be avoided from contamination of each other samples. Before casting, samples were grinded up to be fine. The result shows that casting product is ready to be used for natural radionuclide analysis

  3. Biological rhythms, metabolic syndrome and current depressive episode in a community sample.

    Science.gov (United States)

    Moreira, Fernanda Pedrotti; Jansen, Karen; Mondin, Thaíse Campos; Cardoso, Taiane de Azevedo; Magalhães, Pedro Vieira da Silva; Kapczinski, Flavio; Frey, Benicio N; Oses, Jean Pierre; Souza, Luciano Dias de Mattos; da Silva, Ricardo Azevedo; Wiener, Carolina David

    2016-10-01

    The purpose of this study was to assess the disruption in biological rhythms and metabolic syndrome (MetS) in individuals with depressive episode. This was a cross-sectional, population-based study with a representative sample of 905 young adults. Current depressive episode were confirmed by a psychologist using the Mini International Neuropsychiatric Interview (MINI)-Plus. Self-reported biological rhythms were assessed using the Biological Rhythms Interview of Assessment in Neuropsychiatry (BRIAN). MetS was defined using modified NCEP/ATPIII criteria. Significant main effects of current depressive episode (p<0.001, η(2)=0.163) and MetS (p=0.001, η(2)=0.011) were observed on total BRIAN score. There was a significant interaction between depression and MetS in total biological rhythm scores (p=0.002, η(2)=0.011) as well as sleep (p=0.001, η(2)=0.016) and social domains (p<0.001, η(2)=0.014). In the depressive group, subjects with MetS had a higher disruption in total BRIAN scores (p=0.010), sleep domain (p=0.004), social domain (p=0.005) and in the eating pattern domain approached the level of significance (p=0.098), when compared to subjects with no MetS. The results of the present study showed that self-reported disruptions in biological rhythms are associated with key components of the MetS in community adults with MDD. The understanding of the complex interactions between biological rhythms, MetS and depression are important in the development of preventive and therapeutic strategies. PMID:27343724

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

    Science.gov (United States)

    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 chemical artifacts, in vitro protein and peptide modifications, and contaminations. Those often result in sample loss and affect the sensitivity, dynamic range and accuracy of the mass spectrometric analysis. Here we describe a simple and reproducible phosphoproteomics protocol, where lysis, denaturation, reduction, and alkylation are performed in a single step, thus reducing sample loss and increasing reproducibility. Moreover, unlike standard cell lysis procedures the cell harvesting is performed at high temperatures (99 °C) and without detergents and subsequent need for protein precipitation. Phosphopeptides are enriched using TiO2 beads and the orbitrap mass spectrometer is operated in a sensitive mode with higher energy collisional dissociation (HCD). PMID:26584931

  5. Enhancing sample preparation capabilities for accelerator mass spectrometry radiocarbon and radiocalcium studies

    International Nuclear Information System (INIS)

    With support provided by the LLNL Accelerator Mass Spectrometry Laboratory, the UCR Radiocarbon Laboratory continued its studies involving sample pretreatment and target preparation for both AMS radiocarbon (14C) and radiocalcium (41Ca) involving applications to archaeologically -- and paleoanthropologically- related samples. With regard to AMS 14C-related studies, we have extended the development of a series of procedures which have, as their initial goal, the capability to combust several hundred microgram amounts of a chemically-pretreated organic sample and convert the resultant CO2 to graphitic carbon which will consistently yield relatively high 13C- ion currents and blanks which will yield, on a consistent basis, 14C count rates at or below 0.20% modern, giving an 2 sigma age limit of >50,000 yr BP

  6. Offer of rapid testing and alternative biological samples as practical tools to implement HIV screening programs.

    Science.gov (United States)

    Parisi, Maria Rita; Soldini, Laura; Di Perri, Giovanni; Tiberi, Simon; Lazzarin, Adriano; Lillo, Flavia B

    2009-10-01

    Implementation of HIV testing has the objective to increase screening, identify and counsel persons with infection, link them to clinical services and reduce transmission. Rapid tests and/or alternative biological samples (like oral fluid) give the option for a better general consent in approaching screening, immediate referral of HIV positives to medical treatment and partner notification. We tested the performance characteristics of an oral fluid-based rapid HIV test (Rapidtest HIV lateral flow-Healthchem diag. LLC) in comparison with routinely utilized methods in a selected population of known positive (N = 121) or negative (N = 754) subjects. The sensitivity of the rapid test was 99.1% (one false negative sample) and the specificity 98.8%. Five negatives showed a faint reactivity, 3 of these were reactive also in the reference test, one with a p24 only reaction in Western blot. If these 3 samples were excluded from the analysis the specificity increases to 99.2%. Results from our study confirm that, although a continuous improvement of the test performance is still needed to minimize false negative and positive results, rapid test and alternative biological samples may contribute to HIV prevention strategies by reaching a larger population particularly when and where regular screening procedures are difficult to obtain. PMID:20128446

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

    Science.gov (United States)

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

    2013-09-01

    Rectal drug delivery is currently at the focus of attention. Surfactants promote drug release from the suppository bases and enhance the formulation properties. The aim of our work was to develop a sample preparation method for HPLC analysis for a suppository base containing 95% hard fat, 2.5% Tween 20 and 2.5% Tween 60. A conventional sample preparation method did not provide successful results as the recovery of the drug failed to fulfil the validation criterion 95-105%. This was caused by the non-ionic surfactants in the suppository base incorporating some of the drug, preventing its release. As guidance for the formulation from an analytical aspect, we suggest a well defined surfactant content based on the turbidimetric determination of the CMC (critical micelle formation concentration) in the applied methanol-water solvent. Our CMC data correlate well with the results of previous studies. As regards the sample preparation procedure, a study was performed of the effects of ionic strength and pH on the drug recovery with the avoidance of degradation of the drug during the procedure. Aminophenazone and paracetamol were used as model drugs. The optimum conditions for drug release from the molten suppository base were found to be 100 mM NaCl, 20-40 mM NaOH and a 30 min ultrasonic treatment of the final sample solution. As these conditions could cause the degradation of the drugs in the solution, this was followed by NMR spectroscopy, and the results indicated that degradation did not take place. The determined CMCs were 0.08 mM for Tween 20, 0.06 mM for Tween 60 and 0.04 mM for a combined Tween 20, Tween 60 system. PMID:23727364

  8. Sample preparation of waste water to determine metallic contaminants by X-ray fluorescence spectroscopy

    International Nuclear Information System (INIS)

    Trace X-ray fluorescence spectroscopy analysis in liquid samples is preceded by sample preparation, which usually consists in the precipitation of the metallic ions and concentration over a thin cellulose filter. The samples preparation of waste water by this method is not efficient, due to the great amount of organic and insoluble matter that they contain. The purpose of this work was to determine the optimal value of pH in order to adsorbe all the insoluble matter contained in a waste water sample in the activated charcoal, so that the metallic ions could be precipitated and concentrated on a thin filter and determinated by X-ray fluorescence spectroscopy. A survey about the adsorption of some ions in activated charcoal in function of the pH was made for the following: Cr3+, Fe3+, Ni2+, Cu2+, Zn2+, Se2+, Hg2+, and Pb2+. It was observed that at pH 0, the ions are not adsorbed, but Cu2+ and Zn2+ are adsorbed in small amount; at pH 14, the ions are adsorbed, excluding Se, which is not adsorbed at any value of pH. If a waste water sample is treated at pH 0 with activated charcoal to adsorbe the organic and insoluble matter, most of the metallic ions are not adsorbed by the activated charcoal and could be precipitated with APDC (ammonium 1-pirrolidine dithio carbamate salt) and concentrated on a thin filter. The analysis of the metallic ions contained on the filter and those adsorbed in the activated charcoal by X-ray fluorescence spectroscopy, gave the total amount of the ions in the sample. (author)

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

    Science.gov (United States)

    Boardman, Anna K; Campbell, Jennifer; Wirz, Holger; Sharon, Andre; Sauer-Budge, Alexis F

    2015-01-01

    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 (MSSA)to 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. PMID:25675242

  10. Two Methods for High-Throughput NGS Template Preparation for Small and Degraded Clinical Samples Without Automation

    OpenAIRE

    Kamberov, E.; Tesmer, T.; Mastronardi, M.; Langmore, John

    2012-01-01

    Clinical samples are difficult to prepare for NGS, because of the small amounts or degraded states of formalin-fixed tissue, plasma, urine, and single-cell DNA. Conventional whole genome amplification methods are too biased for NGS applications, and the existing NGS preparation kits require intermediate purifications and excessive time to prepare hundreds of samples in a day without expensive automation. We have tested two 96-well manual methods to make NGS templates from FFPE tissue, plasma,...

  11. 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 nL into the...

  12. Mapping molecular orientational distributions for biological sample in 3D (Conference Presentation)

    Science.gov (United States)

    HE, Wei; Ferrand, Patrick; Richter, Benjamin; Bastmeyer, Martin; Brasselet, Sophie

    2016-04-01

    Measuring molecular orientation properties is very appealing for scientists in molecular and cell biology, as well as biomedical research. Orientational organization at the molecular scale is indeed an important brick to cells and tissues morphology, mechanics, functions and pathologies. Recent work has shown that polarized fluorescence imaging, based on excitation polarization tuning in the sample plane, is able to probe molecular orientational order in biological samples; however this applies only to information in 2D, projected in the sample plane. To surpass this limitation, we extended this approach to excitation polarization tuning in 3D. The principle is based on the decomposition of any arbitrary 3D linear excitation in a polarization along the longitudinal z-axis, and a polarization in the transverse xy-sample plane. We designed an interferometer with one arm generating radial polarization light (thus producing longitudinal polarization under high numerical aperture focusing), the other arm controlling a linear polarization in the transverse plane. The amplitude ratio between the two arms can vary so as to get any linear polarized excitation in 3D at the focus of a high NA objective. This technique has been characterized by polarimetry imaging at the back focal plane of the focusing objective, and modeled theoretically. 3D polarized fluorescence microscopy is demonstrated on actin stress fibers in non-flat cells suspended on synthetic polymer structures forming supporting pillars, for which heterogeneous actin orientational order could be identified. This technique shows a great potential in structural investigations in 3D biological systems, such as cell spheroids and tissues.

  13. Automated sample preparation station for studying self-diffusion in porous solids with NMR spectroscopy

    International Nuclear Information System (INIS)

    In studies of gas diffusion in porous solids with nuclear magnetic resonance (NMR) spectroscopy the sample preparation procedure becomes very important. An apparatus is presented here that pretreats the sample ex situ and accurately sets the desired pressure and temperature within the NMR tube prior to its introduction in the spectrometer. The gas manifold that supplies the NMR tube is also connected to a microbalance containing another portion of the same sample, which is kept at the same temperature as the sample in the NMR tube. This arrangement permits the simultaneous measurement of the adsorption loading on the sample, which is required for the interpretation of the NMR diffusion experiments. Furthermore, to ensure a good seal of the NMR tube, a hybrid valve design composed of titanium, a Teflon registered seat, and Kalrez registered O-rings is utilized. A computer controlled algorithm ensures the accuracy and reproducibility of all the procedures, enabling the NMR diffusion experiments to be performed at well controlled conditions of pressure, temperature, and amount of gas adsorbed on the porous sample

  14. Experiences from Refurbishment of Metallography Hot Cells and Application of a New Preparation Concept for Materialography Samples

    International Nuclear Information System (INIS)

    After more than 30 years of operation the lead shielded metallography hot cells needed a basic renewal and modernisation not least of the specimen preparation equipment. Preparation in hot cells of radioactive samples for metallography and ceramography is challenging and time consuming. It demands a special design and quality of all in-cell equipment and skill and patience from the operator. Essentials in the preparation process are: simplicity and reliability of the machines, and a good quality, reproducibility and efficiency in performance. Desirable is process automation, flexibility and an alara amounto of radioactive waste produced per sample prepared. State of the art preparation equipment for materialography seems to meet most of the demands, however, it cannot be used in hot cells without modifications. Therefore. IFE and Struers in Copenhagen modified a standard model of a Strues precision cutting machine and a microprocessor controlled grinding and polishing machine for Hot Cell application. Hot cell utilisation of the microcomputer controlled grinding and polishing machine and the existing automatic dosing equipment made the task of preparing radioactive samples more attractive. The new grinding and polishing system for hot cells provides good sample preparation quality and reproductibility at reduced preparation time and reduced amount of contaminated waste produced per sample prepared. the sample materials examined were irradiated cladding materials and fuels

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

    International Nuclear Information System (INIS)

    A procedure was developed for preparing bulk carbon-nitride crystals from polymeric α-C3N4.2 at high pressure and high temperature in the presence of seeds of crystalline carbon-nitride films prepared by using a high-voltage discharge plasma combined with pulsed laser ablation of a graphite target. The samples were evaluated by using X-ray photoelectron spectroscopy (XPS), infrared (IR) spectroscopy, Auger electron spectroscopy (AES), secondary-ion mass spectrometry (SIMS), scanning electron microscopy (SEM) and X-ray diffraction (XRD). Notably, XPS studies of the film composition before and after thermobaric treatments demonstrated that the nitrogen composition in the α-C3N4.2 material, which initially contained more than 58 % nitrogen, decreased during the annealing process and reached a common, stable composition of ∼ 45 %. The thermobaric experiments were performed at 10 - 77 kbar and 350 - 1200 .deg. C.

  16. A direct solid sampling analysis method for the detection of silver nanoparticles in biological matrices.

    Science.gov (United States)

    Feichtmeier, Nadine S; Ruchter, Nadine; Zimmermann, Sonja; Sures, Bernd; Leopold, Kerstin

    2016-01-01

    Engineered silver nanoparticles (AgNPs) are implemented in food contact materials due to their powerful antimicrobial properties and so may enter the human food chain. Hence, it is desirable to develop easy, sensitive and fast analytical screening methods for the determination of AgNPs in complex biological matrices. This study describes such a method using solid sampling high-resolution continuum source graphite furnace atomic absorption spectrometry (GFAAS). A recently reported novel evaluation strategy uses the atomization delay of the respective GFAAS signal as significant indicator for AgNPs and thereby allows discrimination of AgNPs from ionic silver (Ag(+)) in the samples without elaborate sample pre-treatment. This approach was further developed and applied to a variety of biological samples. Its suitability was approved by investigation of eight different food samples (parsley, apple, pepper, cheese, onion, pasta, maize meal and wheat flour) spiked with ionic silver or AgNPs. Furthermore, the migration of AgNPs from silver-impregnated polypropylene food storage boxes to fresh pepper was observed and a mussel sample obtained from a laboratory exposure study with silver was investigated. The differences in the atomization delays (Δt(ad)) between silver ions and 20-nm AgNPs vary in a range from -2.01 ± 1.38 s for maize meal to +2.06 ± 1.08 s for mussel tissue. However, the differences were significant in all investigated matrices and so indicative of the presence/absence of AgNPs. Moreover, investigation of model matrices (cellulose, gelatine and water) gives the first indication of matrix-dependent trends. Reproducibility and homogeneity tests confirm the applicability of the method. PMID:26483187

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

    OpenAIRE

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

    2015-01-01

    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...

  18. Stability of heroin, 6-monoacetylmorphine, and morphine in biological samples and validation of an LC–MS assay for delayed analyses of pharmacokinetic samples in rats

    OpenAIRE

    Jones, Jessica M.; Raleigh, Michael D.; Pentel, Paul R.; Harmon, Theresa M.; Keyler, Daniel E.; Remmel, Rory P.; Birnbaum, Angela K

    2012-01-01

    Degradation of heroin to 6-monoacetylmorphine (6-MAM) and then morphine happens rapidly in vivo and in vitro. The rates of heroin and 6-MAM degradation depend on the type of biological samples, and the duration and conditions of storage. In order to optimize conditions for measuring heroin and its metabolites in samples collected for pharmacokinetic studies in rats, we investigated the time course of degradation of heroin, 6-MAM, and morphine in four biological matrices: rat blood, rat brain ...

  19. Evaluation of biological samples for specimen banking and biomonitoring by nuclear methods

    International Nuclear Information System (INIS)

    In a pilot program for environmental specimen banking, human livers and marine mussels (Mytilus edulis) were sampled, analyzed and banked. Nuclear methods played a major role in the evaluation of the samples by providing concentration data for up to 37 major, mineral, and trace elements. Instrumental neutron activation analysis was complemented by neutron-capture prompt gamma activation analysis, radiochemical separations and, for the mussels, by instrumental X-ray fluorescence analysis. A cryogenic homogenization procedure was applied for sample preparation and evaluated. Assessment of accuracy was made by analyzing Standard Reference Materials and by intercomparing the techniques. Results are reported for 66 individual human liver specimens, collected at three locations in the United States, and for batches of 65 mussels from a collection made at Narragansett Bay, RI. 19 references, 23 figures, 4 tables

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

    Directory of Open Access Journals (Sweden)

    Chui E. Wong

    2012-10-01

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

  1. microPREP: a new laser tool for high-volume sample preparation

    Science.gov (United States)

    Wagner, Uwe; Petsch, Tino; Krause, Michael; Höche, Thomas

    2016-03-01

    Over the past fifty year, lasers have perpetuated to find new, often groundbreaking applications in science and technology. The most important features of lasers are that photons are inherently free of elemental contamination, extremely high energy densities can be focused in very small areas and the laser beam can be precisely positioned using deflection mirrors. By reducing pulse lengths from a few nanoseconds down to the picosecond or femtosecond range, material's ablation is becoming increasingly "athermal", i.e. structure damage by local heating is reduced to well below a few microns. In view of these outstanding characteristics of lasers as tools for micromachining, it is very surprising that sample preparation for microstructure diagnostics so far hasn't made use of laser technology. microPREPTM, the all-new, patented laser-micromachining tool developed by 3D-Micromac is the first instrument to make fast, clean, and efficient laser ablation available for the preparation of samples for microstructure diagnostics. Exemplified for a sample to be investigated by transmission electron microscopy (TEM) and following a three-stage approach, a supporting basic structure is cut from the feedstock first. Second, the supported structure is thinned down to a few micron of residual thickness and third, the supported and thinned structure is polished using an ion broad beam. Illustrated by numerous examples, it is shown that this technology is ready to be applied on different areas of microstructure diagnostics and has very high potential for failure diagnostics.

  2. On reactivity of metallic zinc used for preparation of samples for hydrogen isotope ratio measurement

    International Nuclear Information System (INIS)

    As the reagent which is suitable to the reduction of water to hydrogen for preparing the samples for hydrogen isotope ratio measurement, the supply of the zinc of BDH Co. which has been widely used so far was stopped, consequently, for the purpose of searching for its substitute, several kinds of metallic zinc were obtained, and their reactivity was examined. As the criteria of the reactivity, the points that the experimental setup used so far can be used and that the accuracy of measurement and efficiency similar to those of heretofore can be obtained were selected, then, it was found that the zinc made by Bio Geochemical Laboratory, Indiana University, and the powder zinc on the market satisfied the criteria. In order to measure hydrogen isotope ratio within the measurement error of ±1%, it is necessary to maintain the quantities of zinc and water to be used and reaction temperature constant, to prepare the standard sample and an unknown sample under the same conditions, and to do the mass analysis as quickly as possible. The researches carried out so far, the reactivity test on various kinds of zinc and so on are reported. The optimum reaction conditions are shown. (K.I.)

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

    DEFF Research Database (Denmark)

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

    2012-01-01

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

  4. Preparation and Biological Properties of Platinum(II Complex-Loaded Copolymer PLA-TPGS

    Directory of Open Access Journals (Sweden)

    Ha Phuong Thu

    2013-01-01

    Full Text Available A new nanodrug system containing bis(menthone thiosemicarbazonato Platinum(II complex (Pt-thiomen encapsulated with the block copolymers polylactide-d-α-tocopheryl polyethylene glycol 1000 succinate (PLA-TPGS was prepared by a modified solvent extraction/evaporation technique. The characteristics of the nanoparticles including surface morphology, size distribution, structure, and biological activities such as antimicrobial and cytotoxic activities were in vitro investigated. The spherical nanoparticles were around 50 nm in size with core-shell structure and narrow-size distribution. The encapsulated Pt-thiomen can avoid interaction with proteins in the blood plasma. The inhibitory activity of Pt-thiomen-loaded PLA-TPGS nanoparticles on the growth of some bacteria, fungi, and Hep-G2 cells suggests a possibility of developing PLA-TPGS-Pt-thiomen nanoparticles as one of the potential chemotherapeutic agents.

  5. Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

    International Nuclear Information System (INIS)

    Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrPC. In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrPC at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

  6. 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

  7. Surface-enhanced Raman scattering detection of silver nanoparticles in environmental and biological samples.

    Science.gov (United States)

    Guo, Huiyuan; Xing, Baoshan; Hamlet, Leigh C; Chica, Andrea; He, Lili

    2016-06-01

    Growing concerns over the potential release and threat of silver nanoparticles (AgNPs) to environmental and biological systems urge researchers to investigate their fate and behavior. However, current analytical techniques cannot meet the requirements for rapidly, sensitively and reliably probing AgNPs in complex matrices. Surface-enhanced Raman spectroscopy (SERS) has shown great capability for rapid detection of AgNPs based on an indicator molecule that can bind on the AgNP surface. The objective of this study was to exploit SERS to detect AgNPs in environmental and biological samples through optimizing the Raman indicator for SERS. Seven indicator molecules were selected and determined to obtain their SERS signals at optimal concentrations. Among them, 1,2-di(4-pyridyl)ethylene (BPE), crystal violet and ferric dimethyl-dithiocarbamate (ferbam) produced the highest SERS intensities. Further experiments on binding competition between each two of the three candidates showed that ferbam had the highest AgNPs-binding ability. The underlying mechanism lies in the strong binding affinity of ferbam with AgNPs via multiple sulfur atoms. We further validated ferbam to be an effective indicator for SERS detection of as low as 0.1mg/L AgNPs in genuine surface water and 0.57 mg/L in spinach juice. Moreover, limited interference on SERS detection of AgNPs was found from environmentally relevant inorganic ions, organic matter, inorganic particles, as well as biologically relevant components, demonstrating the ferbam-assisted SERS is an effective and sensitive method to detect AgNPs in complex environmental and biological samples. PMID:26956173

  8. Bayesian model comparison and parameter inference in systems biology using nested sampling.

    Science.gov (United States)

    Pullen, Nick; Morris, Richard J

    2014-01-01

    Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focuses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design. PMID:24523891

  9. Bayesian model comparison and parameter inference in systems biology using nested sampling.

    Directory of Open Access Journals (Sweden)

    Nick Pullen

    Full Text Available Inferring parameters for models of biological processes is a current challenge in systems biology, as is the related problem of comparing competing models that explain the data. In this work we apply Skilling's nested sampling to address both of these problems. Nested sampling is a Bayesian method for exploring parameter space that transforms a multi-dimensional integral to a 1D integration over likelihood space. This approach focuses on the computation of the marginal likelihood or evidence. The ratio of evidences of different models leads to the Bayes factor, which can be used for model comparison. We demonstrate how nested sampling can be used to reverse-engineer a system's behaviour whilst accounting for the uncertainty in the results. The effect of missing initial conditions of the variables as well as unknown parameters is investigated. We show how the evidence and the model ranking can change as a function of the available data. Furthermore, the addition of data from extra variables of the system can deliver more information for model comparison than increasing the data from one variable, thus providing a basis for experimental design.

  10. General guidelines for safe and expeditious international transport of samples subjected to biological dosimetry assessment

    International Nuclear Information System (INIS)

    It has been observed that victims of accidental overexposures show better chance of survival if they receive medical treatment early. The increased risk of scenarios involving mass casualties has stimulated the scientific community to develop tools that would help the medical doctors to treat victims. The biological dosimetry has become a routine test to estimate the dose, supplementing physical and clinical dosimetry. In case of radiation emergencies, in order to provide timely and effectively biological dosimetry assistance it is essential to guarantee an adequate transport of blood samples in principal, for providing support to countries that do not have bio-dosimetry laboratories. The objective of the present paper is to provide general guidelines, summarised in 10 points, for timely and proper receiving and sending of blood samples under National and International regulations, for safe and expeditious international transport. These guidelines cover the classification, packaging, marking, labelling, refrigeration and documentation requirements for the international shipping of blood samples and pellets, to provide assistance missions with a tool that would contribute with the preparedness for an effective bio-dosimetric response in cases of radiological or nuclear emergencies. (authors)

  11. Rapid methods to detect organic mercury and total selenium in biological samples

    Directory of Open Access Journals (Sweden)

    Basu Niladri

    2011-01-01

    Full Text Available Abstract Background Organic mercury (Hg is a global pollutant of concern and selenium is believed to afford protection against mercury risk though few approaches exist to rapidly assess both chemicals in biological samples. Here, micro-scale and rapid methods to detect organic mercury ( Results For organic Hg, samples are digested using Tris-HCl buffer (with sequential additions of protease, NaOH, cysteine, CuSO4, acidic NaBr followed by extraction with toluene and Na2S2O3. The final product is analyzed via commercially available direct/total mercury analyzers. For Se, a fluorometric assay has been developed for microplate readers that involves digestion (HNO3-HClO4 and HCl, conjugation (2,3-diaminonaphthalene, and cyclohexane extraction. Recovery of organic Hg (86-107% and Se (85-121% were determined through use of Standard Reference Materials and lemon shark kidney tissues. Conclusions The approaches outlined provide an easy, rapid, reproducible, and cost-effective platform for monitoring organic Hg and total Se in biological samples. Owing to the importance of organic Hg and Se in the pathophysiology of Hg, integration of such methods into established research monitoring efforts (that largely focus on screening total Hg only will help increase understanding of Hg's true risks.

  12. The scope of detector Medipix2 in micro-radiography of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Dammer, J., E-mail: jiri.dammer@utef.cvut.cz [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ-12800 Prague 2 (Czech Republic); Weyda, F. [Biology Centre of the Academy of Sciences of the Czech Republic, Institute of Entomology, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic); Faculty of Science, University of South Bohemia, Branisovska 31, CZ-37005 Ceske Budejovice (Czech Republic); Jakubek, J. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ-12800 Prague 2 (Czech Republic); Skrabal, P. [Faculty of Biomedical Engineering, Czech Technical University in Prague, Nam. Sitna 3105, CZ-272 01 Kladno (Czech Republic); Sopko, V.; Vavrik, D. [Institute of Experimental and Applied Physics, Czech Technical University in Prague, Horska 3a/22, CZ-12800 Prague 2 (Czech Republic)

    2011-05-15

    We present our experimental setup devoted to high resolution X-ray micro-radiography that is suitable for imaging of small biological samples. The photon source is a FeinFocus micro-focus X-ray tube. The single photon counting pixel device Medipix2 serves as imaging area. Recently used imaging detectors as radiography films or scintillator detectors, cannot visualize required information about inner structure of scanned sample. Detectors Medipix2 do not suffer from so-called dark current noise and work in unlimited dynamic range. These features of detectors confer high quality and high contrast of final images. The radiographic imaging with detectors Medipix2 represents non-invasive and non-destructive method of investigation. Hereby, we demonstrate results of micro-radiographic study of internal structures of tiny biological samples. In addition to morphological and anatomical studies, we would like to present preliminary study of dynamic processes inside of organisms using micro-radiographic video-capturing.

  13. A study of the Perkin-Elmer laboratory robotic system for analytical sample preparation

    Energy Technology Data Exchange (ETDEWEB)

    Hartenstein, S.D.; Delmastro, J.R.

    1988-09-01

    The purpose of this study was to evaluate the abilities of a Perkin-Elmer (PE) robotic system in performing complex analytical sample preparation procedures. Until this time, reports have been written describing the physical capabilities of the robotic arm marketed by PE and the use of this arm in a pick-and-place application at the Idaho Chemical Processing Plant (ICPP). Since the robotic arm is only capable of handling and transporting objects, the ability of the PE system is dependent upon the performance capabilities of the auxiliary devices marketed with the arm. 2 refs., 2 figs., 1 tab.

  14. Evaluation of sample preparation procedures for micro-mechanical testing of trabecular bone

    Czech Academy of Sciences Publication Activity Database

    Kytýř, Daniel; Valach, Jaroslav; Doktor, Tomáš; Jiroušek, Ondřej; Zlámal, Petr; Kostelecká, M.

    Chemnitz : Chemnitz University of Technology , 2011 - (Stockmann, M.; Kretzschmar, J.), s. 71-72 ISBN 978-3-941003-34-7. [Youth Symposium on Experimental Solid Mechanics /10./. Chemnitz (DE), 25.05.2011-28.05.2011] R&D Projects: GA ČR(CZ) GAP105/10/2305 Institutional research plan: CEZ:AV0Z20710524 Keywords : micro-mechanical testing * sample preparation * trabecular bone Subject RIV: JJ - Other Materials http://www.tu-chemnitz.de/mb/FestKoerpMech/YSESM/proceedings.php

  15. Sample preparation for scanning Kelvin probe microscopy studies on cross sections of organic solar cells

    Directory of Open Access Journals (Sweden)

    Michael Scherer

    2013-09-01

    Full Text Available We prepared cross sections of P3HT:PCBM bulk heterojunction (BHJ organic solar cells (OSCs for the characterization of their potential distribution with scanning Kelvin probe microscopy. We compared results of samples obtained by microtome cutting of OSCs on plastic substrates, cleaving of OSCs on glass substrates, and milling with a focused ion beam. Their potential distributions were in good agreement with each other. Under short circuit conditions, potential gradients were detected in vicinity of the electrode/organics interfaces, with negligible electric fields within the bulk. We contacted the OSCs in a defined manner and studied their potential distribution under operating conditions.

  16. Preparation of quality control samples in radioimmunoassay for thyroid stimulating hormone (TSH)

    International Nuclear Information System (INIS)

    To days, the radioimmunoassay is becomes the best technique to analysis different concentrations of substance, especially in medical and research laboratories. Although the specificity of RIA techniques, the quality controls must takes place to give good results as possible. In this dissertation i prepared quality control samples of thyroid stimulating hormone (TSH), to use it in RIA techniques and to control the reliability results of those laboratories which used these methods. We used China production kits of RIA method to determine the level of hormone (low-normal-high) concentration. Statistical parameters were used to drown the control chart of the mean to these data.(Author)

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

    International Nuclear Information System (INIS)

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

  18. Cations in mammalian cells and chromosomes: Sample preparation protocols affect elemental abundances by SIMS

    Science.gov (United States)

    Levi-Setti, R.; Gavrilov, K. L.; Neilly, M. E.

    2006-07-01

    The focus of our current research aims at detailing and quantifying the presence of cations, primarily Ca and Mg, in mammalian cells and chromosomes throughout the different stages of the cell cycle, using our high resolution scanning ion microprobe, the UC-SIM. The 45 keV Ga + probe of this instrument, typically ˜40 nm in diameter, carries a current of 30-40 pA, appropriate for surface SIMS studies, but limited in sample erosion rate for dynamic SIMS mapping over cell-size areas, of order 100 μm × 100 μm. Practical and reliable use of this probe toward the above SIMS goals requires a careful matching of the latter factors with the physical and chemical consequences of sample preparation protocols. We examine here how the preferred sample cryo-preservation methodologies such as freeze-fracture and lyophilization affect high resolution SIMS analysis, and, from this standpoint, develop and evaluate the advantages and disadvantages of fast alternate approaches to drying frozen samples. The latter include the use of methanol, ethanol, and methanol/acetic acid fixative. Methanol-dried freeze-fractured samples preserve histological morphology and yield Ca and Mg distributions containing reliable differential dynamical information, when compared with those following lyophilization.

  19. Background and Artifacts Generated by the by the Sample Preparation Experiment on SAM

    Science.gov (United States)

    Belmahdi, Imene; Buch, Arnaud; Szopa, Cyril; Freissinet, Caroline; Glavin, Daniel; Coll, Patrice; Cabane, Michel; Millan, Maeva; Eigenbrode, Jennifer; Navarro-Gonzalez, Rafael; Stern, Jennifer; Coscia, David; Bonnet, Jean-Yves; Teinturier, Samuel; Morisson, Marietta; Stambouli, Moncef; Dequaire, Tristan; Mahaffy, Paul

    2016-04-01

    Sample Analysis at Mars (SAM) is one of the instruments of the Mars Science Laboratory mission. Three analytical devices composed the SAM experiment: the Tunable Laser Spectrometer (TLS), the Gas Chromatography (GC) and the Mass Spectrometer (MS). To adapt the nature of a sample to the analytical devices used, a sample preparation and gas processing system implemented with (a) a pyrolysis system, (b) wet chemistry: MTBSTFA and TMAH (c) the hydrocarbon trap (silica beads, Tenax® TA and Carbosieve G) and the injection trap (Tenax® GR composed of Tenax® TA and 30% of graphite) are employed to concentrate volatiles released from the sample prior to GC-MS analysis. Our study investigates several propositions for chlorinated hydrocarbon formation detected in the SAM background by looking for: (a) all products coming from the interaction of Tenax® and perchlorates present on Mars, (b) also between some soil sample and perchlorates and (c) sources of chlorinated hydrocarbon precursors. Here we report on the detection of chlorohydrocarbon compounds and their potential origin.

  20. Chemical and biological assessment of Angelica herbal decoction: comparison of different preparations during historical applications.

    Science.gov (United States)

    Zhang, Wendy Li; Zheng, Ken Yu-Zhong; Zhu, Kevin Yue; Zhan, Janis Ya-Xian; Bi, Cathy Wen-Chuan; Chen, Jian-Ping; Du, Crystal Ying-Qing; Zhao, Kui-Jun; Lau, David Tai-Wai; Dong, Tina Ting-Xia; Tsim, Karl Wah-Keung

    2012-08-15

    The commonly used Angelica herbal decoction today is Danggui Buxue Tang (DBT), which is a dietary supplement in treating menopausal irregularity in women, i.e. to nourish "Qi" and to enrich "Blood". According to historical record, many herbal decoctions were also named DBT, but the most popular formulation of DBT was written in Jin dynasty (1247 AD) of China, which contained Astragali Radix (AR) and Angelicae Sinensis Radix (ASR) with a weight ratio of 5:1. However, at least two other Angelica herbal decoctions recorded as DBT were prescribed in Song (1155 AD) and Qing dynasties (1687 AD). Although AR and ASR are still the major components in the DBT herbal decoctions, they are slightly varied in the herb composition. In order to reveal the efficiency of different Angelica herbal decoctions, the chemical and biological properties of three DBT herbal extracts were compared. Significantly, the highest amounts of AR-derived astragaloside III, astragaloside IV, calycosin and formononetin and ASR-derived ferulic acid were found in DBT described in 1247 AD: this preparation showed stronger activities in osteogenic, estrogenic and erythropoetic effects than the other two DBT. The current results supported the difference of three DBT in chemical and biological properties, which could be a result of different herbal combinations. For the first time, this study supports the popularity of DBT described in 1247 AD. PMID:22902230

  1. State-of-the-art technologies for rapid and high-throughput sample preparation and analysis of N-glycans from antibodies.

    Science.gov (United States)

    Aich, Udayanath; Lakbub, Jude; Liu, Aston

    2016-06-01

    Glycosylation is a PTM that occurs during production of many protein-based biologic drugs and can have a profound impact on their biological, clinical, and pharmacological properties. Quality by design, process optimization, and advance in manufacturing technology create a demand for robust, sensitive, and accurate profiling and quantification of antibody glycosylation. Potential drawbacks in antibody glycosylation profiling include the high hands-on time required for sample preparation and several hours for data acquisition and analysis. Rapid and high-throughput (HTP) N-glycan profiling and characterization along with automation for sample preparation and analysis are essential for extensive antibody glycosylation analysis due to the substantial improvement of turnaround time. The first part of this review article will focus on the recent progress in rapid and HTP sample preparation and analysis of antibody glycosylation. Subsequently, the article will cover a brief overview of various separation and mass spectrometric methods for the rapid and HTP analysis of N-glycans in antibodies. Finally, we will discuss the recent developments in process analytical technologies for the screening and quantification of N-glycans in antibodies. PMID:26829758

  2. Magnetic induction spectroscopy: non-contact measurement of the electrical conductivity spectra of biological samples

    International Nuclear Information System (INIS)

    Measurement of the electrical conductivity of biological tissues as a function of frequency, often termed ‘bioelectrical impedance spectroscopy (BIS)’, provides valuable information on tissue structure and composition. In implementing BIS though, there can be significant practical difficulties arising from the electrode–sample interface which have likely limited its deployment in industrial applications. In magnetic induction spectroscopy (MIS) these difficulties are eliminated through the use of fully non-contacting inductive coupling between the sensors and sample. However, inductive coupling introduces its own set of technical difficulties, primarily related to the small magnitudes of the induced currents and their proportionality with frequency. This paper describes the design of a practical MIS system incorporating new, highly-phase-stable electronics and compares its performance with that of electrode-based BIS in measurements on biological samples including yeast suspensions in saline (concentration 50–400 g l−1) and solid samples of potato, cucumber, tomato, banana and porcine liver. The shapes of the MIS spectra were in good agreement with those for electrode-based BIS, with a residual maximum discrepancy of 28%. The measurement precision of the MIS was 0.05 S m−1 at 200 kHz, improving to 0.01 S m−1 at a frequency of 20 MHz, for a sample volume of 80 ml. The data-acquisition time for each MIS measurement was 52 s. Given the value of spectroscopic conductivity information and the many advantages of obtaining these data in a non-contacting manner, even through electrically-insulating packaging materials if necessary, it is concluded that MIS is a technique with considerable potential for monitoring bio-industrial processes and product quality. (paper)

  3. 3D nanoscale imaging of biological samples with laboratory-based soft X-ray sources

    Science.gov (United States)

    Dehlinger, Aurélie; Blechschmidt, Anne; Grötzsch, Daniel; Jung, Robert; Kanngießer, Birgit; Seim, Christian; Stiel, Holger

    2015-09-01

    In microscopy, where the theoretical resolution limit depends on the wavelength of the probing light, radiation in the soft X-ray regime can be used to analyze samples that cannot be resolved with visible light microscopes. In the case of soft X-ray microscopy in the water-window, the energy range of the radiation lies between the absorption edges of carbon (at 284 eV, 4.36 nm) and oxygen (543 eV, 2.34 nm). As a result, carbon-based structures, such as biological samples, posses a strong absorption, whereas e.g. water is more transparent to this radiation. Microscopy in the water-window, therefore, allows the structural investigation of aqueous samples with resolutions of a few tens of nanometers and a penetration depth of up to 10μm. The development of highly brilliant laser-produced plasma-sources has enabled the transfer of Xray microscopy, that was formerly bound to synchrotron sources, to the laboratory, which opens the access of this method to a broader scientific community. The Laboratory Transmission X-ray Microscope at the Berlin Laboratory for innovative X-ray technologies (BLiX) runs with a laser produced nitrogen plasma that emits radiation in the soft X-ray regime. The mentioned high penetration depth can be exploited to analyze biological samples in their natural state and with several projection angles. The obtained tomogram is the key to a more precise and global analysis of samples originating from various fields of life science.

  4. [Cell biology researches aboard the robotic space vehicles: preparation and performance].

    Science.gov (United States)

    Tairbekov, M G

    2006-01-01

    The article reviews the unique aspects of preparation and performance of cell biology experiments flown on robotic space vehicles Bion and Foton, and gives an overview of key findings in researches made under the author's leadership over the past decades. Described are the criteria of selecting test objects, and the conditions required for preparation and implementation of space and control (synchronous) experiments. The present-day status and issues of researches into cell responsivity to space microgravity and other factors are discussed. Also, potentialities of equipment designed to conduct experiments with cell cultures in vitro and populations of single-celled organisms are presented, as well as some ideas for new devices and systems. Unveiled are some circumstances inherent to the development and performance of space experiments, setting up laboratory facilities at the launch and landing site, and methods of safe transportation and storage of biosamples. In conclusion, the author puts forward his view on biospecies, equipment and areas of research aboard future space vehicles. PMID:17357620

  5. Metal Complexes of Macrocyclic Schiff-Base Ligand: Preparation, Characterisation, and Biological Activity

    Science.gov (United States)

    Ahmed, Riyadh M.; Yousif, Enaam I.; Hasan, Hasan A.; Al-Jeboori, Mohamad J.

    2013-01-01

    A new macrocyclic multidentate Schiff-base ligand Na4L consisting of two submacrocyclic units (10,21-bis-iminomethyl-3,6,14,17-tricyclo[17.3.1.18,12]tetracosa-1(23),2,6,8,10,12(24),13,17,19,21,-decaene-23,24-disodium) and its tetranuclear metal complexes with Mn(II), Co(II), Ni(II), Cu(II), and Zn(II) are reported. Na4L was prepared via a template approach, which is based on the condensation reaction of sodium 2,4,6-triformyl phenolate with ethylenediamine in mole ratios of 2 : 3. The tetranuclear macrocyclic-based complexes were prepared from the reaction of the corresponding metal chloride with the ligand. The mode of bonding and overall geometry of the compounds were determined through physicochemical and spectroscopic methods. These studies revealed tetrahedral geometries about Mn, Co, and Zn atoms. However, square planar geometries have been suggested for NiII and CuII complexes. Biological activity of the ligand and its metal complexes against Gram positive bacterial strain Staphylococcus aureus and Gram negative bacteria Escherichia coli revealed that the metal complexes become more potentially resistive to the microbial activities as compared to the free ligand. However, these metal complexes do not exhibit any effects on the activity of Pseudomonas aeruginosa bacteria. There is therefore no inhibition zone. PMID:23935414

  6. Electrospinning preparation and electrical and biological properties of ferrocene/poly(vinylpyrrolidone composite nanofibers

    Directory of Open Access Journals (Sweden)

    Ji-Hong Chai

    2013-03-01

    Full Text Available Nanofibers containing ferrocene (Fc have been prepared for the first time by electrospinning. In this paper, Fc was dispersed uniformly throughout the poly(vinypyrrolidone (PVP matrix for the purpose of combining the properties of PVP and Fc. The effects of solvents and Fc concentration on the morphologies and diameters of nanofibers were investigated. In the DMF/ethanol solvent, the morphologies of the obtained nanofibers significantly changed with the increase of Fc concentration. The results demonstrated that the morphologies of the nanofibers could be controlled through adjusting solvents and Fc concentration. Scanning electron microscopy (SEM showed that the diameters of the obtained composite fibers were about 30–200 nm at different Fc concentrations. Thermogravimetric analysis (TGA results confirmed the presence of ferrocene within the PVP nanofibers. X-ray diffraction (XRD results showed that the crystalline structure of Fc in the fibers was amorphous after the electrospinning process. A biological evaluation of the antimicrobial activity of Fc/PVP nanofibers was carried out by using Gram-negative Escherichia coli (E. coli as model organisms. The nanofibers fabricated by this method showed obvious antibacterial activity. Electrochemical properties were characterized based on cyclic voltammetry measurements. The CV results showed redox peaks corresponding to the Fc+/Fc couple, which suggested that Fc molecules encapsulated inside PVP nanofibers retian their electrochemical activity. The properties and facile preparation method make the Fc/PVP nanofibers promising for antibacterial and sensing applications.

  7. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples.

    Science.gov (United States)

    Schütz, C L; Brochhausen, C; Hampel, G; Iffland, D; Kuczewski, B; Otto, G; Schmitz, T; Stieghorst, C; Kratz, J V

    2012-10-01

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis. PMID:22918535

  8. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Schuetz, C.L. [University of Mainz, Institute for Nuclear Chemistry, Mainz (Germany); Johannes Gutenberg-University of Mainz, Institute for Nuclear Chemistry, Mainz (Germany); Brochhausen, C. [University of Mainz, Institute of Pathology, Mainz (Germany); Hampel, G.; Iffland, D.; Schmitz, T.; Stieghorst, C.; Kratz, J.V. [University of Mainz, Institute for Nuclear Chemistry, Mainz (Germany); Kuczewski, B. [Regional Council Darmstadt, Darmstadt (Germany); Otto, G. [University of Mainz, Department of Hepatobiliary, Pancreatic and Transplantation Surgery, Mainz (Germany)

    2012-10-15

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis. (orig.)

  9. Intercomparison of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples

    International Nuclear Information System (INIS)

    Boron determination in blood and tissue samples is a crucial task especially for treatment planning, preclinical research, and clinical application of boron neutron capture therapy (BNCT). Comparison of clinical findings remains difficult due to a variety of analytical methods, protocols, and standard reference materials in use. This paper addresses the comparability of inductively coupled plasma mass spectrometry, quantitative neutron capture radiography, and prompt gamma activation analysis for the determination of boron in biological samples. It was possible to demonstrate that three different methods relying on three different principles of sample preparation and boron detection can be validated against each other and yield consistent results for both blood and tissue samples. The samples were obtained during a clinical study for the application of BNCT for liver malignancies and therefore represent a realistic situation for boron analysis. (orig.)

  10. Non-destructive high-resolution thermal imaging techniques to evaluate wildlife and delicate biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Lavers, C; Franklin, P; Franklin, P; Plowman, A; Sayers, G; Bol, J; Shepard, D; Fields, D, E-mail: brnc-radarcomms1@nrta.mod.u [Sensors Team, Plymouth University at Britannia Royal Naval College, Dartmouth, Devon (United Kingdom) and Paignton Zoological Park, Paignton, Devon (United Kingdom); Thermal Wave Imaging, Inc., 845 Livernoise St, Ferndale, MI (United States); Buckfast Butterfly and Otter Sanctuary, Buckfast, Devon (United Kingdom)

    2009-07-01

    Thermal imaging cameras now allows routine monitoring of dangerous yet endangered wildlife in captivity. This study looks at the potential applications of radiometrically calibrated thermal data to wildlife, as well as providing parameters for future materials applications. We present a non-destructive active testing technique suitable for enhancing imagery contrast of thin or delicate biological specimens yielding improved thermal contrast at room temperature, for analysis of sample thermal properties. A broad spectrum of animals is studied with different textured surfaces, reflective and emissive properties in the infra red part of the electromagnetic spectrum. Some surface features offer biomimetic materials design opportunities.

  11. Quenching effect of iron on uranium concentration measurements by fluorimetry in biological samples

    International Nuclear Information System (INIS)

    Iron is considered as a strong quencher that reduce the uranium fluorescence in biological sample. This effect was studied by two methods. In the first method iron concentration was fixed to study the effect on different uranium standard solutions. In the second method the concentration of uranium standard solutions were fixed while different amounts of iron were added if has been found that the quenching effect of iron is the same in low concentration of uranium, while in high concentration of uranium the quenching effect is greater. (author). 1 ref., 4 tabs

  12. Imaging material properties of biological samples with a Force Feedback Microscope

    CERN Document Server

    Costa, Luca; Newman, Emily; Zubieta, Chloe; Chevrier, Joel; Comin, Fabio

    2013-01-01

    Mechanical properties of biological samples have been imaged with a force feedback microscope. The force, force gradient and the dissipation are simultaneously measured quantitatively from solely the knowledge of the spring constant. The results are preliminary but demonstrate that the method can be used to measure material properties, it is robust and produce quantitative high force resolution measurements of interaction characteristics. The small stiffness and oscillation of the cantilever results in an vibrational energy much smaller than the thermal energy, reducing the interaction to a minimum. Because the lever is over-damped, the excitation frequency can be chosen arbitrarily.

  13. On the Applications of IBA Techniques to Biological Samples Analysis: PIXE and RBS

    International Nuclear Information System (INIS)

    The analytical techniques based on ion beams or IBA techniques give quantitative information on elemental concentration in samples of a wide variety of nature. In this work, we focus on PIXE technique, analyzing thick target biological specimens (TTPIXE), using 3 MeV protons produced by an electrostatic accelerator. A nuclear microprobe was used performing PIXE and RBS simultaneously, in order to solve the uncertainties produced in the absolute PIXE quantifying. The advantages of using both techniques and a nuclear microprobe are discussed. Quantitative results are shown to illustrate the multielemental resolution of the PIXE technique; for this, a blood standard was used

  14. Separation Technique for the Determination of Highly Polar Metabolites in Biological Samples

    Directory of Open Access Journals (Sweden)

    Yusuke Iwasaki

    2012-08-01

    Full Text Available Metabolomics is a new approach that is based on the systematic study of the full complement of metabolites in a biological sample. Metabolomics has the potential to fundamentally change clinical chemistry and, by extension, the fields of nutrition, toxicology, and medicine. However, it can be difficult to separate highly polar compounds. Mass spectrometry (MS, in combination with capillary electrophoresis (CE, gas chromatography (GC, or high performance liquid chromatography (HPLC is the key analytical technique on which emerging "omics" technologies, namely, proteomics, metabolomics, and lipidomics, are based. In this review, we introduce various methods for the separation of highly polar metabolites.

  15. 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.

  16. Three approaches for direct analysis of biological samples by Total reflection X-Ray Fluorescence analysis

    International Nuclear Information System (INIS)

    One of the main advantages of the Total reflection X-Ray Fluorescence technique is feasibility of the direct analysis of the sample. taking in account this fact, three methods for the direct analysis of biological samples were evaluated For the evaluation of the method of Compton peak standardization serum, brain tissue, urine and amniotic fluid matrices were analyzed using compton Peak and the elements Co, and V as internal standard. In the case the sample itself is used as calibration standard. The method is reliable for the analysis of serum and brain tissue samples. The analytical quality of the results was similar to that obtained by the conventional method. The results were in good agreements with those obtained by the atomic absorption technique. The second method was applied to the certified Bovine Liver Standard sample 1577a. Experimental conditions for the microwave acid digestion of the solid sample directly on the quartz reflector were found, The percent of recovery of the elements S, Ci, K, Ca, Mn, Fe, Cu, Zn, Se, Br, and Rb carried between 85% and 115% and The precision was below the 10% of relative standards deviations for ten independent replicates. In the third method the concept of chemical modifications is adapted to the Total reflection X-Ray Fluorescence technique. In these experiments the main objective was the elimination of Chlorine from the matrix following the in situ addition of the reactive ammonium nitrate and heating. The method was applied to high saline content samples, i.e. amniotic fluid samples, Special care was given to the volatile elements and to the quality of the thin layer. an enhancement of the sensitivity was found for those elements with signals near the chlorine k-Alfa signal after the modifications procedure

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

    Science.gov (United States)

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

    2015-03-21

    Desalination as a sample preparation step is essential for noise reduction and reproducibility of mass spectrometry measurements. A specific example is the analysis of proteins for medical research and clinical applications. Salts and buffers that are present in samples need to be removed before analysis to improve the signal-to-noise ratio. Capacitive deionization is an electrostatic desalination (CDI) technique which uses two porous electrodes facing each other to remove ions from a solution. Upon the application of a potential of 0.5 V ions migrate to the electrodes and are stored in the electrical double layer. In this article we demonstrate CDI on a chip, and desalinate a solution by the removal of 23% of Na(+) and Cl(-) ions, while the concentration of a larger molecule (FITC-dextran) remains unchanged. For the first time impedance spectroscopy is introduced to monitor the salt concentration in situ in real-time in between the two desalination electrodes. PMID:25607349

  18. Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

    International Nuclear Information System (INIS)

    Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

  19. Sample sizing of biological materials analyzed by energy dispersion X-ray fluorescence

    Energy Technology Data Exchange (ETDEWEB)

    Paiva, Jose D.S.; Franca, Elvis J.; Magalhaes, Marcelo R.L.; Almeida, Marcio E.S.; Hazin, Clovis A., E-mail: dan-paiva@hotmail.com, E-mail: ejfranca@cnen.gov.br, E-mail: marcelo_rlm@hotmail.com, E-mail: maensoal@yahoo.com.br, E-mail: chazin@cnen.gov.b [Centro Regional de Ciencias Nucleares do Nordeste (CRCN-NE/CNEN-PE), Recife, PE (Brazil)

    2013-07-01

    Analytical portions used in chemical analyses are usually less than 1g. Errors resulting from the sampling are barely evaluated, since this type of study is a time-consuming procedure, with high costs for the chemical analysis of large number of samples. The energy dispersion X-ray fluorescence - EDXRF is a non-destructive and fast analytical technique with the possibility of determining several chemical elements. Therefore, the aim of this study was to provide information on the minimum analytical portion for quantification of chemical elements in biological matrices using EDXRF. Three species were sampled in mangroves from the Pernambuco, Brazil. Tree leaves were washed with distilled water, oven-dried at 60 deg C and milled until 0.5 mm particle size. Ten test-portions of approximately 500 mg for each species were transferred to vials sealed with polypropylene film. The quality of the analytical procedure was evaluated from the reference materials IAEA V10 Hay Powder, SRM 2976 Apple Leaves. After energy calibration, all samples were analyzed under vacuum for 100 seconds for each group of chemical elements. The voltage used was 15 kV and 50 kV for chemical elements of atomic number lower than 22 and the others, respectively. For the best analytical conditions, EDXRF was capable of estimating the sample size uncertainty for further determination of chemical elements in leaves. (author)

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

    Science.gov (United States)

    Yokochi, Reika

    2016-09-01

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

  1. ASPIRE: An automated sample positioning and irradiation system for radiation biology experiments at Inter University Accelerator Centre, New Delhi

    International Nuclear Information System (INIS)

    An automated irradiation setup for biology samples has been built at Inter University Accelerator Centre (IUAC), New Delhi, India. It can automatically load and unload 20 biology samples in a run of experiment. It takes about 20 min [2% of the cell doubling time] to irradiate all the 20 samples. Cell doubling time is the time taken by the cells (kept in the medium) to grow double in numbers. The cells in the samples keep growing during entire of the experiment. The fluence irradiated to the samples is measured with two silicon surface barrier detectors. Tests show that the uniformity of fluence and dose of heavy ions reaches to 2% at the sample area in diameter of 40 mm. The accuracy of mean fluence at the center of the target area is within 1%. The irradiation setup can be used to the studies of radiation therapy, radiation dosimetry and molecular biology at the heavy ion accelerator. - Highlights: • Automated positioning and irradiation setup for biology samples at IUAC is built. • Loading and unloading of 20 biology samples can be automatically carried out. • Biologicals cells keep growing during entire experiment. • Fluence and dose of heavy ions are measured by two silicon barrier detectors. • Uniformity of fluence and dose of heavy ions at sample position reaches to 2%

  2. Restricted access magnetic materials prepared by dual surface modification for selective extraction of therapeutic drugs from biological fluids

    Energy Technology Data Exchange (ETDEWEB)

    Wang Yu; Wang Yuxia; Chen Lei [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China); Wan Qianhong, E-mail: qhwan@tju.edu.cn [School of Pharmaceutical Science and Technology, Tianjin University, Tianjin 300072 (China)

    2012-02-15

    Magnetic porous particles with dual functionality have been prepared by a two-step procedure and evaluated as novel restricted access materials for extraction of therapeutic agents from biological fluids. The magnetic silica particles served as scaffolds were first modified with diol groups, which were then converted to octadecyl esters through reaction with stearoyl chloride. In the second step, the octadecyl esters on the exterior surface were hydrolyzed by the action of lipase to yield magnetic particles with hydrophobic reversed-phase ligands on the inner surface and biocompatible diol groups on the outer surface. The restricted access behavior of the resulting materials was confirmed by differential binding of small molecules such as methotrexate (MTX), leucovorin (LV) and folic acid (FA) relative to bovine serum albumin. While MTX, LV and FA were all bound to the magnetic particles with high affinity, the adsorption of the protein was markedly reduced due to size exclusion effect. The utility of the magnetic particles for sample preparation was tested in solid-phase extraction of MTX, LV and FA from spiked human serum and the effects of the SPE conditions on the recovery of the analytes were systematically studied. Moreover, the magnetic particle-based sample preparation procedure coupled with reversed-phase liquid chromatography analysis was validated in terms of specificity, linearity and reproducibility. The method was shown to be free from interference of endogenous compounds and linear over the concentration range of 0.5-10 {mu}g/mL for the three drugs studied. The limits of detection for the three drugs in serum were in the range of 0.160-0.302 {mu}g/mL. Reproducibility expressed as the RSD of the recovery for ten replicated extractions at three different concentrations was found to be less than 8.93%. With a unique combination of surface functionality with magnetic cores, the restricted access magnetic particles may be adapted in automated and high

  3. Combined LIBS-Raman for remote detection and characterization of biological samples

    Science.gov (United States)

    Anderson, Aaron S.; Mukundan, Harshini; McInroy, Rhonda E.; Clegg, Samuel M.

    2015-03-01

    Laser-Induced Breakdown Spectroscopy (LIBS) and Raman Spectroscopy have rich histories in the analysis of a wide variety of samples in both in situ and remote configurations. Our team is working on building a deployable, integrated Raman and LIBS spectrometer (RLS) for the parallel elucidation of elemental and molecular signatures under Earth and Martian surface conditions. Herein, results from remote LIBS and Raman analysis of biological samples such as amino acids, small peptides, mono- and disaccharides, and nucleic acids acquired under terrestrial and Mars conditions are reported, giving rise to some interesting differences. A library of spectra and peaks of interest were compiled, and will be used to inform the analysis of more complex systems, such as large peptides, dried bacterial spores, and biofilms. These results will be presented and future applications will be discussed, including the assembly of a combined RLS spectroscopic system and stand-off detection in a variety of environments.

  4. Towards a new method for the quantification of metabolites in the biological sample

    International Nuclear Information System (INIS)

    The quantification of metabolites is a key step in drug development. The aim of this Ph.D. work was to study the feasibility of a new method for this quantification, in the biological sample, without the drawbacks (cost, time, ethics) of the classical quantification methods based on metabolites synthesis or administration to man of the radiolabelled drug. Our strategy consists in determining the response factor, in mass spectrometry, of the metabolites. This approach is based on tritium labelling of the metabolites, ex vivo, by isotopic exchange. The labelling step was studied with deuterium. Metabolites of a model drug, recovered from in vitro or urinary samples, were labelled by three ways (Crab tree's catalyst ID2, deuterated trifluoroacetic acid or rhodium chloride ID20). Then, the transposition to tritium labelling was studied and the first results are very promising for the ultimate validation of the method. (author)

  5. Enzymatic determination of carbon-14 labeled L-alanine in biological samples

    International Nuclear Information System (INIS)

    A method for determination of L-alanine-specific radioactivity in biological samples is presented. This method is based on the specific enzymatic transformation of L-alanine to pyruvic acid hydrazone catalyzed by the enzyme L-alanine dehydrogenase, formation of the pyruvic acid 2,4-dinitrophenylhydrazone derivative, and quantitative trapping in Amberlite XAD-7 columns, followed by radioactivity counting of the lipophilic eluate. No interferences from other 14C-labeled materials such as D-glucose, glycerol, L-lactate, L-serine, L-glutamate, L-phenylalanine, glycine, L-leucine, and L-arginine were observed. This inexpensive and high-speed method is applicable to the simultaneous determination of L-alanine-specific radioactivity for a large number of samples

  6. Enzymatic determination of carbon-14 labeled L-alanine in biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Serra, F.; Palou, A.; Pons, A.

    1987-07-15

    A method for determination of L-alanine-specific radioactivity in biological samples is presented. This method is based on the specific enzymatic transformation of L-alanine to pyruvic acid hydrazone catalyzed by the enzyme L-alanine dehydrogenase, formation of the pyruvic acid 2,4-dinitrophenylhydrazone derivative, and quantitative trapping in Amberlite XAD-7 columns, followed by radioactivity counting of the lipophilic eluate. No interferences from other UC-labeled materials such as D-glucose, glycerol, L-lactate, L-serine, L-glutamate, L-phenylalanine, glycine, L-leucine, and L-arginine were observed. This inexpensive and high-speed method is applicable to the simultaneous determination of L-alanine-specific radioactivity for a large number of samples.

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

    Directory of Open Access Journals (Sweden)

    Evangelyn C. Alocilja

    2013-01-01

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

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

    Science.gov (United States)

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

    2014-03-01

    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. PMID:24560367

  9. High-efficiency sample preparation approach to determine acrylamide levels in high-fat foods.

    Science.gov (United States)

    Li, Xiaodan; Li, Jinwei; Cao, Peirang; Liu, Yuanfa

    2016-08-01

    An improved sample preparation method was developed to enhance acrylamide recovery in high-fat foods. Prior to concentration, distilled deionized water was added to protect acrylamide from degradation, resulting in a higher acrylamide recovery rate from fried potato chips. A Chrome-Matrix C18 column (2.6 μm, 2.1 × 100 mm) was used for the first time to analyze acrylamide levels using ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry, displaying good separation of acrylamide from interference. A solid-phase extraction procedure was avoided, and an average recovery of >89.00% was achieved from different food matrices for three different acrylamide spiking levels. Good reproducibility was observed, with an intraday relative standard deviation of 0.04-2.38%, and an interday relative standard deviation of 2.34-3.26%. Thus, combining the improved sample preparation method for acrylamide analysis with the separation on a Chrome-Matrix C18 column (2.6 μm, 2.1 × 100 mm) using ultra high performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry is highly useful for analyzing acrylamide levels in complex food matrices. PMID:27279364

  10. 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. PMID:27041299

  11. Characterisation of radiation field for irradiation of biological samples at nuclear reactor-comparison of twin detector and recombination methods

    International Nuclear Information System (INIS)

    Central Laboratory for Radiological Protection is involved in achieving scientific project on biological dosimetry. The project includes irradiation of blood samples in radiation fields of nuclear reactor. A simple facility for irradiation of biological samples has been prepared at horizontal channel of the nuclear reactor MARIA in NCBJ in Poland. The radiation field, composed mainly of gamma radiation and thermal neutrons, has been characterised in terms of tissue kerma using twin-detector technique and recombination chambers. Radiobiological measurements in neutron radiation fields always should be accompanied with careful dosimetric measurement because of large variations in composition and neutron energy. In the case of measurements described here, the main problem was the requirement of precise determination of neutron absorbed dose. It was decided to use two measuring methods-twin-detector and recombination method, both based on the use of ionisation chambers. The application of the same type of detectors greatly simplified and shortened the measuring campaign. Total kerma rate was determined with the same chamber for both methods, whereas the determination of?γ is independent and the measured values could be compared for cross-check of the results. The use of combined recombination method using concepts of RMM and RIQ appeared to be very useful. The value of RIQ for neutrons alone was additionally determined and can be used in further evaluation of radiobiological data. Time needed for the determination of saturation curve makes it possible to observe stability of the beam. It was concluded that the neutron kerma rate was high enough to perform radiobiological irradiations. Stability of the beam was very good and continuous monitoring of the beam intensity was practically needed only for the case of unexpected changes in the reactor operation. (authors)

  12. Evaluation Of ARG-1 Samples Prepared By Cesium Carbonate Dissolution During The Isolok SME Acceptability Testing

    International Nuclear Information System (INIS)

    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 and Custom Equipment Development (MS and 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 (Cs2CO3) 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 Cs2CO3 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 from this work was

  13. 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

  14. 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.

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

    International Nuclear Information System (INIS)

    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-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 μg g-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)

  16. 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. PMID:27257079

  17. 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)

  18. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Beasley, D.G., E-mail: dgbeasley@ctn.ist.utl.pt [IST/C2TN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Alves, L.C. [IST/C2TN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Barberet, Ph.; Bourret, S.; Devès, G.; Gordillo, N.; Michelet, C. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Le Trequesser, Q. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Institut de Chimie de la Matière Condensée de Bordeaux (ICMCB, UPR9048) CNRS, Université de Bordeaux, 87 avenue du Dr. A. Schweitzer, Pessac F-33608 (France); Marques, A.C. [IST/IPFN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal); Seznec, H. [Univ. Bordeaux, CENBG, UMR 5797, F-33170 Gradignan (France); CNRS, IN2P3, CENBG, UMR 5797, F-33170 Gradignan (France); Silva, R.C. da [IST/IPFN, Universidade de Lisboa, Campus Tecnológico e Nuclear, E.N.10, 2686-953 Sacavém (Portugal)

    2014-07-15

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans – a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed.

  19. A comparison of quantitative reconstruction techniques for PIXE-tomography analysis applied to biological samples

    International Nuclear Information System (INIS)

    The tomographic reconstruction of biological specimens requires robust algorithms, able to deal with low density contrast and low element concentrations. At the IST/ITN microprobe facility new GPU-accelerated reconstruction software, JPIXET, has been developed, which can significantly increase the speed of quantitative reconstruction of Proton Induced X-ray Emission Tomography (PIXE-T) data. It has a user-friendly graphical user interface for pre-processing, data analysis and reconstruction of PIXE-T and Scanning Transmission Ion Microscopy Tomography (STIM-T). The reconstruction of PIXE-T data is performed using either an algorithm based on a GPU-accelerated version of the Maximum Likelihood Expectation Maximisation (MLEM) method or a GPU-accelerated version of the Discrete Image Space Reconstruction Algorithm (DISRA) (Sakellariou (2001) [2]). The original DISRA, its accelerated version, and the MLEM algorithm, were compared for the reconstruction of a biological sample of Caenorhabditis elegans – a small worm. This sample was analysed at the microbeam line of the AIFIRA facility of CENBG, Bordeaux. A qualitative PIXE-T reconstruction was obtained using the CENBG software package TomoRebuild (Habchi et al. (2013) [6]). The effects of pre-processing and experimental conditions on the elemental concentrations are discussed

  20. Preparation of Environmental and Food Samples to Support the Heavy Metals Detection by Stripping Electrochemical

    International Nuclear Information System (INIS)

    Preparation of environmental and food samples to support the heavy metals detection by stripping electrochemistry was done. The water samples taken directly from the ground water were acidified with 1 mL of HNO3 acic suprapure was not digested, while the soils samples which have already dried in the oven at 105 oC, ware grinded and sieved through 150 μm, werte digested with HNO3 acic suprapure in the digestion bomb at 150 oC for 3-4 hours. The mussels samples which have already freezed in the freezer were peeled, dried with N2 liquid, grinded and dried again in the freeze drier at the pressure of ≅ 10-2 mBar, and then were grinded again, weighted, digested with HNO3 acic and HClO4 suprapure in the digestion bomb at 150 oC for 3 hours. Food samples were homogenized by electric mixer, dried with freeze dried, homogenized again by using ZrO2 ball mill, weighted, digested by HPA (high Pressure Asher). The heavy metals in the food samples solution of digestion product were detected by using Polarographic Analyzer EGandG of SWV and DPASV methods, while in the water, soils and the mussels solution were detected by using PDV 2000 and Polarograf E-505, DPASV method. The method validity were tested with SRM materials such as soil-5, soil-7, water W-4, and coppepoda. The heavy metals detection results in the water, soils, mussels, and food by electrochemical method were reported in this paper. (author)

  1. 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.

  2. Bioassay alpha spectrometry: energy resolution as a function of sample source preparation and counting geometry

    International Nuclear Information System (INIS)

    Alpha particle counting is based on the response of an electronic counting system to an incident alpha particle. Alpha spectrometry is used in our employee surveillance bioassay program to measure the concentration of isotopes of Am, Pu and U contained on sample source preparations. Nuclides of Am, Pu and U are separated from the sample matrix by anion exchange and are electroplated on a stainless steel disc. The plated source diameter is 12.7 mm. A tracer is added to the sample before anion exchange as a quality control procedure to provide a measure of chemical yield. Tracer alpha-particle emissions are recorded in a preassigned calibrated area of the energy spectrum and chemical recovery is calculated by the ratio of tracer counts per second divided by the tracer activity in becquerels (Bq). Percent tracer recovery may also be calculated by introducing the average counting efficiency factor in the denominator. Tracer yield is then used to provide a reliable estimate of the sample's analyte counts that are recorded in other preassigned energy dependent areas of the spectrum. The tracer spectrum in the presence or absence of other nuclides also provides evidence of the performance characteristics of the alpha spectrometer, for example, chamber vacuum and electronics. Electroplated samples are counted in any one of 96 detectors. The backgrounds of these detectors are maintained at less than 3 counts per 70,000 s over a 190 keV energy window to provide a limit of detection of less than 0.37 mBq per sample at the 95% confidence level. In this paper, resolution of the photopeak is shown to be a function of the source to detector distance and a function of degraded alpha energies due to Fe or other extraneous materials on the plated surface

  3. Methylmercury determination in biological samples using electrothermal atomic absorption spectrometry after acid leaching extraction

    Energy Technology Data Exchange (ETDEWEB)

    Saber-Tehrani, Mohammad; Hashemi-Moghaddam, Hamid; Givianrad, Mohammad Hadi; Abroomand-Azar, Parviz [Islamic Azad University, Department of Chemistry, Science and Research Branch, Tehran (Iran)

    2006-11-15

    An efficient and sensitive method for the determination of methylmercury in biological samples was developed based on acid leaching extraction of methylmercury into toluene. Methylmercury in the organic phase was determined by electrothermal atomic absorption spectrometry (ETAAS). The methylmercury signal was enhanced and the reproducibility increased by formation of certain complexes and addition of Pd-DDC modifier. The complex of methylmercury with DDC produced the optimum analytical signal in terms of sensitivity and reproducibility compared to complexes with dithizone, cysteine, 1,10-phenanthroline, and diethyldithiocarbamate. Method performance was optimized by modifying parameters such as temperature of mineralization, atomization, and gas flow rate. The limit of detection for methylmercury determination was 0.015 {mu}g g{sup -1} and the RSD of the whole procedure was 12% for human teeth samples (n=5) and 15.8% for hair samples (n=5). The method's accuracy was investigated by using NIES-13 and by spiking the samples with different amounts of methylmercury. The results were in good agreement with the certified values and the recoveries were 88-95%. (orig.)

  4. Label-free three-dimensional reconstruction of biological samples (Conference Presentation)

    Science.gov (United States)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

  5. Label-free three dimensional reconstruction of biological samples (Conference Presentation)

    Science.gov (United States)

    Aknoun, Sherazade; Bon, Pierre; Savatier, Julien; Monneret, Serge; Wattellier, Benoit F.

    2016-03-01

    We describe the use of spatially incoherent illumination combined with quantitative phase imaging (QPI) [1] to make tridimensional reconstruction of semi-transparent biological samples. Quantitative phase imaging is commonly used with coherent illumination for the relatively simple interpretation of the phase measurement. We propose to use spatially incoherent illumination which is known to increase lateral and axial resolution compared to classical coherent illumination. The goal is to image thick samples with intracellular resolution [2]. The 3D volume is imaged by axially scanning the sample with a quadri-wave lateral shearing interferometer used as a conventional camera while using spatially incoherent white-light illumination (native microscope halogen source) or NIR light. We use a non-modified inverted microscope equipped with a Z-axis piezo stage. A z-stack is recorded by objective translation along the optical axis. The main advantages of this approach are its easy implementation, compared to the other state-of-the-art diffraction tomographic setups, and its speed which makes even label-free 3D living sample imaging possible. A deconvolution algorithm is used to compensate for the loss in contrast due to spatially incoherent illumination. This makes the tomographic volume phase values quantitative. Hence refractive index could be recovered from the optical slices. We will present tomographic reconstruction of cells, thick fixed tissue of few tens of micrometers using white light, and the use of NIR light to reach deeper planes in the tissue.

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

    International Nuclear Information System (INIS)

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

  7. Sample preparation with microwave. Experiences in the environmental- and industrial analytics laboratory of Voest Alpine (P1)

    International Nuclear Information System (INIS)

    Full text: Since around one and a half year two microwave sample preparation units tested and used in the environmental- and industrial analytics laboratory of Voest Alpine. On basis of the experiences the technique offered good results for the specific applications in a steel company. In comparison with the traditional sample preparation of iron oxides for ICP-OES determination through an open vessel wet-chemical acid pulping sample preparation with closed vessel microwave digestion got a large quantity of advantages. The problem with simultaneously sample preparation and determination of silica and other compounds in ultra-pure iron oxides could be solved. We obtained an excellent recovery and reproducibility with microwave pulping. In the range of environmental analytics the possibilities of microwave sample preparation to prepare typical dusts, landfill wastes, process and waste water of a steel company was analyzed. The microwave sample preparation showed good reproducibility to the conventional techniques, e.g. pulping and Soxleth-extraction. Someone of them are already replaced by the new method. Here also the microwave technique possess a large potential for more uses. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-05-07

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

  9. 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). PMID:16390175

  10. Development of a radioimmunoassay for the determination of buprenorphine in biological samples

    International Nuclear Information System (INIS)

    The development of a specific and sensitive radioimmunoassay for the detection of buprenorphine in urine samples is described. With minor adjustments, the assay was also applied to the analysis for buprenorphine in plasma samples. The 2-diazobenzoic acid derivative of buprenorphine has been prepared as a hapten. The immunization of rabbits with the hapten-bovine serum albumin conjugate resulted in the production of antibodies, which cross-reacted with N-dealkylbuprenophine up to about the 90% level. The antibodies showed very low cross-reactivities with the 3-O-glucuronides and with the structural analogue etorphine. The assay was mainly used to prescreen for buprenorphine in urine samples of persons suspected of Temgesic misuse and to determine buprenorphine in plasma samples. A linear calibration graph for buprenorphine was obtained after logit-log regression. The spiking recovery study showed a linear regression. Intra-and inter-assay relative standard deviations were -1 (Student's t-distribution, p 0.01, degrees of freedom = 8). (Author)

  11. Alteration in sample preparation to increase the yield of multiplex Polymerase Chain Reaction assay for diagnosis of genital ulcer disease

    Directory of Open Access Journals (Sweden)

    G Rao

    2013-01-01

    Full Text Available Purpose: Genital Ulcer Disease (GUD is common sexually transmitted infection (STI. Multiple studies have shown that GUDs are strongly associated with the transmission and the acquisition of HIV infection. An accurate diagnosis of common etiology of GUD namely Herpes, syphilis and Chancroid is possible using Multiplex PCR (M-PCR. However, frequent presence of Polymerase Chain Reaction inhibitors in the ulcer swab specimen limits the performance of the assay. In order to overcome this problem, alternative specimen preparation method was used. Materials and Methods: To determine the common etiology, GUD specimens obtained under an STI operations research study were tested with M-PCR after the samples were prepared using Roche Amplicor specimen preparation kit. PCR inhibiting samples were identified from that, which showed negative results. These samples were subjected to phenol-chloroform extraction and ethanol precipitation before the conduct of M-PCR on them. Results: Of the 237 GUD specimens tested, in 145 etiologies could be detected, whereas 92 samples were found negative. Further spiking with one of the target DNA, 128 of the negative samples were found to contain the inhibitors. These 126 samples were then subjected to phenol chloroform extraction and ethanol precipitation followed by M-PCR. Using this method for sample preparation, etiology could be determined in 46 (23% additional samples. This success rate of altered sample preparation method has been lower than that has reported. Conclusion: The results indicate that sample preparation using phenol chloroform extraction and ethanol precipitation, prior to M-PCR helps to eliminate the inhibitors and increase the yield of the assay. However, being a laborious procedure, it may be used for samples giving negative results after the screening by Roche Amplicor specimen preparation kit.

  12. speciation of selenium in human biological samples using online hyphenation of HPLC and ICP-MS

    International Nuclear Information System (INIS)

    Selenium is an important trace element that plays specific biological role in organism. Since bioactivity of selenium is a consequence of individual chemical species, there is considerable interest in the speciation of selenium in the mammalian organism. Inasmuch as selenium is primarily present in the form of selenoproteins in mammalian tissues, speciation studies of Se-containing proteins are focused on the various organs and tissues. Serum and urine samples can be used for study of Se metabolites in vivo. Hyphenation of chromatographic separation with element-specific detection has been proved as a powerful technique for Se speciation analysis recently. In present study, using an ion-pair reversed-phase liquid chromatography, Se species such as selenite (Se(IV>), selenate (Se(VI>), trimethyl selenonium (TMSe+), selenocystine (SeCys), selenourea (SeUr), selenomethionine (SeMet), and selenocystamine (SeCM) are separated and followed by the online coupling detection as introduced below. A 5-μm Symmetry Shield RP18 column was applied for the analysis of Se compounds using 0.1% HFBA in 1:99 methanol-water buffer as mobile phase. Elemental signal detected by ICP-MS geminated in case of collision cell technique (CCT) mode, since the most abundant isotope 80Se instead of 82Se or 78Se monitored in ordinary model. More sensitive technique based on ICP-MS and CCT can recognize signals of Se standard compounds, whose concentrations were less than l ppb in hyphenation experiment, and Se concentrations of quantitative analysis could reach several ppb. Human liver cytoplasm and serum samples gave legible chromatograms with a few peaks recognized easily, while urine samples of human gave much more complex chromatograms according to the intricate components. The uncertainty of measurement will be estimated too.Nevertheless, both of serum and urine samples give quantifiable elemental signals, while cytoplasm samples gave weaker signals referring to the lower concentrations of Se

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

    Science.gov (United States)

    Hoffman, Gerald L.

    1996-01-01

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

  14. Preparation, Spectroscopic Investigation and Biological Activity of New Mixed Ligand Chelates

    International Nuclear Information System (INIS)

    Preparation and investigation of new Co(II), Ni(II), Zn(II) and Cr(III) chelates with mixed ligands including Schiff base (L1) formed from the condensation of 4-dimethylaminobenzaldehyde with 2-aminophenol and anthranilic acid (L2) were studied. The obtained Schiff base and mixed ligand chelates were subjected to several physiochemical techniques, in terms of CHN elemental analyses, molar conductivity, magnetic moment measurements, infrared, proton nuclear magnetic resonance, electronic and mass spectra. The analytical data showed the formation of the Schiff base compound and the ratio of metal to ligands of the chelates are 1:1:1(M:L1:L2). The infrared spectral data exhibited that the used ligands behaving as bidentate ligands towards the metal ions. The proton nuclear magnetic resonance spectral data showed the signals of the active groups in the ligands which entered in chelation with Zn(II) metal ion. The electronic spectral results showed the existence of pie (phenyl ring) and n = pie (C=N) of the ligands and suggested the geometrical structures of the chelates. Meanwhile, the mass spectral data revealed the fragmentations of the Schiff base, anthranilic acid and their Ni(II) mixed ligand chelate has been preformed the only chelate conducted for justification. All the prepared mixed chelates were non-electrolyte in nature. The antibacterial activity of the Schiff base, anthranilic acid, metal salts and mixed ligand chelates were studied and found to be that mixed ligand chelates have the most biological activity in comparison to the free ligands and salts. (author)

  15. An optimised sample preparation method for NMR-based faecal metabonomic analysis.

    Science.gov (United States)

    Wu, Junfang; An, Yanpeng; Yao, Jianwu; Wang, Yulan; Tang, Huiru

    2010-05-01

    Faecal metabonomic NMR analysis plays an essential role in investigating the interactions between mammalian metabolism and symbiotic gut microbiota. However, the faecal metabolite extraction method remains to be optimised and standardised to take into consideration signal-to-noise ratios, pH and chemical shift consistency. In the current investigation, we compared extraction consistency of three homogenisation methods including manual ultrasonication, automatic homogenization with tissuelyser and their combination, and systematically optimised faecal metabolite extraction parameters, including the faeces-to-buffer ratio (W(f) : V(b)), extraction repetition times and duration. We found that automatic homogenisation with tissuelyser was the choice of extraction method owning to its good metabolite extraction consistency and high throughput. We also recommend W(f) : V(b) of 1 : 10 (mg microl(-1)) and use of the combined first two extracts as the resultant samples to represent faecal metabolite composition. Such recommendation is based on considerations of maximisation of the spectral signal-to-noise ratio, pH and chemical shift consistency, completeness of metabolite extraction and sample preparation throughput so that the method is suitable for analysing a large number of samples especially in human population studies. PMID:20419252

  16. Polymer monolithic capillary microextraction on-line coupled with inductively coupled plasma-mass spectrometry for the determination of trace Au and Pd in biological samples

    International Nuclear Information System (INIS)

    A novel method based on on-line polymer monolithic capillary microextraction (CME)-inductively coupled plasma mass spectrometry (ICP-MS) was developed for the determination of trace Au and Pd in biological samples. For this purpose, poly(glycidyl methacrylate-ethylene dimethacrylate) monolith was prepared and functionalized with mercapto groups. The prepared monolith exhibited good selectivity to Au and Pd, and good resistance to strong acid with a long life span. Factors affecting the extraction efficiency of CME, such as sample acidity, sample flow rate, eluent conditions and coexisting ion interference were investigated in detail. Under the optimal conditions, the limits of detection (LODs, 3σ) were 5.9 ng L−1 for Au and 8.3 ng L−1 for Pd, and the relative standard deviations (RSDs, c = 50 ng L−1, n = 7) were 6.5% for Au and 1.1% for Pd, respectively. The developed method was successfully applied to the determination of Au and Pd in human urine and serum samples with the recovery in the range of 84–118% for spiked samples. The developed on-line polymer monolithic CME-ICP-MS method has the advantages of rapidity, simplicity, low sample/reagent consumption, high sensitivity and is suitable for the determination of trace Au and Pd in biological samples with limited amount available and complex matrix. - Highlights: • An on-line CME-ICP-MS method was developed for Au and Pd analysis in human fluids. • Poly(GMA-EDMA-SH) monolith exhibited good selectivity for Au/Pd and acid-resistance. • The method is rapid, simple, and sensitive with low sample/reagents consumption

  17. Absorbed dose measurements using TLDS in biological samples from beta radiation

    Directory of Open Access Journals (Sweden)

    José Eduardo Manzoli

    2006-01-01

    Full Text Available Irradiation of samples in peculiar experimental apparatus, subject to radiation spread, requires a special evaluation of absorbed dose implanted to the sample. Indirect calibration of the irradiation source, obtained in a different apparatus, and the spread, usually of very difficult theoretical evaluation, can cause very serious measurement errors, sometimes reaching 50%. In this work, the procedure for dose evaluation in an apparatus for beta irradiation of samples, usually biological ones,is presented, making use of calibration curves, obtained by irradiation in advance of thermoluminescent detectors in air, and so irradiating them in the same position of the sample. An application in blood sample irradiation is also presented.A irradiação de amostras em arranjos experimentais peculiares sujeitos a espalhamento necessita de uma determinação própria da dose absorvida que a amostra irá receber. A calibração indireta da fonte de irradiação, que ocorre em arranjo diferente, e o espalhamento, geralmente de difícil estimativa teórica, podem causar erros de medição muito elevados, não raro atingindo 50%. Neste trabalho é apresentado o procedimento para determinação da dose absorvida em um arranjo para irradiação beta de amostras, normalmente biológicas, utilizando curvas de calibração obtidas pela irradiação de dosímetros termoluminescentes no ar, e os irradiando na mesma posição das amostras. É apresentado um exemplo de aplicação para amostra irradiada de sangue.

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

    Science.gov (United States)

    Bartok, A.; Kustov, M.; Cohen, L. F.; Pasko, A.; Zehani, K.; Bessais, L.; Mazaleyrat, F.; LoBue, M.

    2016-02-01

    Magnetocaloric materials with composition of Mn1.3Fe0.65P0.5 Si0.5 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.

  19. Preparation of a K(+) -imprinted polymer for the selective recognition of K(+) in food samples.

    Science.gov (United States)

    Hashemi, Beshare; Shamsipur, Mojtaba; Seyedzadeh, Zahra

    2016-05-01

    An analytical method is reported for the preparation of K(+) -imprinted nanoparticles using cryptand 222 as the complexing agent, methacrylic acid as the functional monomer, ethylene glycol dimethacrylate as the crosslinker and 2,2'-azobisisobutyronitrile as the radical initiator. The prepared particles have a diameter of 200-250 nm. The maximum adsorption capacity of potassium ion-imprinted polymer particles was 120 μmol/g. The optimum pH for quantitative extraction was 9.0. The nature of the eluent, eluent concentration, adsorption and desorption times, weight of the polymer material, aqueous phase, and desorption volumes were also studied. The relative selectivity coefficients of K(+) /Li(+) , K(+) /Na(+) , K(+) /Rb(+) and K(+) /Cs(+) were 48.10, 4.80, 29.70, and 43.4, respectively. The relative standard deviation and limit of detection of the method were obtained 1.61% and 4.62 ng/L, respectively. Finally, the method was applied for the determination of potassium ions from different samples using flame photometry. PMID:27005866

  20. 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.

  1. Sample preparation and analytical strategies for large-scale phosphoproteomics experiments.

    Science.gov (United States)

    Kanshin, Evgeny; Michnick, Stephen; Thibault, Pierre

    2012-10-01

    Reversible protein phosphorylation is an important post-translational modification that controls a wide range of protein functions including enzyme activity, subcellular localisation, protein degradation, intra- and inter-molecular protein interactions. Significant advances in both phosphopeptide enrichment methods and sensitive mass spectrometry instrumentation have been achieved over the past decade to facilitate the large-scale identification of protein phosphorylation in humans and different animal and microbial model systems. While mass spectrometry provides the ability to identify thousands of phosphorylation sites in a single experiment, the further understanding of the functional significance of this modification on protein substrates requires detailed information on the changes in phosphorylation stoichiometry and protein abundance across experimental paradigms. This review presents different sample preparation methods and analytical strategies used in mass spectrometry-based phosphoproteomics to profile protein phosphorylation and unravel the regulation of this modification on protein function. PMID:22683502

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

    International Nuclear Information System (INIS)

    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. 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.

  4. Sample preparation for arsenic speciation in terrestrial plants--a review.

    Science.gov (United States)

    Amaral, Clarice D B; Nóbrega, Joaquim A; Nogueira, Ana R A

    2013-10-15

    Arsenic is an element widely present in nature. Additionally, it may be found as different species in several matrices and therefore it is one of the target elements in chemical speciation. Although the number of studies in terrestrial plants is low, compared to matrices such as fish or urine, this number is raising due to the fact that this type of matrix are closely related to the human food chain. In speciation analysis, sample preparation is a critical step and several extraction procedures present drawbacks. In this review, papers dealing with extraction procedures, analytical methods, and studies of species conservation in plants cultivated in terrestrial environment are critically discussed. Analytical procedures based on extractions using water or diluted acid solutions associated with HPLC-ICP-MS are good alternatives, owing to their versatility and sensitivity, even though less expensive strategies are shown as feasible choices. PMID:24054594

  5. Preparation of 15N labelled protein sample by gene engineering technology

    International Nuclear Information System (INIS)

    Using the advanced multi-dimension heteronuclear pulses and isotope labelled protein technique, nuclear magnetic resonance spectroscopy has become an important tool in analysis of the solution conformation of protein. On the basis of the high level expression of a protein-trichosanthin in recombinant E.coli using DNA, 15N was used to label the protein, the 15N labelled trichosanthin was obtained by affinity chromatography on Ni-NTA agarose. Terminating pregnant effect in mice showed that this recombinant protein had the same activity as natural trichosanthin. A 1H-15N heteronuclear single-quantum coherence (HSQC) spectrum was obtained from an AM-500 NMR spectrometer, demonstrating that this method is suitable in preparing labelled protein sample for NMR

  6. Preparation and Application of Novel Magnetic Molecularly Imprinted Composites for Recognition of Sulfadimethoxine in Feed Samples.

    Science.gov (United States)

    Feng, Min; Li, Hengye; Zhang, Lin; Zhang, Jingyou; Dai, Jianping; Wang, Xiaojin; Zhang, Lingli; Wei, Yunji

    2016-01-01

    Novel magnetic molecularly imprinted composites were prepared through a facile method using sulfadimethoxine (SDM) as template. The inorganic magnetic nanoparticles were linked with the organic molecularly imprinted polymer (MIP) through irreversibly covalent bond. So, the resulted composites showed excellent stability and reusability under acidic elution conditions. The magnetic MIP composites showed good selectivity, high binding capacity and excellent kinetics toward SDM. Adopting the magnetic MIP composites as extraction material, an off-line magnetic solid-phase extraction (SPE)/high performance liquid chromatography (HPLC) method was established. The calibration curve was linear in the range of 0.05 - 15 mg kg(-1) (r(2) = 0.9976). The LOD and LOQ were 0.016 and 0.052 mg kg(-1), respectively, while the recoveries were in the range of 89.3 - 107.0%. These novel magnetic MIP composites may become a powerful tool for the extraction of template from complex samples with good efficiency. PMID:27169650

  7. Development of a harmonised method for the profiling of amphetamines: IV. Optimisation of sample preparation.

    Science.gov (United States)

    Andersson, Kjell; Jalava, Kaisa; Lock, Eric; Huizer, Henk; Kaa, Elisabet; Lopes, Alvaro; Poortman-van der Meer, Anneke; Cole, Michael D; Dahlén, Johan; Sippola, Erkki

    2007-06-14

    The suitability of liquid-liquid extraction (LLE) and solid-phase extraction (SPE) for the preparation of impurity extracts intended for gas chromatographic profiling analyses of amphetamine were evaluated. Both techniques were optimised with respect to the extraction of selected target compounds by use of full factorial designs in which the variables affecting the performance were evaluated. Test samples consisted of amphetamine synthesised by the Leuckart reaction, by reductive amination of benzyl methyl ketone and by the nitrostyrene route. The performance of LLE and SPE were comparable in terms of repeatability and recovery of the target compounds. LLE was considered the better choice for the present harmonised amphetamine profiling method due to the lack of information on the long-term stability of SPE columns. PMID:17134863

  8. Molecular dynamics simulations of biological membranes and membrane proteins using enhanced conformational sampling algorithms.

    Science.gov (United States)

    Mori, Takaharu; Miyashita, Naoyuki; Im, Wonpil; Feig, Michael; Sugita, Yuji

    2016-07-01

    This paper reviews various enhanced conformational sampling methods and explicit/implicit solvent/membrane models, as well as their recent applications to the exploration of the structure and dynamics of membranes and membrane proteins. Molecular dynamics simulations have become an essential tool to investigate biological problems, and their success relies on proper molecular models together with efficient conformational sampling methods. The implicit representation of solvent/membrane environments is reasonable approximation to the explicit all-atom models, considering the balance between computational cost and simulation accuracy. Implicit models can be easily combined with replica-exchange molecular dynamics methods to explore a wider conformational space of a protein. Other molecular models and enhanced conformational sampling methods are also briefly discussed. As application examples, we introduce recent simulation studies of glycophorin A, phospholamban, amyloid precursor protein, and mixed lipid bilayers and discuss the accuracy and efficiency of each simulation model and method. This article is part of a Special Issue entitled: Membrane Proteins edited by J.C. Gumbart and Sergei Noskov. PMID:26766517

  9. Rare earth analysis in human biological samples by atomic absorption using electrothermal atomization

    International Nuclear Information System (INIS)

    The determination of Sc and seven rare earth elements, Nd, Sm, Dy, Ho, Eu, Tm, and Yb, in biological samplesby atomic absorption spectrophotometric analysis (AAS) using electrothermal atomization in a pyrolytic graphite tube is shown to be rapid, precise and accurate. The technique utilizes the method of standard additions and linear regression analysis to determine results from peak area data. Inter-elemental interferences are negligible. The elements found sensitive enough for this type of analysis are, in order of decreasing sensitivity, Yb, Eu, Tm, Dy, Sc, Ho, Sm and Nd. The determination in these types of materials of Gd and elements less sensitive to AAS detection than Gd does not appear to be feasible. Results are presented on the concentrations of these elements in 41 samples from human subjects, cows and vegetables with normal environmental exposure to the rare earth elements. The composite percent mean deviation in peak-area readings for all samples and all elements examined was 4%. The mean standard error in the results among samples was about 6.5%

  10. Shear mechanical anisotropy of side chain liquid-crystal elastomers: Influence of sample preparation

    Science.gov (United States)

    Rogez, D.; Francius, G.; Finkelmann, H.; Martinoty, P.

    2006-08-01

    We study the mechanical anisotropy of a series of uniaxial side chain nematic elastomers prepared with the same chemical composition but with different preparation protocols. For all the compounds, the experiments performed as a function of temperature show no discontinuity in both G'// and G'⊥ (the labels // and ⊥ stand for the director parallel, respectively perpendicular to the shear displacement) around the nematic-isotropic (N-I) phase transition temperature determined by DSC. They also all show a small decrease in G'// starting at temperatures well above this temperature (from ˜ 4°C to ˜ 20°C depending on the compound studied) and leading to a small hydrodynamic value of the G'⊥/G'// ratio. The measurements taken as a function of frequency show that the second plateau in G'// and the associated dip in G//” expected from dynamic semi-soft elasticity are not observed. These results can be described by the de Gennes model, which predicts small elastic anisotropy in the hydrodynamic and linear regimes. They correspond to the behavior expected for compounds beyond the mechanical critical point, which is consistent with the NMR and specific heat measurements taken on similar compounds. We also show that a reduction in the cross-linking density does not change the non-soft character of the mechanical response. From the measurements taken as a function of frequency at several temperatures we deduce that the time-temperature superposition method does not apply. From these measurements, we also determine the temperature dependence of the longest relaxation time τE of the network for the situations where the director is either parallel or perpendicular to the shear velocity. Finally, we discuss the influence on the measurements of the mechanical constraint associated with the fact that the samples cannot change their shape around the pseudo phase transition, because of their strong adherence on the sample-bearing glass slides.

  11. Education catching up with science: preparing students for three-dimensional literacy in cell biology.

    Science.gov (United States)

    Kramer, Ijsbrand M; Dahmani, Hassen-Reda; Delouche, Pamina; Bidabe, Marissa; Schneeberger, Patricia

    2012-01-01

    The large number of experimentally determined molecular structures has led to the development of a new semiotic system in the life sciences, with increasing use of accurate molecular representations. To determine how this change impacts students' learning, we incorporated image tests into our introductory cell biology course. Groups of students used a single text dealing with signal transduction, which was supplemented with images made in one of three iconographic styles. Typically, we employed realistic renderings, using computer-generated Protein Data Bank (PDB) structures; realistic-schematic renderings, using shapes inspired by PDB structures; or schematic renderings, using simple geometric shapes to represent cellular components. The control group received a list of keywords. When students were asked to draw and describe the process in their own style and to reply to multiple-choice questions, the three iconographic approaches equally improved the overall outcome of the tests (relative to keywords). Students found the three approaches equally useful but, when asked to select a preferred style, they largely favored a realistic-schematic style. When students were asked to annotate "raw" realistic images, both keywords and schematic representations failed to prepare them for this task. We conclude that supplementary images facilitate the comprehension process and despite their visual clutter, realistic representations do not hinder learning in an introductory course. PMID:23222839

  12. DEVELOPMENT OF TETRAZEPAM-SELECTIVE MEMBRANE SENSORS AND THEIR APPLICATIONS IN PHARMACEUTICAL PREPARATIONS AND BIOLOGICAL FLUIDS

    Directory of Open Access Journals (Sweden)

    MAHA EL-TOHAMY

    2010-06-01

    Full Text Available The construction and performance characteristics of tetrazepam selective electrodes were developed. Two types of electrodes: plastic membrane I and coated wire II were constructed based on the incorporation of tetrazepam with phosphomolybdic acid. The influence of membrane composition, kind of plasticizer, pH of the test solution, soaking time, and foreign ions on the electrodes were investigated. The electrodes showed a Nernstain response with a mean calibration graph slope of 58.88±0.5 and 59.18±0.1 mV decade-1 at 25ºC for electrode I and II respectively, over tetrazepam concentration range from 5x10-3-1x10-6M and 1x10-2-1x10-6M, and with detection limit 5.0x10-7 M and 4.8 x10-7M for electrode I and II respectively. The constructed electrodes gave average selective precise and usable within the pH range 4-6. Interferences from common cations, alkaloids, sugars, amino acids and drug excipients were reported. The results obtained by the proposed electrodes were also applied successfully to the determination of the drug in pharmaceutical preparations and biological fluids.

  13. Preparation and biological behavior of 99m Tc(V)-DMS as a tumor imaging agent

    International Nuclear Information System (INIS)

    A new 99m Tc - labelled radiopharmaceutical has been developed for tumor imaging under commercial name of DMS-PENTATEC. We used for the preparation 2,3 meso dimercaptosuccinic acid (DMSA), as ligand, and SnCl2 x 2H2O, as reducing agent. The mass ratio DMSA: SnCl2 is 1:0.43 in the mixture of inositol, ascorbic acid and natrium chloride as the antioxidant system. The labelling with 99m Tc was performed at an alkaline pH (7.5 - 8.5) with the result of a new coordination complex DMS - 99m Tc(V) with higher uptake by the tumor cells. The biological studies were made on Wistar London rats with Walker tumors. After intravenous (i.v.) administration of 30 mCi DMS - 99m Tc(V), the biodistribution measurements were carried out at 5 min, 15 min, 30 min and 60 min for the tumors and following organs: blood, liver, spleen, kidneys. The DMS - 99m Tc(V) accumulates quantitatively in the tumor 30 min after i.v. injection. The present study provides a good basis for DMS-99'm Tc(V) clinical application as a tumor imaging agent, mainly for head and neck squamous cell carcinomas, medullar thyroid cancers and soft-tissue tumors. (authors)

  14. Large area synchrotron X-ray fluorescence mapping of biological samples

    International Nuclear Information System (INIS)

    Large area mapping of inorganic material in biological samples has suffered severely from prohibitively long acquisition times. With the advent of new detector technology we can now generate statistically relevant information for studying cell populations, inter-variability and bioinorganic chemistry in large specimen. We have been implementing ultrafast synchrotron-based XRF mapping afforded by the MAIA detector for large area mapping of biological material. For example, a 2.5 million pixel map can be acquired in 3 hours, compared to a typical synchrotron XRF set-up needing over 1 month of uninterrupted beamtime. Of particular focus to us is the fate of metals and nanoparticles in cells, 3D tissue models and animal tissues. The large area scanning has for the first time provided statistically significant information on sufficiently large numbers of cells to provide data on intercellular variability in uptake of nanoparticles. Techniques such as flow cytometry generally require analysis of thousands of cells for statistically meaningful comparison, due to the large degree of variability. Large area XRF now gives comparable information in a quantifiable manner. Furthermore, we can now image localised deposition of nanoparticles in tissues that would be highly improbable to 'find' by typical XRF imaging. In addition, the ultra fast nature also makes it viable to conduct 3D XRF tomography over large dimensions. This technology avails new opportunities in biomonitoring and understanding metal and nanoparticle fate ex-vivo. Following from this is extension to molecular imaging through specific anti-body targeted nanoparticles to label specific tissues and monitor cellular process or biological consequence

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

    Energy Technology Data Exchange (ETDEWEB)

    Santos, D. Jr.; Barbosa, F. Jr.; Tomazelli, A.C.; Krug, F.J. [Centro de Energia Nuclear na Agricultura, Piracicaba (Brazil); Nobrega, J.A. [Departamento de Quimica, UFSCar, Sao Carlos (Brazil); Arruda, M.A.Z. [Instituto de Quimica, UNICAMP, Campinas (Brazil)

    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) HNO{sub 3} containing 0.04% (v/v) Triton X-100 and sonication for 30 s, before transferring into the platform previously coated with 250 {mu}g W and 200 {mu}g Rh. Use of a tungsten carbide-rhodium permanent modifier combined with NH{sub 4}H{sub 2}PO{sub 4} 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{sup -1} Cd and 75 ng g{sup -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. (orig.)

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

    Science.gov (United States)

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

    2015-10-01

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

  17. Comparison of sample preparation methods for the determination of essential and toxic elements in important indigenous medicinal plant Aloe barbadensis

    International Nuclear Information System (INIS)

    The role of elements particularly traces elements in health and disease is now well established. In this paper we investigate the presence of various elements in very important herb Aloe barbadensis, it is commonly used in different ailments especially of elementary tract. We used four extraction methods for the determination of total elements in Aloe barbadensis. The procedure, which is found to be more efficient and decompose the biological material, is nitric acid and 30% hydrogen peroxide as compared to other method. The sample of plants was collected from surrounding of Hyderabad; Sindh University and vouches specimens were prepared following the standard herbarium techniques. Fifteen essential, trace and toxic elements such as Zn, Cr, K, Mg, Ca, Na, Fe, Pb, Al, Ba, Mn, Co, Ni and Cd were determined in plant and in its decoction. Using Flame Atomic Absorption Spectrophotometer Hitachi Model 180-50. It is noted that, level of essential elements was found high as compare to the level of toxic elements. (author)

  18. Determination of steroid hormones in biological and environmental samples using green microextraction techniques: an overview.

    Science.gov (United States)

    Aufartová, Jana; Mahugo-Santana, Cristina; Sosa-Ferrera, Zoraida; Santana-Rodríguez, José Juan; Nováková, Lucie; Solich, Petr

    2011-10-17

    Residues of steroid hormones have become a cause for concern because they can affect the biological activity of non-target organisms. Steroid hormones are a potential risk for wildlife and humans through the consumption of contaminated food or water. Their determination requires extraction and clean-up steps, prior to detection, to reach low concentration levels. In recent years, a great effort has been made to develop new analytical methodologies, such as microextraction techniques, that reduce environmental pollution. Researchers have modified old methods to incorporate procedures that use less-hazardous chemicals or that use smaller amounts of them. They are able to do direct analysis using miniaturised equipment and reduced amounts of solvents and wastes. These accomplishments are the main objectives of green analytical chemistry. In this overview, we focus on microextraction techniques for the determination of steroid hormones in biological (e.g., human urine, human serum, fish, shrimp and prawn tissue and milk) and environmental (e.g., wastewaters, surface waters, tap waters, river waters, sewage sludges, marine sediments and river sediments) samples. We comment on the most recent applications in sorptive-microextraction modes, such as solid phase microextraction (SPME) with molecularly imprinted polymers (MIPs), in-tube solid-phase microextraction (IT-SPME), stir-bar sorptive extraction (SBSE) and microextraction in packed sorbent (MEPS). We also describe liquid-phase microextraction (LPME) approaches reported in the literature that are applied to the determination of steroid hormones. PMID:21907019

  19. Monitoring prion protein expression in complex biological samples by SERS for diagnostic applications

    Energy Technology Data Exchange (ETDEWEB)

    Manno, D; Filippo, E; Fiore, R; Serra, A [Dipartimento di Scienza dei Materiali, Universita del Salento, Lecce (Italy); Urso, E; Rizzello, A; Maffia, M [Dipartimento di Scienze e Tecnologie Biologiche ed Ambientali, Universita del Salento, Lecce (Italy)

    2010-04-23

    Surface-enhanced Raman spectroscopy (SERS) allows a new insight into the analysis of cell physiology. In this work, the difficulty of producing suitable substrates that, besides permitting the amplification of the Raman signal, do not interact with the biological material causing alteration, has been overcome by a combined method of hydrothermal green synthesis and thermal annealing. The SERS analysis of the cell membrane has been performed with special attention to the cellular prion protein PrP{sup C}. In addition, SERS has also been used to reveal the prion protein-Cu(II) interaction in four different cell models (B104, SH-SY5Y, GN11, HeLa), expressing PrP{sup C} at different levels. A significant implication of the current work consists of the intriguing possibility of revealing and quantifying prion protein expression in complex biological samples by a cheap SERS-based method, replacing the expensive and time-consuming immuno-assay systems commonly employed.

  20. Determination of rhenium in biological and environmental samples by radiochemical neutron activation analysis

    International Nuclear Information System (INIS)

    Radiochemical neutron activation procedures using liquid-liquid extraction with tetraphenylarsonium chloride in chloroform from 1 M HCl and solid extraction with ALIQUAT 336 incorporated in a polyacrylonitrile binding matrix from 0.1 M HCl were developed for accurate determination of rhenium in biological and environmental samples at the sub-ng.g-1 level. Concentrations of Re in the range of 0.1 to 2.4 ng.g-1 were determined in several botanical reference materials (RM), while in a RM of road dust a value of approx. 10 ng.g-1 was found. Significantly elevated values of Re, up to 90 ng.g-1, were found in seaweed (brown algae). Results for Re in the brown algae Fucus vesiculosus in which elevated 99Tc values had previously been determined suggest possible competition between Re and Tc in the accumulation process. (author)

  1. Double-stacked dielectric ring resonator for EPR measurements of biological samples

    Energy Technology Data Exchange (ETDEWEB)

    Jaworski, M.; Sienkiewicz, A. [Inst. of Physics, Polish Academy of Sciences, Warsaw (Poland); Scholes, C.P. [Chemistry Dept., State Univ. of New York at Albany, Albany, NY (United States)

    1997-12-31

    We discuss the microwave properties of a newly developed double-stacked dielectric ring resonator (DR) for applications in Electron Paramagnetic Resonance (EPR) spectroscopy. This design leads to a substantial improvement of the signal-to-noise ratio (S/N), as well as enables one to measure biological samples characterized by high dielectric losses and often limited in supply. The paper presents a new theoretical approach for calculating the resonant frequency, resonator filling factor and resonator Q-factor for the double DR system. The comparison of experimentally and theoretically determined technical parameters reveals a very good accuracy that is better than 1% for the resonant frequency. (author). 9 refs, 6 figs, 1 tab.

  2. Cryogenic coherent X-ray diffraction imaging of biological samples at SACLA: a correlative approach with cryo-electron and light microscopy.

    Science.gov (United States)

    Takayama, Yuki; Yonekura, Koji

    2016-03-01

    Coherent X-ray diffraction imaging at cryogenic temperature (cryo-CXDI) allows the analysis of internal structures of unstained, non-crystalline, whole biological samples in micrometre to sub-micrometre dimensions. Targets include cells and cell organelles. This approach involves preparing frozen-hydrated samples under controlled humidity, transferring the samples to a cryo-stage inside a vacuum chamber of a diffractometer, and then exposing the samples to coherent X-rays. Since 2012, cryo-coherent diffraction imaging (CDI) experiments have been carried out with the X-ray free-electron laser (XFEL) at the SPring-8 Ångstrom Compact free-electron LAser (SACLA) facility in Japan. Complementary use of cryo-electron microscopy and/or light microscopy is highly beneficial for both pre-checking samples and studying the integrity or nature of the sample. This article reports the authors' experience in cryo-XFEL-CDI of biological cells and organelles at SACLA, and describes an attempt towards reliable and higher-resolution reconstructions, including signal enhancement with strong scatterers and Patterson-search phasing. PMID:26919369

  3. Application of a powdered-internal-standard method combined with correction for self-absorption of x-rays to geological, environmental and biological samples

    International Nuclear Information System (INIS)

    Availability of a powdered internal standard method developed in the previous report has been investigated in detail for geological, mineralogical, environmental and biological samples. It is found that this method is effective for various powdered samples composed of high-Z elements. A computer program for correcting self-absorption of x-rays, which is based on the method we previously reported, was developed and it has been applied to soil samples of varied thickness. As a result, it is found that the method is quite effective even for a pretty thick target where particles overlap with each other. Moreover, the method was applied to several rock samples, which were prepared by grinding and consist of particles of divergent size, and found to be applicable. Lastly, the powered internal standard method was applied to a biological sample and found to be almost satisfactory, too. These results demonstrate the availability of the powdered internal standard method combined with the method of x-ray-absorption correction for samples in many research fields. (author)

  4. Optimization of Sample Preparation for 1-Hydroxypyrene as a Major Biomarker of Exposure to Polycyclic Aromatic Hydrocarbons Prior to High Performance Liquid Chromatography

    Directory of Open Access Journals (Sweden)

    SJ Shahtaheri

    2006-05-01

    Full Text Available Urinary 1-hydroxypuren (1-OHP is commonly used as a major metabolite and biological indicator of the overall exposure to polycyclic aromatic hydrocarbons (PAHs. For evaluation of human exposure to such compounds, biological monitoring is an essential process, in which, preparation of samples is one of the most time-consuming and error-prone aspects prior to chromatographic techniques. In this study, non classic form of liquid-liquid extraction (LLE was optimized with regard to solvent type, solvent volume, extraction temperature, mixing type, and mixing duration. Through the extraction process, a mild temperature was used to keep the compound of interest as stable as possible. In this study, a high performance liquid chromatography, using reverse-phase column was used. The isocratic run was done at a constant flow rate of 0.8 ml/min, the mobile phase was methanol/water and a fluorescence detector was used, setting at 242 nm and 388 nm. At the developed conditions, the extraction recovery was exceeded 87.3%, achieving detection limit of 0.2 µg/l. The factors were evaluated statically and the procedure was validated with three different pools of spiked urine samples and showed a good reproducibility over six consecutive days as well as experiments. It was concluded that, this optimized method could simplify sample preparation for trace residue analysis of PAHs metabolites.

  5. Magnetically responsive polycaprolactone nanoparticles for progesterone screening in biological and environmental samples using gas chromatography.

    Science.gov (United States)

    Es'haghi, Zarrin; Nezhadali, Azizollah; Khatibi, Aram-Dokht

    2016-08-01

    A new Fe3O4/poly(є-caprolactone) (PCL) magnetite nanocomposite was fabricated and used as a sorbent for magnetically mediated PCL microspheres solid-phase extraction (MM-PCL-SPE) followed by gas chromatography-flame ionization detection (GC-FID) for monitoring of progesterone (PGN) hormone in biological and environmental matrices, namely blood serum, tap water, urine, and hospital wastewater. The nanomagnetite core of the sorbent was synthesized by a co-precipitation method. Magnetic nanoparticles (MNPs) were then microencapsulated with PCL microspheres using emulsion polymerization. The nanocomposite was characterized by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). The magnetite sorbent can be effectively dispersed in aqueous solution and attracted to an external magnetic field. The MM-PCL-SPE process for PGN assay involved (a) dispersion of the sorbent in the donor phase aqueous solution with sonication, (b) exposure to a magnetic field to collect sorbent that had adsorbed the analyte, and (c) solvent desorption of extracted PGN for GC-FID analysis. The work demonstrates the usefulness of MM-PCL-SPE in the rapid and sensitive monitoring of trace amounts of PGN in real samples. The limit of detection (LOD) and limit of quantification (LOQ) were 1.00 and 3.30 ng/mL, respectively. The relative recoveries in real samples were adequate. Linearity was observed over a wide range of 2.2-10,000.0 ng/mL in aqueous media and urine and 0.01-70.0 μg/mL in blood serum. Graphical Abstract In this research new Fe3O4/poly(є-caprolactone) (PCL) magnetite microspheres were developed as an efficient sorbent for solid-phase extraction of progesterone hormone in biological and environmental matrices. PMID:27299775

  6. Integrated quantification and identification of aldehydes and ketones in biological samples.

    Science.gov (United States)

    Siegel, David; Meinema, Anne C; Permentier, Hjalmar; Hopfgartner, Gérard; Bischoff, Rainer

    2014-05-20

    The identification of unknown compounds remains to be a bottleneck of mass spectrometry (MS)-based metabolomics screening experiments. Here, we present a novel approach which facilitates the identification and quantification of analytes containing aldehyde and ketone groups in biological samples by adding chemical information to MS data. Our strategy is based on rapid autosampler-in-needle-derivatization with p-toluenesulfonylhydrazine (TSH). The resulting TSH-hydrazones are separated by ultrahigh-performance liquid chromatography (UHPLC) and detected by electrospray ionization-quadrupole-time-of-flight (ESI-QqTOF) mass spectrometry using a SWATH (Sequential Window Acquisition of all Theoretical Fragment-Ion Spectra) data-independent high-resolution mass spectrometry (HR-MS) approach. Derivatization makes small, poorly ionizable or retained analytes amenable to reversed phase chromatography and electrospray ionization in both polarities. Negatively charged TSH-hydrazone ions furthermore show a simple and predictable fragmentation pattern upon collision induced dissociation, which enables the chemo-selective screening for unknown aldehydes and ketones via a signature fragment ion (m/z 155.0172). By means of SWATH, targeted and nontargeted application scenarios of the suggested derivatization route are enabled in the frame of a single UHPLC-ESI-QqTOF-HR-MS workflow. The method's ability to simultaneously quantify and identify molecules containing aldehyde and ketone groups is demonstrated using 61 target analytes from various compound classes and a (13)C labeled yeast matrix. The identification of unknowns in biological samples is detailed using the example of indole-3-acetaldehyde. PMID:24745975

  7. Determination of total mercury and methylmercury in biological samples by photochemical vapor generation

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Mariana A.; Ribeiro, Anderson S.; Curtius, Adilson J. [Universidade Federal de Santa Catarina, Departamento de Quimica, Florianopolis, SC (Brazil); Sturgeon, Ralph E. [National Research Council Canada, Institute for National Measurement Standards, Ottawa, ON (Canada)

    2007-06-15

    Cold vapor atomic absorption spectrometry (CV-AAS) based on photochemical reduction by exposure to UV radiation is described for the determination of methylmercury and total mercury in biological samples. Two approaches were investigated: (a) tissues were digested in either formic acid or tetramethylammonium hydroxide (TMAH), and total mercury was determined following reduction of both species by exposure of the solution to UV irradiation; (b) tissues were solubilized in TMAH, diluted to a final concentration of 0.125% m/v TMAH by addition of 10% v/v acetic acid and CH{sub 3}Hg{sup +} was selectively quantitated, or the initial digests were diluted to 0.125% m/v TMAH by addition of deionized water, adjusted to pH 0.3 by addition of HCl and CH{sub 3}Hg{sup +} was selectively quantitated. For each case, the optimum conditions for photochemical vapor generation (photo-CVG) were investigated. The photochemical reduction efficiency was estimated to be {proportional_to}95% by comparing the response with traditional SnCl{sub 2} chemical reduction. The method was validated by analysis of several biological Certified Reference Materials, DORM-1, DORM-2, DOLT-2 and DOLT-3, using calibration against aqueous solutions of Hg{sup 2+}; results showed good agreement with the certified values for total and methylmercury in all cases. Limits of detection of 6 ng/g for total mercury using formic acid, 8 ng/g for total mercury and 10 ng/g for methylmercury using TMAH were obtained. The proposed methodology is sensitive, simple and inexpensive, and promotes ''green'' chemistry. The potential for application to other sample types and analytes is evident. (orig.)

  8. Determination of gadolinium-based MRI contrast agents in biological and environmental samples: A review

    Energy Technology Data Exchange (ETDEWEB)

    Telgmann, Lena [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany); Sperling, Michael [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany); European Virtual Institute for Speciation Analysis (EVISA), Münster (Germany); Karst, Uwe, E-mail: uk@uni-muenster.de [University of Münster, Institute of Inorganic and Analytical Chemistry, Münster (Germany)

    2013-02-18

    Highlights: ► All major methods for the analysis of Gd-based MRI contrast agents are discussed. ► Biological and environmental samples are covered. ► Pharmacokinetics and species transformation can be investigated. ► The figures of merit as limit of detection and analysis time are described. -- Abstract: The development of analytical methods and strategies to determine gadolinium and its complexes in biological and environmental matrices is evaluated in this review. Gadolinium (Gd) chelates are employed as contrast agents for magnetic resonance imaging (MRI) since the 1980s. In general they were considered as safe and well-tolerated, when in 2006, the disease nephrogenic systemic fibrosis (NSF) was connected to the administration of MRI contrast agents based on Gd. Pathogenesis and etiology of NSF are yet unclear and called for the development of several analytical methods to obtain elucidation in this field. Determination of Gd complex stability in vitro and in vivo, as well as the quantification of Gd in body fluids like blood and urine was carried out. Separation of the Gd chelates was achieved with high performance liquid chromatography (HPLC) and capillary electrophoresis (CE). For detection, various methods were employed, including UV–vis absorbance and fluorescence spectroscopy, electrospray ionization mass spectrometry (ESI-MS) and inductively coupled plasma mass spectrometry (ICP-MS). A second challenge for analysts was the discovery of high concentrations of anthropogenic Gd in surface waters draining populated areas. The source could soon be determined to be the increasing administration of Gd complexes during MRI examinations. Identification and quantification of the contrast agents was carried out in various surface and groundwater samples to determine the behavior and fate of the Gd chelates in the environment. The improvement of limits of detection (LOD) and limits of quantification (LOQ) was and still is the goal of past and ongoing

  9. Pre-separation of biological samples using of preparative divergent flow isoelectric focusing

    Czech Academy of Sciences Publication Activity Database

    Vykydalová, Marie; Moravcová, Dana; Kahle, Vladislav; Šlais, Karel

    Brno : Ústav analytické chemie AV ČR, v. v. i, 2010 - (Foret, F.). s. 107 ISBN 978-80-254-6631-5. [International Symposium on Microscale BioSeparations /25./. 21.03.2010-25.03.2010, Praha] R&D Projects: GA AV ČR IAAX00310701; GA MŠk LC06023 Institutional research plan: CEZ:AV0Z40310501 Keywords : divergent flow isoelectric focusing * monolithic column * extract of weat flour Subject RIV: CB - Analytical Chemistry, Separation

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

    Czech Academy of Sciences Publication Activity Database

    Šťastná, Miroslava; Šlais, Karel

    2010-01-01

    Roč. 31, č. 3 (2010), s. 433-439. ISSN 0173-0835 R&D Projects: GA AV ČR IAAX00310701 Institutional research plan: CEZ:AV0Z40310501 Keywords : carrier-free divergent flow IEF * proteins * yeast lysate Subject RIV: CB - Analytical Chemistry, Separation Impact factor: 3.569, year: 2010

  11. Microscopic linear liquid streams in vacuum: Injection of solvated biological samples into X-ray free electron lasers

    International Nuclear Information System (INIS)

    Microscopic linear liquid free-streams offer a means of gently delivering biological samples into a probe beam in vacuum while maintaining the sample species in a fully solvated state. By employing gas dynamic forces to form the microscopic liquid stream (as opposed to a conventional solid-walled convergent nozzle), liquid free-streams down to 300 nm diameter have been generated. Such 'Gas Dynamic Virtual Nozzles' (GDVN) are ideally suited to injecting complex biological species into an X-ray Free Electron Laser (XFEL) to determine the structure of the biological species via Serial Femtosecond Crystallography (SFX). GDVN injector technology developed for this purpose is described.

  12. 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

  13. Sample preparation methods for quantitative detection of DNA by molecular assays and marine biosensors

    International Nuclear Information System (INIS)

    Highlights: • DNA extraction methods affected measured qPCR target recovery. • Recovery and variability differed, sometimes by more than an order of magnitude. • SCODA did not offer significant improvement with PCR-inhibited seawater. • Aggressive lysis did appear to improve target recovery. • Reliable and affordable correction methods are needed for quantitative PCR. -- Abstract: The need for quantitative molecular methods is growing in environmental, food, and medical fields but is hindered by low and variable DNA extraction and by co-extraction of PCR inhibitors. DNA extracts from Enterococcus faecium, seawater, and seawater spiked with E. faecium and Vibrio parahaemolyticus were tested by qPCR for target recovery and inhibition. Conventional and novel methods were tested, including Synchronous Coefficient of Drag Alteration (SCODA) and lysis and purification systems used on an automated genetic sensor (the Environmental Sample Processor, ESP). Variable qPCR target recovery and inhibition were measured, significantly affecting target quantification. An aggressive lysis method that utilized chemical, enzymatic, and mechanical disruption enhanced target recovery compared to commercial kit protocols. SCODA purification did not show marked improvement over commercial spin columns. Overall, data suggested a general need to improve sample preparation and to accurately assess and account for DNA recovery and inhibition in qPCR applications

  14. Immunoglobulin preparations for intravenous administration. A review of their biologic activities and comparison of various preparation methods

    DEFF Research Database (Denmark)

    Nielsen, H

    1994-01-01

    Substitution therapy with human immunoglobulin preparations is well established in disorders of primary or secondary deficiencies of humoral immunity. However, modifications of the immunoglobulins are required to achieve tolerance for the preferred intravenous route of administration. Several...... before being given to immunodeficient patients....

  15. Stability Study and Kinetic Monitoring of Cefquinome Sulfate Using Cyclodextrin-Based Ion-Selective Electrode: Application to Biological Samples.

    Science.gov (United States)

    Yehia, Ali M; Arafa, Reham M; Abbas, Samah S; Amer, Sawsan M

    2016-01-01

    Two novel cefquinome sulfate (CFQ)-selective electrodes were performed with dibutyl sebacate as a plasticizer using a polymeric matrix of polyvinyl chloride. Sensor 1 was prepared using sodium tetraphenylborate as a cation exchanger without incorporation of ionophore, whereas 2-hydroxy propyl β-cyclodextrin was used as ionophore in sensor 2. A stable, reliable, and linear response was obtained in concentration ranges 3.2 × 10(-5) to 1 × 10(-2) mol/L and 1 × 10(-5) to 1 × 10(-2) mol/L for sensors 1 and 2, respectively. Both sensors could be sufficiently applied for quantitative determination of CFQ in the presence of degradation products either in bulk powder or in pharmaceutical formulations. Sensor 2 provided better selectivity and sensitivity, wider linearity range, and higher performance. Therefore it was used successfully for accurate determination of CFQ in biological fluids such as spiked plasma and milk samples. Furthermore, an online kinetic study was applied to the CFQ alkaline degradation process to estimate the reaction rate and half-life with feasible real-time monitoring. The developed sensors were found to be fast, accurate, sensitive, and precise compared with the manufacturer's reversed-phase chromatographic method. PMID:26822094

  16. Assessment of DDT levels in selected environmental media and biological samples from Mexico and Central America.

    Science.gov (United States)

    Pérez-Maldonado, Iván N; Trejo, Antonio; Ruepert, Clemens; Jovel, Reyna del Carmen; Méndez, Mónica Patricia; Ferrari, Mirtha; Saballos-Sobalvarro, Emilio; Alexander, Carlos; Yáñez-Estrada, Leticia; Lopez, Dania; Henao, Samuel; Pinto, Emilio R; Díaz-Barriga, Fernando

    2010-03-01

    Taking into account the environmental persistence and the toxicity of DDT, the Pan American Health Organization (PAHO) organized a surveillance program in Mesoamerica which included the detection of residual DDT in environmental (soil) and biological samples (fish tissue and children's blood). This program was carried out in communities from Mexico, Guatemala, El Salvador, Honduras, Nicaragua, Costa Rica and Panama. This paper presents the first report of that program. As expected, the results show that the levels for [summation operator] DDT in soil (outdoor or indoor) and fish samples in the majority of the locations studied are below guidelines. However, in some locations, we found children with high concentrations of DDT as in Mexico (mean level 50.2 ng/mL). Furthermore, in some communities and for some matrices, the DDT/DDE quotient is higher than one and this may reflect a recent DDT exposure. Therefore, more efforts are needed to avoid exposure and to prevent the reintroduction of DDT into the region. In this regard it is important to know that under the surveillance of PAHO and with the support of UNEP, a regional program in Mesoamerica for the collection and disposal of DDT and other POPs stockpiles is in progress. PMID:20092871

  17. Synchrotron-based X-ray fluorescence, imaging and elemental mapping from biological samples

    Indian Academy of Sciences (India)

    D V Rao; M Swapna; R Cesareo; A Brunetti; T Akatsuka; T Yuasa; T Takeda; G E Gigante

    2011-02-01

    The present study utilized the new hard X-ray microspectroscopy beamline facility, X27A, available at NSLS, BNL, USA, for elemental mapping. This facility provided the primary beam in a small spot of the order of ∼ 10 m, for focussing. With this spatial resolution and high flux throughput, the synchrotron-based X-ray fluorescent intensities for Mn, Fe, Zn, Cr, Ti and Cu were measured using a liquid-nitrogen-cooled 13-element energy-dispersive high-purity germanium detector. The sample is scanned in a `step-and-repeat’ mode for fast elemental mapping measurements and generated elemental maps at 8, 10 and 12 keV, from a small animal shell (snail). The accumulated trace elements, from these biological samples, in small areas have been identified. Analysis of the small areas will be better suited to establish the physiology of metals in specific structures like small animal shell and the distribution of other elements.

  18. 3D surface scan of biological samples with a Push-broom Imaging Spectrometer

    Science.gov (United States)

    Yao, Haibo; Kincaid, Russell; Hruska, Zuzana; Brown, Robert L.; Bhatnagar, Deepak; Cleveland, Thomas E.

    2013-08-01

    The food industry is always on the lookout for sensing technologies for rapid and nondestructive inspection of food products. Hyperspectral imaging technology integrates both imaging and spectroscopy into unique imaging sensors. Its application for food safety and quality inspection has made significant progress in recent years. Specifically, hyperspectral imaging has shown its potential for surface contamination detection in many food related applications. Most existing hyperspectral imaging systems use pushbroom scanning which is generally used for flat surface inspection. In some applications it is desirable to be able to acquire hyperspectral images on circular objects such as corn ears, apples, and cucumbers. Past research describes inspection systems that examine all surfaces of individual objects. Most of these systems did not employ hyperspectral imaging. These systems typically utilized a roller to rotate an object, such as an apple. During apple rotation, the camera took multiple images in order to cover the complete surface of the apple. The acquired image data lacked the spectral component present in a hyperspectral image. This paper discusses the development of a hyperspectral imaging system for a 3-D surface scan of biological samples. The new instrument is based on a pushbroom hyperspectral line scanner using a rotational stage to turn the sample. The system is suitable for whole surface hyperspectral imaging of circular objects. In addition to its value to the food industry, the system could be useful for other applications involving 3-D surface inspection.

  19. Biological Monitoring of Human Exposure to Neonicotinoids Using Urine Samples, and Neonicotinoid Excretion Kinetics.

    Directory of Open Access Journals (Sweden)

    Kouji H Harada

    Full Text Available Neonicotinoids, which are novel pesticides, have entered into usage around the world because they are selectively toxic to arthropods and relatively non-toxic to vertebrates. It has been suggested that several neonicotinoids cause neurodevelopmental toxicity in mammals. The aim was to establish the relationship between oral intake and urinary excretion of neonicotinoids by humans to facilitate biological monitoring, and to estimate dietary neonicotinoid intakes by Japanese adults.Deuterium-labeled neonicotinoid (acetamiprid, clothianidin, dinotefuran, and imidacloprid microdoses were orally ingested by nine healthy adults, and 24 h pooled urine samples were collected for 4 consecutive days after dosing. The excretion kinetics were modeled using one- and two-compartment models, then validated in a non-deuterium-labeled neonicotinoid microdose study involving 12 healthy adults. Increased urinary concentrations of labeled neonicotinoids were observed after dosing. Clothianidin was recovered unchanged within 3 days, and most dinotefuran was recovered unchanged within 1 day. Around 10% of the imidacloprid dose was excreted unchanged. Most of the acetamiprid was metabolized to desmethyl-acetamiprid. Spot urine samples from 373 Japanese adults were analyzed for neonicotinoids, and daily intakes were estimated. The estimated average daily intake of these neonicotinoids was 0.53-3.66 μg/day. The highest intake of any of the neonicotinoids in the study population was 64.5 μg/day for dinotefuran, and this was <1% of the acceptable daily intake.

  20. Toward a Fieldable Atomic Mass Spectrometer for Safeguards Applications: Sample Preparation and Ionization

    Energy Technology Data Exchange (ETDEWEB)

    Barinaga, Charles J.; Hager, George J.; Hart, Garret L.; Koppenaal, David W.; Marcus, R. Kenneth; Jones, Sarah MH; Manard, Benjamin T.

    2014-10-31

    The International Atomic Energy Agency’s (IAEA’s) long-term research and development plan calls for the development of new methods to detect misuse at nuclear fuel cycle facilities such as reprocessing and enrichment plants. At enrichment plants, for example, the IAEA’s contemporary safeguards approaches are based on a combination of routine and random inspections that include collection of UF6 samples from in-process material and selected cylinders for subsequent analyses. These analyses include destructive analysis (DA) in a laboratory (typically by mass spectrometry [MS]) for isotopic characterization, and environmental sampling (ES) for subsequent laboratory elemental and isotopic analysis (also both typically by MS). One area of new method development includes moving this kind of isotope ratio analytical capability for DA and ES activities into the field. Some of the reasons for these developments include timeliness of results, avoidance of hazardous material shipments, and guidance for additional sample collecting. However, this capability does not already exist for several reasons, such as that most lab-based chemical and instrumental methods rely on laboratory infrastructure (highly trained staff, power, space, hazardous material handling, etc.) and require significant amounts of consumables (power, compressed gases, etc.). In addition, there are no currently available, fieldable instruments for atomic or isotope ratio analysis. To address these issues, Pacific Northwest National Laboratory (PNNL) and collaborator, Clemson University, are studying key areas that limit the fieldability of isotope ratio mass spectrometry for atomic ions: sample preparation and ionization, and reducing the physical size of a fieldable mass spectrometer. PNNL is seeking simple and robust techniques that could be effectively used by inspectors who may have no expertise in analytical MS. In this report, we present and describe the preliminary findings for three candidate