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Sample records for automated on-line solid-phase

  1. Determination of talinolol in human plasma using automated on-line solid phase extraction combined with atmospheric pressure chemical ionization tandem mass spectrometry.

    Science.gov (United States)

    Bourgogne, Emmanuel; Grivet, Chantal; Hopfgartner, Gérard

    2005-06-01

    A specific LC-MS/MS assay was developed for the automated determination of talinolol in human plasma, using on-line solid phase extraction system (prospekt 2) combined with atmospheric pressure chemical ionization (APCI) tandem mass spectrometry. The method involved simple precipitation of plasma proteins with perchloric acid (contained propranolol) as the internal standard (IS) and injection of the supernatant onto a C8 End Capped (10 mmx2 mm) cartridge without any evaporation step. Using the back-flush mode, the analytes were transferred onto an analytical column (XTerra C18, 50 mmx4.6 mm) for chromatographic separation and mass spectrometry detection. One of the particularities of the assay is that the SPE cartridge is used as a column switching device and not as an SPE cartridge. Therefore, the same SPE cartridge could be used more than 28 times, significantly reducing the analysis cost. APCI ionization was selected to overcome any potential matrix suppression effects because the analyte and IS co-eluted. The mean precision and accuracy in the concentration range 2.5-200 ng/mL was found to be 103% and 7.4%, respectively. The data was assessed from QC samples during the validation phase of the assay. The lower limit of quantification was 2.5 ng/mL, using a 250 microL plasma aliquot. The LC-MS/MS method provided the requisite selectivity, sensitivity, robustness accuracy and precision to assess pharmacokinetics of the compound in several hundred human plasma samples. PMID:15866498

  2. Determination of aflatoxins in food samples by automated on-line in-tube solid-phase microextraction coupled with liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Nonaka, Y; Saito, K; Hanioka, N; Narimatsu, S; Kataoka, H

    2009-05-15

    A simple and sensitive automated method for determination of aflatoxins (B1, B2, G1, and G2) in nuts, cereals, dried fruits, and spices was developed consisting of in-tube solid-phase microextraction (SPME) coupled with liquid chromatography-mass spectrometry (LC-MS). Aflatoxins were separated within 8 min by high-performance liquid chromatography using a Zorbax Eclipse XDB-C8 column with methanol/acetonitrile (60/40, v/v): 5mM ammonium formate (45:55) as the mobile phase. Electrospray ionization conditions in the positive ion mode were optimized for MS detection of aflatoxins. The pseudo-molecular ions [M+H](+) were used to detect aflatoxins in selected ion monitoring (SIM) mode. The optimum in-tube SPME conditions were 25draw/eject cycles of 40 microL of sample using a Supel-Q PLOT capillary column as an extraction device. The extracted aflatoxins were readily desorbed from the capillary by passage of the mobile phase, and no carryover was observed. Using the in-tube SPME LC-MS with SIM method, good linearity of the calibration curve (r>0.9994) was obtained in the concentration range of 0.05-2.0 ng/mL using aflatoxin M1 as an internal standard, and the detection limits (S/N=3) of aflatoxins were 2.1-2.8 pg/mL. The in-tube SPME method showed >23-fold higher sensitivity than the direct injection method (10 microL injection volume). The within-day and between-day precision (relative standard deviations) at the concentration of 1 ng/mL aflatoxin mixture were below 3.3% and 7.7% (n=5), respectively. This method was applied successfully to analysis of food samples without interference peaks. The recoveries of aflatoxins spiked into nuts and cereals were >80%, and the relative standard deviations were Aflatoxins were detected at <10 ng/g in several commercial food samples. PMID:19328492

  3. Automated solid-phase synthesis of oligosaccharides containing sialic acids

    Directory of Open Access Journals (Sweden)

    Chian-Hui Lai

    2015-05-01

    Full Text Available A sialic acid glycosyl phosphate building block was designed and synthesized. This building block was used to prepare α-sialylated oligosaccharides by automated solid-phase synthesis selectively.

  4. Semi-automated microwave assisted solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Pedersen, Søren Ljungberg

    with microwaves for SPPS has gained in popularity as it for many syntheses has provided significant improvement in terms of speed, purity, and yields, maybe especially in the synthesis of long and "difficult" peptides. Thus, precise microwave heating has emerged as one new parameter for SPPS, in addition...... to coupling reagents, resins, solvents etc. We have previously reported on microwave heating to promote a range of solid-phase reactions in SPPS. Here we present a new, flexible semi-automated instrument for the application of precise microwave heating in solid-phase synthesis. It combines a slightly modified...... Biotage Initiator microwave instrument, which is available in many laboratories, with a modified semi-automated peptide synthesizer from MultiSynTech. A custom-made reaction vessel is placed permanently in the microwave oven, thus the reactor does not have to be moved between steps. Mixing is achieved...

  5. Fully automated on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry for the simultaneous analysis of alkylphenol polyethoxylates and their carboxylic and phenolic metabolites in wastewater samples.

    Science.gov (United States)

    Ciofi, Lorenzo; Ancillotti, Claudia; Chiuminatto, Ugo; Fibbi, Donatella; Pasquini, Benedetta; Bruzzoniti, Maria Concetta; Rivoira, Luca; Del Bubba, Massimo

    2016-05-01

    Three different sorbents (i.e. endcapped octadecylsilane, octasilane and styrene-N-vinylpiperidinone co-polymer) were investigated in order to develop an on-line solid phase extraction-liquid chromatographic tandem mass spectrometric method (on-line SPE-LC-MS/MS) for the simultaneous analysis of alkylphenols polyethoxylate (AP(n)EOs, n = 1-8) and corresponding monocarboxylate (AP1ECs) and phenolic (APs) metabolites. The endcapped octadecylsilane was selected due to its full compatibility with a chromatographic approach, which allowed the elution of positively and negatively ionisable compounds in two distinct retention time windows, using a water-acetonitrile-tetrahydrofuran ternary gradient and a pellicular pentafluorophenyl column. On this SPE sorbent, the composition of the loading/clean-up solution was then optimized in order to achieve the best recoveries of target analytes. Under the best experimental conditions, the total analysis time per sample was 25 min and method detection limits (MDLs) were in the sub-nanograms per litre to nanograms per litre range (0.0081-1.0 ng L(-1)) for AP(n)EOs with n = 2-8, AP1ECs and APs, whereas for AP1EOs, an MDL of about 50 ng L(-1) was found. Using the mass-labelled compound spiking technique, the method performance was tested on inlet and outlet wastewater samples from three activated sludge treatment plants managing domestic and industrial sewages of the urban areas and the textile district of Prato and Bisenzio valley (Tuscany, Italy); in most cases, apparent recovery percentages approximately in the ranges of 50-110% and 80-120% were found for inlet and outlet samples, respectively. The on-line SPE-LC-MS/MS analysis of wastewater samples highlighted the presence of target analytes at concentrations ranging from few nanograms per litre to thousands nanograms per litre, depending on the compound and matrix analysed. AP2ECs were also tentatively identified in outlet samples. PMID:26897380

  6. Automated solid-phase peptide synthesis to obtain therapeutic peptides

    Directory of Open Access Journals (Sweden)

    Veronika Mäde

    2014-05-01

    Full Text Available The great versatility and the inherent high affinities of peptides for their respective targets have led to tremendous progress for therapeutic applications in the last years. In order to increase the drugability of these frequently unstable and rapidly cleared molecules, chemical modifications are of great interest. Automated solid-phase peptide synthesis (SPPS offers a suitable technology to produce chemically engineered peptides. This review concentrates on the application of SPPS by Fmoc/t-Bu protecting-group strategy, which is most commonly used. Critical issues and suggestions for the synthesis are covered. The development of automated methods from conventional to essentially improved microwave-assisted instruments is discussed. In order to improve pharmacokinetic properties of peptides, lipidation and PEGylation are described as covalent conjugation methods, which can be applied by a combination of automated and manual synthesis approaches. The synthesis and application of SPPS is described for neuropeptide Y receptor analogs as an example for bioactive hormones. The applied strategies represent innovative and potent methods for the development of novel peptide drug candidates that can be manufactured with optimized automated synthesis technologies.

  7. Determination of tetracyclines residues in honey by on-line solid-phase extraction high-performance liquid chromatography.

    Science.gov (United States)

    Li, Jiantao; Chen, Ligang; Wang, Xiao; Jin, Haiyan; Ding, Lan; Zhang, Kun; Zhang, Hanqi

    2008-06-15

    An automated system using on-line solid-phase extraction (SPE) high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection was developed for the determination of tetracyclines (TCs), such as tetracycline (TC), oxytetracycline (OTC), chlortetracycline (CTC), metacycline (MC), and doxycycline (DC) in honey. One milliliter diluted honey sample was injected into a conditioned C18 SPE column and the matrix was washed out with water for 3 min. By rotation of the switching valve, TCs were eluted and transferred to the analytical column by the chromatographic mobile phase. Chromatographic conditions were optimized. TCs were separated in less than 8 min with a gradient elution using a mixture of 0.8% formic acid and acetonitrile. The UV detection was performed at 365 nm. The conditions for on-line SPE, including solvent and total time for loading sample and washing matrix were also optimized. Time for extraction and separation decreased greatly. For the five kinds of TCs, the limits of detection (LODs) at a signal-to-noise of 3 ranged from 5 to 12 ng g(-1). The relative standard deviations (R.S.D.) for the determination of TCs ranged from 3.4 to 7.1% within a day and ranged from 3.2 to 8.9% in 3 days, respectively. PMID:18585209

  8. Rapid and convenient semi-automated microwave-assisted solid-phase synthesis of arylopeptoids

    DEFF Research Database (Denmark)

    Rasmussen, Jakob Ewald; Boccia, Marcello Massimo; Nielsen, John;

    2014-01-01

    A facile and expedient route to the synthesis of arylopeptoid oligomers (N-alkylated aminomethyl benz-amides) using semi-automated microwave-assisted solid-phase synthesis is presented. The synthesis was optimized for the incorporation of side chains derived from sterically hindered or unreactive...

  9. Coupling device for desorption of drugs from solid-phase extraction-pipette tips and on-line gas chromatographic analysis

    NARCIS (Netherlands)

    van Hout, M.W J; de Zeeuw, R.A; de Jong, G.J.

    1999-01-01

    Solid-phase extraction-pipette tips were used for micro solid-phase extraction of lidocaine and diazepam. Off-line desorption was done after in-vial collection for reference purposes, whereas with on-line desorption the eluate was directly introduced in the gas chromatograph. With both methods the t

  10. Development of a novel graphene/polyaniline electrodeposited coating for on-line in-tube solid phase microextraction of aldehydes in human exhaled breath condensate.

    Science.gov (United States)

    Li, Yu; Xu, Hui

    2015-05-22

    In this work, we introduced a novel graphene/polyaniline (G/PANI) electrodeposited coating for on-line in-tube solid phase microextraction (IT-SPME) for the first time. The G/PANI coating was prepared on the internal surface of stainless steel tube by a facile in-situ electrodeposition method. The morphology and formation of the composite coating were confirmed by scanning electronic microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR). Some important experimental parameters that could affect the extraction and separation such as the coating thickness, internal diameter of tube, sampling flow rate as well as sample volume were optimized. The extraction performance of the IT-SPME coating was evaluated systematically. The coating exhibited enhanced mechanical stability, long lifespan, large specific surface area and good biocompatibility compared with polyaniline coating. The on-line IT-SPME method showed higher enrichment efficiency, faster analysis speed and higher automation level than off-line manual mode. Six aldehydes were determined simultaneously with low limits of detection of 0.02-0.04nmolL(-1) and good linearity (R(2)≥0.9920). The method has been applied successfully for the determination of aldehydes in human exhaled breath condensates with good recovery (70-120%) and satisfied reproducibility (relative standard deviation: 1.1-11.9%). This on-line IT-SPME method provides a promising approach for the determination of trace aldehydes with approving sensitivity in human exhaled breath condensates. PMID:25863926

  11. Data correlation in on-line solid-phase extraction-gas chromatography-atomic emission/mass spectrometric detection of unknown microcontaminants

    NARCIS (Netherlands)

    Hankemeier, Th.; Rozenbrand, J.; Abhadur, M.; Vreuls, J.J.; Brinkman, U.A.Th.

    1998-01-01

    A procedure is described for the (non-target) screening of hetero-atom-containing compounds in tap and waste water by correlating data obtained by gas chromatography (GC) using atomic emission (AED) and mass selective (MS) detection. Solid-phase extraction (SPE) was coupled on-line to both GC system

  12. Redox speciation analysis of dissolved iron in estuarine and coastal waters with on-line solid phase extraction and graphite furnace atomic absorption spectrometry detection.

    Science.gov (United States)

    Chen, Yaojin; Feng, Sichao; Huang, Yongming; Yuan, Dongxing

    2015-05-01

    An automatic on-line solid phase extraction (SPE) system employing the flow injection (FI) technique directly coupled to a graphite furnace atomic absorption spectrometer (GFAAS) was established for speciation and determination of dissolved iron in estuarine and coastal waters. Fe(II) was mixed with ferrozine solution in a sample stream to form the Fe(II)-ferrozine complex which was extracted onto a C18 SPE cartridge, eluted with eluent and detected with GFAAS. In a parallel flow channel, Fe(III) was reduced to Fe(II) with ascorbic acid and then detected in the same way as Fe(II). The home-made interface between FI-SPE and GFAAS efficiently realized the sample introduction to the furnace in a semi-automated way. Parameters of the FI-SPE system and graphite furnace program were optimized based on a univariate experimental design and an orthogonal array design. The salinity effect on the method sensitivity was investigated. The proposed method provided a detection limit of 1.38 nmol L(-1) for Fe(II) and 1.87 nmol L(-1) for Fe(II+III). With variation of the sample loading volume, a broadened determination range of 2.5-200 nmol L(-1) iron could be obtained. The proposed method was successfully applied to analyze iron species in samples collected from the Jiulongjiang Estuary, Fujian, China. With the 2-cartridge FI-SPE system developed, on-line simultaneous determination of Fe species with GFAAS was achieved for the first time. PMID:25770602

  13. Flow-injection interface for on-line coupling solid-phase extraction and X-ray fluorescence measurements

    International Nuclear Information System (INIS)

    A flow-injection (FI) manifold including a solid-phase extraction (SPE) mini-column has been coupled on-line to an energy-dispersive X-ray fluorescence detector (EDXRFD) by locating a lab-modified 18-μL flow-cell, 10-mm path length, connected to the SPE column by PTFE tubing of 0.5 mm i.d., in the X-ray spectrometer chamber. The optical window of the flow-cell was adjusted and fixed to the X-ray irradiation zone of the spectrometer. Two PTFE tubes connected the flow-cell to the FI device and were introduced into the spectrometer chamber by a small orifice without distortion nor modification of the instrument. The SPE-EDXRFD coupling was tested for Pb and Cd aqueous solutions using Dowex 50 cation-exchange resin as sorbent, and flushing the eluate through the flow-cell for monitoring. The LODs and LOQs thus obtained were 1 and 3.2 μg for Pb and 1.8 and 4.8 μg for Cd, respectively; values which allow using the approach for the analysis of waste water by injecting 20 mL of sample into the FI manifold. The linear dynamic ranges are a function of the sample volume circulated through the mini-column. For a sample volume of 20 mL the ranges are between 1 and 4000 μg for Pb and between 1.8 and 2000 μg for Cd. The method was validated by the standard addition method using ground-water samples. The SPE-EDXRFD coupling enables to carry out the study of those variables influencing the SPE process - namely, the effect of the sample volume flushed through the column, concentration of analytes in the sample, amount of resin packed, breakthrough volume of the resin, elution profiles, sample pH and retention and elution flow-rates - in an automatic, cheap, fast and precise way

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

    NARCIS (Netherlands)

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

    1994-01-01

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

  15. Evaluation of the effect of TM208 on the activity of five cytochrome P450 enzymes using on-line solid-phase extraction HPLC-DAD: a cocktail approach.

    Science.gov (United States)

    Lin, Wensi; Zhang, Jianmei; Ling, Xiaomei; Yu, Ning; Li, Jing; Yang, Haisong; Li, Runtao; Cui, Jingrong

    2013-04-01

    A rapid, simple, and sensitive on-line solid-phase extraction HPLC-DAD method for simultaneous evaluation of the activity of five CYP450 isoforms (CYP1A2, CYP2C19, CYP2D6, CYP2E1 and CYP3A4) in vivo has been developed and validated. The five specific probe substrates include caffeine (1A2), metoprolol (2D6), dapsone (3A4), omeprazole (2C19) and chlorzoxazone (2E1). Automated pre-purification of plasma and enrichment of analytes were performed using a C18 on-line solid-phase extraction cartridge. After being eluted from the cartridge, the analytes and the internal standard antipyrine were separated on a C18 RP analytical column and analyzed by DAD. The method was validated to quantify the concentration ranges of 0.05-50.0 μg/ml for dapsone and omeprazole, 0.1-50.0 μg/ml for caffeine and 0.2-50.0 μg/ml for metoprolol and chlorzoxazone. The linearity (R(2)) for all analytes tested was exceeded 0.99. The intra-day precision ranged from 0.29 to 13% and the inter-day precision ranged from 5.0 to 15%, respectively. The intra-day and inter-day accuracy were between 86.7% and 113.6%. The extraction recoveries were in the range 82.8-109.9% for all the analytes and internal standard antipyrine. This method was successfully applied to evaluate the effects of TM208 on rat five CYP450 isoforms.

  16. Screening for Anabolic Steroids in Urine of Forensic Cases Using Fully Automated Solid Phase Extraction and LC–MS-MS

    DEFF Research Database (Denmark)

    Andersen, David Wederkinck; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards...... and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids....... Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic...

  17. Screening for anabolic steroids in urine of forensic cases using fully automated solid phase extraction and LC-MS-MS.

    Science.gov (United States)

    Andersen, David W; Linnet, Kristian

    2014-01-01

    A screening method for 18 frequently measured exogenous anabolic steroids and the testosterone/epitestosterone (T/E) ratio in forensic cases has been developed and validated. The method involves a fully automated sample preparation including enzyme treatment, addition of internal standards and solid phase extraction followed by analysis by liquid chromatography-tandem mass spectrometry (LC-MS-MS) using electrospray ionization with adduct formation for two compounds. Urine samples from 580 forensic cases were analyzed to determine the T/E ratio and occurrence of exogenous anabolic steroids. Extraction recoveries ranged from 77 to 95%, matrix effects from 48 to 78%, overall process efficiencies from 40 to 54% and the lower limit of identification ranged from 2 to 40 ng/mL. In the 580 urine samples analyzed from routine forensic cases, 17 (2.9%) were found positive for one or more anabolic steroids. Only seven different steroids including testosterone were found in the material, suggesting that only a small number of common steroids are likely to occur in a forensic context. The steroids were often in high concentrations (>100 ng/mL), and a combination of steroids and/or other drugs of abuse were seen in the majority of cases. The method presented serves as a fast and automated screening procedure, proving the suitability of LC-MS-MS for analyzing anabolic steroids.

  18. Determination of thymol in human plasma by automated headspace solid-phase microextraction-gas chromatographic analysis.

    Science.gov (United States)

    Kohlert, Claudia; Abel, Gudrun; Schmid, Eleonora; Veit, Markus

    2002-02-01

    A reliable and sensitive method was developed for determination of thymol in human plasma by automated headspace solid-phase microextraction (SPME). After enzymatic cleavage of thymol sulfate thymol was extracted by a 65 microm polydimethylsiloxane-divinylbenzene crimped fiber (Supelco) after addition of sodium chloride and phosphoric acid (85%). Desorption of the fiber was performed in the injection port of a gas chromatograph at 220 degrees C (HP 5890; 50 m x 0.2 mm I.D., 0.2 microm HP Innowax capillary column; flame ionization detection). Fibers were used repeatedly up to 40 analysis. The recovery was 5% after 35 min of extraction. The calibration curve was linear in the range of 8.1-203.5 ng ml(-1) with a limit of quantitation (LOQ) of 8.1 ng ml(-1). The within-day and between-day precision and accuracy were thymol-containing herbal extract only thymol sulfate, no free thymol, could be detected in human plasma, thus analysis of thymol was after enzymatic cleavage of thymol sulfate. It is concluded that the newly developed automated method can be used in clinical trials on bioavailability and pharmacokinetics of thymol-containing herbal medicinal products. PMID:11863281

  19. Automated Solid-Phase Subcloning Based on Beads Brought into Proximity by Magnetic Force

    DEFF Research Database (Denmark)

    Hudson, Elton P.; Nikoshkov, Andrej; Uhlén, Mathias;

    2012-01-01

    gene are immobilized to separate paramagnetic beads and brought into proximity by magnetic force. Ligation events were directly evaluated using fluorescent-based microscopy and flow cytometry. The highest ligation efficiencies were obtained when gene- and vector-coated beads were brought into close...... contact by application of a magnet during the ligation step. An automated procedure was developed using a laboratory workstation to transfer genes into various expression vectors and more than 95% correct clones were obtained in a number of various applications. The method presented here is suitable for...

  20. Automated flow system for sildenafil enrichment using surfactant coated solid-phase with fluorescence detection.

    Science.gov (United States)

    Wang, Chien Chun; Sombra, Lorena; Fernández, Liliana

    2012-08-30

    In this work, Amberlite XAD-1180 resin is used for on-line surfactant-mediated pre-concentration of sildenafil as a prior step for its fluorescent detection. In order to activate the column for sildenafil pre-concentration, the cationic surfactant (hexadecyltrimethylammoniunm bromide, HTAB) is adsorbed onto the resin. In these conditions, sildenafil is retained by HTAB-resin and then it is eluted with ethanol and analyzed by spectrofluorimetry. Drug-surfactant association produces a considerable fluorescence enhancement, increasing considerably the sensitivity of detection. Therefore, sildenafil can be pre-concentrated and quantitatively determined, with a detection limit of 0.2 ng mL(-1). The proposed method was successfully applied to the analysis of bulk drug, human urine, tablets, and local herbal medicine. Validation processes were performed by recovering studies and statistical analysis with satisfactory results.

  1. Ultraviolet vapor generation atomic fluorescence spectrometric determination of mercury in natural water with enrichment by on-line solid phase extraction

    Science.gov (United States)

    Qin, Deyuan; Gao, Feng; Zhang, Zhaohui; Zhao, Liqian; Liu, Jixin; Ye, Jianping; Li, Junwei; Zheng, Fengxi

    2013-10-01

    A novel method, which coupled an on-line solid phase extraction (SPE) enrichment with ultraviolet vapor generation (UVG) atomic fluorescence spectrometry (AFS), was developed to improve the sensitivity of mercury determination and to remove the interference of some anion and organics to UVG of mercury. A high mercury retention efficiency and maximum exclusion of inorganic and organic matrix in water samples were achieved by using C18 SPE mini cartridge modified with sodium diethyldithiocarbamate (DDTC). Fast and efficient elution from the cartridge was found by using L-cysteine mixing solution. Furthermore, through the investigation of different UV reactor designs, the most important factor was the structure of the reactor (which corresponded roughly to the photon flux) wherein the tubing was sintered into the UV lamp to give the highest UV generation efficiency. The second factor was the materials of the tubing (which roughly corresponded to the working wavelength). Synthetic quartz, characterized by the highest transparency at 185 nm, attained the highest UVG efficiency, suggesting that the most favorable wavelength for UVG was 185 nm. Under optimum conditions, the achievable detection limit (3σ) with sample loadings of 10.0 mL was 0.03 ng L- 1 and 0.08 ng L- 1 with different manifolds, respectively. The method was successfully applied to the determination of Hg in tap water, river water and lake water samples.

  2. Metabolic profiling for the identification of Huntington biomarkers by on-line solid-phase extraction capillary electrophoresis mass spectrometry combined with advanced data analysis tools.

    Science.gov (United States)

    Pont, Laura; Benavente, Fernando; Jaumot, Joaquim; Tauler, Romà; Alberch, Jordi; Ginés, Silvia; Barbosa, José; Sanz-Nebot, Victoria

    2016-03-01

    In this work, an untargeted metabolomic approach based on sensitive analysis by on-line solid-phase extraction capillary electrophoresis mass spectrometry (SPE-CE-MS) in combination with multivariate data analysis is proposed as an efficient method for the identification of biomarkers of Huntington's disease (HD) progression in plasma. For this purpose, plasma samples from wild-type (wt) and HD (R6/1) mice of different ages (8, 12, and 30 weeks), were analyzed by C18 -SPE-CE-MS in order to obtain the characteristic electrophoretic profiles of low molecular mass compounds. Then, multivariate curve resolution alternating least squares (MCR-ALS) was applied to the multiple full scan MS datasets. This strategy permitted the resolution of a large number of metabolites being characterized by their electrophoretic peaks and their corresponding mass spectra. A total number of 29 compounds were relevant to discriminate between wt and HD plasma samples, as well as to follow-up the HD progression. The intracellular signaling was found to be the most affected metabolic pathway in HD mice after 12 weeks of birth, when mice already showed motor coordination deficiencies and cognitive decline. This fact agreed with the atrophy and dysfunction of specific neurons, loss of several types of receptors, and changed expression of neurotransmitters. PMID:26685060

  3. Simultaneous determination of antifouling herbicides in marina water samples by on-line solid-phase extraction followed by liquid chromatography-mass spectrometry.

    Science.gov (United States)

    Ferrer, I; Barceló, D

    1999-08-27

    Solid-phase extraction (SPE) coupled on-line with either liquid chromatography-diode array detection (LC-DAD) or liquid chromatography-atmospheric pressure chemical ionization mass spectrometry was applied to the simultaneous analysis of several antifouling herbicides such as diuron, TCMTB (2-thiocyanomethylthiobenzothiazole), Irgarol and chlorothalonil in seawater samples. SPE was carried out on polymeric cartridges (PLRP-s) after the percolation of 100 ml of seawater sample, with recoveries ranging from 96 to 111% for the antifouling compounds. LC-MS detection was used in negative and positive ion mode. In positive ion mode, additional structural information for diuron and Irgarol was obtained by increasing the fragmentor voltage, thus permitting the unequivocal identification of these compounds in environmental waters. Method detection limits were in the range of 0.005 microg/l. This methodology was also compared to LC-DAD in terms of selectivity and sensitivity. Finally, the method was evaluated for the analysis of environmental seawater samples, from the Ebre Delta area and Masnou marina, in Catalonia (Spain). PMID:10497940

  4. [Determination of 28 organochlorine and pyrethroid pesticides in pine nuts using solid-phase extraction and on-line gel permeation chromatography-gas chromatography/mass spectrometry].

    Science.gov (United States)

    Kang, Qinghe; Wu, Yan; Gao, Kaiyang; Li, Zhibin

    2009-03-01

    An analytical method has been developed for the determination of 28 organochlorine pesticides and pyrethroid pesticides in pine nuts. The sample was extracted With acetonitrile-water (4:1, v/v) as the extraction solution by means of high-speed homogenization. The crude extract was purified by an Aluminium-N solid phase extraction column to remove most of the fat and sterols in the sample, then on-line gel permeation chromatography-gas chromatography/ mass spectrometry (GPC-GC/MS) analysis was performed. The recoveries for the most of pesticides in the sample spiked with the standards of 0.05 mg/kg were 70%-120%, and the relative standard deviations were less than 15%. The limits of detection of 28 organochlorine pesti- and pyrethroid pesticides were 0.002-0.05 mg/kg. The linear relationship and the recovery results were satisfactory. The method is rapid, accurate, highly senstive, and can be used for the simultaneous determination of pesticide residues in pine nuts.

  5. Mixed-mode isolation of triazine metabolites from soil and aquifer sediments using automated solid-phase extraction

    Science.gov (United States)

    Mills, M.S.; Thurman, E.M.

    1992-01-01

    Reversed-phase isolation and ion-exchange purification were combined in the automated solid-phase extraction of two polar s-triazine metabolites, 2-amino-4-chloro-6-(isopropylamino)-s-triazine (deethylatrazine) and 2-amino-4-chloro-6-(ethylamino)-s-triazine (deisopropylatrazine) from clay-loam and slit-loam soils and sandy aquifer sediments. First, methanol/ water (4/1, v/v) soil extracts were transferred to an automated workstation following evaporation of the methanol phase for the rapid reversed-phase isolation of the metabolites on an octadecylresin (C18). The retention of the triazine metabolites on C18 decreased substantially when trace methanol concentrations (1%) remained. Furthermore, the retention on C18 increased with decreasing aqueous solubility and increasing alkyl-chain length of the metabolites and parent herbicides, indicating a reversed-phase interaction. The analytes were eluted with ethyl acetate, which left much of the soil organic-matter impurities on the resin. Second, the small-volume organic eluate was purified on an anion-exchange resin (0.5 mL/min) to extract the remaining soil pigments that could foul the ion source of the GC/MS system. Recoveries of the analytes were 75%, using deuterated atrazine as a surrogate, and were comparable to recoveries by soxhlet extraction. The detection limit was 0.1 ??g/kg with a coefficient of variation of 15%. The ease and efficiency of this automated method makes it viable, practical technique for studying triazine metabolites in the environment.

  6. Determination of six microcystins and nodularin in surface and drinking waters by on-line solid phase extraction-ultra high pressure liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Beltrán, Eduardo; Ibáñez, María; Sancho, Juan Vicente; Hernández, Félix

    2012-11-30

    Microcystins and nodularin are cyclic peptides hepatotoxins produced by cyanobacterial genera (blue-green algae). Toxic cyanobacterial blooms are a worldwide problem, as reported in several countries, like China, Australia, or the United States. Therefore, it is necessary to develop sensitive and reliable analytical methodology to determine this type of toxins in water at parts per billion levels, or even lower. In this work, the potential of solid-phase extraction coupled on-line to ultra-high-pressure liquid chromatography/electrospray tandem mass spectrometry (SPE-UHPLC-MS/MS) has been investigated for the efficient quantification and confirmation of microcystins LR, RR, YR, LY, LW, LF and nodularin in surface and drinking water samples, at sub-ppb levels. The method developed involves the injection of only 1 mL of water sample into the on-line SPE-UHPLC-MS/MS system and allows the rapid determination of the compounds selected (8 min of chromatographic run), avoiding laborious sample treatment. The method was validated in surface and drinking water by means of recovery experiments at 0.25 and 1 μg L(-1). Average recoveries (n=5) ranged from 71 to 116%, with relative standard deviations (RSDs) lower than 15%. For microcystins LR, RR, YR and nodularin, a third level was also assayed (0.1 μg L(-1)) obtaining satisfactory data too. Limits of detection between 0.002 and 0.0405 μg L(-1) were estimated (0.0005 μg L(-1) for nodularin). The developed method was applied to the analysis of water samples collected in the province of Castellón (Spain). The acquisition of three MS/MS transitions for each compound allowed the unequivocal confirmation of positive samples, which was supported by the accomplishment of ion intensity ratios and retention time when compared with reference standards. PMID:23107121

  7. Performance characteristics of two automated solid-phase red cell adherence systems for pretransfusion antibody screening: a cautionary tale.

    Science.gov (United States)

    Quillen, K; Caron, J; Murphy, K

    2012-01-01

    Out institution has implemented two instruments, the Galileo and the Echo, that use different solid-phase red cell adherence assays for antibody screening in pretransfusion compatibility testing.During the initial implementation of these two instruments, we noticed very different problems: falsely positive results on the Galileo, and falsely negative results and lack of reproducibility on the Echo. Comparison of falsely positive antibody screen results from approximately equivalent numbers of samples run on the Galileo and samples tested by standard manual tube technique using low-ionic-strength saline enhancement showed a false-positive rate of 1.4 percent on the Galileo (defined as a positive screen with a negative panel). Testing using the Echo identified four cases of falsely negative antibody screens, (defined as a negative screen on a patient sample subsequently shown to be positive by the same method). In addition, we note a lack of reproducibility on the Echo, which emphasizes the importance of replicate testing during validation of automated antibody screening platforms.

  8. Submicrometric Magnetic Nanoporous Carbons Derived from Metal-Organic Frameworks Enabling Automated Electromagnet-Assisted Online Solid-Phase Extraction.

    Science.gov (United States)

    Frizzarin, Rejane M; Palomino Cabello, Carlos; Bauzà, Maria Del Mar; Portugal, Lindomar A; Maya, Fernando; Cerdà, Víctor; Estela, José M; Turnes Palomino, Gemma

    2016-07-19

    We present the first application of submicrometric magnetic nanoporous carbons (μMNPCs) as sorbents for automated solid-phase extraction (SPE). Small zeolitic imidazolate framework-67 crystals are obtained at room temperature and directly carbonized under an inert atmosphere to obtain submicrometric nanoporous carbons containing magnetic cobalt nanoparticles. The μMNPCs have a high contact area, high stability, and their preparation is simple and cost-effective. The prepared μMNPCs are exploited as sorbents in a microcolumn format in a sequential injection analysis (SIA) system with online spectrophotometric detection, which includes a specially designed three-dimensional (3D)-printed holder containing an automatically actuated electromagnet. The combined action of permanent magnets and an automatically actuated electromagnet enabled the movement of the solid bed of particles inside the microcolumn, preventing their aggregation, increasing the versatility of the system, and increasing the preconcentration efficiency. The method was optimized using a full factorial design and Doehlert Matrix. The developed system was applied to the determination of anionic surfactants, exploiting the retention of the ion-pairs formed with Methylene Blue on the μMNPC. Using sodium dodecyl sulfate as a model analyte, quantification was linear from 50 to 1000 μg L(-1), and the detection limit was equal to 17.5 μg L(-1), the coefficient of variation (n = 8; 100 μg L(-1)) was 2.7%, and the analysis throughput was 13 h(-1). The developed approach was applied to the determination of anionic surfactants in water samples (natural water, groundwater, and wastewater), yielding recoveries of 93% to 110% (95% confidence level). PMID:27336802

  9. Determination of As(III) and total inorganic As in water samples using an on-line solid phase extraction and flow injection hydride generation atomic absorption spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Sigrist, Mirna, E-mail: msigrist@fiq.unl.edu.ar [Laboratorio Central, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2654-Piso 6, (3000) Santa Fe (Argentina); Albertengo, Antonela; Beldomenico, Horacio [Laboratorio Central, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2654-Piso 6, (3000) Santa Fe (Argentina); Tudino, Mabel [Laboratorio de Analisis de Trazas, Departamento de Quimica Inorganica, Analitica y Quimica Fisica/INQUIMAE, Facultad de Ciencias Exactas y Naturales, Pabellon II, Ciudad Universitaria (1428), Buenos Aires (Argentina)

    2011-04-15

    A simple and robust on-line sequential injection system based on solid phase extraction (SPE) coupled to a flow injection hydride generation atomic absorption spectrometer (FI-HGAAS) with a heated quartz tube atomizer (QTA) was developed and optimized for the determination of As(III) in groundwater without any kind of sample pretreatment. The method was based on the selective retention of inorganic As(V) that was carried out by passing the filtered original sample through a cartridge containing a chloride-form strong anion exchanger. Thus the most toxic form, inorganic As(III), was determined fast and directly by AsH{sub 3} generation using 3.5 mol L{sup -1} HCl as carrier solution and 0.35% (m/v) NaBH{sub 4} in 0.025% NaOH as the reductant. Since the uptake of As(V) should be interfered by several anions of natural occurrence in waters, the effect of Cl{sup -}, SO{sub 4}{sup 2-}, NO{sub 3}{sup -}, HPO{sub 4}{sup 2-}, HCO{sub 3}{sup -} on retention was evaluated and discussed. The total soluble inorganic arsenic concentration was determined on aliquots of filtered samples acidified with concentrated HCl and pre-reduced with 5% KI-5% C{sub 6}H{sub 8}O{sub 6} solution. The concentration of As(V) was calculated by difference between the total soluble inorganic arsenic and As(III) concentrations. Detection limits (LODs) of 0.5 {mu}g L{sup -1} and 0.6 {mu}g L{sup -1} for As(III) and inorganic total As, respectively, were obtained for a 500 {mu}L sample volume. The obtained limits of detection allowed testing the water quality according to the national and international regulations. The analytical recovery for water samples spiked with As(III) ranged between 98% and 106%. The sampling throughput for As(III) determination was 60 samples h{sup -1}. The device for groundwater sampling was especially designed for the authors. Metallic components were avoided and the contact between the sample and the atmospheric oxygen was carried to a minimum. On-field arsenic species

  10. On-line coupling of solid-phase extraction with mass spectrometry for the analysis of biological samples III. Determination of prednisolone in serum

    NARCIS (Netherlands)

    van Hout, MWJ; Hofland, CM; Niederlander, HAG; Bruins, AP; de Zeeuw, RA; de Jong, GJ

    2003-01-01

    Solid-phase extraction (SPE) was directly coupled to mass spectrometry (MS) to assess the feasibility of the system for the rapid determination of prednisolone in serum. A C-18 stationary phase allowed washing of the cartridge with 25% methanol. Elution was performed by switching the methanol percen

  11. Sequential injection/bead injection lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by ETAAS and ICPMS

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald; Miró, Manuel

    2003-01-01

    This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions...... are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material...

  12. Determination of amlodipine in human plasma using automated online solid-phase extraction HPLC-tandem mass spectrometry: application to a bioequivalence study of Chinese volunteers.

    Science.gov (United States)

    Shentu, Jianzhong; Fu, Lizhi; Zhou, Huili; Hu, Xing Jiang; Liu, Jian; Chen, Junchun; Wu, Guolan

    2012-11-01

    An automated method (XLC-MS/MS) that uses online solid-phase extraction coupled with HPLC-tandem mass spectrometry was reported here for the first time to quantify amlodipine in human plasma. Automated pre-purification of plasma was performed using 10 mm × 2 mm HySphere C8 EC-SE online solid-phase extraction cartridges. After being eluted from the cartridge, the analyte and the internal standard were separated by HPLC and detected by tandem mass spectrometry. Mass spectrometric detection was achieved in the multiple reaction monitoring mode using a quadrupole tandem mass spectrometer in the positive electrospray ionization mode. The XLC-MS/MS method was validated and yielded excellent specificity. The calibration curve ranged from 0.10 to 10.22 ng/mL, and both the intra- and inter-day precision and accuracy values were within 8%. This method proved to be less laborious and was faster per analysis (high-throughput) than offline sample preparation methods. This method has been successfully applied in clinical pharmacokinetic and bioequivalence analyses. PMID:22770846

  13. On-line solid-phase enrichment coupled to packed reactor flow injection analysis in a green analytical procedure to determine low levels of folic acid using fluorescence detection

    Directory of Open Access Journals (Sweden)

    Emara Samy

    2012-12-01

    Full Text Available Abstract Background Analysis of folic acid (FA is not an easy task because of its presence in lower concentrations, its lower stability under acidic conditions, and its sensitiveness against light and high temperature. The present study is concerned with the development and validation of an automated environmentally friendly pre-column derivatization combined by solid-phase enrichment (SPEn to determine low levels of FA. Results Cerium (IV trihydroxyhydroperoxide (CTH as a packed oxidant reactor has been used for oxidative cleavage of FA into highly fluorescent product, 2-amino-4-hydroxypteridine-6-carboxylic acid. FA was injected into a carrier stream of 0.04 M phosphate buffer, pH 3.4 at a flow-rate of 0.25 mL/min. The sample zone containing the analyte was passed through the CTH reactor thermostated at 40°C, and the fluorescent product was trapped and enriched on a head of small ODS column (10 mm x 4.6 mm i.d., 5 μm particle size. The enriched product was then back-flush eluted by column-switching from the small ODS column to the detector with a greener mobile phase consisting of ethanol and phosphate buffer (0.04M, pH 3.4 in the ratio of 5:95 (v/v. The eluent was monitored fluorimetrically at emission and excitation wavelengths of 463 and 367 nm, respectively. The calibration graph was linear over concentrations of FA in the range of 1.25-50 ng/mL, with a detection limit of 0.49 ng/mL. Conclusion A new simple and sensitive green analytical procedure including on-line pre-column derivatization combined by SPEn has been developed for the routine quality control and dosage form assay of FA at very low concentration level. The method was a powerful analytical technique that had excellent sensitivity, sufficient accuracy and required relatively simple and inexpensive instrumentation.

  14. Determination of propoxur in environmental samples by automated solid-phase extraction followed by flow-injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection

    Energy Technology Data Exchange (ETDEWEB)

    Perez-Ruiz, Tomas [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)]. E-mail: tpr@um.es; Martinez-Lozano, Carmen [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain); Garcia, Maria Dolores [Department of Analytical Chemistry, Faculty of Chemistry, University of Murcia, 30071 Murcia (Spain)

    2007-02-19

    A sensitive method for the analysis of propoxur in environmental samples has been developed. It involves an automated solid-phase extraction (SPE) procedure using a Gilson Aspec XLi and flow-injection analysis (FI) with chemiluminescence (CL) detection. The FI-CL system relies on the photolysis of propoxur by irradiation using a low-pressure mercury lamp (main spectral line 254 nm). The resultant methylamine is subsequently detected by CL using tris(2,2'-bipyridyl)ruthenium(III), which is on-line generated by photo-oxidation of the ruthenium(II) complex in the presence of peroxydisulfate. The linear concentration range of application was 0.05-5 {mu}g mL{sup -1} of propoxur, with a detection limit of 5 ng mL{sup -1}. The repeatability was 0.82% expressed as relative standard deviation (n = 10) and the reproducibility, studied on 5 consecutive days, was 2.1%. The sample throughput was 160 injection per hour. Propoxur residues below ng mL{sup -1} levels could be determined in environmental water samples when an SPE preconcentration device was coupled on-line with the FI system. This SPE-FI-CL arrangement provides a detection limit as low as 5 ng L{sup -1} using only 500 mL of sample. In the analysis of fruits and vegetables, the detection limit was about 10 {mu}g kg{sup -1}.

  15. Determination of propoxur in environmental samples by automated solid-phase extraction followed by flow-injection analysis with tris(2,2'-bipyridyl)ruthenium(II) chemiluminescence detection.

    Science.gov (United States)

    Pérez-Ruiz, Tomás; Martínez-Lozano, Carmen; García, María Dolores

    2007-02-19

    A sensitive method for the analysis of propoxur in environmental samples has been developed. It involves an automated solid-phase extraction (SPE) procedure using a Gilson Aspec XLi and flow-injection analysis (FI) with chemiluminescence (CL) detection. The FI-CL system relies on the photolysis of propoxur by irradiation using a low-pressure mercury lamp (main spectral line 254 nm). The resultant methylamine is subsequently detected by CL using tris(2,2'-bipyridyl)ruthenium(III), which is on-line generated by photo-oxidation of the ruthenium(II) complex in the presence of peroxydisulfate. The linear concentration range of application was 0.05-5 microg mL(-1) of propoxur, with a detection limit of 5 ng mL(-1). The repeatability was 0.82% expressed as relative standard deviation (n=10) and the reproducibility, studied on 5 consecutive days, was 2.1%. The sample throughput was 160 injection per hour. Propoxur residues below ng mL(-1) levels could be determined in environmental water samples when an SPE preconcentration device was coupled on-line with the FI system. This SPE-FI-CL arrangement provides a detection limit as low as 5 ng L(-1) using only 500 mL of sample. In the analysis of fruits and vegetables, the detection limit was about 10 microg kg(-1).

  16. On-line electrochemically controlled in-tube solid phase microextraction of inorganic selenium followed by hydride generation atomic absorption spectrometry.

    Science.gov (United States)

    Asiabi, Hamid; Yamini, Yadollah; Seidi, Shahram; Shamsayei, Maryam; Safari, Meysam; Rezaei, Fatemeh

    2016-05-30

    In this work, for the first time, a rapid, simple and sensitive microextraction procedure is demonstrated for the matrix separation, preconcentration and determination of inorganic selenium species in water samples using an electrochemically controlled in-tube solid phase microextraction (EC-in-tube SPME) followed by hydride generation atomic absorption spectrometry (HG-AAS). In this approach, in which EC-in-tube SPME and HG-AAS system were combined, the total analysis time, was decreased and the accuracy, repeatability and sensitivity were increased. In addition, to increases extraction efficiency, a novel nanostructured composite coating consisting of polypyrrole (PPy) doped with ethyleneglycol dimethacrylate (EGDMA) was prepared on the inner surface of a stainless-steel tube by a facile electrodeposition method. To evaluate the offered setup and the new PPy-EGDMA coating, it was used to extract inorganic selenium species in water samples. Extraction of inorganic selenium species was carried out by applying a positive potential through the inner surface of coated in-tube under flow conditions. Under the optimized conditions, selenium was detected in amounts as small as 4.0 parts per trillion. The method showed good linearity in the range of 0.012-200 ng mL(-1), with coefficients of determination better than 0.9996. The intra- and inter-assay precisions (RSD%, n = 5) were in the range of 2.0-2.5% and 2.7-3.2%, respectively. The validated method was successfully applied for the analysis of inorganic selenium species in some water samples and satisfactory results were obtained. PMID:27154830

  17. 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.

  18. 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

  19. On-line Ultrasound-Assisted Dispersive Micro-Solid-Phase Extraction Based on Amino Bimodal Mesoporous Silica Nanoparticles for the Preconcentration and Determination of Cadmium in Human Biological Samples.

    Science.gov (United States)

    Shirkhanloo, H; Falahnejad, M; Zavvar Mousavi, H

    2016-06-01

    On-line ultrasound-assisted dispersive micro-solid-phase extraction (USA-DμSPE) has been developed for preconcentration and separation of trace amounts of Cd(II) ions in 0.5 mL of human biological samples. In a syringe with a nylon membrane, new synthetic bulky amino bimodal mesoporous silica nanoparticles (NH2-UVM7) were dispersed as a nanoadsorbent in 5 mL of diluted serum sample (1:10), and after ultrasonic shaking, the liquid phase was separated from the solid phase. At the optimized pH, the chemical and physical adsorption of cadmium ions occurred, respectively, based on complexation with amine groups of UVM7 (Cd:NH2-UVM7) and silica nanoparticles. The analyte was then back-extracted from the sorbent with nitric acid solution (0.2 M), and its concentration was determined by electrothermal atomic absorption spectrometry (ETAAS). Under the optimized conditions, the linear range, limit of detection (LOD), and preconcentration factor (PF) were obtained as 0.01-0.56 μg L(-1), 0.002 μg L(-1), and 25, respectively. The adsorption capacity of NH2-UVM7 was found to be 108.6 mg g(-1) of cadmium. The validation of the methodology was performed by the human standard reference material (HSRM). PMID:26475301

  20. On-line solid-phase separation/preconcentration for the determination of copper in urine by flame atomic absorption spectrometry

    International Nuclear Information System (INIS)

    A new on-line separation/preconcentration system was developed for the determination of Cu(II) ions by flame atomic absorption spectrometry in urine samples. A newly synthesized chelating resin, by anchoring eriochrome blue black R reagent to Amberlite XAD-16 resin, was used as a packing material for the selective separation/preconcentration of Cu(II) ions. The influence of the parameters on the determination of Cu(II) ions such as pH of sample solution, amount of the resin, eluent type, interfering ions and flow variables was studied. The detection limit of the method was 1.0 μg L−1 while precision was 2.3% (n = 15) at 50 μg L−1 Cu(II) level. The adsorption capacity of the resin was 217 μg g−1 Cu(II). The accuracy of the method was proven using TMDA-64 standard lake water and synthetic urine sample. The developed method has been applied successfully to the determination of copper in urine with satisfactory results. - Highlights: • The method was applied to the urine samples taken from Wilson’s patients. • The on-line determination of copper and satisfactory results were obtained. • All processes are made automatically by the system itself in the proposed method

  1. Automated serological technique with special emphasis on a solid phase test for red cell antibody detection in routine blood banking

    OpenAIRE

    Sallander, Suzanne

    1999-01-01

    Automated serological techniques for erythrocyte antigen typing and antibody screening are presented and evaluated in a larger number of samples and throughout routine processing. Both techniques are microplate-adapted with computerised sample identification, sample and reagent dispensing, and interpretation of results. The method described for typing of the RBC antigens K, Fya, and C, c, E, e compared well to the manual haernagglutination test. The concurrence was >= 99.4 %...

  2. Quantitative analysis of maytansinoid (DM1) in human serum by on-line solid phase extraction coupled with liquid chromatography tandem mass spectrometry - Method validation and its application to clinical samples.

    Science.gov (United States)

    Heudi, Olivier; Barteau, Samuel; Picard, Franck; Kretz, Olivier

    2016-02-20

    A sensitive and specific method was developed and validated for the quantitation of maytansinoid (DM1) in human serum using on-line solid phase extraction (SPE)-liquid chromatography-tandem mass spectrometry (LC-MS/MS). Because DM1 contains a free thiol moiety, likely to readily dimerize or react with other thiol-containing molecules in serum, samples were pre-treated with a reducing agent [tris (2-carboxyethyl) phosphine] (TCEP) and further blocked with N-ethylmaleimide (NEM). The resulting samples were diluted with acetonitrile prior to the on-line solid phase extraction (SPE) on a C18 cartridge. A C18 (150×4.6mm ID 3μm particle size) column was used for chromatographic separation with a 10.0min HPLC gradient and DM1-NEM was detected in the selected reaction monitoring mode of a triple quadrupole mass spectrometer. DM1 concentrations were back-calculated from DM1-NEM amount found in the human serum samples. The quantitation range of the method was 0.200-200ng/mL when using 0.25mL serum. Within-run day precisions (n=6) were 0.9-4.4% and between-run day (3 days runs; n=18) precisions 2.5-5.6%. Method biases were between 3.5-14.5% across the whole calibration range. DM1-NEM exhibited sufficiently stability under all relevant analytical conditions and no DM1 losses from the ADC were observed. Finally, the assay was used for DM1 determination in human serum concentration after the intravenous administration of an investigational antibody drug conjugate (ADC) containing DM1 as payload. PMID:26771131

  3. [Determination of five avermectins in bovine liver by on-line solid-phase extraction with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Li, Xin; Zhang, Yaoqin; Ai, Lianfeng; Wang, Xuesheng; Wang, Manman; Xu, Houjun; Hao, Yulan

    2015-06-01

    A method based on on-line solid-phase extraction (SPE) with hydrophobic monolithic column coupled with high performance liquid chromatography-tandem mass spectrometry was developed for the simultaneous determination of five avermectins in bovine liver. A poly(butyl methacrylate-co-ethylene dimethacrylate) monolithic column was used as the sorbent. The parameters influenced on on-line SPE and separation process such as the loading mobile phase, the eluting flow rate and the solvent for the separation were investigated in detail. Blank samples, spiked samples, matrix effect and recovery experiments were investigated to evaluate the extraction efficiency and potential interfering compounds originating from the matrix. Under the optimized conditions, the method showed a linear range of 1-100 µg/L and the quantification limit of 5 µg/kg for each analyte. The presented method gave recoveries of 77.4%-98.4%. The relative standard deviations of intra-day and inter-day were 4.46%-8.03% and 4.79%-8.68%, respectively. Moreover, no significant changes were found in the extraction performance after more than 400 usages on one monolithic column, and even on the monoliths with various batches. The feasibility of the developed poly (butyl methacrylate-coethylene dimethacrylate) monolithic column based on the on-line SPE method for the determination of avermectins was further demonstrated by the analysis of real samples.

  4. Ultra-trace levels analysis of microcystins and nodularin in surface water by on-line solid-phase extraction with high-performance liquid chromatography tandem mass spectrometry.

    Science.gov (United States)

    Balest, Lydia; Murgolo, Sapia; Sciancalepore, Lucia; Montemurro, Patrizia; Abis, Pier Paolo; Pastore, Carlo; Mascolo, Giuseppe

    2016-06-01

    An on-line solid phase extraction coupled with high-performance liquid chromatography in tandem with mass spectrometry (on-line SPE/HPLC/MS-MS) method for the determination of five microcystins and nodularin in surface waters at submicrogram per liter concentrations has been optimized. Maximum recoveries were achieved by carefully optimizing the extraction sample volume, loading solvent, wash solvent, and pH of the sample. The developed method was also validated according to both UNI EN ISO IEC 17025 and UNICHIM guidelines. Specifically, ten analytical runs were performed at three different concentration levels using a reference mix solution containing the six analytes. The method was applied for monitoring the concentrations of microcystins and nodularin in real surface water during a sampling campaign of 9 months in which the ELISA method was used as standard official method. The results of the two methods were compared showing good agreement when the highest concentration values of MCs were found. Graphical abstract An on-line SPE/HPLC/MS-MS method for the determination of five microcystins and nodularin in surface waters at sub μg L(-1) was optimized and compared with ELISA assay method for real samples. PMID:27052778

  5. Fully automated lab-on-valve-multisyringe flow injection analysis-ICP-MS system: An effective tool for fast, sensitive and selective determination of thorium and uranium at environmental levels exploiting solid phase extraction

    OpenAIRE

    Avivar, Jessica; Ferrer, Laura; Casas, Montserrat; Cerdà, Víctor

    2012-01-01

    An on-line solid-phase extraction method linked to inductively coupled mass spectrometry (ICP-MS) has been developed for the determination of low levels of uranium and thorium in environmental samples. The hyphenation of lab-on-valve (LOV) and multisyringe flow injection analysis (MSFIA), coupled to an ICP-MS, allows the simultaneous determination of thorium and uranium in different types of environmental sample matrices achieving high selectivity and sensitivity levels. On-line separation an...

  6. Accelerated solvent extraction followed by on-line solid-phase extraction coupled to ion trap LC/MS/MS for analysis of benzalkonium chlorides in sediment samples

    Science.gov (United States)

    Ferrer, I.; Furlong, E.T.

    2002-01-01

    Benzalkonium chlorides (BACs) were successfully extracted from sediment samples using a new methodology based on accelerated solvent extraction (ASE) followed by an on-line cleanup step. The BACs were detected by liquid chromatography/ion trap mass spectrometry (LC/MS) or tandem mass spectrometry (MS/MS) using an electrospray interface operated in the positive ion mode. This methodology combines the high efficiency of extraction provided by a pressurized fluid and the high sensitivity offered by the ion trap MS/MS. The effects of solvent type and ASE operational variables, such as temperature and pressure, were evaluated. After optimization, a mixture of acetonitrile/water (6:4 or 7:3) was found to be most efficient for extracting BACs from the sediment samples. Extraction recoveries ranged from 95 to 105% for C12 and C14 homologues, respectively. Total method recoveries from fortified sediment samples, using a cleanup step followed by ASE, were 85% for C12BAC and 79% for C14-BAC. The methodology developed in this work provides detection limits in the subnanogram per gram range. Concentrations of BAC homologues ranged from 22 to 206 ??g/kg in sediment samples from different river sites downstream from wastewater treatment plants. The high affinity of BACs for soil suggests that BACs preferentially concentrate in sediment rather than in water.

  7. Automated mini-column solid-phase extraction cleanup for high-throughput analysis of chemical contaminants in foods by low-pressure gas chromatography – tandem mass spectrometry

    Science.gov (United States)

    This study demonstrated the application of an automated high-throughput mini-cartridge solid-phase extraction (mini-SPE) cleanup for the rapid low-pressure gas chromatography – tandem mass spectrometry (LPGC-MS/MS) analysis of pesticides and environmental contaminants in QuEChERS extracts of foods. ...

  8. Minimization of mass interferences in quadrupole inductively coupled plasma mass spectrometric (ICP-MS) determination of palladium using a flow injection on-line displacement solid-phase extraction protocol

    Energy Technology Data Exchange (ETDEWEB)

    Fang Jing [Key Laboratory of Functional Polymer Materials (Nankai University), Ministry of Education, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071 (China); Liu Liwen [Key Laboratory of Functional Polymer Materials (Nankai University), Ministry of Education, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071 (China); Yan Xiuping [Key Laboratory of Functional Polymer Materials (Nankai University), Ministry of Education, Research Center for Analytical Sciences, College of Chemistry, Nankai University, Tianjin 300071 (China)]. E-mail: xpyan@nankai.edu.cn

    2006-07-15

    A flow injection on-line displacement solid-phase extraction protocol was employed to minimize mass interferences with determination of palladium by inductively coupled plasma mass spectrometry (ICP-MS). The developed method involved in on-line complexing of Ag{sup +} with pyrrolidine dithiocarbamate (PDC), presorption of the resultant Ag-PDC onto a microcolumn packed with the cigarette filter, displacement sorption of Pd{sup 2+} through loading the sample solution onto the microcolumn due to on-line displacement reaction between Pd{sup 2+} and the presorbed Ag-PDC, elution of the retained Pd{sup 2+} with 50 {mu}L of ethanol for on-line ICP-MS detection. Interferences from co-existing heavy metal ions with lower stability of their PDC complexes relative to Ag-PDC were minimized/eliminated. No interferences from 5 mg L{sup -1} Zn and 3 mg L{sup -1} Pb for {sup 104}Pd, 0.4 mg L{sup -1} Cu for {sup 105}Pd, 6 mg L{sup -1} Zn and 2 mg L{sup -1} Cd for {sup 106}Pd, 6 mg L{sup -1} Zn and 3 mg L{sup -1} Cd for {sup 108}Pd, and 2 mg L{sup -1} Cd for {sup 110}Pd were observed for the determination of 100 ng L{sup -1} Pd. The enhancement factors of 71-75, sample throughput of 23 samples h{sup -1} and detection limits of 2.8-3.5 ng L{sup -1} were achieved with the consumption of 3.0 mL of sample solution. The precision (RSD) for eleven replicate determinations of Pd at the 100 ng L{sup -1} level was 1.8-2.7%. The developed method was applied to the determination of palladium in rock samples.

  9. Minimization of mass interferences in quadrupole inductively coupled plasma mass spectrometric (ICP-MS) determination of palladium using a flow injection on-line displacement solid-phase extraction protocol

    Science.gov (United States)

    Fang, Jing; Liu, Li-Wen; Yan, Xiu-Ping

    2006-07-01

    A flow injection on-line displacement solid-phase extraction protocol was employed to minimize mass interferences with determination of palladium by inductively coupled plasma mass spectrometry (ICP-MS). The developed method involved in on-line complexing of Ag + with pyrrolidine dithiocarbamate (PDC), presorption of the resultant Ag-PDC onto a microcolumn packed with the cigarette filter, displacement sorption of Pd 2+ through loading the sample solution onto the microcolumn due to on-line displacement reaction between Pd 2+ and the presorbed Ag-PDC, elution of the retained Pd 2+ with 50 μL of ethanol for on-line ICP-MS detection. Interferences from co-existing heavy metal ions with lower stability of their PDC complexes relative to Ag-PDC were minimized/eliminated. No interferences from 5 mg L - 1 Zn and 3 mg L - 1 Pb for 104Pd, 0.4 mg L - 1 Cu for 105Pd, 6 mg L - 1 Zn and 2 mg L - 1 Cd for 106Pd, 6 mg L - 1 Zn and 3 mg L - 1 Cd for 108Pd, and 2 mg L - 1 Cd for 110Pd were observed for the determination of 100 ng L - 1 Pd. The enhancement factors of 71-75, sample throughput of 23 samples h - 1 and detection limits of 2.8-3.5 ng L - 1 were achieved with the consumption of 3.0 mL of sample solution. The precision (RSD) for eleven replicate determinations of Pd at the 100 ng L - 1 level was 1.8-2.7%. The developed method was applied to the determination of palladium in rock samples.

  10. Minimization of mass interferences in quadrupole inductively coupled plasma mass spectrometric (ICP-MS) determination of palladium using a flow injection on-line displacement solid-phase extraction protocol

    International Nuclear Information System (INIS)

    A flow injection on-line displacement solid-phase extraction protocol was employed to minimize mass interferences with determination of palladium by inductively coupled plasma mass spectrometry (ICP-MS). The developed method involved in on-line complexing of Ag+ with pyrrolidine dithiocarbamate (PDC), presorption of the resultant Ag-PDC onto a microcolumn packed with the cigarette filter, displacement sorption of Pd2+ through loading the sample solution onto the microcolumn due to on-line displacement reaction between Pd2+ and the presorbed Ag-PDC, elution of the retained Pd2+ with 50 μL of ethanol for on-line ICP-MS detection. Interferences from co-existing heavy metal ions with lower stability of their PDC complexes relative to Ag-PDC were minimized/eliminated. No interferences from 5 mg L-1 Zn and 3 mg L-1 Pb for 104Pd, 0.4 mg L-1 Cu for 105Pd, 6 mg L-1 Zn and 2 mg L-1 Cd for 106Pd, 6 mg L-1 Zn and 3 mg L-1 Cd for 108Pd, and 2 mg L-1 Cd for 110Pd were observed for the determination of 100 ng L-1 Pd. The enhancement factors of 71-75, sample throughput of 23 samples h-1 and detection limits of 2.8-3.5 ng L-1 were achieved with the consumption of 3.0 mL of sample solution. The precision (RSD) for eleven replicate determinations of Pd at the 100 ng L-1 level was 1.8-2.7%. The developed method was applied to the determination of palladium in rock samples

  11. Flow injection on-line solid phase extraction coupled with inductively coupled plasma mass spectrometry for determination of (ultra)trace rare earth elements in environmental materials using maleic acid grafted polytetrafluoroethylene fibers as sorbent.

    Science.gov (United States)

    Wang, Zhao-Hui; Yan, Xiu-Ping; Wang, Zhi-Peng; Zhang, Zheng-Pu; Liu, Li-Wen

    2006-09-01

    A new sorbent, maleic acid grafted polytetrafluoroethylene fiber (MA-PTFE), was prepared and evaluated for on-line solid-phase extraction coupled with inductively coupled plasma mass spectrometry (ICP-MS) for fast, selective, and sensitive determination of (ultra)trace rare earth elements (REEs) in environmental samples. The REEs in aqueous samples at pH = 3.0 were selectively extracted onto a microcolumn packed with the MA-PTFE fiber, and the adsorbed REEs were subsequently eluted on-line with 0.9 mol l(-1) HNO3 for ICP-MS determination. The new sorbent extraction system allows effective preconcentration and separation of the REEs from the major matrix constituents of alkali and alkali earth elements, particularly their separation from barium that produces considerable isobaric interferences of 134Ba16O1H+, 135Ba16O+, 136Ba16O1H+, and 137Ba16O+ on 151Eu+ and 153Eu+. With the use of a sample loading flow rate of 7.4 ml min(-1) for 120 s preconcentration, enhancement factors of 69-97 and detection limits (3s) of 1-20 pg l(-1) were achieved at a sample throughput of 22 samples h(-1). The precision (RSD) for 16 replicate determinations of 50 ng l(-1) of REEs was 0.5-1.1%. The developed method was successfully applied to the determination of (ultra)trace REEs in sediment, soil, and seawater samples. PMID:16814561

  12. Automated method for determination of dissolved organic carbon-water distribution constants of structurally diverse pollutants using pre-equilibrium solid-phase microextraction.

    Science.gov (United States)

    Ripszam, Matyas; Haglund, Peter

    2015-02-01

    Dissolved organic carbon (DOC) plays a key role in determining the environmental fate of semivolatile organic environmental contaminants. The goal of the present study was to develop a method using commercially available hardware to rapidly characterize the sorption properties of DOC in water samples. The resulting method uses negligible-depletion direct immersion solid-phase microextraction (SPME) and gas chromatography-mass spectrometry. Its performance was evaluated using Nordic reference fulvic acid and 40 priority environmental contaminants that cover a wide range of physicochemical properties. Two SPME fibers had to be used to cope with the span of properties, 1 coated with polydimethylsiloxane and 1 coated with polystyrene divinylbenzene polydimethylsiloxane, for nonpolar and semipolar contaminants, respectively. The measured DOC-water distribution constants showed reasonably good reproducibility (standard deviation ≤ 0.32) and good correlation (R(2)  = 0.80) with log octanol-water partition coefficients for nonpolar persistent organic pollutants. The sample pretreatment is limited to filtration, and the method is easy to adjust to different DOC concentrations. These experiments also utilized the latest SPME automation that largely decreases total cycle time (to 20 min or shorter) and increases sample throughput, which is advantageous in cases when many samples of DOC must be characterized or when the determinations must be performed quickly, for example, to avoid precipitation, aggregation, and other changes of DOC structure and properties. The data generated by this method are valuable as a basis for transport and fate modeling studies. PMID:25393710

  13. Fully automated analysis of beta-lactams in bovine milk by online solid phase extraction-liquid chromatography-electrospray-tandem mass spectrometry.

    Science.gov (United States)

    Kantiani, Lina; Farré, Marinella; Sibum, Martin; Postigo, Cristina; López de Alda, Miren; Barceló, Damiá

    2009-06-01

    A fully automated method for the detection of beta-lactam antibiotics, including six penicillins (amoxicillin, ampicillin, cloxacillin, dicloxacillin, oxacillin, and penicillin G) and four cephalosporins (cefazolin, ceftiofur, cefoperazone, and cefalexin) in bovine milk samples has been developed. The outlined method is based on online solid-phase extraction-liquid chromatography/electrospray-tandem mass spectrometry (SPE-LC/ESI-MS-MS). Target compounds were concentrated from 500 microL of centrifuged milk samples using an online SPE procedure with C18 HD cartridges. Target analytes were eluted with a gradient mobile phase (water + 0.1% formic acid/methanol + 0.1% formic acid) at a flow rate of 0.7 mL/min. Chromatographic separation was achieved within 10 min using a C-12 reversed phase analytical column. For unequivocal identification and confirmation, two multiple reaction monitoring (MRM) transitions were acquired for each analyte in the positive electrospray ionization mode (ESI(+)). Method limits of detection (LODs) in milk were well below the maximum residue limits (MRLs) set by the European Union for all compounds. Limits of quantification in milk were between 0.09 ng/mL and 1.44 ng/mL. The developed method was validated according to EU's requirements, and accuracy results ranged from 80 to 116%. Finally, the method was applied to the analysis of twenty real samples previously screened by the inhibition of microbial growth test Eclipse 100. This new developed method offers high sensitivity and accuracy of results, minimum sample pre-treatment, and uses for the first time an automated online SPE offering a high throughput analysis. Because of all these characteristics, the proposed method is applicable and could be deemed necessary within the field of food control and safety. PMID:19402673

  14. Análise de fármacos em material biológico: acoplamento microextração em fase sólida "no tubo" e cromatografia líquida de alta eficiência Analysis of drugs in biological samples: automated "in-tube" solid-phase microextraction and high performance liquid chromatography

    Directory of Open Access Journals (Sweden)

    Maria Eugênia C. Queiroz

    2005-10-01

    Full Text Available A new solid phase microextraction (SPME system, known as in-tube SPME, was recently developed using an open tubular fused-silica capilary column, instead of an SPME fiber, as the SPME device. On-line in-tube SPME is usually used in combination with high performance liquid chromatography. Drugs in biological samples are directly extracted and concentrated in the stationary phase of capillary columns by repeated draw/eject cycles of sample solution, and then directly transferred to the liquid chromatographic column. In-tube SPME is suitable for automation. Automated sample handling procedures not only shorten the total analysis time, but also usually provide better accuracy and precision relative to manual techniques. In-tube SPME has been demonstrated to be a very effective and highly sensitive technique to determine drugs in biological samples for various purposes such as therapeutic drug monitoring, clinical toxicology, bioavailability and pharmacokinetics.

  15. Simple and quick determination of analgesics and other contaminants of emerging concern in environmental waters by on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ferrer-Aguirre, Alejandra; Romero-González, Roberto; Vidal, J L Martínez; Frenich, Antonia Garrido

    2016-05-13

    A simple and quick analytical method has been developed for the determination of pharmaceutical compounds in water. An on-line solid-phase extraction (SPE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been optimized to determine 7 contaminants of emerging concern in environmental waters at ngL(-1) levels. This procedure requires minimal sample handling and small sample volume (900μL) with a total running time of 18min. Several SPE parameters were evaluated and optimized in order to achieve a high sample throughput. Therefore sample volume, carryover and reusability of the cartridges were evaluated. Performance characteristics were evaluated and good linearity was obtained (R(2)>0.98). Recoveries were evaluated in spiked samples at three concentrations and the values ranged from 71 to 104%. Intra and inter-day precision was lower than 10 and 13% respectively. Limits of quantification were equal to or lower than 10ngL(-1), except for 1,7-dimethylxanthine (20ngL(-1)) and ibuprofen (50ngL(-1)). The method was applied to 20 environmental water samples, and ibuprofen was the compound most widely detected at concentrations up to 42.06μgL(-1), whereas the other compounds were detected in fewer samples at lower concentrations (up to 15.99μgL(-1)). PMID:27063372

  16. Simple and quick determination of analgesics and other contaminants of emerging concern in environmental waters by on-line solid phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Ferrer-Aguirre, Alejandra; Romero-González, Roberto; Vidal, J L Martínez; Frenich, Antonia Garrido

    2016-05-13

    A simple and quick analytical method has been developed for the determination of pharmaceutical compounds in water. An on-line solid-phase extraction (SPE) coupled to liquid chromatography-tandem mass spectrometry (LC-MS/MS) method has been optimized to determine 7 contaminants of emerging concern in environmental waters at ngL(-1) levels. This procedure requires minimal sample handling and small sample volume (900μL) with a total running time of 18min. Several SPE parameters were evaluated and optimized in order to achieve a high sample throughput. Therefore sample volume, carryover and reusability of the cartridges were evaluated. Performance characteristics were evaluated and good linearity was obtained (R(2)>0.98). Recoveries were evaluated in spiked samples at three concentrations and the values ranged from 71 to 104%. Intra and inter-day precision was lower than 10 and 13% respectively. Limits of quantification were equal to or lower than 10ngL(-1), except for 1,7-dimethylxanthine (20ngL(-1)) and ibuprofen (50ngL(-1)). The method was applied to 20 environmental water samples, and ibuprofen was the compound most widely detected at concentrations up to 42.06μgL(-1), whereas the other compounds were detected in fewer samples at lower concentrations (up to 15.99μgL(-1)).

  17. Sequential injection-bead injection-lab-on-valve schemes for on-line solid phase extraction and preconcentration of ultra-trace levels of heavy metals with determination by electrothermal atomic absorption spectrometry and inductively coupled plasma mass spectrometry

    International Nuclear Information System (INIS)

    This communication presents an overview of the state-of-the-art of the exploitation of sequential injection (SI)-bead injection (BI)-lab-on-valve (LOV) schemes for automatic on-line sample pre-treatments interfaced with ETAAS and ICPMS detection as conducted in the authors' group. The discussions are focused on the applications of SI-BI-LOV protocols for on-line microcolumn based solid phase extraction of ultra-trace levels of heavy metals, employing the so-called renewable surface separation and preconcentration manipulatory scheme. Two types of sorbents have been employed as packing material, that is, the hydrophilic SP Sephadex C-25 cation exchange and iminodiacetate based Muromac A-1 chelating resins, and the hydrophobic poly(tetrafluoroethylene) (PTFE) and poly(styrene-divinylbenzene) copolymer alkylated with octadecyl groups (C18-PS/DVB). Using ETAAS as detection device, the easy-to-handle hydrophilic renewable reactors hold the features of improved R.S.D.s and LODs as compared to those operated in the conventional, permanent mode, in addition to the elimination of flow resistance. The hydrophobic columns fall into two categories, that is, the renewable one packed with C18-PS/DVB beads entails analogous R.S.D.s and LODs with respect to the conventional approach, while those with PTFE beads result in slightly inferior R.S.D.s and LODs by similar comparison, yet offering a wider dynamic range than when using an external permanent column. Moreover, the hydrophilic materials result in much higher enrichment of the analyte than the hydrophobic ones, although PTFE is the packing material that exhibits the best retention efficiency

  18. Flight flutter testing technology at Grumman. [automated telemetry station for on line data reduction

    Science.gov (United States)

    Perangelo, H. J.; Milordi, F. W.

    1976-01-01

    Analysis techniques used in the automated telemetry station (ATS) for on line data reduction are encompassed in a broad range of software programs. Concepts that form the basis for the algorithms used are mathematically described. The control the user has in interfacing with various on line programs is discussed. The various programs are applied to an analysis of flight data which includes unimodal and bimodal response signals excited via a swept frequency shaker and/or random aerodynamic forces. A nonlinear response error modeling analysis approach is described. Preliminary results in the analysis of a hard spring nonlinear resonant system are also included.

  19. Development of a fully automated sequential injection solid-phase extraction procedure coupled to liquid chromatography to determine free 2-hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid in human urine

    International Nuclear Information System (INIS)

    2-Hydroxy-4-methoxybenzophenone and 2-hydroxy-4-methoxybenzophenone-5-sulphonic acid, commonly known as benzophenone-3 (BZ3) and benzophenone-4 (BZ4), respectively, are substances widely used as UV filters in cosmetic products in order to absorb UV radiation and protect human skin from direct exposure to the deleterious wavelengths of sunlight. As with other UV filters, there is evidence of their percutaneous absorption. This work describes an analytical method developed to determine trace levels of free BZ3 and BZ4 in human urine. The methodology is based on a solid-phase extraction (SPE) procedure for clean-up and pre-concentration, followed by the monitoring of the UV filters by liquid chromatography-ultraviolet spectrophotometry detection (LC-UV). In order to improve not only the sensitivity and selectivity, but also the precision of the method, the principle of sequential injection analysis was used to automate the SPE process and to transfer the eluates from the SPE to the LC system. The application of a six-channel valve as an interface for the switching arrangements successfully allowed the on-line connection of SPE sample processing with LC analysis. The SPE process for BZ3 and BZ4 was performed using octadecyl (C18) and diethylaminopropyl (DEA) modified silica microcolumns, respectively, in which the analytes were retained and eluted selectively. Due to the matrix effects, the determination was based on standard addition quantification and was fully validated. The relative standard deviations of the results were 13% and 6% for BZ3 and BZ4, respectively, whereas the limits of detection were 60 and 30 ng mL-1, respectively. The method was satisfactorily applied to determine BZ3 and BZ4 in urine from volunteers that had applied a sunscreen cosmetic containing both UV filters.

  20. On-line solid phase extraction-high performance liquid chromatography-isotope dilution-tandem mass spectrometry approach to quantify N,N-diethyl-m-toluamide and oxidative metabolites in urine.

    Science.gov (United States)

    Kuklenyik, Peter; Baker, Samuel E; Bishop, Amanda M; Morales-A, Pilar; Calafat, Antonia M

    2013-07-17

    Human exposure to N,N-diethyl-m-toluamide (DEET) occurs because of the widespread use of DEET as an active ingredient in insect repellents. However, information on the extent of such exposure is rather limited. Therefore, we developed a fast on-line solid phase extraction-high performance liquid chromatography-isotope dilution tandem mass spectrometry (HPLC-MS/MS) method to measure in urine the concentrations of DEET and two of its oxidative metabolites: N,N-diethyl-3-(hydroxymethyl)benzamide and 3-(diethylcarbamoyl)benzoic acid (DCBA). To the best of our knowledge, this is the first HPLC-MS/MS method for the simultaneous quantification of DEET and its select metabolites in human urine. After enzymatic hydrolysis of the conjugated species in 0.1 mL of urine, the target analytes were retained and pre-concentrated on a monolithic column, separated from each other and from other urinary biomolecules on a reversed-phase analytical column, and detected by atmospheric pressure chemical ionization in positive ion mode. The limits of detection ranged from 0.1 ng mL(-1) to 1.0 ng mL(-1), depending on the analyte. Accuracy ranged between 90.4 and 104.9%, and precision ranged between 5.5 and 13.1% RSD, depending on the analyte and the concentration. We tested the usefulness of this method by analyzing 75 urine samples collected anonymously in the Southeastern United States in June 2012 from adults with no known exposure to DEET. Thirty eight samples (51%) tested positive for at least one of the analytes. We detected DCBA most frequently and at the highest concentrations. Our results suggest that this method can be used for the analysis of a large number of samples for epidemiological studies to assess human exposure to DEET. PMID:23830449

  1. Preliminary results on the determination of ultratrace amounts of cadmium in tea samples using a flow injection on-line solid phase extraction separation and preconcentration technique to couple with a sequential injection hydride generation atomic fluorescence spectrometry.

    Science.gov (United States)

    Duan, Taicheng; Song, Xuejie; Jin, Dan; Li, Hongfei; Xu, Jingwei; Chen, Hangting

    2005-10-31

    In this work, a method was developed for determination of ultra-trace levels of Cd in tea samples by atomic fluorescence spectrometry (AFS). A flow injection solid phase extraction (FI-SPE) separation and preconcentration technique, to on-line couple with a sequential injection hydride generation (SI-HG) technique is employed in this study. Cd was preconcentrated on the SPE column, which was made from a neutral extractant named Cyanex 923, while other matrix ions or interfering ions were completely or mostly separated off. Conditions for the SPE separation and preconcentration, as well as conditions for the HG technique, were studied. Due to the separation of interfering elements, Cd hydride generation efficiency could be greatly enhanced with the sole presence of Co(2+) with a concentration of 200mugL(-1), which is much lower than those in other works previously reported. Interferences on both the Cd separation and preconcentration, and Cd hydride generation (HG) were investigated; it showed that both the separation and preconcentration system, and the HG system had a strong anti-interference ability. The SPE column could be repeatedly used at least 400 times, a R.S.D. of 0.97% was obtained for 6 measurements of Cd with 0.2mugL(-1) and a correlation coefficiency of 1.0000 was obtained for the measurement of a series of solutions with Cd concentrations from 0.1 to 2mugL(-1). The method has a low detection limit of 10.8ngL(-1) for a 25mL solution and was successfully validated by using two tea standard reference materials (GBW08513 and GBW07605).

  2. A fully automated system for analysis of pesticides in water: on-line extraction followed by liquid chromatography-tandem photodiode array/postcolumn derivatization/fluorescence detection.

    Science.gov (United States)

    Patsias, J; Papadopoulou-Mourkidou, E

    1999-01-01

    A fully automated system for on-line solid phase extraction (SPE) followed by high-performance liquid chromatography (HPLC) with tandem detection with a photodiode array detector and a fluorescence detector (after postcolumn derivatization) was developed for analysis of many chemical classes of pesticides and their major conversion products in aquatic systems. An automated on-line-SPE system (Prospekt) operated with reversed-phase cartridges (PRP-1) extracts analytes from 100 mL acidified (pH = 3) filtered water sample. On-line HPLC analysis is performed with a 15 cm C18 analytical column eluted with a mobile phase of phosphate (pH = 3)-acetonitrile in 25 min linear gradient mode. Solutes are detected by tandem diode array/derivatization/fluorescence detection. The system is controlled and monitored by a single computer operated with Millenium software. Recoveries of most analytes in samples fortified at 1 microgram/L are > 90%, with relative standard deviation values of < 5%. For a few very polar analytes, mostly N-methylcarbamoyloximes (i.e., aldicarb sulfone, methomyl, and oxamyl), recoveries are < 20%. However, for these compounds, as well as for the rest of the N-methylcarbamates except for aldicarb sulfoxide and butoxycarboxim, the limits of detection (LODs) are 0.005-0.05 microgram/L. LODs for aldicarb sulfoxide and butoxycarboxim are 0.2 and 0.1 microgram, respectively. LODs for the rest of the analytes except 4-nitrophenol, bentazone, captan, decamethrin, and MCPA are 0.05-0.1 microgram/L. LODs for the latter compounds are 0.2-1.0 microgram/L. The system can be operated unattended. PMID:10444834

  3. On-line solid phase extraction-high performance liquid chromatography–isotope dilution–tandem mass spectrometry approach to quantify N,N-diethyl-m-toluamide and oxidative metabolites in urine

    Energy Technology Data Exchange (ETDEWEB)

    Kuklenyik, Peter; Baker, Samuel E.; Bishop, Amanda M.; Morales-A, Pilar; Calafat, Antonia M., E-mail: aic7@cdc.gov

    2013-07-17

    Graphical abstract: -- Highlights: •A fast assay to quantify the concentrations of N,N-Diethyl-m-Toluamide and two urinary metabolites was developed •It uses online SPE, reversed phase HPLC and tandem mass spectrometry •The method is precise and accurate with limits of detection ≤1 ng mL{sup −1} -- Abstract: Human exposure to N,N-diethyl-m-toluamide (DEET) occurs because of the widespread use of DEET as an active ingredient in insect repellents. However, information on the extent of such exposure is rather limited. Therefore, we developed a fast on-line solid phase extraction–high performance liquid chromatography–isotope dilution tandem mass spectrometry (HPLC-MS/MS) method to measure in urine the concentrations of DEET and two of its oxidative metabolites: N,N-diethyl-3-(hydroxymethyl)benzamide and 3-(diethylcarbamoyl)benzoic acid (DCBA). To the best of our knowledge, this is the first HPLC-MS/MS method for the simultaneous quantification of DEET and its select metabolites in human urine. After enzymatic hydrolysis of the conjugated species in 0.1 mL of urine, the target analytes were retained and pre-concentrated on a monolithic column, separated from each other and from other urinary biomolecules on a reversed-phase analytical column, and detected by atmospheric pressure chemical ionization in positive ion mode. The limits of detection ranged from 0.1 ng mL{sup −1} to 1.0 ng mL{sup −1}, depending on the analyte. Accuracy ranged between 90.4 and 104.9%, and precision ranged between 5.5 and 13.1% RSD, depending on the analyte and the concentration. We tested the usefulness of this method by analyzing 75 urine samples collected anonymously in the Southeastern United States in June 2012 from adults with no known exposure to DEET. Thirty eight samples (51%) tested positive for at least one of the analytes. We detected DCBA most frequently and at the highest concentrations. Our results suggest that this method can be used for the analysis of a large

  4. On-line solid phase extraction-high performance liquid chromatography–isotope dilution–tandem mass spectrometry approach to quantify N,N-diethyl-m-toluamide and oxidative metabolites in urine

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •A fast assay to quantify the concentrations of N,N-Diethyl-m-Toluamide and two urinary metabolites was developed •It uses online SPE, reversed phase HPLC and tandem mass spectrometry •The method is precise and accurate with limits of detection ≤1 ng mL−1 -- Abstract: Human exposure to N,N-diethyl-m-toluamide (DEET) occurs because of the widespread use of DEET as an active ingredient in insect repellents. However, information on the extent of such exposure is rather limited. Therefore, we developed a fast on-line solid phase extraction–high performance liquid chromatography–isotope dilution tandem mass spectrometry (HPLC-MS/MS) method to measure in urine the concentrations of DEET and two of its oxidative metabolites: N,N-diethyl-3-(hydroxymethyl)benzamide and 3-(diethylcarbamoyl)benzoic acid (DCBA). To the best of our knowledge, this is the first HPLC-MS/MS method for the simultaneous quantification of DEET and its select metabolites in human urine. After enzymatic hydrolysis of the conjugated species in 0.1 mL of urine, the target analytes were retained and pre-concentrated on a monolithic column, separated from each other and from other urinary biomolecules on a reversed-phase analytical column, and detected by atmospheric pressure chemical ionization in positive ion mode. The limits of detection ranged from 0.1 ng mL−1 to 1.0 ng mL−1, depending on the analyte. Accuracy ranged between 90.4 and 104.9%, and precision ranged between 5.5 and 13.1% RSD, depending on the analyte and the concentration. We tested the usefulness of this method by analyzing 75 urine samples collected anonymously in the Southeastern United States in June 2012 from adults with no known exposure to DEET. Thirty eight samples (51%) tested positive for at least one of the analytes. We detected DCBA most frequently and at the highest concentrations. Our results suggest that this method can be used for the analysis of a large number of samples

  5. An automated flow injection system for metal determination by flame atomic absorption spectrometry involving on-line fabric disk sorptive extraction technique.

    Science.gov (United States)

    Anthemidis, A; Kazantzi, V; Samanidou, V; Kabir, A; Furton, K G

    2016-08-15

    A novel flow injection-fabric disk sorptive extraction (FI-FDSE) system was developed for automated determination of trace metals. The platform was based on a minicolumn packed with sol-gel coated fabric media in the form of disks, incorporated into an on-line solid-phase extraction system, coupled with flame atomic absorption spectrometry (FAAS). This configuration provides minor backpressure, resulting in high loading flow rates and shorter analytical cycles. The potentials of this technique were demonstrated for trace lead and cadmium determination in environmental water samples. The applicability of different sol-gel coated FPSE media was investigated. The on-line formed complex of metal with ammonium pyrrolidine dithiocarbamate (APDC) was retained onto the fabric surface and methyl isobutyl ketone (MIBK) was used to elute the analytes prior to atomization. For 90s preconcentration time, enrichment factors of 140 and 38 and detection limits (3σ) of 1.8 and 0.4μgL(-1) were achieved for lead and cadmium determination, respectively, with a sampling frequency of 30h(-1). The accuracy of the proposed method was estimated by analyzing standard reference materials and spiked water samples. PMID:27260436

  6. Automated flow-injection method for cadmium determination with pre-concentration and reagent preparation on-line

    Directory of Open Access Journals (Sweden)

    María S. Di Nezio

    2005-02-01

    Full Text Available The spectrophotometric determination of Cd(II using a flow injection system provided with a solid-phase reactor for cadmium preconcentration and on-line reagent preparation, is described. It is based on the formation of a dithizone-Cd complex in basic medium. The calibration curve is linear between 6 and 300 µg L-1 Cd(II, with a detection limit of 5.4 µg L-1, an RSD of 3.7% (10 replicates in duplicate and a sample frequency of 11.4 h-1. The proposed method was satisfactorily applied to the determination of Cd(II in surface, well and drinking waters.

  7. Automated flow-injection method for cadmium determination with pre-concentration and reagent preparation on-line

    OpenAIRE

    María S. Di Nezio; Miriam E. Palomeque; Fernández Band, Beatriz S.

    2005-01-01

    The spectrophotometric determination of Cd(II) using a flow injection system provided with a solid-phase reactor for cadmium preconcentration and on-line reagent preparation, is described. It is based on the formation of a dithizone-Cd complex in basic medium. The calibration curve is linear between 6 and 300 µg L-1 Cd(II), with a detection limit of 5.4 µg L-1, an RSD of 3.7% (10 replicates in duplicate) and a sample frequency of 11.4 h-1. The proposed method was satisfactorily ap...

  8. Enantioselective determination of methylphenidate and ritalinic acid in whole blood from forensic cases using automated solid-phase extraction and liquid chromatography-tandem mass spectrometry

    DEFF Research Database (Denmark)

    Thomsen, Ragnar; B. Rasmussen, Henrik; Linnet, Kristian;

    2012-01-01

    by solid-phase extraction. The LC–MS-MS method was linear in the range of 0.5 to 500 ng/g for the enantiomers of both analytes. For concentrations above the limit of quantification, coefficients of variation were 15% or less, and the accuracy was 89 to 94%. For 12 postmortem samples in which...... methylphenidate was not determined to be related to the cause of death, the femoral blood concentration of d-methylphenidate ranged from 5 to 58 ng/g, and from undetected to 48 ng/g for l-methylphenidate (median d/l-ratio 5.9). Ritalinic acid was present at concentrations 10–20 times higher with roughly equal...

  9. Solid phase transformations

    CERN Document Server

    Čermák, J

    2008-01-01

    This special-topic book, devoted to ""Solid Phase Transformations"" , covers a broad range of phenomena which are of importance in a number of technological processes. Most commercial alloys undergo thermal treatment after casting, with the aim of imparting desired compositions and/or optimal morphologies to the component phases. In spite of the fact that the topic has lain at the center of physical metallurgy for a long time, there are numerous aspects which are wide open to potential investigative breakthroughs. Materials with new structures also stimulate research in the field, as well as n

  10. Solid phase transformations II

    CERN Document Server

    Čermák, J

    2009-01-01

    This topical volume includes ten invited papers that cover selected areas of the field of solid phase transformations. The first two contributions represent a burgeoning branch; that of the computer simulation of physical phenomena. The following three articles deal with the thermodynamics of phase transformations as a basic theory for describing the phenomenology of phase changes in matter. The next paper describes the interconnections between structural stability and the electronic structure of phases. Two further articles are devoted to displacive transformations; a field where there are ma

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

    Energy Technology Data Exchange (ETDEWEB)

    Tan, H.

    1999-03-31

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

  12. Performance of an automated solid-phase red cell adherence system compared with that of a manual gel microcolumn assay for the identification of antibodies eluted from red blood cells.

    Science.gov (United States)

    Finck, R H; Davis, R J; Teng, S; Goldfinger, D; Ziman, A F; Lu, Q; Yuan, S

    2011-01-01

    IgG antibodies coating red blood cells (RBCs) can be removed by elution procedures and their specificity determined by antibody identification studies. Although such testing is traditionally performed using the tube agglutination assay, prior studies have shown that the gel microcolumn (GMC) assay may also be used with comparable results. The purpose of this study was to compare an automated solid-phase red cell adherence (SPRCA) system with a GMC assay for the detection of antibodies eluted from RBCs. Acid eluates from 51 peripheral blood (PB) and 7 cord blood (CB) samples were evaluated by both an automated SPRCA instrument and a manual GMC assay. The concordance rate between the two systems for peripheral RBC samples was 88.2 percent (45 of 51), including cases with alloantibodies (n = 8), warm autoantibodies (n = 12), antibodies with no identifiable specificity (n = 2), and negative results (n = 23). There were six discordant cases, of which four had alloantibodies (including anti-Jka, -E, and -e) demonstrable by the SPRCA system only. In the remaining 2 cases, anti-Fya and antibodies with no identifiable specificity were demonstrable by the GMC assay only. All seven CB specimens produced concordant results, showing anti-A (n = 3), -B (n = 1), maternal anti-Jka (n = 2), or a negative result (n = 1). Automated SPRCA technology has a performance that is comparable with that of a manual GMC assay for identifying antibodies eluted from PB and CB RBCs.

  13. Recent developments in automatic solid-phase extraction with renewable surfaces exploiting flow-based approaches

    DEFF Research Database (Denmark)

    Miró, Manuel; Hartwell, Supaporn Kradtap; Jakmunee, Jaroon;

    2008-01-01

    Solid-phase extraction (SPE) is the most versatile sample-processing method for removal of interfering species and/or analyte enrichment. Although significant advances have been made over the past two decades in automating the entire analytical protocol involving SPE via flow-injection approaches......,on-line SPE assays performed in permanent mode lack sufficient reliability as a consequence of progressively tighter packing of the bead reactor, contamination of the solid surfaces and potential leakage of functional moieties. This article overviews the current state-of-the-art of an appealing tool...

  14. A fully automated method for simultaneous determination of aflatoxins and ochratoxin A in dried fruits by pressurized liquid extraction and online solid-phase extraction cleanup coupled to ultra-high-pressure liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Campone, Luca; Piccinelli, Anna Lisa; Celano, Rita; Russo, Mariateresa; Valdés, Alberto; Ibáñez, Clara; Rastrelli, Luca

    2015-04-01

    According to current demands and future perspectives in food safety, this study reports a fast and fully automated analytical method for the simultaneous analysis of the mycotoxins with high toxicity and wide spread, aflatoxins (AFs) and ochratoxin A (OTA) in dried fruits, a high-risk foodstuff. The method is based on pressurized liquid extraction (PLE), with aqueous methanol (30%) at 110 °C, of the slurried dried fruit and online solid-phase extraction (online SPE) cleanup of the PLE extracts with a C18 cartridge. The purified sample was directly analysed by ultra-high-pressure liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) for sensitive and selective determination of AFs and OTA. The proposed analytical procedure was validated for different dried fruits (vine fruit, fig and apricot), providing method detection and quantification limits much lower than the AFs and OTA maximum levels imposed by EU regulation in dried fruit for direct human consumption. Also, recoveries (83-103%) and repeatability (RSD < 8, n = 3) meet the performance criteria required by EU regulation for the determination of the levels of mycotoxins in foodstuffs. The main advantage of the proposed method is full automation of the whole analytical procedure that reduces the time and cost of the analysis, sample manipulation and solvent consumption, enabling high-throughput analysis and highly accurate and precise results.

  15. Automated headspace-solid-phase micro extraction-retention time locked-isotope dilution gas chromatography-mass spectrometry for the analysis of organotin compounds in water and sediment samples.

    Science.gov (United States)

    Devosa, Christophe; Vliegen, Maarten; Willaert, Bart; David, Frank; Moens, Luc; Sandra, Pat

    2005-06-24

    An automated method for the simultaneous determination of six important organotin compounds namely monobutyltin (MBT), dibutyltin (DBT), tributyltin (TBT), monophenyltin (MPhT), diphenyltin (DPhT) and triphenyltin (TPhT) in water and sediment samples is described. The method is based on derivatization with sodium tetraethylborate followed by automated headspace-solid-phase micro extraction (SPME) combined with GC-MS under retention time locked (RTL) conditions. Home-synthesized deuterated organotin analogues were used as internal standards. Two high abundant fragment ions corresponding to the main tin isotopes Sn118 and Sn120 were chosen; one for quantification and one as qualifier ion. The method was validated and excellent figures of merit were obtained. Limits of quantification (LOQs) are from 1.3 to 15 ng l(-1) (ppt) for water samples and from 1.0 to 6.3 microg kg(-1) (ppb) for sediment samples. Accuracy for sediment samples was tested on spiked real-life sediment samples and on a reference PACS-2 marine harbor sediment. The developed method was used in a case-study at the harbor of Antwerp where sediment samples in different areas were taken and subsequently screened for TBT contamination. Concentrations ranged from 15 microg kg(-1) in the port of Antwerp up to 43 mg kg(-1) near a ship repair unit. PMID:16038329

  16. Quantification of five compounds with heterogeneous physicochemical properties (morphine, 6-monoacetylmorphine, cyamemazine, meprobamate and caffeine) in 11 fluids and tissues, using automated solid-phase extraction and gas chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Bévalot, Fabien; Bottinelli, Charline; Cartiser, Nathalie; Fanton, Laurent; Guitton, Jérôme

    2014-06-01

    An automated solid-phase extraction (SPE) protocol followed by gas chromatography coupled with tandem mass spectrometry was developed for quantification of caffeine, cyamemazine, meprobamate, morphine and 6-monoacetylmorphine (6-MAM) in 11 biological matrices [blood, urine, bile, vitreous humor, liver, kidney, lung and skeletal muscle, brain, adipose tissue and bone marrow (BM)]. The assay was validated for linearity, within- and between-day precision and accuracy, limits of quantification, selectivity, extraction recovery (ER), sample dilution and autosampler stability on BM. For the other matrices, partial validation was performed (limits of quantification, linearity, within-day precision, accuracy, selectivity and ER). The lower limits of quantification were 12.5 ng/mL(ng/g) for 6-MAM, morphine and cyamemazine, 100 ng/mL(ng/g) for meprobamate and 50 ng/mL(ng/g) for caffeine. Analysis of real-case samples demonstrated the performance of the assay in forensic toxicology to investigate challenging cases in which, for example, blood is not available or in which analysis in alternative matrices could be relevant. The SPE protocol was also assessed as an extraction procedure that could target other relevant analytes of interest. The extraction procedure was applied to 12 molecules of forensic interest with various physicochemical properties (alimemazine, alprazolam, amitriptyline, citalopram, cocaine, diazepam, levomepromazine, nordazepam, tramadol, venlafaxine, pentobarbital and phenobarbital). All drugs were able to be detected at therapeutic concentrations in blood and in the alternate matrices. PMID:24790060

  17. Analysis of biogenic carbonates by inductively coupled plasma-mass spectrometry (ICP-MS). Flow injection on-line solid-phase preconcentration for trace element determination in fish otoliths.

    Science.gov (United States)

    Arslan, Z; Paulson, A J

    2002-04-01

    The aragonite deposits within the ear bones (otoliths) of teleost fish retain a chemical signal reflecting the life history of fish (similar to rings of trees) and the nature of fish habitats. Otoliths dissolved in acid solutions contain high concentrations of calcium and a variety of proteins. Elimination of matrix salts and organic interferences during preconcentration is essential for accurate determination of trace elements in otolith solutions by inductively coupled plasma-quadrupole mass spectrometry. An iminodiacetate-based chelating resin (Toyopearl AF-Chelate 650 M) has been used for on-line preconcentration and matrix separation for the determination of 31 transition and rare elements. Successful preconcentration of the elements was achieved at pH 5 by on-line buffering, except Mn which required pH 8.8. Sample solutions were loaded on to the column for 1 min at 3.2 mL min(-1), and then eluted directly into the mass spectrometer with 4% v/v nitric acid. This procedure enabled up to 25-fold preconcentration with successful removal of the calcium matrix. The effect of heat-assisted oxidation with concentrated nitric acid was investigated to eliminate the organic matrix. It was found that heating to dryness after dissolution and further mineralization with the acid significantly improved the retention of the transition elements. The method was validated by analysis of a certified reference material produced from saggittal otoliths of emperor snapper ( Lutjanus sebae), and then applied to the determination of trace metal concentrations in juvenile bluefin tuna ( Thunnus thynnus) from the Western Pacific Ocean.

  18. Analysis of biogenic carbonates by inductively coupled plasma-mass spectrometry (ICP-MS). Flow injection on-line solid-phase preconcentration for trace element determination in fish otoliths

    Energy Technology Data Exchange (ETDEWEB)

    Arslan, Z.; Paulson, A.J. [National Oceanic and Atmospheric Administration (NOAA), Northeast Fisheries Science Center (NFSC), James J. Howard Marine Sciences Laboratory, Highlands, NJ (United States)

    2002-04-01

    The aragonite deposits within the ear bones (otoliths) of teleost fish retain a chemical signal reflecting the life history of fish (similar to rings of trees) and the nature of fish habitats. Otoliths dissolved in acid solutions contain high concentrations of calcium and a variety of proteins. Elimination of matrix salts and organic interferences during preconcentration is essential for accurate determination of trace elements in otolith solutions by inductively coupled plasma-quadrupole mass spectrometry. An iminodiacetate-based chelating resin (Toyopearl AF-Chelate 650 M) has been used for on-line preconcentration and matrix separation for the determination of 31 transition and rare elements. Successful preconcentration of the elements was achieved at pH 5 by on-line buffering, except Mn which required pH 8.8. Sample solutions were loaded on to the column for 1 min at 3.2 mL min{sup -1}, and then eluted directly into the mass spectrometer with 4% v/v nitric acid. This procedure enabled up to 25-fold preconcentration with successful removal of the calcium matrix. The effect of heat-assisted oxidation with concentrated nitric acid was investigated to eliminate the organic matrix. It was found that heating to dryness after dissolution and further mineralization with the acid significantly improved the retention of the transition elements. The method was validated by analysis of a certified reference material produced from saggittal otoliths of emperor snapper (Lutjanus sebae), and then applied to the determination of trace metal concentrations in juvenile bluefin tuna (Thunnus thynnus) from the Western Pacific Ocean. (orig.)

  19. Fast Analysis of Vitamin A and E in Animal Derived Foods by On-Line Solid Phase Extraction Coupled with High Performance Liquid Chromatography%在线固相萃取-高效液相色谱联用测定动物源食品中的维生素A、E

    Institute of Scientific and Technical Information of China (English)

    谢云峰; 王浩; 刘佟; 任丹丹; 杨永坛

    2014-01-01

    采用固相萃取与双梯度高效液相色谱联用技术,建立了一种在线固相萃取-高效液相色谱同时测定动物源食品中维生素A、E的分析方法。样品于80℃下皂化反应30 min,经离心沉淀后引入一维C8固相萃取柱,采用60%( V/V)甲醇溶液对目标物进行在线富集净化,然后通过阀切换将其转移至二维液相分析系统进行分离检测。考察了萃取填料、上样溶剂及洗脱条件对猪肝、鸡蛋和配方乳粉的维生素A、E富集和基质净化效果。结果表明,在优化条件下,方法线性范围为0.02~20 mg/L,线性相关系数R2≥0.9998,对维生素A、E的检出限(S/N=3)为3.0~30.0μg/L,实际样品加标回收率为87.3%~115.0%,相对标准偏差(RSD)为1.8%~4.6%。本方法操作简便,灵敏度高,可用于动物源食品中维生素A、E的快速测定。%An automated analytical method for simultaneous determination of vitamin A and E in livers, fortified infant formulae and eggs has been developed based on on-line solid phase extraction (SPE) coupled with a dual gradient high performance liquid chromatography system with column-switching. Firstly, food samples were centrifuged after saponified in mixture solution of anhydrous alcohol, potassium hydroxide and ascorbic acid at 80 ℃ for 30 min. Secondly, the saponified sample was loaded and washed on the first dimension extraction column using methanol-water (60∶40, V/V). Afterwards, the targeted analytes were trapped and enriched on the SPE column. Finally, the trapped analytes were transferred to the second dimension analysis column by valve-switching technique for the following separation and determination. Several key factors such as the type of SPE columns, elution buffer as well as pH of washing solution were optimized. The results showed that the calibration curves of vitamin A and E were linear in the range of 0 . 02-20 mg/L with correlation coefficient (R2) more than 0. 9998. In addition, the limits of detection

  20. Solid-Phase Random Glycosylation

    DEFF Research Database (Denmark)

    Agoston, K.; Kröger, Lars; Dekany, Gyula;

    2009-01-01

    Two different approaches were employed to study solid phase random glycosylations to obtain oligosaccharide libraries. In approach I, Wang resin esters were attached to the acceptors structures. Following their glycosylation and resin cleavage, the peracetylated components of the oligosaccharide...

  1. One year of ICTP diploma courses on-line using the automated EyA recording system

    International Nuclear Information System (INIS)

    The 12-month pre-Ph.D ICTP Diploma Courses in the fields of Condensed Matter Physics, High Energy Physics, Mathematics, Earth System Physics and Basics Physics have been recorded using the automated, low cost recording system called EyA developed in-house. We discuss the technical details on how these recordings were implemented, together with some web usage statistics and students feedback. As yet, no similar endeavor has been made to put on-line a complete high-level Diploma Programme, due to the high costs involved when using alternative recording solutions. These recordings are freely available on the website www.ictp.tv. (author)

  2. Towards On-line Automated Semantic Scoring of English-Chinese Translation

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Described and exemplified a semantic scoring system of students' on-line English-Chinese translation.To achieve accurate assessment, the system adopted a comprehensive method which combines semantic scoring with keyword matching scoring. Four kinds of words-verbs, adjectives, adverbs and "the rest" including nouns, pronouns, idioms, prepositions, etc. , are identified after parsing. The system treats different words tagged with different part of speech differently. Then it calculated the semantic similarity between these words of the standard versions and those of students'translations by the distinctive differences of the semantic features of these words with the aid of HowNet. The first semantic feature of verbs and the last semantic features of adjectives and adverbs are calculated. "The rest" is scored by keyword matching. The experiment results show that the semantic scoring system is applicable in fulfilling the task of scoring students'on-line English-Chinese translations.

  3. Quantitative determination of wine highly volatile sulfur compounds by using automated headspace solid-phase microextraction and gas chromatography-pulsed flame photometric detection. Critical study and optimization of a new procedure.

    Science.gov (United States)

    López, Ricardo; Lapeña, Ana Cristina; Cacho, Juan; Ferreira, Vicente

    2007-03-01

    The quantitative determination of wine volatile sulfur compounds by automated headspace solid-phase microextraction (HS-SPME) with a carboxen-polydimethylsiloxane (CAR-PDMS) fiber and subsequent gas chromatography-pulsed flame photometric detection (GC-PFPD) has been evaluated. The direct extraction of the sulfur compounds in 5 ml of wine has been found to suffer from matrix effects and short linear ranges, problems which could not be solved by the use of different internal standards or by multiple headspace SPME. These problems were attributed to saturation of the fiber and to competitive effects between analytes, internal standards and other wine volatiles. Another problem was the oxidation of analytes during the procedure. The reduction in sample volume by a factor 50 (0.1 ml diluted with water or brine) brought about a reduction in the amount of sulfur compounds taken in the fiber by a factor just 3.3. Consequently, a new procedure has been proposed. In a sealed vial containing 4.9 ml of saturated NaCl brine, the air is thoroughly displaced with nitrogen, and the wine (0.1 ml) and the internal standards (0.02 ml) are further introduced with a syringe through the vial septum. This sample is extracted at 35 degrees C for 20 min. This procedure makes a satisfactory determination possible of hydrogen sulfide, methanethiol, ethanethiol, dimethyl sulfide, diethyl sulfide and dimethyl disulfide. The linear dynamic ranges cover the normal ranges of occurrence of these analytes in wine with typical r2 between 0.9823 and 0.9980. Reproducibility in real samples ranges from 10 to 20% and repeatability is better than 10% in most cases. The method accuracy is satisfactory, with errors below 20% for hydrogen sulfide and mostly below 10% for the other compounds. The proposed method has been applied to the analysis of 34 Spanish wines.

  4. Solid-phase techniques in blood transfusion serology.

    Science.gov (United States)

    Beck, M L; Plapp, F V; Sinor, L T; Rachel, J M

    1986-01-01

    For nearly a century, erythrocyte agglutination has persisted as the most widely used method for the demonstration of antigen-antibody reaction in immunohematology. So far, no other system has been developed which can match its simplicity, versatility, and general reliability. The major disadvantage of agglutination reactions is the lack of an objective endpoint, which has severely hindered attempts to automate routine pretransfusion tests. To overcome this problem, we have designed a series of solid-phase assays for ABO and Rh grouping, antibody screening, compatibility, and hepatitis tests. Each of these solid-phase assays shares a common endpoint of red cell adherence, which is easily interpreted visually or spectrophotometrically. Computer interface permits the automatic interpretation and recording of results. We believe this solid-phase system should finally bring the blood bank laboratory into the age of automation.

  5. TOPS On-Line: Automating the Construction and Maintenance of HTML Pages

    Science.gov (United States)

    Jones, Kennie H.

    1994-01-01

    After the Technology Opportunities Showcase (TOPS), in October, 1993, Langley Research Center's (LaRC) Information Systems Division (ISD) accepted the challenge to preserve the investment in information assembled in the TOPS exhibits by establishing a data base. Following the lead of several people at LaRC and others around the world, the HyperText Transport Protocol (HTTP) server and Mosaic were the obvious tools of choice for implementation. Initially, some TOPS exhibitors began the conventional approach of constructing HyperText Markup Language (HTML) pages of their exhibits as input to Mosaic. Considering the number of pages to construct, a better approach was conceived that would automate the construction of pages. This approach allowed completion of the data base construction in a shorter period of time using fewer resources than would have been possible with the conventional approach. It also provided flexibility for the maintenance and enhancement of the data base. Since that time, this approach has been used to automate construction of other HTML data bases. Through these experiences, it is concluded that the most effective use of the HTTP/Mosaic technology will require better tools and techniques for creating, maintaining and managing the HTML pages. The development and use of these tools and techniques are the subject of this document.

  6. SOLID PHASE SYNTHESIS OF ISOXAZOLINES

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin isreported. 2-Polystyrylsuifonamidoethanol resin 1 was reacted with acryloyl chloride to afford2-polystyrylsulfonylamidoethyl acrylate resin 2, which was further reacted with brominatedaldoximes by [3+2] cycioaddition to give isoxazoline resin 4. Resin 4 was treated with aqueous 6mol/L HCI solution to obtain isoxazolines in good yield and purity.

  7. Solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Jensen, Knud Jørgen

    2013-01-01

    This chapter provides an introduction to and overview of peptide chemistry with a focus on solid-phase peptide synthesis. The background, the most common reagents, and some mechanisms are presented. This chapter also points to the different chapters and puts them into perspective....

  8. Demonstration of an automated on-line surveillance system at a commercial nuclear power plant

    International Nuclear Information System (INIS)

    As a first step in demonstrating the practicality of performing continuous on-line surveillance of the performance of nuclear steam supply systems using noise related techniques, Oak Ridge National Laboratory is operating a computerized noise signal data acquisition and processing system at the Sequoyah Unit 1 Nuclear Plant, an 1148 MWe four-loop Westinghouse pressurized water reactor (PWR) located near Chattanooga, Tennessee. The principal objective is to establish, with a degree of continuity and completeness not previously achieved, the long-term characteristics of signals from neutron detectors and process sensors in order to evaluate the feasibility of detecting and diagnosing anomalous reactor conditions by means of changes in these signals. The system is designed to automatically screen the gathered data, using a number of descriptors derived from the power spectra of the monitored signals, and thereby select for the noise analyst's perusal only those data which differ statistically from norms which the system has previously established

  9. Implementation of automated, on-line fatigue monitoring in a boiling water reactor

    International Nuclear Information System (INIS)

    A workstation-based, on-line fatigue monitoring system for tracking fatigue usage applied to a Japanese operating boiling water reactor (BWR), Tsuruga Unit 1, is described. The system uses the influence function approach and rainflow cycle counting methodology, operates on a workstation computer, and determines component stresses using temperature, pressure, and flow rate data that are made available via signal taps from previously existing plant sensors. Using plant-unique influence functions developed specifically for the feedwater nozzle location, the system calculates stresses as a function of time and computes the fatigue usage. The analysis method used to compute fatigue usage complies with MITI Code Notification number-sign 501. Fatigue values are saved automatically on files at times defined by the user for use at a later time. Of particular note, this paper describes some of the details involved with implementing such a system from the utility perspective. Utility installation details, as well as why such a system was chosen for implementation are presented. Fatigue results for an entire fuel cycle are presented and compared to assumed design basis events to confirm that actual plant thermal duty is significantly less severe than originally estimated in the design basis stress report. Although the system is specifically set up to address fatigue duty for the feedwater nozzle location, a generic shell structure was implemented so that any other components could be added at a future time without software modifications. As a result, the system provides the technical basis to more accurately evaluate actual reactor conditions as well as the justification for plant life extension

  10. SOLID PHASE SYNTHESIS OF ISOXAZOLINES

    Institute of Scientific and Technical Information of China (English)

    SUNWeimin; LUOJuntao; 等

    2002-01-01

    The solid-phase synthesis of isoxazolines on 2-polystyrylsulfonamidoethanol resin is reported.2-Polystyrylsulfonamidoethanol resin 1 was reacted with acryloyl chloride to afford 2-polystyrylsulfonylamidoethyl acrylate resin 2,which was further reacted with brominated aldoximes by [3+2] cycloaddition to give isoxazoline resin 4.Resin 4 was treated with aqueous 6 mol/L HCl solution to obtain isoxazolines in good yield and purity.

  11. Determination of Biogenic Amines in Cheese by On-line Solid Phase Extraction Coupled with Capillary High Performance Liquid Chromatography%在线固相萃取-毛细管高效液相色谱联用测定奶酪中的生物胺

    Institute of Scientific and Technical Information of China (English)

    杨姗姗; 杨亚楠; 李雪霖; 张燕

    2016-01-01

    An on-line solid phase extraction coupled with capillary HPLC method was established for the simultaneous determination of fifteen kinds of biologic amines in cheese. The biogenic amines were concentrated on the solid phase extraction column, and transferred by the six-way valve to analytical column for separation and detection. Separation conditions on capillary HPLC, composition of on-line SPE mobile phase, pH of the sample solution and switching time of six-way switching valve were investigated to get better separation conditions of 15 biogenic amines. Optimum on-line SPE conditions including 5% of the acetonitrile-water as mobile phase for SPE column, pH=11 of the sample solution and 3 min of valve switching time were employed in the analytical method. The linear range of standard curve for fifteen biogenic amines was 0. 25-50. 0 mg/L;LOD were within the range of 0. 05-0. 25 mg/L. At spiked levels of 1, 20, 40 mg/kg, the recoveries of fifteen biogenic amines on four kinds of cheese ranged from 79 . 6% to 118 . 7% except methylamine, ethylamine, 3-methylbutanamine and 5-hydroxytryptamine; with RSDs from 0. 3% to 14. 9%except 3-methylbutanamine and 5-hydroxy-tryptamine. The method is accurate and reliable, and can be used to detect biogenic amines in cheese.%采用双二元泵毛细管液相色谱,通过六通阀实现了样品的在线净化与分离定量的自动切换,建立了同时测定奶酪中的15种生物胺的在线固相萃取-毛细管高效液相色谱联用方法。通过优化毛细管高效液相色谱的分离条件,考察在线固相萃取流动相的组成、上样溶液pH值以及六通阀的切换时间对生物胺回收率的影响,确定最佳分析条件为:5%乙腈-水作为固萃柱(Zorbax SB-C18)的流动相,上样溶液pH=11,上样3 min后切换六通阀。采用内标法定量,15种生物胺标准曲线的线性范围为0.25~50.0 mg/L,检出限( LOD)为0.05~0.25 mg/L,定量限(LOQ)为0.15~0.80 mg/L。除了甲胺、乙胺、3-

  12. 管内固相微萃取-气相色谱法在线联用技术用于水样中的痕量分析%On-Line Coupling of In-Tube Solid Phase Microextraction to Capillary Gas Chromatography for Trace Analysis of Aqueous Samples

    Institute of Scientific and Technical Information of China (English)

    关亚风; 王涵文; 刘文民

    2004-01-01

    Since the development of solid phase microextraction ( SPME ) method, many modifications have been made to improve the availability and application of the technique The in-tube SPME (ITSPME) was emerged and employed in high performance liquid chromatography (HPLC)

  13. 在线固相萃取-超高效液相色谱-串联质谱法测定乳制品中双酚A等4种内分泌干扰物%Determination of 4 Environmental Endocrine Disruptors Involving Bisphenol A in Dairy Products by On-line Solid Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    张品; 张晶; 陈洁君; 段鹤君; 邵兵

    2014-01-01

    A simple analytical method by means of on-line solid phase extraction followed liquid chromatography-tandem mass spectrometry ( SPE-LC-MS/MS) was developed for the simultaneous quantitation of 4 endocrine disruptors ( triclosan, triclocarban, bisphenol A and nonylphenol) in dairy products. Infant formula and milk samples were dissolved in acetic acid buffer and hydrolyzed by β-glucuronidase/arylsulfatase. Acetonitrile was used as the extract. Then, the mixture was freeze-centrifuged for 10 min and the supernatant was diluted with water, and analyzed via on-line SPE-LC-MS/MS. The sample extracts were concentrated by an Xbridge C8 cartridge and separated on a BEH C18 column with a gradient mobile phase of methanol and water; then analyzed by triple quadrupole mass spectrometry. Mass acquisition was conducted under negative electrospray ionization mode. Quantification was performed by isotopic internal standard calibration. Acceptable linearity (R2>0. 99) was achieved over the range of 0. 005-5. 0 μg/L, with limits of quantification of 0. 03-1. 0μg/kg. Average recoveries of four target compounds (spiked at three concentration levels) ranged from 80. 2%-106. 7%,with relative standard deviation less than 15%. Due to its rapidity, simplicity, and high sensitivity, the method is suitable for the analysis of endocrine disruptors in dairy products. It has been applied in the analysis of raw milk and milk products collected in Beijing. As a result, nonylphenol was found with a high detectable frequency.%建立了乳制品中三氯生、三氯卡班、双酚A和壬基酚4种内分泌干扰物的在线固相萃取超高压液相色谱-串联质谱(On-line SPE LC-MS/MS)检测方法。液态乳制品或奶粉样品中加入乙酸缓冲液,目标物经β-葡糖醛酸苷肽酶/芳基磺酸酯酶酶解后,用乙腈提取,冷冻离心10 min后,取上清液,用水稀释,在线固相萃取串联质谱法测定。样品溶液经Xbridge C8柱富集,BEH C18色谱柱分离,甲醇和

  14. 在线固相萃取-二维液相色谱串联质谱法测定人脑脊液中替考拉宁浓度%Determination of Teicoplanin in Human Cerebrospinal Fluid Using an On-line Solid Phase Extraction-Two Dimensional Liquid Chromatography-Tandem Mass Spactrometry

    Institute of Scientific and Technical Information of China (English)

    左利民; 姚静; 王强; 周洁; 冯梦雪; 山广志

    2014-01-01

    A method of on-line solid phase extraction ( SPE )-two dimensional liquid chromatography electrospary-tandem mass spectrometric method was established for the determination of Teicoplanin concentrations in human cerebrospinal fluid. Cerebrospinal fluid samples were treated by the on-line SPE treatment, and analyzed by LC-MS/MS. The chromatographic separation was performed on a Shiseido CAPCALL-PAK C18 column with gradient elution by using 25 mmol/L ammonium acetate ( pH 6. 0 )-acetonitrile as mobile phases, and the flow rate of 1 mL/min. Detection was carried out under the selected reaction monitoring ( SRM) in positive ionization mode with scopolamine hydrobromide as internal standard. Matrix-matched calibration curves with good correlation coefficients (R2=0. 9993, n=6) were obtained in the concentration range of 25-5000 μg/L. The average recoveries varied from 100. 8% to 109. 9%. The intra-and inter-day precisions were less than 6%. The method is proved to be rapid, sensitive, accurate, and suitable to determine Teicoplanin concentrations in human cerebrospinal fluid.%建立测定人脑脊液中替考拉宁浓度的在线固相萃取-二维液相色谱-串联质谱( SPE-2DLC-MS/MS)法。脑脊液样品经在线固相萃取处理后,通过阀切换二维色谱技术,转载至Shiseido CAPCALL-PAK C18分析柱上进行分离,以25mmol/L乙酸铵(pH 6.0)-乙腈为流动相梯度洗脱,流速1.0 mL/min。采用电喷雾离子源( ESI),以选择反应监测( SRM)方式进行正离子检测,采用氢溴酸东莨菪碱为内标,对脑脊液样本中替考拉宁浓度进行定量检测。本方法中替考拉宁浓度在25~5000μg/L的范围内线性关系良好(R2=0.9993,n=6);日间和日内精密度RSD均小于6%,低中高3个浓度的回收率在100.8%~109.9%之间。结果表明,本方法的选择性好,线性、精密度、准确度和灵敏度高,可用于临床监测替考拉宁浓度。

  15. Evaluation of different lactation curve models fitted for milk viscosity recorded by an automated on-line California Mastitis Test.

    Science.gov (United States)

    Neitzel, Anne-Christin; Stamer, Eckhard; Junge, Wolfgang; Thaller, Georg

    2015-05-01

    Laboratory somatic cell count (LSCC) records are usually recorded monthly and provide an important information source for breeding and herd management. Daily milk viscosity detection in composite milking (expressed as drain time) with an automated on-line California Mastitis Test (CMT) could serve immediately as an early predictor of udder diseases and might be used as a selection criterion to improve udder health. The aim of the present study was to clarify the relationship between the well-established LSCS and the new trait,'drain time', and to estimate their correlations to important production traits. Data were recorded on the dairy research farm Karkendamm in Germany. Viscosity sensors were installed on every fourth milking stall in the rotary parlour to measure daily drain time records. Weekly LSCC and milk composition data were available. Two data sets were created containing records of 187,692 milkings from 320 cows (D1) and 25,887 drain time records from 311 cows (D2). Different fixed effect models, describing the log-transformed drain time (logDT), were fitted to achieve applicable models for further analysis. Lactation curves were modelled with standard parametric functions (Ali and Schaeffer, Legendre polynomials of second and third degree) of days in milk (DIM). Random regression models were further applied to estimate the correlations between cow effects between logDT and LSCS with further important production traits. LogDT and LSCS were strongest correlated in mid-lactation (r = 0.78). Correlations between logDT and production traits were low to medium. Highest correlations were reached in late lactation between logDT and milk yield (r = -0.31), between logDT and protein content (r = 0.30) and in early as well as in late lactation between logDT and lactose content (r = -0.28). The results of the present study show that the drain time could be used as a new trait for daily mastitis control. PMID:25731191

  16. Solid phase sequencing of biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Cantor, Charles (Del Mar, CA); Koster, Hubert (La Jolla, CA)

    2010-09-28

    This invention relates to methods for detecting and sequencing target nucleic acid sequences, to mass modified nucleic acid probes and arrays of probes useful in these methods, and to kits and systems which contain these probes. Useful methods involve hybridizing the nucleic acids or nucleic acids which represent complementary or homologous sequences of the target to an array of nucleic acid probes. These probes comprise a single-stranded portion, an optional double-stranded portion and a variable sequence within the single-stranded portion. The molecular weights of the hybridized nucleic acids of the set can be determined by mass spectroscopy, and the sequence of the target determined from the molecular weights of the fragments. Nucleic acids whose sequences can be determined include DNA or RNA in biological samples such as patient biopsies and environmental samples. Probes may be fixed to a solid support such as a hybridization chip to facilitate automated molecular weight analysis and identification of the target sequence.

  17. Solid phase sequencing of biopolymers

    Energy Technology Data Exchange (ETDEWEB)

    Cantor, Charles R.; Hubert, Koster

    2014-06-24

    This invention relates to methods for detecting and sequencing target nucleic acid sequences, to mass modified nucleic acid probes and arrays of probes useful in these methods, and to kits and systems which contain these probes. Useful methods involve hybridizing the nucleic acids or nucleic acids which represent complementary or homologous sequences of the target to an array of nucleic acid probes. These probes comprise a single-stranded portion, an optional double-stranded portion and a variable sequence within the single-stranded portion. The molecular weights of the hybridized nucleic acids of the set can be determined by mass spectroscopy, and the sequence of the target determined from the molecular weights of the fragments. Probes may be affixed to a solid support such as a hybridization chip to facilitate automated molecular weight analysis and identification of the target sequence.

  18. Development of an automated sequential injection on-line solvent extraction-back extraction procedure as demonstrated for the determination of cadmium with detection by electrothermal atomic absorption spectrometry

    DEFF Research Database (Denmark)

    Wang, Jianhua; Hansen, Elo Harald

    2002-01-01

    An automated sequential injection (SI) on-line solvent extraction-back extraction separation/preconcentration procedure is described. Demonstrated for the assay of cadmium by electrothermal atomic absorption spectrometry (ETAAS), the analyte is initially complexed with ammonium...

  19. Automation of beta spectra photometry on the base of the on-line microphotometer with pitch driver of a carriage

    International Nuclear Information System (INIS)

    To process spectrograms obtained by means of beta spectrographs an automatic photometric device has been developed which has two-axis stepped-motor carriage drives and operates on-line with a computer. Data from this device is applied to the computer in the data addition mode as a result of multiple runs of the carriage. Along with two-line scanning this allows a great decrease in the photometry time. The device uses the FEU-92 photomultiplier operating at great light fluxes. The device permits processing 80x400 mm spectrograms at a minimum scanning step of 1000/240 μm or at a step multiple to the minimum one: nx1000/240 μm, where n=1,2,...64. The device can be controlled both by a separate control device (in manual or automatic modes) and by a computer

  20. Automatic reactor for solid-phase synthesis of molecularly imprinted polymeric nanoparticles (MIP NPs) in water

    OpenAIRE

    Poma, Alessandro; Guerreiro, Antonio; Caygill, Sarah; Moczko, Ewa; Piletsky, Sergey

    2014-01-01

    We report the development of an automated chemical reactor for solid-phase synthesis of MIP NPs in water. Operational parameters are under computer control, requiring minimal operator intervention. In this study, “ready for use” MIP NPs with sub-nanomolar affinity are prepared against pepsin A, trypsin and α-amylase in only 4 hours.

  1. Towards automated on-line adaptation of 2-Step IMRT plans: QUASIMODO phantom and prostate cancer cases

    International Nuclear Information System (INIS)

    the geometry of the day using the relocated isocenter, MU transfer from the planning geometry; 2) Adaptation of the widths of S2 segments to the geometry of the day; 3) Imitation of DMPO fine-tuning for the geometry of the day. We have performed automated 2-Step IMRT adaptation for ten prostate adaptation cases. The adapted plans show statistically significant improvement of the target coverage and of the rectum sparing compared to those plans in which only the isocenter is relocated. The 2-Step IMRT method may become a core of the automated adaptive radiation therapy system at our department

  2. Automated on-line liquid-liquid extraction system for temporal mass spectrometric analysis of dynamic samples.

    Science.gov (United States)

    Hsieh, Kai-Ta; Liu, Pei-Han; Urban, Pawel L

    2015-09-24

    Most real samples cannot directly be infused to mass spectrometers because they could contaminate delicate parts of ion source and guides, or cause ion suppression. Conventional sample preparation procedures limit temporal resolution of analysis. We have developed an automated liquid-liquid extraction system that enables unsupervised repetitive treatment of dynamic samples and instantaneous analysis by mass spectrometry (MS). It incorporates inexpensive open-source microcontroller boards (Arduino and Netduino) to guide the extraction and analysis process. Duration of every extraction cycle is 17 min. The system enables monitoring of dynamic processes over many hours. The extracts are automatically transferred to the ion source incorporating a Venturi pump. Operation of the device has been characterized (repeatability, RSD = 15%, n = 20; concentration range for ibuprofen, 0.053-2.000 mM; LOD for ibuprofen, ∼0.005 mM; including extraction and detection). To exemplify its usefulness in real-world applications, we implemented this device in chemical profiling of pharmaceutical formulation dissolution process. Temporal dissolution profiles of commercial ibuprofen and acetaminophen tablets were recorded during 10 h. The extraction-MS datasets were fitted with exponential functions to characterize the rates of release of the main and auxiliary ingredients (e.g. ibuprofen, k = 0.43 ± 0.01 h(-1)). The electronic control unit of this system interacts with the operator via touch screen, internet, voice, and short text messages sent to the mobile phone, which is helpful when launching long-term (e.g. overnight) measurements. Due to these interactive features, the platform brings the concept of the Internet-of-Things (IoT) to the chemistry laboratory environment. PMID:26423626

  3. Solid Phase Red Cell Adherence Assay: a tubeless method for pretransfusion testing and other applications in transfusion science.

    Science.gov (United States)

    Ching, Eric

    2012-06-01

    Solid Phase Red Cell Adherence Assay (SPRCA) is one of the two tubeless methods developed to improve sensitivity and specificity in blood group serology. The SPRCA (solid phase) and the column agglutination (gel) technology have gained wide acceptance following successful adaptation to fully automated platforms, The purpose of this paper is to discuss the development, principle, procedures as well as laboratory and clinical applications of the SPRCA in transfusion medicine.

  4. Determination of 18 Organic Phosphorus and Pyrthroid Pesticides in Dried Vegetables using Solid-phase Extraction and On-line Gel Permeation Chromatography-GC/MS%固相萃取-在线凝胶渗透色谱-气相色谱质谱联用测定蔬菜干制品中的18种有机磷和拟除虫菊酯残留

    Institute of Scientific and Technical Information of China (English)

    薛丽; 钟艳梅

    2012-01-01

    建立了蔬菜干制品中18种有机磷农药和拟除虫菊酯农药残留的在线凝胶渗透色谱-气相色谱/质谱(GPC-GC/MS)分析方法.样品以乙腈为提取剂超声波高速匀浆提取,提取液经ENVI-Carb固相萃取柱净化,除去样品中大部分的色素等干扰基质,再经在线GPC进一步净化除去大分子干扰物质,有效降低了样品基质带来的背景干扰.采用外标法定量,在质量浓度为0.02 mg/kg~0.5mg/kg有良好的线性关系,加标水平为0.4 mg/kg时,18种农药的回收率基本都在80%~130%,相对标准偏差小于10%,检出限为0.001mg/kg~0.026 mg/kg.经实验证明,该方法是一种快速,准确,灵敏度高的同时检测梅菜干中多种农药残留的检测方法.%An on-line gel permeation chromatography-GC/MS analytical method was developed for the determination of 18 organic phosphorus pesticide and pyrethroid pesticides in dried vegetables.The samples were extracted with acetonitrile by means of ultrasonic high-speed homogenization, cleaned up by an ENVI-Carb solid phase extraction column to remove pigment in the sample and analyzed by on-line gel permeation chromatography-GC/MS. All the compounds demonstrated good linear relationship in the range of 0.02-0.5 mg/kg. The recoveries for the most of pestive standards of 0.4 mg/kg were 80%-130% and the relative standard deviations were less than 10%. The limits of detection were from 0.001 mg/kg to 0.026 mg/kg. The method was rapid, accurate and highly sensitive, which can be used for the simultaneous determination of pesticide residues in dried vegetables.

  5. Simultaneous Determination of 5 Antidepressants in Blood by Automated Solid Phase Extraction and Liquid Chrommatography-Tandem Mass Spectrometry%自动固相萃取-液相色谱-串联质谱法同时测定血液中5种抗抑郁类药物

    Institute of Scientific and Technical Information of China (English)

    郭璟琦; 石银涛; 王绘军; 张盼; 郑经; 王俊伟

    2014-01-01

    建立了血液中5种抗抑郁类药物的自动固相萃取-液相色谱-串联质谱( ASPE-LC-MS/MS)分析方法。样品经HLB固相萃取柱提取后,采用LC-MS/MS进行测定,外标法定量。在Waters AtlantisTM dC18反相柱上分离,梯度洗脱,流动相为甲醇-0.1%甲酸(1:4, V/V)溶液,质谱采集为电喷雾正离子多反应监测模式。采用基质匹配标准溶液校正,5种目标物在1~500μg/L范围内具有良好的线性关系,相关系数( R)大于0.9975,检出限在0.1~0.6μg/L之间;添加浓度水平为10,100和500μg/L时,方法回收率为70.6%~93.8%,相对标准偏差在3.9%~9.2%之间。本方法可用于血液中5种抗抑郁类药物的法庭与临床毒物分析。%An efficient and accurate analytical method was developed for the simultaneous determination of 5 antidepressants in blood, by automated solid phase extraction-liquid chromatography tandem mass spectrometry ( ASPE-LC-MS/MS) . The samples were cleaned up by HLB solid phase extraction cartridge, and the analyses were carried out on LC-MS/MS. The chromatographic separation was performed on a Waters AtlantisTM dC18 column with gradient elution by using methanol and formic acid in water as mobile phases. Detection was carried out under the multiple reaction monitoring ( MRM) in positive ionization mode. Matrix-matched calibration curves with good correlation coefficients ( R>0 . 9975 ) were obtained in the concentration range of 1-500 μg/L. The detection limits of the method were 0. 1-0. 6 μg/L. The mean recoveries at the three spiked levels of 10-500 μg/L were 70 . 6%-93 . 8%, and the relative standard deviations were 3 . 9%-9. 2%. The method is applicable to analyze antidepressants in forensic and clinical toxicology.

  6. [Solid phase techniques in blood group serology].

    Science.gov (United States)

    Uthemann, H; Sturmfels, L; Lenhard, V

    1993-06-01

    As alternatives to hemagglutination, solid-phase red blood cell adherence assays are of increasing importance. The adaptation of the new techniques to microplates offers several advantages over hemagglutination. Using microplates the assays may be processed semiautomatically, and the results can be read spectrophotometrically and interpreted by a personal computer. In this paper, different red blood cell adherence assays for AB0 grouping, Rh typing, Rh phenotyping, antibody screening and identification, as well as crossmatching will be described.

  7. DNA Extraction: Organic and Solid-Phase.

    Science.gov (United States)

    Altayari, Wafa

    2016-01-01

    DNA extraction remains a critical step in DNA profiling of biological material recovered from scenes of crime. In the forensic community several methods have gained popularity, including Chelex(®), organic extraction, and solid-phase extraction. While some laboratories streamlined their processes and only use one method we have retained several methods and continue to use these for different sample types. In this chapter we present three methods that have been used for several years in our laboratory. PMID:27259731

  8. Solid-phase fluoroimmunoassay for treponemal antibody.

    OpenAIRE

    Stevens, R W; Schell, R F

    1982-01-01

    An objective, solid-phase fluoroimmunoassay for treponemal antibody was developed with a lysate of virulent Treponema pallidum (Nichols strain) adsorbed on cellulose acetate disks. A probe containing both the antigen and control disks is inserted successively into a serum specimen dilution, a buffer rinse, fluoroscein isothiocyanate-conjugated goat anti-human immunoglobulin G, and a second buffer rinse. Fluorescence signal units are measured with a fluorometer. To establish test calibration c...

  9. Quantitative Determination of ABT-925 in Human Plasma by On-Line SPE and LC-MS/MS: Validation and Sample Analysis in Phase II Studies

    OpenAIRE

    Katty Wan; Matthew Rieser; Tawakol El-Shourbagy

    2010-01-01

    A fully automated 96-well On-Line Solid Phase Extraction (SPE) followed by High Performance Liquid Chromatography (HPLC)-Tandem Mass Spectrometric (MS/MS) method for the determination of ABT-925 (2-{3-[4-(2-tert-Butyl-6-trifluoromethyl-pyrimidin-4-yl)-piperazin-1-yl)-propyl-sulfanyl}-3H-pyrimidin-4-one fumarate) in human plasma was developed, validated and utilized in Phase II clinical studies. 50 µL of plasma sample was fortified with internal standard (IS, d8-ABT-925) and extracted on-line ...

  10. Innovative combination of QuEChERS extraction with on-line solid-phase extract purification and pre-concentration, followed by liquid chromatography-tandem mass spectrometry for the determination of non-steroidal anti-inflammatory drugs and their metabolites in sewage sludge.

    Science.gov (United States)

    Rossini, D; Ciofi, L; Ancillotti, C; Checchini, L; Bruzzoniti, M C; Rivoira, L; Fibbi, D; Orlandini, S; Del Bubba, M

    2016-09-01

    For the first time QuEChERS extraction of sewage sludge was combined with the automatic solid-phase pre-concentration and purification of the extract (following indicated as SPE) and LC-MS/MS analysis, for the determination of the non-steroidal anti-inflammatory drugs acetylsalicylic acid (ASA), diclofenac (DIC), fenbufen (FEN), flurbiprofen (FLU), ketoprofen (KET), ibuprofen (IBU) and naproxen (NAP), and their metabolites salicylic acid (SAL), 4'-hydroxydiclofenac (4'-HYDIC), 1-hydroxyibuprofen (1-HYIBU), 2-hydroxyibuprofen (2-HYIBU), 3-hydroxyibuprofen (3-HYIBU) and o-desmethylnaproxen (O-DMNAP). Various commercial pellicular stationary phases (i.e. silica gel functionalized with octadecyl, biphenyl, phenylhexyl and pentafluorophenyl groups) were preliminarily investigated for the resolution of target analytes and different sorbent phases (i.e. octyl or octadecyl functionalized silica gel and a polymeric phase functionalized with N-benzylpyrrolidone groups) were tested for the SPE phase. The optimized method involves the QuEChERS extraction of 1 g of freeze-dried sludge with 15 mL of water/acetonitrile 1/2 (v/v), the SPE of the extract with the N-benzylpyrrolidone polymeric phase and the water/acetonitrile gradient elution on the pentafluorophenyl stationary phase at room temperature. Matrix effect was always suppressive and in most cases low, being it ≤20% for ASA, DIC, FLU, KET, IBU, 1-HYIBU, 2-HYIBU, 3-HYIBU, NAP and O-DMNAP, and included in the range of 35-47% for the other analytes. Recoveries were evaluated at three spiking levels, evidencing almost quantitative values for HYIBUs and O-DMNAP; for ASA, SAL and KET the recoveries were included in between 50 and 76%, whereas for the other compounds they ranged from 36% to 55%. The proposed method showed better analytical performances than those so far published, being suitable for target compound determination in real samples from tens of pg g(-1) to ng g(-1) of freeze-dried sludge, with a total analysis

  11. Automated Solid-Phase Radiofluorination Using Polymer-Supported Phosphazenes

    DEFF Research Database (Denmark)

    Mathiessen, Bente; Zhuravlev, Fedor

    2013-01-01

    The polymer supported phosphazene bases PS-P2tBu and the novel PS-P2PEG allowed for efficient extraction of [18F]F− from proton irradiated [18O]H2O and subsequent radiofluorination of a broad range of substrates directly on the resin. The highest radiochemical yields were obtained with aliphatic...

  12. Modification of guanine bases by nucleoside phosphoramidite reagents during the solid phase synthesis of oligonucleotides.

    OpenAIRE

    Pon, R T; Damha, M J; Ogilvie, K K

    1985-01-01

    Nucleoside 3'-phosphoramidite and chlorophosphite reagents have been found to react with the lactam function of guanine. This reaction caused unsatisfactory results when oligodeoxyribonucleotides containing a large number of guanine bases were prepared in an automated solid phase synthesizer. The guanine modification is unstable, and leads to depurination and chain cleavage. This side reaction can be eliminated by protecting the O6-position. A new O6-p-nitrophenylethyldeoxyguanosine phosphora...

  13. Solid phase microextraction device using aerogel

    Science.gov (United States)

    Miller, Fred S.; Andresen, Brian D.

    2005-06-14

    A sample collection substrate of aerogel and/or xerogel materials bound to a support structure is used as a solid phase microextraction (SPME) device. The xerogels and aerogels may be organic or inorganic and doped with metals or other compounds to target specific chemical analytes. The support structure is typically formed of a glass fiber or a metal wire (stainless steel or kovar). The devices are made by applying gel solution to the support structures and drying the solution to form aerogel or xerogel. Aerogel particles may be attached to the wet layer before drying to increase sample collection surface area. These devices are robust, stable in fields of high radiation, and highly effective at collecting gas and liquid samples while maintaining superior mechanical and thermal stability during routine use. Aerogel SPME devices are advantageous for use in GC/MS analyses due to their lack of interfering background and tolerance of GC thermal cycling.

  14. Generic solid phase extraction-liquid chromatography-tandem mass spectrometry method for fast determination of drugs in biological fluids

    NARCIS (Netherlands)

    Schellen, A.; Ooms, B.; Lagemaat, D. van de; Vreeken, R.; Dongen, W.D. van

    2003-01-01

    A generic method was developed for the fast determination of a wide range of drugs in serum or plasma. The methodology comprises generic solid-phase extraction, on-line coupled to gradient HPLC with tandem mass spectrometric detection (SPE-LC-MS/MS). The individual components of the SPE-LC-MS/MS sys

  15. On-line distillation and solid phase extraction preconcentration of volatile phenolic compounds in water samples with detection by spectrophotometry%水中挥发酚的在线蒸馏-固相萃取分离富集及测定

    Institute of Scientific and Technical Information of China (English)

    陈明丽; 胡海珠; 王建华; 王静; 霍玉美

    2011-01-01

    A novel sequential injection on-line distillation procedure for volatile phenolic compounds is developed. The derivative between phenol and 4-aminoantipyrine (4-APP) is adsorbed onto an Amberlite XAD-7 resin packed mini-column. The phenol-4-APP derivative retained on the mini-column is effectively recovered by using a small amount of ethanol followed by spectromphotometric detection. The present procedure is suitable for the direct determination of volatile phenolic compounds at mg/L levels. It can also be used for the quantification of much lower concentration of volatile phenolic compounds at ug/L level after preconcentration with a larger sample volume. With the sample loading volume of 4 mL, a linear range of 0.004-0.3 mg/L is obtained along with a detection limit is 0.002 mg/L. A relative standard deviation of 1.4% (? = 9) is achieved at 0.1 mg/L. The procedure is applied to the determination of low level of volatile phenolic compounds in water samples and spiking recoveries within 96%-102% are achieved.%在顺序注射系统中实现了挥发酚的快速自动在线蒸馏,并用Amberlite XAD-7树脂微填充柱对其与4-氨基安替比林的衍生物在线固相萃取,被富集的衍生物可用少量乙醇有效地洗脱回收,以分光光度法检测.方法可用于较高浓度挥发酚(mg/L)样品的测定,也可根据需要适当增大进样体积,经富集后实现更低浓度水平(μg/L)挥发酚的测定.当富集过程中进样体积为4mL时,方法测定挥发酚的线性范围为0.004~0.3 mg/L,检出限为0,002 mg/L,相对标准偏差为1.4%(0.1 mg/L,n=9).对多种实际水样中的挥发酚进行了测定,加标回收实验的回收率在96%~102%之间.

  16. 在线固相萃取-超高效液相色谱-串联质谱法测定乳制品中双酚A等4种内分泌干扰物%Determination of 4 Environmental Endocrine Disruptors Involving Bisphenol A in Dairy Products by On-line Solid Phase Extraction Coupled with Liquid Chromatography-Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    张品; 张晶; 陈洁君; 段鹤君; 邵兵

    2014-01-01

    建立了乳制品中三氯生、三氯卡班、双酚A和壬基酚4种内分泌干扰物的在线固相萃取超高压液相色谱-串联质谱(On-line SPE LC-MS/MS)检测方法。液态乳制品或奶粉样品中加入乙酸缓冲液,目标物经β-葡糖醛酸苷肽酶/芳基磺酸酯酶酶解后,用乙腈提取,冷冻离心10 min后,取上清液,用水稀释,在线固相萃取串联质谱法测定。样品溶液经Xbridge C8柱富集,BEH C18色谱柱分离,甲醇和水梯度洗脱,三重四极杆质谱电喷雾负离子模式下采集数据,同位素内标法定量。4种目标化合物的线性范围为0.005~5.0μg/L,相关系数R2>0.99;方法的定量限为0.03~1.0μg/kg,3个添加水平的平均加标回收率为80.2%~106.7%, RSD0. 99) was achieved over the range of 0. 005-5. 0 μg/L, with limits of quantification of 0. 03-1. 0μg/kg. Average recoveries of four target compounds (spiked at three concentration levels) ranged from 80. 2%-106. 7%,with relative standard deviation less than 15%. Due to its rapidity, simplicity, and high sensitivity, the method is suitable for the analysis of endocrine disruptors in dairy products. It has been applied in the analysis of raw milk and milk products collected in Beijing. As a result, nonylphenol was found with a high detectable frequency.

  17. Recent Developments and Applications of Solid Phase Microextraction (SPME in Food and Environmental Analysis—A Review

    Directory of Open Access Journals (Sweden)

    Sybille Merkle

    2015-06-01

    Full Text Available Solid-phase microextraction (SPME is a simple, sensitive, rapid and solvent-free technique for the extraction of analytes from gaseous, liquid and solid samples and takes a leading position among microextraction methods. Application of SPME in sample preparation has been increasing continuously over the last decade. It is most often used as an automatized fiber injection system coupled to chromatographic separation modules for the extraction of volatile and semivolatile organic compounds and also allows for the trace analysis of compounds in complex matrices. Since SPME was first introduced in the early 1990s, several modifications have been made to adapt the procedure to specific application requirements. More robust fiber assemblies and coatings with higher extraction efficiencies, selectivity and stability have been commercialized. Automation and on-line coupling to analytical instruments have been achieved in many applications and new derivatization strategies as well as improved calibration procedures have been developed to overcome existing limitations regarding quantitation. Furthermore, devices using tubes, needles or tips for extraction instead of a fiber have been designed. In the field of food analysis, SPME has been most often applied to fruit/vegetables, fats/oils, wine, meat products, dairy and beverages whereas environmental applications focus on the analysis of air, water, soil and sediment samples.

  18. Stable solid-phase Rh antigen.

    Science.gov (United States)

    Yared, M A; Moise, K J; Rodkey, L S

    1997-12-01

    Numerous investigators have attempted to isolate the Rh antigens in a stable, immunologically reactive form since the discovery of the Rh system over 56 years ago. We report here a successful and reproducible approach to solubilizing and adsorbing the human Rh antigen(s) to a solid-phase matrix in an antigenically active form. Similar results were obtained with rabbit A/D/F red blood cell antigens. The antigen preparation was made by dissolution of the red blood cell membrane lipid followed by fragmentation of the residual cytoskeleton in an EDTA solution at low ionic strength. The antigenic activity of the soluble preparations was labile in standard buffers but was stable in zwitterionic buffers for extended periods of time. Further studies showed that the antigenic activity of these preparations was enhanced, as was their affinity for plastic surfaces, in the presence of acidic zwitterionic buffers. Adherence to plastic surfaces at low pH maintained antigenic reactivity and specificity for antibody was retained. The data show that this approach yields a stable form of antigenically active human Rh D antigen that could be used in a red blood cell-free assay for quantitative analysis of Rh D antibody and for Rh D antibody immunoadsorption and purification.

  19. Combinatorial Solid-Phase Synthesis of Balanol Analogues

    DEFF Research Database (Denmark)

    Nielsen, John; Lyngsø, Lars Ole

    1996-01-01

    The natural product balanol has served as a template for the design and synthesis of a combinatorial library using solid-phase chemistry. Using a retrosynthetic analysis, the structural analogues have been assembled from three relatively accessible building blocks. The solid-phase chemistry inclu...

  20. 自动固相萃取-高效液相色谱串联质谱法测定生活污水中13种抗精神病药物%Simultaneous Determination of 13 Psychiatric Pharmaceuticals in Sewage by Automated Solid Phase Extraction and Liquid Chromatography-Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    袁圣柳; 李晓锋; 姜晓满; 张海霞; 郑少奎

    2013-01-01

    A method has been developed for the determination of 13 psychiatric pharmaceuticals in wastewater by automated solid phase extraction-high performance liquid chromatography coupled with electrospray ioniza-tion tandem mass spectrometry (ASPE-HPLC-ESI-MS/MS) in positive ion mode and multiple reactions monitoring ( MRM). The ASPE extracts were further purified using an amino SPE cartridge prior to HPLC analysis. HPLC separation was performed on an Waters X-bridge C18 column utilizing a gradient elution program of the organic mixture ( acetonitrile : methanol =50:50 (V/V)) and ammonium formate buffer solution (containing 0. 2% formic acid, and adjusted to pH 3. 5 with ammonium hydroxide) as the mobile phase. Recoveries of all analytes from matrix spiking experiments in the sewage WWTP's influent and effluent at three concentrations ranged from 93. 2% to 106. 8% . The matrix effects were 77. 3% -98. 6% except that for citalopram. Method detection limits for 4, 4 and 5 analytes in the sewage WWTP's influent and effluent were <1. 5, 4-12 ng/L and 20 - 80 ng/L, respectively. Based on this method, 11 psychiatric pharmaceuticals were detected in 35 wastewater samples from sewage WWTPs except clonazepam and fluvoxamine.%建立了自动固相萃取-高效液相色谱-电喷雾串联三重四级杆质谱(ASPE-HPLC-ESI-MS/MS)联用技术分析生活污水中13种抗精神病药物的方法.样品经ASPE提取和氨基柱净化后,采用Waters X-bridgeC18色谱柱,流动相有机部分为甲醇-乙腈(50∶50,V/V)混合溶液,水溶液部分为0.2%甲酸溶液(用氨水调至pH 3.5),梯度洗脱后,电喷雾离子源电离,在正离子多反应监测模式(MRM)下定性和定量分析抗精神病药物.经过固相萃取和氢基柱净化后,除西酞普兰(Citalopram,CIT)外,其它12种药物基质效应为77.3%~98.6%;检测方法回收率为932% ~ 106.8%;苯海索(Trihexyphenidyl)、卡马西平(Carbamazepine)、西酞普兰

  1. Automated on-line column-switching high performance liquid chromatography isotope dilution tandem mass spectrometry method for the quantification of bisphenol A, bisphenol F, bisphenol S, and 11 other phenols in urine.

    Science.gov (United States)

    Zhou, Xiaoliu; Kramer, Joshua P; Calafat, Antonia M; Ye, Xiaoyun

    2014-01-01

    Human exposure to bisphenol A (BPA) is widespread. However, in recent years, bisphenol analogs such as bisphenol S (BPS) and bisphenol F (BPF) are replacing BPA in the production of some consumer products. Because human exposure to these alternative bisphenols may occur, biomonitoring of these bisphenol analogs is warranted. In the present study, we developed and validated a sensitive and selective method that uses on-line solid phase extraction coupled to high performance liquid chromatography-isotope dilution tandem mass spectrometry with peak focusing to measure BPA, BPF, BPS, and 11 other environmental phenols in urine. The method required a small amount of sample (100μL) and minimal sample pretreatment. The limits of detection were 0.03ng/mL (BPS), 0.06ng/mL (BPF), 0.10ng/mL (BPA), and ranged from 0.1ng/mL to 1.0ng/mL for the other 11 phenols. In 100 urine samples collected in 2009-2012 from a convenience group of anonymous adults in the United States, of the three bisphenols, we detected BPA at the highest frequency and median concentrations (95%, 0.72ng/mL), followed by BPS (78%, 0.13ng/mL) and BPF (55%, 0.08ng/mL). This sensitive, rugged, and labor and cost-effective method could be used for the analysis of large number of samples for epidemiologic studies.

  2. Diccionarios on line

    OpenAIRE

    de Moya Anegón, Félix; Muñoz, J. M.; Hipola, Pedro

    1986-01-01

    Son conocidas las prestaciones de los diccionarios "on line " en tanto que herramientas para el análisis a automatico de documentación textual, l a elaboración de productos de indización, para la traducción asistida por ordenador (TAO) y para la preparación de léxicos especializados. Como útiles del análisis automático, los diccionarios pueden constituir, en primer lugar, instrumentos para automatizar los procesos de reducción de las diferentes formas lingüísticas flexion...

  3. Chromatographic Separations Using Solid-Phase Extraction Cartridges: Separation of Wine Phenolics

    Science.gov (United States)

    Brenneman, Charles A.; Ebeler, Susan E.

    1999-12-01

    We describe a simple laboratory experiment that demonstrates the principles of chromatographic separation using solid-phase extraction columns and red wine. By adjusting pH and mobile phase composition, the wine is separated into three fractions of differing polarity. The content of each fraction can be monitored by UV-vis spectroscopy. When the experiment is combined with experiments involving HPLC or GC separations, students gain a greater appreciation for and understanding of the highly automated instrumental systems currently available. In addition, they learn about the chemistry of polyphenolic compounds, which are present in many foods and beverages and which are receiving much attention for their potentially beneficial health effects.

  4. Recent developments in automated determinations of trace level concentrations of elements and on-line fractionations schemes exploiting the micro-sequential injection - lab-on-valve approach

    DEFF Research Database (Denmark)

    Hansen, Elo Harald; Miró, Manuel; Long, Xiangbao;

    2006-01-01

    are presented as based on the exploitation of micro-sequential injection (μSI-LOV) using hydrophobic as well as hydrophilic bead materials. The examples given comprise the presentation of a universal approach for SPE-assays, front-end speciation of Cr(III) and Cr(VI) in a fully automated and enclosed set...

  5. Controlador automático On Line en la Planta de separación de Ni y Co en clonación artificial

    OpenAIRE

    Moner Antonio Muñoz; Alonso Guevara; Javier Ballesteros

    2007-01-01

    El trabajo muestra los resultados de la investigación sobre el desarrollo de sistemas de medición y control avanzados para la Planta de Separación de Ni y Co, basado en la clonación artificial de un sensor de composición química on line y el control inteligente de los parámetros asociados al transductor-analizador.

  6. Design and implementation of an automated liquid-phase microextraction-chip system coupled on-line with high performance liquid chromatography

    DEFF Research Database (Denmark)

    Li, Bin; Petersen, Nickolaj J.; Payán, María D Ramos;

    2014-01-01

    An automated liquid-phase microextraction (LPME) device in a chip format has been developed and coupled directly to high performance liquid chromatography (HPLC). A 10-port 2-position switching valve was used to hyphenate the LPME-chip with the HPLC autosampler, and to collect the extracted....... The composition of the supported liquid membrane (SLM) and carrier was optimized in order to achieve reasonable extraction performance of all the five alkaloids. With 1-octanol as SLM solvent and with 25mM sodium octanoate as anionic carrier, extraction recoveries for the different opium alkaloids ranged between...... analytes, which then were delivered to the HPLC column. The LPME-chip-HPLC system was completely automated and controlled by the software of the HPLC instrument. The performance of this system was demonstrated with five alkaloids i.e. morphine, codeine, thebaine, papaverine, and noscapine as model analytes...

  7. Automation of plasma-process fultext bibliography databases. An on-line data-collection, data-mining and data-input system

    International Nuclear Information System (INIS)

    Searching for relevant data, information retrieval, data extraction and data input are time- and resource-consuming activities in most data centers. Here we develop a Linux system automating the process in case of bibliography, abstract and fulltext databases. The present system is an open-source free-software low-cost solution that connects the target and provider databases in cyberspace through various web publishing formats. The abstract/fulltext relevance assessment is interfaced to external software modules. (author)

  8. The Integration of On-Line Monitoring and Reconfiguration Functions using EDAA - European design and Automation Association1149.4 Into a Safety Critical Automotive Electronic Control Unit

    CERN Document Server

    Jeffrey, C; Prosser, S; Lickess, M; Richardson, A; Riches, S

    2011-01-01

    This paper presents an innovative application of EDAA - European design and Automation Association 1149.4 and the Integrated Diagnostic Reconfiguration (IDR) as tools for the implementation of an embedded test solution for an Automotive Electronic Control Unit implemented as a fully integrated mixed signal system. The paper described how the test architecture can be used for fault avoidance with results from a hardware prototype presented. The paper concludes that fault avoidance can be integrated into mixed signal electronic systems to handle key failure modes.

  9. Manual of process automation. On-line control systems for devices in the process technology. 3. tot. rev. and enl. ed.; Handbuch der Prozessautomatisierung. Prozessleittechnik fuer verfahrenstechnische Anlagen

    Energy Technology Data Exchange (ETDEWEB)

    Maier, U.; Frueh, K.F. (eds.)

    2004-07-01

    This is a reference manual for engineers who need answers to automation problems in chemical engineering. Some new current subjects have been introduced to complement the information. The following chapters are new or have been rewritten by new authors: Internet and intranet technologies; Outline of process-related functions; Control systems in industrial applications; Problems and solutions; Model-based predicative control (MPC); Report archive analysis; Control Loop Performance Monitoring (CPM); Automation structures; Explosion protection; Remote-I/O; Integration of intelligent field equipment in PLS; Weighing and filling techniques; Safety; Maintenance - structures and strategies. The other chapters have been revised and updated as well. (orig.) [German] Das grundsaetzliche Konzept des Handbuchs ist unveraendert: Es dient als Nachschlagewerk fuer Ingenieure, die sich in verschiedenen Taetigkeitsbereichen mit Fragen der Automatisierung verfahrenstechnischer Anlagen auseinandersetzen muessen. Einige Themen wurden neu aufgenommen - wegen ihrer Aktualitaet und zur Abrundung des Themenspektrums. Folgende Kapitel sind voellig neu oder mit neuen Autoren wesentlich erweitert: Internet-/Intranettechnologien; Uebersicht ueber prozessnahe Funktionen; Industrielle Regelung: Probleme und Problemloesungen; Modellgestuetzte praediktive Regelung (MPC); Meldearchivanalyse; Control Loop Performance Monitoring (CPM); Automatisierungsstrukturen; Explosionsschutz; Remote-I/O; Integration intelligenter Feldgeraete in PLS; Waege- und Abfuelltechnik; Anlagensicherheit; Ganzheitliche Instandhaltung - Strukturen und Strategien. Die uebrigen Kapitel wurden aktualisiert und teilweise auch wesentlich ueberarbeitet. (orig.)

  10. SOLID PHASE TRANSITION OF SYNDIOTACTIC POLYSTYRENE IN SUPERCRITICAL CO2

    Institute of Scientific and Technical Information of China (English)

    Yu-ying Li; Jia-song He

    2002-01-01

    Solid phase transition of the a form crystals to the β form crystals in syndiotactic polystyrene (sPS) samples has occurred in supercritical CO2. This transformation is different from those detected under other conditions. The effects of some factors (e.g. time, temperature, and pressure) on the solid phase transformation of sPS in supercritical CO2 were analyzed in detail. Experimental results show that longer time, higher temperature or higher pressure favors the transformation of the α form crystals to the β form crystals.

  11. Magnetic Solid Phase Extraction Applied to Food Analysis

    Directory of Open Access Journals (Sweden)

    Israel S. Ibarra

    2015-01-01

    Full Text Available Magnetic solid phase extraction has been used as pretreatment technique for the analysis of several compounds because of its advantages when it is compared with classic methods. This methodology is based on the use of magnetic solids as adsorbents for preconcentration of different analytes from complex matrices. Magnetic solid phase extraction minimizes the use of additional steps such as precipitation, centrifugation, and filtration which decreases the manipulation of the sample. In this review, we describe the main procedures used for synthesis, characterization, and application of this pretreatment technique which were applied in food analysis.

  12. Diagnostic immunoassay by solid phase separation for digoxin

    Energy Technology Data Exchange (ETDEWEB)

    Grenier, F.C.; Pry, T.A.; Kolaczkowski, L.

    1988-11-29

    A method is described for conducting a diagnostic immunoassay for digoxin, comprising: (a) forming a reaction mixture of a test sample with a molar excess of labeled anti-digoxin antibodies whereby the labeled antibodies are capable of forming complex with digoxin present in the sample; (b) contacting the reaction mixture with a solid phase material having immobilized thereon a compound; (c) separating the solid phase material from the reaction mixture; and (d) determining the presence of digoxin in the test sample by measuring the amount of complex present in the liquid phase.

  13. LC-UV-solid-phase extraction-NMR-MS combined with a cryogenic flow probe and its application to the identification of compounds present in Greek oregano

    NARCIS (Netherlands)

    Exarchou, V.; Godejohann, M.; Beek, van T.A.; Gerothanassis, I.P.; Vervoort, J.J.M.

    2003-01-01

    Structure elucidation of natural products usually relies on a combination of NMR spectroscopy with mass spectrometry whereby NMR trails MS in terms of the minimum sample amount required. In the present study, the usefulness of on-line solid-phase extraction (SPE) in LC-NMR for peak storage after the

  14. Acquisition of data from on-line laser turbidimeter and calculation of some kinetic variables in computer-coupled automated fed-batch culture

    International Nuclear Information System (INIS)

    Output signals of a commercially available on-line laser turbidimeter exhibit fluctuations due to air and/or CO2 bubbles. A simple data processing algorithm and a personal computer software have been developed to smooth the noisy turbidity data acquired, and to utilize them for the on-line calculations of some kinetic variables involved in batch and fed-batch cultures of uniformly dispersed microorganisms. With this software, about 103 instantaneous turbidity data acquired over 55 s are averaged and convert it to dry cell concentration, X, every minute. Also, volume of the culture broth, V, is estimated from the averaged output data of weight loss of feed solution reservoir, W, using an electronic balance on which the reservoir is placed. Then, the computer software is used to perform linear regression analyses over the past 30 min of the total biomass, VX, the natural logarithm of the total biomass, ln(VX), and the weight loss, W, in order to calculate volumetric growth rate, d(VX)/dt, specific growth rate, μ [ = dln(VX)/dt] and the rate of W, dW/dt, every minute in a fed-batch culture. The software used to perform the first-order regression analyses of VX, ln(VX) and W was applied to batch or fed-batch cultures of Escherichia coli on minimum synthetic or natural complex media. Sample determination coefficients of the three different variables (VX, ln(VX) and W) were close to unity, indicating that the calculations are accurate. Furthermore, growth yield, Yx/s, and specific substrate consumption rate, qsc, were approximately estimated from the data, dW/dt and in a ‘balanced’ fed-batch culture of E. coli on the minimum synthetic medium where the computer-aided substrate-feeding system automatically matches well with the cell growth. (author)

  15. Screening of plant and fungal metabolites in wheat, maize and animal feed using automated on-line clean-up coupled to high resolution mass spectrometry.

    Science.gov (United States)

    Ates, Ebru; Godula, Michal; Stroka, Joerg; Senyuva, Hamide

    2014-01-01

    A wide range of plant and fungal metabolites can occur in cereals and feed but only a limited number of target compounds are sought. This screening method is using a database of over 600 metabolites to establish contamination profiles in food and feed. Extracts were injected directly into an automated turbulent flow sample clean-up system, coupled to a liquid-chromatography-high-resolution-mass-spectrometer (Orbitrap). Compound identification criteria for database searching were defined and the approach was validated by spiking plant and fungal metabolites into cereals and feed. A small survey of market samples (15) and quality control materials (9) of maize, wheat and feed was conducted using this method. Besides regulated and known secondary metabolites, fumiquinazoline F, fusarochromanone and dihydrofusarubin were identified for the first time in samples of maize and oats. This method enables clean-up of crude extracts within 18min and screening and confirmation of a wide range of different compound classes.

  16. Integrated Solid-Phase Extraction-Capillary Liquid Chromatography (speLC) Interfaced to ESI-MS/MS for Fast Characterization and Quantification of Protein and Proteomes

    DEFF Research Database (Denmark)

    Falkenby, Lasse Gaarde; Such-Sanmartín, Gerard; Larsen, Martin Røssel;

    2014-01-01

    prior to ESI-MS/MS for peptide sequencing. This speLC-MS/MS system eliminates sample-to-sample carry-over by using disposable micropipette solid-phase extraction tips (StageTips) for peptide sample loading, concentration, and desalting. Automated analysis of 192 replicates of E. coli peptide mixtures in...

  17. Use of semi-permeable membrane devices and solid-phase extraction for the wide-range screening of microcontaminants in surface water by GC-AED/MS

    NARCIS (Netherlands)

    Stee, van L.L.P.; Leonards, P.E.G.; Loon, van W.M.G.M.; Hendriks, A.J.; Maas, J.L.; Struijs, J.; Brinkman, U.A.T.

    2002-01-01

    An automated GC-MS-based screening method was developed for over 400 industrial, agrochemical and household chemicals. Extracted ion chromatograms were used and the method was aimed at creating a minimum number of false positives. The compound polarity range usually associated with solid-phase extra

  18. Liquid chromatography-mass spectrometry platform for both small neurotransmitters and neuropeptides in blood, with automatic and robust solid phase extraction

    Science.gov (United States)

    Johnsen, Elin; Leknes, Siri; Wilson, Steven Ray; Lundanes, Elsa

    2015-03-01

    Neurons communicate via chemical signals called neurotransmitters (NTs). The numerous identified NTs can have very different physiochemical properties (solubility, charge, size etc.), so quantification of the various NT classes traditionally requires several analytical platforms/methodologies. We here report that a diverse range of NTs, e.g. peptides oxytocin and vasopressin, monoamines adrenaline and serotonin, and amino acid GABA, can be simultaneously identified/measured in small samples, using an analytical platform based on liquid chromatography and high-resolution mass spectrometry (LC-MS). The automated platform is cost-efficient as manual sample preparation steps and one-time-use equipment are kept to a minimum. Zwitter-ionic HILIC stationary phases were used for both on-line solid phase extraction (SPE) and liquid chromatography (capillary format, cLC). This approach enabled compounds from all NT classes to elute in small volumes producing sharp and symmetric signals, and allowing precise quantifications of small samples, demonstrated with whole blood (100 microliters per sample). An additional robustness-enhancing feature is automatic filtration/filter back-flushing (AFFL), allowing hundreds of samples to be analyzed without any parts needing replacement. The platform can be installed by simple modification of a conventional LC-MS system.

  19. Solid Phase Synthesis of Ethyl β-Substituted Indolepropionates

    Institute of Scientific and Technical Information of China (English)

    刘占祥; 阮秀秀; 黄宪

    2003-01-01

    A facile solid phase synthesis of ethyl β-substituted indolepropionates is reported. Condensation between indole, polymer-supported cyclic malonic acid ester and aldehyde yielded the trimolecular adducts, which was cleaved by pyridine/EtOH to release the final products in good yield with high purity.

  20. Solid-phase synthesis of complex and pharmacologically interesting heterocycles

    DEFF Research Database (Denmark)

    Nielsen, Thomas Eiland

    2009-01-01

    Efficient routes for the creation of heterocycles continue to be one of the primary goals for solid-phase synthesis. Recent advances in this field rely most notably on transition-metal-catalysis and N-acyliminium chemistry to mediate a range of cyclization processes for the generation of compounds...

  1. Combinatorial solid-phase synthesis of hapalosin mimetics

    DEFF Research Database (Denmark)

    Olsen, Jacob A.; Jensen, Knud J.; Nielsen, John

    2000-01-01

    The solid-phase synthesis of a small library of mimetics of the cyclic depsipeptide hapalosin is described. 3-Amino-4-hydroxy-5-nitrobenzoic acid was anchored through the anilino moiety to a backbone amide linker (BAL) handle support. Using chemoselective reactions and without the need for...

  2. Solid-phase oligosaccharide and glycopeptide synthesis using glycosynthases

    DEFF Research Database (Denmark)

    Tolborg, Jakob Fjord; Petersen, Lars; Jensen, Knud Jørgen;

    2002-01-01

    Enzymatic approaches for the preparation of oligosaccharides are interesting alternatives to traditional chemical synthesis, the main advantage being the regio- and stereoselectivity offered without the need for protecting groups. The use of solid-phase techniques offers easy workup procedures an...

  3. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Lyngsø, Lars O.; Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to α,β-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2- pyrazolines....

  4. N-Acyliminium Intermediates in Solid-Phase Synthesis

    DEFF Research Database (Denmark)

    Quement, Sebastian Thordal le; Petersen, Rico; Meldal, M.;

    2010-01-01

    N-Acyliminium ions are powerful intermediates in synthetic organic chemistry. Examples of their use are numerous in solution-phase synthesis, but there are unmerited few reports on these highly reactive electrophiles in solid-phase synthesis. The present review covers the literature to date...

  5. Solid-phase synthesis of 3-amino-2-pyrazolines

    DEFF Research Database (Denmark)

    Nielsen, John

    1998-01-01

    The development of a solid-phase synthesis of 3-amino-2-pyrazolines is described. Conjugate addition of hydrazines to alpha,beta-unsaturated nitriles followed by cyclization yields 3-amino-2-pyrazolines. Acylation or sulfonation of the free amino-group yields a 24 member library of 3-amino-2...

  6. Solid-phase-supported synthesis of morpholinoglycine oligonucleotide mimics

    Directory of Open Access Journals (Sweden)

    Tatyana V. Abramova

    2014-05-01

    Full Text Available An efficient solid-phase-supported peptide synthesis (SPPS of morpholinoglycine oligonucleotide (MorGly mimics has been developed. The proposed strategy includes a novel specially designed labile linker group containing the oxalyl residue and the 2-aminomethylmorpholino nucleoside analogues as first subunits.

  7. Solid-phase microextraction for the analysis of biological samples

    NARCIS (Netherlands)

    Theodoridis, G; Koster, EHM; de Jong, GJ

    2000-01-01

    Solid-phase microextraction (SPME) has been introduced for the extraction of organic compounds from environmental samples. This relatively new extraction technique has now also gained a lot of interest in a broad field of analysis including food, biological and pharmaceutical samples. SPME has a num

  8. Solid Phase Characterization of Tank 241-C-105 Grab Samples

    Energy Technology Data Exchange (ETDEWEB)

    Ely, T. M. [Washington River Protection Solutions LLC, Richland, WA (United States); LaMothe, M. E. [Washington River Protection Solutions LLC, Richland, WA (United States); Lachut, J. S. [Washington River Protection Solutions LLC, Richland, WA (United States)

    2016-01-11

    The solid phase characterization (SPC) of three grab samples from single-shell Tank 241-C-105 (C-105) that were received at the laboratory the week of October 26, 2015, has been completed. The three samples were received and broken down in the 11A hot cells.

  9. Solid Phase Characterization of Solids Recovered from Failed Sluicer Arm

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Gary A.

    2015-03-09

    The Enclosure to this memo discusses the solid phase characterization of a solid sample that was retrieved from the single-shell Tank 241-C-111 extended reach sluicer #2. This sluicer, removed from riser #3 on September 25, 2014, was found to have approximately 0.4 gallons of solid tank waste adhering to the nozzle area.

  10. A Facile Solid -phase Synthesis of 3-Carboxycoumarins

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    3-Carboxycoumsrins were synthesized via the solid phase synthesis conviently. The resin bound cyclic malonic ester reacted with o-methoxy or o-hydroxybenzaldehydes. Then cyclization was processed under H2SO4 to afford the products in excellent purities and yields.

  11. Determination of benzoylureas in ground water samples by fully automated on-line pre-concentration and liquid chromatography-fluorescence detection.

    Science.gov (United States)

    Gil García, M D; Martínez Galera, M; Barranco Martínez, D; Gisbert Gallego, J

    2006-01-27

    An on-line pre-concentration method for the analysis of five benzoylureas (diflubenzuron, triflumuron, hexaflumuron, lufenuron and flufenoxuron) in ground water samples was evaluated using two C(18) columns, and fluorescence detection after photochemical induced fluorescence (PIF) post-column derivatization. The trace enrichment was carried out with 35 mL of ground water modified with 15 mL of MeOH on a 50 mm x 4.6 mm I.D. first enrichment column (C-1) packed with 5 microm Hypersil Elite C(18). Retention properties of pesticides and humic acids usually contained in ground water were studied on C-1 at concentration levels ranging between 0.04 and 14.00 microg/L in water samples. The results obtained in this study show that the pesticides are pre-concentrated in the first short column while the humic acids contained in the ground water samples are eluted to waste. Pesticides recoveries ranged between 92.3 and 109.5%. The methodology proposed was used to determine benzoylureas in ground water samples at levels lower than 0.1 microg/L (maximum levels established by the European Union). PMID:16337641

  12. Automated separation for heterogeneous immunoassays

    OpenAIRE

    Truchaud, A.; Barclay, J; Yvert, J. P.; Capolaghi, B.

    1991-01-01

    Beside general requirements for modern automated systems, immunoassay automation involves specific requirements as a separation step for heterogeneous immunoassays. Systems are designed according to the solid phase selected: dedicated or open robots for coated tubes and wells, systems nearly similar to chemistry analysers in the case of magnetic particles, and a completely original design for those using porous and film materials.

  13. The evolution of pretransfusion testing: from agglutination to solid-phase red cell adherence tests.

    Science.gov (United States)

    Plapp, F V; Sinor, L T; Rachel, J M

    1989-01-01

    Hospital transfusion services and blood centers still use manual hemagglutination tests for most of their serological procedures. Automation of hemagglutination reactions has proven to be difficult, primarily because hemagglutination lacks an objective endpoint which can be easily interpreted by inexpensive instruments. Alternatively, solid-phase red cell adherence assays for ABO cell and serum grouping, Rh typing, red cell and platelet antibody screening, red cell and platelet crossmatching, IgA deficiency screening, hepatitis B surface antigen, and HIV antibody screening have been developed. The performance of these assays compares favorably with current hemagglutination and enzyme immunoassay methods. All of these tests share a common objective endpoint of adherence or nonadherence of indicator red cells. This uniformity allows easy interpretation of results visually, spectrophotometrically, or by image analysis. The latter technique has the potential to revolutionize the reading and interpretation of all agglutination tests. Solid-phase red cell adherence tests in microplates are ideal for batch processing large numbers of specimens. However, adherence tests are not restricted to this format. Therefore, blood grouping dipsticks have been produced, which permit testing of individual blood samples even outside of the laboratory.

  14. Isolation of genomic DNA using magnetic nanoparticles as a solid-phase support

    International Nuclear Information System (INIS)

    In recent years, techniques employing magnetizable solid-phase supports (MSPS) have found application in numerous biological fields. This magnetic separation procedure offers several advantages in terms of subjecting the analyte to very little mechanical stress compared to other methods. Secondly, these methods are non-laborious, cheap, and often highly scalable. The current paper details a genomic DNA isolation method optimized in our laboratory using magnetic nanoparticles as a solid-phase support. The quality and yields of the isolated DNA from all the samples using magnetic nanoparticles were higher or equivalent to the traditional DNA extraction procedures. Additionally, the magnetic method takes less than 15 min to extract polymerase chain reaction (PCR) ready genomic DNA as against several hours taken by traditional phenol-chloroform extraction protocols. Moreover, the isolated DNA was found to be compatible in PCR amplification and restriction endonuclease digestion. The developed procedure is quick, inexpensive, robust, and it does not require the use of organic solvents or sophisticated instruments, which makes it more amenable to automation and miniaturization

  15. Entransy dissipation minimization for liquid-solid phase change processes

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The liquid-solid phase change process of a simple one-dimensional slab is studied in this paper.By taking entransy dissipation minimization as optimization objective,the optimal external reservoir temperature profiles are derived by using optimal control theory under the condition of a fixed freezing or melting time.The entransy dissipation corresponding to the optimal heat exchange strategies of minimum entransy dissipation is 8/9 of that corresponding to constant reservoir temperature operations,which is independent of all system parameters.The obtained results for entransy dissipation minimization are also compared with those obtained for the optimal heat exchange strategies of minimum entropy generation and constant reservoir temperature operations by numerical examples.The obtained results can provide some theoretical guidelines for the choice of optimal cooling or heating strategy in practical liquid-solid phase change processes.

  16. Studies in Solid Phase Peptide Synthesis: A Personal Perspective

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R

    2007-06-01

    By the early 1970s it had became apparent that the solid phase synthesis of ribonuclease A could not be generalized. Consequently, virtually every aspect of solid phase peptide synthesis (SPPS) was reexamined and improved during the decade of the 1970s. The sensitive detection and elimination of possible side reactions (amino acid insertion, N{sup {alpha}}-trifluoroacetylation, N{sup {alpha}{var_epsilon}}-alkylation) was examined. The quantitation of coupling efficiency in SPPS as a function of chain length was studied. A new and improved support for SPPS, the 'PAM-resin', was prepared and evaluated. These and many other studies from the Merrifield laboratory and elsewhere increased the general acceptance of SPPS leading to the 1984 Nobel Prize in Chemistry for Bruce Merrifield.

  17. Determination of thyroid antimicrosomal antibodies by solid-phase radioimmunoassay

    Energy Technology Data Exchange (ETDEWEB)

    Lacka, K.; Kasowicz, J.; Furmaniak-Wehr, J.; Gembicki, M. (Akademia Medyczna, Poznan (Poland))

    1984-01-01

    Thyroid antimicrosomal antibodies have been detected in patient's serum by immunofluorescence and hemagglutination techniques as well as by radioimmunoassay. The aim was to introduce the solid-phase radioimmunoassay for thyroid antimicrosomal antibodies determination. The microsomal fraction was adsorbed on the walls of polystyrene tubes. In the next stage patient's serum was added. The retention of antibodies bound to microsomes on the tube walls was detected by adding /sup 125/I-protein A. The occurrence of antimicrosomal antibodies in the group of patients with Graves' disease was 88%; in case of myxedema autoantibodies were found in 70%. In patients with chronic thyroiditis antimicrosomal antibodies were present in 90% and in the group of non-toxic goiter the incidence was 25%. In the control group antimicrosomal antibodies were found in 8%. The solid-phase radioimmunoassay for thyroid antimicrosomal antibody determination proved to be a useful, sensitive and reproducible method for clinical studies.

  18. Solid-phase cloning for high-throughput assembly of single and multiple DNA parts

    DEFF Research Database (Denmark)

    Lundqvist, Magnus; Edfors, Fredrik; Sivertsson, Åsa;

    2015-01-01

    is needed or where multiple inserts are to be assembled. In this approach, the solid support allows for head-to-tail assembly of DNA fragments based on hybridization and polymerase fill-in. The usefulness of head-to-tail SPC was demonstrated by assembly of >150 constructs with up to four DNA parts......We describe solid-phase cloning (SPC) for high-throughput assembly of expression plasmids. Our method allows PCR products to be put directly into a liquid handler for capture and purification using paramagnetic streptavidin beads and conversion into constructs by subsequent cloning reactions. We...... present a robust automated protocol for restriction enzyme based SPC and its performance for the cloning of >60 000 unique human gene fragments into expression vectors. In addition, we report on SPC-based single-strand assembly for applications where exact control of the sequence between fragments...

  19. Solid-phase synthesis of molecularly imprinted nanoparticles.

    Science.gov (United States)

    Canfarotta, Francesco; Poma, Alessandro; Guerreiro, Antonio; Piletsky, Sergey

    2016-03-01

    Molecularly imprinted polymers (MIPs) are synthetic materials, generally based on acrylic or methacrylic monomers, that are polymerized in the presence of a specific target molecule called the 'template' and capable of rebinding selectively to this target molecule. They have the potential to be low-cost and robust alternatives to biomolecules such as antibodies and receptors. When prepared by traditional synthetic methods (i.e., with free template in solution), their usefulness has been limited by high binding site heterogeneity, the presence of residual template and the fact that the production methods are complex and difficult to standardize. To overcome some of these limitations, we developed a method for the synthesis of MIP nanoparticles (nanoMIPs) using an innovative solid-phase approach, which relies on the covalent immobilization of the template molecules onto the surface of a solid support (glass beads). The obtained nanoMIPs are virtually free of template and demonstrate high affinity for the target molecule (e.g., melamine and trypsin in our published work). Because of an affinity separation step performed on the solid phase after polymerization, poor binders and unproductive polymer are removed, so the final product has more uniform binding characteristics. The overall protocol, starting from the immobilization of the template onto the solid phase and including the purification and characterization of the nanoparticles, takes up to 1 week.

  20. Determination of Synthetic Food Colorants in Sports Drink and Application of Automated Solid Phase Extraction%运动功能饮料中合成着色剂测定及全自动固相萃取仪的应用

    Institute of Scientific and Technical Information of China (English)

    谭恩灵

    2016-01-01

    建立了应用全自动固相萃取仪进行样品净化,高效液相色谱DAD检测器测定运动功能饮料中6种合成着色剂的方法。样品用去离子水稀释,经过固相萃取小柱净化后,经高效液相色谱仪DAD检测器测定。结果表明:6种合成着色剂3个水平(0.001、0.005、0.050g/kg)加标回收率为94.5%~100.9%,相对标准偏差为0.32%~1.02%(n=6),检出限分别为柠檬黄0.05mg/kg、日落黄0.1mg/kg、胭脂红0.1mg/kg、诱惑红0.1mg/kg、苋菜红0.1mg/kg、亮蓝0.1 mg/kg。此方法具有简单、快速、准确等优点,适用于运动饮料中柠檬黄、日落黄、胭脂红、诱惑红、苋菜红和亮蓝的同时测定。%Samples was diluted by water,and purified by solid phase extraction column,then determined by HPLC with DAD detector. The recoveries for synthetic food colorants standard spiked in the range of 0.001 to 0.05 g/kg were between 94.5% to 100.9% with a relative standard deviation(RSD)being between 0.32%to 1.02%(n=6). The detection limit was Lemon yellow: 0.1 mg/kg,Sunset yellow: 0.1 mg/kg,Carmine: 0.1 mg/kg,Allura red: 0.1mg/kg,Amaranth:0.1 mg/kg,Brilliant blue: 0.1 mg/kg. This method is suitable for the determination of synthetic food colorants in sports drink.

  1. A comparison of observables for solid-solid phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Smilowitz, Laura B [Los Alamos National Laboratory; Henson, Bryan F [Los Alamos National Laboratory; Romero, Jerry J [Los Alamos National Laboratory

    2009-01-01

    The study of solid-solid phase transformations is hindered by the difficulty of finding a volumetric probe to use as a progress variable. Solids are typically optically opaque and heterogeneous. Over the past several years, second harmonic generation (SHG) has been used as a kinetic probe for a solid-solid phase transition in which the initial and final phases have different symmetries. Bulk generation of SHG is allowed by symmetry only in noncentrosymmetric crystallographic space groups. For the organic energetic nitramine octahydro-1,3 ,5,7 -tetranitro-1,3 ,5,7 -tatrazocine (HMX), the beta phase is centro symmetric (space group P2{sub 1}/c) and the delta phase iS noncentrosymmetric (space group P6{sub 1}22) making SHG an extremely sensitive, essentially zero background probe of the phase change progress. We have used SHG as a tool to follow the progress of the transformation from beta to delta phase during the solid-solid transformation. However, kinetic models of the transformation derived using different observables from several other groups have differed, showing later onset for the phase change and faster progression to completion. In this work, we have intercompared several techniques to understand these differences. The three techniques discussed are second harmonic generation, Raman spectroscopy, and differential scanning calorimetry (DSC). The progress of the beta to delta phase transition in HMX observed with each of these different probes will be discussed and advantages and disadvantages of each technique described. This paper compares several different observables for use in measuring the kinetics of solid-solid phase transitions. Relative advantages and disadvantages for each technique are described and a direct comparison of results is made for the beta to delta polymorphic phase transition of the energetic nitramine, octahydro-1,3,5,7-tetranitro-1,3,5,7-tatrazocine.

  2. Wax Precipitation Modeled with Many Mixed Solid Phases

    DEFF Research Database (Denmark)

    Heidemann, Robert A.; Madsen, Jesper; Stenby, Erling Halfdan;

    2005-01-01

    The behavior of the Coutinho UNIQUAC model for solid wax phases has been examined. The model can produce as many mixed solid phases as the number of waxy components. In binary mixtures, the solid rich in the lighter component contains little of the heavier component but the second phase shows......-temperature and low-temperature forms, are pure. Model calculations compare well with the data of Pauly et al. for C18 to C30 waxes precipitating from n-decane solutions. (C) 2004 American Institute of Chemical Engineers....

  3. Solid phase microextraction fills the gap in tissue sampling protocols.

    Science.gov (United States)

    Bojko, Barbara; Gorynski, Krzysztof; Gomez-Rios, German Augusto; Knaak, Jan Matthias; Machuca, Tiago; Spetzler, Vinzent Nikolaus; Cudjoe, Erasmus; Hsin, Michael; Cypel, Marcelo; Selzner, Markus; Liu, Mingyao; Keshavjee, Shaf; Pawliszyn, Janusz

    2013-11-25

    Metabolomics and biomarkers discovery are an integral part of bioanalysis. However, untargeted tissue analysis remains as the bottleneck of such studies due to the invasiveness of sample collection, as well as the laborious and time-consuming sample preparation protocols. In the current study, technology integrating in vivo sampling, sample preparation and global extraction of metabolites--solid phase microextraction was presented and evaluated during liver and lung transplantation in pig model. Sampling approaches, including selection of the probe, transportation, storage conditions and analyte coverage were discussed. The applicability of the method for metabolomics studies was demonstrated during lung transplantation experiments. PMID:24216199

  4. Solid Phase Peptide Synthesis of Fusukang for AIDS

    Institute of Scientific and Technical Information of China (English)

    甘一如; 戴琦; 张雪竹; 高晨昊

    2003-01-01

    A 36-residue peptide is designed to cure acquired immunodeficiency syndrome(AIDS), and is synthesized by the manual solid phase peptide synthesis technique. Different reaction conditions of the synthesis process were discussed. Stirring efficiency of mechanics and nitrogen was compared. The mechanical method displays a predominant performance. Although the coupling efficiencies of diisopropylcarbodiimide(DIC) and dicyclohexylcarbodiimide(DCC) are virtually identical, DIC offers several advantages over DCC in practice due to different physical characters. Wash conditions after deprotection and coupling were investigated to monitor washing efficiency. 0.369 2 g crude peptide was obtained.

  5. Sensitive and fast mutation detection by solid phase chemical cleavage

    DEFF Research Database (Denmark)

    Hansen, Lise Lotte; Justesen, Just; Kruse, Torben A

    1996-01-01

    We have developed a solid phase chemical cleavage method (SpCCM) for screening large DNA fragments for mutations. All reactions can be carried out in microtiterwells from the first amplification of the patient (or test) DNA through the search for mutations. The reaction time is significantly...... reduced compared to the conventional chemical cleavage method (CCM), and even by using a uniformly labelled probe, the exact position and nature of the mutation can be revealed. The SpCCM is suitable for automatization using a workstation to carry out the reactions and a fluorescent detection-based DNA...

  6. Solid Phase Synthesis of Helically Folded Aromatic Oligoamides.

    Science.gov (United States)

    Dawson, S J; Hu, X; Claerhout, S; Huc, I

    2016-01-01

    Aromatic amide foldamers constitute a growing class of oligomers that adopt remarkably stable folded conformations. The folded structures possess largely predictable shapes and open the way toward the design of synthetic mimics of proteins. Important examples of aromatic amide foldamers include oligomers of 7- or 8-amino-2-quinoline carboxylic acid that have been shown to exist predominantly as well-defined helices, including when they are combined with α-amino acids to which they may impose their folding behavior. To rapidly iterate their synthesis, solid phase synthesis (SPS) protocols have been developed and optimized for overcoming synthetic difficulties inherent to these backbones such as low nucleophilicity of amine groups on electron poor aromatic rings and a strong propensity of even short sequences to fold on the solid phase during synthesis. For example, acid chloride activation and the use of microwaves are required to bring coupling at aromatic amines to completion. Here, we report detailed SPS protocols for the rapid production of: (1) oligomers of 8-amino-2-quinolinecarboxylic acid; (2) oligomers containing 7-amino-8-fluoro-2-quinolinecarboxylic acid; and (3) heteromeric oligomers of 8-amino-2-quinolinecarboxylic acid and α-amino acids. SPS brings the advantage to quickly produce sequences having varied main chain or side chain components without having to purify multiple intermediates as in solution phase synthesis. With these protocols, an octamer could easily be synthesized and purified within one to two weeks from Fmoc protected amino acid monomer precursors. PMID:27586338

  7. Solid-Phase Preparation and Characterization of Chitosan

    Institute of Scientific and Technical Information of China (English)

    GaoLe-ping; DuYu-min; ZhangDao-bin; ShiXiao-wen; ZhanHuai-yu; SongWen-hua

    2003-01-01

    Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carborr13 magnetic resonance sperctroscopy (13C NMR). Chitosan with a deacetylation degree (DD) of 76. 1% was obtained at a mass ratio 0.2 : 1 : 1 for H20/chitin/NaOH at 160℃ for 12 mirL Compared to conventional solution method(usually 1 : 10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,M. 1.54 X 10s ) was lower than that obtained by suspension method(Y2,Mw3. 34×105). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitirL It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13C NMR showed that structures of chitosans prepared by solid-phase method were not changed.

  8. Solid-Phase Preparation and Characterization of Chitosan

    Institute of Scientific and Technical Information of China (English)

    Gao Le-ping; Du Yu-min; Zhang Dao-bin; Shi Xiao-wen; Zhan Huai-yu; Song Wen-hua

    2003-01-01

    Chitosan was prepared with stressing method by blending chitin and solid alkali in a single-screw extruder at given temperature and characterized by potentiometric titration, gel permeation chromatography (GPC), infrared spectrum (IR) and carbon-13 magnetic resonance sperctroscopy(13C NMR). Chitosan with a deacetylation degree (DD) of 76.1% was obtained at a mass ratio 0.2∶1∶1 for H2O/chitin/NaOH at 160 ℃ for 12 min. Compared to conventional solution method(usually 1∶10 for chitin/NaOH), the alkali assumption greatly decreased. Molecular weight of chitosan obtained by solid-phase method(S3,Mw1.54×105) was lower than that obtained by suspension method(Y2,Mw3.34×105). During deacetylation, molecular weight decreased with high reaction temperature and long reaction time but remained same at different initial ratios of NaOH/chitin. It might be concluded that degradation of chitosan was caused by breakout of the main chain of the oxidized chitosan catalyzed by alkali during the deactylation. IR and 13C NMR showed that structures of chitosans prepared by solid-phase method were not changed.

  9. Improved resins and novel materials and methods for solid phase extraction and high performance liquid chromatography

    Energy Technology Data Exchange (ETDEWEB)

    Freeze, R.

    1997-10-08

    Solid-phase extraction (SPE) has grown to be one of the most widely used methods for isolation and preconcentration of a vast range of compounds from aqueous solutions. By modifying polymeric SPE resins with chelating functional groups, the selective uptake of metals was accomplished. The resin, along with adsorbed metals, was vaporized in the ICP and detection of the metals was then possible using either mass or emission spectroscopy. Drug analyses in biological fluids have received heightened attention as drug testing is on the increase both in sports and in the work environment. By using a direct-injection technique, biological fluids can be injected directly into the liquid chromatographic system with no pretreatment. A new surfactant, a sulfonated form of Brij-30 (Brij-S) is shown to prevent the uptake of serum proteins on commercial HPLC columns by forming a thin coating on the silica C18 surface. Excellent separations of eight or more drugs with a wide range of retention times were obtained. The separations had sharper peaks and lower retention times than similar separations performed with the surfactant sodium dodecylsulfate (SDS). Quantitative recovery of a number of drugs with limits of detection near 1 ppm with a 5 {micro}l injection volume were obtained. Finally, a method for solid-phase extraction in a syringe is introduced. The system greatly reduced the volume of solvent required to elute adsorbed analytes from the SPE bed while providing a semi-automated setup. SPE in a syringe consists of a very small bed of resin-loaded membrane packed into a GC or HPLC syringe. After extraction, elution was performed with just a few {micro}l of solvent. This small elution volume allowed injection of the eluent directly from the syringe into the chromatographic system, eliminating the handling problems associated with such small volumes.

  10. Solid-Phase Extraction Strategies to Surmount Body Fluid Sample Complexity in High-Throughput Mass Spectrometry-Based Proteomics

    Directory of Open Access Journals (Sweden)

    Marco R. Bladergroen

    2015-01-01

    Full Text Available For large-scale and standardized applications in mass spectrometry- (MS- based proteomics automation of each step is essential. Here we present high-throughput sample preparation solutions for balancing the speed of current MS-acquisitions and the time needed for analytical workup of body fluids. The discussed workflows reduce body fluid sample complexity and apply for both bottom-up proteomics experiments and top-down protein characterization approaches. Various sample preparation methods that involve solid-phase extraction (SPE including affinity enrichment strategies have been automated. Obtained peptide and protein fractions can be mass analyzed by direct infusion into an electrospray ionization (ESI source or by means of matrix-assisted laser desorption ionization (MALDI without further need of time-consuming liquid chromatography (LC separations.

  11. Solid-solid phase transitions via melting in metals

    Science.gov (United States)

    Pogatscher, S.; Leutenegger, D.; Schawe, J. E. K.; Uggowitzer, P. J.; Löffler, J. F.

    2016-04-01

    Observing solid-solid phase transitions in-situ with sufficient temporal and spatial resolution is a great challenge, and is often only possible via computer simulations or in model systems. Recently, a study of polymeric colloidal particles, where the particles mimic atoms, revealed an intermediate liquid state in the transition from one solid to another. While not yet observed there, this finding suggests that such phenomena may also occur in metals and alloys. Here we present experimental evidence for a solid-solid transition via the formation of a metastable liquid in a `real' atomic system. We observe this transition in a bulk glass-forming metallic system in-situ using fast differential scanning calorimetry. We investigate the corresponding transformation kinetics and discuss the underlying thermodynamics. The mechanism is likely to be a feature of many metallic glasses and metals in general, and may provide further insight into phase transition theory.

  12. A rapid easy—to—perform solid phase digoxin radioimmunoassay

    Institute of Scientific and Technical Information of China (English)

    LiBin; ZhouMei-Ying; 等

    1998-01-01

    A solid-phase-radioimmunoassay(SPRIA) for the monitoring of blood digoxin level has been developed,in which a secondary antibody-coated polystyrene tubes are used.This noval method seems to be simple to use and only takes about an half hour.The standard curve is linear from 0.25to 4μg/L.The sensitivity of the detection is 0.1μg/L.Reproducibility studies with 3 control sera of 0.5-2.5μg/L give intraassay CV<5% and interassay CV<10%.The specimens are measured and compared with those of the conventional radioimmunoassay and the values are well correlated(r=0.96,Y=1.022X+0.04μg/L)。

  13. Development of a solid phase RIA for human plasma somatostatin

    International Nuclear Information System (INIS)

    Somatostatin is widely distributed in tissues of biological fluids. In the present study we tested the validity of a new radioimmunoassay by a solid phase immunoextraction. Sensitivity was 1.8 pg/mL and the within-assay precision with two different pools of human plasma was 12.2% (CV) at a concentration of 19.2 ± 2.34 pg/ml (mean ± SD) and 11.9% at 8.53 ± 1.02 pg/ml. The between assay precision was 14.2% (CV) at a concentration of 11.8 ± 1.68 pg/ml. The accuracy was good as tested by the dilution test and the recovery test. The method had good correlation with a current extraction method. Basal value of somatostatin in the plasma of 32 normal subjects was 11.5 ± 5.80 pg/ml. (author)

  14. Hydrogen cleavage by solid-phase frustrated Lewis pairs.

    Science.gov (United States)

    Xing, Jun-Yi; Buffet, Jean-Charles; Rees, Nicholas H; Nørby, Peter; O'Hare, Dermot

    2016-08-18

    We report the direct synthesis of a solid-phase frustrated Lewis pair (s-FLP) by combining a silica-supported Lewis acid ([triple bond, length as m-dash]SiOB(C6F5)2, s-BCF) with a Lewis base (tri-tert-butylphosphine, (t)Bu3P) to give [[triple bond, length as m-dash]SiOB(C6F5)2][(t)Bu3P]. Reaction of this s-FLP with H2 under mild conditions led to heterolytic H-H bond cleavage and the formation of [[triple bond, length as m-dash]SiOB(H)(C6F5)2][(t)Bu3PH].

  15. Solid phase epitaxial regrowth of (001) anatase titanium dioxide

    Energy Technology Data Exchange (ETDEWEB)

    Barlaz, David Eitan; Seebauer, Edmund G., E-mail: eseebaue@illinois.edu [Department of Chemical and Biomolecular Engineering, University of Illinois, 600 S Mathews Ave., Urbana, Illinois 61801 (United States)

    2016-03-15

    The growing interest in metal oxide based semiconductor technologies has driven the need to produce high quality epitaxial films of one metal oxide upon another. Largely unrecognized in synthetic efforts is that some metal oxides offer strongly polar surfaces and interfaces that require electrostatic stabilization to avoid a physically implausible divergence in the potential. The present work examines these issues for epitaxial growth of anatase TiO{sub 2} on strontium titanate (001). Solid phase epitaxial regrowth yields only the (001) facet, while direct crystalline growth by atomic layer deposition yields both the (112) and (001). The presence of amorphous TiO{sub 2} during regrowth may provide preferential stabilization for formation of the (001) facet.

  16. On line portal imaging

    International Nuclear Information System (INIS)

    Purpose/Objective: The purpose of this presentation is to examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine geometric errors quantitatively; discuss some of the ways that portal imaging has been incorporated into routine clinical practice; describe quality assurance procedures for these devices, and discuss the use of portal imaging devices for dosimetry applications. Discussion: Verification of patient positioning has always been an important aspect of external beam radiation therapy. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same structures on a digitized simulator film. Once the anatomic structures have been registered, any discrepancies in the position of the patient can be identified. However, the task is not nearly as straight-forward as it sounds. One problem

  17. Automation in immunohematology.

    Science.gov (United States)

    Bajpai, Meenu; Kaur, Ravneet; Gupta, Ekta

    2012-07-01

    There have been rapid technological advances in blood banking in South Asian region over the past decade with an increasing emphasis on quality and safety of blood products. The conventional test tube technique has given way to newer techniques such as column agglutination technique, solid phase red cell adherence assay, and erythrocyte-magnetized technique. These new technologies are adaptable to automation and major manufacturers in this field have come up with semi and fully automated equipments for immunohematology tests in the blood bank. Automation improves the objectivity and reproducibility of tests. It reduces human errors in patient identification and transcription errors. Documentation and traceability of tests, reagents and processes and archiving of results is another major advantage of automation. Shifting from manual methods to automation is a major undertaking for any transfusion service to provide quality patient care with lesser turnaround time for their ever increasing workload. This article discusses the various issues involved in the process.

  18. Automation in Immunohematology

    Directory of Open Access Journals (Sweden)

    Meenu Bajpai

    2012-01-01

    Full Text Available There have been rapid technological advances in blood banking in South Asian region over the past decade with an increasing emphasis on quality and safety of blood products. The conventional test tube technique has given way to newer techniques such as column agglutination technique, solid phase red cell adherence assay, and erythrocyte-magnetized technique. These new technologies are adaptable to automation and major manufacturers in this field have come up with semi and fully automated equipments for immunohematology tests in the blood bank. Automation improves the objectivity and reproducibility of tests. It reduces human errors in patient identification and transcription errors. Documentation and traceability of tests, reagents and processes and archiving of results is another major advantage of automation. Shifting from manual methods to automation is a major undertaking for any transfusion service to provide quality patient care with lesser turnaround time for their ever increasing workload. This article discusses the various issues involved in the process.

  19. Automation in immunohematology.

    Science.gov (United States)

    Bajpai, Meenu; Kaur, Ravneet; Gupta, Ekta

    2012-07-01

    There have been rapid technological advances in blood banking in South Asian region over the past decade with an increasing emphasis on quality and safety of blood products. The conventional test tube technique has given way to newer techniques such as column agglutination technique, solid phase red cell adherence assay, and erythrocyte-magnetized technique. These new technologies are adaptable to automation and major manufacturers in this field have come up with semi and fully automated equipments for immunohematology tests in the blood bank. Automation improves the objectivity and reproducibility of tests. It reduces human errors in patient identification and transcription errors. Documentation and traceability of tests, reagents and processes and archiving of results is another major advantage of automation. Shifting from manual methods to automation is a major undertaking for any transfusion service to provide quality patient care with lesser turnaround time for their ever increasing workload. This article discusses the various issues involved in the process. PMID:22988378

  20. Bioactive phenols in algae: the application of pressurized-liquid and solid-phase extraction techniques.

    Science.gov (United States)

    Onofrejová, L; Vasícková, J; Klejdus, B; Stratil, P; Misurcová, L; Krácmar, S; Kopecký, J; Vacek, J

    2010-01-20

    A new extraction technique based on the off-line combination of pressurized-liquid with solid-phase extraction (PLE-SPE) is described. The method was used for the extraction of bioactive phenolic acids (protocatechuic, p-hydroxybenzoic, 2,3-dihydroxybenzoic, chlorogenic, vanillic, caffeic, p-coumaric, salicylic acid), cinnamic acid and hydroxybenzaldehydes (p-hydroxybenzaldehyde, 3,4-dihydroxybenzaldehyde, vanillin) from in vitro culture of two freshwater algae (Anabaena doliolum and Spongiochloris spongiosa) and from food products of marine macroalgae Porphyra tenera (nori) and Undaria pinnatifida (wakame). For the identification and quantification of the compounds the molecular ions [M-H](-) and specific fragments were analyzed by quadrupole mass spectrometry analyzer connected on-line with a reversed-phase HPLC system. Our analysis showed that the freshwater algae and marine algal products contained submicrogram or microgram level of above-mentioned phenols per gram of lyophilized sample. In addition, the total phenol content (Folin-Ciocalteu assay) and antioxidant activity (TEAC assay, Trolox equivalent antioxidant capacity assay) of the PLE-SPE extracts were determined and discussed. PMID:19410410

  1. [Determination of aflatoxins in hot chilli products by matrix solid-phase dispersion and liquid chromatography].

    Science.gov (United States)

    Zheng, Ping; Sheng, Xuan; Yu, Xiaofeng; Hu, Yanyun

    2006-01-01

    A new method based on matrix solid-phase dispersion (MSPD) extraction with neutral alumina and co-column purification with graphitized carbon black has been developed to determine aflatoxins B1, B2, G1, G2 in hot chilli products. The method includes liquid chromatography and fluorescence detection with on-line post-column derivatization with bromine. Optimization of different parameters, such as the type of solid supports for matrix dispersion and co-column clean-up was carried out. The recoveries of aflatoxins B1, B2, G1 and G2 were 95.4%, 87.3%, 91.5% and 92.6%, respectively, with relative standard deviations ranging from 3.3% to 6.1%. The limits of detection were in the range of 0.10 ng/g (B2, G2) to 0.25 ng/g (B1, G1). In addition, the comparison of the extraction and purification effect of MSPD with immunity affinity column showed that, MSPD is a valid method to analyze aflatoxins in hot chilli products.

  2. On-chip solid phase extraction coupled with electrophoresis using modified magnetic microspheres as stationary phase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    A poly(dimethylsiloxane)(PDMS)/glass hybrid microchip for on-line solid phase extraction (SPE) and electrophoresis separation has been developed and evaluated. The SPE microchannel was crossed to the electrophoresis microchannel. All the microfluidic channels were etched on the glass substrate. The magnetic microspheres were coated with hydroxyl-terminated poly-dimethylsiloxane (PDMS-OH) serving as extraction phase,which could be conveniently immobilized into the sample pretreatment channel by magnetic field. The PDMS-OH microspheres were mobilized into and out of the pretreatment channel by injection flow. The 0.1 μmol/L solution of fluorescence isothiocyanate (FITC)-labeled phenylalanine (Phe) was electrically injected into the SPE channel and extracted onto the PDMS-OH microspheres bed. The enriched FITC-labeled Phe was electrically eluted by 9 mmol/L sodium acetate containing 10% acetonitrile and electrically driven into the electrophoresis channel and then separated. The preconcentration factor could reach 87.5 after sufficient extraction. A linear preconcentration curve was obtained with the initial FITC-labeled Phe concentration ranging from 6 nmol/L to 300 nmol/L (R2=0.9922) with 200 s loading time. The detection limit (S/N=3) for the FITC-labeled Phe was 3 nmol/L.

  3. Applications of monolithic solid-phase extraction in chromatography-based clinical chemistry assays.

    Science.gov (United States)

    Bunch, Dustin R; Wang, Sihe

    2013-04-01

    Complex matrices, for example urine, serum, plasma, and whole blood, which are common in clinical chemistry testing, contain many non-analyte compounds that can interfere with either detection or in-source ionization in chromatography-based assays. To overcome this problem, analytes are extracted by protein precipitation, solid-phase extraction (SPE), and liquid-liquid extraction. With correct chemistry and well controlled material SPE may furnish clean specimens with consistent performance. Traditionally, SPE has been performed with particle-based adsorbents, but monolithic SPE is attracting increasing interest of clinical laboratories. Monoliths, solid pieces of stationary phase, have bimodal structures consisting of macropores, which enable passage of solvent, and mesopores, in which analytes are separated. This structure results in low back-pressure with separation capabilities similar to those of particle-based adsorbents. Monoliths also enable increased sample throughput, reduced solvent use, varied support formats, and/or automation. However, many of these monoliths are not commercially available. In this review, application of monoliths to purification of samples from humans before chromatography-based assays will be critically reviewed.

  4. Molecularly imprinted polymer cartridges coupled on-line with high performance liquid chromatography for simple and rapid analysis of human insulin in plasma and pharmaceutical formulations.

    Science.gov (United States)

    Moein, Mohammad Mahdi; Javanbakht, Mehran; Akbari-adergani, Behrouz

    2014-04-01

    In this paper, a novel method is described for automated determination of human insulin in biological fluids using principle of sequential injection on a molecularly imprinted solid-phase extraction (MISPE) cartridge as a sample clean-up technique combined with high performance liquid chromatography (HPLC). The water-compatible molecularly imprinted polymers (MIPs) were prepared using methacrylic acid as a functional monomer, ethylene glycol dimethacrylate as a cross-linker, chloroform as a porogen and insulin as a template molecule. The imprinted polymers were then employed as the solid-phase extraction sorbent for on-line extraction of insulin from human plasma samples. To achieve the best condition, influential parameters on the extraction efficiency were thoroughly investigated. Rapid and simple analysis of the hormone was successfully accomplished through the good selectivity of the prepared sorbent coupled with HPLC. Limits of detection (LOD) and quantification (LOQ) of 0.2 ng mL(-1), 0.7 ng mL(-1), and 0.03 ng mL(-1), 0.1 ng mL(-1) were obtained in plasma and urine respectively. The obtained data exhibited the great recoveries for extraction of insulin from human plasma and pharmaceutical samples, higher than 87%. PMID:24607106

  5. Quasi in situ observation of Si lateral solid phase epitaxy

    Science.gov (United States)

    Ueno, T.; Kawai, K.; Morisawa, T.; Hatano, T.; Imai, S.; Kaneko, S.; Ohdomari, I.

    A quasi in situ observation of Si lateral solid phase epitaxy (L-SPE) has been carried out by an anneal-and-observe technique using a transmission electron microscope (TEM). For this observation, 3 mm Ø Si discs, which were thinned physically and chemically, were cut from a non-heated sample which had been prepared by depositing an amorphous Si (a-Si) film on the patterned amorphous insulator substrate. For the L-SPE growth, the thin specimens were heated in a furnace. The same areas of the same sample were repeatedly observed after an additional heating process at each interval. The direct origin of the (111) facet formation during the L-SPE growth has been precisely revealed by this method. Polygrains due to the random nucleation from the a-Si/a-insulator interface have been found to obstruct further L-SPE growth, while the L-SPE growth continued in the adjacent polygrain-free regions. As a result of this non-uniform growth rate, the (111) facets which nucleated at the polygrains grew into V-shaped valleys and finally caused a zig-zag growth front.

  6. Solid phase group specific absorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of this paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by use of the solid phase carbohydrate specific adsorbant concanavalin-A. Puriffication of glycoprotein radioligand after labelling by the chloramine-T method is readily accomplished using a small column of agarose bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose bound concanavalin-A is used to extract and concentrate the glycoproteins from various biologic samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5 fold by using concanavalin-A concentrates of 1.5 ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biologic samples, and for separation of glycoproteins from various interfering factors contained in biologic samples prior to radioligand or radioenzyme assay. (orig.)

  7. On line measurement systems for calorimetric measurements

    International Nuclear Information System (INIS)

    The development of on-line measurement systems for calorimetric measurements for the last twenty years is traced and an attempt of their classification according to the automation level and hardware unification degree is undertaken. Main attention is given to the structure of variuos types of the above systems and the role of computers as a control and calculating device in the system. The methodic problems are considered in brief. Semiautomatic measurement systems for calorimetric measurements on the base of simple controllers, the systems with one or several mini- and microcomputers on-line with an experimental installation as well as the systems with various types of interface buses (CAMAC, IEEE 488, Multibus) are described. Tendencies in the development of the measurement systems related with application of microprocessors into computer and measuring engineering and possible prospects of the on-line measurement systems for calorimetric measurements as a specific variety of on-line systems for physical experiments are considered

  8. 40 CFR 227.32 - Liquid, suspended particulate, and solid phases of a material.

    Science.gov (United States)

    2010-07-01

    ... MATERIALS Definitions § 227.32 Liquid, suspended particulate, and solid phases of a material. (a) For the... 40 Protection of Environment 24 2010-07-01 2010-07-01 false Liquid, suspended particulate, and solid phases of a material. 227.32 Section 227.32 Protection of Environment ENVIRONMENTAL...

  9. Development of novel solid-phase protein formulations

    Science.gov (United States)

    Montalvo Ortiz, Brenda Liz

    Proteins are the next-generation drugs for the treatment of several diseases. However, the number of protein drugs is still limited due to the physical or chemical instability of proteins during processing, formulation, storage, and delivery. The formulation of proteins at the solid state has advantages over liquid state, such as improved stability during long-term storage and delivery and decreases transportation costs. In this dissertation, we developed new solid-phase protein formulations in which the integrity of the protein was not compromised. The long term goal of this research was to use these protein formulations to improve protein stability in drug delivery devices, such as poly(lactic-co-glycolic) acid (PLGA). The first solid-phase protein formulation developed in this investigation was named "glassification". We proposed glassification as an alternative protein dehydration technique to the common used one, lyophilization, because this last method involves a series of steps which are detrimental to protein structure and stability. The glassification method consisted on protein dehydration by the use of organic solvents. As a result of the glassification process a small (micrometer size range) protein solid bead was obtained. The proteins used to study the glassification process were lysozyme (LYS), alpha-chymotrypsin (CHYMO) and horseradish peroxidase (HRP). These studies revealed that the glassification process itself did not alter protein structure and the activity was preserved. Ethyl acetate was the most effective organic solvent for protein glassification because it led to the highest protein residual activity, no insoluble aggregate formation and is a relatively non-toxic solvent, which allow the incorporation of these protein microparticles in PLGA microspheres. The incorporation of spherical HRP microparticles into PLGA microspheres resulted in superior properties when compared with encapsulated lyophilized HRP powder, such as improved release

  10. Solid-phase synthesis of peptide-4-nitroanilides.

    Science.gov (United States)

    Kaspari, A; Schierhorn, A; Schutkowski, M

    1996-11-01

    A wide variety of Glu/Asp and Gln containing peptide-4-nitroanilides and other chromogenic peptidyl-arylamides could be quickly synthesized by a Fmoc-based solid-phase synthesis strategy employing the side-chain carboxyl groups for transient anchoring to the resin. Suitable synthons for this method, Fmoc-Glu-NH-Np and Fmoc-Asp-NH-Np, were prepared using a diphenylphosphinic chloride-mediated coupling reaction. Peptides of the common structure Suc-Ala-Phe-Pro-Xaa-NH-Np (Xaa = Glu/Asp, Gln) were synthesized and were shown to be substrates for the protease subtilisin Carlsberg (E.C.3.4.21.14a) and for peptidyl-prolyl cis/trans-isomerases (PPIases E.C. 5.2.1.8.). The method was extended to amino acids possessing a side chain missing an anchor for binding to the matrix. We synthesized Suc-Ala-Phe-Pro-Gln-Phe-NH-Np anchoring the dipeptide derivative Fmoc-Glu-Phe-NH-Np with the carboxyl group to Rink amide resin using standard SPPS procedures. Additionally this procedure allowed us the preparation of peptidyl-arylamides, utilizing the commercial available Fmoc-Glu-OAll as building block. A mixture of pentapeptide-4-nitroanilides with the general sequence Ala-Ala-Xaa-Pro-Gln-NH-Np was synthesized. Electrospray ionization mass spectrometry (ESI-MS) was used to evaluate the hydrolysis of the peptide mixture by the protease subtilisin Carlsberg. It could be shown that peptides with the hydrophobic amino acids Phe, Tyr, Leu and Val in the varied P3-position were most rapidly cleaved under the chosen conditions. Hydrolysis of the Gln-NH-Np bond in Ala-Ala-Pro-Pro-Gln-NH-Np has not been observed.

  11. Application of solid phase microextraction on dental composite resin analysis.

    Science.gov (United States)

    Wang, Ven-Shing; Chang, Ta-Yuan; Lai, Chien-Chen; Chen, San-Yue; Huang, Long-Chen; Chao, Keh-Ping

    2012-08-15

    A direct immersion solid phase microextraction (DI-SPME) method was developed for the analysis of dentin monomers in saliva. Dentine monomers, such as triethylene glycol dimethacrylate (TEGDMA), urethane dimethacrylate (UDMA) and 2,2-bis-[4-(2-hydroxy-3-methacryloyloxypropoxy) phenyl]-propane (Bis-GMA), have a high molecular weight and a low vapor pressure. The polydimethylsiloxane/divinylbenzene (PDMS/DVB) fiber with a medium polarity was employed for DI-SPME, and 215 nm of detection wavelength was found to be optimum in the chromatogram of HPLC measurement. The calibration range for DI-SPME was 0.30-300 μg/mL with correlation coefficients (r) greater than 0.998 for each analyte. The DI-SPME method achieved good accuracy (recovery 96.1-101.2%) and precision (2.30-8.15% CV) for both intra- and inter-day assays of quality control samples for three target compounds. Method validation was performed on standards dissolved in blank saliva, and there was no significant difference (p>0.2) between the DI-SPME method and the liquid injection method. However, the detection limit of DI-SPME was as low as 0.03, 0.27 and 0.06 μg/mL for TEGDMA, UDMA and Bis-GMA, respectively. Real sample analyses were performed on commercial dentin products after curing for the leaching measurement. In summary, DI-SPME is a more sensitive method that requires less sample pretreatment procedures to measure the resin materials leached in saliva.

  12. Versatile Solid Phase Syntheses of Structured Nanoparticle Hybrids

    Science.gov (United States)

    Koberstein, Jeffrey

    2011-03-01

    While it is widely recognized that nanoparticles can exhibit a wide variety of exciting size-dependent properties and responses, it is equally important to recognize that devices and systems cannot be created from bare nanoparticles alone. The potential of nanoparticles can only be achieved by proper consideration of matrices that not only provide mechanical support and integrity to the nanoparticles, but can also control various aspects of their spatial assembly such as geometry and interparticle spacing. Polymers represent a logical and robust matrix for the creation of nanocomposite assemblies, however, phenomena such as aggregation are often problematic when blending nanoparticles and homopolymers. These problems can be avoided by preparation of nanoparticle hybrids wherein all required polymers are covalently tethered to the nanoparticles prior to assembly so that a polymer matrix is not necessary. We report on a new method for covalent decoration of nanoparticles with polymers of tailored molecular design that is based upon a solid phase synthesis strategy. The modular process, much like molecular Tinker Toys, is capable of decorating nanoparticles with essentially any type of branched or copolymeric structure using only a few elementary heterobifunctional building blocks. Because end group functionality is always retained in the process, functional nanoparticles can be readily crosslinked by simple orthogonal reactions such as azide-alkyne click chemistry. The method can be used to create sophisticated hybrid nanoparticle structures important to drug delivery applications, to form highly functional crosslinkers that gel at conversions as low as a few percent, or to fabricate crosslinked matrix-free nanocomposites. Supported by grants DMR-0704054 from the NSF and W911NF-10-1-0184 from the US Army Research Office.

  13. Ultrarapid mutation detection by multiplex, solid-phase chemical cleavage

    Energy Technology Data Exchange (ETDEWEB)

    Rowley, G.; Saad, S.; Giannelli, F.; Green, P.M. [Guy`s & St. Thomas`s Hospitals, London (United Kingdom)

    1995-12-10

    The chemical cleavage of mismatches in heteroduplexes formed by probe and test DNA detects and locates any sequence change in long DNA segments ({approximately}1.8 kb), and its efficiency has been well tested in the analysis of both average (e.g., coagulation factor IX) and large, complex genes (e.g., coagulation factor VIII and dystrophin). In the latter application RT/PCR products allow the examination of all essential sequences of the gene in a minimum number of reactions. We use two specific chemical reactants (hydroxylamine and osmium tetroxide) and piperidine cleavage of the above procedure to develop a very fast mutation screening method. This is based on: (1) 5{prime} or internal fluorescent labeling to allow concurrent screening of three to four DNA fragments and (2) solid-phase chemistry to use a microliter format and reduce the time required for the procedure, from amplification of sequence to gel loading inclusive, to one person-working-day. We test the two variations of the method, one entailing 5{prime} labeling of probe DNA and the other uniform labeling of both probe and target DNA, by detecting 114 known hemophilia B (coagulation factor IX) mutations and by analyzing 129 new patients. Uniform labeling of both probe and target DNA prior to formation of the heteroduplexes leads to almost twofold redundancy in the ability to detect mutations. Alternatively, the latter procedure may offer very efficient though less than 100% screening for sequence changes with only hydroxylamine. The full method with two chemical reactions (hydroxylamine and osmium tetroxide) should allow one person to screen with virtually 100% accuracy more than 300 kb of sequence in three ABI 373 gels in 1 day. 26 refs., 7 figs., 1 tab.

  14. On line portal imaging

    International Nuclear Information System (INIS)

    Purpose/Objective: The purpose of this presentation is to review the physics of imaging with high energy x-ray beams; examine the various imaging devices that have been developed for portal imaging; describe some of the image registration methods that have been developed to determine errors in patient positioning quantitatively; and discuss some of the ways that portal imaging has been incorporated into routine clinical practice. Verification of patient positioning has always been an important aspect of external beam radiation therapy. Checks of patient positioning have generally been done with film, however, film suffers from a number of drawbacks, such as poor image display and delays due to film development. Over the past decade many portal imaging devices have been developed by individual investigators and most accelerator manufacturers now offer 'on-line' portal imaging systems, which are intended to overcome the limitations of portal films. The commercial devices can be classified into three categories: T.V. camera-based systems, liquid ionisation chamber systems, and amorphous silicon systems. Many factors influence the quality of images generated by these portal imaging systems. These include factors which are unavoidable (e.g., low subject contrast), factors which depend upon the individual imaging device forming the image (e.g., dose utilisation, spatial resolution) as well as factors which depend upon the characteristics of the linear accelerator irradiating the imaging system (x-ray source size, image magnification). The fundamental factors which limit image quality and the characteristics of individual imaging systems, such as spatial resolution, temporal response, and quantum utilisation will be discussed. One of the major advantages of on-line portal imaging is that many quantitative techniques have been developed to detect errors in patient positioning. The general approach is to register anatomic structures on a portal image with the same

  15. Accelerated solvent extraction of vitamin K1 in medical foods in conjunction with matrix solid-phase dispersion.

    Science.gov (United States)

    Chase, G W; Thompson, B

    2000-01-01

    An extraction technique is described for vitamin K1 in medical foods, using accelerated solvent extraction (ASE) in conjunction with matrix solid-phase dispersion (MSPD). The medical food sample is treated as it would be with MSPD extraction, followed by ASE for a hands-free automated extraction. The vitamin K1 in the ASE extract is then quantitated by reversed-phase liquid chromatography with fluorescence detection. The chromatography specifications are identical to those in previous work that used MSPD only, with a limit of detection of 6.6 pg and a limit of quantitation of 22 pg on column. Recoveries, which were determined for an analyte-fortified zero control reference material for medical foods, averaged 97.6% (n = 25) for vitamin K1. The method provides a rapid, automatic, specific, and easily controlled assay for vitamin K1 in fortified medical foods with minimal solvent usage. PMID:10772179

  16. Determining the solid phases hosting arsenic in Mekong Delta sediments

    Science.gov (United States)

    Wucher, M.; Stuckey, J. W.; McCurdy, S.; Fendorf, S.

    2011-12-01

    The major river systems originating from the Himalaya deposit arsenic bearing sediment into the deltas of South and Southeast Asia. High rates of sediment and organic carbon deposition combined with frequent flooding leads to anaerobic processes that release arsenic into the pore-water. Arsenic concentrations in the groundwater of these sedimentary basins are often above the World Health Organization drinking water standard of 10 μg As L-1. As a result, 150 million people are at risk of chronic arsenic poisoning through water and rice consumption. The composition of the iron bearing phases hosting the arsenic in these deltaic sediments is poorly understood. Here we implemented a suite of selective chemical extractions to help constrain the types of arsenic bearing solid phases, which were complimented with synchrotron-based X-ray absorption spectroscopy and X-ray diffraction analyses to define the arsenic and iron mineralogy of the system. Sediment cores were collected in triplicate from a seasonally-inundated wetland in Cambodia at depths of 10, 50, 100, and 150 centimeters. We hypothesize that (i) arsenic will be predominantly associated with iron oxides, and (ii) the ratio of crystalline to amorphous iron oxides will increase with sediment depth (and age). We performed four selective extractions in parallel to quantify the various pools of arsenic. First, 1 M MgCl2 was used to extract electrostatically-bound arsenic (labile forms) from the sediment. Second, 1 M NaH2PO4 targeted strongly adsorbed arsenic. Third, 1 M HCl was used to liberated arsenic coprecipitated with amorphous Fe/Mn oxides, carbonates, and acid-volatile sulfides. Finally, a dithionite extraction was used to account for arsenic associated with reducible Fe/Mn oxides. Through this work, we identified the composition of the phases hosting arsenic at various depths through the soil profile, improving our understanding of how arsenic persists in the aquifer. In addition, defining the arsenic and

  17. Porous, High Capacity Coatings for Solid Phase Microextraction by Sputtering.

    Science.gov (United States)

    Diwan, Anubhav; Singh, Bhupinder; Roychowdhury, Tuhin; Yan, DanDan; Tedone, Laura; Nesterenko, Pavel N; Paull, Brett; Sevy, Eric T; Shellie, Robert A; Kaykhaii, Massoud; Linford, Matthew R

    2016-02-01

    We describe a new process for preparing porous solid phase microextraction (SPME) coatings by the sputtering of silicon onto silica fibers. The microstructure of these coatings is a function of the substrate geometry and mean free path of the silicon atoms, and the coating thickness is controlled by the sputtering time. Sputtered silicon structures on silica fibers were treated with piranha solution (a mixture of concd H2SO4 and 30% H2O2) to increase the concentration of silanol groups on their surfaces, and the nanostructures were silanized with octadecyldimethylmethoxysilane in the gas phase. The attachment of this hydrophobic ligand was confirmed by X-ray photoelectron spectroscopy and contact angle goniometry on model, planar silicon substrates. Sputtered silicon coatings adhered strongly to their surfaces, as they were able to pass the Scotch tape adhesion test. The extraction time and temperature for headspace extraction of mixtures of alkanes and alcohols on the sputtered fibers were optimized (5 min and 40 °C), and the extraction performances of SPME fibers with 1.0 or 2.0 μm of sputtered silicon were compared to those from a commercial 7 μm poly(dimethylsiloxane) (PDMS) fiber. For mixtures of alcohols, aldehydes, amines, and esters, the 2.0 μm sputtered silicon fiber yielded signals that were 3-9, 3-5, 2.5-4.5, and 1.5-2 times higher, respectively, than those of the commercial fiber. For the heavier alkanes (undecane-hexadecane), the 2.0 μm sputtered fiber yielded signals that were approximately 1.0-1.5 times higher than the commercial fiber. The sputtered fibers extracted low molecular weight analytes that were not detectable with the commercial fiber. The selectivity of the sputtered fibers appears to favor analytes that have both a hydrophobic component and hydrogen-bonding capabilities. No detectable carryover between runs was noted for the sputtered fibers. The repeatability (RSD%) for a fiber (n = 3) was less than 10% for all analytes tested

  18. Biological treatment of soils contaminated with hydrophobic organics using slurry and solid phase techniques

    International Nuclear Information System (INIS)

    Both slurry-phase and solid-phase bioremediation are effective ex situ soil decontamination methods. Slurry is energy intensive relative to solid-phase treatment, but provides homogenization and uniform nutrient distribution. Limited contaminant bioavailability at concentrations above the required cleanup level reduces biodegradation rates and renders solid phase bioremediation more cost effective than complete treatment in a bioslurry reactor. Slurrying followed by solid-phase bioremediation combines the advantages and minimizes the weaknesses of each treatment method when used alone. A biological treatment system consisting of slurrying followed by aeration in solid phase bioreactors was developed and tested in the laboratory using a silty clay load contaminated with diesel fuel. The first set of experiments was designed to determine the impact of the water content and mixing time during slurrying on the ate and extent of contaminant removal in continuously aerated solid phase bioreactors. The second set of experiments compared the volatile and total diesel fuel removal in solid phase bioreactors using periodic and continuous aeration strategies

  19. RESEARCH ON METHOD TO CALCULATE VELOCITIES OF SOLID PHASE AND LIQUID PHASE IN DEBRIS FLOW

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Velocities of solid phase and liquid phase in debris flow are one key problem to research on impact and abrasion mechanism of banks and control structures under action of debris flow. Debris flow was simplified as two-phase liquid composed of solid phase with the same diameter particles and liquid phase with the same mechanical features. Assume debris flow was one-dimension two-phase liquid moving to one direction,then general equations of velocities of solid phase and liquid phase were founded in twophase theory. Methods to calculate average pressures, volume forces and surface forces of debris flow control volume were established. Specially, surface forces were ascertained using Bingham's rheology equation of liquid phase and Bagnold's testing results about interaction between particles of solid phase. Proportional coefficient of velocities between liquid phase and solid phase was put forward, meanwhile, divergent coefficient between theoretical velocity and real velocity of solid phase was provided too. To state succinctly before, method to calculate velocities of solid phase and liquid phase was obtained through solution to general equations. The method is suitable for both viscous debris flow and thin debris flow. Additionally, velocities every phase can be identified through analyzing deposits in-situ after occurring of debris flow. It is obvious from engineering case the result in the method is consistent to that in real-time field observation.

  20. Solid phase precipitates in (Zr,Th)-OH-(oxalate, malonate) ternary aqueous system

    Energy Technology Data Exchange (ETDEWEB)

    Kobayashi, T.; Sasaki, T.; Takagi, I.; Moriyama, H. [Kyoto Univ. (Japan). Dept. of Nuclear Engineering

    2009-07-01

    The solubility-limiting solid phases in the ternary aqueous systems of Zr(IV)/OH/oxalate, Zr(IV)/OH/malonate, Th(IV)/OH/oxalate and Th(IV)/OH/malonate were characterized by elemental analysis, X-ray diffraction, thermogravimetric analysis and differential thermal analysis. The ternary solid phase of M(IV)/OH/carboxylate was observed to form, even under acidic conditions, depending on the pH and the concentration of carboxylate ligand. In the presence of a large excess of carboxylic acid, however; the binary M(IV)-carboxylate solid phase formed. (orig.)

  1. Atomic absorption spectrometric determination of some metal ions after preconcentration by solid phase extraction using amberlite XAD 16 resin loaded with thenoyltrifluoroacetone

    International Nuclear Information System (INIS)

    Complete text of publication follows. The direct determination of extremely low concentrations of trace elements by modern atomic spectroscopic methods, such as atomic absorption spectrometry and inductively coupled plasma atomic emission spectrometry is often difficult because of insufficient sensitivity and selectivity of the methods used. For this reason, the preliminary separation and preconcentration of trace elements from the matrix are often required. Solid phase extraction shows several major advantages such as simplicity, rapidity and high enrichment factor, the ability of combination with different detection techniques in the form of on-line or off-line mode and finally cost saving (Tokalioglu et al., Microchim Acta 164 (2009) 471-477.). A new solid phase extraction method for the separation and preconcentration of Cu(II), Pb(II), Ni(II), Co(II), Mn(II) and Fe(III) ions was developed. As solid phase material, Amberlite XAD-16 resin loaded with thenoyltrifluoroacetone (TTA) was used. For this purpose, 0.5 g of the resin was saturated with 10 mL of 0.5% (w/v) TTA solution. After preconcentrating, the metals retained on the resin were eluted with 10 mL of 2 mol L-1 HCl and then determined by flame atomic absorption spectrometry. The effect of some parameters for the preconcentration of the metal ions was investigated. The optimum pH was found as 6. Eluent for quantitative elution was 10 mL of 2 mol L-1 HCl.

  2. Solid-Phase Thermophilic Aerobic Reactor (STAR) Processing of Fecal, Food, and Plant Residues

    OpenAIRE

    2006-01-01

    A description of the Solid Waste Resource Recovery ALS-NSCORT projects: Solid Phase Thermophilic Aerobic Reactor (STAR), Nitrogen Cycling in Advanced Life Support Systems, and Plant-based Anaerobic-Aerobic Bioreactor Linked Operation (PAABLO). 26 pages.

  3. Study on New Sensitive Method of Determination of Phosphorus by Solid Phase Spectrophotometry

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    The use of solid phase spectrophotometry for the determination of trace phosphorus in the system of phosphomolybdate-fructose is described. The adsorption of the system on anion-exchange resin is reported.

  4. Facile synthesis of aliphatic isothiocyanates and thioureas on solid phase using peptide coupling reagents

    DEFF Research Database (Denmark)

    Boas, Ulrik; Andersen, Heidi Gertz; Christensen, Jørn B.;

    2004-01-01

    Peptide coupling reagents can be used as versatile reagents for the formation of aliphatic isothiocyanates and thioureas on solid phase from the corresponding solid-phase anchored aliphatic primary amines. The formation of the thioureas is fast and highly chemoselective, and proceeds via formation...... of the intermediate isothiocyanate. The isothiocyanate and subsequent thiourea formation take place under standard peptide coupling conditions using carbon disulfide as the 'amino acid'. The thioureas are released from the resin and isolated in moderate to high yields....

  5. SOLID PHASE SPECTROPHOTOMETRIC DETERMINATION OF SELENIUM(IV) USING DITHISONE IMMOBILIZED IN A POLYMETHACRYLATE MATRIX

    OpenAIRE

    Gavrilenko, N. A.; Saranchina, N. V.; Gavrilenko, M. A.

    2014-01-01

    This paper presents a solid-phase spectrophotometric method for the determination selenium(IV). The proposed method is based on the reaction between the selenium(IV) and dithizone immobilized into transparent polymethacrylate matrix in strongly acidic solution. It was shown that the interaction of selenium(IV) with dithizone in solid phase was accompanied by the formation of the complex with an absorption maximum 420 nm. The change of absorption at wavelength 610 nm corresponding to absorptio...

  6. Design of molecularly imprinted polymers for sensors and solid phase extraction

    OpenAIRE

    Subrahmanyam, Sreenath

    2002-01-01

    This thesis presents broadly the applications of molecularly imprinted polymers in sensors and solid phase extraction. Sensors for creatine and creatinine have been reported using a novel method of rational design of molecularly imprinted polymers (MIPs), and solid phase extraction of aflatoxin-B 1 has also been described in the thesis. A method for the selective detection of creataine and creatinine is reported in this thesis, which is based on the reaction between polymeri...

  7. Preparation of Pt/C Catalyst with Solid Phase Reaction Method

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    The Pt/C catalyst was prepared with solid phase reaction method (Pt/C(S)) for the first time. Its performances were compared with that prepared by the traditional liquid phase reaction method. The results demonstrate that the electrocatalytic activity of Pt/C catalyst with solid phase reaction method for methanol oxidation is higher than that with liquid phase reaction method. XRD and TEM measurements indicate that the Pt/C(S) possesses low crystalline extent and small particle size.

  8. Nuclear Energy Research Initiative Project No. 02 103 Innovative Low Cost Approaches to Automating QA/QC of Fuel Particle Production Using On Line Nondestructive Methods for Higher Reliability Final Project Report

    Energy Technology Data Exchange (ETDEWEB)

    Ahmed, Salahuddin; Batishko, Charles R.; Flake, Matthew; Good, Morris S.; Mathews, Royce; Morra, Marino; Panetta, Paul D.; Pardini, Allan F.; Sandness, Gerald A.; Tucker, Brian J.; Weier, Dennis R.; Hockey, Ronald L.; Gray, Joseph N.; Saurwein, John J.; Bond, Leonard J.; Lowden, Richard A.; Miller, James H.

    2006-02-28

    This Nuclear Energy Research Initiative (NERI) project was tasked with exploring, adapting, developing and demonstrating innovative nondestructive test methods to automate nuclear coated particle fuel inspection so as to provide the United States (US) with necessary improved and economical Quality Assurance and Control (QA/QC) that is needed for the fuels for several reactor concepts being proposed for both near term deployment [DOE NE & NERAC, 2001] and Generation IV nuclear systems. Replacing present day QA/QC methods, done manually and in many cases destructively, with higher speed automated nondestructive methods will make fuel production for advanced reactors economically feasible. For successful deployment of next generation reactors that employ particle fuels, or fuels in the form of pebbles based on particles, extremely large numbers of fuel particles will require inspection at throughput rates that do not significantly impact the proposed manufacturing processes. The focus of the project is nondestructive examination (NDE) technologies that can be automated for production speeds and make either: (I) On Process Measurements or (II) In Line Measurements. The inspection technologies selected will enable particle “quality” qualification as a particle or group of particles passes a sensor. A multiple attribute dependent signature will be measured and used for qualification or process control decisions. A primary task for achieving this objective is to establish standard signatures for both good/acceptable particles and the most problematic types of defects using several nondestructive methods.

  9. Coupling solid-phase extraction and enzyme-linked immunosorbent assay for ultratrace determination of herbicides in pristine water

    Science.gov (United States)

    Aga, D.S.; Thurman, E.M.

    1993-01-01

    Solid-phase extraction (SPE) and enzyme-linked immunosorbent assay (ELISA) were coupled for automated trace analysis of pristine water samples containing 2-chloro-4-ethylamino-6-isopropylamine-s-triazine (atrazine) and 2-chloro-2???,6???-diethyl-N-(methoxymethyl)acetanilide (alachlor). The isolation of the two herbicides on a C18-resin involved the selection of an elution solvent that both removes interfering substances and is compatible with ELISA. Ethyl acetate was selected as the elution solvent followed by a solvent exchange with methanol/water (20/80, % v/v). The SPE-ELISA method has a detection limit of 5.0 ng/L (5 ppt), >90% recovery, and a relative standard deviation of ??10%. The performance of a microtiter plate-based ELISA and a magnetic particle-based ELISA coupled to SPE was also evaluated. Although the sensitivity of the two ELISA methods was comparable, the precision using magnetic particles was improved considerably (??10% versus ??20%) because of the faster reaction kinetics provided by the magnetic particles. Finally, SPE-ELISA and isotope dilution gas chromatography/ mass spectrometry correlated well (correlation coefficient of 0.96) for lake-water samples. The SPE-ELISA method is simple and may have broader applications for the inexpensive automated analysis of other contaminants in water at trace levels.

  10. Volume Overload Cleanup: An Approach for On-line SPE-GC, GPC-GC and GPC-SPE-GC

    NARCIS (Netherlands)

    Kerkdijk, H.; Mol, J.G.J.; Nagel, van der B.

    2007-01-01

    A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the determi

  11. Volume overload cleanup: An approach for on-line SPE-GC, GPC-GC, and GPC-SPE-GC

    NARCIS (Netherlands)

    Kerkdijk, H.; Mol, H.G.J.; Nagel, B. van der

    2007-01-01

    A new concept for cleanup, based on volume overloading of the cleanup column, has been developed for on-line coupling of gel permeation chromatography (GPC), solid-phase extraction (SPE), or both, to gas chromatography (GC). The principle is outlined and the applicability demonstrated by the determi

  12. Determination of amphetamine-type stimulants in oral fluid by solid-phase microextraction and gas chromatography-mass spectrometry

    Energy Technology Data Exchange (ETDEWEB)

    Souza, Daniele Z., E-mail: daniele.dzs@dpf.gov.br [Setor Tecnico-Cientifico, Superintendencia Regional do Departamento de Policia Federal no Rio Grande do Sul, 1365 Ipiranga Avenue, Azenha, Zip Code 90160-093 Porto Alegre, Rio Grande do Sul (Brazil); Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Boehl, Paula O.; Comiran, Eloisa; Mariotti, Kristiane C. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil); Pechansky, Flavio [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Duarte, Paulina C.A.V. [Secretaria Nacional de Politicas sobre Drogas (SENAD), Esplanada dos Ministerios, Block ' A' , 5th floor, Zip Code 70050-907 Brasilia, Distrito Federal (Brazil); De Boni, Raquel [Centro de Pesquisa em Alcool e Drogas (CPAD), Hospital de Clinicas de Porto Alegre, Universidade Federal do Rio Grande do Sul, 2350, Ramiro Barcelos Street, Zip Code 90035-903 Porto Alegre, Rio Grande do Sul (Brazil); Froehlich, Pedro E.; Limberger, Renata P. [Programa de Pos-Graduacao em Ciencias Farmaceuticas, Faculdade de Farmacia, Universidade Federal do Rio Grande do Sul, 2752 Ipiranga Avenue, Santana, Zip Code 90610-000 Porto Alegre, Rio Grande do Sul (Brazil)

    2011-06-24

    Graphical abstract: Highlights: > Propylchloroformate derivatization of amphetamine-type stimulants in oral fluid. > Direct immersion solid-phase microextraction/gas chromatography-mass spectrometry. > Linear range 2(4)-256 ng mL{sup -1}, detection limits 0.5-2 ng mL{sup -1}. > Accuracy 98-112%, precision <15% of RSD, recovery 77-112%. > Importance of residual evaluation in checking model goodness-of-fit. - Abstract: A method for the simultaneous identification and quantification of amphetamine (AMP), methamphetamine (MET), fenproporex (FEN), diethylpropion (DIE) and methylphenidate (MPH) in oral fluid collected with Quantisal{sup TM} device has been developed and validated. Thereunto, in-matrix propylchloroformate derivatization followed by direct immersion solid-phase microextraction and gas chromatography-mass spectrometry were employed. Deuterium labeled AMP was used as internal standard for all the stimulants and analysis was performed using the selected ion monitoring mode. The detector response was linear for the studied drugs in the concentration range of 2-256 ng mL{sup -1} (neat oral fluid), except for FEN, whereas the linear range was 4-256 ng mL{sup -1}. The detection limits were 0.5 ng mL{sup -1} (MET), 1 ng mL{sup -1} (MPH) and 2 ng mL{sup -1} (DIE, AMP, FEN), respectively. Accuracy of quality control samples remained within 98.2-111.9% of the target concentrations, while precision has not exceeded 15% of the relative standard deviation. Recoveries with Quantisal{sup TM} device ranged from 77.2% to 112.1%. Also, the goodness-of-fit concerning the ordinary least squares model in the statistical inference of data has been tested through residual plotting and ANOVA. The validated method can be easily automated and then used for screening and confirmation of amphetamine-type stimulants in drivers' oral fluid.

  13. Pesticide residue analysis by off-line SPE and on-line reversed-phase LC-GC using the through-oven-transfer adsorption/desorption interface.

    Science.gov (United States)

    Perez, M; Alario, J; Vazquez, A; Villén, J

    2000-02-15

    A new method to determine pesticide residue in water is presented. The described method includes using off-line solid-phase extraction (SPE) and on-line reversed-phase liquid chromatography-gas chromatography (RPLC-GC). An interface, based on a modified programmed temperature vaporizer (PTV) injector, packed with a suitable trapping material, is used for on-line RPLC-GC. The changes made in the PTV injector affect the pneumatic system, sample introduction, and solvent elimination. The new interface is easily capable of automation. Methanol/wate (70/30) is used as the eluent in the LC preseparation step. The LC column flow during elution is different from the flow during the transfer step. The transferred volumes range from 500 to 1400 microL (volume of the fractions of interest). Solvent elimination is almost 100% before the sample reaches the GC column. The described system does not show any variation of the peak retention times. The detection limit for real samples ranges from 0.04 to 1.5 ng/L, using NP detection.

  14. Enhanced denitrification of Pseudomonas stutzeri by a bioelectrochemical system assisted with solid-phase humin.

    Science.gov (United States)

    Xiao, Zhixing; Awata, Takanori; Zhang, Dongdong; Zhang, Chunfang; Li, Zhiling; Katayama, Arata

    2016-07-01

    The denitrification reactions performed by Pseudomonas stutzeri JCM20778 were enhanced electrochemically with the use of solid-phase humin, although P. stutzeri itself was incapable of receiving electrons directly from the graphite electrode. Electrochemically reduced humin enhanced the microbial, but not abiotic, denitrification reactions. Electric current and cyclic voltammetry analyses suggested that the solid-phase humin functioned as an electron donor for the denitrification reactions of P. stutzeri. Nitrogen balance study and the estimation of the first-order rate constants of the consecutive denitrification reactions suggested that the solid-phase humin enhanced all reducing reactions from nitrate to nitrogen gas. Considering the wide distribution of humin in the environment, the findings that solid-phase humin can assist in electron transfer, from the electrode to a denitrifying bacterium that has little ability to directly utilize external electrons, has important implications for the widespread application of bioelectrochemical systems assisted by solid-phase humin for enhancing microbial denitrification.

  15. Headspace solid phase microextraction (HSSPME) for the determination of volatile and semivolatile pollutants in soils

    Energy Technology Data Exchange (ETDEWEB)

    Llompart, Maria [Departamento de Quimica Analitica Nutricion y Bromatologia, Facultad de Quimica, Universidad de Santiago de Compostela, E-15706 Santiago de Compostela (Spain); Li, Ken; Fingas, Merv [Emergencies Science Division, Environment Canada, Environmental Technology Centre, 3439 River Road, Ottawa, ON (Canada)

    1999-02-08

    We have investigated the use of headspace solid phase microextraction (HSSPME) as a sample concentration and preparation technique for the analysis of volatile and semivolatile pollutants in soil samples. Soil samples were suspended in solvent and the SPME fibre suspended in the headspace above the slurry. Finally, the fibre was desorbed in the Gas Chromatograph (GC) injection port and the analysis of the samples was carried out. Since the transfer of contaminants from the soil to the SPME fibre involves four separate phases (soil-solvent-headspace and fibre coating), parameters affecting the distribution of the analytes were investigated. Using a well-aged artificially spiked garden soil, different solvents (both organic and aqueous) were used to enhance the release of the contaminants from the solid matrix to the headspace. It was found that simple addition of water is adequate for the purpose of analysing the target volatile organic chemicals (VOCs) in soil. The addition of 1 ml of water to 1 g of soil yielded maximum response. Without water addition, the target VOCs were almost not released from the matrix and a poor response was observed. The effect of headspace volume on response as well as the addition of salt were also investigated. Comparison studies between conventional static headspace (HS) at high temperature (95C) and the new technology HSSPME at room temperature (=20C) were performed. The results obtained with both techniques were in good agreement. HSSPME precision and linearity were found to be better than automated headspace method and HSSPME also produced a significant enhancement in response. The detection and quantification limits for the target VOCs in soils were in the sub-ng g{sup -1} level. Finally, we tried to extend the applicability of the method to the analysis of semivolatiles. For these studies, two natural soils contaminated with diesel fuel and wood preservative, as well as a standard urban dust contaminated with polyaromatic

  16. Development and Optimization of Sepharose Solid Phase Radioimmunoassay for Estimation of Thyroid Stimulating Hormone

    International Nuclear Information System (INIS)

    The aim of the present study was oriented to develop, optimize and validate solid phase radioimmunoassay, through many studies on Sepharose, for estimation of thyroid stimulating hormone in humane serum. Preparation of polyclonal antibodies was carried out in host rabbit animals against TSH antigen followed by partial purification of 1gG. Linkage of antibody 1gG to activated Sepharose CL-4B was carried out after activation of Sepharose with 1,1- carbonyldiimidazole. Labeling of TSH was carried out using chloramine-T as an oxidizing agent and the labeled tracer was purified through PD-10 column. Extensive studies were carried out to obtain the optimum conditions of using solid phase Sepharose to reach higher separation efficiency. The results of validation tests reveal that the local solid phase system is precise and accurate for evaluation of thyroid disorders

  17. Solid-phase microextraction for bioconcentration studies according to OECD TG 305

    Energy Technology Data Exchange (ETDEWEB)

    Duering, Rolf-Alexander; Boehm, Leonard [Land Use and Nutrition (IFZ) Justus Liebig University Giessen, Institute of Soil Science and Soil Conservation, Research Centre for BioSystems, Giessen (Germany); Schlechtriem, Christian [Fraunhofer Institute for Molecular Biology and Applied Ecology (IME), Schmallenberg (Germany)

    2012-12-15

    An important aim of the European Community Regulation on chemicals and their safe use is the identification of (very) persistent, (very) bioaccumulative, and toxic substances. In other regulatory chemical safety assessments (pharmaceuticals, biocides, pesticides), the identification of such (very) persistent, (very) bioaccumulative, and toxic substances is of increasing importance. Solid-phase microextraction is especially capable of extracting total water concentrations as well as the freely dissolved fraction of analytes in the water phase, which is available for bioconcentration in fish. However, although already well established in environmental analyses to determine and quantify analytes mainly in aqueous matrices, solid-phase microextraction is still a rather unusual method in regulatory ecotoxicological research. Here, the potential benefits and drawbacks of solid-phase microextraction are discussed as an analytical routine approach for aquatic bioconcentration studies according to OECD TG 305, with a special focus on the testing of hydrophobic organic compounds characterized by log K{sub OW}> 5. (orig.)

  18. Solid-Phase Synthesis of Amine/Carboxyl Substituted Prolines and Proline Homologues: Scope and Limitations.

    Science.gov (United States)

    Zhou, Ziniu; Scott, William L; O'Donnell, Martin J

    2016-03-15

    A solid-phase procedure is used to synthesize racemic peptidomimetics based on the fundamental peptide unit. The peptidomimetics are constructed around proline or proline homologues variably substituted at the amine and carbonyl sites. The procedure expands the diversity of substituted peptidomimetic molecules available to the Distributed Drug Discovery (D3) project. Using a BAL-based solid-phase synthetic sequence the proline or proline homologue subunit is both constructed and incorporated into the peptidomimetic by an α-alkylation, hydrolysis and intramolecular cyclization sequence. Further transformations on solid-phase provide access to a variety of piperazine derivatives representing a class of molecules known to exhibit central nervous system activity. The procedure works well with proline cores, but with larger six- and seven-membered ring homologues the nature of the carboxylic acid acylating the cyclic amine can lead to side reactions and result in poor overall yields.

  19. Proposed method for controlling turbid particles in solid-phase bioluminescent toxicity measurement.

    Science.gov (United States)

    Yeo, Seul-Ki; Park, Jun-Boum; Ahn, Joo-Sung; Han, Young-Soo

    2015-06-01

    In the recent half century, numerous methods have been developed to assess ecological toxicity. However, the presence of solid-particle turbidity sometimes causes such tests to end with questionable results. Many researchers focused on controlling this arbitrary turbidity effect when using the Microtox® solid-phase toxicity system, but there is not yet a standard method. In this study, we examined four solid-phase sample test methods recommended in the Microtox® manual, or proposed from the literature, and compared the existing methods with our proposed method (centrifuged basic solid-phase test, c-BSPT). Four existing methods use the following strategies to control turbid particles: complete separation of liquid and solid using 0.45-μm filtration before contacting solid samples and bacteria, natural settlement, moderate separation of large particles using coarser pore size filtration, and exclusion of light loss in the toxicity calculation caused by turbidity after full disturbance of samples. Our proposed method uses moderate centrifugation to separate out the heavier soil particles from the lighter bacteria after direct contact between them. Among the solid-phase methods tested, in which the bacteria and solid particles were in direct contact (i.e., the three existing methods and the newly proposed one, c-BSPT), no single method could be recommended as optimal for samples over a range of turbidity. Instead, a simple screening strategy for selecting a sample-dependent solid-phase test method was suggested, depending on the turbidity of the solid suspension. The results of this study highlight the importance of considering solid particles, and the necessity for optimal selection of test method to reduce errors in the measurement of solid-phase toxicity.

  20. Extraction of Pb2+ using Silica from Rice Husks Ash (RHA – Chitosan as Solid Phase

    Directory of Open Access Journals (Sweden)

    Hanandayu Widwiastuti

    2013-03-01

    Full Text Available The existence of lead (Pb compounds in waters can be caused of waste pollution from industrial activities such as dye and battery industries. Lead has toxic characteristic and is able to causing deseases. The levels of Cr(VI can be decreased by methods such as electroplating, oxidation, reduction, and membrane separation. But this methods require high cost and produce a lot of waste. Furthermore, those methods cannot determine the small concentration of Pb2+. Therefore, solid phase extraction is used because it’s a simple method and can be used to preconcentrate Pb2+ ion. The aim of this study is to create solid phase from nature material as an alternative method to determine Pb2+ in water samples. The solid phase is silica from rice husks ash (RHA that was modified using chitosan. To achieve that aim, the optimization of silica : chitosan composition was done. The influence of Pb2+ concentration and citric acid concentration was studied to obtain optimum recovery of Pb2+. Interaction between Pb2+ ion and solid phase silica – chitosan could be estimated based on the result. The result showed the optimum composition of silica : chitosan is 65% silica : 35% chitosan with Cation Exchange Capacity (CEC 0.00455 mek/g. Mass Adsorbed Pb2+for 1 g silica : chitosan 65% is 9.715 mg/g. Optimum recovery of Pb2+ on solid phase extraction is reached at concentration of Pb2+ 10 ppm and citric acid concentration 0.05 M (88.25 % and 81.18 %. This result showed that solid phase extraction using silica – chitosan can be used as an alternative method to determine Pb2+ in water.

  1. Solid-Phase Spectrophotometric Analysis of 1-Naphthol Using Silica Functionalized with m-Diazophenylarsonic Acid.

    Science.gov (United States)

    Zaitseva, Nataliya; Alekseev, Sergei; Zaitsev, Vladimir; Raks, Viktoria

    2016-12-01

    The m-aminophenylarsonic acid (m-APAA) was immobilized onto the silica gel surface with covalently grafted quaternary ammonium groups via ion exchange. The diazotization of ion-bonded m-APAA resulted in a new solid-phase spectrophotometric reagent for detection of 1-naphtol in environmental water samples. The procedure of solid-phase spectrophotometric analysis is characterized by 20 μg L(-1) limit of detection (LOD) of 1-naphtol, up to 2000 concentration factor, and insensitivity to the presence of natural water components as well as to 30-fold excess of phenol, resorcinol, and catechol. PMID:26979727

  2. CuAAC: An Efficient Click Chemistry Reaction on Solid Phase.

    Science.gov (United States)

    Castro, Vida; Rodríguez, Hortensia; Albericio, Fernando

    2016-01-11

    Click chemistry is an approach that uses efficient and reliable reactions, such as Cu(I)-catalyzed azide-alkyne cycloaddition (CuAAC), to bind two molecular building blocks. CuAAC has broad applications in medicinal chemistry and other fields of chemistry. This review describes the general features and applications of CuAAC in solid-phase synthesis (CuAAC-SP), highlighting the suitability of this kind of reaction for peptides, nucleotides, small molecules, supramolecular structures, and polymers, among others. This versatile reaction is expected to become pivotal for meeting future challenges in solid-phase chemistry.

  3. Solid-Phase Synthetic Route to Multiple Derivatives of a Fundamental Peptide Unit

    Directory of Open Access Journals (Sweden)

    Martin J. O’Donnell

    2010-07-01

    Full Text Available Amino acids are Nature’s combinatorial building blocks. When substituted on both the amino and carboxyl sides they become the basic scaffold present in all peptides and proteins. We report a solid-phase synthetic route to large combinatorial variations of this fundamental scaffold, extending the variety of substituted biomimetic molecules available to successfully implement the Distributed Drug Discovery (D3 project. In a single solid-phase sequence, compatible with basic amine substituents, three-point variation is performed at the amino acid a-carbon and the amino and carboxyl functionalities.

  4. A Convergent Solid-Phase Synthesis of Actinomycin Analogues - Towards Implementation of Double-Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Tong, Glenn; Nielsen, John

    1996-01-01

    with the requirements for combinatorial synthesis and furthermore, the final segment condensation allows, for the first time, double-combinatorial chemistry to be performed where two combinatorial libraries can be reacted with each other. Copyright (C) 1996 Elsevier Science Ltd....... of peptide-aryl-peptide conjugates modeled upon natural actinomycins. The features of this method include the use of Fmoc solid-phase peptide synthesis, side-chain to side-chain cyclization on the solid phase, a chemoselective cleavage step and segment condensation. The synthetic scheme is consistent...

  5. Synthesis of a Small Library of Imidazolidin-2-ones using Gold Catalysis on Solid Phase.

    Science.gov (United States)

    La-Venia, Agustina; Medran, Noelia S; Krchňák, Viktor; Testero, Sebastián A

    2016-08-01

    An efficient and high-yielding solid phase synthesis of a small library of imidazolidin-2-ones and imidazol-2-ones was carried out employing a high chemo- and regioselective gold-catalyzed cycloisomerization as a key step. Polymer-supported amino acids derivatized with several alkyne functionalities combined with tosyl- and phenylureas have been subjected to gold-catalysis exhibiting exclusively C-N bond formation. The present work proves the potential of solid phase synthesis and homogeneous gold catalysis as an efficient and powerful synthetic tool for the generation of drug-like heterocycles. PMID:27337593

  6. Detection of ibuprofen and ciprofloxacin by solid-phase extraction and UV/Vis spectroscopy

    Science.gov (United States)

    Zhou, Zhengwei; Jiang, Jia Qian

    2012-07-01

    A simple and economic solid-phase extraction coupled with UV/Vis spectrophotometric method is described for the analysis of ibuprofen and ciprofloxacin. Following solid-phase extraction from model wastewater samples containing standard ibuprofen or ciprofloxacin, elutes were analyzed by a UV/Vis spectrophotometer at 225 nm for ibuprofen and 280 nm for ciprofloxacin. The assay was linear for both compounds with good coefficients of correlation. This method shows good recoveries for both compounds with 101.0 ± 9.8% for ibuprofen and 99.4 ± 11.8% ciprofloxacin.

  7. Solid Phase Extraction: Applications to the Chromatographic Analysis of Vegetable Oils and Fats

    Energy Technology Data Exchange (ETDEWEB)

    Panagiotopoulout, P. M.; Tsimidou, M.

    2002-07-01

    Applications of solid-phase extraction for the isolation of certain lipid classes prior to chromatographic analysis are given. More information was found for sterols and related compounds, polar phenols and contaminants such as polycyclic aromatic hydrocarbons. Detailed analytical protocols are presented and discussed in many cases. (Author) 120 refs.

  8. Solid-phase Synthesis of a Novel Kind of Hydroxylated Heterocyclic Ketene Aminals

    Institute of Scientific and Technical Information of China (English)

    Tao PENG; Chu Yi YU; Zhi Tang HUANG

    2006-01-01

    An efficient solid-phase synthesis method for novel heterocyclic ketene aminals containing a hydroxyl group has been developed. The loading of the substrate on the resin through the hydroxyl group and the protection of the amine by the Schiff base were the key steps in the synthesis.

  9. Solid phase stability of molybdenum under compression: Sound velocity measurements and first-principles calculations

    International Nuclear Information System (INIS)

    The high-pressure solid phase stability of molybdenum (Mo) has been the center of a long-standing controversy on its high-pressure melting. In this work, experimental and theoretical researches have been conducted to check its solid phase stability under compression. First, we performed sound velocity measurements from 38 to 160 GPa using the two-stage light gas gun and explosive loading in backward- and forward-impact geometries, along with the high-precision velocity interferometry. From the sound velocities, we found no solid-solid phase transition in Mo before shock melting, which does not support the previous solid-solid phase transition conclusion inferred from the sharp drops of the longitudinal sound velocity [Hixson et al., Phys. Rev. Lett. 62, 637 (1989)]. Then, we searched its structures globally using the multi-algorithm collaborative crystal structure prediction technique combined with the density functional theory. By comparing the enthalpies of body centered cubic structure with those of the metastable structures, we found that bcc is the most stable structure in the range of 0–300 GPa. The present theoretical results together with previous ones greatly support our experimental conclusions

  10. A Photolabile Linker for the Solid-Phase Synthesis of Peptide Hydrazides and Heterocycles

    DEFF Research Database (Denmark)

    Qvortrup, Katrine; Komnatnyy, Vitaly V.; Nielsen, Thomas Eiland

    2014-01-01

    A photolabile hydrazine linker for the solid-phase synthesis of peptide hydrazides and hydrazine-derived heterocycles is presented. The developed protocols enable the efficient synthesis of structurally diverse peptide hydrazides derived from the standard amino adds, including those with side...

  11. A Solid Phase Synthesis of Chalcones by Claisen-Schmidt Condensations

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    In order to accelerate the development of relatively inexpensive antimalarials that are effective against chloroquine-resistant strains of Plasmodium falclparum, a methodology for the solid phase synthesis of chalcone (l, 3-diphenyl-2-propen-l-one) analogues in reasonably high yields has been developed.

  12. Matrix solid-phase dispersion for the liquid chromatographic determination of phenolic acids in Melissa officinalis.

    Science.gov (United States)

    Ziaková, Alica; Brandsteterová, Eva; Blahová, Eva

    2003-01-01

    Matrix solid-phase dispersion (MSPD) was used for sample preparation of plant material (Melissa officinalis, Lemon Balm) prior to liquid chromatography of rosmarinic, caffeic and protocatechuic acids, phenolic compounds present in this herb. Different MSPD sorbents and various elution agents were tested and the optimal extraction conditions determined with the aim to obtain extraction recoveries greater than 90% for all analytes. PMID:12568390

  13. Use of Solid Phase Extraction in the Biochemistry Laboratory to Separate Different Lipids

    Science.gov (United States)

    Flurkey, William H.

    2005-01-01

    Solid-phase extraction (SPE) was used to demonstrate how various lipids and lipid classes could be separated in a biochemistry laboratory setting. Three different SPE methods were chosen on their ability to separate a lipid mixture, consisting of a combination of a either a fatty acid, a triacylglycerol, a mono- or diacylglycerol, phospholipid,…

  14. Kinetic study of solid phase crystallisation of expanding thermal plasma deposited a-Si:H

    NARCIS (Netherlands)

    Law, F.; Hoex, B.; Wang, J.; Luther, J.; Sharma, K.; Creatore, M.; M. C. M. van de Sanden,

    2012-01-01

    In-situ X-ray diffraction was used to study the dynamics of the solid phase crystallisation (SPC) of hydrogenated amorphous silicon (a-Si:H) films deposited by expanding thermal plasma technique. The Johnson-Mehl-Avrami-Kolmogorov model was used for the analysis of the dynamic data and the activatio

  15. Side-chain-anchored N(alpha)-Fmoc-Tyr-OPfp for bidirectional solid-phase synthesis

    DEFF Research Database (Denmark)

    Olsen, Christian A; Jørgensen, Malene; Hansen, Steen H;

    2005-01-01

    [reaction: see text] A mild resin-immobilization strategy employing a readily prepared trityl bromide resin for anchoring building blocks via a phenol group has been developed. With N(alpha)-Fmoc-Tyr-OPfp as a starter building block, it was possible to prepare asymmetrically substituted hybrids o...... of spider- and wasp-type polyamine toxins using solid-phase peptide synthesis conditions....

  16. Dynamic speciation analysis of atrazine in aqueous latex nanoparticle dispersions using solid phase microextraction (SPME)

    NARCIS (Netherlands)

    Benhabib, K.; Town, R.M.; Leeuwen, van H.P.

    2009-01-01

    Solid phase microextraction (SPME) is applied in the dynamic speciation analysis of the pesticide atrazine in an aqueous medium containing sorbing latex nanoparticles. It is found that the overall rate of extraction of the analyte is faster than in the absence of nanoparticles and governed by the co

  17. Indirect solid-phase immunosorbent assay for detection of arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A. (Institute of Poliomyelitis anU Viral Encephalities of the U.S.S.R. Academy of Medical Sciences, Moscow)

    1984-05-01

    Indirect enzyme-linked immunosorbent assay (ELISA) and solid phase radioimmunoassay (SPRIA) using either enti-human or anti-mouse IgG labelled with horseradish peroxidase and /sup 125/I, respectively, were developed for the detection of Junin, Machupo, Tacaribe, Amapari, Tamiami, Lassa and LCM arenaviruses. Both methods allow high sensitivity detection of arenavirus antigens and antibodies.

  18. Solid-solid and liquid-solid phase equilibria for the restricted primitive model

    NARCIS (Netherlands)

    Smit, B.; Esselink, K.; Frenkel, D.

    1996-01-01

    A Monte Carlo simulation study is made of the phase diagram of the restricted primitive model and of the solid-liquid and solid-solid phase coexistence curves in particular. At low temperatures, there is liquid-bcc coexistence and with increasing density there is bcc-fcc coexistence. These coexisten

  19. Micro versus macro solid phase extraction for monitoring water contaminants: a preliminary study using trihalomethanes.

    Science.gov (United States)

    Alexandrou, Lydon D; Spencer, Michelle J S; Morrison, Paul D; Meehan, Barry J; Jones, Oliver A H

    2015-04-15

    Solid phase extraction is one of the most commonly used pre-concentration and cleanup steps in environmental science. However, traditional methods need electrically powered pumps, can use large volumes of solvent (if multiple samples are run), and require several hours to filter a sample. Additionally, if the cartridge is open to the air volatile compounds may be lost and sample integrity compromised. In contrast, micro cartridge based solid phase extraction can be completed in less than 2 min by hand, uses only microlitres of solvent and provides comparable concentration factors to established methods. It is also an enclosed system so volatile components are not lost. The sample can also be eluted directly into a detector (e.g. a mass spectrometer) if required. However, the technology is new and has not been much used for environmental analysis. In this study we compare traditional (macro) and the new micro solid phase extraction for the analysis of four common volatile trihalomethanes (trichloromethane, bromodichloromethane, dibromochloromethane and tribromomethane). The results demonstrate that micro solid phase extraction is faster and cheaper than traditional methods with similar recovery rates for the target compounds. This method shows potential for further development in a range of applications.

  20. Final Report for Nucleation and growth of semiconductor nanocrystals by solid-phase reaction

    Energy Technology Data Exchange (ETDEWEB)

    P. D. Persans; T. M. Hayes

    2005-12-12

    This final report describes the technical output of a scientific program aimed at understanding the formation and structure of II-VI nanocrystals formed by solid phase precipitation within a glass environment. The principle probes were optical absorption spectroscopy to determine crystallite sizes, Raman scattering to determine composition, and x-ray absorption spectroscopy to study the evolution of local reactant environments.

  1. A convenient procedure for the solid-phase synthesis of hydroxamic acids on PEGA resins

    DEFF Research Database (Denmark)

    Nandurkar, Nitin Subhash; Petersen, Rico; Qvortrup, Katrine;

    2011-01-01

    An efficient method for the solid-phase synthesis of hydroxamic acids is described. The method comprises the nucleophilic displacement of esters immobilized on PEGA resins with hydroxylamine/sodium hydroxide in isopropanol. The hydroxyaminolysis protocol is compatible with a broad range of PEGA...

  2. Linkers, resins, and general procedures for solid-phase peptide synthesis

    DEFF Research Database (Denmark)

    Shelton, Anne Pernille Tofteng; Jensen, Knud Jørgen

    2013-01-01

    and linkers for solid-phase synthesis is a key parameter for successful peptide synthesis. This chapter provides an overview of the most common and useful resins and linkers for the synthesis of peptides with C-terminal amides, carboxylic acids, and more. The chapter finishes with robust protocols for general...

  3. The Pictet-Spengler reaction in solid-phase combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, Thomas E; Diness, Frederik; Meldal, Morten

    2003-01-01

    The Pictet-Spengler reaction is an important reaction for the generation of tetrahydro-beta-carbolines and tetrahydroisoquinoline ring systems, which exhibit a range of biological and pharmacological properties. This review covers the solid-phase Pictet-Spengler reaction, as employed in solid...

  4. Determination of Plant Volatiles Using Solid Phase Microextraction GC-MS

    Science.gov (United States)

    Van Bramer, Scott; Goodrich, Katherine R.

    2015-01-01

    This experiment combines analytical techniques of solid phase microextraction and gas chromatography-mass spectrometry with easily relatable and accessible plant volatile chemistry (floral and vegetative scents of local/available plants). The biosynthesis and structure of these chemicals are of interest in the areas of organic chemistry,…

  5. Solid-phase microextraction of hydrocarbons from water in a centrifuge

    Science.gov (United States)

    Ryabov, A. Yu.; Chuikin, A. V.; Velikov, A. A.

    2016-06-01

    The results of our study of solid-phase microextraction of substances using a centrifuge for determining the microquantities of hydrocarbon impurities in water are presented. The cartridge diameter, sorbent mass, and solvent volume were shown to affect the percent extraction of substances and the analytical signal intensity. The relationship between the cartridge geometry, the sorbent mass, and the solvent volume was considered.

  6. Total synthesis of human urotension-Ⅱ by microwave-assisted solid phase method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    Human urotension-Ⅱ was synthesized efficiently on Wang resin under microwave irradiation using Fmoc/tBu orthogonal protection strategy. Disulphide bridge was formed on solid phase with the irradiation of microwave, then the whole peptide was cleaved from the resin. The purity of crude peptide cyclized under microwave irradiation was higher than that under room temperature.

  7. Solid-phase oligosaccharide synthesis with tris(alkoxy)benzyl amine (BAL) safety-catch anchoring

    DEFF Research Database (Denmark)

    Tolborg, Jakob Fjord; Jensen, Knud Jørgen

    2000-01-01

    A tris(alkoxy)benzylamine (BAL) handle strategy was developed for safety-catch anchoring of D-glucosamine derivatives in solid-phase synthesis of oligosaccharides; the linkage between the BAL handle and the amine proved stable to conc. TFA and Lewis acids, but after N-acylation the amide could...

  8. An amine-derivatized, DOTA-loaded polymeric support for Fmoc Solid Phase Peptide Synthesis

    OpenAIRE

    Yoo, Byunghee; Sheth, Vipul R.; Pagel, Mark D.

    2009-01-01

    An amine-derivatized DOTA has been used to modify the surface of a polymeric support for conventional Solid Phase Peptide Synthesis (SPPS) following standard Fmoc chemistry methods. This methodology was used to synthesize a peptide-DOTA conjugate that was demonstrated to be a PARACEST MRI contrast agent. Therefore, this synthesis methodology can facilitate Fmoc SPPS of molecular imaging contrast agents.

  9. Solid-phase synthesis of polyfunctional polylysine dendrons using aldehyde linkers

    DEFF Research Database (Denmark)

    Svenssen, Daniel K.; Mirsharghi, Sahar; Boas, Ulrik

    2014-01-01

    A straightforward method for the solid-phase synthesis of C-terminally modified polylysine dendrons has been developed by applying bisalkoxybenzaldehyde and trisalkoxybenzaldehyde linkers. The method has been used for the synthesis of polylysine dendrons with a variety of C-terminal ‘tail groups’...

  10. Microwave-assisted solid-phase Ugi four-component condensations

    DEFF Research Database (Denmark)

    Nielsen, John

    1999-01-01

    An 18-member library was constructed from 2 isocyanides, 3 aldehydes and 3 carboxylic acids via microwave-assisted solid-phase Ugi reactions on TentaGel S RAM. Products of high purity were obtained in moderate to excellent yields after reaction times of 5 minutes or less (irradiation at 60W). (C)...

  11. Solid-Phase Synthesis of Smac Peptidomimetics Incorporating Triazoloprolines and Biarylalanines

    DEFF Research Database (Denmark)

    Le Quement, Sebastian T.; Ishoey, Mette; Petersen, Mette T.;

    2011-01-01

    -Me)AVPF sequence, peptides incorporating triazoloprolines and biarylalanines were synthesized by means of Cu(I)-catalyzed azide–alkyne cycloaddition and Pd-catalyzed Suzuki cross-coupling reactions. Solid-phase procedures were optimized to high efficiency, thus accessing all products in excellent crude purities...

  12. Direct detection of Mycobacterium tuberculosis in sputum: A validation study using solid phase extraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Mourão, Marta P B; Kuijper, Sjoukje; Dang, Ngoc A; Walters, Elisabetta; Janssen, Hans-Gerd; Kolk, Arend H J

    2016-02-15

    Tuberculosis (TB) remains a worldwide health problem, especially in developing countries. Correct identification of Mycobacterium tuberculosis (MTB) infection is extremely important for providing appropriate treatment and care to patients. Here we describe a solid phase extraction-gas chromatography-mass spectrometry method (SPE-THM-GC-MS) for the detection of five biomarkers for M. tuberculosis. The method for classification is developed and validated through the analysis of 112 sputum samples from patients suspected of having TB. Twenty of twenty-five MTB culture-positive sputum samples were correctly classified as positive by our improved SPE-THM-GC-MS method. Eighty-five of eighty-seven MTB culture-negative samples were also negative by SPE-THM-GC-MS. The overall sensitivity of the new SPE-THM-GC-MS method is 80% (20/25) and the specificity is 98% (85/87) compared with culture. The method proved to be reliable and, although complex in principle, easy to operate due to the high degree of automation. PMID:26807702

  13. Biological nitrate removal from water and wastewater by solid-phase denitrification process.

    Science.gov (United States)

    Wang, Jianlong; Chu, Libing

    2016-11-01

    Nitrate pollution in receiving waters has become a serious issue worldwide. Solid-phase denitrification process is an emerging technology, which has received increasing attention in recent years. It uses biodegradable polymers as both the carbon source and biofilm carrier for denitrifying microorganisms. A vast array of natural and synthetic biopolymers, including woodchips, sawdust, straw, cotton, maize cobs, seaweed, bark, polyhydroxyalkanoate (PHA), polycaprolactone (PCL), polybutylene succinate (PBS) and polylactic acid (PLA), have been widely used for denitrification due to their good performance, low cost and large available quantities. This paper presents an overview on the application of solid-phase denitrification in nitrate removal from drinking water, groundwater, aquaculture wastewater, the secondary effluent and wastewater with low C/N ratio. The types of solid carbon source, the influencing factors, the microbial community of biofilm attached on the biodegradable carriers, the potential adverse effect, and the cost of denitrification process are introduced and evaluated. Woodchips and polycaprolactone are the popular and competitive natural plant-like and synthetic biodegradable polymers used for denitrification, respectively. Most of the denitrifiers reported in solid-phase denitrification affiliated to the family Comamonadaceae in the class Betaproteobacteria. The members of genera Diaphorobacter, Acidovorax and Simplicispira were mostly reported. In future study, more attention should be paid to the simultaneous removal of nitrate and toxic organic contaminants such as pesticide and PPCPs by solid-phase denitrification, to the elucidation of the metabolic and regulatory relationship between decomposition of solid carbon source and denitrification, and to the post-treatment of the municipal secondary effluent. Solid-phase denitrification process is a promising technology for the removal of nitrate from water and wastewater. PMID:27396522

  14. Development of solid-phase extraction and solid-phase microextraction methods for the determination of chlorophenols in cork macerate and wine samples.

    Science.gov (United States)

    Insa, S; Salvadó, V; Anticó, E

    2004-08-20

    Tri-, tetra- and pentachlorophenol (TCP, TeCP and PCP) can be considered the precursors in the formation of corresponding chloroanisoles, known to be powerful odorants in corks and wine. Determining the presence of these chlorophenolic compounds in cork soaking solutions (ethanol/water mixtures, 12% (v/v) ethanol used for cork quality control testing), or in wine can be achieved by acetylation/gas chromatography electron-capture detection. In order to reach the required sensitivity, a previous preconcentration step is necessary. Solid-phase extraction (SPE) and headspace solid-phase microextraction (HS-SPME) have given good results for the preconcentration of TCP, TeCP and PCP in such matrices. The use of Oasis HLB cartridges gives acceptable recoveries for the three compounds when different volumes (50-250 mL) of cork macerate with concentrations ranging from 20 to 150 ng/L are processed. Preconcentration based on HS-SPME has also been optimised with a 100 microm polydimethylsiloxane fibre and in situ derivatization. The HS-SPME method allows chlorophenols in a cork soaking solution and in wine to be determined with a limit of detection of 1 ng/L for each compound (in cork macerate) and a repeatability of around 0.5%-5% (n=8) for a concentration level of 30 ng/L. PMID:15481456

  15. Ethanol/Water extraction combined with solid-phase extraction and solid-phase microextraction concentration for the determination of chlorophenols in cork stoppers.

    Science.gov (United States)

    Insa, Sara; Besalú, Emili; Iglesias, Cristina; Salvadó, Victoria; Anticó, Enriqueta

    2006-02-01

    The appearance of 2,4,6-trichloroanisole (TCA) in cork stoppers is of great concern because it can cause off-flavors in bottled wine. To prevent this sensorial defect, there should not be any traces of 2,4,6-trichlorophenol (TCP), 2,3,4,6-tetrachlorophenol (TeCP), or pentachlorophenol (PCP) in the finished corks, because they are the direct precursors of TCA. In the course of this study two methodologies based upon an extraction with ethanol/water mixtures to determine the chlorophenolic content in cork matrices were developed. The cork extract is preconcentrated using both solid-phase extraction and solid-phase microextraction methodologies. The latter was optimized by applying a full two-level factorial design. Finally, spiked ground corks at nanogram per gram levels of each chlorophenol were analyzed under optimal conditions and by applying both procedures. The obtained results demonstrate that chlorophenols can be detected in corks contaminated at the nanogram per gram level and, thus, these approaches can be successfully applied as quality control measures in the cork industry. PMID:16448159

  16. Solid-phase radioimmunoassay of immunoglobulins G, A and M: applicability in analysis of sucrose gradients

    Energy Technology Data Exchange (ETDEWEB)

    Eriksen, E.F.; Danielsen, H. (Aarhus Kommunehospital (Denmark). Medical Department C); Johansen, A.S. (Aarhus Univ. (Denmark). Institute of Medical Biochemistry); Larsson, L.I. (Unit of Histochemistry, University Institute of Pathology, Copenhagen, Denmark)

    1984-01-01

    A simple and sensitive solid-phase radioimmunoassay for the detection of immunoglobulins G, A and M in sucrose gradients is described. The solid-phase consisted of immunoglobulins adsorbed to polystyrene tubes. Using buffers without detergent and /sup 125/I-labeled sheep anti-rabbit IgA as radioligand, the assay was able to detect 0.8 ng per tube in the IgG assay and 1.6 ng per tube in the IgA and IgM assays. Standard curves with antigen dissolved in 10% and 32% sucrose were superimposable and did not deviate from standard curves with antigen dissolved in buffer without sucrose. Using these techniques on ultracentrifugation samples from patients with systemic lupus erythematosus, Schoenlein-Henoch nephritis and IgA glorulonephritis is was possible to detect both immunoglobulin fragments and immunoglobulin aggregates at the same time without prior dialysis of the samples.

  17. Quantitation of Binding, Recovery and Desalting Efficiency in Solid Phase Extraction Micropipette Tips

    Energy Technology Data Exchange (ETDEWEB)

    Palmblad, M N; Vogel, J S

    2004-08-02

    Micropipette-tip solid phase extraction systems are common in proteomic analyses for desalting and concentrating samples for mass spectrometry, removing interferences, and increasing sensitivity. These systems are inexpensive, disposable, and highly efficient. Here we show micropipette-tip solid phase extraction is a direct sample preparation method for {sup 14}C-accelerator mass spectrometry (AMS), removing salts or reagent from labeled macromolecules. We compared loading, recovery and desalting efficiency in commercially available SPE micro-tips using {sup 14}C-labeled peptides and proteins, AMS, and alpha spectrometry ion energy loss quantitation. The polypropylene in the tips was nearly {sup 14}C-free and simultaneously provided low-background carrier for AMS. The silica material did not interfere with the analysis. Alpha spectrometry provided an absolute measurement of desalting efficiency.

  18. Solid phase epitaxy amorphous silicon re-growth: some insight from empirical molecular dynamics simulation

    CERN Document Server

    Krzeminski, Christophe; 10.1140/epjb/e2011-10958-7

    2011-01-01

    The modelling of interface migration and the associated diffusion mechanisms at the nanoscale level is a challenging issue. For many technological applications ranging from nanoelectronic devices to solar cells, more knowledge of the mechanisms governing the migration of the silicon amorphous/crystalline interface and dopant diffusion during solid phase epitaxy is needed. In this work, silicon recrystallisation in the framework of solid phase epitaxy and the influence on orientation effects have been investigated at the atomic level using empirical molecular dynamics simulations. The morphology and the migration process of the interface has been observed to be highly dependent on the original inter-facial atomic structure. The [100] interface migration is a quasi-planar ideal process whereas the cases [110] and [111] are much more complex with a more diffuse interface. For [110], the interface migration corresponds to the formation and dissolution of nanofacets whereas for [111] a defective based bilayer reor...

  19. Micro-solid phase extraction of ochratoxin A, and its determination in urine using capillary electrophoresis

    International Nuclear Information System (INIS)

    We describe a simple, environmentally friendly and selective technique for the determination of ochratoxin A (OTA) in urine. It involves (a) the use of a molecularly imprinted polymer as a sorbent in micro-solid-phase extraction in which the sorbent is contained in a propylene membrane envelope, and (b) separation and detection by capillary electrophoresis (CE). Under optimized conditions, response is linear in the range between 50 and 300 ng mL−1 (with a correlation coefficient of 0.9989), relative standard deviations range from 4 to 8 %, the detection limit for OTA in urine is 11.2 ng mL−1 (with a quantification limits of 32.5 ng mL−1) which is lower than those of previously reported methods for solid-phase extraction combined with CE. The recoveries of OTA from urine spiked at levels of 50, 150 and 300 ng mL−1 ranged from 93 to 97 %. (author)

  20. Solid-phase route to Fmoc-protected cationic amino acid building blocks

    DEFF Research Database (Denmark)

    Clausen, Jacob Dahlqvist; Linderoth, Lars; Nielsen, Hanne Mørck;

    2012-01-01

    was developed. A versatile solid-phase protocol leading to selectively protected amino alcohol intermediates was followed by oxidation to yield the desired di- or polycationic amino acid building blocks in gram-scale amounts. The synthetic sequence comprises loading of (S)-1-(p-nosyl)aziridine-2-methanol onto......Diamino acids are commonly found in bioactive compounds, yet only few are commercially available as building blocks for solid-phase peptide synthesis. In the present work a convenient, inexpensive route to multiple-charged amino acid building blocks with varying degree of hydrophobicity...... blocks having an Fmoc/Boc protection scheme. This strategy facilitates incorporation of multiple positive charges into the building blocks provided that the corresponding partially protected di- or polyamines are available. An array of compounds covering a wide variety of ¿-aza substituted analogs...

  1. Silica-Based Solid Phase Extraction of DNA on a Microchip

    Institute of Scientific and Technical Information of China (English)

    陈晓芳; 沈科跃; 刘鹏; 郭旻; 程京; 周玉祥

    2004-01-01

    Micro total analysis systems for chemical and biological analysis have attracted much attention.However,microchips for sample preparation and especially DNA purification are still underdeveloped.This work describes a solid phase extraction chip for purifying DNA from biological samples based on the adsorption of DNA on bare silica beads prepacked in a microchannel.The chip was fabricated with poly-dimethylsiloxane.The silica beads were packed in the channel on the chip with a tapered microchannel to form the packed bed.Fluorescence detection was used to evaluate the DNA adsorbing efficiency of the solid phase.The polymerase chain reaction was used to evaluate the quality of the purified DNA for further use.The extraction efficiency for the DNA extraction chip is approximately 50% with a 150-nL extraction volume.Successful amplification of DNA extracted from human whole blood indicates that this method is compatible with the polymerase chain reaction.

  2. A Facile, Choline Chloride/Urea Catalyzed Solid Phase Synthesis of Coumarins via Knoevenagel Condensation

    Directory of Open Access Journals (Sweden)

    Hosanagara N. Harishkumar

    2011-01-01

    Full Text Available The influence of choline chloride/urea ionic liquid in solid phase on the Knoevenagel condensation is demonstrated. The active methylene compounds such as meldrum’s acid, diethylmalonate, ethyl cyanoacetate, dimethylmalonate, were efficiently condensed with various salicylaldehydes in presence of choline chloride/urea ionic liquid without using any solvents or additional catalyst. The reaction is remarkably facile because of the air and water stability of the catalyst, and needs no special precautions. The reactions were completed within 1hr with excellent yields (95%. The products formed were sufficiently pure, and can be easily recovered. The use of ionic liquid choline chloride/urea in solid phase offered several significant advantages such as low cost, greater selectivity and easy isolation of products.

  3. The Use of Aryl Hydrazide Linkers for the Solid Phase Synthesis of Chemically Modified Peptides

    Energy Technology Data Exchange (ETDEWEB)

    Woo, Y; Mitchell, A R; Camarero, J A

    2006-11-03

    Since Merrifield introduced the concept of solid phase synthesis in 1963 for the rapid preparation of peptides, a large variety of different supports and resin-linkers have been developed that improve the efficiency of peptide assembly and expand the myriad of synthetically feasible peptides. The aryl hydrazide is one of the most useful resin-linkers for the synthesis of chemically modified peptides. This linker is completely stable during Boc- and Fmoc-based solid phase synthesis and yet it can be cleaved under very mild oxidative conditions. The present article reviews the use of this valuable linker for the rapid and efficient synthesis of C-terminal modified peptides, head-to-tail cyclic peptides and lipidated peptides.

  4. 西仑吉肽的固相合成%Solid phase synthesis of cilengitide

    Institute of Scientific and Technical Information of China (English)

    张波; 王卫国; 康武; 智小霞; 姚忠; 徐红岩

    2012-01-01

    Fully-protected linear peptide was synthesized by Fmoc solid phase peptide synthesis methods. The solid phase carrier was 2-chlorotrityl chloride resin. HATU/HOBt and HBTU/HOBt were used as the coupling reagents. The synthesis of fully-protected cyclic peptide used THF/DCM ( at a ratio of 1: 1 by volume) as the solvent and HATU/HOBt as the coupling reagents. Finally cilengitide could be obtained by deprotection reaction.%采用Fmoc固相合成法,选用2-氯三苯甲基氯树脂作为固相载,HBTU/HOBt和HATU/HOBt为缩合剂,合成全保护线性肽.以V(DCM)∶V(THF)= 1∶1为溶剂,HATU/HOBt为缩合剂,合成全保护环肽.最后脱除保护基得终产物西仑吉肽.

  5. Solid phase microextraction for profiling volatile compounds in liquered white wines

    OpenAIRE

    Henryk H. Jeleń; Anna Szczurek

    2010-01-01

    Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME) was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tes...

  6. HPLC WITH SOLID PHASE EXTRACTION FOR IDENTIFICATION AND DIAGNOSIS OF ORGANOPHOSPHOROUS POISONING IN GOATS

    Directory of Open Access Journals (Sweden)

    S. Manna

    2014-12-01

    Full Text Available High performance liquid chromatographic determination of organophosphorous compound has been done by reverse phase chromatography in goats. The goats were dying showing the symptoms of organophosphorous poisoning. The viscera and stomach contents sample were received from Project Co-Ordinator, Animal Disease Research Institute, Phulnakhara, Cuttack, Orissa. The analysis of samples by HPLC with UV detector after cleaning up in Solid Phase Extraction (SPE revealed presence of malathion that was later quantified.

  7. Solid-phase reduction of Cr2O3 under chemical catalytic conditions

    Science.gov (United States)

    Simonov, V. K.; Grishin, A. M.

    2016-06-01

    The kinetics of the solid-phase reduction of Cr2O3 with carbon under chemical catalytic action on the reacting system is studied. A significant intensification of the process in the presence of small amounts of potassium and sodium salts is established. The concepts of the catalyst action mechanism are considered and experimentally substantiated. Manufacture of iron-chromium master alloys with a restricted content of carbon can be organized at low temperatures, and they can be used in steelmaking.

  8. Solid-phase de novo synthesis of a (+/-)-2-deoxy-glycoside.

    Science.gov (United States)

    Lucchesi, Céline; Arboré, Amélie; Pascual, Sagrario; Fontaine, Laurent; Maignan, Christian; Dujardin, Gilles

    2010-04-19

    The solid-phase synthesis of methyl 2-deoxy-3-O-benzyl-D,L-arabino-hexopyranoside was achieved in a six-step sequence via a de novo strategy based on the hetero-Diels-Alder reaction of a vinyl ether supported on an azalactone-functionalized polystyrene resin, followed by the functional modification of the heteroadduct and the final release of the methyl glycoside by acidic solvolysis. PMID:20171610

  9. Zirconyl chloride promoted highly efficient solid phase synthesis of amide derivatives

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    An efficient solid phase route for the synthesis of amide derivatives by the reaction of carboxylic acids with urea in the presence of catalytic amount of zirconyl chloride under microwave irradiation conditions was described. In this way, a range of interesting amide derivatives was obtained in good to excellent yields. The catalyst was recycled with fresh reactants and it gave almost similar results without significant loss of activity up to the third run.

  10. Determination of fungicides in residual tanning floats using solid phase micro extraction

    OpenAIRE

    Font Vallès, Joaquim; Reyes Reyes, Maria; Cuadros, Sara; Bacardit Dalmases, Anna; Ollé Otero, Lluís; Marsal Monge, Agustín

    2013-01-01

    Solid-phase microextraction (SPME) was optimized for extraction of the leather preservative agents 2-(thiocyanomethylthio)-benzothiazole (TCMTB), 4-chloro-3-methylphenol (PCMC), 2-phenylphenol (OPP), 2-Octyl-3(2H)-isothiazolone (OIT), 2-mercaptobenzothiazol (MBT) and 3-iodo-2-propynyl-butylcarbamate (IPBC) in spent tanning floats. Determination was carried out by high performance liquid chromatography (HPLC) with photo diode array detection (PDA). The following parameters were studied to ach...

  11. The sulfamate functional group as a new anchor for solid-phase organic synthesis

    Science.gov (United States)

    Ciobanu; Maltais; Poirier

    2000-02-24

    [reaction: see text] Sulfamate derivatives were loaded on trityl chloride resin, and two variants of cleavage were developed for this sulfamate anchor: an acid treatment to easily restore the free sulfamate and a nucleophilic treatment to generate the corresponding phenol. In addition to loading/cleavage assays and stability experiments, a model sequence of reactions was performed with the new sulfamate anchor to show its applicability in further combinatorial solid-phase synthesis of libraries of biologically relevant sulfamate derivatives.

  12. Design of indirect solid-phase immunosorbent methods for detecting arenavirus antigens and antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Ivanov, A.P.; Rezapkin, G.V.; Dzagurova, T.K.; Tkachenko, E.A.

    1984-05-01

    Specifications have been elaborated for formulating indirect solid-phase enzyme-linked immunosorbent assay (ELISA) and radioimmunoassay (SPRIA) methods that employ anti-human and anti-mice G class immunoglobulin (IgG), conjugated with horseradish peroxidase and /sup 125/I for detecting the arenaviruses Junin, Machupo, Tacaribe, Amalpari, Tamiami, Lassa, and LCM (lymphocytic choriomeningitis). These methods make it possible to identify with a high degree of sensitivity arenavirus antigens and antibodies in various kinds of material.

  13. Volatile profile of yellow passion fruit juice by static headspace and solid phase microextraction techniques

    OpenAIRE

    Gilberto Costa Braga; Adna Prado; Jair Sebastião da Silva Pinto; Severino Matias de Alencar

    2015-01-01

    The profile of volatile compounds of yellow passion fruit juice was analyzed by solid phase microextraction headspace (HS-SPME) and optimized static headspace (S-HS) extraction techniques. Time, temperature, NaCl concentration and sample volume headspace equilibrium parameters was adjusted to the S-HS technique. The gaseous phase in the headspace of samples was collected and injected into a gas chromatograph coupled to a mass spectrometer. In the HS-SPME technique was identified 44 volatile c...

  14. Application of the method of solid-phase spectrometry for test-determination of antioxidants

    OpenAIRE

    Бельтюкова, C. D.; Лівенцова, О. О.; Степанова, А. А.

    2015-01-01

    The work reveals advantages of a method of solid-phase spectrometry, with registration of a luminescent signal of anolyte in a sorbent phase in paticular, compared with usual spectroscopic methods. The possibility of use of a sensitized luminescence of lanthanides (ions of Terbium(III) ) as a luminescent marker when determining antioxidants of polyphenolic type is established. Advantages of this method, allowing to carry out quality control, safety or falsifications of foodstuff are noted. Th...

  15. A New Molecularly Imprinted Polymer for Solid-phase Extraction of Cotinine from Human Urine

    Institute of Scientific and Technical Information of China (English)

    Jun YANG; Xiao Lan ZHU; Ji Bao CAI; Qing De SU; Yun GAO; Liang ZHANG

    2005-01-01

    A molecularly imprinted polymer (MIP), prepared around a cotinine template, has been synthesized. The feasibility of using the polymer for solid-phase extraction (SPE) of cotinine from biological samples has been investigated. The results show that cotinine can be quantitatively retained and eluted from the polymer. Experiments with human urine samples indicate that clean target analyte is obtained for HPLC with UV detection using the protocol.

  16. Solid-phase microextraction for the enantiomeric analysis of flavors in beverages.

    Science.gov (United States)

    Ebeler, S E; Sun, G M; Datta, M; Stremple, P; Vickers, A K

    2001-01-01

    Solid-phase microextraction combined with gas chromatographic/mass spectrometric analysis and separation on a chiral cyclodextrin stationary phase was a rapid, reliable technique for profiling chiral aroma compounds in flavored alcoholic beverages. Several enantiomeric terpenes, esters, alcohols, norisoprenoids, and lactones were identified in berry-, peach-, strawberry-, and citrus-flavored wine and malt beverages (wine coolers). Using this technique, we were able to confirm the addition of synthetic flavoring to several beverages, consistent with label designations. PMID:11324614

  17. R. Bruce Merrifield and Solid-Phase Peptide Synthesis: A Historical Assessment

    Energy Technology Data Exchange (ETDEWEB)

    Mitchell, A R

    2007-12-04

    Bruce Merrifield, trained as a biochemist, had to address three major challenges related to the development and acceptance of solid-phase peptide synthesis (SPPS). The challenges were (1) to reduce the concept of peptide synthesis on a insoluble support to practice, (2) overcome the resistance of synthetic chemists to this novel approach, and (3) establish that a biochemist had the scientific credentials to effect the proposed revolutionary change in chemical synthesis. How these challenges were met is discussed in this article.

  18. Effect of Microwave Radiation on Enzymatic and Chemical Peptide Bond Synthesis on Solid Phase

    Directory of Open Access Journals (Sweden)

    Alessandra Basso

    2009-01-01

    Full Text Available Peptide bond synthesis was performed on PEGA beads under microwave radiations. Classical chemical coupling as well as thermolysin catalyzed synthesis was studied, and the effect of microwave radiations on reaction kinetics, beads' integrity, and enzyme activity was assessed. Results demonstrate that microwave radiations can be profitably exploited to improve reaction kinetics in solid phase peptide synthesis when both chemical and biocatalytic strategies are used.

  19. Preparation of high-quality poly-Si films by a solid phase crystallizing method

    CERN Document Server

    Yao Ruo He

    2002-01-01

    A solid phase crystallizing method has been developed to grow a Si crystal at temperatures as low as 550 degree C. Using this method, a high-quality thin-film polycrystalline silicon (Poly-Si) was obtained. The largest grain size, examined with X-ray diffraction spectroscopy and scanning electron microscopy images of recrystallized samples, is approximately 1 mu m for substrate temperature at 300 degree C and annealed at 550 degree C for 3 hours

  20. Electron Shuttling Capacity of Solid-Phase Organic Matter in Forest Soils

    Science.gov (United States)

    Patel, A.; Zhao, Q.; Yang, Y.

    2015-12-01

    Soil organic matter, as an electron shuttle, plays an important role in regulating the biogeochemical cycles of metals, especially the redox reactions for iron. Microorganisms can reduce soil organic matter under anaerobic conditions, and biotically-reduced soil organic matter can abiotically donate electrons to ferric oxides. Such soil organic matter-mediated electron transport can facilitate the interactions between microorganisms and insoluble terminal electron acceptors, i.e. iron minerals. Most previous studies have been focused on the electron shuttling processes through dissolved soil organic matter, and scant information is available for solid-phase soil organic matter. In this study, we aim to quantify the electron accepting capacity for solid-phase organic matter in soils collected from four different forests in the United States, including Truckee (CA), Little Valley (NV), Howland (ME) and Hart (MI). We used Shewanella oneidensisMR-1 to biotically reduce soil slurries, and then quantified the electrons transferred to solid-phase and solution-phase organic matter by reacting them with Fe(III)-nitrilotriacetic acid (Fe(III)-NTA). The generation of Fe(II) was measured by a ferrozine assay to calculate the electron accepting capacity of soil organic matter. Our preliminary results showed that the Truckee soil organic matter can accept 0.51±0.07 mM e-/mol carbon. We will measure the electron accepting capacity for four different soils and correlate them to the physicochemical properties of soils. Potential results will provide information about the electron accepting capacity of solid-phase soil organic matter and its governing factors, with broad implication on the coupled biogeochemical cycles of carbon and iron.

  1. Determination of Atrazine, Acetochlor, Clomazone, Pendimethalin and Oxyfluorfen in Soil by a Solid Phase Microextraction Method

    OpenAIRE

    Rada Đurović; Jelena Gajić-Umiljendić; Tijana Đorđević

    2008-01-01

    A solid phase microextraction (SPME) method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extractio...

  2. Electrical field assisted matrix solid phase dispersion as a powerful tool to improve the extraction efficiency and clean-up of fluoroquinolones in bovine milk.

    Science.gov (United States)

    da Silva, Mariana Cristina; Orlando, Ricardo Mathias; Faria, Adriana Ferreira

    2016-08-26

    This work presents a new method by electrical matrix solid phase dispersion for the extraction and clean-up of marbofloxacin, ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, difloxacin and sarafloxacin in bovine milk. Composition and pH of the eluent, applied electrical potential and polarity were optimized by experimental designs. The combination of the chromatographic and electrophoretic mechanisms allowed the extraction and clean-up in one step with low organic solvent consumption, high extraction throughput and elution automation. Linearity, precision, trueness and limit of quantification were evaluated and provided values in accordance with other methods recently developed for the analysis of fluoroquinolones in milk. This technique proved to be promising for the extraction and clean-up of ionizable analytes in different milk matrices. PMID:27492598

  3. Use of semi-permeable membrane devices and solid-phase extraction for the wide-range screening of microcontaminants in surface water by GC-AED/MS.

    Science.gov (United States)

    van Stee, Leo L P; Leonards, Pim E G; van Loon, Willem M G M; Hendriks, A Jan; Maas, Johanna L; Struijs, Jaap; Brinkman, Udo A Th

    2002-11-01

    An automated GC-MS-based screening method was developed for over 400 industrial, agrochemical and household chemicals. Extracted ion chromatograms were used and the method was aimed at creating a minimum number of false positives. The compound polarity range usually associated with solid-phase extraction was extended to include very apolar, bioaccumulative, compounds by using the complementary semi-permeable membrane device technique. Real-life samples were taken at four locations in the main Dutch river systems and one in an agricultural area. Some 150 compounds were detected in the low-ng/l to low-microg/l range. Next to the target compounds, several brominated and chlorinated non-target compounds were detected by means of GC with atomic emission detection and tentatively identified using mass spectral library searching.

  4. Electrical field assisted matrix solid phase dispersion as a powerful tool to improve the extraction efficiency and clean-up of fluoroquinolones in bovine milk.

    Science.gov (United States)

    da Silva, Mariana Cristina; Orlando, Ricardo Mathias; Faria, Adriana Ferreira

    2016-08-26

    This work presents a new method by electrical matrix solid phase dispersion for the extraction and clean-up of marbofloxacin, ofloxacin, norfloxacin, ciprofloxacin, enrofloxacin, difloxacin and sarafloxacin in bovine milk. Composition and pH of the eluent, applied electrical potential and polarity were optimized by experimental designs. The combination of the chromatographic and electrophoretic mechanisms allowed the extraction and clean-up in one step with low organic solvent consumption, high extraction throughput and elution automation. Linearity, precision, trueness and limit of quantification were evaluated and provided values in accordance with other methods recently developed for the analysis of fluoroquinolones in milk. This technique proved to be promising for the extraction and clean-up of ionizable analytes in different milk matrices.

  5. Solid phase extraction of uranium (VI) using penicillium chrysogenum immobilized on silica gel

    International Nuclear Information System (INIS)

    Uranium is a metal of strategic importance in the area of Nuclear Technology. It has due to its usage in power generation. Being a toxic element and due to environmental concerns its determination from water, soil and other samples has gained significance. The determination of traces of uranium in such samples requires a preconcentration step. Biosorption methods involving solid phase extraction utilizes various materials of biological origin, including bacteria, fungi, yeast, algae, etc. In the present work a solid phase extraction method for separation and enrichment of uranium (VI) was developed. A solid phase was prepared by immobilization 150 mg of Penicillium and 1.0 g silica. A 350 mg of Penicillium chrysogenum immobilized silica mixed with double distilled water packed in a glass column (150 mm length and 10 mm internal diameter) with wool as support and was systematically investigated to optimize the conditions for quantitative sorption and desorption of uranium (VI). It was determined spectrophotometrically using Arsenazo (III) at 650 nm

  6. Semiautomated solid-phase extraction manifold with a solvent-level sensor.

    Science.gov (United States)

    Orlando, R M; Rath, S; Rohwedder, J J R

    2013-11-15

    A semiautomated solid-phase extraction manifold for multiple extractions is presented. The manifold utilizes commercial solid-phase syringe cartridges and automatically introduces and elutes all the solvents during the extraction, reducing the typical workload and stress of the analyst. The manifold consists of a peristaltic pump with solenoid valves in a flow circuit that contains transmissive photomicrosensors. The photomicrosensors were used to control the solvent dispenser and the solvent level inside the cartridge. As solvent-level sensors, the photomicrosensors determined the exact time the solvent reached the top frit to avoid sorbent drying and accurately perform the solvent exchange. The repeatability of the manifold to introduce a particular volume of solvent into the cartridges was measured, and the precisions were between 0.05 and 2.89% (RSD). To evaluate the manifold, the amount of two fluoroquinolones in a fortified blank milk sample was determined. The results of the intra- and inter-day precision of multiple extractions from the fortified milk samples resulted in precisions better than 9.0% (RSD) and confirmed that the arrangement of the semiautomated manifold could adequately be used in solid-phase extraction with commercial cartridges. PMID:24148370

  7. Preparation of fluorescent DNA probe by solid-phase organic synthesis

    Directory of Open Access Journals (Sweden)

    2009-08-01

    Full Text Available Fluorescent DNA probe based on fluorescence resonance energy transfer (FRET was prepared by solid-phase organic synthesis when CdTe quantum dots (QDs were as energy donors and Au nanoparticles (AuNPs were as energy accepters. The poly(divinylbenzene core/poly(4-vinylpyridine shell microspheres, as solid-phase carriers, were prepared by seeds distillation-precipitation polymerization with 2,2′-azobisisobutyronitrile (AIBN as initiator in neat acetonitrile. The CdTe QDs and AuNPs were self-assembled on the surface of core/shell microspheres, and then the linkage of CdTe QDs with oligonucleotides (CdTe-DNA and AuNPs with complementary single-stranded DNA (Au-DNA was on the solid-phase carriers instead of in aqueous solution. The hybridization of complementary double stranded DNA (dsDNA bonded to the QDs and AuNPs (CdTe-dsDNA-Au determined the FRET distance of CdTe QDs and AuNPs. Compared with the fluorescence of CdTe-DNA, the fluorescence of CdTe-dsDNA-Au conjugates (DNA probes decreased extremely, which indicated that the FRET occurred between CdTe QDs and AuNPs. The probe system would have a certain degree recovery of fluorescence when the complementary single stranded DNA was introduced into this system, which showed that the distance between CdTe QDs and AuNPs was increased.

  8. Simultaneous solid phase extraction of cobalt, strontium and cesium from liquid radioactive waste using microcrystalline naphthalene

    International Nuclear Information System (INIS)

    Most of the procedures developed for the extraction of cobalt, strontium and cesium by solid phase extraction do not employ simultaneous extraction of them. In this study, rapid simultaneous removal of Co2+, Sr2+ and Cs+ on microcrystalline naphthalene as solid-phase extractant was investigated. These ions were allowed to form chelates with oxine and then adsorbed on freshly microcrystalline naphthalene from aqueous solutions. The solid phase extraction procedure (SPE) was optimized by using model solution containing Co2+, Sr2+ and Cs+ in batch system. The effects of different parameters such as variation in pH, reagent concentration, standing time, naphthalene solution concentration and contact time on the simultaneous removal of these ions was studied. The obtained results indicated that, sorption was found to be rapid, and the percentage removal of Co2+, Sr2+ and Cs+ was found to be 98, 79 and 68% within 10 min, respectively. The kinetics of the sorption process was investigated to understand the kinetic characteristics of sorption of metal chelates onto microcrystalline naphthalene. The developed procedure has been successfully applied to the removal and recovery of 60Co and 134Cs from liquid radioactive waste. The parameters can be used for designing a plant for treatment of wastewater economically.

  9. New methodological improvements in the Microtox® solid phase assay.

    Science.gov (United States)

    Burga Pérez, Karen F; Charlatchka, Rayna; Sahli, Leila; Férard, Jean-François

    2012-01-01

    The classic Microtox® solid phase assay (MSPA) based on the inhibition of light production of the marine bacteria recently renamed Aliivibrio fischeri suffers from various bias and interferences, mainly due to physico-chemical characteristics of the tested solid phase. To precisely assess ecotoxicity of sediments, we have developed an alternative method, named Microtox® leachate phase assay (MLPA), in order to measure the action of dissolved pollutants in the aqueous phase. Two hypotheses were formulated to explain the observed difference between MSPA and MLPA results: a real ecotoxicity of the solid phase or the fixation of bacteria to fine particles and/or organic matter. To estimate the latter, flow cytometry analyses were performed with two fluorochromes (known for their ability to stain bacterial DNA), allowing correction of MSPA measurements and generation of new (corrected) IC50. Comparison of results of MLPA with the new IC50 MSPA allows differentiating real ecotoxic and fixation effect in classic MSPA especially for samples with high amount of fines and/or organic matter. PMID:21962521

  10. Engineering customized TALE nucleases (TALENs) and TALE transcription factors by fast ligation-based automatable solid-phase high-throughput (FLASH) assembly.

    Science.gov (United States)

    Reyon, Deepak; Maeder, Morgan L; Khayter, Cyd; Tsai, Shengdar Q; Foley, Jonathan E; Sander, Jeffry D; Joung, J Keith

    2013-07-01

    Customized DNA-binding domains made using transcription activator-like effector (TALE) repeats are rapidly growing in importance as widely applicable research tools. TALE nucleases (TALENs), composed of an engineered array of TALE repeats fused to the FokI nuclease domain, have been used successfully for directed genome editing in various organisms and cell types. TALE transcription factors (TALE-TFs), consisting of engineered TALE repeat arrays linked to a transcriptional regulatory domain, have been used to up- or downregulate expression of endogenous genes in human cells and plants. This unit describes a detailed protocol for the recently described fast ligation-based automatable solid-phase high-throughput (FLASH) assembly method. FLASH enables automated high-throughput construction of engineered TALE repeats using an automated liquid handling robot or manually using a multichannel pipet. Using the automated approach, a single researcher can construct up to 96 DNA fragments encoding TALE repeat arrays of various lengths in a single day, and then clone these to construct sequence-verified TALEN or TALE-TF expression plasmids in a week or less. Plasmids required for FLASH are available by request from the Joung lab (http://eGenome.org). This unit also describes improvements to the Zinc Finger and TALE Targeter (ZiFiT Targeter) web server (http://ZiFiT.partners.org) that facilitate the design and construction of FLASH TALE repeat arrays in high throughput.

  11. Mechanism and microstructures in Ga2O3 pseudomartensitic solid phase transition.

    Science.gov (United States)

    Zhu, Sheng-Cai; Guan, Shu-Hui; Liu, Zhi-Pan

    2016-07-21

    Solid-to-solid phase transition, although widely exploited in making new materials, challenges persistently our current theory for predicting its complex kinetics and rich microstructures in transition. The Ga2O3α-β phase transformation represents such a common but complex reaction with marked change in cation coordination and crystal density, which was known to yield either amorphous or crystalline products under different synthetic conditions. Here we, via recently developed stochastic surface walking (SSW) method, resolve for the first time the atomistic mechanism of Ga2O3α-β phase transformation, the pathway of which turns out to be the first reaction pathway ever determined for a new type of diffusionless solid phase transition, namely, pseudomartensitic phase transition. We demonstrate that the sensitivity of product crystallinity is caused by its multi-step, multi-type reaction pathway, which bypasses seven intermediate phases and involves all types of elementary solid phase transition steps, i.e. the shearing of O layers (martensitic type), the local diffusion of Ga atoms (reconstructive type) and the significant lattice dilation (dilation type). While the migration of Ga atoms across the close-packed O layers is the rate-determining step and yields "amorphous-like" high energy intermediates, the shearing of O layers contributes to the formation of coherent biphase junctions and the presence of a crystallographic orientation relation, (001)α//(201[combining macron])β + [120]α//[13[combining macron]2]β. Our experiment using high-resolution transmission electron microscopy further confirms the theoretical predictions on the atomic structure of biphase junction and the formation of (201[combining macron])β twin, and also discovers the late occurrence of lattice expansion in the nascent β phase that grows out from the parent α phase. By distinguishing pseudomartensitic transition from other types of mechanisms, we propose general rules to predict the

  12. Immobilization and functional reconstitution of antibody Fab fragment by solid-phase refolding.

    Science.gov (United States)

    Kumada, Yoichi; Hamasaki, Kyoto; Nakagawa, Aya; Sasaki, Eiju; Shirai, Tatsunori; Okumura, Masahiro; Inoue, Manami; Kishimoto, Michimasa

    2013-12-31

    In this study, we demonstrated the successful preparation of a Fab antibody-immobilized hydrophilic polystyrene (phi-PS) plate via one- and two-step solid-phase refolding methods. Both polystyrene-binding peptide (PS-tag)-fused Fd fragment of heavy chain (Fab H-PS) and full-length of light-chain (Fab L-PS) were individually produced in insoluble fractions of Escherichia coli cells, and they were highly purified in the presence of 8M of urea. Antigen-binding activities of Fab antibody immobilized were correctly recovered by the one-step solid-phase refolding method that a mixture of Fab H-PS and Fab L-PS was immobilized in the presence of 0.5-2M urea, followed by surface washing of the phi-PS plate with PBST. These results indicate that by genetic fusion of a PS-tag, a complex between Fab H and Fab L was efficiently immobilized on the surface of a phi-PS plate even in the presence of a low concentration of urea, and was then correctly refolded to retain its high antigen-binding activity via removal of the urea. A two-step solid-phase refolding method whereby Fab H-PS and Fab L-PS were successively refolded on the surface of a phi-PS plate also resulted in Fab antibody formation on the plate. Furthermore, both the binding affinity and the specificity of the Fab antibody produced by the two-step method were highly maintained, according to the results of sandwich ELISA and competitive ELISA using Fab antibody-immobilized plate via two-step solid-phase refolding. Thus, the solid-phase refolding method demonstrated in this study should be quite useful for the preparation of a Fab antibody-immobilized PS surface with high efficiency from individually produced Fab H-PS and Fab L-PS. This method will be applicable to the preparation of a large Fab antibody library on the surface of a PS plate for use in antibody screening.

  13. Horizontes del periodismo on line

    Directory of Open Access Journals (Sweden)

    Lizy Navarro Zamora

    2004-12-01

    Full Text Available This paper analyses the development of on line newspapers, their future, the promises which were fulfilled and those which were not. I study the finacial aspect of it, also the problem of concerningreception and the devices for it are considered. There are some considerations about the cyberjournalist, and about the contents, finally there are some advantages and recommendations concerning of on-line papers.

  14. A study of thin film solid phase microextraction methods for analysis of fluorinated benzoic acids in seawater.

    Science.gov (United States)

    Boyacı, Ezel; Goryński, Krzysztof; Viteri, C Ricardo; Pawliszyn, Janusz

    2016-03-01

    Fluorinated benzoic acids (FBAs) are frequently used as tracers by the oil industry to characterize petroleum reservoirs. The demand for fast, reliable, robust, and sensitive approaches to separate and quantify FBAs in produced water, both in laboratory and field conditions, has not been yet fully satisfied. In this study, for the first time, thin film solid phase microextraction (TF-SPME) is proposed as a versatile sample preparation tool for the determination of FBAs in produced water by pursing two different approaches. First, an automated high throughput TF-SPME method using solvent desorption for fast and simultaneous preparation of multiple samples prior to liquid chromatographic separation and high resolution mass spectrometric detection (LC-MS) of FBAs was demonstrated for routine laboratory analysis. This method was optimized in terms of extraction phase chemistry, sample pH and ionic strength, extraction/desorption times using two representative FBAs (4-FBA and 2,3,4,5-tetra FBA). It incorporates a relatively simple sample pretreatment involving pH adjustment prior to the TF-SPME, and obtained limits of quantification (LOQ) are at the 1.0ngmL(-1) level. Second, the applicability of TF-SPME for fast mass spectrometric (MS) determination of FBAs with omission of derivatization and gas chromatographic (GC) separation was proven. This second method consists of manual extractions of analytes from seawater samples with a thermally stable TF-SPME membrane and direct thermal desorption of the extracted FBAs to a MS via a thermal desorption unit (TDU). It was demonstrated that the TF-SPME extracts and thermally releases analytes quantitatively and with good reproducibility. This approach opens up the possibility for on-site measurements with portable analyzers. PMID:26860049

  15. Automation correlation installation on-line with a computer

    International Nuclear Information System (INIS)

    On the base of the SM-4 computer and CAMAC equipment the automatic three-dimensional spectrometer was made in order to carry out the correlation experiment at the U-240 cyclotron at the Institute for Nuclear Research, The Ukr. Ac. of Sci. A block-diagram of correlation installation, units of automatic equipment and software implemented for automatic installation procedure were described. A package of SPECTR programmes for interpretation of linear γ-spectra and γγ-coincidence spectra was established. Reslts of check experiments were cited

  16. 5th Computer Science On-line Conference

    CERN Document Server

    Senkerik, Roman; Oplatkova, Zuzana; Silhavy, Petr; Prokopova, Zdenka

    2016-01-01

    This volume is based on the research papers presented in the 5th Computer Science On-line Conference. The volume Artificial Intelligence Perspectives in Intelligent Systems presents modern trends and methods to real-world problems, and in particular, exploratory research that describes novel approaches in the field of artificial intelligence. New algorithms in a variety of fields are also presented. The Computer Science On-line Conference (CSOC 2016) is intended to provide an international forum for discussions on the latest research results in all areas related to Computer Science. The addressed topics are the theoretical aspects and applications of Computer Science, Artificial Intelligences, Cybernetics, Automation Control Theory and Software Engineering.

  17. Determination of tellurium at ultra-trace levels in drinking water by on-line solid phase extraction coupled to graphite furnace atomic absorption spectrometer

    International Nuclear Information System (INIS)

    In this paper, two time-based flow injection (FI) separation pre-concentration systems coupled to graphite furnace atomic absorption spectrometry (GFAAS) for tellurium determination are studied and compared. The first alternative involves the pre-concentration of the analyte onto Dowex 1X8 employed as packaging material of a micro-column inserted in the flow system. The second set-up is based on the co-precipitation of tellurium with La(OH)3 followed by retention onto XAD resins. Both systems are compared in terms of limit of detection, linear range, RSD%, sample throughput, micro-columns lifetime and aptitude for fully automatic operation. The features of the Dowex system are: 37% efficiency of retention and an enhancement factor of 42 for a pre-concentration time of 180 seconds (sample flow rate = 3 ml min-1) with acetic acid elution volumes of 80 μl. The detection limit (3 s) is 7 ng l-1 and the relative standard deviation (n = 7200 ng l-1) is 5.8%. The analytical performance of the XAD system is: 72% efficiency of retention and an enhancement factor of 25 for a pre-concentration time of 180 s (sample flow rate = 3 ml min-1) with nitric acid elution volumes of 300 μl. The detection limit is 66 ng l-1 and the relative standard deviation (n = 7200 ng l-1) is 8.3%. Applications to the determination of tellurium in tap water and the validation of the analytical methodology employing SRM 1643e as certified reference material are shown

  18. Determination of tellurium at ultra-trace levels in drinking water by on-line solid phase extraction coupled to graphite furnace atomic absorption spectrometer

    Energy Technology Data Exchange (ETDEWEB)

    Pedro, Juana [Area de Quimica Analitica, Departamento de Quimica, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Stripekis, Jorge [Laboratorio de Analisis de Trazas, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina); Bonivardi, Adrian [Area de Quimica Analitica, Departamento de Quimica, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santiago del Estero 2829 (S3000GL.N), Santa Fe (Argentina); Tudino, Mabel [Laboratorio de Analisis de Trazas, Departamento de Quimica Inorganica, Analitica y Quimica Fisica, INQUIMAE, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Ciudad Universitaria (1428), Buenos Aires (Argentina)], E-mail: tudino@qi.fcen.uba.ar

    2008-01-15

    In this paper, two time-based flow injection (FI) separation pre-concentration systems coupled to graphite furnace atomic absorption spectrometry (GFAAS) for tellurium determination are studied and compared. The first alternative involves the pre-concentration of the analyte onto Dowex 1X8 employed as packaging material of a micro-column inserted in the flow system. The second set-up is based on the co-precipitation of tellurium with La(OH){sub 3} followed by retention onto XAD resins. Both systems are compared in terms of limit of detection, linear range, RSD%, sample throughput, micro-columns lifetime and aptitude for fully automatic operation. The features of the Dowex system are: 37% efficiency of retention and an enhancement factor of 42 for a pre-concentration time of 180 seconds (sample flow rate = 3 ml min{sup -1}) with acetic acid elution volumes of 80 {mu}l. The detection limit (3 s) is 7 ng l{sup -1} and the relative standard deviation (n = 7200 ng l{sup -1}) is 5.8%. The analytical performance of the XAD system is: 72% efficiency of retention and an enhancement factor of 25 for a pre-concentration time of 180 s (sample flow rate = 3 ml min{sup -1}) with nitric acid elution volumes of 300 {mu}l. The detection limit is 66 ng l{sup -1} and the relative standard deviation (n = 7200 ng l{sup -1}) is 8.3%. Applications to the determination of tellurium in tap water and the validation of the analytical methodology employing SRM 1643e as certified reference material are shown.

  19. On-line restricted access molecularly imprinted solid phase extraction of ivermectin in meat samples followed by HPLC-UV analysis.

    Science.gov (United States)

    de Lima, Marcela Marília; Vieira, André Coutinho; Martins, Isarita; Boralli, Vanessa Bergamin; Borges, Keyller Bastos; Figueiredo, Eduardo Costa

    2016-04-15

    A new restricted access molecularly imprinted polymer coated with bovine serum albumin (RAMIP-BSA) was synthesized, characterized and used for direct analysis of ivermectin from bovine meat samples, in a two-dimensional liquid chromatography system with UV detection. Ivermectin, 4-vynilpiridine and ethylene glycol dimethacrylate were employed as template, functional monomer and cross-linker, respectively. A BSA layer was cross-linked around the polymer, resulting in a biocompatible chemical barrier able to eliminate about 100% of protein from the samples. Ivermectin was extracted from the minced meat samples through a solvent extraction using methanol:water (70:30, v:v), and the extracts were directly injected into the two-dimensional liquid chromatography system, without any other treatment. Samples, fortified with ivermectin from 50 to 500 μg kg(-1), were used to build the analytical calibration curve (r=0.996). The limit of quantification was 50 μg kg(-1). Precision and accuracy presented variation coefficients, as well as relative errors lower than 17.0% and within -18.5% and 22.0%, respectively.

  20. From Polymer to Small Organic Molecules: A Tight Relationship between Radical Chemistry and Solid-Phase Organic Synthesis

    OpenAIRE

    Danilo Mirizzi; Maurizio Pulici

    2011-01-01

    Since Gomberg’s discovery of radicals as chemical entities, the interest around them has increased through the years. Nowadays, radical chemistry is used in the synthesis of 75% of all polymers, inevitably establishing a close relationship with Solid-Phase Organic Synthesis. More recently, the interest of organic chemists has shifted towards the application of usual “in-solution” radical chemistry to the solid-phase, ranging from the use of supported reagents for radical reactions, to the dev...

  1. Formation of organic solid phases in hydrocarbon reservoir fluids. Final report

    Energy Technology Data Exchange (ETDEWEB)

    Andersen, S.I.; Lindeloff, N.; Stenby, E.H.

    1998-12-31

    The occurrence of solid phases during oil recovery is a potential problem. The present work has mainly been concerned with wax formation due to cooling of oils with a large paraffin content. 8 oils have been included in this project, although only a few of these have till now been subject to all the experimental techniques applied. The oils and wax fractions from these have been characterized using techniques such as GC-MS and Ftir. The goal has in part been to get a detailed description of the oil composition for use in model evaluation and development and in part to get a fundamental understanding of waxy oil properties and behaviour. A high pressure (200 bar) equipment has been developed for automatic detection of wax appearance using a filtration technique and laser light turbidimetry. The latter was found to be far superior to the filtration. The filtration was used to sample the incipient solid phase for characterization. However entrapment of liquid in the filters currently used have hampered this part. A number of model systems and one gas condensate have been investigated. The GC-MS procedure was found only to been able to detect molecules up to n-C45 and the group type analysis was not accurate enough for modelling purposes. Using Ftir it was obvious that incipient phases may contain very complex molecules (asphaltenes) which are not captured by GC-MS especially when fractionation is done using the acetone precipitation at elevated temperature. The latter fractionation procedure has been investigated thoroughly as a tool for understanding wax distribution etc. Within thermodynamic modelling a delta lattice parameter model has been developed which incorporates the non-ideality of the solid phases into the calculation of SLE. The non-ideality is estimated from pure component properties. A new algorithm for phase equilibria involving gas-liquid-solid has been developed. Currently both the model work and the experimental works are continued. (au)

  2. [Selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction].

    Science.gov (United States)

    Zhang, Feng; Guo, Zhimou; Zhang, Feifang; Xue, Xingya; Liang, Xinmiao

    2009-07-01

    A method for selective enrichment of iridoid glucosides in Hedyotis diffusa Willd. by tandem solid phase extraction (SPE) was developed. Oligo(ethylene glycol) (OEG) is a novel type of separation material made in this laboratory. The differences of the surface chemical structures between OEG material and ODS material resulted in their different retention capabilities for iridoid glucosides. Based on the differences, an OEG-ODS solid phase extraction method was designed for selective enrichment of iridoid glucosides. The water extract (150.28 mg) of Hedyotis diffusa Willd. was precipitated by ethanol, and an aliquot (27.03 mg) of the product from the supernatant solution was loaded onto an OEG cartridge and rinsed by 5 mL water. Then, the rinsing solution was loaded onto an ODS cartridge. After it was washed by 5 mL water and eluted by 5 mL methanol, 4.01 mg final product was obtained from the methanol eluent. All the products were characterized by ultra performance liquid chromatography (UPLC), and 14 representative peaks of iridoid glucosides were found. The enrichment results were proved effective by directly comparing the chromatograms each step. To further characterize the enrichment efficiency, the changes of the peak area of iridoid glucosides were investigated. The results showed that the content of 14 iridoid glucosides in the final product reached 6.10 times its original proportion in water extraction product and their recovery was 50.1% on average. Therefore, the iridoid glucosides can be enriched by the tandem solid phase extraction method from water extracting-ethanol precipitating solution of Hedyotis diffusa Willd. with a good selectivity and an acceptable recovery. The proposed method has the advantages of high enrichment efficiency and simple operation. PMID:19938499

  3. E-Business and on line banking in Bangladesh: an Analysis

    OpenAIRE

    Muhammad Mahboob Ali

    2010-01-01

    E-business has created tremendous opportunity all over the globe. On line banking can act as a complementary factor of e-business. Bangladesh Bank has recently argued to introduce automated clearing house system. This pushed upward transition from the manual banking system to the on line banking system. The study has been undertaken to observe present status of the e-business and as its complementary factor on line banking system in Bangladesh. The article analyzes the data that were collecte...

  4. Novel nanoporous sorbent for solid-phase extraction in petroleum fingerprinting

    Science.gov (United States)

    Alayande, S. Oluwagbemiga; Hlengilizwe, Nyoni; Dare, E. Olugbenga; Msagati, Titus A. M.; Akinlabi, A. Kehinde; Aiyedun, P. O.

    2016-04-01

    Sample preparation is crucial in the analysis of petroleum and its derivatives. In this study, developing affordable sorbent for petroleum fingerprinting analysis using polymer waste such expanded polystyrene was explored. The potential of electrospun expanded polystyrene (EPS) as a sorbent for the solid-phase extraction (SPE) technique was investigated, and its efficiency was compared with commercial cartridges such as alumina, silica and alumina/silica hybrid commercial for petroleum fingerprinting analysis. The chromatograms showed that the packed electrospun EPS fibre demonstrated excellent properties for SPE applications relative to the hybrid cartridges.

  5. Ultrasonic detection of solid phase mass flow ratio of pneumatic conveying fly ash

    Science.gov (United States)

    Duan, Guang Bin; Pan, Hong Li; Wang, Yong; Liu, Zong Ming

    2014-04-01

    In this paper, ultrasonic attenuation detection and weight balance are adopted to evaluate the solid mass ratio in this paper. Fly ash is transported on the up extraction fluidization pneumatic conveying workbench. In the ultrasonic test. McClements model and Bouguer-Lambert-Beer law model were applied to formulate the ultrasonic attenuation properties of gas-solid flow, which can give the solid mass ratio. While in the method of weigh balance, the averaged mass addition per second can reveal the solids mass flow ratio. By contrast these two solid phase mass ratio detection methods, we can know, the relative error is less.

  6. Interfacial Behavior of Fatty-Acylated Sericin Prepared by Lipase-Catalyzed Solid-Phase Synthesis

    OpenAIRE

    Ogino, Masato; Tanaka, Rie; 服部, 誠; Yoshida, Tadashi; 横手, よし子; 高橋, 幸資

    2006-01-01

    Fatty-acylated sericin {1:0.7 molar ratio of sericin (Mr 18,700) to oleic acid} was prepared by lipase-catalyzed solid-phase synthesis in n-hexane containing oleic acid to endow sericin with interfacial properties. Acylation with oleic acid was confirmed by 1H-NMR. The fatty-acylated sericin exhibited superior emulsifying activity index and emulsion stability in the presence of 0?0.5 M NaCl, in a temperature range of 30?80 °C and pH range of 2?7, as compared with the control sericin. The fatt...

  7. Synthesis of silicon carbide nanowires by solid phase source chemical vapor deposition

    Institute of Scientific and Technical Information of China (English)

    NI Jie; LI Zhengcao; ZHANG Zhengjun

    2007-01-01

    In this paper,we report a simple approach to synthesize silicon carbide(SiC)nanowires by solid phase source chemical vapor deposition(CVD) at relatively low temperatures.3C-SiC nanowires covered by an amorphous shell were obtained on a thin film which was first deposited on silicon substrates,and the nanowires are 20-80 am in diameter and several μm in length,with a growth direction of[200].The growth of the nanowires agrees well on vapor-liquid-solid (VLS)process and the film deposited on the substrates plays an important role in the formation of nanowires.

  8. Direct MD simulation of liquid-solid phase equilibria for two-component plasmas

    OpenAIRE

    Schneider, A. S.; Hughto, J.; Horowitz, C. J.; Berry, D. K.

    2011-01-01

    We determine the liquid-solid phase diagram for carbon-oxygen and oxygen-selenium plasma mixtures using two-phase MD simulations. We identified liquid, solid, and interface regions using a bond angle metric. To study finite size effects, we perform 27648 and 55296 ion simulations. To help monitor non-equilibrium effects, we calculate diffusion constants $D_i$. For the carbon-oxygen system we find that $D_O$ for oxygen ions in the solid is much smaller than $D_C$ for carbon ions and that both ...

  9. Preparation of A New Fiber by Sol-gel Technology in Solid-phase Microextraction (SPME)

    Institute of Scientific and Technical Information of China (English)

    Li Ming WEI; Qing Yu OU; Ju Bai LI

    2004-01-01

    The sol-gel technology is applied for the preparation of solid-phase microextraction (SPME) fiber. The fiber demonstrates high thermal stability, efficient extraction rate and the selectivity for non-polar or low-polar analytes. Efficient SPME-GC-FID analyses of benzene- toluene-ethylbenzene-xylenes (BTEXs) and low-polar halocarbon were achieved by the sol-gel coated DSDA-DDBT-TiO2 fiber. Some parameters of the SPME fiber for the determination of halocarbon in aqueous sample were investigated.

  10. Direct determination of enthalpies of solid phase reactions by immersion method

    International Nuclear Information System (INIS)

    It is not generally possible to measure the enthalpy change corresponding to solid phase reactions using the dynamic differential thermal analysis method because these reactions are usually too slow at the temperature of operation of present equipment. A ballistic differential thermal analysis apparatus has been developed which is based on an immersion-compensation method; it overcomes the difficulties previously encountered. This apparatus has been used after calibration for determining the enthalpies of formation of calcium and cadmium titanates. and also the Wigner energies of BeO, MgO and Al2O3 samples irradiated at variable dose at a temperature of under 100 deg. C. (authors)

  11. A novel Fmoc-based anchorage for the synthesis of protected peptides on solid phase.

    Science.gov (United States)

    Liu, Y Z; Ding, S H; Chu, J Y; Felix, A M

    1990-02-01

    A novel bifunctional compound, 9-(hydroxymethyl)-2-fluoreneacetic acid, was synthesized, coupled to benzhydrylamine-resin, and evaluated for its application to the solid phase synthesis of protected peptide fragments. Anchor-bond cleavage was achieved with 15% piperidine/DMF. A protected heptapeptide, Boc-Val-Val-Ser(Bzl)-His(Tos)-Phe-Asn-Lys-(Z)-OH, corresponding to the sequence (1-7) of rat-transforming growth factor-alpha, was synthesized using this new support with an overall yield of 46%.

  12. Solid Phase Characterization of Tank 241-AY-102 Annulus Space Particulate

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, G. A.

    2013-01-30

    The Special Analytical Studies Group at the 222-S Laboratory (222-S) examined the particulate recovered from a series of samples from the annular space of tank 241-AY-102 (AY-102) using solid phase characterization (SPC) methods. These include scanning electron microscopy (SEM) using the ASPEX®1 scanning electron microscope, X-ray diffraction (XRD) using the Rigaku®2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon®3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information.

  13. A solid-phase dot assay using silica/gold nanoshells

    OpenAIRE

    Zharov Vladimir; Khlebtsov Boris; Dykman Lev; Bogatyrev Vladimir; Khlebtsov Nikolai

    2006-01-01

    AbstractWe report on the first application of silica-gold nanoshells to a solid-phase dot immunoassay. The assay principle is based on staining of a drop (1 µl) analyte on a nitrocellulose membrane strip by using silica/gold nanoshells conjugated with biospecific probing molecules. Experimental example is human IgG (hIgG, target molecules) and protein A (probing molecules). For usual 15-nm colloidal gold conjugates, the minimal detectable amount of hIgG is about 4 ng. By contrast, for na...

  14. Solid-state dimer method for calculating solid-solid phase transitions

    Energy Technology Data Exchange (ETDEWEB)

    Xiao, Penghao; Henkelman, Graeme, E-mail: henkelman@cm.utexas.edu [Department of Chemistry and the Institute for Computational and Engineering Sciences, University of Texas at Austin, Austin, Texas 78712 (United States); Sheppard, Daniel [Theoretical Division, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Rogal, Jutta [Interdisciplinary Centre for Advanced Materials Simulation, Ruhr-Universität Bochum, 44780 Bochum (Germany)

    2014-05-07

    The dimer method is a minimum mode following algorithm for finding saddle points on a potential energy surface of atomic systems. Here, the dimer method is extended to include the cell degrees of freedom for periodic solid-state systems. Using this method, reaction pathways of solid-solid phase transitions can be determined without having to specify the final state structure or reaction mechanism. Example calculations include concerted phase transitions between CdSe polymorphs and a nucleation and growth mechanism for the A15 to BCC transition in Mo.

  15. Peptidyl Molecular Imaging Contrast Agents Using a New Solid Phase Peptide Synthesis Approach

    OpenAIRE

    Yoo, Byunghee; Pagel, Mark D.

    2007-01-01

    A versatile method is disclosed for solid phase peptide synthesis (SPPS) of molecular imaging contrast agents. A DO3A moiety was derivatized to introduce a CBZ-protected amino group and then coupled to a polymeric support. CBZ cleavage with Et2AlCl/thioanisole was optimized for SPPS. Amino acids were then coupled to the aminoDOTA loaded resin using conventional step-wise Fmoc SPPS to create a product with DOTA coupled to the C-terminus of the peptide. In a second study, the DO3A moiety was co...

  16. Structurally Diverse Polyamines: Solid-Phase Synthesis and Interaction with DNA.

    Science.gov (United States)

    Umezawa, Naoki; Horai, Yuhei; Imamura, Yuki; Kawakubo, Makoto; Nakahira, Mariko; Kato, Nobuki; Muramatsu, Akira; Yoshikawa, Yuko; Yoshikawa, Kenichi; Higuchi, Tsunehiko

    2015-08-17

    A versatile solid-phase approach based on peptide chemistry was used to construct four classes of structurally diverse polyamines with modified backbones: linear, partially constrained, branched, and cyclic. Their effects on DNA duplex stability and structure were examined. The polyamines showed distinct activities, thus highlighting the importance of polyamine backbone structure. Interestingly, the rank order of polyamine ability for DNA compaction was different to that for their effects on circular dichroism and melting temperature, thus indicating that these polyamines have distinct effects on secondary and higher-order structures of DNA.

  17. Solid-phase synthesis and biological evaluation of Joro spider toxin-4 from Nephila clavata

    DEFF Research Database (Denmark)

    Barslund, Anne Fuglsang; Poulsen, Mette Homann; Bach, Tinna Brøbech;

    2011-01-01

    Polyamine toxins from orb weaver spiders are attractive pharmacological tools particularly for studies of ionotropic glutamate (iGlu) receptors in the brain. These polyamine toxins are biosynthesized in a combinatorial manner, providing a plethora of related, but structurally complex toxins...... to be exploited in biological studies. Here, we have used solid-phase synthetic methodology for the efficient synthesis of Joro spider toxin-4 (JSTX-4) (1) from Nephila clavata, providing sufficient amounts of the toxin for biological evaluation at iGlu receptor subtypes using electrophysiology. Biological...

  18. Solid-Phase Immunoassay of Polystyrene-Encapsulated Semiconductor Coreshells for Cardiac Marker Detection

    Directory of Open Access Journals (Sweden)

    Sanghee Kim

    2012-01-01

    Full Text Available A solid-phase immunoassay of polystyrene-encapsulated semiconductor nanoparticles was demonstrated for cardiac troponin I (cTnI detection. CdSe/ZnS coreshells were encapsulated with a carboxyl-functionalized polystyrene nanoparticle to capture the target antibody through a covalent bonding and to eliminate the photoblinking and toxicity of semiconductor luminescent immunosensor. The polystyrene-encapsulated CdSe/ZnS fluorophores on surface-modified glass chip identified cTnI antigens at the level of ~ng/mL. It was an initial demonstration of diagnostic chip for monitoring a cardiovascular disease.

  19. Capture-S, a nontreponemal solid-phase erythrocyte adherence assay for serological detection of syphilis.

    OpenAIRE

    Stone, D L; Moheng, M C; Rolih, S; Sinor, L T

    1997-01-01

    A solid-phase erythrocyte adherence assay has been developed for the serological detection of reagin antibodies in syphilis. Capture-S (Immucor, Inc., Norcross, Ga.) is a nontreponemal, qualitative screening test for the detection of immunoglobulin G (IgG) and IgM antilipid antibodies in serum or plasma samples from blood donors. The Capture-S assay utilizes a modified Venereal Disease Research Laboratory antigen bound to microtitration wells and anti-IgG- plus anti-IgM-coated indicator eryth...

  20. Surface characterization of commercial fibers for solid-phase microextraction and related problems in their application.

    Science.gov (United States)

    Haberhauer-Troyer, C; Crnoja, M; Rosenberg, E; Grasserbauer, M

    2000-02-01

    The surfaces of commercially available polydimethylsiloxane (PDMS) and Carboxen-PDMS fibers for solid-phase microextraction (SPME) were investigated by optical and electron microscopy. Damage to the coating as well as contamination of new fibers and a highly variable number of pores in Carboxen-PDMS coatings were observed. Together with the contamination of the fibers during their use with metallic particles originating from the SPME fiber holder they are possible explanations for the problems encountered in the analysis of organolead, organotin and organosulfur compounds, such as artifact formation and low repeatability. PMID:11220312

  1. Solid-phase radioimmunoassay for the detection of antibodies to collagens

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay using 125I-protein A is described for the detection of antibodies to collagens of different types. The optimal conditions for the adsorption of collagen onto polystyrene microplates, then the incubations with the antiserum and finally with the 125I-protein A have been evaluated. The technique was applied successfully to antisera raised in rabbit, goat, guinea pig and mouse against human type I, II, III, IV, V and bovine type I, II, 1α2α3α, X1-X7 collagens

  2. Personal on-line payments

    OpenAIRE

    Kuttner, Kenneth N.; James J. McAndrews

    2001-01-01

    The swift growth of e-commerce and the Internet has led to the development of a new form of electronic funds transfer—the personal on-line payment—that uses web and e-mail technologies to initiate and confirm payments. This article describes this payment instrument and the trends that have given rise to it. The authors explain that personal on-line payment systems are already providing a convenient alternative to checks, money orders, and cash, and may replace credit cards for some small-scal...

  3. Optimization of automated radiosynthesis of [{sup 18}F]AV-45: a new PET imaging agent for Alzheimer's disease

    Energy Technology Data Exchange (ETDEWEB)

    Liu Yajing; Zhu Lin [Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing, 100875 (China); Department of Radiology, University of Pennsylvania, Philadelphia, PA 19014 (United States); Ploessl, Karl [Department of Radiology, University of Pennsylvania, Philadelphia, PA 19014 (United States); Choi, Seok Rye [Avid Radiopharmaceuticals Inc., Philadelphia, PA 19014 (United States); Qiao Hongwen; Sun Xiaotao; Li Song [Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing, 100875 (China); Zha Zhihao [Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing, 100875 (China); Department of Radiology, University of Pennsylvania, Philadelphia, PA 19014 (United States); Kung, Hank F., E-mail: kunghf@sunmac.spect.upenn.ed [Key Laboratory of Radiopharmaceuticals, Beijing Normal University, Ministry of Education, Beijing, 100875 (China); Department of Radiology, University of Pennsylvania, Philadelphia, PA 19014 (United States)

    2010-11-15

    Introduction: Accumulation of {beta}-amyloid (A{beta}) aggregates in the brain is linked to the pathogenesis of Alzheimer's disease (AD). Imaging probes targeting these A{beta} aggregates in the brain may provide a useful tool to facilitate the diagnosis of AD. Recently, [{sup 18}F]AV-45 ([{sup 18}F]5) demonstrated high binding to the A{beta} aggregates in AD patients. To improve the availability of this agent for widespread clinical application, a rapid, fully automated, high-yield, cGMP-compliant radiosynthesis was necessary for production of this probe. We report herein an optimal [{sup 18}F]fluorination, de-protection condition and fully automated radiosynthesis of [{sup 18}F]AV-45 ([{sup 18}F]5) on a radiosynthesis module (BNU F-A2). Methods: The preparation of [{sup 18}F]AV-45 ([{sup 18}F]5) was evaluated under different conditions, specifically by employing different precursors (-OTs and -Br as the leaving group), reagents (K222/K{sub 2}CO{sub 3} vs. tributylammonium bicarbonate) and deprotection in different acids. With optimized conditions from these experiments, the automated synthesis of [{sup 18}F]AV-45 ([{sup 18}F]5) was accomplished by using a computer-programmed, standard operating procedure, and was purified on an on-line solid-phase cartridge (Oasis HLB). Results: The optimized reaction conditions were successfully implemented to an automated nucleophilic fluorination module. The radiochemical purity of [{sup 18}F]AV-45 ([{sup 18}F]5) was >95%, and the automated synthesis yield was 33.6{+-}5.2% (no decay corrected, n=4), 50.1{+-}7.9% (decay corrected) in 50 min at a quantity level of 10-100 mCi (370-3700 MBq). Autoradiography studies of [{sup 18}F]AV-45 ([{sup 18}F]5) using postmortem AD brain and Tg mouse brain sections in the presence of different concentration of 'cold' AV-136 showed a relatively low inhibition of in vitro binding of [{sup 18}F]AV-45 ([{sup 18}F]5) to the A{beta} plaques (IC50=1-4 {mu}M, a concentration several

  4. Towards automated solid phase radiofluorination for dose-on-demand PET. Retention of activity by solid support

    Energy Technology Data Exchange (ETDEWEB)

    Mathiessen, Bente; Severin, Gregory; Zhuravlev, Fedor [Technical Univ. Denmark, Risoe Campus, Roskilde (Denmark). Hevesy Lab.

    2015-06-01

    On-column [{sup 18}F]fluoride trapping and radiofluorination of 2-(naphthalen-1-yl)ethyl-4-methylbenzenesulfonate (C{sub 10}H{sub 7}(CH{sub 2}){sub 2}OTs), performed on polystyrene supported phosphazene base PS-P{sub 2}{sup tBu} yielded [{sup 18}F]1-(2-fluoroethyl)naphthalene ([{sup 18}F]C{sub 10}H{sub 7}(CH{sub 2}){sub 2}F) in 50% radiochemical yield but left up to 43% of activity unreacted on the resin. This activity could be eluted with Kryptofix/K{sub 2}CO{sub 3} and then used for conventional radiofluorination of the same substrate, suggesting that the column-retained activity was present in the form of [{sup 18}F]fluoride entrapped in polymer matrix. An approach to minimize the amount of entrapped [{sup 18}F]fluoride by use of glass beads functionalized with alkylsilane-derivatized phosphazene residues was attempted but was stymied by fluorolysis/hydrolysis of the alkylsilane spacer. The results suggest that the key to high yield of on-column radiofluorination is to minimize the residual [{sup 18}F]fluoride absorption in the matrix by the judicious choice of solid support.

  5. Identification and quantification of 56 targeted phenols in wines, spirits, and vinegars by online solid-phase extraction - ultrahigh-performance liquid chromatography - quadrupole-orbitrap mass spectrometry.

    Science.gov (United States)

    Barnaba, C; Dellacassa, E; Nicolini, G; Nardin, T; Malacarne, M; Larcher, R

    2015-12-01

    Phenolic compounds seriously affect the sensory and nutritional qualities of food products, both through the positive contribution of wood transfer in barrel-aged products and as off-flavours. A new targeted analytical approach combining on-line solid-phase extraction (SPE) clean-up to reduce matrix interference and rapid chromatographic detection performed with ultrahigh-performance liquid chromatography coupled with quadrupole/high-resolution mass spectrometry (Q-Orbitrap), was developed for the quantification of 56 simple phenols. Considering the advantages of using on-line SPE and a resolving power of 140,000, the proposed method was applied to define phenolic content in red (N=8) and white (8) wines, spirits (8), common (8) and balsamic (8) vinegars. The final method was linear from the limits of quantification (0.0001-0.001μgmL(-1)) up to 10μgmL(-1) with R(2) of at least 0.99. Recovery, used to define method accuracy, ranged from 80 to 120% for 89% of compounds. The method was suitable for analytical requirements in the tested matrices being able to analyse 46 phenols in red wines, 41 phenols in white wines and in spirits, 42 phenols in common vinegars and 44 phenols in balsamic vinegars. PMID:26582576

  6. Reactive magnesium oxide cements: geochemical modelling of pH profile and solid phase composition

    International Nuclear Information System (INIS)

    Due to a range of technical and sustainability advantages, reactive magnesium oxide cements (MgO) are a potential alternative to Portland cement (PC) for conditioning intermediate level radioactive waste (ILW). MgO cements consist of a mixture of hydraulic cement and reactive magnesium oxide to which pozzolans such as silica fume (SF) may be added. While favourable, the mechanical and chemical properties of MgO matrices still require further investigation to ensure effective immobilisation of contaminants. In this study a solubility-speciation model was developed using PHREEQC to simulate blends based on low and high contents of MgO, including SF as a supplementary material. Analyses aimed at characterising binding systems focusing on their equilibrium pH with pure water and saturation index (SI) of solid phases. The geochemical model successfully confirmed that the equilibrium pH is inversely proportional to the fraction of MgO and SF present in the hydrated paste. Comparison with data available on literature mostly gave a consistent picture and the model provided reasonable predictions of existent solid phases. (authors)

  7. Improvement of multilayer graphene crystallinity by solid-phase precipitation with current stress application during annealing

    Science.gov (United States)

    Sahab Uddin, Md.; Ichikawa, Hiroyasu; Sano, Shota; Ueno, Kazuyoshi

    2016-06-01

    To improve the crystallinity of multilayer graphene (MLG) films by solid-phase precipitation, a new method by which current stress is introduced during annealing of a carbon-doped cobalt (Co-C) layer using cobalt (Co) as the catalyst has been investigated. The effects of current stress on the formation and crystallinity of MLG films were investigated by comparing the characteristics of the films annealed at the same temperature with and without current by taking into account the temperature rise due to Joule heating. The characteristics obtained by Raman spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD) measurements revealed that the MLG films produced were crystalline in nature and their crystallinity increased with applied current stress at the same temperature. From SEM observations, beside Joule heating, enhancement of Co grain size by agglomeration induced by current stress may be the potential reason for the improvement of the crystallinity of MLG films. We have also improved the uniformity of MLG films by depositing an additional copper (Cu) capping layer over the Co-C layer. Current stress application can lead to low-temperature fabrication of MLG with higher crystallinity by solid-phase precipitation.

  8. Molecularly imprinted polymer microspheres for solid-phase extraction of protocatechuic acid in Rhizoma homalomenae.

    Science.gov (United States)

    Chen, Fang-Fang; Wang, Guo-Ying; Shi, Yan-Ping

    2011-10-01

    Molecularly imprinted polymers (MIPs) had been prepared by precipitation polymerization method using acrylamide as the functional monomer, ethylene glycol dimethacrylate as the cross-linker, acetonitrile as the porogen solvent and protocatechuic acid (PA), one of phenolic acids, as the template molecule. The MIPs were characterized by scanning electron microscopy and Fourier transform infrared, and their performance relative to non-imprinted polymers was assessed by equilibrium binding experiments. Six structurally similar phenolic acids, including p-hydroxybenzoic acid, gallic acid, salicylic acid, syringic acid, vanillic acid, ferulic acid were selected to assess the selectivity and recognition capability of the MIPs. The MIPs were applied to extract PA from the traditional Chinese medicines as a solid-phase extraction sorbent. The resultant cartridge showed that the MIPs have a good extraction performance and were able to selectively extract almost 82% of PA from the extract of Rhizoma homalomenae. Thus, the proposed molecularly imprinted-solid phase extraction-high performance liquid chromatography method can be successfully used to extract and analyse PA in traditional Chinese medicines. PMID:21809445

  9. Rapid solid-phase extraction and analysis of resveratrol and other polyphenols in red wine.

    Science.gov (United States)

    Hashim, Shima N N S; Schwarz, Lachlan J; Boysen, Reinhard I; Yang, Yuanzhong; Danylec, Basil; Hearn, Milton T W

    2013-10-25

    Red wine has long been credited as a good source of health-beneficial antioxidants, including the bioactive polyphenols catechin, quercetin, and (E)-resveratrol. In this paper, we report the application of reusable molecularly imprinted polymers (MIPs) for the selective and robust solid-phase extraction (SPE) and rapid analysis of (E)-resveratrol (LOD=8.87×10(-3) mg/L, LOQ=2.94×10(-2) mg/L), along with a range of other polyphenols from an Australian Pinot noir red wine. Optimization of the molecularly imprinted solid-phase extraction (MISPE) protocol resulted in the significant enrichment of (E)-resveratrol and several structurally related polyphenols. These secondary metabolites were subsequently identified by RP-HPLC and μLC-ESI ion trap MS/MS methods. The developed MISPE protocol employed low volumes of environmentally benign solvents selected according to the Green Chemistry principles, and resulted in the recovery of 99% of the total (E)-resveratrol present. These results further demonstrate the potential of generic protocols for the analysis of target compound with health beneficial properties within the food and nutraceutical industries using tailor-made MIPs.

  10. Solid phase extraction and spectrophotometric determination of palladium with 2-(2-quinolylazo-5-diethylaminobenzoic acid

    Directory of Open Access Journals (Sweden)

    WEIZU YANG

    2006-07-01

    Full Text Available Asensitive, selective and rapid method for the determination of palladium based on the rapid reaction of palladium(II with 2-(2-quinolylazo-5-diethylaminobenzoic acid (QADEAB and the solid phase extraction of the Pd(II –QADEAB chelate with a reversed phase polymer-based C18 cartridge was developed. In the presence of 0.05 – 0. 5 mol/L of hydrochloric acid solution and cetyl trimethylammonium bromide (CTAB medium, QADEAB reacts with palladium(II to form a violet complex with a mole ratio 1:2 (palladium to QADEAB. The chelate was enriched by solid phase extraction with a reversed phase polymer-based C18 cartridge. An enrichment factor of 200 was obtained by elution of the chelate form the cartridge with the minimal amount of isopentyl alcohol. The molar absorptivity of the chelate in the isopentyl alcohol medium was 1.43 × 105 L mol-1 cm-1 at 628 nm. Beer’s law was obeyed in the range of 0.01 – 1.2 mg/mL. The relative standard deviation for eleven replicate samples at the 0.2 mg/L level was 2.18 %. The attained detection limit amounted to 0.02 mg/L in the original samples. This method was applied to the determination of palladium in environmental samples with good results.

  11. A highly thermal stable solid phase microextraction fiber prepared by an inorganic binder.

    Science.gov (United States)

    Liu, Hongmei; Ran, Fanpeng; Tao, Caihong; Zhao, Mengmeng; Jia, Yulong; Guo, Yong

    2016-04-28

    An easy method to prepare solid phase microextraction fibers by introducing an inorganic binder was demonstrated in this study, where MoS2 was selected as the extraction phase material because of its graphite-like layered structure with large specific adsorption area and good stability, and was then adhered to a stainless steel wire by acid aluminum phosphate binder with the spraying method. The as-prepared solid phase microextraction fiber coupled with gas chromatography was then used to extract some polycyclic aromatic hydrocarbons target analytes including the low-volatile benzo(a)pyrene etc. from a standard sample. Comparing with the MoS2-epoxy resin and commercial polyacrylate fibers, the MoS2-acid aluminum phosphate fiber has a higher thermal stability because of highly thermal stable acid aluminum phosphate, which is durable for a long service life at a high temperature (320 °C), and has the advantage in the extraction of low-volatility analytes. After the optimization of adsorption and desorption factors (ionic strength, adsorption time and temperature, and desorption temperature), method detection limits of service life, which is useful for the detection of low-volatility target analytes in practical applications. PMID:27046208

  12. Development of andrographolide molecularly imprinted polymer for solid-phase extraction

    Science.gov (United States)

    Yin, Xiaoying; Liu, Qingshan; Jiang, Yifan; Luo, Yongming

    2011-06-01

    A method employing molecularly imprinted polymer (MIP) as selective sorbent for solid-phase extraction (SPE) to pretreat samples was developed. The polymers were prepared by precipitation polymerization with andrographolide as template molecule. The structure of MIP was characterized and its static adsorption capacity was measured by the Scatchard equation. In comparison with C 18-SPE and non-imprinted polymer (NIP) SPE column, MIP-SPE column displays high selectivity and good affinity for andrographolide and dehydroandrographolide for extract of herb Andrographis paniculata ( Burm.f.) Nees (APN). MIP-SPE column capacity was 11.9 ± 0.6 μmol/g and 12.1 ± 0.5 μmol/g for andrographolide and dehydroandrographolide, respectively and was 2-3 times higher than that of other two columns. The precision and accuracy of the method developed were satisfactory with recoveries between 96.4% and 103.8% (RSD 3.1-4.3%, n = 5) and 96.0% and 104.2% (RSD 2.9-3.7%, n = 5) for andrographolide and dehydroandrographolide, respectively. Various real samples were employed to confirm the feasibility of method. This developed method demonstrates the potential of molecularly imprinted solid phase extraction for rapid, selective, and effective sample pretreatment.

  13. DNA display III. Solid-phase organic synthesis on unprotected DNA.

    Directory of Open Access Journals (Sweden)

    David R Halpin

    2004-07-01

    Full Text Available DNA-directed synthesis represents a powerful new tool for molecular discovery. Its ultimate utility, however, hinges upon the diversity of chemical reactions that can be executed in the presence of unprotected DNA. We present a solid-phase reaction format that makes possible the use of standard organic reaction conditions and common reagents to facilitate chemical transformations on unprotected DNA supports. We demonstrate the feasibility of this strategy by comprehensively adapting solid-phase 9-fluorenylmethyoxycarbonyl-based peptide synthesis to be DNA-compatible, and we describe a set of tools for the adaptation of other chemistries. Efficient peptide coupling to DNA was observed for all 33 amino acids tested, and polypeptides as long as 12 amino acids were synthesized on DNA supports. Beyond the direct implications for synthesis of peptide-DNA conjugates, the methods described offer a general strategy for organic synthesis on unprotected DNA. Their employment can facilitate the generation of chemically diverse DNA-encoded molecular populations amenable to in vitro evolution and genetic manipulation.

  14. Selective fiber used for headspace solid-phase microextraction of abused drugs in human urine

    Directory of Open Access Journals (Sweden)

    Sunanta Wangkarn

    2007-09-01

    Full Text Available A sensitive and selective fiber for simultaneous analysis of three drugs of abuse (amphetamine, methamphetamine and ephedrine in urine samples was explored using headspace solid phase microextraction and gas chromatography with flame ionization detection. Several parameters affecting extraction such as extraction time, extraction temperature, pH of solution and salt concentrations were investigated. Among five commercially available fibers, divinylbenzene/carboxen/ polydimethylsiloxane is the most sensitive and selective fiber at pH 10.0, extraction temperature at 80 C for 20 min and desorption temperature at 220 C for 2 min. Under the optimal conditions, the proposed solid phase microextraction method provided good linearity in the ranges 0.1-10 µg/ml for amphetamine and methamphetamine and 0.5-20 µg/ml for ephedrine. The detection limits for amphetamine, methamphetamine and ephedrine were 9, 3 and 30 ng/ml, respectively. The recoveries of three drugs in urine samples were exceeding 85%.

  15. Studies on solid phase synthesis,characterization and fluorescent property of the new rare earth complexes

    Directory of Open Access Journals (Sweden)

    Jianwei SHI

    2015-04-01

    Full Text Available Rare earth-β-diketone ligand complex luminescent material has stable chemical properties and excellent luminous property. Using europium oxide and (γ-NTA as raw materials, novel rare earth-β-dione complexes are synthesized by solid state coordination chemistry. The synthesis temperature and milling time are discussed for optimization. Experimental results show that the suitable reaction situation is at 50 ℃ and 20 h for solid-phase synthesis. The compositions and structures of the complexes are characterized by means of elemental analysis, UV-Vis and FTIR methods, and the phase stability of the complex is determined by using TG-DTA technique. It is proved that preparation of waterless binary rare earth complexes by the solid phase reaction method results in a higher product yield. The fluorescence spectra show that between Eu (Ⅲ and γ-NTA, there exists efficient energy transfer, and the rare earth complexes synthesis is an excellent red bright light-emitting material with excellent UV excited luminescence properties.

  16. A comparison of methods to predict solid phase heats of formation of molecular energetic salts.

    Science.gov (United States)

    Byrd, Edward F C; Rice, Betsy M

    2009-01-01

    In this study a variety of methods were used to compute the energies for lattice enthalpies and gas phase heats of formation of the ionic constituents used in Born-Fajans-Haber cycles to produce solid phase heats of formation of molecular ionic energetic crystals. Several quantum mechanically based or empirical approaches to calculate either the heat of formation of the ionic constituents in the gas phase (deltaH(o)f(g)) or the lattice enthalpy (deltaH(o)Lattice) were evaluated. Solid phase heats of formation calculated from combinations of deltaH(o)f(g) and deltaH(o)Lattice determined through various approaches are compared with experimental values for a series of molecular energetic salts with 1:1, 2:1 and 2:2 charge ratios. Recommendations for combinations of deltaH(o)f(g) and deltaH(o)Lattice to produce best agreement with experiment are given, along with suggestions for improvements of the methods.

  17. Solid-Phase Formation Of Isovaline, A Non-Biological, Meteoritic Amino Acid

    Science.gov (United States)

    Hudson, Reggie L.; Lewis, A. S.; Moore, M. H.; Dworkin, J. P.; Glavin, D. P.

    2007-10-01

    Among the Murchison (CM) meteoritic amino acids, isovaline stands out as being non-biological (nonprotein) and having a high abundance. Approximately equal amounts of D- and L-isovaline have been reported in CM meteorites, but the molecule's structure appears to prohibit racemization in aqueous solutions. While it is possible that isovaline could be made by the oft-studied Strecker reaction, laboratory experiments have seldom been able to produce this molecule from realistic molecular precursors. Recently we have investigated the low-temperature solid-phase chemistry of isovaline with an eye toward the molecule's formation, its stability, and the interconversion of its D- and L-enantiomers. Ion-irradiated isovaline-containing ices were examined by IR spectroscopy and highly-sensitive LC/ToF-MS methods to assess both amino acid destruction and racemization. Samples were studied both in the presence and absence of water-ice, and the destruction of isovaline was measured as a function of radiation dose. In addition, we have continued our earlier work on solid-phase amino acid formation, extending it to cover isovaline. In this presentation we will report the results of these newer investigations. This work was supported by a grant to the Goddard Center for Astrobiology through the NASA Astrobiology Institute. AL was supported by an award from the Summer Undergraduate Internship in Astrobiology program.

  18. Dense Pellicular Agarose-Glass Beads for Expanded Bed Application: Flow Hydrodynamics and Solid Phase Classifications

    Institute of Scientific and Technical Information of China (English)

    周鑫; 史清洪; 白姝; 孙彦

    2004-01-01

    Two dense pellicular agarose-glass matrices of different sizes and densities, i.e., AG-S and AG-L, have been characterized for their bed expansion behavior, flow hydrodynamics and particle classifications in an expanded bed system. A 26 mm ID column with side ports was used for sampling the liquid-solid suspension during expanded bed operations. Measurements of the collected solid phase at different column positions yielded the particle size and density distribution data. It was found that the composite matrices showed particle size as well as density classifications along the column axis, i.e., both the size and density of each matrix decreased with increasing the axial bed height. Their axial classifications were expressed by a correlation related to both the particle size and density as a function of the dimensionless axial bed height. The correlation was found to fairly describe the solid phase classifications in the expanded bed system. Moreover, it can also be applied to other two commercial solid matrices designed for expanded bed applications.

  19. Novel polymeric resin for solid phase extraction and determination of lead in waters

    Energy Technology Data Exchange (ETDEWEB)

    Karaaslan, Nagihan M.; Cengiz, Emine; Yaman, Mehmet [Science Faculty, Department of Chemistry, Firat University, Elazig (Turkey); Senkal, B. Filiz [Science and Arts Faculty, Department of Chemistry, Istanbul Technical University, Istanbul (Turkey)

    2010-11-15

    Interest in preconcentration techniques for the determination of metals at ultratrace levels still continues increasingly because of some disadvantages of flameless atomic absorption spectrometry and the high costs of other sensitive methods in compared to flame atomic absorption spectrometry (FAAS). Among preconcentration techniques, solid-phase extraction is the most popular because of a number of advantages. In this work, thiol-containing sulfonamide resin was synthesized, characterized, and applied as a new sorption material for solid phase extraction and determination of lead in natural water samples. The optimization of experimental conditions was performed using the parameters including pH, contact time, and volumes of initial and elution solutions. After preconcentration procedure, FAAS was used for determinations. The synthesized resin exhibits the superiority in compared to the other adsorption reagents because of the fact that there is no necessity of any complexing reagent as well as high sorption capacity. Consequently, 280-fold improvement in the sensitivity of analytical scheme was achieved by combining the slotted tube atom trap-atomic absorption spectrometry (STAT-FAAS) and the developed preconcentration method. The limit of detection was found to be 0.15 ng mL{sup -1}. The Pb{sup 2+} concentrations in the studied water samples were found to be in the range of 0.9-6.7 ng mL{sup -1}. (Copyright copyright 2010 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  20. The effect of surfactant and solid phase concentration on drug aggregates in model aerosol propellent suspensions.

    Science.gov (United States)

    Bower, C; Washington, C; Purewal, T S

    1996-04-01

    The effect of increasing solid phase concentration on the morphology and flocculation rate of model aerosol suspensions has been investigated. Suspensions of micronized salbutamol sulphate and lactose in trichlorotrifluoroethane (P113) were studied under conditions of increasing shear stress. By use of image analysis techniques, measurement of aggregate size, fractal dimension and rate of aggregation was performed. The effect of the surfactant sorbitan monooleate on morphology and flocculation rate was also studied. Increased solid phase concentration caused an increase in the rate of aggregation and average aggregate size at a given value of shear stress. Surfactant addition retarded the aggregation rate, and caused a shift from a diffusion-limited cluster aggregation to a reaction-limited cluster aggregation mechanism. The aggregate profiles showed a corresponding change from rugged and crenellated without surfactant, to increasingly smooth and Euclidian with increasing surfactant concentration. The morphological changes were characterized by a decrease in the average boundary fractal dimension which also correlated well with the corresponding reduction in aggregation rate.

  1. Fragment-based solid-phase assembly of oligonucleotide conjugates with peptide and polyethylene glycol ligands.

    Science.gov (United States)

    Dirin, Mehrdad; Urban, Ernst; Noe, Christian R; Winkler, Johannes

    2016-10-01

    Ligand conjugation to oligonucleotides is an attractive strategy for enhancing the therapeutic potential of antisense and siRNA agents by inferring properties such as improved cellular uptake or better pharmacokinetic properties. Disulfide linkages enable dissociation of ligands and oligonucleotides in reducing environments found in endosomal compartments after cellular uptake. Solution-phase fragment coupling procedures for producing oligonucleotide conjugates are often tedious, produce moderate yields and reaction byproducts are frequently difficult to remove. We have developed an improved method for solid-phase coupling of ligands to oligonucleotides via disulfides directly after solid-phase synthesis. A 2'-thiol introduced using a modified nucleotide building block was orthogonally deprotected on the controlled pore glass solid support with N-butylphosphine. Oligolysine peptides and a short monodisperse ethylene glycol chain were successfully coupled to the deprotected thiol. Cleavage from the resin and full removal of oligonucleotide protection groups were achieved using methanolic ammonia. After standard desalting, and without further purification, homogenous conjugates were obtained as demonstrated by HPLC, gel electrophoresis, and mass spectrometry. The attachment of both amphiphilic and cationic ligands proves the versatility of the conjugation procedure. An antisense oligonucleotide conjugate with hexalysine showed pronounced gene silencing in a cell culture tumor model in the absence of a transfection reagent and the corresponding ethylene glycol conjugate resulted in down regulation of the target gene to nearly 50% after naked application. PMID:27236069

  2. Kinetic study of solid phase crystallisation of expanding thermal plasma deposited a-Si:H

    Energy Technology Data Exchange (ETDEWEB)

    Law, F., E-mail: felixlaw@nus.edu.sg [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Hoex, B. [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Wang, J. [Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Luther, J. [Solar Energy Research Institute of Singapore (SERIS), National University of Singapore (Singapore); Department of Materials Science and Engineering, Faculty of Engineering, National University of Singapore (Singapore); Sharma, K.; Creatore, M.; Van de Sanden, M.C.M. [Department of Applied Physics, Eindhoven University of Technology, Eindhoven (Netherlands)

    2012-06-30

    In-situ X-ray diffraction was used to study the dynamics of the solid phase crystallisation (SPC) of hydrogenated amorphous silicon (a-Si:H) films deposited by expanding thermal plasma technique. The Johnson-Mehl-Avrami-Kolmogorov model was used for the analysis of the dynamic data and the activation energy associated with the SPC process was 2.9 eV, which was lower than a-Si:H films deposited by other techniques. Relationships between the Avrami exponent n, the SPC process stability and the subsequent grain structure were demonstrated. Under certain conditions, the films exhibited columnar grain structure with indications of good grain quality, suggesting that these films are suitable to be further developed into solar cell devices. Structure of the grains and the SPC dynamics in this work lend support to prior work that vacancies decorated by hydrogen clusters are related to nucleation sites. - Highlights: Black-Right-Pointing-Pointer The crystallisation of expanding thermal plasma (ETP) deposited a-Si:H was studied. Black-Right-Pointing-Pointer Johnson-Mehl-Avrami-Kolmogorov model was used to model the crystallisation process. Black-Right-Pointing-Pointer Activation energy of the solid phase crystallisation process was 2.9 eV. Black-Right-Pointing-Pointer Vacancies decorated by hydrogen clusters are suggested nucleation sites. Black-Right-Pointing-Pointer ETP is promising in the fabrication process of pc-Si thin film solar cells.

  3. Electromagnetic properties of high-carbon ferrochrome powders decarburized in solid phase by microwave heating

    International Nuclear Information System (INIS)

    Highlights: • High-carbon ferrochrome powders present diamagnetism. • We study the effect of temperature and time on electromagnetic properties. • The relative permittivity and permeability exhibit an opposite change trend. • The absorption peak shifts to lower frequency with the increasing temperature. - Abstract: During solid-phase decarburization, the changes of the electromagnetic properties can reflect the variation degree of material components. High-carbon ferrochrome powders (HCFCP) with addition of CaCO3 were decarburized in solid phase by microwave heating and the electromagnetic properties of the decarburized materials were investigated. With increasing in heating temperature from 1173 to 1473 K, the relative permittivity of the decarburized materials increases initially and then decreases, whereas the relative permeability exhibits an opposite change trend. As holding time ranges from 40 to 60 min at 1273 K, the relative permittivity and dielectric loss factor tend to decrease while the relative permeability and magnetic loss factor tend to increase, corresponding to the maximum mean velocity of decarburization. In microwave fields, electromagnetic properties of the decarburized materials principally vary with carbon content, C-vacancies and crystal structure, and their changes in turn affect the interaction of microwaves with the decarburized materials

  4. 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.

  5. Determination of amphetamines in hair by integrating sample disruption, clean-up and solid phase derivatization.

    Science.gov (United States)

    Argente-García, A; Moliner-Martínez, Y; Campíns-Falcó, P; Verdú-Andrés, J; Herráez-Hernández, R

    2016-05-20

    The utility of matrix solid phase dispersion (MSPD) for the direct analysis of amphetamines in hair samples has been evaluated, using liquid chromatography (LC) with fluorescence detection and precolumn derivatization. The proposed approach is based on the employment of MSPD for matrix disruption and clean-up, followed by the derivatization of the analytes onto the dispersant-sample blend. The fluorogenic reagent 9-fluorenylmethyl chloroformate (FMOC) has been used for derivatization. Different conditions for MSPD, analyte purification and solid phase derivatization have been tested, using amphetamine (AMP), methamphetamine (MET), ephedrine (EPE) and 3,4-methylenedioxymethamphetamine (MDMA) as model compounds. The results have been compared with those achieved by using ultrasound-assisted alkaline digestion and by MSPD combined with conventional solution derivatization. On the basis of the results obtained, a methodology is proposed for the analysis of amphetamines in hair which integrates sample disruption, clean-up and derivatization using a C18 phase. Improved sensitivity is achieved with respect to that obtained by the alkaline digestion or by the MSPD followed by solution derivatization methods. The method can be used for the quantification of the tested amphetamines within the 2.0-20.0ng/mg concentration interval, with limits of detection (LODs) of 0.25-0.75ng/mg. The methodology is very simple and rapid (the preparation of the sample takes less than 15min). PMID:27108048

  6. CERN Video News on line

    CERN Document Server

    2003-01-01

    The latest CERN video news is on line. In this issue : an interview with the Director General and reports on the new home for the DELPHI barrel and the CERN firemen's spectacular training programme. There's also a vintage video news clip from 1954. See: www.cern.ch/video or Bulletin web page

  7. Determination of illicit drugs in aqueous environmental samples by online solid-phase extraction coupled to liquid chromatography-tandem mass spectrometry.

    Science.gov (United States)

    Yao, Bo; Lian, Lushi; Pang, Weihai; Yin, Daqiang; Chan, Shen-An; Song, Weihua

    2016-10-01

    In this study, a fully automated analytical method, based on online solid phase extraction coupled to liquid chromatography-triple quadrupole tandem mass spectrometry (online SPE-LC-MS/MS), has been developed and optimized for the quantification of 10 illicit drugs and metabolites in environmentally aqueous samples collected from China. The particular attention was devoted to minimize the matrix effects through a washing step, which washed out the interferences effectively and helped to reduce the matrix effect significantly. The key advantages of the method are high sensitivity, selectivity and reliability of results, smaller sample manipulation, full automation, and fairly high throughput. The whole procedure was then successfully applied in the analysis of various surface water and wastewater effluents samples. Pseudoephedrine have been detected at trace levels (several tens ng L(-1) or less), while MDA, MDMA, benzoylecgonine and methadone were below the LOQ in all samples. Caffeine, cotinine and paraxanthine, which may be derived from medicines and foods, were detected with the highest frequencies and concentrations. PMID:27376860

  8. Solid phase electron donors control denitrification in groundwater at agricultural sites

    Science.gov (United States)

    Green, C. T.; Liao, L.; Bekins, B. A.; Bohlke, J. K.

    2011-12-01

    Increased concentrations of nitrate in groundwater caused by agricultural use of chemical and organic fertilizers are a concern because of possible risks to environmental and human health. At many sites, these problems are mitigated by natural attenuation of nitrate as a result of microbially mediated denitrification of nitrate to nitrogen gas. Recent studies have clarified the factors affecting the rates and extents of denitrification in groundwater in agricultural areas. Intensive studies were conducted by the US Geological Survey to study agricultural chemicals in California, Nebraska, Washington, and Maryland using laboratory analyses, field measurements, and flow and transport modeling for monitoring well transects (0.5 to 2.5 km in length) and vertical profiles (0 to 50 m in depth). Groundwater analyses included major ion chemistry, dissolved gases, nitrogen and oxygen stable isotopes, and atmospheric age-tracers. Sediments were analyzed for concentrations of potential electron donors for denitrification, including reduced iron and sulfur, and organic carbon. Geochemical data and mass balance calculations indicated that solid-phase electron donors were an important factor controlling denitrification at these sites. To examine the generality of this result, a mathematical model of vertical flux of water, oxygen, and nitrate was developed and applied at these study sites along with 2 new study sites in Iowa and Mississippi and 8 additional sites from previous studies in Nebraska, Texas, Minnesota, Wisconsin, North Carolina, Maryland (2 sites), and New York. Model results confirmed the importance of solid phase electron donors. The normalized reaction rates on an electron flux basis tended to increase with depth from the shallow oxygen reduction zone to the underlying nitrate reduction zone. The pattern of higher rates at depth is consistent with a reaction rate controlled by solid phase donors that are depleted under oxidizing conditions near the surface and in

  9. Iron solid-phase differentiation along a redox gradient in basaltic soils

    Science.gov (United States)

    Thompson, Aaron; Rancourt, Denis G.; Chadwick, Oliver A.; Chorover, Jon

    2011-01-01

    Iron compounds in soil are multifunctional, providing physical structure, ion sorption sites, catalytic reaction-centers, and a sink for respiratory electrons. Basaltic soils contain large quantities of iron that reside in different mineral and organic phases depending on their age and redox status. We investigated changes in soil iron concentration and its solid-phase speciation across a single-aged (400 ky) lava flow subjected to a gradient in precipitation (2200-4200 mm yr -1) and hence redox history. With increasing rainfall and decreasing Eh, total Fe decreased from about 25% to soil mass. Quantitative speciation of soil solid-phase iron was constrained by combining 57Fe Mössbauer spectroscopy (MBS) at 295 and 4.2 K with powder X-ray diffraction, selective chemical extractions, and magnetic susceptibility measurements. This approach allowed us to partition iron into (1) nanoparticulate and microcrystalline Fe III-(oxy)hydroxides, (2) microcrystalline and bulk Fe III-oxides, (3) organic/silicate bound Fe III, and (4) ferrous iron. The Fe III-(oxy)hydroxide fraction dominated solid-phase Fe, exhibiting a crystallinity continuum based on magnetic ordering temperature. The continuum extended from well-ordered microcrystalline goethite through nanocrystalline Fe III-(oxy)hydroxides to a nano Fe III-(oxy)hydroxide phase of extremely low crystallinity. Magnetic susceptibility was correlated ( R2 = 0.77) with Fe III-oxide concentration, consistent with a contribution of maghemite to the otherwise hematite dominated Fe-oxide fraction. The Fe III-(oxy)hydroxide fraction of total Fe decreased with increasing rainfall and was replaced by corresponding increase in the organic/silicate Fe III fraction. The crystallinity of the Fe III-(oxy)hydroxides also decreased with increasing rainfall and leaching, with the most disordered members of the crystallinity continuum, the nano Fe III-(oxy)hydroxides, gaining proportional abundance in the wetter sites. This finding runs

  10. On-line moisture analysis

    CERN Document Server

    Cutmore, N G

    2002-01-01

    Measurement of the moisture content of iron ore has become a key issue for controlling moisture additions for dust suppression. In most cases moisture content is still determined by manual or automatic sampling of the ore stream, followed by conventional laboratory analysis by oven drying. Although this procedure enables the moisture content to be routinely monitored, it is too slow for control purposes. This has generated renewed interest in on-line techniques for the accurate and rapid measurement of moisture in iron ore on conveyors. Microwave transmission techniques have emerged over the past 40 years as the dominant technology for on-line measurement of moisture in bulk materials, including iron ores. Alternative technologies have their limitations. Infra-red analysers are used in a variety of process industries, but rely on the measurement of absorption by moisture in a very thin surface layer. Consequently such probes may be compromised by particle size effects and biased presentation of the bulk mater...

  11. Comparison of simultaneous distillation extraction and solid-phase micro-extraction for determination of volatile constituents in tobacco flavor

    Institute of Scientific and Technical Information of China (English)

    ZHONG Ke-jun; WEI Wan-zhi; GUO Fang-qiu; HUANG Lan-fang

    2005-01-01

    The volatile and semi-volatile components in tobacco flavor additives were extracted by both simultaneous distillation extraction and solid-phase micro-extraction. Extraction conditions for solid-phase micro-extraction were optimized with information theory. Then, detection were accomplished by gas chromatography-mass spectrometry. Characteristic of each method was compared. Qualitative analysis and quantitative analysis of 6# tobacco flavor sample were accomplished through both simultaneous distillation extraction and solid-phase micro-extraction. The experimental results show that solid-phase micro-extraction method is the first choice for qualitative analysis and simultaneous distillation extraction is another good selection for quantitative analysis. By means of simultaneous distillation extraction, 20 components are identified, accounting for 92.77% of the total peak areas. Through solid-phase micro-extraction, there are 17 components identified accounting for 91.49% of the total peak areas. The main aromatic components in 6# tobacco flavor sample are propanoic acid, 2-hydroxy-, ethyl ester, menthol and menthyl acetate. The presented method has been successfully used for quality control of tobacco flavor.

  12. The use of ferromagnetic dacron as solid-phase in enzyme immunoassays

    Directory of Open Access Journals (Sweden)

    Ana Maria dos A. Carneiro Leão

    1994-06-01

    Full Text Available Ferromagnetic dacron is proposed as an alternative solid-phase for magnetic enzyme immunoassays. Human serum albumin (HSA was covalentlyimmobilized onto ferromagnetic dacron and as enzyme immunoassay was developed using anti-HSA rabbit sera. Peroxidase, o-phenylenediamine (OPD and hydrogen peroxide were used anti-HSA rabbit sera. Peroxidase, o-phenylenediamine (OPD and hydrogen peroxide were used as the enzymatic label and substrates, respectively. Best results were observed when particles of 63-100 µm (diameter and 10 µg of immobilized antigen were used. Positive reactions were detected until dilutions of1:51200 of immune sera. Its reproducibility was similar to standard ELISA. Disruption of the immunocomplexes formed and recuperation of the immobilized antigen in other immunoassays also proved to be reliable.

  13. A solid phase radioimmunoassay for free triiodothyronine in serum:assay development and validation

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    A solid phase radioimmunoassay for free triiodothyroninein serum was developed based on double-antibody coated tubes.The method was turned out to be reliable with good reproducibility,higher sensitivity and easy performance.The measurable range of FT3 in serum was 1.2 to 38pmol/L.The mean coefficients of variationwithin and between assays were 1.79%~3.18% and 4.72%~9.31%,respectively.The FT3 concentrations in euthyroid serum as determined by this methodwere 2.8 to 7.8pmol/L.The FT3 values determined by this new methodcorrelated well with those measured by a commercial radioimmunoassay(r=0.853).

  14. Headspace Solid-Phase Microextraction Analysis of Volatile Components in Phalaenopsis Nobby’s Pacific Sunset

    Directory of Open Access Journals (Sweden)

    Chih-Hsin Yeh

    2014-09-01

    Full Text Available Phalaenopsis is the most important economic crop in the Orchidaceae family. There are currently numerous beautiful and colorful Phalaenopsis flowers, but only a few species of Phalaenopsis have an aroma. This study reports the analysis volatile components present in P. Nobby’s Pacific Sunset by solid-phase microextraction (SPME coupled with gas chromatography (GC and gas chromatography/mass spectrometry (GC-MS. The results show that the optimal extraction conditions were obtained by using a DVB/CAR/PDMS fiber. A total of 31 compounds were identified, with the major compounds being geraniol, linalool and α-farnesene. P. Nobby’s Pacific Sunset had the highest odor concentration from 09:00 to 13:00 on the eighth day of storage. It was also found that in P. Nobby’s Pacific Sunset orchids the dorsal sepals and petals had the highest odor concentrations, whereas the column had the lowest.

  15. Analysis of volatiles of malt whisky by solid-phase microextraction and stir bar sorptive extraction.

    Science.gov (United States)

    Demyttenaere, Jan C R; Martínez, Jorge I Sánchez; Verhé, Roland; Sandra, Pat; De Kimpe, Norbert

    2003-01-24

    Blended Scotch whisky was analysed by solid-phase microextraction (SPME) and stir bar sorptive extraction (SBSE) to study the composition of the volatiles. For SPME analysis, three different fibres were compared, poly(dimethylsiloxane) (PDMS) (100 microm). poly(acrylate) (PA) (85 microm) and divinylbenzene-Carboxen on poly(dimethylsiloxane) (DVB-CAR-(PDMS) (50/30 microm). It was found that the PDMS and DVB-CAR-PDMS fibres showed a higher enrichment capacity than PA as well as a better reproducibility. The influence of sampling time, temperature and salt addition on the enrichment of volatiles as well as the difference between liquid and headspace SPME were studied. An optimum SPME method was developed. Finally a more recent sample preparation technique, namely SBSE was evaluated to extract whisky volatiles.

  16. Separation and Purification of Sulforaphane from Broccoli by Solid Phase Extraction

    Directory of Open Access Journals (Sweden)

    Kyung Ho Row

    2011-03-01

    Full Text Available A simple solid-phase extraction (SPE method for the determination of sulforaphane in broccoli has been developed. The optimal conditions were found to be use of a silica SPE cartridge, and ethyl acetate and dichloromethane as washing and eluting solvents, respectively, which could eliminate interferences originating from the broccoli matrix. The extracts were sufficiently clean to be directly injected into high-performance liquid chromatography (HPLC for further chromatographic analysis. Good linearity was obtained from 0.05 to 200 μg/mL (r = 0.998 for sulforaphane with the relative standard deviations less than 3.6%. The mean recoveries of sulforaphane from broccoli were more than 90.8% and the detection limit (S/N = 3:1 was 0.02 μg/mL. The SPE method provides a higher yield of sulforaphane from crude extracts compared to conventional liquid-liquid extraction.

  17. A simple and safe method for single HLA-antigen-typing by a solid phase assay.

    Science.gov (United States)

    Häcker-Shahin, B; Giannitsis, D J

    1991-01-01

    A rapid solid phase assay for detection of single HLA-antigens on platelets was developed. The platelets were attached to the surface of polystyrene microtitre plate wells by means of a sodium carbonate buffer and centrifugation. Uncovered areas were blocked by a gelatin blocking buffer. After incubation with commercially available anti-HLA-sera the bound anti-HLA-specific antibodies directed against HLA-antigens present on the platelets were made visible by anti-IgG-coated indicator red cells and a brief centrifugation. A positive result, meaning the presence of an HLA-antigen, was indicated by a slight red cell adherence over the reaction surface. In the absence of the HLA-antigen no binding occurred and the indicator red cells formed a small red disc-like pellet.

  18. Improvements in the vapor-time profile analysis of explosive odorants using solid-phase microextraction.

    Science.gov (United States)

    Young, Mimy; Schantz, Michele; MacCrehan, William

    2016-07-15

    A modified approach for characterization of the vapor-time profile of the headspace odors of explosives was developed using solid-phase microextraction (SPME) incorporating introduction of an externally-sampled internal standard (ESIS) followed by gas chromatography/mass spectrometry (GC/MS) analysis. With this new method, reproducibility of the measurements of 2-ethyl-1-hexanol and cyclohexanone were improved compared to previous work (Hoffman et al., 2009; Arthur and Pawliszyn, 1990) through the use of stable-isotope-labeled internal standards. Exposing the SPME fiber to the ESIS after sampling the target analyte proved to be advantageous, while still correcting for fiber variability and detector drift. For the analysis of high volatility compounds, incorporation of the ESIS using the SPME fiber in the retracted position minimized the subsequent competitive loss of the target analyte, allowing for much longer sampling times. PMID:27286650

  19. Solid-phase peptide synthesis: from standard procedures to the synthesis of difficult sequences.

    Science.gov (United States)

    Coin, Irene; Beyermann, Michael; Bienert, Michael

    2007-01-01

    This protocol for solid-phase peptide synthesis (SPPS) is based on the widely used Fmoc/tBu strategy, activation of the carboxyl groups by aminium-derived coupling reagents and use of PEG-modified polystyrene resins. A standard protocol is described, which was successfully applied in our lab for the synthesis of the corticotropin-releasing factor (CRF), >400 CRF analogs and a countless number of other peptides. The 41-mer peptide CRF is obtained within approximately 80 working hours. To achieve the so-called difficult sequences, special techniques have to be applied in order to reduce aggregation of the growing peptide chain, which is the main cause of failure for peptide chemosynthesis. Exemplary application of depsipeptide and pseudoproline units is shown for synthesizing an extremely difficult sequence, the Asn(15) analog of the WW domain FBP28, which is impossible to obtain using the standard protocol.

  20. Direct solid-phase radioimmunoassay for the detection of Aujeszky's disease antibodies

    International Nuclear Information System (INIS)

    A direct solid-phase radioimmunoassy (dRIA) was developed in order to demonstrate antibodies against Aujeszky's disease virus (ADV) in sera obtained from pigs and rabbits. In the presence of guinea-pig complement the above test is 160-fold to 1500-fold more sensitive than the neutralization test (NT) and 320-fold to 150 000-fold more sensitive than sera obtained from an ADV-infected farm, which were found to be negative in the complement assisted NT. It is possible to test a single dilution of unknown serum by dRIA by comparing same with a standard curve and to make a statement regarding its ADV-specific binding capacity to 125I-labelled ADV antigen. The advantages of dRIA in comparison to the indirect RIA and the advantages and disadvantages with regard to ELISA were discussed. (orig.)

  1. Matrix Solid-phase Dispersion Extraction of Alkaloids from the Roots of Aconitum kusnezoffii Reichb.

    Institute of Scientific and Technical Information of China (English)

    WEI Wei; LI Xu-wen; SHI Xiao-lei; ZHOU Hong-yu; YANG Rui-jie; ZHANG Han-qi; JIN Yong-ri

    2011-01-01

    Matrix solid-phase dispersion(MSPD) was developed for the extraction of four alkaloids, including aconitine, mesaconitine, hypaconitine and deoxyaconitine, from the roots of Aconitum kusnezoffii Reichb. The determination of the analyte was carried out by high performance liquid chromatography with UV detection. The alkaline alumina was used as sorbent. The mixture of acetonitrile and water was used as elution solvent. Several extraction parameters, such as type of sorbent, the ratio of sample to solid support material, type of the elution solvent and the volume of the elution solvent were tested. Mean recoveries ranged from 93.16% to 102.73%, with relative standard deviations from 0.27% to 4.17%. With the extraction efficiency and time expenditure taken into account, MSPD extraction should be a comparatively good method.

  2. A carbon nanotube confinement strategy to implement homogeneous asymmetric catalysis in the solid phase.

    Science.gov (United States)

    Hashimoto, Kazuki; Kumagai, Naoya; Shibasaki, Masakatsu

    2015-03-01

    A readily recyclable asymmetric catalyst has been developed based on the self-assembly of a homogeneous catalyst in a fibrous network of multiwalled carbon nanotubes (MWNTs). Dimerization of an amide-based chiral ligand with a suitable spacer allows for the efficient formation of a heterogeneous catalyst by self-assembly on addition of Er(OiPr)3. The self-assembly proceeds in the MWNT fibrous network and small clusters of assembled catalyst are confined in the MWNTs, producing an easily handled solid-phase catalyst. The resulting MWNT-confined catalyst exhibits a good catalytic performance in a catalytic asymmetric Mannich-type reaction, which can be conducted in a repeated batch system and in a continuous-flow platform.

  3. Determination of available phenolic compounds in soils by liquid chromatography with solid-phase extraction.

    Science.gov (United States)

    Matejícek, David; Klejdus, Borivoj; Kubán, Vlastimil

    2002-01-01

    A fast, selective, and sensitive liquid chromatographic (LC) method was developed for determination of derivatives of benzoic and cinnamic acids (gallic, protocatechuic, 2,3,4-trihydroxybenzoic, 4-hydroxybenzoic, vanillic, caffeic, syringic, 4-coumaric, ferulic, sinapic, benzoic, 2-coumaric, cinnamic acids, and 4-hydroxybenzaldehyde and vanillin) in soil samples. The method for sample pretreatment is based on temperature-controlled extraction with water (pH 5.6) for 60 min. Extracts were preconcentrated and purified by solid-phase extraction on OASIS HLB sorbent, with subsequent separation and quantification of individual substances by LC with UV diode-array detection. Limits of detection (3 signal-to-noise LODs) better than 65 ng/g (dry weight) and recoveries from 88 to 99% were found for each compound at absorbance 280 nm. The method was used for determination of bioavailable phenolic compounds in different soil samples. PMID:12477182

  4. Solid phase extraction of uranium(VI) on phosphorus-containing polymer grafted 4-aminoantipyrine

    International Nuclear Information System (INIS)

    Phosphorus-containing polymer grafted 4-aminoantipyrine has been synthesized and used for solid phase extraction of U(VI) prior to its UV-Visible spectrophotometric determination by using arsenazo(III). The adsorbent was characterized by using FT-IR and SEM analysis. The influence of parameters including pH, adsorbent dose, amount of complexing reagent, sample volume and matrix effect have been optimized. The detection limit was determined as 1.4 μg L-1 with preconcentration factor of 30 and RSD of 1.4 %. The accuracy was checked by the analysis of GBW07424 soil and TMDA-64.2 environmental water certified reference materials. The method was applied to natural water and soil samples. (author)

  5. Isolation of tetracyclines in milk using a solid-phase extracting column and water eluent.

    Science.gov (United States)

    Furusawa, Naoto

    2003-01-01

    An isolating method using a solid-phase extraction (SPE) ISOLUTE(R) C8 endcapped syringe-column for routine monitoring of residual tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DC)) in cow's milk is presented. In the simplest and most environmentally harmless method, milk samples could be applied directly to the SPE column, following which all TCs were eluted with water. No organic solvents were used at all. The purified sample was injected into a high-performance liquid chromatography (HPLC) with a photo-diode array detector (PDAD). For the HPLC determination/identification, a LiChrospher(R) 100 RP-8 endcapped column and a mobile phase of acetonitrile -7% (v v(-1)) acetic acid solution (in water) (35:65, v v(-1)) with a PDAD was used. The total time required for the analysis of one sample was 80 and <5%, respectively. PMID:18968895

  6. Development of solid phase immunoradiometric assay for determination of carcinoembryonic antigen as a tumor marker

    International Nuclear Information System (INIS)

    Development of solid phase coated tube immunoradiometric assay for estimation of carcinoembryonic antigen (CEA) was the aim of the present study. Labeling of CEA was carried out using Ch-T and iodogen as oxidizing agents and 125I. The tracers were used to test the presence of antibodies produced by immunization. Production of polyclonal antibody was carried out through immunization of four mice. After purification step, the tubes were coated by purified polyclonal antibodies. Immunoradiometric that system was performed using the commercial IZOTOP 125I-anti hCEA tracer then the validity studies were carried out. The results show that the local coated tubes made the assay is more than sufficient to fulfill the clinical requirement of CEA as a tumor marker. (author)

  7. Simple solid-phase radioimmunoassay for human leukemia-associated cell membrane antigens

    International Nuclear Information System (INIS)

    In the present study, a simple solid-phase radioimmunoassay was developed to determine detergent-extracted human leukemia-associated cell membrane antigens. In the assay, 96-well microtiter plates are coated with human leukemia cell membrane antigens containing a T cell leukemia or a non-T cell leukemia antigen in the presence of a detergent, and treated with 1.6% bovine serum albumin solution. The coated antigens were reacted with an appropriate murine monoclonal antibody (mAb). The bound mAb is determined by a second reaction with 125I-labeled F(ab')2 of goat anti-mouse Ig. The best antigen dose-dependent antibody binding results were obtained using the plates coated with antigens in the presence of taurocholate. In addition, the usefulness of the present assay with taurocholate during the purification of the antigens was demonstrated. (Auth.)

  8. Chemiluminescence Determination of Benzoic Acid Using A Solid-Phase Verdigris Reactor

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new chemiluminescence flow system has been developed for sequential determina-tion of benzoic acid based on the reaction of the compound with copper carbonate entrapped in a solid-phase reactor. It was found that the unsaturated complex of Cu(II) and benzoic acid (1:1) has strong catalytic effect on the luminol-H2O2 chemiluminescence reaction. The calibration graph is linear over the range of 0.025 ~ 60 μg/mL of benzoic acid, with a relative standard deviation of less than 3.0 %, and the detection limit is 0.01μg@mL-1. The proposed method was applied to the determination of benzoic acid content in different pharmaceutical formulations.

  9. HLA antibody detection with solid phase assays: great expectations or expectations too great?

    Science.gov (United States)

    Gebel, H M; Bray, R A

    2014-09-01

    Alloantibodies directed against HLA antigens, are a barrier to long-term solid organ allograft survival. The clinical impact of preformed, donor-directed HLA alloantibodies range from acceptable risk to unequivocal contraindication for organ transplantation. HLA antibodies are key factors that limit patient access to donor organs. Serological methods were once the only approach to identify HLA antigens and antibodies. Limitations in these technologies led to the development of solid phase approaches. In the early 1990s, the development of the polymerase chain reaction enabled DNA-based HLA antigen testing to be performed. By the mid-1990s, microparticle-based technology that utilized flow cytometry for analysis was developed to detect both classes I and II HLA antibodies. These methodologies revolutionized clinical histocompatibility testing. The strengths and weaknesses of these assays are described in detail in this review.

  10. Critical Regimes of Two-Phase Flows with a Polydisperse Solid Phase

    CERN Document Server

    Barsky, Eugene

    2010-01-01

    This book brings to light peculiarities of the formation of critical regimes of two-phase flows with a polydisperse solid phase. A definition of entropy is formulated on the basis of statistical analysis of these peculiarities. The physical meaning of entropy and its correlation with other parameters determining two-phase flows are clearly defined. The interrelations and main differences between this entropy and the thermodynamic one are revealed. The main regularities of two-phase flows both in critical and in other regimes are established using the notion of entropy. This parameter serves as a basis for a deeper insight into the physics of the process and for the development of exhaustive techniques of mass exchange estimation in such flows. The book is intended for graduate and postgraduate students of engineering studying two-phase flows, and to scientists and engineers engaged in specific problems of such fields as chemical technology, mineral dressing, modern ceramics, microelectronics, pharmacology, po...

  11. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    Science.gov (United States)

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong

    2015-11-15

    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen. PMID:26454344

  12. Solid-phase synthesis of phenylalanine containing peptides using a traceless triazene linker.

    Science.gov (United States)

    Torres-García, Carolina; Pulido, Daniel; Carceller, Magdalena; Ramos, Iván; Royo, Miriam; Nicolás, Ernesto

    2012-11-01

    The use of a triazene function to anchor phenylalanine to a polymeric support through its side chain is reported. To prove the usefulness of this strategy in solid-phase peptide synthesis, several bioactive peptides have been prepared including cyclic, C-modified, and protected peptides. The triazene linkage is formed by coupling the diazonium salt of Fmoc-Phe(pNH(2))-OAllyl to a MBHA-polystyrene resin previously functionalized with isonipecotic acid (90%). Further assembly of the peptide chain, cleavage from the resin using 2-5% TFA in DCM, and reduction of the resulting diazonium salt of the peptide with FeSO(4)·7H(2)O in DMF afforded the desired products in high purities (73-94%).

  13. Solid Phase Characterization of Tank 241-C-108 Residual Waste Solids Samples

    Energy Technology Data Exchange (ETDEWEB)

    Cooke, Gary A.; Pestovich, John A.; Huber, Heinz J.

    2013-05-29

    This report presents the results for solid phase characterization (SPC) of solid samples removed from tank 241-C-108 (C-108) on August 12-13,2012, using the off-riser sampler. Samples were received at the 222-S Laboratory on August 13 and were described and photographed. The SPC analyses that were performed include scanning electron microscopy (SEM) using the ASPEX(R)l scanning electron microscope, X-ray diffraction (XRD) using the Rigaku(R) 2 MiniFlex X-ray diffractometer, and polarized light microscopy (PLM) using the Nikon(R) 3 Eclipse Pol optical microscope. The SEM is equipped with an energy dispersive X-ray spectrometer (EDS) to provide chemical information. Gary A. Cooke conducted the SEM analysis, John A. Pestovich performed the XRD analysis, and Dr. Heinz J. Huber performed the PLM examination. The results of these analyses are presented here.

  14. In situ passive solid-phase adsorption of micro-algal biotoxins as a monitoring tool.

    Science.gov (United States)

    MacKenzie, Lincoln A

    2010-06-01

    Laboratory and field studies of the passive solid-phase adsorption toxin tracking (SPATT) method have been carried out around the world. A wide range of marine micro-algal toxins have been detected and the potential of the method to provide reliable, sensitive, time-integrated sampling to monitor the occurrence of toxic algal bloom events has been demonstrated. The method has several important advantages over current phytoplankton and shellfish monitoring methods. Trials of various adsorption substrates have been carried out and the best candidates have been selected for the lipophilic marine biotoxin groups; however, research continues to locate suitable substrates for the more polar water-soluble compounds such as domoic acid and the saxitoxins. The technique has also been successfully applied to the detection of a range of freshwater cyanobacterial toxins.

  15. Determination of phenols in landfill leachate-contaminated groundwaters by solid-phase extraction

    DEFF Research Database (Denmark)

    Ask Reitzel, Lotte; Ledin, Anna

    2002-01-01

    A solid-phase extraction method for phenols in landfill leachates was developed and optimized in order to solve the expected and observed problems associated with an anaerobic matrix containing high concentrations of salts and organic matter. Isolute ENV1 cartridges exhibited the best retention of...... phenols of the four sorbents examined, and was the only cartridge which a 1 L leachate sample could pass through. With the other cartridges, clogging made this impossible. The final method, which included 27 different phenols, gave detection limits of ,0.1 mg/L (drinking water concentration limit for...... identified in leachates from three Danish landfills, ranging in concentration from 0.01 to 29 mg/ L, which is at the lower end of the concentration range usually found for phenols in landfill leachates (sub-mg/L to mg/L).  2002 Elsevier Science B.V. All rights reserved....

  16. Determination of resveratrol in red wine by solid phase extraction-flow injection chemiluminescence method

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A sensitive flow injection chemiluminescence method has been developed for the detection of resveratrol in red wine based on the fact that resveratrol can greatly enhance chemiluminescence reaction between KMnO4 and HCHO in sulfuric acid medium.Analytes were pre-concentrated on solid sorbents (C18 solid-phase extraction cartridges). Under the optimum conditions, the proposed method allows the measurement of resveratrol over the range of 1.32 × 10-s to 1.32 × 10-5 mol/L with a detection limit of 3.30 × 10-9 mol/L, and the relative standard deviation for 1.32 × 10-5 mol/L resveratrol (n = 11 ) is 3.8%. This method has been successfully applied for the determination of the resveratrol in red wine. Furthermore, the possible reaction mechanism was also discussed.

  17. Gaseous Products of Incense Coil Combustion Extracted by Passive Solid Phase Microextraction Samplers

    Directory of Open Access Journals (Sweden)

    Wen-Hsi Cheng

    2015-06-01

    Full Text Available Burning incense indoors is a common behavior in Southeast Asia. In this investigation, needle trap samplers (NTS, a novel, green analytical technology is used for sampling gaseous combustion by-products from sandalwood incense coils. To extract indoor volatile organic compounds (VOCs, two NTS are prepared, one using 60–80 mesh and the other using 100–120 mesh divinylbenzene (DVB particles packed in 22-gauge stainless steel needles. This work compares extraction efficiency of an NTS and that of a commercially available 100 μm polydimethylsiloxane solid phase microextration (PDMS-SPME fiber sampler. Experimental results indicated that the 100–120 mesh DVB-NTS performed best among all samplers during a 1 h sampling period. The main extracted compounds were toluene, ethylbenzene, propane, chloromethane, 1,3-butadiene, methanol and dichloromethane. The potential use of small badge-sized or pen-sized NTS for the indoor atmosphere and occupational hygiene applications is addressed.

  18. A Facile Solid-Phase Route to Renewable Aromatic Chemicals from Biobased Furanics.

    Science.gov (United States)

    Thiyagarajan, Shanmugam; Genuino, Homer C; van der Waal, Jan C; de Jong, Ed; Weckhuysen, Bert M; van Haveren, Jacco; Bruijnincx, Pieter C A; van Es, Daan S

    2016-01-22

    Renewable aromatics can be conveniently synthesized from furanics by introducing an intermediate hydrogenation step in the Diels-Alder (DA) aromatization route, to effectively block retro-DA activity. Aromatization of the hydrogenated DA adducts requires tandem catalysis, using a metal-based dehydrogenation catalyst and solid acid dehydration catalyst in toluene. Herein it is demonstrated that the hydrogenated DA adducts can instead be conveniently converted into renewable aromatics with up to 80% selectivity in a solid-phase reaction with shorter reaction times using only an acidic zeolite, that is, without solvent or dehydrogenation catalyst. Hydrogenated adducts from diene/dienophile combinations of (methylated) furans with maleic anhydride are efficiently converted into renewable aromatics with this new route. The zeolite H-Y was found to perform the best and can be easily reused after calcination. PMID:26684008

  19. A solid-phase dot assay using silica/gold nanoshells

    Directory of Open Access Journals (Sweden)

    Zharov Vladimir

    2006-01-01

    Full Text Available AbstractWe report on the first application of silica-gold nanoshells to a solid-phase dot immunoassay. The assay principle is based on staining of a drop (1 µl analyte on a nitrocellulose membrane strip by using silica/gold nanoshells conjugated with biospecific probing molecules. Experimental example is human IgG (hIgG, target molecules and protein A (probing molecules. For usual 15-nm colloidal gold conjugates, the minimal detectable amount of hIgG is about 4 ng. By contrast, for nanoshell conjugates (silica core diameter of 70 nm and gold outer diameter of 100 nm we have found significant increase in detection sensitivity and the minimal detectable amount of hIgG is about 0.5 ng. This finding is explained by the difference in the monolayer particle extinction.

  20. Solid phase extraction of iron and lead in environmental matrices on amberlite xad-1180/pv

    Directory of Open Access Journals (Sweden)

    Mustafa Soylak

    2006-04-01

    Full Text Available A solid phase extraction procedure using Amberlite XAD-1180/Pyrocatechol violet (PV chelating resin for the determination of iron and lead ions in various environmental samples was established. The procedure is based on the sorption of lead(II and iron(III ions onto the resin at pH 9, followed by elution with 1 mol/L HNO3 and determination by flame atomic absorption spectrometry. The influence of alkaline, earth alkaline and some transition metals, as interferents, are discussed. The recoveries for the spiked analytes were greater than 95%. The detection limits for lead and iron by FAAS were 0.37 µg/L and 0.20 µg/L, respectively. Validation of the method described here was performed by using three certified reference materials (SRM 1515 Apple Leaves, SRM 2711 Montana Soil and NRCC-SLRS-4 Riverine Water. The procedure was successfully applied to natural waters and human hair.

  1. "Reagentless" flow injection determination of ammonia and urea using membrane separation and solid phase basification

    Science.gov (United States)

    Akse, J. R.; Thompson, J. O.; Sauer, R. L.; Atwater, J. E.

    1998-01-01

    Flow injection analysis instrumentation and methodology for the determination of ammonia and ammonium ions in an aqueous solution are described. Using in-line solid phase basification beds containing crystalline media. the speciation of ammoniacal nitrogen is shifted toward the un-ionized form. which diffuses in the gas phase across a hydrophobic microporous hollow fiber membrane into a pure-water-containing analytical stream. The two streams flow in a countercurrent configuration on opposite sides of the membrane. The neutral pH of the analytical stream promotes the formation of ammonium cations, which are detected using specific conductance. The methodology provides a lower limit of detection of 10 microgram/L and a dynamic concentration range spanning three orders of magnitude using a 315-microliters sample injection volume. Using immobilized urease to enzymatically promote the hydrolysis of urea to produce ammonia and carbon dioxide, the technique has been extended to the determination of urea.

  2. Kinetics of liquid-solid phase transition in large nickel clusters

    CERN Document Server

    Yakubovich, Alexander V; Schramm, Stefan; Solov'yov, Andrey V

    2012-01-01

    In this paper we have explored computationally the solidification process of large nickel clusters. This process has the characteristic features of the first order phase transition occurring in a finite system. The focus of our research is placed on the elucidation of correlated dynamics of a large ensemble of particles in the course of the nanoscale liquid-solid phase transition through the computation and analysis of the results of molecular dynamics (MD) simulations with the corresponding theoretical model. This problem is of significant interest and importance, because the controlled dynamics of systems on the nanoscale is one of the central topics in the development of modern nanotechnologies. MD simulations in large molecular systems are rather computer power demanding. Therefore, in order to advance with MD simulations we have used modern computational methods based on the graphics processing units (GPU). The advantages of the use of GPUs for MD simulations in comparison with the CPUs are demonstrated ...

  3. Synthesis and application of cephalexin imprinted polymer for solid phase extraction in milk.

    Science.gov (United States)

    Lata, Kiran; Sharma, Rajan; Naik, Laxmana; Rajput, Y S; Mann, Bimlesh

    2015-10-01

    Molecular imprinted polymer (MIP) against cephalexin was synthesized by co-polymerization of functional monomer, cross-linker, radical initiator, along with target molecule (cephalexin) in a porogenic material. Binding of cephalexin towards prepared MIP was studied in different solvents (water, methanol, 1M NaCl, acetone and acetonitrile) and best binding was observed in methanol. Partition coefficient and selectivity of prepared imprint and non-imprint was also studied. Cross reactivity in terms of binding efficiency was also assessed with other antibiotics. Chromatographic study of MIP was carried out by packing prepared imprint into glass column. MIP was used as matrix in solid phase extraction (SPE) for recovery of cephalexin from spiked milk samples for further estimation by high performance liquid chromatography. No interference was observed from milk components after elution of cephalexin from MIP, indicating selectivity and affinity of MIP. On the other hand, interference was observed in eluate obtained from C18 SPE column. PMID:25872441

  4. Analysis of a solid-phase radioimmunoassay for antibodies to cytoplasmic antigen fractions of Candida albicans

    International Nuclear Information System (INIS)

    An indirect solid-phase radioimmunoassay (SPRIA) in individual polystyrene microtiter cups has been adapted for measurement of antibody to various cytoplasmic and carbohydrate antigen fractions of Candida albicans. The assay was optimized for sensitivity, precision and linearization of serum dilution curves. The optimized procedure allows computerized measurement of anti-Candida antibodies and can be used for measurement of antibody over a wide concentration range. The procedure obviates variation due to changes in day-to-day counts as a result of isotope decay and end-point antibody dilutions. The assay has been used to demonstrate a Poisson-like distribution of antibody levels in the sera of persons showing no symptoms of candidiasis. The minimum antibody level detectable by the assay is about two orders of magnitude lower than the lowest level found in human serum and 4 orders of magnitude lower than the most sensitive test used hitherto, the hemagglutination test. (Auth.)

  5. A novel hybrid metal-organic framework-polymeric monolith for solid-phase microextraction.

    Science.gov (United States)

    Lin, Chen-Lan; Lirio, Stephen; Chen, Ya-Ting; Lin, Chia-Her; Huang, Hsi-Ya

    2014-03-17

    This study describes the fabrication of a novel hybrid metal-organic framework- organic polymer (MOF-polymer) for use as a stationary phase in fritless solid-phase microextraction (SPME) for validating analytical methods. The MOF-polymer was prepared by using ethylene dimethacrylate (EDMA), butyl methacrylate (BMA), and an imidazolium-based ionic liquid as porogenic solvent followed by microwave-assisted polymerization with the addition of 25 % MOF. This novel hybrid MOF-polymer was used to extract penicillin (penicillin G, penicillin V, oxacillin, cloxacillin, nafcillin, dicloxacillin) under different conditions. Quantitative analysis of the extracted penicillin samples using the MOF-organic polymer for SPME was conducted by using capillary electrochromatography (CEC) coupled with UV analysis. The penicillin recovery was 63-96.2 % with high reproducibility, sensitivity, and reusability. The extraction time with the proposed fabricated SPME was only 34 min. PMID:24615770

  6. Facile synthesis of stereoregular carbon fiber precursor polymers by template assisted solid phase polymerization

    Directory of Open Access Journals (Sweden)

    G. Santhana Krishnan

    2012-09-01

    Full Text Available Predominantly isotactic stereoregular polyacrylonitrile copolymers (PAC were prepared by solid phase polymerization techniques using hexagonal crystalline metal salts as template compounds. Stereoregular distributions of the prepared polymer were studied using high resolution 13C nuclear magnetic resonance spectroscopy (13C NMR spectra. The extent of isotacticity was directly determined from the peak intensity of the methine carbon (CH. The triad tacticity from the intensities of methine carbon peaks were examined by statistical methods. It was found that the PAC was predominantly isotactic in stereoregularity, and its sequence distribution obeys Bernoulli statistics. The optimum polymerization conditions ensuring isotactic content over 50% were disclosed experimentally. The chemical composition of PAC was confirmed with 1H NMR data. The obtained polyacrylonitrile copolymers were also characterized for molecular parameters such as viscosity average molecular weight (Mv, number average molecular weight (Mn, weight average molecular weight (Mw and polydispersity index.

  7. Isolation of tetracyclines in milk using a solid-phase extracting column and water eluent.

    Science.gov (United States)

    Furusawa, Naoto

    2003-01-01

    An isolating method using a solid-phase extraction (SPE) ISOLUTE(R) C8 endcapped syringe-column for routine monitoring of residual tetracyclines (TCs) (oxytetracycline (OTC), tetracycline (TC), chlortetracycline (CTC), and doxycycline (DC)) in cow's milk is presented. In the simplest and most environmentally harmless method, milk samples could be applied directly to the SPE column, following which all TCs were eluted with water. No organic solvents were used at all. The purified sample was injected into a high-performance liquid chromatography (HPLC) with a photo-diode array detector (PDAD). For the HPLC determination/identification, a LiChrospher(R) 100 RP-8 endcapped column and a mobile phase of acetonitrile -7% (v v(-1)) acetic acid solution (in water) (35:65, v v(-1)) with a PDAD was used. The total time required for the analysis of one sample was 80 and <5%, respectively.

  8. Determination of metrafenone in vegetables by matrix solid-phase dispersion and HPLC-UV method.

    Science.gov (United States)

    Li, Jianjun; Li, Yangyang; Xu, Dongliang; Zhang, Jingyu; Wang, Yuxi; Luo, Chao

    2017-01-01

    A simple method for determination of metrafenone in vegetables by matrix solid-phase dispersion (MSPD) and HPLC was developed. All vegetable samples were extracted with dichloromethane, and then the extracts were directly separated on a reversed-phase column with isocratic elution without a cleanup step. The linearity of metrafenone was good with the concentration between 0.005 and 5mg/kg, and the limit of detection (LOD) of the metrafenone was 0.002mg/kg. The recoveries ranged from 86.5% to 104.8% with the relative standard deviations (RSDs) in the range of 2.1-7.9% (n=6). The results indicated that the method was simple, rapid, highly sensitive and suitable for the determination of metrafenone in vegetables. PMID:27507450

  9. Soxhlet-assisted matrix solid phase dispersion to extract flavonoids from rape (Brassica campestris) bee pollen.

    Science.gov (United States)

    Ma, Shuangqin; Tu, Xijuan; Dong, Jiangtao; Long, Peng; Yang, Wenchao; Miao, Xiaoqing; Chen, Wenbin; Wu, Zhenhong

    2015-11-15

    Soxhlet-assisted matrix solid phase dispersion (SA-MSPD) method was developed to extract flavonoids from rape (Brassica campestris) bee pollen. Extraction parameters including the extraction solvent, the extraction time, and the solid support conditions were investigated and optimized. The best extraction yields were obtained using ethanol as the extraction solvent, silica gel as the solid support with 1:2 samples to solid support ratio, and the extraction time of one hour. Comparing with the conventional solvent extraction and Soxhlet method, our results show that SA-MSPD method is a more effective technique with clean-up ability. In the test of six different samples of rape bee pollen, the extracted content of flavonoids was close to 10mg/g. The present work provided a simple and effective method for extracting flavonoids from rape bee pollen, and it could be applied in the studies of other kinds of bee pollen.

  10. Problems of Solid-Phase Synthesis in Cylindrical Ampoules under Explosive Loading

    Science.gov (United States)

    Zelepugin, S. A.; Ivanova, O. V.; Yunoshev, A. S.; Zelepugin, A. S.

    2016-04-01

    The peculiarities of solid-phase synthesis are studied experimentally and numerically in the aluminum-fluoroplastic and aluminum-sulfur mixtures in cylindrical ampoules under explosive loading. The experimental results show that the use of a mixture capable of ultrafast exothermic reactions leads to the destruction of a cylindrical ampoule under explosive loading. When the transient shock wave is reflected from the bottom lid of the ampoule as a compression wave, there is a sharp increase in pressure in the lower part of the ampoule, which is accompanied by the increase in rate of the chemical reaction. The high rate of heat release during the chemical reaction in the lower part of the ampoule causes the formation of a gas phase, which leads to a further increase in pressure and destruction of the ampoule.

  11. Solid phase microextraction (SPME) sampling under turbulent conditions and for the simultaneous collecting of tracer gases

    Institute of Scientific and Technical Information of China (English)

    Underwood Susanne W.; Jong Edmund C.; Luxbacher Kray D.; Sarver Emily A.; Ripepi Nino S.; McNair Harold M.

    2015-01-01

    Solid phase microextraction (SPME) is a solvent-free method of sample collection. SPME is an appealing method for sample collection because it is designed for the sampling of trace level analytes with short sampling times in a variety of environments. Additionally, SPME can be used to directly deliver a sample to a gas chromatograph (GC) for analysis by means of thermal desorption. In this paper, the performance of SPME under dynamic conditions was investigated. Additionally, the competence of SPME sampling for the simultaneous analysis of multiple trace analytes was also evaluated. This work is discussed in the context of underground mine ventilation surveys but is applicable to any industry in which ventilation circuits must be evaluated. The results of this paper showed that the performance of the 100 lm PDMS SPME fiber was both precise and rapid under dynamic conditions. This SPME fiber was also able to simultaneously collect sulfur hexafluoride (SF6) and perfluoromethylcyclohexane (PMCH) with adequate sensitivity.

  12. Sol-Gel-Coated Calix[4]arene Fiber for Solid-Phase Microextraction

    Institute of Scientific and Technical Information of China (English)

    LiXiu-juan; XiaoRui-min; LiHai-bing; ZengZhao-rui

    2003-01-01

    5, 11, 17, 23-tetra-tert-butyl-25, 27-diethoxy-26, 28-dihydroxycalix [4] arene/hydroxy-terminated silicone oil coated fiber was first prepared and applied for solid-phase microextraction with sol-gel technology. The properties of the new coating were investigated by analysis of benzene derivatives, polycyclic aromatic hydrocarbons and aromatic amines.The fiber is characterized by good sensitivity and selectivity to these aromatics. The fiber has stable performance at a high temperature of 380℃ and after a long solvent immersing,thus its lifetime is very long. It shows good fiber-to-fiber and batch-to-batch reproducibility. Furthermore, broad linear ranges and low detection limits are also its characteristics.

  13. Reaction Process of Chromium Slag Reduced by Industrial Waste in Solid Phase

    Institute of Scientific and Technical Information of China (English)

    SHI Yu-min; DU Xing-hong; MENG Qing-jia; SONG Shi-wei; SUI Zhi-tong

    2007-01-01

    M, a particular industrial waste, was selected to detoxify chromium slag at a high temperature. The carbon remaining in M reduced Cr (Ⅵ) of Na2CrO4 borne in the chromium slag to Cr (Ⅲ) in the solid phase reaction, and its thermodynamics and kinetics were studied. The reduction process of Na2CrO4 by carbon produced CO, which was endothermic. Under the experimental condition, the apparent activation energy was 4.41 kJ·mol-1, the apparent order of reaction for Na2CrO4 was equal to one, and the partial pressure of CO was only 0.22 Pa at 1 330 ℃.

  14. Quantum computational capability of a two-dimensional valence bond solid phase

    CERN Document Server

    Miyake, Akimasa

    2010-01-01

    Quantum phases of naturally-occurring systems exhibit rich nature as manifestation of their many-body correlations, in contrast to our persistent technological challenge to build at will such correlations artificially from scratch. Here we show theoretically that quantum correlations exhibited in the two-dimensional valence bond solid phase of a quantum antiferromagnet, modeled by Affleck, Kennedy, Lieb, and Tasaki as a precursor of spin liquids and topological orders, are sufficiently complex yet structured enough to simulate universal quantum computation when every single spin can be measured individually. This unveils that an intrinsic complexity of naturally-occuring 2D quantum systems -- which has been a long-standing challenge for traditional computers -- could be tamed as a computationally valuable resource, regardless of our constraint not to create newly entanglement during computation. Our constructive protocol leverages a novel way to herald the correlations suitable for deterministic quantum compu...

  15. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    International Nuclear Information System (INIS)

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2Kb and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and 125I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. (Auth.)

  16. A new method for measuring antibody using radiolabeled protein A in a solid-phase radioimmunoassay

    International Nuclear Information System (INIS)

    A micro solid-phase radioimmunoassay was developed which utilizes radiolabeled staphylococcal Protein A ([125I] Protein A) in place of radiolabeled anti-immunoglobulin ([125I]anti-IgG) for the measurement of antibody. For the assay, antigen is adsorbed to the wells of a microtiter plate followed by dilutions of serum and [125I]-Protein A in subsequent steps. It was found that this assay can be used to measure antibody (Ab) against a variety of antigens in human and rabbit but not goat immune serum. Binding of [125I]-Protein A and [125I]anti-IgG to human and rabbit IgG was comparable. It was possible to quantify this amount of Ab in human serum by reference to immune rabbit serum. The sensitivity of this assay for rabbit antibody was 1 ng/ml. (Auth.)

  17. Solid-phase radioimmunoassay for the measurement of surface antigens expressed on intact lymphocytes

    Energy Technology Data Exchange (ETDEWEB)

    Savion, S.; Sharabi, Y.; Shoham, J.

    1987-02-26

    A solid-phase radioimmunoassay was developed for the measurement of lymphocyte surface antigens. The assay was performed in microplates, using cells that were initially fixed to the wells by air drying. The method was used for the measurement of Thy-1, Lyt-1,2,3, IL-2-R, H-2K/sup b/ and DR antigens on the surface of mouse thymus, spleen and bone marrow cells, mouse cell lines CTLL, EL-4 and DA-1 and human thymocytes and consisted of sequential incubations with rat or mouse monoclonal antibodies directed against the above antigens, rabbit anti-rat or goat anti-mouse IgG and /sup 125/I-protein A. The assay permits the processing of large numbers of samples, is easy to perform, reliable and highly specific. 13 refs.; 10 figs.

  18. Universal solid-phase approach for the immobilization, derivatization, and resin-to-resin transfer reactions of boronic acids.

    Science.gov (United States)

    Gravel, Michel; Thompson, Kim A; Zak, Mark; Bérubé, Christian; Hall, Dennis G

    2002-01-11

    Boronic acid-containing molecules are employed in a broad range of biological, medicinal, and synthetic applications. These compounds, however, tend to be difficult to handle by solution-phase methods. Herein, this problem is addressed with the development of the first general solid-phase approach for the derivatization of functionalized boronic acids. This approach is based on the use of a diethanolamine resin anchor that facilitates boronic acid immobilization by avoiding the need for exhaustive removal of water in the esterification process. The immobilization of a wide variety of boronic acids onto N,N-diethanolaminomethyl polystyrene (DEAM-PS, 1) can be performed within minutes by simple stirring in anhydrous solvents at room temperature. Evidence for the formation of a bicyclic diethanolamine boronate with putative N-B coordination was shown by (1)H NMR analysis of DEAM-PS-supported p-tolylboronic acid. The hydrolytic cleavage of the same model boronic acid from the DEAM-PS resin was studied by UV spectroscopy. Hydrolysis and attachment were shown to occur under a rapidly attained equilibrium, and a large excess of water (>32 equiv) is required to effect a practically quantitative release of boronic acids from DEAM-PS. Despite their relative sensitivity to water and alcohols, DEAM-PS-bound arylboronic acids functionalized with a formyl, a bromomethyl, a carboxyl, or an amino group can be transformed in good to excellent yields into a wide variety of amines, amides, anilides, and ureas, respectively. Ugi multicomponent reactions on DEAM-PS-supported aminobenzeneboronic acids, derivatization of multifunctional arylboronic acids, and sequential reactions can also be carried out efficiently. These new DEAM-PS-supported arylboronic acids can be employed directly into resin-to-resin transfer reactions (RRTR). This type of multiresin process helps eliminate time-consuming cleavage and transfer operations, thereby considerably simplifying the outlook of combinatorial

  19. Cold fiber solid-phase microextraction device based on thermoelectric cooling of metal fiber.

    Science.gov (United States)

    Haddadi, Shokouh Hosseinzadeh; Pawliszyn, Janusz

    2009-04-01

    A new cold fiber solid-phase microextraction device was designed and constructed based on thermoelectric cooling. A three-stage thermoelectric cooler (TEC) was used for cooling a copper rod coated with a poly(dimethylsiloxane) (PDMS) hollow fiber, which served as the solid-phase microextraction (SPME) fiber. The copper rod was mounted on a commercial SPME plunger and exposed to the cold surface of the TEC, which was enclosed in a small aluminum box. A heat sink and a fan were used to dissipate the generated heat at the hot side of the TEC. By applying an appropriate dc voltage to the TEC, the upper part of the copper rod, which was in contact to the cold side of the TEC, was cooled and the hollow fiber reached a lower temperature through heat transfer. A thermocouple was embedded in the cold side of the TEC for indirect measurement of the fiber temperature. The device was applied in quantitative analysis of off-flavors in a rice sample. Hexanal, nonanal, and undecanal were chosen as three off-flavors in rice. They were identified according to their retention times and analyzed by GC-flame ionization detection instrument. Headspace extraction conditions (i.e., temperature and time) were optimized. Standard addition calibration graphs were obtained at the optimized conditions and the concentrations of the three analytes were calculated. The concentration of hexanal was also measured using a conventional solvent extraction method (697+/-143ng/g) which was comparable to that obtained from the cold fiber SPME method (644+/-8). Moreover, the cold fiber SPME resulted in better reproducibility and shorter analysis time. Cold fiber SPME with TEC device can also be used as a portable device for field sampling.

  20. Principles and applications of colorimetric solid-phase extraction with negligible depletion

    Energy Technology Data Exchange (ETDEWEB)

    Dias, Neil C. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States); Porter, Marc D. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States)]. E-mail: mporter@porter1.ameslab.gov; Fritz, James S. [Institute for Combinatorial Discovery, Ames Laboratory-U.S. Department of Energy, Department of Chemistry, Iowa State University, Ames, IA 50011 (United States)

    2006-02-03

    Colorimetric solid-phase extraction (C-SPE) is an integrated technique in which an analyte is selectively concentrated onto a disk and then quantitated by diffuse reflectance spectroscopy. This paper describes the results of an investigation that applies the concept of negligible depletion (ND) to C-SPE, representing the first application of ND concepts to solid-phase extractions. The approach relies on passing the minimal volume of sample through the disk required to reach an equilibrium in which the concentration of analyte in the sample entering and exiting the disk are equal. At this point, the amount of analyte extracted by the disk is proportional to the sample concentration but is independent of the sample volume passed through the disk. With this new method, called C-SPE/ND, the precise measurement of sample volume is no longer necessary. The work herein details the general principles of this new methodology, and validates its basic tenets in an investigation of the extraction of the organic dye methyl violet. The analytical capabilities of C-SPE/ND are then demonstrated by its application to measurements of iodine. Iodine is a biocide increasingly used as a simple and effective disinfectant for water in locations where municipal water treatment systems are potentially compromised. Thus, the ability to operate C-SPE in an ND mode notably enhances the broad-based utility of this methodology as a reliable and an easy-to-use analysis tool for water quality assessments. Since iodine is also the biocide used on NASAs Space Shuttle, C-SPE/ND has the potential to overcome problems associated with the removal of air bubbles entrapped in a water sample in the microgravity environment encountered in space exploration. Extensions of C-SPE/ND to facile determinations of other water quality parameters with respect to both earth- and space-based needs are briefly discussed.

  1. Molecularly imprinted solid-phase extraction of glutathione from urine samples

    Energy Technology Data Exchange (ETDEWEB)

    Song, Renyuan, E-mail: songrenyuan0726@163.com; Hu, Xiaoling; Guan, Ping; Li, Ji; Zhao, Na; Wang, Qiaoli

    2014-11-01

    Molecularly imprinted polymer (MIP) particles for glutathione were synthesized through iniferter-controlled living radical precipitation polymerization (IRPP) under ultraviolet radiation at ambient temperature. Static adsorption, solid-phase extraction, and high-performance liquid chromatography were carried out to evaluate the adsorption properties and selective recognition characteristics of the polymers for glutathione and its structural analogs. The obtained IRPP-MIP particles exhibited a regularly spherical shape, rapid binding kinetics, high imprinting factor, and high selectivity compared with the MIP particles prepared using traditional free-radical precipitation polymerization. The selective separation and enrichment of glutathione from the mixture of glycyl-glycine and glutathione disulfide could be achieved on the IRPP-MIP cartridge. The recoveries of glutathione, glycyl-glycine, and glutathione disulfide were 95.6% ± 3.65%, 29.5% ± 1.26%, and 49.9% ± 1.71%, respectively. The detection limit (S/N = 3) of glutathione was 0.5 mg·L{sup −1}. The relative standard deviations (RSDs) for 10 replicate detections of 50 mg·L{sup −1} of glutathione were 5.76%, and the linear range of the calibration curve was 0.5 mg·L{sup −1} to 200 mg·L{sup −1} under optimized conditions. The proposed approach was successfully applied to determine glutathione in spiked human urine samples with recoveries of 90.24% to 96.20% and RSDs of 0.48% to 5.67%. - Highlights: • Imprinted polymer particles were prepared by IRPP at ambient temperature. • High imprinting factor, high selectivity, and rapid binding kinetics were achieved. • Selective solid-phase extraction of glutathione from human urine samples.

  2. Evaluation of single-walled carbon nanohorns as sorbent in dispersive micro solid-phase extraction

    Energy Technology Data Exchange (ETDEWEB)

    Jimenez-Soto, Juan Manuel; Cardenas, Soledad [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain); Valcarcel, Miguel, E-mail: qa1meobj@uco.es [Department of Analytical Chemistry, Institute of Fine Chemistry and Nanochemistry, Marie Curie Building, Campus de Rabanales, University of Cordoba, 14071 Cordoba (Spain)

    2012-02-10

    Highlights: Black-Right-Pointing-Pointer The potential of single walled carbon nanohorns in dispersive solid phase microextraction has been evaluated. Black-Right-Pointing-Pointer The method was characterized for the extraction of PAHs from waters. Black-Right-Pointing-Pointer Single walled carbon nanohorns were better extractant than carbon nanotubes and carbon nanocones. Black-Right-Pointing-Pointer The limits of detection were adequate for the target analytes in environmental waters. - Abstract: A new dispersive micro solid-phase extraction method which uses single-walled carbon nanohorns (SWNHs) as sorbent is proposed. The procedure combines the excellent sorbent properties of the nanoparticles with the efficiency of the dispersion of the material in the sample matrix. Under these conditions, the interaction with the analytes is maximized. The determination of polycyclic aromatic hydrocarbons was selected as model analytical problem. Two dispersion strategies were evaluated, being the functionalization via microwave irradiation better than the use of a surfactant. The extraction was accomplished by adding 1 mL of oxidized SWHNs (o-SWNHs) dispersion to 10 mL of water sample. After extraction, the mixture was passed through a disposable Nylon filter were the nanoparticles enriched with the PAHs were retained. The elution was carried out with 100 {mu}L of hexane. The limits of detection achieved were between 30 and 60 ng L{sup -1} with a precision (as repeatability) better than 12.5%. The recoveries obtained for the analytes in three different water samples were acceptable in all instances. The performance of o-SWNHs was favourably compared with that provided by carboxylated single-walled carbon nanotubes and thermally treated carbon nanocones.

  3. Solid-phase synthesis of protected peptides using new cobalt(III) ammine linkers.

    Science.gov (United States)

    Arbo, B E; Isied, S S

    1993-08-01

    Cobalt(III) ammine complexes of the type cis-[CoL4(4-AMB)O-AA-Boc](CF3SO3)2, where L4 = bisethylenediamine (en)2 or tetraammine (NH3)4, and 4-AMB = 4-(aminomethyl)benzoic acid, have been synthesized and used as linkers to polystyrene resins for solid-phase synthesis of protected peptides. Boc/t-Bu-protected [Leu5]enkephalin was assembled on the two different Co(III) resins, and then cleaved from the resins by reduction of the Co(III) center in 93-96% yield. HPLC-purified protected [Leu5]enkephalin was obtained in 67-69% overall yield and characterized by amino acid analysis and 1H NMR. Stepwise synthesis on the Co(en)2-resin was also used in the assembly of Boc-Asp(OcHex)-Arg(Mts)-Gly-Asp(OcHex)-Ala-Pro-Lys(2Cl-Z)-Gl y-OH, a sequence from collagen alpha 1 Type 1. The protected peptide was cleaved from the Co(III) resin in 74% yield, and the HPLC-purified nonapeptide was characterized by amino acid analysis, 1H NMR and liquid secondary-ion mass spectrometry (LSIMS). New routes are described for the synthesis of isomerically pure Co(III) anchor complexes. The Co(III) resins were found to be compatible with both the tert-butyloxycarbonyl (Boc) and the 9-fluorenylmethoxycarbonyl (Fmoc) N alpha-protecting group strategies used in solid-phase peptide synthesis.

  4. Characterization and semiquantitative analysis of volatiles in seedless watermelon varieties using solid-phase microextraction.

    Science.gov (United States)

    Beaulieu, John C; Lea, Jeanne M

    2006-10-01

    Seedless triploid watermelons have increased in popularity since the early 1990s, and the demand for seedless fruit is on the rise. Sweetness and sugars are crucial breeding focuses for fruit quality. Volatiles also play an important role; yet, we found no literature for seedless varieties and no reports using solid-phase microextraction (SPME) in watermelon. The objective of this experiment was to identify volatile and semivolatile compounds in five seedless watermelon varieties using carboxen divinylbenzene polydimethylsiloxane solid-phase microextraction (SPME) with gas chromatography-mass spectrometry (GC-MS). Fully ripe watermelon was squeezed through miracloth to produce rapid juice extracts for immediate headspace SPME GC-MS. Aldehydes, alcohols, ketones, and one furan (2-pentyl furan, a lipid oxidation product) were recovered. On the basis of total ion count peak area, the most abundant compounds in five varieties were 3-nonen-1-ol/(E,Z)-2,6-nonadienal (16.5-28.2%), (E)-2-nonenal (10.6-22.5%), and (Z)-6-nonenal (2.0-11.3%). Hexanal was most abundant (37.7%) in one variety (Petite Perfection) [corrected] The most abundant ketone was 6-methyl-5-hepten-2-one (2.7-7.7%). Some sensory attributes reported for these compounds are melon, citrus, cucumber, orange, rose, floral, guava, violet, vegetable, green, grassy, herbaceous, pungent, fatty, sweet, and waxy. Identifying and relating these compounds to sensory attributes will allow for future monitoring of the critical flavor compounds in seedless watermelon after processing and throughout fresh-cut storage. PMID:17002453

  5. A metal organic framework-polyaniline nanocomposite as a fiber coating for solid phase microextraction.

    Science.gov (United States)

    Bagheri, Habib; Javanmardi, Hasan; Abbasi, Alireza; Banihashemi, Solmaz

    2016-01-29

    A metal organic framework-polyaniline (MOF/PANI) nanocomposite was electrodeposited on a stainless steel wire and used as a solid phase microextraction (SPME) fiber coating. The electropolymerization process was carried out under a constant deposition potential and applied to the corresponding aqueous electrolyte containing aniline and MOF particles. The employment of MOFs with their large and small cages and 3-D structures in synthesizing a nanocomposite was assumed to be efficient constitutes to induce more non-smooth and porous structures, approved by scanning electron microscopy (SEM) images. Three different MOFs were incorporated to synthesize the desired nanocomposites and the preliminary experiments showed that all of them, particularly the one containing MOF2, have higher extraction performances in compared with PANI. The applicability of the new fiber coating was examined by headspace-solid phase microextraction (HS-SPME) of some chlorobenzenes (CBs) from aqueous samples. Influencing parameters on the synthesize and extraction processes including the electrodeposition voltage and its duration time, the weight ratio of PANI and MOF, the ionic strength, desorption temperature and time, and extraction time and temperature were optimized. The developed method was validated by analyzing the spiked distilled water and gas chromatography-mass spectrometry (GC-MS). Under optimum condition, the relative standard deviation (RSD%) values for a double distilled water spiked with the selected CBs at 20ngL(-1) were 5-8% (n=3) and the detection limits were below 0.2ngL(-1). The linear dynamic range (LDR) of the method was in the concentration range of 0.5-1000ngL(-1) (R(2)>0.9994). The fiber-to-fiber reproducibility was found to be in the range of 4-7%. Eventually, various real-water samples were analyzed by the MOF/PANI-based HS-SPME and GC-MS and the relative recovery values were found to be in the range of 92-98%. PMID:26792446

  6. Aldolase exists in both the fluid and solid phases of cytoplasm.

    Science.gov (United States)

    Pagliaro, L; Taylor, D L

    1988-09-01

    We have prepared a functional fluorescent analogue of the glycolytic enzyme aldolase (rhodamine [Rh]-aldolase), using the succinimidyl ester of carboxytetramethyl-rhodamine. Fluorescence redistribution after photobleaching measurements of the diffusion coefficient of Rh-aldolase in aqueous solutions gave a value of 4.7 x 10(-7) cm2/S, and no immobile fraction. In the presence of filamentous actin, there was a 4.5-fold reduction in diffusion coefficient, as well as a 36% immobile fraction, demonstrating binding of Rh-aldolase to actin. However, in the presence of a 100-fold molar excess of its substrate, fructose 1,6-diphosphate, both the mobile fraction and diffusion coefficient of Rh-aldolase returned to control levels, indicating competition between substrate binding and actin cross-linking. When Rh-aldolase was microinjected into Swiss 3T3 cells, a relatively uniform intracellular distribution of fluorescence was observed. However, there were significant spatial differences in the in vivo diffusion coefficient and mobile fraction of Rh-aldolase measured with fluorescence redistribution after photobleaching. In the perinuclear region, we measured an apparent cytoplasmic diffusion coefficient of 1.1 x 10(-7) cm2/s with a 23% immobile fraction; while measurements in the cell periphery gave a value of 5.7 x 10(-8) cm2/s, with no immobile fraction. Ratio imaging of Rh-aldolase and FITC-dextran indicated that FITC-dextran was relatively excluded excluded from stress fiber domains. We interpret these data as evidence for the partitioning of aldolase between a soluble fraction in the fluid phase and a fraction associated with the solid phase of cytoplasm. The partitioning of aldolase and other glycolytic enzymes between the fluid and solid phases of cytoplasm could play a fundamental role in the control of glycolysis, the organization of cytoplasm, and cell motility. The concepts and experimental approaches described in this study can be applied to other cellular

  7. Combined liquid and solid-phase extraction improves quantification of brain estrogen content

    Directory of Open Access Journals (Sweden)

    Andrew eChao

    2011-09-01

    Full Text Available Accuracy in quantifying brain-derived steroid hormones (‘neurosteroids’ has become increasingly important for understanding the modulation of neuronal activity, development, and physiology. Relative to other neuroactive compounds and classical neurotransmitters, steroids pose particular challenges with regard to isolation and analysis, owing to their lipid solubility. Consequently, anatomical studies of the distribution of neurosteroids have relied primarily on the expression of neurosteroid synthesis enzymes. To evaluate the distribution of synthesis enzymes vis-à-vis the actual steroids themselves, traditional steroid quantification assays, including radioimmunoassays (RIA, have successfully employed liquid extraction methods (e.g., ether, dichloromethane or methanol to isolate steroids from microdissected brain tissue. Due to their sensitivity, safety and reliability, the use of commercial enzyme immunoassays (EIA for laboratory quantification of steroids in plasma and brain has become increasingly widespread. However, EIAs rely on enzymatic reactions in vitro, making them sensitive to interfering substances in brain tissue and thus producing unreliable results. Here, we evaluate the effectiveness of a protocol for combined, two-stage liquid/solid phase extraction as compared to conventional liquid extraction alone for the isolation of estradiol (E2 from brain tissue. We employ the songbird model system, in which brain steroid production is pronounced and linked to neural mechanisms of learning and plasticity. This study outlines a combined liquid-solid phase extraction protocol that improves the performance of a commercial EIA for the quantification of brain E2 content. We demonstrate the effectiveness of our optimized method for evaluating the region specificity of brain E2 content, compare these results to established anatomy of the estrogen synthesis enzyme and estrogen receptor, and discuss the nature of potential EIA interfering

  8. Multiple headspace-solid-phase microextraction: An application to quantification of mushroom volatiles

    Energy Technology Data Exchange (ETDEWEB)

    Costa, Rosaria; Tedone, Laura; De Grazia, Selenia [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Dugo, Paola [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Centro Integrato di Ricerca (C.I.R.), Università Campus-Biomedico, Via Álvaro del Portillo, 21, 00128 Roma (Italy); Mondello, Luigi, E-mail: lmondello@unime.it [Dipartimento Farmaco-chimico, University of Messina, viale Annunziata, 98168 Messina (Italy); Centro Integrato di Ricerca (C.I.R.), Università Campus-Biomedico, Via Álvaro del Portillo, 21, 00128 Roma (Italy)

    2013-04-03

    Highlights: ► Multiple headspace extraction-solid phase microextraction (MHS-SPME) has been applied to the analysis of Agaricus bisporus. ► Mushroom flavor is characterized by the presence of compounds with a 8-carbon atoms skeleton. ► Formation of 8-carbon compounds involves a unique fungal biochemical pathway. ► The MHS-SPME allowed to determine quantitatively 5 target analytes of A. bisporus for the first time. -- Abstract: Multiple headspace-solid phase microextraction (MHS-SPME) followed by gas chromatography/mass spectrometry (GC–MS) and flame ionization detection (GC–FID) was applied to the identification and quantification of volatiles released by the mushroom Agaricus bisporus, also known as champignon. MHS-SPME allows to perform quantitative analysis of volatiles from solid matrices, free of matrix interferences. Samples analyzed were fresh mushrooms (chopped and homogenized) and mushroom-containing food dressings. 1-Octen-3-ol, 3-octanol, 3-octanone, 1-octen-3-one and benzaldehyde were common constituents of the samples analyzed. Method performance has been tested through the evaluation of limit of detection (LoD, range 0.033–0.078 ng), limit of quantification (LoQ, range 0.111–0.259 ng) and analyte recovery (92.3–108.5%). The results obtained showed quantitative differences among the samples, which can be attributed to critical factors, such as the degree of cell damage upon sample preparation, that are here discussed. Considerations on the mushrooms biochemistry and on the basic principles of MHS analysis are also presented.

  9. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    Energy Technology Data Exchange (ETDEWEB)

    Moon, Sung Won [KIST Gangneung Institute, Gangneung (Korea, Republic of); Ham, Jungyeob [Gangneung-Wonju National University, Gangneung (Korea, Republic of); Chang, Young-Tae [National University of Singapore, Singapore (Singapore); Lee, Jae Wook [University of Science and Technology, Daejon (Korea, Republic of)

    2015-01-15

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds.

  10. Solid-phase Synthesis of Combinatorial 2,4-Disubstituted-1,3,5-Triazine via Amine Nucleophilic Reaction

    International Nuclear Information System (INIS)

    In combinatorial chemistry, solid-phase synthesis is a popular approach formass production of small molecules. Compared to solution-phase synthesis, it is easy to prepare and purify a large number of heterocyclic small molecules via solid-phase chemistry; the overall reaction time is decreased as well. 1,3,5-Triazine is a nitrogen-containing heterocyclic aromatic scaffold that was shown to be a druggable scaffold in recent studies. These structures have been reported as anticancer, antimicrobial, and antiretroviral compounds, as CDKs and p38 MAP kinase inhibitors, as estrogen receptor modulators, and as inosine monophosphate dehydrogenase inhibitors. we designed and synthesized disubstituted triazine compounds as an analog of disubstituted pyrimidine compounds. These disubstituted triazine compounds possess a linear structure which may have biological activity similar to that of disubstituted pyrimidine. Here we report the solid-phase synthesis of disubstituted triazine compounds

  11. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    International Nuclear Information System (INIS)

    Highlights: ► The use of CNTs as sorbent for metal species in solid phase extraction has been described. ► Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. ► Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes – due to their high adsorption and desorption capacities – have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  12. Carbon nanotubes as solid-phase extraction sorbents prior to atomic spectrometric determination of metal species: A review

    Energy Technology Data Exchange (ETDEWEB)

    Herrero Latorre, C., E-mail: carlos.herrero@usc.es [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain); Alvarez Mendez, J.; Barciela Garcia, J.; Garcia Martin, S.; Pena Crecente, R.M. [Universidad de Santiago de Compostela, Dpto. Quimica Analitica, Nutricion y Bromatologia, Facultad de Ciencias, Alfonso X el Sabio s/n, 27002 Lugo (Spain)

    2012-10-24

    Highlights: Black-Right-Pointing-Pointer The use of CNTs as sorbent for metal species in solid phase extraction has been described. Black-Right-Pointing-Pointer Physical and chemical strategies for functionalization of carbon nanotubes have been discussed. Black-Right-Pointing-Pointer Published analytical methods concerning solid phase extraction and atomic spectrometric determination have been reviewed. - Abstract: New materials have significant impact on the development of new methods and instrumentation for chemical analysis. From the discovery of carbon nanotubes in 1991, single and multi-walled carbon nanotubes - due to their high adsorption and desorption capacities - have been employed as sorption substrates in solid-phase extraction for the preconcentration of metal species from diverse matrices. Looking for successive improvements in sensitivity and selectivity, in the past few years, carbon nanotubes have been utilized as sorbents for solid phase extraction in three different ways: like as-grown, oxidized and functionalized nanotubes. In the present paper, an overview of the recent trends in the use of carbon nanotubes for solid phase extraction of metal species in environmental, biological and food samples is presented. The determination procedures involved the adsorption of metals on the nanotube surface, their quantitative desorption and subsequent measurement by means of atomic spectrometric techniques such as flame atomic absorption spectrometry, electrothermal atomic absorption spectrometry or inductively coupled plasma atomic emission spectrometry/mass spectrometry, among others. Synthesis, purification and types of carbon nanotubes, as well as the diverse chemical and physical strategies for their functionalization are described. Based on 140 references, the performance and general properties of the applications of solid phase extraction based on carbon nanotubes for metal species atomic spectrometric determination are discussed.

  13. Solid Phase Reactions of Ni-GaAs Alloys for High Mobility Ⅲ-Ⅴ MOSFET Applications

    Institute of Scientific and Technical Information of China (English)

    LU Li; CHANG Hu-Dong; SUN Bing; WANG Hong; XUE Bai-Qing; ZHAO We; LIU Hong-Gang

    2012-01-01

    The solid phase reactions of Ni with GaAs substrates are investigated.The experimental results reveal that the Ni-GaAs solid phase reaction forms a ternary phase of Ni2GaAs when annealing temperatures are in the range 250 300℃.As the annealing temperature increases to 400℃,the Ni2GaAs phase starts to decompose due to NiAs phase precipitation.Ni-GaAs alloys processed at 400℃ with a 3min annealing time demonstrate a sheet resistance of 30Ω/square after unreacted Ni removal in hot diluted-HCl solutions.Therefore,Ni-GaAs alloys formed by solid phase reaction could be promising metallic source/drain structures with significant low series resistance for high mobility Ⅲ-Ⅴ metal-oxide-semiconductor field effect transistor (MOSFET) applications.%The solid phase reactions of Ni with GaAs substrates are investigated. The experimental results reveal that the Ni-GaAs solid phase reaction forms a ternary phase of Ni2GaAs when annealing temperatures are in the range 250-300℃. As the annealing temperature increases to 400℃, the Ni2GaAs phase starts to decompose due to NiAs phase precipitation. Ni-GaAs alloys processed at 400℃ with a 3 min annealing time demonstrate a sheet resistance of 30Ω/square after unreacted Ni removal in hot diluted-HCl solutions. Therefore, Ni-GaAs alloys formed by solid phase reaction could be promising metallic source/drain structures with significant low series resistance for high mobility III-V metal-oxide-semiconductor field effect transistor (MOSFET) applications.

  14. Synthesis of a highly hydrophobic cyclic decapeptide by solid-phase synthesis of linear peptide and cyclization in solution

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A general method was described to synthesize a highly hydrophobic cyclic peptide,cyclo[LWLWLWLWLQ]where underlines indicate D-configuration of the amino acid,by a two-step solid-phase/solution synthesis strategy.The linear decapeptide was assembled by standard Boc chemistry on solid-phase and subsequently cyclized in solution with high efficiency and reproducibility. In subsequent purification by semi-preparative HPLC,50%(v/v) DMF/H_2O was employed as the solvent to overcome the difficulty of solubilizat...

  15. On line ultrasonic integrated backscatter

    International Nuclear Information System (INIS)

    A new equipment for on-line evaluation of index based on two-dimensional integrated backscatter from ultrasonic images is described. The new equipment is fully integrated into a B-mode ultrasonic apparatus which provides a simultaneous display of conventional information together with parameters of tissue characterization. The system has been tested with a backscattering model of microbubbles in polysaccharide solution, characterized by a physiological exponential time decay. An exponential fitting to the experimental data was performed which yielded r=0.95

  16. PHENIX on-line systems

    Energy Technology Data Exchange (ETDEWEB)

    Adler, S.S.; Allen, M.; Alley, G.; Amirikas, R.; Arai, Y.; Awes, T.C.; Barish, K.N.; Barta, F.; Batsouli, S.; Belikov, S.; Bennett, M.J.; Bobrek, M.; Boissevain, J.G.; Boose, S.; Britton, C.; Britton, L.; Bryan, W.L.; Cafferty, M.M.; Carey, T.A.; Chang, W.C.; Chi, C.Y.; Chiu, M.; Cianciolo, V.; Cole, B.A.; Constantin, P.; Cook, K.C.; Cunitz, H.; Desmond, E.J.; Ebisu, K.; Efremenko, Y.V.; El Chenawi, K.; Emery, M.S.; Engo, D.; Ericson, N.; Fields, D.E.; Frank, S.; Frantz, J.E.; Franz, A.; Frawley, A.D.; Fried, J.; Gannon, J.; Gee, T.F.; Gentry, R.; Giannotti, P.; Gustafsson, H.-A.; Haggerty, J.S.; Hahn, S.; Halliwell, J.; Hamagaki, H.; Hansen, A.G.; Hara, H.; Harder, J.; He, X.; Heistermann, F.; Hemmick, T.K.; Hibino, M.; Hill, J.C. E-mail: jhill@iastate.edu; Homma, K.; Jacak, B.V.; Jagadish, U.; Jia, J.; Kajihara, F.; Kametani, S.; Kamyshkov, Y.; Kandasamy, A.; Kang, J.H.; Kapustinsky, J.; Katou, K.; Kelley, M.A.; Kelly, S.; Kikuchi, J.; Kim, S.Y.; Kim, Y.G.; Kistenev, E.; Kotchetkov, D.; Kurita, K.; Lajoie, J.G.; Lenz, M.; Lenz, W.; Li, X.H.; Lin, S.; Liu, M.X.; Markacs, S.; Matathias, F.; Matsumoto, T.; Mead, J.; Mischke, R.E.; Mishra, G.C.; Moore, A.; Muniruzzamann, M.; Musrock, M.; Nagle, J.L.; Nandi, B.K.; Newby, J.; Nystrand, J.; O' Brien, E.; O' Connor, P.; Ohnishi, H.; Oskarsson, A.; Osterman, L.; Oyama, K.; Paffrath, L.; Pancake, C.E.; Pantuev, V.S.; Petridis, A.N.; Pisani, R.P.; Plagge, T.; Plasil, F.; Purschke, M.L.; Rankowitz, S.; Rao, R.; Rau, M.; Read, K.F.; Ryu, S.S.; Sakaguchi, T.; Sato, H.D.; Seto, R.; Shiina, T.; Silvermyr, D.; Simon-Gillo, J.; Simpson, M.; Sippach, W.; Skank, H.D.; Skutnik, S.; Sleege, G.A.; Smith, G.D.; Smith, M.; Stankus, P.W.; Steinberg, P.; Sugitate, T.; Sullivan, J.P.; Taketani, A.; Tamai, M.; Tanaka, Y.; Thomas, W.D.; Todd, R.; Toldo, F.; Turner, G.; Ushiroda, T.; Velkovska, J.; Hecke, H.W. van; Lith, M. van; Villatte, L.; Achen, W. von; Walker, J.W.; Wang, H.Q.; White, S.N.; Wintenberg, A.L.; Witzig, C.; Wood, L.[and others

    2003-03-01

    The PHENIX On-Line system takes signals from the Front End Modules (FEM) on each detector subsystem for the purpose of generating events for physics analysis. Processing of event data begins when the Data Collection Modules (DCM) receive data via fiber-optic links from the FEMs. The DCMs format and zero suppress the data and generate data packets. These packets go to the Event Builders (EvB) that assemble the events in final form. The Level-1 trigger (LVL1) generates a decision for each beam crossing and eliminates uninteresting events. The FEMs carry out all detector processing of the data so that it is delivered to the DCMs using a standard format. The FEMs also provide buffering for LVL1 trigger processing and DCM data collection. This is carried out using an architecture that is pipelined and deadtimeless. All of this is controlled by the Master Timing System (MTS) that distributes the RHIC clocks. A Level-2 trigger (LVL2) gives additional discrimination. A description of the components and operation of the PHENIX On-Line system is given and the solution to a number of electronic infrastructure problems are discussed.

  17. Formation of target-specific binding sites in enzymes: solid-phase molecular imprinting of HRP

    Science.gov (United States)

    Czulak, J.; Guerreiro, A.; Metran, K.; Canfarotta, F.; Goddard, A.; Cowan, R. H.; Trochimczuk, A. W.; Piletsky, S.

    2016-05-01

    Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike complex protein engineering approaches commonly employed to generate affinity proteins, the method proposed can be used to produce protein-based ligands in a short time period using native protein molecules. These affinity materials are potentially useful tools especially for assays since they combine the catalytic properties of enzymes (for signaling) and molecular recognition properties of antibodies. We demonstrate this concept in an ELISA-format assay where HRP imprinted with vancomycin and ampicillin replaced traditional enzyme-antibody conjugates for selective detection of templates at micromolar concentrations. This approach can potentially provide a fast alternative to raising antibodies for targets that do not require high assay sensitivities; it can also find uses as a biochemical research tool, as a possible replacement for immunoperoxidase-conjugates.Here we introduce a new concept for synthesising molecularly imprinted nanoparticles by using proteins as macro-functional monomers. For a proof-of-concept, a model enzyme (HRP) was cross-linked using glutaraldehyde in the presence of glass beads (solid-phase) bearing immobilized templates such as vancomycin and ampicillin. The cross-linking process links together proteins and protein chains, which in the presence of templates leads to the formation of permanent target-specific recognition sites without adverse effects on the enzymatic activity. Unlike

  18. Polysilicon thin films fabricated by solid phase crystallization using reformed crystallization annealing technique

    International Nuclear Information System (INIS)

    In this work, a reformed crystallization annealing technique is presented for the solid phase crystallization (SPC) of amorphous silicon (a-Si) on SiNx-coated quartz substrate. This technique includes a two-step annealing process which consists of a low-temperature (475 °C) classical furnace annealing for nucleation of Si and a high-temperature (900 °C) grain growth process of polycrystalline silicon (poly-Si) during thermal annealing in classical tube furnace. The aim of this reformed two-step annealing technique is reducing the long (up to 48 h) crystallization annealing duration of single step annealing at low temperatures (∼ 600 °C) while maintaining the film quality, as low-temperature single step annealing, by using reformed technique. Continuous p-type poly-Si film was formed on quartz substrate thanks to exodiffusion of boron, which was deposited prior to a-Si, through Si film by thermal annealing. The stress and degree of crystallinity of the p-type poly-Si were studied by the micro-Raman Spectroscopy. The crystallization fraction value of 95% was deduced for annealed samples at 900 °C, independent from crystallization technique. On the other hand, the Raman analysis points out that compressive stress was induced by increasing the annealing duration at 900 °C. X-ray diffraction (XRD) analysis reveals that the preferred crystallite orientation of the films, independent from crystallization temperature and substrates, is <111>. Additionally, the average crystallite size calculated from XRD patterns increases from 69 Å to 165 Å by using reformed two-step annealing instead of single step annealing at 900 °C for 90 min. The exodiffusion of boron into the silicon film was deduced from secondary ion mass spectrometry (SIMS) analysis and the p+/p graded boron profile was obtained, which may result higher carrier diffusion length and longer carrier life time. Finally, the annealing duration dramatically decrease to 9 h by using reformed two-step annealing

  19. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV < 0.5 %. The intra-day and inter-day CVs are < 15 % for quality control samples with concentrations of 75, 300, 750 and 3000 pg/mL of scopolamine in human saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS

  20. Cheese is a reliable alternative meal for solid-phase gastric emptying study.

    Science.gov (United States)

    Drubach, Laura A; Kourmouzi, Vasiliki; Fahey, Frederic H

    2010-05-01

    We evaluated the labeling stability of several alternative meals that could be used to perform solid-phase gastric emptying study. Cooked egg whites labeled with technetium-99m sulfur colloid served as a control. Packaged instant oatmeal and instant mashed potatoes were prepared by adding hot water. Cheddar cheese was melted. Peanut butter was added to bread. The different meals were mixed with technetium-99m sulfur colloid (2.2-3.7 MBq), chopped into small pieces and placed in a glass tube containing gastric juice. Four samples of each meal were analyzed after 1 and 4 h of agitation with a 3-D rotator (two samples per time point). The meal samples were washed with 2 ml of saline and filtered using a blood transfusion filter. The activity in each sample before and after filtering was assayed in a dose calibrator. The percentage of initial radioactivity remaining with the meal of admixture with gastric juice was measured and the average of the two samples was taken. The percentage of activity bound to the solid phase was 98.2+/-1.9, 95.6+/-1.1, 62.1+/-1.7, 41.8+/-0.6, and 74.5+/-3.8% at 1 h and 98.5+/-1.0, 95.8+/-2.6, 77.2+/-6.8, 55.5+/-3.4 and 40.2+/-22.1 at 4 h for egg whites, cheese, oatmeal, mashed potatoes and peanut butter respectively. For egg whites and cheese, there was no significant difference between the values at 1 and 4 h (P>0.8). Cheddar cheese provides an alternative meal for assessing solid gastric emptying in children comparable to egg whites. Oatmeal and mashed potatoes had low and variable labeling stability and are not recommended. In view of the significant proportion of pediatric patients who refuse to eat scrambled eggs or have allergy to eggs, the availability of other meal choices is essential. The versatility of cheddar cheese, which can be added to macaroni or as a topping on pizza, makes it a useful alternative to labeled eggs. PMID:20145582

  1. Determination of Scopolamine in Human Saliva Using Solid Phase Extraction and LC/MS/MS

    Science.gov (United States)

    Wang, Zuwei; Vaksman, Zalman; Boyd, Jason; Putcha, Lakshmi

    2007-01-01

    Purpose: Scopolamine is the preferred treatment for motion sickness during space flight because of its quick onset of action, short half-life and favorable side-effect profile. The dose administered depends on the mode of administration and usually ranges between 0.1 and 0.8 mg. Such small doses make it difficult to detect concentrations of scopolamine in biological fluids by using conventional HPLC methods. To measure scopolamine in saliva and thereby to evaluate the pharmacokinetics of scopolamine, we developed an LC/MS/MS method using off-line solid phase extraction. Method: Samples (0.5mL) were loaded onto Waters Oasis HLB co-polymer cartridges (10 mg, 1 mL) and eluted with 0.5 mL methanol without evaporation and reconstitution. HPLC separation of the eluted sample was performed using an Agilent Zorbax SB-CN column (50 x 2.1 mm) at a flow rate of 0.2 mL/min for 4 minutes. The mobile phase for separation was 90:10 (v/v) methanol: ammonium acetate (2 mM) in water, pH 5.0 +/- 0.1. Concentrations of scopolamine were determined using a Micromass Quattro Micro(TM) mass spectrometer with electrospray ionization (ESI). ESI mass spectra were acquired in positive ion mode with multiple reaction monitoring for the determination of scopolamine m/z = 304.2 yields 138.1 and internal standard (IS) hyoscyamine m/z = 290.2 yields 124.1. Results: The method is rapid, reproducible, specific and has the following parameters: scopolamine and the IS are eluted at 1.7 and 3.2 min respectively. The linear range is 50-5000 pg/mL for scopolamine in saliva with correlation coefficients > 0.99 with a CV saliva. Conclusion: Solid phase extraction allows more rapid sample preparation and greater precision than liquid extraction. Furthermore, we increased the sensitivity and specificity by adjusting the LC mobile phase and using an MS/MS detector.

  2. Silica-titania xerogel for solid phase spectrophotometric determination of salicylate and its derivatives in biological liquids and pharmaceuticals

    OpenAIRE

    Morosanova, Maria A.; Morosanova, Elena I.

    2015-01-01

    Background Salicylic acid and its derivatives are widely used drugs with potential toxicity. The main areas of salicylate derivatives determination are biological liquids and pharmaceuticals analysis. Results Silica-titania xerogel has been used for solid phase spectrophotometric determination of various salicylate derivatives (salicylate, salicylamide, methylsalicylate). The reaction conditions influence on the interaction of salicylate derivatives with silica-titania xerogels has been inves...

  3. Use of molecularly imprinted solid-phase extraction for the selective clean-up of clenbuterol from calf urine

    NARCIS (Netherlands)

    Berggren, C; Bayoudh, S; Sherrington, D; Ensing, K

    2000-01-01

    A feasibility study was performed in order to study the possibilities in using molecularly imprinted polymers (MIPs) as sorbent material in solid-phase extraction (MISPE) for clean-up of clenbuterol from urine. A binding study of clenbuterol in several solvents was performed on a clenbuterol imprint

  4. Solid-phase synthesis and structural characterization of highly substituted hydroxyproline-based 2,5-diketopiperazines

    DEFF Research Database (Denmark)

    Bianco; Sonksen; Roepstorff;

    2000-01-01

    Two general solid-phase methods for the synthesis of a new class of 2,5-diketopiperazines (DKPs) containing the trans-4-hydroxy-L-proline amino acid residue (Hyp) have been developed. An N-protected hydroxyproline methyl ester was linked through the hydroxyl function to the Ellman resin. The synt...

  5. Combinatorial Solid-Phase Synthesis of Aromatic Oligoamides: A Research-Based Laboratory Module for Undergraduate Organic Chemistry

    Science.gov (United States)

    Fuller, Amelia A.

    2016-01-01

    A five-week, research-based experiment suitable for second-semester introductory organic laboratory students is described. Each student designs, prepares, and analyzes a combinatorial array of six aromatic oligoamides. Molecules are prepared on solid phase via a six-step synthetic sequence, and purities and identities are determined by analysis of…

  6. On the Effect of the Amorphous Silicon Microstructure on the Grain Size of Solid Phase Crystallized Polycrystalline Silicon

    NARCIS (Netherlands)

    Sharma, K.; Branca, A.; Illiberi, A.; Tichelaar, F. D.; Creatore, M.; M. C. M. van de Sanden,

    2011-01-01

    In this paper the effect of the microstructure of remote plasma-deposited amorphous silicon films on the grain size development in polycrystalline silicon upon solid-phase crystallization is reported. The hydrogenated amorphous silicon films are deposited at different microstructure parameter values

  7. Preparation of peptide thioesters through fmoc-based solid-phase peptide synthesis by using amino thioesters

    DEFF Research Database (Denmark)

    Stuhr-Hansen, N.; Wilbek, T.S.; Strømgaard, K.

    2013-01-01

    An effective procedure for the synthesis of peptide alkyl thioesters by 9-fluorenylmethoxycarbonyl (Fmoc) solid-phase peptide synthesis was developed. The free C terminus of a fully protected peptide was coupled in solution with the free amino group of an amino thioester. This furnished the fully...

  8. Solid-Phase Organic Chemistry: Synthesis of 2β-(HeterocyclylthiomethylPenam Derivatives on Solid Support

    Directory of Open Access Journals (Sweden)

    Ernesto G. Mata

    2000-03-01

    Full Text Available The synthesis of 2β-(heterocyclylthiomethylpenam derivatives on solid support has been developed. Compounds are obtained in good to high yields (based on loading of the original resin. The key step is the solid-phase double rearrangement of the corresponding penicillin sulfoxide.

  9. Rapid staining and enumeration of small numbers of total bacteria in water by solid-phase laser cytometry

    Science.gov (United States)

    Broadaway, Susan C.; Barton, Stephanie A.; Pyle, Barry H.

    2003-01-01

    The nucleic acid stain SYBR Green I was evaluated for use with solid-phase laser cytometry to obtain total bacterial cell counts from several water sources with small bacterial numbers. Results were obtained within 30 min and exceeded or equaled counts on R2A agar plates incubated for 14 days at room temperature.

  10. On-fiber derivatization for direct immersion solid-phase microextraction Part I : Acylation of amphetamine with pentafluorobenzoyl chloride

    NARCIS (Netherlands)

    Koster, EHM; Bruins, CHP; Wemes, C; de Jong, GJ

    2001-01-01

    On-fiber derivatization has been used for solid-phase microextraction (SPME) with gas chromatography in order to increase the extractability and detectability. Amphetamine, which has been used as a model compound, was derivatized with pentafluorobenzoyl chloride that was loaded on the fiber prior to

  11. Solid Phase Synthesis of 1, 4-Disubstituted 1, 2, 3-Triazole from Polystyrene-supported Selenium Resin

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; Lu Ling WU; Xian HUANG

    2006-01-01

    We report here a solid-phase synthesis of 1, 4-disubstituted 1, 2, 3-triazole using polystyrene-supported selenium resin. The resin used here not only works as a simple linker, but also assists the crucial α-alkylation reaction and selenoxide syn-elimination, which ensures the purity of the products.

  12. Dissolved and solid-phase arsenic fate in an arsenic-enriched aquifer in the river Brahmaputra alluvial plain.

    Science.gov (United States)

    Baviskar, Shirishkumar; Choudhury, Runti; Mahanta, Chandan

    2015-03-01

    Dissolved arsenic mobility in the environment is controlled by its associations with solid-phase As and other minerals by chemodynamics of adsorptions and co-precipitation. Arsenic mobilization potential and mechanisms in the groundwater of a part of the river Brahmaputra alluvial plain in India were inferred from aqueous and solid-phase geochemical analyses of groundwater samples and sediment cores from various depths. Sediments were analyzed for key parameters, e.g., total and sequentially extracted Fe, As, and Mn; organic carbon content; carbonate phases; and specific surface area, while groundwater samples collected from close proximity of the drilled bore well were analyzed for major and trace element hydrogeochemistry. Result shows Mn- and Fe-oxyhydroxides as the major leachable As solid phases. Median total leachable solid-phase As was found to be ~9.50 mg/kg, while groundwater As ranged between 0.05 and 0.44 mg/L from adjoining water wells. Morphological and mineralogical studies of the aquifer sediments conducted using scanning electronic microscope energy-dispersive X-ray (SEM-EDX) and X-ray diffraction (XRD) analysis indicate the major presence of Fe- and Mn-oxyhydroxides. Sequential leaching experiments along with the mineralogical studies suggest that bacterially mediated, reductive dissolution of MnOOH and FeOOH is probably an important mechanism for releasing As into the groundwater from the sediments. PMID:25663398

  13. Novel restricted access materials combined to molecularly imprinted polymers for selective solid-phase extraction of organophosphorus pesticides from honey.

    Science.gov (United States)

    He, Juan; Song, Lixin; Chen, Si; Li, Yuanyuan; Wei, Hongliang; Zhao, Dongxin; Gu, Keren; Zhang, Shusheng

    2015-11-15

    A novel restricted access materials (RAM) combined to molecularly imprinted polymers (MIPs), using malathion as template molecule and glycidilmethacrylate (GMA) as pro-hydrophilic co-monomer, were prepared for the first time. RAM-MIPs with hydrophilic external layer were characterized by scanning electron microscopy and recognition and selectivity properties were compared with the restricted access materials-non-molecularly imprinted polymers (RAM-NIPs) and unmodified MIPs. RAM-MIPs were used as the adsorbent enclosed in solid phase extraction column and several important extraction parameters were comprehensively optimized to evaluate the extraction performance. Under the optimum extraction conditions, RAM-MIPs exhibited comparable or even higher selectivity with greater extraction capacity toward six kinds of organophosphorus pesticides (including malathion, ethoprophos, phorate, terbufos, dimethoate, and fenamiphos) compared with the MIPs and commercial solid phase extraction columns. The RAM-MIPs solid phase extraction coupled with gas chromatography was successfully applied to simultaneously determine six kinds of organophosphorus pesticides from honey sample. The new established method showed good linearity in the range of 0.01-1.0 μg mL(-1), low limits of detection (0.0005-0.0019 μg mL(-1)), acceptable reproducibility (RSD, 2.26-4.81%, n = 6), and satisfactory relative recoveries (90.9-97.6%). It was demonstrated that RAM-MIPs solid phase extraction with excellent selectivity and restricted access function was a simple, rapid, selective, and effective sample pretreatment method.

  14. Sensing dissolved sediment porewater concentrations of persistent and bioaccumulative poolutants using disposable solid-phase microextraction fibers

    NARCIS (Netherlands)

    Mayer, P.; Vaes, W.H.J.; Wijnker, F.; Legierse, K.C.H.M.; Kraaij, R.H.; Tolls, J.; Hermens, J.L.M.

    2000-01-01

    Polymer coated glass fibers were applied as disposable samplers to measure dissolved concentrations of persistent and bioaccumulative pollutants (PBPs) in sediment porewater. The method is called matrix solid-phase microextraction (matrix-SPME), because it utilizes the entire sediment matrix as a re

  15. Experimental Method Development for Estimating Solid-phase Diffusion Coefficients and Material/Air Partition Coefficients of SVOCs

    Science.gov (United States)

    The solid-phase diffusion coefficient (Dm) and material-air partition coefficient (Kma) are key parameters for characterizing the sources and transport of semivolatile organic compounds (SVOCs) in the indoor environment. In this work, a new experimental method was developed to es...

  16. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencin of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune F. L.; Mutenda, Kudzai E.;

    2006-01-01

    were produced in excellent purity (>95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  17. Fractionation, solid-phase immobilization and chemical degradation of long pectin oligogalacturonides. Initial steps towards sequencing of oligosaccharides

    DEFF Research Database (Denmark)

    Guillaumie, Fanny; Justesen, Sune Frederik Lamdahl; Mutenda, K.E.;

    2006-01-01

    were produced in excellent purity (> 95%). Elution of OGAs followed by direct analysis of the peak fractions by MALDI-TOF MS. Purified OGAs (DP 5-7) were chemoselectively immobilized onto aminooxy-terminated polyethylene glycol polyacrylamide (PEGA) supports. Solid-phase anchoring took place...

  18. Determination of hydrazine in drinking water: Development and multivariate optimization of a rapid and simple solid phase microextraction-gas chromatography-triple quadrupole mass spectrometry protocol.

    Science.gov (United States)

    Gionfriddo, Emanuela; Naccarato, Attilio; Sindona, Giovanni; Tagarelli, Antonio

    2014-07-01

    In this work, the capabilities of solid phase microextraction were exploited in a fully optimized SPME-GC-QqQ-MS analytical approach for hydrazine assay. A rapid and easy method was obtained by a simple derivatization reaction with propyl chloroformate and pyridine carried out directly in water samples, followed by automated SPME analysis in the same vial without further sample handling. The affinity of the different derivatized compounds obtained towards five commercially available SPME coatings was evaluated, in order to achieve the best extraction efficiency. GC analyses were carried out using a GC-QqQ-MS instrument in selected reaction monitoring (SRM) acquisition mode which has allowed the achievement of high specificity by selecting appropriate precursor-product ion couples improving the capability in analyte identification. The multivariate approach of experimental design was crucial in order to optimize derivatization reaction, SPME process and tandem mass spectrometry parameters. Accuracy of the proposed protocol, tested at 60, 200 and 800 ng L(-1), provided satisfactory values (114.2%, 83.6% and 98.6%, respectively), whereas precision (RSD%) at the same concentration levels were of 10.9%, 7.9% and 7.7% respectively. Limit of detection and quantification of 4.4 and 8.3 ng L(-1) were obtained. The reliable application of the proposed protocol to real drinking water samples confirmed its capability to be used as analytical tool for routine analyses.

  19. Polysiloxane/PVA-glutaraldehyde hybrid composite as solid phase for immunodetections by ELISA

    Directory of Open Access Journals (Sweden)

    A.E. Lima Barros

    2002-04-01

    Full Text Available We developed an efficient method to prepare a hybrid inorganic-organic composite based on polyvinyl alcohol (PVA and polysiloxane using the sol-gel disc technique. Antigen obtained from Yersinia pestis was covalently immobilized onto these discs with glutaraldehyde and used as solid phase in ELISA for antibody detection in serum of rabbits experimentally immunized with plague. Using 1.25 µg antigen per disc, a peroxidase conjugate dilution of 1:4,000 and a serum dilution of 1:200 were adequate for the establishment of the procedure. These values are similar to those used for PVA-glutaraldehyde discs, plasticized filter paper discs and the polyaniline-Dacron composite discs. This procedure is comparable to that which utilizes the adsorption of the antigen to conventional PVC plates, with the amount of antigen being one fourth that employed in conventional PVC plates (5 µg/well. In addition to the performance of the polysiloxane/PVA-glutaraldehyde disc as a matrix for immunodetection, its easy synthesis and low cost are additional advantages for commercial application.

  20. Solid phase microextraction for profiling volatile compounds in liquered white wines

    Directory of Open Access Journals (Sweden)

    Henryk H. Jeleń

    2010-03-01

    Full Text Available Background. Profile of volatile compounds is a distinct feature of wine, which is dependent on the type of wine, grapes, fermentation and ageing processes. Profiling volatile compounds in wine using fast method provides information on major groups of compounds and can be used for classification/differentiation purposes. Solid phase microextraction (SPME was used for the profiling of volatile compounds in liquered white wines in this study. Material and methods. Different fibers were tested for this purpose: PDMS, Carboxene/ PDMS, Carboxene/DVB/PDMS, Polyacrylate, Divinylbenzene/PDMS. Different times were compared to optimize extraction process. Profile and amount of volatile compounds extracted by SPME fiber was compared for eight liquered white wines. Results. Carboxene/DVB/PDMS showed the highest efficiency in extracting higher alcohols, esters, carbonyls and terpenes. Of tested extraction times ranging from 5 to 30 min. 20 minutes was chosen providing sufficient peak responses. Using SPME total amount of volatile compounds in eight liquered wines was compared – Riversaltes, Offley Porto and Jutrzenka having the highest amount of adsorbed volatiles. Profiles of volatiles of analysed wines revealed that dominating compounds in 6 wines were esters, followed by higher alcohols, two analysed Muscat wines had high terpene contents compared to remaining wines. Conclusion. SPME can be used for relatively fast profiling of wine volatiles, that can be used for wines classification.  

  1. A numerical investigation into the solids phase chromatography using a combined continuous and discrete approach

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    Solids phase chromatography for particle classification is based on different retention times of particles with different properties when they are elutriated through a confined geometry.This work aims at a fundamental understanding of such a technology by using the combined continuous and discrete method.A packed bed is employed as the model confined geometry.The numerical method is compared first with experimental observations,followed by a parametric analysis of the effects on the flow hydrodynamics and solids behaviour of various parameters including the number of injected particles,the superficial gas velocity,the contact stiffness and the diameter ratio of the packed column to the packed particles.The results show that the modelling captures some important features of the flow of an injected pulse of fine particles in a packed bed. An increase in the number of injected particles or the superficial gas velocity reduces the retention time,whereas the contact stiffness does not show much effect over the range of 5×102 to5×104 N/m.It is also found that the effect on the retention time of the diameter ratio of the packed column to the packed particles seems complex showing a non-monotonous dependence.

  2. Germanium ion implantation to Improve Crystallinity during Solid Phase Epitaxy and the effect of AMU Contamination

    Science.gov (United States)

    Lee, K. S.; Yoo, D. H.; Son, G. H.; Lee, C. H.; Noh, J. H.; Han, J. J.; Yu, Y. S.; Hyung, Y. W.; Yang, J. K.; Song, D. G.; Lim, T. J.; Kim, Y. K.; Lee, S. C.; Lee, H. D.; Moon, J. T.

    2006-11-01

    Germanium ion implantation was investigated for crystallinity enhancement during solid phase epitaxial regrowth (SPE) using high current implantation equipment. Electron back-scatter diffraction(EBSD) measurement showed numerical increase of 19 percent of signal, which might be due to pre-amorphization effect on silicon layer deposited by LPCVD process with germanium ion implantation. On the other hand, electrical property such as off-leakage current of NMOS transistor degraded in specific regions of wafers, which implied non-uniform distribution of donor-type impurities into channel area. It was confirmed that arsenic atoms were incorporated into silicon layer during germanium ion implantation. Since the equipment for germanium pre-amorphization implantation(PAI) was using several source gases such as BF3 and AsH3, atomic mass unit(AMU) contamination during PAI of germanium with AMU 74 caused the incorporation of arsenic with AMU 75 which resided in arc-chamber and other parts of the equipment. It was effective to use germanium isotope of AMU 72 to suppress AMU contamination, however it led serious reduction of productivity because of decrease in beam current by 30 percent as known to be difference in isotope abundance. It was effective to use enriched germanium source gas with AMU 72 in order to improve productivity. Spatial distribution of arsenic impurities in wafers was closely related to hardware configuration of ion implantation equipment.

  3. Determination of Trichloroethylene in Water by Liquid–Liquid Microextraction Assisted Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Mengliang Zhang

    2015-02-01

    Full Text Available A method for the determination of trichloroethylene (TCE in water using portable gas chromatography/mass spectrometry (GC/MS was developed. A novel sample preparation method, liquid–liquid microextraction assisted solid phase microextraction (LLME–SPME, is introduced. In this method, 20 µL of hexane was added to 10 mL of TCE contaminated aqueous samples to assist headspace SPME. The extraction efficiency of SPME was significantly improved with the addition of minute amounts of organic solvents (i.e., 20 µL hexane. The absolute recoveries of TCE at different concentrations were increased from 11%–17% for the samples extracted by SPME to 29%–41% for the samples extracted by LLME–SPME. The method was demonstrated to be linear from 10 to 1000 ng mL−1 for TCE in water. The improvements on extraction efficiencies were also observed for toluene and 1, 2, 4-trichlorobenzene in water by using LLME–SPME method. The LLME–SPME method was optimized by using response surface modeling (RSM.

  4. Solid-phase extraction of antioxidant compounds from commercial cranberry extract and its antiradical activity

    Directory of Open Access Journals (Sweden)

    Tumbas Vesna T.

    2007-01-01

    Full Text Available This study is concerned with the fractionation and determination of major antioxidant compounds (phenols, flavonoids, anthocyanins and vitamin C in commercial cranberry extract. The total content of phenolics, flavonoids and total and monomers of anthocyanins, determined spectrophotometrically, was 1.67 mg/g, 0.41 mg/g, 5.12 mg/g and 3.32 mg/g. The content of vitamin C, determined volumetrically, was 121.74 mg/g. Commercial cranberry extract was dissolved in 80 % acetone and the solution was fractionated using solid phase extraction (SPE in order to abstract vitamin C, neutral and acidic phenols. The free radical scavenging activity of the cranberry extract and its fractions was investigated on stable 2,2-diphenyl-1-picrylhydrazyl (DPPH and reactive hydroxyl radicals employing electron spin resonance (ESR spectroscopy. The most effective fractions were those containing vitamin C (AADPPH= AAOH=100%, neutral (AADPPH=89.50% and AAOH=43.11% and acidic (AADPPH=83.98% and AAOH=38.58% phenols. The presence of vitamin C, abstracted from cranberry extract, was determined by Fe(III-mediated ascorbate oxidation which yields characteristic ESR doublet spectrum of ascorbyl radical.

  5. A solid-phase extraction approach for the identification of pharmaceutical-sludge adsorption mechanisms

    Institute of Scientific and Technical Information of China (English)

    Laurence Berthod; Gary Roberts; Graham A. Mills

    2014-01-01

    It is important to understand the adsorption mechanism of chemicals and active pharmaceu-tical ingredients (API) on sewage sludge since wastewater treatment plants are the last barrier before the release of these compounds to the environment. Adsorption models were developed considering mostly hydrophobic API-sludge interaction. They have poor predictive ability, especially with ionisable compounds. This work proposes a solid-phase extraction (SPE) approach to estimate rapidly the API-sludge interaction. Sludge-filled SPE cartridges could not be percolated with API spiked mobile phases so different powders were tested as SPE sludge supports. Polytetrafluoroethylene (PTFE) was selected and tested at different PTFE/sludge ratios under eight different adsorption conditions with three API ionisable compounds. The PTFE/sludge mixtures with 50% or less sludge could be used in SPE mode for API sorption studies with methanol/water liquid phases. The results gave insights into API-sludge interactions. It was found that π-π, hydrogen-bonding and charge-charge interactions were as important as hydrophobicity in the adsorption mechanism of charged APIs on sludge.

  6. Advanced Si solid phase crystallization for vertical channel in vertical NANDs

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangsoo [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Son, Yong-Hoon [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung 445-701 (Korea, Republic of); Hwang, Kihyun; Shin, Yoo Gyun [Semiconductor R and D Center, Samsung Electronics Co., Ltd., Hwasung 445-701 (Korea, Republic of); Yoon, Euijoon, E-mail: eyoon@snu.ac.kr [Department of Materials Science and Engineering and Inter-university Semiconductor Research Center, Seoul National University, Seoul 151-742 (Korea, Republic of); Energy Semiconductor Research Center, Advanced Institutes of Convergence Technology, Seoul National University, Suwon 443-270 (Korea, Republic of)

    2014-07-01

    The advanced solid phase crystallization (SPC) method using the SiGe/Si bi-layer structure is proposed to obtain high-mobility poly-Si thin-film transistors in next generation vertical NAND (VNAND) devices. During the SPC process, the top SiGe thin film acts as a selective nucleation layer to induce surface nucleation and equiaxial microstructure. Subsequently, this SiGe thin film microstructure is propagated to the underlying Si thin film by epitaxy-like growth. The initial nucleation at the SiGe surface was clearly observed by in situ transmission electron microscopy (TEM) when heating up to 600 °C. The equiaxial microstructures of both SiGe nucleation and Si channel layers were shown in the crystallized bi-layer plan-view TEM measurements. Based on these experimental results, the large-grained and less-defective Si microstructure is expected to form near the channel region of each VNAND cell transistor, which may improve the electrical characteristics.

  7. Organic acids and inorganic anions in Bayer liquors by ion chromatography after solid-phase extraction

    Institute of Scientific and Technical Information of China (English)

    ZHONG Fu-jin; CHEN Xiao-qing; ZHANG Shu-chao; LI Yue-ping

    2007-01-01

    A method for the simultaneous separation and determination of organic acids and inorganic anions in Bayer liquors was developed by gradient ion chromatography with suppressed conductivity detection. Formate, acetate, propionate, oxalate, succinate,glutarate, fluoride, chloride and sulfate were separated and determined in 33 min. The samples were pretreated with solid-phase extraction, which has high selectivity for removing a large number of metallic ions in the Bayer liquors, and filtered with a 0.45 μm filter membrane before being injected into the ion chromatographic system. The separation of six organic acids and three inorganic anions was achieved on an IonPac AS11-HC column with KOH as the eluent, and the detection was performed by a conductivity detection mode. No interference is found in the presence of fluorate, chlorate and sulphate when organic acids are determined. The calibration graphs of peak area for all the analytes are linear over a wide range. The relative standard derivation of the peak area of analytes is less than 2.14%. Under optimum conditions the detection ranges from 0.2 to 100.0 mg/L. The average recoveries of the added standards are between 94.3% and 102.8%.

  8. Case report: solid-phase platelet crossmatching to support the alloimmunized patient.

    Science.gov (United States)

    O'Connell, B A

    1995-01-01

    Platelet crossmatching by a solid-phase red cell adherence assay was used to provide compatible platelets for two alloimmunized patients with leukemia. In this study, a successful platelet transfusion was defined as giving a corrected count increment (CCI) of >7,500 in a posttransfusion sample. For patient A, a total of 205 random platelet concentrates (PCs) were crossmatched. Eleven were considered compatible. These 11 PCs were transfused during five transfusion episodes. Four of the five transfusions produced CCIs of >7,500 and were considered successful. Individually, eight of the eleven units were considered in vivo compatible, and five of the eight donors of these units agreed to become apheresis donors. Platelets from three of these five apheresis donors gave CCIs of >7,500. For patient B, 1,074 random PCs were crossmatched, and 332 were considered compatible. These units were administered during 78 different transfusions. Seventy-one of these transfusion episodes resulted in CCIs of >7,500. In addition, 19 apheresis donors were identified by platelet crossmatching, and they provided platelets for 38 of 39 successful transfusions for Patient B. Platelet crossmatching should therefore be considered when a blood bank is called upon to support a refractory thrombocytopenic patient.

  9. CMOS-compatible method for doping of buried vertical polysilicon structures by solid phase diffusion

    Science.gov (United States)

    Turkulets, Yury; Silber, Amir; Ripp, Alexander; Sokolovsky, Mark; Shalish, Ilan

    2016-03-01

    Polysilicon receives attention nowadays as a means to incorporate 3D-structured photonic devices into silicon processes. However, doping of buried layers of a typical 3D structure has been a challenge. We present a method for doping of buried polysilicon layers by solid phase diffusion. Using an underlying silicon oxide layer as a dopant source facilitates diffusion of dopants into the bottom side of the polysilicon layer. The polysilicon is grown on top of the oxide layer, after the latter has been doped by ion implantation. Post-growth heat treatment drives in the dopant from the oxide into the polysilicon. To model the process, we studied the diffusion of the two most common silicon dopants, boron (B) and phosphorus (P), using secondary ion mass spectroscopy profiles. Our results show that shallow concentration profiles can be achieved in a buried polysilicon layer using the proposed technique. We present a quantitative 3D model for the diffusion of B and P in polysilicon, which turns the proposed method into an engineerable technique.

  10. Analysis of lignocellulose derived phenolic monomers by headspace solid-phase microextraction and gas chromatography.

    Science.gov (United States)

    Kolb, Michaela; Schieder, Doris; Faulstich, Martin; Sieber, Volker

    2013-09-13

    A headspace solid-phase microextraction method with subsequent GC-MS (HS-SPME/GC-MS) was established for the quantitative analysis of volatile lignin derived phenolic monomers in complex aqueous solutions. Extraction was done using a polyacrylate fiber. The optimization of HS-SPME - parameters was performed using a multi component model solution of six representative phenolic monomers identified in liquid hot water (LHW) supernatants of hydrothermally treated lignocellulosic biomass: p-coumaric acid, guaiacol, vanillin, acetosyringone, 4-hydroxy-3-methoxyphenylacetone, and acetophenone. Plackett-Burman design was applied for pre-evaluation and 2(3) central composite designs with star points for parameter optimization. LOQ (S/N>10) and LOD (S/N>3) were determined for 12 phenols yielding LOQ of <0.005-618nM and LOD of <0.005-412nM. Within-day and between-day tests (n=6) showed different results for the tested phenols. RSD ranged from 2% to 30% and recovery rates from 99% to 160% in LHW matrix. Tests on storage of LHW supernatants for several weeks indicated a considerable influence of temperature on the stability of the solutions which may even have to be taken into account for auto sampler handling. All in all the method allows a fast and solvent free analysis requiring low sample volumes making it a powerful tool for screening or high-throughput analysis of aqueous solutions of lignin derived aromatics.

  11. Epitaxially grown polycrystalline silicon thin-film solar cells on solid-phase crystallised seed layers

    Science.gov (United States)

    Li, Wei; Varlamov, Sergey; Xue, Chaowei

    2014-09-01

    This paper presents the fabrication of poly-Si thin film solar cells on glass substrates using seed layer approach. The solid-phase crystallised P-doped seed layer is not only used as the crystalline template for the epitaxial growth but also as the emitter for the solar cell structure. This paper investigates two important factors, surface cleaning and intragrain defects elimination for the seed layer, which can greatly influence the epitaxial grown solar cell performance. Shorter incubation and crystallisation time is observed using a simplified RCA cleaning than the other two wet chemical cleaning methods, indicating a cleaner seed layer surface is achieved. Cross sectional transmission microscope images confirm a crystallographic transferal of information from the simplified RCA cleaned seed layer into the epi-layer. RTA for the SPC seed layer can effectively eliminate the intragrain defects in the seed layer and improve structural quality of both of the seed layer and the epi-layer. Consequently, epitaxial grown poly-Si solar cell on the RTA treated seed layer shows better solar cell efficiency, Voc and Jsc than the one on the seed layer without RTA treatment.

  12. Determination of terpenes in tequila by solid phase microextraction-gas chromatography-mass spectrometry.

    Science.gov (United States)

    Peña-Alvarez, Araceli; Capella, Santiago; Juárez, Rocío; Labastida, Carmen

    2006-11-17

    Solid phase microextraction and capillary gas chromatography-mass spectrometry were used for the determination of seven terpenes in tequila. The method was selected based on the following parameters: coating selection (PA, PDMS, CW/DVB, and PDMS/DVB), extraction temperature, addition of salt, and extraction time profile. The extraction conditions were: PDMS/DVB fiber, Headspace, 100% NaCl, 25 degrees C extraction temperature, 30 min extraction time and stirring at 1200 rpm. The calibration curves (50-1000 ng/ml) for the terpenes followed linear relationships with correlation coefficients (r) greater than 0.99, except for trans,trans-farnesol (r = 0.98). RSD values were smaller than 10% confirmed that the technique was precise. Samples from 18 different trade brands of "Aged" tequila analyzed with the developed method showed the same terpenes in different concentrations. The analytical procedure used is selective, robust (more than 100 analyses with the same fiber), fast and of low-cost.

  13. Determination of Metamizole Sodium and Chlorphenamine Maleate in Zhongganling Tablets by Solid-Phase Extracting HPLC

    Institute of Scientific and Technical Information of China (English)

    HANG Yiying; ZHU Binghui; LU Huiwen; YU Jinxiong; DEN Zhihua

    2002-01-01

    Objective To establish a method for the determination of metamizole sodium and chlorphenamine maleate in Zhongganling tablets. Methods The sample was determined by ion - pair HPLC after it was purified on Sep- Pak C18 microcolumn. The chromatographic conditions included: Hypersil DBS C18 chromatographic column(250mm × 4.6mm, i.d. 5μm) as an analytical column, methanolmixed solution of sodium heptanesulfonate and glacial acetic acid(600:400) as a mobile phase, the demetamizole sodium and chlorphenamine malcate were 99.6% (RSD was 2.1% and n was 6) and 98.0%(RSD was 1.5% and n was 6), respectively. Conclusion Metamizole sodium and chlorphenamine malcate can be determined respectively by HPLC with the same mobile phase when Sep - Pak C18 microcolumn solid- phase extraction method is used to substitute for the traditional sample pretreatment methods - refluxing, extracting and concentrating, and sodim heptanesulfonate ion - pair reagent in acid condition is selected.

  14. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Science.gov (United States)

    Yu, Honglian; Merib, Josias; Anderson, Jared L

    2016-03-18

    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively. PMID:26896916

  15. Numerical studies of integrated concrete with a solid-solid phase change material

    Energy Technology Data Exchange (ETDEWEB)

    Zhang, D.; Fung, A.S.; Siddiqui, O. [Ryerson Polytechnic Univ., Toronto, ON (Canada). Dept. of Mechanical and Industrial Engineering

    2007-07-01

    The thermal storage performance of concrete cement integrated with a hypothetical solid-solid phase change material (PCM) was investigated. The thermal storage material was exposed to solar radiation on a sunny winter day in Toronto. The effects of weight ratio of PCM to cement and the thickness of cement were studied. The integrated PCM cement compound was treated as a homogenous mixture with uniform physical and thermal properties. Finite element modelling (FEM) was used to determine the effective heat capacity method. Governing equations for the heat transfer process in the solid-liquid PCMs included Navier-Stokes equations; mass conservation equations; and the energy conservation equation. The energy equation was the only governing equation for the binary solid state PCMs. The enthalpy method was used to apply governing equations of PCMs over the whole fixed domain of interest. The total energy required for the phase change was determined using the enthalpy function. The simulations showed that PCMs can reduce the fluctuation of temperature. Temperature fluctuations on the upper surface varied mainly in amplitude and in time phase due to thermal storage effects. The total amount of solar gain increased when the PCM ratio increased. However, the effect of the PCM ratio on the amount of released energy became less apparent when the thickness of the PCM was increased. It was concluded that a 30 per cent PCM ratio contributed the maximum overall released energy after the radiation gain vanished. 8 refs., 3 tabs., 11 figs.

  16. Hierarchical Graphene coating for highly sensitive solid phase microextraction of organochlorine pesticides.

    Science.gov (United States)

    Wang, Fuxin; Liu, Shuqin; Yang, Hao; Zheng, Juan; Qiu, Junlang; Xu, Jianqiao; Tong, Yexiang; Zhu, Fang; Ouyang, Gangfeng

    2016-11-01

    Graphene, a novel class of carbon nanostructures, has received great attention as sorbents due to its fascinating structures, ultrahigh specific surface area, and good extraction ability. In this paper, a new type of hierarchical graphene was synthesized through employing a mild and environment-friendly method. Such 3D interconnected graphene own a high specific surface area up to 524m(2)g(-1), which is about 2.5 fold larger than the graphene, since the synthetic material has interlayer pores between nanosheets and in-plane pores. Then a superior solid-phase microextraction fiber was fabricated by sequentially coating the stainless steel fiber with silicone sealant film and hierarchical graphene powder. Since the novel hierarchical graphene possessed large surface area and good adsorption property, the as-prepared fiber exhibited good extraction properties of the organochlorine pesticides (OCPs). As for the analytical performance, the as-prepared fiber achieved low detection limits (0.08-0.80ngL(-1)) and wide linearity (10-30,000ngL(-1)) under the optimal conditions. The repeatability (n=5) for single fiber were between 5.1% and 11%, while the reproducibility (n=3) of fiber-to-fiber were range from 6.2% to14%. Moreover, the fiber was successfully applied to the analysis of OCPs in the Pearl River water. PMID:27591607

  17. Application of solid-phase extraction for determination of phenolic compounds in barrique wines.

    Science.gov (United States)

    Matejícek, D; Klejdus, B; Mikes, O; Sterbová, D; Kubán, V

    2003-09-01

    A fast, selective and sensitive chromatographic method has been developed for determination of gallic, protocatechuic, p-hydroxybenzoic, vanillic, caffeic, syringic, p-coumaric, benzoic, ferulic, sinapic, cinnamic, and ellagic acids and p-hydroxybenzaldehyde, vanillin, syringaldehyde, 2-furfural, 5-methylfurfural, and 5-methoxyfurfural. The compounds from untreated wine samples were pre-concentrated and cleaned using solid-phase extraction on RP-105 polymeric sorbent. The cartridge was conditioned with methanol and water. Co-extracted ballast substances were rinsed from the sorbent with 0.1 mol L(-1) hydrochloric acid-methanol, 1:4 (v/ v). Retained phenolic compounds were selectively eluted with diethyl ether. A linear mobile phase gradient containing 0.3% acetic acid and methanol was used for final baseline chromatographic separation on a Hypersil BDS C18 column. Limits of detection (LOD=3 s(bl)) in the range 5.2 to 181.2 microg L(-1), resolution (R) better than 1.7, and repeatability of 2.7-5.1% (RSD for real samples) were achieved. The method was applied for quantification of individual phenolic compounds in barrique wines. PMID:12923605

  18. Determination of Three Tanshinones from Radix Salvia Miltiorrhiza by Molecularly Imprinted Solid-phase Extraction

    Institute of Scientific and Technical Information of China (English)

    YAN, Hongyuan; TIAN, Minglei; ROW, Kyung Ho

    2009-01-01

    A selective molecularly imprinted solid-phase extraction procedure was developed for the selective separation of tanshinone Ⅰ, tanshinone ⅡA, and cryptotanshinone from Radix Salvia Miltiorrhiza samples. Tanshinone ⅡA imprinted polymers (MIP) synthesized in ethanol-dodecanol system show high affinity to tanshinone ⅡA and its structure analogs in aqueous environment and the affinity can be controlled by adjusting the intensity of the eluents. By using 60% water-40% methanol (volume ratio) and 99.5% methanol-0.5% trifluoroacetic acid (volume ratio) as washing and eluting solvents, most interferences originating from the salvia matrix were eliminated. The extracts were sufficiently clean enough to be directly injected into HPLC for further chromatographic analysis. Good linearity was obtained from 0.4 to 500.0 mg·L~(-1) (r~2=0.999) with the relative standard deviations less than 4.2%. The mean recoveries of tanshinone ⅡA in Radix Salvia Miltiorrhiza were more than 85.6% at three different concentrations and the limits of detection were 0.06-0.09 mg·L~(-1). This method is a viable alternative tool to the existing HPLC methods for analyzing the content of the three tanshinones in Radix Salvia Miltiorrhiza samples.

  19. Solid-phase microextraction to determine micropollutant-macromolecule partition coefficients.

    Science.gov (United States)

    Bridle, Helen L; Heringa, Minne B; Schäfer, Andrea I

    2016-08-01

    Aqueous micropollutants such as estradiol can have a large environmental impact-even at low concentrations. Part of understanding this impact involves determining the extent to which the micropollutants interact with macromolecules in water. In environmental samples, relevant macromolecules to which micropollutants bind are referred to as dissolved organic matter, and the most common examples of these in freshwater and coastal seawater are fulvic and humic acids. In living organisms, the most common macromolecules that affect bioavailability of a drug (or toxin) are proteins such as albumin. Using [2, 4, 6, 7 - (3)H]estradiol as an example compound, this protocol uses solid-phase microextraction and scintillation detection as analytical tools to quantify the amount of radiolabeled micropollutant available in solution. The measured free concentration after exposure to various concentrations of macromolecule (dissolved organic matter or protein) or micropollutant is used to determine the partition coefficient in the case of micropollutant-macromolecule interactions. The calibration and preparatory studies take at least 8 d, and the steps to determine the partition coefficient can be completed within 3 d. The protocol could be modified such that nonlabeled compounds are studied; instead of detection of activity by a liquid scintillation counter (LSC), the compounds can be quantified using gas chromatography-mass spectrometry (GC-MS) or liquid chromatography (LC)-MS(/MS). PMID:27362336

  20. Cholesterol transport via ABCA1: new insights from solid-phase binding assay.

    Science.gov (United States)

    Reboul, Emmanuelle; Dyka, Frank M; Quazi, Faraz; Molday, Robert S

    2013-04-01

    It is now well established that the ATP-binding cassette transporter A1 (ABCA1) plays a pivotal role in HDL metabolism, reverse cholesterol transport and net efflux of cellular cholesterol and phospholipids. We aimed to resolve some uncertainties related to the putative function of ABCA1 as a mediator of lipid transport by using a methodology developed in the laboratory to isolate a protein and study its interactions with other compounds. ABCA1 was tagged with the 1D4 peptide at the C terminus and expressed in human HEK 293 cells. Preliminary experiments showed that the tag modified neither the protein expression/localization within the cells nor the ability of ABCA1 to promote cholesterol cellular efflux to apolipoprotein A-I. ABCA1-1D4 was then purified and reconstituted in liposomes. ABCA1 displayed an ATPase activity in phospholipid liposomes that was significantly decreased by cholesterol. Finally, interactions with either cholesterol or apolipoprotein A-I were assessed by binding experiments with protein immobilized on an immunoaffinity matrix. Solid-phase binding assays showed no direct binding of cholesterol or apolipoprotein A-I to ABCA1. Overall, our data support the hypothesis that ABCA1 is able to mediate the transport of cholesterol from cells without direct interaction and that apo A-I primarily binds to membrane surface or accessory protein(s). PMID:23201557

  1. A Longitudinal Study of Decomposition Odour in Soil Using Sorbent Tubes and Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Katelynn A. Perrault

    2014-07-01

    Full Text Available Odour profiling of decomposed remains is important for understanding the mechanisms that cadaver dogs and forensically-relevant insects use to locate decomposed remains. The decomposition odour profile is complex and has been documented in outdoor terrestrial environments. The purpose of this study was to perform longitudinal analysis of the volatile organic compound (VOC profile in soils associated with decomposed remains across all stages of decomposition. Two VOC collection techniques (sorbent tubes and solid phase microextraction were used to collect a wider analyte range and to investigate differences in collection techniques. Pig carcasses were placed in an outdoor research facility in Australia to model the decomposition process and VOCs were collected intermittently over two months. VOCs of interest were identified over the duration of the trial, showing distinct trends in compound evolution and disappearance. The collection techniques were complementary, representing different subsets of VOCs from the overall profile. Sorbent tubes collected more decomposition-specific VOCs and these compounds were more effective at characterising the matrix over an extended period. Using both collection techniques improves the likelihood of identifying the complete VOC profile of decomposition odour. Such information is important for the search and recovery of victim remains in various stages of decomposition.

  2. Measurement of associations of pharmaceuticals with dissolved humic substances using solid phase extraction.

    Science.gov (United States)

    Ding, Yunjie; Teppen, Brian J; Boyd, Stephen A; Li, Hui

    2013-04-01

    An innovative method was developed to determine association of carbadox, lincomycin and tetracycline with dissolved humic acids using solid phase extraction (SPE). Dissolved organic matter (DOM) and DOM-bound pharmaceuticals passed through the SPE cartridge while the cartridge retained freely dissolved pharmaceuticals from water. This method was validated by comparison with the results measured using the common equilibrium dialysis technique. For the SPE method pharmaceutical interaction with DOM required ∼30h to approach the equilibration, whereas 50-120h was needed for the equilibrium dialysis technique. The uneven distributions of freely membrane-penetrating pharmaceuticals and protons inside vs. outside of the dialysis cell due to the Donnan effect resulted in overestimates of pharmaceutical affinity with DOM for the equilibrium dialysis method. The SPE technique eliminates the Donnan effect, and demonstrates itself as a more efficient, less laborious and more accurate method. The measured binding coefficients with DOM followed the order of carbadoxLeonardite humic acid were greater than those with Aldrich humic acid due to more interaction sites, i.e. carboxylic and phenolic functional moieties, present in the Leonardite humic acid. The results obtained suggest that many pharmaceuticals could be significantly bound to DOM, which alters their fate and mobility in the environment. PMID:23260244

  3. Robust aptamer sol-gel solid phase microextraction of very polar adenosine from human plasma.

    Science.gov (United States)

    Mu, Li; Hu, Xiangang; Wen, Jianping; Zhou, Qixing

    2013-03-01

    Conventional solid phase microextraction (SPME) has a limited capacity to extract very polar analytes, such as adenosine. To solve this problem, aptamer conjugating sol-gel methodology was coupled with an SPME fiber. According to the authors' knowledge, this is the first reported use of aptamer SPME. The fiber of aptamer sol-gel SPME with a mesoporous structure has high porosity, large surface area, and small water contact angle. Rather than employing direct entrapment, covalent immobilization was the dominant method of aptamer loading in sol-gel. Aptamer sol-gel fiber captured a specified analyte from among the analog molecules, thereby, exhibiting an excellent selective property. Compared with commercial SPME fibers, this aptamer fiber was suitable for extracting adenosine, presenting an extraction efficiency higher than 20-fold. The values of repeatability and reproducibility expressed by relative standard deviation were low (9.4%). Interestingly, the sol-gel network enhanced the resistance of aptamer SPME to both nuclease and nonspecific proteins. Furthermore, the aptamer sol-gel fiber was applied in human plasma with LOQ 1.5 μg/L, which is an acceptable level. This fiber also demonstrates durability and regeneration over 20-cycles without significant loss of efficiency. Given the various targets (from metal ions to biomacromolecules and cells) of aptamers, this methodology will extend the multi-domain applications of SPME.

  4. Solid-phase extraction and LC-MS analysis of pyrrolizidine alkaloids in honeys.

    Science.gov (United States)

    Beales, Kerrie A; Betteridge, Keith; Colegate, Steven M; Edgar, John A

    2004-10-20

    Strong-cation-exchange, solid-phase extraction of pyrrolizidine alkaloids and their N-oxides from honey samples was followed by reduction of the N-oxides and subsequent analysis of total pyrrolizidine alkaloids using high-performance liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. A limited survey of 63 preprocessing samples of honey, purposefully biased toward honeys attributed to floral sources known to produce pyrrolizidine alkaloids, demonstrated levels of pyrrolizidine alkaloids up to approximately 2000 parts per billion (ppb) in a sample attributed to Echium plantagineum. Up to 800 ppb pyrrolizidine alkaloids was detected in some honeys not attributed by the collector to any pyrrolizidine alkaloid-producing floral source. No pyrrolizidine alkaloids were detected in approximately 30% of the samples in this limited study, while some honeys showed the copresence of pyrrolizidine alkaloids from multiple floral sources such as E. plantagineum and Heliotropium europaeum. In addition, retail samples of blended honeys (with no labeling to suggest that pyrrolizidine alkaloid-producing floral sources were used in the blends) have been shown to contain up to approximately 250 ppb pyrrolizidine alkaloids. PMID:15479038

  5. Mixed micelle cloud point-magnetic dispersive μ-solid phase extraction of doxazosin and alfuzosin

    Science.gov (United States)

    Gao, Nannan; Wu, Hao; Chang, Yafen; Guo, Xiaozhen; Zhang, Lizhen; Du, Liming; Fu, Yunlong

    2015-01-01

    Mixed micelle cloud point extraction (MM-CPE) combined with magnetic dispersive μ-solid phase extraction (MD-μ-SPE) has been developed as a new approach for the extraction of doxazosin (DOX) and alfuzosin (ALF) prior to fluorescence analysis. The mixed micelle anionic surfactant sodium dodecyl sulfate and non-ionic polyoxyethylene(7.5)nonylphenylether was used as the extraction solvent in MM-CPE, and diatomite bonding Fe3O4 magnetic nanoparticles were used as the adsorbent in MD-μ-SPE. The method was based on MM-CPE of DOX and ALF in the surfactant-rich phase. Magnetic materials were used to retrieve the surfactant-rich phase, which easily separated from the aqueous phase under magnetic field. At optimum conditions, a linear relationship between DOX and ALF was obtained in the range of 5-300 ng mL-1, and the limits of detection were 0.21 and 0.16 ng mL-1, respectively. The proposed method was successfully applied for the determination of the drugs in pharmaceutical preparations, urine samples, and plasma samples.

  6. Rubella serology by solid-phase radioimmunoassay: its potential for screening programmes

    International Nuclear Information System (INIS)

    Sera from 269 adult females who had experienced naturally acquired or vaccine-induced infection by rubella virus, including immune persons challenged intranasally with rubella vaccine (RA27/3) as well as sera from 100 patients attending antenatal clinics, were tested for rubella antibodies by the conventional haemagglutination inhibition tests (HAI), as well as a newly developed solid-phase radioimmunoassay (RIA) for rubella immunoglobulin G(IgG) antibodies. Following both naturally acquired and vaccine-induced infection, titres by RIA were approximately ten-fold higher than by HAI. The RIA test was particularly useful in assessing the true immune status of those with apparently low levels of HAI antibody and has the added advantage that pretreatment of sera to remove inhibitors of haemagglutination and red cell agglutinins is unnecessary. The RIA test has potential for the large-scale screening programmes which need to be carried out if the Department of Health and Social Security recommendation, that women attending antenatal and family planning clinics be screened for rubella antibodies, is to be effectively met. (author)

  7. Electromembrane surrounded solid phase microextraction using electrochemically synthesized nanostructured polypyrrole fiber.

    Science.gov (United States)

    Mohammadkhani, Elham; Yamini, Yadollah; Rezazadeh, Maryam; Seidi, Shahram

    2016-04-22

    Electromembrane surrounded solid phase microextraction using conductive polymers as the sorbent is carried out for the first time for extraction of two antidepressants including amitriptyline (AMI) and doxepin (DOX), as model analytes. The polypyrrole coating was prepared and utilized as both cathode and SPME sorbent. Different variables such as the conditions for preparation of polypyrrole fiber, pH of the donor and the acceptor phases, applied voltage, and extraction time were optimized. Under the optimized conditions, figures of merit of the proposed method were investigated in human whole blood and urine samples. Intra- and inter-assay precisions ranged between 3.1-7.5% and 7.6-12.3%, respectively were obtained in different extraction media. Detection limits of 0.15 and 0.05 for AMI and 0.3 and 0.1ngmL(-1) for DOX were achieved in the urine and blood samples, respectively. Linearity of the method was studied up to 50.0ngmL(-1) for both analytes and coefficients of determination better than 0.9966 were achieved. Regardless of the high sample cleanup, which makes the proposed method suitable for analysis of drugs from complicated matrices, clean chromatograms were obtained. Finally, the proposed method was applied for analysis of AMI and DOX in different real samples and reasonable data were obtained. PMID:27033980

  8. Conductive polymeric ionic liquids for electroanalysis and solid-phase microextraction.

    Science.gov (United States)

    Young, Joshua A; Zhang, Cheng; Devasurendra, Amila M; Tillekeratne, L M Viranga; Anderson, Jared L; Kirchhoff, Jon R

    2016-03-01

    Three novel electropolymerizable thiophene-based ionic liquids (ILs) were synthesized and characterized as potential candidates for developing selective extraction media for chemical analysis. Electropolymerization of the bis[(trifluoromethyl)sulfonyl]imide ([NTf2](-)) analogs successfully produced uniform polymeric thin-films on macro- and microelectrode substrates from both vinyl and methylimidazolium IL monomer derivatives. The resultant conducting polymer IL (CPIL) films were characterized by electrochemical methods and found to exhibit attractive behavior towards anionic species while simultaneously providing an exclusion barrier toward cationic species. Thermogravimetric analysis of the thiophene-based IL monomers established a high thermal stability, particularly for the methylimidazolium IL, which was stable until temperatures above 350 °C. Subsequently, the methylimidazolium IL was polymerized on 125 μm platinum wires and utilized for the first time as a sorbent coating for headspace solid-phase microextraction (HS-SPME). The sorbent coating was easily prepared in a reproducible manner, provided high thermal stability, and allowed for the gas chromatographic analysis of polar analytes. The normalized response of the poly[thioph-C6MIm][NTf2]-based sorbent coating exhibited higher extraction efficiency compared to an 85 μm polyacrylate fiber and excellent fiber-to-fiber reproducibility. Therefore, the electropolymerizable thiophene-based ILs were found to be viable new materials for the preparation of sorbent coatings for HS-SPME. PMID:26873467

  9. Solid-phase synthesis of porcine cholecystokinin-33 in a new resin via FMOC-strategy.

    Science.gov (United States)

    Penke, B; Nyerges, L

    1991-01-01

    Porcine cholecystokinin-33 has been synthesized on solid phase and characterized both chemically and biologically. In order to develop a successful synthetic strategy, a new anchor molecule (4-succinylamido-2,2',4'-trimethoxybenzhydrylamine) was designed and coupled to aminomethyl-polystyrene. The resulting 4-succinylamido-2,2',4'-trimethoxybenzhydrylamine resin was successfully used for the synthesis of cholecystokinin-33 using N-fluorenylmethoxycarbonyl amino acid symmetric anhydrides. Tyrosine-O-sulfate has been synthesized by direct sulfation of tyrosine with chlorosulfonic acid and incorporated into the peptide sequence by coupling as N-fluorenylmethoxy-O-sulfatotyrosine-pentafluorophenyl ester. Side chains of the trifunctional amino acids were protected mostly by t-butyl-type protecting groups. The guanidino function of arginine was protected by the 2,2,5,7,8-pentamethylchromane-6-sulfonyl group. After completion of the synthesis, the peptide was cleaved off the support with 50% trifluoroacetic acid (15 min); this treatment cleaved the side-chain protecting groups simultaneously. Preparative high-performance liquid chromatography resulted in pure cholecystokinin-33 of full biological activity. The structure of the peptide was proved by amino acid analysis, IR and UR spectroscopy, fast atomic bombardment mass spectroscopy and comparative high-performance liquid chromatography of the synthetic and native cholecystokinin-33.

  10. Direct solid-phase synthesis of octreotide conjugates: precursors for use as tumor-targeted radiopharmaceuticals.

    Science.gov (United States)

    Hsieh, H P; Wu, Y T; Chen, S T; Wang, K T

    1999-09-01

    Somatostatin analogues, such as octreotide, are useful for the visualization and treatment of tumors. Unfortunately, these compounds were produced synthetically using complex and inefficient procedures. Here, we describe a novel approach for the synthesis of octreotide and its analogues using p-carboxybenzaldehyde to anchor Fmoc-threoninol to solid phase resins. The reaction of the two hydroxyl groups of Fmoc-threoninol with p-carboxybenzaldehyde was catalyzed with p-toluenesulphonic acid in chloroform using a Dean-Stark apparatus to form Fmoc-threoninol p-carboxybenzacetal in 91% yield. The Fmoc-threoninol p-carboxybenzacetal acted as an Fmoc-amino acid derivative and the carboxyl group of Fmoc-threoninol p-carboxybenzacetal was coupled to an amine-resin via a DCC coupling reaction. The synthesis of protected octreotide and its conjugates were carried out in their entirety using a conventional Fmoc protocol and an autosynthesizer. The acetal was stable during the stepwise elongation of each Fmoc-amino acid as shown by the averaged coupling yield (> 95%). Octreotide (74 to 78% yield) and five conjugated derivatives were synthesized with high yields using this procedure, including three radiotherapy octreotides (62 to 75% yield) and two cellular markers (72 to 76% yield). This novel approach provides a strategy for the rapid and efficient large-scale synthesis of octreotide and its analogues for radiopharmaceutical and tagged conjugates.

  11. Dynamics of Vibrio cholerae abundance in Austrian saline lakes, assessed with quantitative solid-phase cytometry.

    Science.gov (United States)

    Schauer, Sonja; Jakwerth, Stefan; Bliem, Rupert; Baudart, Julia; Lebaron, Philippe; Huhulescu, Steliana; Kundi, Michael; Herzig, Alois; Farnleitner, Andreas H; Sommer, Regina; Kirschner, Alexander

    2015-11-01

    In order to elucidate the main predictors of Vibrio cholerae dynamics and to estimate the risk of Vibrio cholera-related diseases, a recently developed direct detection approach based on fluorescence in situ hybridization and solid-phase cytometry (CARD-FISH/SPC) was applied in comparison to cultivation for water samples from the lake Neusiedler See, Austria and three shallow alkaline lakes over a period of 20 months. Vibrio cholerae attached to crustacean zooplankton was quantified via FISH and epifluorescence microscopy. Concentrations obtained by CARD-FISH/SPC were significantly higher than those obtained by culture in 2011, but were mostly of similar magnitude in 2012. Maximum cell numbers were 1.26 × 10(6) V. cholerae per L in Neusiedler See and 7.59 × 10(7) V. cholerae per L in the shallow alkaline lakes. Only on a few occasions during summer was the crustacean zooplankton the preferred habitat for V. cholerae. In winter, V. cholerae was not culturable but could be quantified at all sites with CARD-FISH/SPC. Beside temperature, suspended solids, zooplankton and ammonium were the main predictors of V. cholerae abundance in Neusiedler See, while in the shallow alkaline lakes it was organic carbon, conductivity and phosphorus. Based on the obtained concentrations a first estimation of the health risk for visitors of the lake could be performed.

  12. Crosslinked polymeric ionic liquids as solid-phase microextraction sorbent coatings for high performance liquid chromatography.

    Science.gov (United States)

    Yu, Honglian; Merib, Josias; Anderson, Jared L

    2016-03-18

    Neat crosslinked polymeric ionic liquid (PIL) sorbent coatings for solid-phase microextraction (SPME) compatible with high-performance liquid chromatography (HPLC) are reported for the first time. Six structurally different PILs were crosslinked to nitinol supports and applied for the determination of select pharmaceutical drugs, phenolics, and insecticides. Sampling conditions including sample solution pH, extraction time, desorption solvent, desorption time, and desorption solvent volume were optimized using design of experiment (DOE). The developed PIL sorbent coatings were stable when performing extractions under acidic pH and remained intact in various organic desorption solvents (i.e., methanol, acetonitrile, acetone). The PIL-based sorbent coating polymerized from the IL monomer 1-vinyl-3-(10-hydroxydecyl) imidazolium chloride [VC10OHIM][Cl] and IL crosslinker 1,12-di(3-vinylbenzylimidazolium) dodecane dichloride [(VBIM)2C12] 2[Cl] exhibited superior extraction performance compared to the other studied PILs. The extraction efficiency of pharmaceutical drugs and phenolics increased when the film thickness of the PIL-based sorbent coating was increased while many insecticides were largely unaffected. Satisfactory analytical performance was obtained with limits of detection (LODs) ranging from 0.2 to 2 μg L(-1) for the target analytes. The accuracy of the analytical method was examined by studying the relative recovery of analytes in real water samples, including tap water and lake water, with recoveries varying from 50.2% to 115.9% and from 48.8% to 116.6%, respectively.

  13. Methylation and Release of Mercury From the Solid Phase. What Comes First?

    Science.gov (United States)

    Regnell, O.

    2004-05-01

    It is a well-known fact that methylation leads to a dramatic increase in the bioavailability of mercury (Hg). All recent observations support the notion that Hg methylation is almost exclusively an anaerobic process. According to the reigning paradigm, methylation of Hg takes place in the cytoplasm of anaerobic bacteria, notably sulfate-reducing bacteria. It is believed that certain forms of inorganic divalent Hg (Hg(II)), can readily diffuse across the cell membrane. In addition, a recent study suggested that active uptake may occur when Hg is bound to low weight organic molecules. In the cytoplasm, cobalamin-dependent biochemical pathways, designed to methylate substrates other than Hg(II), are held responsible for the methylation of Hg(II). However, recent results from studies in a Swedish wetland (within the project "Svartsjoprojektet", aiming at understanding Hg dynamics in a Hg-polluted river-lake system) have led us to question whether Hg methylation does occur exclusively within cells. A provocative interpretation of our results is that methylation preceded the release of Hg from the solid phase, e.g. that Hg(II) sorbed to solid surfaces was methylated and subsequently released as methyl Hg to the sulfidic water. I will discuss this possibility in light of existing evidence that Hg methylation is an intra cellular process.

  14. Solid-Phase Extraction of Sulfur Mustard Metabolites Using an Activated Carbon Fiber Sorbent.

    Science.gov (United States)

    Lee, Jin Young; Lee, Yong Han

    2016-01-01

    A novel solid-phase extraction method using activated carbon fiber (ACF) was developed and validated. ACF has a vast network of pores of varying sizes and microporous structures that result in rapid adsorption and selective extraction of sulfur mustard metabolites according to the pH of eluting solvents. ACF could not only selectively extract thiodiglycol and 1-methylsulfinyl-2-[2-(methylthio)-ethylsulfonyl]ethane eluting a 9:1 ratio of dichloromethane to acetone, and 1,1'-sulfonylbis[2-(methylsulfinyl)ethane] and 1,1'-sulfonylbis- [2-S-(N-acetylcysteinyl)ethane] eluting 3% hydrogen chloride in methanol, but could also eliminate most interference without loss of analytes during the loading and washing steps. A sample preparation method has been optimized for the extraction of sulfur mustard metabolites from human urine using an ACF sorbent. The newly developed extraction method was applied to the trace analysis of metabolites of sulfur mustard in human urine matrices in a confidence-building exercise for the analysis of biomedical samples provided by the Organisation for the Prohibition of Chemical Weapons. PMID:26364317

  15. Determination of aflatoxins in rice samples by ultrasound-assisted matrix solid-phase dispersion.

    Science.gov (United States)

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2015-01-01

    This work describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and sample preparation approach for aflatoxins (B1, B2, G1 and G2) and subsequent determination of them by high-performance liquid chromatography-fluorescence detection. A Box-Behnken design in combination with response surface methodology was used to determine the affecting parameters on the extraction procedure. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent was investigated in the optimization study. C18, primary-secondary amine (PSA) and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The obtained optimized values were sample-to-dispersing phase ratio of 1 : 1, 60 mg of PSA, 11 min ultrasonication time, 30°C ultrasonication temperature and 4 mL acetonitrile. Under the optimal conditions, the limits of detection were ranged from 0.09 to 0.14 ng g(-1) and the precisions [relative standard deviation (RSD%)] were aflatoxins in rice samples.

  16. Rapid fabrication of graphene on dielectric substrates via solid-phase processes

    Science.gov (United States)

    Xiong, W.; Zhou, Y. S.; Hou, W. J.; Lu, Y. F.

    2015-03-01

    To unleash the full potential of graphene in functional devices, high-quality graphene sheets and patterns are frequently required to be deposited on dielectric substrates. However, it generally calls for post-growth catalyst etching and graphene transfer steps in currently existing approaches, which are very time consuming and costly for fabricating functional graphene devices. We developed a rapid and cost-effective growth method to achieve the graphene formation directly on various kinds of dielectric substrates via a novel solid-phase transformation mechanism based on Ni/C thin films. High-quality graphene was obtained uniformly on whole surface of wafers with a controlled number of graphene layers. The monolayer graphene, as obtained, exhibits a low sheet resistance of about 50 Ω/sq and a high optical transmittance of 95.8% at 550 nm. Graphene patterns were successfully fabricated simply by either conventional photolithography or laser direct writing techniques. Various graphene patterns, including texts, spirals, line arrays, and even large-scale integrated circuit patterns, with a feature line width of 800 nm and a low sheet resistance of 205 ohm/sq, were achieved. The developed method provides a facile and cost-effective way to fabricate complex and high-quality graphene patterns directly on target substrates, which opens a door for fabricating various advanced optoelectronic devices.

  17. Determination of diphenylether herbicides in water samples by solid-phase microextraction coupled to liquid chromatography.

    Science.gov (United States)

    Sheu, Hong-Li; Sung, Yu-Hsiang; Melwanki, Mahaveer B; Huang, Shang-Da

    2006-11-01

    Solid-phase microextraction (SPME) coupled to LC for the analysis of five diphenylether herbicides (aclonifen, bifenox, fluoroglycofen-ethyl, oxyfluorfen, and lactofen) is described. Various parameters of extraction of analytes onto the fiber (such as type of fiber, extraction time and temperature, pH, impact of salt and organic solute) and desorption from the fiber in the desorption chamber prior to separation (such as type and composition of desorption solvent, desorption mode, soaking time, and flush-out time) were studied and optimized. Four commercially available SPME fibers were studied. PDMS/divinylbenzene (PDMS/DVB, 60 microm) and carbowax/ templated resin (CW/TPR, 50 microm) fibers were selected due to better extraction efficiencies. Repeatability (RSD, 0.994), and detection limit (0.33-1.74 and 0.22-1.94 ng/mL, respectively, for PDMS/DVB and CW/TPR) were investigated. Relative recovery (81-104% for PDMS/DVB and 83-100% for CW/TPR fiber) values have also been calculated. The developed method was successfully applied to the analysis of river water and water collected from a vegetable garden. PMID:17313105

  18. Volatile profile of yellow passion fruit juice by static headspace and solid phase microextraction techniques

    Directory of Open Access Journals (Sweden)

    Gilberto Costa Braga

    2015-02-01

    Full Text Available The profile of volatile compounds of yellow passion fruit juice was analyzed by solid phase microextraction headspace (HS-SPME and optimized static headspace (S-HS extraction techniques. Time, temperature, NaCl concentration and sample volume headspace equilibrium parameters was adjusted to the S-HS technique. The gaseous phase in the headspace of samples was collected and injected into a gas chromatograph coupled to a mass spectrometer. In the HS-SPME technique was identified 44 volatile compounds from the yellow passion fruit juice, but with S-HS only 30 compounds were identified. Volatile esters were majority in both techniques, being identified ethyl butanoate, ethyl hexanoate, (3z-3-hexenyl acetate, hexyl acetate, hexyl butanoate and hexyl hexanoate. Aldehydes and ketones were not identified in S-HS, but were in HS-SPME. β-Pinene, p-cymene, limonene, (Z-β-ocimene, (E-β-ocimene, γ-terpinene, α-terpinolene and (E -4,8-dimethyl-1, 3,7 - nonatriene terpenes were identified in both techniques. This study showed that the S-HS optimized extraction technique was effective to recovery high concentrations of the major volatile characteristics compounds in the passion fruit, such as ethyl butanoate and ethyl hexanoate, which can be advantageous due to the simplicity of the method.

  19. Solid-phase group-specific adsorbants in assays for glycoproteins

    International Nuclear Information System (INIS)

    The focus of the paper is on several technical advances in the assays for glycoprotein hormones and enzymes that have been achieved by the use of the solid-phase cabohydrate-specific adsorbant concanavalin-A. Purification of glycoprotein radioligand after labelling by the Chloramine-T method is readily accomplished using a small column of agarose-bound concanavalin-A which separates glycoprotein radioligand from radioiodide and radiolabelled unadsorbed contaminants. After concanavalin-A column chromatography, radiolabelled glycoprotein hormone preparations exhibited improved binding to antibodies and tissue receptors. To increase the effective sensitivity of radioimmunoassays for glycoproteins, agarose-bound concanavalin-A is used to extract and concentrate the glycoproteins from various biological samples. For example, the effective sensitivity for the detection of human thyrotropin in serum was improved approximately 5-fold by using concanavalin-A concentrates of 1.5ml of serum. Partial purification of the glycoprotein dopamine-β-hydroxylase from serum using agarose-bound concanavalin-A resulted in separation of the serum factors that interfere with the measurement of enzyme activity. We conclude that in assays for glycoproteins, concanavalin-A is useful for purification of radioligand, for preparation of concentrates of glycoproteins from biological samples and for separation of glycoproteins from various interfering factors contained in biological samples before radioligand or radioenzyme assay. (author)

  20. Bioremediation of diethylhexyl phthalate contaminated soil: a feasibility study in slurry- and solid-phase reactors.

    Science.gov (United States)

    Di Gennaro, P; Collina, E; Franzetti, A; Lasagni, M; Luridiana, A; Pitea, D; Bestetti, G

    2005-01-01

    The aim of the research was to verify the possibility of applying bioremediation as a treatment strategy on a poly(vinyl chloride) (PVC) manufacturing site in the north of Italy contaminated by diethylhexyl phthalate (DEHP) at a concentration of 5.51 mg/g of dry soil. Biodegradation kinetic experiments with DEHP contaminated soil samples were performed in both slurry- and solid-phase systems. The slurry-phase results showed that the cultural conditions, such as N and P concentrations and the addition of a selected DEHP degrading strain, increased the natural DEHP degradation rate. On the basis of these data, experiments to simulate bioventing on contaminated soil columns were performed. The DEHP concentration reached 0.63 mg/g of dry soil in 76 days (89% of degradation). A kinetic equation was developed to fit the experimental data and to predict the concentration of contaminant after treatment. The data obtained are encouraging for a future in situ application of the bioventing technology.

  1. Determination of particulate-bound formaldehyde from burning incense by solid phase microextraction.

    Science.gov (United States)

    Liou, S W; Chen, C Y; Yang, T T; Lin, J M

    2008-04-01

    This work studied the feasibility of using a solid phase microextraction (SPME) fiber for sampling and analysis of gaseous formaldehyde as well as particulate-bound formaldehyde from burning Chinese incense. The SPME fiber with PDMS/DVB coating were partially coated with o-(2,3,4,5,6-pentafluorobenzyl)-hydroxylamine hydrochloride (PFBHA), and used for sampling formaldehyde. The sampling rate for formaldehyde and its dependence on temperature, relative humidity and sampling time were observed. The same PFBHA treated fibers were, in parallel, exposed to incense burning smoke with pre-filtration and without pre- filtration for 0.5-1 min. The NIOSH method 2541 using an XAD-2 tube at a flow rate of 0.1 Lpm was also applied for sampling simultaneously. The results demonstrate that commercially available PDMS/DVB fibers partially coated with PFBHA are capable of sampling the gas phase of formaldehyde as well as particulate-bound formaldehyde. The determined level of formaldehyde was close to the result obtained by the NIOSH method 2541. However, a reduction of the fiber's formaldehyde loading capacity in the aerosol sampling in comparison with gas sampling was noticed. This indicates that the particulate characteristics, and their bound chemicals other than formaldehyde may influence the maximum loading capacity of formaldehyde, and some characteristic particulates in high concentrations may even deteriorate the fiber coating.

  2. Understanding the solid phase chemical fractionation of uranium in soil and effect of ageing.

    Science.gov (United States)

    Rout, Sabyasachi; Kumar, Ajay; Ravi, P M; Tripathi, R M

    2016-11-01

    The aim of the present work is to understand the solid phase chemical fractionation of Uranium (U) in soil and the mechanism involved. This study integrated batch experiments of U(VI) adsorption to soil, study of U in different soil fractions, ageing impact on fractionation of U and spectroscopic investigation of adsorbed U(VI) using X-ray Photoelectron Spectroscopy (XPS). For the study three soils, pedogenically different (S1: Igneous, S2: Sedimentary and S3: Metamorphic) were amended with U(VI) and chemical fractionation of U was studied by sequential extraction after an interval of one month and 12 months. It was found that there occurs a significant rearrangement of U in different fractions with ageing and no correlation was observed between the U content in different fractions and the adsorbents of respective fractions such as soil organic matter (SOM), Fe/Mn oxides (hydroxides) carbonates, soil cation exchange capacity (CEC). XPS study revealed that surface enrichment of U mainly governed by the carbonate minerals and SOM, whereas bulk concentration was controlled by the oxides (hydroxides) of Si and Al. Occlusion of U-Fe-oxides (hydroxides) on silica was identified as an important mechanism for bulk enrichment (Increase in residual fraction) and depletion of U concentration in reducible fraction.

  3. Graphenized pencil lead fiber: facile preparation and application in solid-phase microextraction.

    Science.gov (United States)

    Liu, Qian; Cheng, Mengting; Long, Yanmin; Yu, Miao; Wang, Thanh; Jiang, Guibin

    2014-01-17

    Graphenized pencil lead fiber was facilely prepared by in situ chemical exfoliation of graphite in pencil lead fiber to few-layered graphene sheets via a one-pot, one-step pressurized oxidation reaction for the first time. This new fiber was characterized and demonstrated to be a highly efficient but low-cost solid-phase microextraction (SPME) fiber. The extraction performance of the fiber was evaluated with four bisphenol analogs [bisphenol A (BPA), bisphenol S (BPS), bisphenol AF (BPAF), and tetrabromobisphenol A (TBBPA)] as model analytes in direct SPME mode. Unlike commercially available fibers, the graphenized pencil lead fiber showed an excellent chemical stability in highly saline, acidic, alkaline and organic conditions due to its coating-free configuration. The fiber also showed a very long lifespan. Furthermore, high extraction efficiency and good selectivity for the analytes with a wide polarity range could be obtained due to the exceptional properties of graphene. The detection limits (LODs) for the analytes were in the range of 1.1-25ng/L. The fiber was successfully applied in the analysis of tap water and effluent samples from a waste water treatment plant with spike recoveries ranging from 68.5 to 105.1%. Therefore, the graphenized pencil lead fiber provides a high performance, cheap, robust, and reliable tool for SPME.

  4. Determination of aflatoxins in rice samples by ultrasound-assisted matrix solid-phase dispersion.

    Science.gov (United States)

    Manoochehri, Mahboobeh; Asgharinezhad, Ali Akbar; Safaei, Mahdi

    2015-01-01

    This work describes the application of ultrasound-assisted matrix solid-phase dispersion as an extraction and sample preparation approach for aflatoxins (B1, B2, G1 and G2) and subsequent determination of them by high-performance liquid chromatography-fluorescence detection. A Box-Behnken design in combination with response surface methodology was used to determine the affecting parameters on the extraction procedure. The influence of different variables including type of dispersing phase, sample-to-dispersing phase ratio, type and quantity of clean-up phase, ultrasonication time, ultrasonication temperature, nature and volume of the elution solvent was investigated in the optimization study. C18, primary-secondary amine (PSA) and acetonitrile were selected as dispersing phase, clean-up phase and elution solvent, respectively. The obtained optimized values were sample-to-dispersing phase ratio of 1 : 1, 60 mg of PSA, 11 min ultrasonication time, 30°C ultrasonication temperature and 4 mL acetonitrile. Under the optimal conditions, the limits of detection were ranged from 0.09 to 0.14 ng g(-1) and the precisions [relative standard deviation (RSD%)] were extraction of trace amounts of aflatoxins in rice samples. PMID:24771057

  5. Solid phase extraction and determination of carbamate pesticides in water samples by reverse-phase HPLC

    Energy Technology Data Exchange (ETDEWEB)

    Moreno-Tovar, J.; Santos-Delgado, M.J. [Departamento de Quimica Analitica, Facultad de ciencias Quimicas, Universidad Complutense de Madrid (Spain)

    1995-12-31

    Solid phase extraction. SPE. using C{sub 1}8 bonded silica cartridges for trace amounts determination of carbaryl, propoxur, thiram, propham and methiocarb in water samples was studied and the breakthrough volume of the cartridges was established. The high enrichment factor and large injection volume admissible in the isocratic reverse-phase HPLC system allows pesticides determination with UV detection at 22o nm even at a concentration lower than 0.05 mug/L. Purified tap natural and underground water samples were spiked with carbamate pesticides in the concentration range 0.16-16.0 mug/L. Large volumes of samples (up to 2L) were passed through available C{sub 1}8, cartridges and eluted with acetonitrile. The preconcentrated samples were analyzed by HPLC using a Spherisorb ODS column with a 42.58 acetonitrile-water mobile phase. From replicate samples, recovery for the pesticides ranged from 79.0 to 103.7% except for thiran which is not retained. Tehe relative standard deviation (n=4 at 0.16 to 1.61 mug/L concetration level) range from 1.1 to 6.8%. (Author) 14 refs.

  6. Microporous Carbon Spheres Solid Phase Membrane Tip Extraction for the Analysis of Nitrosamines in Water Samples

    International Nuclear Information System (INIS)

    A simple solid phase membrane tip extraction (SPMTE) utilizing microporous carbon spheres (MCS) was developed for the analysis of nitrosamines in aqueous samples. The method termed MCS-SPMTE was optimized for various important extraction parameters namely conditioning organic solvent, extraction time, effects of salt addition and pH change, desorption time, desorption solvent and sample volume. Under the optimized conditions, the method indicated good linearity in the range of 10-100 μg/ L with coefficients of determination, r2≥0.9984. The method also demonstrated good reproducibility with % RSDs values ranging from 2.2 - 8.9 (n = 3). Limit of detection (LOD) and limit of quantification (LOQ) for the method ranged from 3.2 - 4.8 μg/ L and 10.9 - 15.9 μg/L respectively. Recoveries for both tap-water and lake water samples spiked at 10 μg/L were in the range of 83.2 - 107.5 %. (author)

  7. Knitting aromatic polymers for efficient solid-phase microextraction of trace organic pollutants.

    Science.gov (United States)

    Liu, Shuqin; Hu, Qingkun; Zheng, Juan; Xie, Lijun; Wei, Songbo; Jiang, Ruifen; Zhu, Fang; Liu, Yuan; Ouyang, Gangfeng

    2016-06-10

    A series of knitting aromatic polymers (KAPs) were successfully synthesized using a simple one-step Friedel-Crafts alkylation of aromatic monomers and were characterized by transmission electron microscopy (TEM), Fourier transform infrared (FTIR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Then, as-synthesized KAPs with large surface areas, unique pore structures and high thermal stability were prepared as solid-phase microextraction (SPME) coatings that exhibited good extraction abilities for a series of benzene compounds (i.e., benzene, toluene, ethylbenzene and m-xylene, which are referred to as BTEX) and polycyclic aromatic hydrocarbons (PAHs). Under the optimized conditions, the methodologies established for the determination of BTEX and PAHs using the KAPs-triPB and KAPs-B coatings, respectively, possessed wide linear ranges, low limits of detection (LODs, 0.10-1.13ngL(-1) for BTEX and 0.05-0.49ngL(-1) for PAHs) and good reproducibility. Finally, the proposed methods were successfully applied to the determination of BTEX and PAHs in environmental water samples, and satisfactory recoveries (93.6-124.2% for BTEX and 77.2-113.3% for PAHs) were achieved. This study provides a benchmark for exploiting novel microporous organic polymers (MOPs) for SPME applications. PMID:27155913

  8. Catalytically solid-phase self-organization of nanoporous SnS with optical depolarizability.

    Science.gov (United States)

    Cheng, Chih-Hsien; Chi, Yu-Chieh; Wu, Chung-Lun; Lin, Chun-Jung; Tsai, Ling-Hsuan; Chang, Jung-Hung; Chen, Mu Ku; Shih, Min-Hsiung; Lee, Chao-Kuei; Wu, Chih-I; Tsai, Din Ping; Lin, Gong-Ru

    2016-02-28

    The catalytic solid-phase synthesis of self-organized nanoporous tin sulfide (SnS) with enhanced absorption, manipulative transmittance and depolarization features is demonstrated. Using an ultralow radio-frequency (RF) sputtering power, the variation of the orientation angle between the anodized aluminum oxide (AAO) membrane and the axis of the sputtered ion beam detunes the catalytically synthesized SnS from nanorod to nanoporous morphology, along the sidewall of the AAO membrane. The ultraslow catalytic sputtering synthesis on the AAO at the RF plasma power of 20 W and the orientation angle of 0° regulates the porosity and integrality of nanoporous SnS, with average pore diameter of 80-150 nm. When transferring from planar to nanoporous structure, the phase composition changes from SnS to SnS2-Sn2S3, and the optical bandgap shrinks from 1.43 to 1.16 eV, due to the preferred crystalline orientation, which also contributes to an ultralow reflectance of minimum of >5 × 10(4) cm(-1) at the wavelength between 200 and 700 nm, due to the red-shifting of the absorption spectrum to at least 100 nm. The catalytically self-organized nanoporous SnS causes strong haze and beam divergence of 20°-30° by depolarized nonlinear scattering at the surface, which favors the solar energy conversion with reduced surface reflection and enhanced photon scattering under preserved transmittance. PMID:26842460

  9. Volatile composition of peppermint (Mentha piperita L.) commercial teas through solid phase extraction.

    Science.gov (United States)

    Riachi, L G; Abi-Zaid, I E; Moreira, R F A; De Maria, C A B

    2012-12-01

    Volatiles from aqueous extract of peppermint commercial sachets were investigated through gas chromatography/flame ionization detection (GC/FID) and GC/mass spectrometry (MS). Samples were prepared under similar conditions as in homemade tea. Volatiles were isolated using solid phase extraction method (SPE) with Porapak Q trap followed by desorption with acetone. Estimated mean values for short and medium chain carboxylic acids (C2-C12) and ketones lay in the range of 50-64 microg kg(-1) whilst aliphatic alcohols and acyclic hydrocarbons had values lower than 6 microg kg(-1). The major volatiles were terpenes (275-382 microg kg(-1)) that reached 89 % of the total composition. A total of 16 compounds, among them dodecane, acetoin, acetol, citral, geraniol and octanoic acid have been described by the first time in peppermint tea. These findings could be attributed to the different analytical approach employed, mainly to the use of different extraction/pre-concentration techniques. Given the apparently lower proportion of terpenes in the aqueous extract it may be that the chemical properties of the peppermint essential oil are not entirely reproduced with homemade tea. PMID:24020260

  10. Determination of Atrazine, Acetochlor, Clomazone, Pendimethalin and Oxyfluorfen in Soil by a Solid Phase Microextraction Method

    Directory of Open Access Journals (Sweden)

    Rada Đurović

    2008-01-01

    Full Text Available A solid phase microextraction (SPME method for simultaneous determination of atrazine, acetochlor, clomazone, pendimethalin and oxyfluorfen in soil samples was developed. The method is based on a combination of conventional liquid-solid procedure and a following SPME determination of the selected pesticides. Initially, various microextraction conditions, such as the fibre type, desorption temperature and time, extraction time and NaCl content, were investigated and optimized. Then, extraction efficiencies of severalsolvents (water, hexane, acetonitrile, acetone and methanol and the optimum number of extraction steps within the sample preparation step were optimized. According to the results obtained in these two sets of experiments, two successive extractions with methanol as the extraction solvent were the optimal sample preparation procedure, while the following conditions were found to be most efficient for SPME measurements: 100 μm PDMS fibre, desorption for 7 min at 2700C, 30 min extraction time and 5% NaCl content (w/v. Detection and quantification were done by gas chromatography-mass spectrometry(GC/MS. Relative standard deviation (RSD values for multiple analysis of soil samples fortified at 30 μg/kg of each pesticide were below 19%. Limits of detection (LOD for all the compounds studied were less than 2 μg/kg.

  11. Evaluation of Antibacterial Enrofloxacin in Eggs by Matrix Solid Phase Dispersion-Flow Injection Chemiluminescence

    Directory of Open Access Journals (Sweden)

    Xiaocui Duan

    2014-01-01

    Full Text Available The study based on the chemiluminescence (CL reaction of potassium ferricyanide and luminol in sodium hydroxide medium, enrofloxacin (ENRO could dramatically enhance CL intensities and incorporated with matrix solid-phase dispersion (MSPD technique (Florisil used as dispersant, dichloromethane eluted the target compounds. A simple flow injection chemiluminescence (FL-CL method with MSPD technique for determination of ENRO in eggs was described. Under optimal conditions, the CL intensities were linearly related to ENRO concentration ranging from 4.0×10-8 g.L−1 to 5.0×10-5 g.L−1, with a correlation coefficient of 0.9989 and detection limit of 5.0×10-9 g.L−1. The relative standard deviation was 3.6% at an ENRO concentration of 2.0×10-6 g.L−1. Our testing technique can help ensure food safety, and thus, protect public health.

  12. Solid phase stability of a double-minimum interaction potential system

    Energy Technology Data Exchange (ETDEWEB)

    Suematsu, Ayumi; Yoshimori, Akira, E-mail: a.yoshimori@cmt.phys.kyushu-u.ac.jp; Saiki, Masafumi; Matsui, Jun [Department of Physics, Kyushu University, Fukuoka 812-8581 (Japan); Odagaki, Takashi [School of Science and Engineering, Tokyo Denki University, Hatoyama, Saitama 350-0394 (Japan)

    2014-06-28

    We study phase stability of a system with double-minimum interaction potential in a wide range of parameters by a thermodynamic perturbation theory. The present double-minimum potential is the Lennard-Jones-Gauss potential, which has a Gaussian pocket as well as a standard Lennard-Jones minimum. As a function of the depth and position of the Gaussian pocket in the potential, we determine the coexistence pressure of crystals (fcc and bcc). We show that the fcc crystallizes even at zero pressure when the position of the Gaussian pocket is coincident with the first or third nearest neighbor site of the fcc crystal. The bcc crystal is more stable than the fcc crystal when the position of the Gaussian pocket is coincident with the second nearest neighbor sites of the bcc crystal. The stable crystal structure is determined by the position of the Gaussian pocket. These results show that we can control the stability of the solid phase by tuning the potential function.

  13. Electrodeposited apatite coating for solid-phase microextraction and sensitive indirect voltammetric determination of fluoride ions.

    Science.gov (United States)

    Mao, Yuehong; Chen, Yufei; Chu, Lin; Zhang, Xiaoli

    2013-10-15

    Electrodeposition was used to prepare a new solid phase microextraction (SPME) coatings. Two apatite SPME coatings, dicalcium phosphate dihydrate (DCPD or brushite) and hydroxyapatite (HAP) were validly and homogeneously one-step electrodeposited on glassy carbon electrode (GCE) under different conditions. The coatings were characterized by XRD, FTIR, SEM, CV and EIS. The apatite SPME coatings showed excellent and selective adsorbability to fluoride ions. A novel indirect voltammetric strategy for sensitive detection of fluoride was proposed using K3Fe(CN)6 as indicating probe. The detection principle of fluoride ions was based on the increment of steric hindrance after fluoride adsorption, which resulting in the decrease of the amperometric signal to Fe(CN)6(3-). The liner ranges were 0.5-20.0 μmol/L for n-DCPD/GCE with the limit of detection of 0.14 μmol/L and 0.1-50.0 μmol/L for n-HAP/GCE with the limit of detection of 0.069 μmol/L, respectively. The developed method was applied to the analysis of water samples (lake, spring and tap water) and the recovery values were found to be in the range of 90-106%. PMID:24054624

  14. Solid phase studies and geochemical modelling of low-cost permeable reactive barriers

    Energy Technology Data Exchange (ETDEWEB)

    Bartzas, Georgios, E-mail: gbartzas@metal.ntua.gr [Laboratory of Metallurgy, School of Mining and Metallurgical Engineering, National Technical University of Athens, Zografos Campus, 15780 Athens (Greece); Komnitsas, Kostas [Department of Mineral Resources Engineering, Technical University of Crete, 73100 Chania (Greece)

    2010-11-15

    A continuous column experiment was carried out under dynamic flow conditions in order to study the efficiency of low-cost permeable reactive barriers (PRBs) to remove several inorganic contaminants from acidic solutions. A 50:50 w/w waste iron/sand mixture was used as candidate reactive media in order to activate precipitation and promote sorption and reduction-oxidation mechanisms. Solid phase studies of the exhausted reactive products after column shutdown, using scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and X-ray diffraction (XRD), confirmed that the principal Fe corrosion products identified in the reactive zone are amorphous iron (hydr)oxides (maghemite/magnetite and goethite), intermediate products (sulfate green rust), and amorphous metal sulfides such as amFeS and/or mackinawite. Geochemical modelling of the metal removal processes, including interactions between reactive media, heavy metal ions and sulfates, and interpretation of the ionic profiles was also carried out by using the speciation/mass transfer computer code PHREEQC-2 and the WATEQ4F database. Mineralogical characterization studies as well as geochemical modelling calculations also indicate that the effect of sulfate and silica sand on the efficiency of the reactive zone should be considered carefully during design and operation of low-cost field PRBs.

  15. Adsorption and solid phase extraction of 8-hydroxyquinoline from aqueous solutions by using natural bentonite

    International Nuclear Information System (INIS)

    The nitrogen-heterocyclic compound 8-hydroxyquinoline (8HQ) is one of the components of coal tar and has a wide variety of uses in industry. Because of its toxicity for aquatic organisms and harmful effects for human health, the removal of 8HQ from aqueous solutions by adsorption onto natural bentonite was investigated in the present work. The experimental results show that the optimum pH value of 2.5 is favourable for the 8HQ adsorption. The experimental data were fitted well with the pseudo-second-order kinetic and Langmuir adsorption isotherm models at all studied temperatures. The maximum adsorption capacity obtained from the Langmuir isotherm model at 20 deg. C was 120.6 mg g-1. The calculated thermodynamic results such as ΔGo (-24.3 kJ mol-1) and ΔHo (-9.56 kJ mol-1) indicate that the adsorption process is spontaneous and exothermic in nature. Solid phase extraction of 8HQ was also performed. The X-ray diffractometry (XRD), Fourier Transform Infrared (FTIR) and thermogravimetric (TG) analyses were carried out in order to confirm the 8HQ adsorption onto bentonite. According to the obtained results, natural bentonite can be a reusable and effective adsorbent for the removal of 8HQ.

  16. Thermally stable coexistence of liquid and solid phases in gallium nanoparticles

    Science.gov (United States)

    Losurdo, Maria; Suvorova, Alexandra; Rubanov, Sergey; Hingerl, Kurt; Brown, April S.

    2016-09-01

    Gallium (Ga), a group III metal, is of fundamental interest due to its polymorphism and unusual phase transition behaviours. New solid phases have been observed when Ga is confined at the nanoscale. Herein, we demonstrate the stable coexistence, from 180 K to 800 K, of the unexpected solid γ-phase core and a liquid shell in substrate-supported Ga nanoparticles. We show that the support plays a fundamental role in determining Ga nanoparticle phases, with the driving forces for the nucleation of the γ-phase being the Laplace pressure in the nanoparticles and the epitaxial relationship of this phase to the substrate. We exploit the change in the amplitude of the evolving surface plasmon resonance of Ga nanoparticle ensembles during synthesis to reveal in real time the solid core formation in the liquid Ga nanoparticle. Finally, we provide a general framework for understanding how nanoscale confinement, interfacial and surface energies, and crystalline relationships to the substrate enable and stabilize the coexistence of unexpected phases.

  17. Analysis of Pyrazine and Volatile Compounds in Cocoa Beans Using Solid Phase Microextraction

    Directory of Open Access Journals (Sweden)

    Misnawi Jati

    2011-05-01

    Full Text Available Analisis pirazin dan senyawa volatil pada biji kakao dilakukan dengan perangkat mikroekstraksi fase padat (solid phase micro extraction, SPME, untuk mengembangkan metode ekstraksi tanpa pelarut yang efisien. Perangkat SPME dilengkapi fiber stableflex dengan polimer DVB/Carboxen/PDMS yang menjerap senyawa volatil di area headspace. Biji kakao terfermentasi disangrai dan diambil lemaknya untuk ditempatkan dalam botol bertutup septa. Sampel dipanaskan pada suhu 70OC dan serat SPME ditusukkan menembus septa untuk mengekstrak senyawa volatil dari lemak kakao selama 30 menit. Senyawa volatil lemak kakao akan dijerap oleh serat SPME dan dilepaskan kembali untuk analisis kromatografi gas. Penelitian menunjukkan pirazin dan senyawa volatil yang diekstrak oleh serat SPME dapat terdeteksi dengan baik oleh kromatografi gas. Area puncak yang dihasilkan SPME meliputi 2,83–5,35% dari area puncak yang dihasilkan syringe, kendati demikian kemampuan ekstraksi SPME dapat disetarakan dengan syringe. Lima jenis pirazin yang sering terdapat di biji kakao telah diidentifikasi, meliputi metil pirazin (2MP; 2,3 dan 2,5-dimetilpirazin (DMP; dan 2,3,5 trimetilpirazin (TrMP dan tetrametil pirazin (TMP. Senyawa lainnya juga terdeteksi meliputi alkohol, asam karboksilat, aldehida, keton, ester, pirazin, amin dan senyawa volatil lainnya, dan diketahui erat kaitannya dengan aroma khas cokelat. Keberhasilan SPME dalam ekstraksi pirazin dan senyawa volatilsemi volatil yang berperan penting dalam pembentukan aroma cokelat menandakan SPME dapat digunakan lebih lanjut untuk analisis citarasa.

  18. Polarization effects on the electric properties of urea and thiourea molecules in solid phase

    Energy Technology Data Exchange (ETDEWEB)

    Santos, O. L.; Fonseca, T. L., E-mail: tertius@ufg.br; Sabino, J. R.; Georg, H. C.; Castro, M. A. [Instituto de Física, Universidade Federal de Goiás, Campus Samambaia, 74.690-900 Goiânia, GO (Brazil)

    2015-12-21

    We present theoretical results for the dipole moment, linear polarizability, and first hyperpolarizability of the urea and thiourea molecules in solid phase. The in-crystal electric properties were determined by applying a supermolecule approach in combination with an iterative electrostatic scheme, in which the surrounding molecules are represented by point charges. It is found for both urea and thiourea molecules that the influence of the polarization effects is mild for the linear polarizability, but it is marked for the dipole moment and first hyperpolarizability. The replacement of oxygen atoms by sulfur atoms increases, in general, the electric responses. Our second-order Møller–Plesset perturbation theory based iterative scheme predicts for the in-crystal dipole moment of urea and thiourea the values of 7.54 and 9.19 D which are, respectively, increased by 61% and 58%, in comparison with the corresponding isolated values. The result for urea is in agreement with the available experimental result of 6.56 D. In addition, we present an estimate of macroscopic quantities considering explicit unit cells of urea and thiourea crystals including environment polarization effects. These supermolecule calculations take into account partially the exchange and dispersion effects. The results illustrate the role played by the electrostatic interactions on the static second-order nonlinear susceptibility of the urea crystal.

  19. Solid phase microextraction of volatile constituents from individual fresh Eucalyptus leaves of three species.

    Science.gov (United States)

    Betts, T J

    2000-03-01

    Methyl polysiloxane solid-phase microextraction fibres were used for ten minutes to adsorb volatile constituents from headspace above all or part of a single cut up fresh eucalyptus leaf kept warm at 37 degrees C. The fibres were desorbed at 200 degrees C for programmed gas chromatography (40-187 degrees C) on a methyl polysiloxane capillary. Substances were identified by mass spectra and/or authentic sample retention. Results do not correspond to published values for steam distilled oils, being richer in sesquiterpenes, of which three are common to three different species; and also in esters in two species. Five Eucalyptus citriodora leaves from the same tree over different months gave very similar analyses to a fibre in 10 min of 72.9-80.5% citronellal, 3.5-5.4% citronellol, 1.0-3.8% citronellyl acetate, 9.2-11.8% caryophyllene and 1.4-1.7% bicyclogermacrene. Six E. nicholii leaves yielded 67.2-73.7% cineole and 4.6-9.7% limonene along with 10.5-16.5% sesquiterpenes, mostly hydrocarbons, particularly bicyclogermacrene. E. globulus leaves gave only 54.0-61.3% cineole, with 19.5-24.3% alpha-pinene, 6.7-9.1% limonene and 2.1-5.4% alpha-terpinyl acetate; along with 3.6-7.7% sesquiterpenes, particularly aromadendrene, but no bicyclogermacrene. PMID:10763604

  20. Solid-phase microextraction of volatile compounds from the chopped leaves of three species of Eucalyptus.

    Science.gov (United States)

    Zini, Cláudia A; Zanin, Kelen D; Christensen, Eva; Caramão, Elina B; Pawliszyn, Janusz

    2003-04-23

    Headspace solid-phase microextraction (HS-SPME) coupled with gas chromatography and ion-trap mass spectrometry has been used to identify biogenic volatile organic compounds present in the headspace of chopped leaves of Eucalyptus (E.) dunnii, E. citriodora, and E. saligna. A simple HS-SPME method entailing 30 min of extraction at 30 degrees C was developed for this purpose. Thirty compounds were identified in the headspace of 60 juvenile chopped Eucalyptus leaves, and another 30 were tentatively identified. The presence of compounds such as (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), (E,E)-4,8,12-trimethyl-1,3,7,11-tridecatetraene (TMNT), (E,E)-alpha-farnesene, (E,E,E)-3,7,11,15-tetramethyl-1,3,6,10,14-hexadecapentaene (TMHP), beta-caryophyllene, alpha-humulene, germacrene D, and beta-cubebene in the headspace of the leaves but not in the essential oils from the same Eucalyptus trees and information about the infochemical roles of some of these compounds in other living plant systems suggest they might play a bioactive role in Eucalyptus leaves. PMID:12696957