EarlyView Articles

Skip to Navigation

The very latest articles from the scientific literature
on Wiley Online Library...


You can keep up-to date on these EarlyView articles, which focus on spectroscopy
and separation science:

Earlyview RSS Feed

rss

Filter by Journal

Browse By Journal

Dispersive liquid–liquid microextraction of five chlorophenols in water samples followed by determination using capillary electrophoresis

Published: Jul 27, 2018

Author(s): Fangfang Gao, Wenhui Lu, Huitao Liu, Jinhua Li, Lingxin Chen

Journal: ELECTROPHORESIS

Abstract Dispersive liquid–liquid microextraction (DLLME) coupled with CE was developed for simultaneous determination of five types of chlorophenols (CPs), namely 2‐chlorophenol (2‐CP), 4‐chlorophenol (4‐CP), 2,4‐dichlorophenol (2,4‐DCP), 2,6‐dichlorophenol (2,6‐DCP), and 2,4,6‐trichlorophenol (2,4,6‐TCP) in water samples. Several parameters affecting DLLME and CE conditions were systematically investigated. Under the optimized...

Read More thumbnail image: Dispersive liquidliquid microextraction of five chlorophenols in water samples followed by determination using capillary electrophoresis

Brain investigations of rodent disease models by chemical exchange saturation transfer at 21.1 T

Published: Jul 27, 2018

Author(s): Tangi Roussel, Jens T. Rosenberg, Samuel C. Grant, Lucio Frydman

Journal: NMR in Biomedicine

This study explores opportunities opened up by ultrahigh fields for in vivo saturation transfer brain magnetic resonance imaging experiments. Fast spin‐echo images weighted by chemical exchange saturation transfer (CEST) effects were collected on Sprague–Dawley rats at 21.1 T, focusing on two neurological models. One involved a middle cerebral artery occlusion emulating ischemic stroke; the other involved xenografted glioma cells...

Read More thumbnail image: Brain investigations of rodent disease models by chemical exchange saturation transfer at 21_1T

A robust deconvolution method to disentangle multiple water pools in diffusion MRI

Published: Jul 27, 2018

Author(s): Alberto De Luca, Alexander Leemans, Alessandra Bertoldo, Filippo Arrigoni, Martijn Froeling

Journal: NMR in Biomedicine

The diffusion‐weighted magnetic resonance imaging (dMRI) signal measured in vivo arises from multiple diffusion domains, including hindered and restricted water pools, free water and blood pseudo‐diffusion. Not accounting for the correct number of components can bias metrics obtained from model fitting because of partial volume effects that are present in, for instance, diffusion tensor imaging (DTI) and diffusion kurtosis imaging (DKI)....

Read More thumbnail image: A robust deconvolution method to disentangle multiple water pools in diffusion MRI

High‐resolution echo‐planar spectroscopic imaging at ultra‐high field

Published: Jul 27, 2018

Author(s): Eduardo Coello, Ralph Noeske, Brian L. Burns, Jeremy W. Gordon, Angela Jakary, Bjoern Menze, Axel Haase, Peder E.Z. Larson, Yan Li, Rolf F. Schulte

Journal: NMR in Biomedicine

MR spectroscopic imaging (MRSI) at ultra‐high field (≥7 T) benefits from improved sensitivity that allows the detection of low‐concentration metabolites in the brain. However, optimized acquisition techniques are required to overcome inherent limitations of MRSI at ultra‐high field. This work describes an optimized method for fast high‐resolution 1H‐MRSI of the brain at 7 T. The proposed acquisition sequence combines precise volume...

Read More thumbnail image: Highresolution echoplanar spectroscopic imaging at ultrahigh field

Study of the chromatographic parameters of ultra‐high‐performance supercritical fluid chromatography and method development using a design of experiments approach for the quantification of pesticides in lettuce

Published: Jul 26, 2018

Author(s): Karen Priscila de Lima, Isabel Cristina Sales Fontes Jardim, Márcia Cristina Breitkreitz

Journal: Journal of Separation Science

Abstract We examine the potential of ultra‐high‐performance supercritical fluid chromatography for multiresidue quantification of ten pesticides commonly applied to lettuce and compares it to ultra‐high‐performance liquid chromatography. Initially, a thorough study of the stationary and mobile phase composition and injection solvent was carried out. In a second step, a chemometric approach based on design of experiments was used to...

Read More thumbnail image: Study of the chromatographic parameters of ultrahighperformance supercritical fluid chromatography and method development using a design of experiments approach for the quantification of pesticides in lettuce

The feasibility of early detection and grading of apple bruises using hyperspectral imaging

Published: Jul 26, 2018

Author(s): Wenyi Tan, Laijun Sun, Fei Yang, Wenkai Che, Dandan Ye, Dan Zhang, Borui Zou

Journal: Journal of Chemometrics

Abstract The ability to determine if an apple is bruised and to provide quantitative and objective descriptions of the degree of bruising is not the only important basis for assessing apple quality but also has significance for improving the postharvest handling of apples. In this study, segmented principal component analysis for hyperspectral images in the spectral range of 401 to 1037 nm was carried out, and seven...

Read More thumbnail image: The feasibility of early detection and grading of apple bruises using hyperspectral imaging

Honoring Paul Gemperline for his 11‐year service as editor‐in‐chief of the Journal of Chemometrics

Published: Jul 26, 2018

Author(s): David Haaland

Journal: Journal of Chemometrics

Read More thumbnail image: Honoring Paul Gemperline for his 11year service as editorinchief of the Journal of Chemometrics

Role of Auger electrons in X‐ray excitation by electron beam

Published: Jul 26, 2018

Author(s): Gely V. Pavlinsky, Yury G. Lavrent'ev

Journal: X-Ray Spectrometry

We present an algorithm that allows an estimation of the number of ionizations of atoms with low atomic number by Auger electrons produced in the matrix during excitation of X‐rays by an electron beam. The dependence of Auger ionization on the atomic number of the matrix has a maximum resulting from the increasing energy of Auger electrons and the decrease of their number as a function of the atomic number. Dependence of the contribution...

Read More thumbnail image: Role of Auger electrons in Xray excitation by electron beam

Rapid and adjustable shifted excitation Raman difference spectroscopy using a dual‐wavelength diode laser at 785 nm

Published: Jul 26, 2018

Author(s): Martin Maiwald, Bernd Sumpf, Günther Tränkle

Journal: Journal of Raman Spectroscopy

Abstract In this paper, we present rapid and adjustable shifted excitation Raman difference spectroscopy (SERDS). A dual‐wavelength diode laser emitting at 785 nm is used as the excitation light source. Two laser resonators are realized in a single chip, and two distributed Bragg reflector gratings provide two excitation lines at 785 nm. For each laser line, an optical power of 170 mW is achieved. Two separate heater...

Read More thumbnail image: Rapid and adjustable shifted excitation Raman difference spectroscopy using a dualwavelength diode laser at 785nm

DNA ladders can be used to size polyphosphate resolved by polyacrylamide gel electrophoresis

Published: Jul 26, 2018

Author(s): Stephanie A. Smith, Yan Wang, James H. Morrissey

Journal: ELECTROPHORESIS

Abstract PAGE is often used to resolve inorganic polyphosphates (polyP), but unfortunately polyP size ladders are not commercially available. Since several dyes that are commonly used to detect nucleic acids in gels also stain polyP, we examined the utility of commercially available DNA size ladders for estimating polyP polymer lengths by gel electrophoresis. Narrow size fractions of polyP were prepared and their polymer lengths...

Read More thumbnail image: DNA ladders can be used to size polyphosphate resolved by polyacrylamide gel electrophoresis

Exterior‐electrode electrically driven microconcentrator

Published: Jul 26, 2018

Author(s): Chia‐Chun Hsu, Yan‐Chang Lee, Wen‐Hsin Hsieh

Journal: ELECTROPHORESIS

Abstract This study uses negative dielectrophoresis and AC electroosmosis as a driving mechanism and presents an electrically driven microconcentrator that concentrates the sample in the region exterior to the electrodes (termed as exterior‐electrode electrically driven microconcentrator in this paper). The proposed microconcentrator uses a 3‐D face‐to‐face electrode pair; the top electrode is a relatively large planar electrode,...

Read More thumbnail image: Exteriorelectrode electrically driven microconcentrator

Revisit of wall‐induced lateral migration in particle electrophoresis through a straight rectangular microchannel: Effects of particle zeta potential

Published: Jul 26, 2018

Author(s): Zhijian Liu, Di Li, Maryam Saffarian, Tzuen‐Rong Tzeng, Yongxin Song, Xinxiang Pan, Xiangchun Xuan

Journal: ELECTROPHORESIS

Abstract Previous studies have reported a lateral migration in particle electrophoresis through a straight rectangular microchannel. This phenomenon arises from the inherent wall‐induced electrical lift that can be exploited to focus and separate particles for microfluidic applications. Such a dielectrophoretic‐like force has been recently found to vary with the buffer concentration. We demonstrate in this work that the particle...

Read More thumbnail image: Revisit of wallinduced lateral migration in particle electrophoresis through a straight rectangular microchannel Effects of particle zeta potential

Chromatographic characterization of amphiphilic di‐ and tri‐block copolymers of poly(ethylene oxide) and poly(ε‐caprolactone)

Published: Jul 25, 2018

Author(s): Muhammad Irfan, Adnan Murad Bhayo, Syed Ghulam Musharraf, Muhammad Imran Malik

Journal: Journal of Separation Science

Abstract Amphiphilic di‐ and tri‐block copolymers based on poly(ethylene oxide) as a hydrophilic segment and poly(ε‐caprolactone) as a hydrophobic part are synthesized by the ring‐opening polymerization of ε‐caprolactone while using poly(ethylene glycol)s and methoxy poly(ethylene glycol)s of varying molar masses as macro‐initiators. The synthesized block copolymers are characterized with respect to their total relative molar mass...

Read More thumbnail image: Chromatographic characterization of amphiphilic di and triblock copolymers of polyethylene oxide and polycaprolactone

Second‐order calibration serves as a remedial measure for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations by HPLC without complete baseline separation

Published: Jul 25, 2018

Author(s): Xiao‐Li Yin, Hui‐Wen Gu, Qiao Wu, Tian‐Qin Peng, Shan‐Hui Zhang, Yang Liu

Journal: Journal of Separation Science

Abstract In this work, high‐performance liquid chromatography with diode array detection was applied for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations. As a result of the incomplete baseline separation caused by complex backgrounds, the classical univariate calibration method failed to determine accurate contents of the analytes. On this occasion, chemometric...

Read More thumbnail image: Secondorder calibration serves as a remedial measure for the simultaneous determination of andrographolide and dehydroandrographolide in Andrographis paniculata and its preparations by HPLC without complete baseline separation

Simultaneous enantioseparation of methcathinone and two isomeric methylmethcathinones using capillary electrophoresis assisted by 2‐hydroxyethyl‐β‐cyclodextrin

Published: Jul 25, 2018

Author(s): Paweł Mateusz Nowak, Katarzyna Olesek, Michał Woźniakiewicz, Paweł Kościelniak

Journal: ELECTROPHORESIS

Abstract Methcathinone (ephedrone), 4‐methylmethcathinone (mephedrone), and 3‐methylmethcathinone (metaphedrone) are toxicologically‐important cathinone derivatives used commonly as designer drugs. In this work we show the first method allowing to separate simultaneously all these molecules in a chiral medium, ensuring good resolution between all enantiomers. Eight cyclodextrins have been tested as potential chiral selectors, the...

Read More thumbnail image: Simultaneous enantioseparation of methcathinone and two isomeric methylmethcathinones using capillary electrophoresis assisted by 2hydroxyethylcyclodextrin

Zwitterionic codeine‐derived methacrylate monoliths for enantioselective capillary electrochromatography of chiral acids and chiral bases

Published: Jul 25, 2018

Author(s): Enrique Javier Carrasco‐Correa, Martina Ferri, Ulrich Woiwode, Yubo Ma, José Manuel Herrero‐Martínez, Guillermo Ramis‐Ramos, Wolfgang Lindner, Michael Lämmerhofer

Journal: ELECTROPHORESIS

Abstract Thiol‐ene click reaction of N‐acetyl‐L‐cysteine methyl ester to codeine, followed by reaction with allyl isocyanate and hydrolysis to the corresponding zwitterionic chiral selector and its subsequent bonding to the surface of a methacrylate monolith provided a new chiral capillary column for enantiomer separation of chiral acids and chiral bases. First, the epoxy groups of a poly(glycidyl methacrylate‐co‐ethylene ...

Read More thumbnail image: Zwitterionic codeinederived methacrylate monoliths for enantioselective capillary electrochromatography of chiral acids and chiral bases

Combined detection of AC‐electrokinetic effects: Experiments with three‐axial chicken red blood cells

Published: Jul 25, 2018

Author(s): Jan Gimsa, Kanokkan Titipornpun, Marco Stubbe, Ulrike Gimsa

Journal: ELECTROPHORESIS

Abstract Dielectrophoresis (DEP), electrorotation (ROT), and electro‐orientation were used for the dielectric spectroscopy of nucleated three‐axial chicken red blood cells (CRBCs). Because the different AC‐electrokinetic effects are not mutually independent, their DEP and ROT spectra were combined in ranges separated by the reorientation of the CRBCs in the inhomogeneous linear DEP and circular ROT fields. This behavior can be...

Read More thumbnail image: Combined detection of ACelectrokinetic effects Experiments with threeaxial chicken red blood cells

Determination of antibiotics in feedstuff samples by microemulsion electrokinetic chromatography using fullerene as additive

Published: Jul 25, 2018

Author(s): Nancy K. Nieto, Jose A. Rodriguez, Israel S. Ibarra, Julian Cruz‐Borbolla, Jose M. Vasquez‐Perez

Journal: ELECTROPHORESIS

Abstract A microemulsion electrokinetic chromatography method was developed for the simultaneous detection and quantification of ciprofloxacin, norfloxacin, sulfamethoxazole, tetracycline, and oxytetracycline in feedstuff samples. The BGE composition was optimized by applying a Taguchi parameter design and consisted of phosphate 30 mmol/L, Tween‐80 0.01 mmol/L, and fullerene 3 μmol/L, and adjusted to pH 8.0; the...

Read More thumbnail image: Determination of antibiotics in feedstuff samples by microemulsion electrokinetic chromatography using fullerene as additive

High pressure and temperature effects on the molecular crystal 2‐amino‐5‐methyl‐1,3,4‐thiadiazole

Published: Jul 25, 2018

Author(s): Thiago A. de Toledo, Ricardo R. F. Bento, Thiago R. Cunha, Paulo S. Pizani

Journal: Journal of Raman Spectroscopy

Abstract We report a detailed study of 2‐amino‐5‐methyl‐1,3,4‐thiadiazole (C3H5N3S) using Raman and infrared spectroscopy techniques combined with density functional theory at the condensed phase and for the isolated molecule in gas phase. This information provides the vibrational mode assignments, which will give a basis for the better understanding of the changes in the Raman spectra due to the temperature (from 10 to 413 K) and pressure...

Read More thumbnail image: High pressure and temperature effects on the molecular crystal 2amino5methyl134thiadiazole

Phase composition of the buried silicon interlayers in the amorphous multilayer nanostructures Co 45 Fe 45 Zr 10 a Si H 41 and Co 45 Fe 45 Zr 10 35 Al 2 O 3 65 a Si H 41

Published: Jul 25, 2018

Author(s): Evelina P. Domashevskaya, Yaroslav A. Peshkov, Vladimir A. Terekhov, Yury A. Yurakov, Konstantin A. Barkov

Journal: Surface and Interface Analysis

We consider two amorphous multilayer nanostructures (MLNS) [(Co45Fe45Zr10)/a‐Si:H]41–I and [(Co45Fe45Zr10)35(Al2O3)65/a‐Si:H]41–II that were obtained by ion‐beam sputtering. For determination of the phase composition of the buried amorphous silicon interlayers in these MLNS, we used nondestructive ultrasoft X‐ray emission spectroscopy technique (USXES). The use of the USXES enables to register the silicon Si L2,3–spectra providing the information...

Read More thumbnail image: Phase composition of the buried silicon interlayers in the amorphous multilayer nanostructures  Co 45 Fe 45 Zr 10  a  Si  H  41 and  Co 45 Fe 45 Zr 10  35  Al 2 O 3  65  a  Si  H  41
Page:   Prev 3 4 5 6 7 8 9 10 11 12 13 Next

Social Links

Share This Links

Bookmark and Share

Microsites

Suppliers Selection
Societies Selection

Banner Ad

Click here to see
all job opportunities

Most Viewed

Copyright Information

Interested in spectroscopy? Visit our sister site spectroscopyNOW.com

Copyright © 2018 John Wiley & Sons, Inc. All Rights Reserved