journal
MENU ▼
Read by QxMD icon Read
search

Journal of Chromatography. A

journal
https://www.readbyqxmd.com/read/28089276/simultaneous-separation-of-neutral-and-cationic-analytes-by-one-dimensional-open-tubular-capillary-electrochromatography-using-zeolitic-imidazolate-framework-8-as-stationary-phase
#1
Congjie Pan, Wenjuan Lv, Guoxiu Wang, Xiaoying Niu, Heying Guo, Xingguo Chen
Developing simple methods for separation of analytes that belong to different classes is of great importance. Herein, we developed a simple one-dimensional (1-D) capillary electrochromatography method to demonstrate the simultaneous separation of target fractions that belong to two different classes (i.e., cationic and neutral analytes) without switching buffer solution by a zeolitic imidazolate framework ZIF-8 coated capillary column. Owing to the difference of charge-to-mass ratio of the cationic analytes, the interaction of the cationic analytes and coating material ZIF-8 and the hydrophobic interactions between the neutral analytes and the microporous framework of ZIF-8, six cationic analytes and four neutral analytes were simultaneously separated in a single run by 1-D capillary electrochromatography...
January 11, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28093206/urea-formaldehyde-monolithic-column-for-hydrophilic-in-tube-solid-phase-microextraction-of-aminoglycosides
#2
Jiabin Wang, Qi Zhao, Nan Jiang, Wenbang Li, Li Chen, Xucong Lin, Zenghong Xie, Lijun You, Qiqing Zhang
A novel urea-formaldehyde (UF) monolithic column has been developed and exploited as a sorbent for hydrophilic in-tube solid-phase microextraction (in-tube SPME) of aminoglycosides (AGs). Because of the innate hydrophilicity, UF monolith showed high extraction efficiency towards these hydrophilic analytes. The adsorption capacities for target compounds dissolved in water/ACN (1:1, v/v) were in the range of 5.18-7.36μg/cm. Due to the lack of a chromophore, evaporative light scattering detector (ELSD) was selected as the detector for AGs, and coupled with the online in-tube SPME-HPLC system...
January 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28089277/accurate-determination-of-residual-acrylic-acid-in-superabsorbent-polymer-of-hygiene-products-by-headspace-gas-chromatography
#3
Shu-Xin Zhang, Xin-Sheng Chai, Ran Jiang
This work reports on a method for the determination of residual acrylic acid (AA) in the superabsorbent polymers for hygiene products by headspace analysis. It was based on water extraction for the polymer sample at a room temperature for 50min. Then, the AA in the extractant reacted with bicarbonate solution in a closed headspace sample vial, from which the carbon dioxide generated from the reaction (within 20min at 70°C) was detected by gas chromatography (GC). It was found that there is adsorption partition equilibrium of AA between solid-liquid phases...
January 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28089274/retention-behavior-of-alkyl-substituted-polycyclic-aromatic-sulfur-heterocycle-isomers-in-gas-chromatography-on-stationary-phases-of-different-selectivity
#4
Walter B Wilson, Lane C Sander, Jorge O Oña-Ruales, Stephanie G Mössner, Leonard M Sidisky, Milton L Lee, Stephen A Wise
Retention indices for 10 sets of alkyl-substituted polycyclic aromatic sulfur heterocycles (PASHs) isomers (total of 80 PASHs) were determined using gas chromatography with three different stationary phases: a 50% phenyl phase, a 50% liquid crystalline dimethylpolysiloxane (LC-DMPS) phase, and an ionic liquid (IL) phase. Correlations between the retention behavior on the three stationary phases and PASH geometry [length-to-breadth (L/B) and thickness (T)] were investigated for the following PASHs: 4 methyl-substituted dibenzothiophenes (DBTs), 3 ethyl-substituted DBTs, 15 dimethyl-substituted DBTs, 8 trimethyl-substituted DBTs, 15 methyl-substituted naphthothiophenes, 30 methyl-substituted benzonaphthothiophenes, and 5 methyl-substituted tetrapheno[1,12-bcd]thiophene...
January 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28089272/retention-behavior-of-isomeric-polycyclic-aromatic-sulfur-heterocycles-in-gas-chromatography-on-stationary-phases-of-different-selectivity
#5
Walter B Wilson, Lane C Sander, Jorge O Oña-Ruales, Stephanie G Mössner, Leonard M Sidisky, Milton L Lee, Stephen A Wise
Retention indices for 48 polycyclic aromatic sulfur heterocycles (PASHs) were determined using gas chromatography with three different stationary phases: a 50% phenyl phase, a 50% liquid crystalline dimethylpolysiloxane (LC-DMPS) phase, and an ionic liquid (IL) phase. Correlations between the retention behavior on the three stationary phases and PASH geometry (L/B and T, i.e., length-to-breadth ratio and thickness, respectively) were investigated for the following four isomer sets: (1) 4 three-ring molecular mass (MM) 184Da PASHs, (2) 13 four-ring MM 234Da PASHs, (3) 10 five-ring MM 258Da PASHs, and (4) 20 five-ring MM 284Da PASHs...
January 10, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28088360/hollow-porous-ionic-liquids-composite-polymers-based-solid-phase-extraction-coupled-online-with-high-performance-liquid-chromatography-for-selective-analysis-of-hydrophilic-hydroxybenzoic-acids-from-complex-samples
#6
Xingping Dai, Dongsheng Wang, Hui Li, Yanyi Chen, Zhicheng Gong, Haiyan Xiang, Shuyun Shi, Xiaoqing Chen
Polar and hydrophilic properties of hydroxybenzoic acids usually made them coelute with interferences in high performance liquid chromatography (HPLC) analysis. Then selective analysis of them was necessary. Herein, hollow porous ionic liquids composite polymers (PILs) based solid phase extraction (SPE) was firstly fabricated and coupled online with HPLC for selective analysis of hydroxybenzoic acids from complex matrices. Hollow porous PILs were firstly synthesized using Mobil Composition of Matter No. 48 (MCM-48) spheres as sacrificial support, 1-vinyl-3-methylimidazolium chloride (VMIM(+)Cl(-)) as monomer, and ethylene glycol dimethacrylate (EGDMA) as cross-linker...
January 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28087055/graft-modification-of-cotton-with-phosphate-group-and-its-application-to-the-enrichment-of-phosphopeptides
#7
Xiao-Mei He, Xi Chen, Bi-Feng Yuan, Yu-Qi Feng
Grafting copolymerization, especially "grafting from" approach, has attracted a great attention for the preparation of cellulose-based materials with various functionalities. In this study, a novel phosphate group-containing cotton fiber-based material, CF-NH2-AZO-p(VPA-x), was successfully synthesized by a "grafting from" radical polymerization approach using vinyl phosphonic acid (VPA) as monomer. The phosphate group content of CF-NH2-AZO-p(VPA-x) could be easily regulated by adjusting the concentration of VPA monomer...
January 9, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28093205/characterization-of-peak-capacity-of-microbore-liquid-chromatography-columns-using-gradient-kinetic-plots
#8
Terence Hetzel, Christina Blaesing, Martin Jaeger, Thorsten Teutenberg, Torsten C Schmidt
The performance of micro-liquid chromatography columns with an inner diameter of 0.3mm was investigated on a dedicated micro-LC system for gradient elution. Core-shell as well as fully porous particle packed columns were compared on the basis of peak capacity and gradient kinetic plot limits. The results for peak capacity showed the superior performance of columns packed with sub-2μm fully porous particles compared to 3.0μm fully porous and 2.7μm core-shell particles within a range of different gradient time to column void time ratios...
January 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28087056/extraction-chromatographic-separations-of-tantalum-and-tungsten-from-hafnium-and-complex-matrix-constituents
#9
Mathew S Snow, Martha R Finck, Kevin P Carney, Samuel S Morrison
Tantalum (Ta), hafnium (Hf), and tungsten (W) analyses from complex matrices require high purification of these analytes from each other and major/trace matrix constituents, however, current state-of-the-art Ta/Hf/W separations rely on traditional anion exchange approaches that show relatively similar distribution coefficient (Kd) values for each element. This work reports an assessment of three commercially available extraction chromatographic resins (TEVA, TRU, and UTEVA) for Ta/Hf/W separations. Batch contact studies show differences in Ta/Hf and Ta/W Kd values of up to 10(6) and 10(4) (respectively), representing an improvement of a factor of 100 and 300 in Ta/Hf and Ta/W Kd values (respectively) over AG1×4 resin...
January 8, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28077236/high-resolution-ultrahigh-pressure-long-column-reversed-phase-liquid-chromatography-for-top-down-proteomics
#10
Yufeng Shen, Nikola Tolić, Paul D Piehowski, Anil K Shukla, Sangtae Kim, Rui Zhao, Yi Qu, Errol Robinson, Richard D Smith, Ljiljana Paša-Tolić
Separation of proteoforms for global intact protein analysis (i.e. top-down proteomics) has lagged well behind what is achievable for peptides in traditional bottom-up proteomic approach and is becoming a true bottle neck for top-down proteomics. Herein, we report use of long (≥1M) columns containing short alkyl (C1-C4) bonded phases to achieve high-resolution RPLC for separation of proteoforms. At a specific operation pressure limit (i.e., 96.5MPa or 14Kpsi used in this work), column length was found to be the most important factor for achieving maximal resolution separation of proteins when 1...
January 5, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28089068/the-experimental-design-approach-to-eluotropic-strength-of-20-solvents-in-thin-layer-chromatography-on-silica-gel
#11
Łukasz Komsta, Barbara Stępkowska, Robert Skibiński
The eluotropic strength on thin-layer silica plates was investigated for 20 chromatographic grade solvents available in current market. 35 model compounds were used as test subjects in the investigation. The use of modern mixture screening design allowed to estimate each solvent as a separate elution coefficient with an acceptable error of estimation (0.0913 of RM value). Additional bootstrapping technique was used to check the distribution and uncertainty of eluotropic estimates, proving very similar confidence intervals to linear regression...
January 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28081899/barchan-blob-alignment-for-robust-chromatographic-analysis
#12
Camille Couprie, Laurent Duval, Maxime Moreaud, Sophie Hénon, Mélinda Tebib, Vincent Souchon
Two-dimensional gas chromatography (GC×GC) plays a central role into the elucidation of complex samples. The automation of the identification of peak areas is of prime interest to obtain a fast and repeatable analysis of chromatograms. To determine the concentration of compounds or pseudo-compounds, templates of blobs are defined and superimposed on a reference chromatogram. The templates then need to be modified when different chromatograms are recorded. In this study, we present a chromatogram and template alignment method based on peak registration called BARCHAN...
January 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28069169/the-experimental-design-approach-to-eluotropic-strength-of-20-solvents-in-thin-layer-chromatography-on-silica-gel
#13
Łukasz Komsta, Barbara Stępkowska, Robert Skibiński
The eluotropic strength on thin-layer silica plates was investigated for 20 chromatographic grade solvents available in current market. 35 model compounds were used as test subjects in the investigation. The use of modern mixture screening design allowed to estimate each solvent as a separate elution coefficient with an acceptable error of estimation (0.0913 of RM value). Additional bootstrapping technique was used to check the distribution and uncertainty of eluotropic estimates, proving very similar confidence intervals to linear regression...
January 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28069168/advances-in-organic-polymer-based-monolithic-column-technology-for-high-resolution-liquid-chromatography-mass-spectrometry-profiling-of-antibodies-intact-proteins-oligonucleotides-and-peptides
#14
REVIEW
Sebastiaan Eeltink, Sam Wouters, José Luís Dores-Sousa, Frantisek Svec
This review focuses on the preparation of organic polymer-based monolithic stationary phases and their application in the separation of biomolecules, including antibodies, intact proteins and protein isoforms, oligonucleotides, and protein digests. Column and material properties, and the optimization of the macropore structure towards kinetic performance are also discussed. State-of-the-art liquid chromatography-mass spectrometry biomolecule separations are reviewed and practical aspects such as ion-pairing agent selection and carryover are presented...
January 4, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28081901/development-of-a-multichannel-microfluidic-system-with-schlieren-imaging-microscopy-for-online-chip-based-moving-boundary-electrophoresis
#15
Atefeh S Zarabadi, Janusz Pawliszyn, Mojtaba Hajialamdari
The concentration gradient detection method based on the Schlieren optics employed for electrophoresis analyses by extending the technology to a multi-channel system using a prototyped microfluidic chip (thinXXS Micro-technology, Germany). The results prove that coupling a chip-based microfluidic device with Schlieren detection is an appropriate approach to improve the electrophoretic separations. The effects of channel's geometry and dimension were investigated by conducting the experiments in channels with different cross sectional areas...
January 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28081900/broadening-of-analyte-streams-due-to-a-transverse-pressure-gradient-in-free-flow-isoelectric-focusing
#16
Debashis Dutta
Pressure-driven cross-flows can arise in free-flow isoelectric focusing systems (FFIEF) due to a non-uniform electroosmotic flow velocity along the channel width induced by the pH gradient in this direction. In addition, variations in the channel cross-section as well as unwanted differences in hydrostatic heads at the buffer/sample inlet ports can also lead to such pressure-gradients which besides altering the equilibrium position of the sample zones have a tendency to substantially broaden their widths deteriorating the separations...
January 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28073452/characterization-of-cyclitol-glycosides-by-gas-chromatography-coupled-to-mass-spectrometry
#17
L Ruiz-Aceituno, C Carrero-Carralero, A I Ruiz-Matute, L Ramos, M L Sanz, I Martínez-Castro
Several cyclitol glycosides have been characterised as trimethylsilyl derivatives by their gas chromatographic (GC) retention data (linear retention indices) and electron impact mass spectrometric (MS) profiles. Both GC-MS results have been related to cyclitol glycosides structural features. Abundance ratios of characteristic m/z ions 133/129 and 260/265 have been proposed to distinguish glycosyl-inositols from glycosyl-methyl-inositols. These ratios in combination with the presence or absence of m/z 375 ion allowed the unequivocal characterization of cyclitol glycosides...
January 3, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28073451/implications-of-turbulent-flow-in-connecting-capillaries-used-in-high-performance-liquid-chromatography
#18
John Halvorson, Abraham M Lenhoff, Monika Dittmann, Dwight R Stoll
The ongoing movement in HPLC toward the use of small columns packed with small particles for high speed separations results in eluted peaks with very small volumetric variances. Avoiding degradation of separation performance under these conditions requires careful consideration of all sources of extra-column peak dispersion. Recent trends towards decreased diameters of connecting capillaries and increased flow rates for analytical-scale separations can result in Reynolds numbers that exceed 2000. This raises the possibility of a transition from laminar to turbulent flow, thereby resulting in a higher than expected pressure drop across the capillary at a given flow rate...
December 31, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28063642/preparation-and-characterization-of-magnetic-wells-dawson-heteropoly-acid-nanoparticles-for-magnetic-solid-phase-extraction-of-aromatic-amines-in-water-samples
#19
Amirhassan Amiri, Hamid Reza Saadati-Moshtaghin, Farokhzad Mohammadi Zonoz, Azadeh Targhoo
In this work, aminopropyl modified silica-coated magnetite nanoparticles with Wells-Dawson heteropoly acid (P2W17Fe@APSCMNPs) was first synthesized and underwent highly efficient magnetic solid-phase extraction (MSPE) of aromatic amines from aqueous samples. The resulted nanomaterials were characterized with different physicochemical techniques such as Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and vibrating sample magnetometry (VSM). Aniline, N,N-dimethylaniline, o-toluidine and 3-chloroaniline were selected as target compounds...
December 31, 2016: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28088359/argentation-chromatography-coupled-to-ultrahigh-resolution-mass-spectrometry-for-the-separation-of-a-heavy-crude-oil
#20
Lilla Molnárné Guricza, Wolfgang Schrader
Simplification of highly complex mixtures such as crude oil by using chromatographic methods makes it possible to get more detailed information about the composition of the analyte. Separation by argentation chromatography can be achieved based on the interaction of different strength between the silver ions (Ag(+)) immobilized through a spacer on the silica gel surface and the π-bonds of the analytes. Heavy crude oils contain compounds with a high number of heteroatoms (N, O, S) and a high degree of unsaturation thus making them the perfect analyte for argentation chromatography...
December 30, 2016: Journal of Chromatography. A
journal
journal
31521
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"