23,753 results match your criteria Journal of Chromatography A[Journal]


Capillary electrophoretic determination of heavy-metal ions using 11-mercaptoundecanoic acid and 6-mercapto-1-hexanol co-functionalized gold nanoparticle as colorimetric probe.

J Chromatogr A 2019 Feb 8. Epub 2019 Feb 8.

College of Chemistry, Beijing Normal University, Beijing 100875, China. Electronic address:

Capillary electrophoresis (CE) and gold nanoparticle aggregation based-colorimetric detection (AuNP/ABCD) were incorporated to provide rapid, sensitive and selective detection of Cd, Pb, and Hg. CE and AuNP/ABCD were interfaced by a pressurized electric field decoupler to isolate the colorimetric reaction solution from the separation voltage. The AuNPs co-functionalized with 11-mercaptoundecanoic acid (MUA) and 6-mercapto-1-hexanol (MCH) were used as colorimetric probes, which provided enhanced sensitivity and good selectivity toward the heavy-metal ions. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.010DOI Listing
February 2019

Analysis of acidic organo(fluoro)phosphates as decomposition product of lithium ion battery electrolytes via derivatization gas chromatography-mass spectrometry.

J Chromatogr A 2019 Feb 11. Epub 2019 Feb 11.

University of Münster, MEET Battery Research Center, Corrensstraße 46, 48149, Münster, Germany. Electronic address:

Nowadays, lithium ion batteries (LIBs) are the preferred energy supply for consumer electronics and electric vehicles. But, intrinsic reactions in the LIB system lead to a reduced battery life and impaired safety properties. Organo(fluoro)phosphates (O(F)Ps) as decomposition product of the conducting salt and the organic carbonate solvent molecules of the LIB electrolyte are of high interest due to structural similarities to chemical warfare agents and therefore a supposedly high toxicity. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.022DOI Listing
February 2019

Stir bar sorptive-dispersive microextraction for trace determination of triphenyl and diphenyl phosphate in urine of nail polish users.

J Chromatogr A 2019 Feb 7. Epub 2019 Feb 7.

Department of Analytical Chemistry, University of Valencia, 46100, Burjassot, Valencia, Spain. Electronic address:

This work describes a new analytical method useful for monitoring the human exposure to the endocrine-disrupting plasticizer triphenyl phosphate (TPP) via nail polish use. The method allows trace determination of this parent compound and its main metabolite, namely diphenyl phosphate (DPP), in urine samples of nail polish users. The method is based on a novel microextraction technique termed stir bar sorptive-dispersive microextraction (SBSDME) using a magnetic composite made of CoFeO magnetic nanoparticles embedded into a mixed-mode weak anion exchange polymer (Strata-X-AW), followed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.014DOI Listing
February 2019

Modeling of the static batch desorption and dynamic column elution of geniposidic acid from a porous anion-exchanger.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

School of Resource and Environmental Science and Engineering, Hubei University of Science and Technology, Xianning 437000, PR China.

For several decades, plenty of iridoid glycosides including geniposide (GS) and geniposidic acid (GSA) in the gardenia yellow pigment extraction waste water was not recovered effectively. This study is aimed to supply an efficient GSA recycling route. In this study, a model incorporating a superficial desorption rate constant was applied to the batch GSA desorption process, i. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.060DOI Listing
January 2019
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Oligonucleotide analysis by hydrophilic interaction liquid chromatography-mass spectrometry in the absence of ion-pair reagents.

J Chromatogr A 2019 Feb 7. Epub 2019 Feb 7.

Rieveschl Laboratories for Mass Spectrometry, Department of Chemistry, University of Cincinnati, PO Box 210172, Cincinnati, OH, 45221-0172, United States. Electronic address:

Improving our understanding of nucleic acids, both in biological and synthetic applications, remains a bustling area of research for both academic and industrial laboratories. As nucleic acids research evolves, so must the analytical techniques used to characterize nucleic acids. One powerful analytical technique has been coupled liquid chromatography - tandem mass spectrometry (LC-MS/MS). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.016DOI Listing
February 2019

Operating mode selection for the separation of intermediately-eluting components with countercurrent and centrifugal partition chromatography.

J Chromatogr A 2019 Feb 11. Epub 2019 Feb 11.

Biothermodynamics, TUM School of Life Sciences Weihenstephan, Technical University of Munich, Maximus-von-Imhof-Forum 2, 85354 Freising, Germany. Electronic address:

Two operating modes that can be used for the separation of intermediately-eluting target components from complex mixtures using solid support-free liquid-liquid chromatography (LLC) include batch injections and trapping multiple dual mode (trapping MDM). Batch injections offer the advantage of simpler equipment and process design, while the trapping MDM process, although more complex, can provide improved resolution at low separation factors. In this study, a thorough comparison of batch injection and trapping MDM performance with respect to productivity is made using simulations for a wide range of separation tasks (target component/impurity separation factors; minimum purity and yield requirements). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.020DOI Listing
February 2019

Continuous erythrocyte removal and leukocyte separation from whole blood based on viscoelastic cell focusing and the margination phenomenon.

J Chromatogr A 2019 Feb 10. Epub 2019 Feb 10.

Department of Laboratory Medicine, College of Medicine, Korea University, Korea University Guro Hospital, Guro 2-Dong, Guro-Gu, Seoul, 152-703, Republic of Korea. Electronic address:

The removal of erythrocytes from whole blood is an essential step during sample preparations intended for biomedical analyses and clinical diagnoses. To address the limitations of present methods, such as centrifugation and chemical lysis, we propose a novel microfluidic device for erythrocyte removal with high-efficiency and leukocyte separation from bulk flows of highly concentrated erythrocytes using a viscoelastic non-Newtonian fluid. The proposed device is designed based on the principle of viscoelasticity-induced particle migration toward the center of the microchannel. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S00219673193014
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http://dx.doi.org/10.1016/j.chroma.2019.02.019DOI Listing
February 2019
5 Reads

Gas chromatography system constant database over an extended temperature range for nine open-tubular columns.

Authors:
Colin F Poole

J Chromatogr A 2019 Feb 2. Epub 2019 Feb 2.

Department of Chemistry, Wayne State University, Rm 185 Chemistry, Detroit, MI 48202, USA. Electronic address:

The solvation parameter model is used to characterize the retention properties of poly(octylmethylsiloxane), poly(dimethyldiphenylsiloxane), silphenylene-dimethylsiloxane copolymer, poly(dimethylmethyltrifluoropropylsiloxane), poly(3-cyanopropylphenyldimethylsiloxane), and poly(ethylene glycol) (SPB-Octyl, HP-5, Rxi-17, Rxi-5Sil MS, Rtx-OPP, DB-1701, DB-225, Rtx-440 and HP-INNOWAX) stationary phases over an extended temperature range from 60 °C to close to the maximum column operating temperature. System maps constructed from the system constant database are used to evaluate the influence of temperature on the contribution of intermolecular interactions to differences in selectivity. None of the stationary phases are hydrogen-bond acids. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.028DOI Listing
February 2019

Extraction and identification by high resolution mass spectrometry of bioactive substances in different extracts obtained from pomegranate peel.

J Chromatogr A 2019 Feb 7. Epub 2019 Feb 7.

Departamento de Química Analítica, Química Física e Ingeniería Química, Instituto de Investigación Química "Andrés M. del Río", Universidad de Alcalá, Ctra. Madrid-Barcelona Km. 33.600, 28871, Alcalá de Henares (Madrid), Spain. Electronic address:

This work proposes a method to separate proteins and polyphenols in a food byproduct with high bioactive properties and demonstrate by high performance liquid chromatography tandem mass spectrometry its efficiency. Bioactive substances were extracted using high intensity focused ultrasounds. Resulting extract (SR) was submitted to a step for the purification of proteins and to obtain a protein isolate (PI). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.018DOI Listing
February 2019

Evaluation of volatile bioactive secondary metabolites transfer from medicinal and aromatic plants to herbal teas: Comparison of different methods for the determination of transfer rate and human intake.

J Chromatogr A 2019 Feb 6. Epub 2019 Feb 6.

Dipartimento di Scienza e Tecnologia del Farmaco, Università degli Studi di Torino, via P. Giuria 9, I-10125 Torino, Italy.

A correct botanical identification and analytical quality control of volatile key-markers responsible for aroma and biological activities is necessary to monitor volatile compounds transferred from a plant to the related herbal tea and human intake to guarantee their safe use. This is mainly true for markers limited by regulations or by a recommended maximum amount of consumption per day. GC-MS is the elective technique to analyze volatiles, provided that for aqueous samples (herbal teas) an appropriate sample preparation procedure, and/or a water-compatible GC stationary phases are applied. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.012DOI Listing
February 2019

Column packing elimination in matrix solid phase dispersion by using water compatible magnetic molecularly imprinted polymer for recognition of melamine from milk samples.

J Chromatogr A 2019 Feb 7. Epub 2019 Feb 7.

Chemistry Department, Yasouj University, Yasouj, 75918-74831, Iran.

This paper reports a new variant of sample clean-up procedure based on miniaturized matrix solid phase dispersion (MSPD) combining with water compatible magnetic molecularly imprinted polymers (MMIP) for preconcentration of melamine from milk samples prior high-performance liquid chromatography with UV detection. By employing MMIP as dispersant sorbent matrix interferences could be eliminated completely and the column packing step was interestingly omitted that decreasing in glassware expenditure, labor effort and extraction time which cause improvement of the method performance. In order to investigate the functionality, morphology and magnetic properties of the prepared MMIP, it was fully characterized by FT-IR, VSM, SEM, and TEM. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.015DOI Listing
February 2019

Three-dimensional hierarchical frameworks based on molybdenum disulfide-graphene oxide-supported magnetic nanoparticles for enrichment fluoroquinolone antibiotics in water.

J Chromatogr A 2019 Feb 8. Epub 2019 Feb 8.

Key Laboratory of Bioelectrochemistry & Environmental Analysis of Gansu Province, College of Chemistry & Chemical Engineering, Northwest Normal University, Lanzhou, Gansu 730070, China; Tianjin Key Laboratory of Molecular Optoelectronics, Department of Chemistry, Tianjin University, Tianjin 300072, China. Electronic address:

Recently, water pollution caused by antibiotics is rapidly increasing. Thus, developing efficient, fast and sensitive detection methods for environmental antibiotics monitoring are still remaining elusive. Herein, a method for antibiotics analysis including lecofloxacin, pazcofloxacin and gatifloxacin in water by high performance liquid chromatography (HPLC) using molybdenum disulfide-graphene oxide-supported magnetic nanoparticles (FeO/GO/MoS) as the adsorbent of magnetic solid-phase extraction was developed. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.005DOI Listing
February 2019

Polystyrene bound silica monolith particles of reduced size as stationary phase of excellent separation efficiency in high performance liquid chromatograhy.

J Chromatogr A 2019 Feb 7. Epub 2019 Feb 7.

Department of Chemistry, Inha University, 100 Inharo, Michuhol-gu, Incheon 22212, South Korea. Electronic address:

Ground silica monolith particles of quite smaller average size (2 μm) have been prepared by sol-gel process followed by soft grinding and calcination. Next a highly efficient chromatographic stationary phase has been prepared by reaction of those particles with (3-chloropropyl) trimethoxysilane followed by initiator attachment and modification of polystyrene by reversible addition-fragmentation chain transfer polymerization. The resultant phase of ca 3 μm particle size was packed in micro-columns (1. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.013DOI Listing
February 2019
4.169 Impact Factor

Identification and quantification of perfluorooctane sulfonamide isomers by liquid chromatography-tandem mass spectrometry.

J Chromatogr A 2019 Feb 5. Epub 2019 Feb 5.

Key Laboratory of Pollution Processes and Environmental Criteria, Ministry of Education, Tianjin Key Laboratory of Environmental Remediation and Pollution Control, College of Environmental Science and Engineering, Nankai University, Tianjin, 300350, PR China. Electronic address:

Characterization of the isomers perfluorooctane sulfonamide (PFOSA), a key intermediate of the perfluorooctane sulfonate (PFOS) precursors, is a prerequisite to understand the contribution of precursors to PFOS in the environmental and biological matrices. However, the lack of commercial standards makes quantification of the PFOSA isomers in complex matrices a big challenge. For the first time, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was established to identify and quantify PFOSA isomers. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S00219673193013
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http://dx.doi.org/10.1016/j.chroma.2019.02.008DOI Listing
February 2019
1 Read

Breath analysis by two-dimensional gas chromatography with dual flame ionisation and mass spectrometric detection - Method optimisation and integration within a large-scale clinical study.

J Chromatogr A 2019 Feb 5. Epub 2019 Feb 5.

Department of Chemistry, University of Leicester, University Road, Leicester, LE1 7RH, UK. Electronic address:

Precision medicine has spurred new innovations in molecular pathology leading to recent advances in the analysis of exhaled breath as a non-invasive diagnostic tool. Volatile organic compounds (VOCs) detected in exhaled breath have the potential to reveal a wealth of chemical and metabolomic information. This study describes the development of a method for the analysis of breath, based on automated thermal desorption (TD) combined with flow modulated comprehensive two-dimensional gas chromatography (GC×GC) with dual flame ionisation and quadrupole mass spectrometric detection (FID and qMS). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.001DOI Listing
February 2019

Determination of quinalphos in human whole blood samples by high-performance thin-layer chromatography for forensic applications.

J Chromatogr A 2019 Feb 3. Epub 2019 Feb 3.

Department of Biochemistry, Gulbarga University, Kalaburagi, 585 106, Karnataka, India. Electronic address:

A simple and rapid procedure for the determination of quinalphos in human whole blood using liquid-liquid extraction and high-performance thin-layer chromatography was developed and validated. Seven different organic solvents were tested for optimum extraction of quinalphos from spiked blood samples. The effect of pH on the extraction yield of quinalphos was also examined. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.003DOI Listing
February 2019

High-performance thin-layer chromatography/bioautography and liquid chromatography-mass spectrometry hyphenated with chemometrics for the quality assessment of Morus alba samples.

J Chromatogr A 2019 Feb 4. Epub 2019 Feb 4.

Department of Pharmacognosy, Faculty of Life Sciences, University of Vienna, Althanstraße 14, 1090 Vienna, Austria. Electronic address:

Quality control is a crucial step in the production of effective and safe herbal remedies. The aim of this study was to develop a new, simple, and high throughput procedure for the quality assessment of herbal drugs using a high-performance thin-layer chromatography (HPTLC)/bioautography and UPLC-MS/MS approach combined with chemometrics. This was exemplarily shown for Morus alba L. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.006DOI Listing
February 2019

Preparation of photosensitive diazotized poly (vinyl alcohol-b-styrene) covalent capillary coatings for capillary electrophoresis separation of proteins.

J Chromatogr A 2019 Feb 4. Epub 2019 Feb 4.

Institute of Biomedical Materials and Engineering, College of Chemistry and Chemical Engineering, College of Materials Science and Engineering, Qingdao University, Qingdao, 266071, China; Laboratory for New Fiber Materials and Modern Textile, Growing Base for State Key Laboratory, Qingdao University, Qingdao, 266071, China. Electronic address:

In this paper, we have developed a novel method for the preparation of covalently connected capillary coatings in which diazotized poly (vinyl alcohol-b-styrene) (diazo-P(VA-b-St)) was used as a photosensitive coating agent. Firstly, the diazo-P(VA-b-St) coating was self-assembled on the inner surface of the capillary, and then irradiated by ultraviolet (UV) light to convert the ionic bonding into covalent bonding through the unique photochemical reaction of diazo groups. The covalently connected coatings inhibited the protein adsorption on the inner surface of the capillary, as a result, the baseline protein separation of ribonuclease A (RNase A), lysozyme (Lyz) and bovine serum albumin (BSA) were attained by utilizing the capillary electrophoresis (CE). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.02.004DOI Listing
February 2019
4.169 Impact Factor

Biaryl axially chiral derivatizing agent for simultaneous separation and sensitive detection of proteinogenic amino acid enantiomers using liquid chromatography-tandem mass spectrometry.

J Chromatogr A 2019 Jan 30. Epub 2019 Jan 30.

Institute for Innovation, Ajinomoto Co., Inc., 1-1, Suzuki-cho, Kawasaki-ku, Kawasaki-shi, 210-8681, Japan. Electronic address:

Novel sophisticated derivatizing agents for the efficient enantioselective separation and mass spectrometric detection of d- and l-amino acids have been developed. Two new axially chiral reagents derived from 6,6'-dimethyl-2,2'-biphenyldiamine were synthesized. Their chiral separation and detection abilities were evaluated by derivatizing proteinogenic amino acid standards in reversed-phase liquid chromatography-tandem mass spectrometry (LC-MS/MS). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.075DOI Listing
January 2019

The quantification of chlorinated paraffins in environmental samples by ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry.

J Chromatogr A 2019 Jan 31. Epub 2019 Jan 31.

State Key Laboratory of Organic Geochemistry, Guangdong Key Laboratory of Environment and Resources, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China. Electronic address:

As high-production-volume chemicals, chlorinated paraffins (CPs) have raised an increasing environmental concern in recent years. However, their accurate analysis and quantification is still a huge challenge due to the high complexity of their technical formulations and the interference from CPs congeners and other polychlorinated products. In this study, a novel method for the simultaneous analysis of short-chain (SC) and medium-chain (MC) CPs in a single injection has been developed using ultra-high-performance liquid chromatography coupled with Orbitrap Fusion Tribrid mass spectrometry (UHPLC-Orbitrap Fusion TMS). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.077DOI Listing
January 2019

Prediction of lab and manufacturing scale chromatography performance using mini-columns and mechanistic modeling.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Downstream Process Development and Engineering, Merck & Co., Inc., Kenilworth, NJ, USA.

Chromatography is a cornerstone of biologics downstream purification processes, and there is an ever increasing demand for improved speed and efficiency in process development. Scale-down models are used in process development to optimize operating conditions and study process robustness while expending as little time and material as possible. The advent of automated liquid handling systems and miniature columns has taken the efficiency of process development to another level by allowing up to eight column runs in parallel with column volumes under 1 ml. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.063DOI Listing
January 2019

Stable-bond polymeric reversed-phase/weak anion-exchange mixed-mode stationary phases obtained by simultaneous functionalization and crosslinking of a poly(3-mercaptopropyl)methylsiloxane-film on vinyl silica via thiol-ene double click reaction.

J Chromatogr A 2019 Feb 1. Epub 2019 Feb 1.

Institute of Pharmaceutical Sciences, Pharmaceutical (Bio-)Analysis, University of Tübingen, Auf der Morgenstelle 8, 72076 Tübingen, Germany. Electronic address:

A polymeric reversed-phase/weak anion exchange (Poly-RP/WAX) mixed-mode stationary phase has been prepared by coating of a poly(3-mercaptopropyl)methylsiloxane film on vinyl-modified silica (100 Å, 5 μm) and simultaneous in situ functionalization with N-(10-undecenoyl)-3-aminoquinuclidine as well as crosslinking to the vinyl silica surface by solventless thiol-ene double click reaction. Such bonding chemistry showed greatly enhanced stability compared to brush-type analogs with bifunctional siloxane bonding to silica. Solid-state Si-CP/MAS NMR confirmed the immobilization of the siloxane layer. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.078DOI Listing
February 2019

Analysis of potential cyanide antidote, dimethyl trisulfide, in whole blood by dynamic headspace gas chromatography-mass spectroscopy.

J Chromatogr A 2019 Jan 23. Epub 2019 Jan 23.

Department of Chemistry and Biochemistry, South Dakota State University, Brookings, SD, 57007, USA. Electronic address:

Cyanide is a rapidly acting and highly toxic chemical. It inhibits cytochrome c oxidase in the mitochondrial electron transport chain, resulting in cellular hypoxia, cytotoxic anoxia and potentially death. In order to overcome challenges associated with current cyanide antidotes, dimethyl trisulfide (DMTS), which converts cyanide to less toxic thiocyanate in vivo, has gained much attention recently as a promising next-generation cyanide antidote. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.058DOI Listing
January 2019

Investigating apolipoproteins of human high-density lipoprotein by cyclodextrin-micellar electrokinetic chromatography.

J Chromatogr A 2019 Jan 28. Epub 2019 Jan 28.

Department of Chemistry, National Changhua University of Education, Changhua, Taiwan. Electronic address:

A cyclodextrin-micellar electrokinetic chromatography (CD-MEKC) method has been developed to determine the apolipoproteins (apos) of human high-density lipoprotein (HDL). The optimal CD-MEKC conditions included a separation buffer mixture of 5 mM sodium phosphate, 40 mM bile salts (50% sodium cholate and 50% sodium deoxycholate), 25 mM carboxymethyl-β-CD (CM-β-CD) and pH 7.0. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.073DOI Listing
January 2019
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Preparative fractionation of 5'-O-caffeoylquinic acid oxidation products using centrifugal partition chromatography and their investigation by mass spectrometry.

J Chromatogr A 2019 Jan 27. Epub 2019 Jan 27.

INRA UR1268 BIA - Polyphenols, Reactivity, Processes, F-35653, Le Rheu, France; UMT ACTIA Nova(2)Cidre, F-35653, Le Rheu, France. Electronic address:

When apples are processed into juices or ciders, a great variety of neoformed molecules are generated by enzymatic oxidation of polyphenols. These phenolic oxidation products could be responsible of specific organoleptic properties in apple juices and ciders. 5'-O-Caffeoylquinic acid (CQA) is the major hydroxycinnamic acid in apple and the preferential substrate of apple polyphenoloxidase (PPO). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.071DOI Listing
January 2019

Adsorption of hydrocarbons commonly found in gasoline residues on household materials studied by inverse gas chromatography.

J Chromatogr A 2019 Jan 30. Epub 2019 Jan 30.

Department of Chemistry, Buffalo State, State University of New York, 1300 Elmwood Ave., Buffalo, NY, 14222, USA. Electronic address:

The adsorption of hydrocarbons present in gasoline residues on household materials was investigated via inverse gas chromatography (IGC). A series of hydrocarbons (n-heptane, n-octane, n-nonane, toluene, p-xylene, and 1,2,4-trimethylbenzene) and three household materials (carpet fibers, cotton fabric, and cardboard) were selected in this work. IGC measurements using columns packed with these household materials were conducted to obtain molar enthalpies of adsorption of the selected hydrocarbons over the temperature range of 40 to 70 °C. Read More

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https://linkinghub.elsevier.com/retrieve/pii/S00219673193012
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http://dx.doi.org/10.1016/j.chroma.2019.01.076DOI Listing
January 2019
2 Reads

Simultaneous determination of 58 pesticides and relevant metabolites in eggs with a multi-functional filter by ultra-high performance liquid chromatography-tandem mass spectrometry.

J Chromatogr A 2019 Jan 29. Epub 2019 Jan 29.

Institute of Quality Standards and Testing Technology for Agro-Products, Key Laboratory of Agro-product Quality and Safety, Chinese Academy of Agricultural Sciences, Beijing, 100081, China; Key Laboratory of Agri-food Quality and Safety, Ministry of Agriculture, Beijing, 100081, China. Electronic address:

A sensitive method for the simultaneous determination of 58 pesticides and relevant metabolites in eggs was developed using ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) after clean-up with a multi-functional filter (MFF) based on quick, easy, cheap, effective, rugged, and safe method (QuEChERS). The egg sample was extracted with 5 ml water and 10 ml 1% acetic acid in acetonitrile and then salt out with sodium chloride. The extracted solution was filtered directly through an MFF containing 50 mg PSA, 50 mg C18, and 150 mg magnesium sulphate before UHPLC-MS/MS analysis. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.074DOI Listing
January 2019
1 Read
4.169 Impact Factor

Germanium speciation using liquid chromatography-inductively coupled plasma-triple quadrupole mass spectrometry: Germanium in biological and chemical leaching solutions of fine-grained residues from copper smelting.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Helmholtz Centre for Environmental Research - UFZ, Department of Analytical Chemistry, Permoserstrasse 15, 04318 Leipzig, Germany; University of Leipzig, Institute of Analytical Chemistry, Linnéstrasse 3, 04103 Leipzig, Germany. Electronic address:

A new method for the speciation analysis of inorganic germanium (Ge(OH)), monomethylgermanium (MMGe) and dimethylgermanium (DMGe) in complex acidic aqueous leachates by liquid chromatography coupled to inductively coupled plasma mass spectrometry (LC-ICP-MS) was developed. The species are separated using anion exchange chromatography with tartrate added as complexing agent. When tartrate was added to the sample and the eluent chromatography was not affected by sulfate concentrations up to 100 mM. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.061DOI Listing
January 2019

High performance liquid chromatography of polyolefin plastomers/elastomers (ethylene/1-octene copolymers) - Comparison of different solvent systems.

J Chromatogr A 2019 Jan 25. Epub 2019 Jan 25.

SABIC Technology & Innovation, STC Geleen, P.O. Box 319, 6160 AH, Geleen, Netherlands.

A series of ethylene/1-octene copolymers with different chemical composition was separated in six binary mobile phases using solvent gradients and a column packed with porous graphite Hypercarb. It was found that the elution volumes of the samples were to a larger extent influenced by the choice of desorption promoting solvent (desorli: 1,2-dichlorobenzene vs. 1,2,4-trichlorobenzene) than by the choice of adsorption promoting solvent (2-ethyl-1-hexanol, 1-decanol, n-decane). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.067DOI Listing
January 2019
1 Read

Capillary electrophoresis-mass spectrometry using robust poly(ether ether ketone) capillary for tolerance to high content of organic solvents.

J Chromatogr A 2019 Jan 27. Epub 2019 Jan 27.

Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Ministry of Education, and Wuhan University School of Pharmaceutical Sciences, Wuhan, 430071, China; State Key Laboratory of Transducer Technology, Chinese Academy of Sciences, Beijing, 10080, China. Electronic address:

Nonaqueous capillary electrophoresis (CE) and organic-aqueous CE using high content of organic solvents are common techniques in capillary electrophoresis-mass spectrometry (CE-MS) due to various advantages. However, the long-term stability of commonly used polyimide coated fused silica capillary remains a major problem that polyimide coating is prone to swelling in organic solvents and aminolysis in alkaline buffer, which cause serious problems like irregular electrospray, current drop or clogging event. In this work, robust PEEK capillary was used as separation capillary for tolerance to high content of organic solvents in CE-MS system. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.070DOI Listing
January 2019
1 Read

Development of a highly sensitive liquid chromatography with tandem mass spectrometry method for the qualitative and quantitative analysis of high-intensity sweeteners in processed foods.

J Chromatogr A 2019 Jan 25. Epub 2019 Jan 25.

Tokyo Metropolitan Institute of Public Health, 3-24-1 Hyakunin-cho, Shinjuku-ku, Tokyo, 169-0073, Japan.

A new method for the simultaneous determination of two sweeteners (Advantame and Neotame) in processed foods using liquid chromatography (LC) with tandem mass spectrometry(MS/MS) was developed herein. Chromatographic separations were performed using an ACQUITY UPLC CSH C18 column at 40 °C via a mobile phase comprising 10-mmol/L ammonium formate and methanol. Samples were prepared via rapid dialysis using 30% methanol solution in a thermostatic shaker set at 160 rpm and 50 °C for 1 h. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.036DOI Listing
January 2019

An alternative approach for preparation of amide-embedded stationary phase for reversed-phase liquid chromatography.

J Chromatogr A 2019 Jan 25. Epub 2019 Jan 25.

Jiangsu Hanbon Science & Technology Co., Ltd., Huaian, 223000, China. Electronic address:

Polar-embedded stationary phases are superior to conventional alkyl stationary phases in terms of water-wettability, silanol activity and polar selectivity. A novel method was proposed for efficient preparation of amide-embedded stationary phases bearing extended aliphatic chain and large aromatic ring. The present approach, which simply required isocyanate and desired carboxylic acid, rather than the normal combination of amine/acyl chloride/proton scavenger, produced aromatic pyrenyl amide-embedded (PYE-Amide) and aliphatic docosanyl amide-embedded (C22-Amide) stationary phases. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.054DOI Listing
January 2019

Separation using high-speed counter-current chromatography and identification of 1,3-bis(4-phenylazophenyl)triazene, an impurity in the color additive D&C Red No. 17 (Sudan III).

J Chromatogr A 2019 Jan 28. Epub 2019 Jan 28.

Bioseparation Technology Laboratory, Biochemistry and Biophysics Center, NHLBI, National Institutes of Health, Bethesda, MD, USA.

The present work describes the application of high-speed counter-current chromatography to the preparative separation of a previously unreported impurity in the color additive D&C Red No. 17 (R17, Colour Index No. 26100, Sudan III). Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.072DOI Listing
January 2019

Rapid screening and identification of monoamine oxidase-A inhibitors from Corydalis Rhizome using enzyme-immobilized magnetic beads based method.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Institute of Pharmaceutical Analysis, College of Pharmacy, Jinan University, Guangzhou, 510632, China; Guangdong Province Key Laboratory of Pharmacodynamic Constituents of Traditional Chinese Medicine & New Drug Research, Jinan University, Guangzhou 510632, China. Electronic address:

Monoamine oxidase-A (MAO-A) is considered an important therapeutic target in depression. In order to rapidly screen and identify novel MAO-A inhibitors from natural products, a magnetic bead (MB) based drug discovery tool was developed in this study. MAO-A was first immobilized onto the surface of MBs, and the resulting MAO-A-immobilized MBs (MAO-A-MBs) were then applied to ligand fishing by combining them with high-performance liquid chromatography (HPLC) coupled with quadrupole time-of-flight tandem mass spectrometry (Q-TOF-MS/MS). Read More

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https://linkinghub.elsevier.com/retrieve/pii/S00219673193011
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http://dx.doi.org/10.1016/j.chroma.2019.01.062DOI Listing
January 2019
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Selective recognition and enrichment of carbamazepine in biological samples by magnetic imprinted polymer based on reversible addition-fragmentation chain transfer polymerization.

J Chromatogr A 2019 Jan 26. Epub 2019 Jan 26.

Department of Analytical Chemistry, China Pharmaceutical University, Nanjing, 211198, China; Vocational and Technical College of Guizhou Minzu University, Guiyang, Guizhou, 550025, China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, 211198, China; Key Laboratory of Drug Quality Control and Pharmacovigilance, Ministry of Education, China Pharmaceutical University, Nanjing, 211198, China. Electronic address:

A well-defined molecularly imprinted polymer (FeO@CS@MIP) was synthesized via reversible addition-fragmentation chain transfer polymerization for magnetic solid-phase extraction coupled with high-performance liquid chromatography-diode array detector to detect carbamazepine (CBZ) in biological samples. The composition of FeO@CS@MIP was selected by a two-step screening method. 4-vinyl pyridine, divinylbenzene and dimethylformamide were chosen as the functional monomer, cross-linker and porogen, respectively. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.057DOI Listing
January 2019
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Development of a practical online supercritical fluid extraction-supercritical fluid chromatography/mass spectrometry system with an integrated split-flow method.

J Chromatogr A 2019 Jan 19. Epub 2019 Jan 19.

Division of Metabolomics, Medical Institute of Bioregulation, Kyushu University, 3-1-1 Maidashi, Higashi-ku, Fukuoka, 812-8582, Japan. Electronic address:

Herein, we describe a practical online supercritical fluid extraction-supercritical fluid chromatography/mass spectrometry (SFE-SFC/MS) system with an integrated split-flow method and a pre-column trap method that is well suited for the continuous extraction and separation of a wide range of compounds, including hydrophilic ones. Although an SFE-SFC system with a splitting method is already commercially available, in this study, we added some new features to this system: 1) a splitting method that further reduces the amount of extractant introduced into SFC, 2) a trap column, connected before the analytical column, with a different separation mechanism than the analytical column in the system with the splitting method, and 3) a system for calculating the recovery rate of SFE during online SFE-SFC/MS. In the above setup, part of the analyzed extract is introduced into the separation section at a higher split ratio owing to the make-up pump flow rate, thus reducing the distortion of the target analyte peak shape caused by the use of a strong extractant. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.044DOI Listing
January 2019

Preparation of an O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine-silica hybrid monolithic column for the enantioseparation of amino acids by nano-liquid chromatography.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Departamento de Química Analítica, Química Física e Ingeniería Química, Universidad de Alcalá, Ctra. Madrid-Barcelona Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain; Instituto de Investigación Química "Andrés M. del Río" (IQAR), Universidad de Alcalá, Ctra. Madrid-Barcelona Km. 33.600, 28871 Alcalá de Henares, Madrid, Spain. Electronic address:

An O-[2-(methacryloyloxy)-ethylcarbamoyl]-10,11-dihydroquinidine (MQD)-silica hybrid monolithic column was prepared by a facile "one-step" strategy within a 100 μm I.D. capillary. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.065DOI Listing
January 2019
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Separation of polyprenols from Ginkgo biloba leaves by a nano silica-based adsorbent containing silver ions.

J Chromatogr A 2019 Jan 21. Epub 2019 Jan 21.

Institute of Chemical Industry of Forest Products, CAF, Nanjing 210042, Jiangsu, China; Key Laboratory of Biomass Energy and Material, Nanjing 210042, Jiangsu, China; National Engineering Laboratory for Biomass Chemical Utilization, Nanjing 210042, Jiangsu, China; Key and Open Laboratory on Forest Chemical Engineering, SFA, Nanjing 210042, Jiangsu, China.

Polyprenols extracted from Ginkgo biloba leaves is a kinds of unsaturated compound containing double bonds. Traditionally, the separation methods for the polyprenols are lack of selectivity and their separation efficiency are low. We synthesized two kinds of functional nano-silica containing silver ions materials (AgTCM and AgTCN) which have selectivity for unsaturated compounds to separate Ginkgo biloba leaves polyprenols for the first time. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.047DOI Listing
January 2019

Electrophoretic determination of histamine.

J Chromatogr A 2019 Jan 10. Epub 2019 Jan 10.

State Veterinary Institute, Rantířovská 93/20, 58 601, Jihlava, Czech Republic.

An electrophoretic method (on-line coupled capillary isotachophoresis with capillary zone electrophoresis) with conductometric detection (cITP-CZE-COND) for the determination of histamine in foodstuffs and feedstuffs is described. Under optimised conditions in cationic mode the histamine is well separated from other components of acidic sample extract and detected by conductimeter within 25 min. Method characteristics, i. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.024DOI Listing
January 2019

A liquid chromatographic charge transfer stationary phase based on the thiol-yne reaction.

J Chromatogr A 2019 Jan 21. Epub 2019 Jan 21.

University of Pittsburgh, Chevron Science Center, 219 Parkman Avenue, Pittsburgh, PA 15260, United States. Electronic address:

In the process of developing a pH-stable, highly crosslinked stationary phase using the thiol-yne reaction, a new charge transfer stationary phase was discovered. The first step in the preparation of the crosslinked phase is to attach 1,4-diethynylbenzene (DEB) to thiol functionalized silica particles using the thiol-yne reaction. Upon preparation of that phase, we noticed that the color of the particles was different when the modified particles were wet with aromatic solvents in comparison to wetting with nonaromatic or aqueous solvents. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.051DOI Listing
January 2019

A solid phase microextraction Arrow with zirconium metal-organic framework/molybdenum disulfide coating coupled with gas chromatography-mass spectrometer for the determination of polycyclic aromatic hydrocarbons in fish samples.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Faculty of Materials Science and Chemical Engineering, Ningbo University, Ningbo, 315211, China. Electronic address:

Solid phase microextraction (SPME) Arrows with enlarged sorption phases and Arrow-shaped tips are good alternatives to classic SPME fibers. Developing SPME Arrows with functionalized coatings has become a growing area of SPME research. In this study, a zirconium metal organic framework/molybdenum disulfide (UiO-66/MoS) composite coating modified SPME Arrow was developed and coupled with gas chromatography-mass spectrometry for the headspace extraction and detection of 16 polycyclic aromatic hydrocarbons (PAHs). Read More

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https://linkinghub.elsevier.com/retrieve/pii/S00219673193011
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http://dx.doi.org/10.1016/j.chroma.2019.01.066DOI Listing
January 2019
2 Reads

Editorial on "Multi-way chromatographic calibration - A review" by Graciela M. Escandar and Alejandro Olivieri.

Authors:
Colin F Poole

J Chromatogr A 2019 Feb;1587

Wayne State University, Department of Chemistry, Detroit, MI, USA. Electronic address:

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http://dx.doi.org/10.1016/j.chroma.2019.01.059DOI Listing
February 2019

Using ionic liquid monomer to improve the selective recognition performance of surface imprinted polymer for sulfamonomethoxine in strong polar medium.

J Chromatogr A 2019 Jan 22. Epub 2019 Jan 22.

School of Environment, Henan Key Laboratory for Environmental Pollution Control, Key Laboratory for Yellow River and Huai River Water Environmental Pollution Control, Ministry of Education, Henan Normal University, Xinxiang, Henan 453007, PR China. Electronic address:

Molecularly imprinted polymers (MIPs) synthesized by conventional functional monomers have poor specific recognition ability in strong polar solvent, which is not favorable to their applications in separation and analysis. In this work, an ionic liquid functional monomer, 1-allyl-3-vinylimidazolium chloridize, is introduced to prepare sulfamonomethoxine imprinted polymer on the surface of silica carriers in methanol. H NMR and Cl NMR spectroscopy is performed to discuss the interactions between template and the functional monomer. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.053DOI Listing
January 2019
1 Read
4.169 Impact Factor

Efficient methodology for the extraction and analysis of lipids from porcine pulmonary artery by supercritical fluid chromatography coupled to mass spectrometry.

J Chromatogr A 2019 Jan 24. Epub 2019 Jan 24.

Centre for Analysis and Synthesis, Department of Chemistry, Lund University, SE-22100, Lund, Sweden. Electronic address:

Pulmonary artery grafts are needed as cardiovascular bioprosthetics. For successful tissue recellularization after transplantation, lipids have to be removed from the donor artery. Developing a selective process to remove lipids without damaging the extracellular matrix greatly depends on knowing the amount and type of lipid compounds in the specific tissue. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.064DOI Listing
January 2019

On the performance of conically shaped columns: Theory and practice.

J Chromatogr A 2019 Jan 23. Epub 2019 Jan 23.

Waters Corporation, 34 Maple Street, Milford, MA 01757, USA.

The chromatographic performance (speed, efficiency, and gradient peak capacity for the same analysis time) of conical columns are investigated from fundamental and experimental viewpoints. A stainless steel, conically shaped column (2.1 mm i. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.055DOI Listing
January 2019

Interaction of toluene with polar stationary phases under conditions typical of hydrophilic interaction chromatography probed by saturation transfer difference nuclear magnetic resonance spectroscopy.

J Chromatogr A 2018 Dec 13. Epub 2018 Dec 13.

Department of Chemistry, Umeå University, S-901 87, Umeå, Sweden. Electronic address:

Toluene has been used as void volume (zero retention) marker since the inception of hydrophilic interaction chromatography (HILIC), based on the assumption that its hydrophobicity should prevent it from interacting with stationary phases envisioned to be covered by relatively thick layers of water. Recent work has shown that the void volumes of partly water-swollen HILIC phases are not identical to the volumes probed by toluene, yet the compound is still ubiquitously used as void volume marker. As part of our investigations of the retention mechanisms in HILIC, we probed the extent to which toluene is capable of penetrating into the water-enriched layer and to interact with the functional groups of three commercially available hydrophilic and polar stationary phases with different charge properties and water-retaining abilities, using saturation transfer difference H nuclear magnetic resonance (STD-NMR) spectroscopy at high resolution magic angle spinning (HR-MAS) conditions. Read More

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http://dx.doi.org/10.1016/j.chroma.2018.11.028DOI Listing
December 2018

Modulation of retention and selectivity in oil-in-water microemulsion liquid chromatography: A review.

J Chromatogr A 2019 Jan 19. Epub 2019 Jan 19.

Department of Analytical Chemistry, University of Valencia, Dr. Moliner 50, 46100 Burjassot, Spain. Electronic address:

Microemulsions (MEs) are stable, isotropically clear solutions consisting of an oil and water stabilized by a surfactant and a co-surfactant. Oil-in-water microemuslion liquid chromatography (MELC) is a relatively new chromatographic mode, which uses an O/W ME as mobile phase. Retention, selectivity and efficiency can be modified by changing the concentration of the ME components and the ratio between the aqueous and oil phases. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.046DOI Listing
January 2019

High-performance liquid chromatography drift-tube ion-mobility quadrupole time-of-flight/mass spectrometry for the identity confirmation and characterization of metabolites from three statins (lipid-lowering drugs) in the model plant cress (Lepidium sativum) after uptake from water.

J Chromatogr A 2019 Jan 19. Epub 2019 Jan 19.

Institute of Analytical Chemistry, Johannes Kepler University, Altenberger Strasse 69, 4040 Linz, Austria.

This work describes the metabolization of three different statins (lipid-lowering drugs) namely Atorvastatin, Fluvastatin and Simvastatin in the model plant cress (Lepidium sativum) after uptake from the growing medium. Analyzing plant extracts with HPLC hyphenated with a drift-tube ion-mobility quadrupole time-of-flight / mass spectrometer allowed the identity confirmation of more than 45 metabolites, resulting from oxidation/dehydrogenation, dehydration or hydroxylation of the parent drug or conjugation with amino acids and sugars. Metabolites were characterized by their retention times, m/z ratios, fragmentation patterns in MS/MS experiments, and their collision cross sections. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.049DOI Listing
January 2019

Separation of polystyrene nanoparticles with different coatings using two-dimensional off-line coupling of asymmetrical flow field flow fractionation and capillary electrophoresis.

J Chromatogr A 2019 Jan 23. Epub 2019 Jan 23.

Bundesanstalt für Materialforschung und -prüfung (BAM), Richard-Willstätter-Str. 11, D-12489 Berlin, Germany. Electronic address:

The successful off-line coupling of asymmetrical flow field flow fractionation (AF4) and capillary electrophoresis (CE) for separation of nanoparticles (NPs) with different surface coatings was shown. We could successfully demonstrate that, in a certain NP size range, hyphenation of both techniques significantly improved the separation of differently coated NPs. Three mixtures of polystyrene nanoparticles (PS-NPs) with comparable core sizes but different coatings (no coating/carboxyl-coated) were studied. Read More

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http://dx.doi.org/10.1016/j.chroma.2019.01.056DOI Listing
January 2019