Journal of Chromatography A (J Chrom )

Publisher: Elsevier

Description

The Journal of Chromatography A publishes papers on all aspects of separation science including chromatography, electrochromatography, electrophoresis, hyphenated and other multi-dimensional techniques, sample preparation as well as detection methods such as mass spectrometry. Contributions consist mainly of research papers dealing with chromatographic and electrophoretic theory, instrumental developments and their analytical and preparative applications. Section A covers all areas except biomedical sciences and biomedical applications of separation science, which are published in section B: Biomedical Sciences and Applications. Electronic version.

  • Impact factor
    4.61
  • 5-year impact
    0.00
  • Cited half-life
    7.10
  • Immediacy index
    0.65
  • Eigenfactor
    0.11
  • Article influence
    0.81
  • Website
    Journal of Chromatography A website
  • ISSN
    1873-3778

Publisher details

Elsevier

  • Pre-print
    • Author can archive a pre-print version
  • Post-print
    • Author can archive a post-print version
  • Conditions
    • Pre-print allowed on any website or open access repository
    • Voluntary deposit by author of authors post-print allowed on authors' personal website, arXiv.org or institutions open scholarly website including Institutional Repository, without embargo, where there is not a policy or mandate
    • Deposit due to Funding Body, Institutional and Governmental policy or mandate only allowed where separate agreement between repository and the publisher exists.
    • Permitted deposit due to Funding Body, Institutional and Governmental policy or mandate, may be required to comply with embargo periods of 12 months to 48 months .
    • Set statement to accompany deposit
    • Published source must be acknowledged
    • Must link to journal home page or articles' DOI
    • Publisher's version/PDF cannot be used
    • Articles in some journals can be made Open Access on payment of additional charge
    • NIH Authors articles will be submitted to PubMed Central after 12 months
    • Publisher last contacted on 18/10/2013
  • Classification
    ​ green

Publications in this journal

  • [Show abstract] [Hide abstract]
    ABSTRACT: The separation performance and retention properties of four sub-2 μm underivatised silica materials were evaluated in the hydrophilic interaction chromatography (HILIC) mode. These included an organic/inorganic hybrid silica, conventional silica, narrow particle size distribution silica and a core–shell silica. Van Deemter characterisation was performed using conditions to give high retention factors (k = 5.5–6.0) with 10 cm columns to limit the contribution of extra-column dispersion. The core–shell 1.6 μm bare silica (Cortecs) was shown to be kinetically superior to fully porous particle types. Little column-to-column variation in the reduced b-coefficient was observed for the test analytes as corroborated by arrested elution experiments. However, the reduced b-coefficient was shown to be different between analytes, e.g. cytosine versus nortriptyline. It is speculated that the nature of the retention mechanism (hydrophilic versus ionic retention) and solute physiochemical properties perhaps influence the b-coefficient. Maxwell-Effective Medium Theory (EMT) applied to results for a wider range of solutes indicated that the intra-particle diffusion (Dpart) behaviour for individual compounds is broadly similar irrespective of the particle morphology in HILIC. Finally, the impact of varying buffer concentration for a test mix showed that retention and peak shape varied considerably between different silicas. High efficiency separations can be achieved for hydrophilic and basic solutes using a combination of sub-2 μm core shell bare silica particles and appropriate buffer concentrations.
    Journal of Chromatography A 10/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Six new atropisomeric etheroarenes were synthesized by connecting two 2-alkylbenzimidazole fragments via N-N junction. They differ by the substituent nature (methyl, ethyl, propyl, butyl, pentyl and hexyl) of the aliphatic function. The novel atropisomeric compounds were used as chiral probes to study the chromatographic behaviour of the amylose tris(3,5-dimethylphenyl carbamate) (Chiralpak AD-3) chiral stationary phase (CSP) under normal phase mode. The pivotal role of the length and flexibility of the 2,2’-alkyl groups on retention, enantioselectivity and enantiomer elution order was demonstrated by enantioselective HPLC analysis. Additional information on the chiral recognition mechanism was obtained from the evaluation of the correlated thermodynamic data.
    Journal of Chromatography A 09/2014; 1363:128-136.
  • [Show abstract] [Hide abstract]
    ABSTRACT: An efficient ultra high performance liquid chromatography (UHPLC)–time-of-flight high resolution mass spectrometry (TOF-HRMS) method was elaborated for the determination of hexabromocyclododecane (HBCD) diastereomers in fish samples and compared against UHPLC–Orbitrap-HRMS and UHPLC–triple quadrupole (QqQ) tandem MS (MS/MS) techniques. The TOF-HRMS analyzer was operated at high resolution (>10 000 full width at half maximum (FWHM)) with scanning the m/z range from 600 to 700, to achieve picogram quantitation limits. The effects of various operational parameters on the instrumental response were systematically investigated. Evaluation of the influence of sample clean-up procedure steps on signal suppression effect including removal of the matrix components by means of destructive acidic treatment or non-destructive gel permeation chromatography (GPC), and additional Florisil column chromatography step showed that the analytical response of UHPLC–TOF-HRMS system is much more affected by the presence of matrix components in the final extracts in comparison with UHPLC–Orbitrap-HRMS and UHPLC–QqQ-MS/MS systems. The method was robustly validated and used for the analysis of eel (Anquilla anquilla) samples originating from a Latvian lake. UHPLC–TOF-HRMS showed a suitable performance under the optimized conditions: recoveries for three selected diastereomers in the range of 99–116%; repeatability and intermediate precision expressed as relative standard deviation (RSD) in the ranges of 2.3–7.1% and 2.9–8.1%, respectively. The elaborated method achieved instrumental limits of quantification (i-LOQ) of 0.9–4.5 pg on column that were suitable for the trace analysis of three HBCD diastereomers, corresponding to the method limits of quantification (m-LOQ) of 7.0–29 pg g−1 wet weight (w.w.). The efficiency of UHPLC–TOF-HRMS method was evaluated by comparing the performance characteristics and analytical data from real samples with the validation data and real sample results obtained by applying UHPLC–Orbitrap-HRMS and UHPLC–QqQ-MS/MS techniques for the analysis of HBCD in the same fish samples. Statistical assessment of the experimental data by means of the Fiedman's test revealed that UHPLC–TOF-HRMS, UHPLC–QqQ-MS/MS and UHPLC–Orbitrap-HRMS techniques produced adequate and similar results regarding the HBCD content in fish samples. The presence of HBCD diastereomers was confirmed in all the analyzed eels at concentrations up to 554 pg g−1 w.w. for total HBCD and a diastereomer pattern typical for aquatic biota was observed with strong predominance of α-HBCD. The UHPLC–TOF-HRMS is an appropriate technique for diastereomer-specific quantification of HBCD content in fish samples.
    Journal of Chromatography A 09/2014;
  • [Show abstract] [Hide abstract]
    ABSTRACT: Diazepam and the structurally related 1,4-benzodiazepin-2-ones tetrazepam, prazepam and flunitrazepam are chiral molecules because they adopt a ground state conformation featuring a non-planar seven membered ring devoid of any reflection-symmetry element. The two conformational enantiomers of this class of benzodiazepines interconvert rapidly at room temperature by a simple ring flipping process. Low temperature HPLC on the Whelk-O1 chiral stationary phase allowed us to separate the conformational enantiomers of diazepam and of the related 1,4-benzodiazepin-2-ones, under conditions where the interconversion rate is sufficiently low, compared to the chromatographic separation rate. Diazepam, tetrazepam and prazepam showed temperature dependent dynamic HPLC profiles with interconversion plateaus indicative of on-column enantiomer interconversion (enantiomerization) in the temperature range between -10°C and -35°C, whereas for flunitrazepam on-column interconversion was observed at temperatures between -40°C and -66°C. Simulation of exchange-deformed HPLC profiles using a computer program based on the stochastic model yielded the apparent rate constants for the on-column enantiomerization and the corresponding free energy activation barriers. At -20°C the enantiomerization barriers, ΔG(≠), for diazepam, prazepam and tetrazepam were determined to be in the range 17.6-18.7kcal/mol. At -55°C ΔG(≠) for flunitrazepam was determined to be in the 15.6-15.7kcal/mol range. The experimental dynamic chromatograms and the corresponding interconversion barriers reported in this paper call for a reinterpretation of previously published results on the HPLC behavior of diazepam on chiral stationary phases.
    Journal of Chromatography A 08/2014; 1363:144-149.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Gingivitis is a highly prevalent periodontal disease around the worldwide. Porphyromonas gingivalis (P.g), Treponema denticola (T.d) and Tannerela forsythia (T.f) were considered to be three important periodontal pathogens related to gingivitis, and research shows that the counts of periodontal pathogen cells in the patients before, during, and after fixed orthodontic appliance therapy were quite different. We proposed a simple method to extract the periodontal pathogens from the periodontal pocket in this work and demonstrated a new approach to determine periodontal pathogen level based on capillary electrophoresis (CE). After polymerase chain reaction amplification of P.g (197bp), T.d (311bp), and T.f (641bp), it shows that they can rapidly identified by CE within 5min. The peak area in the eletropherogram is linearly related to the concentration of P.g, T.d, and T.f, and the correlation coefficients R(2) corresponding to them are 0.993, 0.993, and 0.956, respectively. According to this linearly relationship, the estimated concentration of P.g, T.d, and T.f in gingival crevicular fluid from one volunteer was inferred to be about 9.90×10(2), 1.48×10(3), and 9.01×10(2)cells/μl, respectively.
    Journal of Chromatography A 08/2014; 1361:286-290.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The traditional direct bioautography workflow was substantially altered to yield narrow, sharp-bounded effective zones. For the first time, microorganisms quantitatively detected the single effective compounds in complex samples, separated in parallel on a planar chromatogram. This novel effect-directed workflow was demonstrated and optimized for the discovery of endocrine disrupting compounds (EDCs) reacting with the human estrogen receptor down to the femtogram-per-zone range, like 250fg/zone for 17β-estradiol (E2). For application volumes of up to 0.5mL, estrogen-effective compounds could directly be detected in complex samples at the ultratrace level (ng/kg-range). Sharp-bounded, estrogen-effective zones discovered were further characterized by direct elution into the mass spectrometer. HPTLC-ESI-MS mass spectra of (xeno)estrogens were shown for the first time. Owed to the substantially improved zone resolution, compound assignment was reliable and a comparison of the receptor affinities was conducted for six (xeno)estrogens. Also, long-term cell cultivation of the genetically modified yeast was demonstrated on the HPTLC plate. The optimized HPTLC-pYES workflow was proven for real food samples, exemplarily shown for beer. The general applicability of generating sharp-bounded zones was successfully proven by transfer of the fundamentally improved workflow to the Bacillus subtilis bioassay used for discovery of antibiotics in plant extracts. This new era of quantitative direct bioautography in combination with mass spectrometry will accelerate the scientific understanding in a wide application field via the streamlined access to fast and reliable information on effective components in complex samples.
    Journal of Chromatography A 08/2014; 1360:288.
  • [Show abstract] [Hide abstract]
    ABSTRACT: Epinephrine-bonded polymeric monoliths for capillary electrochromatography (CEC) were developed by nucleophilic substitution reaction of epoxide groups of poly(glycidyl-methacrylate-co-ethylenedimethacrylate) (poly(GMA-co-EDMA)) monoliths using epinephrine as nucleophilic reagent. The ring opening reaction under dynamic conditions was optimized. Successful chemical modification of the monolith surface was ascertained by in situ Raman spectroscopy characterization. In addition, the amount of epinephrine groups that was bound to the monolith surface was evaluated by oxidation of the catechol groups with Ce(IV), followed by spectrophotometric measurement of unreacted Ce(IV). About 9% of all theoretical epoxide groups of the parent monolith were bonded to epinephrine. The chromatographic behavior of the epinephrine-bonded monolith in CEC conditions was assessed with test mixtures of alkyl benzenes, aniline derivatives and substituted phenols. In comparison to the poly(GMA-co-EDMA) monoliths, the epinephrine-bonded monoliths exhibited a much higher retention and slight differences in selectivity. The epinephrine-bonded monolith was further modified by oxidation with a Ce(IV) solution and compared with the epinephrine-bonded monoliths. The resulting monolithic stationary phases were evaluated in terms of reproducibility, giving RSD values below 9% in the parameters investigated.
    Journal of Chromatography A 07/2014; 1298:61–67.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A method based on the coupling of ion chromatography (IC) and electrospray ionization mass spectrometry (ESI-MS) for the separation and determination of thermal decomposition products of LiPF6-based organic electrolytes is presented. The utilized electrolytes, LP30 and LP50, are commercially available and consist of 1mol/l LiPF6 dissolved in ethylene carbonate/dimethyl carbonate and ethylene carbonate/ethyl methyl carbonate, respectively. For the separation method development three ion chromatographic columns with different capacity and stationary phase were used and compared. Besides the known hydrolysis products of lithium hexafluorophosphate, several new organophosphates were separated and identified with the developed IC-ESI-MS method during aging investigations of the electrolytes. The chemical structures were elucidated with IC-ESI-MS/MS.
    Journal of Chromatography A 06/2014; 1354:92-100.
  • [Show abstract] [Hide abstract]
    ABSTRACT: The last frontier in the chiral stationary phases (CSPs) field for chromatography enantioseparations is represented by homochiral metal organic frameworks (MOFs), a class of organic-inorganic hybrid materials built from metal-connecting nodes and organic-bridging ligands. The modular nature of these materials allows to design focused structures by combining properly metal, organic ligands and rigid polytopic spacers. Intriguingly, chiral ligands introduce molecular chirality in the MOF-network as well as homochirality in the secondary structure of materials (such as homohelicity) producing homochiral nets in a manner mimicking biopolymers (proteins, polysaccharides) which are characterized by a definite helical sense associated with the chirality of their building blocks (aminoacids or sugars). Nowadays, robust and flexible materials characterized by high porosity and surface area became available by using preparative procedures typical of the so-called reticular synthesis. This review focuses on recent developments in the synthesis and applications of homochiral MOFs as supports for chromatography enantioseparations. Indeed, despite this field is in its infancy, interesting results have been produced and a critical overview of the twelve reported applications for gas chromatography (GC) and high-performance liquid chromatography (HPLC) can orient the reader approaching the field. Mechanistic aspects are shortly discussed and a view regarding future trends in this field is provided.
    Journal of Chromatography A 06/2014; 1363:11-26.
  • [Show abstract] [Hide abstract]
    ABSTRACT: A fast carbohydrate screening platform processible in 96-well format is described. The method is suitable for the determination of various carbohydrates out of complex mixtures as obtained by acidic hydrolysis of carbohydrates polymers. The chromatographic conditions for an efficient separation (12 min) and the derivatization process with 1-phenyl-3-methyl-5-pyrazolone (PMP) were optimized for high resolution separation and simultaneous determination of deoxy-, amino-, anhydro-sugars as well as hexoses, pentoses, dimers, uronic acids and degradation products like furfural and hydroxymethylfurfural (HMF). The potential to quantify with UV- and MS-detector in the same range has been demonstrated for 20 different compounds. Finally, the matrix effects of the hydrolysis were positively evaluated. The micro scale hydrolysis and PMP-derivatization without any extraction or drying steps, both in 96-well format, result in a fast and intuitive sample preparation. In combination with a fast liquid chromatography coupled to UV and electrospray ionization ion trap detection (LC-UV-ESI-MS/MS) for the qualification and quantification of various sugars, dimers and degradation products, this method shows great performance in carbohydrate analysis
    Journal of Chromatography A 05/2014;