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1. Apparent efficiency of serially coupled columns in gradient elution liquid chromatography: Extension to the combination of any column formats

Author:
Codesido, Santiago; Rudaz, Serge; Guillarme, Davy; Horváth, Krisztián; Fekete, Szabolcs
Source:
Journal of chromatography 2019 v.1588 pp. 159-162
ISSN:
0021-9673
Subject:
liquid chromatography,   etc   ; equations; models;     Show all 3 Subjects
Abstract:
... It was shown earlier that in serially coupled column systems, not only retention (selectivity) but peak width as well can change and the apparent peak width depends on the order of the columns. A generic equation has been developed to describe the apparent efficiency of serially coupled columns in gradient elution liquid chromatography mode. In a previous work, the theoretical basis for a two-colu ...
DOI:
10.1016/j.chroma.2018.12.037

2. Experimental and numerical study of band-broadening effects associated with analyte transfer in microfluidic devices for spatial two-dimensional liquid chromatography created by additive manufacturing

Author:
Adamopoulou, Theodora; Nawada, Suhas; Deridder, Sander; Wouters, Bert; Desmet, Gert; Schoenmakers, Peter J.
Source:
Journal of chromatography 2019 v.1598 pp. 77-84
ISSN:
0021-9673
Subject:
comprehensive two-dimensional liquid chromatography; liquid chromatography,   etc   ; fluid mechanics; manufacturing;     Show all 4 Subjects
Abstract:
... Conventional one-dimensional column-based liquid chromatographic (LC) systems do not offer sufficient separation power for the analysis of complex mixtures. Column-based comprehensive two-dimensional liquid chromatography offers a higher separation power, yet suffers from instrumental complexity and long analysis times. Spatial two-dimensional liquid chromatography can be considered as an alternat ...
DOI:
10.1016/j.chroma.2019.03.041

3. Pressure drop in liquid chromatography

Author:
Podgornik, Aleš
Source:
Journal of separation science 2019 v.42 no.1 pp. 72-88
ISSN:
1615-9306
Subject:
liquid chromatography,   etc   ; compressibility; pressure; separation;     Show all 4 Subjects
Abstract:
... Measurement of pressure drop is routinely performed during chromatographic runs. In many cases this information is only used for regulation of mobile phase flow rate to keep pressure drop below defined limit. However, pressure drop can provide additional important information about performance of chromatographic process. In this review different parameters affecting pressure drop such as compressi ...
DOI:
10.1002/jssc.201800882

4. Significance of previtamin D chromatographic resolution in the accurate determination of vitamin D3 by HPLC‒UV

Author:
Woollard, David C.; Indyk, Harvey E.; Gill, Brendon D.
Source:
Subtropical plant science 2019 v.79 pp. 1-4
ISSN:
0889-1575
Subject:
high performance liquid chromatography,   etc   ; absorptivity; cholecalciferol; ergocalciferol;     Show all 4 Subjects
Abstract:
... Conventional methods using HPLC with UV detection have used vitamin D2 as an internal standard with the expectation that this fully compensates for the heat-dependent equilibrium of vitamin D3 with its previtamin. Previtamin D has a different spectral absorptivity from vitamin D and may be present in different proportions in samples and standards. Therefore, vitamin D2 and vitamin D3 and their pre ...
DOI:
10.1016/j.jfca.2019.02.010

5. Challenges in the identification process of phenidate analogues in LC‐ESI‐MS/MS analysis: Information enhancement by derivatization with isobutyl chloroformate

Author:
Shamai Yamin, Tamar; Prihed, Hagit; Weissberg, Avi
Source:
Journal of mass spectrometry 2019 v.54 no.3 pp. 266-273
ISSN:
1076-5174
Subject:
liquid chromatography,   etc   ; derivatization; tandem mass spectrometry;     Show all 3 Subjects
Abstract:
... A new analytical technique for the structural elucidation of four representative phenidate analogues possessing a secondary amine residue, which leads to a major/single amine‐representative fragment/product ion at m/z 84 both in their GC‐EI‐MS and LC‐ESI‐MS/MS spectra, making their identification ambiguous, was developed. The method is based on “in vial” chemical derivatization with isobutyl chlor ...
DOI:
10.1002/jms.4327

6. Correction to: Lloyd R. Snyder: An Appreciation 1931–2018

Author:
Molnár, Imre
Source:
Chromatographia 2019 v.82 no.2 pp. 513
ISSN:
0009-5893
Subject:
high performance liquid chromatography,   etc   ; gas chromatography; scientists;     Show all 3 Subjects
Abstract:
... The original version of this article unfortunately contained a mistake. ...
DOI:
10.1007/s10337-019-03692-2

7. Femtoliter Gradient Elution System for Liquid Chromatography Utilizing Extended Nanofluidics

Author:
Shimizu, Hisashi; Toyoda, Kouto; Mawatari, Kazuma; Terabe, Shigeru; Kitamori, Takehiko
Source:
Analytical chemistry 2019 v.91 no.4 pp. 3009-3014
ISSN:
1520-6882
Subject:
high performance liquid chromatography,   etc   ; models; proteins; pumps;     Show all 4 Subjects
Abstract:
... A gradient system was developed for the separation of proteins on a femtoliter scale utilizing nanofluidic channels. In the history of chromatography, miniaturization of the separation column has been important for efficient separation and downsizing of instruments. Previously, our group developed a small and highly efficient chromatography system utilizing nanofluidic channels, although a flexibl ...
DOI:
10.1021/acs.analchem.8b05302

8. 3D-Printed Stationary Phases with Ordered Morphology: State of the Art and Future Development in Liquid Chromatography

Author:
Salmean, Christopher; Dimartino, Simone
Source:
Chromatographia 2019 v.82 no.1 pp. 443-463
ISSN:
0009-5893
Subject:
liquid chromatography,   etc   ; manufacturing; microchip technology; printers;     Show all 4 Subjects
Abstract:
... Stationary phases with precisely ordered morphology have the potential to drastically improve the performance of chromatographic operations, both in the analytical and in the preparative/industrial fields. The recent wave of additive manufacturing, aka 3D printing, gives the unprecedented ability to fabricate such stationary phases and to experimentally prove the theoretical principles of ordered ...
DOI:
10.1007/s10337-018-3671-5

9. Resolving power in liquid chromatography: A trade‐off between efficiency and analysis time

Author:
Dores‐Sousa, José Luís; De Vos, Jelle; Eeltink, Sebastiaan
Source:
Journal of separation science 2019 v.42 no.1 pp. 38-50
ISSN:
1615-9306
Subject:
liquid chromatography,   etc   ; equipment performance; models; separation;     Show all 4 Subjects
Abstract:
... This review describes chromatographic dispersion and different plate‐height models frequently used to assess the chromatographic performance of ultra‐high‐pressure liquid chromatography column technology. Furthermore, different performance indices, including the resolution, the separation impedance, and kinetic plots are discussed allowing to quantify and visualize the resolving power in liquid ch ...
DOI:
10.1002/jssc.201800891

10. Untargeted LC/MS-based metabolic phenotyping (metabonomics/metabolomics): The state of the art

Author:
Gika, Helen; Virgiliou, Christina; Theodoridis, Georgios; Plumb, Robert S.; Wilson, Ian D.
Source:
Journal of chromatography 2019 v.1117 pp. 136-147
ISSN:
1570-0232
Subject:
high performance liquid chromatography; ultra-performance liquid chromatography,   etc   ; mass spectrometry; metabolome; metabolomics; phenotype;     Show all 6 Subjects
Abstract:
... Liquid chromatography (LC) hyphenated to mass spectrometry is currently the most widely used means of determining metabolic phenotypes via both untargeted and targeted analysis. At present a range of analytical separations, including reversed-phase, hydrophilic interaction and ion-pair LC are employed to maximise metabolome coverage with ultra (high) performance liquid chromatography (UHPLC) incre ...
DOI:
10.1016/j.jchromb.2019.04.009

11. Column selection for comprehensive two-dimensional liquid chromatography using the hydrophobic subtraction model

Author:
Lindsey, Rebecca K.; Eggimann, Becky L.; Stoll, Dwight R.; Carr, Peter W.; Schure, Mark R.; Siepmann, J. Ilja
Source:
Journal of chromatography 2019 v.1589 pp. 47-55
ISSN:
0021-9673
Subject:
comprehensive two-dimensional liquid chromatography; liquid chromatography,   etc   ; chemical species; hydrophobicity; models; moieties; screening;     Show all 7 Subjects
Abstract:
... Two-dimensional (2D) liquid chromatography (2DLC) methods have grown in popularity due to their enhanced peak capacity that allows for resolving complex samples. Given the large number of commercially available column types, one of the major challenges in implementing 2DLC methods is the selection of suitable column pairs. Column selection is typically informed by chemical intuition with subsequen ...
DOI:
10.1016/j.chroma.2018.09.018

12. Fast determination of omeprazole in extemporaneous suspensions used in paediatrics and stability studies

Author:
Kučerová, Kateřina; Reiská, Veronika; Švec, František; Krčmová, Lenka Kujovská; Matysová, Ludmila
Source:
Analytical methods 2019 v.11 no.4 pp. 517-523
ISSN:
1759-9679
Subject:
high performance liquid chromatography; ultra-performance liquid chromatography,   etc   ; acetonitrile; methylparaben; patients; pediatrics; phosphates; therapeutics;     Show all 8 Subjects
Abstract:
... A simple and fast ultra-high-performance liquid chromatography method with UV detection for the separation and quantification of omeprazole and the impurities of omeprazole and methylparaben (the internal standard) in six extemporaneous suspensions has been developed and fully validated. Isocratic elution was carried out using a Kinetex™ C18 column, 50 × 2.1 mm packed with 1.7 μm porous shell part ...
DOI:
10.1039/c8ay02547a

13. Pulsed elution modulation for on-line comprehensive two-dimensional liquid chromatography coupling reversed phase liquid chromatography and hydrophilic interaction chromatography

Author:
Chen, Yingzhuang; Wu, Yajun; Liu, Xiaoming; Li, Bowen; Hu, Deping; Huang, Si; Ma, Ming; Chen, Bo
Source:
Journal of chromatography 2019 v.1583 pp. 98-107
ISSN:
0021-9673
Subject:
comprehensive two-dimensional liquid chromatography; reversed-phase liquid chromatography,   etc   ; fractionation; hydrophilic interaction chromatography; saponins; solvents;     Show all 6 Subjects
Abstract:
... In this work, a reversed phase liquid chromatography (RPLC) coupling to hydrophilic interaction chromatography (HILIC) system has been constructed, combining with pulsed elution reversed phase liquid chromatography (PE-RPLC) and HILIC to comprehensively analyze P. ginseng root extract, which is rich in saponins. By the application of pulsed elution (PE) modulation technique, the proposed RPLC × HI ...
DOI:
10.1016/j.chroma.2018.11.023

14. Measurement of the Band Broadening of UV Detectors used in Ultra-high Performance Liquid Chromatography using an On-tubing Fluorescence Detector

Author:
Vanderlinden, Kim; Desmet, Gert; Broeckhoven, Ken
Source:
Chromatographia 2019 v.82 no.1 pp. 489-498
ISSN:
0009-5893
Subject:
high performance liquid chromatography; ultra-performance liquid chromatography,   etc   ; detectors; fluorescence; variance;     Show all 5 Subjects
Abstract:
... In modern ultra-high performance liquid chromatography set-ups, short columns (max. 10 cm) with a narrow ID (2.1 mm) packed with small, (sub-2 µm) fully or superficially porous particles are used. Since the volume and corresponding peak variance arising from these columns are very small, the dispersion contribution from the chromatographic system has a large effect on the overall separation perfor ...
DOI:
10.1007/s10337-018-3622-1

15. Effect of pressure on macromolecule retention in ion exchange chromatography

Author:
Kristl, Anja; Lokošek, Primož; Pompe, Matevž; Podgornik, Aleš
Source:
Journal of chromatography 2019
ISSN:
0021-9673
Subject:
high performance liquid chromatography; reversed-phase liquid chromatography; ultra-performance liquid chromatography,   etc   ; biomedical research; biopharmaceuticals; ion exchange; ion exchange chromatography; oligonucleotides; pH; plasmids; proteins; salt concentration; temperature;     Show all 13 Subjects
Abstract:
... Shorter analysis times and greater resolving power are contributing factors for transfer of separation methods from an HPLC to a UHPLC system when performing analysis in biopharmaceutical or clinical research. Effect of pressure on separations in reversed phase chromatography is well described, however such investigations on ion exchange columns were previously not conducted. In this study we desc ...
DOI:
10.1016/j.chroma.2019.03.017

16. Quantifying the Prediction Error in Analytical Multivariate Curve Resolution Studies of Multicomponent Systems

Author:
Pellegrino Vidal, Rocío B.; Olivieri, Alejandro C.; Tauler, Romà
Source:
Analytical chemistry 2018 v.90 no.11 pp. 7040-7047
ISSN:
1520-6882
Subject:
liquid chromatography,   etc   ; diodes; prediction;     Show all 3 Subjects
Abstract:
... In multivariate curve resolution (MCR) analysis, a range of feasible solutions is often encountered, because of the rotational ambiguities associated with the bilinear decomposition of data matrices. For quantitative purposes, the analysis is usually applied to a carefully designed set of calibration and test samples having uncalibrated interferents. Under the usual minimal constraints (non-negati ...
DOI:
10.1021/acs.analchem.8b01431

17. Flow-Cell-Induced Dispersion in Flow-through Absorbance Detection Systems: True Column Effluent Peak Variance

Author:
Dasgupta, Purnendu K.; Shelor, Charles Phillip; Kadjo, Akinde Florence; Kraiczek, Karsten G.
Source:
Analytical chemistry 2018 v.90 no.3 pp. 2063-2069
ISSN:
1520-6882
Subject:
liquid chromatography,   etc   ; absorbance; variance;     Show all 3 Subjects
Abstract:
... Following a brief overview of the emergence of absorbance detection in liquid chromatography, we focus on the dispersion caused by the absorbance measurement cell and its inlet. A simple experiment is proposed wherein chromatographic flow and conditions are held constant but a variable portion of the column effluent is directed into the detector. The temporal peak variance (σₜ,ₒbₛ²), which increas ...
DOI:
10.1021/acs.analchem.7b04248

18. Slow injector-to-column sample transport to maximize resolution in liquid chromatography: Theory versus practice

Author:
Gritti, Fabrice; Tanaka, Nobuo
Source:
Journal of chromatography 2019 v.1600 pp. 219-237
ISSN:
0021-9673
Subject:
liquid chromatography,   etc   ; methanol; models; polar compounds; prediction; prices; variance;     Show all 7 Subjects
Abstract:
... A simple chromatographic model including extra-column sample bandspreading is built and validated experimentally. It is used to quantify the advantage of slowly transporting under isocratic elution of the injected sample band along the pre-column volume of the chromatographic system compared to the conventional injection method at constant flow rate. For fast analyses (<30 s), the model predicts a ...
DOI:
10.1016/j.chroma.2019.04.060

19. Evaluation of the tubing material and physical dimensions on the performance of extraction columns for on-line sample preparation-LC–MS/MS

Author:
de Toffoli, Ana Lúcia; Maciel, Edvaldo Vasconcelos Soares; Lanças, Fernando Mauro
Source:
Journal of chromatography 2019 v.1597 pp. 18-27
ISSN:
0021-9673
Subject:
liquid chromatography,   etc   ; humans; silica; sorbents; steel; tandem mass spectrometry;     Show all 6 Subjects
Abstract:
... Nowadays, high analytical throughputs are required considering an increasing demand for faster, simple and improved methods to analyze contaminants in a considerable number of samples. Generally, these compounds are present in complex matrices in contact with a high number of interferents becoming their determination difficult at low concentration. In this context, on-line extraction techniques ar ...
DOI:
10.1016/j.chroma.2019.03.023

20. Suspect screening of glycoalkaloids in plant extracts using neutral loss – High resolution mass spectrometry

Author:
Larcher, R.; Nardin, T.
Source:
Journal of chromatography 2019 v.1596 pp. 59-68
ISSN:
0021-9673
Subject:
liquid chromatography,   etc   ; glycoalkaloids; piperidines; plant extracts; screening; tandem mass spectrometry;     Show all 6 Subjects
Abstract:
... Alkaloids represent a very large and chemically inhomogeneous group of nitrogen compounds isolated from different natural sources. They have long been studied due to their specific toxicological characteristics, as some of them are suspected of having very dangerous properties, but there has still been little investigation of the existence of possible glycoside precursors in plant products. An ana ...
DOI:
10.1016/j.chroma.2019.02.059