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1. 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

2. 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

3. 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

4. Measuring porosities of chromatographic columns utilizing a mass-based total pore-blocking method: Superficially porous particles and pore-blocking critical pressure mechanism

Author:
Devitt, Nicole M.; Moran, Robert E.; Godinho, Justin M.; Wagner, Brian M.; Schure, Mark R.
Source:
Journal of chromatography 2019 v.1595 pp. 117-126
ISSN:
0021-9673
Subject:
high performance liquid chromatography,   etc   ; equations; hydrophilicity; hydrophobicity; porosity; solvents;     Show all 6 Subjects
Abstract:
... Experimentally determined total, interstitial and intraparticle porosity values are necessary to equate theory, simulation and experimental column performance. This paper reports a study of a mass-based technique for determining total, interstitial and intraparticle porosity measurements based on the total pore-blocking (TPB) method. Commercially available superficially porous particle (SPP) colum ...
DOI:
10.1016/j.chroma.2019.02.045

5. A rapid and sensitive enzymatic assay for 2,3-butanediol

Author:
Lee, Gyu Bi; Kim, Yun Jae; Lim, Jae Kyu; Kim, Tae Wan; Kang, Sung Gyun; Lee, Jung-Hyun; Lee, Hyun Sook
Source:
3 Biotech 2019 v.9 no.5 pp. 170
ISSN:
2190-572X
Subject:
high performance liquid chromatography,   etc   ; Clostridium ljungdahlii; enzymes; microorganisms; screening;     Show all 5 Subjects
Abstract:
... In this study, we developed a rapid and sensitive enzymatic assay for 2,3-butanediol (2,3-BDO) detection. The concentration of 2,3-BDO was determined by measuring the reduction of NADP⁺ using Clostridium ljungdahlii 2,3-butanediol dehydrogenase (CL-Bdh). The enzymatic assay could detect as low as 0.01 mM of 2,3-BDO, while the high-performance liquid chromatography (HPLC) method required a much hig ...
DOI:
10.1007/s13205-019-1705-9

6. Retention Modeling of Gradient Elutions: Application of Iso-to-Grad Approach for LC Systems with Dual-Species Eluent

Author:
Stankov, Vladimir; Cvetnić, Matija; Novak Stankov, Mirjana; Rogošić, Marko; Bolanča, Tomislav; Ukić, Šime
Source:
Chromatographia 2019 v.82 no.4 pp. 749-755
ISSN:
0009-5893
Subject:
high performance liquid chromatography,   etc   ; acetonitrile; mathematical models; methanol;     Show all 4 Subjects
Abstract:
... Development of new chromatographic method is often time-consuming and may be shortened by mathematical modeling. Unfortunately, many of the models are limited for predefined elution programs only. The integral model uses iso-to-grad approach to transfer information from isocratic to gradient elution without such limitations, which was successfully tested for IC and HPLC using single-species eluent ...
DOI:
10.1007/s10337-018-3648-4

7. Immobilized Cellulose-Based Chiralpak IC Chiral Stationary Phase for Enantioseparation of Eight Imidazole Antifungal Drugs in Normal-Phase, Polar Organic Phase and Reversed-Phase Conditions Using High-Performance Liquid Chromatography

Author:
Zhang, Junyuan; Sun, Jiayi; Liu, Yanru; Yu, Jia; Guo, Xingjie
Source:
Chromatographia 2019 v.82 no.3 pp. 649-660
ISSN:
0009-5893
Subject:
high performance liquid chromatography,   etc   ; enantiomers; enantioselectivity; ketoconazole; miconazole; polysaccharides;     Show all 6 Subjects
Abstract:
... Due to the remarkable enantioselective performances of polysaccharide derivatives, immobilized cellulose-based columns have high enantioseparation ability, which can be applied under various mobile phase conditions. In the present work, a cellulose-derived chiral stationary phase (CSP), namely Chiralpak IC was evaluated for enantioseparation of eight imidazole antifungal drugs (miconazole, econazo ...
DOI:
10.1007/s10337-019-03688-y

8. Gradual Gradient Two-Dimensional Preparative Liquid Chromatography System for Preparative Separation of Complex Natural Products

Author:
Wang, Zheng; Xie, Ting-Ting; Yan, Xia; Xue, Shi; Chen, Jing-Wei; Wu, Zhen; Qiu, Ying-Kun
Source:
Chromatographia 2019 v.82 no.2 pp. 543-552
ISSN:
0009-5893
Subject:
high performance liquid chromatography,   etc   ; Bufo bufo; bufadienolides; methanol; mixing; solvents;     Show all 6 Subjects
Abstract:
... A low-cost and gradual gradient online two-dimensional preparative liquid chromatography system was developed for the preparative separation of compounds of interest from complex natural products. Medium-pressure liquid chromatography (MPLC) was applied as the first dimension and preparative high-performance liquid chromatography (HPLC) was employed as the second dimension. Two trapping columns an ...
DOI:
10.1007/s10337-018-3652-8

9. “Geländer” macrocycles: Synthesis, chirality and racemisation barriers

Author:
Lar, Claudia; Moisӑ, Mӑdӑlina Elena; Bogdan, Elena; Terec, Anamaria; Hӑdade, Niculina Daniela; Grosu, Ion; David, Luminiţa; Paizs, Csaba; Grosu, Ioana Georgeta
Source:
Tetrahedron letters 2019 v.60 no.4 pp. 335-340
ISSN:
0040-4039
Subject:
high performance liquid chromatography,   etc   ; cations; enantiomerism; enantiomers; organic compounds;     Show all 5 Subjects
Abstract:
... A new class of axially-chiral o,o′-bridged biphenyls containing etheroxime chains was obtained in good yields by the macrocyclisation reaction of o,o′-diformylbiphenyl dioxime with several ditosylated or dibrominated reagents. In all cases the enantiomers of the compounds were separated by HPLC using a chiral column (Chiralpack IC) and the stability of the enantiomers (barriers of racemisation) wa ...
DOI:
10.1016/j.tetlet.2018.12.047

10. Multiplicative On-Column Solute Focusing Using Spatially Dependent Temperature Programming for Capillary HPLC

Author:
Rerick, Michael T.; Groskreutz, Stephen R.; Weber, Stephen G.
Source:
Analytical chemistry 2019 v.91 no.4 pp. 2854-2860
ISSN:
1520-6882
Subject:
high performance liquid chromatography,   etc   ; enthalpy; forensic sciences; solutes; temperature;     Show all 5 Subjects
Abstract:
... The benefits of capillary liquid chromatography columns are truly realized when small, limited sample volumes require signal enhancement, but the available sample volume does not permit on-column focusing during injection onto a larger column. This dilemma is common when samples are naturally small or precious (such as in biological, forensic, art, and archeological investigations) and analyte con ...
DOI:
10.1021/acs.analchem.8b04826

11. Guidelines for tuning the macropore structure of monolithic columns for high‐performance liquid chromatography

Author:
Dores‐Sousa, José Luís; Fernández‐Pumarega, Alejandro; De Vos, Jelle; Lämmerhofer, Michael; Desmet, Gert; Eeltink, Sebastiaan
Source:
Journal of separation science 2019 v.42 no.2 pp. 522-533
ISSN:
1615-9306
Subject:
high performance liquid chromatography,   etc   ; guidelines; macropores; polymers; porosity;     Show all 5 Subjects
Abstract:
... The ability to control the external porosity and to tune the dimensions of the macropore size on multiple length scales provides the possibility of tailoring the monolithic support structure towards separation performance. This paper discusses the properties of conventional polymer–monolithic stationary phases and its limitations regarding the effects of morphology on kinetic performance. Furtherm ...
DOI:
10.1002/jssc.201801092

12. Fluorescence determination of cochineal in strawberry jam in the presence of carmoisine as a quencher by means of four-way PARAFAC decomposition

Author:
Rubio, L.; Sanllorente, S.; Sarabia, L.A.; Ortiz, M.C.
Source:
Food chemistry 2019 v.290 pp. 178-186
ISSN:
0308-8146
Subject:
high performance liquid chromatography,   etc   ; European Union; fluorescence; food colorants; maximum residue limits; strawberries;     Show all 6 Subjects
Abstract:
... The determination of cochineal (E-120) in strawberry jam was carried out in the presence of carmoisine (E-122) using the four-way PARAFAC decomposition and excitation-emission fluorescence matrices. In the measured conditions, there was no fluorescence signal for carmoisine due to a strong quenching effect and this colorant also led to a decrease of the fluorescence signal of cochineal. The Europe ...
DOI:
10.1016/j.foodchem.2019.03.113

13. The rapid quantitative analysis of three pesticides in cherry tomatoes and red grape samples with Tchebichef image moments

Author:
Lu, Shao Hua; Li, Sha Sha; Yin, Bo; Mi, Jia Ying; Zhai, Hong Lin
Source:
Food chemistry 2019 v.290 pp. 72-78
ISSN:
0308-8146
Subject:
high performance liquid chromatography,   etc   ; cherry tomatoes; grapes; models; pesticides; quantitative analysis;     Show all 6 Subjects
Abstract:
... Diverse interferences often affect the determination of pesticide residues in various kinds of food, and complex pretreatments are necessary. An effective approach for the simultaneous quantitative analysis of multi-target components in different substrates was proposed, and applied to the determination of ternary pesticides in cherry tomatoes and red grape samples. By means of HPLC-DAD, the spect ...
DOI:
10.1016/j.foodchem.2019.03.118

14. Dummy molecularly imprinted polymer based microplate chemiluminescence sensor for one-step detection of Sudan dyes in egg

Author:
He, Tong; Wang, Geng Nan; Liu, Ju Xiang; Zhao, Wei Li; Huang, Jing Jie; Xu, Ming Xin; Wang, Jian Ping; Liu, Jing
Source:
Food chemistry 2019 v.288 pp. 347-353
ISSN:
0308-8146
Subject:
high performance liquid chromatography,   etc   ; Sudan dyes; chemiluminescence; egg yolk; eggs; molecular imprinting; polymers; screening;     Show all 8 Subjects
Abstract:
... The objective of this study is to report a molecularly imprinted polymer-based chemiluminescence method for determination of Sudan dyes. A dummy-template molecularly imprinted polymer capable of recognizing seven Sudan dyes was first synthesized and its recognition mechanism was studied by using computation simulation method. The polymer was coated in the wells of conventional microplate to prepar ...
DOI:
10.1016/j.foodchem.2019.03.031

15. Online extraction–HPLC–FRAP system for direct identification of antioxidants from solid Du-zhong brick tea

Author:
Shi, Shuyun; Guo, Keke; Tong, Runna; Liu, Yuge; Tong, Chaoying; Peng, Mijun
Source:
Food chemistry 2019 v.288 pp. 215-220
ISSN:
0308-8146
Subject:
high performance liquid chromatography,   etc   ; antioxidant activity; antioxidants; chlorogenic acid; disease prevention; oxidative stress; tea; China;     Show all 8 Subjects
Abstract:
... Du-zhong brick tea (DBT), a new post-fermented functional tea, is marketed in China for its prevention of diseases from oxidative stress. However, antioxidant compounds in DBT are not clear. Here, a novel online extraction–HPLC–ferric reducing antioxidant power (OLE–HPLC–FRAP) has been developed to screen antioxidants in DBT. For OLE, guard column is packed with DBT (1.0 mg), then compounds are ex ...
DOI:
10.1016/j.foodchem.2019.03.013

16. Quality evaluation and chemometric discrimination of Zanthoxylum bungeanum Maxim leaves based on flavonoids profiles, bioactivity and HPLC-fingerprint in a common garden experiment

Author:
Chen, Xiaoqi; Wang, Wei; Wang, Cheng; Liu, Zijia; Sun, Qi; Wang, Dongmei
Source:
Industrial crops and products 2019 v.134 pp. 225-233
ISSN:
0926-6690
Subject:
reversed-phase high performance liquid chromatography,   etc   ; Takifugu; Zanthoxylum bungeanum; bioactive properties; chemometrics; leaves; quercitrin;     Show all 7 Subjects
Abstract:
... Zanthoxylum bungeanum leaves (ZBL) have rich flavonoids with a variety of bioactivities, which has great values of development and utilization. In this paper, the quality of thirteen varieties of ZBL collected from a common garden was evaluated based on flavonoids compositions, bioactivity and reversed-phase high performance liquid chromatography (RP-HPLC) fingerprint coupled with chemometrics ana ...
DOI:
10.1016/j.indcrop.2019.04.017

17. Quantification of major milk oligosaccharides in a range of formulated milk powder products using high performance liquid chromatography-multi reaction monitoring-mass spectrometry

Author:
Ma, Lin; McJarrow, Paul; Fong, Bertram Y.
Source:
International dairy journal 2019 v.94 pp. 1-6
ISSN:
0958-6946
Subject:
high performance liquid chromatography,   etc   ; children; dried milk; fructooligosaccharides; galactooligosaccharides; infants; markets; mass spectrometry; milk; China;     Show all 10 Subjects
Abstract:
... In formulated milks for infants and children, oligosaccharides such as galacto-oligosaccharides and/or fructo-oligosaccharides are commonly added. This paper, however, discusses the determination of the concentration in infant and follow-on formulations of the major acidic oligosaccharides: 3′-sialylactose (3′SL), 6′-sialylactose (6′SL), 6′-sialyllactosamine (6′SLN) and disialyllactose (DSL) that ...
DOI:
10.1016/j.idairyj.2019.03.001

18. Doing more with less: Evaluation of the use of high linear velocities in preparative supercritical fluid chromatography

Author:
DaSilva, Jimmy O.; Bennett, Raffeal; Mann, Benjamin F.
Source:
Journal of chromatography 2019 v.1595 pp. 199-206
ISSN:
0021-9673
Subject:
high performance liquid chromatography,   etc   ; carbon dioxide; energy; instrumentation; mass transfer; purification methods; solvents; supercritical fluid chromatography;     Show all 8 Subjects
Abstract:
... The evaluation of higher than typical linear velocities is discussed for supercritical fluid chromatographic purifications on the preparative scale. SFC separation efficiency suffers far less at high linear velocities than HPLC by the rapid mass transfer of analytes carried by compressed CO2 through the stationary phase. The technique is discussed using chiral test compounds and columns. In many c ...
DOI:
10.1016/j.chroma.2019.02.047

19. Determination of total or free cefazolin and metronidazole in human plasma or interstitial fluid by HPLC-UV for pharmacokinetic studies in man

Author:
Dorn, Christoph; Kratzer, Alexander; Schießer, Selina; Kees, Frieder; Wrigge, Hermann; Simon, Philipp
Source:
Journal of chromatography 2019 v.1118-1119 pp. 51-54
ISSN:
1570-0232
Subject:
high performance liquid chromatography,   etc   ; acetonitrile; cefazolin; disease control; drugs; humans; intravenous injection; metronidazole; patients; pharmacokinetics; phosphates;     Show all 11 Subjects
Abstract:
... Cefazolin (CFZ) plus metronidazole (MTZ) is commonly used for perioperative antibiotic prophylaxis. An HPLC-UV method is described for the simultaneous determination of total or free cefazolin and metronidazole in human plasma or in microdialysate of subcutaneous tissue. Separation was performed isocratically using a reversed phase column and phosphate buffer/acetonitrile as mobile phase. The vali ...
DOI:
10.1016/j.jchromb.2019.04.025

20. Vibrational and electronic spectroscopic detection and quantification of carminic acid in candies

Author:
Garrido, Carlos; Clavijo, Ernesto; Copaja, Sylvia; Gómez-Jeria, Juan; Campos-Vallette, Marcelo
Source:
Food chemistry 2019 v.283 pp. 164-169
ISSN:
0308-8146
Subject:
high performance liquid chromatography,   etc   ; Raman spectroscopy; aqueous solutions; candy; children; dyes; silver; spectral analysis;     Show all 8 Subjects
Abstract:
... Carminic acid (CA) contained in one kind of gummy candy was detected and quantified by using vibrational and electronic spectroscopy, respectively; the proposed methodology in solution is simple and rapid without sample pretreatment as usually used and reported. The identification of CA in candies was performed through the Raman and surface enhanced Raman scattering (SERS) spectra along with the e ...
DOI:
10.1016/j.foodchem.2018.12.123