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Journal of Separation Science

David Sýkora, Pavel Řezanka, Kamil Záruba, Vladimír Král
The mixed-mode phases have become very popular in the last decade and the number of new mixed/multi-mode sorbents is growing fast. Unlike single-mode stationary phases perfectly suited for the separation of the analytes possessing similar physicochemical properties, for instance reversed-phase chromatography for hydrophobic solutes, mixed-mode sorbents providing multimodal interactions can render a better separation selectivity for complex mixtures of solutes differing significantly in their physicochemical characteristics...
November 14, 2018: Journal of Separation Science
Karina Fraige, R Dario Arrua, Adam T Sutton, Cristiano Soleo Funari, Alberto José Cavalheiro, Emily F Hilder, Vanderlan da Silva Bolzani
Natural deep eutectic solvents have been used as an alternative to organic solvents for the extraction of plants metabolites, allowing for the extraction of compounds of different polarities, while being inexpensive, non-toxic and easy to prepare. This work presents the comparison of the chromatographic profiles by HPLC with diode array detection obtained from Byrsonima intermedia (Malpighiaceae) using five choline chloride-based natural deep eutectic solvents, in addition to the most used traditional extraction solvents, methanol:water 7:3 and ethanol:water 7:3 (v/v)...
November 14, 2018: Journal of Separation Science
Kai-Jun Quan, Xin-Yi Huang, Yuan Gong, Dong Pei, Wen-Da Duan, Duo-Long Di
In this work, to further verify and develop the novel counter-current chromatography modified column separate mode, a melamine modified counter-current chromatography column was prepared. Meanwhile, the modified counter-current chromatography column was used to separate stevioside and rebaudioside A with the same partition coefficient in chosen solvent system to evaluate its separation efficiency. The results show that because the presence of intermolecular forces between melamine and model compounds, better separation could be achieved on the modified column while it's almost impossible to be separated on the unmodified column...
November 14, 2018: Journal of Separation Science
Wen-Dan Zhang, Miao-Miao Jin, Hong-Hong Jiang, Jian-Xi Yang, Qiao Wang, Ying-Feng Du, Liang Cao, Hui-Jun Xu
Betulinic acid is a triterpenoid organic acid with remarkable anti-tumor property and naturally present in many fruits, condiments and Traditional Chinese Medicines. Currently, a strategy was developed for the identification of metabolites following the in vivo and in vitro biotransformation of Betulinic acid with rat intestinal bacteria utilizing ultra-high-performance liquid chromatography-time-of-flight mass spectrometry with polymeric solid phase extraction. As a result, 46 metabolites were structurally characterized...
November 14, 2018: Journal of Separation Science
Aleš Podgornik
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 compressibility of chromatographic media, nature of applied sample and mobile phase flow regime are discussed. Detailed analysis correlating organization of particle based chromatographic media and pressure drop is presented together with its extension to convective media such as membranes and monoliths but also novel 3D printed media...
November 14, 2018: Journal of Separation Science
Rodolfo Mesa, Abuzar Kabir, Victoria Samanidou, Kenneth G Furton
A simple and sensitive analytical methodology is developed for rapid screening and quantification of selected estrogenic endocrine disrupting chemicals and bisphenol A from intact milk using fabric phase sorptive extraction in combination with high performance liquid chromatography-ultraviolet detection/tandem mass spectrometry. The new approach eliminates protein precipitation and defatting step from the sample preparation workflow. In addition, the error prone and time-consuming solvent evaporation and sample reconstitution step used as the sample post-treatment has been eliminated...
November 13, 2018: Journal of Separation Science
Arezou Taghvimi, Samin Hamidi, Yousef Javadzadeh
Ionic liquid-carbon coated magnetic nanoparticles were successfully applied as an adsorbent in mixed hemimicelle magnetic dispersive solid-phase extraction method for the determination of tramadol from urine samples coupled with high-performance liquid chromatography with UV-vis detection. The significant parameters affecting on the extraction efficiency including type and amount of adsorbent, sample volume, pH, ionic strength, type and amount of elution solvent, time of extraction and desorption, time of ionic liquid loading on the adsorbent and stirring rate were studied and optimized...
November 10, 2018: Journal of Separation Science
Xiao-Wei Zhang, Lin Yang, Lin An, Ping Li, Jun Chen
Salviae Miltiorrhizae Radix et Rhizoma is a traditional herbal medicine with anti-cancer activities. In this work, a trace peak enrichment approach combined with a cell proliferation assay was applied for screening cancer cell proliferation inhibitors from the extract of S. miltiorrhiza. A set of 123 peak fractions were prepared, and by comprehensive screening, it was determined that 21 tanshinones were screened out as cancer cell proliferation inhibitors and their structures were tentatively identified by liquid chromatography coupled with quadrupole time-of-flight tandem mass spectrometry analysis...
November 9, 2018: Journal of Separation Science
Radka Pechancová, Changling Qiu, Jonathan Smuts, Karel Lemr, Kevin A Schug
Presented work has been focused on the development and validation of the analytical procedure using gas chromatography equipped with vacuum-ultraviolet detection for the specific and sensitive determination of nine photoinitiators in food packages. Subsequently, a comparison of the combination of vacuum ultraviolet spectroscopy with gas chromatography and a developed gas chromatography-mass spectrometry method was performed. The vacuum-ultraviolet spectra of all tested photoinitiators were collected and found to be highly distinct, even for isomers...
November 9, 2018: Journal of Separation Science
Yang Huang, Olivia Jansen, Michel Frédérich, Ange Mouithys-Mickalad, Gwenaël Nys, Anne-Catherine Servais, Jacques Crommen, Zhengjin Jiang, Marianne Fillet
Rapeseed plants, known for oil production, are also known to contain phenolic compounds such as phenolic acids and flavonoids, with potential antioxidant and anticancer activities. The separation and identification of 11 phenolic acids in rapeseed extracts (including leaves, flowers, Chinese seeds, Belgian seeds and cake) by capillary electrophoresis were investigated. The results were compared with those obtained with high performance liquid chromatography and thin layer chromatography and showed that the capillary electrophoresis technique offers several advantages for the identification of phenolic compounds in various rapeseed extracts...
November 8, 2018: Journal of Separation Science
Reinhard I Boysen
This review documents recent advances in the design, synthesis, characterisation and application of molecularly imprinted polymers in the form of monoliths and particles/beads for the use in the separation and analysis of proteins with SPE or LC. The merits of 3-D molecular imprinting, whereby the molecular template is randomly embedded in the polymer, and 2-D imprinting, in which the template is confined to the surface, are described. Target protein binding can be achieved by either using the entire protein as a template, or by using a protein substructure as template, i...
November 8, 2018: Journal of Separation Science
Wanwan Ma, Kyung Ho Row
A novel method was developed to simultaneously determine the ciprofloxacin and levofloxacin levels in human urine using an ionic liquid-based, dual-molecular imprinted polymer-coated graphene oxide solid-phase extraction monolithic column coupled with high performance liquid chromatography. The molecular imprinted monolithic column was prepared using ciprofloxacin and levofloxacin as templates, 1-vinyl-3-ethylimidazolium bromide as the functional monomer, and graphene oxide as the core material. The resulting imprinted monolithic were characterized by scanning electron microscopy and fourier transform-infrared spectroscopy...
November 8, 2018: Journal of Separation Science
José Luís Dores-Sousa, Alejandro Fernández-Pumarega, Jelle De Vos, Michael Lämmerhofer, Gert Desmet, Sebastiaan Eeltink
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. Furthermore, guidelines to improve the macropore structure are discussed. The optimal monolithic macropore structure is characterized by high external porosity (while maintaining ultra-high-pressure stability), high structure homogeneity, polymer globule clusters in the submicron range, and macropores with a diameter tuned towards speed (small diameter in the 100 - 500 nm range using short beds) or efficiency (larger macropores in the range of 500 nm - 1 μm allowing the use of longer column formats)...
November 6, 2018: Journal of Separation Science
Jing Zhang, Guoxiang Sun
Under the wave of the revival of traditional Chinese medicine, there is a quite imperative duty to study an integrated and comprehensive method of fingerprint data processing and analysis on the quality consistency of traditional Chinese medicine. So, we proposed 6 parameters from two aspects (qualitative and quantitative), three levels (biased to strong peaks, biased to weak peaks, no obvious bias), to comprehensively evaluate the similarity of the two fingerprints. On this basis, another 5 parameters were proposed to evaluate the integrated effects (consistency, volatility, and similarity)...
November 2, 2018: Journal of Separation Science
Anna Kiełbasa, Aneta Krakowska, Katarzyna Rafińska, Bogusław Buszewski
Saponins are widespread secondary metabolites with various beneficial properties: fungicidal, antibacterial, antiviral and anticancer ones. Alfalfa saponin molecules contain mainly: medicagenic acid, hederagenin, bayogenin and soyasapogenol B. Structural diversity of saponins makes their determination in Medicago sativa extracts very difficult. The most popular determination technique is HPLC applied with evaporative light scattering detection. Qualitative and quantitative analysis of sapogenins from Medicago sativa by HPLC with evaporative light scattering detection required hydrolysis and purification of extracts obtained by supercritical fluid extraction...
October 31, 2018: Journal of Separation Science
Yiran Li, Teng Zhang, Jiaxin Huai, Congcong Cheng, Linlin Xie, Siqi Wang, Ronghua Dai
L-isocorypalmine, an active alkaloid compound isolated from Rhizoma Corydalis yanhusuo, has been reported to possess biological activity for treating cocaine use disorder. A high performance liquid chromatography coupled to Fourier transform ion cyclotron resonance mass spectrometry method was established for identification of the metabolites of L-isocorypalmine in urine, plasma and feces samples of rats after a single intragastric gavage of L-isocorypalmine at a dose of 15 mg/kg. As a result, a total of twenty-one metabolites (six phase І metabolites and fifteen phase II metabolites) were detected and tentatively identified by MS data and fragment ions from MS/MS spectra...
October 31, 2018: Journal of Separation Science
Atyeh Rahimi, Saeed Nojavan
In this study, the application of a mixture of organic solvents as a supported liquid membrane for improving the efficiency of the electromembrane extraction procedure was investigated. The extraction process was followed by HPLC analysis of two model drugs (verapamil and riluzole). In this research, four organic solvents, including 1-heptanol, 1-octanol, 2-nitrophenyl octyl ether and 2-ethyl hexanol were selected as model solvents and different binary mixtures (v/v) (2:1, 1:1 and 1:2) were used as the supported liquid membrane...
October 29, 2018: Journal of Separation Science
Ling Zhang, Chunhai Li
2-methylimidazole (2-MID), 4-methylimidazole (4-MID) and 5-hydroxymethylfurfural (5-HMF) are harmful by-products potentially formed via Maillard reaction in fermented soy sauce. The present study proposed a new method based on "quick, easy, cheap, effective, rugged, and safe" purification and ultra-high performance liquid chromatography-tandem mass spectrometry for the simultaneous analysis of 2-MID, 4-MID and 5-HMF in fermented soy sauce. Sample was dissolved in water after addition of internal standard 4-MID-d6 and extracted with acetonitrile...
October 29, 2018: Journal of Separation Science
Kaige Zhang, Shuangying Li, Chuang Liu, Qi Wang, Yunhe Wang, Jing Fan
In recent years, hydrophobic deep eutectic solvents as new generation of green solvents have attracted wide attention in liquid microextraction technique. In this paper, four hydrophobic deep eutectic solvents composed of trioctylmethylammonium chloride and oleic acid were designed and prepared firstly. Combined with HPLC, these deep eutectic solvents were used as extraction solvent in vortex-assisted dispersive liquid-liquid microextraction for the selective enrichment and indirect determination of trace nitrite from real water and biological samples...
October 29, 2018: Journal of Separation Science
Luiz F Ribeiro, Renan L Martins, Diego M de Souza Costa, Jorge C Masini
We demonstrated that the porous structure and the reactivity of the epoxy group in the poly glycidyl methacrylate-co-ethylene dimethacrylate monolith can be a platform for the development of separation and extraction methods based on sequential injection analysis. The epoxy group was functionalized to produce monoliths affording complexing and ion exchange properties. Derivatization with iminodiacetate and sodium sulfite produced weak and strong cation exchangers, respectively. Derivatization with ethylenediamine produced a weak anion exchanger, and the treatment of the ethylenediamine-modified monolith with chloroacetate produced another weak cation exchanger...
October 27, 2018: Journal of Separation Science
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