Journal of Separation Science
Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
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ISI Journal Citation Reports © Ranking: 2012: 25/75 (Chemistry Analytical)
Online ISSN: 1615-9314
Cover pages provided by Journal of Separation Science authors
A polypyrene frit with a porous network structure was introduced as a novel mold of a monolith. The porous network structure as scaffold and the flat geometry can enhance the mechanical strength, reduce the back-pressure, and show specific extraction capacity. This method allows derivatization, extraction, and preconcentration of aldehydes in human serum in one step.
This scheme shows the local thermodynamic path (LTP) during the kth time grid with mesoscopic approaches based on the non-equilibrium thermodynamic separation theory and was developed by Prof. Heng Liang’s group. It is designed to quantitatively describe the state recursion process of nonideal nonlinear chromatography using the spatial distribution of solute bands in time series. On LTP the solute bands evolve from Sik at time tk to the virtual migration state SiM via a virtual net migration process, then to the virtual diffusion state SiD via a virtual net diffusion process, and ultimately, to the state sik+1 at time tk+1 via a virtual net distribution process. The LTP as state recursion is the foundation for the quantitative description as well as offline or online optimal control of the time-variant nonlinear chromatographic process due to LTP’s Markovian and state space characteristics.
Micro-pillar array columns with an inter-pillar spacing down to 500 nm have been designed and fabricated enabling hydrodynamic chromatography separations of fluorescently labeled polystyrene nano-particles. Injecting sub-nanoliter sized sample volumes and detecting the fluorescent signal on-chip, fluorescein, 20 and 40 nm diameter particles could be separated in less than 1.5 minutes.
Separations using a porous-shell pillar array column on a capillary LC instrument, by Wim De Malsche, Selm De Bruyne, Jeff Op De Beeck, Sebastiaan Eeltink, Frederik Detobel, Han Gardeniers, Gert Desmet
A 9 cm silicon long pillar array containing 5 μm diameter silicon pillars cladded with a meso-porous silica layer with a thickness of 300 nm was directly interfaced to a capillary LC instrument, yielding protein digest peak capacities of up to 150.
Separation of peptides with an aqueous mobile phase by temperature-responsive chromatographic column, by Rongji Dai, Zongjian Liu, Yanli Liang, Fangfang Geng, Chen Ge, Kaleem Ullah, Fang Lv, Yukui Zhang, Yulin Deng
A thermoresponsive chromatographic material was prepared through a simple method and employed for the temperature-modulated separation of peptides in an aqueous mobile phase. At 10°C, the grafted polymer chains are hydrophilic and in the form of extended coil. In this case, the peptides were unable to be separated and showed a single peak in chromatograms. In contrast, the polymer is hydrophobic and in the form of collapsed globule at 50°C. In this case, the peptides were completely separated because of the enhanced hydrophobic interaction of peptides and stationary phase.
A hand held digital format of the microextraction by packed sorbent technique (MEPS) has been integrated into the ESI-MS workflow for the rapid screening of drugmetabolites in urine. This at-line approach to sample preparation couples rapid workflows with direct analysis enabling the entire analytical workflow to be achieved in a few minutes. A novel format of MEPS has been introduced which incorporates a two-way valve between the MEPS cartridge and the syringe barrel enabling the direction of the flow to be controlled. By controlling the direction of the flow, sharp concentrated sample bands can be introduced directly into the MS in small volumes.
Europium(III) derivative formed by reaction of the europium ion with a fluorinated β-diketonate reagent and a neutral donor. The resulting non-polar, thermally stable, and luminescent derivative partitions into cyclohexane upon formation and can be subjected to high-resolution capillary gas chromatography. This approach is used to separate derivatives of lanthanides that are adjacent to one another in the periodic table. In addition, an on-fiber SPME derivatization/concentration GC/MS method that uses a fiber preloaded with the same β-diketonate reagent is described for the analysis of beryllium(II) ion.