Physical evidence of two wall effects in liquid chromatography

Shalliker, R. Andrew; Broyles, B.Scott; Guiochon, Georges

doi:10.1016/s0021-9673(00)00517-3

Cited by 119 publications

(70 citation statements)

References 34 publications

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“…Knox [6] and Farkas [7] found there existed a high-velocity-flow stream near the wall, and the work by Shalliker [8] showed conclusively that this was true, confirming the existence of a wall effect whereby a higher-than-average void fraction occurs at the wall because the particles and wall surface cannot bend to accommodate the other. Hence, the solute migrates in this section of the column region at a higher velocity than the bulk [9].…”

Section: Introductionmentioning

confidence: 92%

Preparation of a concentric layered structure of an electrospun nanofiber column for solid-phase extraction of mass viscous crude extracts

et al. 2016

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The packed nanofiber solid-phase extraction of crude extracts of a mass viscous sample is challenging because the interference and recalcitrant particulates in the sample may attach to the nanofiber and block the column, which leads to insufficient sample extraction. A novel concentric layered nanofiber solid-phase extraction (SPE) column using polystyrene-based electrospun nanofiber as the stationary phase has been employed for the pretreatment of mass viscous crude extracts. The layered column was fabricated by using untouched nanofiber with its natural morphology rather than hand-packing of spoiled fiber to the control packing density of the column. In the novel column, the SPE packed bed was divided into a multi-layer structure to provide uniform radial and axial packing and to part the mobile phase stream by the isolated layer with great superiority in aspects such as lower column pressure and faster elution speed. The feasibility and efficiency of the LFSPE column were then evaluated via determination of rhodamine B (RB) from spiked chili samples. Based on the LFSPE column, a linear spiked calibration curve in the range of 0.02-5 mg/kg was obtained. The limit of detection (LOD) and limit of quantification (LOQ) of the method were 0.001 and 0.004 mg/kg, respectively; recoveries at 0.1, 1, and 2 mg/kg (n = 3) were all up to 95 %; and the RSD values of inter-day and intra-day were all below 5 %. This novel LFSPE column overcame heterogeneous packing and exploited the wall effect in subtle ways, and exhibited great superiority by comparison with some existing methods. Graphical Abstract ᅟ.

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Section: Introductionmentioning

confidence: 92%

Preparation of a concentric layered structure of an electrospun nanofiber column for solid-phase extraction of mass viscous crude extracts

et al. 2016

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“…[3,12,13] deal with the influence of temperature gradients, [2,14] with inhomogeneous chromatographic beds and [5,15] with phenomena, which occur due to local maldistributions of the sample coupled with the flow field.…”

Section: Radial Effects In Hplc Columnsmentioning

confidence: 99%

CFD Simulation of Preparative HPLC Columns with Consideration of Nonlinear Isotherms

Boysen¹,

Woźny²,

Laiblin³

et al. 2003

Chem Eng & Technol

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The simulation of chromatography increasingly becomes an important tool for process design. For this purpose, one‐dimensional simulations usually are sufficient. For the simulation of today’s preparative HPLC columns with extreme geometries (length/diameter ratio less than 1), at least two dimensions in space have to be considered so that radial influences are taken into account. A two‐dimensional CFD model has been developed using the commercial software FLUENT.

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“…Physical evidence of the VF phenomena in liquid chromatography has been obtained by several research groups [23,24]. Shalliker et al [25,26] used glass columns and a mobile phase which had the same refractive index as the C18 silica; hence, the otherwise opaque column bed became perfectly transparent. The viscosity between the injection plug and the mobile phase could be adjusted and the VF effect visualized either with the aid of colored samples or by injection of a solvent with a different refractive index to the mobile phase.…”

Section: Introductionmentioning

confidence: 99%

A closer study of peak distortions in supercritical fluid chromatography as generated by the injection

Enmark

Åsberg

Shalliker

et al. 2015

Journal of Chromatography A

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Physical evidence of two wall effects in liquid chromatography

Cited by 119 publications

References 34 publications

Preparation of a concentric layered structure of an electrospun nanofiber column for solid-phase extraction of mass viscous crude extracts

Preparation of a concentric layered structure of an electrospun nanofiber column for solid-phase extraction of mass viscous crude extracts

CFD Simulation of Preparative HPLC Columns with Consideration of Nonlinear Isotherms

A closer study of peak distortions in supercritical fluid chromatography as generated by the injection

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