Physical properties and structure of fine core–shell particles used as packing materials for chromatography

Gritti, Fabrice; Leonardis, Irene; Abia, Jude A.; Guiochon, Georges

doi:10.1016/j.chroma.2010.04.026

Cited by 183 publications

(128 citation statements)

References 48 publications

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“…10,14 The increment of band broadening during tp is represented by the variance (σax,mol 2 ), which originates from the diffusive migration of sample molecules in the axial direction of the column.…”

Section: Discussionmentioning

confidence: 99%

“…There have been extensive studies on the chromatographic behavior and separation efficiency of the superficially porous particles. [1][2][3][4][5][6][7][8][9][10][11][12][13][14] Their advantageous properties of chromatography were studied with considering the structural characteristics of the superficially porous particles. For example, when the thickness of the shell layer is equal to the radius of the inert center core, the volumetric fraction of the porous shell layer is 87.5% of the volume of full porous spherical particles having the same radius.…”

Section: Introductionmentioning

confidence: 99%

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Moment Analysis of Chromatographic Behavior of Superficially Porous Particles

2011

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Peak parking experiments were conducted to study the chromatographic behavior in a RPLC system consisting of a column packed with superficially porous C18-particles and a mixture of methanol and water (70/30, v/v). The values of the surface diffusion coefficient and the retention equilibrium constant of a column packed with superficially porous C18-particles were comparable to those of columns packed with a C18-silica monolith and full-porous C18-silica gel particles. The flow-rate dependence of HETP was hypothetically calculated by using moment equations to clarify the influence of the structural characteristics on the chromatographic behavior. The column efficiency of a column packed with the superficially porous particles is higher in the high flow-rate range than that with full-porous spherical particles. This is attributed to the smaller contribution of the intraparticulate mass transfer in the superficially porous particles to band broadening. The moment equations are effective for the quantitative analysis of chromatographic behavior of superficially porous particles.

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Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Moment Analysis of Chromatographic Behavior of Superficially Porous Particles

2011

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“…In order to demonstrate the effectiveness of the new moment equations, some experimental data in a paper 39 were analyzed as a concrete example in this study because it is one of a series of remarkably prosperous publications reported by Guiochon and his coworkers, who quite extensively studied in more detail the chromatographic characteristics of shell-type particles. [38][39][40][43][44][45][46][47][48][49][50][51][52][53][54] …”

Section: 24mentioning

confidence: 99%

“…(27) - (31), has been used to evaluate the chromatographic performance of shell-type particles. 39,40,[43][44][45][46][47] Case of boundary condition (2). The analytical solution in the Laplace domain is also obtained under another boundary condition (2), i.e., Ci,R 1 = 0.…”

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Moment Equations for Chromatography Using Superficially Porous Spherical Particles

Miyabe

2011

ANAL. SCI.

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IntroductionHigh-performance liquid chromatography (HPLC) has been extensively used as one of the most powerful separation techniques in the field of fine chemistry and biological science. 1 Still, however, it is now strongly required to develop a faster separation system with a high throughput. There are two major approaches for achieving the demand of the times. One is the development of an ultra-fast HPLC system consisting of a column packed with super-fine full-porous spherical particles and a special pump apparatus for delivering the mobile-phase solvent into the column under high-pressure conditions. [2][3][4] However, this approach is accompanied by new problems because the separation conditions are remarkably changed from those for conventional HPLC. Chromatography is carried out under much a faster flow velocity, hence, under extremely higher pressure conditions. The friction of the mobile phase against the packed bed of the super-fine particles leads to the generation of heat. The resulting temperature distribution taking place in both the axial and radial directions of the column provides an unfavorable influence on the peak profile, and hence on the column efficiency. [5][6][7][8] There would be a paradoxical limitation in this approach. Although the separation speed can be amplified with an increase in the mobile-phase flow velocity, the influence of the heterogeneous temperature distribution on the column efficiency must be emphasized. This is an additional problem of the ultra-fast HPLC technique, which can substantially be neglected under conventional HPLC conditions.An alternative is the development of new types of separation media, such as monoliths [9][10][11] and shell-type spherical particles. [12][13][14][15] Compared with the ultra-fast HPLC system described above, the new separation media show a different chromatographic behavior because their structural characteristics, i.e., shapes and porosities, are extremely different from those of the super-fine full-porous spherical particles. For example, in the case of shell-type particles, which consist of an inert center core and a superficial porous shell layer, the following three points can be picked up as their advantageous characteristics. At first, the whole particle size is relatively large. This is effective for preventing any unnecessary elevation of the column back pressure under high flow rate conditions. The size of interparticulate channels in a column packed with spherical particles depends on the particle diameter and their packing density. It is usually estimated to be about one third of the particle diameter, 16 and cannot independently be controlled. Second, the thickness of the superficial porous shell layer is sufficiently thin. It has been well recognized that the column efficiency under high flow-rate conditions primarily rests on the mass-transfer resistance in the stationary phase and that the reduction in the diffusion distance of sample molecules is effective for suppressing band broadening due to intra-stationary phas...

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“…Generally, a C18 stationary phase composed of fully porous particles was used in these methods (18)(19)(20)(21)(22). However, new chromatographic columns packed with core-shell particles improve separation effi ciency for several analytes in comparison to classical porous particles ( 23,24 ). The benefi ts Abstract Plasma F 2 -isoprostanes (F 2 -isoPs) are reliable biomarkers of oxidative stress.…”

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confidence: 99%