Particle-loaded membranes

Figure 11.18 Schematic diagram of an in-line SPE unit for CE using (a) polyester wool frits to hold the sorbent, or (b) a particle-loaded membrane. Reprinted from Journal of Capillary Electrophoresis, 2, A. J. Tomlinson and S. Naylor, Enhanced performance membrane preconcentration-capillary electrophoresis-mass spectrometry (mPC-CE-MS) in conjunction with transient isotachophoresis for analysis of peptide mixtures, pp 225 - 233, 1995, with permission from ISC Technical Publications Inc.

FIGURE 3.11 Particle-loaded membrane adsorbers in different geometries (a) zip-tip millipore adsorber, (b) zip-tip adsorber, higher magnification, (c) flat membrane, (d) flat membrane, higher magnification, (e) full fiber, and (f) hollow fiber. 

Empore 3M Particle-loaded membranes, disks PIPE, PS-DVB, silica lEX, AF... 

Particle-loaded membranes with embedded Cg hydrophobic adsorbents were intensively investigated for several dmg separations. Tricyclic antidepressants, antiarrhythmic dmgs, amiodarone and its metabolite desethylamiodarone, and mexiletine and flecainide were extracted from serum using a 11 mm Cg membrane adsorber with recoveries ranging from 82% to 98% [14,220]. 

Highly hydrophobic sorbents including porous carbon and copolymers of styrene and divinylbenzene (SDB) were widely investigated for environmental applications. The particle-loaded membranes containing modified SDB particles with surface sulfonic acid groups were successfully used for recovering different alcohols, phenols, aldehydes, ketones, or esters from aqueous samples [221]. Carbon-based PLM were also used for isolation of highly polar pesticides from water [222]. 

A mixed particle-loaded membrane consisting of a Cg or Cig hydrophobic adsorbents and a strong cation-exchange material can be used for selective extraction of pigments or imiquimod metabolites from urine with up to 95% recovery [232]. 

Lingeman H and Hoekstra-Oussoren SJE. Particle-loaded membranes for sample concentration and/or clean-up in bioanalysis. 

Lensmeyer GL, Onsager C, Carlson IH, and Wiebe DA. Use of particle-loaded membranes to extract steroids for high-performance liquid chromatographic analyses improved analyte stability and detection. J. Chromatogr. A 1995 691 239-246. 

Wells DA, Lensmeyer GL, and Wiebe DA. Particle-loaded membranes as an alternative to traditional packed-column sorbents for drug estraction—in-depth comparative-study. J. Chromatogr. Sci. 1995 33 386-392. 

Particle-loaded membrane extraction disks, the so-called Empore disks, form an alternative to SPE cartridges [27, 78-79]. With Empore disks, higher sampling flow-rates are possible. They show excellent sorbent capacity. Recoveries at 0.1-pg/l level... 

Wells, D.A. Lensmeyer, G.L. Wiebe, D.A. Particle-Loaded Membranes as an Alternative to Traditional Packed-Column Sorbents for Drug Extraction—In Depth Comparative Study, J. Chromatogr. Sci. 33, 386-392 (1995). 

Larrivee, M. L. and Poole, C. F. 1994. Solvation parameter model for the prediction of breakthrough volumes in solid-phase extraction with particle-loaded membranes. Anal. Chem., 66. 139-146. 

In membrane chromatography, the active sites are immobilized inside the membrane pores. For particle-loaded membranes, the active sides are immobilized at the outer surface of the imbedded particles or, to increase the total active surface area, they can also be located inside the porous particles. In the latest case, if very small pores are involved, the productivity is low even in spite of a high active surface area. This is because the transport of the target molecules to the active sites is by diffusion alone, which is a much slower process than the convection through the big pores. Therefore, the loading step is much more time consuming. The interaction between the... 

Mosaic Systems Mosaic Systems, the Netherlands Particle-loaded membranes, fuU/hollow-fiber modules PES 1EX,AF... 

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