Preparation of silica porous‐layer open‐tubular columns using fused silica capillaries

Huang, Yun; Markides, Karin E.; Lee, Milton L.

doi:10.1002/mcs.1220070209

Cited by 9 publications

(5 citation statements)

References 33 publications

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“…A major challenge is to cast a relatively uniform porous layer on the column, which can provide sufficient retention and sample loading capacity. Several methods have been developed to realize a retentive layer to increase the surface area and phase ratio, e.g., static, dynamic, , and precipitation coating . These procedures usually involve two steps: first a porous silica layer is cast and then the functional group is attached to the prepared layer.…”

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confidence: 99%

Ultratrace LC/MS Proteomic Analysis Using 10-μm-i.d. Porous Layer Open Tubular Poly(styrene−divinylbenzene) Capillary Columns

et al. 2006

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In this paper, the preparation and performance of long, high-efficiency poly(styrene-divinylbenzene) (PS-DVB), 10-microm-i.d. porous layer open tubular (PLOT) capillary columns are described. PLOT capillaries ( approximately 3% RSD column-to-column retention time), with relatively high permeability, were prepared by in-situ polymerization. Relatively high loading capacities, approximately 100 fmol for angiotensin I and approximately 50 fmol for insulin, were obtained with a 4.2 m x 10-microm-i.d. PLOT column. Low detection levels (attomole to sub-attomole) were achieved when the column was coupled on-line with a linear ion trap MS (LTQ). Analysis of human epidermal growth factor receptor (EGFR), a large transmembrane tyrosine kinase receptor with heterogeneous phosphorylation and glycosylation structures, was obtained at the 25 fmol level. The PLOT column yielded a peak capacity of approximately 400 for the separation of a complex tryptic digest mixture when the sample preparation included a 50-microm-i.d. PS-DVB monolithic precolumn and ESI-MS detection. As an example of the power of the column, 3046 unique peptides covering 566 distinct Methanosarcina acetivorans proteins were identified from a 50 ng in-gel tryptic digest sample combining five cuts in a single LC/MS/MS analysis using the LTQ. The results demonstrate the potential of the PLOT column for high-resolution LC/MS at the ultratrace level.

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Ultratrace LC/MS Proteomic Analysis Using 10-μm-i.d. Porous Layer Open Tubular Poly(styrene−divinylbenzene) Capillary Columns

et al. 2006

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“…Unfortunately, the problems are still the same. Open tubular columns with the stationary phase supported on the tubing walls is another way to circumvent the use of particles and the accompanying packing problems . Although open tubular columns were first described nearly three decades ago, they have never become popular in liquid chromatography.…”

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confidence: 99%

Fabrication of Nanocolumns for Liquid Chromatography

He¹,

Tait²,

Regnier³

1998

Anal. Chem.

408

304

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This paper shows that in situ micromachining can be used to simultaneously position and define (i) support particles, (ii) convective transport channels, (iii) an inlet distribution network of channels, and (iv) outlet channels in multiple chromatography columns on a single quartz wafer to the level of a few tenths of a micrometer. Stationary phases were bonded to 5 x 5 x 10 microns collocated monolith support structures separated by rectangular channels 1.5 microns wide and 10 microns deep with a low degree of deviation of channel width between the top and bottom of channels. High aspect ratio microfabrication can only be achieved with deep reactive ion etching. The volume of a 150 microns x 4.5 cm column was 18 nL. Column efficiency was evaluated in the capillary electrochromatography (CEC) mode using rhodamine 123 and a hydrocarbon stationary phase. Plate heights in these columns were typically 0.6 micron in the nonretained and 1.3 microns in the retained modes of operation. Columns were designed to have identical mobile-phase velocity in all channels in an effort to minimize outgassing during operation. When the total lateral cross-sectional area of channels at all points along the separation axis is identical, linear velocity of the mobile phase in a CEC column should be the same. Columns were operated at atmospheric pressure.

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“…It is a relatively straightforward procedure to transfer carrier-free zone electrophoresis and open-tubular chromatography experiments in capillaries to analogous runs in the narrow channels in chips. Many such studies have been reported. − However, to achieve uniform packing of such channels with beads for chromatographic experiments seems to be an impossible task, particularly if the channels are not straight but are curved, for instance, into a serpentine configuration. The difficulty of affixing frits to support the bed is obvious.…”

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Electroosmosis- and Pressure-Driven Chromatography in Chips Using Continuous Beds

et al. 1999

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The application range of microchips can be extended to any mode of chromatography by filling the narrow channels with continuous polymer beds, exemplified by electrochromatography and ion-exchange chromatography. “Wall effects” are eliminated by anchoring the bed to the wall of the channel, an arrangement which has the additional advantage that no frits to support the bed are required. The design of the equipment is based on a quartz chip with all auxiliary pieces (for example, electrode vessels and fluid transfer fittings) placed in a rack, which permits a flexibility of great importance for automation. The same resolution and van Deemter plots were obtained in experiments performed in fused-silica capillaries and in chips for both low-molecular-weight (alkyl phenones, antidepressants) and high-molecular-weight substances (proteins). A sample of uracil, phenol, and benzyl alcohol was separated by electrochromatography in less than 20 s.

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Preparation of silica porous‐layer open‐tubular columns using fused silica capillaries

Cited by 9 publications

References 33 publications

Ultratrace LC/MS Proteomic Analysis Using 10-μm-i.d. Porous Layer Open Tubular Poly(styrene−divinylbenzene) Capillary Columns

Ultratrace LC/MS Proteomic Analysis Using 10-μm-i.d. Porous Layer Open Tubular Poly(styrene−divinylbenzene) Capillary Columns

Fabrication of Nanocolumns for Liquid Chromatography

Electroosmosis- and Pressure-Driven Chromatography in Chips Using Continuous Beds

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