Chemistry: electrical and wave energy – Apparatus – Coating – forming or etching by sputtering
Patent
1992-08-31
1994-06-28
Niebling, John
Chemistry: electrical and wave energy
Apparatus
Coating, forming or etching by sputtering
2041801, G01N 2726, G01N 27447
Patent
active
053244133
ABSTRACT:
An Electrophoresis Capillary with Dispersion-Inhibiting Cross-Section for providing unprecedented levels of detection sensitivity of solutes in a separation column is disclosed. The higher level of sensitivity is accomplished by utilizing larger sample volumes contained in capillaries having non-circular cross-sections. The present invention avoids the unwanted turbulence, viscosity gradients, and gravity siphoning that plague previous conventional devices that employ circular capillaries having equivalent cross-sectional areas. The key to the enhanced performance that is achieved using the present invention is a novel non-circular capillary which has a cross-sectional configuration that maximizes the central area of the capillary without creating the conditions that cause uneven flow through the capillary. The capillary portrayed in FIG. 3(a) has a generally oblong cross-section. An exterior surface encloses a capillary wall which defines two generally radial channels that extend in opposite directions from the center of the capillary along its transverse axis. The maximum width of each channel is approximately fifty microns. The ratio of the length and width of the channels is generally equal to two or greater. Alternative embodiments include circular capillaries that enclose solid filaments. The invention is also designed for use with an integrally-formed, expanded detection cell. The present invention combines the selectivity of a conventional, smaller, round capillary with the sensitivity of a capillary which is ten times larger.
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Hewlett--Packard Company
Niebling John
Starsiak Jr. John S.
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