E.i. Dupont De Nemours and Company

Other

Charles H Dilks, Jr

Joseph J Kirkland

Wallace W Yau

A plastic ring has a circumferential groove formed in its outer peripheral surface. The ring is fitted in a bowl-type centrifuge rotor such that the ring's outer surface contacts the inner wall of the rotor. The channel is defined by the groove and rotor wall. The rotor is filled with a compensating liquid to reduce centrifugal stress on the plastic and to reduce leakage from the channel.

Apparatus and method for sedimentation field flow fractionation

A free floating plastic channel for sedimentation field flow fractionation is suspended in a centrifuge rotor filled with a compensating liquid. The channel is constructed of a plastic central hub assembly fitted with a plastic outer ring preferably of a lower density than the hub. The hub contains a shallow channel on its outer surface and is interference-fitted to the outer ring to insure a liquid tight seal at zero force field. With the liquid totally surrounding the hub-outer ring assembly, stresses on the plastic parts are essentially equalized even under high force fields and leakage from the channel at the hub-ring interface is greatly reduced.

Sedimentation field flow fractionation channel and method

A long, thin annular belt-like channel can be used in sedimentation field flow fractionation. A rotating seal is required to couple fluids to the channel inlet and from the channel outlet. A flexible shaft is used to drive the rotating seal and thereby decouple rotor vibrations, which cause can leakage, from the rotating seal.

Drive for rotating seal

A long, thin annular belt-like channel is designed for use in sedimentation field flow fractionation. The channel has a generally rectangular cross section and a width to thickness aspect ratio lying in the range of 3-50 to 1. The channel may be formed of a flattened capillary tube. The ratio of the thickness of the channel to the characteristic height of the particles to be separated is greater than 5 to 1.

Rotor for sedimentation field flow fractionation

The chromatographic separation efficiency of a sample liquid injected into a resolving zone and eluted through the resolving zone with a liquid carrier or mobile phase is improved if the sample is injected at a point located centrally on the inlet end of the resolving zone and the eluting carrier liquid is applied uniformly across substantially the entire inlet end of the resolving zone surrounding the sample injection point. To accomplish this, the present invention provides a liquid dispensing inlet for a liquid chromatographic column comprising: a housing having formed therein a recess and first and second channels; each channel connecting the recess to the external surface of the housing, and a dispensing tube for dispensing liquid to a point at the inlet end of the column, the dispensing tube being disposed within the recess with one end connected to the second channel of the housing and the second end being disposed adjacent to the inlet end of the column, the inlet further comprises a dispensing member, in the form of a screen or a porous plate, dispose between the inlet end of the column and the recess in the housing.

Growing community of inventors

Newark, DE, United States of America

Charles H Dilks, Jr