Abstract: An injection device (10) includes a carrier inlet (40), a sample inlet (46), waste outlet (44) and a chamber outlet (64) attached to separation column (66). Valves (52, 54, 56) are used to control flow such that sample flows into chamber (22) and is carried into the chamber outlet (42).

Abstract: A flow meter enables a time-of-flight method for non-invasively measuring liquid flow in a fluid conduit. The flow meter comprises a perturbing element in the form of a phase changing device, a heat transfer device, an electrochemical perturbing device or a photochemical perturbing device, and a conductivity detection device spaced downstream from the perturbing element. The perturbing element is applied to a small section of the conduit to cause a perturbation in a portion of the liquid flowing therethrough. This perturbation causes a change in conductivity a liquid plug, and the affected liquid plug continuous to flow in the fluid conduit toward the conductivity detection device. The conductivity detection device then senses the change in conductivity resulting from the perturbation, and flow rate or velocity is determined from the time of detection and the distance between the point of perturbation and the point of conductivity change detection.

Abstract: A photothermal absorbance detection apparatus for performing absorbance measurements of analytes in capillaries having non-conductive walls comprises a light source and a conductivity detection device. The conductivity detection device includes an applied voltage source and at least two electrodes disposed adjacent to the walls of a section of capillary. By using the light source to heat the analytes, the resulting change in conductivity of the liquid containing the analytes can be detected in the liquid. A measurement of absorbance can then be obtained as a function of the change in conductivity.

Abstract: A contactless, resistive heating device applies heat energy non-invasively to a target zone of liquid contained by a non-conductive substrate or capillary. The heating device supplies an AC signal to two spaced-apart electrodes, which are disposed externally of the substrate. A circuit is established in which the source of the AC signal is capacitively coupled with the liquid through each electrode. The zone of liquid between the electrodes is heated due to the resulting flow of electrical current across the zone.

Abstract: A combination liquid chromatography and capillary electrophoresis separation system is disclosed. The system comprises a flow gating interface having an effluent channel and a gating channel formed therein. The gating channel transversely intersects the effluent channel at an intersection portion so that the channels are in fluid communication with one another. The intersection portion divides the effluent channel into an upstream portion and a downstream portion, and divides the gating channel into an upstream portion and a downstream portion. A liquid chromatography column is connected to the effluent channel upstream portion and an electrophoresis capillary is connected to the effluent channel downstream portion. A flush solution inlet line is connected to said gating channel upstream portion, and a flush solution outlet line is connected to the gating channel downstream portion. A valve regulates the flow of flush solution from the flush solution inlet line to the gating channel upstream portion.

Abstract: A combination liquid chromatography and capillary electrophoresis separation system is disclosed. The system comprises a flow gating interface having an effluent channel and a gating channel formed therein. The gating channel transversely intersects the effluent channel at an intersection portion so that the channels are in fluid communication with one another. The intersection portion divides the effluent channel into an upstream portion and a downstream portion, and divides the gating channel into an upstream portion and a downstream portion. A liquid chromatography column is connected to the effluent channel upstream portion and an electrophoresis capillary is connected to the effluent channel downstream portion. A flush solution inlet line is connected to said gating channel upstream portion, and a flush solution outlet line is connected to the gating channel downstream portion. A valve regulates the flow of flush solution from the flush solution inlet line to the gating channel upstream portion.

Abstract: A device and method useful for high-speed electrophoresis is disclosed. The device includes an on-column optical gating apparatus for high-frequency modulation of sample introduction, a variable resistance capillary, and a high voltage power supply to induce differential migration. The device separates charged molecules, including complex organic compounds, quickly and efficiently. The device can be used in multiplex chromatographic and electrophoretic separations.

Abstract: Disclosed is a two-dimensional separation system, comprising a liquid chromatography column having an outlet port; a capillary electrophoresis capillary having an inlet end and an outlet end; buffer supply means for supplying buffer to the capillary; and valve means connecting the capillary inlet end to the chromatography column outlet port and to the buffer supply means, the valve means switchable between a first configuration providing fluid to the capillary inlet end from the buffer supply means and a second configuration providing fluid to the capillary inlet end from the chromatography column. Methods of carrying out two-dimensional separations employing the system are also disclosed.

Abstract: Disclosed is a two-dimensional separation system, comprising a liquid chromatography column having an outlet port; a capillary electrophoresis capillary having an inlet end and an outlet end; buffer supply means for supplying buffer to the capillary; and valve means connecting the capillary inlet end to the chromatography column outlet port and to the buffer supply means, the valve means switchable between a first configuration providing fluid to the capillary inlet end from the buffer supply means and a second configuration providing fluid to the capillary inlet end from the chromatography column. Methods of carrying out two-dimensional separations employing the system are also disclosed.

Abstract: A method of generating an electrospray from a solution is disclosed which is useful for electrospraying at low flow rates, for electrospraying directly into a vacuum, or both. The method comprises the steps of causing the solution to flow through a capillary tube to an outlet opening formed in the terminal portion thereof. The capillary tube terminal portion has an inner diameter of not more than 50 micrometers and an outer diameter of not more than 150 micrometers. An electrical potential difference is provided between the capillary tube terminal portion and a conductor spaced from said terminal portion, with the potential sufficient to cause the solution to electrospray from the capillary outlet.The method is particularly useful for detecting analytes in the solution being electrosprayed by mass spectral analysis.

Abstract: A capillary zone electrophoresis (CZE) system provides for rapid, non-turbulent post-separation diffusional mixing of sample effluent with a fluorogenic-labelling reagent permitting sensitive detection of well-defined sample component zones. A separation capillary extends into a mixing capillary so as to define an annular gap therebetween. The effluent of the separation capillary is mixed with the labelling reagent, which is introduced through the annular gap. A power supply and opposing electrodes establish an electric field which induces electro-osmotic flow of the sample and charge-related differential electrophoretic migration to define component zones. The electric field also causes the separation capillary effluent to diverge as it issues into the mixing capillary so as to facilitate diffusional mixing with the reagent fluid flow without causing significant turbulence. Thus, fluorescence labelling is effective with minimum zone broadening.