Methods of detecting the presence of toxins in a sample using electrophoretic separations and of performing electrophoretic separation of complex samples are provided. The method of detecting the presence of toxins includes reacting a sample and a substrate with a signaling enzyme which converts the substrate to the product in a reaction medium, introducing a run buffer into a separation channel having an inlet end, selectively introducing at least one of the substrate and the product of the reaction medium into the inlet end of the separation channel, electrophoretically separating the substrate and the product, and determining the rate of conversion of the substrate to the product, wherein a change in the rate of conversion is indicative of the presence of toxins. The method of performing electrophoretic separations of complex samples having charged particulates and oppositely charged analytes comprising introducing a run buffer into a separation channel having an inlet end, selectively introducing the oppositely charged analytes in the complex sample into the separation channel, and electrophoretically separating the charged particulates and the oppositely charged analytes. Additionally, a device for varying with respect to time the bulk flow of a fluid in a separation channel of an electrophoretic device having a buffer reservoir in fluid contact with the separation channel is provided. The device includes a pressure sensor in fluid contact with a buffer reservoir, a high pressure reservoir in selective fluidic communication with the buffer reservoir, a low pressure reservoir in selective fluidic communication with the buffer reservoir and in fluidic communication with the high pressure reservoir, and a pumping device for pumping a gas from the low pressure reservoir to the high pressure reservoir.

The present invention relates to a microfluidic analysis device (1) including: a substrate (20) wherein a separation channel (10) is arranged, in which an electrolyte flows, a portion of the separation channel (10) being covered with a polarisable surface (11); two longitudinal field electrodes (8a, 8b) arranged on either side of the separation channel (10); at least one control electrode (6a, 6b) positioned in the separation channel (10), the control electrode (6a, 6b) being suitable for polarising the polarisable surface (11) so as to control the speed of the electro-osmotic flow in the separation channel (10); the microfluidic analysis device (1) being characterised in that the polarisable surface (11) includes an insulating sub-layer (12) made of amorphous silicon carbide (SiC) and an upper polarisable layer (13) in direct contact with the electrolyte, the control electrodes (6a, 6b) being positioned between the insulating sub-layer (12) and the upper polarisable layer (13).

A supercritical fluid apparatus includes a solvent supplier that supplies a solvent, a pressure control device provided in a flow path for a solvent supplied by the solvent supplier, and a controller that controls the pressure control device. The controller includes a first controller that increases a pressure in the flow path, puts the solvent in a supercritical fluid state and maintains an environment for execution of a predetermined process by controlling the pressure control device, and a second controller that sets an intermediate target value for a pressure in the flow path and controls a pressure in the flow path in order to get the pressure to reach the intermediate target value, when ending the environment for execution of a predetermined process.

Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

A mobile phase temperature control device for a supercritical fluid apparatus is used in a supercritical fluid apparatus including a separation column, and includes a cartridge heater, a flow path portion and a first temperature sensor. The cartridge heater has a rod shape. The flow path portion is wound around the cartridge heater, and a mobile phase is guided to the separation column of the supercritical fluid apparatus by the flow path portion. The mobile phase is put in a supercritical state at least in the separation column. The first temperature sensor is attached to the flow path portion, and the temperature of the flow path portion is detected by the first temperature sensor.

Systems and methods for inhibiting translocation of ions across ion exchange barriers include an eluent generator having an ion source reservoir with a first electrode, an eluent generation chamber with a second electrode, an ion exchange barrier disposed therebetween, and means for reversing the polarity of a voltage or current applied across the first and second electrodes. A first polarity voltage or current applied across the electrodes generates an electric field that promotes translocation of eluent counter ions from the reservoir across the barrier, where the counter ions combine with eluent ions electrolytically generated in the chamber. By reversing the polarity of the voltage or current across the electrodes, the resulting electric field inhibits translocation of counter ions across the barrier from the reservoir into the chamber. Reverse voltage or current bias reduces counter ion concentration in the resting chamber to prevent exhaustion of ion suppressor capacity during start up.

A gas chromatography (GC) column system includes an insulation tubing, a metallic GC column disposed within the insulation tubing and having an outer diameter that is less than or equal to an inner diameter of the insulation tubing, a first electrode in contact with the metallic GC column, and a second electrode in contact with the metallic GC column on an opposite side of the insulation tubing from the first electrode. The metallic GC column may be heated by applying a voltage across the first and second electrodes. The voltage may be controlled in response to a measured temperature of the metallic GC column.

This invention discloses a design a capillary column for use with electrochemically modulated liquid chromatography (EMLC). The capillary design, which results in a marked reduction in the flow of current through the column, enables the use of a two-electrode column construction that overcomes the mechanical and electrical shortfalls of the conventional standard bore design.

A gas chromatography (GC) column system includes an insulation tubing, a metallic GC column disposed within the insulation tubing and having an outer diameter that is less than or equal to an inner diameter of the insulation tubing, a first electrode in contact with the metallic GC column, and a second electrode in contact with the metallic GC column on an opposite side of the insulation tubing from the first electrode. The metallic GC column may be heated by applying a voltage across the first and second electrodes. The voltage may be controlled in response to a measured temperature of the metallic GC column.

The present invention relates to a microfluidic analysis device (1) including: a substrate (20) wherein a separation channel (10) is arranged, in which an electrolyte flows, a portion of the separation channel (10) being covered with a polarizable surface (11); two longitudinal field electrodes (8a, 8b) arranged on either side of the separation channel (10); at least one control electrode (6a, 6b) positioned in the separation channel (10), the control electrode (6a, 6b) being suitable for polarizing the polarizable surface (11) so as to control the speed of the electro-osmotic flow in the separation channel (10); the microfluidic analysis device (1) being characterised in that the polarizable surface (11) includes an insulating sub-layer (12) made of amorphous silicon carbide (SiC) and an upper polarizable layer (13) in direct contact with the electrolyte, the control electrodes (6a, 6b) being positioned between the insulating sub-layer (12) and the upper polarizable layer (13).