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 parallel processing system for processing samples is described. In one embodiment, the parallel processing system includes an instrument interface parallel controller to control a tray motor driving system, a close-loop heater control and detection system, a magnetic particle transfer system, a reagent release system, a reagent pre-mix pumping system and a wash buffer pumping system.

Abstract: Systems, devices, and methods to mitigate the pressure disturbance associated with the injection of low-pressure analyte samples into a high-pressure HPLC fluid stream, to enhance chromatographic performance related to retention time and reproducibility. The preferred embodiment coordinates the injection run with active pressure control of a binary solvent delivery system to virtually eliminate the customary pressure drop when the low-pressure loop is brought on line. An additional benefit that enhances reproducibility is accomplished by forcing a consistent timing relationship between the injection run, the mechanical position of the delivery pump pistons, and the start and subsequent gradient delivery.

Abstract: The present invention pertains to a method of ion chromatography wherein a specialized electrodeionization (EDI) apparatus is used for simultaneous ion suppression of cations from a flowing base containing an anion sample of interest and ion suppression of anions from a flowing acid containing a cation sample of interest. The methods described herein allow for the ion suppression of samples containing chloride, nitrate, and other electrochemically active anions, as well as sodium, potassium, and other electrochemically active cations, without causing damage to the suppressor.

Abstract: A cleaning chamber is provided in a seal holder and two cleaning chamber flow paths communicating with the cleaning chamber from outside are provided. A pipe connected to a vessel storing a mobile phase is connected to one of the cleaning chamber flow paths. A pipe as a flow path connected to a mobile phase sucking flow path into a pump chamber is connected to the other cleaning chamber flow path. When the mobile phase is taken in, the mobile phase is sucked into the pump chamber via the cleaning chamber.

Abstract: A micro-channel device provided in a solution analysis system using pressure liquid feed comprises a plurality of straight-line channels and curved channels connecting the ends of the neighboring straight-line channels. The width w of each curved channel is smaller than the width t of each straight-line channel. The radius of curvature r of each curved channel is set so that the value of a expressed by formula (1) is equal to or smaller than the value of a at a local maximum point of the theoretical step height H expressed by formula (2) and based on the shape of the curved channel. a=w/r??(1) H = u c ? w 2 64 ? ? ? ? D m × a 2 ? ( a + 2 ) a + 1 ( 2 ) Where, w is a width of the curved channel, uc is a channel passing speed of a solution in the curved channel, ? is a molecular diffusion inhibition factor by basic members present in the curved channel, and Dm is a molecular diffusion coefficient of the solution.

Abstract: Post-column reaction-ion chromatography (PCR-IC) analysis of drinking water samples for quantity measurements and species identification of haloacetic acid contaminants therein is provided. With the necessity to chlorinate drinking water to remove harmful bacteria and other potential toxins, haloacetic acid byproducts are generated that may harm humans after consumption as well. A reliable manner of measuring such drinking water supplies for haloacetic acids at locations far from the source and closer to dispensers is highly desirable. The PCR-IC analysis method of the invention has been found to be nearly as reliable as source measuring methods for the same purpose, but with the versatility to measure for such haloacetic acid contaminants anywhere along the drinking water supply line.

Abstract: A transfer structure for droplet-based microfluidic analysis is characterized by a first conduit containing a first stream having at least one immiscible droplet of aqueous material and a second conduit containing a second stream comprising an aqueous fluid. The interface between the first conduit and the second conduit can define a plurality of apertures, wherein the apertures are sized to prevent exchange of the first and second streams between conduits while allowing lossless transfer of droplets from the first conduit to the second conduit through contact between the first and second streams.

Abstract: The present invention provides a method and apparatus for substantially eliminating destructive transients of pressure or flow rate which can degrade the efficiency and useful lifetime of chromatography columns. The present invention enables a substantially constant flow of mobile phase liquid to be maintained through the chromatography system by eliminating the flow blockage interval associated with the actuation of sample injection valves. The present invention further provides a method to reduce the pressure and flow rate transients associated with pressurization of the sample loop contents when the sample loop is introduced to chromatography system delivery pressure.

Abstract: Apparatus for GPC/TREF and TREF/GPC characterization of a polymer sample. The apparatus provides for the automated and integrated use of multiple TREF columns and a GPC system employing a multiple flow through detectors. In addition, a method for TREF/GPC characterization of a polymer sample by GPC analysis of TREF fractions at increasing TREF elution temperatures from multiple TREF columns operated in a coordinated and synchronized temperature cycle for increased sample throughput. Also, a method for GPC/TREF characterization of a polymer sample by GPC fractionation followed by TREF fractionation of the GPC fractionations.

Abstract: The present invention enables the automatic change of the number of segments involved in a coupled chromatographic column system, without the need to physically detach and attach the individual segments. The present invention further relates to a method for performing method development in chromatography and for selecting the optimal separation conditions to perform a chromatographic separation using the system of the present invention.

Abstract: A pump portion for taking in and discharging solutions includes a first plunger pump with a small capacity and a second plunger pump with a large capacity. Intake ports of both the plunger pumps are connected in parallel to a common port of a switching valve with a first three-way valve interposed therebetween. The first three-way valve connects the intake port of one of the plunger pumps to the switching valve. Discharge ports of both the plunger pumps are connected in parallel to one port of the switching valve with a second three-way valve interposed therebetween. The second three-way valve connects the discharge port of one of the plunger pumps to the switching valve.

Abstract: A liquid chromatograph includes a mobile phase supplying apparatus including liquid-feeding pumps to feed mobile phases, liquid-feeding flow paths, a mixer to mix the mobile phases, at least one control device to control each liquid-feeding pump, flow rate measuring sections provided downstream in each liquid-feeding flow path configured to measure an actual flow rate and to detect a back-flow, and actual flow rate computing sections configured to compute an actual flow rate in the corresponding liquid feeding flow path. Also included are a sample injecting section downstream of the mobile phase supplying apparatus, a separating column for separating an injected sample into its constituents, and a detector for detecting each of the separated constituents. When one of the actual flow rate measuring sections detects a back-flow, the corresponding actual flow-rate computing section computes an actual back-flow rate and outputs a signal to the corresponding control device to cancel the back-flow.

Abstract: An analyzing device includes a feeder connected to a container in which a sample is contained for sucking the sample from the container and feeding the sample, and a controller for performing control for feeding from the feeder to a measurer. In measuring the sample, the controller performs control so that results of a plurality of times of measurement are obtained with respect to the single container in which the sample is contained, without changing the container. This arrangement allows quick accuracy check.

Abstract: Capillary membrane sampling-flow injection analyzer (CMS-FIA) analyses of drinking water samples for quantity measurements of total trihalomethane and haloacetic acid contaminants therein are provided. With the necessity to chlorinate drinking water to remove harmful bacteria and other potential toxins, trihalomethane and haloacetic acid byproducts are generated that may harm humans after consumption as well. A reliable manner of measuring such drinking water supplies for such trihalomethane and/or haloacetic acids at locations far from the source and closer to dispensers is highly desirable. The CMS-FIA analysis method of the invention has been found to be nearly as reliable as source measuring methods for the same purpose, but with the versatility to measure for such trihalomethane and haloacetic acid contaminants anywhere along the drinking water supply line.

Abstract: Semiconductor devices, chromatography devices and integrated circuits for detecting one or more molecules and methods for forming a semiconductor device for detecting one or more molecules are presented. For example, a semiconductor device for detecting one or more molecules includes a channel formed within a semiconductor structure, and at least one detector formed within the semiconductor structure. The at least one detector detects the one or more molecules in the channel The semiconductor device may optionally comprise one or more additional channels formed within the semiconductor structure. The semiconductor device may, for example, be operative to detect a single molecule.

Abstract: A liquid chromatography device includes a column containing a filler, an injection valve capable of introducing a sample into the column and also capable of introducing a liquid mobile phase into the column, and a mobile phase feeder for feeding the liquid mobile phase from a mobile phase container containing the liquid mobile phase to the column via the injection valve. Between the mobile phase container and the injection valve is provided a storage chamber for temporarily storing the liquid mobile phase sent from the mobile phase container. The device further includes a liquid level detection sensor for detecting the liquid level of the liquid mobile phase in the storage chamber. This structure allows the liquid for use in analysis to be used completely without being wasted.

Abstract: Apparatus for GPC/TREF and TREF/GPC characterization of a polymer sample. The apparatus provides for the automated and integrated use of multiple TREF columns and a GPC system employing a multiple flow through detectors. In addition, a method for TREF/GPC characterization of a polymer sample by GPC analysis of TREF fractions at increasing TREF elution temperatures from multiple TREF columns operated in a coordinated and synchronized temperature cycle for increased sample throughput. Also, a method for GPC/TREF characterization of a polymer sample by GPC fractionation followed by TREF fractionation of the GPC fractionations.

Abstract: An auto-sampler cleaning mechanism is provided, which is capable of maintaining the supply of a liquid in a non-time-consuming manner when a cleaning solution is supplied. The auto-sampler cleaning mechanism of the present invention includes: a sample-metering sample loop 14 having a sample-injecting needle 15 at a front end thereof, a metering pump 24, a multi-ported valve 11a, a multi-position valve 11b, and a liquid-supply valve 11c. A diaphragm pump 25 is disposed between the port of the multi-position valve 11a and the port of the liquid-supply valve 11b, and used to supply a cleaning solution 26 or a mobile phase 20 to the sample loop 14.

Abstract: Embodiments of the invention feature methods and apparatus for the efficient utilization of detectors and other components. The apparatus comprises a pump for receiving and propelling one or more samples in a fluid path. The apparatus further comprises a valve element in fluid communication with the pump for receiving the samples from the pump and directing the sample along one fluid path selected from a group. The group comprises a delay path comprising a delay volume, and a chromatography assembly having at least one chromatography column. The apparatus further comprises a detector or grouping of detectors in fluid communication with the delay path and the chromatography assembly for detecting compounds of interest to allow a single detector or single grouping of detectors to receive samples from the two fluid paths.

Abstract: An apparatus which enables characterization of particles suspended in a liquid includes a housing with a mixing chamber and a collection chamber separated by a wall containing an aperture for passage of particles between, the mixing chamber and the collection chamber, the mixing chamber further containing a mixing member, a first electrode in the mixing chamber and a second electrode in the collection chamber for conduction of an electrical current through the aperture, a processor that is adapted for controlling the measurement sequence of the apparatus and detecting possible blockage of the aperture by detecting extended duration of the electrical pulse caused by the blocking particle, and upon detection of a blockage, reversing the liquid flow while mixing in the mixing chamber for removal of the blocking particle, and restarting particle counting.

Abstract: Analytical methods using hydrogen/deuterium exchange are provided which reduce or eliminate the back-exchange of deuterium for hydrogen. The methods, which are useful in protein and peptide mapping, include the steps of (a) providing a peptide or protein comprising a solvent accessible hydrogen; (b) exchanging the solvent accessible hydrogen for a deuterium; (c) separating the peptide or protein with supercritical fluid chromatography; and (d) analyzing by mass spectrometry the mass of the separated peptide or protein. Supercritical fluid chromatography enables the observation of fast exchanging hydrogen atoms missed using conventional liquid chromatography methods.

Abstract: The invention relates to a miniaturized gas chromatograph and injector for the same. Said micro-GC is compact and simple and economical to construct. Dead volumes are largely avoided in order to achieve reliable and reproducible measured results. Said miniaturized gas chromatograph comprises at least one injector, one separation column and a detector which are combined on a circuit board to give a gas chromatography module. The injector comprises a first sheet with channels, which is provided with a second sheet with channels and which may be displaced relative to the latter, whereby at least one of the sheets is provided with a layer of plastic, in particular a chemically inert plastic on the side of the sheet facing the other side.

Abstract: A fluid separation system (10) for separating compounds of a sample fluid in a mobile phase comprises a detector (50) adapted to detect separated compounds by providing an optical stimulus signal to the sample fluid and receiving a response signal to the optical stimulus signal. The detector (50) comprises a light source (100) adapted to provide an output light beam (230) as the optical stimulus signal. The light source (100) comprises a plurality of light emitting elements (200, 200A, 200Z) each adapted to emit a light beam (210, 210A1, 210A2, 210Z1, 210Z2) having a respective wavelength, and a diffracting element (220). The plurality of light emitting elements (200, 200A, 200Z) are arranged that emitted light beams (210, 210A1, 210A2, 210Z1, 210Z2) impinging, on the diffracting element (220) are diffracted by the diffracting element (220) to form the output light beam (230).

Abstract: The present invention is a pressurized fluid sample injector system consisting of a sample needle, multiport valve, sample loop, metering syringe and a pressure assist pump. The speed of sample transport into the sample loop is increased by pressurizing the fluid in the system and metering the sample into the sample loop. The elevated system pressure allows the fluids to be moved faster than the vapor pressure would normally allow in a system at ambient pressure.

Abstract: A separation column and a liquid chromatograph using the separation column, which are capable of carrying out a high-speed analysis under high pressure and without a reduction in separation performance of the separation column. In the separation column, a sample and a mobile phase are introduced into a packing material. The chromatograph has a covering member for covering an outer surface of the packing material and a supporting member having the packing material covered with the covering member inserted therein, wherein the level of pressure generated within a gap located between the covering member and the supporting member on the outflow side of the gap, where the fluid-flows out of the gap, is lower than that of pressure generated within the gap on the inflow side of the gap, where the fluid is introduced.

Abstract: A flow controller for use with a liquid chromatography detector. The flow controller includes a flow channel comprising an inlet portion, a control channel portion in communication with the inlet portion, and an outlet portion in communication with said control channel portion. The control channel portion has a cross-sectional area smaller than a cross-sectional area of a drift tube of the liquid chromatography detector for channeling the flow of droplets through the smaller cross-sectional area. The flow controller is shaped and sized to reduce pressure fluctuations and turbulence in the droplet stream of the liquid chromatography detector.

Abstract: Systems, devices, and methods to mitigate the pressure disturbance associated with the injection of low-pressure analyte samples into a high-pressure HPLC fluid stream to enhance chromatographic performance related to retention time and reproducibility. The injection event is coordinated with active pressure control of a binary solvent delivery system to virtually eliminate the customary pressure drop when the low-pressure loop is brought on line. Consistent timing with the injection event of the mechanical position of the delivery pump pistons, and the start and subsequent gradient delivery generates reproducible results.

Abstract: A splitter for a pressurized primary flowstream of a mobile phase is provided. The splitter comprises a first splitting stage that divides the primary flowstream between a major split flowstream and a minor split flowstream by means of a first and a second restrictive flow element; a first dilution stage that combines a dilution flow source with the minor split flowstream to create a diluted minor flowstream; a second splitting stage that divides the diluted minor flowstream between a secondary major diluted flowstream and a secondary minor diluted flowstream by means of a third restrictive element in the secondary minor diluted flow stream; and a second dilution stage wherein a conditioning flow source conditions the secondary minor diluted flow stream after the third restrictive element prior to outlet of the secondary minor diluted flowstream from the splitter.

Abstract: A system for testing a drilling fluid including a vessel having a fluid inlet, a filtrate outlet, a fluid outlet, and at least one permeable media disposed within the vessel. The system further including a base fluid container in fluid communication with the fluid inlet, a test fluid container in fluid communication with the fluid inlet, a filtrate container in fluid communication with the filtrate outlet, and a collection container in fluid communication with the fluid outlet.

Abstract: The present invention pertains to a method of ion chromatography wherein a specialized electrodeionization (EDI) apparatus is used for (1) the preparation of a pure acid or pure base for use as an eluent in a chromatographic separation column and/or (2) for ion suppression (or neutralization) of the acid or base after it has been used to elute ions from a chromatographic separation column. Methods for trace ion removal, acid and base neutralization, and ion suppression using a specialized EDI apparatus are also described. The methods described herein allow for the ion suppression of samples containing chloride, nitrate, and other electrochemically active anions, without causing damage to the suppressor.

Abstract: A liquid gas vaporization and measurement system, and associated method, for efficiently vaporizing a continuous sample of liquid gas, such as liquid natural gas (LNG), and accurately determining the constituent components of the gas. A constant flow of liquid gas sampled from a mass storage device is maintained in a vaporizing device. Within the vaporizing device the liquid gas is flash vaporized within heated narrow tubing. The liquid gas is converted to vapor very quickly as it enters one or more independently operating vaporizer stages within the vaporizing device. The vapor gas is provided to a measuring instrument such as a chromatograph and the individual constituent components and the BTU value of the gas are determined to an accuracy of within +/?0.5 mole percent and 1 BTU, respectively.

Abstract: The invention concerns a method for capturing a chemical compound, typically an impurity, and for accumulating said chemical compound on a capture mass CAPT included in at least one removable adsorbant cartridge MC over a long period exceeding 2 days, with a view to the external chemical analysis thereof. The invention also concerns an apparatus ST suitable for capturing at least one chemical compound in a fluid flow for its detection and/or quantification comprising, downstream of said cartridge or cartridges, at least one means for measuring the cumulative flow which has traversed said cartridge or cartridges over a set time period. In a preferred variation of the invention, the capture mass CAPT is fragmented into a plurality of elementary masses CAPTi which allowing the spread of an irreversible adsorption front or the displacement of a chromatographic zone to be determined.

Abstract: A flow controller for use with a liquid chromatography detector. The flow controller includes a flow channel comprising an inlet portion, a control channel portion in communication with the inlet portion, and an outlet portion in communication with said control channel portion. The control channel portion has a cross-sectional area smaller than a cross-sectional area of a drift tube of the liquid chromatography detector for channeling the flow of droplets through the smaller cross-sectional area. The flow controller is shaped and sized to reduce pressure fluctuations and turbulence in the droplet stream of the liquid chromatography detector.

Abstract: A sample analyzing apparatus using centrifugal force and inertia including a rotating body composed of a disk including upper and lower thin-films; a plurality of chambers composed of a polygonal space parts in the rotating body and including apertures on one side corner and a bottom side thereof; paths connected between the apertures of the chambers to transfer fluids mixed or separated in the chambers; sample inputting holes connected to the chambers formed inside of the rotating body through the paths; and balls moving within the chambers.

Abstract: The invention pertains to a sample injector for liquid chromatography, particularly for high performance liquid chromatography, with a controllable injection valve (3) that features at least one waste port (12) for discharging fluid under low pressure, two sample loop ports (13, 16) and two high-pressure ports (14, 15) for supplying and discharging fluid under high pressure, wherein one high-pressure port (15) can be connected to a pump (40) and the other high-pressure port (14) can be connected to a chromatography column (41), with a sample loop (44, 51, 52) that comprises a first sample loop section (51) that is connected to one of the sample loop ports (16) on one end and to a pump volume (V) of a sample conveying device (5) on the other end, as well as a second sample loop section (44, 52) that is connected to the other sample loop port (13) on one end and to the pump volume (V) of the sample conveying device (5) on the other end.

Abstract: A flow controller for use with a liquid chromatography detector. The flow controller includes a flow channel comprising an inlet portion, a control channel portion in communication with the inlet portion, and an outlet portion in communication with said control channel portion. The control channel portion has a cross-sectional area smaller than a cross-sectional area of a drift tube of the liquid chromatography detector for channeling the flow of droplets through the smaller cross-sectional area.

Abstract: A pump device is realized, which accurately detects a flow rate of a pump, performs real-time control of the flow rate, and thus can suppress a flow rate error caused by occurrence of pulsation. Control of a pump rotation speed by a pressure sensor has low responsiveness in a low pressure region, and a correlation between a pressure and a flow rate is incomplete in a high flow rate region. With this taken into consideration, a flow rate sensor 10 is disposed at an outlet port 9 of a second pump 4. A position detection sensor 14 detects a point where a first pump 3 is shifted from a suction mode to a discharge mode. Moreover, the flow rate sensor 10 detects that there is no discharge from the pump 3, and that there is discharge from the pump 4 alone. Accordingly, a controller 15 sets a rotation speed of a motor 12 to a speed double the previous speed (double the normal rotation speed).

Abstract: A shear valve for use in a high performance liquid chromatography system, the shear valve comprising a first shear valve member and a second shear valve member, wherein at least one of the first and second shear valve members is adapted to be moved with respect to the other, one of the first and second shear valve members comprises a plurality of ports, and the other comprises at least one fluid path for fluidly coupling respective ones of the ports in dependency on a relative movement position of the first and second shear valve members with respect to each other, wherein the first shear valve member is at least partially coated with an adhesion-promoting layer and a diamond like carbon layer on the adhesion-promoting layer.

Abstract: A method for controlling operation of a pump unit, where the pump unit includes a primary piston pump having a primary piston and a secondary piston pump having a secondary piston. The primary piston pump is fluidically connected with the secondary piston pump. The primary piston pump includes an inlet valve and an outlet valve, and the pump unit operates periodically according to a pump cycle. The method includes determining a fluid pressure of fluid dispensed by the pump unit, and performing a closed loop control of a position of the primary piston in dependence on the fluid pressure of the fluid dispensed by the pump unit during a first time interval of the pump cycle.

Abstract: A sample injector includes a rotary valve element with a straight passageway through it, which element may be rotated to connect a port communicating with a source of solvent with a port communicating with an inlet to a column. Another passageway connects two adjacent ports. The valve element may be rotated to one position in which it provides a straight path for sample to be injected, a second position in which it provides a path that connects a source of purge gas to the chromatographic system and a third position in which it provides a path that connects solvent to the column for preconditioning.

Abstract: A device for feeding samples to a separating device and for collecting sample fractions generated by means of the separating device, especially for high-performance liquid chromatography, with a first switch valve unit, which has at least eight ports and two switch positions. The device has a dosing device for feeding a sample to the switch valve unit, which is connected to a suction port of the first switch valve unit and which interacts with a removal and discharge device for the removal of a sample from at least one sample-holding container and for the discharge of each fraction into one of several fraction-holding containers, which is connected to a suction and discharge port of the first switch valve unit. The device uses a single switch valve unit configured in a new way to replace the function of two switch valve units, resulting in significantly simpler and cheaper construction.

Abstract: A microfluidic processing system having a manifold with at least one inlet; at least one outlet; and a plurality of microfluidic chip holders. A fluidic jumper is coupled to one of the chip holders and at least two fluidic elements are coupled to at least one of the chip holders. The fluidic jumper controls the fluidic path through the system.

Abstract: An acid or base is generated in an aqueous solution by the steps of: (a) providing a source of first ions adjacent an aqueous liquid in a first acid or base generation zone, separated by a first barrier (e.g., anion exchange membrane) substantially preventing liquid flow and transporting ions only of the same charge as said first ions, (b) providing a source of second ions of opposite charge adjacent an aqueous liquid in a second acid or base generation zone, separated by a second barrier transporting ions only of the same charge as the second ions, and (c) transporting ions across the first barrier by applying an electrical potential through said first and second zones to generate an acid-containing aqueous solution in one of said first or second zones and a base-containing aqueous solution in the other one which may be combined to form a salt. Also, electrolytic apparatus for performing the above method.

Abstract: A disrupter apparatus comprises a nozzle comprising: a converging section; a diverging section; and a throat between the converging section and the diverging section. The disrupter apparatus also comprises a holder configured to receive a fluid conduit, which comprises an outlet located in the converging section; and a channel disposed about the holder and configured to guide a gas past the outlet of the fluid conduit, through the converging section, through the throat and into the diverging section where the gas travels at supersonic speed and establishes a standing shock wave in the diverging section. A mass spectrometer and a method are also described.

Abstract: An IC system including sample preparation. The system includes a liquid sample injection loop, an ion concentrator, an ion separator, and only a single pump for pumping fluid through the system.

Abstract: The invention provides improved methods and apparatus for fluid chromatography, and is particularly appropriate to high-pressure liquid chromatography carried out using eluent flow rates less than 1 ?l/minute, for example on nanoflow columns. In both single- and multi-dimensional chromatography systems, especially those comprising trapping media to facilitate injection of relatively large volumes of sample on to nanoflow columns, the on-line addition of a diluting solvent enables stronger eluents and sample solvents to be employed without causing premature release of analytes from the trapping media or the degradation of the second dimension chromatographic separation. The invention may be advantageously used for two-dimension reverse phase/reverse phase separations, especially for the separation of complex mixtures of peptides.

Abstract: A liquid chromatograph includes a mobile phase supplying apparatus including a plurality of liquid-feeding pumps to feed mobile phases, a plurality of liquid-feeding flow paths, a mixer to mix the mobile phases by merging the liquid-feeding flow paths, at least one control device to control driving of each of the liquid-feeding pumps based on flow rates for the respective liquid-feeding flow paths, a plurality of flow rate measuring sections provided downstream of the liquid feeding pump in each liquid-feeding flow path, the plurality of actual flow rate measuring sections configured to measure an actual flow rate and to detect a back-flow in the corresponding liquid-feeding flow path, and a plurality of actual flow rate computing sections configured to compute an actual flow rate in the corresponding liquid feeding flow path.

Abstract: A rotary valve (10) for distributing a flow of a fluid is provided, the valve comprising a stator (11) and a rotor (12). Furthermore a chromatography system, comprising such a rotary valve and three different components or component groups connected to the valve is provided. With this rotary valve according to the invention the flow direction is kept constant through one of the three components or component groups while the flow direction through the other two component or component groups can be changed.

Abstract: A supply flow path for supplying a solvent is described. The supply flow path includes metering devices each with a piston, the metering devices being adapted for metering the solvent through separate source paths feeding the supply flow path. The supply flow path further includes a control unit adapted for controlling the metering devices' piston movement in accordance with solvent pressure, wherein a variation of the solvent pressure gives rise to a corresponding variation of a solvent volume contained in the supply flow path or a part thereof. The control unit is adapted for compensating for the variation of the solvent volume by corresponding movements or forward or backward displacements of the pistons.