Abstract: The present invention pertains to a liquid chromatography method of separating multicharged ions, and more particularly, to separating both positively charged and negatively charged ions by using a mobile phase composition with doubly charged ions and an ion-exchange column with a charged stationary phase surface.

Abstract: Disclosed is a HPLC system including a first dimension column, a second dimension column, a high pressure switching valve installed along the mobile phase flow path with the usual detector. At a predetermined time after injection of a sample into the mobile phase stream, the valve is actuated so that late eluted components, while still in the first dimension column, are back-flushed to waste by the flow of mobile phase while the analytes get separated in the second dimension column. Mixed-mode cation exchange and anion exchange columns are particularly suited for this application.

Abstract: A gradient high pressure syringe pump usable in a high pressure liquid chromatography system includes a housing defining an internal cavity, a drive piston, and a floating piston unconnected from the drive piston dividing the internal cavity into first and second pumping chambers. Each pumping chamber has an intake inlet with an upstream no-return valve communicating with a source of fluid and a discharge outlet communicating with an inlet of a downstream control valve. The control valve is operable to selectively direct fluid from either of the upstream pumping chambers downstream. In one embodiment, the first pumping chamber defines a cylinder section for the drive piston having an internal diameter smaller than the cylinder section defined by the second pumping chamber for the floating piston. The drive piston is moved linearly between suction and discharge strokes by an attached screw operatively coupled with a controllable stepper motor.

Abstract: A chromatography device includes a unitary body that mounts and connects together as an integrated unit a chromatography column, an sample injector and a detector cell. The device components are arranged generally along X-Y-Z space axes. This arrangement allows hydraulic connection of all the components without additional tubing, fittings, or threaded ports. It also allows an integrated chromatography device to be produced inexpensively by machining or injection molding. The disclosed arrangement allows a user to have convenient access to the components for replacement or service. In addition, the disclosed construction enhances chromatography efficiency, reduces pressure, improves temperature control, and eliminates cross-contamination.

Abstract: A disposable chromatography sample introduction device includes a stylus with a holder and a tubular stem extending from one end of the holder containing porous sample-holding material. The stylus has a pair of spaced openings permitting fluid flow therethrough. An injector housing includes an insertion port for receiving the stylus, a seal, an inlet port for communicating with one stylus opening, and an outlet port for communicating with the other stylus opening. When the stem is immersed in a sample, sample enters the stem by capillary action. Thereafter, the stylus is inserted into the housing insertion port where mobile phase flowing from inlet port to outlet port passes through the stem extracting sample. The holder has a finger grip and an external thread that engages a complementary injector housing thread to secure the holder when the stylus is inserted therein.

Abstract: A chromatography column includes a shell containing packed stationary phase and includes an inlet and an outlet at one end of the shell. A plastic sleeve is positioned in the shell to isolate the stationary phase from the shell. A capillary tube extends from an upstream inlet at the one end of the shell to deliver mobile phase to the upstream end of the stationary phase. Mobile phase travels through the stationary phase and exits the column at the one end. Porous filters and seals are provided. A removable coupling adapter is attached to the one end of the column and provides short flow paths and connection ports for the column inlet and outlet. The coupling adapter may incorporate other chromatography components, such as temperature control elements or flow cell optical detectors.

Abstract: A pump for use in high pressure liquid chromatography includes a housing with a pump head at one end and an axially-movable, high-pressure piston with a small-diameter plunger reciprocating within the pump head to move fluid from an inlet through an outlet at high pressure. An attached motor rotates a circular cam fixed off center on the motor shaft to reciprocate the piston that has an inner end in engaging contact with the cam periphery. An axially-aligned, torque-compensating piston is provided and has an inner end biased by spring force against the cam opposite the high-pressure piston. A large-diameter piston head may be fixed to the outer end of the torque-compensating piston and slidably mounted within a cylinder defined at the housing end opposite the pump head. The outer end of the piston head is open to ambient atmosphere.

Abstract: A fitting for holding a tube in fluid communication with a cooperating component having a port with an internal thread of preselected pitch includes a coupling body with a longitudinal bore for receiving the tube, a grippable portion, and radially displaceable, tube clamping fingers separated by longitudinal slots. An external thread is defined on the surface of the fingers and is engageable with the internal thread of the port. The external thread has a pitch diameter similar to the pitch diameter of the internal thread and a pitch dissimilar to the pitch of the internal thread. Rotation of the fitting relative to the component to engage the threads effects relative axial movement thereof and radial displacement of the fingers into clamping engagement with the tube to hold it within the fitting. A sealing end ferrule may be included on the forward end of the coupling body.

Abstract: An amphibious vehicle that may be driven directly between land and water includes a vehicle with an opposed pair of flotation side hulls and a rear hull. The side hulls are movable between a stowed position above the vehicle and a lowered deployed position outboard thereof. Each side hull is mounted by arm assemblies including an upright bracket fixed to the vehicle and an arm pivotally connected to the bracket that can be extended or retracted linearly by actuators to raise and lower the side hulls. A locking mechanism prevents the extended side hulls from moving laterally but allows vertical adjustment thereof. The side hulls may be horizontally adjusted between compact contracted and extended protracted positions. The rear hull assembly is pivotally mounted to the back of vehicle permitting raising and lowering thereof and includes jet drives providing propulsion for water operation.

Abstract: A magnetic reciprocating pump includes a tube having ends defining intake and discharge ports, first and second magnetic plungers axially aligned within the tube of corresponding cross section for reciprocation therewithin, and a plurality of longitudinally spaced coils circumscribing the tube for driving the plungers axially when electrically energized. A gap is defined between the plungers so that the first plunger is slidable between one tube end and the second plunger and the second plunger is slidable between the other tube end and the first plunger. The first plunger closes one port when moved thereagainst and has a peripheral flow path permitting flow when moved away. The second plunger closes the other port when moved thereagainst and has an outer peripheral flow path and a communicating inner axial flow path permitting flow when moved away. The plungers when moved together close the second plunger axial flow path.

Abstract: A container for holding fluids in isolation includes an outer container and two deformable inner containers carried within the internal space of the outer container. The outer container is provided with a view port enabling the user to visually examine the inner containers. The inner containers have respective ports communicating with their interiors. As fluid is withdrawn from the first inner container its volume is reduced so that the second container may receive a like amount of fluid. The second inner container may hold colorants or absorbents. The container may be used with various chemical applications, such as high performance liquid chromatography or fluid injection analysis, wherein supply fluid is withdrawn from the first inner container, used, and returned as waste fluid to the second inner container so that the overall volume of fluids remains relatively constant.

Abstract: A transport detector for Liquid Chromatography includes a spinning disk covered in a non-wettable, non-transparent material with a wettable transparent channel left for a mobile phase. A mobile phase is delivered from a chromatography column into the channel. A light source with focusing optics is set along the channel path and array of sensors for optical signal detection are mounted along the path of the light. The disk rotation could be set at different speeds by a motor, allowing the operator to control the thickness of the liquid layer in the channel. Varying the thickness of liquid changes the length of the optical cell of the detector, which allows adjusting the sensitivity of the detector. The spinning disk design allows for using of multiple sensors of different kind as well as different detection methods. Also, the array of sensors of the same kind could be used to perform multiple measures of the same portion of the mobile phase. This feature improves the Signal to Noise ratio of the detector.

Abstract: The disclosed fitting has a tubular body externally threaded at one end, to allow the fitting to be positioned over a capillary tube and connected to a cooperating component. The fitting has opposed gripping jaws at its other end suited for being flexed against the capillary tube for holding it relative to the fitting. A tubular nut fits over the gripping jaws, and cam faces provided between the nut and jaws serve to tighten or release the jaws relative to the tube, depending on which direction the nut is shifted axially along the body. The outside tubular face of the actuating member is knurled, providing for reliable manual gripping and axial shifting the actuating member.

Abstract: The disclosed HPLC flow schematic back-flushes the guard column with mobile phase once every operating cycle, the regular cleaning maintaining its effectiveness and useful life. This mobile phase flow reversal is accomplished by imposing a two position multiple port switching valve between the guard and separation columns. In one valve position, the mobile phase is pumped in one flow direction through both the separation and guard columns, but the switched valve maintains the same flow direction only through the separation column and reverses the mobile phase flow direction through the guard column, for effectively cleaning the guard column. Moreover, the mobile phase back flow is directed over the emptied sample drawing needle for cleaning it to reduce possible sample cross contamination. The improved flow circuits use basically only the typical HPLC system components, except for some insignificant modifications from existing injector designs.

Abstract: The disclosed HPLC flow schematic back-flushes the guard column with mobile phase once every operating cycle, the regular cleaning maintaining its effectiveness and useful life. This mobile phase flow reversal is accomplished by imposing a two position multiple port switching valve between the guard and separation columns. In one valve position, the mobile phase is pumped in one flow direction through both the separation and guard columns, but the switched valve maintains the same flow direction only through the separation column and reverses the mobile phase flow direction through the guard column, for effectively cleaning the guard column. Moreover, the mobile phase back flow is directed over the emptied sample drawing needle for cleaning it to reduce possible sample cross contamination. The improved flow circuits use basically only the typical HPLC system components, except for some insignificant modifications from existing injector designs.

Abstract: The fitting includes an elongated cylindrical body with a conical ferrule secured to its forward end, and with the body and ferrule having aligned through bores sized to allow a capillary tube to be passed through them. The elongated body has medially located external helical threads, and a knurled nut is rotatably coupled to these threads. The body also has elongated axially directed gripping fingers with inwardly facing gripping regions thereon normally spaced from but suited to be biased radially against the capillary tube in the fitting bores. A tubular gripping nut is threaded onto the external body threads, suited to be axially shifted along the body upon relative nut/body rotation. The nut and body have cooperating cam surfaces suited to engage upon relative nut/body rotation and bias the finger gripping regions tightly against the capillary tube for securely retaining tube as positioned within the fitting.

Abstract: The preparative column has an inner thin wall HPLC compatible material tube, packed with absorbent particles, with filters and end fittings of HPLC compatible material at the tube ends. An aluminum outer sleeve tightly overlies and reinforces the inner tube, aluminum end caps overlie the end fittings and are secured to the outer sleeve. End connections in the end fittings allow solvent and sample flow through the packed absorbent. Exterior axial flats on the aluminum sleeve and end caps provide broad contact against flat thermal surfaces of conventional temperature controllers, thereby yielding effective thermal transfer there between. The flats further minimize column rolling on flat level surfaces and provide favorable locations for connection taps for conveying coolant flow through passages formed in the sleeve.

Abstract: The disclosed HPLC column is formed with overlying concentric inner and outer tubes. The flow path is established via the inner tube bore that holds packed absorbent, end filters and capping sealing members, and end coupling members cooperate with the inner tube at its ends. The sealing and end coupling members have conventional configurations for establishing a sealed connection with capillary lines and their fittings, for the series flow testing use through the column. The inventive method and manner of assembly provides that the outer tube overlies all of the inner tube and both sealing members, but only part of each end coupling member. The ends of the outer tube are then deformed radially inward to become mechanically interlocked with the end coupling members, as the column, holding also the filters and sealing members within the inner tube.

Abstract: This ion chromatography method utilizes a HPLC column having a stationary phase with two functional groups permanently attached thereto, respectively for ion-exchange and for hydrophobic interaction. The mobile phase will have an organic modifier, and an ionic modifier and will carry sample ions. The mobile phase organic modifier can be conventional HPLC organic solvent, while the mobile phase ionic modifier can be a weak hydrophobic base (for cation-exchange) or a weak hydrophobic acid (for anion-exchange). The stationary phase ion-exchange group can be a base or acid residue and the hydrophobic functional group can be an alkyl chain. The hydrophobic group of ionic modifier has a strong non-ionic interaction with the hydrophobic group of the stationary phase, which facilitates the ion-exchange process and the ion separation as the result.

Abstract: The invention provides a new universal bonded phase material used for separation of a wide variety of organic and inorganic substances by liquid chromatography. The material is produced by bonding a charge-bearing hydrophobic functional group to the surface of a supporting material. The process of preparation of such material and advantages of using the material are described.