Abstract: In various embodiments a fluid control device suitable for high pressure analytical instruments includes a housing having an interior surface with an end wall. The interior surface defines a chamber. A valve assembly disposed in the chamber controls the flow of fluid through the chamber. An end cap is disposed in the housing opposite the end wall to enclose the chamber. The end wall and end cap each have an opening to pass a fluid to the chamber or to remove a fluid from the chamber. The housing and end cap each has an abutment surface to receive the other abutment surface. At least one of the abutment surfaces has a plastic seal coating. A means of compression, such as a compression housing and compression sleeve, is included to engage the end cap to deform the plastic seal coating between the abutment surfaces and thereby seal the chamber.

Abstract: Disclosed herein are an apparatus and method for effectuating increased chromatographic efficiency in a capillary column by employing a retaining frit disposed within an analytical capillary. By disposing the retaining frit within the analytic capillary, the void volume is significantly minimized. The columns and methods described herein produce a simplified analytical capillary and retaining frit apparatus that provides greater chromatographic efficiency. Additionally, the column of the instant invention maintains chromatographic fidelity by reducing the transfer diameter as well as facilitating fluidic connections in situ.

Abstract: Embodiments of the present invention are directed to evaporation light scattering detectors having an evaporative chamber having a wall that is in good thermal contact with a heat sink. The heat has a high thermal mass such that a change in temperature of the wall during an analysis is minimized.

Abstract: The present invention is a capillary interconnection fitting and method of clamping a capillary in the fitting that separates a forward ferrule that holds the capillary from a secondary clamping device. The fitting comprises a sealing ferrule, a compression screw and a clamping device. The ferrule is fitted in a compression screw that mates to a fluidic component. The clamping device is decoupled from the ferrule and coupled to the compression screw.

Abstract: Embodiments of the present invention facilitate servicing or changing a discharge tube or modifying the position of a discharge tube with respect to a orifice of a detector and/or a nebulizing gas conduit. The apparatus features a discharge tube housing that slidably receives a discharge tube. A union coupling the discharge tube to a source of fluid is slidably mounted to a mounting assembly holding the tube housing.

Abstract: Apparatus for the detection of analytes in a fluid, for example the eluant from a liquid chromatography is described. Solvent is evaporated from the eluant to produce a stream of particles when analyte is present in the fluid. The resultant stream of particles is passed through one or more beams of radiation, typically visible light, and radiation scattered by the particles is detected at least at a first angle to a beam of radiation and at a second, different, angle to a radiation beam to produce a signal indicative of the presence of the analyte. Chromatographic apparatus incorporating the detector and methods of operating the detector and chromatographic apparatus are also described.

Abstract: Methods and devices for the management of cryogenic agents within analytical systems using freeze thaw valving having an expansion chamber that limits the flow of the cryogenic agent. The expansion chamber is fitted with an expansion nozzle through which a cryogen flows and a porous frit that allows the cryogen to be exhausted. The porous frit initially allows a rapid flow of cryogen into the expansion chamber. This rapid flow lowers the temperature of the expansion chamber causing fluid contents within a freeze thaw segment to freeze. As the cryogen expands into the expansion chamber and turns into a solid, the porous frit is occluded causing the rapid flow to be restricted. The restriction of the cryogen flow by the occlusion of the porous frit allows the freeze thaw valve to use significantly less cryogen. Sublimation of the cryogen trapped within the porous frit provides sufficient cooling to maintain the valve in its closed position.

Abstract: LC/MS data generated by an LC/MS system is analyzed to determine groupings of ions associated with originating molecules. Ions are grouped initially according to retention time, for example, using retention time or chromatographic peaks in mass chromatograms. After initial groupings are determined based on retention time, ion peak shapes are compared to determine whether ions should be excluded. Ions having peak shapes not matching other ions, or alternatively a reference peak shape, are excluded from the group.

Abstract: A self scanning photodiode array allows low signal pixels to accumulate charge for multiples of predetermined exposure time t0 before being read. The pattern of exposures, the integers Mi where I runs from 1 to N the number of pixels in the array, is chosen such that the pixels of interest accumulate as much charge as possible without exceeding saturation.

Abstract: Gradient performance with high pressure gradient solvent delivery system is optimized by approximation of infinite stroke volume of high pressure pumps by the addition of pulse dampening with backflow prevention to each high pressure pump. The backflow prevention adds sufficient minimum flow resistance, thereby enhancing the performance of the pulse dampening over a wider range of flow rates resulting in consistent gradient performance.

Abstract: A coupling element (1) comprising a male sealing element (5) is disclosed herein. The male sealing element comprises a first end (7), second end (9), and a longitudinal axis extending between the first and second end. The coupling element is housed within a nut (3). In one aspect, the male sealing element has a generally cylindrical shape. Also, the male sealing element defines a fluid passageway therethrough for the transmission of fluid. The male sealing element is secured to a ferrule (13) which is located within a cavity of the nut. The first end of the male sealing element defines a conical sealing surface. In one aspect, the male conical sealing surface (17) mates with a female sealing element (23) which has a receptacle that is defined by a nearly complementary conical geometry. In this aspect, the male conical sealing surface has a mismatched angle when compared to the complementary conical female sealing element.

Abstract: Embodiments of the present invention are directed to methods and devices for conveying or containing fluids under pressure in which seals are provided with a defined path to vent fluid in the event of a seal failure.

Abstract: A liquid chromatography system comprising a chiral mobile phase used to separate enantiomeric molecules present in a sample is disclosed herein. In one aspect, the mobile phase comprises a chiral solvent. In another aspect, the mobile phase includes a chiral solvent but also a buffering agent. The liquid chromatography system described herein includes both high pressure liquid chromatography (HPLC) as well as high pressure capillary liquid chromatography (CapLC).

Abstract: A system and method for detecting leaks includes a sensing circuit including a first thermistor device adapted to detected a leak upon contact with a liquid, and, a second thermistor device functioning as a reference device. The first and second thermistor devices are driven with a current such that both devices operate in self-heated mode at a temperature above an ambient temperature. A control system controls a drive circuit for maintaining a constant application of power through both devices in response to a voltage monitored at a reference point in the sensing circuit including the reference thermistor. The voltage at a reference point in a portion of the sensing circuit including the first thermistor device is additionally monitored and compared with the voltage at the reference point in the sensing circuit including the second thermistor device. A leak condition is determined on the basis of a comparison result of the ambient temperature.

Abstract: An HPLC column holding apparatus used to mount an HPLC column in one of a plurality of positions is disclosed herein. The apparatus comprises a clip-device interface that secures the apparatus to a platform and a clip-column interface that secures the HPLC column to the apparatus.

Abstract: Embodiments of the present invention are directed to an apparatus and method for performing parallel processes. One embodiment of the present invention is directed to an apparatus for performing a process having a plurality of steps in which each step is performed in a vessel by flowing a fluid through said vessel. The steps of the process comprise at least a first step and at least one subsequent step. At least one of the subsequent steps is a final step, and each step has a time associated with its performance, a step period. At least one step has a longest step period, and the total number of steps, times the longest step period equals a process period. The apparatus comprises a plurality of vessels. Each of the plurality of vessels is for performing sequentially all the steps of the process in the process period and each of the plurality of vessels is for performing each step of the process in the longest step period.

Abstract: Disclosed herein is a method of analyzing three-dimensional data obtained from a chromatography/spectrometry process, in particular an LC/MS process using a two-dimensional multi-variant statistical analysis. The LC portion permits separation of analytes within a sample. The information obtained from such a procedure typically depends on retention time (Rt). As the analytes progress through the system, they enter the MS region of the LC/MS system. There they are ionized and a mass detector then detects these ionized species. The information procured from this procedure is generally reported as intensity for a corresponding m/z value. Therefore, an LC/MS system provides at least three pieces of information. Principle component analysis (PCA) is a robust method of multi-variant analysis of this type of data between different samples. However, typically, PCA analysis is performed using only two-dimensional data.

Abstract: Disclosed herein are apparatus and methods for mitigating column bed compression over time. This invention provides for an improved column design and method of controlling bed density in a chromatographic column using a protruding portion of a filter assembly. The invention results in a higher sorbent bed density than can normally be achieved using a fixed length column of conventional design. The invention may be implemented as a unique filter assembly or as a column tailored for the application and a matching filter assembly.

Abstract: Gradient performance with high pressure gradient solvent delivery system is optimized by approximation of infinite stroke volume of high pressure pumps by the addition of pulse dampening with backflow prevention to each high pressure pump. The backflow prevention adds sufficient minimum flow resistance, thereby enhancing the performance of the pulse dampening over a wider range of flow rates resulting in consistent gradient performance.

Abstract: A freeze-thaw valve is provided using a Peltier heat pump where the thermal short-circuit path between a cooled thermal mass and a heated thermal mass is reduced or absent and the valve state transition time is minimized. The freeze-thaw valve comprises a Peltier heat pump mounted to a heat exchange surface that comprises a cross-drilled copper water jacket or manifold. The Peltier heat pump is operated to maintain a cooled thermal mass at a substantially constant low temperature. A resistance heating element is used to produce a heated thermal mass. The freeze-thaw segment of a fluid conduit is commutated to contact either the heated or the cooled thermal mass to thaw and therefore open the valve or cool and thus close the valve. The operation of the Peltier heat pump at a constant temperature avoids problems inherent in the use of a Peltier heat pump to both heat and cool a freeze thaw segment.