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: A mass filter is disclosed comprising an orthogonal acceleration electrode 9. Ions entering the mass filter are orthogonally accelerated by the orthogonal acceleration electrode 9 in a primary acceleration region 2 and enter a flight region 3. The ions 6,7,8 are then reflected by a reflectron 4 and are directed towards an exit region of the mass filter. Ions having a desired mass to charge ratio are arranged to arrive in the primary acceleration region 2 at a time when a voltage pulse applied to the orthogonal acceleration electrode 9 falls from a maximum to zero. Ions having a desired mass to charge ratio are orthogonally decelerated such that they have a zero component of velocity in the orthogonal direction. Accordingly, ions having a desired mass to charge ratio exit the mass filter in an axial direction.

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: Embodiments of the present invention feature devices and methods for holding fluids at high pressures. One embodiment of the present invention features a fluid containing conveying device for receiving and discharging fluids. The device comprises a housing having a chamber for containing a fluid. The housing has a first gasket receiving surface for receiving a gasket. A gasket formed of a deformable material and having a first abutment surface and second abutment surface. The first abutment surface received on the first gasket receiving surface and the second abutment surface for receiving a chamber closing piece. The chamber closing piece having a second gasket receiving surface, the chamber closing piece for closing the chamber. At least one of the first gasket receiving surface of the housing and the second gasket receiving surface of the chamber closing piece having a retaining grove, having at least one edge.

Abstract: A method for using a neural network to deconvolute the effects due to surface topography from the effects due to the other physical property being measured in a scanning probe microscopy (SPM) or atomic force microscopy (AFM) image. In the case of a thermal SPM, the SPM probe is scanned across the surface of a sample having known uniform thermal properties, measuring both the surface topography and thermal properties of the sample. The data thus collected forms a training data set. Several training data sets can be collected, preferably on samples having different surface topographies. A neural network is applied to the training data sets, such that the neural network learns how to deconvolute the effects dues to surface topography from the effects dues to the variations in thermal properties of a sample.

Abstract: Disclosed herein is a sample preparation plate used to prepare a sample for mass spectrometry. In particular, a sample plate used to concentrate a sample as well as remove contaminants from the sample while providing easy manipulation of small liquid droplets on a surface with minimal sample loss.

Abstract: The invention is a method of bonding a first fluid conduit (14) to one or more other fluid conduits (12) or elements such as an electrode (92) or heating element. The method comprises positioning a first fluid conduit (14) substantially in contact with the other fluid conduits or elements (12) wherein a bond region (16) is created. The bond region is wetted with a liquefied thermoplastic polymer (34) which is then subsequently cooled forming a substantially fluid tight bond between the first fluid conduit (14) and the other fluid conduits or elements (14).

Abstract: The present invention is directed to the use of a light absorbing wall material to eliminate stray light paths in light-guiding structures, such as those used for HPLC absorbance detection. More specifically, the present invention relates to the use of carbon-doped Teflon® AF, or “black Teflon® AF,” for all or part of the walls of a light-guiding flowcell adapted for use in HPLC absorbance detection.

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.

Abstract: Embodiments of the present invention are directed to a substrate for performing ionization desorption on porous silicon, methods for performing such ionization desorption and methods of making substrates. One embodiment directed to a substrate for performing ionization desorption on silicon comprises a substrate having a surface having a formula of: As used above, X is H or Y, where at least at least twenty five mole percent of X is Y and Y is hydroxyl, or —O—R1, or O—SiR1, R2, R3 wherein R1, R2, and R3 are selected from the group consisting of alkyl, alkenyl, alkynyl, aromatic, amino alkyl, amino alkenyl, amino alkynyl, pyridinyl, pyrridonyl, and carbonyl, alcohol and carboxylic acid derivatives thereof having one to twenty five atoms, and hydroxyl, amino, amide, carboxyl, ester, carbonyl, sulfhydryl, sulfonyl, phosphoral, bromo, iodo, chloro and fluoro derivatives. The letter “n” represents an integer from 1 to infinity and any vacant valences are silicon atoms, hydrogen or impurities.

Abstract: A material for chromatographic separations, processes for its preparation, and separation devices containing the chromatographic material. In particular, porous inorganic/organic hybrid materials are provided with a decreased concentration of surface organic groups. These materials may be surface modified and have enhanced stability at low pH.

Abstract: A method and apparatus for monitoring and controlling the nano-scale flow rate of fluid in the operating flow path of a HPLC system without relying on a nano-scale sensor in the operating flow path. A main flow sensor is disposed in the main flow path between the pump and a flow-divider. A waste flow sensor is disposed in the waste flow path downstream of the splitter. The output signal of the waste flow sensor is subtracted from the output signal of the main flow sensor in a difference circuit. The difference signal is divided by the output signal from the main flow sensor in a divider circuit. The output of the divider circuit represents an empirical split ratio of the flow-divider and is independent of media composition.

Abstract: Destructible surfactants and methods of using same are provided. The invention includes anionic surfactants having a dioxolane or dioxane functional group which enables the surfactant to be broken down under acidic conditions. The invention also includes methods of making anionic surfactants and methods of using anionic surfactants in a variety of applications.

Abstract: Embodiments of the present invention feature devices and methods for holding fluids at high pressures. One embodiment of the present invention features a device for receiving and discharging fluids. The device comprises a first housing having at least one side wall. The side wall has an interior surface defining at least one chamber and has at least one end cap abutment surface for receiving an end cap. The device has at least one end cap having at least one first housing abutment surface. The first housing abutment surface receives the end cap abutment surface positioning the end cap on the first housing for enclosing the chamber. At least one of the first housing abutment surface and the end cap abutment surface has first seal coating. The first seal coating comprises a deformable plastic adhering to the abutment surface. The device further comprises a fluid path means for receiving and removing fluid from the chamber.

Abstract: A self scanning photodiode array allows low signal pixels to accumulate charge for multiples of predetermined exposure time to 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: A method for supplying solvent to an ultra-high pressure liquid chromatography system using a hydraulic amplifier. The hydraulic amplifier system includes a hydraulic cylinder comprising a primary piston chamber in which a primary piston is disposed and a secondary piston chamber in which a secondary piston is disposed. The cross-sectional area of the primary piston is larger than the cross-sectional area of the secondary piston. The difference in the cross-sectional areas of the pistons creates an amplification of the pressure in the primary piston chamber and a reduction in flow rate.

Abstract: The present invention provides devices and methods for controlling the flow of fluids in very high pressure situations. The devices feature valve shafts having bearings and pins to hold stator surfaces and rotor surfaces in proper alignment.

Abstract: A device (100) for detecting a condition in a fluid system (14) and initiating a response based on the condition. The device consists of a sensor (12) that responds to a first and second condition of the fluid (13) in the system and a control means (10) that receives the responses and generates command signals in based on the received response. In a liquid chromatography system, the device is used to determine the volume of components of the fluid system. In addition, the device allow leaks to be detected and permits the fluid in the system to be transported at a optimum speed. The device is well implemented utilizing to a light emitter and light receptor that are sensitive to the fluid in either a gaseous or liquid state.

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 method and system for calculating a heat flow to a sample in a differential scanning calorimeter (DSC). The DSC has a sensor within an enclosure comprising an absolute temperature measurement detector for measuring the temperature of a base position on the sensor, a first differential temperature detector for measuring the temperature difference between a sample position and the base position, and a second differential temperature detector for measuring the temperature difference between a reference position and a sample position. Thermal resistances and heat capacities of the DSC are calibrated. The DSC is operated, and the heat flow to the sample is calculated using a method that accounts for the leakage heat flows.