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Christopher A. Pohl, Union City US

Christopher A. Pohl, Union City, CA US

Patent application numberDescriptionPublished
20080203027Organosilanes and substrate bonded with same - The present invention, provides novel silicon compounds, methods for making these novel silicon compounds, compositions comprising these novel silicon compounds attached to substrates, methods for attaching the novel silicon compounds to substrates and methods for using the compositions in a variety of chromatographic applications.08-28-2008
20080293959COMPOSITIONS USEFUL AS CHROMATOGRAPHY STATIONARY PHASES - The current invention provides compositions, which are useful as stationary phases for a variety of chromatographic applications, such as high performance liquid chromatography (HPLC). The compositions include a substrate (e.g., silica gel), covalently bound to a compound, which includes both a hydrophobic moiety and a hydrophilic moiety, which is preferably a 1,2-diol moiety. The hydrophobic moiety is sufficiently hydrophobic for the compositions to exhibit reversed phase characteristics and typically incorporates at least 5 carbon atoms in sequence. Based on having both hydrophilic and hydrophobic functionalities, the new stationary phases exhibit unique chromatographic properties. For example, these media can be used in either hydrophilic (HILIC) mode, in which the mobile phase includes a high percentage of an organic solvent, or in reversed phase mode, in which the mobile phase contains a higher percentage of an aqueous solvent. The current invention also provides methods of making and using the compounds and compositions of the invention.11-27-2008
20090101582Recycled Suppressor Regenerants - A suppressed ion chromatographic apparatus using a regenerant recycle loop, comprising (a) an ion separation device, (b) a membrane suppressor, (c) a detector, (d) a container for regenerant solution, (e) a first conduit between the ion separation device and the suppressor, (f) a second conduit between the regenerant solution container and the suppressor, (g) a third conduit between the suppressor and the regenerant solution container, and (h) a regenerant solution recycle loop out of fluid communication with the detector outlet.04-23-2009
20090130767ORGANOSILANES AND SUBSTRATES COVALENTLY BONDED WITH SAME AND METHODS FOR SYNTHESIS AND USE - The present invention provides novel silicon compounds, methods for making these novel silicon compounds, compositions comprising these novel silicon compounds attached to substrates, methods for attaching the novel silicon compounds to substrates and methods for using the compositions in a variety of chromatographic applications.05-21-2009
20090166293CHEMICAL SUPPRESSORS AND METHOD OF USE - A non-electrolytic method and apparatus for treating an aqueous sample stream including analyte ions and matrix ions of opposite charge, for pretreatment or suppression. The apparatus includes an ion exchange membrane capable of passing only ions of opposite charge to the analyte ions, a sample stream flow channel, a first aqueous stream ion receiving flow channel adjacent one side of the sample stream flow channel and separated therefrom by the first ion exchange membrane, and stationary flow-through ion exchange packing disposed in the sample stream flow channel. The ion receiving channel has an ion exchange capacity for the matrix ions less than about 25% of the ion exchange capacity for the matrix ions.07-02-2009
20090211979Ion chromatography system with eluent recycle - Ion chromatography apparatus including (a) a chromatographic column, (b) a source of an aqueous eluent liquid stream, (c) a detector, (d) a recycle line between the detector and the chromatographic column, and (e) a purifying device disposed along the recycle line including ion exchange removal medium. Also, such apparatus with an electrolytic purifying device disposed along the recycle line. Also, methods of using such apparatus.08-27-2009
20090211980ION CHROMATOGRAPHY SYSTEMS WITH FLOW-DELAY ELUENT RECYCLE - A chromatographic method including chromatographically separating sample ionic species in an eluent stream, detecting the separated sample ionic species, catalytically combining hydrogen and oxygen gases or catalytically decomposing hydrogen peroxide in a catalytic gas elimination chamber, and recycling the effluent stream from the chamber to the chromatography separation column. The residence time between the detector and the chamber is at least about one minute. Also, flowing the recycle sequentially through two detector effluent flow channels of an electrolytic membrane suppressor. Also, applying heat or UV energy between the detector and the chamber. Also, detecting bubbles after the chamber. Also, a Platinum group metal catalyst and ion exchange medium in the chamber. Apparatus for performing the methods.08-27-2009
20090221079SAMPLE PRETREATMENT AND EXTRACTION - A method for pretreating and extracting a liquid sample by sorbing an aqueous liquid sample, including an organic analyte and an acid or a base, in a solid sorbent material, and at least partially neutralizing the acid or base by reaction with neutralizing ions retained on a support surface, and contacting the liquid sample-sorbed sorbent material at elevated temperature and pressure with an organic solvent to extract the analyte into said solvent, preferably in a vessel having an extraction chamber with a zirconium metal interior surface.09-03-2009
20090277838Functionalized substrates with ion-exchange properties - The current invention provides compositions, which are useful as stationary phases for a variety of chromatographic applications, such as high performance liquid chromatography (HPLC) and solid-phase extraction (SPE). The compositions include a porous solid support (e.g., silica gels, silica monoliths or synthetic organic resins) having an exterior surface and pore openings defined by “interior walls”. To the solid support are covalently bound organic ion-exchange ligands (e.g., silyl ligands), which incorporate at least one ion-exchange group (e.g., ionic or ionizable group). The compositions further include micro-particles (e.g., latex particles) incorporating ion-exchange groups having a charge that is opposite to the charge found on the support. The micro-particles are bound to the exterior surface of the support (e.g., via electrostatic forces). The micro-particles have a size that is sufficient to minimize the number of particles that can enter the pores of the support thereby reducing or essentially preventing binding of the micro-particles to the interior walls of the pores. While the pores are essentially too small for the micro-particles, they can still be accessed by the analytes present in a chromatographic sample. The physical separation of ion-exchange groups located within the pores and the surface of the micro-particles, respectively, prevents reactions (e.g., formation of salt-bridges) between the oppositely charged groups and provides compositions with both anion-exchange and cation-exchange capabilities within the same stationary phase. The ligands bound to the solid support can optionally include additional (e.g., reverse-phase) functionalities creating multi-modal (e.g., trimodal) stationary phases.11-12-2009
20090289009Ion chromatography systems with flow-delay eluent recycle - A chromatographic method including chromatographically separating sample ionic species in an eluent stream, detecting the separated sample ionic species, catalytically combining hydrogen and oxygen gases or catalytically decomposing hydrogen peroxide in a catalytic gas elimination chamber, and recycling the effluent stream from the chamber to the chromatography separation column. The residence time between the detector and the chamber is at least about one minute. Also, flowing the recycle sequentially through two detector effluent flow channels of an electrolytic membrane suppressor. Also, applying heat or UV energy between the detector and the chamber. Also, detecting bubbles after the chamber. Also, a Platinum group metal catalyst and ion exchange medium in the chamber. Apparatus for performing the methods.11-26-2009
20100038245Electrochemically Driven Pump - A continuous electrochemical pump comprising a water generator compartment, an anode compartment on one side of said generator compartment, a cation exchange barrier, separating the generator compartment from the anode compartment, a first electrode in electrical communication with the anode compartment, a cathode compartment adjacent the generator chamber, an anion exchange barrier, separating the generation compartment from the cathode compartment, and a second electrode in electrical communication with the cathode compartment. Use of the pump as a sample concentrator. A feedback loop for the pump. A reservoir, with or without an intermediate piston, on the output side of the pump.02-18-2010
20100224012FLUID SAMPLE DELIVERY SYSTEM AND METHOD - A fluid delivery system including a filter for filtering solid particles from a liquid sample, the filter including a first filter member configured to filter solid media from a liquid sample, a second filter member fluidly connected to the first filter member, and a third filter member fluidly connected to a downstream end of the second filter member. The second filter member is configured to filter relatively smaller solid media from the liquid sample than the first filter member, and the third filter member is configured to filter relatively larger solid media from the liquid sample than the second filter member. In various aspects, the system includes a displacement-type plunger needle to draw sample fluid from a vial, a cantilevered carousel for rotatably supporting an array of sample holding vials, and a support for supporting the carousel. Method of using the fluid delivery system are also disclosed.09-09-2010

Patent applications by Christopher A. Pohl, Union City, CA US