摘要:
An improved gas chromatography system is presented. The system comprises: an enclosure having an inlet and an outlet, such that the ventilation flow is from the inlet to the outlet; a chamber disposed in the enclosure; a monolithic gas analyzer disposed in the chamber and a temperature control unit disposed in physical contact with the chamber. The monolithic gas analyzer operates to separate and detect molecules from a gas; whereas, the temperature control unit is configured to control temperature inside the chamber.
摘要:
There is provided a method for thermally focusing the elution times of compounds of a liquid chromatography system comprising a pre-column and a separation column as well as to provide a liquid chromatography system, wherein the chromatographic separation of a mixture of substances is optimized.
摘要:
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.
摘要:
A convenient and efficient method for heating or cooling the mobile phase fluid of a chromatographic system prior to its entry into the chromatographic column is described. The “preheating” or “precooling” process is carried out using an apparatus containing a short length of tubing where the mobile phase is heated or cooled. The heating or cooling is performed using a heating or cooling element that is in intimate thermal contact with the exterior of the tubing. The temperature change of the mobile phase is measured downstream by a non-invasive, low-mass sensing element on the exterior of the tubing. With a low mass heating or cooling element, the device can be very responsive and allows for rapid equilibration and convenient temperature programming of the mobile phase. This configuration also requires only a short mobile phase contact time, is non-invasive, adds no dead volume, and allows for use of columns over a wide range of internal diameter, flow rates and temperatures.
摘要:
An apparatus for liquid chromatography comprises a liquid chromatography separation column on a substrate, wherein the separation column is coupled to a heater on the substrate. A chip-based temperature controlled liquid chromatography device comprises a substrate, a thermal isolation zone, and a separation column thermally isolated from the substrate by the thermal isolation zone. An apparatus for chip-based liquid chromatography comprising a cooling device is provided. A temperature gradient liquid chromatography system comprises a chip-based temperature controlled liquid chromatography device, a fluidic coupling, and an electrical interface. Methods of making and methods of using of chip-based temperature gradient liquid chromatography devices are also provided.
摘要:
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.
摘要:
A sub- to super-ambient temperature programmable microfabricated gas chromatography column enables more efficient chemical separation of chemical analytes in a gas mixture by combining a thermoelectric cooler and temperature sensing on the microfabricated column. Sub-ambient temperature programming enables the efficient separation of volatile organic compounds and super-ambient temperature programming enables the elution of less volatile analytes within a reasonable time. The small heat capacity and thermal isolation of the microfabricated column improves the thermal time response and power consumption, both important factors for portable microanalytical systems.
摘要:
A miniaturized total analysis system (".mu.-TAS") comprising a miniaturized planar column device is described for use in liquid phase analysis. The .mu.-TAS comprises microstructures fabricated by laser ablation in a variety of novel support substrates. The .mu.-TAS includes associated laser-ablated features required for integrated sample analysis, such as analyte detection means and fluid communication means. .mu.-TAS constructed according to the invention is useful in any analysis system for detecting and analyzing small and/or macromolecular solutes in the liquid phase and may employ chromatographic separation means, electrophoretic separation means, electrochromatographic separation means, or combinations thereof.
摘要翻译:描述了包括小型化平面柱装置的小型化总分析系统(“mu-TAS”)用于液相分析。 mu-TAS包括通过在各种新型支撑衬底中的激光烧蚀制造的微观结构。 mu -TAS包括用于集成样品分析所需的相关激光烧蚀特征,例如分析物检测装置和流体连通装置。 根据本发明构建的mu-TAS可用于检测和分析液相中的小分子和/或大分子溶质的任何分析系统,并且可以使用色谱分离装置,电泳分离装置,电色谱分离装置或其组合。
摘要:
Miniaturized planar column devices and miniaturized total analysis systems for liquid phase analysis are disclosed. The systems include a temperature control device for regulating temperature, preferably a thermoelectric device comprising Peltier elements.
摘要:
A method of preservation and presentation including the steps of positioning a perishable product having a significant porosity and permeability into a gas impermeable package in the presence of a first agent, thereafter sealing the product in the package in the presence of the agent under a positive pressure and maintaining gas communication between the product and the first agent for a time necessary for the concentration of the first agent to be reduced by 50%.