摘要:
A compact high pressure hydraulic system having no moving parts for converting electric potential to hydraulic force and for manipulating fluids. Electro-osmotic flow is used to provide a valve and means to compress a fluid or gas in a capillary-based system. By electro-osmotically moving an electrolyte between a first position opening communication between a fluid inlet and outlet and a second position closing communication between the fluid inlet and outlet the system can be configured as a valve. The system can also be used to generate forces as large as 2500 psi that can be used to compress a fluid, either a liquid or a gas.
摘要:
A microchip apparatus and method provide fluidic manipulations for a variety of applications, including sample injection for microchip liquid chromatography. The microchip is fabricated using standard photolithographic procedures and chemical wet etching, with the substrate and cover plate joined using direct bonding. Capillary electrophoresis is performed in channels formed in the substrate. Injections are made by electro-osmotically pumping sample through the injection channel that crosses the separation channel, followed by a switching of the potentials to force a plug into the separation channel.
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:
A system and method for electrochemically regenerated ion neutralization and concentration is disclosed. In one aspect of the invention, a system is provided comprising a HPLC column pump, a concentrator column, an analytical column, a suppressor, a detector, a mixed bed deionizing resin, a sample injector, and a neutralization cartridge.
摘要:
To collect analyte from a supercritical fluid extractor, the collector lifts vials into place by a biasing device that guides the file up to the restrictor where it is sealed. The vial can be moved back down from the collecting mechanism even if frost forms on the vial while the restrictor remains stationary. This vial is held in place by a guide that contains the seal for sealing the vial when it is raised in place.
摘要:
In a piston pump for pumping liquid carbon dioxide at a temperature below 30 degrees Fahrenheit and pressures at least as high as 7500 psi, the volume leaving the pump is determined by measuring only pressure or other parameter related to flow and movement of the plunger. The position of the piston is measured and the resulting displacement is integrated to determine volume of fluid pumped.
摘要:
To supply supercritical fluid to an automatic supercritical fluid extractor and collect extract from the extractor, sample holding cartridges are lifted one by one in series by an elevator plug into a pressure chamber. An inlet at the top of the cartridge engages a pressure vessel inlet for the extractant so that extractant flows into the cartridge and into the space between the cartridge and inner walls of the pressure chamber. The outlets from the cartridge and pressure vessel communicate with the collector and exhaust through passageways in the plug. The plug has cleaning ports for cleaning seals and the outlet from the cartridge flows past the seals. The collector lifts vials into place and can precool the collection solvent, and later as part of the collection procedure, heat and pressurize the collector.
摘要:
To avoid deposits on the restrictor that channels extractant into a collector, a heated capillary tube pressure release restrictor, has a thermally insulated outlet end in a collecting trap substantially colder than the capillary tube. The restrictor is heated between the insulation and the capillary tube by Joulean heating. The solvent in the trap is at a pressure of 5 to 200 psi above atmospheric pressure. The thermal resistance of the insulation is selected to reduce the heat added to the extractant to a minimum and yet cause the temperature of the extractant to be in a range within which it is sufficiently hot so it does not freeze when added to the collection solvent but not so hot as to reduce partitioning of the extract and extractant before the extractant leaves the collection solvent. It has a thermal conductivity no greater than 60 BTU's per hour, per square foot, per inch for a one degree Fahrenheit difference.
摘要:
An improved pneumatic control system suitable for use in providing servo control of one or more active devices in an analytical instrument includes a series pass element that effects partial regulation of an unregulated voltage to remove any high frequency supply voltage variations (including but not limited to a ripple component), but need not regulate the low frequency voltage variations, the effects of which are compensated by a loop gain compensation scheme operable in a servo control loop. A digital signal processor employed in the servo control loop uses a voltage sense signal representative of the regulated supply line voltage to generate a correcting term for use in a proportional integral derivative (PID) control algorithm operating in control loop firmware. The correcting term causes an inverse proportional change in the control loop gain. The duty cycle of the drive signal provided to the active device is accordingly modulated, when necessary, to account for changes indicated by the voltage sense signal. The power in the drive signal is therefore made independent of variations in the regulated supply line voltage. As a result, the active device is operated with greater efficiency and accuracy.
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.