摘要:
A method of performing a chromatographic separation includes generating a spatial temperature gradient along a length of a chromatographic column in a liquid chromatography system. A sample is injected into a flow of a mobile phase to the column and a flow of a mobile phase having a composition gradient is provided to the column after the sample is received at the column. The spatial temperature gradient is moved along the length of the column from the column inlet to the column outlet during the time that the composition gradient traverses the column. This coordination of the composition gradient with the movement of the spatial thermal gradient yields a significant increase in peak capacity per unit time compared with conventional separation techniques performed in a conventional isothermal column environment.
摘要:
A flexible, foldable light-weight gas chromatography transfer line suitable for connecting a gas chromatograph (GC) to a spectrometer, such as a mass spectrometer or optical spectrometer, in particular to the ion source of the spectrometer, such as an inductively coupled plasma (ICP) ion source. The transfer line has a heating arrangement that allows maintaining an even temperature profile, which improves quality of spectra. The transfer line has low thermal mass and the heating can be controlled with the control unit of the GC.
摘要:
A suppressor is structured by an ion exchange section being structured by an eluate path forming member forming an eluate path and a regenerant path forming member forming a regenerant path being stacked across an ion exchange film, and a heat-conductive heat block covering the outside of the ion exchange section. A separation column, the suppressor, and an electrical conductivity meter are accommodated in a common constant temperature bath. The inside of the constant temperature bath is feedback-controlled by a temperature control section so as to be maintained at constant temperature.
摘要:
A thermally controlled variable restrictor device provides variable restriction of fluid flow by temperature-induced viscosity changes. The thermally controlled variable restrictor device allows fast variable fluid control by employing a thermo-electric heater-cooler in intimate contact with a fluid channel containing a fluid thereby effecting rapid viscosity changes in the flowing fluid. The permeability and flow rate of fluids through the variable restrictor device can be manipulated by changing the temperature of a restriction element.
摘要:
An instrument including a chromatographic column with a final detector and a mass spectrometer. A temperature of an interface including an output tube and a capillary tube adjusting the flow to the spectrometer is adjusted using a leakage flow or pressure sensor outputting data to a control module that adjusts the interface temperature to equalize flows in the tubes.
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:
A coupling device connecting the output of a microchromatograph (nullCG) to the input of a mass spectrometer (SM), said coupling device comprising a capillary tube with one end connected in sealed fashion to the source under vacuum of the mass spectrometer through the intermediary of an interface device, and with the other end connected to the output of the microchromatograph, in slack fashion, open to the atmosphere; the length and the diameter of the capillary tube being chosen such that the flow rate inside the capillary tube is very close to the flow rate at the output from the microchromatograph; the interface device being, furthermore, provided with heating means for very precise adjustment of the flow rate registered by the capillary.
摘要:
A high-pressure control valve (2) used in chromatography serves as a counter pressure control valve which, in a separating column, is intended to maintain a specific predeterminable pressure. The valve has a valve seat (12) with an outlet channel opening (18) located in its center and a valve body (13) that cooperates with the valve seat. The valve body (13) can be moved with the aid of a piezo transducer, actively in the opening direction and, while being monitored, actively in the closing direction. The opposed faces of the valve seat (12) and the valve body (13) are so shaped that an annular gap (16) that widens radially towards the outside starting from the opening (18) of the outlet channel is produced. When the valve is in the closed position, this results in the formation of a narrow sealing zone directly at the edge of the opening of the outlet channel.
摘要:
This disclosure is concerned with method and apparatus for vaporizing liquid solutions in order to detect, quantitate, and/or determine physical or chemical properties of samples present in liquid solution. Mixtures may be separated by an on-line liquid chromatographic column and the methods used for detection, quantitation, identification, and/or determination of chemical and physical properties include mass spectrometry, photoionization, flame ionization, electron capture, optical photometry, including UV, visible, and IR regions of the spectrum, light scattering, light emission, atomic absorption, and any other technique suitable for detecting or analyzing molecules or particles in a gaseous or vacuum environment. The method and apparatus involves controlled partial vaporization of the solution. Methods are disclosed for controlling the degree of partial vaporization and the temperature at which this vaporization occurs, and for maintaining this degree of vaporization essentially constant even though the solvent flow rate and/or composition may vary in either a controlled or an uncontrolled fashion. ThisGOVERNMENT SUPPORTThe invention described herein was made in the course of work under a grant or award from the Department of Health and Human Services (formerly Health Education and Welfare).CROSS REFERENCE TO RELATED APPLICATIONS
摘要:
This disclosure is concerned with method and apparatus for vaporizing liquid solutions in order to detect, quantitate, and/or determine physical or chemical properties of samples present in liquid solution. Mixtures may be separated by an on-line liquid chromatographic column and the methods used for detection, quantitation, identification, and/or determination of chemical and physical properties include mass spectrometry, photoionization, flame ionization, electron capture, optical photometry, including UV, visible, and IR regions of the spectrum, light scattering, light emission, atomic absorption, and any other technique suitable for detecting or analyzing molecules or particles in a gaseous or vacuum environment. The method and apparatus involves controlled partial vaporization of the solution. Methods are disclosed for controlling the degree of partial vaporization and the temperature at which this vaporization occurs, and for maintaining this degree of vaporization essentially constant even though the solvent flow rate and/or composition may vary in either a controlled or an uncontrolled fashion. This "thermospray" method and apparatus allows the solvent to be substantially vaporized to produce a supersonic free jet containing a fractionGOVERNMENT SUPPORTThe invention described herein was made in the course of work under a grant or award from the Department of Health and Human Services (formerly Health Education and Welfare).