摘要:
A system (Fig 8) for conducting high-temperature liquid chromatographic analysis includes a mobile phase transport tube (202) configured to operably convey mobile phase from a source to respective chromatographic instruments (206) in the system, a pre-heater (212) apparatus operably coupled to the mobile phase transport tube for heating the mobile phase to a desired temperature, a chromatographic column (206) operably coupled to the pre-heater apparatus, and including temperature-maintaining means (204) for maintaining the column at a pre-determined temperature and a counter-flow heat exchanger (212) operably exchanging heat from outlet mobile phase to inlet mobile phase trough conductive heat transfer means. In a particular embodiment, the mobile phase passing through the chromatographic column is maintained in a substantially adiabatic environment.
摘要:
A high speed gas chromatography system includes a heated isothermal region (115) and a gas chromatography column (105) located externally to the isothermal region (115). The system also includes a detector (360) and a flow path (150) between the column (105) and the detector (360). At least a portion of the flow path (150) is positioned in the isothermal region (115).
摘要:
A method for the preparation of liquid samples for analysis involves the feeding of a sample to be reconcentrated into a container-evaporator provided with means for controlling the temperature and internal pressure and containing one or more support materials, the evaporation of the solvent to reconcentrate the sample to the required volume, and sending the reconcentrated sample to an analysis apparatus.
摘要:
A process for the introduction of a liquid sample into an apparatus for gas chromatographic analysis, of the type wherein said sample is injected into a vaporization chamber (2) positioned upstream a gas chromatographic column (1), equipped with means (4) to feed a carrier gas and kept at a temperature at least equal to the boiling temperature of the solvent at the operating pressure, provides to: cut off or partialize the carrier gas flow entering said chamber; evaporate at least partly the introduced sample; cause the resulting vapours to flow from the injection/evaporation position to a second exhaust position (5); perform an at least partial separation between solvent and sample components in the vapours thus obtained during said flow; exhaust said partially separated vapours from said chamber; close or partialize said exhaust and restore the carrier gas feeding sending to the column the sample portion remained in said column.
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 (16) is described. The “preheating” or “precooling” process is carried out using an apparatus (10) containing a short length of tubing (11) where the mobile phase is heated or cooled. The heating or cooling is performed using a heating or cooling element (12) that is in intimate thermal contact with the exterior of the tubing (11). With a low mass heating or cooling element (12), 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 gas chromatography system featuring column bifurcation and pressure tuning. The system of this invention incorporates a bifurcated system in which samples eluting from a first separation column are directed selectively through one of two or more additional separation columns. Flow directing is achieved through the use of valves which switch carrier gas which are outside of the path of the analyte mixture. Effective tuning of the system is provided by adjusting the intermediate pressure which controls the effective lengths of the initial separation column and the additional final separation columns.