Certain configurations are described of column heaters that can be used in gas chromatography applications to provide individual heating zones along a gas chromatography column. The column heater may comprise a plurality of inductive elements that can be used to provide heating zones. A thermally conductive support can be used with the gas chromatography column and the inductive elements if desired. The column heater can be used to provide a travelling wave, a thermal gradient or other heating profiles.

Certain configurations described herein are directed to gas chromatography devices. In some instances, the gas chromatography devices may comprise at least one heating device which can be moved along a chromatography column to provide a thermal gradient to the chromatography column. In other instances, the gas chromatography devices may comprise a heating device that can receive a moving chromatography column to provide a thermal gradient to the chromatography column. The gas chromatography devices may be configured as portable devices which can be used to perform remote analyses.

The invention relates to a method, to a device, and to the use of a method for the gas-chromatic separation and determination of volatile substances in a carrier gas by means of a chromatographic separating capillary (1), wherein the separating capillary and/or an enveloping capillary (2) surrounding the separating capillary (1) is electrically conductive and is heated with current in the form of a resistance heater and is cooled by a forced convective flow by means of a fluid in the form of a gradient flow field in such a way that a continuous temperature gradient arises over the length of the separating capillary.

Exemplary embodiments may compensate for expected frictional heating or Joule-Thomson cooling in chromatography columns. Frictional heating or Joule Thomson cooling are the same thing for a fluid decompressing along a porous material. Either heat is absorbed from or released to the external environment. The exemplary embodiments may cool the mobile phase to a sub-ambient temperature before the mobile phase passes through a chromatography column to compensate for the frictional heating or heat the mobile phase to a super-ambient temperature to compensate for Joule-Thomson cooling. The amount of temperature increase expected from the frictional heating or the amount of temperature decrease expected from the Joule-Thomson cooling may be calculated or estimated. Based on the amount of temperature increase or decrease expected, the set point for the heater/cooler may be determined and applied to the mobile phase. The analyte may be injected solely into a central portion of the chromatography column to further compensate for thermal gradients.

A system and method for sample analysis using a portable gas chromatography (GC)-mass spectrometry (MS) is provided. The GC-MS system includes an injector configured to accept a sample containing a mixture of chemicals and release at least part of the sample for a separation by GC, a MEMS GC column with an integrated heater configured to accept and at least partly separate the mixture of chemicals, and a mass analyzer in a vacuum chamber configured to accept and mass-analyze the released separated chemicals. The MEMS GC column with the integrated heater is located mostly inside the MS vacuum chamber.

Techniques are described for accelerating thermal equilibrium in a chromatographic column. An apparatus comprises a chromatography column, and a plurality of temperature control units in thermal contact with the chromatography column. A method of performing liquid chromatography comprises setting an inlet of a chromatography column to a first temperature using a first temperature control unit in thermal contact with said inlet, setting an outlet of the chromatography column to a second temperature using a second temperature control unit in thermal contact with the outlet, wherein the first temperature is less than the second temperature; and injecting a sample into a liquid stream that flows through the chromatography column after the inlet is set at the first temperature and the outlet is at the second temperature.

The present invention is a system and method for significantly improving gas chromatography resolution using a dynamic and non-linear thermal gradient along the entire column length and is achieved by decreasing the velocity of analytes when approaching the back end of the capillary column in order to compensate for an increase in velocity of carrier gas as the carrier gas expands when approaching the back end, and wherein the thermal gradient is selected so that the analyte achieves a constant velocity through the capillary column.

An apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column wherein the insulating member is formed from a vacuum chamber surrounding the chromatography column. Another apparatus for performing liquid chromatography includes a chromatography column, and an insulating member surrounding the chromatography column, wherein the insulating member includes aerogel. Also described is a method of insulating a chromatography column comprising forming a jacket surrounding the chromatography column, and creating a vacuum chamber in an area between the jacket and the chromatography column.

The exemplary embodiments may determine a temperature set point for an outlet heater or cooler based on available information without requiring user input or requiring only minimal user input. The exemplary embodiments may estimate the temperature set point of the outlet heater based on available information, such as pressure delta along the column, temperature at the inlet of the chromatography column, and volumetric flow rate. In some instances, the estimate may be normalized for column dimensions, such as length and diameter. Tailing factor may also be used in determining the estimate. The estimate is not computationally burdensome and can be recalculated as the chromatography column is in use.

Certain configurations are described of column heaters that can be used in gas chromatography applications to provide individual heating zones along a gas chromatography column. The column heater may comprise a plurality of inductive elements that can be used to provide heating zones. A thermally conductive support can be used with the gas chromatography column and the inductive elements if desired. The column heater can be used to provide a travelling wave, a thermal gradient or other heating profiles.