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.

A method for modulating analytes in a gaseous stream passing through a capillary, wherein the analytes are retained in a trapping zone of the capillary, or allowed to pass therethrough, based on certain conditions. The method includes, during a first time period, heating the trapping zone of the capillary to a first temperature to desorb analytes therewithin and allow the analytes to pass therethrough, and during a second time period, cooling the capillary to a second temperature that is sufficient to trap and focus the analytes within the trapping zone. During the first time period, the method also includes retaining heat at the capillary during to minimize the load on a cooling device thermally connected thereto, and during the second time period, selectively allowing thermal transfer toward the cooling device.

This disclosure relates a device for a chromatographic system, comprising: a chamber defining an internal portion, a capillary disposed within the chamber, the capillary having an input, an output, and an elongate body extending between the input and the output, a cold finger having a first portion in thermal contact with a portion of the elongate body to define a capillary trapping zone, wherein the first portion of the cold finger extends to a second portion that is situated external to the chamber, a heater in thermal contact with the trapping zone of the capillary and configured to transfer heat to the trapping zone, a thermal buffer configured to buffer the heat from the heater into the cold finger and thereby retain the heat within the trapping zone of the capillary, a cooling device arranged external to the chamber and thermally connected to the second portion of the cold finger to define a primary conduction zone, wherein the cooling device is configured to generate a cooling temperature zone at the primary conduction zone, a controller configured to selectively alternate the trapping zone between a cooling temperature by turning off the heat and using the cooling device together with its engagement with the cold finger, and an injection temperature using the heater, wherein the heater alternates between an off state and an on state and a user defined frequency.

A method for modulating analytes in a gaseous stream passing through a capillary, wherein the analytes are retained in a trapping zone of the capillary, or allowed to pass therethrough, based on certain conditions. The method includes, during a first time period, heating the trapping zone of the capillary to a first temperature to desorb analytes therewithin and allow the analytes to pass therethrough, and during a second time period, cooling the capillary to a second temperature that is sufficient to trap and focus the analytes within the trapping zone. During the first time period, the method also includes retaining heat at the capillary during to minimize the load on a cooling device thermally connected thereto, and during the second time period, selectively allowing thermal transfer toward the cooling device.

A sample vessel assembly to carry out a sorption analysis in a container provided with a cooling liquid. The sample vessel assembly includes a sample vessel configured to be suspended within the container. The sample vessel has a sample holding region at a sample end of the vessel to hold a sample to be analyzed. A wick is disposed on the sample vessel and surrounds the sample holding region. The wick extends from the sample holding region to project toward a bottom of the container and draw the cooling liquid over the sample holding region when the sample vessel is disposed in an analysis position in the container.

A sample vessel assembly to carry out a sorption analysis in a container provided with a cooling liquid. The sample vessel assembly includes a sample vessel configured to be suspended within the container. The sample vessel has a sample holding region at a sample end of the vessel to hold a sample to be analyzed. A wick is disposed on the sample vessel and surrounds the sample holding region. The wick extends from the sample holding region to project toward a bottom of the container and draw the cooling liquid over the sample holding region when the sample vessel is disposed in an analysis position in the container.

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.

This disclosure relates a device for a chromatographic system, comprising: a chamber defining an internal portion, a capillary disposed within the chamber, the capillary having an input, an output, and an elongate body extending between the input and the output, a cold finger having a first portion in thermal contact with a portion of the elongate body to define a capillary trapping zone, wherein the first portion of the cold finger extends to a second portion that is situated external to the chamber, a heater in thermal contact with the trapping zone of the capillary and configured to transfer heat to the trapping zone, a thermal buffer configured to buffer the heat from the heater into the cold finger and thereby retain the heat within the trapping zone of the capillary, a cooling device arranged external to the chamber and thermally connected to the second portion of the cold finger to define a primary conduction zone, wherein the cooling device is configured to generate a cooling temperature zone at the primary conduction zone, a controller configured to selectively alternate the trapping zone between a cooling temperature by turning off the heat and using the cooling device together with its engagement with the cold finger, and an injection temperature using the heater, wherein the heater alternates between an off state and an on state and a user defined frequency.

A cryogenic trap for a thermal desorber includes a hollow quartz tube having a tube wall, a tube inlet, a tube outlet, and an interior passageway between the tube inlet and the tube outlet. A sorbent material is within the interior passageway, and a metal covering surrounds at least a portion of the quartz tube. The metal covering may be a metallic coating on an outer surface of the tube wall or a metal tube fitted around the quartz tube. The metal covering may be around a portion of the quartz tube adjacent the tube inlet and/or around a portion of the quartz tube adjacent the tube outlet. The metal covering may be around substantially an entirety of the quartz tube.

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.