Transverse thermal modulation

A method of thermally modulating a tubular member carrying a sample substance therethrough, said method comprising the steps of:

• (a) directing at least one gas stream toward said tubular member in a direction substantially transverse to said tubular member, wherein the temperature of the gas stream differs from the temperature of the tubular member;
• and
• (b) varying the gas flow rate of the at least one gas stream as a function of time to thermally modulate the tubular member,
• wherein said at least one gas stream is supplied from a gas nozzle having a gas outlet, and said step of varying the gas flow rate comprises rotating a baffle between said gas outlet and said tubular member such that said baffle interrupts the flow of said at least one gas stream toward said tubular member.

A method of thermally modulating a tubular member carrying a sample substance therethrough, said method comprising the steps of:

• (a) directing at least one gas stream toward said tubular member in a direction substantially transverse to said tubular member, wherein the temperature of the gas stream differs from the temperature of the tubular member;
• and
• (b) varying the gas flow rate of the at least one gas stream as a function of time to thermally modulate the tubular member,
• wherein said at least one gas stream is supplied by at least one gas nozzle assembly, and the gas flow rate of said at least one gas stream is varied by swiveling said gas nozzle assembly.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• two or more gas stream sources for directing two or more respective gas streams toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said two or more respective gas streams supplied from said two or more gas stream sources with a temperature that differs from the temperature of the tubular. member;
• and
• means for varying a gas flow rate of said two or more respective gas streams supplied from said two or more gas stream sources as a function of time to thermally modulate the tubular member.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• a gas stream source for directing a gas stream toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said gas stream supplied from said gas stream source with a temperature that differs from the temperature of the tubular member;
• and
• means for varying the gas flow rate of said gas stream supplied from said gas stream source as a function of time to thermally modulate the tubular member,
• wherein said means for varying the gas flow rate comprises a rotatable baffle that can be rotated to interrupt a flow of said gas stream toward said tubular member.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• a gas stream source for directing a gas stream toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said gas stream supplied from said gas stream source with a temperature that differs from the temperature of the tubular member;
• and
• means for varying the gas flow rate of said gas stream supplied from said gas stream source as a function of time to thermally modulate the tubular member,
• wherein said gas stream source comprises a gas nozzle assembly, and said means for varying comprises means for swiveling said gas nozzle assembly.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• a gas stream source for directing a gas stream toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said gas stream supplied from said gas stream source with a temperature that differs from the temperature of the tubular member;
• and
• means for varying the gas flow rate of said gas stream supplied from said gas stream source as a function of time to thermally modulate the tubular member,
• wherein said tubular member comprises two chromatographic columns in communication with each other at an intersection, and said gas stream source is positioned adjacent said intersection.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• a gas stream source for directing a gas stream toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said gas stream supplied from said gas stream source with a temperature that differs from the temperature of the tubular member;
• and
• means for varying the gas flow rate of said gas stream supplied from said gas stream source as a function of time to thermally modulate the tubular member,
• wherein a stationary phase is provided within said tubular member and said stationary phase is terminated within a thermal zone formed by said gas stream.

An apparatus for thermal modulation comprising:

• a tubular member for carrying a sample substance therethrough in a fluid medium;
• a gas stream source for directing a gas stream toward said tubular member in a direction substantially transverse to said tubular member;
• means for providing said gas stream supplied from said gas stream source with a temperature that differs from the temperature of the tubular member;
• and
• means for varying the gas flow rate of said gas stream supplied from said gas stream source as a function of time to thermally modulate the tubular member,
• wherein said apparatus is provided with means to form at least one heated region of the tubular member and at least one cooled region of the tubular member, and wherein said at least one heated region is of an unequal length relative to a length of said at least one cooled region.