Passive column pre-heater with sample band spreading reduction feature

A passive pre-heater assembly for use in a chromatographic system in which a fluid mixture is supplied from an injector to a chromatographic column having an active heating source, the pre-heater assembly comprising:

• a) a convoluted tube having first and second ends and a fluid passage extending centrally therebetween;
• b) means associated with the first and second ends of the convoluted tube for fluidly connecting the first end of the convoluted tube to an injector and for fluidly connecting the second end of the convoluted tube to a chromatographic column;
• c) a support element having at least one channel formed in an exterior surface thereof, the channel being adapted for receiving the convoluted tube;
• and
• d) a thermally conductive film attached to the exterior surface of the support element and adapted for conveying heat from an active heating source of a chromatographic column to the support element and convoluted tube when the pre-heater assembly is positioned adjacent to an active heating source for a chromatographic column.

A chromatographic system comprising:

• a) a fluid injector for supplying a fluid mixture at a desired pressure and velocity;
• b) a pre-heater assembly for receiving the fluid mixture from the fluid injector, the pre-heater assembly including:
• i) an elongated tube having first and second ends and a fluid passage extending centrally therebetween, the tube being formed so as to have a convoluted axis such that a secondary flow field is created in a primary flow stream for the fluid mixture;
• and
• ii) first and second end fittings attached respectively to the first and second ends of the tube, the first end fitting being adapted for fluidly connecting the first end of the convoluted tube to the fluid injector and the second end fitting being adapted for fluidly connecting the first end of the convoluted tube to a chromatographic column;
• c) a chromatographic column adapted and configured for receiving the fluid mixture from the pre-heater assembly and adsorbing a portion thereof;
• and
• d) an active heating source in direct contact with the chromatographic column for heating the fluid contained in the column;
• wherein the convoluted tube of the pre-heater assembly is positioned adjacent to the active heating source such that the fluid mixture in the tube is heated thereby.

A chromatographic method comprising the steps of:

• a) providing a fluid injector for supplying a fluid mixture at a desired pressure and velocity;
• b) fluidly attaching a first end of a pre-heater assembly to the injector, the pre-heater assembly adapted for receiving the fluid mixture from the fluid injector and passively providing heat thereto
• c) fluidly attaching a chromatographic column to a second end of the pre-heater assembly, the column being adapted and configured for receiving the pre-heated fluid mixture from the pre-heater assembly and adsorbing a portion thereof;
• d) providing an active heating source in direct contact with the chromatographic column for heating the fluid contained in the column;
• and
• e) positioning the pre-heater assembly adjacent to the active heating source such that the fluid mixture provided to the pre-heater assembly is heated thereby.