Gas chromatograph having cyro blast coolings

Apparatus and methods are disclosed for performing a chromatographic separation of a given compound wherein the compound and a carrier gas are passed through an injection port and onto a column and wherein a portion of the column is contained in an oven. The apparatus and method are shown to include a first heater for heating the injection port in response to a first control signal, a first temperature sensor for sensing the temperature of the injection port and for generating a first temperature signal representative of the temperature of the injection port, a second heater for heating the oven in response to a second control signal, a second temperature sensor for sensing the temperature of the oven and for generating a second temperature signal representative of the temperature of the oven and a cooling member for simultaneously cooling the injection port and the column. The cooling member can include various conduit arrangements for directing a flow of cryogen fluid. There is also shown a valve for controlling the flow of cryogen fluid through the cooling member in response to a third control signal, and a control member for receiving the first and second temperature signals, and for generating the first, second and third control signals in relation to the first and second temperature signals, so that the temperature in the injection port and the oven are maintained at a desired level.