Patent ID: 7291203

Claim:
A method for improving separation efficiencies comprising the step of: providing a gas chromatography (GC) apparatus comprising: a microwave oven adapted to heat the GC column and including: a GC column having: a continuous phase material forming a wall surrounding an interior space for containing a chromatography sample and a microwave absorbing material contained in the continuous phase material, a microwave source, a temperature sensor, a microwave source controller adapted to control a microwave power to the microwave oven by the microwave source and to control a power efficiency of the microwave source, a coolant source, and a coolant source controller adapted to control a flow rate of the coolant, and performing one or a first plurality of positive temperature ramps, where each positive temperature ramp comprises raising a current temperature of the GC column from a lower start temperature or a first plurality of lower start temperatures to a higher stop temperature or a first plurality of higher stop temperatures at a positive controlled rate or at a first plurality of controlled rates, and performing one or a second plurality of negative temperature ramps, where each negative temperature ramp comprises lowering a current temperature of the GC column from a higher start temperature or a second plurality of higher start temperatures to a lower stop temperature or a second plurality of lower stop temperatures at a negative controlled rate or at a second plurality of controlled rates, where the negative temperature ramp improves the separation of lower boiling components from higher boiling components or the improve the separation of components having boiling points within a narrow temperature range.