High performance sub-ambient temperature multi-capillary column preconcentration system for volatile chemical analysis by gas chromatography

A method comprising:

• during a first time period, cooling, with one or more cooling systems, a first trap and a second trap to a trapping temperature, the first trap comprising a first tube and the second trap comprising a first capillary column and a second capillary column coupled in series and situated in a heater, wherein cooling the first trap to the trapping temperature causes water of a chemical sample to transition directly from a gas phase to a solid phase and allows one or more water soluble compounds of the chemical sample to traverse the first trap;
• transferring one or more compounds of the chemical sample to the first trap and the second trap, including transferring the one or more compounds of the chemical sample from the first capillary column of the second trap to the second capillary column of the second trap, while the first trap and second trap are at the trapping temperature, wherein:
• the chemical sample includes a portion of water that remains in the first trap without being transferred to the second trap while the one or more compounds of the chemical sample are transferred to the second trap, and
• transferring the one or more compounds of the chemical sample to the first trap and the second trap comprises controlling a flow, with a flow controller, in a first direction;
• during a second time period after the first time period, heating, with the second heater, the second trap to a desorption temperature;
• and
• transferring the one or more compounds of the chemical sample from the second trap to a chemical analyzer, including transferring the one or more compounds of the chemical sample from the second capillary column of the second trap to the chemical analyzer through the first capillary column of the second trap, wherein transferring the one or more compounds of the chemical sample from the second trap to the chemical analyzer comprises facilitating a flow, with a pressure controller of the chemical analyzer, in a second direction opposite from the first direction without transferring the portion of water from the first trap to the chemical analyzer.