Patent ID: 7824471

Claim:
A chromatographic method for eliminating interference from interfering agents on impurities to be quantified in a gas sample, said method comprising the steps of: a) providing a chromatographic system having a first and a second sample loop, a first and a second separation column and a detector serially connected through a plurality of valves, said system being provided with a carrier gas, said gas sample and a supporting gas doped with a doping element; b) providing the first sample loop with said gas sample for filling said first sample loop with a sample gas volume; c) injecting said sample gas volume into said first separation column to substantially separate the gas sample into a plurality of baseline resolved impurities peaks; d) operatively connecting said first separation column to said second separation column for a predetermined transferring period of time for transferring at least one of said baseline resolved impurities peaks into said second column; e) isolating said second column from said first column after said predetermined transferring period of time; f) providing said second sample loop with said supporting gas for filling said second sample loop with a supporting gas volume; g) injecting said supporting gas volume into said first separation column for sweeping said first column with said supporting gas volume; and h) venting said first separation column outside the system through a vent line.