The present invention relates to a method for repetitive chemical analysis of a gas flow, wherein said gas flow consists of a carrier gas and gaseous chemical compounds, comprising the following method steps: feeding said gas flow to a gas chromatographic separation column by means of a feeding device; collecting at least a part of said gaseous chemical compounds for a defined time period by means of a thermally based collecting device which is coupled to said gas chromatographic separation column and/or said feeding device; releasing said collected gaseous chemical compounds in a temporally focused manner by means of said thermally based collecting device; separating said released gaseous chemical compounds by means of said gas chromatographic separation column; and analyzing said separated gaseous chemical compounds by means of an analyzer. The present invention further relates to a device for performing such a method.