A computer implemented method for automatic peak integration of at least one chromatogram of at least one sample, wherein the sample comprises at least one analyte and at least one chemical related substance, wherein the method comprises the following steps: a) Retrieving at least one chromatogram of the chemical related substance and at least one chromatogram of the analyte; b) Evaluating the chromatogram of the chemical related substance, wherein the evaluating comprises b1) determining at least one initial value for analyte retention time by determining retention time of the chemical related substance and adding the retention time of the chemical related substance with a pre-determined or pre-defined constant offset and/or multiplying the retention time of the chemical related substance with a pre-determined or pre-defined constant factor , b2) determining at least one initial value for analyte peak shape parameters by determining peak shape parameters of at least one peak of the chemical related substance chromatogram ; c) Evaluating the chromatogram of the analyte, wherein the evaluating comprises c1) at least one position determining step , wherein the analyte retention time is determined by considering the initial value of the retention time of the chemical related substance; c2) at least one peak integration step , wherein analyte peak area and analyte peak shape are determined by applying at least one fitting analysis to the chromatogram of the analyte by considering the initial value for analyte peak shape parameters and the analyte retention time. a) Retrieving at least one chromatogram of the chemical related substance and at least one chromatogram of the analyte; b) Evaluating the chromatogram of the chemical related substance, wherein the evaluating comprises b1) determining at least one initial value for analyte retention time by determining retention time of the chemical related substance and adding the retention time of the chemical related substance with a pre-determined or pre-defined constant offset and/or multiplying the retention time of the chemical related substance with a pre-determined or pre-defined constant factor , b2) determining at least one initial value for analyte peak shape parameters by determining peak shape parameters of at least one peak of the chemical related substance chromatogram ; b1) determining at least one initial value for analyte retention time by determining retention time of the chemical related substance and adding the retention time of the chemical related substance with a pre-determined or pre-defined constant offset and/or multiplying the retention time of the chemical related substance with a pre-determined or pre-defined constant factor , b2) determining at least one initial value for analyte peak shape parameters by determining peak shape parameters of at least one peak of the chemical related substance chromatogram ; c) Evaluating the chromatogram of the analyte, wherein the evaluating comprises c1) at least one position determining step , wherein the analyte retention time is determined by considering the initial value of the retention time of the chemical related substance; c2) at least one peak integration step , wherein analyte peak area and analyte peak shape are determined by applying at least one fitting analysis to the chromatogram of the analyte by considering the initial value for analyte peak shape parameters and the analyte retention time. c1) at least one position determining step , wherein the analyte retention time is determined by considering the initial value of the retention time of the chemical related substance; c2) at least one peak integration step , wherein analyte peak area and analyte peak shape are determined by applying at least one fitting analysis to the chromatogram of the analyte by considering the initial value for analyte peak shape parameters and the analyte retention time. <EOS>