The present invention relates to a method for determining the amount of the specific analyte of a sample which may show interferences by photometric assays, wherein the specific analyte is quantified from the change in the optical signal of the reaction mixture after the interaction of the analyte with analyte specific assay reagents. Multiple calibration curves are generated for multiple wavelengths for the specific analyte of a sample to be determined, the measurement results are deposited in a data management system of the instrument platform. An interference test is performed simultaneously to the determination of the specific analyte, for quantifying the amount of interfering substances present in the sample to be determined. The amount of each interfering substances is compared to predetermined cut-off values. The optical signal for the specific analyte of a sample to be determined is measured in the reaction mixture at multiple wavelengths over the complete reaction time, and a calibration curve is selected depending on the interfering substances. Finally, the amount of the specific analyte of a sample to be determined is quantified by comparison with the selected calibration curve for the chosen wavelengths.