This Technical Specification specifies a method for the determination of selected phthalates in sludge, treated biowaste and soil, after extraction and gas chromatographic analysis with mass spectrometric detection. The method is applicable for the determination of phthalates (see Table 2) at the lowest mass content of 0,1 mg/kg to 0,5 mg/kg (expressed as dry matter), depending on the individual substance. The applicability of the method to other phthalates not specified in Table 2 is not excluded except the isomeric mixtures e.g. DiNP (Di-isononylphthalate), but shall be verified in each case.