This Technical Specification specifies a method for the determination by gas chromatography with mass spectrometric detection (GC-MS) of polycyclic hydrocarbons and pesticide residues in drinking water and ground water at mass concentrations above 0,005 µg/l and surface water and waste water at mass concentrations above 0,01 µg/l (for each single compound). This method can apply to non-polar substances other than polycylic aromatic hydrocarbons (PAH) and pesticide residues. However, it is necessary to verify the applicability of this method for these compounds. NOTE 1 A potentially suitable method for this verification is specified in ISO/TS 13530.[3] This Technical Specification can be used for samples containing up to 150 mg/l of suspended matter. NOTE 2 Determination of PAH using GC-MS lies within the scope of ISO 28540.[9]