The Contractor shall use proven instruments and techniques to identify and measure the concentrations of volatile and extractable compounds listed on the Target Compount List (TCL). The Contractor shall employ state-of-the-art GC/MS and GC procedures to perform all analyses, including all necessary preparations for analysis. The EPA provides the Contractor with the specific analytical procedures to be used and defines the specific application of these procedures to this contract. This includes instructions for sample preparation, gas chromatographic screening, mass spectrometric identification and data evaluation. Specific ions used for searching the mass spectral data for each compound are included.