This project serves as a supporting function to the studies on metabolism of various toxic or carcinogenic agents in this Branch. The purity of compounds being investigated for toxicity or carcinogenicity is determined along with pertinent physical characteristics, useful in the design of the experiments. Possible metabolites of various aromatic amines, such as 2, 4-toluenediamine or 2-aminoanthraquinone, are synthesized as reference materials for metabolism studies. Methods for separation of aromatic amines and their metabolites are investigated.