The extraction of precipitates and second phase insoluble intermetallic or metalloid compounds from three commerical aluminium alloys was achieved by anodic dissolution of the aluminium alloy matrix in a methanolic electrolyte containing benzoic acid, oxine and chloroform. Investigated were Aluminium Association alloy 7075 containing principally Al-Zn-Mg-Cu, alloy 6061 containing principally Al-Si, and alloy 2011 containing principally Al-Cu. X-ray diffraction of the extracted residues using the Debye-Scherrer method, identified the compounds MnAl6, MgO and Mg2Si in the 7075 alloy in the aged condition, the insoluble phase Mn12Si7Al5 in the 6061 alloy in both the solution heat-treated and aged conditions. In the 2011 alloy the primary precipitate, CuAl2, was extracted in the aged condition and the lattice parameters for this tetragonal compound were determined to bea=6.064 A andc=4.874 A: Metallic bismuth also was identified in the extraction from this alloy. Several lines, believed to represent an unknown ternary or higher compound, could not be identified.