Copper (II) and nicke (II) chelates of two tetradentate Schiff bases bis (isovalerylacetone) meso-stilbendiimine(meso-SiA2) and bis (isovaleryl-acetone)dl-stillbendiimineDl-SiA2) have been prepared and characterized using IR, NMR and mass spectroscopic techniques. The metal complexes have been assessed spectrophotometrically and their potentialities as analytical reagents have been evaluated. TGA, DTA and DSC of these complexes indicate that the metal complexes are sufficiently volatile and thermally stable at high temperature. The metal complexes can be gas chromatographed on OV 101, 3% on chromosorb 80-100 mesh size. Detection limit, calibration range and separation of dl and meso geometrical isomers are reported. The nickel chelates show greater sensitivity and low detection limits than the corresponding copper complexes at ng levels