An atomic absortion spectrometer,varian-spectrAA600 with zeeman cor-rection,equipped with a varian GTA-100 atomizer linked to an automatic sample dispenser was used for this study.measurement were performed using two varian hollow cathode lamps,for Cr operating at259.7nm,and for Ni operating a 232.0nm.with a current intensity of 10mA in both cases.The bandwidth used was 0.5nm in all cases.Argon was employed as the inert gas at a flow equal to30L .Pyrolitic graphite-coated tubes without atomization platform were used.