Recently, in addition to X-ray and spectroscopic approaches, thermal analysis is often applied to complete the characterization of precipitated metal complexes. However, thermogravimetry itself is frequently not sufficient to explain complex decomposition or releasing steps. To propose the decomposition mechanism of Co(II), Cu(II) and Zn(II) complexes with 1,1-diaminobutane-Schiff base, evolved gas analysis by mass spectrometry (EGA-MS) was used to define the thermally induced steps of precipitated complexes, synthesized following the literature and characterized by hyphenated thermogravimetry-mass spectrometry (TG-MS) that allowed to describe the releasing or decomposition steps. (C) 2015 Elsevier B.V. All rights reserved.