The thermal behaviors of homologues, derivatives and adducts of beta-cyclodextrin (beta-CD) are compared based on thermogravimetry (TG) and gas chromatography coupled to time-of-flight mass spectrometry (GC-TOF-MS) analysis. Our results indicate that the number of glucose units and the introduced groups cause a considerable change in thermal decomposition mechanisms of these carbohydrates. Further, it is observed that the mass loss of the bicomponent aggregate formed by phenylarsonic acid (PAA) and beta-CD is larger than that of each of the components at higher temperatures. Additionally, the decomposition of the adduct produces a series of arsenic compounds with high relative abundances, such as AsO+, As2O2+, As3O4+ and As4O6+, which is rather different from the decomposition behaviors of free PAA and the adduct of beta-CD with sodium arsenite. (C) 2010 Elsevier B.V. All rights reserved.