Combustion-generated ash was synthesized, heated and analyzed by solid-state nuclear magnetic resonance spectroscopy with magic angle spinning (NMR±MAS). The structural information obtained from this study indicates that the ash contains different magnetic resonance environments for Al, Si and Na after combustion. The ®nal ash material contains a major amorphous aluminosilicate glass phase with mullite and corundum crystals. 29 Si NMR spectra showed a single peak at 2110.5 ppm (d ) for the initial powder sample due to SiO 2 . When the sample was heated to 15008C the peak shifts to lower ®eld (d 299 ppm) due to the formation of aluminosilicate amorphous glass containing alkali or alkaline earth metals. The 27 Al NMR spectra of the initial sample gives a single peak at 10.1 ppm due to the AlO 6 (octahedral group) present in the Al 2 O 3 . When the sample is heated to 15008C, a new peak appeared at 50 ppm due to the formation of AlO 4 tetrahedral represent the mullite and aluminosilicate compounds. The 23 Na NMR spectra of both the initial and the heated samples (at 15008C) give rise to a single peak at 214.3 and 228.7 ppm, respectively. The sharp peak at 214.3 ppm is contributed from the crystalline Na 2 O and the broad peak around 228.7 ppm is due to the Na 1 present to compensate SiO 2 present in the amorphous aluminosilicate glass material. The presence of low amounts of heavy metals Cr (2800 ppm), Cd (2700 ppm) and Pb (2800 ppm) in the ash generally does not show any in¯uence on the 27 Al, 29 Si and 23 Na solid-state NMR spectra. On the other hand, the ash sample containing higher amounts of heavy metals (Cd 14210 ppm, Cr 13120 ppm and Pb 13140 ppm) showed signi®cant effect on the 27 Al NMR spectra. The replacement of Al 31 from its octahedral sites by Cr 31 leads to the decrease in the intensity of the AlO 6 octahedral peak. The presence of Cr 31 , Cd 21 and Pb 21 in the aluminosilicate matrix exerts a deshielding effect on 29 Si resonance and thus shifts d to low-®eld. The results clearly indicate an interaction between the heavy metals and the ash matrix compounds.