Figure 1

TEM images and EDS spectra of individual primary particles from the combustion of maize straw. (a) Low magnification TEM image of gel-like OM particles containing K-rich cores in the smoldering phase; (b) Low magnification TEM image of a mixture of OM-K and soot-OM-K particles in the flaming phase; (c and d) Soot particles internally mixed with OM and KCl in the flaming phase; (e) An OM-K particle including KCl and K2SO4 cores in the flaming phase. The corresponding EDS spectra are indicated by the number in square brackets.