From multidomain particles to organic radicals: The multifaceted magnetic properties of tobacco and cigarette ash

We present a detailed investigation by magnetic measurements and EPR spectroscopy of the magnetic fraction of cigarettes and its variation with the smoking process. Our results indicate that both before and after smoking magnetic particles with a broad size distribution occur, presumably mainly composed by iron oxides. The size distribution becomes broader with the smoking process producing particles which range from the nanoscale to the multidomain dimension. Both techniques evidence the presence of a paramagnetic fraction whose main components are Mn(II) and Fe(III), as well as an organic radical. The amount of the paramagnetic component is strongly reduced with the combustion. Moreover ICP analysis reveals that a part of other metal ions are volatilized. In conclusion this investigation points out the relevant and complex magnetic properties of both ashes and tobacco which should then be considered as a possible source of data contamination to be avoided in molecular magnetism laboratories.