Magnetic resonance imaging characterization of intact smoked cigarettes

The interior of intact, extinguished cigarettes following smoldering and puffing combustion was examined by proton magnetic resonance imaging (MRI). Spin-echo imaging sequences were employed to image substances with high molecular mobility such as water, smoke condensate, and waxy materials native to unburned tobacco. Single-point imaging (SPI) methods were employed to image the more rigid components, such as tobacco cell wall polysaccharides and cellulose acetate fibers inside the filter. The distribution of spin–spin relaxation times (T₂) of the tobacco and filters was measured using a low-field ¹H NMR bench-top spectrometer. One-dimensional profiles and two-dimensional images revealed the distribution of combustion and pyrolysis products deposited on the unburned portion of tobacco and in the filter of the cigarette. Image features as small as 25 μm were resolved. The current results demonstrate the feasibility of employing MRI to study combustion in burning cigarettes and other materials in real time.