NEW DATA ON THERMOLUMINESCENCE OF INORGANIC DUST FROM HERBS AND SPICES

Inorganic dusts from different herbs and spices are investigated in this study using both standard thermoluminescence measurements of integrated intensity versus temperature and measurements of the thermoluminescence emission spectra (intensity as a function of both temperature and wavelength). The importance of particular minerals in the composition of glow peaks detected is discussed. Thermoluminescence emission spectra of the samples studied reveal (i) the presence of a broad high-intensity signal in the red to infra-red spectral region in all irradiated polymineral dusts; (ii) the hitherto unsuspected importance of calcite in the polymineral fractions of the dust; (iii) the existence of high-temperature unbleachable peaks from the silicate fraction in the orange to near infra-red portions of the emission spectrum; and (iv) the potential for quantification of absorbed dose. Discrimination between irradiated and un-irradiated spices appears to be feasible.