Thermoluminescence spectra of inorganic dust from irradiated herbs and spices

Thermoluminescence (TL) is used to determine whether certain foodstuffs have been irradiated. A high sensitivity TL spectrometer was used to analyze irradiated and unirradiated inorganic dusts from herbs and spices. Unlike earlier TL work using emissions in the UV-green spectral range, the spectrometer monitored transient TL emissions across the spectral range from UV to infra-red as samples were heated to 400 degrees C. A strong high temperature red emission peak was detected in all irradiated samples. This signal was much higher than the background level, insensitive to post-irradiation light exposure, and has potential for irradiation exposure determination