Light-induced fading of the photostimulated luminescence and thermoluminescence for irradiated silicate samples

By introducing standard physical methods for the detection of irradiated herbs and spices by photostimulated luminescence and thermoluminescence, measurements of different irradiated samples have been undertaken and an analysis of the results has been done. Since luminescence may occur under natural and artificial light stimulation on which herbs and spices may be exposed during storage, leading to false-negative results and disabling their proper identification, studied samples have been kept under different light conditions for different periods. The optical bleaching of the photostimulated luminescence and thermoluminescence signal has been detected in all cases. The strong influence of light, natural and artificial, on the photostimulated luminescence signal has been determined