Luminescence Identification Characteristics for Irradiated Dried Fishery Products

Photostimulated luminescence (PSL) and thermoluminescence (TL) analyses were conducted for the detection of different gamma-irradiated dried fishes (mussel, squid, beka squid, mitra squid, plaice, and saury) at 0, 1, 5 and 10 kGy. For TL analysis, the contaminating silicate minerals were obtained by density separation or acid hydrolysis treatment. PSL determinations indicated that all the non-irradiated samples showed PSL photon counts/60 s (PCs) lower than 700 PCs (negative), but the irradiated mussel sample at 5 and 10 kGy were only possibility identified showing higher than 5000 PCs (positive). Irrespective of sample kinds and methods of mineral separation, all the non-irradiated samples showed TL glow curves in low-intensity with a maximum peak only after 250°C. However, all the irradiated samples produced TL glow curves in high intensity with a maximum peak particularly in the temperature range of 150∼250°C. In conclusion, more distinguishable TL results [glow curve, TL ratio (TL₁/TL₂)] were obtained from the marker minerals separated by acid hydrolysis rather than density method. (author)