A New Fluorometric Dosimetry for Low-medium Gamma Radiation Doses

In this study, for the first-time, solutions of a Schiff base was evaluated as a possible chemical dosimeter for gamma-rays at low-medium dose ranges. The solutions of N-N'-bis(salicylidene)-1,3-propanediamine (LH₂) were prepared at different ethanol/water compositions and the effect of various irradiation doses on the fluorometric response of these solutions were investigated. Fluorescence spectra of non-irradiated and irradiated solutions showed that fluorescence intensity of LH₂ (λ_ex = 375 nm, λ_em = 498 nm) decreased as the radiation dose increased. This decrease was observed over a wider dose range for the solutions that contain 40-60 % water. In order to increase the sensitivity of the method, LH₂-Zn complexes were formed by adding Zn (II) to non-irradiated and irradiated LH₂ solutions. After that, analytical parameters such as linearity, LOD, LOQ, repeatability and reproducibility were determined by measuring fluorescence spectra of these solutions (λ_ex = 350 nm, λ_em = 444 nm). The performance characteristics of the chemical dosimetry system suggest that LH₂ can be used as a dosimeter in dose range 0.04-5 kGy. The proposed method is simple, sensitive, reproducible and cost-effective, and can be useful in measuring doses in food irradiation.