Cyanocobalamin solutions as potential dosimeters in low-dose food irradiations

• Solutions of cyanocobalamin are suitable as dosimeters in food irradiations.
• The dosimeters are usable in the dose range 0.2–1.0 kGy with spectrophotometric response measurements.
• The dose response only weakly depends on the dose rate, irradiation temperature and duration of the dosimeter storage.

Potential of aqueous solutions of cyanocobalamin in gamma radiation dosimetry was investigated. The solutions are inexpensive, nontoxic and easy-to-prepare dosimeters, which could be useful for measuring gamma radiation doses in various applications, such as quarantine treatment of fruit or insect disinfestation of grains and pulses. The optical absorbance of cyanocobalamin solutions of the optimal concentration 0.08 mM decreases with increasing radiation dose. The reproducible dependence of the absorbance decrease on the dose can be described with a polynomial. Pre- and post-irradiation stability of the solution absorbance, as well as effects of the irradiation temperature and dose rate, were studied. The response is not significantly affected by storage of the irradiated dosimeters under ambient conditions for 20 days. The performance characteristics of this chemical dosimetry system suggest that it can be useful to measure doses in irradiations of food.