Dose measurement using a leuco crystal violet film system with high sensitivity for food irradiation applications

Radiation dosimetry is of paramount importance to achieve the desired objectives in radiation processing of food. The low dose range of 0.1-1 kGy is very important for selected food irradiation applications. Inexpensive and easy to handle routine dosimeters that operate in this range are thus highly desirable. To this end, a leuco crystal violet dye based radiochromic film was developed incorporating 2,2,2-trichloroethanol as sensitizer. This system exhibits a linear dynamic response in the 0.1-1 kGy dose range. The sensitivity of the films to spectroscopic readout was found to be similar to 146 kGy(-1) mm(-1) which is higher than that of any previously reported leuco crystal violet film dosimeter. The limit of detection, limit of quantification, and prediction error were determined to be 0.050 kGy, 0.077 kGy, and +/- 0.47%, respectively. The response of the film was also assessed using two image analysis methods - the conventional single channel approach and a novel double channel approach. A prediction error of less than +/- 1.0% was obtained for the latter. The results demonstrate for the first time that the dose response of leuco crystal violet based systems can be studied by inexpensive desktop scanner based colour analysis.

Automated summary

Radiation dosimetry is crucial for the desired objectives in food radiation processing. The development of inexpensive and easy-to-handle dosimeters operating in the low dose range of 0.1-1 kGy is highly desirable. A leuco crystal violet dye-based radiochromic film with 2,2,2-trichloroethanol as sensitizer was developed, demonstrating a linear dynamic response. The response of the film was assessed using both conventional single channel and novel double channel approaches.