A new spectrophotometric readout for the alanine-triphenyl tetrazolium chloride system for high-dose dosimetry

The electron spin resonance (ESR) readout of radical concentration in irrad iated L-alanine is well known as a transfer dosimetry system, however, the high cost of the ESR equipment is a serious handicap for large-scale routin e application. In this study the reaction between irradiated L-alanine powd er and aqueous solution of triphenyl tetrazolium chloride (TTC) was studied . The radical produced by irradiation of alanine reacts during the dissolut ion with TTC forming pink-colored formazans with absorption maxima around 4 01 and 487 nm. This readout method can be used in the 2-200 kGy dose range. (C) 1999 Published by Elsevier Science Ltd. All rights reserved.