Sensitization of glycine (spectrophotometric read-out) dosimetric system using sorbitol

Glycine spectrophotometric read-out systems have a useful dose range of 15–4000 Gy. An attempt was made to sensitize it using sorbitol as a sensitizer. Optimum compositions of aqueous acidic solutions of ferrous ammonium sulphate–xylenol orange (XO), i.e. FX and sorbitol–ferrous ammonium sulphate–xylenol orange, i.e. SFX, for 400 mg of glycine, which gives maximum dosimetric response for any given dose, were established. Molar absorption coefficient values of ferric–XO–glycine complex, i.e. ɛ-values, were determined for glycine system in FX and SFX. These values were found to be 8410 and 15,000 m2 mol−1 respectively, indicating that an enhancement or sensitivity factor of about 1.78 can be achieved by sorbitol for glycine in SFX. This factor was further confirmed by measuring the gamma dose response of glycine in FX and in SFX for four different doses, viz. 37.8, 75.5, 151 and 302 Gy. It was observed that dose response of glycine in SFX is about 77% more than that of glycine in FX. The maximum variation observed in response of glycine in FX or SFX was found to be within ±1.5%.