PROTON SPIN-LATTICE RELAXATION OF WATER-MOLECULES IN FERROUS-FERRIC AGAROSE GEL SYSTEM/

Proton spin-lattice relaxation time (T-1) of water in aqueous solution s of ferrous and ferric ions and in the corresponding agarose,eel syst ems have been studied in the light of NMR relaxation theory. The theor etical analysis of 1/T-1's has revealed that, at the microscopic level , changes in the solvation states of paramagnetic ions in aqueous or g el environment are greater than difference in the paramagnetism betwee n ferric and ferrous ions. The former change is the primary factor for the exhibition of radiation effect. At the phenomenological level, we have confirmed and demonstrated that: (1) Radiation effect is almost exclusively exhibited through changes in 1/T-1 caused by the interacti ons between water proton and ferrous or ferric ions; and (2) fraction of conversion of ferrous to ferric ions induced by radiation is the '' true'' representation of the spatial distribution of radiation dose. ( C) 1996 American Institute of Physics.