Labeling of silica sand with 99mTc for obtaining a solid radiotracer

Abstract

To obtain ^99mTc solid radiotracers, new porous supports are currently needed. Previous studies carried out by other authors showed the possibility of ^99mTc labeling of sediments from rivers with a high content of aluminosilicates. In the present work a methodology for labeling of silica sand with ^99mTcO₄^- as a prospective solid radiotracer was developed. Labeling of the previously treated and untreated silica sand was carried out using variable concentrations of chloride and stannous fluoride as reducing agents and different labeling times. The influence of the pre-treatment stage of the sand on the obtained Tc retention yields was evaluated. The changes in the composition of the silica sand after its previous treatment could be verified from the Scanning Electron Microscopy (SEM-EDS). The results suggested the use of previously treated silica sand and stannous fluoride as a reducing agent, modifications were proposed to the initial methodology of previous treatment of the sand. It was possible to confirm from the SEM-EDS technique that the increase in the percentage of retention of Tc in the sand after its treatment is mainly due to the observed changes in its chemical composition and structure. It was possible to obtain a ^99mTc solid radiotracer on support of silica sand with an estimated preparation time of 4 hours and a retention yield of 74%.