Production optimization of 99Mo/ 99mTc zirconium molybate gel generators at semi-automatic device: DISIGEG

• Published in: Applied radiation and isotopes 2012, Vol.70 (1), p.103-111
• Main Authors: Monroy-Guzman, F., Rivero Gutiérrez, T., López Malpica, I.Z., Hernández Cortes, S., Rojas Nava, P., Vazquez Maldonado, J.C., Vazquez, A.
• Format: Article
• Language: English
• Subjects: Equipment Design; Equipment Failure Analysis; Generator; Mo-99; Molybdates; Molybdenum - chemistry; Molybdenum - radiation effects; Radioisotopes - chemistry; Radionuclide Generators - instrumentation; Robotics - instrumentation; Tc-99m; Technetium - chemistry; Zirconium; Zirconium - chemistry; Zirconium - radiation effects
• ISSN: 0969-8043; 1872-9800
• DOI: 10.1016/j.apradiso.2011.09.017

DISIGEG is a synthesis installation of zirconium 99Mo-molybdate gels for 99Mo/ 99mTc generator production, which has been designed, built and installed at the ININ. The device consists of a synthesis reactor and five systems controlled via keyboard: (1) raw material access, (2) chemical air stirring, (3) gel dried by air and infrared heating, (4) moisture removal and (5) gel extraction. DISIGEG operation is described and dried condition effects of zirconium 99Mo- molybdate gels on 99Mo/ 99mTc generator performance were evaluated as well as some physical–chemical properties of these gels. The results reveal that temperature, time and air flow applied during the drying process directly affects zirconium 99Mo-molybdate gel generator performance. All gels prepared have a similar chemical structure probably constituted by three-dimensional network, based on zirconium pentagonal bipyramids and molybdenum octahedral. Basic structural variations cause a change in gel porosity and permeability, favouring or inhibiting 99mTcO 4 − diffusion into the matrix. The 99mTcO 4 − eluates produced by 99Mo/ 99mTc zirconium 99Mo-molybdate gel generators prepared in DISIGEG, air dried at 80 °C for 5 h and using an air flow of 90 mm, satisfied all the Pharmacopoeias regulations: 99mTc yield between 70–75%, 99Mo breakthrough less than 3×10 −3%, radiochemical purities about 97% sterile and pyrogen-free eluates with a pH of 6. ► 99Mo/ 99mTc generators based on 99Mo-molybdate gels were synthesized at a semi-automatic device. ► Generator performances depend on synthesis conditions of the zirconium 99Mo-molybdate gel. ► 99mTcO 4 − diffusion and yield into generator depends on gel porosity and permeability. ► 99mTcO 4 − eluates satisfy Pharmacopoeias regulations and can be applied for clinical use.