Thermochromatographic Separation of ^94mTc from Enriched Molybdenum Targets and its Large Scale Production for Nuclear Medical Application

Abstract

Positron emitter 94m Tc / p-induced nuclear reaction / Thermochromatographic separation / Routine isotope production AbstractThe thermochromatographic behaviour of "carrier-free" technetium species TcO, (x probably 3) and HTc0 4 was studied in dry and moist air atmospheres. Temperatures of adsorption on quartz surfaces (TJ were measured to be 400±40°C and 300±30°C, respectively, for the two technetium species for 20 min experimental periods. Two alternative routes for fast and quantitative thermochromatographic separation of the short-lived positron emitting technetium isotope 94m Tc from highly enriched molybdenum targets ( 94 Mo0 3 ) were tested. The optimum conditions to separate 94m Tc within 25 min, with overall radiochemical yields of about 80-85% (non-decay-corrected 40-45%) and in high radiochemical purity of >99% as pertechnetate, were developed. The radionuclidic purity at EOB was >90%. The separation process included an almost complete recovery and cyclic use of the enriched target material.

Production and separation of 186gRe from proton bombardment of 186WC

“…After comparing activities from solubilized targets and activities washed from the collection quartz tube of the thermochromatography processing apparatus, a re-designing of the quartz glassware was undertaken. Instead of using a totally vertical arrangement as has been previously used [21,24], collection was done in the horizontal manner. In the horizontal position, the collection area where the volatile material would condense was away from direct heat, and the temperature was below 200°C, a temperature ideal for the collection of the volatile 186g ReO 4 − species [20].…”

“…3 shows the assembled custom made quartz glassware as a single unit that was utilized for the process. The design is based in part on that put forward by Roesch et al [24] and used by Bigott et al [25]. The vertical furnace was preheated to 1000-1100°C before the insertion of the vertical portion of the assembled glassware and target.…”

Medical Radioisotopes Production: A Comprehensive Cross-Section Study for the Production of Mo and Tc Radioisotopes Via Proton Induced Nuclear Reactions on natMo

“…Common medical isotopes sorted by use category and production method (Troyer & Schenter, 2009) 1.3 Molybdenum and technetium in nuclear medicine M o l y b d e n u m i s u s e d a s a t a r g e t m a t e r i a l f o r t h e p r o d u c t i o n o f m e d i c a l l y i m p o r t a n t radioisotopes, such as 99m Tc/ 99 Mo, 96(m+g) Tc and 94m Tc. 94m Tc (52min), has shown its applicability as a PET isotope (Rösch and Qaim, 1993;Nickles, et al, 1993;Sajjad and Lambrecht, 1993;Rösch, et al, 1994;Fabbender, et al, 1994;Qaim, 2000;Hohn, et al, 2008 (Lambrecht and Montner, 1982). One of the most important medical radioisotopes is 99m Tc (T ½ = 6.01 h), which has a gamma ray energy of about 140 keV.…”

Investigation of excitation functions of proton-induced reactions on $^{94,\, 96,\, 98,\, 100}$Mo targets for production of radioisotopes $^{94m,\, 94g,\, 96m,\, 96g,\, 96,\, 99m}$Tc

“…The radioisotopes 94g Tc and 94m Tc are used in PET [4]; in particular, the radionuclide 94m Tc is properly used because of its β + decay property (E + β = 2.47 MeV) [5]. The radioisotopes 96 Tc and 96m Tc are used as tracer isotopes in wear measurements [6] and 96g Tc is used as a potential beam monitor [7].…”