Micro scale preparation of 125mTe as tracer by the batch method using ion-exchange resion

Abstract

Micro scale batch method was used for the isolation of 125mTe from the system of the penta valent antimony-125 {125Sb(V)} and tellulium-125 m (125mTe) system in radioactive equiliblium state. In preliminary experiments, the effects of the volume of bromine water, and the time of adsorption on the adsorption ratio were examined using the best conditions. The effects of acid concentration and the time of elution on the elution ratio were examined using 125mTe as tracer. A hundred microliters (ca. 0.03 g) of anion exchange resin (CI- form) treated with concentrated HC1 was placed in a polypropylene micro-tube (1.5 ml) equipped with a stopper. A hundred microliters of the sample solution [(125mSb(V)-125mTe)/ in 9M HC1 solution including bromine water of 5 vol %] was mixed with the resin and shaken for 10 min, in order to adsorb metal ions. After the resin was precipitated by centrifugation, the supernatant solution including 125mTe(VI) was pipetted off, 9 M HC1 solution including bromine water of 5vol% was added and then analyzed for 125mTe(VI). The aliquots were ajusted to the HC1 concentration of 1 M by adding of 1.0 ml of dil.HCl or deionized water. The samples were again shaken for 10 min and centrifuged. The supernatant solution including 125mTe(IV) was pipetted off. The radioactivities of the supernatant solutions were measured using scintillation counter of Nal (Tl) well-type. The yields of 125mTe(IV) by this method were 75, 97 and ca. 100% respectively for one, two and three time elutions. The elution ratio (contamination ratio) of 125Sb(V) was 0.5~1%. This method was compared with ordinary macro-scale column method. It was found that this method gave higher concentrations of radioactivity and that less amount of radioactive wastes because this method required less volume of the eluting solution and resin. © 1990, The Japan Society for Analytical Chemistry. All rights reserved.