Radiotracer methods, evaluation

The metallic and Ionic cleaning procedures studied by Kern were evaluated by radiotracer methods. This technique requires the use of radionuclide enriched reagents. Recently, a procedure utilizing secondary Ion mass spectrometry (SIMS) has been developed for studying very low levels of contamination on silicon surfaces (18). 

A laboratory membrane brine electrolysis cell, designed for automated operation, was constructed ( 1,2). This system enables the measurement of the sodium ion transport number of a membrane under specific sets of conditions using a radiotracer method. In such an experiment, the sodium chloride anolyte solution is doped with 22Na radio-tracer, a timed electrolysis is performed, and the fraction of current carried by sodium ion through the membrane is determined by the amount of radioactivity that has transferred to the sodium hydroxide catholyte solution. The voltage drop across the membrane during electrolysis is simultaneously measured, so that the overall performance of the material can be evaluated. 

An oxygen-15 radiotracer method was applied to the precise determination of chemically bound oxygen to the liposome-emb ded heme The gas produced with a cyclotron was passed through the liposome-embedded heme solution, and the volume of oxygen bound to the heme was evaluated with the annihilation radiation intensity within a 5% error of the value given above. 

Ikeda I, Inoue O, Kurata K. (1976) Chemical and biological studies on "Tc-DMS-II effect of Sn(II) on the formation of various Tc-DMS complexes. Int J Appl Radiat Isot 27 681-688 Ikeda I, Inoue O, Kurata K. (1977a) Preparation of various Tc-99m dimercaptosuccinate complexes and their evaluation as radiotracers. J Nucl Med 18 1222-1229 Ikeda I, Inoue O, Kurata, K (1977b) Chemical and biological studies on " Tc-DMS-l formation of complexes by four different methods. Int. J Nucl Med Biol 4 56-65 Johannsen B, Spies H (1988) Progress and problems in the chemistry of technetium-99m tracers. Isotopenpraxis 24 449-454... 

Tomcsanyi L, De Battisti A, Hirschberg G, Varga K, Liszi J. The study of the electrooxidation of chloride at Ru02/Ti02 electrode using CV and radiotracer techniques and evaluating by electrochemical kinetic simulation methods. Electrochim Acta 1999 44 2463-72. 

The proper design and execution of radiotracer experiments requires preliminary possession of both the technical background and the basic principles of the tracer method The latter make it possible to evaluate the kinetic aspects of the system under investigation, their possible infiuence on experimental results, and the technical requirements, which should be never overlooked. Attention must emphatically be drawn to these factors, in view of the considerable misuse of radio-tracers in biological investigations which has unfortunately accompanied their growing popularity. 

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