Iodine-131, production adsorption methods

Table 2.7 lists techniques used to characterise carbon-blacks. Analysis of CB in rubber vulcanisates requires recovery of CB by digestion of the matrix followed by filtration, or by nonoxidative pyrolysis. Dispersion of CB within rubber products is usually assessed by the Cabot dispersion test, or by means of TEM. Kruse [46] has reviewed rubber microscopy, including the determination of the microstructure of CB in rubber compounds and vulcanisates and their qualitative and quantitative determination. Analysis of free CB features measurements of (i) particulate and aggregate size (SEM, TEM, XRD, AFM, STM) (ii) total surface area according to the BET method (ISO 4652), iodine adsorption (ISO 1304) or cetyltrimethylammonium bromide (CTAB) adsorption (ASTM D 3765) and (iii) external surface area, according to the dibutylphthalate (DBP) test (ASTM D 2414). TGA is an excellent technique for the quantification of CB in rubbers. However, it is very limited in being able to distinguish the different types of... 

D Sahal. Removal of iodine by solid phase adsorption to charcoal following iodine oxidation of acetamidomethyl-protected peptide precursors to their disulfide bonded products oxytocin and a Pre-S, peptide of hepatitis B illustrate the method. Int J Pept Res 53, 91, 1999. 

The production of iodine isotopes by nuclear reactions from various target materials for medical appHcations is described. Separation and purification methods for iodine isotopes, including distillation (wet and dry) and adsorption techniques, are discussed. 2 lso discussed is the preparation of iodine isotopes in chemical forms other than iodide (I ). 

Carbon-black types are differentiated on particle size and surface area measurements, using techniques such as TEM, PCS (photon correlation spectroscopy), iodine or nitrogen adsorption and mercury porosimetry. The best method for qualitative carbon-black determination is based on accurate measurement of the CB particle size using TEM [222,223], Pyrolysis at 800 to 900 C followed by TEM analysis according to ASTM D 1765 allows identifying carbon-blacks used in rubber products [224]. TEM was used for identiflca-tion of carbon-blacks in vulcanisates [225], TGA has been used for quantitative determination of carbon-black [226,227]. Palla [51] used TEM for the characterisation of rubber components. Ultra-thin sections of rubbers suitable for TEM studies can be prepared by microtoming at low temperatures. 

---