478 



RADIOISOTOPES IN BIOLOGY AND AGRICULTURE 



Radioactive contamination (see Con- 

 tamination) 

 Radioactive decay, 19-23 

 Radioactive equilibrium, 439 

 Radioactive half-life (see Half-life) 

 Radioactive impurities, chemical state, 

 61-62 

 cross section related to, 61 

 detection, 64 

 radiocolloids, 62 

 in radioisotope preparations, 446-451 



(See also individual isotopes) 

 removal or elimination, 65-66 

 by chemical methods, 66 

 by radioassay methods, 66 

 in tracer studies, 61-66 

 Radioactive tracer, 439 

 Radioactive waste disposal (see Waste 



disposal) 

 Radioactivity, artificial, 428 

 definition, 2, 439 

 induced, 434 

 natural, 437 

 Radioactivity units, 86 

 Radioautography (see Autoradiography) 

 Radiobiology, 439 

 Radiochemical analysis (see individual 



isotopes) 

 Radiochemical contamination of radio- 

 isotope preparations, 446-451 

 (See also individual isotopes) 

 Radiochemical fume hoods, 121 

 Radiocolloids, 439 



demonstration of, 341 

 factors promoting, 62 

 prevention of formation by citric acid, 



304, 318, 322 

 in tracer studies, 62, 318, 322-323 

 Radiocontamination, in isotope prep- 

 arations, 61, 446-451 

 (See also individual isotopes; Radio- 

 active impurities) 

 test for, in Zn" preparation, 319 

 Radioelement, 439 



Radioisotopes, autoradiographic prop- 

 erties, 327 

 availability, 446-451 

 definition, 439 



dosage, continuous administration, 

 10, 75, 304 

 general, 139-147 

 inhalation and intratracheal, 147 

 intravenous injection, 144-147 

 oral administration, 141-144 

 parenteral, 144-147 

 to plants, 150-152 

 tracer, physiological and massive, 

 60 



Radioisotopes, incorporation into feed 

 304 



laboratories (see Laboratory design) 

 mixtures assay, by chemical separa- 

 tion, 192 

 by differential absorption, 191 

 by differential decay, 190 

 by radiation differences, 191 

 (<See also Double labeling) 

 naturally occurring, 2, 437 

 in paper chromatography, 378-383 

 in radioactivation analysis, 417-418 

 storage in laboratory, 123-125 

 (*See also individual isotopes) 

 Radiology, 439-440 

 Radionuclide, 440 

 Radioresistance, 440 

 Radiosensitivity, 440 

 Radium, citrate-complex study, 406- 

 407 

 as insect label, 3 

 radiation-effect levels, 67 

 Range, 440 



relation to infinite thickness, 182 

 Rare earths, activation analysis in 

 bone, 424 

 separations, 402 

 Rats, administration of isotopes, 140- 

 142, 144, 146-147 

 blood collection, 147-148 

 iron studies, 46 



management requirements, 129 

 metabolism cages, 129-131 

 radiation effects from isotopes, 67 

 Reactions, equations for first-orcler, 18- 

 39 

 exchange (see Exchange reactions) 

 other than first-order, 38-40 

 nuclear, 440 

 Reactor (see Pile) 



Reagents, for carbon combustion, 164 

 for color development in chroma- 

 tograms, 368-373 

 Red blood cells (see Erythrocytes) 

 Relative abundance of an isotope, 440 

 Relative biological effectiveness (RBE), 

 of different radiations, 88 

 of radiation, 440 

 Relative plateau slope (counter tubes), 



440 

 Removal from one phase, 18-20 

 Renewal rate (see Turnover rate) 

 Reports, identification of, 444-445 

 Resins for ion exchange, 390 

 Respiration apparatus for carbon-14 



studies with cattle, 136 

 Respiration losses from samples, 160 

 Reversed phase, chromatography, 383 



