ZIRCONIUM 323 



Typical Methods. Procedures have been described for preparation of 

 the following labeled colloids for use in biological studies: zirconium oxide 

 in dilute HNO3, zirconium phosphate, zirconium oxide in sodium lactate 

 solution, and various anionic colloids (Zr-2). In studies with rats the 

 usual dosages employed were about 1.6 ml, administered intraperitone- 

 ally, of a 10 per cent sodium citrate solution containing 5 /xc Zr^^ freshly 

 separated from the Nb^^ daughter, with to 40 mg zirconium added as 

 carrier. Two microcuries Zr»^ was used for intravenous injection (Zr-4). 

 Tissues and excreta were dried, then ashed at 650°C for 10 hr, the ash 

 dissolved in 2 A^ HCl, and aliquots placed in i.^-oz metal ointment cap- 

 sules and dried for counting with an end-window tube. Self-absorption 

 corrections were apphed when necessary. 



In a study of uptake by plants (Zr-5), the preparation, received as the 

 oxalate, was treated with H2O2 in strong H2SO4 to destroy the complex. 

 The radioactivity was adsorbed onto clay and soil in amounts of 780 

 counts/min/5 g of soil for leaching studies. Plant uptake from soil 

 treated with Zr^^-Nb^^ was also studied. In another study, about 10 ^c/ 

 liter was added to a bentonite suspension in which barley plants were 

 grown (Zr-6). The uptake in various plant parts, as well as the fixation 

 on clay, was measured by the counting of mechanically separated samples. 



Zr-l. Cochran, Kenneth W., John Doull, Marcella Mazur, and Kenneth P. DuBois: 



Acute Toxicity of Zirconium, Columbium, Strontium, Lanthanum, Cesium, 



Tantalum and Yttrium, Arch. Ind. Hyg. and Occupational Med 1 : 637-650 

 (1950). 



Zr-2. Gofman, John W.: Studies with Colloids Containing Radioisotopes of Yttrium. 

 Zirconium, Columbium, and Lanthanum. L The Chemical Principles and 

 Methods Involved in Preparation of Colloids of Yttrium, Zirconium, Colum- 

 bium, and Lanthanum, J. Lab. Clin. Med., 34: 297-304 (1949). 



Zr-3. Coryell, Charles D., and Nathan Sugarman: "Radiochemical Studies: The 

 Fission Products," Books 1-3, National Nuclear Energy Series, McGraw-Hill 

 Book Company, Inc., New York, 1951. 



Zr-4. Kawin, Bergene, D. H. Copp, and J. G. Hamilton: Studies of the Metabolism 

 of Certain Fission Products and Plutonium, UCRL-812, Aug. 7, 1950. 



Zr-5. Vlamis, J., and G. A. Pearson: Absorption of Radioactive Zirconium and 

 Niobium by Plant Roots from Soils and Its Theoretical Significance, Science 

 111: 112-113 (1950). 



Zr-6. Jacobson, L., and R. Overstreet: Progress Report on Plant Studies: The Fixation 

 and Absorption of Fission Products by Plants, MDDC-571, Dec. 18, 1944. 



