00000nam 2200000zi 4500 9.868299 CaOODSP 20221107162540 m o d f cr nn||||||||| 190213s1958 onc ob f000 0 eng d CaOODSP eng rda CaOODSP M38-1/34-1958E-PDF M38-1/34 Bouvier, J. A. F., author. The “Thorin” colorimetric method for thorium determination : effect of some common ions, and methods for overcoming interferences / by J.A.F. Bouvier and R.J. Guest, Radioactivity Division. Ottawa : Department of Mines and Technical Surveys, Mines Branch, 1958. Ottawa : Queen's Printer and Controller of Stationery, 1959. 1 online resource (ii, 14 pages). text txt rdacontent computer c rdamedia online resource cr rdacarrier Research report ; R 34 Cover title. "November 26, 1958." Digitized edition from print [produced by Natural Resources Canada]. Includes bibliographical references. "The effect of a number of common ions on the Thorin colorimetric method for thorium determination has been investigated. A comparison was carried out on the use of the two reducing agents, ascorbic acid and hydroxylamine hydrochloride, for overcoming the interference of iron and cerium. Molybdenum caused low thorium assays in the presence of ascorbic acid, whereas this effect was not found with hydroxylamine hydrochloride present, or in the absence of a reducing agent. Titanium caused low thorium assays under any conditions tried and a very low tolerance limit must be set for this ion. Zirconium caused high thorium assays under normal conditions, but its effect varied with the form in which it was added, and appeared to be enhanced by the presence of thorium. By using mesotartaric acid as a masking agent for zirconium, approximately 5 mg of zirconium could be tolerated in a final 25 ml volume taken for the colorimetric finish. In the absence of zirconium, mesotartaric acid is not required and a final volume of 250 ml is used"--Abstract, page i. gccst Chemistry Guest, R. J., author. Canada. Department of Mines and Technical Surveys. Canada. Mines Branch. Canada. Radioactivity Division. Research report (Canada. Mines Branch) R 34. (CaOODSP)9.855660 PDF 1.08 MB https://publications.gc.ca/collections/collection_2019/rncan-nrcan/m38-1/M38-1-34-1958-eng.pdf 306650