THE ANALYSIS OF RARE EARTHS AND CADMIUM IN REFERENCE MATERIALS - LI-2SO-4 AND MNSO-4
Reference materials of natural and isotopically enriched or depleted Li-2SO-4 are used for neutron cross section measurements. The detection limits of Sm, Eu, Gd, Dy and Cd in Li-2SO-4 by atomic emission spectroscopy (AES) and instrumental photon activation (IPA), correspond to a total contribution equivalent to the natural lithium (sigma = 70.5 barns), of 0.160 % and 0.0213 % respectively. MnSO-4 solutions are used for the calibration of neutron sources, e.g. 252-Cf. The direct analysis of Sm, Eu, Gd, Dy and Cd in MnSO-4 by AES and IPA, provides detection limits from which the total contributions equivalent to the manganese (sigma = 13.3 b), are respectively 2.38 % and 0.395 %. In order to improve the detection limits of rare earths, a method had been developed for the rare earth - Mn chemical separation which is based on the coprecipitation of rare earths as fluorides with very pure Y added as a carrier, by HF in the presence of ammonium fluoride. A solution of 152+154-Eu(1.11x10**5 Bq) is used to monitor the recovery of the lanthanides. The Sc and Y are determined directly by AES or IPA. As an example, the contributions of Sm, Eu, Gd, and Dy obtained by AES after the chemical separation of a solution containing 300 mg MnSO-4 per gram, are reduced to 0.0114 %. The concentration of Cd found in this solution is 3.7 mug/g MnSO-4 and the total contribution of the 16 rare earths and Cd is 0.107 %.
Bibliographic Reference: COLLOQUIUM SPECTROSCOPICUM INTERNATIONALE XXIV, GARMISCH-PARTENKIRCHEN (GERMANY), SEPT. 15-21, 1985 WRITE TO CEC LUXEMBOURG, DG XIII/A2, POB 1907 MENTIONING PAPER E 31980 ORA
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Record Number: 1989123066500 / Last updated on: 1987-01-01
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