水中54Mn的放射化学测定方法  

RADIOCHEMICAL DETERMINATION OF 54 Mn IN WATER

作　　者：李云龙[1] 

机构地区：[1]中国原子能科学研究院

出　　处：《同位素》1996年第1期17-27,共11页Journal of Isotopes

摘　　要：基于水中的放射性Ｍｎ和加入Ｍｎ（Ｆｅ）载体以Ｍｎ（ＯＨ）２（Ｆｅ）共沉淀浓集，采用ＭｎＯ２沉淀纯化、盐酸－丙酮混合液中的阳离子交换色层法分离纯化Ｍｎ２＋以及ＭｎＮＨ４ＰＯ４·Ｈ２Ｏ沉淀制源，最后用高纯锗－低本底γ谱仪测定５４Ｍｎγ放射性活度。当１０ｌ水中加入２．０３Ｂｑ５４Ｍｎ和９．６３ｍｇＭｎ２＋载体时，全程化学回收率和放化回收率分别为（７６．４±６．１）％和（７７．１±５．９）％。对６０Ｃｏ、６３Ｎｉ、５９Ｆｅ、６５Ｚｎ、５１Ｃｒ、１３７Ｃｓ、９０Ｓｒ、９５Ｚｒ、１０６Ｒｕ－１０６Ｒｈ、１４４Ｃｅ－１４４Ｐｒ的去污系数均大于１×１０４。本法对水中５４Ｍｎ的探测下限为４×１０－３Ｂｑ·ｌ－１。A radiochemical determination procedure has been established for measuring the radioactivity of 54 Mn in water. The procedure is based on the following processes: (1) coprecipitation of hydroxide of manganese and iron to concentrate radioactive manganese in the sample; (2) precipitation of MnO 2 to purify manganese from other impurities; (3) separation by cation exchange chromatography in hydrochloric acid acetone mixture to separate and purify Mn 2+ from impurity nuclides in the sample; and (4) preparation of manganese ammonium phosphate precipitate. Finally, the gamma radioactivity of 54 Mn in the precipitate is counted by a low background gamma spectrometer with a HPGe detector. When 2.03 Bq of 54 Mn and 9.63 mg of Mn 2+ are added into 10 liters of water, the chemical and radiochemical recovery of the procedure are (76.4±6.1)% and (77.1±5.9)%, respectively. The decontamination factors for nuclides 60 Co, 63 Ni, 59 Fe, 65 Zn, 51 Cr, 137 Cs, 90 Sr, 95 Zr, 106 Ru 106 Rh, and 144 Ce 144 Pr are greater than 1×10 4. The minimum deter minable concentration for 54 Mn in water is 4×10 -3 Bq·l -1 。

关 键 词：放射化学分析 锰54 盐酸-丙酮 混合液 

分 类 号：O614.711[理学—无机化学] O657.4[理学—化学]