Lee S C, Hutchinson J M, Inn K G, Thein M
Carlsbad Environmental Monitoring & Research Center, New Mexico State University 88220.
Health Phys. 1995 Mar;68(3):350-8. doi: 10.1097/00004032-199503000-00007.
An intercomparison study of low-level 237Np determination in artificial urine samples has been carried out. The purpose of this study was to find the "optimal" method presently available for use in a routine in-vitro radiobioassay program for occupationally exposed workers. Four synthetic urine samples with differing 237Np concentrations were prepared: (1) 3 mBq kg-1 of 237Np; (2) 3 mBq kg-1 of 237Np with natural uranium, 239Pu and 241Am as interferences; (3) 50 mBq kg-1 of 237Np; and (4) a matrix blank. The solutions were submitted to 10 alpha-particle and 10 inductively coupled plasma-mass spectrometry (ICP-MS) laboratories of which six and four laboratories, respectively, returned results. Two laboratories performed assays using both techniques. The radiochemical method of choice used 239Np as the tracer, which utilized a combination of coprecipitation and anion-exchange separation. The best results obtained by ICP-MS were comparable with but not better than the most accurate results obtained by alpha-particle spectrometry. Alpha-particle spectrometry measurements overall gave consistently better agreement with known values.
开展了一项人工尿液样本中低水平237Np测定的比对研究。本研究的目的是找出目前可用于职业暴露工人常规体外放射生物测定程序的“最佳”方法。制备了四个237Np浓度不同的合成尿液样本：(1) 237Np浓度为3 mBq kg-1；(2) 含有天然铀、239Pu和241Am作为干扰物的237Np浓度为3 mBq kg-1；(3) 237Np浓度为50 mBq kg-1；以及(4) 基质空白样本。这些溶液被送交10个α粒子和10个电感耦合等离子体质谱（ICP-MS）实验室，其中分别有6个和4个实验室返回了结果。有两个实验室同时使用这两种技术进行测定。所选用的放射化学方法使用239Np作为示踪剂，采用共沉淀和阴离子交换分离相结合的方法。ICP-MS获得的最佳结果与α粒子能谱法获得的最准确结果相当，但并不比其更好。总体而言，α粒子能谱法测量结果与已知值的一致性更好。
