10 – RADIOISOTOPE MASS SPECTROMETRY

摘要: Mass spectrometric methods are very sensitive and enable in many cases a multielement determination of trace ultratrace elements combined with good isotopic analysis ( Bacon et al. , 2001 ). Therefore, these techniques also applied for the detection long-lived radionuclides Becker Dietze, 2000 ) mainly environmental samples Adriaens 1992 ; Bailey 1993 Bibler 1998 Eroglu Edmonds 1999 Wendt ), nuclear materials Betti, 1997 Chartier glass ceramics Rohr 1994 Fukuda Sayama, high-purity substances Beer Heumann, Herzner Radiometry, used as standard method radionuclides, has some disadvantages nuclides because limit depends on half-life decay type isotope to be measured. Besides that, beta measurements, pure β-emitters like 90,89 Sr or 99g Tc, careful time consuming chemical separations needed remove other while α-spectroscopy surface barrier detectors, carrier-free almost prerequisite energy resolution, even then, an unambiguous is difficult as, e.g., 239 Pu/ 240 Pu due similar α-energies. Here, mass techniques, which apply direct atom counting different experimental set-ups ionization achieve sensitivity well isobaric selectivity, superior. The fast radioisotopes great interest areas such risk assessment, low-level surveillance environment, studies biological effects, radioactive waste control, management disposal, investigations migration behaviour actinides etc. most important radioisotope thermal spectrometry TIMS Callis Abernathey, 1991 Platzner, glow discharge GDMS 1996 secondary ion SIMS Betti inductively coupled plasma ICP-MS laser ablation LA-ICP-MS Kim Crain, 2002 resonance RIMS accelerator AMS Rucklidge, 1995 Fifield monoelemental precise ratios whereas represent multielemental permitting concentrations abundances elements. Their limits (LOD) range ng/g sub-ng/g solids down sub-pg/L aqueous solutions. A precision low 0.02% relative deviation (RSD) ratio measurements can obtained Becker, With AMS, comparable RIMS, it percentage range. 10 6− 7 (fg) 4 atoms (atg) per sample, respectively.