Method for ultra-trace cesium isotope ratio measurements from environmental samples using thermal ionization mass spectrometry

137Cs Activities and 135Cs/137Cs Isotopic Ratios from Soils at Idaho National Laboratory: A Case Study for Contaminant Source Attribution in the Vicinity of Nuclear Facilities

“…Surface soil samples analyzed in this study were collected in 1972−1974 by Markham et al 29 Samples underwent an initial gamma spectrometry analysis for 137 Cs, following which samples were dissolved and prepared for thermal ionization mass spectrometry analysis (TIMS) using the method of Snow et al 35 A detailed discussion of the sample purification approach and method validations can be found in the Supporting Information section (Discussion SI-1, SI).…”

135Cs/137Cs isotopic composition of environmental samples across Europe: Environmental transport and source term emission applications

“…After sample addition to individual microwave vessels, 4 mL of 16 M HNO 3 and 4 mL 29 M HF were added to each microwave vessel, following which vessels were sealed and microwaved using the procedure of Snow et al [Snow et al, 2015b] Upon cooling, an additional 30 mL of 44 g/L boric acid was added to each vessel, following which vessels were resealed and remicrowaved. In the Fig.…”

“…case of seawater samples, microwave digestion was not performed; 100 mL of 16 M HNO 3 was added directly to 1 L of seawater and samples were filtered through a 0.45 mm filter. After microwave digestion (soils and vegetation) or acid addition and filtration (seawater), samples underwent purification via two ammonium molybdophosphate polyacrylonitrile columns, two anion exchange separations (AG 1x8 resin, OH À form), and a final cation exchange column (AG50W resin) prior to analysis via thermal ionization mass spectrometry (TIMS), with specific details regarding the chemical purification method reported elsewhere in the literature [Snow et al, 2015b].…”

“…137 Cs represents a major radionuclide of environmental concern as it is produced in high yield during nuclear fission (6.19% for thermal fission of 235 U [Baum et al, 2002]), has a 30.07 yr half life, and is a strong b/g emitter. As low levels of 137 [Snow et al, 2015b;Zheng et al, 2014]. On the other hand, 135 Cs has a much longer half life (2.3E6 yrs) and thus 135 Cs/ 137 Cs can provide a valuable tracer for much longer time periods; however, 135 Cs/ 137 Cs ratios are challenging to measure as 135 Cs's long half life and low atomic abundance preclude simple radiometric detection.…”

“…On the other hand, 135 Cs has a much longer half life (2.3E6 yrs) and thus 135 Cs/ 137 Cs can provide a valuable tracer for much longer time periods; however, 135 Cs/ 137 Cs ratios are challenging to measure as 135 Cs's long half life and low atomic abundance preclude simple radiometric detection. Current state-of-the-art 135 Cs/ 137 Cs ratio measurement techniques require extensive sample purification prior to analysis via ultra-high sensitivity mass spectrometry [Snow et al, 2015b;Zheng et al, 2014;Taylor et al, 2008;Shibahara et al, 2014;Russell et al, 2015].…”