Accurate and precise determination of 90Sr at femtogram level in IAEA proficiency test using Thermal Ionization Mass Spectrometry

Abstract

A novel method for the determination of ultra-trace level 90Sr has been recently developed applying thermal ionization mass spectrometry (TIMS). The method includes the chemical separation of Zr (isobaric interference of 90Zr) from the samples followed by determination of 90Sr/88Sr abundance sensitivity (2.1 × 10−10). The analytical performance of this method was assessed in the IAEA-TEL 2017-3 worldwide open proficiency test. For 90Sr determination, tap water and milk powder samples were distributed amongst the participant laboratories with reference values of 11.2 ± 0.3 Bq kg−1 (2.2 ± 0.1 fg g−1) and 99.9 ± 5.0 Bq kg−1 (19.5 ± 1.0 fg g−1), respectively. The stable Sr concentrations were 39.4 ± 0.9 ng g−1 and 2.5 ± 0.1 µg g−1 while the 90Sr/88Sr isotope ratios were 6.47 ± 0.17 × 10−8 and 9.04 ± 0.45 × 10−9 in the tap water and milk powder samples, respectively. For TIMS measurement, 50 mL water and 1 g milk powder samples were taken for analysis. This TIMS method demonstrated an impressive accuracy (relative bias of 4.2% and −2.1%, respectively) and precision (relative combined uncertainty of 4.1% and 7.6%, respectively) when compared with radiometric techniques. For the first time in the history of inorganic mass-spectrometry, 90Sr analysis using a TIMS instrument is confirmed by an independent proficiency test.

Landside tritium leakage over through years from Fukushima Dai-ichi nuclear plant and relationship between countermeasures and contaminated water

“…This tiny drop containing the Sr was loaded onto a degassed single rhenium filament (99.999%) along with one microliter TaF 5 activator. More detail of the TIMS analysis is presented elsewhere 33 .…”

Application of Titanium Dioxide for Zirconium Ions Adsorption and Separation from a Multicomponent Mixture

“…In this case, inductively coupled plasma mass spectrometry (ICP-MS) may be the only method of 90 Sr analysis. Several leading laboratories worldwide [4][5][6] use this method to analyze 90 Sr in the environment. The effectiveness of the ICP-MS method compared to other highly sensitive modern methods is presented in fig.…”

“…Detection limits for common elemental techniques: AA -atomic absorption; ICP-AES -inductively coupled plasma atomic emission spectroscopy; GFAAS -graphite furnace atomic absorption; ICP-MS -inductively coupled plasma mass spectrometry (adapted from ref. [4]).…”

“…are spectroscopic interferences and overlap each other [4][5][6]. 90 Zr, the "granddaughter" of 90 Sr, hurts the mass spectrometry of 90 Sr samples, as described in [5].…”

An Automated SeaFAST ICP-DRC-MS Method for the Determination of 90Sr in Spent Nuclear Fuel Leachates

“…The use of ICP-MS in nuclear decommissioning has been widely discussed in the literature [5,6] and is the preferred technique for long-lived radionuclides due to its analytical characteristics [7]. However the fact that complex matrix may create non-spectral interferences in the plasma, may limit application and makes matrix removal steps necessary [8][9][10][11]. Therefore, an efficient sample preparation protocol is needed in order to remove other elements present in the sample attaining a final solution with low total dissolved solids.…”