Rapid analysis of 237Np and Pu isotopes in small volume urine by SF-ICP-MS and ICP-MS/MS

Guosheng Yang; Jian Zheng; Eunjoo Kim; Shuai Zhang; Hatsuho Seno; Munehiko Kowatari; Tatsuo Aono; Osamu Kurihara

doi:10.1016/j.aca.2021.338431

Rapid analysis of ²³⁷Np and Pu isotopes in small volume urine by SF-ICP-MS and ICP-MS/MS

Anal Chim Acta. 2021 May 8:1158:338431. doi: 10.1016/j.aca.2021.338431. Epub 2021 Mar 20.

Authors

Guosheng Yang¹, Jian Zheng², Eunjoo Kim¹, Shuai Zhang³, Hatsuho Seno¹, Munehiko Kowatari¹, Tatsuo Aono¹, Osamu Kurihara¹

Affiliations

¹ National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan.
² National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan. Electronic address: zheng.jian@qst.go.jp.
³ National Institutes for Quantum and Radiological Science and Technology (QST), 4-9-1 Anagawa, Inage, Chiba, 263-8555, Japan; School of Geographic and Oceanographic Sciences, Nanjing University, Nanjing, 210023, China.

PMID: 33863417
DOI: 10.1016/j.aca.2021.338431

Abstract

Internal contamination with alpha-particle emitting actinides, such as ²³⁷Np, ²³⁹Pu, ²⁴⁰Pu, is likely to bring a large amount of dose to the tissues of persons even if the intake amount is small. To provide timely information for prompt decision-making in radiation emergency therapy, we developed a simple and rapid method for urinary bioassay to determine ultra-trace ²³⁷Np and Pu isotopes using SF-ICP-MS and ICP-MS/MS. To avoid polyatomic interferences and tailing effects from U, ²³⁷Np and Pu isotopes were collected after removing U effectively using a simple single chromatographic column packed with 2 mL AG MP-1M anion exchange resin, exhibiting a high decontamination factor of 10⁸ for ²³⁸U. The overall chemical fractionation between ²³⁷Np and ²⁴²Pu for the whole analytical procedure was 0.974 ± 0.064 (k = 2), allowing us to measure ²³⁷Np and Pu isotopes using ²⁴²Pu as a yield tracer with yields of 76 ± 5%. Using ICP-MS/MS with low background provided the method detection limits for ²³⁷Np, ²³⁹Pu, ²⁴⁰Pu, and ²⁴¹Pu of 0.025, 0.025, 0.015, and 0.020 fg mL^-1, respectively, for 20 mL of urine sample. Those were comparable to detection limits of SF-ICP-MS with high sensitivity. Subsequently, three urine reference materials with Pu spike, provided by the Association for the PROmotion of Quality COntrol in RADiotoxicological Analysis (PROCORAD), France, were analyzed by the developed method and the conventional alpha spectrometry technique for validation. Finally, the developed method was successfully employed to measure the contamination level of ²³⁷Np, ²³⁹Pu, ²⁴⁰Pu, and ²⁴¹Pu in urine samples collected during decorporation therapy using DTPA, after a Pu inhalation exposure accident in Japan. The high throughput (9 h for 12 samples), simplicity, low cost, and high sensitivity of the method will allow greater numbers of related laboratories to be involved in screening activities for unexpected actinide exposure, such as in the case of a large scale radiological disaster.

Keywords: AG MP-1M resin; Actinide inhalation; DTPA; ICP-MS/MS; SF-ICP-MS; Urine.

MeSH terms

Japan
Plutonium* / analysis
Spectrum Analysis
Tandem Mass Spectrometry
Water Pollutants, Radioactive* / analysis

Substances

Water Pollutants, Radioactive
Plutonium