Open AccessOnline Solid-Phase Extraction–Inductively Coupled Plasma–Quadrupole Mass Spectrometry with Oxygen Dynamic Reaction for Quantification of Technetium-99
Author(s) -
Makoto Matsueda,
Kazuaki Yanagisawa,
Kazuma Koarai,
Masanao Terashima,
Kenso Fujiwara,
Hironobu Abe,
Akihiro Kitamura,
Yoshitaka Takagai
Publication year - 2021
Publication title -
acs omega
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.779
H-Index - 40
ISSN - 2470-1343
DOI - 10.1021/acsomega.1c02756
Subject(s) - chemistry , inductively coupled plasma mass spectrometry , isobaric process , mass spectrometry , analytical chemistry (journal) , solid phase extraction , polyatomic ion , detection limit , extraction (chemistry) , quadrupole , radiochemistry , chromatography , ion , physics , atomic physics , organic chemistry , thermodynamics
Quantification of pg/L levels (i.e., 0.6 mBq/L) of radioactive technetium-99 ( 99 Tc) was achieved within 15 min in the presence of isobaric and polyatomic interference sources such as ruthenium-99 ( 99 Ru) and molybdenum hydride ( 98 Mo 1 H) at 3-11 orders of magnitude higher concentrations. Online solid-phase extraction-inductively coupled plasma-quadrupole mass spectrometry (ICP-QMS) with oxygen (O 2 ) dynamic reaction cell (online SPE-ICP-MS-DRC) was shown to be a thorough automatic analytical system, circumventing the need for human handling. At three stepwise separations (SPE-DRC-Q mass filters), we showed that interference materials allowed the coexistence of abundance ratios of 1.5 × 10 -13 and 1.1 × 10 -5 for 99 Tc/Mo and 99 Tc/Ru, respectively. A classical mathematical correction using the natural isotope ratio of 99 Ru/ 102 Ru was used to calculate the residues of 99 Ru. Using this optimized system, a detection limit (DL; 3σ) of 99 Tc was 9.3 pg/L (= 5.9 mBq/L) for a 50 mL injection and sequential measurements were undertaken at a cycle of 24 min/sample. For the measurement of a lower concentration of 99 Tc, an AG1-X8 anion-exchange column was used to study 20 L of seawater. Its DL was approximately 1000 times greater than that of previous methods (70.0 fg/L). Thus, this method withstands coexistences of 5.8 × 10 -18 and 3.5 × 10 -9 for 99 Tc/Mo and 99 Tc/Ru, respectively. Spike and recovery tests were conducted for environmental samples; the resulting values showed good agreement with the spike applied.