Stability of Technetium and Decontamination from Ruthenium and Molybdenum in Determination of ⁹⁹Tc in Environmental Solid Samples by ICPMS

Abstract

A rapid and efficient method for the determination of (99)Tc in environmental solid samples was developed using chromatographic separation combined with inductively coupled plasma mass spectrometry (ICPMS) measurement. The volatility of technetium during sample ashing and solution evaporation was investigated to establish a reliable sample pretreatment procedure. A novel approach was developed to improve the removal of molybdenum and ruthenium in chromatographic separation using 30% H(2)O(2) pretreatment of the loading solution and extraction chromatographic separation using two serial small TEVA columns. The decontamination factors of more than 4 × 10(4) and 1 × 10(5) are achieved for molybdenum and ruthenium, respectively. Chemical yields of technetium in entire procedure range from 60% to 95% depending on the type and amount of samples, and the detection limit of 0.15 mBq/g for (99)Tc was obtained. The method has been successfully applied for the determination of (99)Tc in environmental solid samples.

Seasonal variation of technetium-99 in Fucus vesiculosus and its application as an oceanographic tracer

“…The measured concentration factor of 99 Tc ranges from 1.3 Â 10 5 to 2.4 Â 10 5 L/kg with a mean value and 2SD of (1.9 AE 0.5) Â 10 5 L/kg. This value agrees with the previously reported values of (1.75 AE 0.21) Â 10 5 L/kg (1SE of uncertainty) measured in F. vesiculosus collected from Klint (Denmark) (Masson et al, 1995), and (1.32 AE 0.46) Â 10 5 L/kg (2SD of uncertainty) in F. vesiculosus collected in Irish coast (Smith et al, 2001). The relatively constant concentration factors of 99 Tc in F. vesiculosus measured in this work (Figs.…”

“…To our best knowledge, studies on this topic, especially on the mechanism of seasonal variation of 99 Tc in seaweed are still very rare. In addition, although similar concentration factors of 99 Tc in brown seaweed Fucus vesiculosus have been reported (Aarkrog et al, 1987;Smith et al, 2001), the values are still not representative because they are usually obtained using limited numbers of data on concentration of 99 Tc in seaweed and seawater. Accordingly, a comprehensive investigation on the concentration factor of 99 Tc in seaweed for exploring its temporal variation is needed.…”

Analysis of Technetium Species and Fractions in Natural Seaweed Using Biochemical Separation and ICP-MS Measurement

“…Dry ashing is a simple and effective method to decompose organic matter in solids to be able to extract technetium from the sample using acid solution. However, technetium might be lost through the formation of volatile technetium species such as Tc 2 O 7 during heating at high temperature . On the contrary, organic matter cannot be completely incinerated at low temperature (e.g., <500 °C), which may otherwise lead to complications in the subsequent chemical processing and cause a poor chemical yield of technetium …”

“…Solid fractions, containing Tc-protein, Tc-pigment, Tc-algin, and Tc-cellulose, were dried and analyzed using the same method as for total 99 Tc determination in seaweed. The detailed analytical procedure has been reported in our previous work, and the main steps have been summarized as follows: the solid sample was incinerated at 700 °C for 3 h, and then digested with 8 mol/L HNO 3 . After the enrichment of 99 Tc with Fe­(OH) 3 /Fe­(OH) 2 coprecipitation, 99 Tc in solution was separated and purified using two TEVA columns (2 mL).…”

Rapid determination of technetium-99 by automatic solid phase extraction and inductively coupled plasma mass spectrometry

“…This technique offers several advantages over traditional radiometric methods, including high sensitivity and relatively short measurement times. 7,8 Due to the very low concentrations of 99 Tc in the environment and the need to reduce interference with the matrix, sample separation and purication techniques must be applied to lower the ratio of total dissolved solids, such that the analytic method is concentrated prior to measurement. As previously report, the electrothermal vaporisation (ETV) as a sample introduction has been used to remove ruthenium due to its lower boiling point.…”