Determination of 129I in environmental solid samples using pyrolysis separation and accelerator mass spectrometry measurement

Abstract

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Radioanalysis of ultra-low level radionuclides for environmental tracer studies and decommissioning of nuclear facilities

“…Slowly increased temperature in the carbonization step of the sample combustion was found to be an effective approach for solving this problem. A 2 °C/min temperature increasing rate in 250-400°C for soil/sediment samples, and 1°C/min rate in 230-300 °C for vegetation/wood samples were confirmed to be suitable [27,28].…”

Liquid scintillation counting for determination of radionuclides in environmental and nuclear application

“…5) More LSC methods are still needed for the determination of other uncommon radionuclides for the decommissioning of nuclear facilities, e.g. 93 Mo, 93 Zr, 79 Se, 126 Sn, 151 Sm, etc. A challenge in this aspect will be the calibration and standardization of the LSC for the measurement of these radionuclides, because of luck of standard solution of these radionuclides, and not well established decay properties of these radionuclides.…”

“…For solid samples, such as soil, sediment, vegetation, air particles, 129 I has to be separated from the sample matrix and then purified for its measurement using LSC or other techniques. Based on its volatility, iodine is often separated from solid samples by combustion to release iodine as gaseous form [124][125][126]. The released iodine is trapped in NaOH solution, which is then used to separate iodine by extraction with CCl4 as described above for its measurement.…”

Reconstruction of the Sources and Their Contributions to 129I in Northern Xinjiang, China

“…The 129 I/ 127 I atomic ratios in the samples were calculated using the measured 129 I and 127 I concentrations. The procedure blanks were prepared for each batch of samples using the same procedure as the samples but using combusted soil samples (the residue of deep soil combusted in the tube furnace at 800 °C for 4 h) . The measured 129 I/ 127 I ratios in the procedure blanks (<2 × 10 –13 ) were about two orders of magnitude lower than the values in the soil samples, which were subtracted from the measured values in the samples.…”

“…The detection limits of the method for 127 I and 129 I in the 1 g of soil sample were estimated to be 0.03 μg/g and 4.1 × 10 6 atoms/g, respectively. The detailed measurement method for 127 I and 129 I in soil has been reported elsewhere …”