Marine radioactivity of Cs-134 and Cs-137 in the Malaysian Economic Exclusive Zone after the Fukushima accident

Innovative ICP-MS/MS Method To Determine the 135Cs/137Cs Ratio in Low Activity Environmental Samples

“…While the quantification of 137 Cs by gamma spectrometry is very efficient and allows to reach very low detection limits (down to 0.1 Bq kg –1 ), , the radiometric measurement of 135 Cs is difficult due to its low-energy beta emission (β – , E max 268.9 keV). , Theoretically, 135 Cs (pure beta emitter) can be quantified by radiometric methods but the five-fold higher activity of 137 Cs, which is also a β-emitter, renders the analysis of 135 Cs difficult. , During the last two decades, the quantification of radiocesium ( 135 Cs and 137 Cs) has become possible, thanks to the development of advanced mass spectrometry (MS) techniques . The two main MS techniques used to determine the 135 Cs/ 137 Cs ratio in environmental samples are the triple-quadrupole inductively coupled plasma mass spectrometry (ICP-MS/MS) ,,,, and the thermal ionization mass spectrometry (TIMS). ,,,, A major advantage of these MS techniques is their very low abundance sensitivity (<10 –9 ), which is required to limit the effect of stable cesium ( 133 Cs) peak tailing on the 135 Cs measurement. ,, The measurement of 135 Cs and 137 Cs by mass spectrometry raises other significant metrological difficulties due to the low amount of radiocesium atoms at low levels of contamination and to the presence of many interferences in the mass range of interest ( 135 Ba, 137 Ba, 95 Mo 40 Ar, 97 Mo 40 Ar, 119 Sn 16 O, 121 Sb 16 O) .…”

“…This high potential is nevertheless limited by the fact that its measurement in environmental samples is associated with several analytical challenges. 10,17,19,23 While the quantification of 137 Cs by gamma spectrometry is very efficient and allows to reach very low detection limits (down to 0.1 Bq kg −1 ), 27,28 the radiometric measurement of 135 Cs is difficult due to its low-energy beta emission (β − , E max 268.9 keV). 13,29 Theoretically, 135 Cs (pure beta emitter) can be quantified by radiometric methods but the five-fold higher activity of 137 Cs, which is also a β-emitter, renders the analysis of 135 Cs difficult.…”

Identification of the Origin of Radiocesium Released into the Environment in Areas Remote from Nuclear Accident and Military Test Sites Using The 135cs/137cs Isotopic Signature

“…Radiocesium isotopes including 134 Cs (T1/2 = 2.1 y), 135 Cs (T1/2 = 2.3.10 6 y) and 137 Cs (T1/2 = 30.2 y) rank among the radionuclides that were released in highest quantities 4,5 . With more than 1.4x10 8 Bq dispersed into the environment and its relatively long half-life, 137 Cs is considered as the main source of long-term artificial radiation to the public [4][5][6][7][8] . Its monitoring in the environment is therefore of major interest to evaluate the risks incurred by the population and ecosystems [9][10][11][12] .…”

Development of a Novel DGT Passive Sampler for Measuring Cs-137 In Situ in Marine Environments

“…The current adopted method in most laboratories involves the collection of large volumes of samples ranging from 10 to 200 L, followed by acidification for sample preservation. After that, the sample is preconcentrated by the sorption on ammonium molybdophosphate (AMP) or transition metal ferrocyanides . Finally, the settled solid is filtered, dried, and then counted using the HPGe γ spectrometer.…”

“…After that, the sample is preconcentrated by the sorption on ammonium molybdophosphate (AMP) 10 or transition metal ferrocyanides. 11 Finally, the settled solid is filtered, dried, and then counted using the HPGe γ spectrometer. The drawbacks of this method include the high cost of sampling and transporting large volumes of water, the susceptibility of the sample to changes during storage and transportation, the elaborate sample preparation, and the unrepresentativeness of the bulk sampling.…”