Uranium isotopes in surface soil in Inner Mongolia and northwest China: level, distribution and sources [我国东北地区土壤铀同位素水平, 分布和来源]

作者：Huang Z.; Hou X.-L.^*; Zhao X.; Zhang L.-Y.

来源：China Environmental Science, 2021, 41(5): 2343-2351.

• 234U/238U
• 235U/238U
• Environmental radioactivity
• ICP-MS/MS
• Isotope disequilibrium
• Soil
• Uranium

In total 132 surface soil samples were collected from Northeast China. The ground and homogenized soil was completely dissolved using mixed acids. Uranium was separated from the sample matrix by extraction chromatography using UTEVA resin, and uranium isotopes in the separated sample were then measured by a triple quadrupole Inductively Coupled Plasma Mass Spectrometry (ICP-MS/MS) to learn the level and distribution of 238U, 235U, 234U concentrations in surface soil of the study. The 234U in surface soil of this area was reported first time, and an obvious isotope fractionation of 234U was observed in some soil samples indicated by the increased 234U/238U ratios. The distribution of 235U/238U atomic ratios in these surface soil samples showed an obvious regional deposition of uranium derived from atmospheric nuclear weapon tests the windward slope of the mountain. Consequently, the level of 235U/238U atomic ratios in the surface soil in west site of Greater Khingan Mountain were higher than other places. The level of uranium isotopes in surface soil was comparable to the environmental background level in other places, indicating negligible impacts from human nuclear activities. The source analysis showed that uranium isotopes in surface soil were dominated by rock weathering, human industrial and agricultural activities also contributed moderately in some areas.

• 单位
  中国科学院大学; 黄土与第四纪地质国家重点实验室