ICP-MS method for the determination of uranium concentration and 235U/238U ratio in urine and its uncertainty evaluation / 中华放射医学与防护杂志

ABSTRACT

Objective To establish a method of analyzing total uranium and 235U/238U ratio in urine using inductively coupled plasma mass spectrometry (ICP-MS) and uncertainty assessment.Methods Urine sample was digested with HNO3 and H2O2,and total uranium was determined using ICP-MS method directly.The digested urine sample was separated to concentrate uranium with tributyl phosphate (TBP) column,and 235U/238U ratio was analyzed using ICP-MS.The uncertainty was evaluated through sample pre-treatment,measurement and standard curve calculation.Results The recovery of total uranium in urine was 98.4％-102.4％,detection limit was 0.002 μg/L.The relative expanded uncertainty of total uranium concentration in urine was 0.26 (k =2).235 U/238 U ratio was 0.001 1 (k =2).Conclusions This study offers a low detection limit,good recovery and precision method for rapid determination of total uranium and 235U/238 U ratio in urine samples.It is potential used for both in occupational exposure assessment and nuclear emergency situation.The uncertainty evaluation of total uranium and 235U/238U ratio in urine are reliable.