The Improved Method for Precise Determination of Pu Isotope Ratio using MC-ICP-MS

다중검출기유도결합플라즈마질량분석기를 이용한 Pu 동위원소비 정밀 분석법

  • Received : 2010.08.09
  • Accepted : 2010.09.15
  • Published : 2010.09.30


Plutonium is by far the most important of the transuranic elements which have been released into the environment due to radio-toxicity and long term radiation effects on humans. And Pu isotope ratio ($^{240}Pu/^{239}Pu$) is of great interest because this ratio is used as a fingerprint for different sources. Mass spectrometry has been used as an useful atom counting technique with several advantages over decay counting techniques for the determination of Pu isotopes. It enables a determination of Pu isotope ratio in the environmental samples with a low detection limit and a short determination time. An ICP-MS is the representative mass spectrometry for Pu determination. In this study, the precision of $^{240}Pu/^{239}Pu$ isotope ratio was improved by using 4 multiple ion counters of MC-ICP-MS. The detection limit of $^{239}Pu$ and $^{240}Pu$ were $0.10\;fg\;ml^{-1}$ ($0.24\;{\mu}Bq\;ml^{-1}$), $0.12\;fg\;ml^{-1}$ ($0.97\;{\mu}Bq\;ml^{-1}$), respectively. The relative standard deviation of $^{240}Pu/^{239}Pu$ isotope ratio was less than 1 % in trace level. The various reference materials (seawater, soil and sediment) were analyzed to verify this method and their analytical results were in good agreement with the certified (or recommended value) value.


  1. Muramatsu Y, Yoshida S, Tagami K, Uchida S, Rühm W. ICP-MS analysis of environmental plutonium, Plutonium in the environment. 2001:63-77.
  2. Hirose K, Aoyama M, Katsuragi Y, Sugimura Y. Annual deposition of Sr-90, Cs-137 and Pu-239, 240 from the 1961-1980 Nuclear Explosions: A Simple Model. J. Met. Soc. Japan 1987; 65(2):259-276.
  3. Nagaya Y, Nakamure K. 239,240Pu and 137Cs in the East China and the Yellow Seas. J. Oceanogra Soc. Japan 1992;48(1):23-35.
  4. Talor RN, Warneke T, Milton AM, Croudace IW, Warwick PE, Nesbitt RW. Plutonium isotope ratio analysis at femtogram to nanogram levels by mulmulticollector ICP-MS. J. Anal. At. Spectrom. 2001; 16(3):279-284.
  5. Assinder DJ. A review of the occurrence and behavior of neptunium in the Irish Sea. J. Environm. Radioactivity 1999:44(2-3);335-347.
  6. Kim CS, Kim CK, Martin P, Sansone U. Determination of Pu isotope concentrations and isotope ratio by inductively coupled plasma mass spectrometry: a review of analytical methodology. J. Anal. At. Spectrom. 2007;22(7):827-841.
  7. Kim CS, Kim CK. Lee JI, Lee KJ. Rapid determination of Pu isotopes and atom ratios in small amounts of environmental samples by an on-line sample pre-treatment system and isotope dilution high resolution inductively coupled plasma mass spectrometry. J. Anal, At, Spectrom. 2000:25(3); 247-255.
  8. Chiappini R, Pointurier F, Millies-Lacroix JC, Lepetit G, Hemet P. 240Pu/239Pu isotopic ratios and 239+240Pu total measurements in surface and deep waters around Mururoa and Fangataufa atolls compared with Rangiroa atoll (French Polynesia). The Science of the Total Environ. 1999:237-238;269-276.
  9. Becker JS, Soman RS, Sutton KL, Caruso JA, Dietze HJ. Determination of long-lived radionuclides by inductively coupled plasma quadrupole mass spectrometry using different nebulizers. J. Anal. At. Spectrom. 1999:14(6);933-937.
  10. Taylor RN, Warneke T, Milton JA, Croudace IW, Warwick PE, Nesbitt RW. Multiple ion counting determination of plutonium isotope ratios using multi-collector ICP-MS. J. Anal. At. Spectrom. 2003:18(5);480-484.
  11. Ikeuchi Y, Amano H, Aoyama M, Berezhnov VI, Chaykovskaya E. Hirose K. Anthropogenic radionuclides in seawater of the Far Eastern Seas. The Science of the Total Environ. 1999:237-238; 203-212.
  12. T. Determination of 240Pu/239Pu Ratio in the Ocean by Using HR-ICP-MS. Anal. Sciences. 2001:17(ICAS2001);i29-i32.
  13. Kershaw PJ, Sampson KE, McCarthy W, Scott RD. The measurement of the isotopic composition of plutonium in an Irish Sea sediment by mass spectrometry. J. Radioanal. Nucl. Chem. 1995: 198(1);113-124.
  14. Muramatsu Y, Rühm W, Yoshida S, Tagami K, Uchida S, Wirth E. Concentrations of 239Pu and 240Pu and Their Isotopic Ratios Determined by ICP-MS in Soils Collected from the Chernobyl 30-km Zone. Environ. Sci. Technol. 2000: 34(14);2913-2917.