MnO<sub>2</sub> precipitation and direct beta counting technique for determining <sup>234</sup>Th in small-volume seawater

MA Qiang; CHEN Min; QIU Yu-sheng; HUANG Yi-pu

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MA Qiang, CHEN Min, QIU Yu-sheng, HUANG Yi-pu. MnO2 precipitation and direct beta counting technique for determining 234Th in small-volume seawater[J]. Haiyang Xuebao, 2005, 27(4): 68-75.

Citation:

MA Qiang, CHEN Min, QIU Yu-sheng, HUANG Yi-pu. MnO₂ precipitation and direct beta counting technique for determining ²³⁴Th in small-volume seawater[J]. Haiyang Xuebao, 2005, 27(4): 68-75.

MA Qiang, CHEN Min, QIU Yu-sheng, HUANG Yi-pu. MnO2 precipitation and direct beta counting technique for determining 234Th in small-volume seawater[J]. Haiyang Xuebao, 2005, 27(4): 68-75.

Citation:

MA Qiang, CHEN Min, QIU Yu-sheng, HUANG Yi-pu. MnO₂ precipitation and direct beta counting technique for determining ²³⁴Th in small-volume seawater[J]. Haiyang Xuebao, 2005, 27(4): 68-75.

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MnO₂ precipitation and direct beta counting technique for determining ²³⁴Th in small-volume seawater

1.
Department of Oceanography, Xiamen University, Xiamen 361005, China
2.
Department of Oceanography, Xiamen University, Xiamen 361005, China;State Key Laboratory of Marine Environmental Science, Xiamen University, Xiamen 361005, China

Received Date: 2005-01-21
Rev Recd Date: 2005-03-21

Abstract

Abstract

A method for ²³⁴Th deter mination in small-volume seawater was established by using the alpha/bet a counter with scintillating solid detectors.This method is based on the coprecipitation of thorium with Mn oxides followed by direct beta counting of the precipitation.A series of experiments were conducted in order to examine the blank,chemical yield,detector efficiency of the procedure.Besides,the effect of the amount of MnO₂ precipitation on total yields was tested.Hal-flife determination was used to verify the reliability of the method.The results show that this procedure has stable blanks and total yields,high detector efficiencies and chemical yields.The half-life of the measuring nuclide is consistent with that of ²³⁴Th.This technique has been used to measure ²³⁴Th in surface seawater samples from the subtropical North Pacific.Comparing with previous classic methods,this new technique has the advantage of minimal sample volume,easier processing prior to beta counting,and suitable for ship-board analysis.By using this method for ²³⁴Th determination,much higher spatial and temporal resolution data can be obtained,and knowledge of POC export in the ocean may greatly be increased.
- seawater,
- ²³⁴Th,
- MnO₂ precipitation,
- beta counter

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References(22)

References

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