An improved solvent extraction procedure for Re isotopic measurements

In this paper, we present an improved solvent extraction method for the chemical isolation of Re from the sample matrix using ammonia (NH3 center dot H2O) and butanone instead of the traditional extraction method using NaOH and acetone. With this method, no sodium is introduced, and thus, no subsequent further purification is required prior to inductively coupled plasma mass spectrometry (ICP-MS) measurements. For the extraction, when the volume ratio of NH3 center dot H2O to butanone was 1:2, with 4 mL of NH3 center dot H2O and 8 mL of butanone, the recovery was as high as greater than 90%. The effects of the extraction time, the centrifugal speed, and the centrifugal time were investigated. Re can be efficiently extracted into the butanone in only 1 min, and a centrifugal speed of 2000 r/ min for 5 min was used to separate the butanone from the NH3 center dot H2O. We compared the three chemical methods (anion exchange resin, acetone-NaOH mixture, and butanone-NH3 center dot H2O mixture) for a variety of sample matrixes (sulfides and rock sample). The results show that the new method can completely separate the Re from the matrix with a low blank (2-5 pg). Finally, the proposed method was verified using reference materials (Henderson HLP, JDC, JCBY, and UB-N), and the analytical results were found to be in good agreement with the previously reported data.

Automated summary

An improved solvent extraction method using ammonia and butanone instead of NaOH and acetone is presented in this paper for the chemical isolation of Re from the sample matrix. The new method eliminates the need for further purification and achieves high recovery. Comparison with other chemical methods shows that this method can completely separate Re from the matrix with low background levels.