UT Department of Geological Sciences
Isotope Geochemistry at The University of Texas at Austin
Technical Notes
0.2 ml RE-Spec (50-100 mesh) Columns for Whole Rock Bulk REE Separations
Column Procedure:
1. clean resin
3 ml 0.05 N HNO3
2. precondition column 3 ml 2 N HNO3
3. load sample
dissolved in 0.2 ml 2 N HNO3
4. wash
0.1 ml 2 N HNO3
5. wash
0.1 ml 2 N HNO3
6. wash
0.1 ml 2 N HNO3
7. wash
0.5 ml 2 N HNO3
8. wash
0.5 ml 2 N HNO3
9. wash
1.0 ml 2 N HNO3
10. wash
1.5 ml 2 N HNO3
11. elute REE
4 ml warm* 0.05 N HNO3
* use of warm acid helps overcome a kinetic effect which results in severe tailing of the REE when room temperature acid is used.
Resin Cleaning:
RE-Spec resin is a rare earth element selective extraction
chromatographic material produced by EIChroM Industries, Darien, IL. We preclean the resin
by placing an aliquot in a small Teflon bottle which is then filled with quartz-distilled
water, shaken well, and placed on a hotplate set at around 50ºC overnight. The next day
the water is decanted and the procedure is repeated ten times. Once the resin is ready for
use, it is transferred to a dropper bottle where it is dispensed as needed. The resin in
the columns is disposed of after every use.
For details on this resin, see:
Horwitz, E.P., Chiarizia, R., Dietz, M.L., and Diamond, H., 1993. Separation and
preconcentration of actinides from acidic media by extraction chromatography. Anal. Chim.
Acta, 281: 361-372. (note: this paper discusses TRU-Spec, an analogous extraction
chromatographic material to RE-Spec, but with a lower ratio of CMPO/TBP)
Column Construction and Cleaning:
Start with 5.5 cm KORVEX 4 ´ ½ shrink
tubing. Fit the shrink tubing over the end of a standard test tube with approximately 2.5
cm of the tubing extending beyond the end of the test tube. Shrink this portion of the
tubing with a hot air gun as far as it will go. This will result in a column with an
interior diameter of around 3.6 mm. Place a polystyrene frit in the end of the column and
adjust it so that the volume of the column is 0.2 ml. The reservoir (the unshrunk portion
of the column) has a volume of 3 ml.
After use, the columns are placed in a Teflon bottle which is then
filled with clean water and placed on a hotplate at a low setting for a couple of days.
After this, the water is decanted, the columns are rinsed, and 7 N HNO3 is
added to the bottle and placed back on the hotplate at a low setting for a couple more
days. After this, the HNO3 is decanted and the columns are rinsed with clean
water and are ready for use.
Questions? Contact Todd Housh (mail)