UT Department of Geological Sciences

Isotope Geochemistry at The University of Texas at Austin

Technical Notes

0.2 ml Sr-Spec (50-100 mesh) Columns for Whole Rock Sr Separations

Column Procedure:

1. clean resin                        3 ml quartz-distilled H₂O
2. precondition column         3 ml 3.5 N HNO₃
3. load sample                      dissolved in 0.2  ml 3.5 N HNO₃
4. wash                                 0.1 ml 3.5 N HNO₃
5. wash                                 0.1 ml 3.5 N HNO₃
6. wash                                 0.1 ml 3.5 N HNO₃
7. wash                                 0.5 ml 3.5 N HNO₃
8. wash                                 0.5 ml 3.5 N HNO₃
9. wash                                 2.5 ml 3.5 N HNO₃
10. elute Sr                           3 ml warm 0.05 N HNO₃

Resin Cleaning:
    Sr-Spec resin is a Sr 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., and Dietz, M.L., 1992. A novel strontium-selective extraction chromatographic resin. Solv. Extract. Ion Exch., 10: 313-336.

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)

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