We have been using boric acid to get rid of the fluorides with good success.
Queen's Facility for Isotope Research
Dept. of Geol. Sci. and Geol. Eng.
36 Union Street
Kingston, ON K7L 3N6
From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's). <[log in to unmask]> on behalf of OTTLEY, CHRISTOPHER J. <[log in to unmask]>
Sent: Friday, March 31, 2017 7:34:07 AM
To: [log in to unmask]
Subject: REE in optical glass
I have been asked to analyse La, Gd, Dy and Ge in "special" silicate optical glasses
A typical stoichiometry is believed to be Gd9.2Dy0.05(SiO4)6O2
I have used standard geological HF/HNO3 digestion techniques but have had no success in dissolving this material.
Before I go down the Alkali fusion route does anyone have any experience of dissolving this type of material using standard mineral acids
Dept of Earth Sciences
University of Durham