both REE fluorides and REE phosphates are insoluble so if you use those
acids in the digestion you are going to shift the problem from having to
dissolve an REE silicate to having to dissolve an REE fluoride or
phosphate (which may not be as bad). I think alkali fusion is not a bad
way to go. I would be concerned about REE blanks in your flux but since it
sounds like the REE are a near-stoichiometric constituent of your glass,
that problem may be quite manageable.
By the way, if Ge is one of your analytes, digestion with HF is a bad
choice regardless because, just like Si, you are going to lose Ge as GeF4.
> Dear Chris,
> There is some literature on REE mineral structures that suggests that HCl,
> HClO4 or even H3PO4 might be worth a try. Hydrochloric acid in its
> concentrated form certainly attacks gadolinite and yttrialite.
> I don't know how much material you have to experiment with but it might be
> worth trying at least the HCl and the perchloric acids.
> Dr Bill Perkins
> Reader in Geochemistry
> Department of Geography and Earth Sciences
> Aberystwyth University
> Email: [log in to unmask]
> -----Original Message-----
> From: PLASMACHEM-L: Analytical Chem.(ICP's, DCP's, MIP's).
> [mailto:[log in to unmask]] On Behalf Of OTTLEY, CHRISTOPHER
> Sent: 31 March 2017 12:34
> To: [log in to unmask]
> Subject: REE in optical glass
> Dear All
> I have been asked to analyse La, Gd, Dy and Ge in "special" silicate
> optical glasses A typical stoichiometry is believed to be
> 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
> Chris Ottley
> Dept of Earth Sciences
> University of Durham
> Un o’r 4 prifysgol uchaf yn y DU a’r orau yng Nghymru am fodlonrwydd
> (Arolwg Cenedlaethol y Myfyrwyr 2016)
> Top 4 UK university and best in Wales for student satisfaction
> (National Student Survey 2016)
"If I have seen further, it is by standing on the shoulders of Giants"
"Somewhere I think I have read an alternative quotation "I have stood on
the shoulders of pygmies". It is a clever remark [...] There is, however
the sobering thought that in a land of giants and pygmies there is no
point in standing on the shoulders of a pygmy if one is a pygmy oneself"
"If I have seen further, it is because I was looking in the right direction"
Dr. Johan Schijf
Associate Professor, Aquatic Environmental Geochemistry
UMCES/Chesapeake Biological Laboratory
P.O. Box 38, 146 Williams Street
Solomons, MD 20688-0038
Tel. (410) 326-7387 (office) 7392 (lab)
Fax (410) 326-7341
e-mail: [log in to unmask]