ISSN 1070-4272, Russian Journal of Applied Chemistry, 2006, Vol. 79, No. 8, pp. 1260!1265. + Pleiades Publishing, Inc., 2006.
Original Russian Text + L.N. Skvortsova, E.V. Petrova, M.A. Kiseleva, V.I. Otmakhov, 2006, published in Zhurnal Prikladnoi Khimii, 2006, Vol. 79,
No. 8, pp. 1275!1279.
AND ION-EXCHANGE PROCESSES
Optimization of the Conditions of Sorption Recovery
and Concentration of Noble Metals on Anion Exchangers
and Their Subsequent Determination in Geochemical Objects
by Atomic-Emission Spectroscopy
L. N. Skvortsova, E. V. Petrova, M. A. Kiseleva, and V. I. Otmakhov
Tomsk State University, Tomsk, Russia
Received March 7, 2006
Abstract-Sorption of Au(III), Pt(IV), Pd(II), and Rh(III) ions on ANS-80, AN-108-4 macrocellular anion
exchangers and on AV-17-10P macroporous anion exchanger from hydrogen chloride media was studied in
relation to HCl concentration and time. The residual concentration of matrix elements in analytical concen-
trates of a real object was determined and their influence on the delivery of vapors of noble metals into
the cloud of the arc discharge and on their excitation in the discharge was revealed. The conditions of recov-
ery, concentration, and atomic-emission determination of noble metals were examined. The effect of matrix
elements, combined with a number of supports (NaCl, CdO, TeO
), on the amplitude of analytical
signals was evaluated.
When determining noble metals in geochemical
and industrial objects with complex multicomponent
composition, there is, as a rule, no way of obviating
the stage of separation of matrix elements (ME) even
in the case of high-sensitivity analytical methods
(neutron-activation, mass-spectral, etc.). High sensi-
tivity and determination accuracy can be achieved by
rational combination of separation and concentration
techniques with the potentialities and specific features
of more accessible instrumental analytical procedures.
In the authors’ opinion, the optimal combination is
that of atomic-emission spectroscopy with preliminary
sorption recovery and concentration of microelements.
Their detection limits can be lowered by choosing
those conditions of spectral analysis of the concen-
trate which favor enrichment of the plasma of the light
source with the elements being determined.
Earlier studies of application of sorption methods
for recovery and concentration of noble metals were
based on the ability of their chloro complexes to be
firmly fixed by strongly basic anion exchangers .
However, chelate-forming ion exchangers containing
electron-donor atoms of nitrogen or sulfur are more
promising for selective recovery of noble metals .
The present study is concerned with weakly basic
ANS-80 and AN-108-4 S- and N-containing macro-
cellular anion exchangers obtained by amination with
ethylenediamine of copolymers of methyl acrylate
with a long-chain cross-linking agent (divinyl sulfide
and divinyl ether of diethylene glycol, respectively)
and AV-17-10P macroporous ion exchanger. The phys-
icochemical properties of the sorbents have been
studied previously .
Upon sorption concentration of noble metals, base
elements of natural objects were found in the ion-ex-
change concentrate. These elements can strongly af-
fect the conditions of sample heating in the electrode
crater, delivery of vaporized noble metals into the arc
discharge cloud, and excitation in the cloud. In
the study, the effect of matrix elements was examined
in order to formulate recommendations concerning
their content, and the joint effect of a number of
supports and the residual amount of matrix elements
was analyzed in order to achieve lower determination
limits of noble metals.
To chose the optimal conditions of quantitative re-
covery of noble metals (Au, Pt, Pd, Rh) with the aim
of their concentration and separation from the base
elements of the rock (Ca, Mg, Fe, Al, Na), their sorp-
tion from hydrochloric acid solutions was studied in
the acidity range from 2 M to pH 3. This range of