On the development of a method for
thefor
isolation
of Selenium
On the development of a method
thea isolation
of Seleniuma
a
a, Bombard,
Dirks,
C. , Happel,
S. , Bombard, A.
Dirks, C.a, Happel, S.
A.a
a TrisKem
a
International,
Bruz, France
TrisKem
International, Bruz, France
Introduction
Measurement of Selenium is of importance regarding public health as the ratio between beneficial daily intake and toxicity is rather low [1], [2].
Also from the radiological perspective, Se-79 as a long-lived fission nuclide (T1/2=2.8x105y) with high mobility in environment, is of concern
regarding waste management and decommissioning [3], [4].
Selenium has a complex chemistry due to the existence of different oxidation states which makes separation schemes not straightforward. The
aim of this research work is to develop a fast and easy separation method selective for Selenium. Extraction chromatographic resins have been
tested and characterized for Se in presence of other metals. Elution studies were performed to optimize Se separation conditions.
Batch experiment
Several Prototypes were tested ; an amino compound in ionic liquid showed most promising results for the selective separation of Selenium
Se selective Resin: 50mg of prototype of Se selective resin in contact with 1 mL multielement solution (ME sol) for 1h – Measurement by ICP-MS
Se selective Resin in HCl
As
1,E+04
Ga
Sb
Ge
Se
Te
Se selective Resin in HNO3
In
As
1,E+03
1,E+03
1,E+02
1,E+02
1,E+01
Ga
Sb
Ge
Se
Te
In
1,E+00
1,E+01
1,E-01
1,E+00
1,E-02
1,E-01
1,E-03
1,E-02
1,E-04
1,E-03
1,E-05
1,E-04
1,E-06
pH 7
0.01M HCL
0.1 M HCl
1 M HCl
2 M HCl
3 M HCl
6 M HCl
8 M HCl
0.01 M HNO3
Te
Ge
Se
As
Sb
Te
Ge
100%
90%
90%
90%
80%
80%
80%
70%
70%
70%
60%
60%
60%
50%
50%
50%
40%
40%
40%
30%
30%
20%
20%
10%
10%
2mL Load 2M 3 mL 2M HCl
HCl +3 mL
2M HCl
5mL H2O
2 mL 2M
H2O2
2 mL 2M
H2O2
2 mL 2M
H2O2
2 mL 2M
H2O2
0%
3 M HNO3
6 M HNO3
8 M HNO3
300 mg Se selective Resin Load: 6 M HCl
Se
100%
0%
2 M HNO3
350 mg Se selective Resin Load 1 M HCL
250mg Se selective Resin Load : 2 M HCl
Sb
1 M HNO3
 Good Se uptake at 0.01 M HNO3 (Dw Se ≥ 340).
 At same conditions, only Ga and Sb show a slight uptake (Dw < 50)
 High Se uptake between HCl 0.01 M and 8 M HCl
 In 2 M HCl DwSe ≥ 360, no selectivity for other elements (Dw<10)
As
0.1 M HNO3
As
100%
Sb
Te
Ge
Se
Ga
In
Cd
30%
20%
10%
2mL Load 1M
HCl + 2mL 1M
HCl
3mL 1M HCl
4mL H2O
1mL H2O
5mL 1M H2O2
3mL 1M H2O2
0%
3mL 6M HCl
+ 3mL H2O
5mL H2O
4mL 1M HCl
4mL 1M HCl
4mL 1M
H2O2
4mL 1M
H2O2
Good uptake for Se in 2 M HCl, 1 M HCl and 6 M HCl
• Load from 2 M HCl : 1-2% Se breakthrough during load and rinse when only 250 mg resin were used, Se recovery near 100% in 8 ml 2 M H2O2
• Load from 1 M HCl: no Se breakthrough during load and rinse when 350 mg resin were used; recovery of Se < 80% in 8 ml 1 M H2O2
• Load from 6 M HCl: no Se breakthrough during load and rinse when 300 mg resin were used; recovery of Se < 90% in 10 mL 1 M H2O2
 Loading under different conditions possible
 Se can be recovered in 8-12 mL 1 or 2 M H2O2
Conclusions
9 prototypes tested for DW values of Se and various other elements. Elution studies performed.
Presented resin best suited for Se extraction.
Good separation and appropriate elution volumes
Dw show predominant extraction of Se over other elements tested. On-going work is being performed to optimize Se elution.
Bibliography
[1] Cary L. et al. Applied Geochemistry 48 (2014) 70–82
[2] Chen C. et al. Biological Trace Element Research Vols. 71-72 (1999) 131-138
[3] http://www.irsn.fr/FR/Larecherche/publications-documentation/fiches-radionucleides/Documents/environnement/Selenium_Se79_v2.pdf last access
03/03/2016
[4] Uchida et al. WM2009 Conference, March 1-5, 2009, Phoenix, AZ
TRISKEM INTERNATIONAL – 3, rue des Champs Géons – 35170 Bruz – France
www.triskem.com e-mail : [email protected]
2 mL 1M
H2O2