Transcript Separation and Measurement of Charged

Chromatographic Separation and
Measurement of Charged-Particle Emitting
Radionuclides
Timothy A. DeVol, Ph.D., C.H.P.
Environmental Engineering and Science
Clemson University
16 May 2000
Introduction to Dual Functionality Materials
• Liquid Extractive Scintillators
– Ludwick, Health Physics, 1961, 6, 63-65.
– McDowell and McDowell, Liquid Scintillation Alpha Spectrometry,
CRC Press, Boca Raton, 1994.
• Scintillating Cation and Anion Ion Exchange Resin
– Heimbuch, et al., Radioisotope Sample Measurement Techniques in
Medicine and Biology, Proceedings of the International Atomic
Energy Agency Symposium, Vienna, May 24-28, 1965.
• Solid Extractive Scintillators for 90Sr and 99Tc
– Egorov et al., Anal. Chem 71 (1999) 5420-5429
• Solid Extractive Scintillators for 90Sr, 99Tc and
Actinides
– DeVol et al., Radioactivity&Radiochemistry Vol. 11 #1 (2000)
Separation and Detection Schemes
• Single scintillation crystal, e.g. CaF2:Eu,
anthracene
• Extractant coated onto inert scintillator
• Mixture of extraction resin with granular
scintillator
• Extractant impregnated into a scintillating
chromatographic resin (ScintEx)
Solid Extractive Scintillators
• Sequential Extraction Chromatography and
Flow-cell Detection
Off-line quantification
• Simultaneous Extraction Chromatography
and Flow-cell Detection
On-line quantification
Materials and Methods
• Mixed-Resin
Mixture of:
– 100 - 150 mm TEVA Resin or Sr Resin
– 100 - 200 mm BC-400 Plastic Scintillation Beads (Bicron)
or 63 - 90 mm GS-20 Scintillating Glass (Applied
Scintillation Technology)
Extractive Scintillator Resin
• ScintEx resin (Patent Pending)
– Inert polystyrene chromatographic resin
(Amberchrom CG-161c) impregnated with PPO
and DM-POPOP using a modification of the
Ross 1991 procedure
– Scintillating chromatographic bead impregnated
with extractant (Eichrom proprietary technology)
• Extractant for Sr
• ABEC-2000
• Quaternary Amine, Aliquat-336 (TEVA)
• CMPO extractant in TBP for actinides
Off-Line Evaluation Procedures
• Resin dry packed into
9 mm x 50 mm opaque column
• Conditioning, loading and wash performed with
standard Eichrom procedures
• Column placed in 7-mL HDPE vial WITHOUT
introduction of LSC cocktail
• Activity quantified with Hidex Triathler liquid
scintillator counter
Hidex Triathler
Results and Discussion
• Mini-Column Experiments (Off-Line)
– Compare pulse-height spectra (luminosity) and
detection efficiency
• Flow-Cell Experiments (On-Line)
– Loading and elution profiles (loading and
detection efficiency, and total recovery)
– Regeneration capability
89Sr
Pulse-Height Spectra from Triathler
Net Count Rate (cps)
10
1
Sr ScintEx O; 50.8%
Sr GS20M; 50.3%
Sr BC400M; 81%
SrGS20; 14.4%
Sr ScintEx; 9.1%
0.1
10
100
Channel Number
1000
Triathler Pulse-Height Spectra for
89Sr and 90Sr on Sr ScintEx O
Net Count Rate (cps)
10
Sr-89, 50.8%
Sr90/Y90, 36.0%
Sr-90, 14.4%
1
0.1
10
100
Channel Number
1000
Schematic of On-Line Flow-Cell
Detection System
Flow-cell
Manually controlled pump
PMT
PMT
Effluent
Eluant
Loading
Solution
Sample
Radiation Detector
Computer
LSC
Flow-Cell Radiation Detection System
IN/US b-Ram Model 1
Extractive Scintillator Flow-Cell
Extractive scintillator flow-cell
was constructed of with <0.5 g
of resin packed into 1.5 mm ID
x 140 mm polytetrafluoroethylene tubing to yield an
approximate pore volume of
200-400 mL. The tubing is
coiled to an approximate
diameter of 2.54 cm and placed
between the photomultiplier
tubes of the radiation detector.
Loading and Elution of 99Tc(VII)
TEVA/BC-400 Mixed Resin
1
99
Tc in 2-M HCl
2-M HCl
8-M HCl
1
Count Rate (cps)
e(99Tc) = 7.5%
0.6
0.4
0
10
-1
Flow Rate (mL min )
10
0.8
0.2
-1
0
10
0
500
1000
1500
2000
2500
Time (s)
3000
3500
4000
Loading and Elution of 99Tc
TEVA/BC-400 Mixed-Resin Flow-Cell
137Cs
Interference Test
3
10
2
99Tc;
5 mL; 24 Bq mL-1
99
137Cs;
1 mL; 7.2 kBq mL-1
137
Tc in 2 M HCl
Cs in 2 M HCl
Count Rate (cps)
10
2 M HCl
8 M HNO
3
1
10
0
10
-1
10
0
1000
2000
3000
Time (s)
4000
5000
6000
Loading and Elution of 99Tc
ABEC ScintEx Flow-Cell
1200
Counts per 10 s
1000
Loading Efficiency ~ 100%
Total Tc Recovery ~ 99.5%
Detection Efficiency ~ 79%
800
600
99
Tc in 4M NaOH
400
4 M NaOH
DDI H O
200
2
0
0
500
1000
1500
2000
Time (s)
2500
3000
3500
4000
Loading and Elution of 99Tc
TEVA ScintEx Flow-Cell
1000
Loading Efficiency = 99.9%
Total Tc Recovery = 99.4%
Detection Efficiency = 51%
Counts per 10 s
800
600
99
Tc in 0.1 M HNO
400
3
0.1 M HNO
3
8 M HNO
3
200
0
0
1000
2000
Time (s)
3000
4000
Loading and Regeneration
of TEVA ScintEx
Detection Efficiency (%)
100
Detection Efficiency - 0.1 M HNO3
80
80
Detection Efficiency - 2 M HNO
3
Loading Efficiency
Total Recovery
60
60
40
40
20
20
0
0
1
2
3
4
5
6
7
Trial #
8
9
10
11
Loading Efficiency or Total Recovery (%)
100
89Sr
Loading and Elution Profile on
Sr ScintEx O
Count Rate (cps)
100
80
60
Sr-89
e (89Sr) = 65.4%
40
4 M HNO3
20
DDI
H2O
4 M HNO3
0
0
1000
2000
Time (s)
3000
4000
Loading 90Sr/90Y on Sr ScintEx P
Count Rate (cps)
18
16
Sr/Y-90, 92.5 Bq
14
Y-90, 160
102 Bq
12
10
8
e (90Sr) = 40%
6
4
2
0
0
500
1000
1500
Time (s)
2000
2500
3000
Multiple Loading and Elution of 89Sr
on Sr ScintEx O
120
Avg. Detection efficiency 60  4%
Count Rate (cps)
100
Avg. Loading efficiency 101 ± 1%
80
65.4%
58.8%
57.6%
59.6%
60
40
20
0
0
5000
10000
Time (s)
15000
TRU ScintEx Resin
Pulse Height Spectrum
180
Gross Counts
160
140
U-238
U-238 & Am-241
120
100
80
60
40
20
0
0
100
200
300
400
500
600
700
Channel Number
800
900
1000
Sequential Elution of 241Am, 239Pu and
233U from TRU ScintEx Resin
500
241
Am
239
Pu
233
U
Sample Load in 2-M HNO3
4-M HCl
4-M HCl + 0.02-M TiCl3
2-M HCl
0.1-M Ammonium Bioxalate
400
350
300
250
200
150
On-Line Counting
100
30
50
241
Am,
0
0
2000
4000
6000
Time (s)
Off-Line Counting
8000
10000
Gross Count Rate (cps)
Net Count Rate (cps)
450
239
Pu,
233
U
25
20
239
233
Pu,
U
15
233
U
10
5
0
0
2000
4000
6000
Time (s)
8000
10000
Conclusions
• Extractive scintillator media can be realized a number of ways
• Extractive scintillator media can be selective to analyte of
interest
– demonstrated with technetium-selective, strontium-selective and actinideselective extractant
• Loading, retention, and elution similar to non-scintillating resin
• Quantification has been demonstrated on-line and off-line
• Limited spectroscopy appears to be available with the actinideselective ScintEx resin
• Absolute detection efficiency ranges from ~40% for 90Sr to near
100% for actinide- selective ScintEx resin
Acknowledgments
• James Harvey, Eichrom Industries
Jonathan Duffey, formerly from Eichrom
• From Clemson University:
Robert Fjeld, Alena Paulenova (on leave from Comenius´
University, Slovak Republic), James Roane
• John Leyba, WSRTC
• NSF SBIR Phase I contract # NSF/SBIR-9760934
• South Carolina University Education and Research Foundation
TOA #KC86372-O.
• DOE Environmental Management and Science Program, Project
#70179