Chromatographic Separation and Measurement of Charged-Particle Emitting Radionuclides

1
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

2
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., RadioactivityRadiochemistry Vol.
  11 1 (2000)

3
Separation and Detection Schemes

• Single scintillation crystal, e.g. CaF2Eu,
  anthracene
• Extractant coated onto inert scintillator
• Mixture of extraction resin with granular
  scintillator
• Extractant impregnated into a scintillating
  chromatographic resin (ScintEx)

4
Solid Extractive Scintillators

• Sequential Extraction Chromatography and
  Flow-cell Detection Off-line quantification
• Simultaneous Extraction Chromatography and
  Flow-cell Detection On-line quantification

5
Materials and Methods

• Mixed-ResinMixture 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)

6
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

7
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

8
Hidex Triathler
9
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

10
89Sr Pulse-Height Spectra from Triathler
11
Triathler Pulse-Height Spectra for 89Sr and 90Sr
on Sr ScintEx O
12
Schematic of On-Line Flow-Cell Detection System
Flow-cell
Manually controlled pump
Radiation Detector
Effluent
Loading Solution
Sample
Eluant
Computer
LSC
13
Flow-Cell Radiation Detection System
IN/US b-Ram Model 1
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Extractive Scintillator Flow-Cell
Extractive scintillator flow-cell was constructed
of with lt0.5 g of resin packed into 1.5 mm ID x
140 mm polytetrafluoro- ethylene 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.
15
Loading and Elution of 99Tc(VII)TEVA/BC-400
Mixed Resin
e(99Tc) 7.5
16
Loading and Elution of 99TcTEVA/BC-400
Mixed-Resin Flow-Cell 137Cs Interference Test
99Tc 5 mL 24 Bq mL-1 137Cs 1 mL 7.2 kBq
mL-1
17
Loading and Elution of 99TcABEC ScintEx Flow-Cell
18
Loading and Elution of 99TcTEVA ScintEx Flow-Cell
19
Loading and Regeneration of TEVA ScintEx
20
89Sr Loading and Elution Profile on Sr ScintEx O
e (89Sr) 65.4
21
Loading 90Sr/90Y on Sr ScintEx P
102
e (90Sr) 40
22
Multiple Loading and Elution of 89Sr on Sr
ScintEx O
Avg. Detection efficiency 60 ? 4 Avg. Loading
efficiency 101 1
65.4
58.8
57.6
59.6
23
TRU ScintEx ResinPulse Height Spectrum
24
Sequential Elution of 241Am, 239Pu and 233U from
TRU ScintEx Resin
On-Line Counting
Off-Line Counting
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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 actinide-selective
  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 actinide-selective ScintEx resin
• Absolute detection efficiency ranges from 40
  for 90Sr to near 100 for actinide- selective
  ScintEx resin

26
Acknowledgments

• James Harvey, Eichrom IndustriesJonathan Duffey,
  formerly from Eichrom
• From Clemson UniversityRobert 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