Transcript Eichrom's TEVA Disc

EIChroM
I N D U S T R I E S , I N C.
Introduction of Eichrom TEVA Disc:
Tc-99 Analysis
Anil H. Thakkar, Lawrence Jassin, Michael Fern
Eichrom Industries, Inc.
and John Sisler
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Current Eichrom Tc-99 Method
• TEVA Resin column
• Industry standard
• Flow rate limitation
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Proposition
Perform Tc-99 analysis rapidly with a new
chromatographic configuration of the
TEVA Resin
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TEVA Disc
• Glass fiber filter
• 47 mm diameter
• 0.5 g silica based TEVA Resin
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Outline of Proposed Method
• Place TEVA Disc on a filtering funnel
• Pass 1 liter of sample (at pH 2) through disc (NO
vacuum necessary)
• Rinse disc with 0.01M HNO3
• Transfer disc to LSC vial
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Method (continued)
• Add 15 mL Packard’s Ultima Gold LLT® cocktail
• Stir or shake to form a gel
• Count on liquid scintillation counter
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LSC Parameters
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Counter: Packard Tri Carb 2550 TR/AB
Beta window: 26-350 keV
tSIE: Typically 450-550
Counting efficiency 90%
Count time: 30 minutes
Detection limit: 1.77 pCi/L
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Flow rate
• Typical 33 mL/minutes
(30 minutes for 1 liter sample)
• Achievable at gravity flow
• 200 mL/minute under vacuum
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%Tc-99 Recoveries
DI Water (1 Liter)
Sample #
1
2
3
4
5
6
Average
%Tc-99 recovery
96.2%
96.7%
95.9%
99.7%
100.8%
99.3%
98.1+/-2.08
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%Tc-99 Recoveries
Simulated Hanford Ground Water (1 liter)
Sample #
1
2
3
4
5
6
Average
%Tc-99 recovery
91.3%
97.6%
94.4%
98.2%
96.9%
96.9%
95.9+/-2.59
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%Tc-99 Recoveries
Large Volume SHGW Samples
Volume
2 liter
3 liter
4 liter
5 liter
6 liter
%Tc-99
recovery
96.2%
86.8%
89.9%
85.4%
87.0%
Detection limit
pCi/L
0.89
0.59
0.44
0.35
0.30
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I N D U S T R I E S , I N C.
Field Trial: Tc-99 Analysis
Data Provided by John Sisler
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Method comparison (TBP vs. TEVA Disc)
Performance comparison
Waste reduction
Time savings
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TBP Extraction Method
• Make ~200 mL preserved ground water 6 N
H2SO4 (Requires 40 mL conc. H2SO4)
• Add 1% KMnO4
• Add TBP and shake vigorously
• Collect the TBP and centrifuge
• Mix 4 mL extract with 0.2 mL 20% SnCl2-HCl
and 12 mL Insta-Gel® cocktail
• Count via LSC for 30 minutes
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TEVA Disc Method
• Add 1% KMnO4 to ~200 mL preserved ground
water sample
• Condition TEVA Disc with 20 mL DI water
• Pass sample through disc
• Rinse with 50 mL DI water
• Transfer disc to LSC vial adding 16 mL InstaGel® cocktail and 0.2 mL SnCl2-HCl
• Count via LSC for 30 minutes
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Ground Water Analysis Data (ppm)
Sample
Cl
1
80
2
-
SO4
-2
+2
+2
+
Ca
Mg
Na
TCE
31
123
30
57
1
40
1009
257
101
22
trace
3
85
321
81
40
63
trace
4
75
17300
69
47
57
64
5
74
326
52
39
64
3
6
69
326
69
47
57
66
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Comparison
TBP vs. TEVA Disc
Sample
1
Number of
Replicates
4
TEVA
pCi/L
42434
TBP
pCi/L
42506
Relative %
Difference
0.2
2
2
43.5
41.8
+ 4.1
3
4
419.8
406
+3.4
4
1
51
48
+6.1
5
1
78
80
2.5
6
1
56
50
+11.3
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TEVA Disc Spike Recovery
Sample Activity (dpm) Activity Added
% Recovery
4
13.6
n/a
n/a
4 MS
66.87
57
93.5
5
20.9
n/a
n/a
5 MS
75.4
57
95.6
6
12.46
n/a
n/a
6 MS
66.57
57
94.9%
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Waste and Time Savings (Batch of 20)
Elapsed
Time
TEVA Two Hours
TBP
TBP
Used
none
Four Hours 100 mL
6 N LSC Cocktail
H2SO4
Waste
none
Cocktail
Dependent
5L
Mixed Waste
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Summary
• Eichrom TEVA resin disc provides fast
separation of Tc-99
• Extremely easy sample preparation steps
• Good, reproducible and consistent recoveries
achievable