Transcript New Extraction Methods for Urine and Fecal Samples

New Extraction Methods for Urine and
Fecal Samples
Sherrod L. Maxwell
David J. Fauth
Savannah River Site
00J01587-02.ppt
Bioassay Urine Methods
• Improve chemical recoveries, improve Th-228 removal reduce acid
waste and labor costs/rework
• Replace anion exchange methods and use vacuum-enhanced
extraction chromatography
– Pu (Np when Pu-236 tracer used) on TEVA resin
– Pu, Np, U, Am, Sr
• Single two cartridge TEVA/TRU column plus SR resin
• No iron in urine allows single stacked TEVA+TRU column
• Pu, Np on TEVA; U, Am on TRU cartridge in stacked column
• Sr collected, evaporated, redissolved, separated on SR resin
column
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Pu, Np/Am, U, Sr on TEVA/TRU Resin
(Urine)
1) Adjust to 2.5MHN03 - 1M Al(NO3)3
2) 0.05M sulfamic acid + 0.2M ascorbic acid
3) 0.4 to 0.5M sodium nitrite
Rinse
15mL 3MHN03
Th Removal
3mL 9MHCI/30mL
8MHCI
Pu Elution
30mL
0.10MHC1 - 0.05MHF - 0.1M NH4l
2mL TEVA Resin
(50-100 um)
Remove TRU cartridge:
1) Elute Am with
12mL 4M HCI
2) Elute U with
20mL 0.1M ammonium
bioxalate
2.0mL TRU-Resin
(50-100 um)
4mls 0.02M H2SO4 + 3mls 16M HN03
Evaporate
2nd TEVA
Column
Collect, evaporate, dissolve in 8M HNO3
SRS Resin
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Pu on TEVA Resin (Urine or Fecal)
(2nd Column to Remove all Th-228)
• Redissolve in 7.5mL 3M HN03 + 1mL 2.5M Al(NO3)3
• Add 0.5mL 1.5M ferrous sulfate + 1mL 1.5M ascorbic acid
• Add 1mL 3.M sodium nitrite
• Add 1mL 16M nitric acid
Rinse
10mL 3MHN03
Th Removal
2mL 9MHCI/8mL
8MHCI
Pu Elution
15mL
0.10MHC1 - 0.05MHF - 0.1M NH4l
1mL TEVA Resin
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TEVA Pu Tracer Recoveries
• 500 mL urine sample/ Pu-242 tracer = 1.25 dpm/One TEVA
Column Fe+AA/+NO2
%Recovery
(CeF3 microprecipitation)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
12)
110
93.3
92.6
95.2
101.5
99.3
97.7
115.4
107.9
106.8
101.6
102.6
Avg. = 102.0%
% Recovery
(Electroplating*)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
11)
84.4
72.4
69.3
69.6
79.8
84.5
79.1
85.5
84.8
77.0
82.5
Avg. = 79.0
*Add 4 mL 0.02M H2SO4 to enhance F removal during solution cleanup for plating
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TEVA- Np-237, Pu-236 Recoveries
• 500 mL urine sample/Np-237 spike = 1.40 dpm/Pu-236 = 0.425 dpm
• SA+AA/+NO2/Single TEVA column (CeF3 microprecipitation)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
% Pu-236
Recovery
% Np-237
Recovery
94.0
92.5
101
100
111
91.0
91.9
105
109
88.9
***
***
***
***
***
88.1
86.7
102.9
102
94.2
Avg. = 98.4%
Avg. = 94.8%
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TRU Resin-Am Tracer Recoveries
• 500 mL urine sample/Am-243 tracer = 1.55 dpm/TRU cartridge
after TEVA
• SA+AA/+NO2 /load TEVA and TRU at same time/remove TRU
cart./elute Am
% Am-243 Recovery (Electroplating*)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
93.2
92.1
107.4
70.3
102.4
103.0
100.2
103.3
102.6
94.7
Avg. = 96.9%
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TRU Resin-U Tracer Recoveries
• 500 mL urine sample/U-232 tracer = 0.554 dpm/TRU cartridge
after TEVA
• SA+AA/+NO2 /load TEVA and TRU at same time/remove TRU
cart./elute U
% U-232 Recovery (Electroplating*)
1)
2)
3)
4)
5)
6)
7)
8)
9)
10)
97.9
74.1
85.6
102.9
90.6
83.1
57.7
81.0
80.4
93.3
Avg. = 84.7%
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Accuracy on Spiked Urine Samples
Pu-238
Pu-239
Am-241
Sr-90
Levels
0.145-4.95
dpm/L
0.022-3.62
dpm/L
0.55-3.5 dpm/L
dpm/L
5.4-188
picoCi/L
Number Samples
N=12
N=12
N=7
N=6
Bias
-14.7%
+12.4%
-3.4%
-4.8%
Blanks
0.016 (N=8)
0.012 (N=8)
0.007 (N=23)
-0.05 (N=4)
DOELAP criteria (Bias: -25% to +50%)
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Accuracy on Spiked Urine Samples
U-234
U-238
Levels
0.197-2.04
dpm/L
0.147-3.02
dpm/L
Number Samples
N=4
N=4
Average Bias
+7.8%
+1.5%
Blanks
0.008 (N=12)
0.012 (N=10)
U-235
-0.001 (N=12)
DOELAP criteria (Bias: -25% to +50%)
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Need for Improved Fecal Analysis
for Pu and Am at SRS
• Background
– SRS incident in FB-Line
– Need for improved fecal analysis
• Complete dissolution of any plutonium oxide present
• Effective Th-228 removal
– Problems with microwave vessels
• Corrected pressure release valve problems
• Completed FB-Line incident samples
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New Approach
• Old method:
– Residual undissolved solids in final nitric acid solution
– Solids contained some activity
• New approach:
–
–
–
–
–
–
Continue to use HNO3-HF dissolution/multiple digestion
Apply diphonix resin technology
Used successfully for large soil samples
Allows loading from HCl-HF solutions
Digest Diphonix using SRS microwave method
Apply Eichrom sequential column method
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Method Details
• Microwave digestion of Diphonix resin
– Microwave to 190C for 15 minutes in 10 mL 16M HNO3
– Change disk & microwave to 200C for 20 minutes in 10 mL 16M
HNO3
– Change disk & microwave to 215C for 25 minutes in 10 mL 16M
HNO3
– Add 3.5 mL 30wt% H2O2 and microwave to 21OC for 10 minutes in
10 ml 16M HNO3
• Final wet ashing of resin
– Ash with 30wt% H2O2 four times
– Ash with HNO3 + H2O2 one time, or until does not get any whiter
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Method Details
• Preparation for Pu, Am column separation
– Dissolve in 6 mLs of 5M to 6M HNO3
– Add 6 mLs 2 to 2.5M aluminum nitrate
– Solution ready for TEVA + TRU resin column extraction
• Preparation for Pu, Am column separation
– Valence adjustment for Pu
1) Add 1 mL 1.5M ferrous sulfate + 1 mL 1.5M ascorbic
acid, wait 3 min.
2) Add 1 mL 3.5M sodium nitrite
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Method Details
• Separate Pu using TEVA column
– Th removal 9M HCl+8M HCl
– Use 2nd 1 mL TEVA column to remove all Th-228
– High retention/good clean-up
• Separate Am using TRU column
–
–
–
–
–
Collect load plus rinse from 1st TEVA column
Evaporate to dryness
Redissolve in 15 mls 3 M HNO3
Add 2 mLs 1.5M sulfamic acid + 5 mls 1.5M ascorbic acid
Load to TRU resin
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Pu, Am on TEVA + TRU Resin
(Fecal Method)
Adjust to 2.5MHN03 -1M Al(NO3)3
1) 0.1M ferrous sulfate
2) 0.25M sodium nitrite
Rinse
15 to 20mL 3MHNO3
Th Removal
3mL 9MHCI/30mL
8MHCI
Pu Elution
30mL
0.10MHC1 - 0.05MHF - 0.1M NH4l
2mL TEVA Resin
(50-100 um)
4mls 0.02 H2S04/3mLs 16MHN03
- evaporate
- redissolve in 3M HNO3
- add sulfamic acid + ascorbic acid
Rinse
1) 5mL
2.5M HNO3-0.1M
ascorbic acid
2) 5mL 3M HNO3
0.1M NaNO2
3) 10mL 3M HNO3
evaporate
ash H2O2
1mL
TEVA column to ensure
complete Th-288 removal
Am Elution
3mL 9MHCI/15mL -4M HCI
2ml TRU resin
(50-100 um)
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Pu on TEVA Resin (Urine or Fecal)
(2nd Column to Remove all Th-228)
• Redissolve in 7.5mL 3M HN03 + 1mL 2.5M Al(NO3)3
• Add 0.5mL 1.5M ferrous sulfate + 1mL 1.5M ascorbic acid
• Add 1mL 3.M sodium nitrite
• Add 1mL 16M nitric acid
Rinse
10mL 3MHN03
Th Removal
2mL 9MHCI/8mL
8MHCI
Pu Elution
15mL
0.10MHC1 - 0.05MHF - 0.1M NH4l
1mL TEVA Resin
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TEVA+TRU Pu/Am Tracer Recoveries
Fecal samples: 1.5-4 grams ash/Pu-242 spike = 1.26 dpm
TEVA column+ 2nd 1 mL TEVA column
%Pu-242 Recovery
Fecal blank 1A
Fecal blank 1B
Fecal blank 2
Fecal blank 3 A
Fecal blank 3 B
Fecal blank 4
Avg.
Column Reagent
blank
Column Reagent
blank
Avg.
%Am-243 Recovery
75.3
68.5
72.1
75.6
79.3
78.4
74.9
91.5
103.1
81.5
89.2
95.8
100.8
93.7
74.4
90.8
82.8
78.6
89.8
90.3
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Method Validation
• Analysis of multiple sample blanks
– Complete dissolution
– High tracer recovery
– Good Th-228 removal
• Analysis of artificial fecal sample spiked with Pu oxide from
RESL-Idaho
– Test plan to validate versus known Pu levels
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Assay of of DOE-RESL Fecal Standards
Pu-239
(picocuries)
DOE-RESL values
SR-194 #1
SR-194 #2
2.18
1.860
1.841
Avg.
1.850
SR-234 #1
SR-234 #2
2.062
2.139
Avg.
2.101
% Bias
Am-241
(picocuries)
%Bias
2.76
2.405
2.608
-15.1%
2.507
-9.2%
2.488
2.335
-1.4%
2.411
-10.7%
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Plutonium Results on Leached
EML QAP Soil Samples
Smp. Wt.
Pu-242 Tracer
Recovery
Pu-238
(dpm/g)
Pu-239
(dpm/g)
9403 EML Value
--------
0.672
0.216
9.957g
90%
0.664
0.200
10.100g
80%
0.663
0.223
14.980g
97%
0.632
0.211
Avg.
89%
0.653 (-2.8%)
0.211 (-2.4%)
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Pu Results on Fused EML QAP Soil Samples
Smp. Wt.
Pu-242 Tracer
Recovery
Pu-238
(dpm/g)
Pu-239
(dpm/g)
9609 EML Value
--------
0.068
1.31
10.00g
73%
0.080
1.47
10.00g
82%
0.047
1.43
10.00g
85%
0.053
1.41
10.00g
80%
0.063
1.39
Avg.
80%
0.061 (-10%)
1.42 (+11%)
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Am Results on Fused EML QAP Soil Samples
Smp. Wt.
Am-243 Tracer
Recovery
Am-241
(dpm/g)
9609 EML Value
--------
0.81
10.00g
84%
0.94
10.00g
87%
0.83
10.00g
73%
0.95
Avg.
80%
0.90 (+11%)
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Summary
• Urine
– Pu, Np and Am, U on two cartridge TEVA-TRU column with Sr-90
on SR resin after evaporation
– High recovery/good Th-228 removal
– Rapid column methods for urine will result in significant time/cost
savings/waste reduction
• Fecal
– New fecal method dissolves Pu oxide using HNO3 -HF
– Diphonix method has improved fecal analysis at SRS
• total dissolution
• remove Pu, Am from HCl-HF sample solutions
• excellent Th-228 removal/good results on DOE-RESL samples
00J01587-02.ppt