New Extraction Methods for Urine and Fecal Samples

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New Extraction Methods for Urine and Fecal Samples

• Sherrod L. Maxwell
• David J. Fauth
• Savannah River Site

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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 TEVATRU
  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
Th Removal 3mL 9MHCI/30mL 8MHCI
Rinse 15mL 3MHN03
Pu Elution 30mL 0.10MHC1 - 0.05MHF - 0.1M NH4l
4mls 0.02M H2SO4 3mls 16M HN03
2mL TEVA Resin (50-100 um)
Evaporate
2nd TEVA Column
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)
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

Th Removal 2mL 9MHCI/8mL 8MHCI
Rinse 10mL 3MHN03
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 FeAA/NO2

Recovery Recovery (CeF3 microprecipitation)
(Electroplating)
1) 110 1) 84.4 2) 93.3 2) 72.4 3) 92.6 3)
69.3 4) 95.2 4) 69.6 5) 101.5 5)
79.8 6) 99.3 6) 84.5 7) 97.7 7) 79.1 8)
115.4 8) 85.5 9) 107.9 9) 84.8 10) 106.8 10) 7
7.0 11) 101.6 11) 82.5 12) 102.6 Avg. 102.0
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
• SAAA/NO2/Single TEVA column (CeF3
  microprecipitation)

Pu-236 Np-237 Recovery Recovery
1) 94.0 2) 92.5 3) 101
4) 100 5) 111 6)
91.0 88.1 7) 91.9 86.7 8) 105
102.9 9) 109 102 10) 88.9 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
• SAAA/NO2 /load TEVA and TRU at same
  time/remove TRU cart./elute Am

Am-243 Recovery (Electroplating) 1)
93.2 2) 92.1 3) 107.4 4)
70.3 5) 102.4 6) 103.0 7) 100.2
8) 103.3 9) 102.6 10) 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
• SAAA/NO2 /load TEVA and TRU at same
  time/remove TRU cart./elute U
• U-232 Recovery (Electroplating)
• 1) 97.9
• 2) 74.1
• 3) 85.6
• 4) 102.9
• 5) 90.6
• 6) 83.1
• 7) 57.7
• 8) 81.0
• 9) 80.4
• 10) 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 0.022-3.62 0.55-3.5
dpm/L 5.4-188 dpm/L dpm/L dpm/L picoCi/L Numb
er Samples N12 N12 N7 N6 Bias -14.7 12.4 -
3.4 -4.8 Blanks 0.016 (N8) 0.012 (N8) 0.007
(N23) -0.05 (N4) DOELAP criteria (Bias -25
to 50)
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Accuracy on Spiked Urine Samples
U-234 U-238 U-235

• Levels 0.197-2.04 0.147-3.02
• dpm/L dpm/L
• Number Samples N4 N4
• Average Bias 7.8 1.5
• Blanks 0.008 (N12) 0.012 (N10) -0.001 (N12)
• 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 HCl8M 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
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 ash H2O2 1mL TEVA column
to ensure complete Th-288 removal
- evaporate - redissolve in 3M HNO3 - add
sulfamic acid ascorbic acid
Am Elution 3mL 9MHCI/15mL -4M HCI
Rinse 1) 5mL 2.5M HNO3-0.1M ascorbic
acid 2) 5mL 3M HNO3 0.1M NaNO2 3) 10mL 3M HNO3
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

Th Removal 2mL 9MHCI/8mL 8MHCI
Rinse 10mL 3MHN03
Pu Elution 15mL 0.10MHC1 - 0.05MHF - 0.1M NH4l
1mL TEVA Resin
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TEVATRU 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 Am-243 Recovery

• Fecal blank 1A 75.3 91.5
• Fecal blank 1B 68.5 103.1
• Fecal blank 2 72.1 81.5
• Fecal blank 3 A 75.6 89.2
• Fecal blank 3 B 79.3 95.8
• Fecal blank 4 78.4 100.8
• Avg. 74.9 93.7
• Column Reagent
• blank 74.4 90.8
• Column Reagent
• blank 82.8 89.8
• Avg. 78.6 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 Am-241 (picocuries) Bias
(picocuries) Bias

• DOE-RESL values 2.18 2.76
• SR-194 1 1.860 2.405
• SR-194 2 1.841 2.608
• Avg. 1.850 -15.1 2.507 -9.2
• SR-234 1 2.062 2.488
• SR-234 2 2.139 2.335
• Avg. 2.101 -1.4 2.411 -10.7

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Plutonium Results on Leached EML QAP Soil
Samples

• Smp. Wt. Pu-242 Tracer Pu-238 Pu-239 Recovery (d
  pm/g) (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 Pu-238 Pu-239
• Recovery (dpm/g) (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 Am-241
  Recovery (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