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Updates from Eichrom’s Tech Support Lab

Updates from Eichrom’s Tech Support Lab. Anil Thakkar May 4 th 2004 Charleston, SC. Two Topics. TEVA Resin: Th elution issues DGA Resin: Am Uptake & Iron. Issues: Th Elution on TEVA. Few customers have reported 0%-10% elution of Th-229 tracer with their recent prepacked TEVA columns

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Updates from Eichrom’s Tech Support Lab

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  1. Updates from Eichrom’s Tech Support Lab AnilThakkar May 4th 2004 Charleston, SC

  2. Two Topics • TEVA Resin: Th elution issues • DGA Resin: Am Uptake & Iron

  3. Issues: Th Elution on TEVA • Few customers have reported 0%-10% elution of Th-229 tracer with their recent prepacked TEVA columns • Customer reported Th remained on the resin and did not elute • Prepacked TEVA columns needed to be evaluated were lot # TE3A, TE3B & TE3F

  4. Trouble Shooting the Problem for Th • Initial Tests • Testing prepacked ‘A’ grade TEVA resin columns from year 2002 and 2003 • Testing prepacked ‘S’ grade TEVA resin cartridges • Test the current TEVA resin in inventory

  5. Th Uptake on TEVA Resin Eichrom Procedure ACW08 (Th & Np) 1) Load in 3M HNO3/1M Al(NO3)3. Ferrous sulfamate added to reduce Np and Pu 2) Rinse with 2.5M HNO3/0.1M ferrous sulfamate 3) Rinse with 2.5M HNO3 4) Elute of Th with 9M HCl & 6M HCl 5) Evaporate Th fraction and convert to dilute HCl solution 6) Elute Np fraction with 10 mL of 0.02M HNO3/0.02M HF 6) Prepare samples for alpha spec counting

  6. TEVA Resin Package Types • “Overnight” slurry packed Columns (Eichrom prepacked columns) - slurry in 0.1M HNO3 and soak overnight • “Fresh” Packed Bulk - Usually slurried in DI prior to use by the analyst • Cartridges - Prepacked, dry packed

  7. % Th-229 Yields with Prepacked TEVA Resin

  8. % Th-229 Yields Comparison: “Overnight” Slurry & “Fresh” Packed Columns *Same lot of bulk TEVA Resin used in prepacked column

  9. Resin Package Comparison: Th-229 Yields

  10. New Ideas… More Test… • Possible correlation between Th-229 yields in the presence of Th-232 • Test samples spiked with Th-229 & Th-232 using prepacked columns

  11. Th-229 Yields Improved !

  12. Work in Progress • Dr. Phil Horwitz’s Hypothesis: • Formation of ‘solid’ (viscous) phase with certain lots of Aliquat-336 which inhibits the diffusion and elution on Th • Currently evaluating the ‘impurities’ of Aliquat-336 used in different lots of TEVA resin

  13. DGA Resin: New Extraction Chromatographic Resin Diglycolamide (DGA) Resin: Two Types 1) Tetraalkyl diglycolamide (NORMAL) N,N,N’,N’-tetra-n-alkyl-3-oxopentanediamide (DGA Resin, Normal) 2) Tetra (branched-alkyl) diglycolamide (BRANCHED) N,N,N’,N’-tetra-(branched-alkyl)-3-oxopentanediamide (DGA Resin, Branched)

  14. DGA Resin, Branched Preliminary test data & a proposed method for the separation of actinides using TEVA Resin and DGA Resin, Branched

  15. Column bed volume = 0.5 mL, flow rate = 0.5 mL/minute for load and 0.25 mL/minute for wash and strip

  16. Elution Behavior of Selected Cations on DGA Resin, Normal* *Bed volume = 0.5 mL; Flow rate = 0.1 mL/minute for load, rinse, and strip

  17. Effect of Fe on Am Yields * Iron added as ferrous sulfamate

  18. Effect of Varying Amounts of Fe on %Am Yields *Iron added as ferric nitrate

  19. Proposed Method: Th, Pu, Np, Am & U on TEVA/DGA Resin, Branched 1) Load in 3M HNO3 - 1M Al(NO3)3 2) Add Ferrous Sulfamate 3) Add Na2NO2 a) Th elution with 20 mL of 9M HCl & 5 mL of 6M HCl 2 mL TEVA Resin Cartridge (50-100 µ) b) Pu/Np elution with 25mL 0.05M/ HNO3/0.05M HF/0.02M TiCl3 2 mL DGA Resin, Branched Cartridge (50-100 µ) c) Elute U with 25mL 0.5M HNO3 d) Elute Am with 15mL 1M HCl

  20. Comments/Summary • Any form of Fe has no impact on the retention of Am on DGA Resin • Use of DGA Resin would be a good choice to overcome Fe issues especially in soil samples • DGA Resin in tandem with TEVA Resin could be used to carry out Th, Np, Pu, Am & U analysis • Future work • Performance comparison of DGA Resins: Branched Vs Normal • Soil samples especially high in iron content & other interferences

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