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Anomalous Behavior of TEVA Resin Prepacked Columns : A Technical Update

Anomalous Behavior of TEVA Resin Prepacked Columns : A Technical Update. Anil Thakkar November 1st 2004 Cincinnati, OH. Previously Discussed TEVA Issue: Th Elution on TEVA. Customers reported 0%-10% elution of Th-229 tracer with their recent prepacked TEVA columns

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Anomalous Behavior of TEVA Resin Prepacked Columns : A Technical Update

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  1. Anomalous Behavior of TEVA Resin PrepackedColumns: A Technical Update AnilThakkar November 1st 2004 Cincinnati, OH

  2. Previously Discussed TEVA Issue:Th Elution on TEVA • Customers reported 0%-10% elution of Th-229 tracer with their recent prepacked TEVA columns • Th-229 remained on the resin and did not elute • Prepacked TEVA columns used by customers evaluated • Evaluated various amberchrom & aliquot lots used to manufacture TEVA resin • Testing prepacked ‘S’ grade TEVA resin cartridges

  3. Th Uptake on TEVA Resin Eichrom Procedure ACW08 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 Th with 9M HCl & 6M HCl 5) Evaporate Th fraction and convert to dilute HCl solution 6) Prepare samples for alpha spec counting

  4. % Th-229 Yields with Prepacked Columns and Cartridges

  5. Ongoing Evaluations…Since June 2004 • Production mishaps……..? • Aliquot lots………..........?? • Amberchrom bead size…??? • Shelf life………………...???? • Plastic columns……........????? • Top & bottom frits….......??????

  6. Ongoing Product Improvement…Leads to Some Clues • Eichrom investigates on the improvement of “cartridge” bodies • New frit material also gets evaluated • Some new frit material from the supplier indicates poor Th yields • A suspicion grows on the frit material used in the TEVA columns

  7. Column Frit Evaluation • Investigate ‘top’ and ‘bottom’ frit material used in the columns and cartridges • Use of glass wool plug instead of frit to understand the problem • Several tests performed to isolate the frit material used in the columns

  8. Four Tests Performed • Test #1: TE4A column with glass wool plug (resin removed from TE4A prepacked column) • Test #2: TE4A bulk resin with glass wool plug • Test #3: TE4A bulk resin with cartridge frit • Test #4: TE4A bulk resin with current column frit

  9. Test Results: % Th-229 Yields *Same lot of bulk TEVA Resin used in prepacked column

  10. Current Column Frit material is the Culprit……But Why ?? • Contact frit supplier to educate ourselves on the manufacturing process of the frits • Supplier informs about the use of ‘surfactant’ on the frit material

  11. Another Frit Material Source...More Tests • Seek another frit material for comparison purposes • New frit material supplied ‘without’ surfactant (hydrophobic material) • Th uptake tested: • With the current frits with surfactant: Hydrophilic • New supplier frits without surfactant: Hydrophobic

  12. Test Results: % Th-229 Yields *Same lot of bulk TEVA Resin used in prepacked column

  13. Frit Material Mystery Slowly Unfolds! • Column Frits provided in 3 types • Hydrophobic frits (with no surfactant) do not impact Th elution • Certain hydrophilic frits (with surfactant) do impact Th elution • Certain hydrophilic frits (with surfactant) do not impact Th elution. Historically, Eichrom frits have performed well.

  14. Recent Observations…..Continuing Investigation • Prepacked Columns with Hydrophobic frits: • Measured very slow flow rates at gravity • A mechanical pressure needed to start the flow • Inconsistent flow rates measured • Researching for a ‘hydrophilic surfactant’ which would be best suited for Th elution and optimum flow rate

  15. Conclusions • The current ‘hydrophilic’ frit material used in Eichrom’s prepacked columnsDOES impact Th elution with TEVA resin. • All the ‘hydrophobic’ frits used in the Eichrom’s prepacked cartridges perform well. • Hydrophobic frits used in cartridges don’t pose flow rate issues since cartridges are used with the vacuum box system.

  16. Options Available For Our Users • Consider TEVA cartridges with the vacuum box system • Bulk users of TEVA resin, if experiencing a problem, please contact Eichrom

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