Presentation on theme: "Anomalous Behavior of TEVA Resin Prepacked Columns: A Technical Update Anil Thakkar November 1st 2004 Cincinnati, OH."— Presentation transcript:
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 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
Th Uptake on TEVA Resin Eichrom Procedure ACW08 1) Load in 3M HNO 3 /1M Al(NO 3 ) 3. Ferrous sulfamate added to reduce Np and Pu 2) Rinse with 2.5M HNO 3 /0.1M ferrous sulfamate 3) Rinse with 2.5M HNO 3 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
% Th-229 Yields with Prepacked Columns and Cartridges Prepacked TEVA Column Lot # Th Yields Prepacked Cartridge Lot # Th Yields TE3A2 + 1TESR3I TE3E9 + 1TESR3K TE3F6 + 1____ TE4A0____ 0% - 10%78% -96%
Ongoing Evaluations…Since June 2004 Production mishaps……..? Aliquot lots……… ?? Amberchrom bead size…??? Shelf life………………...???? Plastic columns…… ????? Top & bottom frits… ??????
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
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
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
Test Results: % Th-229 Yields Test #Plugs types% Yields Test #1Column resin* with glass wool Test #2Bulk resin* with glass wool Test #3Bulk resin* with Cartridge frit Test #4Bulk resin* with current column frit *Same lot of bulk TEVA Resin used in prepacked column
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
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
Test Results: % Th-229 Yields Test #Frit type% Yields Test #4 Bulk resin* with hydrophilic frit Test # 5 Bulk resin* with hydrophobic frit *Same lot of bulk TEVA Resin used in prepacked column
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.
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
Conclusions The current hydrophilic frit material used in Eichroms prepacked columns DOES impact Th elution with TEVA resin. All the hydrophobic frits used in the Eichroms prepacked cartridges perform well. Hydrophobic frits used in cartridges dont pose flow rate issues since cartridges are used with the vacuum box system.
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