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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 - PowerPoint PPT Presentation
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Updates from Eichrom’s Tech Support Lab
Anil ThakkarMay 4th 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
• Customer reported Th remained on the resin and did not elute
• Prepacked TEVA columns needed to be evaluated were lot # TE3A, TE3B & TE3F
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
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
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
% Th-229 Yields with Prepacked TEVA Resin
“Overnight” Slurry Lot #
Th Yields
Prepacked Cartridge
Lot #
Th
Yields
TE3A 2 + 1 TESR3I 82 + 4
TE3E 9 + 1 TESR3K 90 + 6
TE3F 6 + 1 ____ ____
TE4A 0 ____ ____
0% - 10% 78% -96%
% Th-229 Yields Comparison: “Overnight” Slurry & “Fresh” Packed Columns
TEVA Lot #
“Overnight” Slurry
“Fresh” Packed*
TE3A 2 + 1 73 + 3
TE3E 9 + 1 75 + 3
TE3F 6 + 1 81 + 3
TE4A 0 83 + 3
*Same lot of bulk TEVA Resin used in prepacked column
Resin Package Comparison: Th-229 Yields
Resin Package Th Yields
“Overnight” slurry 0% - 10%
“Fresh” packed 70% - 86%
Cartridge 80% -100%
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
Th-229 Yields Improved !
“Overnight” slurry
Lot #
% Th-229 Yields
Th-232 added
TE4A 90 + 3 ~29 µg
TE4A 0% 0 µg
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
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)
10-2 10-1 100 101
10-1
100
101
102
103
104
105
106
50-100 m, 1 h Contact Time, 25(2) oC
Dw for Am(III) vs. [HNO
3] on DGA Resins
Dw
[HNO3]
DGA Resin, Normal DGA Resin, Branched
DGA Resin, Branched
Preliminary test data & a proposed method for the separation of actinides using TEVA Resin and DGA Resin,
Branched
10-2 10-1 100 101
10-1
100
101
102
103
104
105
106
Ce(III) Eu(III) Y(III) In(III) Am(III) U(VI)
50-100 m, 1 h Contact Time, 25(2) oC
Dw vs. HNO
3 for DGA Resin, Branched
Dw
[HNO3]
10-2 10-1 100 101
10-1
100
101
102
103
104
105
106
Ce(III) Eu(III) Y(III) In(III) Am(III) U(VI)
50-100 m, 1 h Contact Time, 25(2) oC
Dw vs. HCl for DGA Resin, Branched
Dw
[HCl]
Elution of selected cations onDGA Resin, Normal
Percent of Total
Fraction Bed Vols. Ba(II) Cd(II) Cu(II) Fe(III) Y(III) Zr(IV)
Load (4 M HNO3)
20 90 93 95 92 0 0.9
Rinse 2.0 10 7 3.5 7 0 0.2
(0.5 M HNO3) 2.0 < 0.1 < 0.1 0.4 0.6 0 0
2.0 < 0.1 0 0.4 < .1 0 0
2.0 0 0 0.4 0.4 0 0
2.0 0 0 < 0.1 0 0 0
Strip 2.0 0 0 0 0 71 5
(0.01 M HCl) 2.0 0 0 0 0 27 10
2.0 0 0 0 0 1 11
2.0 0 0 0 0 0.7 10
2.0 0 0 0 0 0.3 10
Column bed volume = 0.5 mL, flow rate = 0.5 mL/minute for load and 0.25 mL/minute for wash and strip
Elution Behavior of Selected Cations on DGA Resin, Normal*
Percent of Total
Fraction Bed Volume
Al(III) Y(III) Th(IV) U(VI)
Load (0.5 M HNO3) 2.0 66 0 0 0
Rinse 2.0 28 0 0 75
(0.1 M HNO3) 2.0 0 0 0 8.4
2.0 0 0 0 0
2.0 0 0 0 0
2.0 0 0 0 0
Strip 2.0 0 24 78 0
(0.1 M HCl) 2.0 0 76 16 0
2.0 0 0 0 0
2.0 0 0 0 0
2.0 0 0 0 0
*Bed volume = 0.5 mL; Flow rate = 0.1 mL/minute for load, rinse, and strip
Effect of Fe on Am Yields
Resin Type Iron added* Ascorbic added
% Am Yields
DGA, Branched 33 mg None 101 + 1
TRU 33 mg None 78 + 14
TRU 33 mg ~200 mg 93 + 4
* Iron added as ferrous sulfamate
Effect of Varying Amounts of Fe on %Am Yields
Fe added* TRU with ascorbic
TRU without ascorbic
DGA, Branched without ascorbic
25 mg 24 + 1 21 + 1 102 + 7
50 mg 15 + 1 14 + 1 100 + 7
100 mg 12 + 1 13 + 1 103 + 7
*Iron added as ferric nitrate
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
c) Elute U with 25mL 0.5M HNO3
2 mL TEVA Resin Cartridge(50-100 µ)
2 mL DGA Resin, Branched Cartridge(50-100 µ)
a) Th elution with 20 mL of 9M HCl & 5 mL of 6M HCl
b) Pu/Np elution with 25mL 0.05M/ HNO3/0.05M HF/0.02M TiCl3
d) Elute Am with 15mL 1M HCl
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