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