Rapid Determination of Actinides
in 10g Emergency Food Samples

AN-1425
Summary of Method U, Pu, Np, Am and Cm are separated and concentrated from 10 gram food samples.
Samples are muffled at 600°C in zirconium crucibles 2 hours to destroy organic content. The residue is wet ashed with
HNO3-H2O2 and then fused with 15g NaOH at 600oC for ten minutes. The fusion cakes are dissolved in water,transferred to 250mL centrifuge tubes and precipitated sequentially with hydrous titanium oxide and lanthanum fluoride
to facilitate matrix removal. Actinides are separated on stacked 2mL cartridges of Eichrom TEVA, TRU and DGA resins.
Actinides are measured by alpha spectrometry following CeF3 microprecipitation onto Eichrom Resolve® Filters.
Chemical yields of tracers ranged from 93-98% for 236Pu, 85-93% for 243Am, and 78-89% for 232U. Measured values
typically agreed to within 10% of reference values. Sample preparation for batches of 12 samples can be completed bya single operator in <8 hours. Alpha spectrometry count times will depend on detection limit and data quality objectives.
Reagents
Figure 1. Sample Preparation
TEVA Resin, 2mL Cartridges (Eichrom TE-R50-S)
10g Food sample + tracers in zirconium crucible .
TRU Resin, 2mL Cartridges (Eichrom TR-R50-S)
DGA Resin, 2mL Cartridges (Eichrom DN-R50-S)
Muffle at 600°C for 2 hours.
Deionized Water
1.25M Ca(NO3)2
Wet ash on hotplate with 5mL 70% HNO3 and 5mL 30% H2O2.
Iron carrier (50mg/mL Fe, as ferric iron nitrate)
242Pu (or 236Pu if meas. Np), 243Am and 232U tracers
Fuse samples with 15g NaOH at 600°C for 10minutes.
Oxalic acid/Ammonium oxalate
La and Ce carriers (1mg/mL)
Dissolve fusion cake with H2O. Transfer to 250mL c-tube.
3.2M (NH4)2HPO4
2M Al(NO3)3
Add 10mL 3M HNO3 to crucible. Heat to dissolve residue.
10% (w:w) TiCl3
HNO3 (70%)
Transfer to same 25mL c-tube.
HCl (37%)
NaOH
HF (49%) or NaF
H2O2 (30%)
Denatured ethanol
Ascorbic Acid

Boric acid
NaNO2
Sulfamic Acid

Equipment
Vacuum Box (Eichrom AR-24-BOX or AR-12-BOX)
Cartridge Reservoir, 20mL (Eichrom AR-200-RV20)
Inner Support Tubes-PE (Eichrom AR-1000-TUBE-PE)
Yellow Outer Tips (Eichrom AR-1000-OT)
Resolve Filters in Funnel (Eichrom RF-DF25-25PP01)
50mL and 250mL Centrifuge TubesCentrifuge
Heat Lamp
Muffle Furnace
Hot Plate
Analytical Balance
250mL Zirconium crucibles with zirconium lids
Stainless Steel Planchets with adhesive tape
Alpha Spectrometry System
Vacuum Pump

Add 125mg Fe and 5mg La to c-tube. Dilute to 180mL.
Add 4mL 1.25M Ca(NO3)2, 5mL 3.2M (NH4)2HPO4,5mL 10% TiCl3. Mix. Cool in ice bath for 10min.
Centrifuge at 3500rpm. Decant Supernate.
Partially dissolve precipitate in 60mL 1M HCl.
Some solids will remain. Dilute to 170mL.
Add 1mg La, 1mL 1.25M Ca(NO3)3, 3mL
10% TiCl3. Mix. Add 20mL 49% HF.
Centrifuge at 3500rpm. Decant Supernate.
Dissolve precipitate in 5mL 3M HNO3-0.25M Boricacid, 7mL 70% HNO3, and 7mL 2M Al(NO3)3.
Fix valence states. Mix between each addition of: 0.5mL
1.5M sulfamic acid, 10uL 50mg/mL Fe, 1.5mL 1M
ascorbic acid, 1mL 3.5M NaNO2, 1.5mL 70% HNO3.

Figure 2. Actinide Separation on TEVA - TRU - DGA* and Source Preparation(1) Precondition stacked 2mL
TEVA, TRU, DGA cartridges
with 10mL 3M HNO3.
(2) Load sample solution.
(3) Rinse sample tube
with 5mL 3M HNO3. Addtube rinse to cartridges.
(4) Rinse cartridges with
10mL 3M HNO3.*(5) Separate TEVA, TRU,and DGA cartridges.

(12) Rinse DGA cartridge sequentially
with: -5mL 3M HCl
TEVA-3mL 1M HNO3-15mL 0.05M HNO3(13) Strip Am and Cm from DGA with
TRU 10mL 0.25M HCl.
(14) Rinse TRU cartridge with 15mL
4M HCl-0.2M HF-0.002M TiCl3 .
DGA(6) Rinse TEVA cartridge with:-10mL 3M HNO3-20mL 9M HCl-5mL 3M HNO3
(7) Strip Pu (and Np) from TEVA
cartridge with 20mL 0.1M HCl0.05MHF-0.01M TiCl3.
(8) Rinse DGA cartridge with 10mL
0.1M HNO3.
(9) Place TRU cartridge above DGA.
(10) Strip Am/Cm from TRU onto
DGA with 15mL 3M HCl .
(11) Separate TRU cartridge fromDGA cartridge.

(22) Rinse filter
funnel with 3mLDI water and 2mL
100%ethanol.
(23) Draw vacuum
until filter is dry.

(24) Remove filter fromfunnel assembly andmount filter on stainless(16) Add 0.5mL 10% TiCl3 to U samples,steel planchet with 2-sided tape.
0.5mL 30% H2O2 to Pu, and 0.2mL
30% H2O2 to Am/Cm samples.
(15) Strip U from TRU with 15mL of
0.1M ammonium bioxalate.

(17) Add 50-100ug Ce carrier to allsamples. Mix well. Add 1mL 49% HF.
Mix well. Wait 15-20 minutes.
(18) Set up Resolve® Filter Funnel onvacuum box.
(19) Wet filter with 3mL 80% ethanol
followed by 3mL DI water.

(25) Dry filter under heat lamp for
3-5 minutes.
(26) Measure actinides by alpha
spectrometry.

(20) Filter sample.
(21) Rinse sample tube with 5mL DI
water and add to filter.

*Adding 50uL 30% H2O2 to the tube rinse can improve Uranium recoveries and decontamination in Pu(Np) fractions.
Method Performance Actinides in 10 Gram Food Samples (16 hour count times)
Analyte Analyte
Analyte Analyte% Tracer (mBq/g) (mBq/g)% Tracer (mBq/g) (mBq/g)
Sample Replicates Analyte Tracer Recovery Reference Measured % Bias Sample Replicates Analyte Tracer Recovery Reference Measured % Bias
238
236
238
236
2.9
2.9 + 0.1 -0.7
Apples5
2.9
2.9 + 0.1 -0.5
Baby Food5
Pu
Pu 93.5 + 7.5
Pu
Pu 98 + 125239

52375241

55236

5239

Pu

236

98 + 12-8.1

5237

Np236-3.5

5241

243

3.7 + 0.3

4.4

5

5.6 + 0.4-1.5

5

5.9 + 0.2-0.3

5

Pu 93.5 + 7.5
236
Pu 93.5 + 7.5

3.63.7

3.4 + 0.2

243

Am 84.6 + 6.3
244
243
Cm
Am 84.6 + 6.3
238
232
U
U 78 + 10

5.1

5.0 + 0.1

3.5
5.7

234

5.9

Pu

Np

5AmU

232

U78 + 10

3.3 + 0.4

-7.9

Pu

3.6

3.6 + 0.4

-0.9

98 + 123.7

3.3 + 0.1

-11.5

Am 93.4 + 8.5
244
243
Cm
Am 93.4 + 8.5
238
232
U
U 89 + 10

5.1

4.9 + 0.3

-2.8

3.5

3.7 + 0.5

6.3

5.7

5.6 + 0.3

-1.2

234

5.9

5.5 + 0.4

-6.4

AmUPu

232

U89 + 10References1) Sherrod L. Maxwell, Brian K. Culligan, Angel Kelsy-Wall, Patrick J. Shaw, “Rapid separation of actinides and in
emergency food samples,” J. Radioanal. Nucl. Chem., 292(1), 339-347 (2011).
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