Rapid Determination of Actinides
in Limestone and Marble

AN-1603-10
Summary of Method Actinides are separated and concentrated from 1.5 gram samples of limestone or marble.
Samples are finely ground and fused in a zirconium crucible for 15 minutes at 600°C with 15 grams of sodiumhydroxide. The fusion cake is dissolved in water, and actinides are concentrated and separated from the matrix using acalcium phosphate precipitate enhanced with iron. A secondary precipitation with calcium fluoride removes additionalmatrix (including silicates) and decreases the volume of precipitate. The calcium fluoride precipitate is dissolved withnitric acid-boric acid-aluminum nitrate to form the load solution. Analytes are separated from remaining matrix andpotentially interfering radionuclides using stacked TEVA, TRU, and DGA Resin cartridges. Actinides are measured byalpha spectrometry after CeF3 microprecipitation onto Resolve(R) Filters. Simultaneous separation of radiostrontium canbe achieved by using the separation method in AN-1604.
Reagents
Sr Resin, 2mL Cartridges (Eichrom SR-R50-S)*
Sr Resin, 1mL Cartridges (Eichrom SR1ML-R50-S)*
TRU Resin, 2mL Cartridges (Eichrom TR-R50-S)
TEVA Resin, 2mL Cartridges (Eichrom TE-R50-S)
DGA Resin, 2mL Cartridges (Eichrom DN-R50-S)
Strontium*, Lanthanum and Cerium Carriers (10mg/mL)
Iron Carrier (50mg/mL Fe, as ferric nitrate)*Only needed if
242Pu (or 236Pu if Np is measured) tracer
Sr is measured.
243Am and 232U tracers
10% TiCl3
90Sr standard*
HF(49%)
30% H2O2
Nitric Acid (70%)
Hydrochloric Acid (37%)
Deionized Water
1.25M Ca(NO3)2
3.2M (NH4)2HPO4
2M Al(NO3)3
Oxalic acid
Boric acid
Sodium Hydroxide
Sulfamic acid
Ascorbic acid
NaNO2

Equipment

Figure 1. Sample Preparation
1.5g finely ground sample in zirconium crucible
Add 4mg Sr carrier* and Pu/U/Am tracers.
Heat samples to dryness on hot plate.
Add 15g of NaOH.
Cover crucibles with zirconium lid and placein muffle furnace at 600°C for 15-20 minutes.
Carefully remove samples from furnaceand cool in fume hood.
Add 25-50mL of water and heat on hotplate to dissolve fusion cake.
Transfer to a 250mL centrifuge tube. Rinse
crucible with water. Dilute to 160mL with water.

Vacuum Box (Eichrom AR-24-BOX or AR-12-BOX)
Cartridge Reservoir, 20mL (Eichrom AR-200-RV20)
Add 20mL conc. HCl (omit if Sr meas.), 125mg Fe, 5mg
Inner Support Tubes-PE (Eichrom AR-1000-TUBE-PE)
La. Mix. Add 5mL 3.2M (NH4)2HPO4 (8.5mL if Sr meas.).
Yellow Outer Tips (Eichrom AR-1000-OT)
Mix. Centrifuge 10min. Decant supernate.
Resolve Filters in Funnel (Eichrom RF-DF25-25PP01)
Dissolve precipitate in 80mL 1.5M HCl. Dilute to 170mL.
50mL and 250mL Centrifuge Tubes
Add 4mL 10% TiCl3 and 15mL 49%HF. Mix. Cool in ice
Cupped Stainless Steel Planchets (~5mL volume)*
bath 10min. Centrifuge 10min. Decant supernate.
250mL Zirconium crucibles with zirconium lids
Alpha Spectrometry System
Stainless Steel planchets with two sided tape
Dissolve precipitate in 7mL 3M HNO3-0.25M Boric acid, 7.5mL
Centrifuge
Gas Flow Proportional Counter* 7M HNO3, and 7mL 2M Al(NO3)3. Adjust valence with 1mg Fe,Muffle Furnace
Hot Plate/Heat Lamp
1.5mL 1M Ascorbic acid. Mix. Add 1mL 3.5M NaNO2.
Analytical Balance
Vacuum Pump

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.

(22) Rinse filter
funnel with 3mL
DI 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 50ug Ce to Pu and Am/Cmsamples, 100ug Ce to U samples. Mix
well. Add 1mL 49% HF. Mix well. Wait
15-20 minutes.

(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 from
DGA cartridge.

(18) Set up Resolve® Filter Funnel onvacuum box.
(19) Wet filter with 3mL 80% ethanol
followed by 3mL DI water.
(20) Filter sample.
(21) Rinse sample tube with 5mL DI
water and add to filter.

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

*Radiostrontium may also be measured by adding a 2mL + 1mL Sr Resin cartridge below DGA and following separation
scheme in Eichrom Application note AN-1604-10.
**Adding 50uL 30% H2O2 to the tube rinse can improve Uranium recoveries and decontamination in Pu(Np) fractions.
Method Performance
Sample1.5g limestone
1.5g limestone

replicates66

1.5g limestone6238

1.5g limestone6237

1.5 g marble

4239/240

1.5 g marble

4241

1.5 g marble

4244

7238

1.5 g marble

analyte239/240Pu
239/240
Pu

tracer
242
Pu
236
Pu

% tracerrecovery
100 + 593 + 6mBq/greference
29.4
23.0

mBq/g
measured
30 + 224 + 1% bias
+5+5Pu236Pu

93 + 628.8

29 + 2+5Np236

Pu

93 + 637.0

39 + 3+7Pu

242

Pu

96 + 329.4

30 + 2+6Am

243

Am89 + 429.1

29 + 1+3Cm

243

Am

89 + 434.8

35 + 3+693 + 650.2

48 + 1+4U

232

UReferences1) Maxwell, Culligan, Hutchinson, Utsey, Sudowe, McAlister, “Rapid Method to Determine Actinides and Sr-89/90 in
Limestone and Marble Samples,” J. Radioanal. Nucl. Chem. accepted (2016). DOI 10.1007/s10967‐016‐4783‐81955 University Lane Lisle, IL 60532, USA+1 (630)963-0320

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