AN-1416

Rapid Determination ofActinides and 210Po in Water

Summary of Method A method for the measurement of 210Po and actinides in terrestrial water samples is
described, offering significant advantages in detection limit, processing time, and resistance to chemical andradiochemical interferences over standard methods where polonium is determined following spontaneous deposition
onto metal planchets. 210Po and actinides are concentrated from up to 1L samples of ground water or 2L samples ofdrinking water using a calcium phosphate precipitate. 210Po and actinides are then separated from matrix ions andpotentially interfering radionuclides using stacked 2mL cartridge of Eichrom TRU and DGA Resin. 210Po and actinides
are measured using alpha spectrometry following bismuth phosphate and cerium fluoride microprecipitation,
respectively, onto Eichrom Resolve® Filters. Tracer recoveries averaged 81.5 + 2.6% for 209Po, 93.4 + 6.8% for 242Pu,
100.2 + 6.9% for 243Am and 96.6 + 2.5 for 232U. Measured values typically agreed to within 3-5% of reference values. A
single operator can prepare batches of 12-24 samples for alpha counting in 4-6 hours. Alpha spectrometry count times
will vary depending on desired detection limit and data quality objectives.
Reagents
TRU Resin, 2mL Cartridges (Eichrom TR-R50-S)
DGA Resin, 2mL Cartridges (Eichrom DN-R50-S)
Ammonium Hydroxide (Listed as 28% NH3 or 56% NH4OH)
209Po, 232U, 243Am, 242Pu tracers
Bi and Ce carriers (1mg/mL)
Nitric Acid (70%)
Hydrochloric Acid (37%)
Hydrofluoric Acid (49%)
Hydrogen Peroxide (30%)
Deionized Water
3.2M (NH4)2HPO4
1.25M Ca(NO3)2
2M Al(NO3)3
10% (w:w) TiCl3
Denatured Ethanol
Oxalic acid/Ammonium Oxalate

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 Tubes
Centrifuge
Alpha Spectrometry System
Analytical Balance
Vacuum Pump
Heat Lamp
Stainless steel planchets (1.25 inch) with adhesive tapeFigure 1. Sample Preparation
1-2L Water Sample.
Add tracers.
Add 1-2mL of 30% H2O2.
Add 1mL 1.25M Ca(NO3)3 and3mL 3.2M (NH4)2HPO4. Mix Well.
Adjust to pH 9 with NH4OH. Mix.
Allow precipitate to settle.
Decant supernate to <200mL.
Transfer remaining supernate and precipitate
to 250mL centrifuge tubes. Centrifuge
3500rpm for 10 minutes. Decant supernate.
Dissolve precipitate in 10mL 8M HNO3,3mL 2M Al(NO3)3, and 100uL 30% H2O2.
Load Solution for resin separation.

Figure 2. TRU/DGA Separation and Source Preparation(1) Precondition TRU/DGA
Resin with 5mL 8M HNO3.
TRU(2) Load samples.
(3) Rinse sample tube with
5mL 8M HNO3, and add
tube rinse to TRU/DGA.*
DGA(4) Rinse TRU/DGA with:-10mL 10M HNO3-15mL 4M HCl.
(5) Separate TRU and DGA.
(6) Strip Pu from TRU with 12mL
3M HCl-0.02M TiCl3. Add 0.5mL
30% H2O2.
(7) Rinse TRU with:-5mL 8M HNO3-20mL 1.5M HCl-0.15M HF.
(8) Strip U from TRU with 15mL 0.1M
ammonium bioxalate. Add 0.5mL
TiCl3 for CeF3 ppt.
(9) Rinse DGA:-5mL 3M HCl-12mL 3M HNO3-0.25M HF-5mL 4M HCl(10) Strip Am/Cm from DGA with 12mL
0.25M HCl. Add 0.2mL 30% H2O2.

(18) Rinse filter funnel
with 2mL 100% ethanol.

(11) Rinse DGA with 6M 8M HNO3.
(19) Draw vacuum until filter is dry.
(12) Strip Po from DGA with 15mL(20) Remove filter from funnel
0.05M HNO3. Add 0.1mL 30% H2O2.
assembly and mount filter on(13) Po samples: Add 125ug Bi carrier,stainless steel planchet with
0.75mL 3.2M (NH4)2HPO4. Mix well.
adhesive tape.
Add 0.2mL 56% NH4OH. Mix well.
Wait 15-20 minutes.
Actinide samples: Add 50-100ug Cecarrier. Mix well. Add 1mL 49% HF.
Mix well. Wait 15-20 minutes.
(14) Set up Resolve® Filter Funnel on
vacuum box. Wet filter with 3mL
80% ethanol and
3mL DI H2O.
(15) Filter sample.
(16) Rinse sample
tube with 5mL
DI water andadd to filter.

(21) Dry filter under heat lamp for
3-5 minutes.
(22) Measure Po and actinides byalpha spectrometry.

(17) Rinse filter funnel
with 3mL DI water.

*Adding 50uL 30% H2O2 to the tube rinse can improve U recoveries and decontamination in Pu(Np) fractions.

AnalyteMethod Performance% Recovery
Tracerof tracer

210

Po and Actinides in Water
Analyte (mBq/L) Analyte (mBq/L)
Reference
Measured% Bias21020981.5 + 2.6

1584

1660 + 3

4.8

238

Pu

242

Pu

93.4 + 6.8

370

381 + 4

3.0

241

Am

243

Am

100.2 + 6.9

244

Cm

243

370
328

381 + 3328 + 43.00.1

238

232

655

627 + 4-4.4PoPoAm

100.2 + 6.9
96.6 + 2.5UU
200mL ground water samples, 6 replicates
8-16 hour count time

References
1) Sherrod L. Maxwell, Brian K. Culligan, Jay B. Hutchinson, Robin C. Utsey, Daniel R. McAlister, “Rapid determinationof 210Po in water samples,” J. Radioanal. Nucl. Chem., 298(3), 1977-1989 (2014).
1955 University Lane Lisle, IL 60532, USA+1 (630)963-0320

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