Rapid Determination of 90Sr in
10g Concrete Samples

AN-1606-10
Summary of Method 90Sr is determined by the direct separation of its daughter 90Y from 10 gram concrete
samples. Samples are finely ground and fused in a zirconium crucible for 30 minutes at 600°C with 40 grams of sodiumhydroxide. The fusion cake is dissolved in water, and strontium is concentrated and separated from the matrix using aferric hydroxide precipitate. A secondary precipitation with Y/Ca-fluoride removes additional matrix (including silicates)and decreases the volume of precipitate. The Y/Ca-fluoride precipitate is dissolved with nitric acid-boric acid-aluminum
nitrate to form the load solution. 90Y is separated from remaining matrix and potentially interfering radionuclides using
stacked 2mL TRU and DGA Resin cartridges. 90Y is measured by gas flow proportional counting following
microprecipitation onto Resolve® Filters. Chemical yields are determined by ICP-AES analysis. Batches of 12-24
samples can be prepared for analysis in less than 8 hours. This method is only suitable for aged samples, where theshorter lived 89Sr (t1/2 = 50.55 days) and fission products such as 91Y are unlikely to be present. For samples notmeeting this criterion, 89/90Sr can be determined from up to 5g
Figure 1. Sample Preparation
concrete samples, using Eichrom Application Note AN-1605.
10g finely ground sample in zirconium crucible
Reagents
DGA Resin, 2mL Cartridges (Eichrom DN-R50-S)
Add 2mg Y carrier.
TRU Resin, 2mL Cartridges (Eichrom TR-R50-S)
Heat samples to dryness on hot plate.
Yttrium Carrier (10mg/mL)
Add 40g of NaOH.
Iron Carrier (50mg/mL Fe, as ferric nitrate)
Covercrucibles
with zirconium lid and place
90Sr standard
HF(49%)
in muffle furnace at 600°C for 30 minutes.
Nitric Acid (70%)
Sodium Hydroxide
Hydrochloric Acid (37%)
Deionized Water
Carefully remove samples from furnace
1.25M Ca(NO3)2
3.2M (NH4)2HPO4
and cool in fume hood.
2M Al(NO3)3
Oxalic acid
Add 50-100mL of water and heat on
Boric acidhot plate to dissolve fusion cake.

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 with funnel (Eichrom RF-DF25-25PP01)
50mL and 500mL Centrifuge Tubes
Stainless Steel Planchets with two sided tape
250mL Zirconium crucibles with zirconium lids
Centrifuge
Gas Flow Proportional Counter
Muffle Furnace
Hot Plate/Heat Lamp
Analytical Balance
Vacuum Pump

Transfer to a 500mL centrifuge tube. Rinse
crucible with water. Dilute to 450mL with water.
Cool to room temp. Add 125mg Fe Mix.
Centrifuge 10min. Decant supernate.
Rinse precipitate with 150mL pH ~9 NaOH.
Centrifuge. Decant Supernate. Repeat.
Dissolve precipitate in 200mL 1.5M HCl. Add 50mL 0.01M
HCl and 15mL 49%HF. Mix. Cool in ice bath 10min.
Centrifuge 10min. Decant supernate.

Dissolve precipitate in 7mL 3M HNO3-0.25M Boric acid, 7mL conc.
HNO3, 7mL 8M HNO3 and 7mL 2M Al(NO3)3. Warm as needed.

Figure 2. TRU-DGA Separation and Gas Flow Proportional Counting(1) Precondition 2mL TRU* + DGA
Resin with 10mL 8M HNO3.
(2) Load sample at 1-2mL/min.
2mL(3) Rinse sample tube withTRU
5mL 8M HNO3.

(8) Add 100ug Ce carrier to samples.
(9) Mix well.
(10) Add 2mL 49% HF.
(11) Mix well.
(12) Wait 15-20 minutes.

(4) Add tube rinse TRU + DGA.
2mL
Elute 1-2 mL/min.
DGA(5) Rinse sequentially with:- 5mL 6M HNO3
- 10mL 3M HNO3
- 12mL 4M HCl(13) Set up Resolve® Filter Funnel on
vacuum box.

(6) Dispose of (1) to (5) as waste.
(7) Discard TRU Resin.

(18) Draw vacuum until filter is dry.
(19) Remove filter from funnel
assembly and mount filter on
stainless steel planchet with 2sided tape.

(14) Wet filter with 3mL 80% ethanol
followed by 3mL DI water.
(15) Filter sample.
(16) Rinse sample tube with 5mL DI
water and add to filter.

(20) Dry filter under heat lamp for
3-5 minutes.

(8) Rinse DGA sequentially with:- 10mL 8M HNO3 (Ca)- 15mL 0.1M HNO3 (U)- 25mL 3M HNO3-0.25M HF (Th)(9) Strip Y with 18mL 0.25M HCl.
(10) Dilute to 20mL with water.
(11) Take 1mL aliquot and dilute to
20mL for ICP-AES yieldmeasurement.

(17) Rinse filter funnel with 3mL DI
water and 2mL 100% ethanol.

(21) Measure Y-90 by gas flow
proportional counting.

*TRU Resin improves decontamination factors for U, Th and Bi isotopes, which could interfere with the measurement of90Y by gas flow proportional counting.
Method Performance (10g gram Concrete, TRU/DGA Resin Method)
Sample1234
AVG% Y tracer
recovery
81.7
83.3
83.7
86.3
84 + 290

Sr Bq/greference
0.03270.03270.03270.032790

Sr Bq/gmeasured
0.031
0.033
0.031
0.0330.032 + 0.001% bias-5.4
1.2-5.0-0.6

References
1) Maxwell, Culligan, Hutchinson, Utsey, Sudowe, McAlister, “Rapid Method to Determine 89/90Sr in Large Concrete
Samples,” J. Radioanal. Nucl. Chem. accepted (2016). DOI 10.1007/s10967‐016‐4787‐4
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