AN-1407

Rapid Determination of Sr in
Animal Tissue Samples

Summary of Method Strontium is separated and concentrated from up to 200g tissue samples. Samples aredigested with aqua regia, wet ashed with HNO3-H2O2 and muffled over night at 550oC to destroy organic content.
Strontium is separated from matrix impurities and potentially interfering radionuclides in the sample using stacked 2mL
and 1mL cartridges of Eichrom Sr Resin. Radiostrontium is measured on a low background gas flow proportionalcounter or liquid scintillation counter. Chemical yield of strontium is determined by gravimetric recovery of stablestrontium or ICP-AES measurement. Average chemical recoveries of strontium are 74-89% for 200g samples of catfish,bass, red drum, mullet, sea trout. Average strontium recoveries for 100 gram samples of deer, hog, bream and shellfish
are 83-96%. A single operator can complete the sample preparation, including 16 hours for muffling, for 12-24 samples
in less than 24 hours.
Figure 1. Sample Preparation
Reagents
Sr Resin, 2mL Cartridges (Eichrom SR-R50-S)
Sr Resin, 1mL Cartridges (Eichrom SR1ML-R50-S)
Nitric Acid (70%)
Hydrochloric Acid (37%)
Hydrogen Peroxide (30%)
Deionized Water
Strontium Carrier (10mg/mL)
Aluminum Nitrate, Nonahydrate
Sr-90 standard
Oxalic acid

Up to 200g Tissue in 600mL glass beaker
Add 4mg Sr carrier
Add 80mL 70% HNO3,and 20mL 37% HCl.
Digest on hotplate medium setting
until complete dryness.
Remove from hot plate and cool.
Carefully add 3mL 70% HNO3 and3mL 30% H2O2 (Foaming may occur).
Evaporate to dryness on hot plate.

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)
Cupped Stainless Steel Planchets (~5mL volume)
Gas Flow Proportional Counter
Muffle Furnace
Hot Plate
Analytical Balance
600mL Glass Beakers
Vacuum Pump

Muffle at 200oC for 10 minutes, 300oC
for 1 hour, and 550oC over night.
Remove samples from muffle furnace and cool.
Wet ash samples with 5mL 70% HNO3
and 5mL 30% H2O2, until residue is white.
Additional muffling at 550oC may be necessary.
Dissolve residue in 12mL 6M HNO3 and12mL 2M Al(NO3)3. Add 3M HNO3 as
necessary to complete dissolution.
Load sample to Sr Resin Separation.

Figure 2. Strontium Resin Separation (Optional 90Y Ingrowth)(1) Precondition Sr Resin with
10mL 8M HNO3.
(2) Load sample at 1-2mL/min.
(3) Rinse sample beaker with 5mL
8M HNO3.
(4) Add beaker rinse to Sr Resin.
Elute at 1-2mL/min.
(5) Rinse Sr Resin sequentially with:- 10 mL 8M HNO3
- 10mL 3M HNO3 - 0.05 oxalic acid- 10mL 8M HNO3

Gas Flow Proportional Counting:**(Options for 89/90Sr Descrimination)(8) Evaporate samples to dryness
on tared cupped stainless steel
planchets.

(a) Sr fraction from step (7) can betransferred to a liquid scintillation vial.
89Sr can be measured by Cerenkov
counting (no LSC cocktail). 89/90Sr
may then be measured after adding
liquid scintillation cocktail.

(9) Rinse Sr sample vials with 2mL
0.05M HNO3. Transfer vial rinse toplanchets. Evaporate to dryness.

(6) Dispose of (1) to (5) as waste.
(7) Strip Sr with 20mL 0.05M HNO3at 1mL/min.

2mL + 1mL
Sr Resin
Cartridges(b) Sr fraction from step (10) can be
dissolved in 10mL 8M HNO3 after >7days of 90Y ingrowth. 89/90Sr can beremoved on Sr Resin. 90Y will elute in
Sr Resin load and can be counted byliquid scintillation or gas flow
proportional counting.

(10) Weigh planchets on an
analytical balance to determine
gravimetric yield of stable Sr(NO3)2.
(11) Measure radiostrontium insamples on low background gas
flow proportional counter.

Actinides may also be measured by adding 2mL TEVA, TRU and DGA cartridges above Sr Resin and following theseparation scheme in Eichrom application note AN-1408, “Rapid Determination of Actinides in Animal Tissue Samples.”Sample
BeefDeer
Fish-Bass
Fish-BreamFish-Catfish

grams
100
100200100200

Sr Carrier Recovery for 100-200g Tissue Samples% Recovery
replicateSr carrier
Samplegrams
Fish-Mullet
200
6
96.3 + 0.5
5983.4 + 3.5
Fish-Red Fish200
72
89.0 + 16
Fish-Sea Trout
200
57
91.7 + 10
Hog100
Shellfish100
69
89.4 + 17

replicate666175% Recovery
Sr carrier
85.6 + 17
77.7 + 21
74.4 + 25
86.0 + 7.1
97.5 + 0.9

References
1) Sherrod L. Maxwell, Donald M. Faison, “Rapid column extraction method for actinides and strontium in fish andother animal tissue samples,” J. Radioanal. Nucl. Chem., 275(3), 605-612 (2007).
1955 University Lane Lisle, IL 60532, USA+1 (630)963-0320

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