National Analytical Management Program (NAMP)U.S. Department of Energy Carlsbad Field Office

Radiochemistry WebinarsRadiochemistry WebinarsActinide Chemistry Series

S P ti f Al h • Source Preparation for Alpha Spectroscopy

In Cooperation with our University Partners

Meet the Presenter…Michael K Schultz2

Meet the Presenter…Michael K. SchultzDr. Schultz is a tenure track Assistant Professor in the Departments of Radiology and Radiation Oncology (Free Radical and Radiation Biology Program) at the University of Iowa. Mike earned a PhD in Oceanography at Florida State University where he studied environmental radiochemistry of naturally occurring and anthropogenic actinides and uranium-series radionuclides in terrestrial y g p gand aquatic systems. Dr. Schultz’s field studies of actinide aquatic chemistry include investigations of the effect of seasonal anoxia and redox-active transition metal cycling on the behavior of actinides (U-nat, Th-nat, 239/240Pu, 238Pu, 241Am) and 210Po in a seasonally anoxic lake (Pond B) at the Savannah River National Laboratory site. Mike joined the University of Iowa in 2006 after a post-doctoral appointment at the National Institute of Standards and Technology in Gaithersburg

i ddi i k i di l i l h d d l f l i i b

He was appointed to his current position in 2009. His research interests include radiochemistry of the elements for nuclear forensics and the development of new synthetic strategies toward novel small molecules and peptides for targeted molecular imaging and therapy for cancer. This research involves application of light radionuclides 3H, 11C, and 18F, as well as transition

MD, in addition to work in radioanalytical methods development for General Engineering Labs, and 5 years as a Business Manager for ORTEC near Oak Ridge National Laboratory.

imaging and therapy for cancer. This research involves application of light radionuclides H, C, and F, as well as transition metal radionuclides 64Cu, 68Ga, 90Y, 213Bi, 212Pb, and rare earth 177Lu for imaging and therapy of disease.

His current projects involve the development of multi-receptor targeted agents for imaging and treatment of metastatic melanoma, as well as clinical translation of new 68Ga labeled peptides for imaging neuroendocrine tumors. His efforts to bring 68Ga labeled compounds from bench to bedside have recently resulted in the first 68Ga labeled peptide for clinical imaging of patients in the United States at the University of Iowa.

In nuclear forensics, the breadth of Dr. Schultz’s experience in radiochemistry, combined with synthetic expertise in radiometal/organic chelator molecular construction, provides a backdrop for the development of innovative new paradigms in the analysis of a variety of natural-matrix and manufactured materials for nuclear forensic applications. Mike currently has collaborative projects with the SRNL and the INLcollaborative projects with the SRNL and the INL.

Contact information:Phone: (319) 335-8017Email: michael-schultz@uiowa.edu

Source Preparation for Alpha SpectroscopyMichael K. Schultz PhD Assistant Professor

National Analytical Management Program (NAMP)National Analytical Management Program (NAMP)U.S. Department of Energy Carlsbad Field Office

TRAINING AND EDUCATION SUBCOMMITTEE

O i

4

Overview• Alpha Emitters and Alpha Spectrometry

Alpha Emitters and Alpha Spectrometry

• Methods of Source Preparation

El d i i Electrodeposition Microprecipitation

Ralf Sudowe PhD Brian Powell PhDWilliam C. Burnett PhDProfessor of OceanographyFlorida State University

Assistant ProfessorHealth Physics and RadiochemistryUniversity of Nevada, Las Vegas

Assistant Professor Environmental EngineeringClemson University

5

Disclaimer

Certain products and manufacturers are mentioned during this presentation for the mentioned during this presentation for the purpose of fostering understanding. The use of these commercial products and manufacturers these commercial products and manufacturers in this presentation does not imply a recommendation or endorsement.

6

Safety

• The contents of this presentation include references and representations of laboratory procedures that utilize radioactive materials, chemical solvents, , ,reagents, and electrical apparatus, which can be dangerous.

• Appropriate use of personal protective equipment and clothing, as well as consultation with laboratory safety literature and personnel, is recommended y p ,before performing any experimental procedure.

7

Takeaways

• Alpha decay• Alpha emitters• Electrodeposition• Rare earth fluoride microprecipitation• Apparatus and methods

l i f l h • Resolution of alpha spectra

Types of Radioactive Decay8

yp y(1) Alpha Decay ()

p+n0

p+

e-“Parent”

(2) Beta Decay (β)

e- p+n0

p+

n0

p+

n0

p+

n0

p+n0

p+

n0

p+n0

p+

n0

n0 p+

n0

p+n0

n0

n0

n0

p+

p+ p+

p+

Rare

β- negatronβ+ positron

l t t

e-n0

Rare/β

electron captureneutrino emission

e- p+n0

p+

p+p+

n0

p+

n0 p+

p+n0

n0n0

e-

E(3) Gamma Emission ()

Internal Conversion (IC)Isomeric Transition (IT)

e- p pn0

n0

p+

n0

p+n0

p+

n0

p+n0

p+

n0

n0

p

n0p+

p+ p+

energetictransition

EH

( )e-

EL

“Daughter”

particle properties9

particle propertiesm =10-27 kg n0n0

p+

p+

5-9 MeV Paper4

He2 22+

Th t j it f h li f d t d

ββ Daughter RecoilPlastic Million

The great majority of helium found today comes from natural gas fields where:

(1) the basement rock is rich in uranium and/or mβ =10-31 kg

<2 MeV

βγ

Where might be an excellent

( ) /thorium (alpha emitters!);

(2) there is heavy, deep-seated faulting so the helium can escape;

Lead

Where might be an excellent place to mine for helium gas?helium can escape;

(3) there is a seal strong enough to keep it underground.

High Energy, Massive, Mono-Energetichttp://www.helium-corp.com/files/Helium-Detection-GM-Reimer.pdf

particle properties10

particle propertiesm =10-27 kg n0n0

p+

p+

5-9 MeV Paper4

He2 22+

ββ Daughter RecoilPlastic Million

mβ =10-31 kg

<2 MeV

βγ

Where might be an excellent Lead

Where might be an excellent place to mine for helium gas?

High Energy, Massive, Mono-Energetic

particle properties11

particle propertiesm =10-27 kg n0n0

p+

p+

5-9 MeV Paper4

He2 22+

ββ Daughter RecoilPlastic Million

mβ =10-31 kg

<2 MeV

βγ

Lead

High Energy, Massive, Mono-Energetic

particle properties12

particle propertiesm =10-27 kg n0n0

p+

p+

5-9 MeV Paper4

He2 22+

ββ Plastic

mβ =10-31 kg

<2 MeV

βγ

Lead

High Energy, Massive, Mono-Energetic

Alpha () Decay Po210

Pb? +

13

Alpha () Decay Po84 126 Pb

? ?

n0

n0

p+ p+

+

National Nuclear Data Center (NNDC) n

Po21084 126

Simple DecayT1/2 = 138 d

( )

Simple Decay100%

Stable

Kim et al., Env Sci tech., 39, 2005Schultz et al., Appl Rad Isot., 65(7), 2007

Alpha () Decay Po210

Pb? +

14

Alpha () Decay Po84 126 Pb

? ?

n0

n0

p+ p+

+

National Nuclear Data Center (NNDC) n

Po21084 126

Simple DecayT1/2 = 138 d

( )

Simple Decay100%

Pb20682 124

Stable

Kim et al., Env Sci tech., 39, 2005Schultz et al., Appl Rad Isot., 65(7), 2007

Alpha () Decay At211

Bi? +

15

Alpha () Decay At85 126 Bi

? ?

n0

n0

p+ p+

+

n

Branching DecaySimple Decay “Series”

At21185 126

Bi207

42% 58% T1/2 = 7 h

Bi83 124

T1/2 = 32 yearsPo21184 127

Z 1 N+1

100%

100% Z-1 N+1

Pb20782 125

T1/2 = 0.5 s100%

Stable

Schultz et al., Appl Rad Isot., 64, 2006

Alpha () Decay At211

Bi? +

16

Alpha () Decay At85 126 Bi

? ?

n0

n0

p+ p+

+

n

Branching DecaySimple Decay “Series”

At21185 126

Bi207

42% 58% T1/2 = 7 h

Bi83 124

T1/2 = 32 yearsPo21184 127

Z 1 N+1

100%

100% Z-1 N+1

Pb20782 125

T1/2 = 0.5 s100%

Mistake!?T 1 9 1019

StableT1/2 = 1.9×1019 yearsMarcillac et al., Nature, 2003U-238 4.5x109 years

Schultz et al., Appl Rad Isot., 64, 2006

Finding Alpha Emitters

17

Finding Alpha Emitters…Heavy Elements (Z > 82)

Earnest Rutherford(Discovery 1898-9)

**E. Rutherford (1899) "Uranium radiation and the electrical conduction produced by it,"

h l h l lPhilosophical Magazine, Series 5, vol. 47, no. 284, pages 109-163.

E. Rutherford (1903) "The magnetic and electric deviation of the easily absorbed rays from radium," Philosophical Magazine, Series 6, vol. 5, no. 26, pages 177-187.

Finding Alpha Emitters

18

Finding Alpha Emitters…Heavy Elements (Z > 82)

Earnest Rutherford(Discovery 1898-9)

**E. Rutherford (1899) "Uranium radiation and the electrical conduction produced by it,"

h l h l lPhilosophical Magazine, Series 5, vol. 47, no. 284, pages 109-163.

E. Rutherford (1903) "The magnetic and electric deviation of the easily absorbed rays from radium," Philosophical Magazine, Series 6, vol. 5, no. 26, pages 177-187.

Among Heavy Elements19

Among Heavy Elements…

Proton Rich

Neutron Rich

Nβ-

β+βAlpha Emitters

Valley of Stability

Z

Where There’s Smoke20

Where There s Smoke…

241Am smoke detectors

• 241Am alpha decay ionizes air, creating continuous currentcurrent

• Smoke interrupts the current and alarm sounds

Where There’s Smoke21

Where There s Smoke…

241Am smoke detectors

• 241Am alpha decay ionizes air, creating continuous currentcurrent

• Smoke interrupts the current and alarm sounds

In Nature… N t l U S i

22

In Nature… Natural U Series

• Sedimentation Rates10 Alpha Emitters Sed e tat o ates• Geologic Formation Growth Rates• Paleo Age Dating• Nuclear Forensics Age Dating

10 Alpha Emitters

ty

Parent (Constant Decay Rate)100

adio

activ

itDaughter “ingrowth”

50dN p dN d

Ra

1 Half life

0

dNdt

dNdt

Ad N dP + D

Time

0P + D

In Nature… N t l U S i

23

In Nature… Natural U Series

• Sedimentation Rates10 Alpha Emitters Sed e tat o ates• Geologic Formation Growth Rates• Paleo Age Dating• Nuclear Forensics Age Dating

10 Alpha Emitters

Is uranium-238 the heaviest naturally-occurring radionuclide?

ty

Parent (Constant Decay Rate)100

naturally occurring radionuclide?

Yesad

ioac

tivit

Daughter “ingrowth”50

dN p dN dNo

Ra

1 Half life

0

dNdt

dNdt

Ad N dP + D

Time

0P + D

In Nature… N t l U S i

24

In Nature… Natural U Series

• Sedimentation Rates10 Alpha Emitters Sed e tat o ates• Geologic Formation Growth Rates• Paleo Age Dating• Nuclear Forensics Age Dating

10 Alpha Emitters

Is uranium-238 the heaviest naturally-occurring radionuclide?

Natural reactorOklo, Gabon (Africa)Kuroda, P. K. (1956). J Chem Phys25 (4): 781–782; 1295–1296

2.5 Tons of Pu-239

ty

Parent (Constant Decay Rate)100

naturally occurring radionuclide?

Yesad

ioac

tivit

Daughter “ingrowth”50

dN p dN dNo

Ra

1 Half life

0

dNdt

dNdt

Ad N dP + D

No, not exactly

Time

0P + D

In Nature… N t l U S i

25

In Nature… Natural U Series

• Sedimentation Rates10 Alpha Emitters Sed e tat o ates• Geologic Formation Growth Rates• Paleo Age Dating• Nuclear Forensics Age Dating

10 Alpha Emitters

Is uranium-238 the heaviest naturally-occurring radionuclide?

Natural reactorOklo, Gabon (Africa)Kuroda, P. K. (1956). J Chem Phys25 (4): 781–782; 1295–1296

2.5 Tons of Pu-239Pu-244 in a haystack…

ty

Parent (Constant Decay Rate)100

naturally occurring radionuclide?

Yesad

ioac

tivit

Daughter “ingrowth”50

dN p dN dNo

Ra

1 Half life

0

dNdt

dNdt

Ad N dP + D

No, not exactlyNo Hoffman et al., Nature 234, 1971.

Time

0P + D

In Medicine…26

In Medicine…Targeted tumor therapies

• Energy deposition/particle mass– α-particles deposit larger amount of

energy over short distance in tissue

Mass = 104 x Mass Tumor

Mean Range in Tissue (Cells)

90Y (2 MeV) 200

Mass 10 x Mass

131I (1 MeV) 211At (7 MeV) α210Po (5 MeV) α

4033

“…is it worth the extra hurdles to pursue alpha emitters for clinical applications?”Zalutsky, J. Nucl. Med., 2006, 47(8):1238

In Energy … 27

In Energy …

Reprocessing

Monitoring

Waste

12 3% ld’ l t i it12.3% world’s electricity13 countries435 nuclear reactors66 new plants under contructionp

Disarmament

28

Disarmament…

SafeguardsSafeguards

Reprocessing

Forensics

29

Sample Preparation Pyramid

Source Preparationelectrodeposition,filtration sources

sourcepreparation Today

Chemical Separationsion exchange, etc.

Preliminary Treatments

chemicalseparations Recent Webinars

Preliminary Treatmentssample collection, filtration,

sample dissolution, etc.preliminary treatments Future Webinar

The various stages of sample preparation may be thought of as a pyramid of steps

Alpha Spectrometry Process30

Alpha Spectrometry ProcessAir filter Water Bioassay

Tracers…

SoilsSediments

Digestion…

SeparationsOils…other

Separations…

Source Prep

Goldstein S.J., et al.Analytical Chem., 69(5), 1997

Tracer/Analyte31

Tracer/AnalyteNuclides of the same element behave exactly the same chemicallysame chemically

Tracers Analytes232U 238U, 235U, 234U229Th 230Th, 232ThTh Th, Th243Am 241Am242P 239/240P 238P

~5.5 MeV overlap

242Pu 239/240Pu, 238Pu

Some energies cannot gbe separated by -spec

Need good separations…

Desirable Alpha Counting Sources

32

Desirable Alpha Counting Sources

• High purity, i.e., good separations• Thin deposit - minimal self-absorptionp p• Uniform deposit - reproducible geometry• Coherent - prevent loss of activity• Coherent - prevent loss of activity• Fast preparation, inexpensive, simple

α Source

Comparing Alpha Spectra33

Comparing Alpha Spectra• Full width at half maximum (FWHM)• Figure of merit for comparing alpha peaks

Sill, 1969

• Smaller number is better

5 3 MeVMaximum

5.3 MeV

Half Maximum5 5 MeV5.5 MeV

Energy (MeV)

Mass Loading Effects Concepts

34

Mass oad g ects Concepts

D t t

Electronics

Detector243Am

FWHM20 keV

241Am243Am

FWHM k V 241A

Eα

55 keV 241Am

Controlled vacuum

Eα

h

“Thicker” 50-100 μg Ce (CeF3)

α Source“Thin” Electrodeposited

Mass loading degrades resolution (attenuates α emission)

Mass Loading Effects Concepts

35

Mass oad g ects Concepts

D t t

Electronics

ill750 Detector243Am

FWHM20 keV

241Am243Am

FWHM k V 241A

Sill, 1969750 μg BaSO4

FWHM

Eα

55 keV 241Am375 keVControlled vacuum

Eα

h

“Thicker” 50-100 μg Ce (CeF3)

α Source“Thin” Electrodeposited

Mass loading degrades resolution (attenuates α emission)

Mass Loading Effects

36

Mass Loading Effects

#1: electrodeposition 24 keV

FWHM

#2: BaSO4 0.075 mg/cm2 75 keV

#3: BaSO 0.75 mg/cm2 325 keV#3: BaSO4 0.75 mg/cm 325 keV

Sill and Williams, Analytical Chem., 1969Sill and Williams, Analytical Chem., 1981

Wh D W N d Hi h R l ti ?

37

Why Do We Need High Resolution?U Pu Am

• Baseline separationsp

• Identify contaminationcontamination

• Accurate peak count integrationcount integration

Modest peak overlap

Sill and Williams, Analytical Chem., 1981

Electrodeposition Concepts

38

Electrodeposition ConceptsDefinition: Electrolytic process in which a metal is deposited at the cathode from a solution of its ions; i l d l t l ti d l t f i Al includes electroplating and electroforming. Also known as electrolytic deposition.

El l (+)

Electrolyte solutioncontainingradionuclide

V (DC)α planchetStainless

radionuclide

Source of electrons at

Stainless(-)

Source of electrons at cathode surface

Plionis et al., J Rad Nucl Chem., 2008

FSU P t t #1 ( i 1989)

39

FSU Prototype #1 (circa 1989)belt drive

spring loadedbelt drive

p gsilver contact

heatcontroller

D C Supply

perspex

stand

• Rotating cathode – reduce heterogeneity of deposition

• Variable D C supplyD.C. Supply

cathode

rotatingcathode

Variable D.C. supply

• Constant V or I

• Control temperatureTeflonbeakerPt anode

water bath

temperature sensor

Control temperature

FSU System40

FSU System

I

41

Iowa

Electrodeposition Basic Procedure

42

Electrodeposition - Basic Procedure• Sample dissolution/digestion• Radiochemical separations (purification)

Elementally pure sources• Evaporation/transition to electroplating medium• Evaporation/transition to electroplating medium• pH adjustment

H2SO4/NaHSo4 mediuml d• Electrodeposition

[1.] Talvitie N.A., Electrodeposition of actinides for alpha spectrometricdetermination (1972), Analytical Chemistry, 44 (2), 280-283.

[2.] Hallstadius L. A., method for the electrodeposition of actinides (1984),Nuclear Instruments and Methods in Physics Research 223 (2-3) 266-267Nuclear Instruments and Methods in Physics Research, 223 (2-3), 266-267.

[3.] Tomé F.V., Sanchez A.M., Optimizing the parameters affecting the yield andenergy resolution in the electrodeposition of uranium (1991), AppliedRadiation and Isotopes, 42 (2) 135-140.

43

Electrodeposition Buffers (many)• Purified solution from column separations• Purified solution from column separations• Add 2 mL 5% NaHSO4 and 0.5 mL HClO4• Heat to fumesHeat to fumes• Cool• Add 1 mL HCl, evaporate, repeat oxidize organic matter – white residue

• 4 mL Na2SO4 (buffer formation)• pH 2 1 to 2 4• pH ~2.1 to 2.4• Transfer to cell with DI water• Constant current around 1AConstant current around 1A

Sherry Stock, MS Thesis

Handling Planchets44

Handling Planchets• Washing and polishing• Soapy water DI water acetone dry• Soapy water, DI water, acetone, dry Wear gloves

• Electropolishing – H2SO4/H3PO4 (1A, 15 min)p g 4/ 3 4 ( , 5 )

W-P W-UP UW-P UW-UP W-P W-UP UW-P UW-UP

Sherry Stock, MS ThesisRalf Sudowe PhD

W – WashedP – PolishedUW – UnwashedUP – Unpolished

O i i i i

45

Optimization Experiments

• Chemical parameters: H SO l i i lpH, SO4 molarity, potential

• Electrodeposition efficiency

Peter CableWilliam Burnett

40000

Thorium10000

Protactinium

46

20000

30000

ount

s

5000

7500

10000

Co

2500

5000

pH00 2 4 6 8 10 12 14

20000 600010000

00 2 4 6 8 10 12 14

p

15000

nts

Uranium4000

5000Americium

7500

Plutonium

pH5000

10000

Cou

n

2000

3000

2500

5000

pH00 2 4 6 8 10 12 14

0

1000

0 2 4 6 8 10 12 14

00 2 4 6 8 10 12 14

20000

Thorium

1000047

10000

15000

ount

s

5000

7500Protactinium

5000

Co

2500

00 0.5 1 1.5 2 2.5 3

20000

U i600010000

00 0.5 1 1.5 2 2.5 3

15000

nts

Uranium

4000

5000Americium

6000

8000Plutonium

5000

10000

Cou

n

2000

3000

4000

00 0.5 1 1.5 2 2.5 3

0

1000

0 0.5 1 1.5 2 2.5 3 3.5

0

2000

0 0.5 1 1.5 2 2.5 3

20000

Thorium10000

Protactinium

48

10000

15000

ount

s 6000

8000

5000

10000

Co

2000

4000

00 1 2 3 4 5

00 1 2 3 4 5

20000 600010000

15000

ts

Uranium

4000

5000Americium

6000

8000

Plutonium

5000

10000

Cou

nt

2000

3000

4000

00 1 2 3 4 5

0

1000

0 1 2 3 4 5

0

2000

0 1 2 3 4 5

100Uranium12 min.

100

Thorium 10 min.

49

10

y = 90.112 * 10 -0.025x

r2 = 0.990

10

y = 106.312 * 10-0.031x

r2 = 0.994

g (%

)

100Americium15 min

10 20 40 60 80 100 120

100

Plutonium

1

n R

emai

ning

0 20 40 60 80 100 120

10

y = 94.726 * 10-0.020x

r2 = 0.994

15 min.

10

y = 96.808 * 10-0.020x

r2 = 0.999

15 min.

Frac

tion

1010

10 20 40 60 80 100 120

10 20 40 60 80 100 120

Time (min)

Constant Current50

Constant Current

U NpU Np

AmPu

Conditions1.2 A

Cm

1.2 ApH 20.52 M Na2SO4/0.06 M NaHSO4

Time (Minutes)Plionis et al., J Rad Nucl Chem., 2008

Talvitia N A Analytical Chem (1972)51

1 M (NH4)2SO4

Talvitia N.A., Analytical Chem (1972)100

pH 2

With and withoutAmni

ng

With and withoutH2C2O4 (inhibits Fe)Pu

Rem

ain

U

Th

% R

“Fi i h d” S

52

“Finished” SourcesIf it takes 10 minutes to plate 50% of the Th, how long will it take to plate 100%?

V. Jobbágy, R. Van Ammel, M. Marouli: Preparation of high resolution 238U α-sources by electrodeposition from aqueous solution. Scientific and Policy report EUR 25356 EN (2012).http://publications.jrc.ec.europa.eu/repository/bitstream/111111111/26553/1/lana25356enn.pdf.

Soil 181 Am (electrodeposition)53

Soil 181 Am (electrodeposition)

241AmFWHM ~19 keV

54

Sample 302 Smaller Sample SizeHigh Resolutiong

FWHM ~27 keV

Uranium “Mass” Effect

55

Uranium Mass Effect“Regular” Resolution

238U234U 232U

FWHM ~38 keV

238U 232U

235U 228Th

Uranium “Mass” Effect

56

Uranium Mass Effect“Regular” Resolution

238U234U 232U

Rule of thumb: Keep the mass of U

FWHM ~38 keV

238U 232Up

to less than about 10-20 micrograms. Less for Th-232.micrograms. Less for Th 232.

Homework: Calculate the activity in Homework: Calculate the activity in Bq of 20 micrograms of natural U.

235U 228Th

S

57

Summary

l d i d id• Electrodeposited sources provide optimum resolution for a-spectrometry

• Electrodeposition can be very efficient once conditions are optimized

• Cells for preparing sources can be relatively simple and inexpensive

S ti ti h i t d • Source preparation, separations chemistry, and mass effects need to be considered

58

What is Microprecipitation?• Co crystallization of metal ion species with • Co-crystallization of metal ion species with

similar chemical characteristics Charge Ce3+Charge Size Solubility

Ce3+ Ce3+

Ce3+ Am3+ + HFC 3+ Ce3+Ce3+ Ce3+

Am3+

IAEA-300 Am (CeF3)59

What might contribute to degraded resolution seen in this IAEA soil for Am?

IAEA-300 Am (CeF3)60

What might contribute to

• Rare earth elements (REE) are frequent constituents of

degraded resolution seen in this IAEA soil for Am?

natural soils and sediments.

G d ti h i t • Good separations chemistry is necessary to remove them prior to source preparationprior to source preparation.

• If significant REE are left

Burnett, W. & Cable, Peter. Radioactivity & Radiochemistry. Vol. 6, No. 3 (1995) 36-44.

Sigg, R.A. et al. "Promethium Separation Using Eichrom Ln Resin" 43rd Annual Conference on g

behind, mass loading effects can degrade alpha source

l i

Eichrom Ln Resin 43rd Annual Conference on Bioassay, Analytical and Environmental Radiochemistry. Charleston, SC. November, 1997.

Pin, Christian et al. Analytica Chimica Acta. 339 (1996) 9 89 (PC196)resolution. 339 (1996) 79-89 (PC196).

What you need…61

y

Rare Earth Fluoride Precipitations62

Rare Earth Fluoride Precipitations

Tracers…

SoilsSediments

Digestion…

SeparationsOils…other

Separations…

Source Prep

Goldstein S.J., et al.Analytical Chem., 69(5), 1997 Same as electrodeposition!

Muskie 63

Muskie Analysis

N 8 Fi h S l

1. Weigh Muskie Tissue

Am-243 tracer @ two levels of

150 mL BeakerN = 11

…..

N = 8 Fish Samples Weigh Each Sample

Am-241 Analysis of MuskieLake Wissota, WI X 2

activity.

50 mBq

1 8

N = 8 Fish Samples

1. Catch the Muskies.2. Weigh Samples.3. Add Tracer (243Am).

500 mBq

dd3 ( )4. Digest Samples.5. Separations Chemistry.6. Source Preparation.

Am-243 Tracer

2. Add Am-243 Tracer

X 2

7. Alpha Spectrometry.

8 Di ?

150 mL BeakerN = 11

…..

…..

8. Dinner?

N = 3 Blanks

1 8

N = 8 Fish Samples

Muskie 64

Muskie Analysis

N 8 Fi h S l

1. Weigh Muskie Tissue

Am-243 tracer @ two levels of

Separate natural rare earths from AmSchultz et al Env Anal II 2003

150 mL BeakerN = 11

…..

N = 8 Fish Samples Weigh Each Sample

Am-241 Analysis of MuskieLake Wissota, WI X 2

activity.

50 mBq

Schultz et al., Env Anal II, 2003

Mass effects…

1 8

N = 8 Fish Samples

1. Catch the Muskies.2. Weigh Samples.3. Add Tracer (243Am).

500 mBq

dd3 ( )4. Digest Samples.5. Separations Chemistry.6. Source Preparation.

Am-243 Tracer

2. Add Am-243 Tracer

X 2

7. Alpha Spectrometry.

8 Di ?

150 mL BeakerN = 11

…..

…..

8. Dinner?

N = 3 Blanks

1 8

N = 8 Fish Samples

CeF Source Preparation

65

CeF3 Source Preparation• Separations Chemistry Transfer Am to teflon/plastic beakers Cerium carrier to each beaker (50 µg)

Add 1 0 mL of concentrated HF to each beaker

0.1 μm polypropylene

filters Add 1.0 mL of concentrated HF to each beaker Swirl to mix Let stand 30 minutes....

filters25 mm

3

Set up a 0.1 micron 25 mm filterAdd L f 8 % th l t h filt Add 3-5 mL of 80% ethanol to each filter

Apply vacuum (leaks?) Add 2-3 mL of water to each filterAdd 2 3 mL of water to each filter

CeF Source Preparation

66

CeF3 Source Preparation• Apply vacuum and transfer the Am samples to

the filter with 5 mL waterthe filter with 5 mL water

• Wash each filter with 3-5 mL of ethanol (helps for drying step)

• Remove filters, place in plastic Petri dishes, and dry under (UV) lamps for a few minutes

• Mount filters on stainless planchets, using double-sided tape or glue stick

C b l h • Count by alpha spectrometry

Lyndsey Kelly, MS Thesis, 2007Sh St k MS Th i Sherry Stock, MS Thesis, 2003Goldstein et al., Analytical Chem, 1997Schultz et al., Env Anal II, 2003www.echrom.com

System Needs67

System Needs

0.1 μm polypropylene filters25 mm

Vacuum source1L Erlenmeyer“HF Trap”

Filter flask

Kelly et al. (Sudowe), 2008

This Old Lab DIY 4@ 1” PVC elbow

68

This Old Lab…DIY 4@ 1 PVC elbow4@ 1” PVC ½” port Ts1@ 1” PVC ½” threaded TPVC ½” threaded adapterPCV l iPCV purple primerPVC cement1 ¾” tube cutterHacksawHigh pressure ½” ID tubing

$104

Local hardware store:PVC tubing and fittingsHigh pressure hose

Assembled Apparatus Assemble with PVC

69

Assembled Apparatus Assemble with PVC primer and cement

Install ½” rubber t d ill dstoppers – drilled

Install polysulfone filter funnels

Connect to vacuum source

70

What Matters?

Whi h h?• Which rare earth?• How much rare earth?• Solution? Interferences?• Temperature?• Temperature?• How long?

R d ?• Redox?

Kelly, MS Thesis, 2009Ralf Sudowe, PhD

Which Rare Earth?

71

Which Rare Earth?

FWHM YieldFWHM Yield

<40 keV >95%

Little to no difference…

<40 keV >95%

Kelly, MS Thesis, 2009Ralf Sudowe PhD

HCl Interference

72

HCl Interference…

FWHM YieldFWHM Yield

40%

~45 keV

HCl can interfere @ < 50 µg carrierKelly, MS Thesis, 2009Ralf Sudowe PhD

73

Temperature?

FWHM i ldFWHM Yield

ld<35 keV

cold warm~100%

Warm it up a bit….Kelly, MS Thesis, 2009Ralf Sudowe PhD

74

Am and Pu Analysis vs Carrier mg

FWHM i ldFWHM Yield

<40 keV >95%

Not much difference…Kelly, MS Thesis, 2009Ralf Sudowe PhD

75

Precipitation Time

FWHM i ldFWHM Yield

<40 keV ~95%10 min 24 hr10 min 24 hr

Not much difference…Kelly, MS Thesis, 2009Ralf Sudowe PhD

CeF Precipitation with Redox Active

76

CeF3 Precipitation with Redox Active Nuclides…• Am3+, Th4+ precipitate (ppt) with CeF3

• Pu U need to be in reduced forms that ppt Pu, U need to be in reduced forms that ppt readily with rare earth fluorides

Pu3+/4+ reductant NaNO• Pu3+/4+ reductant NaNO2

• U4+ reductant TiCl3

Burnett, W. & Cable, Peter. Radioactivity & Radiochemistry. Vol. 6, No. 3 (1995) 36-44.

Sigg, R.A. et al. "Promethium Separation Using Eichrom Ln Resin" 43rd Annual f i l i l d i l di h i h lConference on Bioassay, Analytical and Environmental Radiochemistry. Charleston, SC.

November, 1997.

Pin, Christian et al. Analytica Chimica Acta. 339 (1996) 79-89. (PC196).

Recoil Contamination Prevention77

Recoil Contamination Prevention

Detectorrecoil contaminationAggregate recoil

Controlled vacuum

α Source α emission“daughter”

Recoil Contamination Prevention78

Recoil Contamination Prevention

Detectorrecoil contaminationAggregate recoil

Controlled vacuum

α Source α emission“daughter”

Recoil Contamination Prevention79

Recoil Contamination Prevention

Detectorrecoil contaminationAggregate recoil

Controlled vacuum

α Source α emission“daughter”

Recoil Contamination Prevention80

Recoil Contamination Prevention

Detectorrecoil contaminationAggregate recoil

Controlled vacuum

α Source α emission“daughter”

Rare Earth Fluorides81

Rare Earth Fluorides

Simple procedures• Simple procedures• Inexpensive apparatus• Acceptable resolutionp• Flexible• Fast

M l i l l• Multiple samples• Easy• Caveats:Caveats: Redox Recoil

82

Thank you!

83

Future NAMP Radiochemistry Webinars Webinars

• Actinide Chemistry Series Sample Dissolution

N t i Ch i t Neptunium Chemistry Trivalent Actinides

• Radium Chemistry

NAMP website: www.inl.gov/namp