determination of naturally-occurring actinides and …/67531/metadc702847/...obiective use icp-ms in...

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Determination of Naturally-Occurring Actinides and their I=- 609 Progeny in Fresh Water using Inductively Coupled Plasma-

Mass Spectrometry and Batch Separation

Jeffrey S. Crain Lesa L. Smith

Judith S. Yaeger James T. Kiely

Jorge A. Alvarado Fred G. Smith' by a contractor of the U. S. Government under contract No. W-31-104ENG-38. Accordingly, the U. S. Government retains a nonexclusive, royalty-free license to publtsh or reproduce the published form of this contribution, or allow others to do Io. for

Argonne National Laboratory, 9700 South Cass Avenue, Argonne, IL 'CETAC Technologies, 5600 South 42nd Street, Omaha, NE

Work supported by the U. S. Department of Energy, Office of Environmental Restoration and Waste Management (EM-263)

Obiective Use ICP-MS in combination with appropriate preparative techniques for the determination of actinide elements in the environment.

Approach Examine and identify the sample introduction and sample preparation techniques necessary to achieve required detection limits and mitigate interferences.

Potential Benefits Increased measurement speed, reduced preparative requirements (isobaric purity vs. radiochemical purity), and improved method detection limits.

_ _ ~ ~~ ~


DlSCLAlMER

This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, make any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply its endorsement, recommendation, or favoring by the United States Government or any agency thereof. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or any agency thereof.

DISCLAIMER

Portions of this document may be illegible in electronic image products. Images are produced from the best available original document

I

Reauired Detection Limits for Actinides with tfi > lo3 pears

Nuclide

Required Detection Limit a

soil/Bq kg-' water/mBq L" water/ng L" - ~~ ~ ~ ~~~ _ _ ~~ ~

230rh 18 37 0.05 1

232Th 18 37 9000

1 1 22 0.038

11 22 280

1 1 22 1800

233u + 234u

235u

2 3 8 ~

237Np 18 37 1.4

239pu + 240pu 1.1 0.37 3.5 x 10-5 c

a

b

General Radiochemistry and Routine Analytical Services Protocol - Part B, EG&G Rocky Flats, Golden, CO (1991), p. 10

assumes that the mass detection limits for 233i234U are equal. assumes that the mass detection limits for 239*% are equal. C


Radioisotope Concentrations in Natural Water Samples Determined by alpha spectrometry

pci/L

Sample 226Ra 230Th 232Th 2 3 4 ~ 2 3 8 ~

Fox River

Kankakee River

Herrick Lake

Borden, IN Spring

Borden, IN Farm Well

Lemont, IL Municipal Well

Lemont, IL City Water

Chicago City Water

MINIMUM ( P a )

0.4 f 0.1 0.049 f 0.009 0.030 f 0.007 0.43 f 0.02 0.31 f 0.02

0.10 f 0. 04 0.03 f 0.01 0.007 0.69 f. 0.02 0.51 f 0.02

0.5 f 0.2 c 0.02 < 0.01 0.09 f 0.01 0.055 f 0.008

0.06 f 0.04 0.021 f 0.006 c 0.007 0.035 f 0.007 0.042 f 0.008

0.34 f 0.09 0.05 f 0.01 < 0.005 N/A 0.021 f 0.004

10.3 f 0.9 0.021 f 0.005 c 0.01 - 1.59 0.06 0.10 f 0.01

5.7 f 0.8 < 0.03 c 0.01 1.72 f 0.05 0.10 f 0.01

0.4 f 0.1 < 0.02 < 0.02 0.17 f 0.01 0.092 f 0.008

0.06 1 4x lo4 5 6x104


ICP-MS Sensitivitv versus Radiometric Sensitivity for electrothermal vaporization sample introduction

1 o8

1 o6 1 07

105 .s 104 4 103 i? '9 102 2 10' cA 100

lo-' l o 2

lo4

*d

0

.r(

103

i o 0 101 io2 103 104 io5 io6 107 108 109 1010 1011

half-life/y

M. Smith et al., J. Radioanal. Nucl. Chem., 160, 341 (1992).


0

53

.-I

b 4

l ' " ' 1 ' ' ' I " " ' ' ' ' I " ' ' ' '

0 . .

m

4 0

0

2

Sensitivitv of Solution ICP-MS for Various Isotopes using nebulizers of direrent eficiency

106

105

104 0

/ --d P--

/ d

40 80 1 20 m/z

160 200 240


ICP-MS Limits of Detection (in mBa L1) for Actinide Isotopes in Solution using direrent nebulizers and diferent modes of data acquisition

scanning multiple ion monitoring

isotope PN USN PN USN

23%

232n

233u

2 3 4 ~

235u

236u

2 3 8 ~

237Np

239pu

2000

0.04

2000

900

0.4

10

0.1

100

1x104

50

4x 1 0-3

40

20

8 ~ 1 0 - ~

0.2

0.0 1

3

200

500

0.04

200

200

0.06

2

0.1

20

2000

8

4x 1 Oe3

4

5

2~ 10-3

0.05

9 ~ 1 0 - ~

0.5

50


Polyatomic Ion Interferences in Actinide Determinations

1 lo' 06 ir ll Dissolved Soil, Th & TRUs '

W O ' n ' c

in 105 2 5 104

.S 103 E

rn 102

10'

1 00

Dissolved Soil, U

220 225 230 235 240 245 250

m/Z _________


"\'

I

4

0

2

m r: 0

Analysis of 5 2 Fox River Water, spiked with 229Th and 236U by USN-ICP-MS

Isotope pCi/L, ICP-MS a pCi/L, a-spec

226Ra

230Th

232Th 23423-

238u

ND

c 0.25

NA

0.33 =f: 0.05

0.30 k 0.02

0.4 0.1

0.049 k 0.009

0.030 =f= 0.007

0.43 f 0.02

0.31 =f= 0.02

a mean of five 20-s replicates; propagated uncertainty uncertainty based on counting statistics only

radium was not detected 232Th was not determined due to low 229Th intensity

C

d

102

10'

100

10'


Analytical Considerations for ICP-MS Determination of Actinides based on sensitivity and interferences

1. Preconcentrate analytes as necessary 2. Eliminate matrix to minimize non-spectroscopic interference/sampler

occlusion Separate U from other actinides (if necessary) to minimize spectral interferences Incorporate yield and matrix effect corrections into procedure

3.

4.


Determination of Actinides in Fresh Water bv ICP-MS with batch concentratiodmatrix elimination and isotope dilution

1. 2. 3.

4.

5.

Equilibrate 229Th and 236U spikes with 250 mL sample by repetitive acid digestion Reconstitute sample in appropriate matrix for separation Mix sample thoroughly with separation medium

Anion exchanger (quaternary ammonium) Chelating ion exchanger (iminodiacetate)

e Cation exchanger (sulfonate/phosphonate) IIS Adsorbed extractant (CMPORBP)

Isolate separation medium (filtration) Release analytes from separation medium (back extraction or resin dissolution)


Batch Concentration of Actinides via Anion Exchange AGlX4, 100-200 mesh (BioRad)

1, 2.

3.

4-n Th lv+ n NO; Th(NO3)n

4-n Th(N03)n + (n-4) R- NH, NO, * (n-4) R- NH3: Th(N03)i-" + (n-4) NO;

Load 1.5 g resin from 50 mL 3M Ca(NO,), Filtedrinse resin with 10 mL 1OM NH4N0, Release analyte with 10 mL 0.1M HNO,

(50% uptake of 229Th tracer) (26% of bound tracer retained) (13% of tracer recovered)

Yields with real samples were approximately 1 Ox lower Low retention during load and rinse minimizes utility of separation


Batch Concentration of Actinides via Chelating Ion Exchange SPR-IDA (0.1 (urn PSIDVB resin) suspension and DSX-100 (CETAC)

ThIv+ R-N(CH2C02)g- * R-N(CH2C02)$-: Th

1. Load 20 mg 2. Isolate resin

resin from pH 8 sample (KMy > on hollow fiber filter (matrix

10" for Th(1V) and U(1V)) elimination)

precision) 3. 4.

Backflush filter with carrier Acidify mixture and centrifuge

(concentration) (releases analyte - better


Preliminarv Observations on SPR-IDA Chemistrv

1. Iron can destabilize sample-SPR mixture at operating pH [Fe(OH), K,, = 2 . 7 ~ 1 0 - ~ ~ ]

Sample Fe, mg/L mL sample/mL SPR Stability @ pH 9 (hrs)

DuPage River 0.04 600 5

Kankakee River 0.29 600 3

Mississippi River 0.89 600 2

Borden, IN farm well 21.3 600 0

all samples contained e 83 mg/L Ca [Ca(OH), K,, = 7.9~10'~Iand c 34 mg/L Mg [Mg(OH), K, = 5.7~10"~]

Fe must be stabilized (masked) to avoid filter clogging and memory


Analvsis of Chicago Domestic Water with iminodiacetate batch separation

Isotope pCi/L, ICP-MS pCi/L, a-spec mass yield, %

226Ra

230Th

232Th 234u

2 3 8 ~

ND

c 0.02

(4.9k0.2)~

0.13 k 0.02

0.099 f 0.005

0.4 f 0.1

< 0.02

c 0.02

0.17 -F. 0.01

0.092 k 0.008

16

13

Signal enhancement was only 4- to 6-fold using this procedure (25gold expected)

_ _ ~~~


3 d u U

h .

0 a U

8 0

+I 0

0 M

9 2 N N

w 0 0 6

+I 0 0

V m 0 0

3 0 X d

s g 0 0

+I 00 0

V

m 0 0

+I m \o 0

v) 0

+I

fi

0

M

0

PI 0

+I 0

m 0

+I v) #

0

0

Batch Concentration of Actinides via Cation Exchange DiphonixTM, 100-200 mesh (EIChroM)

1. 2.

Load 1 g resin from 125 rnL 0.5M HNO, (Kd 2 lo6 for Th(1V) and U(V1)) Filter and rinse resin with 18 Ma-cm water

3. Release analyte from resin w 1 .OM 1 -hydroxyethane- 1,l -diphosphonic acid (HEDPA)

Resin destruction J J

microwave digestion (e.g., EPA method 3051) hotplate digestion using H20, and Vv


Recovery of Actinides from DiDhonixTM Resin 0 . M 1 -hydro.xyethane-1,l -diphosphonic acid (HEDPA)

105

104

101

1 oo 228 230 232 234

d Z

236 238 240


Analvsis of Fresh Waters with DiphonixTM Batch Separation resin digest diluted to 50 mL (1.6 mg/mL dissolved solid)

234u. PCi/L 238u. PCi/L

sample ICP-MS a-spec ICP-MS a-spec

Chicago domestic 0.14 0.17 0.099 0.092

Lemont, IL domestic 1.67 1.72 0.09 1 0.095

Lemont, IL deep well 1.56 1.59 0.084 0.099

Hemck Lake 0.085 f 0.009 a 0.086 0.075 f 0.003 a 0.055

Fox River 0.40 f: 0.02 a 0.43 0.31 1 0.004 a 0.3 1

Kankakee River 0.68 0.69 0.55 0.5 1

a mean and standard deviation of triplicate analyses (3 sample aliquots prepared independently).

Work supported by the U. S. Department of Energy, Office of Environmental Restoration and Waste Management (EM-263) b

Figures of Merit for Batch Actinide Concentration on DiphonixTM using USN-ICP-MS detection

230Th 2 3 4 u 2 3 8 u A234’A238

MDL (pCi/L)

IDL (pCi/L)

% RSD (ca. 0.5 pCi/L)

0.2

0.2

paired t (n = 6)

0.02

0.1

5

2.1

4x 1 0-3

2x10-4

1 5

0.6 1.5


Batch Concentration of Actinides via Solid-Phase Extraction TRUoFPS TM (EIChroM)

TH'v+tiN03+CMPO:X4D # X4D:CMPO: Th(N03),

CMPO: octyl(phenyl)-N,N-diisobutylcarbamoylme~ylphosphine oxide

1. 2.

3.

Load 0.5 g resin from 30 mL 2M HNO, Filter and rinse resin with 5 mL 2M HNO, Release analyte with 6 mL 0.1M Ammonium Binoxalate (Binox, NH4HC,04)


Recovery of Actinides from TRUeFPSTM 0. IM Ammonium Binoxalate

106

105

2 $ 103 .?+ 6 m

lo2

10'

1 00 228 230 232 234

d . 2

236 238 240


Analvsis of Kankakee River Water with Batch Concentration on TRU-FPSTM (0.05M Binox)

234u, pci/L 238u, pci/L A234'A238

Aliquot 1

Aliquot 2

Aliquot 3

mean

0.7 1 0.61 1.153

0.69

0.69

0.60

0.59

1.148

1.159

0.69 0.01 0.60 A 0.01 - 1.153 * 0.005

230Th MDL for this procedure was 0.02 pCi/L (0.03 pCVL 230Th expected in sample) Tracer yields were between 12% (236U) and 33% (22gTh)


L

F

r

~~ ~

Summary- 230Th and 234s8U in Fresh Water

1.

2.

3.

4.

5.

From dilute solution, USN-ICP-MS IDLs are adequate for regulatory purposes, but inadequate for more demanding applications (e.g., hydrogeology).

Dissolved solids present in fresh waters prohibit simple evaporative concentration and direct analysis by USN-ICP-MS.

Batch concentration with isotope dilution offers the chemical specificity and quality assurance needed for most Umh measurements.

Various schemes for batch actinide concentration and matrix elimination seem promising, but extraction resin (TRU*FPSTM) yielded acceptable results with the least preparative effort.

In spite of low yields, batch concentration with TRU-FPSTM yielded improved 23@Th detection limits (1 pg/L) and excellent method precision (0.4% RSD for a 234:238 atom ratio of ca. 6~10-~) .


r j c

rcc 0

u5

ccc 0

rcr 0

rcr 0

determination of naturally-occurring actinides and …/67531/metadc702847/...obiective use icp-ms in...

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