234Th Generator
AN-1621-10
Summary of Method A method for the preparation of 234Th (t1/2 = 24.1 days) from natural or depleted Uranium(t1/2 = 4.47E9 years) source material is presented. The method utilizes extraction chromatography with a column of DGA,
Normal resin and 2mL cartridges of DGA and UTEVA resins to obtain high purity 234Th in small volumes of eluate, while
preserving 238U material. The source material is adjusted to 2M HNO3 and loaded onto a column of DGA, Normal resin.
234Th is retained on DGA Resin from up to 0.2M uranium, while uranium is unretained. The uranium source is recovered
and, following a suitable ingrowth period, can be used to produce additional 234Th. 234Th is stripped from the DGA resin
column and further purified using 2mL cartridges of DGA and TEVA resins.
Equipment
Glass/Plastic bottles for storage of Uranium source.
Glass or plastic vials/bottles for collection of 234Th andwaste.
10, 20 or 30mL plastic luer lock syringes.
Gamma Spectrometry System or alternative formeasurement of 234Th.
ICP-AES or alternative for measurement of U.
1.9cm i.d. glass or plastic column, minimum 15cm height,
with 250mL-1L reservoir.
Glass wool or frit material for top bed support.
Peristaltic pump or alternative to increase flow rate.

Reagents
TEVA Cartridges (Eichrom TE-R50-S)
DGA Cartridges (Eichrom DN-R50-S)
DGA, Normal Resin (Eichrom DN-B25-A)
Natural or Depleted U Source
Deionized Water
Oxalic Acid
Ammonium Oxalate
HCl
HNO3

Ingrowth of
100

238

Th from

238

U

Decay of234

Th from

238

4060

U100
U80

234

80

Th% Activity% Activity

23460
402060234

Th40200002040Days6080020Days80

234

Th Separation (50g U/17Ci 234Th)*(1) Slurry pack a column of 12g DGA,
Normal resin (100-150um), 1.9cmi.d. x 12.5cm height.**(2) Place top bed support on column.
Rinse column with 2-3 bed volumes of 0.1M HNO3. Store column
in 0.1M HNO3 between uses.
(3) Precondition column with 2 bed
volumes of 2M HNO3.
(4) Load 50g U source in 1L 2M HNO3
at 10-20mL/min. Discard first 20mLof eluate. Collect remaining eluate
containing U source material. Savefor future 234Th production.
(5) Rinse DGA column with 200mL of
1M HNO3. First 20mL may becollected and added to source.

(6) Strip 234Th from DGA with 200mLof 0.05M HNO3-0.05M Oxalic Acid.
(7) Add 29mL of conc. HNO3
to acidify eluate to 2M HNO3.
(8) Load onto 2mL cartridge of
DGA Resin.
(9) Rinse DGA with 25mL 0.5M
HNO3.
(10) Strip 234Th from DGA with 20mL
0.1M ammonium bioxalate.

**DGA resin can be difficult to wet.
Slurry the resin in 2x its volume of 1.0-1.5M HNO3 by gently swirling for 2-3minutes (avoid vigorous shaking as
this can incorporate air bubbles andcause resin to float). Centrifuge resin
slurry for 5-10 minutes. Repeat until
most of the resin sinks to the bottomof tube. Repeat swirling/
centrifugation, if needed. Use only
well wetted resin to pack the column(omit floating resin). The column may
be reused many times if stored indilute acid between uses.

(11) Acidify with 8mL conc. HNO3.
(12) Precondition 2mL TEVA
cartridge with 5mL 4M HNO3.
(13) Load onto TEVA.
(14) Rinse TEVA w/ 25mL4M HNO3.
(15) Strip 234Th w/ 15mL 0.5M HCl.

TODGA

6*Separation is scalable. Simply adjust
volumes of the initial DGA column andload solution to accommodate othersource sizes.

64Dowex 1x10TEHDGA

53Th(IV)
U(VI)5101010no U
4410100.1 M U

3kd
210100.5 M U

110210k'

0.1 M U

1100.2 M U U(VI)100

1010-1-1

10-1

10010
[HNO3]

1

10100.5 M U

010U(VI)

1

10100Th(IV)

Th(IV)

no U

10k' Th

0.2 M U2310210k' Th

10310TEVA

410 1010-110 10-1 -1
10 10-1

100010 10[HNO[HNO] 3]
31110 10-110010[HNO3]

110References1) E. P. Horwitz and D. R. McAlister, “The recovery of trace thorium from large quantities of uranium,” Solv. Extr. Ion
Exch., 27, 474-488, (2009).
1955 University Lane Lisle, IL 60532, USA+1 (630)963-0320

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