SWRHL-8r
A METHOD FOR POSITIVE COLLECTION OF IODINE
FROM AIRBORNE CARBON-IODINE BONDED COMPOUNDS
by
E. L. Whittaker, E. W. Bretthauer, R. J. Griffin,
T. F. Worford, and R. D. Rawson
Radiochemistry Laboratories Program
June 26, 1964
SOUTHWESTERN RADIOLOGICAL HEALTH LABORATORY
Las Vegas, Nevada
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SWRHL-8r
A METHOD FOR POSITIVE COLLECTION OF IODINE
FROM AIRBORNE CARBON-IODINE BONDED COMPOUNDS
by
E. L. Whittaker, E. W. Bretthauer, R. J. Griffin
T. F. Worford, and R. D. Rawson
Radiochemistry Laboratories Program
Southwestern Radiological Health Laboratory
Las Vegas, Nevada
for
Bio environmental Research Program
Southwestern Radiological Health Laboratory
Las Vegas, Nevada
Copy No. 3
J. R. McBride, Assistant Officer in
Charge
SWRHL, Las Vegas, Nevada
June 26, 1964
Department of Health, Education, and Welfare
Public Health Service
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ABSTRACT
A method for quantitative collection of iodine from carbon-iodine bond-
ed compounds is described. This method utilizes a high-frequency elec-
tric spark to rupture the carbon-iodine bond followed by collection of
the resultant ionic and molecular iodine forms on ion-exchange resin.
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PREFACE
This method was developed by the authors for the Bioenvironmental Re-
search Program, Southwestern Radiological Health Laboratory, as a
part of the Iodine Investigation Studies they are conducting under the
sponsorship of the Atomic Energy Commission.
The authors gratefully acknowledge the support of the Bioenvironmental
ResearchProgram, SWRHL, and of the Nevada Operations Office, AEC.
11
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TABLE OF CONTENTS
ABSTRACT i
PREFACE ii
TABLE OF CONTENTS iii
Introduction 1
Materials and Methods 2
Results and Discussion 4
REFERENCES 6
DISTRIBUTION
TABLES
Table 1. Iodine recoveries without using spark discharge. 4
Table 2. Iodine recoveries using spark discharge. 4
FIGURE
Figure 1. Flow diagram of apparatus.
111
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A METHOD FOR POSITIVE COLLECTION OF IODINE
FROM AIRBORNE CARBON-IODINE BONDED COMPOUNDS
Introduction
This paper is published as part of a comprehensive study toward
development of an efficient sampling system for all forms of airborne
iodine.
Recent evidence has indicated that the iodine from gaseous carbon -
iodine bonded compounds is not efficiently collected by air sampling
systems which use either activated charcoal1'2 or basic ion-exchange
resin3 as adsorbents. As it is known that both activated charcoal4'5'6
and basic ion-exchange resin7 display excellent retentive properties for
gaseous ionic and molecular forms of iodine, a method for practical
immediate rupture of the carbon-iodine bond would prove meaningful.
Spark discharge -was preferred for such dissociation both from
kinetic and thermochemical considerations. The stoichiometry8 of the
pyrolysis should follow the equation:
2RI-»-olefin + RH+I2
with some minor contribution from
RI-Kjlefin + HI
Unsaturated or conjugated iodides such as allyl I or Q5CH2 I 9 follow a
simpler course:
2RI-»- R2 + I2
This is also true of di-iodides1 °» ' l which proceed as
RI2*^ hydrocarbon +I2
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Thus in every case, the pyrolysis of carbon-iodine bonded compounds
leaves the iodine in either the molecular or the iodide form.
Materials and Methods
The apparatus (Figure 1) used for determining the efficiency of
spark discharge for carbon-iodine bond rupture consisted of: a flow-
through type glass generator flask, a dual tungsten electrode glass re-
action chamber using aTesla coil as spark source, dry, strongly basic
ion-exchange resin (Dowex 1 X-8, 50-100 mesh) packed in a 7. 6 cm by
3. 2 cm I.D. (3"x 1.25"I.D.) plexiglass cylinder fitted at either end
with Millipore filters (MF Type HA, 0. 45fi jt 0. 02|j. ), and a Gelman
pump (Model 13152) and rotameter.
Basic ion-exchange resin was used in preference to charcoal for
adsorption of inorganic ionic and molecular iodine forms because of its
stronger iodine bond and its lower rate of surface erosion. Surface
erosion causes iodine losses due to particulate escape through the Milli-
pore filter, i.e., particles smaller than 0.45(ju
All recoveries •were determined at room temperature (25 to 30°C)
with the air flow regulated between 14.1 to 19.8 1pm (0.5 to 0.7 cfm)
during and for five additional hours after volatilization. The compounds
tested were labeled methyl, ethyl, butyl, octyl, and phenyl iodides.
These compounds were labeled by 14 Mev neutron activation utilizing
the (n, 2n) reaction. A Texas Nuclear (Model 9500) generator provided
the neutron source. This method of labeling provides rather low spe-
cific activity iodine compounds. The volume of the compounds used in
the experiments ranged from 0. 1 to 1.0 ml.
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0.2 MM (0.050 INCH)
TUNGSTEN
!2.7MM(l/2 INCH)
ATMOSPHERIC
AIR
VENT
-IODINE
SOLUTION
VACUUM PUMP
Figure 1. Flow diagram of apparatus.
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Results and Discussion
When the spark was not used during volatilization, very low re-
tention was exhibited by basic ion-exchange resin for iodine in the above
compounds (Table 1). However, when the spark discharge was used
during volatilization, quantitative retention of the iodine was displayed
by the resin for all the above compounds (Table 2). The results are
even more striking considering the low specific activity of the labeled
iodine compounds. Thus the iodine in carbon-iodine bonded compounds
can be permanently and quantitatively collected by suitable ionic and
molecular iodine absorber s by fir st dissociating the compounds by spark
discharge.
Table 1. Iodine recoveries without using spark discharge.
Compound Activity Added Activity Recovered
Tested (cpm) (cpm)
Methyl Iodide 28,755 2,444
Ethyl Iodide 8,137 1,196
Butyl Iodide 12,276 1,079
Octyl Iodide 22,473 3,724
Phenyl Iodide 9,276 925
Table 2. Iodine recoveries using spark discharge.
Compound Activity Added Activity Recovered
Tested (cpm) (cpm)
Methyl Iodide 14,264 15,102
Ethyl Iodide 6,274 6,241
Butyl Iodide 8,991 8,576
Octyl Iodide 12,843 11,988
Phenyl Iodide 7,745 7,700
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A sampler for airborne iodine, which incorporates a spark dis-
charge to dissociate any carbon-iodine bonded compounds, hasbeenfab-
ricated. Tests are currently under way for development of pertinent
parameters, i. e. , discharge energy, discharge frequency, coefficients
of energy absorption of the respective gasses, and adsorption bed thick-
ness .
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REFERENCES
1. A.E.J. Eggleton and D.H. Atkins, A.E.R.E., Identification of
Radio-iodine Compounds Formed on Releasing Carrier-Free I1 31
in Air; presented at the Annual Meeting of the American Nuclear
Society, (1963).
2. D.A. Collins, R. Taylor and W.D. Yhille, Experience in Trapping
Iodine-131 and Other Fission Products Released From Irradiated
AGR-type Fuel Elements, TID-17677. presented before the Eighth
Annual AEC Air Cleaning Conference, (1963).
3. S. Forberg and C.E. Holmquist, Nucleonic 3, 31, (1961).
4. C.K. Cederberg andD.K. MacQueen, Containment of Iodine-131
Released by RaLa Process, Document IDO-14566, (1961).
5. Oak Ridge National Laboratory Status and Progress Report, Jan.
1961, p.9, (1961).
6. R.M. Watkins, D.D. Busch, L..R. Zimwalt, Nuclear Engineering 6,
427, (1961).
7. S. Forberg and C.E. Holmquist, Nucleonic 3, 31, (1961).
8. R.A. Ogg, J. Am. Chem. Soc. 56, 532, (1934).
9. A. Shaw, M.S. thesis, University of Manchester, (1948).
10. L.B. Arnold and G. B. Kistiakowsky, J. Chem. Phys. 1, 166, (1933)
11. S.W. Benson and A. Amano, J. Chem. Phys. 36, 3464, (1962).
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DISTRIBUTION LIST
Copy No.
1 - 15 SWRHL, Las Vegas, Nevada
16 James E. Reeves, Manager, NVOO, AEG, Las Vegas, Nevada
17 - 19 Otto H. Roehlk, OSD, NVOO, AEC, Las Vegas, Nevada
20 Henry G. Vermillion, NVOO, AEC, Las Vegas, Nevada
21 Col. E.G. Halligan, DASA, NVOO, AEC, Las Vegas, Nevada
22 John S. Kelly, DPNE, AEC, Washington, D.C.
23 RobertE. Baker, Div. of Licensing & Regulations, AEC,
Washington, D.C.
24 - 29 Gordon M. Dunning, DOS, AEC, Washington, D.C.
30 G. D. Ferber, USWB, MRPB, (R-3.3), Washington, D.C.
31 PhillipW, Allen, USWB, NVOO, AEC, Las Vegas, Nevada
32 Frank D. Cluff, USWB, NVOO, AEC, Las Vegas, Nevada
33 Donald L. Snow, RSC, DRH, PHS, Washington, D.C.
34 Bernd Kahn.DRH, RATSEC, Cincinnati, Ohio
35 Ernest C. Anderson, TOB, DRH, PHS, Washington, D.C.
36 Raymond Moore, DRH, PHS, Region VII, Dallas, Texas
37 John Philip, San Francisco Regional Office, PHS,
San Francisco, California
38 Northeastern Radiological Health Laboratory, Winchester, Mass
39 Southeastern Radiological Health Laboratory, Montgomery, Ala.
40 Rockville Radiological Health Laboratory, Rockville, Md.
41 Geraldine Werdig, TOB, DRH, PHS, Washington, D.C.
42 Samuel Weider, RRHL, Rockville, Maryland
43 James G. Terrill, Jr., DRH, PHS, Washington, D.C.
44 Edmund L. Fountain, USA, MEDS, VS, Chicago, Illinois
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Copy No.
45 Victor M. Milligan, REECo, Mercury, Nevada
46 Clinton S. Maupin, REECo, Mercury, Nevada
47 Gary G. Higgins, LRL, Livermore, California
48 John W. Gofman, LRL, Livermore, California
49 Robert H. Goeckermann, LRL, Livermore, California
50 Edward H. Fleming, LRL, Livermore, California
51 Bryce L. Rich, LRL, Mercury, Nevada
52 Alvin C. Graves, LASL, Los Alamos, New Mexico
53 Harry Jordan, LASL, Los Alamos, New Mexico
54 Charles I. Browne, LASL, Los Alamos, New Mexico
55 William E. Ogle, LASL, Mercury, Nevada
56 Mail & Records, NVOO, AEC, Las Vegas, Nevada
57 - 106 Authors' Copies
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