Table 1. (Continued)

Table 2. (Continued)

CAS No. Chemical Log Koy Source Chemical _CLOP@___AERLD Literature®
2524-09-6 _0,0,S-triethylester 3.12 e Dieldrin 4.09 + 0.05 4.3411
phosphorodithioic (n=2)
acid 4,6-dinitro- 3.75  4.12+0.04
66-75-1 Uracil mustard 0.16 e 0-cyclohelxyl (n=4)
1330-20-7____Xylene(ortho) 3.12 f phenol
Endosulfan 4.52 £0.10
a. Standard deviation (n=3)
b. Generally, use of Kgws for charged or ionizable species
as a predictive sorption parameter is unwarranted (see Endrin 432 4.92£0.18 33h
Results and Discussion). (n=4) oe
c. Nitrogen mustard alkylating agents — half-life in water °
at pH 7 and 25°C. is usually less than one day. Ethylene- -2.70 + 0.07
d, Measured at ERL-Athens bis-(dithio- (n=3)
e. CLOGP carbamic acid)
f. Starlist as disodium
g. CAS No. refers to Thiodan, a mixture of Endosuifan | salt
and Endosuifan Wt , Heptachlor 4.61 5.53+0.22 5.446
h. CAS No. refers to “Trichlorobenzene,” Kow of the 1.2.4 (n=4) 4.418
‘somer was measured. Kepone 5.30 + 0.09 2.008
(n=4)
Table 2. Comparative Log Kow Values Lasiocarpine 0.93«1.28 40.14 0.998
Chemical CLOP@ _AERLD Literatures (n=4)
Aldrin 5.09 5.11+0.04d 5.528 Pronamide 295 3.43+0.10
(n=4) (n=4)
Azaserine -2.00 +0.06 -1.085 Pyrene 5.05+ 5.0540.27 5.22+0.05
(n=3) 0.16 (n=13) (n=2)4
Biphenyl 4.0940.12  3.9940.12 Toxaphene 4.02 04.63 +0.33 5.502
(n=8) (n=5)4 (n=4) 2.927
3.884 3.308
Chlorambucil 3.61.‘ Hydrolysis rate 2.745 1,2,4- 4.28 4.16+40.11  4.06+0.11
too fast Trichloro- (n=2) (n=4yt2.13
tye<2 hrs at benzene
25°C, BHT Calculated using CLOGP
a alculat ISI
Chlordane 554 601s030° 6.004 B Meseued at ESLAthens
(Tech) — (n=4) 2.78! c. Superscript numbers identify data sources listed in
6.41 +0.10F 5.486 “References.”
(n=4) d. Standard deviation
Diallate 4.49 £0.06 0.738 e. cis isomer of chlordane
(n=4) f._ traris isomer of chlordane
(Continued)

United States
Environmental Protection
Agency

Center for Environmental Research
Information
Cincinnati OH 45268

BULK RATE
POSTAGE & FEES PAID
EPA
PERMIT No. G-35

Official Business
Penaity for Private Use $300

EPA/600/M-88/010


United States
Environmental Protection
Agency

Environmental
Research Laboratory
Athens, GA 30613

Research and Development

EPA/600/M-88/010 August 1988,

EPA

ENVIRONMENTAL

RESEARCH BRIEF

Octanol/Water Partition Coefficients for Evaluation of
Hazardous Waste Land Disposal: Selected Chemicals

J. Jackson. Ellington.and.Frank.E.. Stancil, .Jr.

Abstract

Octanol/water partition coefficients were extracted from the
literature, calculated using a molecular fragment data base
(CLOGP), or measured in: the laboratory for selected
chemicals. Agreement between measured values and
calculated values was good for chemicals for which both
types of information was available. Partition coefficients are
reported for members of six chemical classes: polynuclear
aromatic hydrocarbons, chlorinated hydrocarbons,
phosphate esters, nitrogen mustards, alkylamines, and
amines. Measurements of the octanol/water partition
coefficients of two standard reference chemicals, pyrene
(log Kow =5.05 +0.27) and biphenyl! (log Kow = 4.09 + 0.12),
were interspersed with determinations. of log Kow of
compounds of interest to serve as quality assurance
indicators.

Background

The Hazardous and Solid Waste Amendments of 1984 to
the Resource Conservation and Recovery Act (PL 98-616)
stipulate that land disposal of "hazardous wastes” is
prohibited unless the EPA Administrator determines that
specific compounds are not likely to reach unacceptable
levels in ground water at an individual disposal site. The
amendments define hazardous waste as any of 362 specific
compounds (either part~of or inclusive of Appendix~VIIl
compounds): In compiling this list, major considerations
were toxicity of the material and quantity of waste material
generated annually.

To provide a practical tool for determining which listed
hazardous materials may be accepted for land disposal and
under what conditions, a relatively simple model that would

The authors are with the U.S. Environmental Protection Agency's
Environmental Research Laboratory, Athens, GA 30613.

estimate potential ground-water contamination for each
listed chemical at a specified withdrawal point downgradiant
from a failed facility was developed. The model calculates
horizontal chemical movement in the aquifer based on
advection, dispersion, sorption, and transformation.

To implement this modeling approach, it was necessary to
acquire octanol/water partition coefficients for each of the
362 chemicals identified by the U.S. Environmental
Protection Agency's Office of Solid Waste. The
octanol/water partition coefficients are used to estimate
sorption equilibrium constants (kg). Karickhoff and Ellington
et al. reported log Kow values for 251 and 40 chemicals,
respectively. This report presents the octanol/water partition
data developed by Ellington and coworkers along with
values for an additional six chemicals. Included are
members of six chemical classes: polynuclear aromatic
hydrocarbons, chlorinated hydrocarbons, phosphate esters,
nitrogen mustards, alkylamines, and amides. Because of
the procedures followed in their development, the Kow data
may be used with confidence in any appropriate modeling
application.

Each chemical was evaluated with regard to applicability of
a sorption estimation protocol. Where applicable, Kow
values were obtained from a data base compiled by Veith’.
The Kow values. in Veith:s data-base were-obtained-from
Medchem Software Release 3-33, a data base developed
by Leo and Weininger?. Medchem Software Release 3-33
contains STARLIST, a data base of measured log Kow
values3, and CLOGP, a data base that contains values for
molecular fragments that allow calculation of a log Kow.

Laboratory Procedures

The method of Karickhoff et al.4 was used at the
Environmental Research Laboratory, Athens GA (ERL-
Athens) to determine the log Kow values. Reagent grade

IS» S»»


octano! was extracted once with 0.1 N sodium hydroxide,
and twice with distilled water. It was subsequently distilled
at atmospheric pressure. The first 15 ml of distillate were
discarded, then approximately 70% of the remaining
volume was collected and stored in an amber bottle.
Mutually presaturated water (deionized, organic free) and
octanol were used in the experiments.

Log Kow Greater than 1000

Those chemicals for which the Kow was expected to be
greater than 1000 were dissolved in octanol, and 2 mi of
this solution was added to 40 ml of. octanol-saturated
water contained in 50-mi stainless steel centrifuge tubes.
The tubes were sealed and gently mixed by hand-swirling
for 15 minutes. After standing for a minimum of 12 hours,
the tubes were centrifuged for 30 min at 15,000 rpm
(Sorvall SS-34) and the phases sampled directly from the
centrifuge tubes To perform the analysis an aliquot of
octanol (0.25 - 1.0 ml) was removed from the centrifuge
tube and added either directly into an analysis cell (UV) or a
diluting solvent suitable for subsequent analysis by gas
chromatography (GC) or high performance liquid
chromatography (HPLC). The remaining octanol and top 1
ml of water were removed from the tube and discarded
before withdrawing an aliquot of the water layer for analysis.
Care was taken to avoid touching the inner wall of the tube.
If the aqueous layer had been contaminated with even a
trace of the octanol containing the test chemical, significant
error in Kow Measurement could have resulted.

For analysis by GC, the aqueous phase was extracted with
three 2-ml portions of hexane. The hexane extract was
concentrated to 1 ml by nitrogen blowdown before addition
of an internal standard and subsequent quantitation by GC.
After establishing GC detector response for the hexane
extract of the aqueous layer, the octanol aliquot was serially
diluted with hexane until detector response for the analysis
of the octanol dilution and hexane extract were within a
factor of two. An internal standard then was added to the
octanol: dilution before quantitation by GC. The internal
standard allowed normalization of the amounts of chemical
in each layer, and when combined with the dilution and
concentration factors in equation 1, permitted calculation of
the Kow.

_ [ORWDCF) qa)
ow” [WRIIDCF]
where:
OR = Value obtained from octanol layer
WR = __ Value obtained from water layer
DCF = _ Dilution or concentration factor

If the chemical is intractable to analysis by GC, alternative
analytical methods (UV, HPLC, etc.) must be established to
allow calculation of the ratio expressed in equation 1.

Log Kow Less Than 1000

Measurement of KowsS for chemicals having expected
values less than 1000 is illustrated by the following
example. Lasiocarpine was dissolved in 5 ml of octanol and
added to 5 mi of water. After gentle mixing, standing, and
centrifugation, aliquots from each phase were diluted with
CH3CN and subsequently analyzed by HPLC. The two

compounds having high water solubility, [azaserine and
ethylene-bis (dithiocarbamic ‘acid)], were dissolved in
water rather than octanol. The partition equilibrium was
established using equal volumes of stock solution water and
octanol. Concentrations in the water and octanol were
determined by appropriate HPLC and UV methods,
respectively. Partition coefficients were calculated using
equation 1 and the response values and dilution or
concentration factors obtained for the octanol and water
phases.

Results and Discussion

Table 1 contains the list of chemicals and corresponding
log Kow values from Ellington et al. plus recently measured
values for six more compounds.. The log Kgw value for each
chemical was either measured at ERL-Athens, obtained
from literature sources, or calculated using CLOGP. The
higher ERL-Athens values for pronamide and lasiocarpine
(Table 2) may reflect the difficulty in obtaining CLOGP
calculations for polyfunctional compounds. Many literature
KowS were given as single measurements. For two
chemicals, literature values varied over two orders of
magnitude (chlordane and toxaphene). The ERL-Athens
values for diallate and kepone showed the greatest
deviation from literature values. Generally, the CLOGP-
calculated values were in good agreement with measured
values except as noted previously for pronamide and
lasiocarpine.

fonizable compounds listed in Table 1 are present in
aqueous solution as both ionized and unionized species.
The pKa or pKp of such ionizable compounds as well as the;
pH and ionic strength of the aqueous systems must bi

known when using their respective Kows to predict
sorption!4, '

Measurement of the Kows for pyrene and biphenyl was
interspersed with measurement of the Kows of the other
chemicals. Reproduction of the Kows of these standard
reference compounds (SRCs) ensured that the
experimental conditions were of known precision and
helped in evaluating the accuracy and precision of
measurements for other compounds.

Acknowledgments

A note of appreciation to Dr. Gilman Veith (Environmental
Research Laboratory, USEPA, Duluth, MN) for providing the
STARLIST and CLOGP values, and Drs. William Steen and
Chad Jafvert (ERL-Athens) for reviewing the. manuscript.

References

1. QSAR: A structure-activity based chemical modeling
and information system developed jointly by the U.S.
EPA, Duluth, Minnesota, and Montana State University
Institute for Biological and Chemical Process Analysis.

2. Leo, A. and D. Weininger. 1985. Medchem Software
Release 3.33, Medicinal Chemistry Project. Pomona
College, Claremont, CA.

3. Leo, A. C. Hansch and D. Elkins. 1971. Partition
Coefficients and Their Uses. Chem. Rev. 71:525-616.

4. Karickhoff, S.W., D.S. Brown and T.A. Scott. 1979
Sorption of Hydrophobic Pollutants on Natural
Sediments. Water Research, 13 (2): 241-248.


10.

. Kanazawa J.

Jaber, H:'M. et al. 1984. Data Acquisition for
Environmental Transport and Fate Screening for
Compounds of Interest to the Office of Solid Waste.
U.S. Environmental Protection Agency, Washington,
DC. EPA-600/6-84-010 and EPA-600/6-84-011.

Veith, G.D. et al. 1979. Measuring and Estimating the
Bioconcentration Factor of Chemicals in Fish. J. Fish
Res. Board Can., 36, 1040-1048.

Sanborn, J.R. et al. 1976. The Fate of Chlordane and
Toxaphene in a Terrestial-Aquatic Model Ecosystem.
Environ, Entomol., 5, 533-538.

Mabey, W.R. et al. 1982. Aquatic Fate Process Data for
Organic Priority Pollutants. U.S. Environmental
Protection Agency, Washington, DC. EPA-440/4-
81-014.

Neely, W.B., D.R. Branson, and G.E. Blau. 1974.
Partition Coefficients to Measure Bioconcentration
Potential of Organic Chemicals in Fish. Environmental
Sci. and Tech., Vol. 8, pp. 1113-1115.

Garten, C.T. and J.R. Trabalka. 1983. Evaluation of
Models for Predicting Terrestrial Food Chain Behaviour
of Zenobiotics. Environmental Sci. and Tech., 17, pp.
590-595.

1981. Measurement of the
Bioconcentration Factors of Pesticides by Freshwater
Fish and Their Correlation with Physicochemical
Properties or Acute Toxicities. Pesticide Science, 12,
pp. 417-424.

. Geyer, H.G., Politzki, and D. Freitag. 1984. Prediction

of Ecotoxicological Behaviour of Chemicals:
Relationship Between n-Octanol/Water Partition
Coefficient and Bioaccumulation of Organic Chemicals
by Alga Chlorella. Chemosphere, 13, 2, pp. 269-284.

. Kenega, E.£. and C.A1. Goring. 1978. Proc. Third

Aquatic Toxicology Symposium. Amer. Soc. Testing
Materials, New Orleans, LA.

. Westall, J.C., C. Levenberger and R.P. Schwarzenback.

1985. Influence of pH and lonic Strength on the
Aqueous-Nonaqueous Distribution of Chlorinated
Phenols. Environ. Sci. Tech. 19, pp. 193-198.

Table 1. Compilation of Log Kow Values for Appendix

Vill Chemicals
CAS No. Chemical Log Kow _ Source
309-00-2 Aldrin 5.11 40.048 d
(n=4)
115-02-6 Azaserine -2.00 + 0.06> d
(n=4)
56-55-3 Bena(a)anthracene 5.66 e
205-99-2 Benzo(b)fluoranthene 6.12 e
225-51-4 Benz(c)acridine 461 e
305-03-3 Chlorambucil¢ 3.61 e
87-74-9 Chlordane (Tech) 5.54 e
494-03-1 Chlornaphthazinec 4.53 e
50-18-0 Cyclophosphamidet 0.63 f
72-54-8 DDD (p,p’isomer) 6.02 t
2303-16-4 Diallate 4.49 +0.06 a
(n=4)
(Continued)

Table 1. (Continued)

CAS No. Chemical Log Koy _ Source
189-55-9 1,2,7,8- 6.94 e
Dibenzopyrene
60-57-1 Dielarin 4.094007 d
1615-80-1 N,N’ e
Diethyihydrazine
311-45-5 Diethy!-p- 1.98 f
nitropheny!
phosphate
3288-58-2 _0,0-Diethyl-S- 2.79 e
methyl-
dithiophosphate
124-40-3 Dimethylamine -0.49 e
540-73-8 1,2- 1.36 e
Dimethythydrazine
131-89-5 4,6-Di-Nitro-O 4.12+0.04 d
cyclohexyl phenol (n=4)
298-04-4 Disulfoton 3.94 +0.05 a
(n=5)
115-29-79  Thiodan (Endo- 4.524010 d
sulfan {l measured) (n=3)
72-20-8 Endrin 4.92 +0.18 d
(n=4)
111-54-6 Ethylene- -2.70+0.07 d
bis(dithiocarbamic (n=3)
acid) as disodium salt
62-74-8 Fluoroacetic acid, -0.06 e
sodium-salt
50-00-0 Formaldehyde 0.35 f
765-34-4 Glycidytaldehyde 1.05 e
76-44-8 Heptachlor 5.53 +0.22 d
(n=4)
757-58-4 Hexaethyl- 5.25 e
tetraphosphate
143-50-4 Kepone 5.30 + 0.09 d
(n=4)
303-34-4 Lasiocarpine 1.284014 d
(n=4)
148-82-3 Melphalane -0.21 e
91-80-5 Methapyriline 2.74 e
16752-77-5 — Methomyl 0.60 f
72-43-5 Methoxychlor 4.68 f
298-00-0 Methyl parathion 2.86 f
4549-40-0 N-Nitroso- 0.003 e
methyivinylamine
56-38-2 Parathion 3.83 f
298-02-2 Phorate 2.92 f
23950-58-5 — Pronamide 3.43 +£0.10 d
(n=4)
18883-66-4 — Streptozocin “1.45, e
3689-24-5 0,0,0,0-Tetraethy! 3.83 +0.10 d
dithiopyrophosphate (n=4)
8001-35-2 Toxaphene 4.63 + 0.33 d
(n=4)
12002-48-1 1,2,4- 4.16 40.11 d
Trichlorobenzeneh (n=2)

(Continued)