&EPA
United States
Environmental Protection
Agency
Environmental Research
Laboratory
Athens GA 30605
EPA-600/3-78-060
June 1978
Research and Development
Surfactant Effects
on Pesticide
Photochemistry
in Water and Soil
-------
RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into nine series. These nine broad cate-
gories were established to facilitate further development and application of en-
vironmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The nine series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
6. Scientific and Technical Assessment Reports (STAR)
7 Interagency Energy-Environment Research and Development
8. "Special" Reports
9. Miscellaneous Reports
This report has been assigned to the ECOLOGICAL RESEARCH series. This series
describes research on the effects of pollution on humans, plant and animal spe-
cies, and materials. Problems are assessed for their long- and short-term influ-
ences. Investigations include formation, transport, and pathway studies to deter-
mine the fate of pollutants and their effects. This work provides the technical basis
for setting standards to minimize undesirable changes in living organisms in the
aquatic, terrestrial, and atmospheric environments.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
-------
EPA-600/3-78-060
June 1978
SURFACTANT EFFECTS ON PESTICIDE
PHOTOCHEMISTRY IN WATER AND SOIL
by
Richard R. Hautala
Department of Chemistry
University of Georgia
Athens, Georgia 30602
Grant No. R-802959
Project Officer
Dr. Richard G. Zepp
Environmental Processes Branch
Environmental Research Laboratory
Athens, Georgia 30605
ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
ATHENS, GEORGIA 30605
-------
DISCLAIMER
This report has been reviewed by the Environmental Research Laboratory, U.S.
Environmental Protection Agency, Athens, Georgia, and approved for publication.
Approval does not signify that the contents necessarily reflect the views and policies
of the U S. Environmental Protection Agency, nor does mention of trade names or
commercial products constitute endorsement or recommendation for use.
ii
-------
FOREWORD
Environmental protection efforts are increasingly directed towards the preven-
tion of adverse health and ecological effects associated with specific compounds of
natural or human origin. As part of this laboratory's research on the occurrence,
movement, transformation, impact, and control of environmental contaminants, the
Environmental Processes Branch studies the microbiological,, chemical, and physico-
chemical processes that control the transport, transformation, and impact of pollutants
in soil and water.
The toxicity and persistence of pesticides and their decomposition products are
problems of major concern to those concerned with environmental quality. Unfortu-
nately, much information is lacking on the fate of these materials. The study reported
here investigates the photodecomposition of three pesticides on soil surfaces and
examines the influence that surfactants have on the photodecomposition of these pestici-
des in aqueous solutions. The report contributes to the overall perspective of the
pesticide problem and provides quantitative rate data that can be used in environ-
mental modeling studies.
David W. Duttweiler
Director
Environmental Research Laboratory
Athens, Georgia
in
-------
ABSTRACT
The effects of surfactants on the photochemical decomposition of selected
pesticides are examined both in aqueous solution and on selected soil surfaces. Typi-
cal surfactants usually enhance the rate of pesticide photodecomposition. In solution,
increased quantum efficiencies and increased overlap with available solar irradiation
are observed. In addition, surfactants enhance the solubility of-otherwise sparingly
soluble pesticides. Photodecomposition on soil surfaces is inefficient. Surfactants
enhance the rates of decomposition in certain cases on soil surfaces, but the effects
do not appear to be sufficiently large to make such a mode of decomposition com-
petitive. It has been postulated that the reason pesticide photochemistry on soils
is so inefficient is that excitation energy is lost to pigments in the soil. This report
was submitted in fulfillment of Grant No. R-802959 by The University of Georgia
under the sponsorship of the U.S. Environmental Protection Agency. Work was com-
pleted as of November 30, 1977.
IV
-------
CONTENTS
Page
Foreword iii
Abstract iv
List of Figures vi
List of Tables vii
Acknowledgments viii
Sections
Conclusions 1
Recommendations 2
Introduction 3
Results and Discussion 7
Aqueous Phase Studies 7
Soil Studies 19
Experimental 33
References 42
G lossary 46
Appendix 47
-------
FIGURES
Number Page
1 Surfactants and Pesticides Used in this Study 7
2 Photolysis of 2,4-D Methyl Ester with Cationic Detergent 13
3 Photolysis of 2,4-D Methyl Ester in Water 14
4 Photolysis of 2,4-D Methyl Ester with Anionic Detergent 15
5 Photolysis of Sevin in Water 16
6 Photolysis of Sevin with Cationic Detergent 17
7 Photolysis of Sevin with Anionic Detergent 18
8 Apparatus for Photolysis on Soil Surfaces 20
9 Photodecomposition of 2,4-D on Soil I (Dry) as a Function 21
of Time
10 Graphical Representation of the Extent of Photolysis of 26
2,4-D on Soils
11 Graphical Representation of the Extent of Photolysis of 27
Sevin on Soils
12 Graphical Representation of the Extent of Photolysis of 28
Parathion on Soils
13 Fluorescence Spectra of 1-Naphthol 32
14 Schematic Diagram of the High Resolution Time Resolved 33
Emission Spectrometer
VI
-------
TABLES
Number Page
1 Extinction Coefficients for 2,4-D Methyl Ester 8
2 Extinction Coefficients for Sevin 9
3 Extinction Coefficients for Parathion 10
4 Calculated Photolysis Half-lives for Aqueous Solutions 12
of 2,4-D Methyl Ester, Sevin and Parathion Irradiated
by Sunlight
5 Soil Characteristics 19
6 Effects of Soil Types, Detergents and Soil Water Content on 23
the Time Required for 50% Photodecomposition of 2,4-D
7 Effects of Soil Types, Detergents and Soil Water Content 24
on the Time Required for 50% Photodecomposition of Sevin
8 Effects of Soil Types, Detergents and Soil Water Content on the 25
Time Required for 50% Photodecomposition of Parathion
9 Calculated Photolysis Half-lives for 2,4-D Acid, Sevin and 29
Parathion on Soil Surfaces Irradiated by Sunlight
10 Effects of Parameter Variations on the Photodecomposition 30
of Parathion on Soil III
VII
-------
ACKNOWLEDGMENTS
We gratefully acknowledge the generous gift of soils and their characterization
by Professor H. F. Perkins, Department of Agronomy, University of Georgia.
We also acknowledge helpful discussions with Dr. Richard G. Zepp, project
officer.
Laboratory studies were ably performed by Dr. Ram D. Laura, Dr. M. P. Neary,
and Dr. Shuya A. Chang. They were assisted by Thomas Mayer, John Gordon,
Nancy Seabolt, Shohreh Tabanfar, Riley Hastings and Robert Fincher.
VIM
-------
SECTION 1
CONCLUSIONS
Surfactants increase the solubility of otherwise sparingly soluble pesticides
thereby increasing the likelihood of their decomposition in aqueous solution.
Surfactants alter the light absorbing characteristics of certain pesticides by
generally shifting the absorption bands to lower energy. This alteration has the effect
of increasing the overlap of the absorption band and the solar radiance spectrum.
In certain cases, surfactants enhance the quantum efficiency of pesticide
photodecomposition in solution. In combination with above-mentioned factors, a
significant enhancement in the "rate" of photodecomposition is realized.
The photochemical decomposition of these pesticides on soils is far less efficient
than in solution. Although detergents and soil water have been shown to enhance
the rate of decomposition on soils in certain cases, it is unlikely that this mode of
decomposition will be environmentally important unless actual aqueous solutions
of the pesticides are formed. For certain pesticides which absorb strongly in the
near UV and visible spectral regions, the rates of photolysis might be sufficiently
fast (in spite of low quantum efficiencies) to invalidate this conclusion. It has been
postulated that loss of excitation energy to pigments in the soil may be responsible
for the slow rates of photodecomposition observed. Fluorescence experiments on soil
surfaces are consistent with this hypothesis.
Experiments have verified that photodecomposition on soil surfaces would occur
only at the outermost surface of the soil. Thus any penetration by a pesticide into
the soil would diminish further the already slow photodecomposition process.
-------
SECTION 2
RECOMMENDATIONS
It appears that sunlight Induced decomposition of pesticides is likely to be
important only in solution (and perhaps in the atmosphere) rather .than on soil sur-
faces. Therefore, the rate and nature of pesticide photodecomposition should be
studied in aqueous solution in the presence of the formulating agent. In addition,
naturally occurring surfactants and emulsifying agents may exert a similar effect
in accelerating pesticide decomposition in water runoff conditions and should be
examined.
-------
SECTION III
INTRODUCTION
A problem of major concern to the environmentalist is the fate of pesticides
both as persistent species and with regard to the toxicity and persistence of their
decomposition products. Contributing to the complexity of the problem is the
increasing variety of types of pesticides that are replacing those such as DDT for
which data show intolerable levels of persistence and toxicity. An alarming aspect
of employing new pesticides is the lack of reliable information concerning the over-
all cumulative effect on the environment of /their persistence and of the toxicity and
persistence of their decomposition products. ' The problem is likely to become more
severe, but even now briad attempts to trace the fate of pesticides account for only
some 10% of that which has been applied.
The action of sunlight on pesticides in the field, in air-suspended droplets,
and in water runoff is likely to be an important mode of pesticidal decomposition in
competition with microbial decomposition and to some extent, with ordinary chemical
decomposition. Ultimately to obtain an intelligent perspective of the pesticide
problem an overall picture must be assembled that includes: (1) the probable rates
of decomposition by these various means as determined under conditions closely
resembling those in the environment and (2) knowledge of the decomposition products
and their subsequent fate. To this end, numerous studies of the photochemistry of
a variety of pesticides have been pursued. Many of these studies are subject to the
criticism that they were carried out under laboratory conditions bearing little resem-
blance to those found in the environment. In defense of such studies, however, it
has been pointed out numerous times that analytical difficulties and other problems
make studies of pesticide photochemistry in the "field" exceedingly complicated.
The purpose of this study was to consider the effects of such environmental perturbants,
namely surfactants (also called detergents),and their role in altering pesticidal
photochemical behavior. Surfactants enter the environment through a variety of
natural sources and as water pollutants in waste effluent, but perhaps the most im-
portant source of surfactants with regard to pesticides is the simultaneous co-applica-
tion of pesticides and surfactants in pesticidal formulations. The effect of surfac-
tants and their aggregates (micelles) on chemical and photochemical reactions is a
topic of intensive investigation. Studies have shown that surfactants can dramatically
alter the course of photochemical reactions." Among the effects potentially pert?-
nent to pesticide photochemistry are:
-------
(1) Shifts of the ultraviolet absorption spectra of the photoreactant
(2) Dramatic enhancements of energy transfer efficiencies as manifested by
by photosensitization and quenching of electronically excited states
(3) Changes in the quantum efficiencies of photochemical reactions
(4) Changes in the local molecular environment of the photoreactant that
can alter the relative energies of excited states (resulting in entirely
different observed photochemical products)
(5) Availability of locally high concentrations of micellar counterions capable
of reacting with or quenching photoexcited states
(6) Sizeable enhancements in the water solubility of otherwise insoluble
compounds
(7) Changes in the surface properties of solids through adsorption
Q
Surfactants are quite remarkable species. They usually consist of a long hydro-
carbon chain with a polar or ionic functional group at one end. In spite of their
appreciable hydrocarbon content, they are usually soluble in water to an almost un-
limited extent and, in turn, solubilize non-polar organic compounds that would
otherwise be highly insoluble in water. A variety of chemical reactions have been
studied in aqueous solutions containing surfactants, and the "catalytic" effects of the
micelles on reaction rates can be quite striking. The wide variety of examples in
the literature are too numerous to summarize here, but recent reviews are available
in References 8,10 and 11. An example we have previously observed will serve to
illustrate the remarkable effects possible.' The photochemical reaction in equation 1
has a quantum yield in the presence of 1 x 10~2 M concentration of the cationic
surfactant hexadecyltrimethylammonium bromide That is at least 6800 times that
observed in the absence of the detergent. This dramatic effect is a result of primarily
N
+ NO2" J_
OCH3
OCH3
two features of the surfactant micelle: (1) its ability to efficiently organize both
reactants into a common region of the solution thereby providing the photoexcited
nitroaromatic with a highly effective concentration of cyanide ion and (2) its "solvent"
effect on the micellized aromatic that in this case, alters the nature of the lowest-
lying excited state. In contrast, the anionic surfactant sodium lauryl sulfate com-
pletely insulates the micellized nitroaromatic from the anionic nucleophiles and
inhibits such photoreactions. For example, similar substitution reactions of p-nitro-
phenyl decyl ether are inhibited by a factor of at least 200.
Significant changes in the ultraviolet and visible absorption spectra of com-
pounds solubilized by micelles have been observed.** The effects arise from the local
-------
solvent and electrostatic character of the micelle and are, of course, most commonly
observed for compounds that exhibit a sensitivity to solvent shifts. Another typical
case for which spectral shifts are observed arises from changes in acid-base equilibria
of dissolved materials. For example, a -naphthol (a decomposition product of the
pesticide Sevin) exhibits a large increase in observed pKa (ApKa= 1.2) in the pre-
sence of even nonionic detergents. '*
Co-solubilization of two or more substrates by surfactant micelles can have
dramatic effects on the efficiency of biomolecular reactions particularly those involv-
ing short-lived excited states. This is illustrated by the following case of very
efficient energy transfer. Singhal and coworkers'^ showed that, in aqueous solution
containing 1 x 10~5M methylene blue, 1 x 10~5 M thionine and 3 x 10~3M sodium
lauryl sulfate, direct excitation of thionine resulted in sensitization of methylene
blue fluorescence with an efficiency of ca. 90% under these conditions. In the ab-
sence of the surfactant, no detectable energy transfer is observed.
The concentration of a surfactant is a crucial factor in the sense that below
the well-defined critical -micelle-concentration (erne) surfactants are monomeric
and behave as simple salts (ionic) or organic solutes (non-ionic)." At the erne,
through a process somewhat analogous to precipitation, micellar aggregates (typically
consisting of 50-100 monomers) are formed. It is the micelle that exerts these
effects on dissolved substrates. At concentrations above the cmc, the number of
micelles increases, but no significant change in the character of the micelle occurs
unless high concentrations (typically >0.1 M) are present. The capacity of the
micelle to solubilize otherwise sparingly soluble substrates will, of course, increase
with increasing "micelle" concentration, but the "catalytic" effects of micelles on
chemical or photochemical reactions are generally rather insensitive to surfactant
concentrations above the cmc (unless co-solub?lizat!on of two reactive substrates is
required). The surfactant concentrations employed in the following study were all
above the cmc values for the surfactants used. The cmc values for hexadecyltri-
methylammonium bromide (HDTBr), sodium dodecyl sulfate (SDS) and Brif 35 are
9 x lO^M, 8 x 10~3 M and 7 x 10"5M, respectively.8 There is evidence in the
literature that, for certain cases, micellar effects can occur below the cmc. This
*is ostensibly due to complexes between surfactant and substrate and to substrate-
induced micellization.14'15
The degree to which surfactants (the term is used here in a broad sense to cover
all types of amphiphilic molecules such as detergents, soaps, bile acid salts and
membrane constituents that exhibit surface active properties and form micelles in
solution) perturb the photochemistry of pesticides is a factor that deserves con-
siderable attention. An understanding of these effects is becoming increasingly
more important as the use of surfactants in pesticidal formulations increases.
Studies concerning the penetration ability, translocation, effective toxicity, biolo-
gical activity, and water solubility of pesticides as influenced by surfactant for-.,
mulations attest to the practical significance of pesticide-surfactant interactions.
For example, Lichtenstein has found that surfactants increase the persistence and
-------
toxicity of paratfiion and diazinon in soils. Rosen has discussed several cases of
pesticides with ultraviolet absorption bands that do not overlap with the spectrum
of available solar light but are readily photolyzed by sunlight.' Explanations of
this apparent paradox include sensitization by impurities or oxidation products of the
pesticides and possible changes in the absorption spectrum resulting from surface
adsorption of the pesticide. In addition, however, spectral shifts caused by surfac-
tants can significantly alter the fraction of light directly absorbed by the pesticide
and must be considered.
The important of differing surface characteristics on the photochemistry of
pesticides has been discussed by Plimmer. The interesting observation that a series of
methylcarbamates were readily photolyzed on glass or leaf surfaces but not on silica
gel surfaces was noted. Rosen observed a similar case in the photochemistry of the
pyrethroid SBP-1382 and was left with the dismaying conclusion that, if studies
between glass and silica gel surfaces differ significantly, any extrapolation of these
studies to predict photochemistry on soil surfaces must be risky at best.' Considerable
value, however, is derived from these observations in that we are made aware of the
possible sensitivity of certain pesticide photochemistry to very specific surface effects.
Clearly the specific character of various soils differs as much if not more from one
sample to the next as does glass from silica gel. Furthermore, the character of soil
surfaces might be expected to change in the presence of surfactants. The question
of the importance of pesticide photolysis on soil surfaces has not been dealt with in
any systematic manner although several reports have indicated that pesticide photo-
chemistry does indeed occur on soils. Lichtenstein and coworkers have observed evi-
dence for photochemical transofmrations of pesticides on soils.*3 Woodrow, Crosby
and coworkers have observed a rapid conversion of parathion to paraoxon induced by
UV light on orchard soil surfaces.24 Baker and Applegate found that UV light
accelerated the breakdown of parathion and DDT on soil surfaces.25 They found no
paraoxon (or p-nitrophenol) as photoproducts, however.
One of the two major objectives of the following study was to investigate the
photodecomposition of several pesticides on soil surfaces by systematically varying
several parameters likely to influence the photolysis "rates". The other principal
objective was to determine the influence that surfactants have on the photodecom-
position of these pesticides in aqueous solution. For both systems it was intended
to obtain quantitative rate data that could be used in environmental modelling studies.
A secondary objective involving the isolation and identification of all photoproducts
was hampered by numerous experimental difficulties and only indirect evidence for
the nature of the photoproducts was obtained.
-------
SECTION IV
RESULTS AND DISCUSSION
AQUEOUS PHASE STUDIES
Absorption Spectra
We have examined the effects of three different types of surfactantscationic-
hexadecyltrimethylammonium bromide (HDTBr), j^; anionic-sodium dodecylsulfate
(SDS), II ; and nonionic-Brif 35, Illon the solubilization and electronic absor-
ption spectra of Sevin, IV, 2,4-D esters, V, and parathion, VI, in aqueous solution
(Figure 1). We have not determined the upper limit of solubility of these pesticides
CH3(CH2)15N(CH3)3Br"
CH3(CH2)irOSO3~Na+
),, O-(CH2CH2O)23-OH
O
11
O-C-NHCH3
OCH2CO2R O2N
OC2H5
IV
V
VI
III
Figure 1. Surfactants and pesticides used in study.
in detergent solutions, but it is clear that solubility limits would not be reached by
any reasonable environmental concentrations. For example, we have prepared (with
no difficulty) detergent solutions of the sparingly soluble butoxyethyl ester of 2,4-D
in concentrations as high as 10~3M . This compares with an aqueous saturation
solubility of ca. 4 x 10~5M.
-------
Surfactants shift the UV spectra of these pesticides significantly to the red.
The spectra for 2,4-D resemble those in hexane and methanol. The overall influence
in the case of 2,4-D esters is far more important than for Sevin or parathion in that
the natural overlap of the spectra with the available sunlight is marginal for 2,4-D.
At pertinent wavelengths (Tables 1, 2 and 3), it is seen that the increase in net ab-
sorption at wavelengths greater than 290 nm is significant.
An interesting effect was observed for solutions of parathion. The wavelength
absorption maximum for parathion varies from 269 nm in n-hexane to 276 nm in water
(273 nm in methanol; 273 nm in acetonitrile and 274 nm in 50% aqueous methanol). It
is reasonable to expect that the addition of detergents to aqueous solutions would result
in absorption shifts toward those values found for less polar solvents; however, the
absorption maxima of parathion in 0.05 M HDTBr and 0.05 M SDS were found to be
280 and 281 nm, respectively. An explanation for this unusual effect may involve
a specific interaction between the thiophosphate ester group with the ionic head groups
Table 1. EXTINCTION COEFFICIENT FOR METHYL ESTER OF 2,4-D
Xnm
297.5
300
302.5
305
307.5
310
312.5
315
317.5
320
322.5
325
327.5
330
Molar Extinction Coefficient (I -mole'1 -cm'1)
H2O
236
78.7
52.5
39.4
39.4
26.2
26.2
13.1
13.1
0
0
lx!0'2M HDTBr
(cationic)
499
197
78.7
39.4
26.2
13.1
0
0
0
5xlO"2M SDS
(an ionic)
407
171
78.7
52 05
39.4
26.2
26.2
26.2
13.1
13.1
0
0
lxlO"3MBrif 35
(nonionic)
341
131
65.6
39.4
26.2
26.2
13.1
13.1
13.1
0
0
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Table 2. EXTINCTION COEFFICIENT FOR SEVIN
Xnm
297.5
300
302.5
305
307.5
310
312.5
315
317.5
320
322.5
325
327.5
330
332.5
335
337.5
340
342.5
345
347.5
350
352.5
355
357.5
360
Molar Extinction Coefficient (i -mole'1 -cm'1)
H,O
1 .41xl03
9.3 xlO2
737
529
409
351
378
259
236
112
57.9
29.0
19.3
13.2
9.3°
6.6°
4.6°
3.2°
1 x!0"2MHDTBr
(cationic)
2. 45x1 03
1.73xl03
1 .32xl03
1 .04xl03
803
683
622
529
440
332
247
216
134
57.9
30.9
15.4
15.4
11.6
8.1a
6.0°
4.4°
3.2°
5xlO"2 M SDS
(anionic)
1 .88xl03
1.21xl03
880
649
478
386
375
305
239
143
69.5
38.6
23.2
15.9°
11. 0°
7.9°
5.4°
3.7°
lxlO"3MBri| 35
(nonionic)
1 .64xl03
l.llxlO3
876
659
511
444
435
320
228
157
103
66.5
36.3
18.1
9.1
5.2°
3.2°
2.9a
a) Calculated from logarithmic extrapolation.
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Table 3. EXTINCTION COEFFICIENT FOR PARATHION
Xnm
297.5
300
302.5
305
307.5
310
312.5
315
317.5
320
322.5
325
327.5
330
332.5
335
337.5
340
342.5
345
347.5
350
Molar Extinction Coefficient (f. -mole"1 -cm )
H2O
4800
4500
4250
3750
3250
2750
2350
2000
1600
1550
1400
1200
1100
950
750
700
600
550
550
500
500
400
5x 10~2MHDTBr
6250
5800
5150
4500
3800
3100
2900
2200
1850
1600
1450
1000
950
900
900
800
650
600
550
500
500
450
5 x 10"2M SDS
6350
5850
5500
4800
4200
3700
3400
2800
2450
2100
1850
1650
1500
1300
1250
1100
1000
950
900
800
750
650
10
-------
of the micelles. Such an effect might allow greater interaction between the ring-
substituted oxygen and the nitro group such as is found in p-nitroanisole (X max: 317
nm).
Quantum Yield and Rate Studies
The "rate" of any photochemical reaction is intrinsically related to the inten-
sity of the light source used, and,even though much of the data reported here are
expressed in terms related to "rates", it must be understood that such values have
meaning only with respect to the experimental conditions employed. Although these
studies were carried out under controlled laboratory conditions, it is desirable to
relate the results to real environmental conditions. In order to do this, one must
have detailed knowledge of the wavelength dependent intensities of the sources used
(sunlight versus laboratory lamps) and the wavelength dependent extinction coeffi-
cients of the photochemical reactant. The common link between two such systems is
the quantum efficiency, . The actual "rate" of a photochemical reaction is then
given by equation 1.
where: I = wavelength dependent light intensity
a= wavelength and concentration dependent absorptivity of the reactant
a = l-10~^e c (i is the pathlength, « is the molar extinction coefficient,
and c is the concentration of the photoreactant)
$= quantum efficiency. This value is rarely wavelength dependent in
condensed phases.
For those conditions in which the photoreactant does not completely (<99%) absorb
the incident light, the function a (v) is time-dependent. Under such circumstances,
the course of the photolysis follows a first order dependence on the concentration of
the photoreactant, and thus the "half-life" of the photoreaction is inversely proportio-
nal to the quantum yield as indicated in equation 2. The proportionality constant, k,
embodies the characteristics of the overlap integral in equation 1 .
Solar insolation data as a function of geographical location, atmospheric conditions,
time-of-day and season of year have been compiled by Zepp and coworkers^° and
used to calculate photolysis rates for pesticide photodecomposition using values of
quantum efficiencies and extinction coefficients obtained from the laboratory. The
agreement between empirically determined half-lives and those calculated has been
excellent. °' Data obtained in our studies have been treated accordingly to pre-
-------
diet actual half-lives for photolysis in sunlight. These data are compiled in the
apprendix and selected values given in Table 4. The quantum yields for disappearance
of 2,4-D methyl ester and for Sevin were determined using optically matched solu-
tions (at 290 nm) using 290 nm monochromatic light isolated with a monochromator
on a conventional optical bench. The quantum yields for disappearance of parathion
were measured using 313 nm light isolated from a medium pressure Hg arc filtered
through a dichromate solution on a merry-go-round apparatus. Preliminary studies
using the non-ionic surfactant Brif-35 resulted in extensive analytical interference
from impurities in the detergent. Because our attempts to purify the surfactant by
standard procedures^ did not alleviate this problem and because, in virtually all
known examples of micellar catalysis, the effects of~non-ionic.detergents are inter-
mediate between the effects exerted by cationics and anionics , no further studies
were undertaken.
The influence of detergents on the photolysis of 2,4-D methyl ester and Sevin
can also be seen by examining spectral scans of the solutions taken after various photo-
lysis periods. These are given in Figures 2-7. Of particular interest for 2,4-D are
the clean isosbestic points at 279 and 298 nm for the solution containing the cationic
detergent (Figure 2). For the solution containing the anionic detergent (Figure 4),
secondary photodecomposition is apparent from the lack of isosbestic points, and for
the solution in the absence of detergents (Figure 3) and overall increase in the absorp-
tion spectra, unlike either of the detergent solutions, occurs. Qualitatively different
spectra scans were also obtained for the Sevin photolyses.
Table 4. CALCULATED PHOTOLYSIS HALF-LIVES FOR AQUEOUS SOLUTIONS
OF 2,4-D METHYL ESTER, SEVIN AND PARATHION IRRADIATED BY
SUNLIGHT
Pesticide
Solution
Ha If-life (days)
2,4-D Methyl ester
Sevin
Parathion
H2O
0.01 M HDTBr
0.05 M SDS
H2O
0.01 M HDTBr
0.05 M SDS
H2O
0.05M HDTBr
0.05 M SDS
0.06
0.1
0.1
0.01
0.03
0.01
0.0002
0.0006
0.001
62.
500.
21.
11.
1.2
9.6
9.2
2.9
1.3
a) Average on clear days during midsummer at 40 N latitude. See appendix for
complete data.
12
-------
Photodecomposition Products
The nature of the photoproducts obtained for the photolysis of 2,4-D esters in
aqueous solution has been studied by several groups. Zepp and coworkers^' have
found that in dilute aqueous solution 2,4-D esters are converted to 2,4-dichloro-
phenol, the ester of 2-chloro-4-hydroxy-4-chlorophenoxyacetic acid, which rapidly
lactonizes under the conditions of analysis (gas chromatography). At higher
concentrations in aqueous solution (forming emulsions) or in organic solvents, Zepp
and coworkers^' found the ester of 4-chlorophenoxyacetic acid to be the major photo-
product along with some of the ester of 2-chlorophenoxyacetic acid. Crosby and
coworkers have shown that the photolysis of 2,4-D acid in aqueous solution yields
2,4-dichlorophenol, 2-chloro-4-hydroxyphenoxyacetic acid and 4-chloro-2-hydroxy-
phenoxyacetic acid as primary photoproducts. ° These undergo secondary photo-
chemistry to ultimately produce humic-like materials. Binkley and Oakes have also
studied photodecomposition of the esters of 2,4-D^ but apparently at concentrations
at which emulsions form because the photochemistry they observed is similar to that
found by Zepp and coworkers in organic solvents and aqueous emulsions.
330
FIGURE 2 Photolysis of 2,4-D methyl ester with cationic detergent
a initial spectrum
b after 66 min photolysis period
c after 120 min photolysis period
d after 180 min photolysis period
e after 240 min photolysis period
f after ca. 360 min photolysis period
13
-------
320
nm
FIGURE 3 Photolysis of 2,4-D methyl ester in water
a initial spectrum
b after 120 min photolysis period
c after 240 min photolysis period
d after 360 min photolysis period
The photodecomposFtion products from SevFn have been rather problematic
in the literature. Crosby and coworkers1'0 reported that 1-naphthol and several
cholFnesterase inhibitors were photoproducts. We have ruled out 1-naphthol as a
photoproduct under our conditions, but have not identified any primary photoproducts.
Furthermore, we have shown that photolysis of 1-naphthol in water or
methanol does not give the photoproducts observed for Sevin. In addition, we have
shown that 1-methoxynaphthalene is not a photoproduct from the photolysis of Sevin
in methanol. The isolable product distribution is highly dependent on the length of
time following the photolysis that workup is initiated. Available analytical
information (UV and NMR) indicates that the complex mixture is characteristic of
that expected for subsequent oxidation. When photolyzed to about 60^conversion
in 50% EtOH: H2O, the Sevin is converted to at least 5 different products three
of which are exceedingly polar (cannot be moved on silica tic). Several of these
fluoresce and the long wavelength fluorescence and absorption of one of the non-
polar products (compound A) implies a system of extended conjugation. Compound A
has emission bands at 415, 440 and 458 cm. A high resolution mass spectrum of this
compound is relatively clean with a molecular ion of m/e equal to 268.0870, which
14
-------
corresponds to a molecular formula C2oH12O. Two major peaks In the IR at 3005 cm""1
and 1200 cm'1 correspond to that published for:
We have examined the effect of the presence and absence of O2 on the photolysis
in H2O. When photolyzed for 1 hour (1 .5 x 10"^ M Sevin; 254 nm irradiation) in
air saturated water, only a small fraction of Sevin remains. The aqueous solution
is light brown. Sevin appears to be the only ether extractable material remaining.
A weak fluorescence band at 425 nm was noted. The Rayleigh scatter (apparent by
inspection of the solution) implies an insoluble suspension in the aqueous solution.
Addition of K2CO3 clears the suspension immediately implying a phenolic-type
functional group. When photolyzed after N2 purging in water, the solution remains
270
290
310
330
nm
FIGURE 4 Photolysis of 2,4-D methyl ester with anionic detergent
a initial spectrum
b after 120 min photolysis period
c after 180 min photolysis period
d after 240 min photolysis period
15
-------
330
FIGURE 5 Photolysis of Sevin in water
a initial spectrum
b after 60 min photolysis period
c after 120 min photolysis period
d after 300 min photolysis period
16
-------
270
290
310
330
FIGURE 6 Photolysis of Sevin with cationic detergent
a initial spectrum
b after 15 min photolysis period
c after 30 min photolysis period
d after 60 min photolysis period
17
-------
330
FIGURE 7 Photolysis of Sevin with anionic detergent
a initial spectrum
b after 75 min photolysis period
c after 180 min photolysis period
d after 390 min photolysis period
18
-------
colorless but a similar suspension forms. The dispersion does not clear up upon
addition of K2CO3 and air. Photolysis of this solution, however, does clear up the
dispersion, and the solution becomes light brown. The UV spectra is identical to
the solution originally containing oxygen. We conclude that the intial Sevin photo-
chemistry is not sensitive to oxygen but that the secondary photochemistry is. Singlet
oxygen produced by the decomposition of potassium perchromate (K^CrC^) in water*''
does not produce any changes in the absorption spectrum of Sevin.
The photodecomposition of parathion has been reported to result in the
formation of paraoxon,^ p-nitrophenop3 and other unidentified products.32 |n our
studies neither p-nitrophenol nor paraoxon was detected in quantities greater than 2%
of the workup mixture at conversions of approximately 50%. Two volatile (gas
chromatography) photoproducts remain unidentified.
SOIL STUDIES
The soils used in our studies are typical arable types differing widely in phi
level, organic content, nature of exchangeable cations present, etc. Pertinent
characteristics are given in Table 5. The surfactants studied were of the anionic (SDS)
and cationic (HDTBr) types. The moisture content of the soils was varied and can be
categorized as follows:
(1) Dry; soil that was dried with no additional water added.
(2) Saturated; dried soil to which a quantity of water was added to fill
the "pore space". This quantity depends on the individual soil and
amounts to roughly 1 milliliter per gram soil. It has been found that when
detergents are co-applied, an additional quantity of water is required
to give the visual appearance of saturation. The additional quantity is
probably used in hydration of the surfactant head group.
(3) Wet-dry soils to which quantities of water (up to 4 ml) were added
to form slurries.
Table5. SOIL CHARACTERISTICS
Type
1
II
III
IV
Name
Etowah
Holston
Conasauga
Siltloam
Holston -sub
soil
Slurry
PH
4.4
6.3
7.6
4.9
% Carbon
0.13
0.60
2.79
Bulk Density
1.70
1.90
1.57
1.80
%Pore Space
35.8
28.3
40.8
32.0
19
-------
The general procedure (referred to as "standard conditions ") involves preparation of
a uniform soil surface by spreading an aqueous slurry containing 1 gram soil on a
10x15 cm surface (Figure 8) and allowing the surface to dry completely. This pro-
duces an average soil thickness of ca. 0.003 cm. The pesticide (5 mg) and, in
certain case, detergent (100 mg) are dissolved in 5 ml acetone or methanol and spread
uniformly on the thin soil film. The solvents are evaporated completely. This
corresponds to a coverage of 2.9 Ibs. pesticide per acre and 58 Ibs. surfactant per
acre. For those experiments involving water-saturated or wet soils, an appropriate
amount of water is uniformly added to surface! The vessel is then sealed and photo-
lyzed. An identical vessel is simultaneously prepared and stored in the dark for an
equivalent time period. The samples are photolyzed on a custom-built glass tray
with cooling water circulating on the under side to avoid evaporative losses and to
maintain the initial moisture content. The trays are tightly covered with Pyrex glass
on top and are placed about 14 cm under a horizontal water-cooled Pyrex-facketted
medium pressure Hg arc (450 W) as shown in Figure 8. The radiant density is reason-
ably uniform over the entire surface.
The output of the lamp, as constructed and filtered by Pyrex, provides ra-
diation with approximately the following photo flux on the plate surface.
PYREX Jacket
Hg Arc Source
PYREX Plole Cover
ir Tight Seal
Cooling Water
15 cm
Figure 8 Apparatus for photolysis on soil surfaces
20
-------
X(nm) total incident light (Einsteins-sec~ )
297
303
313
334
0.58x10-
1.4 x 10"
4.4 x 10~
1.1 x 10
,-7
Longer wavelength light is not absorbed by the pesticides used and shorter
wavelength light is totally filtered by the Pyrex. As determined by the extinction
coefficients, the quantity applied is such that only a fraction of the incident inten-
sity is absorbed. Consequently, it is expected that the extent of photolysis should
fall off exponentially with time. Experiments at various time intervals have con-
firmed this expectation (see Figure 9). The bulk of our experiments were run at
exposure times of 18-150 hrs, but in order to facilitate comparison, the results are
reported in terms of the time required for 50% photodecomposition. Very crude
100
90
80
70
60
50
O
Z
=? 40
<
LU
* 30
20 -
20 40 60 80 100 120 140
TIME (Hours)
Figure 9 Photodecomposition of 2,4-D on soil I (dry) as a
function of time
21
-------
quantum yields can be calculated by assuming that extinction data in solution is
applicable to soil surfaces (see experimental section).
The photolysis of 2,4-D was carried out on the acid rather than the various
esters actually used as pesticides because it was found that hydrolysis of the ester to
the acid occurred very rapidly on the soils studied. Reproducibility of the 2,4-D
experiments was a problem, particularly with the experiments carried out on "wet"
soils. Our early experiments under such conditions exhibited substantially faster
decomposition rates. The amount of water was not as carefully controlled in those
experiments and exceeded 4 ml. The results presented in Table 6 are the most recent
and "best values. The photodecomposition rates vary by a factor of seven over the
conditions studied. No meaningful trends were observed, and the most important con-
clusion to be derived is that the photolysis of 2,4-D on soils is very slow and inefficient.
In the most favorable case, a crude quantum yield of 0.003 has been estimated. This
is approximately 30 times lower than the efficiency observed in aqueous solution.
As noted above, excessive quantities of water added to the soil may enhance the
photodecomposition rates substantially but this effect is likely due to solubilization
into the aqueous phase in which the photochemistry is significantly more efficient
(particularly in the presence of detergents).
Similar studies using the pesticide Sevin are presented in Table 7. In the
absence of detergents, the photochemistry is very slow; with increasing water con-
tent, it is literally inert. The presence of detergents retards the "dry" soil photo-
chemistry somewhat; however, as moisture is added the decomposition becomes very
facile. The observation that detergents catalyze the dark hydrolysis of Sevin to
1-naphthol and the observation that 1-naphthol can be detected in the photochemical
experiments only when short irradiation periods are used, lead to the conclusion that
the non-photochemical hydrolysis catalyzed by detergents is primarily responsible
for the dramatic effects. Again very crude quantum yields can be calculated for
these experiments. A value of 0.0003 for the experiment on "dry" soil I with no
detergent is so obtained. In aqueous solution, the value is approximately 30 times
greater. A fourth type of soil (designated soil IV) was used in a few experiments.
It was employed as a replacement for soil I, the supply of which was exhausted. Both
are acidic soils (pH~4), and the behavior of IV was found to be similar to that of
soil I.
In Table 8 are listed the results for a similar study with parathion. The acidic
soil IV was used exclusively as a replacement for soil I. For parathion, the rate
of photodecomposition was not found to correlate with soil type or soil moisture content.
The effect of added detergent was also insignificant except for the slight retardation
(approximately a factor of two) observed using the cationic detergent. Again the
"quantum yields" of photolysis were found to be very low on soil surfaces (but closer
to those in solution).
Graphical representations of the data presented in Tables 6-8 are given in
Figures 10-12. The calculated "quantum yields" are included in these figures. As
22
-------
indicated previously (section on photolysis rates-Part A), it is useful to calculate
actual photolysis half-lives for sunlight conditions. Using the "quantum yields" as
obtained above and extinction coefficient data from aqueous solution, these half-
lives for sunlight conditions have been calculated and are included in the appendix.
A summary of the pertinent data is given in Table 9.
Each of the studies reported above for the decomposition of 2,4-D, Sevin, and
parathion on soil surfaces was carried out under a standard set of conditions in order
to facilitate comparison. The conditions chosen were environmentally realistic ones
Soil
Table 6. EFFECTS OF SOIL TYPES, DETERGENTS AND SOIL WATER
CONTENT ON THE TIME REQUIRED FOR 50% PHOTO-
DECOMPOSITION of 2,4-D
Time Required for 50%
Detergent Water Content Photodecomposition (hours)
I
1
1
II
II
II
III
III
III
1
1
1
II
II
II
III
III
111
1
1
1
II
II
II
III
III
III
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
none
HDTBr
SDS
dry
dry
dry
dry
dry
dry
dry
dry
dry
satd.
satd.
satd.
satd.
satd.
satd.
satd.
satd.
satd.
wet
wet
wet
wet
wet
wet
wet
wet
wet
86
93
71
99(282)°
88
115
160
102(221)°
242
99(202)°
154
130
105(282)°
173
149
187
149(220)°
69
80(101)°
205
121
141(234)°
285
101
149(168)°
121(149)°
42
a) Half-life of dark control for those cases in which it is significant.
23
-------
Table 7. EFFECTS OF SOIL TYPES, DETERGENTS AND SOIL WATER CONTENT
ON THE TIME REQUIRED FOR 50% PHOTODECOMPOSITION OF
SEVIN
Soil
1
1
1
II
II
II
III
III
III
1
1
1
IV
II
II
II
III
III
III
1
I
1
IV
II
II
III
III
III
Detergent
none
none
none
none
none
none
none
none
none
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
Water Content
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
wet
dry
wet
dry
satd.
wet
Time Required for 50%
Photodecomposition (hrs)
97
529
538
251
688
458
. 105
(286)a
538
251
159
(34)b
(35)c
358
(201 )a
(20-60)d
251
(41 )b
(10-50)d
274
251
(30)b
(64)c
251
(29)d
251
224
(24)d
a) The dark control in this case gave identical results; hence the slow
decomposition might not be photochemical in nature
b) The dark control showed large conversion of Sevin to a -naphthol;
no a-naphthol was found in the photochemical experiment
c) At short reaction times, both the dark control and the photochemical
experiment showed extensive conversion of Sevin to a -naphthol
d) Variable results were obtained; the dark controls indicated extensive
conversion to a-naphthol; a-naphthol was detected in the photo-
chemical experiments only for short irradiation times.
24
-------
Table 8. EFFECTS OF SOIL TYPES, DETERGENTS AND SOIL WATER CONTENT
ON THE TIME REQUIRED FOR 50% PHOTODECOMPOSITION OF
PARATHION
Soil
IV
IV
IV
II
II
II
III
III
II
IV
IV
IV
II
II
II
III
III
III
IV
IV
IV
II
II
II
III
III
III
Detergent
none
none
none
none
none
none
none
none
none
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
HDTBr
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
SDS
Water Content
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
dry
satd.
wet
Time Required for 50%
Photode composition (hours)
52
34
47
61
31
44
70
36
36
134
191
51
106
93
61
90
65
102
43
70
34
38
72
32
109
61
36
25
-------
T C0.02.
S-
w£
U- D
j _2
^p* O
^~ ^^
^0.01 .
S°i 1 123123123
Water D S W
Detergent NONE
123 123 123
D S W
CATIONIC
123 123123
D S W
ANIONIC
-0.003
-0.002
hO. 001
FIGURE 10 Graphical representation of the extent of photocomposition of
2,4-D on soils
(0,5, and W correspond to dry, saturated and wet respectively)
26
-------
0.06-
o o
^ -jj 0.04
v C
U_-Q
_J O
0.02-
hi ih
Ul
III III
-0.002
0.0015
0.001
-0.0005
Soil 123123123
Water D S W
Detergent NONE
123 123 123
D S W
CATIONIC
123 123 123
D S W
ANIONIC
FIGURE 11 Graphical Representation of the Extent of Photodecomposition of
Sevin on Soils
(D,S, and W correspond to dry, saturated and wet respectively;
see text for details of experiments graphed with broken lines)
27
-------
0.04 -
c
o
C E
3 =
o t.
0.02 -
Soil 423 423 423
Water D S W
Detergent NONE
'0.0003
0.0002
0.0001
423 423 423
D S W
CATIONIC
423 423 423
D S W
ANIONIC
FIGURE 12 Graphical Representation of the Extent of Photodecomposition
of Parathion on Soils
(D,S, and W correspond to dry, saturated and wet respectively)
28
-------
Table 9. CALCULATED PHOTOLYSIS HALF-LIVES FOR 2,4-D SEVIN AND
PARATHION ON SOIL SURFACES IRRADIATED BY SUNLIGHT
Pesticide
2,4-D acid
Sevin
Para th ion
"Quantum Yield"0
0.003
0.001
0.0005
0.002
0.0003
0.00005
0.00022
0.0001
0.000037
Half-Life (days)b
1250.
3750.
7500.
51.
380.
2500.
8.5
18.
50.
a) The "quantum yields" represent the extreme values and a typical value for the
various conditions studied as taken from Figures 10, 11, and 12.
b) Average clear days during midsummer at 40°N latitude. See appendix for
complete data.
but were nonetheless fixed. In order to ascertain whether the specific quantities of
materials chosen for the "standard" conditions gave representative results, these
parameters were varied using the parathion-soil III system. The following factors
were systematically varied:
standard values parameter varied
1 g soil 3 g soil
5 mg pesticide 1 mg pesticide
100 mg detergent 20 mg detergent
The results of this study are presented in Table 10. Inspection of these results shows
that the only variable that affects the results is the quantity of soil used. As the
amount of soil is increased the decomposition rate decreases slightly in all cases.
This small effect is readily attributable to screening of the pesticide from the available
light. This suggest that the already very inefficient photochemistry on soil surfaces
diminishes rapidly with penetration into the soil. It should be noted that studies
29
-------
employing the greater quantity of soil still results in a very thin layer of soil (ca.
0.01 cm). Allied to our studies of pesticide photochemistry on soil surfaces was a
study of the absorption and emission spectroscopy of adsorbed species on surfaces.
We were interested in determining whether adsorption on soils results in shifts in the
UV absorption spectra. Such studies are best carried out using a double monochrome-
tor UV spectrophotometer (due to the enormous background absorption of soils). In
principle, however, such information can be obtained by taking the excitation spec-
trum of a species that fluoresces. We have readily observed such spectra with poly-
condensed dramatics such as anthracene on glass surfaces, but such species have
highly structured spectra. Any subtle changes due to adsorption either do not exist
or are not discernible by this approach.
Table 10. EFFECTS OF PARAMETER VARIATIONS ON THE PHOTODECOMPO-
SITION OF PARATHION ON SOIL III
Time Required for 50%
Detergent Photodecomposition (hrs)
Soil
Paration
Water Content
ig
ig
iga
iga
ig
3g
3g
ig
ig
ig
ig
iga
iga
iga
3g
3g
ig
ig
ig
ig
iga
iga
iga
3g
3g
1 mg
1 mg
5 mg
5 mg
5 mg
5 mg
5 mg
1 mg
1 mg
5 mg
5 mg
5 mg
5 mg
5 mg
5 mg
5 mg
1 mg
1 mg
5 mg
5 mg
5 mg
5 mg
5 mg
5 mg
5mg
dry
satd.
dry
satd.
wet
dry
satd.
dry
satd.
dry
satd.
dry
satd.
wet
dry
satd.
dry
satd.
dry
satd.
dry
satd.
wet
dry
satd.
100 mg cation ic
100 mg cation ic
20 mg cation ic
20 mg cation ic
100 mg cation ic
100 mg cationic
100 mg cationic
100 mg cationic
100 mg cationic
100 mg anionic
100 mg anionic
20 mg anionic
20 mg anionic
100 mg anionic
100 mg anionic
100 mg anionic
100 mg anionic
100 mg anionic
75
31
70
36
36
93
45
90
63
93
65
90
65
102
149
65
86
31
57
32
109
61
36
158
85
a) Refers to standard conditions.
30
-------
One of the important conclusions we have reached regarding photochemistry on
soils is that it is very slow and inefficient. A reasonable explanation for this obser-
vation is that the photoexcited pesticide is quenched (possibly through energy transfer)
by pigments in the soil. We have attempted to gain information on this'point by
examining the fluorescence of various species deposited on soil surfaces and comparing
them with the corresponding results on glass surfaces. If the hypothesis is correct,
both the fluorescence intensity and the fluorescence lifetime should be lowered for
samples on soils (if competitive absorption by the soils is responsible only the intensity
would decrease). The experiments have been carried out in the following manner.
Glass slides (with and without soil films) are sprayed (misted) with dilute ethereal
solutions of the fluorescer. The soil treated and untreated slides are placed side by
side to ensure uniform application. Front surface emission spectra are recorded after
each spray (numerous sprays are required before fluorescence is detectable under
any conditions). We have found that on plain glass surfaces the fluorescence becomes
readily detectable. Under identical conditions on the soil slides no fluorescence is
detected (it is totally quenched). The fluorescence lifetimes for trie glass slide
experiments are readily determined and are generally comparable to solution values.
The extraordinarily weak emission from the "soil" experiments gives a decay so short
it can not be resolved from the short lamp decay. Of course, the weak decay ob-
served could simply be residual light scatter if there were no fluorescence at all.
See Figure 13 for typical results using a-naphthol. These findings support our con-
clusions concerning the inefficient soil photochemistry.
Product Studies on Soils
Our analysis conditions have shown that no low molecular weight, volatile
products (detectable by gas chromatography) are produced from the photolysis of
any pesticide we have photolyzed on soils. Controls of expected photoproducts
and/or hydrolysis products indicate that we can recover these quantitatively from
the soil samples.
31
-------
£
to
Z
LU
I"
Z
LU
P
5
LU
oi
0 -
30
i
i x~--,b
i -_' V
\ 1 -N
1 ' V
. / v
1 / *
lb /
\ / r-^
\ i j ^^ ^v
\ / x v
\ i i *. ^ >.
V.X / -X. X. -
/ X ^
a / X V
x^
c v^ j a "~*~-
> i « ' | i i r i
0 400 5
_ 0
DO
WAVELENGTH (nm)
Figure 13. Puorescence Spectra of
1-Naphthol
a on soil III
b on glass
c in solution (ether)
32
-------
SECTION V
EXPERIMENTAL
MATER IALS
2,4-Dichlorophenoxyacetic acid, 4-chlorophenoxyacetic acid, and 2-chloro-
phenoxyacetic acid were re crystallized twice from chloroform-hexane mixtures. The
corresponding methyl and butoxyethyl esters were prepared by acid catalyzed esterifi-
cation in benzene. The esters were purified by vacuum distillation and re crystalliza-
tion when possible. Authentic samples of chlorohydroxyphenoxyacetic acids for use
as gas chromatography standards were obtained from R. G . Zepp. Sevin was prepared
by reacting 1-naphthol with methyl isocyanate in benzene containing 2% pyridine for
5 hours at 80 C in a bomb. Although recrystallization (from toluene and from ether/
hexane/gave a sharp melting material (mp. 141.8-142.9°C) it was not chromatographi-
cally (TLC) homogeneous. Following column chromatography (silica gel eluted with
methylene chloride) and recrystallization from methylene chloride, white crystalline
material that was homogeneous by TLC was obtained ( m.p. 141.0-141.5 C). N-
methyl-l-hydroxy-2-naphthamide and methyl 4-hydroxy-l-naphthoate obtained from
R.G.Zepp were purified by silica-gel column chromatography (chloroform and 1:3
ether/benzene, respectively, aseluents). Parathion was prepared by heating p-nitro-
phenol, sodium carbonate and diethyl chlorothiophosphate in acetone. After appro-
priate washings, the parathion was distilled under vacuum. Paraoxon was prepared
both by bromine oxidation of parathion and by treatment with sodium p-nitrophenoxide
and chlorodiethylphosphate. Hexadecy I trime thy I ammonium bromide was prepared by
heating (50°C) trimethylamine and freshly distilled 1-bromo-hexadecane in ethanol
for 5 hours under a dry-ice acetone condenser. The material was re crystallized four
times from ether/ethanol. Commercially available material was found to be unsatis-
factory (even after several recrystallization) in certain cases. Sodium dodecyl sulfate
(Pfaltz and Bauer) was recrystallized from 95% ethanol taking care not to overheat
(<55 C). Brif-35 (Baker) was used as received and was chromatographed on silica gel
(hexane-chloroform) with no apparent improvement. The water used in these studies
was triply-distilled first from dichromate, then from alkaline permanganate and finally
from an all-glass still. The soil samples were purified and characterized in the labora-
tories of Professor H. F. Perkins (Agronomy Department, University of Georgia). All
other materials used were reagent grade quality.
33
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EQUIPMENT
Ultraviolet-visible spectra were recorded using a Gary 15 spectrophotometer
or a Gilford Model 222 spectrophotometer. Fluorescence spectra were measured with a
Hitachi-Perkin Elmer MPF-3A spectrofluorimeter. Fluorescent lifetimes were measured
by the single-photon-counting technique using the Ortec Model 9500 instrument
schematically illustrated in Figure 14. Gas chromatographic analyses were made using
a Varian 2740 dual flame ionization instrument. High-pressure liquid chromatography
was first carried out with a Waters liquid chromatograph equipped with UV and refractive
index detectors. The bulk of the experiments reported, however, were done using a
Varian 8500 gradient elution instrument equipped with variable wavelength UV detector.
Routine nmr spectra were taken on Varian T-60 or HA-100 instruments and routine
infrared spectra were taken on a Perkin-Elmer 621 spectrophotometer.
Soil surface photolyses were carried out using the setup illustrated in Figure
8. The sample holder was cooled by running water underneath the glass surface con-
taining the soil sample. A 2-mm-thick optical quality Pyrex plate was sealed with
masking tape atop the vessel after the application was made. Irradiation was provided
by a 450 W Hanovia medium pressure Hg arc cooled by a standard Pyrex immersion
well, which also provided two 1 ,5-mm thicknesses of Pyrex glass to filter the light.
Certain (as indicated in the text) solution phase quantum yields were measured
on an optical bench with a thermostatted cell compariment accommodating standard
1 -cm quartz cuvettes . Light of 290 nm was provided by a 200-W super pressure Hg
arc (Bausch and Lomb power supply and lamp housing) and was isolated through a high
intensity Bausch and Lomb grating monochromator. The light intensity was fairly.
constant and was monitored routinely using ferrioxalate actinometry ($= 1 .24).
Other solution phase quantum yields were measured on a standard photochemical merry-
go-round apparatus. Light was provided by a 450-W Hanovia medium pressure mercury
arc inside a Pyrex immersion well. The immersion well was cooled by circulating an
aqueous solution containing 1 .5 x 10"3 M K2CrO4 and 3% K2CO3. This filter solution
in combination with the Pyrex walls effectively isolates the 313 nm line of the Hg arc.
Visible light is filtered out through four Corning 7-54 filters mounted in a metal sheath
that surrounds the immersion well . Sample tubes on the moving outer turn-table of
the merry-go-round are irradiated equivalently and simultaneously. The light intensity
with this setup was found to be very constant and was monitored routinely be ferrioxa-
^ or valerophenone*" actinometry.
Preparative photochemical experiments were carried out in sealed vessels
surrounding the Pyrex immersion well containing a Hanovia 450-W medium-pressure
Hg arc. Vessels of several shapes and sizes accommodating solution volumes from 75
ro 1200 ml were used. In each case, the capability to purege the solution with nitrogen
and maintain an oxygen-free atmosphere was available.
34
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CJ
en
High Voltage
Power Supply
M
T
Mono
Lamp
High Voltage
Power Supply
r
1
SS-Sample Slide
Timing
Filter
Amplifier
Constant
Fraction
Discriminator
Rate Meter
Teletype
Tapepunch
Constant
Fraction
Discriminator
D
e
I
a
y
n.
Dual
Counter
Timer
Delay
stop
"start
Biased Time to
Amplitude
Converter
Multichannel
Analyzer
(MCA)
Figure 14. Schematic Diagram for the High Resolution time Resolved Emission Spectrometer
-------
"QUANTUM YIELD" DETERMINATIONS ON SOIL SURFACES
Determinations of approximate "quantum yields" were based on the assumption
that the pesticide absorbed the fraction of available light predicted by extinction co-
efficient values in aqueous solution. This assumption would be invalid if (1) distribution
of the pesticide over the surface were not reasonably uniform, (2) the soTl particles
masked access to the light, (3) pigments in the soil competitively absorbed the light or
(4) adsorption of the pesticide on to the soil surface resulted in spectral shifts of the
pesticide. We have no evidence that any of these factors exists to any appreciable
extent for the thin soil surfaces and techniques used in these studies. There is, of
course, no question that factor (2) would be dominant with thicker soil layers.
Solution extinction coefficients, («), expressed in units of i-mole""'-cm" , can be
converted into values (e1;e" = 1000 e ) applicable to, surfaces of any depth and,
therefore, the fraction of incident absorbed (1-10~6 c ) by a given quantity of pesti-
cide per centimeter can be caluclated. For the standard conditions employed in these
experiments (5 mg pesticide), the number of moles-cm~2 (cr) of 2,4-D, Sevin and
parathion were 1.5 x 10~7, 1.9 x 10~ and 1.1 x 10~7, respectively. The light source
employed in these experiments was not monochromatic but rather consisted of lines at
297, 303, 313 and 334 nm (longer wavelength lines are inconsequential and shorter
wavelength lines are absorbed by the glass filteres before reaching the surface). The
intensities of these lines (Einsteins-sec"1 -150 cm ) incident to the surface were
calculated from manufacturer's specifications and were attenuated by calculating the
fraction of each absorbed by the three glass filters in between the lamp and the soil
surface. The values so obtained (listed in the text) were assumed to be rather crude.
In order to test the validity of these values, an aqueous solution containing 1.0 x
10~* M p-nitroanisole and 1.0 x 10 M NaOH was photolyzed in the compartment.
It Is known that the quantum efficiency for production of p-nitrophenoxide is 0.0052.
The fraction of light absorbed by this solution was similarly calculated. The solution
was photolyzed for 6 minutes and analyzed for p-nitrophenox?de. The intensity of
the lamp calculated by this "actinometer" was within 20% of that predicted by the
above calculations. Thus, this approach was deemed satisfactory for obtaining suf-
ficiently accurate values consistent with the nature of the experiment. The stability
of the light source over long periods of time was very good. This was monitored by
periodically repeating one of the highly reproducible soil experiments. Small cor-
rections were made to adjust the experimental half-lives to a consistent intensity value
throughout the course of this work.
QUANTUM YIELDS FOR SOLUTION STUDIES
The photolysis equipment used for these determinations has been described
above. The solutions were prepared so that the concentrations were near 1 x 10"4 M
(this was done so that studies in detergent-free aqueous solutions could be done under
comparable conditions). The fraction of light absorbed was measured at the exciting
wavelength and the solutions were worked-up and analyzed in a manner identical to
that described for the preparative experiments. Because the small amounts of materials
36
-------
used were subjected to extensive extraction and workup procedures, the error in these
experiments is larger than typical for a quantum yield determination. Consequently the
values obtained are reported to only one significant figure and are likely to have error
limits of ± 30% although this was not statistically determined.
DETERMINATION OF EXTINCTION COEFFICIENTS
Extinction coefficients were determined in a conventional manner by preparing
solutions of accurately known concentrations. In each case, however the materials
were sparingly soluble and the accuracy of values obtained diminishes as the wave-
length increases. Ordinarily a higher concentration solution could be prepared to ob-
tain such values, but solubility limitations preclude this in water. In the cases of de-
tergent solutions, the solubility of a solute can be enhanced markedly; however, this
frequently requires days of stirring to gain appreciable increases in solubility. Because
the pesticides were found to undergo micelle catalyzed hydrolysis reactions in certain
cases, no attempt was made to make quantitative measurements in more concentrated
solutions.
In each case the reference solution contained the appropriate detergent.
FLUORESCENCE MEASUREMENTS ON SURFACES
Glass slides were cut to fit diagonally into the sample holder of the fluores-
cence spectrometer and the time-resolved emission spectrometer. This configuration
allows for front-surface excitation and for observation of front-surface emission. Slides
were dipped into an aqueous slurry of the soil (soil III) and allowed to oven dry. The
thickness of the soil sample appeared to be comparable to those used in the photo-
chemical studies. A clean glass slide was placed adjacent to a soil-coated one for
each experiment. An ether solution.of the fluorescing species was prepared and placed
in a pump spray bottle. (Commercial hair spray bottles that produce a fine mist were found
to be satisfactory for this purpose.( The solution was sprayed at the two slides taking
care to make the application uniform. The slides were placed in the fluorescence
spectrometer and removed to respray until a desirable level of fluorescence was de-
tected. In each case, the soil-coated and the soil-free slide received the same
spray treatment. After the spectra were recorded for both slides, they were placed
in the time-resolved emission spectrometer and emission decay curves were taken. The
results obtained for. l-naphthol are presented in Figure 13 and are typical. Similar
results were obtained for N-methylquinolinium iodide, naphthalene and Sevin. With
naphthalene, volatilization was a serious problem. The intensity of the emission on the
glass plate steadily decreased while taking the spectra, although the results obtained
were qualitatively similar. For N-methylquinolinium, iodide solubility problems pre-
cluded the use of ether. Methanol was used although this was not entirely satisfactory
as evaporation required lengthier times and "puddling" effects occurred on the surface.
37
-------
SOIL SURFACE PHOTOCHEMICAL STUDIES
The general procedure for applying the soil, pesticide, detergent and water
along with a description of the apparatus have been discussed in the Results section.
It should be noted that this procedure evolved out of numerous attempts to prepare the
surfaces in a uniform and reproducible fashion. Attempts to apply aqueous solutions
containing the pesticide and detergent were found to be totally unsatisfactory for
numerous reasons including the unwieldy volume of water necessary, the excessive
evaporation times necessary, loss of the pesticide through volatilization and hydrolysis,
lack of uniform water content after evaporation and obvious (visually) disturbances
of the uniformity of the soil surface. The final procedure used eliminated each of these
problems. For each experiment, two identical surfaces were prepared. One was kept
in the dark for the same period of time as the sample photolyzed. The photolysis proce-
dure has been described previously in the experimental section. The surfaces were
"worked-up" and analyzed as described below. A standard solution containing the exact
quantity of pesticide applied was prepared in each case. The dark control and the
photolyzed sample were compared relative to the standard. Except as noted, the con-
centration of pesticide in the dark control was identical (±5%) with the standard
solution.
For experiments involving 2,4-D acid, the soil samples were extracted with
four 50-ml portions of 1 N NaHCO3. The extract was filtered through Whatman No. 1
filter paper and 25 cm3 of concentrated HCI was added. The acidified extract was
extracted with six 50-ml portions of ether. After evaporation of the ther, the residue
was esterified by taking 2 ml of mefhanolic BF3, which was heated at 70°C for 1 hour.
Then 5 ml of saturated NaCl was added and the solution was extracted five times with
50-ml portions of benzene. The benzene was evaporated and the residue dissolved
in 5 ml of acetone for analysis by gas chromatography. For experiments with HDTBr,
2 ml of 1 M Kl was added after the initial bicarbonate extraction. The precipitate
of hexadecyltrimethylammonium iodide was filtered off. Otherwise the procedure
was identical. For experiments involving SDS, 1 M BaCl2 was added to precipitate
the detergent. The solutions were analyzed by gas chromatography.
For experiments involving Sevin, the soils were extracted with four 50-ml
portions of acetone and filtered. The acetone was evaporated and the residue diluted
to 5 ml with ethanol. This solution was analyzed by liquid chromatography (C-18
reversed phase column with 10% ethanol-water). When HDTBr was present, the soils
were extracted with methanol, potassium iodide was added to precipitate the deter-
gent and the precipitate washed with ether which was evaporated. Finally, the residue
was diluted to volume with ethanol and analyzed by liquid chromatography. For ex-
periments involving SDS, the detergent was precipitated with BaCI2.
For experiments with parathion, the extraction was identical to that for Sevin.
The residue was diluted to volume with acetone and analyzed by gas chromatography.
For all of the soil experiments, known or expected hydrolysis and photolysis products
of the pesticides were subjected to the workup procedures and analysis. In all cases,
38
-------
the absence of these and other volatile products (gas chromatography) were observed
in the photolysis mixture.
PRODUCT ANALYSIS OF SOLUTION PHOTOLYSES
For 2,4-D methyl ester, Sevin and parathion, preparative scale photolyses
were carried out in order to identify photoproducts. These were photolyzed in water
and in aqueous solutions of HDTBr and SDS. In addition, Sevin was photolyzed in
methanol and aqueous ethanol. The photochemical equipment used for the photolyses
are described elsewhere in the experimental section.
Studies involving the methyl ester of 2,4-D were carried out with initial
concentrations of 4 x 10~4 M . The 1-liter solutions were not deoxygenated. The
photolysis times were varied from 10 minutes to 2 hours. The solutions were extracted
with methylene chloride, which was dried and evaporated in vacuo . The residue
was diluted to volume with acetone and analyzed by gas chromatography. For the
runs with HDTBr, a ten-fold excess of cation exchange resin was added to the aqueous
solution after photolysis. The resin was filtered and extracted with ether. The deter-
gent free aqueous solution was extracted with ether. The ether extracts were combined,
dried and evaporated in vacuo. The residue was diluted to volume with acetone and
analyzed by gas chromatography. For the runs with SDS, BaCl2 was added to precipi-
tate the detergent. The precipitate was washed and solution extracted with ether.
Workup was otherwise similar.
In aqueous solution, photolysis for 10 minutes netted 17% loss of 2,4-D
methyl ester with tiny amounts (<2% each) of seven photoproducts. Longer photolysis
times (20 and 40 minutes) increased the yields of these products but not proportional to
the loss of 2,4-D. A 2-hour photolysis resulted in virtually total loss of 2,4-D but
also loss of the initial photoproducts. The retention times of 2,4-dichlorophenol,
methyl p-chlorophenoxyacetate, methyl o-chlorophenoxyacetate and methyl 2-
chloro-4~-hydroxyphenoxyacetate corresponded to four of the photoproducts. Preparative
thick-layer and gas chromatography were used to attempt to isolate the photoproducts.
This was unsuccessful.
The photolysis carried out in solution containing HDTBr (20 minutes) was
analyzed and a complex chromatogram resulted. This was later shown to be related
to small amounts of impurities in the detergent. The only obvious feature of the chro-
matogram was an absence of the peak related to 2,4-dichlorophenol and a major peak
presumably due to methyl p-chlorophenoxyacetate.
The photolysis carried out in SDS solution (10 minutes) gave no peaks that
could be related to known photoproducts. Again, the chromatogram was obscured by
detergent impurities.
The photolysis of parathion was studied in aqueous solution and in aqueous
solution containing HDTBr (2.8 x 10"3M) and SDS (1.0 x 10~2 M). In each case, an
39
-------
800-ml solution containing 5 x 10~5M parathion was photolyzed for approximately
3 hours (2 hours for the solution containing SDS). The solutions were extracted with
ether (after precipitating the detergents with either Kl or BaCI2), which was dried and
evaporated in vacuo. The residue were diluted to volume with acetone and analyzed
by gas chromatography. In each case, 200 ml of an identical solution was kept in the
dark and worked up at the same time as the photolysis mixture. The dark controls
revealed small losses of parathion for the non-detergent and SDS solutions. Approxi-
mately 42% of the parathion was lost in the dark control for the cationic detergent
solution. In the photolyzed solutions, 48% of the parathion in the aqueous solution,
83% in the HDTBr solution and 92% in the SDS solution. In none of the cases was
p-nitrophenol or paraoxon present in quantities over 2-3%. Two unidentified peaks
were present in the gas chromatograph.
Numerous attempts were made to photolyze aqueous solutions of Sevin (with
and without detergents) in order to determine its elusive photochemical fate. Aqueous
solutions (350 ml) containing 3.5 x 10~4 M Sevin (and 1 x 10~2 M HDTBr or 5 x 10~2
M SDS in certain cases) were photolyzed in "doughnut" shaped vessels fitted around
a Pyrex immersion well. Photolysis times were varied in half-hour increments from
30 min to 4 hours. After photolysis, 1 g Kl was added to the HDTBr solutions and the
precipitate was filtered after stirring. For the SDS solutions, 3 g BaC^ was added.
In all cases, the solutions were then extracted with ether (along with the precipitates).
The ether was evaporated and the residue diluted to volume with ethanol. The solutions
were analyzed by liquid chromatography (10% ethanol-water on a reversed phase
column). The following results were obtained:
Photolysis time (hr) % Photolyzed
Water 1 x 10~2M HDTBr 5 x 10~2M SDS
0.5 12. 29.
1.0 17. 37.
1.5 25. 65. 29
2.0 28. 74.
2.5 32. 0
3.0 34. - -
4.0 39
For each of these runs, no a-naphthol was detected. Judging by the color
of the solutions a photoproduct more soluble in water than in ether (or other organic
solvents) was present.UV spectra of the aqueous solution after extraction clearly showed
the instability of this product as the broad structureless spectra (X 350 mm) changed
with time. An unidentified peak in the LC had the same retentionmvoiume as N-methyl-
1 -hydroxyl-2-naphthamide. None of methyl 4-hydroxy-l -naphthoate was detected
by LC. Thin layer chromatography (CHCI3 on silica) also ruled out the latter, which
40
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exhibited a bright blue fluorescence (Re = 0.6) not observed in the TLC of the reaction
mixture. If any N-methyl-1-hydroxy-2-naphthamide were present, it could not be
detected by thin layer chromatography (Rf = 0.5). Other than Sevin only a spot at
the origin showed up by TLC.
Other liquid chromatography conditions (C|gNH2 column, THF: heptane (1:8)
or silica gel column and 30% mixture of 1% 2-propanol in hexane with 70%
10% 2-propanol in methylene chloride) revealed nothing new. Several wavelengths
were used for detection.
The initial concentration of Sevin in aqueous solution was varied from 1 .0
x 10~4 M to 5.67 x 10~4 M with no unusual effects. Again no a -naphthol was de-
tected .
The concentration of HDTBr was varied from 0 to 1 x 10"3 M to 5 x TO"3 M
to 1 x 10~2 M . The maximum photolysis was observed at 5 x 10~3 M but the amount
was not significantly greater than that of 1 x 10~2 M.
In order to gain more information on the elusive photoproducts, Sevin was
photolyzed in methanol and in aqueous ethanol. Photolysis of Sevin in methanol
followed by evaporation of methanol gave a residue which was analyzed by nmr and
TLC. No a-naphthol or 1-methoxynaphthaIene were present. A singlet observed
at 6 3.9 ppm, however, was indicative of an aryl methoxyl group. Photolyses in
aqueous-ethanol and several studies involving photolysis of Sevin in water using a
254-nm lamp on aerated and deoxygenated solutions were carried out, the salient
features of which were described in the results section.
41
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SECTION VI
REFERENCES
1 . Edwards, C.A., Persistent Pesticides in the Environment. Cleveland, Chemi-
cal Rubber Co. Press, 1970.
2. Plenary Lectures of the International Symposium on the Chemical Control
of the Human Environment, Johannesburg, South Africa, July, 1969. Pure and
Appl. Chem. 21(3) 1970.
3. Matsumura, F., Current Pesticide Situation in the United States. In:
Environmental Toxicology of Pesticides, Matsumura, F. (ed.). New York,
Academic Press, 1972, p. 33-60.
4. Lichtenstein, E.P., Persistence and Fate of Pesticides in Soils, Water
and Crops: Significance to Humans. In: Fate of Pesticides in the Environment,
Tahori, A.S. (ed.). New York, Gordon and Breach Publishers, 1972, p. 1-22.
5. Crosby, D.G., K.W.Moilanen, M.Nakagawa, and A.S.Wong, Photonu-
cleophilic Reactions of Pesticides. IN: Environmental Toxicology of Pestici-
des, Matsumura, F. (ed.). New York, Academic Press, 1972 p. 423-433.
6. Yates, W.E. and N.B.Akesson, Reducing Chemical Drift. IN: Pesticide
Formulations, Van Valkenburg,W. (ed.). New York, Marcel Dekker, 1973,
p. 275-341.
7. Rosen, J.D., The Photochemistry of Several Pesticides. IN: Environmental
Toxicology of Pesticides, Matsumura, F. (ed.). New York, Academic Press,
1972, p 435-447.
8. Fendler, J.H. and E.J.Fendler, Catalysis in Micellarand Macromolecular
Systems. New York, Academic Press, 1975. p 545.
9. Hautala, R.R. and R. L. Letsinger, Effects of Micelles on the Efficiency
of Photoinduced Substitution Reactions and Fluorescence Quencing. J.Org.
Chem. 36 (24): 3762-3768, December 1971.
10. Cordes, E. Reaction Kinetics in Micelles. New York, Plenum Press, 1973.
p 157.
42
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11. Cordes, E. and C. Gitler, Reaction Kinetics in the Presence of Micelle-
Forming Surfactants. IN: Progress in Bioorganic Chemistry, Vol. 2, Kaiser,
E.T. and F.J.Kezdy (eds.). New York, Wiley Interscience, 1973, p 1-53.
12. long, L.K.J. and M.C.GIesmann. The Mechanism of Dye Formation in Color
Photography. V. The Effect of a Non-ionic Surfactant on the lonization of
Couplers. J.Am.Chem.Soc. 79 (16): 4305-4310, August, 1957.
13. Singhal, G.S., E.Rabinowitch, J.Hevesi, and V.Srinivasan, Migration
of Excitation Energy from Thionine to Methylene Blue in Micelles. Photo-
chem. Photobiol. 1J_(6): 531-545, June, 1970.
14. Bunton, D.A., E.J.Fendler, L.Sepulvada, and K.-U. Yang, Micellar-
Catalyzed Hydrolysis of Nitrophenyl Phosphates. J.Am.Chem .Soc. 90
(20): 5512-5518, September 1968. ~~
15. Bruice, T.C., J. Katzhendler and L.R.Fedor. Nucleophilic Micelles. II.
The Effects on the Rate of Solvolysis of Neutral, Positively, and Negatively
Charged Esters of Varied Chain Length when Incorporated into Nonfunctional
and Functional Micelles of Neutral, Positive, and Negative Charge. J.Am.
Chem. Soc. 90 (5): 1333-1348, February 1968.
16. Fay, C.L. and L.W.Smith, The Role of Surfactants in Modifying the Activity
of Herbicidal Sprays. IN: Pesticidal Formulations Research, Advances in
Chemistry Series No. 86, Gould, R.F. (ed.). Washington, D.C., American
Chemical Society, 1969, p 55-69.
17. Van Valkenburg, J.W., The Physical and Colloidal Chemical Aspects
of Pesticidal Formulations Research: A Challenge. IN: Pesticidal Formulations
Research, Advances in Chemistry Sereis No. 86, Gould, R.F. (ed.).
Washington, D.C., American Chemical Society, 1969. p 1-6.
18. Mysels, K.J., Contribution of Micelles to the Transport of a Water-Insoluble
Substance through a Membrane. IN: Pesticidal Formulations Research,
Advances in Chemistry Series, No. 86, Gould, R.F. (ed.). Washington,
D.C., American Chemical Society, 1969, p 24-38.
19. Freed, V.H. and J.M.Witt, Physicochemical Principles in Formulating
Pesticides Relating to Biological Activity. IN: Pesticidal Formulations
Research, Advances in Chemistry Series No. 86, Gould, R.F. (ed.). Wash-
ington, D.C., American Chemical Society, 1969. p 70-80.
20. Kenaga, E.D., Factors Related to Bioconcentration of Pesticides. IN:
Environmental Toxicology of Pesticides, Matsumura, F. (ed.). New York,
Academic Press, 1972, p 193-228.
43
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21 . Lichtenstein, E.P., Increase of Persistence and Toxicify of Parathion and
Diazinon in Soils with Detergents. J.Econom.Entomol. 59(4): 985-993,
August, 1966.
22. Plimmer, J.R., Photochemistry of Pesticides: A Discussion of the Influence
of Some Environmental Factors. IN: Fate of Pesticides in the Environment,
Tahori, A.S. (ed.). New York, Gordon and Breach Publishers, 1972, p 47-
76.
23. Lichtenstein, E.P., K.R.ShuIz, T.W.Fuhremann, and T.T.Liang, Degradation
of Aldrin and Heptachlor in Field Soils During a Ten-year Period. Translocation
into Crops. J.Agr.Food Chem. Jj3 (1): 100-106, January 1970.
24. Woodrow, J.E., J.N.Seiber, D.G.Crosby, K.W.Moilanen, C. Mourer,
C.J.Soderquist, and W.L.Winterlin. The Environmental Fate of Parathion
in a Treated Orchard. Abstracts of Papers, 170th National ACS Meeting,
Chicago, August, 1975. Pest. 125.Pest. 125.
25. Baker, R.D. and H.G .Applegate, Effect of Temperature and Ultraviolet
Radiation on the Persistence of Methyl Parathion and DDT in Soils.
Agronomy J. 62(4): 509-512, July-August 1970.
26. Zepp, R.G. and Cline, D.M., Rates of Direct Photolysis in the Aquatic
Environment. Env.Sci. and Technol. l_h 359-366, April 1977.
27. Zepp, R.G., N.L.Wolfe, J.A.Gordon, and G.L.Baughman, Dynamics
of 2,4-D Esters in Surface Waters, Env.Sci. and Technol. 9(13): 1144-
1150, December 1975.
28. Crosby, D.G. and H.O.Tutass, Photodecomposition of 2,4-Dichloro-
phenoxyacetic Acid. J.Agr.Food Chem. 14(6): 596-599, November-
December 1966.
29. Binkley, R.W. and T.R.Oakes, Photochemical Reactions of Alkyl 2,4-
Dichlorophenoxyacetates. Chemosphere. 3(1): 3-4, January 1974.
30. Crosby, D.G., E.Leitis, andW. L. Winterlin, Photodecomposition of
Carbamate Insecticides. J.Agr.Food Chem. 13(3): 204-207,March 1965.
31. Peters, J.W., J.N.Pitts, Jr., I.Rosenthal and H.Fuhr. A New and
Unique Chemical Source of Singlet Molecular Oxygen. Potassium Perchro-
mate. J.Am.Chem.Soc. 94(12): 4348-4350, June 1972.
32. Frawley, J.P., J.W.Cook, J.R.Blake, and O.G .Fitzhugh, Effect of Light
on Chemical and Biological Properties of Parathion. J.Agr.Food Chem. 6:
28-30, January 1958.
44
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33. Lykken, L. and J.E. Casida. Metabolism of Organic Insecticide Chemicals.
Can. Med. Assoc. J. 100(4): 145-154, April 1969.
34. Caivert, J.G. and J.N.Pitts, Jr., Photochemistry. New York, John Wiley,
1966. p. 783-786.
35. Wagner, P.J. and A.E.Kemppainen. Type II Photoprocesses of Phenyl Ketones.
Triplet State Reactivity as a Function of /and 6 Substituents. J.Am. Chem.
Soc. 94(21): 7495-7499, October 1972.
45
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SECTION VII
GLOSSARY
Brij-35; A non-ionic detergent (see text for structure)
CMC: Critical micelle concentration-the concentration at which micelles form
Detergent; A term used interchangeably with surfactant to designate an amphilic
molecule (one with a large distinct non-polar and a distinct polar or ionic region)
2,4-D; 2,4-Dichlorophenoxyacetic acid (see text for structure)
Einstein; 6.023 x 1023 photons of light
Extinction coefficient; A quantitative measure of the light absorbing characteristics
of a compound; expressed in units of liters-mole'1 cm"1
HDTBr; Hexadecyltrimethylammonium bromide, a cationic detergent (see text for
structure); also abbreviated CTAB
X: Wavelength (expressed in nanometers)
Micelle; An aggregate of several (~ 100) detergent molecules in solution
nm: Nanometers (10"9 meters)
: Quantum yield
(jxJis; Quantum yield for disappearance of a compound undergoing photoae composition
Quantum efficiency; see quantum yield
Quantum yield: The ratio of molecules undergoing a particular light-reduced process
relative to the number of photons of light absorbed
Sevin: N-methyl-1-naphthyIcarbamate, often refered to as Carbaryl (see text for
structure)
SDS: Sodium dodecyl sulfate, an anionic detergent (see text for structure)
Solar spectral irradiance; The distribution of sunlight reaching the earth's surface
in terms of intensity as a function of wavelength
Surfactant; see Detergent
UV: Ultraviolet region of the electromagnetic spectrum
46
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SECTION VIII
APPENDIX
The rates of photodecomposition of 2,4-D, Sevin and parathion under typical
solar conditions have been caluclated and are presented in this appendix. Values for
extinction coefficients and quantum yields were taken from this study. The calcula-
tions were carried out by Dr. Richard G. Zepp of the Environmental Protection Agency,
Athens, Georgia. For a brief discussion of the approach see the section on Photolysis
Rates; for a detailed discussion see reference 26.
47
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System: 2,4-D methyl ester in aqueous solution
XENORIQTIC
WATER TDFNTIFICA
QUANTUM YIELD:
I MITT AT, DEPTH:
DEPTH INCREMENT:
FINAL DEPTH:
FSTFR
TTON: PURE
0.0*000
0.00100
10.00000
5.00000
REFRACTIVE I^DEX:
'A A
VE L
(MM
297
300
302
305
307
310
312
315
317
320
FK'^T
)
.50
.00
.50
.00
.50
.00
.50
.00
.50
.00
H*.%ATF
*
*
*
*
*
*
*
*
*
*
LATITUDE 40 WAS
ALL SEASON
1.0
TI
ry
NGIT
UDR
ME-OF-DA
PICA
I, F.P
s WERE
SELECT
f COMP
HEMERI
P
0
0
0
o
0
0
0
0
n
0
1 . 34000
AKSOPPTlOf
.002RO
.OQ2HO
.002*0
.00250
.00240
.00230
.00220
.00710
.0020P
.00190
*
*
*
*
*
*
*
*
*
*
*
o
0
0
0
0
0
0
0
0
0
EP.sn.n*
.2360E+03
.7B70Ft()2
.5250F+P2
.3940E+02
..3940E + 02
.?*20E-fO?
.2f>20F + 02
.1 310F+02
.1310E+02
.OOOOE+00
SELECTED.
SELECTED.
H-n
(IT
DE
: "0.00
ATJONS APE
AND nzof-E
RE
VA
Ol'ESTBD.
LUES WFPF
48
-------
XF.NOBTDTIC NAMF.I 2,4-1
fcATER IDENTIFICATION:
LAT. SEASON SOLAR
ALT.
40.00 SPRING 0.00
5.00
10.00
20.00
30.00
40.00
bO.OO
60.00
MIDDAY 60.09
ESTEP
PURE
MORN EVE
TT
1
1
5
5
6
7
7
«
9
1
1
ME TI
0
ij
^
*
2^
81
25
12
99
91
8
H
7
6
5
4
93 13
75 12
92 1 1
ty
ME
.
.
.
.
.
.
.
55
04
60
73
85
94
9?
10
92
0.
0.
0.
0.
0.
0.
0.
0.
0.
T PK
RATE
/SEC
OOOE+00
798E-JO
207F-09
621E-08
320E-07
1 35E-0(-
27PF-06
374E-06
375E-06
G.I
T
HAL
unp;: 90.00
F MFE
HOURS
0
0
0
0
0
0
0
0
0
^
GOOF +00
241E+07
93 IF. + 06
310F+05
601F+04
1 43F+04
692E+03
515E+03
514F>03
AVG RATF. DUPING HALITECSKC**-! ) 0.179F-06
RATp- INTFGRATFO OVFR FULL DAY(PAY**-1) O.H54F-02
HALF LTFF INTFGPATFD OVF.R- FULL DAY(DAYS) 0 . 6 1 1 F+2
NPAP SUPFACF
40.00 SU
40.00
MIDDAY
0.00
5.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
70.09
4.74
5.29
5.76
6.65
7.52
3.39
9.2fr
10.74
11.84
11.99
19.24
18.69
18.22
17.33
16.46
15.59
14.70
13.74
12.14
11.99
O.OOOF. + OO
0.798F-10
0.207F-09
0.621R.-08
0.320F-07
0.135F.-06
0.278F.-06
0.374E-06
0.449F-06
0.449F-06
O.OOOE' + OO
0.241F+07
0.931F406
0.310F+05
0.601R+04
0.143E+04
0.692F+03
0.515F-»03
0.429F+03
0.429F-f03
AVG RATF DURING DAI,ITF(SFC**-1 ) 0.212F-06
PATF rMTFGPATFjn (JVF.R FULL DAY(PAY**-1) 0.11 IF-01
HALF LJFF JNTFGRATFD GVFR FULL DAY (DAYS) 0
NP.AR SURFACF:
0.00
5.00
10.00
20.00
30.00
6.10
6.72
7.18
8.16
9.30
17.19
16.66
16.20
15.22
14. OH
O.OOOF+00
0.7<48E-10
('.207E-09
0.621E-OH
0.320F-07
C.OOOFi 00
0.241F407
0.«31F + 0(3
0.310F+05
0.601R>04
40.00 11.52 11.86 0.135K-06 0.143F404
40.06 11.69 11.69 0.136F-06 0.1^"?i-+04
AVG RATE DURING
RATF INTEGRATED
HALF LTFE M" .
NFAR S"PFACE
DALITECSi- C**-.l ) 0.665F-07
OVF'- rl.J[-L DAY(DAY**-1) 0.263F-02
Al ED OVER EULI DAYCDAYS) 0.264E+3
49
-------
0.00
5.00
io.no
20.00
29.86
7.21
7.7«
fl.31
0.52
12.08
]ft.95
16.38
15.85
14.64
12.08
O.OOOF+00
0.79RFT-10
0.207^-09
0 . b 2 \ F - 0 o
0.317F-07
O.OOOF+00
0.2*lF-f07
0.93U. + Oe
0.310F+05
0 . ^ 0 8 F + 0 4
40.00 W1NTFR
"1DDAY
AVT, RATE DURING DAI .ITE (SEC**- I ) 0.182F-07
RATE INTEGRATED OVER FULL DAY(DAY**-1) 0.638F-03
HALF LIFE IKTEGKATFD OVER FULL PAY(DAYS) 0.109E>4
NEAR SURFACE
System: 2/4-D merhyl ester in aqueous solution with cationic surfactant
XENOBlOTlC NAME: 2 , 4-D , METHYL ESTER
VlATER IDENTIFICATION: . 0 1 M CTAB
QUANTUM YIELD:
INITIAL DEPTH:
DEPTH INCREMENT:
FINAL DEP'IH:
REFRACTIVE INDEX
WAVE Ll
0.10000
0.00100
10.00000
5.000QO
1.34000
ABSORPTION*
EPS1LON
(NM)
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.00 *
312.50 *
315.00 *
317.50 *
320.00 *
LATITUDE 40 WAS I
ALL SEASONS wF.'PK
0.00280
0.00280
0.00260
0.00250
0.00240
0.00730
0.00220
0.00210
0.00200
0.00190
SELECTED.
SELECTED.
*
*
*
*
*
*
*
*
*
*
0.4990F+03
0.1 97 OF. + 03
0.7870E+02
0.3940E+02
0.2620E+02
0.1310E+02
O.OOOOE+00
O.OOOOE+00
O.OOOOE+00
O.OOOOE+00
LONGITUDE SELECTED: 90.00
TIME-OF-DAY COMPUTATIONS ARE REQUESTED.
TYPICAL EPHEMERIDE AND OZONE VALUES WERE
SFI.J-CTED.
50
-------
XF.NOBIOTIC NAME: 2,4-
riATER IDENTIFICATION:
LAT. SEASON SOLAR
ALT.
40.00 SPRING 0.00
5. no
10.00
20.00
30.00
40.no
50.00
60.00
MIDDAY 6n.o9
40.00
MIDDAY
40.00 FALL
0,VETHYL ESTER
. 0 1 M
MORN
TTNF-03
HALF LIFE INTEGRATED OVER FUM, DAY(DAYS) 0.71frF43
NFAr- SURFACE
o.or>
s.oo
10.00
20.no
3n.oo
40.00
50.00
60.00
70.00
70.09
4.74
5.29
5.7b
6.65
7.52
R.39
9.2H
10.24
11 .84
11 .99
19.24
1.8.69
18.22
17.33
16.46
15.59
14.70
13.74
12.14
11 .99
O.OOOE+00
0.517E-12
0.165E-12
0. 167E-10
0.723E-09
O.B22F-OH
0.3C4E.-07
0.476E-07
0.642E-C7
0.643E-07
C .OOOE+00
0.372F+09
0.117F+10
0.115t +08
0.266F+06
0.234F+05
0.633F+04
0.405F+04
0.300F+04
G.300F+04
AVG PATE DUPING DAI, I TE ( SEC**-11 0.266E-07
RATE INTEGRATED OVER FULL DAY(DAY**-1) 0.139F-0?
HALF LIFE INTEGRATED OVER FULL DAY(DAYS) r.'.-tii'j-.^
NEAP SURFACE
O.on 6.19 17.19 O.OOOE+00 O.OOOF+00
5
10
20
30
40
.on
.on
.00
.00
.00
6
7
8
9
11
72
18
16
30
52
1
1
1
1
1
6.
6.
5.
4.
1.
66
20
22
OH
86
0.
0.
0.
0.
0.
517E-12
165E-12
167E-10
723E-09
822E-08
0
0
0
0
0
.372E+09
.117F+10
.1 15E-+OH
.266E+06
.234F+n*
40.06 11.69 11.69 0.834E-08 n, o >.
AVG RATE. DURING
RATE INTEGRATED
HALE LIEF. iM-t.v....
NEAR SUPFACE
DALITEf1' '
OVER FULL
f.TED OVER FULL
) n.373fc-()8
>PY**-1) 0.14HK-03
DAY(DAYS) 0.470E+4
51
-------
40.00 WINTER
MIDDAY
0.
5.
10.
20.
29.
00
00
00
00
8
-------
XENOBTOTtC KAMK: 7,4-D,MFTHYL KSTFR
WATER IDENTIEi
LAT. SEASON
40.00 SPRING
MIDDAY
40.00 SUMMER
MIDDAY
40.00 FALL
MIDDAY
:ATTOIV:
50LAR MO
M,T.
0.
5.
10.
20.
30.
40.
50.
60.
60.
AVG
05M
pv
TTMF
00
00
00
00
00
00
00
00
09
P
RATE
HAL
F
NEAR
o.
5.
10.
20.
30.
40.
50.
60.
70.
70.
AVG
R^ T
HAL
00
00
00
00
00
00
00
00
00
09
5
5
6
7
7
H
9
1 1
1 1
ATE
.29
.81
.25
.12
.99
.91
.93
.75
.92
OUM
sns
EVt-JN
TI
1
1
1
1
1
1
1
1
1
H'G
8
8
7
6
5
4
3
2
1
INTEGRATED
LTFF
SURF
1
5
5
6
7
H
9
10
1 1
1 1
IN
ACE
.74
.29
.76
.65
.52
.39
.28
.24
. H4
.99
ME
.55
.04
.60
.73
.85
.94
.92
.10
.92
DAL1
OVER
TEGRATED
1
1
1
1
1
1
1
1
1
1
9
8
8
7
6
5
4
3
2
1
HATE DUPJkG
F
7MTE
LIFE
GRft
.24
.69
.2?
.33
.46
.59
.70
.74
.14
.99
LO
PATE
f-GITUI'F: 90.00
H A I F L 1 F F
/SEC Kni)R5
0.
0.
0.
o.
0.
o.
0.
0.
0.
OOOE+OU
412F.-09
125F.-OF
279F-07
122F-06
445E-06
H46F-06
1 11E-05
13 1F-05
TE(SFC**-1
FULL DAY(
OVER FULL
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
DAHTE(
OVFP
INTEGRATED
OOOE+00
412F-09
125F-08
279E-07
122E-06
445F-06
846F-06
1 1 1E-05
131F-05
3 31E-05
st:c**-i
0
0
0
0
0
0
0
0
0
)
DAY
r*
0
0
0
0
0
0
0
0
0
0
)
FULL DAY (DAY
0V
tH FULL
0
*
Y
m
m
.
.
0
*
HAY
OCOF +00
4 6 7 F + 0 6
1 S 5 E + 0 6
690F+04
158F+04
432F+03
228F +03
173F+03
173F+03
.54bt-0b
*-l) 0.26 IF -01
(PAYS) 0.266K+2
OOOF+00
467F+06
155F+Ob
690F+04
1 5PE+04
432F+03
72RE+03
173E+03
147F-+03
1 47F+03
,637F-(:6
*-1) 0.333F-OI
(PAYf) 0.7r.PKt2
MEAR SURFACE
0.
O
30.
20.
30.
00
00
00
00
00
6
6
7
ft
9
.19
.72
.18
-16
.30
1
1
1
1
1
7
6
6
5
4
. 1 9
.66
.20
.72
.08
0.
0.
0.
0.
0.
OOOF+00
412F-09
125F-08
279E-07
127F-06
0
0
0
0
0
OOOE+00
4b7F +06
1 5 5 E + 0 6
690F+04
1 5 8 E + 0 4
40.00 11.52 11.86 0.445F-06 0.432H03
40.06 11.69 11.69 0.44RF-06 0.430F+OA
AVG PATE DUPING DALITF. ( SFC** - J ) 0.224F-06
PATF TVTFGRATFJD OVKR Fl'; I. .)AY(DAY**-1) O.HP7F-(y
HiT,F LTFF TNTF/GPETfT; (WFP. FULL DAYCDAYS) 0.7R2K+2
NEAR SURFACF
53
-------
40.00
MIDDAY
0 . 0 f )
s.oo
10. no
20.00
29. R6
7.21
7.79
?. 31
9.52
12. OH
16. OS
1 ft . 3 H
15.85
1 4.64
12.08
O.OOOF. + CO
C.412F-09
0.12SE-OH
0.279F-07
0.120E-06
O.OOOFtOC
0.4ft7F4f.t»
0.155F+06
0.690F+04
U.lftOfc>04
AVG RATE PURING DAT..ITECSFC**-1 ) 0.703E-07
PATE INTEGRATED OVER FULL DAYCDAV**-!) o.246t>o?
HALF t,TFP INTEGRATED OVFR FULL DAY(DAYS) 0.2«lF+3
NEAP SURFACF
System: 2/4-D acid on soil surfaces. The data here are calculated for
conditions producing a "quantum yield" of 0.001. See complete
data for 2,4-D -soil experiments to obtain actual "quantum yields"
for specific conditions.
WATER
NAME: 2, 4-0, ACID
IDENTIFICATION: SOIL SURFACE
QUANTUM YIELD:
INITIAL DFPTH:
DEPTH INCREMENT:
FINAL DEPTH:
REFRACTIVE INDEX:
WAVE LFNGTH*rtATER
CNM)
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.00 *
312.50 *
315.00 *
317.50 *
320.00 *
LATITUDE 40 *AS 5
ALL SEASONS KEHF
0.00100
0.00100
10.00000
5.00000
1 .34000
ABSORPTION*
O.OQ280 *
0.002ftO *
0.00760 *
0.00250 *
0.00240 *
0.00230 *
0.00220 *
0.00210 *
0.00700 *
0.00190 *
.rt.FCTFO.
SFLFCTFM).
EPSILON
n.73feOF+03
0.7870F.+02
0.5250F-I-02
0.3940F+02
0.3940F+02
0.2620F+02
0.2620F+07
0. 1310L-J-02
0.1310F+02
O.OOOOE+00
LONGITUDE SELECTED: 90
TYPICAL EPHErtFRlDE AKiO
00
ARE
07.0WE
VALUES WFPF SEIECTFD.
54
-------
XFMOPIOTTC NAME: 2,4
WATER IDENTIFICATION
LAT. SKASOM SOLAR
ALT.
40.00 sPRJNG 0.00
5.
10.
20.
30.
40.
so .
60.
MIDDAY 60.
AVG
00
on
00
on
00
no
00
09
R
HATP;
HAL
F
NF:AR
40.00 s'JWMFR 0.
*.
10.
20.
30.
40.
50.
60.
70.
00
00
00
00
00
00
00
00
00
-0, AC ID
: SOU, ?HKFAC
MORN FVEf.N
TTMK TJMF:
5.79 18.55
1
1
ATF
5
6
7
7
P
9
1
1
.HI
.75
.\7
.99
. 91
.93
.75
.97
1
\
]
]
1
1
1
1
ft
7
6
5
4
3
2
1
DURING
INTF
LJF
F'
GPATF
D
.04
.60
.73
.85
.94
.92
.10
.92
DAL
OVK
F
0
0
0
0
0
0
0
0
0
ITF
PATF
ASFC
.OOOF+OO
. 1 33F-1 1
.345K-J 1
. 103F-09
.533F-09
. 7 2 5 F - 0 K
.464F-0*
.623F -0£
.624F.-OF
(SF.C**-1
P FULL DAY(
IMTFGRATFD OVFP FULL
'- G I
()
C
0
0
0
G
C
o
0
)
DAY
DA
TUPF: 90. On
I F LJFF
HOP PS
, (l 0 0 F 1 0 0
. 145F too
,559FtOft
. 1 P 6 F 1 0 7
.361 Ft 06
.P!S6Ft05
.415FtC5
.309F t05
,308Ft05
0.298F-08
**-!) 0.142F-03
Y(PAYS) 0.4H7F^4
SUPFACF
1
1
4
5
5
^
7
P
9
0
1
.74
.29
.76
.65
.52
.39
.28
.24
.84
1
1
1
1
1
1
1
1
1
9
8
8
7
6
5
4
3
2
.24
.69
.22
.33
.46
.59
.70
.74
.14
0
0
0
0
0
0
0
0
0
. 0 0 0 E' 1 0 0
. 1 3 3 f - 1 1
.345F-1 1
. 103K-00
.533F-09
.725F-08
.464FJ-OH
. f 23RX'fc
.748F-08
C
0
0
0
0
0
0
0
0
. 0 0 0 F t f - 0
.145F tu9
.559F tOB
. 1 86F t 07
. 361 Ft06
. P 5 6 E ' t 0 5
,415fc:t05
.309F t05
.258f.tOE>
MIDDAY
40.00 FALL
MIDHAY
70.09 11.99 11.99 0.748F-OP C.?57E>05
AVG PATF DURING DAL ITE(SFC**-l) 0.354F-CP
PAIR TNTKGPATFD OVtR FUIJ, DAY (! A Y**- 1 ) 0.1P5F-03
HAIiF LTFF 1NTFGHA1FD HVFiP FULL DAY(DAYS) 0.275f +4
NFAR SUPFACF
0.00
6.19 17.19 O.OOOF.tOO O.OOOFtOO
5.00
10. on
20.00
30.00
40.00
6.72
7.18
8.16
9.30
11 .52
je. .66
16.20
15.22
14.06
1 1.86
0.133F-1 1
0.345F>1 1
0.1 03h>09
0.533F-OM
0.27.5F-U8
0. 145Ft09
0 . 5 5 9 F t 0 K
0.1 P6F+07
0.361F+06
0 . 8 5 6 F. 1 0 5
40.06 11.69 11.69 0.226F-08 O.R51F-H.'t>
AVG PATF Df.JPT'vG DAL1TF (SFT * *- 1) C.111F-0«
PATF TN'TFGPATFD OVF.'P FU .L DAY ( OA Y **-!.) 0.43hF>04
HALF T.TFF INTFGPA'" < 0 HVFP FULL DAY (DAYS) 0.158Ft5
55
-------
40.00
MTDDAY
o.oo
S.OO
in. on
20.00
29.S6
7.21
7.79
8.31
0.52
12. OH
16.95
If). 38
15. H5
14.64
12.08
O.OOOF+00
0.133K-11
0.345E-1 1
0.103E-OQ
0.52fiE-09
O.OOOF'iOO
C.145E+09
0.559E+P8
0.1 86M07
0.365F+06
AVG RATE DUHTNG DALITE(SEC**-1) 0.303F-09
RATE INTEGRATED OVER FULL DAY(DAY**-!) U.10hK-04
HALF LIFE TNTFGRATKD OVFP FULI DAY(DAYP) 0.652F+5
NFAP SUPFACF.
Sysfem: Sevin in aqueous solution
XENQBlQflC NAME: f
*ATER TDENTIFICATI
QUANTUM YIELD:
INITIAL DEPTH:
DEPTH INCREMENT:
FIN'AL DEPTH:
REFRACTIVE INDEX:
WAVE LENGTH**IATEP
(NM
297
300
302
305
307
310
312
315
317
320
323
330
340
350
)
.50
!oo
.50
.00
.50
.00
.50
.00
.50
.00
.10
.00
.00
.00
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0
0
0
0
0
0
0
0
0
0
o
0
0
0
ON: PURE i-.ATt
o.oiooo
0.00] 00
1 0.00000
5.00000
1.34000
ABSORPTION*
*
»
*
*
00280
00280
00260
00250
00240
00230
00220
00210
00200
00190
OOIRO
00152
00122
00100
*
*
*
*
*
*
*
*
*
*
*
*
4-
*
0
0
0
0
0
0
0
0
0
0
0
0
0
0
EPS I LOW
.1410E+04
.9300E+03
.7370E+03
.5290E+03
.4090E+03
.3510E+03
.3780F+03
.2580K+03
.2360E+03
.1 1 20E+03
.5790E+02
. 13BOF+02
.OOOOE+00
.OOOOE+00
LATITUDE 40 WAS SFLFfTED.
ALL SEASONS ^FPF SELECTED.
LONGITUDE SFLFCTFO: 90.00
TIME-OF-DAY COMPUTATTHNS APE
TYPICAL FPHEMEP1DE A^!D OZONE
PKOUESTFD.
VALUES UERF
SELECTED,
56
-------
XENOBIOTIC NAME:
WATER IDENTIF1CAT
LAT. SEASON SOL
40.00 SPRING
MIDDAY
40.00 SUMMER
MIDDAY
40.00 FALL
MIDDAY
AT TO^1:
OLAP
LT.
0.00
5.00
10.00
20.00
30.00
40.00
50.00
60.00
60.09
PURE
MORN
TIME
5.29
5.81
6.25
7.12
7.99
8.91
9.93
1 1 .75
11.92
VvATER
EVFJlv
TIME
18.55
18.04
17.60
16.73
15.85
14.94
13.92
12.10
11 .92
LOGITUPF: 00
PATF. HALF 1 IKE
/SEC
O.OOOE+00
0.1 11F-07
0.277F-07
0.121E-06
0.333E-06
0.898F-Ot>
0.154F-05
0.198F-05
0.198E-05
HOHP5
O.OOOF 400
0.174F+05
0.695F+04
0.] 60F+04
0.578F+03
0.214F+03
0.1 25F+03
0.975F+02
0.973F+02
,00
AVG HftTF DUPING DALITE(SFC**-1) 0.102F-05
PATE INTEGRATED OVER FULL OAYCDAY**-!} 0.4P5F-01
HALF LIFE INTEGRATED OVER FULL DAYCDAYS) 0.143E+2
SURFACE
o.oo
5.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
70.09
4.74
5.29
5.76
6.65
7.52
8.39
9.28
10.24
11.84
11 .99
19.24
18.69
18.22
17.33
16.46
15.59
14.70
1 3.74
12.14
11.99
O.OOOE+00
0.11 1E-07
0.277E-07
0.121E-06
0.333F-06
0.898F-06
0.154E-05
0.19SE>Ob
0.229E-05
0.229F-05
0. OOOF + 00
C.174E+05
0.695F+04
O.J60F+C4
0.576F+03
0.21 4F+03
0.125E+03
0.975F+02
O.P4U+02
0.840F+02
AVG RATE DURING DALITF C SEC**-11 O.H7F-05
RATE INTEGRATED UVEP FULL DAY(DAY**-1 ) 0.609F-01
HALF LIFE INTEGRATED OVER FULL DAY (DAYS'* 0 . 1 j 4F+2
SURFACE
0.00
5.00
10.00
20.00
30.00
40.00
40.06
6.19
6.72
7.18
8.16
9.30
11 .52
1 1 .69
17.19
16.66
16.20
15.22
14.08
11.86
11.69
O.OOOE+00
0.11 1F-07
0.277E-07
0.121F-06
0.333F-06
0.898E-06
0.902F-06
0. 00 OF +00
0.174E+05
0.695F+04
0 . ] 60F+04
0.578F+03
C.214E+03
A-?l3F-f03
AVG RATE DURING DALlTFCSFC**-!3 0.485E-06
RATF INTEGRATED OVFP FULI DAYCDAY**-!) o.i92F-oi
HALF LIFE INTFV.-ATFO OVER FULL DAY(DAYS) 0.361F+2
NEAR SURFACE
57
-------
40.00 WINTER
MIDDAY
0.00
s.oc
10.00
20.00
29.ft6
7.21
7.79
B.31
Q.52
12. OH
16.95
16.38
15.85
14.64
12.08
O.OOOF+00
0.1 1 1E-07
0.277F-07
0. 1 21E-Or
0.330F--06
O.COOF+00
0.174F405
0.695F+04
C.16CE+04
0.5H3E«03
AVG pftTF DURING HALITFCSEC**-!) o.2o*F-06
PATE INTEGRATED ovtP FULL DAYCPAY**-!) G.
HALF LIFE TNTEGRATFJD OVFP FULl PAY(DAYS) 0.952F+2
MEAR SURFACE
System: Sevin in aqueous solution with cationic surfactant
XENOBlflTlC NAME: CARBAPYI,
WATER TDENTIFTCATTON: .01M CTAB
QUANTUM YItLD:
INITIAL DEPTH:
DEPTH INCREMENT :
FINAL DEPTH:
REFRACTIVE INDEX:
WAVE LFNGTH*wATER
(NM1
297,
300.
302,
305,
307.
310,
312.
315.
317,
320.
323.
330.
340,
350.
)
.50
.00
.50
.00
.50
.00
.50
.00
.50
.00
.10
.00
.00
.00
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0.03000
0.00100
10.00000
5.00000
1 .34000
ABSORPTION*
.00280
.00780
.00760
.00250
.00240
.00730
.00720
.00710
.00200
.00190
.001 80
.00157
.001 27
.001 00
*
*
*
4
*
*
*
*
*
*
*
*
*
*
0
0
0
0
0
0
0
0
0
0
0
0
0
0
EPS I LOW
.2450E+04
.1730FJ + 04
.1320Et04
. 1 0 4 0 F + 0 4
.H030E+03
.6830F+03
.6220E+03
.5290E+03
.4400FJ + 03
.3320F+03
.2470E+03
. 5790 F + 02
.1 160E402
.5800F+01
LATITUDE 40 nAS SELECTED.
ALL SEASONS dEPK SELECTED.
LONGITUDE SELECTED: 90.00
TIME-OF-DAY COMPUTATIONS ARF
TYPICAL EPHbiMERIDE AND OZONE
HEQIIESTED.
VALUES WERE
SFl.-ECTFO,
58
-------
XF.NOBIQTIC NAM£: CARBARYI
*ATEP IDENTIFICATION
LAT. SEASON SOLAR
ALT
40.00 SPRING o
5
10
20
30
40
50
oO
MIDDAY 60
: .01 M
MORN
TTMF
4
00
00
00
00
00
00
0 I'l
00
09
5
5
6
7
7
8
9
1 1
1 1
AVG RATF
RATF
HALF
.29
.81
.25
.12
.99
.91
.93
.75
.92
DIJP1
CTAB
FVF.M
IT
1
1
1
1
1
1
1
1
1
M;
8
8
7
6
5
4
3
2
1
i
TNTFGRATFD
I, IFF;
MF
.55
.04
.60
.73
.85
.94
.92
.10
.92
I.' A!, I
OVFP
TNTFGRATFD
0.
0.
0.
0.
0.
0.
0.
0.
0.
TF(
FI;
T.OMGI1
RATF: HA;
/SKC
OOOF400
232F-06
553F-06
184F-05
424F-05
939F-05
147E-04
184E>04
184F-04
SKC**-1
II. T, HAY(
OVER FUI.T,
'UPF: 90.00
F LIFF
HOUFS
n m
0.
0.
0.
0.
o.
0.
o.
o.
) 0
0 COM 00
P31F+03
348t +03
1 04F+03
454F+0?
2 0 5 F -f 0 2
1 3U + 02
1 04fc 402
104F+02
.995F-05
DAY**-1) 0.475F. + 00
DAY(DAY.S) 0.14hV+
*FAR SURFACE
40.00 SUMMER 0
5
10
20
30
40
50
60
70
MIDDAY 70
m
*
AVG
00
on
00
00
00
00
00
00
On
09
4
s
5
6
7
8
9
10
11
11
PATF:
PAT'T
HA
NF
40.00 FALL 0
5
10
20
30
40
MIDDAY 40
r*
.74
.29
.76
.65
.52
.39
.28
.24
.84
.99
OUR I
i
i
i
i
i
t
i
1
i
i
*G
INTEGRATED
MFF;
9
8
fi
7
6
5
4
3
2.
1
.24
.69
.22
.33
.46
.59
.70
.74
.14
.99
DALI
OVER
INTEGRATED
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
TF(
000 F. 4 0 0
232F-P6
553fe>0ft
184F-OS
424F-05
939F-05
147F-04
1 84E-04
210F-04
211F-04
5F.C**-1
FULL DAY(
OVER FULL
0.
0.
0.
0.
0.
0.
0.
0.
0.
n
f .
) o
DfiY*
TAY
0 0 0 F 4 0 0
831F+03
34PF+03
1 O^F.-f 03
A54F+02
205F+02
1 31F>02
1 0 4 F + 0 2
915F+01
91 4F+01
. 1 12F-04
* - 1 ) 0 . 5 8 f-- F 4- 0 0
(DAYS) 0.118F+'
AR SHPFACF.
»
m
00
no
on
00
00
nn
06
6
6
7
fi
9
1 1
11
.19
.72
.18
.16
.30
.52
.69
1
1
1
1.
1
1
1
7
h
6
5
4
1
1
.19
.66
.20
.22
.Ob
. 80
.69
0.
0.
0.
0.
0.
0 .
0.
OOOF+00
232F-06
553F--C6
164F-05
424F-05
9 3 ** F. - 0 5
941F-05
0.
G.
f .
c.
c .
0.
0.
0 0 0 F 4 0 f)
S3 IF 4-0 3
3 4 8 fc 4 0 3
1 0 4 F 4 0 3
4 ri 4 F 4 0 2
205F+02
204F+02
AVG RATF DURING DAMTF( SFf**- 1 .) 0 .^ 36F-05
RATF TWTFGPATfP OVKP F'lF' ': A V U) i Y **- 1 ) 0.212F + 00
HAI,F T.l^F INTFGPATFP C.'-KH r ULL DAYCOAY?) 0.327K + 1
MFAR SllRFACt
59
-------
40.00 WINTER
MIDDAY
0.00
5.00
10.00
20.00
29. R6
7.21
7.79
R . 3 1
9.52
1O Q
£ w O
16.95
16.38
1 b .as
14.64
1 2.09
O.OOOE+00 C.
0.232E-06 0.
0.553F-0^ 0.
0.184F.-0^ 0.
0.421t:-0l> C,
OOOF+00
P31F. + 03
34BF+03
104h+03
45PF-»02
&VG PATE DUPING DALTl.'F(SfcC**-n 0.27SK-05
HZi.TF T*'TFGRATfc!D OVER FULL HAY I DAY**-1) 0.9b6K-01
HALF LIFF. INTEGRATED OVF.P FULt DfY(DAYS) 0.71PF*!
NEAP SUPFACF
System: Sevin in aqueous solution with anionic surfactant
XFNOBIOTIC
N
WATER IDFNTI
QUANTUM YIFL
INITIAL DEP
AME:
FICAT
D:
r
A
RRARY
TOM; .05M SOS
TH:
DEPTH INCREMENT:
FINAL DEPTH
REFRACTIVE
0.01
D.OO
000
100
10.00000
: 5.00000
INDEX:
WAVE LFNGTH*IMATER
(NM)
297.50
300.00
302.50
305.00
307.50
310.00
312.50
315.00
317.50
320.00
323.10
330.00
340.00
350.00
LATITUDE 40
ALL SEASONS
*
*
*
*
*
*
*
*
*
*
*
*
*
*
WAS S
0
o
0
n
0
0
0
0
0
0
0
0
0
0
1 .34000
APSQRPTinM*
.
.
.
.
.
.
.
.
.
.
.
.
*
.
L
00280
00280
00260
00250
00240
00230
00220
r.0210
00200
00190
00180
00152
00122
001 00
ECTED
.
*
*
*
*
*
*
*
*
*
*
*
*
*
*
0
0
0
0
0
0
0
0
0
0
0
0
0
0
FPSILON
.1 880F. + 04
.1210E+04
.8800E+03
.6490F+03
.4780E+03
.3H60E+03
.37SOE+03
. 3050F+03
.2390K+03
.1430F+03
.6950F+02
.1 160E402
.5800E+01
.OOOOE+00
WERE SELECTED.
LONGITUDE SFLECTFP: 90.00
TYPICAL FPHEMfPIOP- AND OZONE
REQUESTED.
VALUES WERE
SfLF.CTFH
60
-------
XFNOPIOTIC NAME: TARBARYL
WATER JDE^TIF
LAT. SEASON
40.00
MIDDAY
CATTON:
SOLAR
ALT.
o.oo
5.00
10.00
20.00
30.00
40.0 0
50.00
60.00
60.09
.05M
MOP 1C
TIME
5.29
5. HI
6.25
7.1?
7.9 c.}
9.91
9.93
11 .75
11.92
SDS
EVEN
TIME
18.55
18.04
17.60
16.73
15. R5
14.94
13.92
12.10
11.92
PATF
/SEC
O.OOOF+OC
0.196F-07
0.471F-07
0.172F.-06
0.436F-06
0. 1 09t -05
0.182E-05
0.233F-05
0.233F.-05
C-GJTUOF: 00
HALF LIFF
HOURS
O.OOOF +00
0.9P1 F+04
0.409E+04
0.1 12E+04
C . 4 4 1 1 + 0 3
0.176F+03
0.1 06F-+G3
0.827F+02
O.K25F+02
,00
AVG RATF DURING DALI TF ( SF.C**-1) O.J22F.-05
PATE INTEGRATED OVFP FULL PAY (0/> Y **-! ) 0.5B1F-01
HALF LIFF INTEGRATED OVFP FULl DAY (DAYS) 0.119E+2
NEAP SURFACE
40.00
MIDDAY
0.00
5.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
70.09
4.74
5.2V
5.76
6.65
7.52
8.39
9.28
10.24
11 .84
1 1.99
19.24
18.69
IS. 22
17.33
16.46
15.59
14.70
1 3.74
12.14
11.99
O.OOOK+00
0.196F-07
0.471F-07
0.172F-06
0.436F-06
0.109F-05
0.182F-05
0.233P--05
0.269F-05
0.269E-05
o.oonf-f oo
0.9R1F4-04
0.409F +04
O.I 1-2F+04
C.44U+03
G.176F +03
0.106F+03
0.827F+02
0.716F+02
0.715fc-»02
AVG RATF DURING PAI.ITF.(StC**-l ) 0.139F-05
RATP I^TFGRATFD OVFP FULL DAYCDAY**-!) 0.
HALF r.iFF INTEGRATED ovtp FULL DAYCDAYS)
NEAP SURFACE
40.00 FALL
MIDDAY
o.oo
5.00
1 0.00
20.00
30.00
40.00
40.06
6.19
6.72
7.18
8. 16
9.30
11 .52
11 .69
17.19
16.66
16.20
15.22
1 4 . 0 H
1 1 .86
11.69
O.OOOF-fOO
0.196F-07
0.471E-07
0.172F.-06
0.4-ibh-06
0.109F-05
0.1 10F-05
O.OOOF+00
C.981F404
0.409F+04
0.112F+04
0.441F+03
0.176F+IH
0 i-»^K403
AVG RATF
RATF T^TFGRATED
HfiLF LIFF .K'TK,
NEAR
DAL!TF(5r-'
OVFP f'li/.L
,TF[) Ov/FP
-v-t) 0.602F-06
LAYCCAY**-!) 0.23HF-01
FULL PAYCDAYS) 0.291E+2
61
-------
40.00 WINTER
MIDDAY
0
5
10
20
29
00
00
00
no
86
7
7
B
q
12
.21
.79
.31
.b2
.08
16.
16.
15.
14.
12,
,95
.38
,85
.64
.08
0
0
0
0
0
*
OOOE+00
196F-07
471E-0/
1 7 2 fc' - 0 »>
433E-06
0
0
0
0
0
.OOOF400
.981F404
.409F404
.1 121:404
.445F403
AVC RAT£ DHFTNG 0 AL T TEf SFC*=» - 1) 0.777F-06
RATF INTEGRATED OVER FULL, DAY(n0Y**-i) o.972t>o2
HATF tTf'E INTEGRATED OVFP Fbl-L DAY(DAYS) 0.713F>2
System: Sevin on soil surfaces. Tha data here are calculated for
conditions producing a "quantum yield" of 0.0003. -See
complete data for Sevin-soil experiments to obtain actual
"quantum yields" for specific conditions.
Xt'NOBlOTTC NAMR: CflRRARYL
WATER IDENTIFICATTDM: SOIL SURFACE
QUANTUM YIELD:
INITIAL DEPTH:
UF.FTH INCREMfc.NT:
FINAL DEPTH:
REFRACTIVE INDEX
WAVE LENGTHtx'ATF
(NM)
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.00 *
312.50 *
315.00 *
317.50 *
320.00 *
323.10 *
330.00 *
340.00 *
350.00 *
0.00030
0.00100
1 0.00000
5.00000
: 1.34000
P ABSORPTION
0.00?PO
0.00280
0.00260
0.00250
0.00240
0.00230
0.00220
0.00210
0.00700
0.00190
0 . 0 0 1 P 0
0.00157
0.00172
0.00100
*
*
*
*
*
*
*
*
*
*
*
*
«
*
*
fc'PSILON
0.1410F: + 04
0.9300E+03
0.7370E+03
0.5290F+03
0.4090E+03
0.3510E403
0.3780F+03
0.2580E+03
n.2360F403
0.1 120E+03
0.5790E+02
0.1380F+02
O.OOOOE+00
O.OOOOE+00
LATITUDE 40 -vAS SELECTED.
ALL SEASONS WERE SELECTED.
LONGITUDE SELECTED: 90.00
TIME-OF-DAY COMPUTATION'S ARE
TYPICAL EPHEMERIDE AND
-i.UES
.0.
i»EkE
SFLhCTBD.
62
-------
xFNORioTic NAME: CAPRARYL
WATER IDENTIF
LAT. SEASON
40.00
VIDDAY
40.00
MIDDAY
40.00 FALL
MIDDAY
CATION: SOIL SUPFACF
SOLAR MORN F'VFJN
ALT. TIME TIME
0.00 5.29 18.55
5.00 5.81 18.04
10.00 6.25 17.60
20.00 7.12 16.73
30.00 7.9^ 15.85
40.00 P. 91 14.94
50.00 9.93 13.92
60.00 11.75 12.10
60.09 11.92 11.92
AVG RATE DUPING DALIT
RATF INTEGRATED OVER
HALF LIFF INTF'CHATED
NFAP SURFACE
0.00 4.74 19.24
5.00 5.29 18.69
10.00 5.76 18.22
20.00 6.65 17.33
30.00 7.52 1.6.46
40.00 R.39 15.59
50.00 9.28 14.70
60.00 10.24 13.74
70.00 11. H4 12.14
70.09 11.99 11.99
I ."'
RATE
/SFC
O.OOOE-fOO
0.332F-09
0.831E-09
0.362E-OH
0.999F-0&
0.270E-07
0 . 4 6 1 F - 0 7
0.593E-07
0,593E-07
'E(SfcC**-l
Fl:LL PAY(
OVER FULL
O.OOOF-fOO
0.332E-09
O.H31F-09
0.362F-OK
0.999E-OP
0.270F-H7
0.461E-07
0.593E-C7
0.687E-07
0.688F-07
AVG PATF DUPING f) A I, I TE ( SEC* *- 1
PATE INTEGRATED OVER
HALF LIFE INTEGRATED
NEAR SURFACE
0.00 6.1^ 17.19
S.OO 6.72 16.66
10.00 7.18 16.20
20. on ft. 16 15.22
30.00 9.30 14.0?
40.00 1 1 .52 1 1 .P6
40.06 1 1 .69 1 1 .69
FULL PAY(
OVER EliLT
O.OOOE-fOO
0.332F-0Ci
O.P31E-09
0.36?E-Oft
0.999E-C'ft
0.270E-07
0.271F-07
^GiTi'DF: ^o.cn
HALF I IFF
HOUf S
0 . 0 0 0 F -t 0 0
r- . 5 e o F + o 6
0.232E-K)6
0.532F+05
0.193E-f05
0.714E-fC4
0 . 4 1 7 b -f 0 4
0. 325F+04
0.324F+04
) 0.305F-07
DAY**-1 ) 0. 14hE-02
PAY (PAY?) 0.476F+3
O.OOOF-fOO
O.S80F -f06
0.232f +06
0.532F-f05
0.1 93F+05
0.71 4E-f04.
G.417E+04
0.325F+04
G.2ROE+04
G.280t-f04
) 0.350E-(7
F'AV**-1) 0.183F-02
D A Y f [ i A Y S ) 0 . "" 7 : E f 3
f .OOOF-fOO
0 . 580F+06
0.232F>06
0.53?E-f 05
0.193t+05
C .71 4E + 04
0 . 7 1 1 r t 0 4
AVG HATF DUPING PALITFCSFC->-1) 0.145F-07
PMF TN'-TFGPATFD PVFP F.^I, PAY u)CY**-n 0.575F-03
HALF LTFF H'TFir. ;rr nVc.P FULL PAYCPAYS) 0.120E44
NFAK
63
-------
40.00
MIDDAY
o.oo
5.00
10.00
20.00
23.86
7.21
T.79
«.3l
9.5?
12.08
16.95
16.18
15. PS
H.64
1 2.08
O.OOOF+00
0.332K-09
O.P31E-09
0.362F-08
0.991F.-08
O.OOOF+00
0.5fr0fc+0b
C.232E+06
C.512F+05
0.194F+05
AVG PATF. DUPIN'C DAF.ITFC SF.C**-1 ) 0.623F-08
RATF. INTEGRATED OVER FULL DAYCPAY**-!) o.2iBt-03
HALF LTFF J.vTFRRATFP OVEF FHI.I, DAY(OAYS) 0.317F+4
NF^F'1 SUPFACF
System: Parathion in aqueous solution
XENOBIOTIC NAME: PAPATHION
WATER IDENT1MCATLON: PUR?, WATh P
QUANTUM YIELD! 0.00020
INITIAL DEPTH: °-°!!^!L
DEPTH INCREMENT: 10.00000
FINAL DEPTH: 5.00000
REFRACTIVE INDEX: 1.34000
WAVE LENGTH*WATF.R ABSORPTION'*
CNM-)
.50
.00
.50
.00
.50
.00
.50
.00
.50
.00
.10
.00
.00
>.oo
LATITUDE 40 HAS SFL
SEASON « i is su
SELECTED:
297.
300.
302,
305
307.
310,
312,
315.
317,
320,
323.
330,
340,
*
*
*
*
*
*
*
*
*
0.
0.
0.
0
0
0
0
0
0
0
0
0
0
0
^0280
00280
00260
00250
00240
00230
00220
00210
.00200
.001 90
.00180
.00152
.00122
.001 00
*
*
*
*
*
*
*
*
*
*
*
*
90.00
COMPUTATIONS ARE
TYPICAL EPHEMERIDF AND OZONE
tPSILON
0.
0.
0.
0
0
0
U
0
0
0
0
0
0
0
48 OOF.+ 04
4500E+04
4250F+04
3750E+04
, 3250F. + 04
.2750F+04
.2350E+04
.2000F+04
.1600E+04
. ] 5 5 0 r, 0 4
.1400E+04
.9500E+03
.5500F.+03
.4000E+03
HEOUESTFD.
VALUES T:;
SKLECTE.P,
64
-------
XENOB10TIC NAVE:
WATER TDENTIEICAT
LAT. SEASON SOT.
ALT
40.00 SUMMER 0
5
1 0
20
30
40
50
60
70
MlnoAY 70
P A P A T H i !.l N
TON; PURE wATKR
A P >' H P \ F V F fj
TIME TIMF
.00 4.74 19.24
.00 5.29 lfi.69
.00
.00
.00
.00
.00
.00
.00
.09
5
6
7
8
Q
1 0
1 1
1 1
.76 18
.65 1 7
.52 16
.39 :
.28 '
.24 :
.M '
.99 :
IS
I 4
13
12
1 1
.22
. 33
.46
.59
.70
.74
.14
.99
0.
0.
0.
0.
0.
0.
0.
0.
0.
0.
LONGITUDE:
HATt- HALF LI
/SFC nnrps
OOOF+On O.OOOF.
699E-07 0.275F
170E-06
45RF-06
874F-06
135F-05
181E-OS
219F-05
245E-C5
245F-05
0
0
0
0
0
0
0
G
.1
.4
.2
.1
.1
.8
.7
.7
1 31=
2 OF
20F
43E
07F
90.00
FF:
+ 00
+ 04
+ 04
+ 03
+ 03
+ 03
+ 03
7PF+02
B7E
86F
+ 02
+ 02
HATF DURING D A LI TF ( SFC* * - 1 ) 0.144F-OS
RATF INTF^RAIFD OVFP FULL 0 A Y (PAY * * - 1 ) 0.752F-01
HAf,F I, IFF TM'F.GPATF-D OVFR FUl L I^AY(PAYS) 0.921F+1
MFAP SHRFACE
System: Parathion in aqueous solution with cationic surfactant
XENOBIOTIC
WATER IDENTIFICATION:
QUANTUM YIELD:
INITIAL DEPTH:
DEPTH INCREMENT:
FINAL DEPTH:
REFRACTIVE INDEX:
WAVE LENGTh*i*ATfr R
(N'M)
50 *
00 *
50 *
oo *
50 *
00 *
50 *
QO *
50 *
00 *
10 »
oo *
00 *
oo *
fT 40 t\AS f.
SELECTED
LONGITllDE SEIFJCTEH: 90 ^r
TIME-OF-DAY CP'-'PUTATTP -S APE
TYPICAL FPHEVKpini r,.vo OZQWE
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.QO *
312.50 *
315.QO *
317.50 *
320.00 *
323.10 *
330.00 *
340.00 *
350.00 *
LATITUDE 40 t\AS
ALL SEASONS *EPE
0(
o,
o,
0,
o.
0.
o.
o.
0.
o.
0.
0.
0.
0.
SEI
SF
POM: .05^ CTAB
0.00060
0.001 00
10.00000
5.00000
1 .34000
ABSORPTION* F.PSILOM
'.00280
.00260
.00260
.00250
.00240
.00730
.00220
.00?! 0
.00200
.001,90
.001 80
.00152
.OOJ22
.00100
* 0.6250E+04
* 0.5POOE+04
* 0.5150E+-04
* 0.4500E+04
* 0.3POOE+04
* 0.3100E+04
* 0.2900E+04
* 0.2200E+04
* 0.1»50F^-04
* 0.1600E+04
* 0.1450E+04
* 0.9000E+03
* 0.6000E+0?
* 0.4500".uJ
VALUES WEKE SFLFJCIFD.
65
-------
XRNORJDTIC fc
: PfiPATHTON
ATER IDENTTF]
LAT. SEASON
40.00 SPRING
MIDDAY
LCAT
SOL
ALT
0
5
10
20
30
40
50
60
60
ION:
AP
.00
.00
.00
.00
.00
.00
.00
.00
»
05M
CT
AH
V 0 R K E V F
TT
5
5
6
7
7
R
9
1 1
1 1
MF.
.29
.81
.25
.12
o^9
.91
.93
.75
.92
T
1
1
1
1
1
1
1
1
1
M
IMF
p.
p.
7.
6.
5.
4.
3.
2.
1 .
55
04
60
73
85
94
92
10
92
0
0
0
0
0
0
0
0
0
1. 1'/
PATF
/SEC
.OOOF+00
.210E-06
.505F-06
.137F-05
.263E-05
.414F-05
.558E-05
,67PE-05
.679E-05
iGI
HP
0
o
0
0
0
0
0
0
0
xunF: 90
LF LIFt
HOURS
.OOOF+00
. 9 1 ^ f - + o 3
.3P1F+03
.140F+03
.731F+02
.465E+02
.345E+02
.2P4F+02
.2P4F+02
40.00 SUMMER
MIDDAY
AVG PC,TF DUPING HALITE (SFC**-1 ) 0.405F-05
RATF: TMTFGPATFD OVEP FULL DAY(DAY**-I) o.i93K-fOo
HALF T,IFF INTFGPATFJD OVER FULL TAYCDAYS) o.359t"4i
NFAR SMRKACK
0.00
^.00
10.00
20.00
30.00
40.00
50.00
60.00
70. on
70.09
4.74
5.29
5.76
6.65
7.52
S.39
9.78
10.24
11 .34
11.99
19.24
lfl.69
1 8.22
17.33
1 ft. 46
15.59
14.70
i. 3 . 7 4
1 2.14
1 1 .99
O.OOOK+00
0.220E-06
0.535F-06
0.144E-05
0.277F-05
0 . 4 3 0 F - 0 5
0.577E-05
0.703E-05
0.785F-05
0.785E-05
C.OOOF-fOO
0.876E+03
0.360F. + 03
0.133F+03
0.695F. + 02
0.448F+02
0.333F+02
0.274F+02
0.245E+02
0.245E+02
AVG PATF DUKIK'G DALITE( SFC**-1 ) 0.461F-05
PATF INTFGPATF.D PVFP FULL PP-Y (Pi Y**-1) 0.241F. + 00
HALF LIFF INTEGRATED OVFP FULL CAY (DAYS) 0.. 2886^1
NFAP SURFACE
40.00 FALL
" I DO AY
o.no
5.no
J 0 . 0 0
20.00
30.00
40. on
6.19
6.72
7.1 8
P. 16
9.30
1 1 .52
17.19
1 6 . 6 b
16.20
15.22
1 4 , r' P.
11 .86
O.OOOF. + OO
0.230F-06
0.567F-06
0.152F-05
0.2° IF -05
0.445E-05
O.OOOF+00
0.837F+03
0.340F +03
0.127F+03
0.661F+02
0.432F-fO?
40.06 11.69 11.69 0.446F-05 0.431c-K'2
OALITE ( S^f * »- \1 0.288F-05
OVF» ' ,n I, DA Y (PM **-! ) C . 1 1 4IL>00
-AT KD OVFR FULL PAY(PaYS) 0.608E+1
AVG R*TK
P«TF INTEGRATED
HAF.F T.1FF I
NEAR RUPFfiCt
66
-------
40.00 WINTER
MIDDAY
o.no
5.00
in. on
2 0.00
29.86
7.21
7.79
9.31
4.52
12.08
16. 9b
16.38
15. *5
14.64
12. OR
O.OGOF+00
0.218F-Oo
0.531F-06
0. 1 44F-05
0.274F-05
C.OOOF+00
O.PP1F+03
C.362F+03
0.1 34F+03
0.703F+02
AVG RATE DUPING HALITE ( SFC**- 1) 0.18PE-05
RATF 1NTRGRATKD OVER FULL DAY (DAY **-! ) 0.658F.-01
HALF T,TFF; INTEGRATED OVFR FULL DAYCDAYS) o.io5F.+2
»,FAP SURFACF.
System: Parathion in aqueous solution with anionic surfactant
XFNOBIOTlC NAMh: i--APATHTf.'\
WATER IDFNTIFICATTDN: .05«
SDS
QUANTUM YIELD:
INITIAL DEPTH:
DFPTH INCREMENT:
FINAL DEPTH:
REFRACTIVE INDEX:
WAVE LENGTH*WATCR
(NM)
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.00 *
312.50 *
315.00 *
317.50 *
320.00 *
323.10 *
330.00 *
340.00 *
350.00 *
0.00100
0.00100
10.00000
5.00000
1 .34000
ABSORPTION*
0.00280
0.00280
0.00260
0.00250
0.00240
0.00230
0.00220
0.00210
0.00200
0 . 0 0 \ a o
0.001 KO
0.00152
0.00122
0.00100
*
*
*
if
*
*
*
*
*
*
*
*
*
4
F.PSILON
0.6350E+04
0.5R50E-f04
0.5500E+0*
0.4800E+04
0.4200E+04
0.3700K+04
0.3400E+04
0.2800E+04
0.2450E+04
0.2100F.+ 04
0.1850R+04
0.1 300E+04
0.9500F+0}
0.6500E+03
LATITUDE 40 ^AS SFLFCTKD.
ALL SEASONS wFPF SELECTED.
LONGITUDE SELECTED: 90.00
TlfoE-OF-OAY COMPUTATIONS APE
TYPICAL EPHEMERIDE AND OZONE
PEQUESTF' .
V" -KS WEf-f.
SE! FCTf [i.
67
-------
XfNOBIOTlC NAME: PARATHTQN
w/ATEP IOFNTIK
LAT. SEASON
40.00
MIDDAY
40.00
MIDDAY
40.00 FALL
MIDDAY
CATION:
SOLfiP
ALT
0
5
10
20
30
4'.'
bO
6n
60
.05M
M n P N
TIN-F:
.00
.00
.00
,00
.00
.on
.00
.00
.09
5.
5.
6.
7.
7.
«.
9.
1 l.
1 1.
29
*J
25
12
Q'j
91
93
75
92
SDS
FVFM
TI*
18,
i«.
17.
16.
15.
14,
13.
12.
1 1 ,
.55
.04
.60
.73
.85
.94
.92
.10
.92
0
0
0
0
0
0
0
0
o
V
LONG I
PAT'f HA
/SFC
ooot+oo
51 1F-06
122F.-05
327E-05
620F-05
965F-05
129F-04
156F-04
156F.-04
C
0
0
0
0
0
0
0
0
TUDF:
LF 1,1
HODPS
.OOOF
-377f
.156F
90
FF
400
403
403
.5RPF.402
.310F
.200F
.149F
.123h
.123fc
402
402
402
402
402
AVG P£TF DUPING DALITF.(SEC**-1) 0.937F-05
RATF IN'TFGPATFD OVFR FUI,I, DAY (PAY *>-1 ) 0.447F400
HALF LIFF IMFGfrATFD OVF.P FULL OAY(DAYS) 0.155F+]
NFAr> SHRFACF
0.00
5.00
10.00
20.00
30.00
40.00
50. on
60.00
70.00
70.09
4.74
5.29
5.76
6.65
7.52
8.39
9.28
10.24
1 1 .84
11.99
19. 2*
lh.69
1 *.22
17.33
16.46
15.59
14.70
13.74
12.14
11 .99
O.OOOF+00
0.533H-06
0. 129F-05
0.343F-05
0.649F-05
0.997F-05
0.133F-04
O.I61F -04
0.179F-04
0.179F.-04
O.OOOt 400
0.361F403
0.1 50F403
C.562F402
0.297F402
0.193F402
0.1 1 5 F 4 0 2
0.120M02
0.107F402
0.107F40?
AVG PRTF DUKIMG PAMTE: ( SF.C**- 1 ) 0.106F-04
pftTF INTF:GPATfe.n OVFR FULL DAY CP-AY**-! ) 0.553F+00
HALF I,IFF IMTFGPATFD OV^P FULL DAY (DAYS) 0,|25E + 1
SUPFACF
1
2
3
4
0
=;
0
0
0
0
.00
.00
.00
.00
.00
.00
6.
ft ,
1 .
». .
9.
11 .
19
72
1 O
16
30
52
17
16
16
15
14
11
.19
.66
.20
.22
.08
.86
0
0
0
0
0
0
OOOfc+00
555F-06
136F-05
359F-05
678F-05
103F-04
0
0
0
0
0
0
,OOOF:+'00
.347F+03
.142F403
.536fc402
.284F402
.187F40?
40.06 11.69 11.69 0.103F-04 ".197^+02
AVG RATF DUPJNC- DM,1TE( SEO f' 1 ) 0.669F-05
HATF IWTFGRATFD OVFR i-ULL DAY f DA Y**-l) 0.265F400
HALF LIFF 1NTEGPUTFP OVFR FDI.l, t'AY(DAYS) 0.262E + 1
NFAP SURFACE"
68
-------
40.00
MIDDAY
O.Of)
s.oo
10. on
2o.no
29, B6
7 . 21
7.79
H.31
9.52
1 2 . 0 H
16.95
1 ti.3w
lb.8?>
14.64
12. OP
O.OOOF+OO
G.51GF~("^
0.128F:-OS
0.34 If -0^
0.642F-05
f-.OOOF + OO
0.363^+03
O.i 50V +03
O.SfrSF+O?
0.300E+02
AVG RATE nUKJKG DALITF.(SFC**-1 ) 0.441F-OS
PATF T'-iTFGRATKD OVER FI'LI. PAY(PAY**-1) O.
HALF i,IFF INTEGRATED OVFP FCLL nAvrr-AYS) o.447t+l
MFAR S
System: Parathion on soil surfaces. The dota here are calculated for
conditions producing a "quantum yield" of 0.0001 . See
complete data for Parathion-soil experiments to obtain actual
"quantum yields" for specific conditions.
XENQBIOTiC MAMfc: PARATHTfj'«i
rfATF.R inENTlFiCATTON: SnjL
FACE
QUANTUM YIELD: 0.00010
INITIAL DEPTH: o.ooioo
DEPTH INCREMENT: 10.00000
FINAL DEPTH: 5.0^000
REFRACTIVE INDtX: 1.34000
WAVE LFNGTH*KATFR ABSORPTION*
(MM)
297.50 *
300.00 *
302.50 *
305.00 *
307.50 *
310.00 *
312.50 *
315.00 *
317.50 *
320.00 *
323.10 *
330.00 *
340.00 *
350.00 *
0.002PO *
0.00280 *
0.00260 *
0.00250 *
0.00240 *
0.00230 *
0.00220 *
0.00210 *
o.oo2no *
n. 001 90 *
0.00180 *
0.001 S? *
0.00122 *
o.ooioo *
EPSILON
0.4ftOOE+04
0.4500F.+ 04
0.4250E+04
0.3750E+C4
0.3250E-r04
0.2750E+04
0.2350E+04
0.2000K+04
0.1 600F+04
0. 1550E+04
0. 1 400F + 04
0.9SOOE+03
0 , 5 h 0 0 F i- 0 3
0.4000E+03
LATITUDE 40 WAS SELECTED.
ALL SEASONS *F.
LONGITUDE SELF:
TIME-OF-DAY co
RE SFLFfTFP.
CTEO: 90.00
MPMTATinNS APE *
-------
XEMOBlDTic NA*E: PAPATHION
WATER IDENTIFICATION:
LAT. SEASON SOLAR
ALT
40.00 SPRING 0
S
1 0
20
30
4<".
V>
60
MIDDAY 60
SMJL
MORN
TIME
.00
.00
.00
.00
.00
.00
.00
.00
.09
5.
5 .
6.
7.
-»
' .
8 .
9.
11.
H.
29
81
25
12
09
^1
93
75
92
SURFACE
EVEN
TTvt:
1
1
1
1
1
1
1
1
1
8
8
7
6
5
4
3
2
1
.55
.04
.60
.73
.85
.94
.92
.10
.92
0
0
0
0
0
0
0
0
0
m
*
*
i ON
RATE
/SEC
OOOF+00
334F-07
804F-07
218E-06
416F-06
651F-0(r
8746.-06
106F-05
106F-05
GITI'DF: 90
MALE LIFE
0
0
0
0
0
0
0
0
0
HOURS
.OOOF+00
.577F+Q4
.239E+04
.8R4F+03
.463F+03
.296F>03
.220F+03
.1P2F+03
.1R1F+03
,00
40.00 SUMMER
MIDDAY
40.00 FALL
MIDDAY
AVG RATE DURING DAI,TTE(SEC**-1 ) 0.635F-06
RATE IN'TEGPATED OVFP FULL PAY (DAY*f-l ) 0.303F-01
HALF LIFE INTEGRATED OVER FULL DAYCDAYS) 0.229E+2
SURFACE
0.00
5.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
70.09
4.74
5.?9
5.76
6.65
7.52
8.39
9.2R
10.54
11 ,S4
11 .99
19.24
19.69
18.22
17.33
16.46
15.59
14.70
1 3.74
1 2.14
11 -99
O.OOOF+00
0.34PE-07
0.851F-07
0.229F-06
0.437F-06
0.675F-06
0.903E-Of
O.HOE-05
0.122E-05
0.122E-05
O.OOOh+00
0.551F+04
0.226F+04
O.P40F+03
0.441F+03
0.285F+03
0.213F+03
0.176F+03
0.157F+03
0.157E+03
AVG RATE DUPING DAI.ITE( SEC**-1 ) 0.720F-06
RAVE INTEGRATED OVER FULL DAY(DA\**-1) 0.376F-01
HALF LIFE INTEGRATED OVER EULT DAYCHAYS) 0.184E+2
SURFACE
0.00
5.00
10.00
20.00
30.00
40.00
6.19
6.72
7. IP
P. 16
9.30
1 1 .52
17.19
1ft. f-6
16.70
15.22
1 4. OS
11 .86
O.OOOE+00
0.366F-07
0.901F.-07
0.241E-06
0.45RE-06
0.697F-06
O.OOOF+00
0.526F-H)4
0.214E+04
0.799E-K)3
0.420F+03
0.776F+03
40.06 11.69 11.69 f>.699F-Oe 0.27^ /-i.M
AVG PATE DUPING DALIT.E ( SFC*--1 ) 0.452F-06
PAT'1' INTEGRATED OVFP F .... PAYCDAY**-!) 0.179t-01
HALF L.TFF INTFG'^'iKi l>Vf-p FU! I, PAY (DAYS) 0.387E+2
NEAP SURFACE
70
-------
40.00 wINTFR 0.00 7.21 lb.95 O.OOOf+oO O.OQOP+00
5.00 7.79 16.38 0.34RF-07 C.S^4F+04
10.00 fl . 3 1 1 5 . P *> 0.845fc>07 0.92&M04
20.00 9.52 1 4 . b 4 0 . 2 2 R F - 0 ft f . R 4 S t- + 0 3
MIDDAY 29.H6 12.08 12.08 0.
AVr, PATF UHpir-'C; Dftl.ITEf StC**-l ) ('
PATF T'OTfclCHATf'-D OVFR FI'LI HAYCOAY**-!) 0.104F-01
HAF.K LTFF. IVTKGRATFD OVER FULL DAY(DAYS)
NFAP SHRFACF:
71
-------
TECHNICAL REPORT DATA
(Please read Instructions on the reverse before completing)
REPORT NO.
EPA-600/3-78-060
3. RECIPIENT'S ACCESSION-NO.
. TITLE AND SUBTITLE
Surfactant Effects on Pesticide Photochemistry
in Water and Soil
5. REPORT DATE
June 1978 issuing date
6. PERFORMING ORGANIZATION CODE
. AUTHOR(S)
Richard R.
8. PERFORMING ORGANIZATION REPORT NO.
Hautala
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Department of Chemistry
University of Georgia
Athens, GA 30602
10. PROGRAM ELEMENT NO.
1BB770
11. CONTRACT/GRANT NO.
R-802959
12. SPONSORING AGENCY NAME AND ADDRESS
Environmental Research LaboratoryAthens, GA
U.S. Environmental Protection Agency
College Station Road
Athens, GA 30605
13. TYPE OF REPORT AND PERIOD COVERED
Final 4/74-11/77
14. SPONSORING AGENCY CODE
EPA/600/01
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The effects of surfactants on the photochemical decomposition of
selected pesticides are examined both in aqueous solution and on selec-
ted soil surfaces. Typical surfactants usually enhance the rate of
pesticide photodecomposition. In solution, increased quantum efficien-
cies and increased overlap with available solar irradiation are observed
In addition, surfactants enhance the solubility of otherwise sparingly
soluble pesticides. Photodecomposition on soil surfaces is inefficient.
Surfactants enhance the rates of decomposition in certain cases on soil
surfaces, but the effects do not appear to be sufficiently large to
make such a mode of decomposition competitive. It has been postulated
that the reason pesticide photochemistry on soils is so inefficient is
that excitation energy is lost to pigments in the soil.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lDENTIFIERS/OPEN ENDED TERMS c. COS AT I Field/Group
Pesticides, Photolysis, Soils,
Surfactants, Photochemical
reactions, Quantum efficiency
Ultraviolet-absorp-
tion spectra
68E
99E
21. NO. OF PAGES
80
18. DISTRIBUTION STATEMENT
RELEASE TO PUBLIC
19. SECURITY CLASS (ThisReport}'
UNCLASSIFIED
20. SECURITY CLASS (Thispage)
UNCLASSIFIED
22. PRICE
EPA Form 2220-1 (9-73)
72
. S. GOVERNMENT PRINTING OFFICE: 1978-757-140/1347 Region No. SHI
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