Photoinduced addition of the fungicide anilazine to cyclohexene and methyl oleate as model compounds of plant cuticle constituents

Article abstract of DOI:10.1016/S0045-6535(99)90553-2

Photoreactions, initiated by sunlight irradiation, between organochlorine pesticides and olefinic compounds of plant cuticles have been postulated. Concerning the formation of bound residues, which so far have not been detectable by common analytical techniques, photoaddition reactions are of main interest. In order to study the photochemical behavior of chlorinated fungicides, anilazine was irradiated in cyclohexene and methyl oleate as model compounds for olefinic plant cuticle constituents. Anilazine extensively reacted with the cis-double bond of both model compounds via radical mechanisms. In addition to a dechlorinated photoproduct several addition products were formed showing plausible reaction pathways for the formation of bound residues in plant cuticles. Photoproducts were isolated by preparative HPLC and analyzed by HPLC, MS, ¹H-, and ¹³C-NMR. (C) 2000 Elsevier Science Ltd.

Full text of DOI:10.1016/S0045-6535(99)90553-2

Chemosphere 41 (2000) 1401±1406
Photoinduced addition of the fungicide anilazine to
cyclohexene and methyl oleate as model compounds of plant
cuticle constituents q
1
*
Dietmar Ernst Breithaupt , Wolfgang Schwack
Institut fuÈr Lebensmittelchemie, Universitat Hohenheim, Garbenstr. 28, D-70593 Stuttgart, Germany
Received 1 September 1999; accepted 30 November 1999
Abstract
Photoreactions, initiated by sunlight irradiation, between organochlorine pesticides and ole®nic compounds of plant
cuticles have been postulated. Concerning the formation of bound residues, which so far have not been detectable by
common analytical techniques, photoaddition reactions are of main interest. In order to study the photochemical
behavior of chlorinated fungicides, anilazine was irradiated in cyclohexene and methyl oleate as model compounds for
ole®nic plant cuticle constituents. Anilazine extensively reacted with the cis-double bond of both model compounds via
radical mechanisms. In addition to a dechlorinated photoproduct several addition products were formed showing
plausible reaction pathways for the formation of bound residues in plant cuticles. Photoproducts were isolated by
preparative HPLC and analyzed by HPLC, MS, 1H-, and 13C-NMR. Ó 2000 Elsevier Science Ltd. All rights reserved.
Keywords: Anilazine; Fungicide; Photoreactions; Bound residues
1. Introduction
the group of chlorinated non-systemic foliar fungicides
with protective action, was selected. Investigations on
the photochemistry of anilazine, especially with respect
to photodegradation products, have not been reported
yet.
After application, pesticides ®rst cover the plant cu-
ticle by adsorption with subsequent distribution in this
compartment, where they can directly be a€ected by
sunlight. Photoinduced processes are of great impor-
tance for the transformation and decomposition of
pesticide residues on plant surfaces. Being in contact
with the plant cuticle, pesticides can either be degraded
or react with cuticle constituents. In this experiments,
anilazine (N-(2-chlorophenyl)-N-(4,6-dichloro-1,3,5-tri-
azine-2-yl)-amine (1), Fig. 1), a pesticide belonging to
To investigate the photochemical reactivity of
anilazine on plant surfaces model photoreactions in or-
ganic solvents simulating natural constituents of cutin
and plant waxes were performed. For this purpose sol-
vents containing cis-con®gurated double bonds, repre-
senting unsaturated cutin acids and wax molecules, were
used (cyclohexene, methyl oleate).
2. Experimental
q Presented in parts on the Second European Residue
Workshop '98; Almeria, Spain, 24±27 May 1998.
* Corresponding author. Tel.: +49-0-711-459-4097.
E-mail addresses: breithau@uni-hohenheim.de (D.E. Bre-
ithaupt), wschwack@uni-hohenheim.de (W. Schwack).
2.1. Reagents and materials
The solvents used were of analytical grade. Aceto-
nitrile, diethyl ether, and light petroleum (40±60°C) were
1
Fax: +49-0-711-4594096.
0045-6535/00/$ - see front matter Ó 2000 Elsevier Science Ltd. All rights reserved.
PII: S 0 0 4 5 - 6 5 3 5 ( 9 9 ) 0 0 5 5 3 - 6

1402
D.E. Breithaupt, W. Schwack / Chemosphere 41 (2000) 1401±1406
Fig. 1. Hydrogen/carbon numbering for compounds 1±7.
purchased from Merck, cyclohexene and n-hexane from
Fluka, methanol from Baker and methyl oleate (> 99%)
from ICN. All solvents were distilled before use. Cy-
clohexene was dried over P2O5 before distillation. For
high performance liquid chromatography (HPLC)
analysis, Milli-Q water was employed.
detection at 254 nm. The following retention times (min)
were obtained: 2 (19,72), 3 (43,03), 4 (21,70), 5 (45,84), 6
(29,50), 7 (39,91).
2.2.4. High performance liquid chromatography/mass
spectrometry analysis (LC/MS)
Anilazine was synthesized following a procedure de-
scribed in literature (MacDougall et al., 1964) and re-
crystallized twice from n-hexane yielding colorless
needles. Melting point, MS (70 eV El)- and 13C-NMR
data were identical with those cited in (Hutzinger et al.,
1971; Haider et al., 1993; Tomlin, 1994). A test for
purity by HPLC gave a content > 99%, compared to
LC/MS analyses were performed on a HPLC system
which was equipped with a gradient pump model 140b
(Applied Biosystems, Weiterstadt, Germany), a variable
wavelength detector model 785A (Applied Biosystems)
and a Finnigan TSQ 700 (Bremen, Germany) mass
spectrometer; ¯ow rate 0,7 ml min 1; For column and
detection wavelengths see ``HPLC''.
certi®ed
Dr. Ehrenstorfer, Augsburg, Germany.
reference
material,
purchased
from
2.2.5. Nuclear magnetic resonance spectroscopy (NMR)
1H-and 13C-NMR spectra were recorded on a ARX-
500 spectrometer (Bruker, Karlsruhe, Germany) at 500
MHz and 126 MHz nominal frequency, respectively, in
CDCl3. Chemical shifts are given in d (ppm) relative
to tetramethylsilane (TMS) as internal standard;
s ˆ singlet, d ˆ doublet, t ˆ triplet, q ˆ quartet,
m ˆ multiplet, with dt, dq, tt, ddd and ddt denoting a
combination of the respective multiplicities. Hydrogen/
carbon assignment is validated by 1H,1H-COSY and
13C-DEPT techniques.
2.2. Apparatus
2.2.1. Photolysis equipment
For irradiation a metal halogen lamp (SOL 500, Dr.

K. Honle, Martinsried, Germany) equipped with glass
®lters WG 295 or WG 320 (Schott Glaswerke, Mainz,
Germany) was used.
2.2.2. High performance liquid chromatography (HPLC)
The HPLC system consisted of a HP1050 autosam-
pler (Hewlett Packard, Waldbronn, Germany),
a
HP1050 gradient pump and a HP1050 DAD module.
For data acquisition and processing, a HP3D chem
station software system was used. Column (Bischo€,
Leonberg, Germany): Nucleosil RP 18, 5 lm, 250 Â 4
mm; ¯ow rate 0,8 ml min 1; detection wavelengths
(diode array detector, DAD): 254 and 237 nm.
2.2.6. UV-spectroscopy
Ultraviolet (UV) spectra were measured with a Per-

kin-Elmer Lambda 2 instrument (Uberlingen, Germany)
or a HP1050 DAD module (Hewlett Packard, Wald-
bronn, Germany), respectively.
2.2.3. Preparative HPLC
2.2.7. Mass spectrometry
The system consisted of a Knauer 64 pump (Berlin,
Germany), an A0293 variable wavelength detector
(Knauer) and a Kronlab (Sinsheim, Germany) HPLC
column (guard column 50 Â 20 mm, column 250 Â 20
mm; Nucleosil RP 18, 7 lm); eluent: methanol/water
(75/25 v/v); ¯ow rate 10 ml min 1; injection volume: 1 ml;
Mass spectrometry was carried out with a Finnigan
Quadrupol-MS 4500 (Bremen, Germany), positive CH4±
Cl mode or 70 eV El mode, direct inlet. High resolution
mass spectrometry (HRMS) was conducted with a
Varian MAT 311-A instrument (Darmstadt, Germany),
70 eV El, direct inlet.

D.E. Breithaupt, W. Schwack / Chemosphere 41 (2000) 1401±1406
2.4. Photoproducts
1403
2.2.8. Melting points
Melting points were determined on a digital melting
point apparatus model 8100 (Electrothermal, Southend-
on-Sea, UK) and are not corrected.
1
For assignment of H- and 13C-NMR spectroscopic
data, the following hydrogen/carbon numbering was
used (Fig. 1):
N-(4,6-Dichloro-1,3,5-triazine-2-yl)-N-phenylamine
(2). MS (pos. CH4±Cl): m=z ˆ 281 (6.0%); 283 (3.5%);
2.3. Methods
‡
285 (0.6%) ‰M ‡ C3H5Š =269 (22.5%); 271 (14.4%); 273
2.3.1. Kinetic degradation experiments in cyclohexene
Anilazine (3 mg) was dissolved in cyclohexene (100
ml) and the solution degassed with helium for 10 min.
Aliquotes of 40 ml were irradiated for up to 100 min in
round quartz cuvettes with te¯on caps. Progress of de-
gradation was monitored by HPLC analyses with a
methanol/water gradient (40 (0) ± 40 (5) ± 95 (30) ± 95
(35) ± 40 (40) ± 40 (45) [% methanol (min)]) as eluent.
The retention times (min) were as follows (for com-
pound names see below): 1 (25.73), 2 (26.11), 3 (31.55), 4
(27.61), 5 (31.85), 6 (29.70), 7 (31.16).
‡
(1.8%) ‰M ‡ C2H5Š =241 (100%); 243 (63.8%); 245
‡
(9.4%) [MH] /205 (16.2%); 207 (4.7%) [C9H6ClN4]/144
(21.6%) [C8H6N3]. HRMS: C9H365Cl2N4 calculated:
239.99695, found: 239.99570. UV (acetonitrile), kmax
[nm], (log e): 270 (4.24). 1H-NMR: 7.59 (s, 1H, NH),
7.54 (m, 2H, 20-H/60-H), 7.41 (m, 2H, 30-H/50-H), 7.23
(m, 1H, 40-H). 13C-NMR: 170.3/171.4 (C-4/C-6), 164.1
(C-2), 135.7 (C-10), 129.4 (C-30/C-50), 125.9 (C-40), 121.2
(C-20/C-60).
N-(2-Cyclohexylphenyl)-N-(4,6-dichloro-1,3,5-triazine
-2-yl)amine (3). MS (pos. CH4±Cl): m=z ˆ 363 (6.0%);
‡
‡
365 (3.4%); 367 (0.6%) ‰M ‡ C3H5Š =351 (19.1%); 353
2.3.2. Isolation of photoproducts formed in cyclohexene
Anilazine (38.4 mg) was dissolved in cyclohexene
(1280 ml) and aliquotes of 40 ml irradiated for 100 min
each (WG 295). The photolysis mixtures were combined,
evaporated to dryness, the residue dissolved in aceto-
nitrile (5 ml) and subjected to preparative HPLC. For
product isolation, methanol was removed from the col-
lected fractions in vacuum. The remaining aqueous so-
lution was extracted with light petroleum/diethyl ether
(80/20 v/v). Further puri®cation was achieved by thin
layer chromatography on silica gel plates (silica gel 60
(11.8%); 355 (1.8%) ‰M ‡ C2H5Š =323 (100%); 325
‡
(59.2%); 327 (9.3%) [MH] /287 (43.8%); 289 (16.4%)
[C15H16ClN4]/226
(1.6%)
[C14H16N3].
HRMS:
C15H3156Cl2N4 calculated: 322.07520, found: 322.07780.
UV (acetonitrile), kmax [nm], (log e): 237 (4.17). 1H-
NMR: 7.53 (s, 1H, NH), 7.47 (m, 1H, 60-H), 7.35 (m,
1H, 30-H), 7.30 (m, 1H, 40-H), 7.25 (m, 1H, 50-H), 2.59
(tt, 1H, 100-H), 1.81 (m, 5H), 1.24 (m, 5H). 13C-NMR:
170.7/171.9 (C-4/C-6), 165.8 (C-2), 142.3 (C-10), 132.4
(C-20), 128.3 (C-30), 127.5 (C-50), 126.9 (C-40), 126.2 (C-
60), 39.4 (C-100), 34.1 (C-200/C-600), 27.2 (C-300/C-500), 26.4
(C-400).
F
254, 2 mm, Merck) with light petroleum/diethyl ether
(80/20 v/v). All photoproducts were obtained as color-
less powders (2: 2.5 mg, 3: 5.6 mg, 4: 1.8 mg, 5: 0.6 mg, 6:
1.7 mg, 7: 2.0 mg).
trans-2-{2-[(4,6-Dichloro-1,3,5-triazine-2-yl)amino]phe-
nyl}-1-cyclohexanol (4). MS (pos. CH4±Cl): m=z ˆ 339
‡
(100%); 341 (65.9%); 343 (10.9%) [MH] /321 (14.6%);
323 (8.7%); 325 (1.2%) [C15H15Cl2N4]/303 (3.1%)
[C15H16ClN4O]/285 (4.7%); 287 (1.5%) [C15H14ClN4].
HRMS: C15H3165Cl2N4O calculated: 338.07012, found:
338.07380. UV (acetonitrile), kmax [nm], (log e): 259
2.3.3. Kinetic degradation experiments in methyl oleate
Anilazine (56 mg) was suspended in methyl oleate (2
g), degassed with helium for 10 min and irradiated in a
quartz test-tube for 32 h (WG 295). The supernatant of
the reaction mixture was chromatographed in portions
of 200 mg on silica gel plates (silica gel 60 F254, 2 mm
layer thickness, Merck) to separate the addition prod-
ucts from excessive methyl oleate and anilazine. Light
petroleum/diethyl ether (80/20 v/v) was used as devel-
oping solvent. The isolated material was dissolved in
acetonitrile (2 ml) and analyzed by HPLC and LC/MS,
respectively. With a methanol/water gradient (70 (0) ± 70
(10) ± 90 (11) ± 90 (45) ± 70 (50) ± 70 (55) [% methanol
(min)] as eluent the following retention times (min) were
obtained: 22:86=23:29=25:83 (peaks of group A);
27:83=29:06=31:40=31:92 (peaks of group B); 32.56
(peak C); 35:76=36:43 (peaks of group D). Due to their
instability, we did not succeed in isolating individual
addition products, which were formed upon irradiation
of anilazine in methyl oleate.
1
(3.90). H-NMR: 8.99 (s, 1H, NH), 7.59 (m, 1H, 60-H),
7.35 (m, 1H, 30-H), 7.31 (m, 2H, 40-H/50-H), 3.55 (ddt,
1H, 3Jꢀ2
2.6 Hz, 200-H), 2.77 (ddd, 1H, 3Jꢀ1
00 -H;200 -OH†
00 -H;200 -H†
10.2 Hz, 100-H), 2.10 (m, 1H, 600-He), 1.95 (d, 1H, 200-
OH), 1.8 (m, 2H, 300-Ha/300-He), 1.58 (ddt, 1H, 600-Ha).
13C-NMR: 170.8/171.6 (C-4/C-6), 165.0 (C-2), 137.9 (C-
10), 135.2 (C-20), 127.6 (C-30), 127.3 (C-50), 126.9 (C-40),
125.4 (C-60), 77.8 (C-200), 45.4 (C-100), 36.7 (C-300), 30.9
(C-600), 26.1/25.3 (C-400/C-500).
cis-2-{2-[(4,6-Dichloro-1,3,5-triazine-2-yl)amino]phenyl}
-1-cyclohexanol (5). MS (70 eV El): m=z ˆ 338 (42.4%);
340 (28.8%); 342 (5.3%) [M‡ꢁ]/320 (29.6%); 322 (21.0%);
324 (4.9%) [C15H14Cl2N4]/303 (13.8%); 305 (5.1%)
[C15H16ClN4O]/285 (15.6%); 287 (6.2%) [C15H14ClN4].
HRMS: C15H3165Cl2N4O calculated: 338.07012, found:
338.06850. 1H-NMR: 10.38 (s, 1H, NH), 8.09 (m, 1H, 60-
H), 7.34 (m, 2H, 40-H/50-H), 7.17 (m, 1H, 30-H), 3.65

1404
D.E. Breithaupt, W. Schwack / Chemosphere 41 (2000) 1401±1406
‡
3
(m, 1H, 200 H), 2.05 (ddd, 1H, Jꢀ1
ꢂ 1:3 Hz,
‰MHŠ =505 (23.1%); 507 (15.5%); 509 (2.8%)
00 -H;200 -H=600 -He†
100-H).
[C27H39Cl2N4O].
trans-N-[2-(2-Chlorocyclohexyl)-phenyl]-N-(4,6-dichloro-
1,3,5-triazine-2-yl)amine (6). MS (pos. CH4±Cl): m=z ˆ
‡
3. Results and discussion
397 (5.2%); 399 (5.1%); 401 (1.5%) ‰M ‡ C3H5Š =385
‡
(16.5%); 387 (15.7%); 389 (4.7%) ‰M ‡ C2H5Š =357
‡
UV-irradiation of anilazine (Fig. 1, 1) in the presence
of cyclohexene resulted in rapid degradation. The cor-
responding half-lives were determined to be only 8 min
(WG 295) and 15 min (WG 320), respectively.
(100%); 359 (95.0%); 361 (30.0%); 363 (2.8%) [MH] /321
(85.5%); 323 (59.0%); 325 (12.8%) [C15H15Cl2N4].
HRMS: C15H3155Cl3N4 calculated: 356.03623, found:
356.03110. UV (acetonitrile), kmax [nm], (log e): 236
1
(3.95). H-NMR: 7.58 (s, 1H, NH), 7.46 (m, 1H, 60-H),
With both ®lters, photolysis of anilazine in cyclo-
hexene yielded six photoproducts (2±7), which were iso-
lated, structurally characterized and quanti®ed. After an
irradiation period of 100 min 3 was the main degradation
product whereas 2 and 4±7 were obtained as minor
products (Table 1). Photoproducts 3±7 are described here
for the ®rst time. Additionally, some substances with
smaller Rf values compared to those of 2±7 were detected
by thin layer chromatography on silica gel plates.
Based on the structures of 2±7, the following pho-
tochemical reaction pathways can be postulated (Fig. 2).
The initial step is the cleavage of the aryl C±Cl bond of
1, resulting in the formation of radical 1a. Hydrogen
transfer from the solvent to 1a yields photoproduct 2.
The photochemical formation of 2, starting from
anilazine, so far is not described in the literature.
7.33 (m, 1H, 30-H), 7.27 (m, 2H, 40-H/50-H), 3.93 (ddd,
3
1H, 200-H), 2.95 (ddd, 1H, Jꢀ1
10.9 Hz, 100-H),
00 -H;200 -H†
2.40 (m, 1H, 300-He), 1.95 (m, 1H, 600-He), 1.80 (m, 1H,
300-Ha), 1.64 (ddt, 1H, 600-Ha). 13C-NMR: 170.5/171.6
(C-40/C-6), 165.4 (C-2), 138.6 (C-10), 133.2 (C-20), 128.2
(C-300), 127.4 (C-50), 126.6 (C-40), 126.4 (C-60), 66.4
(C-2 ), 46.9 (C-100), 37.8 (C-300), 33.9 (C-600), 26.4/25.5
(C-400/C-500).
cis-N-[2-(2-Chlorocyclohexyl)phenyl]-N-(4,6-dichloro-
1,3,5-triazine-2-yl)amine (7). MS (pos. CH4-Cl): m=z ˆ
‡
357 (42.7%); 359 (39.3%); 361 (9.3%); 363 (0.7%) [MH] /
321 (100%); 323 (61.1%); 325 (12.3%) [C15H15Cl2N4]/285
(13.0%); 287 (3.1%) [C15H14ClN4]. HRMS: C15H3155Cl3N4
calculated: 356.03623, found: 356.03890. UV (acetonit-
rile), kmax [nm], (log e): 236 (3.75). 1H-NMR: 7.37 (m,
1H, 60-H), 7.34 (m, 1H, 30-H), 7.27 (m, 2H, 40-H/50-H),
7.19 (s, 1H, NH), 4.32 (q, 1H, 200-H), 3.00 (dt, 1H,
3Jꢀ1
2.8 Hz, 100-H), 2.18 (dq, 1H, 600-Ha), 2.07 (m,
00 -H;200 -H†
1H, 600-He), 1.8 (m, 2H, 300-Ha/300-He).
2.5. LC/MS data (pos. APcl-mode) of anilazine methyl
oleate addition products
Peaks of group A: m=z ˆ 553 (100%); 555 (55.8%);
‡
557 (11.1%) [MH] /535 (30.4%); 537 (15.7%); 539 (3.2%)
[C28H41Cl2N4O2].
Peaks of group B: m=z ˆ 557 (12.6%); 559 (8.6%);
‡
561 (1.5%) ‰M ‡ NaŠ =535 (100%); 537 (71.1%); 539
‡
(14.5%) [MH] /503 (20.3%); 505 (12.9%); 507 (2.8%)
[C27H37Cl2N4O].
Peak C: m=z ˆ 593 (2.2 %); 595 (2.0 %)
‡
‰M ‡ NaŠ =571 (100%); 573 (94.9%); 575 (32.0%); 577
‡
(4.3%) ‰MHŠ =535 (61.2%); 537 (42.5%); 539 (12.3%)
[C28H41Cl2N4O2].
Peaks of group D: m=z ˆ 559 (4.9%); 561 (2.5%)
Fig. 2. Photoreaction pathways of anilazine (1) in the presence
of cyclohexene.
‡
‰M ‡ NaŠ =537 (100%); 539 (68.3%); 541 (13.2%)
Table 1
Quanti®cation of 2±7 after irradiating anilazine in cyclohexene for 100 min (c ˆ 30 mg l
1
)
Product
2
3
4
5
6
7
Mol% of the initial quantity of anilazine (WG 295)
Mol% of the initial quantity of anilazine (WG 320)
9.1
10.1
16.1
22.2
4.8
7.0
1.6
1.5
4.3
5.3
4.9
4.5

D.E. Breithaupt, W. Schwack / Chemosphere 41 (2000) 1401±1406
1405
Table 2
Proposed structure and molecular weights of photoaddition products of anilazine with methyl oleate
R ˆ ``Anilazinyl'' (1a)
‡
‡
X
Double bonds
m=z ([MH] )
Di€erence of [MH] compared to m=z ˆ 537
Peaks of group A
Peaks of group B
Peak C
OH
±
None
One
553
535
571
537
+16
)2
+34
0
Cl
H
None
None
Peaks of group D
The reaction of 1a with cyclohexene leads to radical
3a, which can either be saturated with hydrogen (genesis
of 3) or react with chlorine atoms or remaining oxygen
still present in the reaction mixture. The latter pathways
lead to the formation of the cyclohexanol derivatives 4/5
and the chlorocyclohexane derivatives 6/7 of anilazine,
respectively. Products 4/5 and 6/7 were identi®ed by
their 1H-NMR data as stereoisomeric substances. Hy-
drogen abstraction from 3a, resulting in the formation
of a cyclohexene derivative of anilazine, did not occur.
On the basis of the above results it seems justi®ed to
expect that the photochemical reaction of anilazine with
methyl oleate leads to analogous addition products. For
isolation of these substances it was necessary to separate
them from the starting materials by thin layer chroma-
tography. Because of their instability, further puri®ca-
tion and isolation was impossible. Consequently, the
only method to determine the molecular weights of the
reaction products was by LC/MS (pos. APcl mode).
Fig. 3 shows the extended section from 22 to 40 min of a
chromatogram, obtained by HPLC analysis. According
to their molecular weights, isomeric compounds were
summarized in ``peakgroups'' and marked by the letters
A±D.
Photoinduced addition of the anilazine radical 1a
(Fig. 2) to methyl oleate with subsequent hydrogen
transfer to the resulting radical leads to the formation of
methyl stearate derivatives of anilazine (m=z ˆ 537
‡
[MH] , Table 2). This molecular ion is shown by the
peaks of group D, proving that the photochemical ad-
dition of 1 to methyl oleate took place in the predicted
manner. In the case of this photochemical reactions the
formation of two positional isomers is likely, which
cannot be distinguished by LC/MS analysis.
From molecular ions at m=z ˆ 553, 535 and 571 it
can be derived that the fatty acid backbone contains a
‡
hydroxy group (m=z ˆ 553 [MH] , peaks of group A), a
‡
double bond (m=z ˆ 535 [MH] , peaks of group B) or a
‡
chlorine (m=z ˆ 571 [MH] , peak C), respectively,
(Table 2). Apart from the ole®nic substances (peaks of
group B), these results are in accordance with the
structures of photoproducts 3±7.
4. Conclusion
The results present proof that the photoinduced ad-
dition of anilazine to methyl oleate leads to analogous
products as they can be obtained by irradiation of the
fungicide in cyclohexene. This demonstrates that
anilazine shows a high anity to lipid double bonds in
the course of photochemical degradation. Therefore, the
formation of bound residues of the fungicide with un-
saturated biomolecules under outdoor conditions can be
explained by photochemical reactions within the plant
cuticle.
Acknowledgements
We thank Mr. J. Rebell (Institute of Organic
Chemistry, University of Stuttgart) for NMR measure-
ments as well as Ms. I. Klaiber (Institute of Chemistry,
Fig. 3. HPLC chromatogram (254 nm; extended section) of an
1
irradiation mixture of anilazine in methyl oleate (28 mg g
irradiation time: 32 h; WG 295).
;

1406
D.E. Breithaupt, W. Schwack / Chemosphere 41 (2000) 1401±1406
Hutzinger, O., Jamieson, W.D., Safe, S., 1971. Mass spectra of
®fteen chlorinated aromatic fungicides. J. AOAC 54,
178±186.
University of Hohenheim) for carrying out LC/MS
analysis.
MacDougall, D., Burch®eld, H.P., Storrs, E., 1964. Dyrene. In:
Zweig, G. (Ed.). Analytical Methods for Pesticides, Plant
Growth Regulators and Food Additives III. Academic
Press, New York, pp. 79±98.
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