Supporting Information
Composition of the surfactant Aerosol OT and its influence
on the properties of an agrochemical formulation
Johannes Glaubitz1,2, Karl Molt, Torsten C. Schmidt* 1
1 University Duisburg-Essen. Instrumental Analytical Chemistry. Universitätsstr. 5.
45141 Essen. Germany
2 Bayer CropScience, BCS-D-FT-A&S, Alfred-Nobel-Straße 50, 40789 Monheim am Rhein
* Corresponding author:
E-mail: torsten.schmidt@uni-due.de
Phone: +49 201 183-6774
Fax: +49 201 183-6773
Table of Contents
1.
Sample for testing on mass calibration of ToF-MS ................................................................................... 4
2.
Content of diester 1, monoester 2 and monoester 3 in different production batches of commercially
available AOT of different suppliers ................................................................................................................. 6
3.
Sedimentation in trail storage formulation samples ............................................................................... 8
4.
Centrifugation of a model agrochemical formulation containing AOT of supplier A1 .............................. 8
5.
Results of the analysis of AOT of different production batches for inorganic anions and cations of
different suppliers ............................................................................................................................................ 9
6.
Analysis of the composition of the solvent in AOT on differences between the suppliers ..................... 16
7.
Statistical evaluation of the usefulness of the contents of diester 1 and monoester 2 and 3 for product
identification .................................................................................................................................................. 21
1
List of Figures
Figure S 1: Test on sedimentation after 0.5 a storage at room temperature of a model
agrochemical formulation containing AOT of supplier A1, B and D. Increasing amount of
visible sediment from supplier A1 to supplier D ....................................................................... 8
Figure S 2: Chormatographic seperation of the cations Na+and Ca2+(a) and the anions Cl-,
NO3- and SO42-via ion chromatography. .................................................................................. 11
Figure S 3: Content of (a) Na+, (b) NH4+, (c) Ca2+, (d) Cl-, (e) NO3- and (f) SO42- in selected
production batches of AOT of supplier A1, B, C and D displayed as box-plots. .................... 12
Figure S 4: Chromatographic separation of the light-aromatic naphtha solvent in AOT, shown
in (a) are the earlier eluting and in (b) the late eluting compounds. ......................................... 17
Figure S 5: Comparison of the chromatographic pattern of the light-aromatic naphtha solvent
of selected production batches of AOT of the suppliers A1, C and D. The analysis of the
solvent was conducted on GC-MS ........................................................................................... 20
2
List of Tables
Table S 1: Retention time and exact masses for compounds in the test sample for checking on
mass calibration .......................................................................................................................... 4
Table S 2: Content of diester 1 and monoester 2 and 3 in AOT together with their expanded
measurement uncertainty. Analysis of five independently weight samples each batch number
averaged. The expended measurement uncertainty is calculated according to GUM
encompassing 95% of the distribution of values [1] .................................................................. 6
Table S 3: Content of diester 1, monoester 2 and monoester 3 in sediment given as percentage
of the AOT-content in the formulation. The sediment was obtained after centrifugation of the
modell agrochemical formulation containing AOT of supplier A1. Each value is the average
of five replicates analyses, given together with its interval of confidence of 95%. ................... 9
Table S 4: Content of Na+, Ca2+, Cl-, NO3- and SO42-in selected production batches of AOT of
supplier A1, supplier B, supplier C and supplier D. Those ions, which contents were below
the LOQ of the used method were indicated with “<LOQ”. .................................................... 12
Table S 5: Compounds in the light-aromatic naphtha solvent in AOT, which were identified
via spectra library. Shown are the most likely hits according to retention time and spectrum. 18
3
1. Sample for testing on mass calibration of ToF-MS
The retention times and exact masses for the compounds in the test sample for checking on
mass calibration of the used ToF-MS are given in Table S 1.
Table S 1: Retention time and exact masses for compounds in the test sample for checking on mass
calibration
Compound
Imidacloprid
Thiacloprid
Tebuconazole (1.Isomer)
Triadimenol
Tebuconazole (2.Isomer)
Distyrylethoxylate-5-EO
Distyrylethoxylate-6-EO
Distyrylethoxylate-7-EO
Distyrylethoxylate-8-EO
Distyrylethoxylate-9-EO
Distyrylethoxylate-10-EO
Distyrylethoxylate-11-EO
Distyrylethoxylate-12-EO
Distyrylethoxylate-13-EO
Distyrylethoxylate-14-EO
Distyrylethoxylate-15-EO
Distyrylethoxylate-16-EO
Distyrylethoxylate-17-EO
Distyrylethoxylate-18-EO
Distyrylethoxylate-19-EO
Distyrylethoxylate-20-EO
Distyrylethoxylate-21-EO
Distyrylethoxylate-22-EO
Distyrylethoxylate-23-EO
Distyrylethoxylate-24-EO
Distyrylethoxylate-25-EO
Distyrylethoxylate-26-EO
Distyrylethoxylate-27-EO
Distyrylethoxylate-28-EO
Distyrylethoxylate-29-EO
Distyrylethoxylate-30-EO
Nonylphenolethoxylate-5-EO
Nonylphenolethoxylate-6-EO
Nonylphenolethoxylate-7-EO
Nonylphenolethoxylate-8-EO
Nonylphenolethoxylate-9-EO
Nonylphenolethoxylate-10-EO
Nonylphenolethoxylate-11-EO
Nonylphenolethoxylate-12-EO
Nonylphenolethoxylate-13-EO
Nonylphenolethoxylate-14-EO
Nonylphenolethoxylate-15-EO
tN/min
2.0
2.5
4.3
4.6
4.9
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.8
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
6.6
6.3
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
Exact mass/amu
254.0450
252.0236
307.1451
295.1088
307.1451
522,2981
566,3244
610,3506
654,3768
698,4030
742,4292
786,4554
830,4816
874,5079
918,5341
962,5603
1006,5865
1050,6127
1094,6389
1138,6651
1182,6914
1226,7176
1270,7438
1314,7700
1358,7962
1402,8224
1446,8486
1490,8749
1534,9011
1578,9273
1622,9535
440,3138
484,3400
528,3662
572,3924
616,4186
660,4449
704,4711
748,4973
792,5235
836,5497
880,5759
4
Nonylphenolethoxylate-16-EO
Nonylphenolethoxylate-17-EO
Nonylphenolethoxylate-18-EO
Nonylphenolethoxylate-19-EO
Nonylphenolethoxylate-20-EO
Nonylphenolethoxylate-21-EO
Nonylphenolethoxylate-22-EO
Nonylphenolethoxylate-23-EO
Nonylphenolethoxylate-24-EO
Nonylphenolethoxylate-25-EO
Nonylphenolethoxylate-26-EO
Nonylphenolethoxylate-27-EO
Nonylphenolethoxylate-28-EO
Nonylphenolethoxylate-29-EO
Nonylphenolethoxylate-30-EO
Tristyrylethoxylate-5-EO
Tristyrylethoxylate-6-EO
Tristyrylethoxylate-7-EO
Tristyrylethoxylate-8-EO
Tristyrylethoxylate-9-EO
Tristyrylethoxylate-10-EO
Tristyrylethoxylate-11-EO
Tristyrylethoxylate-12-EO
Tristyrylethoxylate-13-EO
Tristyrylethoxylate-14-EO
Tristyrylethoxylate-15-EO
Tristyrylethoxylate-16-EO
Tristyrylethoxylate-17-EO
Tristyrylethoxylate-18-EO
Tristyrylethoxylate-19-EO
Tristyrylethoxylate-20-EO
Tristyrylethoxylate-21-EO
Tristyrylethoxylate-22-EO
Tristyrylethoxylate-23-EO
Tristyrylethoxylate-24-EO
Tristyrylethoxylate-25-EO
Tristyrylethoxylate-26-EO
Tristyrylethoxylate-27-EO
Tristyrylethoxylate-28-EO
Tristyrylethoxylate-29-EO
Tristyrylethoxylate-30-EO
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
6.2
5.9
5.9
5.9
5.9
5.9
5.9
5.9
5.9
6.5
5.9
5.9
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
6.0
5.9
5.9
5.9
5.9
5.9
5.8
5.8
5.8
5.8
5.8
924,6022
968,6284
1012,6546
1056,6808
1100,7070
1144,7332
1188,7594
1232,7857
1276,8119
1320,8381
1364,8643
1408,8905
1452,9167
1496,9429
1540,9692
626,3607
670,38695
714,4132
758,4394
802,4656
846,4918
890,5180
934,5442
978,5705
1022,5967
1066,6229
1110,6491
1154,6753
1198,7015
1242,7278
1286,7540
1330,7802
1374,8064
1418,8326
1462,8588
1506,8850
1550,9113
1594,9375
1638,9637
1682,9899
1727,0161
5
2. Content of diester 1, monoester 2 and monoester 3 in different production
batches of commercially available AOT of different suppliers
In Table S 2 were given the content of diester 1 and the monoesters 2 and 3 in AOT of at least
eight production batches each investigated supplier A, B, C and D. The given data for each
production batch are average values of five independently weighed repetition analyses after
the removal of outliers with a Grubbs outlier test. The displayed data is given together with its
interval of confidence of 95%.
Table S 2: Content of diester 1 and monoester 2 and 3 in AOT together with their expanded measurement
uncertainty. Analysis of five independently weight samples each batch number averaged. The expended
measurement uncertainty is encompassing 95% of the distribution of values.
Sample
[SupplierBatch No.]
a-1
a-2
a-3
a-4
a-5
a-6
a-7
a-8
AOT
(w/w /%)
Monoester 2
(w/w /%)
Monoester 3
(w/w /%)
62.9 ± 1.2
58.6 ± 1.2
60.2 ± 0.6
61.3 ± 3.3
62.4 ± 2.1
61.2 ± 0.9
62.6 ± 1.2
62.2 ± 1.1
1.3 ± 0.02
1.5 ± 0.04
1.7 ± 0.02
1.2 ± 0.05
2.0 ± 0.04
1.3 ± 0.01
1.5 ± 0.03
1.3 ± 0.03
0.72 ± 0.02
0.58 ± 0.01
0.93 ± 0.01
0.48 ± 0.02
0.82 ± 0.03
0.72 ± 0.01
0.83 ± 0.01
0.69 ± 0.01
A-1
A-2
A-3
A-4
A-5
64.5 ± 1.0
57.8 ± 1.0
58.0 ± 1.6
56.3 ± 1.0
60.6 ± 0.6
2.8 ± 0.02
2.3 ± 0.05
2.6 ± 0.05
2.4 ± 0.04
2.5 ± 0.08
1.7 ± 0.03
2.1 ± 0.05
2.0 ± 0.04
1.9 ± 0.01
1.8 ± 0.05
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
65.8 ± 0.7
65.0 ± 3.5
65.3 ± 2.1
73.1 ± 1.3
61.3 ± 1.1
62.1 ± 0.7
63.0 ± 1.0
71.3 ± 1.0
0.82 ± 0.01
0.58 ± 0.02
0.80 ± 0.02
1.2 ± 0.03
1.3 ± 0.04
1.0 ± 0.01
0.88 ± 0.01
1.2 ± 0.03
0.15 ± 0.004
0.26 ± 0.01
0.15 ± 0.003
0.36 ± 0.01
0.28 ± 0.02
0.31 ± 0.01
0.21 ± 0.01
0.30 ± 0.01
6
C-1
C-2
C-3
C-4
C-5
C-6
C-7
C-8
61.4 ± 1.0
58.8 ± 0.7
55.7 ± 0.9
62.9 ± 0.6
60.1 ± 0.7
59.0 ± 0.8
57.1 ± 0.9
58.7 ± 0.9
3.2 ± 0.06
2.5 ± 0.06
3.4 ± 0.02
2.5 ± 0.05
3.3 ± 0.05
2.3 ± 0.04
2.4 ± 0.04
2.4 ± 0.03
0.67 ± 0.03
1.0 ± 0.02
1.0 ± 0.02
1.5 ± 0.03
0.73 ± 0.02
0.60 ± 0.01
0.53 ± 0.01
0.54 ± 0.01
D-1
D-2
D-3
D-4
D-5
D-6
D-7
D-8
D-9
D-10
D-11
D-12
D-13
D-14
D-15
D-16
63.9 ± 0.3
61.6 ± 1.1
64.8 ± 1.0
65.1 ± 0.9
64.1 ± 0.7
61.2 ± 1.3
64.6 ± 0.2
64.2 ± 1.0
65.0 ± 1.0
64.4 ± 0.5
65.3 ± 0.7
65.2 ± 0.4
65.2 ± 0.8
60.9 ± 0.7
63.3 ± 0.4
62.5 ± 0.8
3.8 ± 0.09
3.4 ± 0.11
4.1 ± 0.06
4.0 ± 0.09
3.9 ± 0.08
4.1 ± 0.06
3.9 ± 0.05
3.8 ± 0.03
4.0 ± 0.03
3.1 ± 0.08
3.2 ± 0.07
3.0 ± 0.06
2.8 ± 0.09
2.9 ± 0.21
2.9 ± 0.05
3.3 ± 0.05
2.7 ± 0.09
2.4 ± 0.03
2.7 ± 0.08
2.5 ± 0.04
2.3 ± 0.07
2.8 ± 0.04
2.0 ± 0.07
2.3 ± 0.03
2.0 ± 0.03
2.0 ± 0.05
2.2 ± 0.05
2.1 ± 0.04
1.9 ± 0.05
1.8 ± 0.09
2.0 ± 0.04
2.2 ± 0.06
7
3. Sedimentation in trail storage formulation samples
The observed sediment in the formulation samples after storage was photographed from above
and shown in Figure S 1.
Figure S 1: Test on sedimentation after 0.5 a storage at room temperature of a model agrochemical
formulation containing AOT of supplier A1, B and D. Increasing amount of visible sediment from supplier
A1 to supplier D
4. Centrifugation of a model agrochemical formulation containing AOT of
supplier A1
A model agrochemical formulation containing AOT of supplier A1 was centrifuged with a
HEREAUS Labofuge 400 with 3000 r/min. The supernatant was removed and the sediment
analyzed on diester 1 and monoester 2 and monoester 3. The results of the analyses given as
percentage of the AOT-content in the formulation are shown in Table S 3. Each value is the
average of five replicate analyses given together with its interval of confidence of 95%.
8
Table S 3: Content of diester 1, monoester 2 and monoester 3 in sediment given as percentage of the AOTcontent in the formulation. The sediment was obtained after centrifugation of the model agrochemical
formulation containing AOT of supplier A1. Each value is the average of five replicates analyses, given
together with its interval of confidence of 95%.
Sediment sample
AOT
(w/w /%)
236.0 ± 36.2
Monoester 2
(w/w /%)
1.8 ± 0.1
Monoester 3
(w/w /%)
0.9 ± 0.08
5. Results of the analysis of AOT of different production batches for inorganic
anions and cations of different suppliers
Selected production batches of AOT of supplier A1, B, C and D were investigated on
difference in their content of inorganic cations and anions, which are known to influence both
ionic and non-ionic surfactants [1;2]. The samples were screened on the content of the cations
Li+ Na+, NH4+, K+, Mg2+ and Ca2+, as well as, the anions of Br-, Cl-, F-, NO3-, PO43- and SO42-.
Variations in the content of inorganic ions between the suppliers of AOT may explain the
differences observed in sedimentation behavior after storage of a model agrochemical
formulation containing AOT of either supplier A1, B or D.
Analysis was conducted on an ICS 2000 ion chromatography instrument from Dionex.
Chromatographic separation of the cations was performed with an IonPa CS12A column (250
x 2.0 mm). For mobile phase methanesulfonic acid (MSA) was taken. The sample was
injected with a volume of 5.0 µL and gradient elution was applied for separation of the target
analytes. Starting with a concentration of 30 mM MSA and raised to 40 mM in 10 min,
lowered to 30 mM MSA in 1.0 min to 30mM MSA by column flushing and equilibration
afterwards. Total run time was 15 min with a flow of 0.25 mL/min and a column temperature
of 30°C.
9
For chromatographic separation of the anions an IonPac AS11 HC column (250 mm x
2.0 mm) was used. As mobile phase water plus 30mM KOH was taken. The sample was
injected with 2.5 µL and the target analytes were eluted isocratically. Total run time was
15 min with a flow of 0.38 mL/min and column temperature of 30 °C. For detection an
electrochemical detector connected upstream with a suppressor was used.
For analysis of the cations Dionex Six Cation-II Standard was used, containing lithium
(c(Li+) = 50 mg/L), sodium (c(Na+) = 201 mg/L), ammonium (c(NH4+) = 251 mg/L),
potassium (c(K+) = 501 mg/L), magnesium (c(Mg2+) = 250 mg/L) and calcium (c(Ca2+) =
50 mg/L). This solution had to be further diluted by 1:10 (v/v) diluted to obtain the stock
solution for the analysis of cations.
For the analysis of the anions a commercially available multi-element ion chromatography
anion standard supplied by Fluka was used as standard solution containing, bromide (c(Br-) =
20 mg/L), chloride (c(Cl-) = 10 mg/L), fluoride (c(F-) = 3 mg/L), nitrate (c(NO3-) = 20 mg/L),
phosphate (c(PO43-) = 20 mg/L) and sulfate (c(SO42-) = 20 mg/L).
For preparation of the standard solutions the both stock solutions were diluted to fit the
concentration range 20 mg/L to 1 mg/L.
10
For analysis the light aromatic solvent in AOT was evaporated. An amount of 100 mg of the
remainder was diluted with 50 mL of a mixture of 95/5 (v/v) water/methanol. The obtained
solution could be directly injected without further dilution accepted for the analysis of Na+,
where the sample solution had to be diluted 1:10 (v/v) to be inside the linear range.
Of all investigated inorganic ions only the contents of Na+, Ca2+, Cl-, NO3- and SO42- were
above the limit of quantification (LOQ) of 1 mg/L of the used analytical method. As this
LOQ corresponds to a content of 0.05 % (w/w) in AOT with the given sample preparation, no
further attempts were made to detect the other inorganic ions screened for, as their content
was considered negligible. In Figure S 2 is shown the chromatographic separation of the target
cation (a) and anions (b) for the analysis of the production batch a-1.
(a)
(b)
Figure S 2: Chromatographic separation of the cations Na+ and Ca2+(a) and the anions Cl-, NO3- and SO42via ion chromatography.
11
The obtained results are shown in Table S 4 and are visualized as box-plots in were indicated with
“<LOQ”.
Sample
[Supplier-Batch No.]
a-1
a-2
a-3
a-4
a-5
a-6
a-7
a-8
Na+
(w/w /%)
4.7
5.3
5.2
7.5
5.1
3.8
3.7
4.8
Ca2+
(w/w /%)
0.07
Cl(w/w /%)
NO3(w/w /%)
SO42(w/w /%)
<LOQ
< LOQ
0.06
0.08
0.05
0.06
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.09
0.07
0.08
< LOQ
< LOQ
< LOQ
0.5
0.3
0.6
0.4
0.7
0.4
0.3
0.5
<LOQ
0.1
0.1
0.1
<LOQ
0.08
B-1
B-2
B-3
B-4
B-5
B-6
B-7
B-8
5.0
5.2
4.8
5.4
4.9
5.3
5.2
5.4
<LOQ
<LOQ
<LOQ
<LOQ
<LOQ
<LOQ
<LOQ
<LOQ
0.09
0.06
0.06
0.16
0.06
0.14
0.14
0.14
0.1
0.08
0.07
0.2
0.07
0.1
0.1
0.2
0.4
0.3
0.3
0.5
0.5
0.5
0.6
0.5
C-1
C-2
C-3
C-4
C-5
C-6
C-7
C-8
5.7
3.0
4.5
3.5
6.0
4.4
4.9
5.9
<LOQ
< LOQ
< LOQ
< LOQ
0.05
0.06
< LOQ
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.07
0.08
0.05
< LOQ
< LOQ
0.3
0.2
0.3
0.3
0.4
0.3
0.4
0.4
D-1
D-2
D-3
D-4
D-5
D-6
D-7
D-8
D-9
D-10
D-11
D-12
D-13
D-14
D-15
D-16
4.2
6.9
5.9
6.8
5.7
5.5
5.8
2.7
3.8
5.3
5.5
4.7
5.7
5.7
5.6
5.3
0.1
0.1
0.07
0.09
0.1
0.06
0.05
0.2
< LOQ
0.05
0.1
0.1
0.07
0.05
0.1
0.08
0.05
0.05
0.05
0.2
0.06
0.06
0.07
0.07
< LOQ
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.05
0.1
0.05
0.05
0.05
0.1
0.08
0.08
0.4
0.4
0.3
0.4
0.3
0.3
0.3
0.3
0.3
0.3
0.4
0.3
0.6
0.4
0.5
0.4
0.2
0.2
0.09
0.1
0.08
0.07
<LOQ
<LOQ
0.08
0.05
0.2
0.1
0.1
0.07
0.3
0.2
0.1
12
a)
(b)
13
(c)
(d)
14
(e)
Figure S 3 (a) for Na+, in (b) for Ca2+, in (c) for Cl-, in (d) for NO3- and in (e) for SO42-. Those
ions, which contents were below the LOQ of the used method, were indicated with “<LOQ”
and were not considered for the box-plot figures.
Table S 4: Content of Na+, Ca2+, Cl-, NO3- and SO42-in selected production batches of AOT of supplier A1,
supplier B, supplier C and supplier D. Those ions, which contents were below the LOQ of the used method
were indicated with “<LOQ”.
Sample
[Supplier-Batch No.]
a-1
a-2
a-3
a-4
a-5
a-6
a-7
a-8
B-1
B-2
B-3
B-4
Na+
(w/w /%)
4.7
5.3
5.2
7.5
5.1
3.8
3.7
4.8
5.0
5.2
4.8
5.4
Ca2+
(w/w /%)
0.07
Cl(w/w /%)
NO3(w/w /%)
SO42(w/w /%)
<LOQ
< LOQ
0.06
0.08
0.05
0.06
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.09
0.07
0.08
< LOQ
< LOQ
< LOQ
0.5
0.3
0.6
0.4
0.7
0.4
0.3
0.5
<LOQ
<LOQ
<LOQ
<LOQ
0.09
0.06
0.06
0.16
0.1
0.08
0.07
0.2
0.4
0.3
0.3
0.5
<LOQ
0.1
0.1
0.1
<LOQ
0.08
15
B-5
B-6
B-7
B-8
4.9
5.3
5.2
5.4
<LOQ
<LOQ
<LOQ
<LOQ
0.06
0.14
0.14
0.14
0.07
0.1
0.1
0.2
0.5
0.5
0.6
0.5
C-1
C-2
C-3
C-4
C-5
C-6
C-7
C-8
5.7
3.0
4.5
3.5
6.0
4.4
4.9
5.9
<LOQ
< LOQ
< LOQ
< LOQ
0.05
0.06
< LOQ
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.07
0.08
0.05
< LOQ
< LOQ
0.3
0.2
0.3
0.3
0.4
0.3
0.4
0.4
D-1
D-2
D-3
D-4
D-5
D-6
D-7
D-8
D-9
D-10
D-11
D-12
D-13
D-14
D-15
D-16
4.2
6.9
5.9
6.8
5.7
5.5
5.8
2.7
3.8
5.3
5.5
4.7
5.7
5.7
5.6
5.3
0.1
0.1
0.07
0.09
0.1
0.06
0.05
0.2
< LOQ
0.05
0.1
0.1
0.07
0.05
0.1
0.08
0.05
0.05
0.05
0.2
0.06
0.06
0.07
0.07
< LOQ
< LOQ
< LOQ
< LOQ
< LOQ
0.05
0.05
0.1
0.05
0.05
0.05
0.1
0.08
0.08
0.4
0.4
0.3
0.4
0.3
0.3
0.3
0.3
0.3
0.3
0.4
0.3
0.6
0.4
0.5
0.4
0.2
0.2
0.09
0.1
0.08
0.07
<LOQ
<LOQ
0.08
0.05
0.2
0.1
0.1
0.07
0.3
0.2
0.1
16
a)
(b)
17
(c)
(d)
18
(e)
Figure S 3: Content of (a) Na+, (b) NH4+, (c) Ca2+, (d) Cl-, (e) NO3- and (f) SO42- in selected production
batches of AOT of supplier A1, B, C and D displayed as box-plots.
As shown the content of the investigated inorganic ions, Na+, NH4+, K+, Mg2+, Ca2+, Cl-, NO3and SO42-in AOT was not different between the supplier A1, B, C and D. Therefore the
observed differences in the physico-chemical properties of a model agrochemical formulation,
containing AOT of either supplier A1, B or D, could not be explained by differences in the
content of inorganic ions.
6. Analysis of the composition of the solvent in AOT on differences between
the suppliers
Selected production batches of supplier A1, C and D were analyzed via GC-MS, to
investigate, if there are differences in the composition of the light-aromatic naphtha solvent in
which the actual surfactant of AOT, diester 1, is solved in, between the different suppliers.
19
The analysis was performed via gas chromatography coupled to mass spectrometry with
electron impact ionization on an Agilent 5973 GC/MS. The sample was injected with 0.2 µL,
with a split of 1:60 (GC:waste) on a HP-5 capillary column of Agilent with an inner diameter
of 0.18 mm, a length of 20 m and film thickness of 0.18 mm. Separation of the analytes was
achieved with a temperature gradient, starting with 60 °C, raising temperature to 200 °C in 28
min. For column cleaning the temperature was then raised to 280 °C in 4 min and held for 3
min at 280 °C. Total run time was 35 min with N2-gas stream set at 150 kPa constant pressure.
The Inlet temperature was set at 260 °C, the aux temperature at 280 °C, the temperature in the
MS inlet at 250°C and in the MS quadrupole at 150 °C.
An amount of 20 mg each AOT sample was solved in 50 mL of a mixture of 1:1 (v/v)
ACN/H2O. The obtained solution was then injected into the GC-MS, without further dilution
or treatment.
The main components of the light-aromatic naphtha solvent was chromatographically
separated and identified via a spectra library. The chromatographic separation is shown in
Figure S 4 (a) for the early eluting and in Figure S 4 (b) for the late eluting compounds. The
most likely hit regarding retention time and spectrum for the main components are displayed
in
20
Table S 5.
(a)
(b)
Figure S 4: Chromatographic separation of the light-aromatic naphtha solvent in AOT, shown in (a) are
the earlier eluting and in (b) the late eluting compounds.
21
Table S 5: Compounds in the light-aromatic naphtha solvent in AOT, which were identified via spectra
library. Shown are the most likely hits according to retention time and spectrum.
Retention time [min]
2.48
2.79
3.15
3.30
3.42
3.95
3.99
4.23
4.43
4.66
4.69
4.77
4.83
4.88
4.98
5.18
5.34
5.97
6.06
7.19
8.99
29.24
30.24
Compound
1,3-dimethyl-benzene
(1-methylethyl)-benzene
Propyl-benzene
1-ethyl-3-methyl-benzene
1-ethyl-2-methly-benzene
(2-methylpropyl)-benzene
(1-methylpropyl)-benzene
1, 2, 3-trimethylbenzene
Indane
1, 3-diethyl-benzene
1-methly-3-propyl-benzene
Diethyl-benzene
4-ethyl-1,2-dimethyl-benzene
1, 2-diethyl-benzene
1-methly-4-propyl-benzene
2-ethyl-1, 4-dimethyl-benzene
2-ethyl-1 ,3-dimethyl-benzene
1, 2, 4, 5-teramethly-benzene
1, 2, 3, 4-teramethly-benzene
alpha, 4-diemethyl-benzene-methanol
6-methylheptyl ester 2- propionic acid
Bis(2-ethylhexyl) maleate
1 ,2-Cyclohexanedione
As shown the main compounds identified are benzyl derivates of benzene, which confirms the
characterization of the light-aromatic naphtha solvent by its supplier [3;4]. 8 different
production batches each supplier A1, C and D were analyzed accordingly, on the composition
of their light-aromatic solvent. Exemplary, are given in Figure S 5 the results for one
production batch of AOT each supplier, as variations between the analyzed production
batches for suppliers were not detected. Shown are separately the range of time 0-10 min in
A1-1, C-1 and D-1 and the time range 10-35min in A1-2, C-2 and D-2.
22
(A1-1)
(A1-2)
(C-1)
23
(C-2)
(D-1)
(D-2)
Figure S 5: Comparison of the chromatographic pattern of the light-aromatic naphtha solvent of selected
production batches of AOT of the suppliers A1, C and D. Shown are separately the retention time range
0-10 min (A1-1), C-1 and D-1) and 10-35 min (A1-2, C-2 and D-2). The analysis of the solvent was
conducted on GC-MS
The compounds listed in
24
Table S 5 were found for all three suppliers. Observed were, however, differences between the
investigated suppliers of AOT regarding the abundance of some compounds in the retention
time window 2.0-7.0 min.
7. Statistical evaluation of the usefulness of the contents of diester 1 and
monoester 2 and 3 for product identification
After having analyzed the content of diester 1, monoester 2 and monoester 3 in AOT samples
from production batches of different suppliers the question arose if in the future such
analytical data could be potentially helpful for identifying the supplier from which an
unknown sample originates. The corresponding statistical analysis was performed with R, a
language and environment for statistical computing and graphics [5]. Therefore two further
documents are provided in the Supporting Information. The first one is the document
"evaluation.pdf" which explains the statistical evaluation in detail. The second one is a standalone R script (evaluation.R) which can be immediately executed by the reader. This needs
the input files "data_set_1.txt" (samples from batches of various suppliers) and
"data_set_2.txt" (trial storage formulation samples) which are also included in the Supporting
Information.
Reference List
1. Porter MR (1994) Handbook of Surfactants. vol. 2 Chapman & Hall, Glasgow
2. Tadros TF (2008) In: Applied Surfactants, Principles and Applications. Wiley-VCH,
Weinheim.
3. Shell Chemicals (Accesed: December 2013) Material Safety data sheat ShellSol A100
http://aglayne.com/wp-content/uploads/2010/10/Shellsol-A-100.pdf.
4. Exxon Mobil Chemical (Accesed: December 2013) Material safety data sheat Solvesso
100
https://www.exxonmobilchemical.com/Chem-English/Files/Resources/aromatic100-product-safety-summary.pdf
5. R Development Core Team (2012) R: A Language and Enviroment for Statistical
Computing. R Foundation for Statistical Computing, Vienna, Austria, ISBN 3-90005107-0.
25