Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Experimental starting date: 12 October 2016 Experimental completion date: 22 October 2016
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2017
Report Date:
2017

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Qualifier:
according to
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Test material form:
liquid
Specific details on test material used for the study:
Information as provided by the Sponsor. The Certificate of Analysis provided by the Sponsor is presented as Annex 1 (Please see Attachment Section of this Summary).

Identification: X-19574
Appearance/Physical state: Amber colored viscous liquid
Batch: X-19574-00-00
Purity: 100% (UVCB)
Expiry date: 01 June 2017
Storage conditions: Room temperature, in the dark

Study design

Details on sampling:
Analysis of the Sample Solutions
The sample solutions were taken from the water bath at 24 and 120 hours and the pH of each solution recorded.
The concentration of test item in the standard, sample and matrix blank solutions was determined by liquid chromatography – mass spectroscopy (LC-MS) using the conditions detailed in the Analysis Section below.
Samples
An aliquot of each sample solution was diluted by a factor of 2 using tetrahydrofuran.
Standards
Calibration standard solutions of test item were prepared in THF:buffer (1:1 v/v) in the range of 0.01 to 2.5 mg/L with a duplicate standard prepared at a nominal concentration of 0.5 mg/L.
Matrix Blank
THF:buffer (1:1 v/v)

Further Testing
Results from the Preliminary Test indicated that additional testing was required.

Testing was performed in 10% pH 9 buffer at 37 °C over a period of 24 hours of incubation and analyzed directly from vials containing test solution in the heated sampling tray of the instrument.

Preparation of the Test Solutions
A stock solution of test item was prepared at a nominal concentration of 300 mg/L in tetrahydrofuran. An aliquot of the stock solution (1 mL) was added to 100 mL of a 10% solution of pH 9 buffer to give a nominal concentration of 3 mg/L of test item (matrix THF:10% buffer 1:99 v/v).
The test solution was transferred to low adsorption amber vials, placed in the autosampler set at a temperature of 40 °C and analysed at multiple time points over a period of approximately 21 hours.

Analysis of the Sample Solutions
The concentration of test item in the sample solutions was determined by liquid chromatography – mass spectroscopy (LC-MS).

Samples
Samples were injected directly from the incubated vials.
Standards
Calibration standard solutions of test item were prepared in THF:buffer (1:99 v/v) in the nominal concentration range of 0.1 to 5 mg/L with a duplicate standard prepared at a nominal concentration of 3 mg/L.
Matrix Blank
THF:buffer (1:99 v/v)
Buffers:
The test system consisted of sterile buffer solutions at pH’s 4.0, 7.0 and 9.0.

Specification of Buffer Solutions
Table 1
Buffer solution
(pH) Components Concentration
(mol dm-3)
4 Citric acid 0.06
Sodium chloride 0.04
Sodium hydroxide 0.07
7 Disodium hydrogen orthophosphate (anhydrous) 0.03
Potassium dihydrogen orthophosphate 0.02
Sodium chloride 0.02
9 Disodium tetraborate 0.01
Sodium chloride 0.02

These solutions were subjected to ultrasonication and degassing with nitrogen to minimize dissolved oxygen content.
Details on test conditions:
Preliminary Test / Tier 1
Preparation of the Test Solutions
A stock solution of test item was prepared at a nominal concentration of 100 mg/L in tetrahydrofuran. An aliquot of the stock solution (10 mL) was added to 1 L of a 10% solution of each buffer to give a concentration of 1 mg/L of test item in each buffer. The test solutions were split into individual glass vessels for each time point. The solutions were shielded from light whilst being maintained at the test temperature.
Sample solutions at pH 4, 7 and 9 were maintained at 50.0 ± 0.5 °C for a period of 120 hours.

Positive controls:
no
Negative controls:
no

Results and discussion

Transformation products:
no
Dissipation DT50 of parent compound
Key result
Remarks on result:
not determinable
Remarks:
Determination of the rate constants and half-lives of the test item at pH 4, 7 and 9 was not possible due to surface effects of the test item.

Any other information on results incl. tables

Results

Preliminary Test / Tier 1

The mean peak areas relating to the standard and sample solutionsfor the initial and
24-hour time points for pH 4 samplesare shown in the following tables:

pH 4, initial, 24 hour samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

3.455E+05

ND

Standard2.523E+00mg/L

9.916E+06

2.239E+05

Standard5.055E-01mg/L

2.217E+06

1.870E+04

Standard2.018E+00mg/L

8.184E+06

1.764E+05

Standard1.009E-02mg/L

3.095E+05

ND

Standard1.514E+00mg/L

5.937E+06

7.566E+04

Standard2.523E-02mg/L

3.716E+05

ND

Standard1.009E+00mg/L

4.237E+06

8.810E+04

Standard5.045E-02mg/L

4.619E+05

ND

Standard5.045E-01mg/L

2.227E+06

2.360E+04

Standard5.045E-01mg/L

2.249E+06

2.766E+04

Standard5.055E-01mg/L

2.219E+06

1.331E+04

pH4 Blank

3.170E+05

ND

pH4 0 hr A

2.030E+06

2.395E+04

pH4 0 hr B

2.095E+06

2.525E+04

pH4 24 hr A

1.600E+06

2.540E+04

pH4 24 hr B

1.600E+06

2.110E+04

ND: None detected

 

The mean peak areas relating to the standard and sample solutionsfor the 120 hour time points for pH 4 samplesare shown in the following table:

pH 4, 120 Hr samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

2.076E+05

ND

Standard2.523E+00mg/L

1.125E+07

4.039E+05

Standard5.055E-01mg/L

2.333E+06

ND

Standard2.018E+00mg/L

9.212E+06

3.457E+05

Standard1.009E-02mg/L

2.156E+05

ND

Standard1.514E+00mg/L

6.669E+06

1.165E+05

Standard2.523E-02mg/L

2.569E+05

ND

Standard1.009E+00mg/L

4.657E+06

2.722E+05

Standard5.045E-02mg/L

3.413E+05

ND

Standard5.045E-01mg/L

2.331E+06

ND

Standard5.045E-01mg/L

2.509E+06

ND

Standard5.055E-01mg/L

2.367E+06

ND

pH4 Blank

2.080E+05

ND

pH4 120 hr A

1.335E+06

ND

pH4 120 hr B

1.715E+06

ND

ND: None detected


 

The mean peak areas relating to the standard and sample solutionsfor the initial and 24-hour time points for pH 7 samplesare shown in the following table:

pH 7, initial, 24 Hr samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

ND

ND

Standard2.523E+00mg/L

9.316E+06

5.359E+05

Standard5.055E-01mg/L

1.661E+06

7.792E+04

Standard2.018E+00mg/L

7.382E+06

3.685E+05

Standard1.009E-02mg/L

ND

ND

Standard1.514E+00mg/L

5.320E+06

2.430E+05

Standard2.523E-02mg/L

ND

2.897E+03

Standard1.009E+00mg/L

3.117E+06

1.364E+05

Standard5.045E-02mg/L

4.930E+04

8.144E+03

Standard5.045E-01mg/L

1.617E+06

8.030E+04

Standard5.045E-01mg/L

1.631E+06

8.321E+04

Standard5.055E-01mg/L

1.621E+06

8.291E+04

pH7 Blank

ND

ND

pH7 0hr A

1.320E+06

9.565E+04

pH7 0hr B

1.435E+06

8.765E+04

pH7 24 hr A

2.995E+05

8.080E+04

pH7 24 hr B

3.360E+05

8.160E+04

ND: None detected

 


 

The mean peak areas relating to the standard and sample solutionsfor the 120 hour time points for pH 7 samplesare shown in the following table:

pH 7 120 Hr samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

ND

ND

Standard2.523E+00mg/L

1.040E+07

9.887E+05

Standard5.055E-01mg/L

1.525E+06

1.072E+05

Standard2.018E+00mg/L

8.180E+06

6.534E+05

Standard1.009E-02mg/L

ND

ND

Standard1.514E+00mg/L

5.982E+06

4.069E+05

Standard2.523E-02mg/L

ND

ND

Standard1.009E+00mg/L

3.476E+06

2.125E+05

Standard5.045E-02mg/L

ND

ND

Standard5.045E-01mg/L

1.674E+06

1.168E+05

Standard5.045E-01mg/L

ND

1.203E+05

Standard5.055E-01mg/L

ND

1.212E+05

pH7 Blank

ND

ND

pH7 120 hr A

ND

3.185E+05

pH7 120 hr B

ND

1.340E+05

ND: None detected

 


 

The mean peak areas relating to the standard and sample solutions for the initial and 24-hour time points for pH 9 samplesare shown in the following table:

pH 9, initial, 24 Hr samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

ND

3.052E+04

Standard2.523E+00mg/L

1.079E+07

9.569E+05

Standard5.055E-01mg/L

2.007E+06

2.248E+05

Standard2.018E+00mg/L

8.084E+06

7.577E+05

Standard1.009E-02mg/L

ND

3.240E+04

Standard1.514E+00mg/L

6.088E+06

5.743E+05

Standard2.523E-02mg/L

ND

3.619E+04

Standard1.009E+00mg/L

4.025E+06

3.897E+05

Standard5.045E-02mg/L

8.031E+04

4.352E+04

Standard5.045E-01mg/L

1.665E+06

1.962E+05

Standard5.045E-01mg/L

1.637E+06

2.006E+05

Standard5.055E-01mg/L

2.012E+06

2.312E+05

pH9 Blank

ND

2.950E+04

pH9 0 hr A

1.530E+06

2.640E+05

pH9 0 hr B

1.625E+06

2.705E+05

pH9 24 hr A

4.565E+04

2.630E+05

pH9 24 hr B

5.285E+04

2.640E+05

ND: None detected


 

The mean peak areas relating to the standard and sample solutionsfor the 120 hour time points for pH 9 samplesare shown in the following table:

pH 9, 120 Hr samples

 

Solution

Mean peak area

Amine Component

Thiophosphate Component

Blank

ND

3.969E+04

Standard2.523E+00mg/L

1.293E+07

1.794E+06

Standard5.055E-01mg/L

2.284E+06

4.079E+05

Standard2.018E+00mg/L

9.723E+06

1.426E+06

Standard1.009E-02mg/L

ND

4.252E+04

Standard1.514E+00mg/L

7.266E+06

1.078E+06

Standard2.523E-02mg/L

ND

4.913E+04

Standard1.009E+00mg/L

4.705E+06

7.254E+05

Standard5.045E-02mg/L

ND

6.167E+04

Standard5.045E-01mg/L

1.755E+06

3.386E+05

Standard5.045E-01mg/L

1.833E+06

3.482E+05

Standard5.055E-01mg/L

2.277E+06

4.098E+05

pH9 Blank

ND

3.970E+04

pH9 120 hr A

ND

4.535E+05

pH9 120 hr B

ND

4.560E+05

ND: None detected

 

The test item concentrations at the given time points are shown in the following tables:

Amine Component              pH 4 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

0.904

0.941

-

-

24

0.683

0.680

74.1

73.8

120

0.536

0.707

58.1

76.7

Thiophosphate Component             pH 4 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

1.04

1.08

-

-

24

1.08

0.954

102

90.1

120[1]

-

-

-

-

Amine Component             pH 7 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

0.852

0.919

-

-

24

0.237

0.257

26.5

29.0

120*

-

-

-

-

Thiophosphate Component            pH 7 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

1.37

1.26

-

-

24

1.17

1.18

88.7

89.5

120

2.62[2]

1.25

-

95.3

 

[*]Poor instrument response, no peak areas reported.

[2]Anomalous result


Amine Component              pH 9 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

0.851

0.900

-

-

24

7.40 x 10-2

7.78 x 10-2

8.45

8.89

120

ND

ND

-

-

Thiophosphate Component             pH 9 at 50.0 ± 0.5 ºC

Time (Hours)

Concentration (mg/L)

Percentage of mean initial concentration

A

B

A

B

0

1.31

1.35

-

-

24

1.31

1.31

98.3

98.7

120

1.24

1.24

93.0

93.5

Where the result indicates greater than 90% of initial concentration, this is equivalent to less than 10% hydrolysis after 5 days at 50 °C, equivalent to a half-life of greater than 1 year at 25 °C.

 

Further Testing

The mean peak areas relating to the standard and sample solutionsfor theshown in the following tables:

pH 9 at 37 °C

 

Solution

Mean total peak area

Amine Component

Thiophosphate Component

Standard5.55mg/L

5.382E+06

2.140E+06

Standard3.31mg/L

4.189E+06

1.300E+06

Standard0.111mg/L

3.227E+05

2.709E+04

Standard4.436mg/L

4.925E+06

1.783E+06

Standard0.333mg/L

6.552E+05

1.145E+05

Standard3.33mg/L

3.946E+06

1.392E+06

Standard1.11mg/L

1.850E+06

4.407E+05

Standard2.22mg/L

2.958E+06

9.042E+05

pH9 initial

4.88E+06

1.33E+06

pH9 0.182 hr

4.46E+06

1.41E+06

pH9 0.364 hr

4.19E+06

1.36E+06

pH9 0.545 hr

3.91E+06

1.36E+06

pH9 0.727 hr

4.00E+06

1.35E+06

pH9 0.909 hr

3.35E+06

1.38E+06

pH9 1.09 hr

4.17E+06

1.36E+06

pH9 1.86 hr

3.35E+06

1.43E+06

pH9 2.38 hr

2.37E+06

1.44E+06

pH9 2.89 hr

2.29E+06

1.46E+06

pH9 3.41 hr

2.50E+06

1.47E+06

pH9 3.92 hr

2.53E+06

1.48E+06

pH9 4.44 hr

2.55E+06

1.49E+06

pH9 7.04 hr

2.44E+06

1.56E+06

pH9 9.05 hr

2.30E+06

1.56E+06

pH9 11.1 hr

2.11E+06

1.59E+06

pH9 13.1 hr

1.83E+06

1.59E+06

pH9 15.1 hr

1.57E+06

1.73E+06

pH9 17.1 hr

2.62E+06

1.74E+06

pH9 19.1 hr

1.80E+06

1.78E+06

pH9 21.1 hr

1.97E+06

1.86E+06


 

The test item concentrations at the given time points are shown in the following table:

pH 9 at 37 °C

Time (hours)

Concentration (mg/L)

Percentage of mean initial concentration

Amine

Thiophosphate

Amine

Thiophosphate

Initial

4.46

3.27

-

-

0.182

3.82

3.49

85.6

107

0.364

3.46

3.35

77.5

102

0.545

3.12

3.36

70.0

103

0.727

3.22

3.32

72.2

101

0.909

2.51

3.41

56.4

104

1.09

3.43

3.34

77.0

102

1.86

2.52

3.53

56.4

107

2.38

1.62

3.57

36.4

109

2.89

1.55

3.63

34.7

111

3.41

1.73

3.65

38.8

111

3.92

1.76

3.67

39.4

112

4.44

1.78

3.71

39.9

113

7.04

1.68

3.89

37.6

119

9.05

1.56

3.89

34.9

119

11.1

1.41

3.97

31.5

121

13.1

1.18

3.96

26.5

121

15.1

0.982

4.35

22.0

133

17.1

1.83

4.39

41.1

134

19.1

1.15

4.49

25.9

137

21.1

1.29

4.70

29.0

144

The increase in concentration of the thiophosphate component may be rationalized by the observed increase in check standard response by approx. 25% over the course of the analysis.


Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
Determination of the rate constants and half-lives of the test item at pH 4, 7 and 9 were not possible due to surface effects of the test item.

Evaluation of the testing is summarized below:

The hydrolysis of the test item was evaluated at pH 4, 7 and 9 at 50 °C for 120 hours and at pH 9 at 37 °C for approximately 21 hours. Test item concentrations for the C16-C18 alkyl amine components were observed to decrease. This was considered to be due to surface effects rather than hydrolysis, since there are no hydrolyzable groups present and fatty amines are known to strongly adhere to surfaces by chemical or physical processes. Test item concentrations for the dibuylthiophosphate component were not observed to change significantly over the course of testing the and therefore this component was considered to be stable at pH 4, 7 and 9.
Executive summary:

The determination was carried out using a procedure designed to be compatible with Method C7 Abiotic Degradation, Hydrolysis as a Function of pH of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 111 of the OECD Guidelines for Testing of Chemicals, 13 April 2004.

Conclusion

Determination of the rate constants and half-lives of the test item at pH 4, 7 and 9 were not possible due to surface effects of the test item.

Evaluation of the testing is summarized below:

The hydrolysis of the test item was evaluated at pH 4, 7 and 9 at 50 °C for 120 hours and at pH 9 at 37 °C for approximately 21 hours. Test item concentrations for the C16-C18 alkyl amine components were observed to decrease. This was considered to be due to surface effects rather than hydrolysis, since there are no hydrolyzable groups present and fatty amines are known to strongly adhere to surfaces by chemical or physical processes. Test item concentrations for the dibuylthiophosphate component were not observed to change significantly over the course of testing the and therefore this component was considered to be stable at pH 4, 7 and 9.