Registration Dossier

Administrative data

Endpoint:
hydrolysis
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Experimental starting date: 13 August 2015 Experimental completion date: 19 January 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 111 (Hydrolysis as a Function of pH)
Deviations:
no
Qualifier:
according to guideline
Guideline:
EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)
Deviations:
no
GLP compliance:
yes

Test material

Constituent 1
Chemical structure
Reference substance name:
(3S,6E)-3,7,11-trimethyldodeca-6,10-dienal
EC Number:
810-298-1
Cas Number:
194934-66-2
Molecular formula:
C15H26O
IUPAC Name:
(3S,6E)-3,7,11-trimethyldodeca-6,10-dienal
Test material form:
liquid
Radiolabelling:
no

Study design

Analytical monitoring:
yes
Details on sampling:
After preparation using purified water, these solutions were subjected to ultrasonication and degassing with nitrogen to minimize dissolved oxygen content.

Performance of the Test
Preparation of the Test Solutions

Stock solutions were prepared in stoppered glass flasks at a nominal concentration of 0.1 mg/L in the three 10% buffer solutions. A 1% co-solvent of acetonitrile (MeCN) was used to aid solubility. The sample solutions were split into individual vessels for each data point and were shielded from light whilst maintained at the test temperature.

Analysis of the Sample Solutions

The sample solutions were taken from the water bath at various times and the pH of each solution recorded.
The concentration of the sample solution was determined by gas chromatography (GC).
Samples
An aliquot (200 mL) of each sample was passed through a previously primed solid phase extraction cartridge. The cartridge was dried with nitrogen and the analyte eluted with acetone (5 mL).
Standards
Duplicate standard solutions of test item were prepared in at a nominal concentration of 2 mg/L.
Sample blanks
Relevant 10% pH buffer treated as sample.

Standard blank
Acetone.






Buffers:
Specification of 10% pH Buffer Solutions
Table 1
Buffer solution
(pH) Components Concentration
(mol dm-3)
4 Citric acid 0.006
Sodium chloride 0.004
Sodium hydroxide 0.007
7 Disodium hydrogen orthophosphate (anhydrous) 0.003
Potassium dihydrogen orthophosphate 0.002
Sodium chloride 0.002
9 Disodium tetraborate 0.001
Sodium chloride 0.002
Details on test conditions:
Refer to details on sampling and analytical methods.
Positive controls:
no
Negative controls:
no
Statistical methods:
Not specified.

Results and discussion

Test performance:
The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0.2 to 10 mg/L in acetone The results were satisfactory with a correlation coefficient (r) of 1.000 being obtained.
Recovery of analysis of the sample procedure was assessed and proved adequate for the test.
Transformation products:
not specified
Dissipation DT50 of parent compoundopen allclose all
Key result
pH:
4
Temp.:
25 °C
Hydrolysis rate constant:
0.268 h-1
DT50:
2.58 h
Type:
(pseudo-)first order (= half-life)
Key result
pH:
7
Temp.:
25 °C
Hydrolysis rate constant:
0.012 h-1
DT50:
57.8 h
Type:
(pseudo-)first order (= half-life)
Key result
pH:
9
Temp.:
25 °C
Hydrolysis rate constant:
0.009 h-1
DT50:
80.6 h
Type:
(pseudo-)first order (= half-life)
Details on results:
The linearity of the detector response with respect to concentration was assessed over the nominal concentration range of 0.2 to 10 mg/L in acetone.              
The results were satisfactory with a correlation coefficient (r) of 1.000 being obtained.

Applicant's summary and conclusion

Validity criteria fulfilled:
yes
Conclusions:
The estimated rate constant and half-life at 25 °C of the test item are shown in the following table:

pH Rate constant (h-1) Estimated half-life at 25 °C
4 0.268 2.58 Hours
7 1.20 x 10-2 57.8 Hours
9 8.60 x 10-3 80.6 Hours
Executive summary:

The determination was carried out using a procedure designed to be compatible with Method C.7 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.

The test system consisted of sterile buffer solutions at pH’s 4, 7 and 9.

Conclusion

The estimated rate constant and half-life at 25 °C of the test item are shown in the following table:

Table 27

pH

Rate constant (h-1)

Estimated half-life at 25 °C

4

0.268

2.58 Hours

7

1.20 x 10-2

57.8 Hours

9

8.60 x 10-3

80.6 Hours