Propanoic acid, 2,2,3-trifluoro-3-[1,1,2,2,3,3-hexafluoro-3-(trifluoromethoxy)propoxy]-

Hydrolysis

Administrative data

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 10, 2007- July 19, 2007

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: guideline study conducted under GLP compliance with acceptable restriction. Study of ammonium salt

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2007

Report date:

2007

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

E-19729

IUPAC Name:

E-19729

Details on test material:

- Name of test material (as cited in study report): E-19729
- Substance type: single-constituent substance
- Physical state: colorless, transparent, viscous liquid
- Analytical purity: approximately 30 % (w/w) aqueous solution
- Lot/batch no.:VV87-10+12
- Expiration date of the lot/batch: December 31, 2008
- Storage condition of test material: Ambient temperature, 10-30°C

Radiolabelling:

no

Study design

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: About 0.60 g of the test item solution was weighed in 50 ml volumetric flasks in a glove box filled with nitrogen. Test bottles with buffers of pH 4, 7 and 9 were sampled at 2.4 hours and 5 days;
- Sampling method: The flasks containing the hydrolysis mixtures were placed in a thermostatically controlled water bath at 50 ± 0.5 °C for 2.4 hours and 5 days. Thereafter aliquots of each flask were taken. The volumetric flasks were flooded with nitrogen again. The aliquots were diluted 0.1 ml to 1 ml with the
mobile phase at the beginning of the HPLC-measurement.
- Sampling intervals/times for pH measurements: None
- Sample storage conditions before analysis: None

Buffers:

- pH: 4,7,9
- Type and final molarity of buffer:
pH 4 buffer: 21.01 g citric acid monohydrate dissolved in 200 mL of 1 mol/I NaOH solution, and bring to 1000 ml with distilled water. 44 ml of mol/I of HCl
were added to 560 ml of citric acid monohydrate/NaOH and bring to 1000 ml with distilled water. The pH value was adjusted to pH 4.

pH 7 buffer: 13.61 g of KH2PO4 were dissolved in 1000 ml distilled water. 30 ml of 1 mol/I NaOH were added to 500 ml of KH2PO4 solution and bring to 1000 ml with distilled water. The pH was adjusted to pH 7.
pH 9 buffer: 7.46 9 KCl and 6.18 g boric acid (H3BO3) were dissolved in 1000 ml distilled water. 21 ml of 1 mol/I NaOH were added to 500 ml of KCl/H3BO3 solution and bring to 1000 ml with distilled water. The pH value was adjusted to pH 9.

- Composition of buffer:
pH 4 buffer: citric acid monohydrate/NaOH/HCl
pH 7 buffer: KH2PO4/NaOH
pH 9 buffer: KCl /H3BO3/NaOH

Details on test conditions:

TEST SYSTEM

-Type, material and volume of test flasks, other equipment used: 50 mL volumetric flasks
- Measures to exclude oxygen: test item was weighted in a glove box filled with nitrogen .The volumetric flasks were flooded with nitrogen.

TEST MEDIUM
- Kind and purity of water: distilled water
- Identity and concentration of co-solvent: no co-solvent

OTHER TEST CONDITIONS
- Adjustment of pH: none
- Dissolved oxygen: flooded with nitrogen

Duration of test

Duration:

5 d

Temp.:

50 °C

Initial conc. measured:

12.11 - 12.62 g/L

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Results and discussion

Transformation products:

not measured

Details on hydrolysis and appearance of transformation product(s):

- Formation and decline of each transformation product during test: not measured

The % decomposition at pH 4, pH 7 and pH 9 ranged from 0 to 1.12% after 2.4 hours and 5 days in the hydrolysis pre-tests.

Total recovery of test substance (in %)

% Recovery:

98.88 - 101.54

pH:

7

Temp.:

50 °C

Duration:

2.4 - 120 h

Dissipation DT50 of parent compound

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Details on results:

- Formation and decline of each transformation product during test: not measured

Decomposition of test substance E-19729 by hydrolysis was not significant in all pH buffers after 2.4 hours and 5 days at 50 °C. At pH 4, the % of decomposition was 0 to 0.05; at pH 7, the % of decomposition was 0 to 1.12; at pH 9, the % of decomposition was 0 to 0.22. Seven out of twelve measured concentrations at the end of the study were slightly higher than the initial measured concentration, resulting in negative values of % decomposition. However, these values were the results of analytical uncertainty, and were not considered to be statistically different from the initial measured concentrations. Therefore, the % decomposition at pH 4, pH 7 and pH 9 is reported to range from 0 to 1.12% after 2.4 hours and 5 days at 50 °C.

Less than 10 % of the reaction was observed after 5 days at 50°C at pH 4, pH 7 and pH 9; the half life for E-19729 was reported as > 1 year. The test substance is considered to be hydrolytically stable.

Any other information on results incl. tables

Table 1. Results of the hydrolysis of E-19729
Experiment	pH	Duration	C0(g/L)	Ct(g/L)	Ct/C0	% Decomposition
1	4	2.4 h	12.22	12.33	1.0091	0
		2.4 h	12.23	12.27	1.0034	0
2	4	5 d	12.22	12.21	0.9995	0.05
		5 d	12.23	12.27	1.0033	0
3	7	2.4 h	12.62	12.49	0.9895	1.05
		2.4 h	12.23	12.42	1.0154	0
4	7	5 d	12.62	12.48	0.9888	1.12
		5 d	12.23	12.2	0.9973	0.27
5	9	2.4 h	12.31	12.45	1.0119	0
		2.4 h	12.11	12.19	1.0071	0
6	9	5 d	12.31	12.28	0.9978	0.22
		5 d	12.11	12.4	1.0244	0
C0 = concentration measured by HPLC at time )
Ct= concentration at time 2.4 h or 5 days

Applicant's summary and conclusion

Conclusions:

E-19729 has a hydrolysis half life of > 1 year, it is considered hydrolytically stable.

Executive summary:

DONA is an acid that is expected to be deprotonated at pH 4,7,and 9. E-19729 is the ammonium salt of DONA. Hydrolysis data from E-19729 can therefore be used to assess DONA hydrolysis.

Hydrolysis study for E-19729 was performed according to the OECD 111: hydrolysis as a Function of pH.

About 0.60 g of E-19729 was weighed in 50 ml volumetric flasks with buffers of pH 4, 7 and 9 and placed at 50 ± 0.5 °C for 2.4 hours and 5 days. Concentrations of E-19729 at the initial and the end of hydrolysis experiment were measured by HPLC. Hydrolysis rate were determined by % decomposition of the test material.

The % decomposition of E-19729 at pH 4, pH 7 and pH 9 ranged from 0 to 1.12% after 2.4 hours and 5 days at 50°C, the hydrolysis half life is reported as > 1 year. The ammonium salt of DONA is considered hydrolytically stable.

This is a guideline study conducted under GLP. Therefore, it is considered to be reliable with acceptable restriction.