Reaction mass of (R*,R*)-7-methoxy-3,7-dimethyl-2-octanol and (R*,S*)-7-methoxy-3,7-dimethyl-2-octanol

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 2017

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

Study conducted according to OECD Guideline 111 without deviation, not under GLP and with certificate of analysis included.

Reason / purpose for cross-reference:

reference to other study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Version / remarks:

only 1st trial was conducted.

Deviations:

no

Remarks:

Only 1st trial was conducted.

GLP compliance:

no

Remarks:

This study is a preliminary study, this the reason why it was not conducted according to GLP.

Specific details on test material used for the study:

Colour: Colourless to slightly yellow liquid
Purity: 99.7%
Test substance storage: Refrigeration (+2°C to +8°C) under nitrogen. Keep away from light and humidity
Date of manufacture: 15 December 2015
Expiry date: 14 December 2017
Physico-chemical Properties:
Specific Gravity: 0.899 at 20°C
Solubility in water: 12.04 mg.L-1 at 20°C (Slow-stirring method)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

A stock test item solution was prepared at 127 g/L in acetone by adding 1.27 g of the test item in 10mL of acetonitrile. The solution is then shake. For each pH condition, solutions at 1.27 g/L of test item were prepared by mixing 1 mL of the stock solution with 100 mL buffer solutions, and the solutions obtained were divided in 10 replicates of 10 mL by filling the flasks totally. Each replicate is shake again.

Buffers:

pH=4: CH3COOH at 8.49x10-3 mol.L-1 and CH3COONa,3H2O at 1.51x10-3 mol.L-1.
102 mg of CH3COOH were weighed into a 200mL graduated flask containing 150 mL of ultrapure water. 41 mg of CH3COONa,3H2O were added to the solution and the total volume was adjusted to 200 mL with water. This buffered solution was prepared on 08/08/2017

pH=7: NaH2PO4,H2O at 4.23x10-3 mol.L-1 and Na2HPO4,7H2O at 5.77x10-3 mol.L-1.
116.8 mg of NaH2PO4,H2O were weighed into a 200 mL graduated flask containing 150 mL of ultrapure water. 309.4 mg of Na2HPO4,7H2O were added to the solution and the total volume was adjusted to 200 mL with water. This buffered solution was prepared on 08/08/2017

pH=9: Na2B4O7,10H2O at 9.99x10-3 mol.L-1.762.6 mg of Na2B4O7,10H2O were weighed into a 200 mL graduated flask containing 180 mL of ultrapure water. pH was adjusted to 9 with HCl 0.1M and the total volume was completed to 200 mL with water. This buffered solution was prepared on 08/08/2017

Duration:

5 d

Temp.:

50 °C

Number of replicates:

Two replicates per pH condition were analysed at each sampling date (15 min, 1 day, 2 days, 5 days)

Positive controls:

no

Negative controls:

yes

Remarks:

The sampling corresponding to incubation times of 15 min at day 0 is considered as a control solution that underwent a very short incubation at 50°C

Preliminary study:

Two replicates per pH condition were analysed at each sampling date (15 min, 1 day, 2 days, 5 days). The sampling corresponding to incubation times of 15 min at day 0 is considered as a control solution that underwent a very short incubation at 50°C. All the analyses were carried out on replicates that were not previously opened since their preparation. The replicates were discarded after analysis.
The samples were let to equilibrate to room temperature a few minutes before sampling and analysis.
A dilution in water by a factor of 10 was carried out prior to the analysis (100 µL sample + 900 µL water).
Final pH of the test solutions was controlled at the end of the study.

Transformation products:

not measured

Remarks:

Only the first trial of OECD 111 study was conducted and no transformation product was checked.

Key result

Remarks on result:

hydrolytically stable based on preliminary test

Remarks:

The substance is hydrolytically stable based on a preliminary test, therefore no further study was performed.

Other kinetic parameters:

Hydrolysis half-life at 25°C is higher than one year.

The following tables present the corrected concentrations (in g/L) for each pH condition and for each sampling time:

Condition	pH=4
Incubation time	15 min	1 day	4 days	5 days
replicate 1	1.19	1.14	1.22	1.13
replicate 2	1.20	1.19	1.13	1.20
Mean	1.19	1.16	1.17	1.16

Condition	pH=7
Incubation time	15 min	1 day	4 days	5 days
replicate 1	1.21	1.18	1.21	1.11
replicate 2	1.08	1.00	1.23	1.06
Mean	1.15	1.09	1.22	1.09

Condition	pH=9
Incubation time	15 min	1 day	4 days	5 days
replicate 1	1.14	1.17	1.09	1.08
replicate 2	1.20	1.17	1.21	1.04
Mean	1.17	1.17	1.15	1.06

The following table presents the pH values of the solutions at the beginning and at the end of the experiment.

pH values
	Day 0	Day 5
pH=4 solution	4.02	3.95
pH=7 solution	7.08	7.05
pH=9 solution	9.07	9.02

Validity criteria fulfilled:

yes

Conclusions:

For each pH condition, the total test item loss was calculated by subtracting the mean concentration between the two replicates obtained after 15 minutes of incubation by the mean concentration between the two replicates obtained on day 5. The relative losses observed after 5 days of incubation in the dark and at 50°C in solutions buffered at pH 4, pH 7 and pH 9 were:
- 2.6% loss at pH 4
- 5.2% loss at pH 7
- 9.4% loss at pH 9
The total loss is below 10% for all the pH conditions. Therefore, test item 7-METHOXY-3,7-DIMETHYLOCTAN-2-OL MULTICONSTITUENT is stable to hydrolysis (hydrolysis half-life > one year at 25°C) and no additional testing is required.

Executive summary:

A study was performed in accordance with OECD Guidline for Testing of Chemicals No. 111, "Hydrolysis as a function of pH"

to determine the stability to hydrolysis of test item 7-METHOXY-3,7-DIMETHYLOCTAN-2-OL MULTICONSTITUENT.

In the preliminary study, two replicates per pH condition were analysed at each sampling date (15 min, 1 day, 2 days, 5 days). The sampling corresponding to incubation times of 15 min at day 0 is considered as a control solution that underwent a very short incubation at 50°C.

The total loss of the test item was calculated by subtracting the initial concentration from the concentration obtained after 5 days of incubation. The concentrations were corrected by an analytical detector response factor, calculated from control solutions, in order to compensate the slight response variation from day to day. The relative losses, corresponding to the hydrolysis of the test item after 5 days of incubation atin the dark, were:

- 2.6% loss at pH 4,

- 5.2% loss at pH7,

- 9.4% loss at pH 9.

The total loss is below 10% for all the pH conditions.

Therefore, test item 7-METHOXY-3,7-DIMETHYLOCTAN-2-OL MULTICONSTITUENT is stable to hydrolysis (hydrolysis half-life > one year at) and no additional testing is required.

Description of key information

Test item 7-METHOXY-3,7-DIMETHYLOCTAN-2-OL MULTICONSTITUENT is stable to hydrolysis (hydrolysis half-life is higher than one year at 25°C) and no additional testing is required.

Additional information

The stability to hydrolysis of the test item was determined in a study performed in accordance with OECD Guidline for Testing of Chemicals No. 111 (first trial only).