Reaction mass of 2,6-Bis[(dimethylamino)methyl]-4-(1-{3-[(dimethylamino)methyl]-4-hydroxyphenyl}-1-methylethyl)phenol and 4-(1-{3,5-Bis[(dimethylamino)methyl]-4-hydroxyphenyl}-1-methylethyl)-2,6-bis[(dimethylamino)methyl]phenol

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Qualifier:

equivalent or similar to guideline

Guideline:

EU Method C.7 (Degradation: Abiotic Degradation: Hydrolysis as a Function of pH)

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Remarks:

HPLC-UV

Details on sampling:

The hydrolysis test solutions were analyzed by HPLC at defined time intervals.

Buffers:

Buffer pH 4 Citric acid/NaOH/NaCl; Fluka, order no.: 33643
Buffer pH 7 KH2PO4/Na2HPO4, Fluka, order no.: 33646
Buffer pH 9 Na2B4O7/HCl, Fluka, order no.: 33648

Details on test conditions:

Preparation of the calibration solution
21.2 mg of the test item was dissolved with acetonitrile to a volume of 100 mL. Aliquots of this stock solution were further diluted with acetonitrile to obtain individual calibration solutions covering a concentration range from 10.6 mg/L to 106 mg/L.

Preparation of the solution used for verification of the system suitability
During the study three control solutions were prepared by dissolving of approx. 21 mg/L of the test item in acetonitrile to a volume of 100 mL. These stock solutions were further diluted with acetonitrile to obtain control solutions with a concentration of approx. 85 mg/L. These control solutions were used for verification of the system suitability on every day before analyzing the test solutions. The HPLC chromatogram of the control solutions show that the main components of the test item are clearly separated from each other.

Preparation of the hydrolysis test solutions
A stock solution of the test item was prepared by weighing of 257.4 mg of the test item in a 25 mL measuring flask. The flask was then filled up to the mark with acetonitrile, resulting in a final concentration of 10296 mg/L.
For each pH separate hydrolysis test solutions were prepared by dilution of 2.5 mL of the test item stock solution to 250 mL of the corresponding buffer systems (pH 4, 7, 9). Test item concentrations of 102.96 mg/L were obtained. Aliquots of the fresh prepared test solution were directly filled into separate vials to obtain individual samples for each test point.

Duration:

126.8 h

pH:

4

Temp.:

50 °C

Duration:

126.9 h

pH:

7

Temp.:

50 °C

Duration:

126.9 h

pH:

9

Temp.:

50 °C

Transformation products:

no

% Recovery:

96.8

pH:

4

Temp.:

50 °C

Duration:

126.8 h

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

94.8

pH:

7

Temp.:

50 °C

Duration:

126.9 h

Remarks on result:

hydrolytically stable based on preliminary test

% Recovery:

91

pH:

9

Temp.:

50 °C

Duration:

126.9 h

Remarks on result:

hydrolytically stable based on preliminary test

Remarks on result:

hydrolytically stable based on preliminary test

Details on results:

No half-life times and hydrolysis rates were calculated.
Recovery rate is given for the main component Mannich Base (4x substituted). The other components (3x and 2x substituted) of the test item do not hydrolyse more than 10 %, either.

Validity criteria fulfilled:

yes

Conclusions:

HPP 12879-1 shows hydrolysis < 10 % after 5 d at 50 °C. Therefore, it can be considered as hydrolytically stable at 25 °C and no half-life times and hydrolysis rates were calculated.

Executive summary:

The tests were performed according to OECD Guidelines for Testing of Chemicals, Section 1 – Physical-Chemical Properties, OECD 111 (Preliminary test, Tier 1), Council Regulation (EC) No 440/2008, Guideline Part C – Methods for the Determination of Ecotoxicity, C.7. “Abiotic Degradation: Hydrolysis as a Function of pH”.

The hydrolysis behaviour of HPP 12879 -1 was investigated at 50 °C and pH 4, pH 7 and pH 9 over a period of 5 days according to OECD 111 (Preliminary test, Tier 1). The stability was monitored by HPLC analysis with UV-detection.

According to the data of the sponsor and investigated and reported in the material balance (CURRENTA file no.: 2014/0048/03) the test item consists of three different Mannich Bases (2x substituted, 3x substituted and 4x substituted) as major constituents representing a total content of > 99 %.

The developed analytical HPLC-UV method can distinguish between these similar components. Therefore the hydrolytically behaviour of each component could be investigated and monitored separately.

At all three pH-values hydrolysis < 10 % was detected for each of the three components. Thus, HPP 12879 -1 can be considered as hydrolytically stable at 25 °C, too.

Description of key information

The tests were performed according to OECD Guidelines for Testing of Chemicals, Section 1 – Physical-Chemical Properties, OECD 111 (Preliminary test, Tier 1), Council Regulation (EC) No 440/2008, Guideline Part C – Methods for the Determination of Ecotoxicity, C.7. “Abiotic Degradation: Hydrolysis as a Function of pH”.

The hydrolysis behaviour of HPP 12879 -1 was investigated at 50 °C and pH 4, pH 7 and pH 9 over a period of 5 days according to OECD 111 (Preliminary test, Tier 1). The stability was monitored by HPLC analysis with UV-detection.

According to the data of the sponsor and investigated and reported in the material balance (CURRENTA file no.: 2014/0048/03) the test item consists of three different Mannich Bases (2x substituted, 3x substituted and 4x substituted) as major constituents representing a total content of > 99 %.

The developed analytical HPLC-UV method can distinguish between these similar components. Therefore the hydrolytically behaviour of each component could be investigated and monitored separately.

At all three pH-values hydrolysis < 10 % was detected for each of the three components. Thus, HPP 12879 -1 can be considered as hydrolytically stable at 25 °C, too.