N-(3-aminopropyl)-N-dodecylpropane-1,3-diamine

Hydrolysis

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From February 21, 2002 to March 27, 2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Cited as Directive 84/449/EEC, C.10

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

Sterile test buffer solutions of pH 4.0, 7.0 and 9.0 were prepared and purged with nitrogen. The bottles were tightly closed and placed in a thermostatically controlled waterbath at 50 ± 0.5°C in the dark. When the buffer solutions had equilibrated with the temperature of the waterbath the test substance was added and the pH was checked.
The concentration of the test substance in the buffer solutions did not exceed 0.01 M or its half-saturation concentration in water. A final concentration of about 300 mg/L was obtained by adding 5 mL stock solution of test substance to 1000 mL of test buffer solution for each pH.
At each sampling time about 25 mL of sample was taken and transferred into a 30 mL sample vial. To the samples of buffer pH 4 400 µL of 5 M NaOH was added, to the samples of buffer pH 7 250 µL of 5M NaOH was added and to the samples of buffer pH 9 200 µL of 5 M NaOH was added. The samples were stored in refrigerator until they were subjected to the analytical procedure. The temperature of the thermostatic waterbath was checked at least at the start and end of the tests and at each sampling time.
The test at pH 4 was repeated using a buffer, which did not interact with the test substance. During the first test at pH 4 a precipitate was detected in the test buffer. During this test two samples of 25 mL were taken at the beginning of the test and two at the end of the test. At each sample 1 mL of 5M NaOH was added. The samples were stored in refrigerator until they were subjected to the analytical procedure. The temperature of the thermostatic waterbath was checked at least at the start and end of the tests and at each sampling time.

Buffers:

- pH 4: Composition of buffer: 50 mL 0.5M Boric acid and 50 mL 0.5M Potassium chloride diluted to 500 mL with deionized water
- pH 7: Composition of buffer: 50 mL 0.5M Potassium dihydrogen phosphate and 2.96 mL 5 M NaOH and diluted to 500 mL with deionized water
- PH 9: Composition of buffer: 50 mL 0.5M Boric acid and 50 mL 0.5M Potassium chloride and 2.16 mL 5 M NaOH and diluted to 500 mL with deionized water

pH of buffer solutions were measured at 50 °C using a pH meter and adjusted with 0.5 M HCl or 0.5 M NaOH.

All chemicals used were of reagent grade. Only the potassium chloride was from Baker grade quality (assay 99.0 – 100.5%) and sodium hydroxide was from Fluka, purum p.a. quality (≥ 97%).

Estimation method (if used):

Not applicable

Details on test conditions:

TEST TYPE: EEC Directive 92/69/EEC C.7 "Degradation: Abiotic Degradation: Hydrolysis as a Function of pH".
- Test medium: Deionized water
- Test system: The study was conducted in air-tight glass vessels. Thermostatic water bath with lid so that the vessels are placed in the dark,
calibrated thermometer, pH meter (Consort P501 Salm en Kipp bv, Breukelen, The Netherlands).
- Concentration of test substance: 300 mg a.i. /L

DURATION: 5 days (Tier 1)

REFERENCE SUBSTANCE: No

CONTROLS: None

Analytical determinations are done by gas chromatography.

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

ca. 271.1 other: mg/g

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

ca. 312.1 other: mg/g

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

ca. 285.6 other: mg/g

Positive controls:

no

Negative controls:

no

Preliminary study:

preliminary test was performed to find a suitable buffer system causing no precipitation.

Transformation products:

no

Key result

pH:

4

Temp.:

50 °C

DT50:

> 1 yr

Key result

pH:

7

Temp.:

50 °C

DT50:

> 1 yr

Key result

pH:

9

Temp.:

50 °C

DT50:

> 1 yr

Details on results:

The hydrolytic stability was determined at pH 4, 7 and 9. The results of the first preliminary tests at pH 4, 7 and 9 and the results of the second preliminary test at pH 4 are presented in Tables 1 to 4. A second test at pH 4 was performed because a precipitate was formed during the test with the test buffer at pH 4. Due to this precipitate a decrease of 70% of Dodecyl dipropylene triamine was detected. The second preliminary test at pH 4 using a buffer, which did not interact with the test substance showed no significant decrease of Dodecyl dipropylene triamine.
The peak of Dodecyl dipropylene triamine in the GC chromatogram found at about 6.2 minutes was used for interpretation of the hydrolysis rate. The decrease of the area of this peak was less than 4% after five days at all three pH values tested indicating that no hydrolyses occurred. Therefore, it can be concluded that Dodecyl dipropylene triamine is hydrolytically stable with a half-life equal to or greater than a year at pH 4, 7 and 9 at 25°C.

According to the results of the preliminary tests no further tests were necessary.

Results with reference substance:

-

After 5 d at 50°C less than 10% decrease in test substance concentration was measured at all three pH values. It is therefore concluded that the test substance is hydrolytically stable with a half-life equal to or greater than one year at pH 4, 7 and 9 at ambient temperatures. During the first test with the test buffer at pH 4 a precipitate was formed. Due to this precipitate a decrease of 70% of dodecyl dipropylene triamine was detected. Therefore, a second test at pH 4 was performed using a buffer, which did not interact with the test substance. DT50 = equal to or greater than one year.

Table 1

Results of the first preliminary test; concentration of Dodecyl dipropylene triamine with the

standard deviation of the duplo analysis and the decrease of the test substance during the test at pH 4 and 50°C.

 

Sampling time (minutes)	Average Dodecyl dipropylene triamine concentration	STDEV	Decrease
	(mg/g)		(%)
5	249.2	3.2
7252	74.1	0.4	70.3 (precipitation)

 

Table 2

Results of the second preliminary test; concentration of Dodecyl dipropylene triamine with the standard

deviation of the duplo analysis and the decrease of the test substance during the test at pH 4 and 50°C.

 

Sampling time (minutes)	Average Dodecyl dipropylene triamine concentration	STDEV	Decrease
	(mg/g)		(%)
5	271.1	1.8
7230	279.0	1.4	-2.9

 

 

Table 3

Results of the preliminary test; concentration of Dodecyl dipropylene triamine with the

standard deviation of the duplo analysis and the decrease of the test substance during the test at pH 7 and 50°C.

 

Sampling time (minutes)	Average Dodecyl dipropylene triamine concentration	STDEV	Decrease
	(mg/g)		(%)
10	312.1	2.6
7255	312.7	2.8	-0.2

 

 

Table 4

Results of the preliminary test; concentration of Dodecyl dipropylene triamine

with the standard deviation of the duplo analysis and the decrease of the test substance during the test at pH 9 and 50°C.

 

Sampling time (minutes)	Average Dodecyl dipropylene triamine concentration	STDEV	Decrease
	(mg/g)		(%)
5	285.6	1.5
7223	274.4	0	3.9

 

 

Table 5

pH and temperature ranges during hydrolysis tests.

 

Nominal pH	Nominal temp. (°C)	Initial pH	Final pH	Measured temp.range (°C)
4 (first test)	49.9	4.03	3.97	49.8 – 49.9
4 (second test)	49.9	4.02	3.97	49.8 – 50.0
7	49.9	7.04	6.99	49.8 – 49.9
9	49.9	9.04	9.05	49.8 – 49.9

 

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the test substance was considered to be hydrolytically stable with a half-life (DT50) equal to or greater than one year at pH 4, 7 and 9 at 50°C.

Executive summary:

A study was conducted to determine the hydrolysis of the test substance according to EU Method C7, in compliance with GLP. Approximately 300 mg/L of the test substance was placed in air-tight glass vessels in the dark for 5 d and the hydrolytic stability was determined at pH 4, 7 and 9. Less than 10% disappearance was observed at all pH conditions after 5 d at 50°C. Under the study conditions, the test substance was considered to be hydrolytically stable with a half-life (DT50) equal to or greater than one year at pH 4, 7 and 9 at 50°C (van Haperen, 2002).

Reference 2

Endpoint:

hydrolysis

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

1996

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Radiolabelling:

no

Analytical monitoring:

yes

Duration:

5 d

pH:

4

Temp.:

50 °C

Initial conc. measured:

200 other: µg/mL

Duration:

5 d

pH:

7

Temp.:

50 °C

Initial conc. measured:

200 other: µg/mL

Duration:

5 d

pH:

9

Temp.:

50 °C

Initial conc. measured:

200 other: µg/mL

Transformation products:

no

Key result

pH:

4

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

7

Temp.:

25 °C

DT50:

> 1 yr

Key result

pH:

9

Temp.:

25 °C

DT50:

> 1 yr

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the test substance did not hydrolyse, therefore any toxicological or ecotoxicological effects of the test substance were not a consequence of hydrolytic degradation products.

Executive summary:

A study was conducted to determine the hydrolysis rate of the test substance according to EU Method C.7, in compliance with GLP. Degradation was measured at pH 4, 7 and 9. The test substance concentration and temperature were stable: 200 µg/mL and 50°C, respectively. Under the study conditions, the substance did not hydrolyse, with an estimated DT50 of more than one year (Howes, 1996).

Key value for chemical safety assessment

Half-life for hydrolysis:

1 yr

at the temperature of:

50 °C

Additional information

A study was conducted to determine the hydrolysis of the test substance according to EU Method C7, in compliance with GLP. Approximately 300 mg/L of the test substance was placed in air-tight glass vessels in the dark for 5 d and the hydrolytic stability was determined at pH 4, 7 and 9. Less than 10% disappearance was observed at all pH conditions after 5 d at 50°C. Under the study conditions, the test substance was considered to be hydrolytically stable with a half-life (DT50) equal to or greater than one year at pH 4, 7 and 9 at 50°C (van Haperen, 2002).

A study was conducted to determine the hydrolysis rate of the test substance according to EU Method C.7, in compliance with GLP. Degradation was measured at pH 4, 7 and 9. The test substance concentration and temperature were stable: 200 µg/mL and 50°C, respectively. Under the study conditions, the substance did not hydrolyse, with an estimated DT50 of more than one year (Howes, 1996).