Amides, from C8-10-fatty acids and tetraethylenepentamine

Hydrolysis

Link to relevant study record(s)

Reference

Endpoint:

hydrolysis

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study performed according to OECD 111 and following the GLP principles

Justification for type of information:

Refer to read-across justification document attached in section 13

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

OECD Guideline 111 (Hydrolysis as a Function of pH)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Radiolabelling:

no

Analytical monitoring:

yes

Details on sampling:

- Sampling intervals for the parent/transformation products: 0.5 hour - 1 day, depending on test temperature
- Sampling method: diluted in magnesiumchloride solution in methanol/2-propanol
- Sampling intervals/times for pH measurements: At the start of the test
- Sampling intervals/times for sterility check: no check, all glassware used was sterilized
- Sample storage conditions before analysis: no storage

Buffers:

- pH:
- Type and final molarity of buffer:
pH 9: Clark and Lubs Borate buffer, 0.1M H3BO3 in 0.1M KCl + 0.1N NaOH
pH 7: Clarck and Lubs Phosphate buffer, 0.1M monopotassium phosphate + 0.1N NaOH
pH 4: Kolthoff and Vleeschhouwer Citrate buffer, 0.1M monopotassium citrate and 0.1N NaOH
- Composition of buffer:
pH 9 buffer: 21.3 mL 0.1N NaOH + 50 mL boric acid to 100 mL
pH 7 buffer: 29.63 0.1N NaOH +50 mL phosphate to 100 mL
pH 4 buffer: 9.0 mL 0.1N NaOH + 50 mL citrate to 100 mL

Details on test conditions:

TEST SYSTEM
- Type, material and volume of test flasks, other equipment used: glass vials of 10 mL volume and capped with teflon crimp caps
- Sterilisation method: autoclave at 121°C for 20 min.
- Lighting: dark
- Measures to exclude oxygen: purge with nitrogen
- If no traps were used, is the test system closed/open: closed
- Is there any indication of the test material adsorbing to the walls of the test apparatus? yes
TEST MEDIUM
- Volume used/treatment: 10 mL
- Kind and purity of water: HPLC water
- Preparation of test medium: pH buffers
- Renewal of test solution: no
- Identity and concentration of co-solvent: n.a.
OTHER TEST CONDITIONS
- Adjustment of pH: if necessary adjustment with 0.1N HCl or 0.1N NaOH

Duration:

24 h

pH:

4

Temp.:

50 °C

Initial conc. measured:

994 µg/L

Duration:

4 h

pH:

7

Temp.:

50 °C

Initial conc. measured:

668 µg/L

Duration:

3 h

pH:

9

Temp.:

50 °C

Initial conc. measured:

863 µg/L

Duration:

144 h

pH:

4

Temp.:

30 °C

Initial conc. measured:

992 µg/L

Duration:

24 h

pH:

7

Temp.:

30 °C

Initial conc. measured:

696 µg/L

Duration:

720 h

pH:

4

Temp.:

20 °C

Initial conc. measured:

963 µg/L

Duration:

24 h

pH:

9

Temp.:

30 °C

Initial conc. measured:

767 µg/L

Duration:

48.5 h

pH:

7

Temp.:

20 °C

Initial conc. measured:

700 µg/L

Duration:

75 h

pH:

9

Temp.:

20 °C

Initial conc. measured:

868 µg/L

Number of replicates:

2

Positive controls:

no

Negative controls:

no

Preliminary study:

pH 4
Measured Conc. Conc. Conc. corrected
Sample Nominal T conc. T=0 T measured Extracted total Hydrolysis Hydrolysis
(µg/L) (hrs) (µg/L) (hrs) (µg/L) (µg/L) (µg/L) (%) (%)
M339 8827 0 5043 120 1,1 14,0 15,1 100,0 99,8
M361 8827 0 5276 120 92,3 2184,2 2276,5 98,2 74,2
M434 8827 0 4984 120 3786,5 59,4 3846,0 24,0 56,4
M452 8827 0 4648 120 4388,3 991,3 5379,6 5,6 39,1
M460 8827 0 5007 120 4123,6 37,8 4161,4 17,6 52,9


pH 7
Measured Conc. Conc. Conc. corrected
Sample Nominal T conc. T=0 T measured extracted total Hydrolysis Hydrolysis
(µg/L) (hrs) (µg/L) (hrs) (µg/L) (µg/L) (µg/L) (%) (%)
M339 8827 0 3820 120 0,0 0,3 0,3 100,0 100,0
M361 8827 0 7613 120 7,9 68,1 76,0 99,9 99,1
M434 8827 0 6294 120 372,4 11,9 384,3 94,1 95,6
M452 8827 0 6161 120 7438,1 3365,7 10803,8 -20,7 -22,4
M460 8827 0 6375 120 684,6 7,6 692,2 89,3 92,2


pH 9
Measured corrected
Sample Nominal T conc. T=0 T Measured Extracted Total Hydrolysis Hydrolysis
(µg/L) (hrs) (µg/L) (hrs) (µg/L) (µg/L) (µg/L) (%) (%)
M339 8827 0 4179 120 0,0 0,1 0,1 100,0 100,0
M361 8827 0 4893 120 29,5 15,0 44,5 99,4 99,5
M434 8827 0 5103 120 11,1 3,2 14,3 99,8 99,8
M452 8827 0 4246 120 60,9 73,8 134,7 98,6 98,5
M460 8827 0 4754 120 94,4 16,3 110,6 98,0 98,7

Test performance:

Hydrolysis of test substance was determined for 5 different molar masses: 339, 361 434, 452 and 460, all being part of the composition of the test substance. Thereby the absorbance of the test substance to the wall of the test vessel was determined and used for correction of the results

Transformation products:

not specified

No.:

#1

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

see picture in Ilustration/graph tab.

pH:

4

Temp.:

50 °C

Hydrolysis rate constant:

0.12 h-1

DT50:

5.7 h

St. dev.:

0.06

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=-0.0522x+2.8059, r2=0.8856; regression equation #2: y=-0.0529x+2.842, r2=0.9341

pH:

4

Temp.:

30 °C

Hydrolysis rate constant:

0.01 h-1

DT50:

47.5 h

St. dev.:

0.89

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=0.0064x+2.9731, r2=0.9907; regression equation #2: y=0.0063x+2.9661, r2=0.9824

pH:

4

Temp.:

20 °C

Hydrolysis rate constant:

0.002 h-1

DT50:

371 h

St. dev.:

17

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: -0.0008x+2.972, r2=0.9495; regression equation #2: -0.0008x+2.9352, r2=0.9206

pH:

7

Temp.:

50 °C

Hydrolysis rate constant:

0.59 h-1

DT50:

1.2 h

St. dev.:

0.03

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation#1: y=0.25x+2.5649, r2=0.8051; regression equation#2: y=0.2606x+2.5967, r2=0.83

pH:

7

Temp.:

30 °C

Hydrolysis rate constant:

0.12 h-1

DT50:

5.6 h

St. dev.:

0.12

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=0.0543x+2.5318, r2=0.8836; regression equation #2: y=0.0526x+2.5172, r2=0.8642

pH:

7

Temp.:

20 °C

Hydrolysis rate constant:

0.04 h-1

DT50:

16.3 h

St. dev.:

0.79

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=-0.0192x+2.5641, r2=0.8679; regression equation #2: y=-0.0179x+2.563, r2=0.8627

pH:

9

Temp.:

30 °C

Hydrolysis rate constant:

0.12 h-1

DT50:

5.6 h

St. dev.:

0.05

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=0.0543x+2.767, r2=0.9545; regression equation #2: y=0.0536x+2.7621, r2=0.9435

pH:

9

Temp.:

50 °C

Hydrolysis rate constant:

1.12 h-1

DT50:

0.6 h

St. dev.:

0.01

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation#1: y=0.4905x+2.8409, r2=0.9761; regression equation#2: y=0.4811x+2.8349, r2=0.9796

pH:

9

Temp.:

20 °C

Hydrolysis rate constant:

0.04 h-1

DT50:

19.5 h

St. dev.:

2.12

Type:

(pseudo-)first order (= half-life)

Remarks on result:

other: regression equation #1: y=-0.0167x+2.8116, r2=0.9378; regression equation #2: y=-0.0144x+2.8122, r2=0.8764

Details on results:

TEST CONDITIONS
- pH, sterility, temperature, and other experimental conditions maintained throughout the study: Yes
- Anomalies or problems encountered (if yes): no

MAJOR TRANSFORMATION PRODUCTS
At pH5:
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
- Range of maximum concentrations in % of the applied amount at end of study period:
on the - the and -th day of incubation, respectively. At the end of the study period, the corresponding concentrations were - and -- % of the applied amount, respectively.

At pH7:
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
- Range of maximum concentrations in % of the applied amount at end of study period:
on the - the and -th day of incubation, respectively. At the end of the study period, the corresponding concentrations were - and -- % of the applied amount, respectively.

At pH9:
- Range of maximum concentrations in % of the applied amount and day(s) of incubation when observed:
- Range of maximum concentrations in % of the applied amount at end of study period:
on the - the and -th day of incubation, respectively. At the end of the study period, the corresponding concentrations were - and -- % of the applied amount, respectively.

MINOR TRANSFORMATION PRODUCTS
Maximum concentrations in % of the applied amount
- at pH5:
- at pH7:
- at pH9:

MINERALISATION (distinguish between dark and irradiated samples)
- % of applied radioactivity present as CO2 at end of study:



PATHWAYS OF HYDROLYSIS
- Description of pathwayS:
- Figures of chemical structures attached: Yes

SUPPLEMENTARY EXPERIMENT (if any): RESULTS:

Test temperature: 50°C

			Kobs	t1/2	AVG t1/2	St.dev. t1/2
		slope	(hrs^-1)	(hrs)	(hrs)	(hrs)
pH 4	series 1	-0,0522	0,12	5,77	5,7	0,06
	series 2	-0,0529	0,12	5,69
pH 7	series 1	-0,2500	0,58	1,20	1,2	0,03
	series 2	-0,2606	0,60	1,16
pH 9	series 1	-0,4905	1,13	0,61	0,6	0,01
	series 2	-0,4811	1,11	0,63

Test temperature: 30°C

			Kobs	t1/2	AVG t1/2	St.dev. t1/2
		slope	(hrs^-1)	(hrs)	(hrs)	(hrs)
pH 4	series 1	-0.0064	0.01	46.89	47.5	0.89
	series 2	-0.0063	0.01	48.14
pH 7	series 1	-0.0543	0.12	5.55	5.6	0.12
	series 2	-0.0526	0.12	5.72
pH 9	series 1	-0.0543	0.12	5.55	5.6	0.05
	series 2	-0.0536	0.12	5.62

Test temperature 20°C

			Kobs	t1/2	AVG t1/2	St.dev. t1/2
		slope	(hrs^-1)	(hrs)	(hrs)	(hrs)
pH 4	series 1	-0.0008	0.002	358.89	371	17.0
	series 2	-0.0008	0.002	382.87
pH 7	series 1	-0.0192	0.04	15.70	16.3	0.79
	series 2	-0.0179	0.04	16.82
pH 9	series 1	-0.0167	0.04	17.97	19.5	2.12
	series 2	-0.0144	0.03	20.97

Validity criteria fulfilled:

yes

Conclusions:

The M339 component, representing the most condensed and main fraction of the test substance, showed hydrolysis at all pH values and at all temperatures, hydrolysis rate increased at higher temperatures and at higher pH values. The hydrolysis rate observed at a pH value of 7 and 9 was more or less equal.

Executive summary:

The rate of hydrolysis of Tall oil, reaction products with tetraethylenepentamine was determined at 20°C, 30°C and 50°C and at the pH values of 4, 7 and 9 in agreement with OECD guideline 111.For the most condensed fraction, TEPA tall oil diimidazoline with molar mass M339, hydrolysis was observed at all tested pH values and temperatures. ForTEPA tall oil diimidazolinethe half life(t_½) at a temperature of 25°C could be calculated for all tested pH values using the Arrhenius relationship.

At pH 4the half-lives (t_½) for the M339 component of the test item at a temperature of 20, 30 and 50°C were observed to be 371 hours, 47.5 hours and 5.7 hours respectively. Using the Arrhenius relationship a t_½at 25°C was calculated of 136 hours.

At pH 7 the half-lives (t_½) for the M339 component of the test item at a temperature of 20, 30 and 50°C were observed to be 16.3 hours, 5.6 hours and 1.2 hours respectively. Using the Arrhenius relationship a t_½at 25°C was calculated of 9.6 hours.

At pH 9 the half-lives (t_½) for the M339 component of the test item at a temperature of 20, 30 and 50°C were observed to be 19.5 hours, 5.6 hours and 0.6 hours respectively. Using the Arrhenius relationship a t_½at 25°C was calculated of 10.3 hours.

For two intermediate hydrolysis products of the test item the half-lives have been determined. Using specified time periods for the half life determination of TEPA tall oil monoimidazoline (M434) and TEPA tall oil monoamide (M452) the following results were calculated.

		M434		M452
pH	Temp.	t½	Time period	t½	Time period
	°C		(hr.)		(hr.)
4	20	156 days	162.5-720	79 days	262-720
	30	39 days	6-144	44 days	6-144
	50	54.0 hr.	2-24	66.6 hr.	2.24
7	20	158 hr.	1-48.5	28 days	1-48.5
	30	Infinite	2-24	Infinite	2-24
	50	13.5 hr.	0.5-4	29.1 hr.	0.5-4
9	20	141 hr.	7-75	7487 days	7-75
	30	10.7 hr.	2-24	52.4 hr.	2-24
	50	5.8 hr.	0.5-3	Infinite	0.5-3

Description of key information

The half-life of 28 d at 20 °C based on the half-life of the third hydrolysis reaction of the TEPA based imidazoline.

The TEPA based imidazoline consists of a large fraction of di-imidazoline.

The first half life of 16.3 h at 20°C is linked to the hydrolysis of the first imidazoline ring

The second half-life of 158 h at 20°C is linked to the hydrolysis of the first amide bond detaching one alkyl chain

The third half-life of 28 d at 20°C is linked to the hydrolysis of the second imidazoline ring of the TEPA based di-imidazoline.

Data used for read-across from test material 68555 -22 -6 to 85029 -55 -6

Key value for chemical safety assessment

Half-life for hydrolysis:

28 d

at the temperature of:

20 °C

Additional information

The imidazoline ring(s) of Amidoamines/Imidazolines probably undergo(es) hydrolysis under alkaline, neutral and acidic conditions (Akzo Nobel 2010; Watts, 1990).

A hydrolysis rate of an imidazoline has been measured using a Tetraethylene pentamine based imidazoline. For this imidazoline a number of hydrolysis rates were measured as the imidazolines are in general a mixture of imidazolines and amides (non ring closed imidazolines). The tetraethylene pentamine based imidazoline contains di-imidazolines. The shortest half-lifes of 16.3 h at 20°C were found under neutral conditions for the hydrolysis of the first imidazoline ring of the di-imidazoline. For the next step in the hydrolysis degradation route i.e. the hydrolysis of the amide by which the alkyl chain is detached a half-life of 158 h at 20°C was derived. This second reaction step is considered to be representative of the hydrolysis of the DETA based imidazoline as this is also a monoimidazoline. The next step in hydrolysis degradation route would be the opening of the second imidazoline and here a half life of 28 days at 20 °C is derived. The order in which these last two hydrolysis reactions take place is not completely clear.

The amidoamines formed are under alkaline conditions hydrolysed further to ethyleneamines.