Fatty acids, linseed-oil, reaction products with 2-amino-2-(hydroxymethyl)-1,3-propanediol and formaldehyde

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-10-19 to 2017-02-28

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Key result

Water solubility:

28.8 - 38.7 mg/L

Temp.:

20 °C

Remarks on result:

other: See remarks

Remarks:

As solubility was dependent on nominal concentration, no exact value for the solubility of the test item in water can be stated. The solubility range for the tested nominal concentration 1002 to 10002 mg/L is 28.8 to 38.7 mg/L at 20.0 ± 0.5°C. The mean value was stated as 33.3 ± 4.3 mg/L. Dependency of pH value on amount of the test item (nominal load) was not perceived.

Details on results:

As solubility of the test item in water was dependent on nominal concentration, the solubility range was stated
The higher the nominal load of the test item the lower is the dissolved part
Dependency of pH value on amount of the test item (nominal load) was not perceived

Dependency of solubility on amount of the test item (nominal load) was perceived

Table 1: Measurements used for calculation of solubility
Flask	Measurement conc. test item [mg/L]	Nominal conc. test item [mg/L]	Dissolved part [%]	pH value
2	28.82	1002	2.88	4.37
3	29.00	3009	0.96	4.63
4	34.11	6005	0.57	4.70
5	35.84	8002	0.45	4.73
6	38.66	10002	0.39	4.73

 

In a 10 mL centrifuge vial, 102.5 mg of the test item was weighed. In a stepwise procedure, increasing volumes of water were added, namely 0.1 mL, 0.5 mL, 1.0 mL, 2 mL and 10 mL (final volumes). After each addition of an amount of water, the mixture was shaken for 10 minutes and was visually checked for any undissolved parts of the sample. As undissolved particles were visible after addition of 10 mL H₂O, the experiment was continued with 100.2 mg test item in 100 mL water in a Schott flask (concentration 1 g/L), but still no dissolution was observed, even after 10 minutes shaking.

Table 2: Preliminary study
Added volume [mL]	0.1	0.5	1	2	10	100
Approx. solubility [g/L]	> 1000	1000-200	200-100	100-50	50-10	10-1
Dissolution	No	No	No	No	No	No

 

In order to determine the dependency of the water solubility on the amount of the test item added, six different loading rates were chosen in the range 1000 to 10000 mg/L (in the guideline the range 100 to 1000 mg/L is proposed). Higher range was used in this case because during the preliminary test, the measured concentration of DOC in 1 g/L of test item solution was in low calibration range (< 15 mg/L). Flask 1A was intended for the sampling point 24h, flask 1B for the sampling point 48h and flask 1C for the sampling points 72h. The following amounts were added to the flasks.

Table 3: Content of flasks
Flask no.	Amount test item in mg	Volume H2O in mL	Resulting nominal concentration in mg/L
1A	500.3	100	5003
1B	500.7	100	5007
1C	500.4	100	5004
2	100.2	100	1002
3	300.9	100	3009
4	600.5	100	6005
5	800.2	100	8002
6	1000.2	100	10002

 

The data acquired during equilibration time (flask 1A-C, days 1-8) is presented in the following table:

Table 4: Data acquired during equilibration
Day	Temperature [°C]	pH*	Conc. DOC [mg/L]	Conc. test item [mg/L]	Difference to previous sample
1	20.0	5-6	20.34	26.20	-
2	20.0	5-6	20.67	26.63	+ 1.6%
3	20.0	5-6	21.81	28.09	+ 5.5%
6	20.0	5-6	51.14	65.88	+ 134.5%
7	20.0	5-6	39.72	51.17	- 22.3%
8	20.0	5-6	39.62	51.04	- 0.3%

*measured via pH paper

The measurement value in the blank flask was below the LOQ of TC (< 1.10 mg/L). After the analysis of the sample of day 8, the plateau was considered as reached.

Table 5: Values measured at plateau in flasks 2-6
Flask	pH*	Conc. DOC [mg/L]	Conc. test item [mg/L]
2	4.37	22.37	28.82
3	4.63	22.51	29.00
4	4.70	26.48	34.11
5	4.73	27.82	35.84
6	4.73	30.01	38.66

*measured via calibrated pH meter

The measurements on day 8 (flasks 2-6) were included in the calculation of the solubility of the test item in water. Flasks 1A-C were only used during equilibration.

Table 6: Measurements used for calculation of solubiltiy
Flask	Measured conc. test item [mg/L]	Nominal conc. test item [mg/L]	Dissolved part [%]	pH value
2	28.82	1002	2.88	4.37
3	29.00	3009	0.96	4.63
4	34.11	6005	0.57	4.70
5	35.84	8002	0.45	4.73
6	38.66	10002	0.39	4.73

Conclusions:

Interpretation of results: Slightly soluble (0.1-100 mg/L)
In conclusion, the water solubility of the test item VOELOFA Monomer was determined by the "flask method". The results demonstrate that the solubility of the test item in water was dependent on the nominal concentration (the higher the nominal load of the test item, the lower the dissolved part). The solubility range for the tested nominal concentration 1002 -10002 mg/L was stated as 28.8 - 38.7 mg/L at 20 °C.

Executive summary:

In this study the water solubility of VOELOFA Monomer was determined in accordance to OECD guideline 105. The solubility of the test item VOELOFA Monomer in water was determined by measurement of DOC concentration in the filtrated test solutions using TOC analyser. The main test was performed with six different loading rates. Dependency of solubility on the amount of test item (nominal load) was perceived. The solubility range for the tested nominal concentration 1002 -10002 mg/L was stated as 28.8 -38.7 mg/L at 20 °C. Thus, the mean value can be stated as 33.3 ± 4.3 mg/L. As dissolved carbon as a sum parameter for dissolved test item was measured, this study cannot distinguish between water solubility and hydrolysis of the test item.

Description of key information

In this study the water solubility of VOELOFA Monomer was determined in accordance to OECD guideline 105. The solubility of the test item VOELOFA Monomer in water was determined by measurement of DOC concentration in the filtrated test solutions using TOC analyser. The main test was performed with six different loading rates. Dependency of solubility on the amount of test item (nominal load) was perceived. The solubility range for the tested nominal concentration 1002 -10002 mg/L was stated as 28.8 - 38.7 mg/L at 20 °C. Thus, the mean value can be stated as 33.3 ± 4.3 mg/L. Because dissolved carbon as a sum parameter for dissolved test item was measured, this study cannot distinguish between water solubility and hydrolysis of the test item.

Key value for chemical safety assessment

Water solubility:

38.7 mg/L

at the temperature of:

20 °C