Fatty acids, C16-18, reaction products with ethanolamine

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes

Type of method:

column elution method

Key result

Water solubility:

< 5 mg/L

Temp.:

20 °C

pH:

ca. 6

Details on results:

Column 1
A column was prepared in a narrow bore glass pipette. A plug of glass wool (0.5ml) was placed at the bottom of the column followed by a base of clean dry sand. The exit tubing for the column was attached and fixed in a vertical position to prevent eluent outflow. The exit tubing for the column was attached and fixed in a vertical position to prevent eluent outflow. The tubing used in the column was clean and made of a good grade PET material.
A 10 g/l solution of sample was prepared weighing out 1.0018g of sample into a 100ml volumetric flask in DCM. 0.6054 g of clean dry sand was placed in a 100ml round bottomed flask and 50ml of 10g/l solution of sample was added to the sand. The flask was swirled to mix up the content and waited three days until all solvent had evaporated. After equilibration 0.927g of the sand and water was added to the column. The flask and funnel were rinsed with more water and then a further bed of clean sand was added with a final plug of glass wool on top. Tubing was attached to the top of the column and the system attached through more inert tubing to a peristaltic membrane pump to allow circulation of the eluent, the column was left to equilibrate at 20±1°C. After equilibration in order to get rid of all the bubbles, the pump was started and adjusted to give a flow rate of 25ml/hr. Subsequently the return/sampling tube was redirected to the reservoir to allow recirculation of the eluent. After 24 hours the efficiency of the set-up and also the presence of undissolved particles was checked. The system did not show any particles undissolved and therefore was considered
acceptable. After the first check a Sample of 1.5ml was then taken at 24 hour intervals and then transferred into 2ml GC vials and refrigerated prior to extraction and analysis (1A-10A). The pH of samples was measured (6.0) and the temperature was recorded (19.2-20.6ºC) at each sampling.

Column 2
A column was prepared in a narrow bore glass pipette. A plug of glass wool (0.5ml) was placed at the bottom of the column followed by a base of clean dry sand. The exit tubing for the column was attached and fixed in a vertical position to prevent eluent outflow. The exit tubing for the column was attached and fixed in a vertical position to prevent eluent outflow. The tubing used in the column was clean and made of a good grade PET material. A 10 g/l solution of Sample was prepared weighing out 1.0018g of sample into a 100ml volumetric flask in DCM. 0.6085 g of clean dry sand was placed in a 100ml round bottomed flask and 50ml of 10g/l solution of sample was added to the sand. The flask was swirled to mix up the content and waited three days until all solvent had evaporated. After equilibration 0.9527 g of the sand and water was added to the column. The flask and funnel were rinsed with more water and then a further bed of clean sand was added with a final plug of glass wool on top. Tubing was attached to the top of the column and the system attached through more inert tubing to a peristaltic membrane pump to allow circulation of the eluent, the column was left to equilibrate at 20°C±1 . After equilibration in order to get rid of all the bubbles, the pump was started and adjusted to give a flow rate of 12.5 ml/hr. Subsequently the return/sampling tube was redirected to the reservoir to allow recirculation of the eluent. After 24 hours the efficiency of the set-up and also the presence of undissolved particles was checked. The system did not show any particles undissolved and therefore was considered acceptable.
After the first check a Sample of 1.5ml was then taken at 24 hour intervals and then transferred into 2ml GC vials and refrigerated prior to extraction and analysis (1B-10B). The pH of samples was measured (6.0) and the temperature was recorded (19.2-20.6ºC) at each sampling.

The protocol states that for each run, the mean value and standard deviation from at least five consecutive samples taken from the saturation plateau should be calculated. The mean values obtained from two tests with different flows should not differ by more than 30%.

The samples 2, 3, 4, 5 and 6 from Column 1 were considered for the calculations of the average and the standard deviation.

The samples 2, 3, 4, 5 and 6 from Column 2 were considered for the calculations of the average and the standard deviation.

Also, the average value of the temperatures recorded at sampling 2,3,4,5 and 6 were 19.7°C for the minimum and 20.0°C for the maximum, therefore the final solubility reported at 20± 0.4 °C.

No peak was detected in these samples and therefore the sample solubility in H2O

was found to be < 5mg/l(LOD) at 20 ± 0.4 °C using the column elution method.

The difference between the mean values from the Column 1 and the Column 2 are within ≤30%.

There was no evidence of chemical instability seen during this study.

Conclusions:

No peak was detected in these samples and therefore the sample solubility in water was found to be < 5mg/L (LOD) at 20 ± 0.4 °C using the column elution method.

Executive summary:

The water solubility of fatty acids, C16 -18, reaction with ethanolamine, was evaluated in accordance with the OECD Testing Guideline 105. Following a preliminary test, a column elution method was performed and two columns were used, with 10 samples each.

The protocol states that for each run, the mean value and standard deviation from at least five consecutive samples taken from the saturation plateau should be calculated. The mean values obtained from two tests with different flows should not differ by more than 30%.

The samples 2, 3, 4, 5 and 6 from Column 1 were considered for the calculations of the average and the standard deviation.

The samples 2, 3, 4, 5 and 6 from Column 2 were considered for the calculations of the average and the standard deviation.

Also, the average value of the temperatures recorded at sampling 2,3,4,5 and 6 were 19.7°C for the minimum and 20.0°C for the maximum, therefore the final solubility reported at 20± 0.4 °C.

No peak was detected in these samples and therefore the sample solubility in H2O was found to be < 5mg/L (LOD) at 20 ± 0.4 °C using the column elution method.

The difference between the mean values from the Column 1 and the Column 2 are within ≤30%.

There was no evidence of chemical instability seen during this study.

Description of key information

The water solubility of fatty acids, C16 -18, reaction with ethanolamine, was evaluated in accordance with the OECD Testing Guideline 105. Following a preliminary test, a column elution method was performed and two columns were used, with 10 samples each.

The protocol states that for each run, the mean value and standard deviation from at least five consecutive samples taken from the saturation plateau should be calculated. The mean values obtained from two tests with different flows should not differ by more than 30%.

The samples 2, 3, 4, 5 and 6 from Column 1 were considered for the calculations of the average and the standard deviation.

The samples 2, 3, 4, 5 and 6 from Column 2 were considered for the calculations of the average and the standard deviation.

Also, the average value of the temperatures recorded at sampling 2,3,4,5 and 6 were 19.7°C for the minimum and 20.0°C for the maximum, therefore the final solubility reported at 20± 0.4 °C.

No peak was detected in these samples and therefore the sample solubility in H2O was found to be < 5mg/L (LOD) at 20 ± 0.4 °C using the column elution method.

The difference between the mean values from the Column 1 and the Column 2 are within ≤30%.

There was no evidence of chemical instability seen during this study.

Key value for chemical safety assessment

Water solubility:

5 mg/L

at the temperature of:

20 °C