Glycine, N-methyl-, N-coco acyl derivs.

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13 September 2017 to 2 October 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

not specified

GLP compliance:

not specified

Type of method:

column elution method

Water solubility:

< 0.5 mg/L

Temp.:

20 °C

pH:

7

Preliminary Test Results

The preliminary test was conducted on 8th September 2017 at a temperature of 20.0 ºC (DT-22). A mass of 0.105 g of pulverised (using an agate pestle and mortar) sample was weighed into a glass-stoppered 10 ml measuring cylinder and water added according to table 1 in methods section. The experiment was continued in a 100 ml measuring cylinder. The mixture was shaken vigorously for 10 minutes after each addition and the following observations were made:

WaterAddition(ml)	Observation
0.1	No evidence of any dissolution, little interaction between water and sample.
0.5	No evidence of any dissolution, little interaction between water and sample.
1.0	No evidence of any dissolution,little interaction between water and sample. Some particulates carried on vessel walls.
2.0	No evidence of any dissolution, little interaction between water and sample. Some particulatesc arried on vessel walls.
10	No evidence of any dissolution.Sample particulates becoming dispersed and giving a cloudy appearance to liquid.Majority of sample particulates accumulating at the surface of the water.
100	No evidence of any dissolution. Sample particulates very finely dispersed in the water with some collecting at the surface.This increased with time but the body of liquid remained cloudy. Observations and agitation of the solution continued for a further 96 hrs without further changes being observed.

There was no evidence of any chemical reaction between the sample and water. Based on the result of the preliminary test, the column elution method was chosen for the definitive test.

Final results

Water solubility is < 0.5 mg/L, based on two separate flow rate results, as shown below.

 

Sample	Loading Concentration	Flow rate	pH	Temp °C	Solubility (Mean of 5 runs)	Std deviation
A	1.06g/l	25ml/hr	7.0	20.0	<0.5mg/l	-
B	1.12g/l	12.5ml/hr	7.0	20.0	<0.5mg/l	-

Temperature Dependence -

Given the behaviour of the material during the study there was no reason to suggest that solubility would be temperature dependent (>3% per °C), however, this was investigated as follows:

A mixture was prepared by adding 0.1g of sample to 100ml of water and shaking vigorously for 24hrs at 20.0 °C. This was heated to 30.0°C and observations made regarding any change in appearance. The mixture was filtered at this temperature and the resulting filtrate cooled back to 20°C and observed to see if any material came out of solution.

No changes were observed on heating this mixture and no material came out of solution after cooling the filtrate.

This procedure was then repeated at 90°C and the same behaviour was observed.

It is concluded that the solubility of this sample is not temperature dependent as defined in the study plan.

 

Chemical Instability -

There was no evidence of chemical instability or reaction with water of this material during the test.

 

Discussion –

The sample is insoluble for all practical purposes.

It should be noted that although a detection limit has been derived from experimentation by the standard methods there was no indicative evidence (e.g. trace peaks below the detection threshold) of the presence of the material in the samples from the experiment.

Samples from the preliminary test and the temperature test were kept until the completion of the main study (over 1 month) and showed no evidence of any chemical of physical change during that time.

Description of key information

Water solubility is < 0.5 mg/L at 20.0 ºC (OECD 105, column elution method).