N,N'-ethane-1,2-diylbis(12-hydroxyoctadecan-1-amide)

Water solubility

Administrative data

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

13. Mar. 2019 - 27.Jun. 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Test material

Test material information

Constituent 1

Reference substance name:

N,N'-ethane-1,2-diylbis(12-hydroxyoctadecan-1-amide)

EC Number:

204-613-6

EC Name:

N,N'-ethane-1,2-diylbis(12-hydroxyoctadecan-1-amide)

Cas Number:

123-26-2

Molecular formula:

C38H76N2O4

IUPAC Name:

12-hydroxy-N-[2-(12-hydroxyoctadecanamido)ethyl]octadecanamide

Test material form:

solid

Results and discussion

Water solubility

Key result

Water solubility:

>= 0.605 - <= 2.281 mg/L

Conc. based on:

test mat. (dissolved fraction)

Incubation duration:

7 d

Temp.:

20 °C

pH:

>= 4.78 - <= 4.98

Remarks on result:

other: A dependency of the test item solubility on the nominal concentration was observed: The more test item was added, the less was dissolved in water.

Applicant's summary and conclusion

Conclusions:

A dependency of the test item solubility on the nominal concentration was observed: The more test item was added, the less was dissolved in water. A reason for this behaviour could possibly be aggregation of the hydrophobic test item particles in water which increases with more test item present. As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test item in water can be stated. No dependency on pH was observed. The solubility range for the tested nominal concentration range of 104 – 1001 mg/L is 0.605 – 2.281 mg/L. All validity criterias are fulfilled. The study can be considered as valid.

Executive summary:

The solubility of the test item Bisamid in water was determined by measurement of the DOC (dissolved organic carbon) concentration in the filtrated test solutions using a TOC analyser. In the preliminary test, flasks with the nominal concentrations 10 mg/L and 1000 mg/L were shaken at room temperature for 66.2 h and measured for the DOC concentration af-ter membrane filtration (0.45 μm, PTFE). After this time, undissolved particles were ob-served in both solutions. The measured DOC concentration was below the LOQ (limit of quantification) of the device (0.3 mg/L) for the nominal concentration 10 mg/L. For the nominal concentration 1000 mg/L, the measured DOC concentration was determined as 2.944 mg/L. As a dependency of the water solubility on the amount of the test item added was observed, different loading rates were used in the main test. According to the guideline the slowly shaking flask method was used for the determination of the solubility of the test item in water. In the main test, six different loading rates of the test item were chosen to study the effect of the loading rate on the measured water solubility: 100, 300, 500, 600, 800 and 1000 mg/L. Three flasks (1A – 1C) with the same loading rate (500 mg/L) were used during equilibration. Seven vessels (flasks blank, 1C (for the sampling point 72 h) and 2 – 6) were set onto the shaking apparatus immediately and shaking at 100 rpm was started. After 24 ± 2 h, flask 1B (for the sampling point 48 h) and after 48 ± 2 h, flask 1A (for the sampling point 24 h) were set onto the shaker and all flasks were shaken for further 24 ± 2 h at room temperature. Then, flasks 1A – 1C were removed from the shaker, tempered at 20.0 ± 0.5 °C, samples were taken, membrane filtered and analysed for the DOC concentration using a TOC analyser. Due to an upward tendency of the test item concentration, the test was prolonged and flasks 1A – 1C were measured on days 4 – 7. Because of a difference of less than 15 % in the concentrations on days 6 and 7 and no upward tendency in the last three values, the test was finished. The final measurement was performed as determination from flasks 2 – 6. The DOC concentration was measured using the TOC analyser. The pH value in the flasks 2 – 6 lay in the range of 4.78 – 4.98. No Tyndall effect (i.e. a laser beam was not scattered when transmitted through the liquid) could be observed indicating that no colloidally dispersed particles were present. A dependency of the test item solubility on the nominal concentration was observed: The more test item was added, the less was dissolved in water. A reason for this behaviour could possibly be aggregation of the hydrophobic test item particles in water which increases with more test item present. As the solubility was dependent on the nominal concentration, no exact value for the solubility of the test item in water can be stated.

Therefore, the concentration of the test item in water was stated as

0.605 – 2.281 mg/L at 20.0 °C

0.605 – 2.281 * 10-3 kg/m3 (SI units)

for a nominal concentration range of the test item in water of 104 – 1001 mg/L.