2,6-dibromo-4-cyanophenyl heptanoate

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15-29 May 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes

Type of method:

column elution method

Water solubility:

0.16 mg/L

Temp.:

20 °C

pH:

6.9

Preliminary test:

Even in a total volume of 1000 mL added to ca. 10 mg of the test item, still undissolved particles could be observed after 96 h. This result indicated that the water solubility of the test item was probably below 10 mg/L. Therefore the column elution method was chosen for the study.

Preparation of the column and sample preparations for runs 1, 2, 3:

The following amounts of the test item were weighed into a round bottom flask: RUN 1 = 42.0 mg / RUN 2 = 53.8 mg / RUN 3 = 51.3 mg. Approximately 2.5 g of glass beads (2 mm in diameter) were added and then the test item was dissolved in some drops of acetonitrile. Then the solvent was removed using a nitrogen stream while the flask was shaken carefully. The dry coated glass beads were placed into the distilled water containing column of the test apparatus (column temperature: 20°C, bidistilled water at room temperature: measured pH = 6.9). After a minimum swelling time of approximately 2 h, the pump was started. The fractions were collected using test tubes.

To ensure the stability of the fractions during the sampling period all test tubes provided for the HPLC measurement were prepared with 50 µL of a 0.1 M H3PO4 solution prior to the start. The test tubes for pH measurement were left blank.

The volume of the collected aqueous fractions was estimated and the pH at room temperature was measured in each fifth test tube. 10 mL of each fraction were added with 2 mL of acetonitrile to a total volume of 12 mL (5 mL per fraction + 1 mL acetonitrile for RUN 3) and then analysed by HPLC. The concentration of the test item in the individual fractions was determined by HPLC.

Individual conditions and results:

Run (flow rate)	Rotation period of the fraction collector	Flow rate, measured	Average fraction volume (calc.)	Duration of sampling	Average solubility (mg/L) (RSD)	Remarks
Run 1 (25 mL/h)	35 min per fraction	25.3 mL/h	14.8 mL	Approx. 14.6 h	0.154 (5.8%)	Fractions 6 to 9 and 11 to 14 of 25 in total. The solubility varied between 0.140 and 0.164 mg/L.
Run 2 (12.5 mL/h)	66 min per fraction	12.7 mL/h	14.0 mL	Approx. 22 h	0.167 (2.4%)	Fractions 6 to 9 and 11 of 20 in total. The solubility varied between 0.163 and 0.174 mg/L.
Run 3 (6.25 mL/h)	99 min per fraction	6.24 mL/h	10.3 mL	Approx. 33 h	0.148 (2.7%)	Fractions 7 to 9, 11 to 14 and 16 to 17 of 20 in total. The solubility varied between 0.142 and 0.154 mg/L.

Kryostat error began with fraction 12 of Run 2. Therefore temperature control was not ensured for samples beginning with fraction 12. Room temperature for those fractions was approximately 26 °C. In consequence Run 3 was performed with a flow rate of 6.25 mL/h.

Coating check

At the end of each column elution experiment it was confirmed that there was still enough test item on the elution columns. Therefore the residual test item was eluted completely from the column into a 100 mL volumetric flask using acetonitrile. An aliquot (1.0 mL) of this solution was filled up with the HPLC eluent to a volume of 50 mL for Run 1 (100 mL for Run 2 and Run 3) and analyzed by HPLC. The results below show that there was a sufficient amount of test item on the column in order to ensure the saturation of the eluted aqueous phase.

Sample	Amount used for coating (mg)	Concentrate of eluate solution (mg/L)	Amount of residual test item found (mg)	Mean amount needed for the saturation of one fraction (µg)	Theoretical number of fractions to be saturated by residual amount
Run 1	42.0	133.2	13.3	2.28	5833
Run 2	53.8	329.9	33.0	2.12	15566
Run 3	51.3	262.5	26.3	0.92	28587

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

23 Dec 1992 - 22 Apr 1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Deviations:

yes

Remarks:

no preliminary testing

GLP compliance:

yes

Type of method:

column elution method

Water solubility:

0.17 mg/L

Temp.:

20 °C

pH:

5

Remarks on result:

other: temperature reported as ambient (20-25 °C)

Water solubility:

0.08 mg/L

Temp.:

20 °C

pH:

7

Remarks on result:

other: temperature reported as ambient (20-25 °C)

Water solubility:

0.15 mg/L

Temp.:

20 °C

pH:

9

Remarks on result:

other: temperature reported as ambient (20-25 °C)

Description of key information

0.16 mg/L at 20 °C, pH 6.9 (EU A.6, OECD 105, column elution method)

Key value for chemical safety assessment

Water solubility:

0.16 mg/L

at the temperature of:

20 °C

Additional information

In an earlier experiment, conducted according to OECD 105 (column elution method), the following results were obtained at 20 °C: 0.17 mg/L (pH 5), 0.08 mg/L (pH 7), 0.15 mg/L (pH 9). They are supporting.