Tetraesters of pentaerythritol with 2-ethylhexanoic acid and heptanoic acid and nonanoic acid

Water solubility

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

17 -19 Nov 2015

Reliability:

3 (not reliable)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

yes (incl. QA statement)

Type of method:

column elution method

Water solubility:

< 0.01 g/L

Remarks on result:

other: estimated solubility

HPLC Method Development An HPLC method was developed for the analysis of C5-10 Fatty acids esters with pentaerythritol. The method showed the sample to be multi component with limited UV response.

HPLC Analysis Apparatus, Method and Test Conditions

Equipment : HPLC

Detector : UV

Detection wave length (nm) : 205

Oven temperature (°C) : 40

Temperature of determination (°C) : 20

Column : Zorbax SB C18 4.6x75mm, 3.5 μm

Injection Volume (μl) : 20

Mobile Phase A : Water

Mobile Phase B : Acetonitrile

Water used : HPLC grade

pH of water : 8.6

Flow Rate (ml.hr-1) : 1

Mobile Phase Settings

Time (min)	% Mobile phase A	% Mobile phase B
0.0	0	100
15.0	0	100

The conclusion was that the solubility of C5-10 Fatty acids esters with pentaerythritol was below the limit of detection of the HPLC method.

Reference 2

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

2008-08-28 to 2008-12-04

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study, tested with the source substance 68424-31-7 (Tetra-esterification products of C5, C7, C8, C10 fatty acids with pentaerythritol). In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Principles of method if other than guideline:

A modified flask method employing slow stirring was used.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Water solubility:

< 0.02 mg/L

Temp.:

20 °C

pH:

6.5 - 7.2

Results

The detector calibration was found to be linear over the range 0 to 10 mg/L of standard solutions in acetone with a regression coefficient of 0.9993 (table 1).

Table 2 presents a summary of the results of the test and shows that the water solubility of the test item was less than 0.02 mg/L. Table 3 presents the primary data for this test.

Neither an absolute value, nor a lower limit value, could be determined due to the presence of interfering peaks. An acceptable mean recovery of approximately 107% of the test item from samples fortified at the 0.02 mg/L level was achieved and, given the level of background interference, this was considered to be the limit of quanitification.

Standard calibration for the test item by GC

Table 1:

Standard calibration (mg/L)	Peak area
9.900	51888
7.920	40492
5.940	29349
3.960	18858
1.980	8890.3
0.9900	4231.1
0.4950	1845.6

Linear regression: y = 5245x -1000

(including x = 0, y = 0) r = 0.9993

x = concentration

y = peak area

Measurement of water solubility at 20 °C

Table 2:

Sample number	Time (days)	Concentration (mg/L)	Mean concentration (mg/L)	pH
1A, 1B	1	< 0.02, < 0.02	< 0.02	6.6, 6.5
2A, 2B	2	< 0.02, < 0.02	< 0.02	6.7, 6.7
3A, 3B	3	< 0.02, < 0.02	< 0.02	7.0, 7.0
6A, 6B	6	< 0.02, < 0.02	< 0.02	6.5, 7.0
7A, 7B	7	< 0.02, < 0.02	< 0.02	7.1, 7.2

Mean solubility: < 0.02 mg/L

HPLC analysis of sample from the water solubility test for the test item

Table 3:

Sample	Peak area	CA(mg/L)	Dilution factor	CB(mg/L)
1.980 mg/L std	7673.4	-	-	-
Sample 1A	*	< 2	0.01	< 0.02
Sample 1B	*	< 2	0.01	< 0.02
Sample 2A	*	< 2	0.01	< 0.02
Sample 2B	*	< 2	0.01	< 0.02
1.980 mg/L std	11632	-	-	-
1.980 mg/L std	11594	-	-	-
Sample 3A	*	< 2	0.01	< 0.02
Sample 3B	*	< 2	0.01	< 0.02
Sample 6A	*	< 2	0.01	< 0.02
Sample 6B	*	< 2	0.01	< 0.02
1.980 mg/L std	12230	-	-	-
Sample 7A	*	< 2	0.01	< 0.02
Sample 7B	*	< 2	0.01	< 0.02
1.980 mg/L std	11973	-	-	-

* there were peaks present in the samples, but generally of much lower magnitude than those seen in the bracketing standards. There were more significant peaks in sample 2A and 3A, but the pattern of peaks was not consistent with these being due to dissolved test item.

Recovery of test item from purified water

Table 4:

Sample	Peak area	CA (mg/L)	Dilution factor	CB (mg/L)	Fortified concentration (mg/L)	Recovery (%)
1.980 mg/L std	12230	-	-	-	-	-
Spike 1	13287	2.174	0.01	0.02174	0.01980	110
Spike 2	13310	2.178	0.01	0.02178	0.01980	110
1.980 mg/L std	11973	-	-	-	-	-
Spike 3	13911	2.304	0.01	0.02304	0.01980	116
Spike 4	13541	2.238	0.01	0.02238	0.01980	113
Spike 5	10544	1.747	0.01	0.01747	0.01980	88
Spike 6	12484	2.068	0.01	0.02068	0.01980	104
1.980 mg/L std	11934	-	-	-	-	-

Mean recovery = 107%

Reference 3

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

31 Jul-23 Dec 2008

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study, tested with the source substance 71010-76-9. In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

Principles of method if other than guideline:

A modified flask method employing slow stirring was used, this being deemed most appropriate for the oily test substance. This involved sampling the saturated aqueous solution from the bottom of the test sample, thus eliminating potential contamination precluding the need for filtration or centrifugation.

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Remarks:

modified

Water solubility:

< 0.02 mg/L

Temp.:

20 °C

pH:

6.5 - 7.2

Results at 20 °C:

Sample number	Time (days)	Concentration (mg/l)	Mean concentration (mg/l)	pH
1A, 1B	1	<0.02; <0.02	<0.02	6.6; 6.5
2A, 2B	2	<0.02; <0.02	<0.02	6.7; 6.7
3A, 3B	3	<0.02; <0.02	<0.02	7.0; 7.0
6A, 6B	6	<0.02; <0.02	<0.02	6.5; 7.0
7A, 7B	7	<0.02; <0.02	<0.02	7.1; 7.2

Reference 4

Endpoint:

water solubility

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

09 - 11 Jan 2012

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

Guideline study, tested with the source substance 85586-24-9. In accordance to the ECHA guidance document "Practical guide 6: How to report read-across and categories (March 2010)", the reliability was changed from RL1 to RL2 to reflect the fact that this study was conducted on a read-across substance.

Qualifier:

according to guideline

Guideline:

EU Method A.6 (Water Solubility)

GLP compliance:

no

Type of method:

column elution method

Water solubility:

< 0.15 mg/L

Temp.:

20 °C

pH:

6.2 - 7.2

Quantitative determination of the analyte:

Flow rate (mL/h)	Fraction No.	Water solubility of Fatty acid, C16-18, tetraesters with 3,3’ oxybis(1,2-propanediol), mg/L	pH value
25.0	1 (1-2)	< 0.15	7.2
	2 (3-4)	< 0.15	6.9
	3 (5-6)	< 0.15	6.8
	4 (7-8)	< 0.15	6.8
	5 (9-10)	< 0.15	6.6
	6 (11-12)	< 0.15	6.7
	7 (13-14)	< 0.15	6.5
	8 (15-16)	< 0.15	6.6
12.5	1 (1-2)	< 0.15	7.2
	2 (3-4)	< 0.15	7.1
	3 (5-6)	< 0.15	6.8
	4 (7-8)	< 0.15	6.7
	5 (9-10)	< 0.15	6.4
	6 (11-12)	< 0.15	6.6
	7 (13-14)	< 0.15	6.2
	8 (15 -16)	< 0.15	6.4

Description of key information

<0.15 mg/L at 20 °C (read-across from similar substances)

Additional information

The water solubility of this substance was deduced from the measurement of a similar substances: Tetra-esterification products of C5, C7, C8, C10 fatty acids with pentaerythritol (CAS-No. 68424 -31 -7); Decanoic acid, mixed esters with heptanoic acid, octanoic acid, pentaerythritol and valeric acid (CAS-No. 71010 -76 -9) and Fatty acids, C8-10, tetraesters with pentaerythritol (CAS 85586 -24 -9). The water solubility for first two substances was determined to be <0.02 mg/L at 20 °C and for the last (Fatty acids, C8-10, tetraesters with pentaerythritol) was <0.15 mg/L. For analogue substances with the same structural backbone, water solubility is a property where increasing chain length leads to decreasing solubility. Therefore, the water solubility can be deduced to be <0.15 mg/L at 20 °C. The estimated water solubility for target substance <0.01 g/L is supporting.