Neodecanoic acid, iron salt

Water solubility

Link to relevant study record(s)

Reference

Endpoint:

water solubility

Remarks:

Aqueous Solubility

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was initiated on 13 April 2017 and completed on the date the final report was signed by the Study Director.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 105 (Water Solubility)

Version / remarks:

The standard shake flask method

Deviations:

no

Qualifier:

according to guideline

Guideline:

other: slow stir adaptation is based on procedure described in OECD Guideline 123, partition coefficient by slow stir, and on the publication of Letinski et al. Slow-stir water solubility measurements

Version / remarks:

The slow stir adaptation is based on the procedure described in the OECD Guideline 123, partition coefficient by slow stir, and on the publication of Letinski et al. Slow-stir water solubility measurements of selected alcohols and diesters, Chemosphere 48 (2002) 257-265.

GLP compliance:

yes (incl. QA statement)

Type of method:

other: Shake Flask Method & Slow Stir Method

Specific details on test material used for the study:

Sponsor batch: E01133-065
Purity: 100 %
Arrival date: 6 March 2017
Re-test date: 31 July 2019
Storage conditions: Refrigerated (2 to 8°C) under nitrogen. The test substance was supplied in a translucent HDPE container and has been stored in this container. The test substance was stored in a fridge, in the dark when not in use.

Key result

Water solubility:

16 other: ug/mL

Conc. based on:

test mat.

Temp.:

20 °C

pH:

4

Details on results:

Shake Flask Method
Due to issues with formation of emulsions, which caused variable results (at pH 4 values ranged from 24.21 to 242.54 µg/mL and at pH 7 values ranged from 19.56 to 120.65 µg/mL) even after centrifugation, and the higher than expected concentrations the results from this test were considered unreliable and have not therefore been reported.
Slow Stir Method
At pH 4; equilibrium was considered achieved after 121 hours stirring (deviation was <15% with no rising tendency) and the mean solubility of test item was 16.00 µg/mL. The test temperature was 20 ± 0.5°C. The turbidity of each sample was = 0.085 NTU, confirming that true solutions were being analysed.
At pH 7; equilibrium was not achieved, the mean maximum solubility of test item was 398.83 µg/mL after 550.08 hours. As time progressed the contents of the vessel became more of a suspension and had altered in colour. This suggested that test item was reacting with the pH 7 buffer; this was confirmed to probably be the case after discussions with the sponsor. However there was no change in chromatography other than the increase in the test substance concentration over time. It was concluded that it was not possible to determine the solubility of test item in pH 7 buffer. The test temperature was 20 ± 0.5°C except for a period from 08:53 to 13:38 on 15 November 2017, a period of 4 hours and 45 minutes where the temperature reached a maximum of 21.1°C. This only effected the last sample taken on 15 November at 13:38 and as equilibrium was not reached at pH 7 this is not considered to have adversely affected the results of the test.
The full results are shown in the attached Table 11 and graphically in Figure 27.

Table 1: Aqueous Solubility of the test item:

pH 4 Buffer

		Aqueous solubility (µg/mL)
Date and Time	Experiment Time (hours)	Sample 1	Sample 2	Sample 3	Mean	pH
04/10/2017 09:30	0.00		Test Start		0
05/10/2017 11:20	25.83	7.83949	7.63545	8.04552	7.84	4.03
06/10/2017 13:25	51.92	8.94943	10.78882	9.91646	9.88	4.02
09/10/2017 10:30	121.00	14.79581	14.31409	14.98981	14.70	4.04
10/10/2017 10:30	145.00	14.78913	16.92473	17.05386	16.26	4.02
11/10/2017 08:35	167.08	16.51285	16.59572	15.61433	16.24	4.05
12/10/2017 08:35	191.08	16.78026	16.96388	16.10225	16.62	4.02
13/10/2017 08:30	215.00	15.76272	16.46207	16.37103	16.20	4.06
Mean results from 09/10/17					16.00

pH 7 Buffer

		Aqueous solubility (µg/mL)
Date and Time	Experiment Time (hours)	Sample 1	Sample 2	Sample 3	Mean	pH
23/10/2017 15:30	0.00		Test Start		0	-
24/10/2017 13:20	21.83	23.72935	23.17883	20.37061	22.43	7.01
25/10/2017 11:40	44.17	31.77849	31.22199	28.76357	30.59	7.02
26/10/2017 10:55	67.42	48.67237	49.55399	48.03761	48.75	7.02
27/10/2017 11:00	91.50	68.41414	63.81013	65.79996	66.01	7.01
30/10/2017 11:10	163.67	91.59389	100.38872	96.87321	96.29	7.00
31/10/2017 09:40	186.17	155.01273	176.12057	152.91428	161.35	7.00
01/11/2017 11:25	211.92	157.43282	110.95941	127.74153	132.04	6.99
02/11/2017 11:30	236.00	176.12134	166.82256	171.89270	171.61	7.00
03/11/2017 11:45	260.25	183.24679	188.96197	183.70235	185.30	7.01
06/11/2017 11:20	331.83	224.62012	211.31075	229.41304	221.78	7.02
15/11/2017 13:35	550.08	407.59469	412.37409	376.531530	398.83	7.06

 

Conclusions:

Aqueous solubility (20°C) OECD 105 (1995)
pH 4 buffer: 16.00 µg/mL
pH 7 buffer could not be determined due to probable reaction with the buffer.

Executive summary:

The water solubility of the test item was determined by the shake flask method (according to OECD 105) and the slow stir method (according to OECD 123) and is 16 mg/L at 20°C.

Description of key information

The water solubility of the test item was determined by the shake flask method (according to OECD 105) and the slow stir method (according to OECD 123) and is 16 mg/L at 20°C.

Key value for chemical safety assessment

Water solubility:

16 mg/L

at the temperature of:

20 °C