Neodecanoic acid, iron salt

Partition coefficient

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

partition coefficient

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 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)

Version / remarks:

Preliminary solubility suggested that shake flask was the appropriate method. This was performed according to OECD Guideline 107.

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Remarks:

Preliminary solubility suggested that shake flask was the appropriate method. This was performed according to OECD Guideline 107.

Partition coefficient type:

octanol-water

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.

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

3.03

Temp.:

25 °C

pH:

4

Key result

Type:

log Pow

Partition coefficient:

1.98

Temp.:

25 °C

pH:

7

Details on results:

Two tests were performed at pH 4, on the first test the acceptance criteria (log Pow results within 0.3) were not met, with three results being inexplicably low and a repeat test was required. The results from the first test at pH 4 have not been reported.
The Log Pow for pH 4 was 3.03 and 1.98 for pH 7. The criteria for the Log Pow results all to be within 0.3 log units for both pH 4 and pH 7 were met.
The full results are shown in the tables below.

Table 1: Partition Coefficient at pH 7 for the test item

Buffered at pH 7
Sample No	Volume ratio	Volume (mL)		Measured conc (μg/mL)		Aqueous pH	Mass (μg)			Recovery (%)	Pow	Log Pow
		Octanol	Aqueous	Organic	Aqueous		Organic	Aqueous	Total
pH 7, 1	1	7.5	7.5	5039.578	62.272	7.18	37796.8	467.0	38263.9	103.46	80.929	1.908
pH 7, 2	1	7.5	7.5	4908.086	48.605	7.23	36810.6	364.5	37175.2	100.52	100.980	2.004
pH 7, 3	2	10	5	4790.790	50.776	7.18	47907.9	253.9	48161.8	97.67	94.352	1.975
pH 7, 4	2	10	5	4616.758	60.249	7.26	46167.6	301.2	46468.8	94.23	76.627	1.884
pH 7, 5	0.5	5	10.00	4870.788	46.910	7.14	24353.9	469.1	24823.0	100.68	103.832	2.016
pH 7, 6	0.5	5	10.00	4999.475	42.359	7.21	24997.4	423.6	25421.0	103.10	118.026	2.072
										Mean	95.791	1.977
										SD	15.3373	0.07020
										RSD	16.01	3.55

Due to the results for the test at pH 4 not agreeing within ± 0.3 log units and the fact that the peak areas for aqueous samples for pH 4, 1, pH 4,5 and pH 4,6 were below the peak area of the lowest standard the results for the first test at pH 4 have not been reported. The test at pH 4 was repeated.

Table 2: Repeat Partition Coefficient at pH 4 for the test item

Buffered at pH 4
Sample No	Volume ratio	Volume (mL)		Measured conc (μg/mL)		Aqueous pH	Mass (μg)			Recovery (%)	Pow	Log Pow
		Octanol	Aqueous	Organic	Aqueous		Organic	Aqueous	Total
pH 4, 1	1	7.5	7.5	4045.825	5.292	4.01	30343.7	39.7	30383.4	98.90	764.517	2.883
pH 4, 2	1	7.5	7.5	4215.243	4.498	4.03	31614.3	33.7	31648.1	103.01	937.173	2.972
pH 4, 3	2	10	5	4107.229	2.798	4.02	41072.3	14.0	41086.3	100.30	1467.722	3.167
pH 4, 4	2	10	5	4199.697	3.742	4.05	41997.0	18.7	42015.7	102.57	1122.361	3.050
pH 4, 5	0.5	5	10.00	4085.769	4.311	4.06	20428.8	43.1	20472.0	99.95	947.671	2.977
pH 4, 6	0.5	5	10.00	4220.084	3.296	4.01	21100.4	33.0	21133.4	103.18	1280.416	3.107
										Mean	1086.643	3.026
										SD	256.696	0.103
										RSD	23.623	3.392

Conclusions:

Partition coefficient (25°C) OECD 107 (1995)
Buffered at pH 4, Log Pow: 3.03
Buffered at pH 7, Log Pow: 1.98

Executive summary:

The partition coefficient has been determined in accordance with OECD 107 (1995). The Log Pow (25°C) for pH 4 was 3.03 and 1.98 for pH 7.

Reference 2

Endpoint:

partition coefficient

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

supporting study

Justification for type of information:

For details and justification of read-across please refer to the report attached in section 13 of IUCLID.

Reason / purpose for cross-reference:

read-across source

Key result

Type:

log Pow

Partition coefficient:

2.1

Temp.:

25 °C

pH:

6.7

Key result

Type:

log Pow

Partition coefficient:

4.3

Temp.:

25 °C

pH:

2.5

Conclusions:

The n-octanol/water partition coefficient values for neodecanoic acid, determined by a reverse-phase HPLC method at pH 2.5 and 6.7 respectively, are 20000 (log Pow 4.3) and 130 (log Pow 2.1).

Executive summary:

In a study, according to OECD 117, the partition coefficient of neodecanoic acid has been characterised. The n-octanol/water partition coefficient values for neodecanoic acid, determined by a reverse-phase HPLC method at pH 2.5 and 6.7 respectively, are 20000 (log Pow 4.3) and 130 (log Pow 2.1). The value at pH 6.7 indicates a low potential for the compound to accumulate from water into organisms.

This information is used in a read-across approach in the assessment of the target substance. For details and justification of read-across please refer to the read-across report attached to IUCLID section 13.

Description of key information

The partition coefficient has been determined in accordance with OECD 107 (1995). The log Pow (25°C) at pH 4 was 3.03 and 1.98 at pH 7.

As a supporting approach, read-across to neodecanoic acid (EC No. 248-093-9; CAS No. 26896-20-8) has been established. Since the determined values at pH 2.5 and 6.7 are 4.3 and 2.1, respectively, and are therefore in the same range as that of neodecanoic acid, iron salt, the read-across approach to the structural analogue can therefore be considered as justified.

Key value for chemical safety assessment

Log Kow (Log Pow):

1.98

at the temperature of:

25 °C