Benzenesulfonic acid, mono- and dialkylation products with C16-20 (even numbered, branched and linear) olefins, barium salts, barium carbonate, overbased, including distillates (petroleum), hydrotreated, solvent-refined, solvent-dewaxed, or catalytic dewaxed, light or heavy paraffinic C15-C50

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

20 June 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

1.71

Temp.:

23 °C

pH:

6

Details on results:

OBSERVATIONS
- The test was conducted at neutral pH (no buffers were used). All test material peaks eluted before 10 minutes. One peak eluted prior to the void volume marker so it was excluded. The second peak eluted after the void volume marker but before the lowest Kow standard. Extrapolation was used to make the best estimate of the Kow for this peak.

RESULTS
- The test material was composed of 5 main peaks, with retention times of approximately 1.7, 2.4, 4.0, 5.4 and 8.8 minutes. The first peak at 1.7 minutes eluted prior to the void volume marker and was not included in the calculations. The second peak at 2.4 minutes eluted after the void volume marker but before the lowest Kow standard (acetanilide 3.6 minutes). Extrapolation was used to make the best estimate of the Kow for this peak. Only peaks with an area greater than 5% of the total were included in the calculations of Kow.
- The individual log Kow values and the weighted average log Kow were determined, the results are summarised in Table 1. Note that only the peaks greater than 5% total area are included in this table.
- The error in the measurements was estimated using the relative percent difference (RPD) of the two independent preparations analysed in these experiments. The difference between the two preparations was 0.29 log units, corresponding to an RPD of 16.9%.
- The test material displayed a weight-averaged log Kow of 1.71 ± 0.29 at neutral pH as per the method in OECD Test No. 117.

Table 1: Summary of Partition Coefficient Data in Neutral Conditions

Preparation Number	Concentration (mg/mL)	Peak Retention Time (min)	Peak Area (%*)	log Kow	Weighted Average log Kow
1	2.91	2.275**	8.7	-1.86	1.56
		3.655	57.7	1.26
		5.068	23.5	2.52
		8.094	10.1	3.97
2	2.90	2.381**	7.9	-1.39	1.85
		3.995	61.6	1.64
		5.429	22.9	2.75
		8.759	7.7	4.19
Average					1.71
Relative Percent Difference (RPD, %)					16.9 %
Absolute Difference (log units)					0.29

* The weighted average log Kow was based on peaks with percentage area greater than 5% of the total area.

** The retention time for first peak of the test material was below the range obtained from standards. The Kow determined was less than the lowest Kow standard acetanilide which has a Kow of 1.0.

Conclusions:

Under the conditions of this study, the test material displayed a weight-averaged log Kow of 1.71 ± 0.29 at neutral pH.

Executive summary:

The partition coefficient of the test material was determined in accordance with the standardised guideline OECD 117 under GLP conditions using the HPLC method.

The test was conducted at neutral pH (no buffers were used). All test material peaks eluted before 10 minutes. The test material was composed of 5 main peaks, with retention times of approximately 1.7, 2.4, 4.0, 5.4 and 8.8 minutes. The first peak at 1.7 minutes eluted prior to the void volume marker and was not included in the calculations. The second peak at 2.4 minutes eluted after the void volume marker but before the lowest Kow standard (acetanilide 3.6 minutes). Extrapolation was used to make the best estimate of the Kow for this peak. Only peaks with an area greater than 5% of the total were included in the calculations of Kow.

The error in the measurements was estimated using the relative percent difference (RPD) of the two independent preparations analysed in these experiments. The difference between the two preparations was 0.29 log units, corresponding to an RPD of 16.9 %.

Under the conditions of this study, the test material displayed a weight-averaged log Kow of 1.71 ± 0.29 at neutral pH.

Description of key information

Under the conditions of this study, the test material displayed a weight-averaged log Kow of 1.71 ± 0.29 at neutral pH.

Key value for chemical safety assessment

Log Kow (Log Pow):

1.71

at the temperature of:

23 °C

Additional information

The partition coefficient of the test material was determined in accordance with the standardised guideline OECD 117 under GLP conditions using the HPLC method. The study was awarded a reliability score of 1 in accordance with the criteria set forth by Klimisch et al. (1997).

The test was conducted at neutral pH (no buffers were used). All test material peaks eluted before 10 minutes. The test material was composed of 5 main peaks, with retention times of approximately 1.7, 2.4, 4.0, 5.4 and 8.8 minutes. The first peak at 1.7 minutes eluted prior to the void volume marker and was not included in the calculations. The second peak at 2.4 minutes eluted after the void volume marker but before the lowest Kow standard (acetanilide 3.6 minutes). Extrapolation was used to make the best estimate of the Kow for this peak. Only peaks with an area greater than 5% of the total were included in the calculations of Kow.

The error in the measurements was estimated using the relative percent difference (RPD) of the two independent preparations analysed in these experiments. The difference between the two preparations was 0.29 log units, corresponding to an RPD of 16.9%.

Under the conditions of this study, the test material displayed a weight-averaged log Kow of 1.71 ± 0.29 at neutral pH.