Reaction products of benzenesulfonic acid, mono-C20-24 (even)-sec-alkyl derivs. para-, calcium salts

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2017-03-28 - 2017-09-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

from 2004-04-13

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Version / remarks:

from 2008-05-30

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

>= 5.38 - <= 7.44

Temp.:

40 °C

pH:

6.9

Preliminary Estimate

The estimated log10 Pow was calculated for the representative structure to be: >10

Definitive Test

Calibration

The retention times of the dead time and the retention times, capacity factors (k') and lg Pow values fo rthe reference standards are shown in the following table:

Standard	Retention Time (min)			Capacity Factor (k')	lg k'	lg Pow
	Injection 1	Injection 2	Injection 3
Thiourea (dead time)	0,912	0,915	0,913	-	-	-
Benzyl alcohol	1,075	1,075	1,075	0,177	-0,753	1,1
Naphtalene	1,730	1,732	1,731	0,895	-4,81 x 10E-2	3,6
Triphenylamine	3,867	3,872	3,869	3,24	0,510	5,7
1-Phenylnonane	11,065	11,082	11,074	11,1	1,05	7,1
1-Phenylundecane	20,582	20,616	20,599	21,6	1,33	8,1
1-Phenyldodecane	28,394	28,440	28,417	30,1	1,48	8,7
1-Phenyltridecane	39,394	39,452	39,423	42,2	1,62	9,4
1-Phenyltetradecane	54,961	55,044	55,002	59,2	1,77	10,0

Partition coefficient of sample

The retention times, capacity factor and log10 Pow value determined for the sample are shown in the following table:

Peak	Injection	Retention time (min)	Capacity Factor (k')	lg k'	lg Pow	Mean lg Pow	Mean Area %
1	1	0,973	6,56 x 10E-2	-1,18	<1,1	<1,1	3,8
	2	0,970	6,20 x 10E-2	-1,21	<1,1
2	1	3,700	3,05	0,484	5,38	5,38	3,2
	2	3,700	3,05	0,485	5,39
3	1	6,617	6,24	0,795	6,45	6,45	28,6
	2	6,597	6,22	0,794	6,45
4	1	9,303	9,19	0,963	7,03	7,03	14,4
	2	9,253	9,13	0,961	7,02
5	1	11,910	12	1,08	7,44	7,44	0,5
	2	11,973	12	1,08	7,44
6 and 7	1	≥75,977	>59,2	>1,77	>10,0	>10,0	5,4
	2	≥75,997	>59,2	>1,77	>10,0
8	1	77,947	>59,2	>1,77	>10,0	>10,0	44,1
	2	77,970	>59,2	>1,77	>10,0

Overall lg Pow: 5.38 to 7.44

Overal partition coefficient: 2.42 x 10E5 to 2.75 x 10E7

Discussion

The result from the preliminary test and with the test item being a complex mixture indicated that the HPLC method would be the most suitable for determination of partition coefficient.

The test was modified from that stated in the guidelines to allow assessment of the partition coefficient up to a value of log10 Pow 10.0 by the use of additional reference standards. Additionally, the mobile phase contained only 20% water, instead of the guideline recommended minimum of 25%, to reduce the retention time of the highly retained additional reference standards.

Peak number 8 that eluted on the solvent gradient was shown to be an oil used by the Sponsor in its products. A sample of this oil was available to make a direct chromatographic comparison with the test item. It was unknown what components peaks 1, 6 and 7 were.

The partition coefficient preliminary estimate was based on the representative structure supplied by the Sponsor, but was significantly greater than the test result. This was because it was observed that the representative structure was not definitively detected, but rather the dissociated organic parts of the molecule were. These were also detected as the four ion masses in the analysis of the water solubility test.

The test result was based on peaks 2 to 5 which represented the main components of the test item.

Conclusions:

The partition coefficient of the test item has been determined to be 2.42 x 10E5 to 2.75 x 10E7, log10 Pow of 5.38 to 7.44.

Executive summary:

Partition Coefficient (n-octanol/water) 2.42 x 10E5 to 2.75 x 10E7, log10 Pow of 5.38 to 7.44, using the HPLC method, designed to be compatible with Method A.8 Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 117 of the OECD Guidelines for Testing of Chemicals, 13 April 2004.

Description of key information

Partition Coefficient (n-octanol/water) 2.42 x 10E5 to 2.75 x 10E7, log10 Pow of 5.38 to 7.44, using the HPLC method, designed to be compatible with Method A.8 Partition Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008 and Method 117 of the OECD Guidelines for Testing of Chemicals, 13 April 2004.

Furthermore, a supporting value is reported for the calcium sulfonate read-across substance CAS 70024 -69 -0, which was determined in an estimation which is comparable to OECD 107 (Fox & White, 2011a). Neither the shake-flask nor the HPLC method are applicable for the test substance, based on its chemical structure. Therefore, an estimation of the partition coefficient was performed using the solubilities in octanol and water using a procedure designed to be compatible with OECD Guideline 117. The solubility in n-octanol is done by visual assessment. The approximate solubility in n-octanol was >500 g/L; the solubility in water ≤was 1.69E-3 g/L, the approximate Pow >2.95E5 and the Log Pow was therefore, > 5.47.

Finally, another supporting value is reported for the calcium sulfonate read-across substance CAS 61789 -86 -4, which was also determined in an estimation which is comparable to OECD 107 (Fox&White, 2011b). As specified above, neither the shake-flask nor the HPLC method are applicable for the test substance. Therefore, an estimation was performed. A definitive value for solubility of this test item in octanol could not be determined visually above 500 g/L where it was clearly highly soluble. However, the water solubility test showed that the test item was essentially insoluble. The partition coefficient of the test item has been estimated to be > 4.43E6 , logPow > 6.65.

The partition coefficient of the undissociated test substance would be expected to be significantly higher than the estimated results of > 6.65. Based on a prediction with KOWWINv1.68 (Sept 2010), the logPow is 26.14 and 27.90 taking into account the different alkylated chain lengths.

Key value for chemical safety assessment

Log Kow (Log Pow):

5.38

at the temperature of:

40 °C