Sulphophthalic acid derivatives reaction products of fatty alcohol C12-C14 and sodium hydroxide

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January from 25 to 30, 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Reason / purpose for cross-reference:

reference to other study

Remarks:

validated analytical method

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 105 (Water Solubility)

Version / remarks:

adopted July 27, 1995

Qualifier:

according to guideline

Guideline:

other: EU Method A.8 (Partition Coefficient)

Version / remarks:

31 May 2008

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7550 (Partition Coefficient, n-octanol / H2O, Shake Flask Method)

Version / remarks:

August 1996

GLP compliance:

yes (incl. QA statement)

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

Pow

Partition coefficient:

< 0.002

Temp.:

20 °C

Remarks on result:

other: estimation method (solubility ratio)

Details on results:

Test item is miscible in water and 900 g/l has been considered for Pow estimation; the solubility in n-octanol resulted to be ~2 g/l.
The partition coefficient (Pow) of the substance in n-octanol - water was estimated to be lower than 0.002 at 20 °C, using the individual solubilities of test item in n-octanol and water.

Estimation of the Partition Coefficient

Solubility of the Test Item, g/l		Pow
in n-octanol	1.98	< 0.002
in water	> 900*

* calculated using the ratio 90:10 (test item : water)

Determination of the Solubility in n-Octanol

Sampling time	Measured concentration of Test Item, g/l
After 24h	1.98
After 48h	2.02
After 72h	1.94
Solubility of the test item in n-octanol (g/l) (mean with the 95 % confidence intervals)	1.98 ± 0.10
RSD%	2

Water miscibility test

Test item (ml)	Ultra-pure water (ml)	Observation	pH value
90	10	clear, homogeneous single-phase liquid	6.03
10	90	clear, homogeneous single-phase liquid	6.00
50	50	clear, homogeneous single-phase liquid	5.91

Conclusions:

Pow < 0.002 at 20 °C

Executive summary:

The objective of the study was to determine the partition coefficient of the test item; since the substance is surface active, the partition coefficient was estimated based on individual solubilities in water and octanol. The partition coefficient is the ratio of equilibrium concentrations of a dissolved test item in a two-phase system consisting of two largely immiscible solvents, e.g. n-octanol and water.

About 2.5 g quantity of test item was weighed into three glass stoppered Erlenmeyer flasks. After the addition of 50 ml n-octanol, the flasks were agitated at 30 °C. Passing 1, 2 and 3 days flasks were removed and re-equilibrated at 20 °C for 1 day.

The saturated samples were centrifuged at 20 °C, at 4000 rpm (5 min). The samples were extracted with ultra-pure water and were diluted hundred-fold with ultra-pure water before the analysis.

Test item is miscible in water and 900 g/l has been considered for Pow estimation; the solubility in n-octanol resulted to be ~2 g/l.

The partition coefficient (Pow) of the substance in n-octanol - water was estimated to be lower than 0.002 at 20 °C, using the individual solubilities of test item in n-octanol and water.

Conclusion

Pow < 0.002 at 20 °C

Description of key information

Pow < 0.002 at 20 °C (log Pow < - 2.7)

Key value for chemical safety assessment

Log Kow (Log Pow):

-2.7

at the temperature of:

20 °C

Additional information

OECD 105 - estimation method (solubility ratio)