Tetrasodium 7,7'-(carbonyldiimino)bis[4-hydroxy-3-[(2-methyl-4-sulphonatophenyl)azo]naphthalene-2-sulphonate]

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June from 19th to 21st, 2018

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted July 27, 1995

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

flask method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Type:

log Pow

Partition coefficient:

-3.34

Temp.:

20 °C

pH:

7 - 8

Details on results:

The nine log Pow values were within a range of ± 0.3 log units and thus complied with the guidelines.

Calculated partition coefficient (Pow) and log Pow

Ratio of solvents (n-octanol : Water)	Partition coefficient		Log Partition coefficient		pH conditions
	Pow	Mean	Log Pow	Mean	Mean
10:01	0.0004	0.0004	-3.40	-3.45	7.56
	0.0004		-3.40
	0.0003		-3.55
05:01	0.0005	0.0005	-3.30	-3.29	7.86
	0.0005		-3.29
	0.0005		-3.29
20:01	0.0003	0.0003	-3.57	-3.56	7.32
	0.0003		-3.56
	0.0003		-3.56
Mean all ± 95 % confidence interval	0.0004 ± 0.0001	-	-3.43	-	-

Measured concentrations

Ratio of solvents (n-Octanol : Water)	Measured concentration in n-octanol phase (µg/ml)	Measured concentration in aqueous phase (µg/ml)	pH
10:1	0.13	313.5	7.56
	0.13	314.1
	0.09	309.1
Mean	0.11	312.2
RSD %	20	1	-
Measured quantity of test item (Mo; Mw)	4.8 µg	1311.3 µg	-
Total nominal quantity of test item (Ms)	1272 µg
Total quantity of test item (Mo+Mw) in the two-phase system	1316 µg
Recovery	104 %
05:1	0.09	173.1	7.86
	0.09	176.1
	0.09	175.0
Mean	0.09	174.7
RSD %	2	1	-
Measured quantity of test item (Mo; Mw)	3.4 µg	1345.6 µg	-
Total nominal quantity of test item (Ms)	1272 µg
Total quantity of test item (Mo+Mw) in the two-phase system	1349 µg
Recovery	106 %
20:1	0.17	626.7	7.32
	0.17	617
	0.17	615.8
Mean	0.17	619.8
RSD %	1	1	-
Measured quantity of test item (Mo; Mw)	7.51 µg	1363.6 µg	-
Total nominal quantity of test item (Ms)	1272 µg
Total quantity of test item (Mo+Mw) in the two-phase system	1371 µg
Recovery	108 %

Conclusions:

logPow: -3.43 at 20 °C and pH 7/8

Executive summary:

The partition coefficient of the test item was determined using shake-flask method, in accordance with the method and procedures outlined into the OECD guideline 107. Three parallel tests were carried out: in the first, the calculated volume ratio was applied, in the second, this ratio was divided by two and in the third, this ratio was multiplied by two

Three experiments were carried out applying different solvent ratios. The test was performed at 20 ± 1 °C. Three parallel tests were carried out at all solvent ratios.

The partition coefficient (Pow) of test item in n-octanol - water was determined to be 0.0004 ± 0.0001 (95 % confidence interval) at 20 °C and pH 7 -8, which corresponds to log Pow of -3.43. The nine log Pow values were within a range of ± 0.3 log units and thus complied with the guidelines.

Conclusion

logPow: -3.43 at 20 °C and pH 7/8

Description of key information

logPow: -3.43 at 20 °C and pH 7/8

Key value for chemical safety assessment

Log Kow (Log Pow):

-3.43

at the temperature of:

20 °C

Additional information

OECD 107 - Shake Flask Method