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Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
Testing was conducted between 1st September to 10th October 2005
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Meets the criteria for classification as Reliable without restriction according to Klimisch et al (1997)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2005
Report date:
2005

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
other: 92/69/EEC, A8 (shake-flask method)
GLP compliance:
yes
Type of method:
shake-flask method to: flask method
Partition coefficient type:
octanol-water

Test material

Constituent 1
Chemical structure
Reference substance name:
-
EC Number:
471-980-9
EC Name:
-
Cas Number:
1016986-95-0
Molecular formula:
Hill formula: C42 H24 Lim N9 Nan O15 S6 m+n=5 3=
IUPAC Name:
7-{2-[2-(2-{5-cyano-4-methyl-2,6-bis[(4-sulfophenyl)amino]pyridin-3-yl}diazen-1-yl)-4-(naphthalen-2-yl)-1,3-thiazol-5-yl]diazen-1-yl}naphthalene-1,3,5-trisulfonic acid trilithium hydride disodium hydride

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Type:
log Pow
Partition coefficient:
< -3.16
Temp.:
22 °C
pH:
7

Any other information on results incl. tables

Results

Preliminary estimate

Approximate solubility in n-octanol: 4.90 x 10 -3 g/l

Approximate solubility in water: >136.300 g/l

Approximate Pow< 1.3 9 x 10-5

Log10 Pow <-4.86

Definitive test

The mean peak areas or absorbances obtained for the standard, stock and sample solutions are shown in the following two tables:

 Organic Phase
 Solution  Mean Peak Absorbance
 Standard 0.503 mg/l  1.437 x 10 -2
 Standard 0.509 mg/l  1.457 x 10 -2
 Sample 1  8.960 x 10 -2
 Sample 2  5.890 x 10 -3
 Sample 3  1.414 x 10 -2
 Sample 4  1.118 x 10 -2
 Sample 5  9.950 x 10 -3
 Sample 6  1.257 x 10 -2

 Aqueous Phase
 Solution  Mean Peak Area
 Standard 201 mg/l  1.474 x 10 3
 Standard 204 mg/l  1.494 x 10 3
 Sample 1  1.528 x 10 3
 Sample 2  1.515 x 10 3
 Sample 3  1.530 x 10 3
 Sample 4  1.467 x 10 3
 Sample 5  1.586 x 10 3
 Sample 6  1.603 x 10 3
 Stock Solution A  1.491 x 10 3
 Stock Solution B  1.464 x 10 3

The total weights (mg) and analysed concentration (mgll) of the respective phases are shown in the following table:

 
 Sample Number  Volume of Water Saturated n-octanol (ml)  Volume of n-octanol Stock solution (ml)  Total weight (mg) Oraganic Phase (Analysed Concentration mg/l)  Organic Phase (Weight mg)  Aqueous Phase (Analaysed Concentration mg/l)  Aqueous Phase (weight mg)  Aqueous Phase (pH) 
 1  440  110  94.8  0.536  0.236  891  98.0  5.5
 2  480  120  103  0.352  0.169  884  106  6.7
 3  560  70  60.3  0.846  0.474  893  62.5  6.8
 4  560  70  60.3  0.669  0.375  856  59.9  6.8
 5  560  35  30.2  0.595  0.333  925  32.4  6.8
 6  560  35  30.2  0.752  0.421  935  32.7  6.8

pH of n-octanol saturated water: 7.0

pH of stock solution: 7.0

Temperature: 21.6 +/- 0.5°C

The partition coefficient determined for each sample is shown in the following table:

 Table 8.5
 Sample Number  N-octanol/Water Volume Ratio  Partition Coefficient  Log10 Pow  Mean Partition Coefficient
1 & 2  4:1 6.02 x 10 -4 (1) 3.99 x 10 -4 (2)  -3.22 (1) -3.40 (2)  5.00 x 10 -4
3 & 4  8:1  9.48 x 10 -4 (1) 7.82 x 10 -4 (2)  -3.02 (1)-3.11 (2)  8.65 x 10 -4
5 & 6  16.1  6.44 x 10 -4 (1) 8.05 x 10 -4 (2)  -3.19 (1) -3.09 (2)  7.24 x 10 -4

Mean Pow : 6.96 x 10-4, log10 Pow 3.16 Pow standard deviation : 1.9 1 x 10 -4

Linearities of the detector response with respect to concentration were assessed over the nominal concentration range of 0 to 2 mg/l for the organic phase and 0 to 300 mgll for the aqueous phase.

These were satisfactory with correlation coefficients of 1.000 and 0.999 being obtained.

Discussion

Substances having a log10 Pow of greater than 3 are regarded as having the potential to bioaccumulate in the environment.

It is evident from the information obtained in the hydrolysis test and data relating to the pH of the test material in water that negligible hydrolysis of the sample solutions occurred during the course of the partition coefficient test.

The n-octanol saturated water was adjusted to pH 7. Testing at neutral pH by the flask method is the preferred choice for test materials that are salts.

Applicant's summary and conclusion

Conclusions:
The partition coefficient of the test material has been determined to be 6.96 x l0-4 at 21.6°C +/- 0.5°C. The log10 Pow = - 3.16.
Executive summary:

Introduction:

The study has been conducted according to 92/69/EEC, EC method A8 (shake-flask method)

Results and Conclusions

The partition coefficient of the test material has been determined to be 6.96 x l0-4 at 21.6°C +/- 0.5°C. The log10 Pow = - 3.16.