Acetamide, N-(2,4-dinitrophenyl)-, reaction products with 1-methyl-2,4-dinitrobenzene and sodium sulfide (Na2(Sx)), leuco derivatives

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

27 September - 08 October, 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 105 (“Water Solubility”)

Version / remarks:

adopted July 27, 1995

Deviations:

not applicable

Principles of method if other than guideline:

The determination of the log Pow using the respective OECD guideline methods was technically not feasible due to the intrinsic properties of the test item:
- The test item is a UVCB and the flask-shake (OECD TG 107) and slow-stir method (OECD TG 123) for the determination of the log Pow are not applicable to complex mixtures.
- The test item cannot be chromatographed under the conditions described in the HPLC-method (OECD Guideline 117) since it is insoluble in the solvents used for the reverse phase HPLC.
- The test item has no defined chemical structure; therefore the calculation of the log Pow with a QSAR tool is not possible.
Hence, the log Pow has to be estimated based on individual solubilities of the test item in water and n-octanol.

GLP compliance:

yes (incl. QA statement)

Type of method:

estimation method (solubility ratio)

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Acetamide, N-(2,4-dinitrophenyl)-, reaction products with 1-methyl-2,4-dinitrobenzene and sodium sulfide (Na2(Sx)), leuco derivatives

EC Number:

288-896-1

EC Name:

Acetamide, N-(2,4-dinitrophenyl)-, reaction products with 1-methyl-2,4-dinitrobenzene and sodium sulfide (Na2(Sx)), leuco derivatives

Cas Number:

85940-08-5

Molecular formula:

not applicable

IUPAC Name:

Reaction product of N-(2,4-dinitrophenyl)acetamide with 1-methyl-2,4-dinitrobenzene and polysulfide, leuco derivatives

Test material form:

solid: particulate/powder

Details on test material:

Test item: Leuco Sulphur Brown 46
Appearance: Brown powder
CAS No: 85940-08-5

Study design

Analytical method:

photometric method

other: observation of precipitated substance particles in n-octanol

Results and discussion

Partition coefficient

Partition coefficient 1

Key result

Type:

log Pow

Partition coefficient:

< -0.6

Temp.:

20 °C

pH:

>= 7.06 - <= 7.41

Remarks on result:

other: pH as determined in water solubility study

Partition coefficient 2

Key result

Type:

Pow

Partition coefficient:

< 0.2

Temp.:

20 °C

pH:

>= 7.06 - <= 7.41

Remarks on result:

other: pH as determined in water solubility study

Details on results:

Undissolved particles were still observed in the test item / n-octanol mixture at the concentration ca. 2 mg test item / 500 mL n-octanol after 24 hours.
Based on this observation, the solubility of the test item in n-octanol is less than 4 mg/L.
The solubility of the test item in water is 16.5 mg/L as determined in a separate GLP study (see "water solubility").
The Pow value of the test item is calculated by dividing the value for octanol solubility by the value for water solubility.
Based on the individual solubility of test item in water and n-octanol, the estimated Pow: < 0.2, the estimated log Pow: <-0.6.

Applicant's summary and conclusion

Conclusions:

Based on the individual solubility of test item in water and n-octanol, the estimated Pow: < 0.2, the estimated log Pow: <-0.6.

Executive summary:

The test item is a UVCB substance with an unknown and highly complex composition. Therefore, neither the estimation of the log Pow by QSAR nor its determination with OECD Guideline 107 (shake flask method) is feasible. For the HPLC-method (OECD Guideline 117), which is the recommended method for mixtures, the structural formula of the test item should be known and the test item must be soluble in the mobile phase in sufficient concentration. The test item does not meet those requirements since its structural formula is not known and it is insoluble in the mobile phases applicable for this method. Consequently, the HPLC-method (OECD Guideline 117) is also not feasible and the log Pow of the test item can only be estimated from its individual solubility in water and in n-octanol.

Considering the water solubility of 16.4 mg/L and the n-octanol solubility of < 4 mg/L a log Pow of <-0.6 has been estimated.