Castor oil, oligomeric reaction products with maleic anhydride

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

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

Deviations:

yes

Remarks:

LC / GPC

Principles of method if other than guideline:

OECD 107 states that measurements should be made on ionisable substances only in their non-ionized form (free acid or free base) produced by the use of an
appropriate buffer with a pH of at least one unit below (free acid) or above (free base) the pKa. ln this instance, as the test substance is a polymeric mixture, the work was performed at the natural pH of the test substance.

GLP compliance:

yes

Type of method:

flask method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Castor oil, oligomeric reaction products with maleic anhydride

EC Number:

500-202-3

EC Name:

Castor oil, oligomeric reaction products with maleic anhydride

Cas Number:

68308-83-8

Molecular formula:

n.a (UVCB)

IUPAC Name:

Castor oil, oligomeric reaction products with maleic anhydride

Test material form:

liquid: viscous

Study design

Analytical method:

liquid chromatography

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Partition coefficient:

> 1.96

Temp.:

25 °C

Remarks on result:

other: measured at given pH of the substance

Applicant's summary and conclusion

Conclusions:

The test substance, was detected in all noctanol solutions. Test substance was measured in one (Test 1A) of the water solutions, with no substance detected visually in the other water solutions. From comparison of Test 1A and the pre-saturated water blank, a rising baseline was observed in the blank and there was an indication that there was test substance present but this is not conclusive.
As the reported concentration of Test 1A is 37mg/L and the LOD of the method is 40mg/L, it was decided that all the water test solutions should be assigned as <40mg/L. There would be no considerable impact to the result (Log P mean).
The LOD of the method was based on the lowest standard concentration of 0.02mg/ml (20mg/L). As the water layers were diluted 1:1 with the mobile phase before analysis, this becomes 40 mg/L (reported as <40mg/L). Based on the raw data, the LOD of the method is confirmed as approximately <40mg/L. As the LOD is a "less than" value, the Log P is reported as a > value (>1.96) as the actual concentration of substance in test solution is lower than the assigned value.
The LOD value is based on the lowest Iimit of the developed method to give a more accurate Log P value. A more sensitive method could be developed but given the nature of the test substance this would be very difficult.

Executive summary:

OECD 107 Guideline states that individual Log P should be within ±0.3 units of the mean.

The values calculated are between ±0.42, due to the use of LOD values giving greater

variance but this is not regarded as a significant difference and the reported log mean P of

>1.96 is appropriate.