Registration Dossier

Administrative data

Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
Qualifier:
according to
Guideline:
EU Method A.8 (Partition Coefficient)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC method
Partition coefficient type:
octanol-water

Test material

Reference
Name:
Unnamed
Type:
Constituent

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
Type:
log Pow
Partition coefficient:
>= 0.463 - <= 0.467
Temp.:
22 °C
pH:
>= 5.4 - <= 5.5

Any other information on results incl. tables

The chromatogram of the test item gave 10 peaks. With the help of the calibration function log K versus log Pow, the corresponding log Pows were determined as:

 Peak  Mean retention time (min)

 Log Pow (Mean +-sd)

 1

1.128 

-1.842 (+-0.093) 
 2 1.638  0.465 (+-0.002) 
 3 2.152  1.069 (+-0.000) 
 4 2.599  1.391 (+-0.006) 
 5 2.902  1.559 (+-0.005) 
 6 3.127  1.666 (+-0.003) 
 7 4.115  2.030 (+-0.028) 
 8 6.018  2.480 (+-0.003) 
 9 6.752  2.608 (+-0.003) 
 10 7.902  2.778 (+-0.003) 

Peak 2 shows much larger areas than the other peaks. Although area is not necessarily correlated to absolute concentration if a UV detector is used, it is believed that the test item B 1061 consists mainly of this main peak, indicating, that the log Pow of the test item should be regarded as approx. 0.465.

As the first peak of the test item lies outside the range of the reference items, the log Pow of this peak should be stated as < 0.3 (log Pow of the first reference item).

Applicant's summary and conclusion

Conclusions:
Peak 2 shows much larger areas than the other peaks. Although area is not necessarily correlated to absolute concentration if a UV detector is used,
it is believed that the test item B 1061 consists mainly of this main peak, indicating, that the low Pow of the test item schould be regarded as approx.
0.465.
Executive summary:

The study was performed using a HPLC with a C18 column. Seven reference items with different retention times were used to produce a calibration curve, since retention time on hydrophobic columns and Pow are correlated. The reference items were chosen on behalf of the retention time of the test item on the column.

First, a solution of the reference items was analysed with HPLC, then a solution of the test item, and finally again the solution with the reference items. Each analysis was performed three times. For each reference item, the capacity factor K was calculated from the retention time of thio urea and the retention time of the respective reference item. A calibration function (log K versus log Pow, linear fit) was determined using the literature values for log Pow of the reference items and mean log K of the six determinations. The chromatogram of the test item gave 10 peaks. With the help of the calibration function log K versus log Pow, the corresponding log Pows were determined.

Peak 2 shows much larger areas than the other peaks. Although area is not necessarily correlated to absolute concentration if a UV detector is used, it is believed that the test item B 1061 consists mainly of this main peak, indicating, that the low Pow of the test item schould be regarded as approx. 0.465.