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Administrative data

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

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
according to guideline
OECD Guideline 107 (Partition Coefficient (n-octanol / water), Shake Flask Method)
GLP compliance:
yes (incl. QA statement)
Type of method:
shake-flask method to: flask method
Partition coefficient type:

Test material

Constituent 1
Test material form:
solid: particulate/powder
migrated information: powder

Study design

Analytical method:
high-performance liquid chromatography

Results and discussion

Partition coefficient
log Pow
Partition coefficient:
20 °C
ca. 4.89

Applicant's summary and conclusion

During the preliminary test, the log Pow of ucb 22060 was estimated to be -1.3. Therefore
the flask shaking method was chosen to conduct the main test.
During the main study, three tests were carried out, each in duplicate, with volume ratios of
both solvents of 1:1, 2:1 and 1:2. After equilibration the concentration of the test item was
determined in every phase by HPLC. The results of the individual measurements are
summarised in Table 3. The tabulated values represent rounded results, which were obtained
by calculation using the exact raw data. The log Pow was calculated for each of the six
vessels and was found to be in the range of -0.65 to – 0.67.
In order to check the anal~tcal work, the mass balance for each vessel was calculated, too,
and the recovery of the test item was found to be in the range of 97 YO to 99 Yo. Details are
given in Table 4. The tabulated results represent rounded-off values obtained by calculations
based on the exact raw data.
A typical chromatogram of a standard solution is given in Figure 3. A typical chromatogram of
an aqueous sample solution is given in Figure 4. A typical chromatogram of a sample
solution in n-octanol is given in Figure 5. The calibration data for test item-standards are
given in Table 5. The r’ fit was 0.9999 (optimum 1.0000). This reflects the linearity of the
HPLC-system within the calibration range of 0.080 pg/ml to 1.334 pg/ml of the test item.
In conclusion, the partition coefficient of ucb 22060 was determined to be
log Pow = -0.7
using the flask shaking method.