Dipotassium titanium oxide dioxalate

Partition coefficient

Administrative data

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)

Deviations:

no

GLP compliance:

no

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Test material

Test material information

Constituent 1

Reference substance name:

Dipotassium titanium oxide dioxalate

EC Number:

238-475-3

EC Name:

Dipotassium titanium oxide dioxalate

Cas Number:

14481-26-6

Molecular formula:

C4K2O9Ti

IUPAC Name:

dipotassium oxotitaniumbis(ylium) dioxalate

Results and discussion

Partition coefficient

Key result

Type:

log Pow

Remarks on result:

not determinable because of methodological limitations

Details on results:

The partition coefficient (n-octanol/water) of the test item was estimated by performing the OECD
guideline 117. No information was available on the dissociation coefficient of the test item. So in a first
time, the HPLC method was applied with 6 reference items on C18 column eluated with water / Methanol
(45/55) without buffer.
In these conditions, the retention time of the test item was observed in the dead time. So the Log Pow
of the test item was estimated < 0. Consequentially, the Log Pow estimated was not in the applicability
range of the method (0 to 6) as described in the OECD guideline 117 § 4.
In addition, this result may suppose that the test item was dissociated in the mobile phase used.
Thus, additional tests on the solubility of the test item was carried out with mobile phase buffered in acid
and basic conditions.
These tests shown that the test item is soluble in the mobile phase at pH 2 but not soluble in the mobile
phase buffered at pH 9 (probably in their non-ionised form).
To conclude, the test OECD 117 is not applicable on the test item in their non-ionised form and can not
be performed.

Applicant's summary and conclusion

Conclusions:

The Log Pow of the test item was estimated < 0 so it is not in the applicability range 0 to 6 of the OECD
guideline 117 (§ 4 of the guideline). This result may suppose that the test item was dissociated in the
mobile phase used (Ultra-pure water / Methanol (45/55) without buffer).
No information was available on the dissociation coefficient of the test item, so additional tests on the
solubility was carried out with acid and basic buffer in order to performed the OECD 117 with the test
item in their non-ionised form. As recommended in the OECD guideline § 9.
The solubility tests (figure 1) shown that the test item is not soluble in the mobile phase buffered at pH
9 (probably in their non-ionised form).
To conclude, the test OECD 117 is not applicable on the test item in their non-ionised form and can not
be performed.