Reaction product of o-cresol and camphene, obtained by addition, hydrogenation and distillation

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 - 19 Jul 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes (incl. QA statement)

Remarks:

Swiss Federal Office of Public Health

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

>= 5.71 - <= 6.04

Temp.:

20 °C

pH:

7.6

Remarks on result:

other: evaluation based on six peaks representing >90% of the test item

Results of the calibration

The R² fit of the calibration curve used was 0.9955. The deviations of calculated log Pow values from actual log Pow values were 3 % at maximum. This reflects the linear correlation between the logarithms of the capacity factors of the HPLC system and the log Pow values of the reference items in the applied range of 2.7 to 6.5.

 

 

Results of the partition coefficient determination for the test item

The test item showed a chromatographic profile consisting of several peaks. It could be verified that the six peaks with retention times between 16.8 and 20.8 minutes are representing more than 90 % of the test item (area %). The evaluation was based on these peaks. The log Pow values for the compounds relating to these peaks were found to be 5.71 (Peak 1), 5.75 (Peak 2), 5.81 (Peak 3), 5.92 (Peak 4), 5.97 (Peak 5) and 6.04 (Peak 6). The data are given in the following table.

 

Peak Number	Solution	Run	Retention Time [min]	log k’	Log POW	Mean	Standard Deviation
Peak 1	Solution 1	1^strun	16.773	1.132	5.714	5.71	±0.01
		2^ndrun	16.767	1.132	5.714
	Solution 2	1^strun	16.767	1.129	5.705
		2^ndrun	16.747	1.128	5.703
Peak 2	Solution 1	1^strun	17.220	1.144	5.755	5.75	±0.01
		2^ndrun	17.213	1.144	5.754
	Solution 2	1^strun	17.213	1.141	5.745
		2^ndrun	17.187	1.140	5.742
Peak 3	Solution 1	1^strun	17.960	1.164	5.819	5.81	±0.01
		2^ndrun	17.953	1.163	5.818
	Solution 2	1^strun	17.953	1.161	5.809
		2^ndrun	17.920	1.160	5.806
Peak 4	Solution 1	1^strun	19.253	1.196	5.925	5.92	±0.01
		2^ndrun	19.253	1.196	5.925
	Solution 2	1^strun	19.253	1.193	5.915
		2^ndrun	19.213	1.192	5.912
Peak 5	Solution 1	1^strun	19.887	1.211	5.974	5.97	±0.01
		2^ndrun	19.887	1.211	5.974
	Solution 2	1^strun	19.887	1.208	5.964
		2^ndrun	19.847	1.207	5.961
Peak 6	Solution 1	1^strun	20.813	1.232	6.042	6.04	±0.01
		2^ndrun	20.807	1.232	6.042
	Solution 2	1^strun	20.807	1.229	6.033
		2^ndrun	20.78	1.228	6.031

 

 

There were two more peaks to see on the test item chromatogram with retention times of 52.1 and 57.3 minutes (see Figure 3). These peaks were beyond the acceptability range of the Guideline, and represent less than 10 % of the test item (area %). They were not evaluated.

 

Conclusion

During this study, the partition coefficient (n-octanol/water) of the test item was determined using the HPLC method. The log Pow values based on six peaks representing more than 90 % of the test item ranged from 5.71 to 6.04.

Conclusions:

A partition coefficient range of 5.71 to 6.04 (at 20 °C) was determined for the test substance according to OECD 117.

Description of key information

Log Pow range: 5.71 to 6.04 at 20°C (OECD 117, HPLC Method)

Key value for chemical safety assessment

Log Kow (Log Pow):

6.04

at the temperature of:

20 °C

Additional information

The test item showed a chromatographic profile consisting of several peaks. The log Pow values based on six peaks representing more than 90 % of the test item ranged from 5.71 to 6.04.