Hexamethylene diisocyanate, trimers, reaction products with 2-hydroxyethyl acrylate

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 Jul - 07 Sep 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP guideline study

Qualifier:

according to guideline

Guideline:

EU Method A.8 (Partition Coefficient - HPLC Method)

Version / remarks:

adopted in 2008

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted in 2004

GLP compliance:

yes (incl. QA statement)

Remarks:

Hess. Ministerium für Umwelt, Energie, Landwirtschaft und Verbraucherschutz, Wiesbaden, Germany

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Specific details on test material used for the study:

Storage conditions: Ambient temperature, keep container tightly closed, protected from sunlight

Analytical method:

other: The partition coefficient of the test item was obtained by interpolation of the calculated capacity factor on the calibration graph of the test items.

Type:

log Pow

Partition coefficient:

4.23

Temp.:

20 °C

Remarks on result:

other: pH not measured

Results
Preliminary test
The preliminary test at room temperature showed that the water solubility of the test item was below 9.74 mg/L (Table 1).

Table 1 – Water solubility preliminary test

Amount of test item [mg]	Added volume of water [mL]	Stirring time [min]	Remark
108.7	0.1	--	Not dissolved
	0.5	--
	1.0	--
	2.0	--
	10.0	--
	100.0	6*
9.74	1000	7145

*Treatment in ultrasonic bath

The preliminary test at room temperature showed that the octanol solubility of the test item was below 0.32 mg/L (Table 2).

Table 2 – Octanol solubility preliminary test

Amount of test item [mg]	Added volume of octanol [mL]	Stirring time at room temperature [min]	Remark
408.1	10	30	Not dissolved
	10	40
	50	85
	65	65
	100	1075
47.3	50	35
	100	1390

 

With the water solubility of < 10 mg/L and the octanol solubility of < 0.32 g/L, the partition coefficient was estimated to be above 1.5. Therefore, to determine the logP_OW, the HPLC method is recommended and was executed. 

Main test
After measurement of the retention times t_R, the log k values of the reference items were plotted as a function of their log P_OW values. The test item’s partition coefficient was obtained by interpolation of the calculated capacity factor on the calibration graph of the reference items. Table 3 shows the measurements of the dead time marker and tabled 4 and 5 show the results of the reference items for the 1^st and 2^nd measurement series respectively.

Table 3 – Retention time of dead time marker

	1^strun	2^ndrun	Mean value
t0(min)	1.491	1.495	1.493

 

Table 4 – Retention times of the reference items (1^st measurement)

Reference item	tR	k	Log k	Log POW*
Acetanilide	2.686	0.799	-0.097	1.0
4-methyl benzyl alcohol	3.299	1.210	0.083	1.6
Cinnamyl alcohol	3.620	1.425	0.154	1.9
Allyl phenyl ether	10.556	6.070	0.783	2.9
Diphenyl ether	20.778	12.917	1.111	4.2
Fluoroanthene	47.731	30.970	1.491	5.1

*literature values of logP_OW from OECD Test Guideline 117 (2004)

The first measurement and the linear regression of the calibration graph leads to an equation for the log P_OW of:

log P_OW= 2.479 . log k + 1.327
correlation coefficient r = 0.9919

Table 5 - Retention times of the reference items (2^ndmeasurement)

Reference item	tR	k	Log k	Log POW*
Acetanilide	2.683	0.797	-0.099	1.0
4-methyl benzyl alcohol	3.300	1.210	0.083	1.6
Cinnamyl alcohol	3.625	1.428	0.155	1.9
Allyl phenyl ether	10.588	6.092	0.785	2.9
Diphenyl ether	20.829	12.951	1.112	4.2
Fluoroanthene	47.805	31.019	1.492	5.1

*literature values of logP_OWfrom OECD Test Guideline 117 (2004)

The second measurement and the linear regression of the calibration graph leads to an equation for the log P_OWof:

log P_OW= 2.477 . log k + 1.327
correlation coefficient r = 0.9919

With the determined regression coefficients ‘a’ and ‘b’, the log P_OW of the test item can be calculated for both measurements. Table 6 shows the measured retention times of the test item and the calculated log P_OW values for both measurement series.

Table 6 – Test item retention times

Test item	tR	k	log k	log POW	POW
1^stmeasurement	23.595	14.804	1.170	4.23	16931
2^ndmeasurement	23.691	14.868	1.172	4.23	17008
Mean value				4.23	16969
Standard deviation				< 0.01	54

The test item has a partition coefficient at 20 °C of log P_OW= 4.23 ± < 0.01

Description of key information

log P_OW = 4.23 ± < 0.01 at 20 °C (OECD 117, HPLC method)

Key value for chemical safety assessment

Log Kow (Log Pow):

4.23

at the temperature of:

20 °C

Additional information

pH not measured