1-(4-methyl-2-nitrophenylazo)-2-naphthol

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 Apr - 06 May 2022

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7570 (Partition Coefficient, n-octanol / H2O, Estimation by Liquid Chromatography)

Version / remarks:

August 1996

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

April 2004

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

Key result

Type:

log Pow

Partition coefficient:

5.4

Temp.:

25 °C

pH:

7

Details on results:

The partition coefficient was determined based on a calibration curve using nine reference items.
The logarithmic partition coefficient (n-octanol/water) of the test item was determined to be 5.4 at 25 °C using the HPLC-method.

Capacity Factor k' and log P_ow of Reference Test Item

Test item	Retention Time	Capacity Factor	log k'	log Pow	log Pow
1,4 Dichlorbenzol	[min]				literature value
10 mg/L	2.473	2.090	0.320	3.838	3.4
10 mg/L	2.471	2.087	0.320	3.836	3.4
10 mg/L	2.471	2.087	0.320	3.836	3.4
100 mg/L	2.482	2.101	0.322	3.844	3.4
100 mg/L	2.478	2.096	0.321	3.841	3.4
100 mg/L	2.474	2.091	0.320	3.839	3.4
mean value	2.475	2.092	0321	3.839
standard deviation	0.004	0.005	0.001	0.003
rel.standard deviation	0.176%	0.26%	0.35%	0.1%

 

Capacity Factor k' and log P_ow of Reference Items:

Item	Replicate of analysis	Retention Time[min]	Capacity Factor	log Pow	log k
Formamide (dead time)	3	0.800	n.a.	n.a.	n.a.
Anilin	3	0.934	0.167	0.9	-0.777
1-Naphthol	3	1.323	0.653	2.7	-0.185
4-Phenylphenol	3	1.561	0.950	3.2	-0.022
Diphenylamine	3	1.974	1.466	3.4	0.166
1,2,4-Trichlorbenzene	3	3.934	3.915	4.2	0.593
Phenanthrene	3	4.498	4.621	4.5	0.665
Fluoranthene	3	6.375	6.965	5.1	0.843
Triphenylamine	3	9.246	10.552	5.7	1.023
DDT (Peak1;p,p'-DDT)	3	13.454	15.810	6.5	1.199

 

Capacity Factor k' and log P_ow of Test Item

Test Item	Retention Time	Capacity Factor	log k'	log Pow
	[min]
Test Item 5 mg/L	7.109	7.883	0.897	5.374
Test Item 5 mg/L	7.099	7.870	0.896	5.372
Test Item 5 mg/L	7.093	7.863	0.896	5.371
Test Item 50 mg/L	7.100	7.871	0.896	5.373
Test Item 50 mg/L	7.104	7.876	0.896	5.373
Test Item 50 mg/L	7.117	7.893	0.897	5.376
mean value	7.104	7.876	0.896	5.4
standard deviation	0.008	0.011	0.001	0.002
rel. standard deviation	0.119%	0.134%	0.065%	0.029%

Conclusions:

The partition coefficient was determined based on a calibration curve using nine reference items.
The logarithmic partition coefficient (n-octanol/water) of the test item was determined to be 5.4 at 25 °C using the HPLC-method.

Executive summary:

Test Method: The partition coefficient of the test item was estimated using HPLC-method. The solutions of the test item were injected three times in two different concentrations (< 5 mg/L and < 50 mg/L).

Results:

The partition coefficient was determined based on a calibration curve using nine reference items. The logarithmic partition coefficient (n-octanol/water) of the test item was determined to be 5.4 at 25 °C using the HPLC-method.

 

Key value for chemical safety assessment

Log Kow (Log Pow):

5.4

at the temperature of:

25 °C