Potassium hexadecyl hydrogen phosphate

Partition coefficient

Link to relevant study record(s)

Reference

Endpoint:

partition coefficient

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 2020-03-13 to 2020-04-18

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 123 (Partition Coefficient (1-Octanol / Water), Slow-Stirring Method)

Version / remarks:

2006

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

slow-stirring method

Partition coefficient type:

octanol-water

Analytical method:

high-performance liquid chromatography

mass spectrometry

Key result

Type:

log Pow

Partition coefficient:

2.66

Temp.:

25 °C

pH:

6.3

Stirring Time [hours]	Measured Concentration in n-Octanol [μg/L]	Sample Preparation Factor	Determined Concentration in n-Octanol [μg/L]	Measured Concentration in Water [μg/L]	Sample Preparation Factor	Determined Concentration in Water [μg/L]	Log Pow	Mean
Assay 1
24	159	100	15942	10.59	10	105.9	2.18
29	155	100	15481	8.02	10	80.2	2.29
34	158	100	15763	8.86	10	88.6	2.25
48	165	100	16497	5.60	10	56.0	2.47
53	164	100	16350	5.09	10	50.9	2.51
58	119	100	11867	5.03	10	50.3	2.37
72	173	100	17291	4.60	10	46.0	2.58
77	162	100	16191	4.85	10	48.5	2.52
144	168	100	16835	3.93	10	39.3	2.63	2.62 ± 0.03
149	174	100	17361	4.40	10	44.0	2.60
168	158	100	15832	4.10	10	41.0	2.59
173	162	100	16185	3.59	10	35.9	2.65
Assay 2
24	169	100	16854	8.38	10	83.8	2.30
29	166	100	16594	5.05	10	50.5	2.52
34	158	100	15754	3.27	10	32.7	2.68
48	169	100	16880	3.83	10	38.3	2.64
53	155	100	15489	3.22	10	32.2	2.68
58	165	100	16537	3.73	10	37.3	2.65
72	161	100	16067	3.36	10	33.6	2.68
77	162	100	16241	3.43	10	34.3	2.68
144	155	100	15511	3.13	10	31.3	2.70	2.66 ± 0.09
149	163	100	16261	2.82	10	28.2	2.76
168	152	100	15156	3.63	10	36.3	2.62
173	141	100	14092	3.88	10	38.8	2.56
Assay 3
24	155	100	15452	211	10	2108	2.21
29	158	100	15779	9.64	10	96.4	2.39
34	170	100	17024	6.44	10	64.4	2.46
48	168	100	16807	5.88	10	58.8	2.58
53	162	100	16233	4.37	10	43.7	2.62
58	174	100	17424	3.93	10	39.3	2.67
72	163	100	16252	3.77	10	37.7	2.67
77	174	100	17355	3.45	10	34.5	2.72
144	151	100	15069	3.27	10	32.7	2.73	2.71 ± 0.05
149	163	100	16274	2.84	10	28.4	2.77
168	150	100	15044	2.75	10	27.5	2.68
173	147	100	14680	3.13	10	31.3	2.65
Overall Mean (n = 12)								2.66 ± 0.08

Conclusions:

The log Pow of the test item was determined to be 2.66 ± 0.08.

Executive summary:

A study was conducted according to OECD No. 123 to determine the octanol-water partition coefficient with the slow-stirring method. The slow-stirring method was used, because the test item was expected to have surface active properties. Thermostated glass flasks containing the aqueous phase and n-octanol were slowly stirred, after dosing the test item dissolved in water, until equilibrium distribution of the test item between the two phases was achieved. The temperature was kept constant at 25 °C ± 1 °C. The log Pow was calculated from the determined analytical concentrations of the test item in both phases. The equilibrium distribution was defined to be achieved, when four sampling intervals separated by at least 5 hours yielded similar log Pow values. The testing was performed in triplicate. The log Pow of the test item was determined to be 2.66 ± 0.08.

Description of key information

The log Pow of the test item was determined to be 2.66 ± 0.08.

Key value for chemical safety assessment

Log Kow (Log Pow):

2.66

at the temperature of:

25 °C

Additional information

A study was conducted according to OECD No. 123 to determine the octanol-water partition coefficient with the slow-stirring method. The slow-stirring method was used, because the test item was expected to have surface active properties. Thermostated glass flasks containing the aqueous phase and n-octanol were slowly stirred, after dosing the test item dissolved in water, until equilibrium distribution of the test item between the two phases was achieved. The temperature was kept constant at 25 °C ± 1 °C. The log Pow was calculated from the determined analytical concentrations of the test item in both phases. The equilibrium distribution was defined to be achieved, when four sampling intervals separated by at least 5 hours yielded similar log Pow values. The testing was performed in triplicate. The log Pow of the test item was determined to be 2.66 ± 0.08.