1,1-diethoxyethane

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 2018-03-20 to 2018-12-04

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)

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

EU A.24

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:

< 1

Temp.:

20 °C

pH:

7.1

Preliminary Test

The preliminary test at room temperature showed, that the octanol solubility of the test item was above 62.1 kg/L.

Table 1: Preliminary test for the octanol solubility

Amount of test item [g]	Volume of octanol [mL]	Stirring time at RT [min]	Remark
1.42	30	130	directly dissolved
40.4	5	40	directly dissolved
23.2	1	45	directly dissolved
31.1	0.5	30	directly dissolved

With the water solubility of 72 to 191 g/L, determined in the preliminary test of the water solubility study, and the solubility in octanol, determined in this study, the partition coefficient was estimated to be above 0.

For the determination of the log POW at this value the HPLC method was carried out.

 

Main Test

Table 2: Retention times of the test item

test item	tR	k	log k	log Pow	Pow
1st measurement	1.921	0.118	-0.930	0.47	2.95
2nd measurement	1.921	0.118	-0.930	0.47	2.94
mean value				0.47	2.95
standard deviation				< 0.01	<0.01

 

Due to the fact that the measured retention time of the test item was below the one of the reference item with the lowest log Pow (1.0, acetanilide) the partition coefficient of the test item at 20 °C and pH 7.1 could only be estimated to be log Pow < 1.0.

Conclusions:

The partition coefficient of the test item was estimated to be to be below 1.0.

Executive summary:

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. 0.2 mg of the test item were dissolved in 100 mL acetonitrile and an aliquot diluted from 0.75 mL to 1 mL with double distilled water. After equilibration of the HPLC system, the calibration mixture was injected twice, followed by the test chemical solution twice. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The partition coefficient of the test item was obtained by interpolation of the calculated capacity factor on the calibration graph of the reference items. The value determined for the partition coefficient n-octanol/water for the test item was 0.47. Due to the fact that the measured retention time of the test item was below the one of the reference item with the lowest log Pow (1.0, acetanilide) the partition coefficient of the test item at 20 °C and pH 7.1 could only be estimated, according to Regulation EC No. 440/2008 method A.8. and OECD Test Guideline 117, to be log Pow < 1.0.

Description of key information

The partition coefficient of the test item was estimated to be to be below 1.0.

Additional information

A study was conducted in accordance with OECD TG 117 and Regulation (EC) No 440/2008 method A.8 to determine the partition coefficient of the test substance using the HPLC method. 0.2 mg of the test item were dissolved in 100 mL acetonitrile and an aliquot diluted from 0.75 mL to 1 mL with double distilled water. After equilibration of the HPLC system, the calibration mixture was injected twice, followed by the test chemical solution twice. Retention times tR were measured and averaged and the decimal logarithms of the capacity factors k were calculated. The partition coefficient of the test item was obtained by interpolation of the calculated capacity factor on the calibration graph of the reference items. The value determined for the partition coefficient n-octanol/water for the test item was 0.47. Due to the fact that the measured retention time of the test item was below the one of the reference item with the lowest log Pow (1.0, acetanilide) the partition coefficient of the test item at 20 °C and pH 7.1 could only be estimated, according to Regulation EC No. 440/2008 method A.8. and OECD Test Guideline 117, to be log Pow < 1.0 (reference 4.7-1).