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Partition coefficient

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Reference
Endpoint:
partition coefficient
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2012-01-20 to 2012-01-23
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Qualifier:
according to
Guideline:
OECD Guideline 117 (Partition Coefficient (n-octanol / water), HPLC Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC method
Partition coefficient type:
octanol-water
Analytical method:
high-performance liquid chromatography
Type:
log Pow
Partition coefficient:
< 0.5
Temp.:
50 °C
pH:
5.8
Details on results:
The mean value of the log Pow is < 0.5. This result issued from the 3 determinations is in the guideline
tolerance for repeatability (+/- 0.1 log units.).

The results of the partition coefficient determination of N,N DIETHYLHYDROXYLAMINE are given in the following tables:

 

Products

Mean Retention Time (min)

Value of log k’

Value of log Pow

Formamide

3.54

-

-

4-Acetylpyridine

4.498

-0.56763775

0.5

Aniline

5.269

-0.31120827

0.9

Acetanilide

5.541

-0.24775617

1.0

Benzylalcohol

5.981

-0.16143548

1.1

Acetophenone

7.962

0.096615476

1.7

Benzene

13.874

0.465265195

2.1

Toluene

25.016

0.782950133

2.7

 

 

Using the Capacity factor k’ and the partition coefficient log Pow of the reference items, the following calibration curve was obtained:

 

log Pow = 1.6246 log k’ + 1.4154         r2 = 0.9931

 

The following table gives the log Pow values of N,N DIETHYLHYDROXYLAMINE obtained for 3 determinations:

 

 

Retention time, min.

 

Average retention time, min.

 

  log Pow

 

Average log Pow

 

3.67

 

 

3.67

 

<0.5

 

 

<0.5

 

3.67

 

<0.5

 

3.67

 

<0.5

 

The mean value of the log Pow is <0.5. This result issued from the 3 determinations is in the guideline tolerance for repeatability (+/-0.1log units.).

Conclusions:
The mean value of the log Pow is < 0.5. This result issued from the 3 determinations is in the guideline tolerance for repeatability (+/- 0.1 log units.).

Validity criteria
The temperature during the measurement did not vary by more than +/- 1°C.

Repeatability
The value of log Pow derived from repeated measurements made under identical conditions and using the same set of reference substances did fall within a range of +/- 0.1 log units.

Reproducibility
If the measurements are repeated with a different set of reference substances, results may differ. Typically, the correlation coefficient for the relationship between log k’ and log Pow for a set of test substances is around 0.9. The correlation coefficient was 0.9931.
Executive summary:

The mean value of log Pow of the different components of N,N DIETHYLHYDROXYLAMINE determined according to OECD 117 and GLP requirements was <0.5. During the analysis, the temperature was 50°C and the pH value was 5.8. Validity criteria were fulfilled.

 

Description of key information

The Log Kow of  N,N-diethylhydroxylamine is determined to be = 0.5.

Key value for chemical safety assessment

Log Kow (Log Pow):
0.5
at the temperature of:
23 °C

Additional information

The mean value of log Pow of the different components of N,N DIETHYLHYDROXYLAMINE determined according to OECD 117 and GLP requirements was<0.5 (Study report, 2012a). During the analysis, the temperature was 50°C and the pH value was 5.8.Validity criteria were fulfilled.

Another study performed according the EU Method A.8 confirmed that the main compound has a log Kow = 0.5 at 23°C and a pH between 6 and 8 (Study report, 2012b).