N,N''-(methylenedi-4,1-phenylene)bis[N'-octylurea]

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 15, 2003 - July 30, 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))

Version / remarks:

(2001)

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Details on study design: HPLC method:

CHROMATOGRAPY CONDITIONS
Pump: 114M (Beckman)
Mobile phase: 55/45 (v/v) methanol/water
Flow rate: 1 mL/min
Column: Zorbax CN, 150 mm x 4.6 mm i.d., dp= 5 µm (Interchim)
Detector: SpectraSERIES UV150 (TSP)
Column temperature: 25°C ± 1°C
Injector: 717plus (Waters)
Injection volume: 50 µL
UV detection: 210 nm (reference substance and formamide); 254 nm (test substance)
Analysis time: approx. 40 minutes

Reference substance: 4,4’-DDT (log Koc 5.63 according to OECD 121 based on soil adsorption data).
Determination of dead time: Formamide

PREPARATION OF SOLUTIONS
The 3 substances were dissolved in methanol and diluted in the mobile phase. Their concentrations were 500 µg/mL. Injected amounts:
4,4-DDT: 2652 ng
KY-UN: 4980 ng
Formamide: 260 ng

PERFORMANCE OF THE STUDY
The solutions were analysed by single injection. The test substance results were compared with the results of the reference substance.

Key result

Type:

log Koc

Value:

> 5.63 dimensionless

Remarks on result:

other: Koc: > 4.3 E5 L/kg

Details on results (HPLC method):

- In the HPLC chromatogram of the test substance solution, one peak with a retention time of 31.7 minutes was observed. Under the same analytical conditions, the retention time of 4,4’-DDT (log Koc 5.63) was 15.8 minutes
- The retention time of Formamide was 1.9 minutes

Validity criteria fulfilled:

yes

Conclusions:

Using the HPLC method and using soil-adsorption-reference data, the log Koc of KY-UN was determined to be > 5.63 (Koc > 4.27 E5).

Executive summary:

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of the substance. The mobile phase was 55/45 (v/v) methanol/water. The column temperature was 25°C. The HPLC chromatogram of the test substance showed one peak at 31.7 minutes. Under the same analytical conditions, the retention time of reference substance 4,4’-DDT (log Koc = 5.63) was 15.8 minutes. Hence, it was concluded that the log Koc of the test substance at neutral pH was > 5.63 (Koc > 4.27E5). The study was performed in accordance with OECD 121 and according to the principles of GLP.

Description of key information

Using the HPLC method and using soil-adsorption-reference data, the log Koc of KY-UN was determined to be > 5.63.

Using KOCWIN (v2.00), the Koc of KY-UN is calculated to be 859600 L/kg (log Koc = 5.93) based on the log Kow method, and 3612000 L/kg (log Koc = 6.56) based on the MCI method.

Key value for chemical safety assessment

Koc at 20 °C:

3 612 000

Additional information

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of the substance. The mobile phase was 55/45 (v/v) methanol/water. The column temperature was 25°C. The HPLC chromatogram of the test substance showed one peak at 31.7 minutes. Under the same analytical conditions, the retention time of reference substance 4,4’-DDT (log Koc = 5.63) was 15.8 minutes. Hence, it was concluded that the log Koc of the test substance at neutral pH was > 5.63 (Koc > 4.27E5). The study was performed in accordance with OECD 121 and according to the principles of GLP.

Using KOCWIN (v2.00), the Koc of KY-UN is calculated to be 859600 L/kg (log Koc = 5.93) based on the log Kow method, and 3612000 L/kg (log Koc = 6.56) based on the MCI method. The log Kow of 9.25 (KOWWIN calculation) is used in the log Kow method.

As the log Kow of 9.25 (KOWWIN calculation) used in the log Kow method is outside of the range of both the training set and validation set for this method, the result derived with the MCI method is considered to be the most reliable.