3-methoxy-N,N-dimethylpropionamide

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:

From 06 October 2011 to 08 October 2011

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

Qualifier:

according to guideline

Guideline:

EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))

Version / remarks:

2008

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Radiolabelling:

no

Details on study design: HPLC method:

HPLC CONDITIONS
- HPLC system with autosampler, column oven and UV detector
- Column: LiChrospher 100 CN 250 x 4 mm, 5 µm
- Column temperature: 25°C
- Mobile phase: 30/70 (v/v) methanol/water
- Flow: 1 mL/min
- Injection volume: 20 μL
- UV detection: 210 and 254 nm

UNRETAINED SUBSTANCE, REFERENCE SUBSTANCES AND TEST SUBSTANCE SOLUTIONS
- Unretained substance: sodium nitrate
- 6 Reference substances with known log Koc values ranging from 1.25 to 3.31: Acetanilide, Methyl benzoate, Isoproturon, Linuron, Naphthalene and Fenthion
- Solution of the unretained substance in mobile phase (ca. 100 mg/L).
- Solutions of the reference substances in mobile phase (ca. 10 mg/L).
- Test item solution in mobile phase (ca. 10 mg/L).

INJECTIONS
-Three series of the above reference solutions and the test item solution were measured alternately, with two replicate injections.
-For the determination of t0 (retention time of the unretarded component) sodium nitrate solution was injected.
-The retention times were determined.

DATA HANDLING
- Dead time t0 =1.45 min (mean)
- Capacity factors (k') for each reference substance were calculated from the retention times (tr). k'= (tr-t0)/t0
- Log k’ values (mean) of the references substances were plotted against the known log Koc values.
- Linear regression analysis (least squares method) resulted in the regression line log k’ = 0.4059 log Koc– 0.3524 (r^2=0.986, n=6)

Key result

Type:

log Koc

Value:

< 1.25 dimensionless

Temp.:

25 °C

Remarks on result:

other: non-buffered mobile phase

Conclusions:

The log Koc of the substance at ca. 20°C is < 1.25.

Executive summary:

The HPLC estimation method was used for the determination of the adsorption coefficient (Koc) of the substance. The study was performed in accordance with EC C.19 and OECD 121 and in compliance with GLP. The mobile phase was 30/70 (v/v) methanol/water and the wavelength of detection 210 nm or 254 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. The substance eluted before the reference substance with known log Koc of 1.25: log Koc of the substance at ca. 20°C is < 1.25.

Description of key information

log Koc at 20°C is < 1.25 (EC C.19, OECD 121: HPLC estimation method).

Key value for chemical safety assessment

Koc at 20 °C:

17.8

Additional information

HPLC-UV system with 30/70 (v/v) methanol/water as mobile phase and the wavelength of detection 210 nm or 254 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. The substance eluted before the reference substance with known log Koc of 1.25.