1-Butanone, 2-(dimethylamino)-2-[(4-methylphenyl)methyl]-1-[4-(4-morpholinyl)phenyl]-

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:

2002

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))

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Test temperature:

25°C

Details on study design: HPLC method:

HPLC conditions (HPLC with UV/Vis detector, reversed phase column and aqueous mobile phase):
- Apparatus: Varian Autosampler 9100, Varian Pump ProStar 230, Varian Detector ProStar 310m Jones Column Oven 7990
- Column: Bondapack Phenyl, part. size 5 μm, 300 mm x 3.9 mm
Eluent A: methanol and water (40:60; v/v)
Eluent B: acetonitrile, ethanol and water (50:45:5, v/v/v)
- Mobile phase:
0 min: 100% A, 0% B
0-8 min: 100% A, 0% B
8-15 min: 40% A, 60% B (gradient)
15-17 min: 40% A, 60% B
17-17.1 min: 10% a, 90% B
17.1-22 min: 10% A, 90% B
22-22.1 min: 100% A, 0% B
22.1-28 min: 100% A, 0% B
- Detection: 210 nm for the reference items and for sodium nitrate, 254 nm for the test item solution
- Injection volume: 20 μL
- Flow: 1.0 mL/min

First a test was performed to elute the test substance with methanol/water as eluting solvent and with a CN-column as mentioned in the guideline. The test item was not elutable with these parameters. Therefore the HPLC method was adjusted as described above.

Test system:
- Test item solution:
12.5 mg of test substance were dissolved in methanol (100 mL) to prepare a stock solution of 125 μg/mL. The pH value of the test item solution was determined to be 7.8.
The test item solution was injected three times.
- Reference solutions:
The reference items were chosen from the list given in the OECD guideline no. 121.
Stock solutions of the reference items in methanol were prepared as described: 10 μL of the reference item fenthion and 10 mg of the reference items isoproturon; triadimenol, linuron, 2,4-DDT and pyrazophos, respectively, were each dissolved in 10 mL methanol.
A combined reference solution was prepared by transferring 0.5 mL of the isoproturon, 1 mL of the triadimenol , 0.225 mL of the linuron, 1 mL of the pyrazophos, 0.25 mL of the fenthion and 0.5 mL of the 2,4-DDT stock solution into one volumetric flask and diluting to a volume of 10 mL with methanol. This reference solution was injected six times.
Sodium nitrate (10 mg) was diluted to 10 mL with methanol to obtain a stock solution. The stock solution (10 μL) was diluted to 1 mL with methanol. This sodium nitrate solution was injected two times and was used for the determination of the dead time of the HPLC system.

The whole test item handling was performed under red light.

Type:

Koc

Value:

3 431

Temp.:

25 °C

Remarks on result:

other: HPLC analysis

Type:

log Koc

Value:

3.5

Temp.:

25 °C

Remarks on result:

other: HPLC analysis

Type:

Koc

Value:

>= 3 067

Remarks on result:

other: calculation using water solubility

Type:

Koc

Value:

4 049

Remarks on result:

other: calculation using logPow

Details on results (HPLC method):

The log Koc was calculated using a regression curve (log k' vs. log koc) and was found to be 3.5 which is equal to a Koc value of 3431. In the present study the reference items covered the range of log Koc 1.86 to log Koc 5.63.
The retention times of the individual measurements of the reference items, test item and for the determination of the dead time are given in the section "Any other information on results incl. tables" as well as the mean retention times and the derived capacity factors.
Using the corresponding log Koc values of the reference items from the OECD guideline, the regression coefficient was calculated. The log Koc value of the test item was calculated from the calibration equation.

The chromatography of the test item resulted in one sharp main peak with a welldefined and reproducible retention time. The HPLC method was, therefore, considered to be suitable for the purpose of the study. Based on the chromatographic data, the test substance was considered to be stable during the test procedure.
It was not possible to determine the adsorption coefficient of the test substance with methanol/water as eluting solvent and with a CN-column as mentioned in the guideline. Referring to this a adjusted HPLC method with a gradient system was used. Additionally the adsorption coefficient (Koc) of the test substance was estimated using a calculation method to be 3067 or higher. This means that the test substance is classified as immobile in soils.

In conclusion, the log of the adsorption coefficient (Koc) of the test substance was estimated to be log Koc = 3.5 which is equal to a Koc value of 3431, using the HPLC method.
This value indicates that the test substance is immobile and remains preferably in soil.

Retention times in minutes of the reference items and the test item:

	1st run	2nd run	3rd run	4th run	5th run	6th run
Sodium nitrate (= dead time)	1.728	1.727
Reference items
Isoproturon	15.249	15.294	15.251	15.273	15.319	15.260
Triadimenol	16.311	16.348	16.316	16.333	16.346	16.325
Linuron	16.928	16.963	16.940	16.948	16.944	16.942
Fenthion	18.476	18.527	18.485	18.477	18.482	18.483
Pyrazophos	18.965	19.021	18.971	18.958	18.965	18.971
DDT	20.825	20.843	20.818	20.809	20.802	20.820
Test item	18.133	18.111	18.139

Deetemrination of the adsorption coefficient (Koc) of the test substance:

	Number of analysis	Mean retention time (min)	k'	logk'	logKoc
Sodium nitrate (= dead time)	2	1.73
Reference items
Isoproturon	6	15.27	7.84	0.89	1.86
Triadimenol	6	16.33	8.45	0.93	2.40
Linuron	6	16.94	8.81	0.94	2.59
Fenthion	6	18.49	9.70	0.99	3.31
Pyrazophos	6	18.98	9.98	1.00	3.65
DDT	6	20.82	11.05	1.04	5.63
Test item	3	18.13	9.50	0.98	3.54
		18.11	9.48	0.98	3.52
		18.14	9.50	0.98	3.54
Linear regression	slope				0.039
	y-axis intercept				0.840
	coefficient of regression				0.956

Validity criteria fulfilled:

yes

Conclusions:

The logKoc of the test substance was estimated to be 3.5 at 25 °C which is equal to a Koc value of 3431, using the HPLC method. Therefore, adsorption to solid soil phase is expected.

Executive summary:

In this guideline (OECD 121) study conducted to GLP standards, the test material (EC 438-340-0) was determined to have a logKoc = 3.5 at 25 °C

Description of key information

Study conducted to recognised testing guidelines with GLP.

Key value for chemical safety assessment

Koc at 20 °C:

3 431

Additional information

The determination of the adsorption coefficient of the test substance was performed according to the OECD guideline no. 121 (RCC Ltd. 2002c). The logKoc was found to be 3.5 (Koc = 3431).

Additionally the adsorption coefficient was estimated using a calculation to be 3067 or higher.

These values indicate that the test substance is immobile and remains preferably in soil - adsorption to solid soil phase is expected.

[LogKoc: 3.5]