Producto P0310

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

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

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Radiolabelling:

no

Test temperature:

25 ºC

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:
Varian autosampler 9095
Varian Pump 9012
Varian UV/VIS detector 9050
Jones column oven 7990
- Type, material and dimension of analytical (guard) column: LiChrospher 100 CN, particle size 5 μm, 250 mm x 4 mm
- Detection system: UV/VIS
Test item: 350 nm
Reference items: 210 nm
Sodium nitrate: 210 nm

MOBILE PHASES
- Type: Water / methanol (45:55; v/v); pH 7.1

DETERMINATION OF DEAD TIME
- Method: Sodium nitrate (12.83 mg) was dissolved in 10 ml of methanol to obtain a stock solution. The stock solution (10 μl) was diluted to 1 ml with a solvent mixture of water and methanol (45:55; v/v). This sodium nitrate solution was injected twice for the determination of the dead time of the HPLC system.

REFERENCE SUBSTANCES
- Identity: Sodium nitrate; Acetanilide; Isoproturon; Linuron; Pyrazophos; Diclofop-methyl; 2,4-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: The test substance (34.95 mg) was dissolved in a solvent mixture of water and methanol
(45:55; v/v) (100 ml) to prepare a stock solution of 349.5 μg/ml. The stock solution (2 ml) was diluted with a solvent mixture of water and methanol (45:55; v/v) to 10 ml to obtain a standard solution of 69.9 μg/ml. The pH value of the test item solution was determined to be 6.9. This test item solution was injected three times.

REPETITIONS
- Number of determinations: The test item solution was injected three times and the combined reference solution was injected six times.

Key result

Type:

Koc

Value:

< 18

Temp.:

25 °C

Details on results (HPLC method):

The log KOC of the test item peak was calculated using a regression curve (log k' vs. log KOC) and was found to be < 1.25 (below the lowest reference item used), which is equal to a KOC value of < 18. In the present study the reference items covered the range of log KOC 1.25 to log KOC 5.63.

Validity criteria fulfilled:

yes

Conclusions:

In conclusion, the log of the adsorption coefficient (KOC) of the test substance was estimated to be log KOC < 1.25 which is equal to a KOC value of < 18 using the HPLC method. This value indicates that the test substance is of high mobility.

Executive summary:

The determination of the adsorption coefficient (KOC) of the test substance was performed according to the OECD Guideline for the Testing of Chemicals, No. 121, Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January, 2001 and the EC Directive 2001/59, C.19. The test item solution was injected three times and the combined reference solution was injected six times. The log KOC of the test item peak was calculated using a regression curve

(log k' vs. log KOC) and was found to be < 1.25 (below the lowest reference item used), which is equal to a KOC value of < 18. In the present study the reference items covered the range of log KOC 1.25 to log KOC 5.63. The chromatography of the test item

resulted in one main peak. The retention time of the peak was reproducible. The HPLC method was therefore considered to be suitable for the purpose of the study. The capacity factor (k’) was calculated for each reference item using the retention times. In conclusion, the log of the adsorption coefficient (KOC) of the test substance was estimated to be log KOC < 1.25 which is equal to a KOC value of < 18 using the HPLC method. This value indicates that the test substance is of high mobility.

Description of key information

Key study: OECD guideline 121 and EU method C.19. GLP study.

In conclusion, the log of the adsorption coefficient (KOC) of the test substance was estimated to be log KOC < 1.25 which is equal to a KOC value of < 18 using the HPLC method. This value indicates that the test substance is of high mobility.

Key value for chemical safety assessment

Koc at 20 °C:

18

Additional information

Key study: OECD guideline 121 and EU method C.19. GLP study.

In conclusion, the log of the adsorption coefficient (KOC) of the test substance was estimated to be log KOC < 1.25 which is equal to a KOC value of < 18 using the HPLC method. This value indicates that the test substance is of high mobility.

[LogKoc: 1.25]