6-ethyl-5-fluoro-4(3H)-pyrimidone

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 1998-11-13 to 1999-03-03

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:

April 1994

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Specific details on test material used for the study:

Batch No.: 960509
Purity: 92.3%

Radiolabelling:

no

Test temperature:

20 ℃

Details on study design: HPLC method:

EQUIPMENT
- Type, material and dimension of analytical (guard) column: Cyano Apex. 5 μm, 25 cm x 4.6 mm id.
- Detection system: Model 481, Waters Associates

MOBILE PHASES
- Type: Methanol/0.01 M citrate buffer, 55/45, vv
- pH: 6.53
- Solutes for dissolving test and reference substances: methanol / 0.01 M citrate buffer

DETERMINATION OF DEAD TIME
- Method: The dead time (the average time a solvent molecule needs to pass through the column) was taken as 3.222 minutes, the time of the earliest consistently appearing peak (mean of 3.220 and 3.223 minutes). Thiourea (a recommended organic compound for the measurement of the dead time) was used.

REFERENCE SUBSTANCES
- Identity: Monuron, Triapenthenol, Triadimeton, Azinphos-methyl, Fenthion, Trifluralin

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: No peaks were seen in either of the blank solution chromatograms at the characteristic retention time of the test substance.


REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': (tR-t0)/t0
- Determination of the log Koc value: (logk-l)/S (l: intercept derived from linear regression of reference compounds, S: slope derived from linear regiession of reference compounds)

Type:

Koc

Value:

< 98

pH:

6.55

Temp.:

20 °C

Details on results (HPLC method):

- Retention times of reference substances used for calibration: ranging from 4.573 to 14.400 minutes
- Details of fitted regression line (log k' vs. log Koc): log k' = -1.2286 + 0.45444log Koc
- Graph of regression line attached
- Average retention data for test substance: 3.095 minites

Validity criteria fulfilled:

yes

Conclusions:

The soil adsorption coefficient of test substance has been determined as Koc < 98 at 20℃. The result indicates that the test substance is likely to have high mobility in soils.

Executive summary:

The soil adsorption coefficient was determined by the high performance liquid chromatography (HPLC) method as described in OECD121.

The retention time obtained for test item was lower than the reference compounds.

Therefore, the soil adsorption coefficient of test substance has been determined as Koc < 98 at 20℃. The result indicates that the test substance is likely to have high mobility in soils.

Description of key information

The soil adsorption coefficient was determined by the high performance liquid chromatography (HPLC) method as described in OECD121.

The soil adsorption coefficient of test substance has been determined as Koc < 98 at 20℃

Key value for chemical safety assessment

Koc at 20 °C:

98