Reaction mass of 3-phenoxybenzyl (1R,3R)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropanecarboxylate and 3-phenoxybenzyl (1R,3S)-2,2-dimethyl-3-(2-methylprop-1-en-1-yl)cyclopropanecarboxylate (4:1)

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:

other: GLP study according to guideline without deficiencies.

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 (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other: Column with mobile and stationary phases

Details on study design: HPLC method:

d-Phenothrin (10 mg) was dissolved in acetonitrile (25 ml) to prepare a stock solution of 400 μg/ml. The stock solution (1 ml) was diluted with a solvent mixture of methanol and water (55:45; v/v) to 10 ml to obtain a standard solution of 40.0 μg/ml. The pH value of the test item solution was determined to be 7.1. The test item solution was injected three times.
Stock solutions of the reference items were prepared in methanol. A combined reference solution was prepared and injected six times.
Sodium nitrate (20.2 mg) was diluted to 20 ml with methanol to obtain a stock solution. The stock solution (10 μl) was diluted to 1 ml with a solvent mixture of methanol and water (55:45; v/v). This sodium nitrate solution was injected two times and was used for the determination of the dead time of the HPLC system.

Key result

Type:

Koc

Value:

171 133 dimensionless

pH:

7.1

Temp.:

25 °C

Remarks on result:

other:

Remarks:

mean value of triplicate measurement

Type:

log Koc

Value:

5.23

pH:

7.1

Temp.:

25 °C

Remarks on result:

other:

Remarks:

mean value of triplicate measurement

Details on results (HPLC method):

The chromatography of the test item resulted in one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study.

Validity criteria fulfilled:

yes

Conclusions:

The log Koc of the test item was calculated using a regression curve (log K' vs. log Koc) established by the correlation of the log Koc values of various reference compounds with their log k' values (capacity factor, calculated from the retention time of the reference items/the test item and an unretarded item, sodium nitrate in this case).
The adsorption coefficient (Koc) of d-Phenothrin was estimated to be: log Koc = 5.2 which is equal to a Koc value of 171133

Executive summary:

The adsorption coefficient (Koc) of d-Penothrin was estimated to be: log Koc = 5.2 which is equal to a Koc value of 171133

Description of key information

Tognucci (2002) investigated the adsorption/desorption behaviour of d-phenothrin calculating the log Koc of the test item using a regression curve (log K' vs. log Koc) established by the correlation of the log Koc values of various reference compounds with their log k' values (capacity factor, calculated from the retention time of the reference items/the test item and an un-retarded item, sodium nitrate in this case). The adsorption coefficient (Koc) of d-Phenothrin was estimated to be 171133 (log Koc = 5.2).

Key value for chemical safety assessment

Koc at 20 °C:

171 133