Cyclopentane, methoxy-

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:

07 February 2003 - 29 May 2003

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study was conducted according to OECD test guidelines and in compliance with GLP, so the data is considered reliable without restriction.

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:

soil

Specific details on test material used for the study:

- Analytical purity: 99.9%
- Lot/batch No.: 020618

Radiolabelling:

no

Test temperature:

Ambient / room temperature (HPLC column oven setting)

Details on study design: HPLC method:

EQUIPMENT
- Apparatus:HPLC-UV
- Type: Reverse Phase
- Type, material and dimension of analytical column: Cyano Apex RP, 5µm, 25 cm x 4.6 mm i.d.
- Detection system: UV, 210 nm

MOBILE PHASES
- Type: Methanol / Water, 55/45 (v/v)
- Experiments with additives carried out on separate columns: no
- pH: Not adjusted
- Solutes for dissolving test and reference substances: As per mobile phase (methanol / water, 55/45 (v/v)).

DETERMINATION OF DEAD TIME
- Method: by inert substances which are not retained by the column (Thiourea)

REFERENCE SUBSTANCES
- Identity:
Thiourea (dead-time standard)
Acetanilide
Methylbenzoate
Triadimenol
Naphthalene
Pyrazophos
Phenanthrene

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 1.53 mg (test 1), 1.77 mg (test 2).
- Quantity of reference substances: Refer to table in "any other details" field
- Intervals of calibration: Refer to table in "any other details" field

REPETITIONS
- Number of determinations: 2 tests, duplicate injections per test

EVALUATION
- Calculation of capacity factors k': Yes
- Calculation of retention times: Yes
- Determination of the log Koc value: Yes

Type:

log Koc

Value:

2.07

Type:

Koc

Value:

118.04

Details on results (HPLC method):

- Retention times of reference substances used for calibration: Refer to table in "any other information" field
- Details of fitted regression line (log k' vs. log Koc): log Koc = (log k + 1.5806)/0.24834 Correlation coefficient = 0.99625
- Average retention data for test substance: 3.6 minutes

Average retention times and log k values of reference substances

Reference compound	Mean retention time (minutes)	k	log k
Thiourea	3.307	-	-
Acetanilide	3.471	0.04975	-1.303
Methylbenzoate	3.561	0.07687	-1.114
Triadimenol	3.664	0.10797	-0.967
Naphthalene	3.752	0.12967	-0.887
Pyrazophos	4.064	0.21737	-0.663
Phenanthrene	4.154	0.25639	-0.591

Conclusions:

The soil adsorption coefficient of NZE has been determined as 118.04 at 20°C (log Koc = 2.07). This result indicates that the test substance is likely to have a high mobility in soils.

Description of key information

Koc = 118.04 at 20°C

Key value for chemical safety assessment

Koc at 20 °C:

118.04

Additional information

A soil adsorption coefficient measurement was conducted as part of a package of physicochemical testing on the substance (Huntingdon Life Sciences, 2003, Study ZCE111). The study was conducted in compliance with GLP and the soil adsorption coefficient determination was performed according to OECD test guideline 121. The soil adsorption coefficient was determined by the HPLC method.

The soil adsorption coefficient of the substance was determined as K_oc = 118.04 at 20°C. The result indicated that the substance is likely to have a high mobility in soil.