1-(5-ethyl-5-methylcyclohex-1-en-1-yl)pent-4-en-1-one

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:

23-07-2018 to 24-07-2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study performed under GLP. All relevant validity criteria were met.

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

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/sewage sludge

Radiolabelling:

no

Test temperature:

35 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Acquity UPLC system.
- Type: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm
- Type, material and dimension of analytical (guard) column: None reported.
- Detection system: UV-diode array detection, 210 nm wavelength

MOBILE PHASES
- Type: Methanol : purified water (55:45 v/v) with flow rate 0.4 mL per minute at 35 °C.
- Experiments with additives carried out on separate columns: No
- pH: mobile phase: pH = approximately neutral.
- Solutes for dissolving test and reference substances: None.

DETERMINATION OF DEAD TIME
- Method: The dead time was determined by measuring the retention time of formamide (purity: 99.2%, as certified by supplier), 5 g/L stock solution in methanol diluted into methanol:purified water (55:45 v/v). Determined in duplicate.

REFERENCE SUBSTANCES
- Identity: Acetanilide, CAS 103-84-4, Purity > 99.9%, log Koc 1.26 (OECD Guideline 121)
- Identity: Monuron, CAS 150-68-5, Purity 99.9%, log Koc 1.99 (OECD Guideline 121)
- Identity: 2,5-Dichloroaniline, CAS 95-82-9, Purity 99.9%, log Koc 2.55 (OECD Guideline 121)
- Identity: Naphthalene, CAS 91-20-3, Purity 99.5%, log Koc 2.75 (OECD Guideline 121)
- Identity: Benzoic acid phenylester, CAS 93-99-2, Purity 99.9%, log Koc 2.87 (OECD Guideline 121)
- Identity: Fenthion, CAS 55-38-9, Purity 96.2%, log Koc 3.31 (OECD Guideline 121)
- Identity: Phenanthrene, CAS 85-01-8, Purity 98.1%, log Koc 4.09 (OECD Guideline 121)
- Identity: DDT, CAS 50-29-3, Purity 98.2%, log Koc 5.63 (OECD Guideline 121)

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 5 μL per injection; an aliquot of test item (13.2 mg/L final concentration) was introduced in duplicate..
- Quantity of reference substances: 5 μL per injection; the concentration of each reference substance injected in duplicate was not reported.
- Intervals of calibration: The calibration was performed once specific for the study; with a range of log Koc suitable for the test item estimation of adsorption to sewage sludge and soil under EU Method C.11 and OECD TG 121 guidelines.

REPETITIONS
- Number of determinations: Two.

EVALUATION
- Calculation of capacity factors k': Calculated as a ratio of retention time of retained compounds relative to unretained substances after determination of the column dead time.
- Calculation of retention times: Determined empirically relative to the known column dead time.
- Determination of the log Koc value: Capacity factors (log k') for reference substances were plotted against absorption coefficients (log Koc). The log Koc for the test item was then calculated using the resultant equation for the calibration curve and the experimentally determined log k'.

Type:

log Koc

Value:

ca. 3.8 dimensionless

pH:

7

Temp.:

35 °C

Type:

Koc

Value:

ca. 7 000 L/kg

pH:

7

Temp.:

35 °C

Details on results (HPLC method):

EVALUATION
- Calculation of capacity factors k': Calculated as a ratio of retention time of retained compounds relative to unretained substances after determination of the column dead time.
- Calculation of retention times: Determined empirically relative to the known column dead time.
- Determination of the log Koc value: Capacity factors (log k') for reference substances were plotted against absorption coefficients (log Koc). The log Koc for the test item was then calculated using the resultant equation for the calibration curve and the experimentally determined log k'.

- Calculation of capacity factors k': Calculated as a ratio of retention time of retained compounds relative to unretained substances after determination of the column dead time.
- Calculation of retention times: Determined empirically relative to the known column dead time.
- Determination of the log Koc value: Capacity factors (log k') for reference substances were plotted against absorption coefficients (log Koc). The log Koc for the test item was then calculated using the resultant equation for the calibration curve and the experimentally determined log k'.
- Retention times of reference substances used for calibration: Reference sample injections completed in duplicate.
- Identity: Acetanilide, CAS 103-84-4, ca. 0.90 min
- Identity: Munuron, CAS 150-68-5, ca. 1.11 min
- Identity: 2,5-Dichloroaniline, CAS 95-829, ca. 1.26 min
- Identity: Naphthalene, CAS 91-20-3, ca. 1.46 min
- Identity: Benzoic acid phenylester, CAS 93-99-2, ca. 1.72min
- Identity: Fenthion, CAS 55-38-9, ca. 2.31 min
- Identity: Phenanthrene, CAS 85-01-8, ca. 2.54 min
- Identity: DDT, CAS 50-29-3, ca. 6.34 min

- Dead-Time: 0.693 minutes
- Details of fitted regression line (log k' vs. log Koc): Linear regression of all reference substances; y = 0.324x – 0.853 , (R = 0.98, n = 16)
- Retention data for test substance: Single peak (main constituent). The average retention time; peak 3: 2.399 minutes (Log Koc = 3.84)

Validity criteria fulfilled:

yes

Conclusions:

The test item adsorption coefficient (log Koc) for soil/sewage sludge according to EU Method C.19 and OECD Guideline 121 was estimated to be log Koc = 3.84 at 35°C by HPLC analysis.

Executive summary:

The study was performed to EU Method C.19 and OECD TG 121 to assess the adsorption coefficient (Koc) of the test item in accordance with GLP using a high performance chromatography system. The retention times of the test substance and selected reference items were accurately measured using UPLC fitted with a cyanopropyl column. The retention times were consistent over the course of the study. The dead time of the instrument was also measured, and capacity factors were calculated for each reference substance. Calibration curves were constructed by plotting the capacity factor (log k') for the reference substances against their adsorption coefficients (log Koc). Linear regression analysis was performed, and this showed a good relationship between the capacity factors and the adsorption coefficients. The test was performed at a singular approximately neutral pH as the test item does not possess ionisable moieties in an environmentally relevant pH range. The adsorption coefficient of the test item was estimated using the calibration curve constructed from all reference items. Under the conditions of this study, the test item adsorption coefficient (log Koc) for soil/sewage sludge was estimated to be log Koc 3.84 at 35°C and pH 7.0 by UPLC analysis.

Description of key information

log Koc = 3.84 (Koc 7000 L/kg), 35 °C, ca. pH 7 and 1 atm, EU Method C.19, 2015

Additional information

Key Study : EU Method C.19, 2015 : The study was performed to EU Method C.19 and OECD TG 121 to assess the adsorption coefficient (Koc) of the test item in accordance with GLP using a high performance chromatography system. The retention times of the test substance and selected reference items were accurately measured using UPLC fitted with a cyanopropyl column. The retention times were consistent over the course of the study. The dead time of the instrument was also measured, and capacity factors were calculated for each reference substance. Calibration curves were constructed by plotting the capacity factor (log k') for the reference substances against their adsorption coefficients (log Koc). Linear regression analysis was performed, and this showed a good relationship between the capacity factors and the adsorption coefficients. The test was performed at a singular approximately neutral pH as the test item does not possess ionisable moieties in an environmentally relevant pH range. The adsorption coefficient of the test item was estimated using the calibration curve constructed from all reference items. Under the conditions of this study, the test item adsorption coefficient (log Koc) for soil/sewage sludge was estimated to be log Koc 3.84 at 35°C and pH 7.0 by UPLC analysis.