3-(4,4-dimethylcyclohex-1-en-1-yl)propanal

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:

16-12-2009 to 27-01-2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

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:

equivalent or similar 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)

Remarks:

inspected: September 2009 ; signature: November 2009

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

40 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Agilent Technologies HPLC
- Type: Hypersil Gold CN 5μ (150 x 4.6 mm id)
- Type, material and dimension of analytical (guard) column: None reported.
- Detection system: UV-diode array detection, 210 nm for the test item sample solution, 210 nm for the reference item and deadtime solutions

MOBILE PHASES
- Type: Methanol : purified water (55:45 v/v) Flow rate 1 mL per minute.
- Experiments with additives carried out on separate columns: No
- pH: mobile phase: pH = 6.9
- 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: > or = 99.5%, as certified by supplier), 608 mg/L solution in methanol : purified water (55:45 v/v). Determined in duplicate.

REFERENCE SUBSTANCES
- Identity: Acetanilide, CAS 103-84-4, Purity 99%+, log Koc 1.25 (OECD Guideline 121); concentration 100 mg/L
- Identity: Phenol, CAS 108-95-2, Purity 99%+, log Koc 1.32 (OECD Guideline 121); concentration 117 mg/L
- Identity: Atrazine, CAS 1912-24-9, Purity 97.2%, log Koc 1.81 (OECD Guideline 121); concentration 103 mg/L
- Identity: Isoproturon, CAS 34123-59-6, Purity 99.8%, log Koc 1.86 (OECD Guideline 121); concentration 106 mg/L
- Identity: Triadimenol, CAS 55219-65-3, Purity 98.4%, log Koc 2.40 (OECD Guideline 121); concentration 102 mg/L
- Identity: Linuron, CAS 330-55-2, Purity 99.7%, log Koc 2.59 (OECD Guideline 121); concentration 120 mg/L
- Identity: Naphthalene, CAS 91-20-3, Purity > or = 98%, log Koc 2.75 (OECD Guideline 121); concentration 101 mg/L
- Identity: Endosulfan-diol, CAS 2157-19-9, Purity 99.8%, log Koc 3.02 (OECD Guideline 121); concentration 100 mg/L
- Identity: alpha-Endosulfan, CAS 959-98-8, Purity 99.6%, log Koc 4.09 (OECD Guideline 121); concentration 115 mg/L
- Identity: Diclofop-methyl, CAS 51338-27-3, Purity 99.5%, log Koc 4.20 (OECD Guideline 121); concentration 101 mg/L
- Identity: Phenanthrene, CAS 85-01-8, Purity > or = 97.0%, log Koc 4.09 (OECD Guideline 121); concentration 101 mg/L
- Identity: DDT, CAS 50-29-3, Purity 98.0%, log Koc 5.63 (OECD Guideline 121); concentration 104 mg/L

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 5 μL per injection; an aliquot of test item (0.1008 g) was diluted to 100 mL with methanol to give a concentration of 1008 mg/L.
- Quantity of reference substances: 10 μL per injection; the concentration of each reference substance is indicated above injected in duplicate.
- Intervals of calibration: The calibration was performed once specific for the study; with a range of log Koc suitable for the test item which cover both substances suitable for sewage sludge and soil under OECD TG 121 guideline.

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'.

Key result

Type:

log Koc

Remarks:

mean ; (n=2)

Value:

2.6 dimensionless

pH:

7

Temp.:

40 °C

Key result

Type:

Koc

Remarks:

mean ; (n=2)

Value:

399 L/kg

pH:

7

Temp.:

40 °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'.
- Retention times of reference substances used for calibration: Reference sample injections completed in duplicate.
- Identity: Acetanilide, Retention time average: 2.399 minutes
- Identity: Phenol, Retention time average: 2.412 minutes
- Identity: Atrazine, Retention time average: 2.565 minutes
- Identity: Isoproturon, Retention time average: 2.671 minutes
- Identity: Triadimenol, Retention time average: 2.911 minutes
- Identity: Linuron, Retention time average: 3.122 minutes
- Identity: Naphthalene, Retention time average: 3.027 minutes
- Identity: Endosulfan-diol, Retention time average: 3.495 minutes
- Identity: α-Endosulfan, Retention time average: 4.205 minutes
- Identity: Phenanthrene, Retention time average: 3.913 minutes
- Identity: Diclofop-methyl, Retention time average: 4.222 minutes
- Identity: DDT, Retention time average: 6.137 minutes

- Dead-Time: 2.170 minutes
- Details of fitted regression line (log k' vs. log Koc): - Details of fitted regression line (log k' vs. log Koc): Linear regression of all reference substances; A = - 1.207 , B = 0.281 and R = 0.973
- Retention data for test item : Single peak. The average retention time; peak : 2.8967 minutes (Log Koc = 2.60)

Validity criteria fulfilled:

yes

Conclusions:

The test item adsorption coefficient (log Koc) for soil/sewage sludge according to OECD Guideline 121 was estimated to be log Koc = 2.60 at 40°C and ca. pH 7 by HPLC analysis.

Executive summary:

The study was performed in accordance with EU Method C.19 and equivalent or similar to OECD TG 121 under GLP to assess the adsorption coefficient (Koc) of the test item using a high performance chromatography system. The retention times of the test item and selected reference items were accurately measured using HPLC 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 test/reference item. 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 reasonable relationship (R = 0.973) between the capacity factors and the adsorption coefficients. The test was performed at a singular pH ca. 7.0 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 substance adsorption coefficient (log Koc) for soil/sewage sludge was estimated to be log Koc 2.60 at 40°C and pH 7.0 by HPLC analysis.

Description of key information

log Koc = 2.60, 40 °C, ca. pH 7 and 1 atm, EU Method C.19, 2010

Supporting information:

The determination was performed at 40°C (column temperature), however the values can be considered to represent the values at an unspecified, probably ambient temperature since no mention is made in the guidelines of the temperature at which the tabulated reference substances log Koc values were determined. Partition coefficients of the test and reference substances are assumed to vary with temperature in the same way.

The substance lacks relevant basic or acid moieties and/or potential significant dissociation (i.e. greater than 10% within the pH range of 5.5 to 7.5). The substance presents a neutral molecular form over the whole of the environmentally relevant pH range.

Key value for chemical safety assessment

Koc at 20 °C:

2.6

Additional information

Key study : EU Method C.19, 2010 : The study was performed in accordance with EU Method C.19 and equivalent or similar to OECD TG 121 under GLP to assess the adsorption coefficient (Koc) of the test item using a high performance chromatography system. The retention times of the test item and selected reference items were accurately measured using HPLC 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 test/reference item. 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 reasonable relationship (R = 0.973) between the capacity factors and the adsorption coefficients. The test was performed at a singular pH ca. 7.0 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 substance adsorption coefficient (log Koc) for soil/sewage sludge was estimated to be log Koc 2.60 at 40°C and pH 7.0 by HPLC analysis.