4-methylcyclohexanone

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:

2016-01-06 until 2016-04-26

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other: cyanopropyl solid phase HPLC column, for simulation of soil and sewage sludge effect

Specific details on test material used for the study:

test substance stored below 30°C

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Waters Acquity HPLC with Waters TUV detector and Waters tandem quadrupole MS TQ detector
- Type, material and dimension of analytical column: Luna CN 100A, 150 x 4.6 mm, 5 µm, Phenomenex
- Detection systems: UV(at 220 nm) and MS (Electrospray positive (ES+))

MOBILE PHASES
- Type: acetonitrile/water 50:50 (v:v)
- Experiments with additives carried out on separate columns: no
- pH: -
- Solutes for dissolving test and reference substances: acetonitrile

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

REFERENCE SUBSTANCES
- Identity: Acetanilide, Aniline, Atrazine, Isoproturon, Phenol, Triadimenol A

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10 µg (20 µL of a 500 µg/mL solution)
- Quantity of reference substances: 2 µg (20 µL of a 100 µg/mL solution)
- Intervals of calibration: All reference compounds were injected before (injection A) and after (injection B) the test item to confirm that retention times had not drifted.

REPETITIONS
- Number of determinations: Two replicates (injections) per reference compounds and test item

EVALUATION
- Calculation of capacity factors k': k' and log k' were calculated using the measured retention times
- Determination of the log Koc value: correlation graph was produced by plotting the log k' value versus the log Koc value for each reference compound; literature log Koc values were obtained from OECD Guideline 121. A log Koc value for the test item was then extrapolated from the correlation graph.

Analytical monitoring:

not required

Key result

Type:

Koc

Value:

56

Temp.:

25 °C

Details on results (HPLC method):

See Overall remarks, attachments.

Transformation products:

not measured

Validity criteria fulfilled:

yes

Conclusions:

The KOC estimated from the log KOC for the test material was 56, which would be predicted to have a “high” potential mobility in soil, as estimated by the use of a HPLC screening method. Log Koc = 1.75.

Executive summary:

The adsorption coefficient of test substance was estimated according to the OECD Guideline for Testing of Chemicals, 121, Estimation of the Adsorption Coefficient (K_OC) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC).

The test item was chromatographed on a cyanopropyl solid phase HPLC column concurrently with 7 reference compounds of known adsorption coefficient values. UV- and MS-detection was performed where possible.

Following chromatography using acetonitrile:water (50:50, v:v) as mobile phase, a correlation graph was produced by plotting the Log k’ value versus the Log₁₀K_OCvalue for each compound. Literature Log₁₀K_OCvalues were obtained from OECD Guideline 121.

 

Log₁₀K_ocvalues for the test items were then extrapolated from the correlation graph.

 

A good correlation between Log₁₀k’ and Log₁₀K_OCis observed for the reference compounds tested with a coefficient of determination r²of 0.6925. Both reference compounds and test substance were injected onto the HPLC system as solutions in acetonitrile.

A peak was observed for the test substance by mass spectrometry with a retention time of 4.9 minutes.

The mean adsorption coefficient of duplicate determinations of test item was estimated to be as follows:

 

Test Item	Log10KOC	KOC
	1.75	56

 

Description of key information

A single study investigating the absorption of 4 -methylcyclohexanone is available. The study was conducted under GLP using the OECD guideline 121. The log KOC for the test item was 1.75, which would be predicted to have a “high” potential mobility in soil, as estimated by the use of a HPLC screening method. The study is considered to be relevant and reliable. Because there is a low potential for absorption, and the substance is readily biodegradable, these results are considered to be adequate and no further testing is required at this or higher tonnage bands.

Key value for chemical safety assessment

Koc at 20 °C:

56

Additional information

The experiment was conducted at 25°C (column temperature).

[LogKoc: 1.75]