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Reference
Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Justification for type of information:
Experimental test result performed using standard test guidelines
Reference:
Composition 0
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Principles of method if other than guideline:
Adsorption coefficient of test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5) was determined by using HPLC method.
GLP compliance:
not specified
Type of method:
HPLC estimation method
Media:
soil/sewage sludge
Test material information:
Composition 1
Specific details on test material used for the study:
- Name of test material (IUPAC name): (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one- Common name: Menthone - Molecular formula: C10H18O- Molecular weight: 154.2512 g/mol- Smiles notation: C1([C@@H](CC[C@@H](C1)C)C(C)C)=O- InChl: 1S/C10H18O/c1-7(2)9-5-4-8(3)6-10(9)11/h7-9H,4-6H2,1-3H3- Substance type: Organic- Physical state: Liquid
Radiolabelling:
no
Test temperature:
25°C
Details on study design: HPLC method:
HPLC Procedure:The solutions of the test substance and reference substances were prepared in solvent mentioned in 4.3. Each of the reference substance and test substance were analysed by HPLC at 210 nm. After equilibration of the HPLC system, Urea was injected first, the reference substances were injected in duplicate, followed by the test chemical solution in duplicate. Reference substances were injected again after test sample, no change in retention time of reference substances was observed. Retention time tR were measured, averaged and the decimal logarithms of the capacity factors k were calculated. The graph was plotted between log Koc versus log k(table 3).The linear regression parameter of the relationship log Koc vs log k were also calculated from the data obtained with calibration samples and therewith, log Koc of the test substance was determined from its measured capacity factor.Operating Conditions:HPLC Model No. : Agilent Technologies,1260 InfinityFlow Rate : 1.0ml/minColumn : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μmMobile phase : Methanol: water (55:45)Temperature : 25°CDetector : Diode Array Detector @210nmInjector : AutosamplerInjector volume : 10μlData Acquisition software : ChemStationOpen lab Control Panel
Analytical monitoring:
not specified
Key result
Sample No.:
#1
Type:
log Koc
Value:
1.805 dimensionless
Temp.:
25 °C
Remarks on result:
other: other details not specified
Details on results (HPLC method):
The Adsorption coefficient (KOC) on soil and on sewage sludge of the (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (89-80-5) was determined to be 1.805 at 25°C
Transformation products:
not specified

Tables 1

Reference substance

Log Koc

Rt1

Rt2

Rt3

Mean Rt ± S.D.

k

Log k

Urea

NA

0.968

0.968

NA

0.968±0.000

0

0

Benzamide

1.239

1.333

1.334

NA

1.3335±0.001

0.3775

-0.4231

Nitrobenzene

2.35

3.117

3.121

NA

3.119±0.003

2.222

0.3467

4-Nitrobenzamide

1.43

1.519

1.519

NA

1.519±0.000

0.569

-0.2449

N,Ndimethylbenzamide

1.52

1.717

1.719

NA

1.718±0.001

0.774

-0.1113

N-methylbenzamide

1.3

1.472

1.47

NA

1.471±0.001

0.519

-0.2848

2-nitrophenol

2.47

3.108

3.108

NA

3.108±0.000

2.21

0.3444

Table 2

Test substance

K

Log k

Log koc

by Generalized Calibration Graph

 

Mean of Log Koc ± S.D.

 

Rt1

1.916

0.979

-0.009

1.804

1.805± 0.001

 

Rt2

1.917

0.980

-0.009

1.805

Validity criteria fulfilled:
yes
Conclusions:
The Adsorption Coefficient of test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5) was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was determined to be 1.805 dimensionless at 25°C. Thus based on the result it is concluded that the test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.
Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge of test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 . The reference substances were chosen according to functional similarity with the test substance and calibration graph prepared.

The reference substances were Benzamide, Nitrobenzene, 4- Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, 2 - nitrophenol having Koc value ranging from 1.239 to 2.47. The Log Koc value was determined to be 1.805 dimensionless at 25°C.

Thus based on the result it is concluded that the test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge of test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 . The reference substances were chosen according to functional similarity with the test substance and calibration graph prepared.

The reference substances were Benzamide, Nitrobenzene, 4- Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, 2 - nitrophenol having Koc value ranging from 1.239 to 2.47. The Log Koc value was determined to be 1.805 dimensionless at 25°C.

Thus based on the result it is concluded that the test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.

Key value for chemical safety assessment

Koc at 20 °C:
63.8

Additional information

Experimental study and predicted data for the target compound (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS No. 89-80-5) and varioussupporting studiesfor its structurally similar read across substance were reviewed for the adsorption end point which are summarized as below:

In first experimental study the adsorption coefficient Koc in soil and in sewage sludge of test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5)was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No. 121 . The reference substances were chosen according to functional similarity with the test substance and calibration graph prepared.

The reference substances were Benzamide, Nitrobenzene, 4- Nitrobenzamide, N,N-dimethylbenzamide, N-methylbenzamide, 2 - nitrophenol having Koc value ranging from 1.239 to 2.47. The Log Koc value was determined to be 1.805 dimensionless at 25°C.

Thus based on the result it is concluded that the test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one has a low sorption to soil and sediment and therefore has moderate migration potential to ground water.

In next experimental study the Adsorption experiment was conducted for estimating the adsorption coefficient (Koc) value of test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one (CAS no. 89-80-5). The adsorption coefficient (Koc) value was calculated using a water solubility of 688 mg/l and regression derived equation. The adsorption coefficient (Koc) value of test substance (2R,5S)-5 -methyl-2 -(propan-2 -yl)cyclohexan-1 -one was estimated to be 120 (Log Koc = 2.079). This Koc value indicates that the substance (2R,5S)-5 -methyl-2 -(propan-2 -yl)cyclohexan-1 -one has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

Further another adsorption study was conducted for estimating the adsorption coefficient (Koc) value of test chemical. The adsorption coefficient (Koc) value was calculated using a structure estimation method based on molecular connectivity indices. The adsorption coefficient (Koc) value of test substance was estimated to be 88 dimensionless (Log Koc = 1.944). This Koc value indicates that the substance has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

On the basis of above overall results for target chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one(from authoritative database HSDB, PubChem, EPI suite and ACD labs,2017) and for its read across substance (from authoritative database HSDB, 2017), it can be concluded that the Koc value of test substance (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one ranges from 120–638 indicating that the test chemical (2R,5S)-5-methyl-2-(propan-2-yl)cyclohexan-1-one has a low sorption to soil and sediment and therefore have moderate migration potential to ground water.

[LogKoc: 1.805]