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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:
To determine Adsorption coefficient (KOC) on soil and on sewage sludge of the (±)-menthone (CAS No. 1074-95-9) using HPLC.
GLP compliance:
no
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 the test material: 2-isopropyl-5-methylcyclohexanone ((±)-menthone)
- Molecular formula: C10H18O
- Molecular weight: 154.2512 g/mol
- Substance type: Organic
- Physical state: Liquid
- Physical Appearance : colourless mobile liquid
- Date of manufacturing : 2016-12-17
- Date of expiry : 2019-12-16
- Purity : Not available in CoA
- Stability : Stable in recommended storage conditions
- Storage Conditions : 1. Ambient Temp (23 to 27 °C) (Keep container tightly closed in a dry & wellventilated place. Store in cool place. Do not expose to air, light & moisture.)
Radiolabelling:
not specified
Test temperature:
25°C
Details on study design: HPLC method:
The solutions of the test substance and reference substances were prepared in the mobile phase. 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(Annex - 2).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 Infinity
Flow Rate : 1.0 mL/min
Column : ZORBAX Eclipse Plus C18, 4.6×100mm, 3.5 μm
Mobile phase : Acetonitrile: water (55:45)
Temperature : 25°C
Detector : Diode Array Detector @210nm
Injector : Autosampler
Injector volume : 10μl
Data Acquisition software : ChemStationOpen lab Control Panel
Key result
Type:
log Koc
Value:
2.629 dimensionless
pH:
6.27
Temp.:
25 °C
Remarks on result:
other: Koc reported as 2.629 ± 0.0005
Transformation products:
not specified

Test substance

(±)-menthone

K

Log k

Log Koc

by Generalized Calibration

Graph

Mean of Log Koc ± S.D.

tR1

4.256

3.39669

0.53105

2.62900

2.629 ± 0.0005

tR2

4.26

3.40082

0.53158

2.62983

Validity criteria fulfilled:
yes
Conclusions:
The Adsorption Coefficient of test substance (±)-menthone (CAS No. 1074-95-9)was determined as per the HPLC method (OECD Guideline-121). The Log Koc value was found to be 2.629 ± 0.0005 at 25°C.
Executive summary:

The adsorption coefficient Koc in soil and in sewage sludge (±)-menthone(CAS No.1074-95-9) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No.121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances chosen were 4 -chloroaniline, 4-methylaniline, N-methylaniline, 2 - nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,Ndimethylbenzamide,N-methylbenzamide and Benzamide, having Koc value ranging from 1.239 to 2.47. The Log Koc value was found to be 2.629 ± 0.0005at 25°C.

Description of key information

The adsorption coefficient Koc in soil and in sewage sludge (±)-menthone(CAS No.1074-95-9) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No.121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances chosen were 4 -chloroaniline, 4-methylaniline, N-methylaniline, 2 - nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,Ndimethylbenzamide,N-methylbenzamide and Benzamide, having Koc value ranging from 1.239 to 2.47. The Log Koc value was found to be 2.629 ± 0.0005at 25°C.

Key value for chemical safety assessment

Koc at 20 °C:
425.59

Additional information

Five studies including Experimental result and Predicted model data for Adsorption endpoint of target chemical 2-isopropyl-5-methylcyclohexanone (Cas no. 1074-95-9) and its relevant read across chemical which is 100% structurally similar to target were reviewed to summarize as follows:  

 

First key study from experimental study result performed by UERL lab;2017 which suggest the adsorption coefficient Koc in soil and in sewage sludge (±)-menthone(CAS No.1074-95-9) was determined by the Reverse Phase High Performance Liquid Chromatographic method according to OECD Guideline No.121 for testing of Chemicals. The reference substances were chosen according to estimated Koc range of the test substance and generalized calibration graph was prepared. The reference substances chosen were 4 -chloroaniline, 4-methylaniline, N-methylaniline, 2 - nitrophenol, Nitrobenzene, 4-Nitrobenzamide, N,Ndimethylbenzamide,N-methylbenzamide and Benzamide, having Koc value ranging from 1.239 to 2.47. The Log Koc value was found to be 2.629 ± 0.0005at 25°C.

And Estimation from EPI suite Program using KOCWIN (v2.00) model indicated Soil Adsorption Coefficient i.e Koc value of 2-isopropyl-5-methylcyclohexanone was estimated as Koc 136.2 L/kg (log Koc=2.134)  by means of MCI method at 25 deg.C. This Koc value indicates that the substance 2-isopropyl-5-methylcyclohexanone has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

 

Whereas from chemspider prediction database, the soil adsorption coefficient i.e Koc value of test substance 2-isopropyl-5-methylcyclohexanone was estimated to be 1240.21 i.e Log Koc= 3.093 at pH 5.5 and 7.4 at temp.25 deg.C .This Koc value indicates that the substance 2-isopropyl-5-methylcyclohexanone has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

 

Above both predicted results are supported by experimental data from HSDB database; (2017) for the read across chemical menthone (Cas no. 89-80-5), using a water solubility of 688 mg/l and a regression derived equation, which indicate the Koc of menthone is estimated as approximately 120.This estimated Koc value suggests that menthone is expected to have high mobility in soil.

 

Whereas SciFinder, American Chemical Society (ACS); 2017 predicted database for same read across i.e menthone (Cas no. 89-80-5) indicate the soil adsorption coefficient i.e Koc value was estimated to be 751 i.e Log Koc= 2.875 at pH range 1-10 and temperature 25 deg.C. This Koc value at all range of pH condition indicates that the substance Methanone has a low sorption to soil and sediment and therefore have moderate migration potential to groundwater.

 

Thus based on the above all available studies for target and read across chemical gives the common conclusion that the test substance 2-isopropyl-5-methylcyclohexanone (Cas no. 1074-95-9) has high to moderate mobility in soil/sediment.

[LogKoc: 2.629]