Cyclohexanone, 4-methoxy-

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:

2006-06-07 to 2006-09-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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))

Version / remarks:

2001

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))

Version / remarks:

2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil/sewage sludge

Radiolabelling:

no

Test temperature:

40 °C

Details on study design: HPLC method:

The HPLC method is based on the correlation between the retention of a substance on a reversed phase column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and the adsorption coefficient KOC.
The dead time is determined by using a homologous series of n-alkyl methyl ketones. For calibration, retention times of selected reference compounds with known adsorption coefficients are measured. In a further step the log KOC of the test item should be derived from its retention time. The alkyl ketones and calibration substances, respectively, were injected in duplicate as solutions in acetonitrile. The test item was also injected in duplicate as a solution in acetonitrile.

HPLC equipment:
Agilent HPLC system 1100 with pump G1312A, UV/VIS detector
G1314 A, autosampler G1313 A and column oven G1316 A
Software Chromeleon Vers. 6.70, Fa. Dionex

Column:
Material: stainless steel (Bischoff)
dimensions: 250 x 4.0 mm
stationary phase: Zorbax CN, 5 µm
column temperature: 40°C

Mobile Phase:
Water / acetonitrile 60/40 (v/v), (isocratic elution)

Flow rate: 1.0 mL/min

Injected volume: 10 µL

Detection wavelength:
275 nm (determination of t0)
254 nm (calibration graph)
282 nm (analysis of the test item)

Injected amounts:
n-Alkyl methyl ketones: 78.67 - 84.98 µg
Calibration substances: 0.70-21,04 µg
Test item: 61.1 µg
The alkyl ketones and calibration substances, respectively, were injected in duplicate as solutions in acetonitrile. The test item was also injected in duplicate as a solution in acetonitrile.

Type:

Koc

Value:

16

Temp.:

40 °C

Key result

Type:

log Koc

Value:

1.2

Temp.:

40 °C

Details on results (HPLC method):

9 calibration substances were injected into a HPLC-system under the same analytical conditions(column temperature 40°C) as the test item. A calibration curve was created by using the measured retention times (log k'-values) and the known log K0c-values of the calibration substances for linear regression.

Transformation products:

no

Validity criteria for the measurement of the adsorption/ desorption:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
Determinations should be run at least in duplicate. The values of log Koc derived from individual measurements should be within a range of 0.25 log unit.	The alkyl ketones and calibration substances, respectively, were injected in duplicate as solutions in acetonitrile. The test item was also injected in duplicate as a solution in acetonitrile. The values of log Koc between the individual measurements of the test item differed in 0.01 log unit.	Yes
To correlate the measured HPLC-retention data of a test substance with its adsorption coefficient Koc, a calibration graph of log Koc versus log k’ has to be established. A minimum of six reference points, at least one above and one below the expected value of the test substance should be used.	A calibration curve was created by using the measured retention times (log k'-values) and the known log Koc-values of the calibration substances for linear regression. 9 calibration substances were used with log Koc ranging between 1.25 - 4.09. The lowest measured log Koc with a calibration substance is not beneath the measured log Koc of the test substance, but as both log Koc are very close the measurement is acceptable.	Yes
Several mobile phases have been tested and the following two are recommended: - methanol/water (55/45% v/v) - methanol/0.01M citrate-buffer pH 6.0 (55/45% v/v) HPLC grade methanol and distilled water or citrate-buffer are used to prepare the eluting solvent.	Water / acetonitrile 60/40 (v/v), (isocratic elution) was used as the mobile phase. According to OECD 121 other organic solvent/water mixtures may be tried, e.g. ethanol/water or acetonitrile/water mixtures if methanol/water mixtures are not appropriate.	Yes

 

Validity criteria fulfilled:

yes

Remarks:

See 'Any other information on results incl. tables'.

Conclusions:

The substance has a low potential for adsorption (log Koc < 3).

Executive summary:

The adsorption coefficient (K_oc) of the substance was determined according to the guideline OECD 121 and EEC-guideline 2001/59/EEC C.19. Therefore, 9 calibration substances were injected into a HPLC-system under the same analytical conditions(column temperature 40°C) as the test item. A calibration curve was created by using the measured retention times (log k'-values) and the known log K0c-values of the calibration substances for linear regression.The measured k'-value of the test item is within the calibrated range. The adsorption coefficient (K_oc) of the test item was (mean value): log Koc 1.2 (Koc = 16).

Description of key information

The adsorption coefficient (K_OC) of the test item was (mean value): log Koc 1.2 (K_OC = 16).

Key value for chemical safety assessment

Koc at 20 °C:

16