1-Ethoxy-2,3-difluoro-4-[trans-4-(trans-4-propylcyclohexyl)-cyclohexyl]-benzene

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:

2014-03-10

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))

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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Radiolabelling:

no

Test temperature:

25 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC System Agilent 1100 series
- Type, material and dimension of analytical (guard) column: commercially available cyanopropyl solid phase containing lipophilic and polar moieties, stainless steel, 150 mm x 4.6 mm, particle size: 5 µM

MOBILE PHASES
- Type: methanol/distilled water 70:30 % (v/v)
- pH: 5.4

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

REFERENCE SUBSTANCES
- Identity: Acetanilide, Atrazin, Triadimenol, Linuron, Pyrazophos, Diclofop-methyl, 4,4`-DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 50 µL (0.41 µg)
- Quantity of reference substances: 10 µL (0.2 - 1.16 µg)

REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': according to OECD TG 121
- Calculation of retention times: were measured
- Determination of the log Koc value: according to OECD TG 121

Key result

Type:

log Koc

Value:

> 5.6 dimensionless

pH:

5.4

Temp.:

25 °C

Details on results (HPLC method):

- Average retention data for test substance: retention time = 10.44 (1st measurement), 10.48 (2nd measurement)

Table 1: Determination of the dead time t₀ 

Dead time marker	tR/min  1^stinjection	tR/min  2^nd injection	tR/min  3^rd injection
Formamide	1.72	1.72	1.72

 

 dead time t₀=1.72 min 

 

Table 2: Calibration data 1^st injection 

Calibration substance	tR/min	k	Log k	Log Koc
Acetanilide	1.89	0.10	-1.02	1.25
Atrazin	1.96	0.14	-0.85	1.81
Triadimenol	2.11	0.23	-0.64	2.40
Linuron	2.28	0.32	-0.49	2.59
Pyrazophos	2.61	0.51	-0.29	3.65
Diclofop-methyl	2.66	0.55	-0.26	4.20
4,4’-DDT	3.43	0.99	0.00	5.63

 

Regression: log K_oc = a+ b · log k 

Parameters: a=5.17, b=4.13, r²=0.9432 

 

Table 3: Log P_ow of the test item 1^st injection 

	tR/min	k	Log k	Log Koc
Test item	10.44	5.07	0.70	>5.6 ^1) (8.1) ^2)

¹⁾ above the highest log Koc value of calibration substances (DDT) 

²⁾ via extrapolation

 

Table 4: Calibration data 2^nd injection 

Calibration substance	tR/min	k	Log k	Log Koc
Acetanilide	1.89	0.10	-1.02	1.25
Atrazin	1.96	0.14	-0.85	1.81
Triadimenol	2.11	0.23	-0.64	2.40
Linuron	2.28	0.33	-0.49	2.59
Pyrazophos	2.61	0.52	-0.29	3.65
Diclofop-methyl	2.67	0.55	-0.26	4.20
4,4’-DDT	3.43	0.99	0.00	5.63

 

Regression: log K_oc = a+ b · log k 

Parameters: a=5.17, b=4.12, r²=0.9424 

 

Table 5: Log P_ow of the test item 2^nd injection 

	tR/min	k	Log k	Log Koc
Test item	10.48	5.08	0.71	>5.6 ^1) (8.1) ^2)

¹⁾ above the highest log Koc value of calibration substances (DDT) 

²⁾ via extrapolation

 

Within two injections, the adsorption coefficient K_oc of the test item was determined to be: 

Log K_oc  > 5.6 ¹⁾ (log K_oc  = 8.1) ²⁾

¹⁾ above the highest log Koc value of calibration substances (DDT) 

²⁾ via extrapolation

Validity criteria fulfilled:

yes

Conclusions:

The log Koc of the test substance was determined to be > 5.6.

Executive summary:

A study was conducted in accordance with OECD 121 to determine the adsorption coefficient of the test substance using the HPLC method. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The retention time of the test item was above the retention time of the highest calibration standard (log Koc 5.63) and thus out of the calibration range. Therefore, the adsorption coefficient of the test substance was determined to be above 5.6.

Description of key information

The adsoprtion coefficient (log Koc) of the test item was determined to be greater than 5.6 according to OECD Guideline 121. Since the log Koc is greater than 3 the test substance has an adsorption potential.

Key value for chemical safety assessment

Koc at 20 °C:

398 107

Additional information

A study was conducted in accordance with OECD 121 to determine the adsorption coefficient of the test substance using the HPLC method. The adsorption coefficient of the test substance was derived from its retention time and the calibration graph. The retention time of the test item was above the retention time of the highest calibration standard (log Koc 5.63) and thus out of the calibration range. Therefore, the adsorption coefficient of the test substance was determined to be above 5.6.