rac-(1R,4S,4aR,8R,8aS)-9-(dichloromethylidene)-8-hydroxyoctahydro-1,4-methanonaphthalen-5(1H)-one

Adsorption / desorption

Link to relevant study record(s)

Reference

Endpoint:

adsorption / desorption, other

Remarks:

estimation of the soil adsorption coefficient of the test item according to the procedures described in OECD Guideline 121

Type of information:

experimental study

Adequacy of study:

key study

Study period:

25 Jul 2014 to 12 Sep 2014

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))

Version / remarks:

January 2001

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Radiolabelling:

no

Details on study design: HPLC method:

EQUIPMENT
- Type: HPLC with column, detector, pump
- Type, material and dimension of analytical (guard) column: Zorbax CN, 250 x 4.6 mm, 5 μm
- Detection system: UV @ 210 nm

MOBILE PHASES
- Type: 55/45 (v/v) Methanol/Water
- Flow rate: 1.2 mL/min
- Experiments with additives carried out on separate columns: no
- pH: Not reported
- Solutes for dissolving test and reference substances: Not reported

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

REFERENCE SUBSTANCES
- Identity: Formamide, Acetanilide, Aniline, Naphthalene, 1,2,3-Trichlorobenzene, Phenanthrene, 4,4'-DDT
- Stock reference solutions: 0.5 mg/mL in methanol of each reference substance
- Mixed reference compound solution: 1.0, 1.0, 2.0, 0.2, 1.0, 0.5, 2.8 mL respectively of each reference substance; diluted to 50mL with 55:45 v/v methanol:water
- Mixed test item solution: 1.0, 1.0, 2.0, 0.2, 1.0, 0.5, 2.8 mL respectively of each reference substance and 1.0 mL of the test item; diluted to 50mL with 55:45 v/v methanol:water

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 1 μL of a 0.5 mg/mL methanol solution
- Quantity of reference substances: 10 μL of mixed reference compound and mixed test item solutions []
- Intervals of calibration: Not reported


REPETITIONS
- Number of determinations: 2

EVALUATION
- Calculation of capacity factors k': k'=(tR-t0)/t0; tR=retention time of reference compound (min), t0= dead time of column (tR of Formamide) (min)
- Determination of the log Koc value: intrapolated from the log k' vs. log Koc correlation graph

Key result

Type:

log Koc

Value:

2.86 dimensionless

Details on results (HPLC method):

- Retention times of reference substances used for calibration: See Tables 1 and 2 in "Any other information on results incl. tables"
- Details of fitted regression line (log k' vs. log Koc): See "Any other information on results incl. tables"
- Average retention data for test substance: In the duplicate test item solutions was observed to elute at 5.30 and 5.27 minutes

Transformation products:

no

Table 1. Capacity Factor (k’) and Adsorption Coefficient (Koc) values for the Mixed Test Item Solution A

Compound	Retention Time (min)	Capacity Factor k’	Log10k’	Log10Koc
Formamide	2.360	0.000	Unretained	Unretained*
Acetanilide	3.309	0.402	-0.396	1.25*
Aniline	3.104	0.315	-0.501	2.07*
Naphthalene	6.157	1.609	0.207	2.75*
1,2,3-Trichlorobenzene	8.096	2.431	0.386	3.16*
Phenanthrene	13.040	4.525	0.656	4.09*
4, 4’-DDT	17.149	6.267	0.797	5.63*
Test item	5.304	1.247	0.096	2.86†

* Reference Compound Literature values taken from OECD Guideline 121

† Calculated from equation of calibration plot (see below)

Equation of calibration plot: y = 0.3173x – 0.8107 Correlation coefficient of calibration plot = 0.9132

Table 2. Capacity Factor (k’) and Adsorption Coefficient (Koc) values for the Mixed Test Item Solution B

Compound	Retention Time (min)	Capacity Factor k’	Log10k’	Log10Koc
Formamide	2.360	0.000	Unretained	Unretained
Acetanilide	3.301	0.399	-0.399	1.25*
Aniline	3.099	0.313	-0.504	2.07*
Naphthalene	6.107	1.588	0.201	2.75*
1,2,3-Trichlorobenzene	8.008	2.393	0.379	3.16*
Phenanthrene	12.829	4.436	0.647	4.09*
4, 4’-DDT	16.357	5.931	0.773	5.63*
Test item	5.267	1.232	0.091	2.86†

* Reference Compound Literature values taken from OECD Guideline 121

† Calculated from equation of calibration plot (see below)

Equation of calibration plot: y = 0.3127x – 0.8049 Correlation coefficient of calibration plot = 0.9099

Validity criteria fulfilled:

not specified

Conclusions:

The adsorption coefficient of the test item (Koc) was estimated to be 724. The log10 Koc of the test item was estimated to be 2.86.

Executive summary:

The adsorption coefficient of the test item was estimated according to the OECD Guidelines for Testing of Chemicals, 121, Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge using High Performance Liquid Chromatography (HPLC), January 2001. The test item was chromatographed on a cyanopropyl solid phase HPLC column concurrently with 7 reference compounds of known adsorption coefficient values. Following chromatography, a correlation graph was produced by plotting the Log k’ value versus the Log10 Koc value, for each compound. Literature Log10 Koc values were obtained from OECD Guideline 121. A Log10 Koc value for the test item was then extrapolated from the correlation graph.

The adsorption coefficient of the test item (Koc) was estimated to be 724. The log10 Koc of the test item was estimated to be 2.86.

Description of key information

LogKoc=2.86; Koc=724, HPLC, OECD 121, (Clipston 2014)

Key value for chemical safety assessment

Koc at 20 °C:

724

Additional information

This endpoint was addressed by Estimation of the Adsorption Coefficient (Koc) by HPLC according to OECD TG 121 under GLP . The adsorption coefficient of duplicate determinations of the test item was estimated to be Log10 Koc of the test item = 2.86, Koc = 724.