Reaction mass of rel-(2R,3aR,6R,7aR)-2,6-dimethyl-3a-(propan-2-yl)octahydro-1-benzofuran and rel-(2R,3aR,6S,7aR)-2,6-dimethyl-3a-(propan-2-yl)octahydro-1-benzofuran and rel-(2R,3aS,6S,7aS)-2,6-dimethyl-3a-(propan-2-yl)octahydro-1-benzofuran

Adsorption / desorption

Link to relevant study record(s)

Reference

Reference 1

Endpoint:

adsorption / desorption, other

Remarks:

The Feasibility of Quantifying Adsorption and Desorption Behaviour Using a Batch Equilibrium Method

Study period:

The study was conducted on 03 March 2016.

Data waiving:

study technically not feasible

Justification for data waiving:

other:

Justification for type of information:

It was concluded to be unfeasible to determine the adsorption and desorption behaviour of IFF 215 (Floriane) to soils of differing pH, organic carbon content and textural classification, using a batch equilibrium method, as detailed in Method C.18 Adsorption Coefficient of Commission Regulation (EC) No 440/2008 of 30 May 2008, and Method 106 of the OECD Guidelines for Testing of Chemicals, 21 January 2000. This was due to a number of characteristics of the test item, but predominantly the high adsorption properties presented by the test item. With reference to the regulatory methods, the domain of the batch equilibrium method is specified as for substances within a partition coefficient range of log10 Pow 1.3 to 4.0, whereas the known partition coefficient range of the test item is log10 Pow 5.06 to 5.59. The weakness of the method for substances of higher partition coefficient values is that the degree of adsorption onto the soils is so high that insufficient test item remains in the aqueous phase to allow accurate quantification. The regulatory methods recommend that an alternative estimation method is used for this very reason for substances with high partitioning characteristics. In addition it is recommended that the test substance has a purity of at least 95%, whereas in this case the test item has a purity below 95% and more significantly, this composition is distributed across a number of isomers. The evaluation of multi-component substances is much better addressed by the HPLC estimation method, as individual component adsorption coefficient values can be generated from the retention times of the resolved peaks.

Reference 2

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

The study was conducted between 03 November 2015 and 23 November 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

The study is considered to be reliability 1 as it was conducted according to OECD Test Guideline 121 using an HPLC screening method and in compliance with GLP.

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

Media:

soil/sewage sludge

Radiolabelling:

no

Details on study design: HPLC method:

Performance of the Test
Preparation of the test item sample solution
Test item (0.1262 g) was diluted to 50 mL with methanol, to give a concentration of 2.54E+03 mg/L.

Preparation of the dead time solution
The dead time was determined by measuring the retention time of thiourea (purity* >99%, 1.01E+03 mg/L solution in a matrix of methanol: water (55:45 v/v)).
* value quoted by supplier

Preparation of the reference item solutions
Solutions of reference items were prepared in methanol: water (55:45 v/v) for the first six standards and methanol (100%) for the remaining standards.

Determination of retention time
The sample, dead time and reference standard solutions were injected in duplicate.

Evaluation of Data
Construction of the calibration curve
A calibration curve was constructed from the retention time data of the dead time and reference standard solutions. Each capacity factor (k') was calculated using

k' = (tr - t0) / t0

where:
k' = capacity factor
tr = retention time (min)
t0 = dead time (min)

A correlation of log k' versus log Koc of the reference standards was plotted using linear regression.

Adsorption coefficient of the sample
The capacity factor for each test item solution injection was calculated using the equation and the log10 Koc values determined using teh equation below, with reference to the calibration curve.

The adsorption coefficient was calculated using the equation below.

Log10Koc = (Log10 k' - A) / B

where:
Koc = adsorption coefficient
k' = capacity factor
A = intercept of the calibration curve
B = slope of the calibration curve

Key result

Type:

log Koc

Value:

>= 3.59 - <= 3.76 dimensionless

Temp.:

30 °C

Key result

Type:

Koc

Value:

>= 3 910 - <= 5 770 dimensionless

Temp.:

30 °C

Details on results (HPLC method):

Adsorption coefficient of the sample
Log10 Koc range: 3.59 to 3.76
Adsorption coefficient range: 3.91E+03 to 5.77E+03

Calibration

The retention times of the dead time and the retention times, capacity factors (k') and log₁₀K_ocvalues for the reference standards are shown in the two following tables:

Dead Time	Retention Time (mins)		Mean Retention Time (mins)
	Injection 1	Injection 2
Thiourea	2.268	2.268	2.268

Standard	Retention Time (mins)		Mean Retention Time (mins)	Capacity Factor (k')	Log10k'	Log10Koc
	Injection 1	Injection 2
Acetanilide	3.002	3.002	3.002	0.324	-0.490	1.25
Atrazine	4.018	4.010	4.014	0.770	-0.114	1.81
Isoproturon	4.255	4.255	4.255	0.876	-5.74 x 10^-2	1.86
Aniline	2.959	2.952	2.956	0.303	-0.518	2.07
Triadimenol	5.558	5.566	5.562	1.452	0.162	2.40
Linuron	5.674	5.681	5.677	1.503	0.177	2.59
Naphthalene	4.918	4.925	4.921	1.170	6.81 x 10^-2	2.75
Endosulfan-diol	6.804	6.804	6.804	2.000	0.301	3.02
Fenthion	8.158	8.172	8.165	2.600	0.415	3.31
a-Endosulfan	11.275	11.239	11.257	3.963	0.598	4.09
Phenanthrene	8.755	8.762	8.759	2.862	0.457	4.09
Diclofop-methyl	12.240	12.240	12.240	4.397	0.643	4.20
DDT	24.221	24.271	24.246	9.690	0.986	5.63

Adsorption coefficient of the sample

The retention times, capacity factor and log₁₀K_ocvalue determined for the sample are shown in the following table:

Peak Number	Injection	Retention Time (mins)	Capacity Factor (k')	Log10k'	Log10Koc	Mean  Log10Koc	Adsorption Coefficient
1	1	7.913	2.489	0.396	3.59	3.59	3.91 x 10^3
	2	7.927	2.495	0.397	3.59
2	1	8.690	2.832	0.452	3.76	3.76	5.77 x 10^3
	2	8.712	2.841	0.454	3.76

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient (Koc) of the test item has been evaluated to be in the range 3.91E+03 to 5.77E+03; log10 Koc 3.59 to 3.76.

Executive summary:

The adsorption coefficient (K_oc) of the test substance, IFF 215 (Floriane), was assessed according to OECD 121 using an HPLC estimation method. The adsorption coefficient was 3.91 x 10³to 5.77 x 10³, with a log₁₀K_oc of 3.59 to 3.76.

Description of key information

The adsorption coefficient (Koc) of the test substance, IFF 215 (Floriane), was assessed according to OECD 121 using an HPLC estimation method. The adsorption coefficient was 3.91E+03 to 5.77E+03, with a log10Koc of 3.59 to 3.76.

Key value for chemical safety assessment

Koc at 20 °C:

5.77

Additional information

[LogKoc: 3.76]