1,6-Octadien-3-ol, 3,7-dimethyl-, acid-isomerized

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:

June-October 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))

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

soil

Specific details on test material used for the study:

Details on properties of test surrogate or analogue material (migrated information):
Not appliable

Radiolabelling:

no

Test temperature:

30°C

Details on study design: HPLC method:

The test system utilized a high performance liquid chromatograph and a cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties. Test item (0.1010 g) was diluted to 100 mL with methanol to give a concentration of 1.01 e3 mg/L. The dead time was determined by measuring the retention time of formamide (purity* 99%, 1.34 x 103 mg/L solution in mobile phase). Solutions of reference standards (see following table) were prepared in either mobile phase (acetanilide to linuron inclusive) or methanol (naphthalene to DDT inclusive).
The HPLC system used was an Agilent Technologies 1200, incorporating autosampler and workstation. The column used was a Waters Xselect HSS Cyano 5 μm (150 x 4.6 mm id). The mobile phase was methanol: water (55:45 v/v). The flow rate was 1.0 mL/min and te injection volume was 25 μL.

Analytical monitoring:

not required

Details on sampling:

Not applicable

Details on matrix:

Not applicable

Details on test conditions:

Not applicable

Computational methods:

Not applicable

Type:

log Koc

Value:

2.1 - 3.45

Temp.:

30 °C

Type:

Koc

Value:

127 - 2 840

Temp.:

30 °C

Details on results (HPLC method):

On analysis, two distinct groups of test item were observed at retention times of approximately 4 and 7.5 minutes. Based on compositional information, these can be tentatively attributed to the cyclic monoterpene ethers and hydrocarbon monoterpenes respectively, due to the more hydrophilic nature of the ether functional groups promoting aqueous solubility and thus mobility in soils.
Based on this tentative assignment, the adsorption coefficient values for the two chemical classes are an adsorption coefficient (Koc) value in the range 127 to 203, log10 Koc 2.10 to 2.31, for the cyclic monoterpene ethers and an adsorption coefficient (Koc) value of 2.84 e3, log10 Koc 3.45, for the hydrocarbon monoterpenes.

Adsorption and desorption constants:

Not applicable

Recovery of test material:

Not applicable

Concentration of test substance at end of adsorption equilibration period:

Not applicable

Concentration of test substance at end of desorption equilibration period:

Not applicable

Details on results (Batch equilibrium method):

Not applicable

Statistics:

A calibration curve was constructed from the retention time data of the dead time and reference standard solutions.
The adsorption coefficient log10 Koc values were calculated using the equation below, with reference to the calibration curve.

Log10Koc = (Log10k' - A)/B

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

Table 1: HPLC results for test substance

Peak	Injection	Retention Time (mins)	Capacity Factor (k’)	Log10k’	Log10Koc	Mean Log10Koc	Adsorption Coefficient
1	1	4.010	0.888	-5.15 x10^-2	2.11	2.10	127
	2	4.003	0.885	-5.32 x10^-2	2.10
2	1	4.334	1.04	1.73 x10^-2	2.31	2.31	203
	2	4.327	1.04	1.59 x10^-2	2.31
3	1	7.466	2.52	0.401	3.45	3.45	2.84 x10^3
	2	7.459	2.51	0.400	3.45

Validity criteria fulfilled:

yes

Conclusions:

The adsorption coefficient values for the two chemical classes are an adsorption coefficient (Koc) value in the range 127 to 203, log10 Koc 2.10 to 2.31, for the cyclic monoterpene ethers and an adsorption coefficient (Koc) value of 2.84 e3, log10 Koc 3.45, for the hydrocarbon monoterpenes.

Executive summary:

An OECD 121 HPLC test was conducted in order to determine the adsorption coefficient of Lime Oxide.

The test system utilized a high performance liquid chromatograph and a cyanopropyl reverse phase HPLC column containing lipophilic and polar moieties. Test item (0.1010 g) was diluted to 100 mL with methanol to give a concentration of 1.01 x10³ mg/L.

On analysis, two distinct groups of test item were observed at retention times of approximately 4 and 7.5 minutes. Based on compositional information, these can be tentatively attributed to the cyclic monoterpene ethers and hydrocarbon monoterpenes respectively, due to the more hydrophilic nature of the ether functional groups promoting aqueous solubility and thus mobility in soils. Based on this tentative assignment, the adsorption coefficient values for the two chemical classes are an adsorption coefficient (Koc) value in the range 127 to 203, log10 Koc 2.10 to 2.31, for the cyclic monoterpene ethers and an adsorption coefficient (Koc) value of 2.84 x10³, log10 Koc 3.45, for the hydrocarbon monoterpenes.

Key value for chemical safety assessment

Koc at 20 °C:

2 840

Additional information

An OECD 121 HPLC test was conducted in order to determine the adsorption coefficient of Lime Oxide. Two distinct groups of test item were observed at retention times of approximately 4 and 7.5 minutes. Based on compositional information, these can be attributed to the cyclic monoterpene ethers and hydrocarbon monoterpenes respectively. Based on this assignment, the adsorption coefficient (Koc) value for the unsaturated monoterpene hydrocarbons is 2840 (Log Koc 3.445). This value has been assigned to the assessment entity "unsaturated monoterpene hydrocarbons" for the purpose of environmental exposure assessment. It has also been used in the calculation of PNECsediment and soil using the equilibrium partitioning method for this constituent group.

[LogKoc: 3.45]