2,2'-(2-methylpropylidene)bis[4,6-xylenol]

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:

18 May 2016 to 21 July 2016

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:

Organization for Economic Co-operation and Development (OECD), OECD Guideline for the Testing of Chemicals no. 121: "Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)”, January 22, 2001.

Deviations:

no

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:

European Community (EC), EC no. 440/2008, Part C: Methods for the Determination of Ecotoxicity, Guideline C.19: “Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)”, Official Journal of the European Union no. L142, May 31, 2008.

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Specific details on test material used for the study:

Test item: 207366/A
Identification: Lowinox® 22IB46
Appearance: White to cream coloured powder
Batch: WB44L0016
Purity/Composition: 99.7%
Test item storage: At room temperature
Stable under storage conditions until: 18 November 2018 (retest date)
Purity/composition correction factor: No correction factor required
Test item handling: No specific handling conditions required

Radiolabelling:

not specified

Test temperature:

Column temperature 35°C ± 1°C

Details on study design: HPLC method:

Analytical conditions
Instrument: Acquity UPLC system (Waters, Milford, MA, USA)
Detector: Acquity UPLC PDA detector (Waters)
Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 μm (Waters)
Column temperature: 35°C ± 1°C
Mobile phase: 55/45 (v/v) methanol/water
Flow: 0.4 mL/min
Injection volume: 5 μL
UV detection: 210 nm

Preparation of the solutions
Solution of the unretained compound
A 5.0 g/L stock solution of formamide (99.2%, [75-12-7], Alfa Aesar, Karlsruhe, Germany) in methanol was used. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The formamide blank solution was 55/45 (v/v) methanol/water.

Reference substance solutions
Stock solutions of the reference substances at concentrations of approximately 1 g/L in methanol were used. The stock solutions were diluted to obtain an end solution of 55/45 (v/v) methanol/water.
The blank solution for the mixture of reference substances was 55/45 (v/v) methanol/water.

Test solution
A 1000 mg/L stock solution of the test item was prepared in methanol. The stock solution was diluted to obtain an end solution of 55/45 (v/v) methanol/water. The final concentration of the test item solution was 10.0 mg/L.
The test item blank solution was 55/45 (v/v) methanol/water.

Injections
The reference substance and test item solutions were injected in duplicate. Blank solutions were analysed by single injection.

Type:

Koc

Value:

38 000 dimensionless

pH:

7

Temp.:

35 °C

Type:

log Koc

Value:

4.58 dimensionless

pH:

7

Temp.:

35 °C

Details on results (HPLC method):

Determination of the Koc
In the chromatogram of the test solution, one test item peak was observed.
The equation of the regression line was: log k’ = 0.328 x log Koc – 0.807 (r = 0.98, n = 16).

Calculation of pK_avalues

The following pK_avalues in the logarithm range of 1 – 14 for acidic and basic groups in the molecular structure of the test item were calculated using the Perrin calculation method:

 

Acidic		Basic
PHENOL PHENOL	pKa10.5 pKa11.5	Not available

 

K_ocof the test item

Substance	tr,1 [min]	tr,2 [min]	Mean tr (n=2)	Log Koc	Koc
Formamide (t0)   Acetanilide Monuron 2,5-Dichloroaniline Naphthalene Benzoic acid phenylester Fenthion Phenanthrene 4,4’-DDT   Test item	0.669   0.896 1.118 1.291 1.509 1.795 2.462 2.718 7.047   3.979	0.667   0.896 1.117 1.293 1.512 1.793 2.464 2.714 7.052   3.977	0.668                     3.978	1.26 1.99 2.55 2.75 2.87 3.31 4.09 5.63   4.58	3.8 x 10^4

 

Validity criteria fulfilled:

yes

Conclusions:

Koc 3.8e4
Log Koc 4.58

Executive summary:

The purpose of the study was to determine the physico-chemical properties for Lowinox® 22IB46.

 

The HPLC method using soil-adsorption-reference data was applied for the determination of the adsorption coefficient (Koc) of Lowinox® 22IB46 in accordance with the following guidelines:

European Community (EC), EC no. 440/2008, Part C: Methods for the Determination of Ecotoxicity, Guideline C.19: “Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)”, Official Journal of the European Union no. L142, May 31, 2008.

Organization for Economic Co-operation and Development (OECD), OECD Guideline for the Testing of Chemicals no. 121: "Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC)”, January 22, 2001.

 

The K_ocand log K_ocvalue of the test item at neutral pH was:

K_oc3.8 x 10⁴

Log K_oc4.58

Description of key information

Key value determined in a GLP accredited laboratory study using the HPLC method in accordance with OECD Guideline 121 and EU Method C19.

Key value for chemical safety assessment

Koc at 20 °C:

38 000

Additional information

[LogKoc: 4.58]