Phenol, 4-methyl-, reaction products with dicyclopentadiene and isobutylene

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:

27 July 2010- 29 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: This study has been performed according to OECD and EC guidelines and according to GLP principles.

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

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

GLP compliance:

yes (incl. QA statement)

Type of method:

HPLC estimation method

Media:

other: soil adsorption reference data

Details on study design: HPLC method:

Performance of the study
The principle of the test method is similar to that of the OECD guideline no. 117: "Partition coefficient (n-octanol/water), high performance liquid chromatography (HPLC) method". While passing through the column along with the mobile phase the test substance interacts with the stationary phase. As a result of partitioning between mobile and stationary phases, the test substance is retarded. The dual composition of a cyanopropyl stationary phase, having polar and non-polar sites allows for interaction of polar and non-polar groups of a molecule in a similar way as is the case for organic matter in soil or sewage sludge matrices. This enables the relationship between the retention time on the column and the Koc on organic matter to be established.

Solutions of one reference substance and the test substance were analysed. Based on the retention times of the compounds the Koc and log Koc values of the test substance were determined.

Analytical conditions
Instrument: Alliance Separation Module 2695 (Waters, Milford, MA, USA)
Detector: Dual λ Absorbance Detector 2487 (Waters)
Column: Hypersil BDS-CN, 150 mm x 4.6 mm i.d., dp = 5 µm (Thermo Fisher Scientific, Waltham, MA, USA)
Column temperature: 35°C +/- 1°C
Mobile phase: 75/25 (v/v) methanol/water
Flow: 1 ml/min
Injection volume: 10 µl
UV detection: 210 nm

Preparation of the solutions
Reference substance solution: A stock solution of the reference substance 2,4-DDT (purity 97.2%, Supelco, Bellefonte, PE, USA, log Koc= 5.63#) at concentration of approximately 1 g/l in methanol was used. The blank solution was methanol.

# value according to the OECD 121 guideline based on soil adsorption data

Test solution: A 1300 mg/l stock solution of the test substance was prepared in methanol and diluted to 100 mg/l in methanol.
The test substance blank solution was methanol.

Type:

log Koc

Value:

> 5.63

Temp.:

20 °C

Details on results (HPLC method):

Calculation of pKa values:
No pKa values for acidic and basic groups in the molecular structure of the test substance in the logarithm range of 1 – 14 were calculated.

Determination of the Koc:
In the chromatogram of the test substance solution, three peaks with a retention time of respectively 2.5, 2.8 and 4.9 minutes were observed. Under the same analytical conditions, the retention time of 2,4-DDT (log Koc = 5.63) was 2.3 minutes. Hence, it was concluded that the log Koc of test substance was > 5.63 (Koc > 4.27 x 10E5).

Since 75/25 (v/v) methanol/water had to be used as eluens to effectively elute the test substance and since the retention time of 2,4-DDT was already very short under these conditions, extrapolation of the Koc value was not performed.

Validity criteria fulfilled:

yes

Conclusions:

The HPLC method using soil-adsorption-reference data was chosen for the determination of the adsorption coefficient of Lowinox® CPL .
It was concluded that the log Koc of test substance was > 5.63 (Koc > 4.27 x 10E5).

Description of key information

Soil adsorption data

Key value for chemical safety assessment

Koc at 20 °C:

427 000

Additional information

The HPLC method using soil-adsorption-reference data was chosen for the determination of the adsorption coefficient of Lowinox® CPL . It was concluded that the log Koc of test substance was > 5.63 (Koc > 4.27 x 10E5). These values are taken as definitive for the purposes of hazard assessment.

[LogKoc: 5.63]