Cyclohexylidenebis[tert-butyl] peroxide

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:

2012-02-21 to 2012-02-23

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

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

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

Test temperature:

22 °C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC system: Hitachi LaChrom Elite
L-2000 Organizer, No.: 23E94-012
L-2130 HPLC pump, No.: 23E60-024
L-2200 Autosampler, No.: 23E90C-003
L-2400 UV Detector, No.: 23E88-004
L-2350 Column Oven, No.: 2383-009
Balance: BL120S Sartorius, No.: 15307011
Ultrasonic bath: Branson 3210, No.: A700343D
Water purification system: MILLIPORE, DIRECT Q5, No.: FODA13956K
- Type, material and dimension of analytical (guard) column: LiChrospher 100 CN (5 μm) 250x4, No: 933278
- Detection system:
UV 254 nm (Reference Items)
UV 200 nm (Test Item)

MOBILE PHASES
- Type: Methanol : water = 55 : 45 (v/v)
- Solutes for dissolving test and reference substance: The reference items were dissolved in methanol. The concentrations of the stock solutions were about 1 mg/mL. These stock solutions were diluted with eluent resulting in concentrations of the test solutions of approximately 10 μg/mL. The DDT and the Sodium nitrate stock solutions were diluted with eluent resulting in concentration of the test solution of approximately 100 μg/mL. The test item was dissolved in methanol. The concentration of this solution was about 2 mg/mL. It was twofold diluted with eluent to 1 mg/mL.

REFERENCE SUBSTANCES
- Identity:
Sodium nitrate
Acetanilide
Methyl Benzoate
Isoproturon
Linuron
Naphthalene
Phenanthrene
DDT

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 10 µL
- Intervals of calibration: 1.25 to 5.63

REPETITIONS
- Number of determinations: Three series of the reference solutions were measured with two parallel injections, each. Three series of the test item solution were measured with two parallel injections, each. The retention times were determined. The three calibration series and three test item series were measured alternately.

EVALUATION
- Calculation of retention times: For the determination of t0 (t0 = retention time of the unretarded component) three series of Sodium Nitrate solution were injected twice.
- Determination of the log Koc value: log k = a + b*log Koc

Key result

Type:

Koc

Value:

488

Temp.:

22 °C

Remarks on result:

other: ± 3.6 (95 % confidence interval)

Key result

Type:

log Koc

Value:

2.69

Temp.:

22 °C

Remarks on result:

other: ± 0.003 (95 % confidence interval)

Details on results (HPLC method):

- Retention times of reference substances used for calibration:
Sodium nitrate: 1.50 minutes
Acetanilide: 3.27 minutes
Methyl Benzoate: 3.77 minutes
Isoproturon: 3.90 minutes
Linuron: 5.05 minutes
Naphthalene: 5.61 minutes
Phenanthrene: 8.95 minutes
DDT: 16.11 minutes

Validity criteria fulfilled:

yes

Conclusions:

Using the HPLC method the adsorption coefficient (Koc and Log Koc) of the test item was estimated to be 488 and 2.69, respectively.

Executive summary:

The purpose of this study was to estimate the adsorption coefficient Koc of the test item using HPLC in accordance with OECD guideline 121 and EU method C.19. This method is applicable for substances, which have log Koc value ranging from 1.5 to 5.0. The log Koc and Koc of the test substance were estimated to be 2.69 ± 0.003 (95 % confidence interval) and 488 ± 3.6 (95 % confidence interval), respectively.

Description of key information

Using the HPLC method the adsorption coefficient (Koc and Log Koc) of the test item was estimated to be 488 and 2.69, respectively.

Key value for chemical safety assessment

Koc at 20 °C:

488

Additional information

The purpose of this study was to estimate the adsorption coefficient Koc of the test item using HPLC in accordance with OECD guideline 121 and EU method C.19. This method is applicable for substances, which have log Koc value ranging from 1.5 to 5.0. The log Koc and Koc of the test substance were estimated to be 2.69 ± 0.003 (95 % confidence interval) and 488 ± 3.6 (95 % confidence interval), respectively.