Condensation products of phenol and salicylaldehyde

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:

09 May 2019 to 16 May 2019

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/sewage sludge

Radiolabelling:

no

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: Dionex Ultima 3000 UHPLC
- Type, material and dimension of analytical (guard) column: YMC-Pack CN; 2.1x150 mm; S-3 μm, 12 nm
- Detection system: DAD detection at 210 nm (7 min run time)

MOBILE PHASES
- Type: HPLC water and methanol was mixed in 45:55 (V/V) ratio was used as the diluent
- Solutes for dissolving test and reference substances: Reference substances and test material were diluted with Diluent to achieve the desired concentrations.

DETERMINATION OF DEAD TIME
- Method: Approx. 100 mg Urea was weighed with 0.01 mg precision into 10 mL volumetric flask and filled up with Diluent. The solution was mixed well by hand. The concentrations of the urea was approx. 10 mg/mL. Urea was injected for the determination of dead-time (t0). The t0 value was found to 0.913 min.

REFERENCE SUBSTANCES
- Identity: Acetanilide (Log Koc: 1.25), Phenol (Log Koc: 1.32), 3,5-Dinitrobenzamide (Log Koc: 2.31), Naphthalene (Log Koc: 2.75), 1,2,3-Trichlorobenzene (Log Koc: 3.16), Pyrazophos (Log Koc: 3.65), Phenanthrene (Log Koc: 4.09), 4,4’-DDT (Log Koc: 5.63)

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: Not reported
- Quantity of reference substances: Not reported

REPETITIONS
- Number of determinations: Retention times for the reference substances and test material were determined in triplicate.

EVALUATION
- Calculation of capacity factors k': The capacity factors (k) of the reference substances were calculated according to the following equation:

k = (tR - t0) / t0

where:
tR is the retention time of the test material (min)
t0 is the retention time of the urea (dead-time) (min)

The log Koc was determined:

log Koc = a x log k + b

where a and b are linear regression coefficients determined from the retention data of the reference materials.

Key result

Type:

log Koc

Value:

2.35 dimensionless

Details on results (HPLC method):

- Retention times of reference substances used for calibration: Acetanilide (1.053 - 1.057 min), Phenol (1.070 - 1.073 min), 3,5-Dinitrobenzamide (1.173 - 1.177 min), Naphthalene (1.423 - 1.427 min), 1,2,3-Trichlorobenzene (1.587 min), Pyrazophos (1.733 - 1.737 min), Phenanthrene (1.897 - 1.900 min), 4,4’-DDT (3.207 - 3.210 min)
- Details of fitted regression line (log k' vs. log Koc): The equation of the curve fitted to the calibration plot is:
log k' = 3.4661 × log Koc + 3.9312 (r² = 0.9740)
- Graph of regression line attached
- Average retention data for test substance: 1.233 min

Validity criteria fulfilled:

yes

Conclusions:

The main fraction of the test material was detected at 1.23 minute retention time. The average logKoc of the test material was estimated to be 2.35.

Executive summary:

The adsorption coefficient of the test material was investigated using the HPLC method in accordance with the standardised guidelines OECD 121 under GLP conditions.

The study was carried out using an UHPLC system with DAD detection. The mobile phase was HPLC water:methanol (45:55) v/v ratio. The reference substances used to create the calibration curve were Acetanilide, Phenol, 3,5-Dinitrobenzamide, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos, Phenanthrene, and 4,4’-DDT.

Under the conditions of the study, the test material eluted with a retention time of 1.23 minutes. The average logKoc of the test material was estimated to be 2.35.

Description of key information

The average logKoc of the test material was estimated to be 2.35.

Key value for chemical safety assessment

Koc at 20 °C:

223.872

Additional information

The adsorption coefficient of the test material was investigated using the HPLC method in accordance with the standardised guidelines OECD 121 under GLP conditions.

The study was carried out using an UHPLC system with DAD detection. The mobile phase was HPLC water:methanol (45:55) v/v ratio. The reference substances used to create the calibration curve were Acetanilide, Phenol, 3,5-Dinitrobenzamide, Naphthalene, 1,2,3-Trichlorobenzene, Pyrazophos, Phenanthrene, and 4,4’-DDT.

Under the conditions of the study, the test material eluted with a retention time of 1.23 minutes. The average logKoc of the test material was estimated to be 2.35.