Registration Dossier

Administrative data

Endpoint:
adsorption / desorption: screening
Type of information:
experimental study
Adequacy of study:
key study
Study period:
29 June 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report Date:
2016

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method C.19 (Estimation of the Adsorption Coefficient (KOC) on Soil and Sewage Sludge Using High Performance Liquid Chromatography (HPLC))
Version / remarks:
2008
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 121 (Estimation of the Adsorption Coefficient (Koc) on Soil and on Sewage Sludge using High Performance Liquid Chromatography (HPLC))
Version / remarks:
2001
Deviations:
no
GLP compliance:
yes (incl. certificate)
Type of method:
HPLC estimation method
Media:
soil

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
Appearance: White crystalline solid
Storage conditions: At room temperature protected from light
Radiolabelling:
no

Study design

HPLC method

Details on study design: HPLC method:
CALCULATION OF PKA
-Perrin calculation method (pKalc 5.0, module in Pallas 3.0, CompuDrug International, USA) for the logarithm range of 1 - 14.
-Result: pKa acidic: none; pKa basic: none

HPLC CONDITIONS
- Instrument: Acquity UPLC system (Waters,USA)
- Detector: Acquity UPLC TUV (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

UNRETAINED SUBSTANCE, REFERENCE SUBSTANCES AND TEST SUBSTANCE SOLUTIONS
- Unretained substance: formamide.
- Reference substances with known log Koc values (log Koc values according to OECD 121, based on soil adsorption data).
- Solutions of the unretained substance and of the reference substances were prepared in 55/45 (v/v) methanol/water.
- Test substance solution: A 10 mg/L solution of the substance in 55/45 (v/v) methanol/water was prepared from a 1000 mg/L stock solution in methanol.
- All solutions containing the substance were protected from light.

INJECTIONS
- Solutions of the unretained substance, the reference substances and the test substance were injected in duplicate.
- Single injection of the blank solution (55/45 (v/v) methanol/water).

DATA HANDLING
- Dead time (t0)= mean retention time of the unretained substance
- Duplicate capacity factors (k') for each reference substance were calculated from the retention times (tr): k'= (tr-t0)/t0
- Log k’ values of the references substances were plotted against the known log Koc values.
- Linear regression analysis (least squares method) resulted in the regression line log k’ = 0.323 log Koc – 0.812 (r=0.98, n=16)
- Capacity factor (k') of the substance was calculated from its retention time and the dead time.
- Log Koc of the substance was calculated by substituting its mean log k’ in the regression line.
- The value of log Koc obtained from duplicate measurements was within ± 0.25 log units.

Results and discussion

Adsorption coefficient
Key result
Type:
log Koc
Value:
5.15 dimensionless
Temp.:
20 °C
Remarks on result:
other: Non-buffered mobile phase

Results: HPLC method

Details on results (HPLC method):
The chromatogram of the 10 mg/L test substance solution showed one peak, with a retention time of ca. 5.6 minutes.

Any other information on results incl. tables

Table: Results Adsorption coefficient (HPLC estimation method)

Substance

tr,1
[min]

tr,2
[min]

mean tr

log Koc

Koc

 

 

 

 

 

 

Formamide (t0)

0.703

0.689

0.696

 

 

 

 

 

 

 

 

Acetanilide

0.944

0.915

 

1.26

 

Monuron

1.169

1.123

 

1.99

 

2,5-Dichloroaniline

1.346

1.300

 

2.55

 

Naphthalene

1.565

1.503

 

2.75

 

Benzoic acid phenylester

1.848

1.780

 

2.87

 

Fenthion

2.510

2.410

 

3.31

 

Phenanthrene

2.778

2.670

 

4.09

 

4,4’-DDT

6.985

6.704

 

5.63

 

 

 

 

 

 

 

Test substance

5.674

5.554

5.614

5.15

1.4E05

Applicant's summary and conclusion

Conclusions:
The log Koc was determined to be 5.15 (Koc= 1.4E05).

Executive summary:

The HPLC estimation method based on soil-adsorption reference data was used for the determination of the adsorption coefficient (Koc) of the substance. The study was performed in accordance with EC C.19 and OECD 121 and in compliance with GLP. The mobile phase was 55/45 (v/v) methanol/water and the wavelength of detection 210 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. Duplicate measurements were performed. Both chromatograms of the 10 mg/L test substance solution showed one test substance peak. The corresponding log Koc value was determined to be 5.15 (Koc= 1.4E05).