Ceratonia siliqua, ext.

Adsorption / desorption

Administrative data

Endpoint:

adsorption / desorption: screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 18 Sep 2017 to 11 Oct 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

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:

2016

Deviations:

no

Test guideline 2

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:

2001

Deviations:

no

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

soil

Test material

Test material information

Constituent 1

Test material form:

liquid

Details on test material:

- Physical appearance: Dark brown to black liquid
- Storage of test material: At room temperature

Radiolabelling:

no

Study design

Test temperature:

Column temperature: 35°C ± 1°C

HPLC method

Details on study design: HPLC method:

JUSTIFICATION
The test item is a UVCB, therefore the HPLC method was performed (at pH 7).

HPLC CONDITIONS
- Apparatus: Acquity UPLC system (Waters, USA)
- Column: Acquity UPLC HSS Cyano, 100 mm x 2.1 mm i.d., dp = 1.8 µm (Waters)
- Injection volume: 5 μL
- Detector: Acquity UPLC TUV (Waters)
- UV detection: 210 nm

MOBILE PHASE
- Type: buffered mobile phase
- Preparation of buffer pH 7: Solution of 0.01 M potassium di-hydrogenphosphate in water adjusted to pH 7 using 1N sodium hydroxide. Sodium azide content: 0.0009% (w/v). Type of water: Tap water purified by a Milli-Q water purification system.
- Composition: 55/45 (v/v) methanol/buffer pH 7
- Flow: 0.4 mL/min

DETERMINATION OF DEAD TIME
Not conducted.

REFERENCE SUBSTANCES
- Identity: Acetanilide (log Koc 1.26).
- A solution of the reference substance was prepared in 55/45 (v/v) methanol/buffer pH 7 from a stock solution (1 g/L) in methanol.

TEST ITEM
A 550 mg/L test item solution was prepared in 55/45 (v/v) methanol/buffer pH 7 from a stock solution (1000 mg/L) in methanol.

DETERMINATION OF RETENTION TIMES
- Duplicate injections of the reference substance and test item.
- Single injection of the blank (55/45 (v/v) methanol/buffer pH 7).

Results and discussion

Adsorption coefficient

Key result

Type:

log Koc

Value:

< 1.26 dimensionless

pH:

7

Temp.:

20 °C

Results: HPLC method

Details on results (HPLC method):

Retention time of acetanilide (log Koc 1.26): 1.038 minutes.

In the chromatogram of the test item solution, two major peaks with a mean retention time of 0.435 and 0.489 minutes and one small peak with a retention time of 0.677 minutes were observed.

Any other information on results incl. tables

 Table: result HPLC method - adsorption coefficient (Koc)

	Koc	log Koc	Peak area (%)
Test item – peak 1	< 18	< 1.26	35
Test item – peak 2	< 18	< 1.26	61
Test item – peak 3	< 18	< 1.26	3.5

Applicant's summary and conclusion

Conclusions:

The log Koc of the substance at pH 7 was estimated to be < 1.26 (Koc< 1.8E01).

Executive summary:

The HPLC estimation method 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/buffer pH 7 and the wavelength of detection was 210 nm. The stationary phase contained cyanopropyl chains chemically bonded to silica. One reference substance was used: acetanilide (log Koc 1.26 based on soil-adsorption reference data). Duplicate injections of the test item and reference substance. In the chromatogram of the test item solution, two major peaks with a mean retention time of 0.435 and 0.489 minutes and one small peak with a retention time of 0.677 minutes were observed. The mean (n=2) retention time of acetanilide was 1.038. From this it was concluded that the log Koc of the substance is < 1.26 (Koc < 1.8E01).