2-Naphthalenesulfonic acid, 7-amino-4-hydroxy-8-[2-[2-sulfo-4-[[2-(sulfooxy)ethyl]sulfonyl]phenyl]diazenyl]-, potassium sodium salt (1:?:?), coupled with diazotized 2-[(4-amino-5-methoxy-2-methylphenyl)sulfonyl]ethyl hydrogen sulfate

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:

Experiment start date - 22 July 2003; Experiment completion date - 23 July 2003; Study completion date - 16 December 2003.

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

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: HPLC test

Specific details on test material used for the study:

Identity: FAT 40812/A
Batch: WP 8/03
Purity: approx. 75 %
Appearance: Solid, dark red-brownish powder
Expiration date: 23 April 2010
Storage: At room temperature at about 20 °C

Radiolabelling:

no

Details on study design: HPLC method:

This method utilises a high performance liquid Chromatograph with UV/VIS detector, reversed phase column and an aqueous mobile phase. An analytical column packed with a commercially available cyanopropyl solid phase containing lipophilic and polar moieties and a moderately polar stationary phase based on a silica matrix was used.

Test item solution:
FAT 40812/A (34.17 mg) was dissolved in water (100 mL) to prepare a stock solution of 341.7 µg/mL. The stock solution (6 mL) was diluted with water to 50 mL to obtain a standard solution of 41.004 µg/mL. The pH value of the test item solution was determined to be 6.7. The test item solution was injected three times.

HPLC Conditions:
- Apparatus: Varian pump ProStar 230, Varian autosampler 9100, Varian Detector ProStar 310, Jones column oven 7990
- Column: LiChrospher 100 CN, particle size 5 µm, 250 mm x 4 mm
- Mobile Phase: Water / methanol (45:55; v/v);
- pH 7.6
- Detection: Test item: 517 nm for test item, 210 nm for reference item and for sodium nitrate.
- Temperature: 25°C
- Injection Volume: 20 µL
- Flow: 1.0 mL/min

Type:

log Koc

Value:

< 1.32

Temp.:

25 °C

Remarks on result:

other: pH not available

Type:

Koc

Value:

< 21

Temp.:

25 °C

Remarks on result:

other: pH not available

Details on results (HPLC method):

- The test item solution was injected three times and the reference item solutions were injected six times.
- The chromatography of the test item resulted in one main peak with a well-defined and reproducible retention time. The HPLC method was therefore considered to be suitable for the purpose of the study. Based on the chromatographic data, FAT 40812/A was considered to be stable during the test procedure.

Transformation products:

no

Validity criteria fulfilled:

yes

Conclusions:

With a log Koc of <1.32 (equivalent to a Koc value of <21 L/kg) the substance may be considered mobile.

Executive summary:

In a GLP-compliant study, the determination of the adsorption coefficient (Koc) of the test substance was performed according to OECD Guideline 121 using the HPLC method. The test item solution was injected on the HPLC column. The Koc of the test substance was determined to be lower than 1.32 which is equal to a Koc value of <21. This value indicates that the test substance will not be absorbed by organic carbon in soil and can be classified to be of very high mobility.

Description of key information

In a GLP-compliant study, the determination of the adsorption coefficient (Koc) of the test substance was performed according to OECD Guideline 121 using the HPLC method. The test item solution was injected on the HPLC column. The log Koc of the test substance was determined to be lower than 1.32 which is equal to a Koc value of <21. This value indicates that the test substance will not be absorbed by organic carbon in soil and can be classified to be of very high mobility. [LogKoc: 1.32]

Key value for chemical safety assessment

Koc at 20 °C:

21