Reaction mass of lithium sodium hydrogen 4-amino-6-({5-[(5-chloro-2,6-difluoropyrimidin-4-yl)amino]-2-sulfonatophenyl}diazenyl)-5-hydroxy-3-[(4-{[2-(sulfonatooxy)ethyl]sulfonyl}phenyl)diazenyl]naphthalene-2,7-disulfonate and lithium sodium hydrogen 4-amino-6-({5-[(5-chloro-2,6-difluoropyrimidin-4-yl)amino]-2-sulfonatophenyl}diazenyl)-5-hydroxy-3-{[4-(vinylsulfonyl)phenyl]diazenyl}naphthalene-2,7-disulfonate

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:

29-02-2001 to 28-05-2001

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:

not specified

GLP compliance:

yes

Type of method:

HPLC estimation method

Media:

other: Cyanopropyl solid phase chemically bonded on silica

Radiolabelling:

no

Test temperature:

23°C

Details on study design: HPLC method:

EQUIPMENT
- Apparatus: HPLC Pump SP 8810, Spectra-Physics Inc. and differential refractometer, Knauer Inc.
- Type, material and dimension of analytical (guard) column: Zorbax CN, 250 x 4.0 mm, 5 µm
- Detection system: refractive index

MOBILE PHASES
- Type: methanol/buffer (55:45) v/v, buffer is aqueous solution of 0.05 mole of potassium dihydrogen phosphate with phosphoric acid to pH 3
- Experiments with additives carried out on separate columns: no
- pH: 3
- Solvent for dissolving test substance: methanol/purified water 70:30 (v/v)

REFERENCE SUBSTANCES
- Identity: urea (inert marker), phenol, acetanilide, monuron, triapenthenol, linuron, fenthion and trifluralin

DETERMINATION OF RETENTION TIMES
- Quantity of test substance introduced in the column: 48.9 mg/25 mL
- Quantity of reference substances: urea - 21.7 mg/25 mL eluent, phenol - 15.1 mg/25 mL solvent, acetanilide - 19.8 mg/25 mL solvent, monuron - 17.6 mg/25 mL solvent, triapenthenol - 16.0 mg/25 mL solvent, linuron - 19.2 mg/25 mL solvent, fenthion - 18.5 mg/25 mL solvent, trifluralin - 13.7 mg/25 mL

REPETITIONS
- Number of determinations: two per reference substance, two for test substance

EVALUATION
- Calculation of capacity factors k': k' value was calculated from the two retention times of the test substance.
- Determination of the log Koc value: log Koc of the test substance was determined from the calibration plot of log k' versus the log Koc of the selected reference substances.

Key result

Type:

Koc

Value:

0.8 dimensionless

pH:

3

Temp.:

23 °C

Remarks on result:

other: log Koc is -0.1

Validity criteria fulfilled:

yes

Conclusions:

Under the study conditions, the adsorption coefficient (Koc) of the test substance was determined to be 0.8 (log Koc = -0.1).

Executive summary:

A study was conducted to determine the adsorption coefficient of the test substance (64% purity) in accordance with draft OECD Guideline 121. The HPLC method was employed for the determination of adsorption coefficient with methanol/phosphate buffer (55:45) as the mobile phase at pH 3 and at a temperature of 23°C. Reference substances were used for calibration and the adsorption coefficient of the test substance was determined from the plot of log k' and log Koc of the reference substances by extrapolation. Under the study conditions, the adsorption coefficient (Koc) of the test substance was determined to be 0.8 (log Koc = -0.1) (Schleich, 2001).

Key value for chemical safety assessment

Koc at 20 °C:

0.8

Additional information

A study was conducted to determine the adsorption coefficient of the test substance (64% purity) in accordance with draft OECD Guideline 121. The HPLC method was employed for the determination of adsorption coefficient with methanol/phosphate buffer (55:45) as the mobile phase at pH 3 and at a temperature of 23°C. Reference substances were used for calibration and the adsorption coefficient of the test substance was determined from the plot of log k' and log Koc of the reference substances by extrapolation. Under the study conditions, the adsorption coefficient (Koc) of the test substance was determined to be 0.8 (log Koc = -0.1) (Schleich, 2001).

[LogKoc: -1.0]